Autoimmunity; Immunology; Neurobiology
My research is aimed at understanding the roles of the innate and adaptive immune systems in health and disease. The organs of my interest are the two specialized filtration units, glomeruli and blood-brain barrier, of the kidney and brain respectively. Recently, our understanding of the immune system has undergone a substantial paradigm shift: researchers now recognize that the innate immune system, the body’s first line of defense, assesses the level of danger of a particular event and initiates an adaptive immune response that subsequently confers protection. My studies focus on the role of an important arm of the innate immune system, the complement cascade in inflammatory conditions such as glomerulonephritis and lupus. For both disease conditions, the perfect therapy remains an enigma. Using a gamut of techniques, we are attempting to define the molecular mechanisms involved and the resulting behavioral aberrations. Once molecular targets are identified, therapeutic strategies will be defined. I teach in UB’s Discovery Seminar Program, which is geared for first- and second-year undergraduates. The seminars are taught in a small-class environment to students who share common goals and similar interests, in ways that enhance their academic, civic and personal growth. I teach “The Yin-Yang of Biology” and “Brain: Day and Night,” and I teach as well in UB’s Honors College. I also mentor students through the CLIMB-PRO program. One of my recent students conducted research that resulted in a publication in the journal Kidney International.
Apoptosis and cell death; Bioinformatics; Molecular Basis of Disease; Molecular and Cellular Biology; Molecular genetics; Neurobiology; Regulation of metabolism
My laboratory studies the cell-autonomous and non-cell-autonomous mechanisms of axon degeneration, a process akin to programmed cell death. In other words, we are attempting to elucidate what causes axon breakdown from within neurons and which external (glial) events trigger axon loss. Degeneration of axons is a hallmark in many neurodegenerative conditions, including those associated with abnormal glia. We have great hope that understanding why and how axons degenerate may lead to more efficient neuroprotective therapies tailored specifically to support axons and their surrounding glia. Axons are the longest cellular projections of neurons relaying electrical and biochemical signals in nerves and white-matter tracts of the nervous system. As such, they are critical for neuronal wiring and transport of neuronal maintenance signals. Because of their incredible length and energetic demand (human motor neurons can be one meter long), however, axons are very vulnerable and at continuous risk of damage. Axons do not exist in isolation but are inextricably and intimately associated with their enwrapping glia (Schwann cells and oligodendrocytes) to form a unique axon-glia unit. The most relevant neurological symptoms in a number of debilitating neurodegenerative conditions are due to compromised axon integrity. Thus, neuroprotective therapies promoting axon stability have great potential for more effective treatment. Recent studies indicate that axonal degeneration, at least in experimental settings, is an active and highly regulated process akin to programmed cell death (‘axonal auto-destruction’). Moreover, it is increasingly realized that axonal maintenance relies not only on neuron-derived provisions but also on trophic support from their enwrapping glia. The mechanism for this non-cell-autonomous support function remains unknown, but emerging evidence indicates that it is distinct from the glial role in insulating axons with myelin. We are pursuing the intriguing question of whether abolished support by aberrant delivery of metabolites and other trophic factors from glia into axons is mechanistically linked to the induction of axonal auto-destruction. This concept is supported by our recent finding that metabolic dysregulation exclusively in Schwann cells is sufficient to trigger axon breakdown.
Ion channel kinetics and structure; Membrane Transport (Ion Transport); Molecular and Cellular Biology; Neurobiology; Pathophysiology; Gene Expression; Signal Transduction
Neuronal firing patterns are highly diverse because neurons regulate a wide variety of different behaviors and physiological functions including cognition and memory. Whether a neuron exhibits regular spiking, burst firing, adaptation or high frequency firing will largely be determined by which specific ion channel genes a neuron chooses to express. I am interested in a class of potassium channels that are sensitive to intracellular sodium. There are two members in this family, known as Slack and Slick, and both channel subunits are expressed in many different types of neurons. I am particularly interested in how these channels contribute to the firing patterns of pain-sensing neurons and neurons of the cerebral cortex. Understanding when, where and how these channels are working should provide important information on sensory and cortical processing and will provide insights on nociception, psychiatric disorders such as schizophrenia and bipolar disorder and neurological diseases such as epilepsy.
Molecular and Cellular Biology; Neurobiology; Neuropharmacology
The goal of my research is the elucidation of the role of brainstem systems in motivated behaviors. My current focus is the function of neuropeptide systems, specifically urotensin II (UII). Ultimately I would like to exploit this system to better treat people with neuropsychiatric disorders. Currently my lab is pursuing the following: 1) Determine the role of UIIR activation and the UIIR expressing neurons in reward-related behaviors:. Our results support the need for further investigation of the UII-system as a therapeutic target for treating drug abuse disorders. In addition, we are investigating the i) bias-signaling properties of the endogenous UIIR ligands, and ii) the impact of UIIR single-nucleotide polymorphisms on receptor signaling. 2) Establish the contribution of cholinergic PPT to Parkinsonism-related behaviors: We designed a toxin that selectively targets UIIR expressing neurons (cholinergic PPT). In rats the toxin-mediated lesion mimics Progressive Supranuclear Palsy (the most common atypical parkinsonism) on multiple fronts: selective ablation of cholinergic PPT neurons, impaired motor function, and deficits in acoustic startle reaction (MacLaren et al, 2014a; MacLaren et al, 2014b). Similarly, the collection of deficits found after non-selective manipulations of the PPT overlap with that of Parkinson’s Disease [e.g. reduced prepulse inhibition, impaired attention, cognitive deficits, sleep disturbances]. Traditional dopamine-depletion models do not produce similar sensorimotor and cognitive deficits. Therefore, PPT lesions as an adjunct or stand alone preclinical models of Parkinsonism may be useful in identifying non-dopaminergic pharmacotherapeutics. We are pursuing further studies utilizing our selective cholinergic depletion and a viral-mediated tauopathy method with support from the CurePSP Foundation.
Autoimmunity; Bioinformatics; Genomics and proteomics; Immunology; Infectious Disease; Molecular and Cellular Biology; Molecular genetics; Neurobiology
My primary research is in the field of biomedical ontology development. An ontology is a controlled, structured vocabulary intended to represent knowledge within a particular domain. Terms in an ontology have logical relationships to each other and to terms in other ontologies, to allow for reasoning and inference across the ontology. Biomedical ontologies allow annotation and integration of scientific data within particular fields of science and medicine, and their careful curation and logical structure facilitate data analysis. My work in biomedical ontology is strongly informed by my earlier experience in laboratory research in immunology, genetics, molecular biology and virology. My research group works on ontologies for both basic and clinical applications, in collaboration with researchers both at UB and other institutions. I led efforts to revise and extend the Cell Ontology, which is intended to represent in vivo cell types from across biology. We worked extensively to bring it up to community-accepted standards in ontology development, placing particular emphasis on improving the representation of hematopoietic cells and neurons. We are developing the Cell Ontology as a metadata standard for annotation and analysis of experimental data in immunology in support of the National Institute of Allergy and Infectious Diseases (NIAID) ImmPort Immunology Database and Analysis Portal and Human Immunology Project Consortium. We have also developed ways to use the Cell Ontology in support of the analysis of gene expression data linked to cell types and have contributed to the Functional Annotation of the Mammalian Genome (FANTOM) 5 Consortium‘s work on identifying gene transcription start sites across multiple cell types and tissues. My research team is also developing the Neurological Disease Ontology to represent clinical and basic aspects of neurological diseases in order to support translational research in this area. In collaboration with clinical colleagues at UB, we are initially focusing on Alzheimer’s disease and dementia, multiple sclerosis and stroke. We have as well developed a companion ontology, the Neuropsychological Testing Ontology, to aid in the annotation and analysis of neuropsychological testing results used as part of the diagnosis of Alzheimer‘s disease and other neurological diseases. I am a long-term member of the Gene Ontology (GO) Consortium and have a particular interest in the representation of immunology and neuroscience in the GO. I am also involved in UB’s contribution to the Protein Ontology and contribute as well to the work of the Infectious Disease Ontology Consortium, Immunology Ontology Consortium and Vaccine Ontology Consortium. I teach and mentor students at the master’s and doctoral levels, and advise undergraduate, graduate, and medical students in summer research projects as well.
Addictions; Drug abuse; Behavioral pharmacology; Cytoskeleton and cell motility; Gene Expression; Gene therapy; Neurobiology; Neuropharmacology; Signal Transduction; Transcription and Translation
Drug addiction is a disabling psychiatric disease leading to enormous burdens for those afflicted, their friends and family, as well as society as a whole. Indeed, the addict will seek out and use illicit substances even in the face of severe negative financial, family and health consequences. It is believed that drugs of abuse ultimately “hijack” the reward circuitry of the CNS leading to cellular adaptations that facilitate the transition to the “addicted” state As is the case with both rodent models of drug taking, and well as throughout the global human population, not all individuals exposed to drugs of abuse will meet the classical definition of being truly “addicted”. We are looking at how molecular and behavioral plasticity mediates susceptibility to drug abuse and relapse like behaviors.
Apoptosis and cell death; Molecular Basis of Disease; Neurobiology
Professional Summary: The research in my laboratory has been focused on the effects of chronic ethanol abuse on aging neurons and the effects of ethanol on development of neuronal systems. These investigations are associated with major socioeconomic issues that will become more pronounced with time. For example, alcoholism in the elderly will become more pronounced as the alcohol-drinking baby boomer generation reaches old age. In addition, alcohol consumption during pregnancy remains the number one cause of mental retardation in the western world. In our aging and alcohol studies, extensive investigation of the Purkinje neuron (PN) of the cerebellar cortex have demonstrated that dendritic regression accompanies chronic ethanol consumption in aging Fischer 344 rats. Dendritic regression in PN alters synaptic transmission from the cerebellum, the major brain center for coordination. Further ethanol-induced alteration of regressing dendrites include dilation of the smooth endoplasmic reticulum (SER), a major calcium homeostatic component, and the formation of degenerating structures in dendrites of Purkinje neurons following chronic ethanol consumption in aging rats. These morphologic changes have been recently shown to be accompanied by decreased levels of the SERCA 2b pump which pumps calcium back into the SER following an action potential. Homeostasis between uptake and release of calcium from the SER is essential for cell health as uncontrolled release of calcium results in activation of a myriad of cellular pathways and cell death. Current investigations in the laboratory as focusing on the role ATF6 and caspase 12, both residents of the SER, in the development of ethanol-induced SER stress as a result of chronic ethanol consumption. Future investigations will include other ethanol-induced alterations to calcium homeostatic systems and the role of ethanol-induced alterations in epigenetics in decreases in calcium buffering mechanisms. The fetal alcohol study has focused on the effects of ethanol on the eye and the heart in the zebrafish model. Zebrafish are good models for developmental studies because they are transparent the short developmental period of three days between fertilization and hatching. Early investigations in collaboration with Dr. Richard Rabin established that the zebrafish was sensitive to ethanol and that the sensitivity was dose and strain dependent. Later studies focused on morphological and pharmacological assessment of ethanol-induced alterations to the heart and eye using pharmacologically relevant effects of ethanol. Current plans include focus on determining the mechanisms of ethanol’s actions on retinal ganglion cells and dopaminergic centers in the zebrafish.
Clinical Neurophysiology; Physical Medicine and Rehabilitation; Neurobiology
As director of UB’s Neuroengineering and Informatics for Rehabilitation Laboratory (NIRlab), I conduct interdisciplinary research in neural engineering, the application of engineering to the neurosciences. My academic and research training in neurotechnology, motor rehabilitation, clinical neurophysiology and cerebrovascular medicine provides me with the expertise for translational research focused on developing computational models and hardware technologies for neural interfaces to monitor and activate beneficial neural function. My research transcends conventional academic boundaries in my overarching goal to treat, cure and even prevent neurological disorders using ‘electroceuticals’--bioelectronics that stimulate the nervous system. Specifically, my research is directed toward an enhanced understanding of the neurophysiological mechanisms associated with the relearning of visomotor function. My special focus on neurorehabilitation uses neuroengineering and informatics to leverage human-machine interfaces. Here, the human brain and body act in concert with biofeedback and multilevel neurostimulation to promote neuroplasticity and lead to neurorestorative therapy. I am developing electroencephalography (EEG) and electromyography (EMG) and near-infrared spectroscopy-based (NIRS) portable multimodal imaging to understand skeletal, muscle and brain physiology during noninvasive electrical stimulation. If achieved, the bench-to-bedside translation of electroceuticals, developed through innovations in computational methods and instrumentation, will have a very high societal impact since neurological disorders—e.g., stroke and dementia-- will likely dramatically increase as the world population ages. I collaborate with researchers from industry and academia locally as well as from across the globe in conducting the interdisciplinary translational research of NIRlab. I welcome undergraduate, graduate engineering students and medical students to work with me. I am particularly interested in medical students who are focused on clinical neurophysiology, physical medicine and rehabilitation, e.g. students from the departments of Neurology, Neurosurgery, Orthopaedics and the Rehabilitation Sciences. Additionally, I teach courses in neural and rehabilitation engineering. My courses are open to engineering students and medical students, especially those with interest in the application of engineering methods to the clinical neurophysiology and rehabilitation sciences.
Neurology; Cytoskeleton and cell motility; Molecular and Cellular Biology; Molecular Basis of Disease; Molecular genetics; Neurobiology; Signal Transduction; Inherited Metabolic Disorders; Transgenic organisms
My laboratory seeks to understand the molecular basis of myelination and myelin diseases. Myelin is a multi-lamellar sheath that invests large axons and permits rapid conduction of nerve signals. Failure in myelin synthesis and myelin breakdown cause several important neurological diseases, including multiple sclerosis, leukodystrophies and peripheral dysmyelinating neuropathies. In some of these diseases, genetic mutations cause defects in cytoskeletal, adhesion and signaling molecules. I work with a team of undergraduate and graduate students, postdoctoral fellows, technicians, senior scientists and many international collaborators to discover how these molecules normally coordinate cell-cell and cell-extracellular matrix interactions to generate the cytoarchitecture of myelinated axons. We use a variety of approaches, including generation of mice carrying genetic abnormalities, cultures of myelinating glia and neurons, imaging, biochemistry and morphology to understand the role of these molecules in normal and pathological development. By comparing normal myelination to the abnormalities occurring in human diseases, we aim to identify molecular mechanisms that pharmacological intervention might correct. For example, we described how the protein dystroglycan associates with different proteins, some of which impact human neuropathies, depending on a proteolitic cleavage that can be regulated to improve the disease. Similarly, we found that molecules such as integrins and RhoGTPAses are required for glia to extend large processes that will become myelin around axons. In certain neuromuscular disorders, defective signaling pathways that converge on these molecules cause failure to produce or mantain an healthy myelin Finally, in collaborations with scientists and clinicians in the Hunter J. Kelly Research Institute, we are generating transgenic forms of GalC, an enzyme deficient in Krabbe leukodystrophy, to investigate which cells requires the enzyme. Investigating how GalC is handled may help find a cure for this devastating disease.
Neurology; Neurodegenerative disorders; Pathophysiology; Apoptosis and cell death; Cytoskeleton and cell motility; Molecular and Cellular Biology; Molecular genetics; Neurobiology; Protein Folding; Gene Expression; Transcription and Translation; Signal Transduction; Toxicology and Xenobiotics
My research is aimed at finding the cause and a cure for Parkinson’s disease. Parkinson’s disease (PD) is defined by a characteristic set of locomotor symptoms (rest tremor, rigidity, bradykinesia and postural instability) that are believed to be caused by the selective loss of dopaminergic (DA) neurons in substantia nigra. The persistent difficulties in using animals to model this human disease suggest that human nigral dopaminergic neurons have certain vulnerabilities that are unique to our species. One of our unique features is the large size of the human brain (1350 grams on average) relative to the body. A single nigral dopaminergic neuron in a rat brain (2 grams) has a massive axon arbor with a total length of 45 centimeters. Assuming that all mammalian species share a similar brain wiring plan, we can estimate (using the cube root of brain weight) that a single human nigral dopaminergic neuron may have an axon with gigantic arborization that totals 4 meters. Another unique feature of our species is our strictly bipedal movement, which is affected by Parkinson’s disease, in contrast to the quadrupedal movement of almost all other mammalian species. The much more unstable bipedal movement may require more dopamine, which supports the neural computation necessary for movement. The landmark discovery of human induced pluripotent stem cells (iPSC) made it possible to generate patient-specific human midbrain dopaminergic neurons to study Parkinson’s disease. A key problem for dopaminergic neurons is the duality of dopamine as a signal required for neural computation and a toxin as its oxidation produces free radicals. Our study using iPSC-derived midbrain dopaminergic neurons from PD patients with parkin mutations and normal subjects shows that parkin sustains this necessary duality by maintaining the precision of the signal while suppressing the toxicity. Mutations of parkin cause increased spontaneous release of dopamine and reduced dopamine uptake, thereby disrupting the precision of dopaminergic transmission. On the other hand, transcription of monoamine oxidase is greatly increased when parkin is mutated. This markedly increases dopamine oxidation and oxidative stress. These phenomena have not been seen in parkin knockout mice, suggesting the usefulness of parkin-deficient iPSC-derived midbrain DA neurons as a cellular model for Parkinson’s disease. Currently, we are using iPS cells and induced DA neurons to expand our studies on parkin to idiopathic Parkinson’s disease. We are also utilizing the molecular targets identified in our studies to find small-molecule compounds that can mimic the beneficial functions of parkin. The availability of human midbrain DA neurons should significantly speed up the discovery of a cure for Parkinson’s disease.
Apoptosis and cell death; Inherited Metabolic Disorders; Molecular Basis of Disease; Molecular and Cellular Biology; Neurobiology; Regulation of metabolism; Transgenic organisms; Vision science
Our lab is focused on studies of retinal degenerations caused by metabolic defects, particularly dyslipidemias involving defective cholesterol metabolism (e.g., Smith-Lemli-Opitz syndrome), using pharmacological and transgenic animal models. Current studies are focused on the role of lipid and protein oxidation in the underlying mechanisms of photoreceptor cell death in such retinal degenerations, using a combination of genomic, proteomic, and lipidomic approaches.
Bioinformatics; Genomics and proteomics; Immunology; Membrane Transport (Ion Transport); Molecular and Cellular Biology; Molecular Basis of Disease; Molecular genetics; Neurobiology; Gene Expression
The current focus of my lab is on iron metabolism in animals and humans. From the practical viewpoint, iron is an important nutrient, but its ability to act in the ferrous and ferric state also makes it toxic. Thus, iron deficiency is the most frequent disorder in the world and hereditary hemochromatosis (HH) is the most common Mendelian disorder in the United States. Our research is related to erythroid differentiation on the fundamental level and to genetic and acquired diseases on the applied level, with four long-term themes: 1.) analysis of the molecular basis of differential gene expression among tissues and during development, with hemoglobin synthesis and red blood cell (RBC) development as models; 2.) application of molecular and genetic advances to inherited diseases; 3.) iron metabolism; 4.) study of gene variation in populations and divergence of gene loci during evolution. New vistas have opened recently for the anemia of chronic diseases, leading us to re-exam how microbes and their human hosts fight for iron. We approach these issues by working on rodent models like the Belgrade rat, plus a series of genetically engineered mice. The rat has a hypochromic, microcytic anemia inherited as an autosomal recessive. The defect is in an iron transporter called DMT1 (or slc11a2, previously called Nramp2 or DCT1) that is responsible for iron uptake by enterocytes and is also responsible for iron exiting endosomes in the transferrin cycle. The rats appear to have a severe iron deficiency, and although dietary iron and iron injection increase the number of RBCs, they do not restore the RBCs nor the rat itself to a normal phenotype. Recent discoveries show that DMT1 is ubiquitous and responsible for transport of other metals such as Mn and Ni. It occurs in the kidney, brain and lung at even higher levels than in the GI tract or in erythroid cells. It also has multiple isoforms, and we have cloned them and developed cell lines that express high levels of particular isoforms. We have specific antibodies to the isoforms and assays for each of the mRNAs too. Future projects in my lab will continue to address whether DMT1 is dysregulated in HH. We will also tackle how DMT1 functions in neurons, pneumocytes and other tissues, look at isoforms of DMT1 under circumstances where we suspect that they must have different functions from one another, and examine DMT1’s relevance to iron metabolism and human disease. Because we cloned the gene and identified the mutation, a number of molecular and cellular approaches can now be used. As evidence indicates that metal ion homeostasis fails in Parkinson’s disease, Alzheimer’s disease and Huntington’s disease, research on DMT1 has opened new vistas for these disorders.
Bioinformatics; Cell growth, differentiation and development; Genomics and proteomics; Molecular and Cellular Biology; Molecular Basis of Disease; Molecular genetics; Neurobiology; Gene Expression; Stem Cells; Transgenic organisms
My research goal is to gain a better understanding of how proteins that interact with DNA regulate RNA transcription, DNA replication and metazoan development. I mentor undergraduate and graduate students in my lab; we focus on the structure and function of the Nuclear Factor I (NFI) family of site-specific DNA binding proteins, and we are investigating their roles in development. Our work has been made possible by our development of loss-of-function mutations of the NFI genes in the mouse and C. elegans. We are addressing four major questions in my laboratory and in collaboration with a number of talented collaborators: What is the structure of the NFI DNA-binding domain? How does NFI recognize and interact with DNA? Does NFI change the structure of DNA when it binds? What proteins interact with NFI to stimulate RNA transcription and/or DNA replication? These research questions are explored in my lab through two major projects focused on the role of NFIB in lung development and the role of NFIX in brain development. When NFIB is deleted from the germline of mice the animals die at birth because their lungs fail to mature normally. This provides a good model for the problems that occur with premature infants, whose lungs also fail to mature normally. We are using this model to determine how NFIB promotes lung maturation with the goal of being able to stimulate this process in premature infants. In our NFIX knockout animals, the brains of the animals are actually larger than normal and contain large numbers of cells in an area known to be the site of postnatal neurogenesis. We have evidence that NFIX may regulate the proliferation and differentiation of neural stem cells, which produce new neurons throughout adult life. Our aim is to understand the specific target genes that NFIX regulates in the adult brain to control this process of neurogenesis.
Endocrinology, Diabetes and Metabolism; Psychiatry; Behavioral pharmacology; Endocrinology; Neurobiology
My research is broadly concerned with studies of the biology of affective disorders and the development of biological markers and clinical laboratory tests for major depressive disorder. Hormonal modulation of brain and behavior with the emphasis on gonadal hormones and the hypothalamic-pituitary-adrenal system neurotransmitter and their metabolites. A second area of work involves studies of premenstrual changes and menopause and hormone related changes in mood and behavior in women. Studies include: influence of hormonal replacement therapy; the development of clinical and diagnostic procedures; the association between gonadal hormones and other hormones, their change over time and clinical pathology, and the relationship between affective symptomatology during periods of change in the woman‘s life cycle and affective disorders.
Neuroimmunology; Behavioral pharmacology; Gene therapy; Immunology; Molecular and Cellular Biology; Molecular Basis of Disease; Neurobiology; Gene Expression; Signal Transduction; Protein Function and Structure; Neuropharmacology
My research spans three interrelated fields: chronic pain, depression and inflammation. Experiments in my laboratory focus on how brain-derived pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF), function as modulators of brain-body interactions during neuropathic pain and how brain-TNF is involved in the mechanism of action of antidepressant drugs. My overall goal is to advance knowledge of, and therapeutic efficacy for pain, depression, neuro-inflammation and drug addiction. This research is based on my earlier work showing that neurons produce the pro-inflammatory cytokine TNF and that the production of TNF by macrophages is regulated by neurotransmitters. Cytokines and neurotransmitters are principal signaling molecules that mediate bidirectional communication between the nervous and immune systems--the crosstalk important in maintaining homeostasis. Consequently, aberrant production of either of these two classes of mediators could profoundly affect signaling by the other, thereby impacting health. A shift in balanced cytokine-neuron interactions that regulate neurotransmitter release in the central nervous system (CNS), and that have potential behavioral consequences, manifest themselves as states of depression and chronic pain. My research uses both cell systems and animal models to test these hypotheses. Colleagues and I use a combination of imaging techniques to localize cytokine production, bioassays and ELISA (enzyme-linked immunosorbent assays) for pharmacological and functional analyses, electrophysiological (brain slice stimulation) and molecular methods for our studies. In addition to investigating neuron functioning in the brain, trainees in my laboratory also study the peripheral macrophage, a major source of TNF during inflammation. Specifically studying neurotransmitter regulation of TNF production in the periphery is enhancing our knowledge of how the brain controls a peripheral inflammatory lesion. Our studies are designed to investigate the mechanisms of centrally mediated pain as associated with immune dysfunction and to elucidate mechanisms of drugs used to treat such pain states. My projects are evolving to investigate the mechanisms and neural pathways involved in TNF neuromodulator functions during chronic pain (due to peripheral nerve injury and diabetes) and stress-induced depressive behavior. We also study mechanisms contributing to the comorbidity of chronic pain and depression. I collaborate with researchers in several UB departments and at other institutions. Our projects include using noninvasive methods for delivery of anti-TNF therapeutics for chronic pain, elucidating the neural-immune mechanisms involved in the rapid recovery afforded by centrally administered anti-TNF therapy and using nanotechnology-mediated, targeted gene silencing within the CNS. I am invested in helping my undergraduate and graduate students, medical residents and postdoctoral fellows realize their potential and achieve their goals. Previous students have advanced professionally and hold clinical, academic and industrial positions.
Drug abuse; Behavioral pharmacology; Neurobiology
I have two primary research interests. First, I use pharmacological approaches to seek novel therapeutics for pain. Pain is an agonizing symptom and disease that affects millions of people. Analgesics like opioids (e.g., OxyContin) are powerful for treating many pain conditions. However, opioids are not efficacious for some pain (e.g., neuropathic pain) and prolonged use of opioids has many side effects, including tolerance and dependence. My research has found that drugs acting on imidazoline I2 receptors may produce analgesic effects that are devoid of opioid-like side effects. I am continuing this line of research to further delineate the pharmacological properties of these drugs--how they work, how effective and safe they are, and how long the beneficial effects last--as a novel class of analgesics. Second, I am interested in pharmacotherapy of stimulant abuse. Stimulants represent a large family of abused drugs, including traditional drugs of abuse such as cocaine and methamphetamine (“meth”) and valuable pharmacotherapies such as Adderall and Ritalin. Stimulant abuse and addiction remain challenging problems that lack FDA-approved pharmacotherapies. We use powerful behavioral pharmacological approaches, in animal models that are predictive of human stimulant abuse conditions, to study novel drug targets and evaluate potential pharmacotherapeutic treatments. One unifying theme of the ongoing research in my laboratory is the application of receptor theory to the guidance and interpretation of the drug interactions in behaving animals. The long-term goal of my laboratory is to develop new analgesics for pain control and pharmacotherapeutics for stimulant addiction.
Apoptosis and cell death; Bioinformatics; Endocrinology; Gene Expression; Gene therapy; Genomics and proteomics; Immunology; Molecular Basis of Disease; Molecular and Cellular Biology; Neurobiology; RNA; Viral Pathogenesis
Dr. Mahajan has established herself as an investigator in the area of neuropathogenesis of HIV-1 in the context of drug abuse. She has initiated several new projects that investigate the role of a unique key signaling molecule in the dopaminergic pathway that impacts drug addiction, depression and other neurological disorders. Her focus has always been on collaborative, interdisciplinary partnerships between various Departments within UB that include the Institute of Lasers, Photonics and Biophotonics, Research Institute of Addiction, Dept of Computer Science and Engineering, Dept of Pharmaceutical sciences and the Department of Bioengineering. This inclusive strategy has facilitated the emergence of a robust, innovative clinical translational research program for our Division that continues to grow steadily. Dr Mahajan has obtained independent research funding from NIDA, the pharmaceutical Pfizer, US- Fulbright and other Private Foundations such as Dr. Louis Skalrow Memorial trust to conduct some of these research projects. Dr. Mahajan is Director of Research of the Division of Allergy, Immunology & Rheumatology. She supervises the research training of the Allergy fellows,Medical residents, graduate and undergraduate students. Dr. Mahajan has presented her research work at National and International conferences and was an invited speaker at several seminars and colloquiums. She has authored over 95 publications in several top quality peer reviewed journals and has thus demonstrated a high level of scholarly productivity. She is a reviewer and an adhoc member of the editorial board of several journals in her field. The following is a brief synopsis of her research interests. HIV neuropathogenesis in the context of drug abuse: We proposed that Opiates act as co-factors in the pathogenesis of HIV-1 infections by directly suppressing immune functions of the host through interactions with mu-opioid receptors on lymphocytes. Exacerbation of HIV encephalopathy (HIVE) is observed with opiate abuse. The mechanisms underlying HIVE are currently undetermined however, they likely to include the generation of endogenous neurotoxins combined, perhaps synergistically, with bioreactive HIV-1 envelope proteins. We believe that these proposed mechanisms may work through a common signal transduction mechanism activating dopamine D1 receptors in the nucleus accumbens of the brain. Opiate abuse by HIV-1 infected subjects may exacerbate the progression of HIVE as a consequence of the combined effects of HIV-1 induced neurotoxins plus opiate induced increases in the D1 receptor activation. We hypothesize that the dopaminergic signaling pathway is the central molecular mechanism that integrates the neuropathogenic activities of both HIV-1 infections and the abuse of opiate drugs. In this context our investigation is focused on the DARPP-32 signalling pathway. Addictive drugs act on the dopaminergic system of the brain and perturb the function of the dopamine- and cyclic-AMP-regulated phosphoprotein of molecular weight 32 kD (DARPP-32). DARPP-32 is critical to the pathogenesis of drug addiction by modulating both transcriptional and post-translational events in different regions of the brain. DARPP-32 is localized within neurons containing dopamine receptors and is a potent inhibitor of another key molecule in the dopaminergic signaling pathway, protein phosphatase 1 (PP-1). We propose that the sustained silencing of DARPP-32 gene expression using specific siRNA delivered to the brain is an innovative approach for the treatment of drug addiction. The specific challenge of the proposed project is the non-invasive delivery of biologically stable, therapeutic siRNA molecules to target cells within the brain. We are developing biocompatible nanoparticles to both protect DARPP-32 specific siRNA against degradation and deliver it from the systemic circulation across the BBB to specific dopaminergic neurons in the brain of patients with opiate addictions. BBB Research: While examining neuropathogenesis of HIV, we became interested in the role of the blood-brain barrier (BBB) in HIV neuropathogenesis with the objective of developing therapeutic interventions to prevent and limit the progression of HIV associated neurological disease. The blood-brain barrier is an intricate cellular system composed of vascular endothelial cells and perivascular astrocytes that restrict the passage of molecules between the blood stream and the brain parenchyma. We evaluated and validated both the 2 and 3 dimensional human in-vitro BBB models in my laboratory, that allowed examining permeability of virus, effects of drugs of abuse on BBB permeability, mechanisms of BBB transport, and tight junction modulation. Our goal remains to determine the impact of current and potential CNS antiretrovirals, psychopharmacologic, and other medications on the integrity of the BBB in HIV associated neurological disorder and other neurodegenerative diseases. Additionally, We also investigate mechanisms that underlie drugs of abuse induced neuronal apoptosis. Systems biology approach: We expanded our investigation to include functional genomic/proteomic analyses that allowed characterization of gene/ protein modulation in response to a drug stimulus or under a specific disease condition. We developed an expertise in these large-scale genomic and proteomic studies and the genomic studies helped identify key genes that underlie molecular mechanisms in drug addiction, HIV diseases progression, and allowed examination of the interplay of genes and environmental factors. The proteomic studies confirmed the presence of specific proteins that regulate key biological processes in drug addiction and HIV diseases progression. Recently, We have expanded my research program to include microbiome analyses and incorporated the utility of the computational drug discovery platform (CANDO) model that allows studying interaction between protein structures from microbiome genomes and determine the interactions that occur between them and small molecules (drugs and human/bacterial metabolites that are already a part of or continue to be added to the CANDO library. Using the CANDO Platform we are able to do the hierarchical fragment-based docking with dynamics between those compounds/drugs and the microbiome proteins/proteomes to determine which ones of the drugs and metabolites will work most efficaciously in patients using specific drugs. NanoMedicine: Over the last couple of years, We have become increasingly interested in nanomedicine and have developed several interdisciplinary clinical translational research focused collaborations that include 1) Nanotechnology based delivery systems to examine antitretroviral transport across the BBB; 2) Nanotherapeutics using siRNA/Plasmid delivery to specific regions in the brain to target various genes of interest specifically those pertaining to the dopaminergic pathway that includes a phosphor protein called “DARPP-32”. Targeting various key genes in the dopaminergic pathway results in the modulation of behavioral response which we observed in animal models of addiction/depression, 3) Biodistribution studies of various nanotherapeutic formulations using PET small animal imaging. Additionally, We are also focused on exploring epigenetic mechanisms that under drug addiction and mechanisms that underlie oxidative stress in neurodegenerative diseases.
Ion channel kinetics and structure; Molecular and Cellular Biology; Neurobiology; Neuropharmacology
Our research program focuses on brain development, studying the development of the oligodendroglial and astroglial cell lineages in the central nervous system in normal, mutant and transgenic mice. The primary focus in the laboratory is on ion channels that regulate specification, migration and differentiation of these glial cells. The oligodendrocyte generates CNS myelin, which is essential for normal nervous system function. Thus, investigating the regulatory and signaling mechanisms that control its differentiation and the production of myelin is relevant to our understanding of brain development and of adult pathologies such as multiple sclerosis. We have recently discovered that voltage-gated Ca++ channels are necessary for normal myelination acting at multiple steps during oligodendrocyte progenitor cells (OPCs) development, however nothing is known about its role in demyelination or remyelination events. Our research aims to determine if voltage-gated Ca++ channels plays a functional role in myelin repair. Using transgenic mice and new imaging techniques we are testing the hypothesis that voltage-gated Ca++ entry promotes OPC survival and proliferation in the remyelinating adult brain. Therefore, this work is relevant to developing means to induce remyelination in myelin degenerative diseases and for myelin repair in damaged nervous tissue. Astrocytes are the most abundant cell of the human brain. They perform many functions, including biochemical support of endothelial cells that form the blood brain barrier, provision of nutrients to the nervous tissue and a role in the repair and scarring process of the brain and spinal cord following traumatic injuries. Our lab has made the novel finding of voltage-gated Ca++ channels function in astrocyte Ca++ homeostasis, and this has implications for plasticity in astrocyte development and for Ca++ regulation in general. We are testing the hypothesis that voltage-gated Ca++ entry plays a key role in astrocyte function and glial-neuronal interactions. We have generated a conditional knockout mice for voltage-gated Ca++ channels in astrocytes, these conditional knockout mice will allow the functional analysis of voltage-gated Ca++ channels in astroglia of the postnatal and adult brain. Analyzing such mice using a combination of behavioral, electrophysiological, imaging, and immunohistochemical techniques will provide new insights in our understanding of astroglial contribution to brain function. These projects have been supported for many years by grants from the NIH and the National Multiple Sclerosis Society.
Behavioral pharmacology; Neurobiology; Neuropharmacology; Regulation of metabolism; Signal Transduction
Catecholamines such as dopamine and norepinephrine in the brain play important roles in a wide range of disparate physiological and behavioral processes such as reward, stress, sleep-wake cycle, attention and memory. The catecholamines are also well known for their treatment of neural disorders and many other diseases. Therefore, the examination of the catecholamines is of great importance not only in pharmaceutical formulations but also for diagnostic and clinical processes. The role and contribution of catecholaminergic innervation in the limbic system to biological functions and behavior are still poorly understood, however, due to the complicated functional heterogeneity, the small size of the limbic brain nuclei. In vivo and in vitro electrochemical measurement at microelectrodes has enabled direct monitoring of neuronal communication by chemical messengers in real time, which provides new insight into the way in which information is conveyed between neurons. Such information enables to study the basis for understanding the mechanisms that regulate it, the behavioral implications of the chemical messengers, and the factors regulate normal and altered chemical communication in various disease states (e.g. cardio vascular disease, degenerative nerve diseases, and drug addiction). My overall research focuses on two areas. Firstly, the design and implementation of development of new types of electrochemistry-based sensors and ancillary tools to monitor catecholamines and nonelectroactive neurochemicals in a chemically complex environment in the peripheral and central nervous systems of test animals. Secondly, application of the newly developed analytical techniques or existing methodologies for real-time monitoring of the neurochemicals i) to understand role of the neurochemicals in the brain in stress- and reward-related behaviors, ii) define and understand dysfunctions of the central and peripheral nervous systems in disease states by observing fundamental changes in neurochemical transmission in anesthetized and awakened animals.
Bioinformatics; Cell growth, differentiation and development; Neurobiology
My laboratory seeks to understand the transcriptional regulatory network governing the differentiation of oligodendrocytes and central nervous system (CNS) myelination, with the long-term goal of translating this knowledge into the treatment of demyelinating diseases. CNS myelination by oligodendrocytes is important not only for saltatory conduction of action potentials but also for trophic support of nerve axons. An improved understanding of how the differentiation of oligodendrocytes is regulated for CNS myelination should provide a firm basis on which to develop more effective therapeutics for demyelinating diseases. Toward this goal, we are currently pursuing two different research directions. The first is to elucidate the functional mechanism of Myrf, a key transcription factor for CNS myelination. Conditional knockout mice in which Myrf is knocked out in the oligodendrocyte lineage cells completely fail to develop CNS myelin and exhibit severe neurological symptoms, eventually prematurely dying. Recently, we and the Emery laboratory have independently made the surprising discovery that Myrf is generated as an integral membrane protein that is auto-cleaved by its ICA domain into two fragments. This discovery invokes a number of fundamental questions about how Myrf drives the differentiation of oligodendrocytes for CNS myelination. We employ both computational and experimental laboratory methodologies to elucidate the functional mechanism of Myrf. The second direction is to identify new transcription factors for CNS myelination. By taking advantage of our computational expertise, we have performed integrated computational analysis of functional genomics data that are publicly available to predict a number of new transcription factors for oligodendrocyte differentiation. We are currently characterizing them using primary oligodendrocyte cultures. Promising hits will be further analyzed by generating knockout mice to test for in vivo relevance.
Gene Expression; Gene therapy; Molecular Basis of Disease; Molecular and Cellular Biology; Neurobiology; Neuropharmacology; Transcription and Translation
The efforts in my lab are broadly directed at the translational research of neuroprotective/neurorestorative agents. Specifically, I am focused on the preclinical and clinical development of therapies used to prevent behavioral and cognitive deficits following traumatic brain injury (TBI) and stroke. Over 800,000 patients each year in the US suffer stroke and more than twice that number suffer TBI. Unfortunately there are currently no FDA approved therapies for TBI. TPA is the only therapy approved for stroke but is only applied in about 4% of stroke patients. Furthermore, while TPA is thrombolytic, it does not limit the cascade of pathology initiated by the original occlusion. We have demonstrated that low dose methamphetamine is highly neuroprotective when administered as an acute treatment (within 12 hours after injury) following severe stroke or TBI. We have show that treatment with methamphetamine significantly improve cognition and functional behavior in rat models of these injuries. This effect is primarily mediated through the activation of a dopamine/PI3K/AKT signaling cascade and results in the preservation of primary neurons, and axons, as well as enhanced granule cell neurogenesis and white mater track remodeling. Furthermore, gene expression analysis suggests methamphetamine treatment significantly reduces pro-inflammatory signals and stabilizes the blood brain barrier. These observations led us to further investigate the potential of low dose methamphetamine to reduce or prevent post-traumatic epilepsy. Using long-term video/EEG monitoring, we determined that methamphetamine treatment significantly reduces the incidence and susceptibility to post traumatic epilepsy/seizures after severe TBI in rats. This becomes quite relevant when one considers that many patients with post-traumatic epilepsy are pharmacoresistant. We are continuing to use the TBI model to investigate the causes of post-traumatic epilepsy and test novel therapeutics. In addition to single severe injury, we are also very interested in the effects of repeated mild TBIs. It has now been observed that multiple mild TBIs can cause clinical seizures in about 50% of rats. Therefore, we are also using this model to investigate the causes of post-traumatic epilepsy and potential therapeutic interventions. We have now completed a phase I human trial of methamphetamine in healthy volunteers and are moving to conduct a phase IIa dose escalation safety study in TBI patients. In addition, we are currently using NGS to examine plasma miRNA changes as potential biomarkers and objective measures of activity to support the phase IIa study. In addition to small molecules, my lab also is investigating the development of Adeno- associated virus (AAV) vector based gene therapy approaches to the treatment of CNS injuries such as post-traumatic epilepsy. Specifically, we are using recombinant AAV vectors to modulate targeted gene expression in a temporal, tissue-specific and cell type-specific manner within the CNS.
Drug abuse; Apoptosis and cell death; Molecular and Cellular Biology; Neurobiology; Signal Transduction; Toxicology and Xenobiotics
My laboratory is focused on understanding the molecular and cellular actions of drugs of abuse such as ethanol and hallucinogens such as lysergic acid diethylamide (LSD). This information is a requisite step in the ultimate development of therapeutic interventions to alleviate the major healthcare and social burden associated with use and abuse of these drugs. In addition, these drugs provide an avenue to explore the basic workings of the brain under pathological conditions that are manifested as various psychiatric disorders. Previous studies, in collaboration with Dr JC Winter in the Dept of Pharmacology and Toxicology at UB, have investigated the roles of the various serotonin receptors subtypes and their associated signaling pathways as well as glutamatergic neurotransmission in the subjective effects of LSD-type hallucinogens. Our other studies have been aimed at understanding the adverse developmental effects of ethanol exposure that result in the fetal alcohol spectrum disorders with the fetal alcohol syndrome (FAS) as the most severe manifestation. Using zebrafish and neuronal cells in culture as model systems, my laboratory in collaboration with Dr CA Dlugos in the Dept of Pathology and Anatomical Sciences at UB have investigated the morphological and histological changes associated with ethanol exposure during different developmental stages as well as the mechanisms by which developmental ethanol exposure causes neuronal loss. Currently, we are investigating the neurotoxic interaction of ethanol with pesticides. Because of the wide-spread use of pesticides, people are continually exposed both voluntarily and involuntarily to an array of toxic chemicals. In addition, since consumption of alcohol is pervasive in our society with a very high prevalence of alcohol use and abuse, it is extremely likely that people with be co-exposed to both ethanol and pesticides. Because simultaneous or sequential exposure to multiple chemicals can dramatically modify the ensuing toxicological responses, we are using both in vitro (e.g., cells in culture) and in vivo (e.g., zebrafish) model systems to begin assessing the possible health risk of co-exposure to ethanol and pesticides. Using the herbicide paraquat, which is widely used throughout the world, as a test compound, we have found that ethanol synergistically increases the in vitro neurotoxicity of this pesticide. Our efforts are now aimed at ascertaining whether a similar interaction occurs in vivo as well as determining the molecular mechanism responsible for this synergistic neurotoxicity. Teaching is a naturally complement to research. Accordingly, I have also been engaged in efforts to both improve how we provide the knowledge base to our undergraduate, graduate, and professional students, and also how we help students learn to integrate and apply this information in problem-solving at the clinical and basic science levels. Efforts include: 1. using “clickers” in large class formats to assess student’s understanding of the material and well as provide each student instantaneous feedback for their own self-assessment; 2. using cases studies and a small group learning format; and 3. Having students write short grant proposals based upon the current literature as well as reviewing and critiquing their classmate’s proposals.
Gene therapy; Genomics and proteomics; Immunology; Infectious Disease; Neurobiology; Neuropharmacology; Viral Pathogenesis; Virology
As a postdoctoral fellowship in the Division of Allergy, Immunology & Rheumatology at University at Buffalo I received a NIDA funded National Research Service Award (NRSA) F32 to study the mechanisms of cocaine-induced HIV-1 infection in astrocytes. This was a two year fellowship award ($99,224). I received several Young Investigator Travel Awards to attend and present my research at national conferences including the Society for NeuroImmune Pharmacology, the College on Problems of Drug Dependence and the International Society for NeuroVirology. I was the first to demonstrate that cocaine enhances the replication of HIV in astrocytes, specialized glial cells in the central nervous system. During this time I was first author on 3 publications and contributed as a co-author on 6 publications in internationally recognized, peer reviewed journals including the Journal of Immunology, Brain Research and Biochimica et Biophysica Acta. As a Research Assistant Professor in the Division of Immunology I was funded through a NIDA Mentored Research Scientist Development Award (K01) award to investigate targeted nanoparticles for gene silencing in the context of HIV and drug abuse. This K01, was a five year award, $785000 that allowed for advanced training in nanotechnology and immunology. I applied this new expertise in nanotechnology to the development of innovative methods to control HIV-1 infections, particularly those associated with methamphetamine abuse. I was an invited panel speaker at the International Symposium on NeuroVirology and the American College of Neuropsychopharmacology. During this time, I published approximately 30 peer-reviewed publications in internationally recognized, peer-reviewed journals, including journals such as the Journal of Immunology, Brain Research, and the Journal of Pharmacology Experimental Therapeutics. Six as first author, 1 as senior author and 23 as a co-author. Presently, I am a Associate Professor and Proposal Development Officer in the Department of Medicine at University at Buffalo where I continue to develop my research in drug delivery methods. I am currently investigating exosomes as potential delivery vehicles. Exosomes are one of several types of membrane vesicles known to be secreted by cells including microvesicles, apoptotic bodies, or exosome-like vesicles. Exosomes, unlike synthetic nanoparticles, are released from host cells and have the potential to be novel nanoparticle therapeutic carriers I have recently been invited to be a panel speaker at the American Society of Nanomedicine and the American Society of Gene & Cell Therapy conferences. I have been a principal investigator and co-instigator on NIH funded projects studying multimodal nanoparticles for targeted drug delivery and immunotherapy in Tuberculosis and HIV and a co-investigator on a NYS Empire Clinical Research Investigator Program (ECRIP) to develop a Center for Nanomedicine at UB and Kaleida Health. I have had over eight years of NIH supported funding.
Dermatology; Immunology; Neurobiology
As a physician with clinical expertise in dermatology and a bench scientist with over 15 years of experience in cutaneous immunology, my research focuses on autoimmune disorders and neuroimmunology of the skin. I am particularly interested in the blistering autoimmune skin disease Pemphigus vulgaris (PV), which, while rare, serves as an excellent model to investigate the basic aspects of autoimmune disease in general. The work in our laboratory is patient-based, and we have an unparalleled collection of blood samples and clinical information from over 200 individuals affected by PV enrolled in our IRB-approved studies focusing on mechanisms of autoimmunity (T effector and regulatory cells, immunoglobulin subtypes, auto-antigen and auto-antibody profiles) as well as clinical expression of disease. We have also recently applied cutting-edge atomic force microscopy technology to the investigation of antibody effects in the tissue level in PV. Another main interest of mine is investigating the role of stress hormones and neural transmitters in skin diseases, in particular the effect of adrenaline on Langerhans cells (resident dendritic cells within the epidermis). It has long been postulated that stress can affect certain skin conditions, but only recent experimental evidence has established a role of the neuroendocrine system in cutaneous inflammation. Exploring the role of stress hormones and neural transmitters promises to affect greatly the way we view and treat many skin diseases including, but not limited to atopic dermatitis and psoriasis. As a research assistant professor in the department of dermatology I oversee the work of postdoctoral fellows, MD/PhD students and medical students involved in the day-to-day operations of our basic science laboratory. I also actively participate in dermatology resident teaching through regularly scheduled basic science journal clubs and by supervising resident research rotations in the laboratory.
Genomics and proteomics; Neurobiology; Neurodegenerative disorders
My lab investigates the molecular control of cell fate and homeostasis of resident stem and progenitor cells in the human brain. Using a combination of multicolor cell sorting techniques and whole genome analysis, we are characterizing the signaling pathways which regulate the formation and fate of human oligodendrocyte progenitor cells. We are testing the functional significance of these pathways using both pharmacological and viral methods in culture and animal-based models of myelination and demyelination.
Behavioral pharmacology; Cardiac pharmacology; Ion channel kinetics and structure; Membrane Transport (Ion Transport); Molecular Basis of Disease; Neurobiology; Neuropharmacology; Signal Transduction; Transgenic organisms
With over 400 genes coding for them in humans, ion channels play a significant role in most physiological functions. Drug-induced channel dysfunction often leads to a variety of disorders and results in significant incidence of serious injury and death. We investigate molecular mechanisms underlying neurodegenerative disorders and cardiac arrhythmias induced by ion channel dysfunction arising from genetic factors and/or drug interactions. The tools used for these investigations include genetic, electrophysiologic, pharmacologic, molecular and cell culturing methods. Preparations used for experiments include Drosophila as a genetic model system, and human cell lines expressing human ion channels that play an important role in critical-to-life functions including cardiac rhythm, respiration and the central nervous system.
Cell growth, differentiation and development; Gene Expression; Molecular and Cellular Biology; Neurobiology; Signal Transduction
The long term mission of my research has been to understand developmental and regenerative processes within the mammalian CNS. Towards these goals I have employed stereological and microscopic imaging techniques, stem cell cultures and in vivo models to analyze brain development, regenerative capacity, etiology of neurodevelopmental and neurodegenerative diseases. I have established a quantitative Neuroanatomy Stereology laboratory within a multi-disciplinary Molecular and Structural Neurobiology and Gene Therapy Program. Current projects: Developmental disorder- Schizophrenia The studies that I have been engaged in the last several years have addressed fundamental aspects of organismal development, their pathological disruptions and their targeting for regenerative medicine. With the advent of multicellular organisms, mechanisms emerged that imposed new controls which limited the natural propensity of organisms composed of single cells to proliferate, and to invade new locales, which ultimately results in the formation of tissues and organs. How such an immense task is accomplished has been largely unknown. Our collaborative studies have revealed a pan-ontogenic gene mechanism, Integrative Nuclear Fibroblast Growth Factor Receptor 1 (FGFR1) Signaling (INFS), which mediates global gene programing through the nuclear form of the FGFR1 receptor (nFGFR1) and its partner CREB Binding Protein, so as to assimilate signals from diverse signaling pathways. My work, which has contributed to these findings, has been focused on the role of INFS in cellular development. I have shown that INFS is central to the development of neural cells and that pluripotent ESC and multipotent NPCs can be programmed to exit from their cycles of self-renewal, and to undergo neuronal differentiation simply by transfecting a single protein, nFGFR1. Using viral and novel, nanotechnology based gene transfers, I have demonstrated that it is possible to reactivate developmental neurogenesis in adult brain by overexpressing nFGFR1 in brain stem/progenitor cells. We have shown that similar effects can be produced by small molecules that activate the INFS. These findings may revolutionize treatments of abnormal brain development, injury and neurodegenerative diseases by targeting INFS to reactivate brain neurogenesis. Schizophrenia (SZ) has been linked to the abnormal development of multiple neuronal systems, and to changes in genes within diverse ontogenic networks. Genetic studies have established a link between FGFs and nFGFR1 with these networks and SZ. nFGFR1 integrates signals from diverse SZ linked genes (>200 identified) and pathways[2-6] and controls developmental gene networks. By manipulating nFGFR1 function in the brain of transgenic mice I have established a model that mimics important characteristics of human schizophrenia: including its neurodevelopmental origin, the hypoplasia of DA neurons, increased numbers of immature neurons in cortex and hippocampus, disruption of brain cortical layers and connections, a delayed onset of behavioral symptoms, deficits across multiple domains of the disorder, and their correction by typical and atypical antipsychotics[6, 7]. To understand how SZ affects neural development, I have begun to generate induced pluripotent stem cells (iPSCs) using fibroblast of SZ patients with different genetic backgrounds. In my studies I employ 3-dimensional cultures of iPSCs, co-developmental grafting of the iPSCs neural progeny into murine brain, FISH (Fluorescent In Situ Hybridization), gene transfer and quantitative stereological analyses. I am testing how genomic dysregulation affects the developmental potential of schizophrenia NPCs (formation of 3D cortical organoids, in vivo development of grafted iPSCs) which may be normalized by correcting nFGFR1 and miRNA functions. In summary, my studies are aimed to develop to new treatments for Schizophrenia and other neurodevelopmental disorders including potential preventive therapies. Effect of maternal diet and metabolic deficits on brain development (collaboration with Dr. Mulchand Patel, Department of Biochemistry, UB) Approximately 36% of the adults in the US are classified as obese. Available evidence from epidemiological and animal studies indicate that altered nutritional experiences early in life can affect the development of obesity and associated metabolic diseases in adulthood and subsequently in the offspring of these people. Furthermore, there is an increased risk for mental health disorders that is associated with these conditions. Our studies show that an altered maternal environment in female rats produced by consuming a high fat (HF) or high sugar diet (HS) negatively impacts the development of brain stem cells and fetal brain circuitry in the offspring[8, 9]. Increased numbers of immature, underdeveloped neurons are found in the hypothalamus, which controls feeding behavior. Similar changes are found in areas of the cerebral cortex involved in other diverse behavioral functions. These changes reveal an alarming predisposition for neurodevelopmental abnormalities in the offspring of obese female rats. Blast induced brain injury and regeneration (collaboration with Dr. Richard Salvi, Department of Communicative Disorders and Sciences, UB) Sound blast induced brain injury is a major concern in military exposure to excessive noise. In mice exposed to the sound blast we found marked loss of myelinated fibers and neuronal apoptosis in brain cortex. These degenerative changes were accompanied by increased proliferation of brain neural progenitor cells in the subventricular zone of the lateral ventricles. Immunohistochemical and stereological analyses reveal that these initial changes are followed by the gradual reappearance of myelinated cortical fibers. This is accompanied by increased proliferation of oligodendrocytic progenitors. I found that these progenitors also differentiate to mature oligodendrocytes in brain cortex. Our findings show that the blast-induced activation of the brain neural stem/progenitor cells generates predominantly new oligodendrocytes. The capacity of these new cells to myelinate damaged and regenerating neurons will be addressed in my planned future investigation.
Bioinformatics; Cell growth, differentiation and development; Gene Expression; Gene therapy; Genome Integrity; Genomics and proteomics; Molecular Basis of Disease; Molecular and Cellular Biology; Neurobiology; Signal Transduction; Stem Cells; Transcription and Translation
The long term mission of our laboratory, which I co-direct with Dr. Ewa Stachowiak, is to understand the principles governing molecular control of neural development, the implications for developmental- and aging-related diseases and the wide ranging effects on brain functions including behavior. The main achievement of our program has been the discovery of “Integrative Nuclear FGFR1 Signaling”, INFS a universal signaling mechanism which plays a novel integral role in cell development and complements other universal mechanisms such as mitotic cycle and pluripotency .Based on these revolutionary findings we have formulated a new theory called “Feed-Forward End-Gate Signaling” that explains how epigenetic factors either extracellular like neurotransmitters, hormonal or growth factors or intracellular signaling pathways control developmental gene programs and cellular development. This discovery is a product of our twenty-year multidisciplinary research that has been reported in several peer-reviewed papers in major journals including Proc. Natl. Acad. of Science (USA), Integrative Biology, Molecular Biology of the Cell, Journal of Cell Biology, Journal of Biological Chemistry, Journal of Physical Chemistry (etc.). In addition, we have applied this theory to analyze the etiology of neurodevelopmental /neurodegenerative disorders, and cancer in order to utilize it in new potential therapies. Towards these goals we have employed new technologies for an in vivo gene transfer, developed new transgenic mouse models for Schizophrenia and Parkinson-like diseases and established an interdisciplinary Molecular and Structural Neurobiology and Gene Therapy Program which has o engaged researchers from the different UB departments, other universities in the US as well as foreign institutions including Hannover Medical School (Germany), Gdansk Medical University, and Polish Academy of Science. Detailed research activities and future goals of our research program: 1. Molecular mechanisms controlling development of neural stem and related cells. In studying molecular mechanisms controlling development of neural stem and related cells we have established a novel universal signal transduction mechanism -Feed-Forward-And Gate network module that effects the differentiation of stem cells and neural progenitor cells. In the center of this module is the new gene-controlling mechanism "Integrative Nuclear Fibroblast Growth Factor Receptor-1 (FGFR1) Signaling" (INFS), which integrates diverse epigenetic signals and controls cell progression through ontogenic stages of proliferation, growth, and differentiation. We have shown that, Fibroblast Growth Factor Receptor-1 (FGFR1) a protein previously thought to be exclusively involved with transmembrane FGF signaling, resides in multiple subcellular compartments and is a multifactorial molecule that interacts with diverse cellular proteins In INFS, newly synthesized FGFR1 is released from the endoplasmic reticulum and translocates to the nucleus. In the nucleus, FGFR1 associates with nuclear matrix-attached centers of RNA transcription, interacts directly with transcriptional coactivators and kinases, activates transcription machinery and stimulates chromatin remodeling conducive of elevated gene activities. Our biophotonic experiments revealed that the gene activation by nuclear FGFR1 involves conversion of the immobile matrix-bound and the fast kinetic nucleoplasmic R1 into a slow kinetic chromatin binding population This conversion occurs through FGFR1’s interaction with the CBP and other nuclear proteins. The studies support a novel general mechanism in which gene activation is governed by FGFR1 protein movement and collisions with other proteins and nuclear structures. The INFS governs expression of developmentally regulated genes and plays a key role in the transition of proliferating neural stem cells into differentiating neurons development of glial cells, and can force neoplastic medulloblastoma and neuroblastoma cells to exit the cell cycle and enter a differentiation pathway and thus provides a new target for anti-cancer therapies. In our in vitro studies we are using different types of stem cells cultures, protein biochemistry, biophotonics analyses of protein mobility and interactions [Fluorescence Recovery after Photobleaching (FRAP), Fluorescence Loss In Photobleaching (FLIP), and Fluorescence Resonance Energy Transfer (FRET)] and diverse transcription systems to further elucidate the molecular circuits that control neural development. 2. Analyses of neural stem cell developmental mechanisms in vivo by direct gene transfer into the mammalian nervous system. An understanding of the mechanisms that control the transition of neural stem/progenitor cells (NS/PC) into functional neurons could potentially be used to recruit endogenously-produced NS/PC for neuronal replacement in a variety of neurological diseases. Using DNA-silica based nanoplexes and viral vectors we have shown that neuronogenesis can be effectively reinstated in the adult brain by genes engineered to target the Integrative Nuclear FGF Receptor-1 Signaling (INFS) pathway. Thus, targeting the INFS in brain stem cells via gene transfers or pharmacological activation may be used to induce selective neuronal differentiation, providing potentially revolutionizing treatment strategies of a broad range of neurological disorders. 3. Studies of brain development and neurodevelopmental diseases using transgenic mouse models. Our laboratory is also interested in the abnormal brain development affecting dopamine and other neurotransmitter neurons and its link to psychiatric diseases, including schizophrenia. Changes in FGF and its receptors FGFR1 have been found in the brains of schizophrenia and bipolar patients suggesting that impaired FGF signaling could underlie abnormal brain development and function associated with these disorders. Furthermore the INFS mechanism, integrates several pathways in which the schizophrenia-linked mutations have been reported. To test this hypothesis we engineered a new transgenic mouse model which results from hypoplastic development of DA neurons induced by a tyrosine kinase-deleted dominant negative mutant FGFR1(TK-) expressed in dopamine neurons. The structure and function of the brain’s DA neurons, serotonin neurons and other neuronal systems including cortical and hippocampal neurons are altered in TK- mice in a manner similar to that reported in patients with schizophrenia. Moreover, TK- mice express behavioral deficits that model schizophrenia-like positive symptoms (impaired sensory gaiting), negative symptoms (e.g. low social motivation), and impaired cognition ameliorated by typical or atypical antipsychotics. Supported by the grants from the pharmaceutical industry we are investigating new potential targets for anti-psychotic therapies using our preclinical FGFR1(TK-) transgenic model. Our future goals include in vivo gene therapy to verify whether neurodevelopmental pathologies may be reversed by targeting endogenous brain stem cells. Together with the other researchers of the SUNY Buffalo we have established Western New York Stem Cells Analysis Center in 2010 which includes Stem Cell Grafting and in vivo Analysis core which I direct. Together with Dr. E. Tzanakakis (UB Bioengineering Department) we have written book “ Stem cells- From Mechanisms to Technologies’ (World Scientific Publishing, 2011). Educational Activities and Teaching: I have participated together with the members of our neuroscience community in developing a new Graduate Program in Neuroscience at the SUNY, Buffalo. I am teaching neuroanatomy courses for dental students (ANA811) and for graduate students (NRS524). At present I participate in team-taught graduate courses in Neuroscience and Developmental Neuroscience (NRS 520, 521 and NRS 524). I am serving as a mentor for several undergraduate, graduate (masters and doctoral students) and postdoctoral fellows in the Neuroscience Program, Anatomy and Cell Biology Program and in the IGERT program in the Departments of Chemistry and Engineering. Additionally to mentoring master and Ph.D. students at the UB, I have helped to train graduate students in the University of Camerino (Italy) and Hannover Medical School (Germany). The works of our graduate students have been described in several publications.
My research is aimed at determining how nerve cells establish appropriate connections during the development of the nervous system. In recent years, my work has focused on the role of glutamate receptors in the development and regeneration of connections between the spinal cord and the muscle at the neuromuscular junction. Under normal conditions, each muscle fiber is innervated by a single nerve fiber, and Dr. Kirk Personius and I have recently begun to clarify the fact that glutamate receptors are integral to this process. Until our work, this transmitter system had never been examined as a contributing factor. We now are exploring the mechanisms by which glutamate influences these important events. For many years prior to this work, I studied related questions in a very different systems. My work focused on how early visual input influences the formation of topographic binocular connections in the midbrain optic tectum of the frog, Xenopus laevis. The relay for visual input from each eye to the ipsilateral tectum, is a tegmental structure called the nucleus isthmi. The axons from this structure are guided to the optic tectum by unknown non-visual processes, but within the tectum, their final connections are completely dependent on the visual input coming from the 2 eyes. Only if both eyes are open, optically normal and exposed simultaneously to patterned input, will the isthomotectal projection form a map of the ipsilateral eye‘s field which is in proper topographic registration with the contralateral eye‘s field. Absence of visual input during development prevents the isthmic axons from terminating in a topographically organized way, and strabismus causes the isthmic axons to form an orderly but abnormal map which is in register with the map from the misaligned eye. The NMDA (N-methyl-D-aspartate) glutamate receptor is essential to this process, and the transmitters acetylcholine and GABA also are being investigated for their roles in control of plasticity. The techniques that have been used in these experiments include extracellular electrophysiological recording methods, immunocytochemistry, electron microscopy, calcium imaging, receptor binding, whole-cell patch-clamping, knockdown techniques to control activation of transmitter systems, and anatomical tracing methods.
Neurodegenerative disorders; Pathophysiology; Cytoskeleton and cell motility; Molecular Basis of Disease; Molecular and Cellular Biology; Neurobiology; Neuropharmacology; Signal Transduction
Synaptic Mechanisms of Mental Health and Disorders Our research goal is to understand the synaptic action of various neuromodulators that are linked to mental health and illness, including dopamine, stress hormones, and disease susceptibility genes. Specifically, we try to understand how these neuromodulators regulate glutamatergic and GABAergic transmission in prefrontal cortex (PFC), which is important for emotional and cognitive control under normal conditions. We also try to understand how the aberrant action of neuromodulators under pathological conditions leads to dysregulation of synaptic transmission in PFC, which is commonly implicated in brain disorders. The major techniques used in our studies include: • whole-cell patch-clamp recordings of synaptic currents, • viral-based in vivo gene transfer, • biochemical and immunocytochemical detection of synaptic proteins, • molecular analysis of genetic and epigenetic alterations, • chemogenetic manipulation of neuronal circuits, • behavioral assays. By integrating the multidisciplinary approaches, we have been investigating the unique and convergent actions of neuromodulators on postsynaptic glutamate and GABAA receptors, and their contributions to the pathogenesis of a variety of mental disorders, including ADHD, autism, schizophrenia, depression, PTSD and Alzheimer's disease.
Ophthalmology; Retina; Apoptosis and cell death; Gene Expression; Gene therapy; Molecular Basis of Disease; Molecular and Cellular Biology; Neurobiology; Protein Folding; Regulation of metabolism; Signal Transduction; Vision science
The research in my lab has focused on two main areas: 1). molecular mechanisms of inflammation, angiogenesis, vascular and neuronal degeneration in retinal diseases; 2). potential roles of angiogenic inhibitors in obesity, insulin resistance and diabetes. The first line of research centers on gene regulation and signal transduction pathways underlying the neurovascular injury in diabetic retinopathy, retinopathy of prematurity and age-related macular degeneration. In recent years, we are focusing our efforts on the function and mechanism of the UPR signaling in normal and diseased retinal cells. The latter one combines basic and clinical research to study biomarkers and mechanism of type 2 diabetes. 1. ER stress and the UPR signaling in retinal neurovascular injury and diabetic retinopathy. The endoplasmic reticulum (ER) is the primary site for protein synthesis and folding. Failure of this machinery to fold newly synthesized proteins presents unique dangers to the cell and is termed “ER stress.” In response to the stress, cells have evolved an intricate set of signaling pathways named the unfolded protein response (UPR) to restore the ER homeostasis. In addition, the UPR is known to regulates many genes involved in important physiological processes to modulate cell activity and cell fate. The project in my laboratory is aimed to understand the role of ER stress and the UPR in retinal vascular endothelial cell dysfunction and neuronal degeneration in diabetic retinopathy. Our previous work has implicated several key UPR branches such as IRE-XBP1 and ATF4-CHOP in retinal inflammation and vasculopathy in diabetes. Currently, we are employing integrated genetic tools and animal models to study the function of UPR genes in the retina and to dicepher the molecular links between the UPR signaling and inflammatory pathways in retinal cells. Findings from these studies are anticipated to identify novel therapeutic targets and develop new treatments for diabetic retinopathy. 2. Mechanisms and potential therapies for RPE death in age-related macular degeneration. The retinal pigment epithelium (RPE) plays an essential role in maintaining the normal structure and function of photoreceptors. RPE dysfunction and cell death is a hallmark pathological characteristic of age-related macular degeneration (AMD), a disease that accounts for the majority of vision impairment in the elderly. Using transgenic mouse models, we discovered that the transcription factor XBP1 is a critical regulator of oxidative stress and cell survival in RPE cells. Genetic depletion or inhibition of XBP1 sensitizes the RPE to stress resulting in cell death. Our ongoing studies focus on identifying the target genes of XBP1 in RPE cells through which the protein regulates cell survival. We are also investigating if these proteins could offer potential salutary effects to protect RPE cells from oxidative injury and degeneration in disease conditions such as AMD. 3. Roles and mechanisms of angiogenic/anti-angiogenic factors in obesity, insulin resistance and diabetes. Obesity, insulin resistance and Type 2 diabetes are clustered as the most important metabolic disorders, substantially increasing morbidity and impairing quality of life. Excess body fat mass, particularly visceral fat, leads to dysregulation of adipokines (proteins secreted from fat cells), resulting in higher risk of cardiovascular diseases. Our recent findings indicate that angiogenic/anti-angiogenic factors are associated with obesity, diabetes and diabetic complications. For example, pigment epithelium-derived factor (PEDF), a major angiogenic inhibitor, is an active player in adipose tissue formation, insulin resistance and vascular function. In the future, we hope to futher understand the functions and mechanisms of these proteins in lipid metabolism and adiposity. In collaboration with a number of clinical investigators, we are exploring the physiological application of these factors as novel biomarkers and therapeutic targets in the diagnosis and treatment of diabetes, metabolic disorders and peripheral vascular diseases.