Apoptosis and cell death; Cell Cycle; Cytoskeleton and cell motility; Gene Expression; Genomics and proteomics; Molecular Basis of Disease; Molecular and Cellular Biology; Signal Transduction
One-third of our tissue mass is extracellular matrix (ECM). The ECM provides structural support for cells in tissues and varies from being stiff, like bone, to soft, like skin. Importantly, the stiffness of the ECM, which can be changed by injury or disease, affects how cells proliferate and migrate. My research is in blood vessels, particularly in arterial stiffening, which is a significant risk factor for the progression of cardiovascular disease- the leading worldwide cause of death. While medications reduce hypertension and cholesterol, none specifically treat arterial stiffness. My lab will identify what happens to cells when arteries become stiffened, and determine how this contributes to cardiovascular disease. To understand how arterial stiffening affects cells, my lab will use mouse and cellular models to mimic the stiffening process in patients. We believe that cells within a stiffer matrix overproduce certain proteins that lead to uncontrolled cell growth, which then begets even more stiffening. Identifying and understanding the proteins in these pathways will allow for the development of drugs to counteract their function. The goal of my research is to contribute new fundamental knowledge about arterial stiffness, which will lead to new medications that help reduce a key cause of cardiovascular disease.
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.
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.
Mucociliiary Transport; Cell growth, differentiation and development; Cytoskeleton and cell motility; Molecular and Cellular Biology; Signal Transduction
Our lab is involved in two major projects: 1) Cell motility research – mucociliary transport. We have developed a series of real “models” or simplifications of the respiratory mucociliary epithelium (primary cultures, isolated epithelial sheets, isolated ciliated cells, demembranated and MgATP-reactivated cell models, and isolated, demembranated and reactivated ciliary axonemes) that allow one to study mucociliary transport at number of levels of organization. We have studied these models using biochemical methods, stroboscopic imaging, high speed image analysis, and EM to analyze the control of the beat frequency, waveform and coordination of respiratory cilia. We have developed correlative LM/EM methods and correlative live/immunofluorescence methods for this purpose. These studies have import for 1) detecting and understanding abnormal parameters of ciliary function, as in primary ciliary diskinesis (PCD) 2) for the testing of exogenous agents (drugs, environmental agents, etc.) on mucociliary transport. 2) Along with 4 other UB labs in Chemistry and Engineering, plus 1 lab in Head and Neck Surgery Dept. at Roswell Park, our lab is involved in an interdisciplinary project to develop a “high tech bandage” that is doped with tissue specific growth factors and cytokines that can be released with full activity and at known rates to stimulate wound healing in scrape and burn types of acute (and potentially, chronic) injuries. These agents are selected to promote: a) the motogenic and mitogenic activity of epithelia and b) blood vessel formation. Our lab specifically is responsible for the in-vitro testing of doped membranes for their ability to promote wound closure (re-epithelialization of 9 mm wounds) in a human epidermal cell line by image analysis of wound closure kinetics and cell division and cell death rates. We also are responsible for the in-vivo testing of such membranes in animals using a porcine burn model to assay inflammation, epithelial closure rates, blood vessel formation, and inflammation. As a faculty member and Co-Director of one of the oldest biological imaging courses in the U.S. (Optical Microscopy and Imaging in the Biomedical Sciences Course, Marine Biology Laboratory, Woods Hole, MA) my lab frequently is asked to help other researchers with digital imaging problems and has contributed computerized digital image analyses in a number of scientific publications.
Cardiovascular Disease; Cytoskeleton and cell motility; Molecular Basis of Disease; Molecular and Cellular Biology
My primary research interest is the behavior of endothelial cells, which form the inner lining of blood vessels and are key players in the remodeling events that occur during wound healing, aneurysm formation, tumor growth, and a wide variety of disease conditions. There are two questions about endothelial behavior that drive most of the research in my laboratory: (1) How does an endothelial cell migrate during wound healing and blood-vessel remodeling? We are particularly interested in the motor protein, myosin II, and how it exerts force within the cytoskeleton to push or pull the cell as it moves. In order to study the organization and movements of cytoskeletal proteins - and not just there biochemical properties - we use a variety of light microscopic methods to examine the dynamics and biochemistry of cytoskeletal proteins in living migrating endothelial cells. We also use conventional biochemical, genetic, and pharmacological manipulations to investigate the regulatory events that control myosin II behavior in situ. (2) How do endothelial cells sense and respond to their mechanical environment? Blood vessels remodel to accommodate long-term changes in blood flow. Certain flow environments can cause destructive remodeling that leads to cerebral aneurysms (local “ballooning” of vessels). Working with biomedical engineers in the laboratory of Dr. Hui Meng at the Toshiba Stroke Research Center, we use cell culture and whole animal systems to examine how endothelial cells respond to specific hemodynamic micro-environments in order to understand the mechanism and regulation of flow-induced remodeling, especially as it relates to cerebral aneurysms. A third interest is understanding the response of cultured endothelial cells to electrical fields, which have been shown to orient endothelial migration in vitro and to suppress edema in vivo by enhancing the endothelial permeability barrier.
Apoptosis and cell death; Cell growth, differentiation and development; Cytoskeleton and cell motility; Immunology; Signal Transduction; Stem Cells
My independent research at The University at Buffalo focuses on targeting the mammary gland microenvironment by evaluating cellular and tissue responses during specific developmental windows of mammary gland remodeling including puberty, the period of hormonal withdrawal during estrous cycling, or post-lactational involution. My choice to focus on discrete times of development for chemopreventive intervention, rather than long-term (and often life-time) intervention, represents a unique approach of short-term exposure at critical points of mammary gland development. Our goal is to allow women to bypass the need for lifelong compliance to a chemopreventive diet or drug regimen in order to attain lifelong protection against breast cancer. Developmentally targeted dietary interventions being investigated in our lab include continuous administration of oral contraceptives, dietary exposure to conjugated linoleic acid, and ethanol.
Cardiopulmonary physiology; Cytoskeleton and cell motility; Ion channel kinetics and structure; Membrane Transport (Ion Transport); Molecular and Cellular Biology; Molecular Basis of Disease; Signal Transduction
My research interests center on mechanical and electrical biophysics, from molecules to organs, and the development of new tools. And, in recent years I worked in transitional science; bringing basic science to the clinic and to industry. My basic research interests are on cell mechanics and the mechanisms by which mechanical forces are transduced into messages such as voltage and chemicals such as ATP and Ca2+. I discovered mechanosensitive ion channels in 1983. My methodology has included patch clamp, high resolution bright field light microscopy, low light fluorescence microscopy, high speed digital imaging, TIRF, digital image analysis, high voltage EM with tomography, Atomic Force Microscopy, molecular biology, natural product and recombinant protein biochemistry, NMR and microfabrication and microfluidics. We discovered the only known specific inhibitor of mechanosensitive ion channels and uncovered its remarkable mode action by using a combination of electrophysiology and chiral chemistry. We have demonstrated potential clinical applications of the peptide for cardiac arrhythmias, oncology, muscular dystrophy, and incontinence. We have developed many scientific tools. Recently we developed a sensor chip to measure cell volume in real time, and that is now entering production with Reichert Instruments of Buffalo. We also have an Small Business Innovation Research contract to develop a microfluidic, bipolar, temperature jump chip with ALA Scientific and developed a microfabricated Atomic Force Microscopy probe that is an order of magnitude faster and more stable than any commercial probes. We have made probe operable with two independent degrees of freedom on a standard Atomic Force Microscopy. This permits us to remove all drift and coherent noise by using one axis to measure the substrate position and the other the sample position. These probes are being produced by a new company in Buffalo, kBtwist. We have used the Atomic Force Microscope combined with electrophysiology to study the dynamics of single voltage dependent ion channels. This technique provides a resolution of >0.01nm in a kHz bandwidth. I have developed other hardware including the first automated microelectrode puller, a micron sized thermometer and heater and a high speed pressure servo. Some of these devices have been patented by the University of Buffalo and some are in current production. To analyze the reaction kinetics of single molecules, we developed and made publicly available (www.qub.buffalo.edu) a complete software package for Windows that does data acquisition and Markov likelihood analysis. The development was funded by the National Science Foundation, National Institutes of Health and Keck over the last fifteen years, and has been applied to ion channels, molecular motors and the even the sleep patterns of mice. We have taught at UB hands-on course to use the software, and the course was attended by an international group of academic scientists and students, government and industry.
Cell growth, differentiation and development; Cytoskeleton and cell motility; Stem Cells
Development of regenerative therapeutics involves understanding and application of molecular, cellular and tissue engineering principles. Integrated strategies include biomaterials, therapeutic molecules and stem cells to create bioengineered systems for regenerative medicine. Therefore, understanding fundamental interactions between different components and utilizing these concepts will provide tools to engineer tissue regeneration and develop treatment options for diseases. The translational aspect of regenerative medicine depends on proper integration of engineering and medicine. This hierarchical roadmap is tissue or disease specific and thus requires step-wise approaches. Our current goals are to develop strategies for therapeutic angiogenesis, soft and elastic tissue regeneration and delivery of drugs. We are interested to integrate the different components for effective therapeutic strategies
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.
Cytoskeleton and cell motility; Genomics and proteomics; Ion channel kinetics and structure; Membrane Transport (Ion Transport); Molecular and Cellular Biology; Pathophysiology; Regulation of metabolism
1. Mechanism and regulation of gastric acid secretion: Regulation of gastric acid secretion is the major treatment of many GI diseases including GERD, gastric, duodenal and esophageal ulcers. The spending in treating these conditions is substantial. The gastric parietal cell, lining the lumen of the stomach, is responsible for the secretion of isotonic HCl (0.15M) into stomach. One ATP is consumed for every proton secreted into the stomach lumen and a lot of proton pump (H,K-ATPase, the alpha and beta subunits of this enzyme were discovered in 1967(1) and 1990(2)) is required for this job. To accommodate these many proton pumps, the apical plasma membrane, in the resting state, is expanded in the form of numerous invaginations which express relatively short microvilli, and a large compartment of cytoplasmic membranes, commonly called tubulovesicles, fully loaded with proton pumps. Upon stimulation by hismatine initiated PKA signaling, these tubulovesicles traffic to and fuse with apical membrane, forming densely packed microvilli comparable to those found on the brush border membrane of small intestine. This intracellular trafficking and fusion events bring proton pumps to their post for active acid secretion. In time, these proton pumps are brought back into the cytoplasm (by way of endocytosis) for a reliable mechanism to turn off acid secretion. Although the membrane recycling theory was raised a long time ago(3), there are still many major gaps in the understanding of the mechanism for the regulation of acid secretion, which are the research interests of our laboratory. Techniques employed include isolation and primary culture of gastric parietal cells, measurement of acid secretion, fractionation of different membranes by differential and gradient centrifugation. 2. Using gastric parietal cell model to study general cell biological questions: how membrane trafficking is regulated by small G-proteins, how filamentous actin supports the dynamic change of microvilli on apical membrane. The parietal cell has a remarkably large volume of intracellular membrane trafficking adapted to the elegant mechanism for the regulation of acid secretion. This means that this cell is abundant in those protein machineries required for membrane trafficking and fusion, exocytosis and endocytosis. For instance, no other cell type expresses the amount of syntaxin3 found in parietal cell. Therefore, parietal cell is the top choice for elucidating many of the core questions in cell biology. Techniques used to attack these questions include immunoabsorption, differential ultra-centrifugation, IMAC, 2D-electrophoresis, LC-MSMS, and confocal microscopy. 3. Pathogenesis of Nonalcoholic Steatohepatitis (NASH) - NASH research is funded by the Peter and Tommy Fund. NASH is a disease of the liver that is associated with obesity and adult onset, or type II, diabetes. NASH is not a benign disease. Many people with NASH have a shorter life expectancy than those who no not have NASH. NASH is associated with cirrhosis and is the third most common reason for liver transplantation in adults. No one knows what causes NASH, but it is known that in obese people there is increased fat in the liver. In addition to fat, cells that cause inflammation are found in the liver in patients with NASH. It is thought that these inflammatory cells may cause liver damage that results in fibrosis, cirrhosis and ultimately liver failure. The purpose of this research is to understand the relationship between obesity and the molecular factors that control inflammation so the interaction of the two can be better understood and treatments developed. NASH and alcoholic steatohepatitis share many histological features. Both NASH and alcoholic steatohepatitis patients exhibit macrovesicular and microvesicular fat in hepatocytes. The number and size of Mallory bodies, and the pattern of pericellular fibrosis are also indistinguishable between two disease groups. Previous studies suggested that intestinal bacteria produced more alcohol in obese mice than lean animals. Therefore, we hypothesized and provided the first molecular evidence that alcohol metabolism contributes to the pathogenesis of NASH (Baker et al, 2010). Fatty liver is a prerequisite for the development of NASH. The homeostasis of hepatic lipid depends on the dynamic balance of multiple metabolic pathways. Previous studies focusing on individual pathway or enzyme drew conflicting conclusions on the molecular mechanism for the accumulation of lipid in hepatocytes. With a high through-put technique, we compared all the major pathways in parallel. We are expecting to publish the exciting results in the near future. Oxidative stress is believed to be a major factor mediating the transition from simple steatosis to NASH. The prevention or mitigation of oxidative stress in patients with simple steatosis could prevent NASH. Our current research examines two facets of this problem: 1) what are the molecular mechanisms causing oxidative stress; 2) what are the molecular mechanisms that our body take to fight oxidative stress. Many novel findings have been observed in the lab and we are in the process of confirming these observations. 4. Pathogenesis of Inflammatory Bowel Diseases (IBD): The etiology of IBD is unknown, but a body of evidence from clinical and experimental observation indicates a role for intestinal microflora in the pathogenesis of this disease. An increasing number of both clinical and laboratory-derived observations support the importance of luminal components in driving the inflammatory response in Crohn‘s disease. Members of the Toll-like receptor family are key regulators of both innate and adaptive immune responses. These receptors bind molecular structures that are expressed by microbes but are not expressed by the human host. Activation of these receptors initiates an inflammatory cascade that attempts to clear the offending pathogen and set in motion a specific adaptive immune response. Defects in sensing of pathogens or mediation of the inflammatory cascade may contribute to the pathophysiology of disease and injure the host by activating a deleterious immune response, such as in inflammatory bowel disease. The focus of this research is to identify specific toll-like receptor mutations that may be associated with the development of inflammatory bowel disease.