| Robert Bonomo, M.D. Professor of Medicine, Pharmacology, and Molecular Biology and Microbiology Professor of Medicine, Pharmacology, and Molecular Biology and Microbiology, Chief of the VA Medical Service, Member of the Translational Therapeutics and Molecular Pharmacology & Cell Regulation Tracks.
Research in the Bonomo laboratory investigates the molecular and clinical aspects of bacterial resistance to beta lactams antibiotics and beta-lactamase inhibitors. The main areas involves understanding the structure function relationships of the class A beta-lactamases, SHV-1 and KPC-2. These chromosomal and plasmid encoded beta-lactamase confers high level resistance to cephalosporins and carbapenems, which can render ineffective the most frequently used drugs to treat serious nosocomial infections. Dr. Bonomo also has projects studying OXA carbapenemases found in Acinetobacter baumannii, the cephalosporinase of Pseudomonas aeruginosa, the class A beta-lactamase of Mycobacterium tuberculosis, and metallo-beta-lactamase, NDM-1. The lab also is studying the bacterial membrane proteins, transpeptidases and carboxypeptidases, involved in cell wall synthesis. A major effort also involves rapid molecular diagnostics and typing.
| Matthias Buck, Ph.D. Professor of Physiology & Biophysics and Pharmacology, Member of the Membrane Structural Biology & Pharmacology Track.
Dr. Buck's research program characterizes the structures and the dynamics of proteins involved in protein-protein interactions with a concentration on the plexin and the Eph-A1 and Eph-B1 transmembrane receptors. Protein interactions determine the basic mechanisms by which proteins transmit signals in cells and how signal-ing is disrupted by mutation in diseased states. Knowing at near-atomic resolution which residues interact in protein complex formation will allow them to rationalize their interaction affinity and specificity. Furthermore, it will provide an opportunity for them to alter the proteins for diagnostic or therapeutic purposes. Both plexin and Eph receptor systems play critical roles in development of the cardiovascular as well as the nervous system, but also have direct relevance to the progression of cancers, making them a target for drug design.
| Chris Dealwis, Ph.D. Associate Professor Associate Professor of Pharmacology, Member of the Membrane Structural Biology & Pharmacology Track
Nearly every major process in a cell is carried out by a complex assembly of several proteins. The main focus of the lab involves understanding the structural organization requirements by multiple protein assemblies to facilitate biological function. Their approach is to use a multidisciplinary cycle to study the structure-function relationship of proteins. They also use structure-based drug and protein design to develop novel therapeutics against cancer, Alzheimer’s disease and microbial infections. These biophysical studies are facilitated by tech-niques such as X-ray & neutron crystallography; molecular modeling; CD, MS, and fluorescence spectroscopy; and ultracentrifugation.
|Analisa DiFeo, Assistant Professor of Oncology, Member of the Cancer Therapeutics Track.
Chemotherapy resistance and tumor recurrence are common in women diagnosed with high-grade epithelial ovarian cancer. Researchers have been unable to predict patient response to therapy because they do not have a thorough understanding of the complex mechanism within the tumor that causes drug resistance and recurrence. Dr. DiFeo’s laboratory is focused on identifying genetic aberrations that are critical for the develop-ment of drug resistance and ovarian cancer progression. These genetic changes will ultimately serve as novel biomarkers of the therapeutic responses to typical chemotherapy of ovarian cancer and/or to innovative targeted molecular therapies that can work alone or in conjunction with current treatment options to combat ovarian cancer. Using a combination of in vitro and in vivo approaches, we strive to better understand the mechanism by which both microRNA’s and the genes they regulate are involved in ovarian tumor biology and chemoresistance at the cellular level as well as in disease development and progression in animals.
| Clark Distelhorst, M.D. Charles S. Britton II Professor of Hematology/Oncology Professor of Medicine and Pharmacology, Member of the Cancer Therapeutics and Translational Therapeutics Tracks.
Glucocorticosteroid hormones such as prednisone and dexamethasone are used in the treatment of virtually all types of lymphoid malignancies, including acute lymphoblastic leukemia, chronic lymphocytic leukemia, cu-taneous T cell lymphoma, and non-Hodgkin lymphoma. The Distelhorst laboratory investigates how glucocorti-coids induce apoptosis in order to provide novel insight on fundamentally important mechanisms of apoptosis induction. Understanding the mechanisms accounting for apoptosis will allow for the development of novel therapies to overcome resistance to glucocorticoid-induced death of cancer cells.
| George Dubyak, Ph.D. Professor Professor of Physiology & Biophysics and Pharmacology, co-Leader of the Molecular Pharmacology and Cellular Regulation Track; Member of the Membrane Structural Biology and Pharmacology Track (MSBP).
The Dubyak laboratory investigates multiple aspects of extracellular ATP-based signal transduction in three areas: inflammation, anti-tumor immunity, and cardiovascular disease. A major focus is to understand how the P2X7 receptor, an ATP-gated ion channel, triggers the caspase-1-based inflammasome signaling pathways in macrophages and dendritic cells (DCs) which mediate interleukin-1β-based innate and adaptive immune re-sponses. Because IL-1β lacks a signal sequence it is released/exported from macrophages/DCs via non-classical secretory mechanisms, and the lab is studying released exosomes and shed plasma membrane mi-crovesicles as likely mechanisms for this atypical export. Related projects are analyzing how inflammasome-triggered exosomes provide a pathway for the externalization of antigen-loaded MHC-II vesicles as a novel link-age between innate and adaptive immunity. Most recent research on P2X7 receptor activation and mechanisms of IL-1Β secretion is linked to exciting new findings which indicate a key role for extracellular ATP, released from apoptotic tumor cells, in the activation of DC/ T lymphocyte paracrine signaling loops that drive anti-tumor immune responses. Additionally, the lab is studying the role of extracellular pyrophosphate (PPi) – which is derived from the hydrolysis of secreted extracellular ATP – as a critical suppressor of the pathological cardio-vascular calcification that occurs in chronic kidney failure, diabetes, and aging. These studies are testing the possible role of the recently identified pannexin-family channels as conduits for the efflux of ATP that is coupled to PPi production.
| Stanton Gerson, M.D. Professor of Medicine, Director of the Comprehensive Cancer Center Professor of Medicine, Director of the Comprehensive Cancer Center, Member of the Cancer Therapeutics and Translational Therapeutics Tracks.
Dr. Gerson plays an active role in development of new therapeutics as the Associate Director for Clinical Research. His laboratory studies the role of the DNA repair protein O6 alkyguanine-DNA alkyltransferase (AGT) in mediating resistance to several chemotherapeutic agents, and they have led in the discovery and develop-ment of the AGT modulator O6benzylguanine as an adjunctive chemotherapeutic agent that enhances the effi-cacy of DNA alkylating agents. In addition, Dr. Gerson's group has evaluated methoxyamine, an inhibitor of base excision repair, as a potentiator of methylating agent chemotherapy. Studies completed through the NCI-RAID and a planned IND submission to pursue a clinical trial of methoxamine and temozolomide for refractory solid tumors are aimed at providing the first agent for inhibition of base excision repair as a therapeutic modality in cancer.
| Clifford Harding, M.D., Ph.D. Professor, Interim Chair of Pathology Professor and Chair of Pathology, Member of the Membrane Structural Biology & Pharmacology and Translational Therapeutics Tracks.
Dr. Harding’s research is focused on topics in immunology, particularly functions of antigen presenting cells, including: 1. Antigen presentation by MHC molecules. 2. Phagosomal processing of antigens, including MHC-I cross processing mechanisms that contribute to immune responses to tumors and pathogens. 3. Regulation of antigen presenting cells and T cell responses by signaling by Toll-like receptors, including TLR9 and TLR2. 4. Induction of type I interferon by Toll-like receptors, particularly TLR9, and its role in induction of MHC-I cross presentation. 5. Inhibition of type I interferon induction by TLR2 signaling and by CpG-B agonists of TLR9. 6. Antigen presenting cell dysfunction in infection by Mycobacterium tuberculosis or HIV and the roles of abnormal Toll-like receptor or interferon responses in these mechanisms.
| Charles Hoppel, M.D. Professor of Pharmacology and Medicine
Chief of Clinical Pharmacology
Director of the Center for Mitochondrial Diseases Professor of Pharmacology and Medicine, Chief of Clinical Pharmacology, Director of the Center for Mitochondrial Diseases, Member of the Membrane Structural Biology & Pharmacology and Translational Therapeutics Tracks.
The main focus of the laboratory is mitochondrial fatty acid oxidation. The organization of the pathway for mitochondrial fatty acid oxidation is of particular interest as a potential site for control of the system. Mitochon-drial contact sites contain the protein translocases for protein translocation into the mitochondria and the pe-ripheral benzodiazepine receptor. The Hoppel group has obtained data that support the localization of key en-zymes, such as the long-chain acyl-CoA synthetase and carnitine palmitoyltransferase of fatty acid oxidation to these contact sites. They have proposed a fatty acid/carnitine shuttle through the contact sites. The character-ization of this shuttle coupled with the determination of its localization within the mitochondria will be essential advances. In addition to the primary basic science focus of the lab which is pertinent to the Membrane Biology Track, Dr. Hoppel's roles as Chief of Clinical Pharmacology and Director of the Mitochondrial Diseases Center put his laboratory at the natural interface of Translational Therapeutics. He oversees many clinical studies aimed at understanding the cell and molecular basis of diseases and approaches to devising and testing novel interventions.
| Yoshikazu Imanishi, Ph.D. Assistant Professor Assistant Professor of Pharmacology, Member of the Membrane Structural Biology & Pharmacology Track.
The Imanishi lab is focused on localization of proteins and chemical intermediates involved in phototransduction and the visual cycle using modern imaging techniques, such as two-photon microscopy. They are interested in how these highly specialized neurons are formed and maintained, and how the major component of the outer segment, rhodopsin, can contribute to the formation of the photoreceptor outer segments. The maintenances of photoreceptor outer segments are subject to regulation by circadian rhythm; however the underlying mechanism is currently unknown. The interactions between photoreceptors and adjacent Retinal Pigment Epithelial (RPE) cells are required for normal metabolism and maintenance of photoreceptor cells. RPE cells retain unique biological functions; RPE cells are the most active phagocyte throughout the body, and this activity is responsible for the maintenance of photoreceptor outer segments. Current research addresses how the RPE and the photoreceptor communicate with each other to orchestrate the biogenesis and degradation of photore-ceptor outer segment structure.
| Thomas Kelley, Ph.D. Associate Professor Associate Professor of Pediatrics and Pharmacology, Member of the Molecular Pharmacology & Cell Regulation Track.
The research focus of the Kelley laboratory centers around three areas. (1) Identifying a mechanistic link be-tween the loss of CFTR function and altered cell-signaling control in CF airway epithelial cells - Currently efforts are devoted to examination of the isoprenoid/cholesterol synthesis pathway. (2) Determining cell signaling con-sequences of impaired intracellular cholesterol transport. These studies focus primarily on elucidating the con-sequences of lost NPC1 function in Niemann-Pick type C disease, a pediatric neurological disorder. (3) The impact of beta-arrestin protein expression on airway disease. The Kelley group has observed an increase in arrestin protein expression in airway cells in response to lost CFTR function and as a response to obesity. The goals of this study are to examine the mechanisms leading to increased arrestin expression and to determine the impact this signaling on the development of asthma symptoms and responses to corticosteroids and beta-agonists in asthmatics.
| Ruth Keri, Ph.D. Professor and Vice Chair
Department of Pharmacology
Associate Director for Basic Research
Case Comprehensive Cancer Center Professor and Vice Chair of Pharmacology, co-Director of the MTTP, co-Leader of the Cancer Therapeutics Track, member of the Molecular Pharmacology & Cell Regulation Track.
The Keri laboratory is focused on mechanisms of HER21Neu and hormonal induction of mammary tumor formation and progression. This has involved the combined used of functional genomics with multiple strains of genetically altered mice. Primary goals of the laboratory are to identify key genes that are regulated by HER21Neu and mediate the tumorigenic effects of this orphan receptor tyrosine kinase. The protein products of these target genes may then become candidates for therapeutic intervention. One such target is mTOR. The Keri group has recently found that an inhibitor of mTOR action, rapamycin, induces regression of HER21Neu induced mammary tumors in mice. They are currently evaluating the mechanisms for this tumor response as well as examining the impact of rapamycin on metastatic progression.
| Timothy Kern, Ph.D. Professor
Director of the Center for Diabetes Research Professor of Medicine, Director of the Center for Diabetes Research, Member of the Translational Therapeutics Track.
The major focus of research in the Kern laboratory is to learn what causes retinopathy in diabetes, and how it can be prevented. Diabetic retinopathy takes many years to develop in most patients, so studies using research animals have been fundamental to present understanding of this problem. The retinal lesions that develop in streptozotocin-diabetic animals are indistinguishable from those that develop in patients, and include microaneurysms, obliterated capillaries, pericyte loss and hemorrhage. The Kern group has also developed a second model of diabetic retinopathy in which blood hexose levels are elevated in nondiabetic animals by feed-ing the sugar, galactose. These animals develop a retinopathy identical to that which develops in diabetes, in-dicating that elevated blood hexose is a major cause of diabetic retinopathy. Efforts currently are directed at identifying how hyperglycemia causes retinopathy, so that new, improved treatment may be devised to inhibit the loss of vision in diabetes.
|Gary Landreth, Ph.D.Professor of Neurosciences Professor of Neurosciences, Member of the Molecular Pharmacology & Cell Regulation and Translational Therapeutics Tracks.
Dr. Landreth’s research program has two distinct areas of interest that are centered on understanding disorders of the nervous system. Alzheimer's disease is the primary focus of work in the laboratory, aimed at under-standing how the beta-amyloid peptides are normally cleared from the brain and the roles of inflammation in AD pathogenesis. The lab is also engaged in identification and validation of new therapeutic agents for the treatment of AD. The lab also has a long standing interest in the roles of the ERK MAP kinases in the nervous system, having developed murine lines in which ERK1 and ERK2 have been knocked out. Analysis of these mice have revealed unexpected roles for these enzymes in neural crest development, patterning of the developing brain and corticogenesis. The ERK knockouts phenocopy neuro-cardiofacial cutaneous, DiGeorge and related syndromes, and a subset of autism spectrum disorders that arise from genetic perturbations of the ERKs or their upstream regulators. The goal is to understand the mechanistic basis of these human disorders.
| Alan Levine, Ph.D. Professor Professor of Pathology and Pharmacology, Member of the Molecular Pharmacology & Cell Regulation Track.
The intestinal mucosa is the largest lymphoid organ, as assessed by antibodies produced, resident leukocytes, and surface area exposure to the environment. Furthermore, the wall of the intestine is continuously bathed by bacteria, parasites, fungi, amoebae, viruses, mitogens, toxins, and immunogenic food proteins. Therefore, a complex multi-tiered host defense system has evolved in the intestine, involving barrier exclusion by an actively regenerating epithelial cell monolayer, innate inflammatory responses mediated by local synthesis of pro- and anti-inflammatory cytokines, and acquired immune responses regulated by T lymphocytes. The Levine laboratory focuses on the mechanisms that regulate these systems: (1) temporal expression and regulation of pro-inflammatory and anti-inflammatory cytokines and immunoregulatory mediators in response to mucosal inflammation; (2) mechanisms by which co-stimulatory molecules and environmental stimuli direct the de-velopment of immune tolerance; (3) biochemical, spatial, temporal, and structural organization of the signal transduction pathway initiating with the anti-specific T cell receptor, and differentially regulated in naive, helper, effector, and mucosal T cells; (4) regulation of integrin affinity/avidity, expression, and activation in both naive and memory T cells by the interstitial extracellular matrix; (5) evaluation of a gene targeted murine model of coli-tis-associated colorectal cancer; and (6) mechanisms for increased intestinal permeability induced by HIV infec-tion and/or exposure to drugs of abuse, such as opioids, methamphetamine, and cocaine.
|Stephen J. Lewis, Ph.D.Professor of Pediatrics Member of the Molecular Pharmacology and Cell Regulation Track
The major focus of the Lewis laboratory is to understand the mechanisms by which endogenous thiols (e.g., cysteine, cysteamine and glutathione) and S-nitrosothiols (e.g., S-nitrosocysteine, S-nitrosocysteamine and S-nitrosoglutathione) as well as their synthesis and degradation pathways influence the central and peripheral regulation of microcirculatory and ventilatory systems in rats and mice under physiological and pathophysiological settings. The laboratory uses a multi-disciplinary approach ranging from whole animal physiology and pharmacology to electrophysiology (e.g., whole fiber neural recordings, single cell patch clamping) to cell/molecular biology (e.g., Western blot, RT-PCR). One current project focuses on our findings in conscious rats and mice that systemic injections of novel S-nitrosothiols and disulfides (1) stimulate minute ventilation, (2) prevent disordered breathing (e.g., apneas, sighs, sniff) in models of sleep apnea, and (3) reverse the deleterious effects of opioids on minute ventilation, arterial blood-gas chemistry, and alveolar gas-exchange without negatively affecting the analgesic actions of the opioids. We are currently evaluating select S-nitrosothiols and disulfides as potential therapeutics for the improvement of ventilatory and hemodynamic function in human disease states (e.g., sleep apnea, sepsis) and to combat opioid-induced respiratory depression.
| Huiping LIu, M.D. Ph.D. Assistant Professor of Pathology Assistant Professor of Pathology, Member of the Translational Therapeutics Track
The Liu laboratory is interested in understanding the role of cancer stem cells in metastasis and therapy resistance as well as developing new nano-therapeutics, including chemically-engineered nanomicelles and biologically-engineered exosomes. Our previous work has established patient-tumor-derived human-in-mouse breast models that develop spontaneous pulmonary metastases in mice. They are ideal for preclinical studies to develop and examine new therapeutics in cancer treatment. With these models, we have demonstrated that breast cancer stem cells are involved in breast cancer spontaneous metastasis. We have also identified microRNAs, such as miR-200 and micR-30, as critical regulators of breast cancer stem cells, metastasis and chemo-resistance. Ongoing projects aim to identify novel biomarkers and develop novel therapeutics, such as miRNAs, to prevent and block breast cancer initiation and metastasis. Nanomicelles and exosomes are two types of nanoparticles to be engineered with peptide ligands or antibody fragments for a specific targeting of cancer stem cells. Our goal is to pursue both basic and translational cancer research in understanding and controlling cancer stem cells, metastasis and therapy resistance, thereby impacting cancer medicine and reducing cancer mortality.
| Paul MacDonald, Ph.D. Professor and Associate Dean of Graduate Studies Associate Professor, Associate Dean of Graduate Education, Member of the Molecular Pharmacology & Cell Regulation and Cancer Therapeutics Tracks.
Vitamin D (Vit D) is required for normal calcium and phosphorus homeostasis and it is essential for the proper development and maintenance of bone. Vit D also exerts profound effects on cellular proliferation and differen-tiation, effectively inhibiting the proliferation of many tumor-derived, malignant cell lines. The vitamin D endo-crine system also profoundly influences normal keratinocyte function and is protective against chemically-induced skin tumorigenesis. The mechanisms underlying its tumor protective and antiproliferative roles are cur-rently unknown. The biological effects of vit D are mediated through a nuclear protein termed the vitamin D re-ceptor, or VDR. The VDR is a member of the superfamily of nuclear receptors that function as ligand-activated transcription factors. Thus, vit D and VDR together regulate the expression of specific genes or gene networks in classic target organs such as the intestine, bone, and skin. The global objective of my laboratory is to understand the molecular details and signaling mechanisms involved in VDR-mediated gene expression. We are currently focusing on in vivo and in vitro models of bone and skin to understand the gene networks that are involved in vit D effects on bone development and skin tumorigenesis.
| Shigemi Matsuyama, Ph.D Associate
Professor, Medicine Associate Professor of Medicine-Hematology/Oncology, Member of the Cancer Therapeutics Track.
Dr. Matsuyama studies (1) the molecular mechanism of programmed cell death, and (2) the development of a drug-delivery system using cell penetrating peptides. His group found that Ku70 keeps Bax (a key protein in-ducing apoptosis) in an inactive form in non-apoptotic cells, and that the dissociation of Bax from Ku70 is re-quired for Bax-mediated apoptosis. Ku70 is a ubiquitously expressed protein that has been known to play an important role for double strand DNA break repair. Dr. Matsuyama's laboratory is investigating how apoptotic stress such as DNA damage modifies Ku70’s activity to regulate Bax activity. The understanding of the mecha-nism of Ku70 modification will contribute to understanding apoptosis-resistance mechanisms of cancer cells. Dr. Matsuyama’s laboratory found a new series of cell permeable pentapeptides and is investigating the mechanism of membrane penetration by these pentapeptides, and the potential application of these peptides for drug delivery into cells.
| Jason Mears, Ph.D. Assistant Professor Assistant Professor of Pharmacology, Member of the Membrane Structural Biology & Pharmacology Track.
Within eukaryotic cells, mitochondria continually divide and fuse. Defects in these processes are associated with an increasing number of human diseases, including cancer, neurodegeneration and aging. Research in the Mears lab is focused on understanding of the cellular machinery that regulates mitochondrial dynamics in yeast and mammalian cells. They use cryo-electron microscopy along with biochemical and computational methods to elucidate the structural and mechanistic roles of proteins in the eukaryotic fission machinery.
| John Mieyal, Ph.D. Professor
Department Vice Chair
Director of the MTTP Professor and Vice-Chair of Pharmacology, Director of the MTTP, Member of the Molecular Pharmacology & Cell Regulation and Translational TherapeuticsTracks.
Reactive oxygen species (ROS) play an important role as second messengers to transduce intracellular signals from hormones, cytokines and growth factors that interact with membrane-associated cell surface receptors. However, little is understood about how ROS selectively modify signaling molecules and influence their activation or deactivation, inter-protein interactions, and translocation to the nucleus. Integral to these processes is reversible S-glutathionylation of cysteine residues on specific proteins. Many diseases, including cardio-vascular and neurodegenerative diseases, cancer, diabetes, and AIDS, involve oxidative stress conditions that likely disrupt normal redox signaling and alter the balance between cell survival and cell death. The Mieyal lab studies the enzymatic mechanisms of reversible glutathionylation, aimed at understanding how these reactions link extracellular stimuli to down-stream cellular events in health and disease. Current research is focused on models of Parkinson’s disease to discover alternative therapeutic approaches.
| Vera Moiseenkova-Bell, Ph.D. Mt. Sinai Scholar
Associate Professor Assistant Professor of Pharmacology, Member of the Membrane Structural Biology & Pharmacology Track.
Pain is a serious public health issue that affects up to 20% of the human population at any time. Ion channels are integral membrane proteins that regulate the flow of ions across cellular plasma membranes in response to a variety of stimuli. The Moiseenkova-Bell laboratory is interested in structural and functional analysis of ion channels which are involved in pain and temperature sensation. The key question in understanding ion channel function is how do the protein domains that respond to stimuli communicate with the pore gates to mediate channel opening. Multiple approaches are used, including biochemistry, electrophysiology, X-ray crys-tallography and single-particle cryo-electron microscopy (cryo-EM) to elucidate activation and gating mecha-nism of these channels.
|Goutham Narla, M.D., Ph.D. Assistant Professor of Medicine, co-Leader of the Translational Therapeutics Track and Member of the Cancer Therapeutics Track.
Research in the Narla laboratory focuses on the understanding of the molecular mechanisms underlying the inactivation of tumor suppressor genes in human cancer. The main areas of research focus are the development and validation of small molecule based therapies to reactivate key negative regulators of oncogenic signaling, mainly protein phosphatases (PP2A), in disease relevant cell culture and mouse models of cancer. Additional areas of research focus in the laboratory include understanding at the genomic and proteomic level how perturbations in transcription factor and protein phosphatase function perturb signaling in cell culture and in vivo models. In addition, comprehensive molecular characterization of these disease relevant drivers of tumor development and progression in human tumor samples is an area of research focus in the laboratory. The ultimate goal of these studies is the clinical translation of these small molecule based approaches to the treatment of a broad range of human cancers.
| Marvin Nieman, Ph.D. Assistant Professor Assistant Professor of Pharmacology, co-Leader of the Translational Therapeutics Track.
The underlying research theme of the Nieman lab is that protease activated receptor (PAR) subtypes interact with one another to mediate the full range of thrombin signaling for activation of platelets, endothelial cells and mononuclear cells. Thrombin is the terminal enzyme in the clotting cascade that activates cells by cleaving PARs. PAR1 and PAR4 interact on the platelet surface and PAR1 enhances PAR4 activation ~10-fold by serv-ing as a cofactor. In other tissues and cell types, PAR1 interacts with and transactivates PAR2. Therefore, studies examining thrombin signaling must take into account contributions of other PARs expressed by the cells of interest. The Nieman lab uses a combination of enzyme kinetics, resonance energy transfer, cell based as-says with cell lines and freshly isolated human and mouse platelets as well as animal models to examine the influence of the interaction of PAR subtypes on thrombin signaling with the aim of discovering new therapeutic approaches to controlling blood clotting.
| Noa Noy, Ph.D. Professor Professor of Pharmacology, Member of the Molecular Pharmacology & Cell Regulation and Cancer Therapeutics Tracks.
Lipophilic hormones, such as retinoic acids, vitamin D, and derivatives of long chain fatty acids, control multiple biological processes both in the embryo and in the adult. These activities are exerted through the ability of these compounds to regulate gene expression, and are mediated by two classes of proteins: the ligand-inducible transcription factors termed nuclear hormone receptors, and members of the family of intracellular lipid-binding proteins. The Noy laboratory aims to understand the molecular mechanisms by which the transcriptional activities of lipophilic hormones (e.g., retionoic acid) are regulated, to map the gene networks that mediate the biological activities of specific hormones and their cognate receptors; and to link these molecular foundations to the functional consequences of receptor activities in health and in disease states.
| Krzysztof Palczewski, Ph.D. Professor and Department Chair Professor and Chair of Pharmacology, and Member of the Membrane Structural Biology & Pharmacology and Translational Therapeutics Tracks.
The light-sensing apparatus of the eye is found within the rods and cones - two types of specialized cells located in the posterior of the retina. Many unresolved issues relevant to phototransduction, light- and dark-adaptation, and the chemical processing of retinoid cycle intermediates remain unanswered, including the enzymology of the retinoid cycle, the mechanisms by which these intermediates diffuse within and between the photoreceptors and the retinal pigment epithelium, and the dependence of phototransduction reactions on the operation of the cycle. The goals of Professor Palczewski's laboratory are to a) understand the biochemical basis underlying the mechanism of rhodopsin inactivation and restoration of the cGMP level; b) delineate the biochemical basis underpinning the similarities and differences between rod and cone cell phototransduction; and c) understand the enzymology of the isomerization of all-trans-retinol to 11-cis-retinol in the retina. Knowledge about phototransduction in the retina, a system with great experimental advantages, will improve further understanding of similar events in hormonal signaling, cellular communication and immune regulation, and provide fundamental information for therapeutic interventions and further studies of retinal disease processes.
| Paul Park, Ph.D. Assistant Professor Assistant Professor of Ophthalmology and Pharmacology, Member of the Molecular Pharmacology & Cell Regulation and Membrane Structural Biology & Pharmacology Tracks.
The goal of the Park laboratory is to understand the mechanisms of signal transmission at the molecular level in phototransduction and other G protein-coupled receptor-mediated signaling systems. The specific aims of the research include: 1) to test the validity of assumptions in classical schemes of signaling and to explore more recent paradigms of signal transmission; 2) develop and characterize methodologies to detect and monitor mo-lecular interactions involving receptors; 3) develop and characterize tools that will allow for live cell and/or in vivo monitoring of signaling events; 4) to understand at a molecular level how mutations in rhodopsin lead to vision-related disorders. The Park lab uses modern biophysical approaches to tackle these issues, including atomic force microscopy (AFM), single-molecule force spectroscopy (SMFS), and fluorescence-based methods.
| Irina Pikuleva, Ph.D. Professor Professor of Ophthalmology and Pharmacology, Member of the Molecular Pharmacology & Cell Regulation and Membrane Structural Biology & Pharmacology Tracks.
Cholesterol is essential for life in mammals. However, if chronically in excess, it becomes a risk factor for cardiovascular and Alzheimer’s diseases, and possibly age-related macular degeneration. The focus of this la-boratory is on the four cytochrome P450 enzymes 7A1, 27A1, 46A1, and 11A1 that are necessary for choles-terol elimination from different organs. They are striving to understand how cholesterol-metabolizing P450s function at the molecular level, what roles they play in the development of different diseases, and whether these enzymes could serve as targets for cholesterol lowering medications. One of the current projects is based on previous structural and biochemical studies of CYP46A1, showing that the enzyme active site is conformational-ly flexible and can accommodate ligands other than sterols. The goal of this project is to identify marketed drugs that can either inhibit or stimulate the CYP46A1-mediated cholesterol hydroxylation in vivo. Another project is focused on understanding how deactivation of the CYP27A1 enzyme under oxidative-stress may alter cholesterol metabolism and contribute to age-dependent macular degeneration. In pursuit of these goals, the lab uses in-silico and in vitro screening of drug libraries, X-ray crystallography, mass spectrometry, and tests on animals.
|Jeremey Rich, Professor of Molecular Medicine, Cleveland Clinic Lerner College of Medicine at CWRU, member of the Cancer Therapeutics Track
| William Schiemann, Ph.D Associate Professor
Leader of the Breast Cancer Program of the Case Comprehensive Cancer Center Associate Professor of Oncology, Leader of the Breast Cancer Program of the Case Comprehensive Cancer Center, co-Leader of the Cancer Therapeutics Track.
Tumorigenesis elicits changes in the TGF-beta signaling pathway that engenders resistance to the normally cytostatic activities of TGF-beta, thereby enhancing the development and progression of human malignancies. These genetic and epigenetic events convert TGF-beta from a suppressor of tumor formation to a promoter of their growth, invasion and metastasis. The dichotomous nature of TGF-beta during tumorigenesis is known as the “TGF-beta paradox.” Dr. Schiemann's research aims to understand the molecular mechanisms underlying the "TGF-beta Paradox" – likely the most important unanswered question concerning the pathophysiological functions of this multifunctional cytokine in regulating mammary tumorigenesis. Particular focus is on the initia-tion of metastasis and disease recurrence. The Schiemann group has made numerous and highly significant contributions toward answering this important question, and in doing so, has established new insights into the molecular mechanisms underlying the TGF-beta Paradox and its ability to influence the response of normal and malignant mammary tissues to TGF-beta.
| Phoebe L. Stewart, Ph.D. Director, Cleveland Center for Membrane and Structural Biology Professor, Department of Pharmacology Case Western Reserve University Professor of Pharmacology, Director of the Cleveland Center for Membrane and Structural Biology, Co-Director of the MTTP, and Member of the Membrane and Structural Biology and Pharmacology Track.
Cryo-electron microscopy (cryo-EM) plays a central role in hybrid methods to determine structures of mem-brane proteins and large complexes in multiple conformations without the need for crystals. Docking of atomic resolution structures and computational models into cryo-EM density maps can provide insight at the near-atomic level. The Stewart lab is applying cryo-EM structural methods to a variety of adenovirus/host factor com-plexes, including defensin and coagulation Factor X. Adenovirus is a common human pathogen, but non-virulent forms have shown great potential for gene delivery and vaccination strategies. When adenovirus is injected intravenously, however, it induces potent innate immune and inflammatory responses, the molecular basis for which remains poorly characterized. Human defensin 5 is a peptide from the innate immune system that blocks viral cell entry. Factor X plays a role in the blood coagulation cascade and leads to highly efficient adenoviral infection of hepatocytes. Thus, elucidating the molecular interactions of these key adenoviral complexes is expected to lead to improved therapeutic approaches with adenoviral vectors. In addition, the Stewart group is studying protein/DNA complexes involved in nonhomologous end joining (NHEJ) and in maintenance of cir-cadian rhythm. DNA damage is a natural occurrence, but If the damage is not repaired correctly, genetic insta-bility may result and lead to cancer or cell death. The human DNA-PKcs enzyme mitigates oncogenesis through NHEJ repair of double strand DNA breaks. Circadian rhythms impact cellular and organismal physiology, regu-lating sleep cycles, as well as hormone and metabolic activities. In both the DNA repair and circadian rhythm systems, cryo-EM provides a way to study the structure of large and conformationally flexible complexes.
| Derek Taylor, Ph.D. Assistant Professor Assistant Professor of Pharmacology, Director of MTTP Admissions, Member of the Membrane Structural Biology and Pharmacology Track
Regulation and deregulation of gene expression are critical events for every process within the cell. Alteration of these intricate processes, for example as consequences of genetic defects or bacterial/viral infections, can readily lead to one of many human ailments. The control of these processes is commonly modulated by multi-protein complexes; in fact, proteins rarely act alone, but interact intimately and precisely with other proteins and nucleic acids to properly perform their cellular functions. The Taylor laboratory studies the structure and molecular mechanisms of macromolecular machines involved in DNA maintenance and RNA maturation and biogenesis. They use cryo-electron microscopy and single particle reconstruction techniques as primary tools for visualizing the macromolecular complexes in order to better understand their functions.
| Gregory Tochtrop, Ph.D. Assistant Professor Associate Professor of Chemistry and Pharmacology, Member of the Translational Therapeutics Track.
Most biological events emanate from the inherently chemical process of a small molecule being recognized by a large biological polymer. Research projects in the lab are designed to push back the boundaries of the tools used to monitor protein small molecule interactions. This work spans from pure synthetic organic chemistry to quantitative biochemistry. For example, the pool of bile acids in the human body is chemically heterogeneous, consisting of at least 100 distinct members. One of the major interactions responsible for bile acid homeostasis (and consequently cholesterol homeostasis) is their recognition by the nuclear receptor FXR. The experimental approach involves synthesis of 13C and 15N isotopically enriched bile acids and monitoring recognition, segregation, and competition, using NMR to detect single bile acids in complex mixtures and understand their effects on the transcription of FXR gene products. Also, the Tochtrop group anticipates generating skeletal diversity through chemistries that 'reorganize' the carbon skeletons of compelx natural products into novel mol-ecules. Cleavage of the B-C unsaturated ring fusion of lanosterol is a prime example of this strategy. Here, oxidative cleavage of the unsaturated ring fusion followed by transannular addition or full condensation affords diverse skeletons depending partly on the oxidation state of carbons C-7 and C-11. These molecules are used to probe biological systems using a 'chemical genetic' approach.
| Focco van den Akker, Ph.D. Associate Professor of Biochemistry, Member of the Membrane Structural Biology & PharmacologyTrack.
The overall goal of research in the van den Akker lab is to elucidate the molecular intricacies of mechanisms of enzyme catalysis and receptor activation, and using that knowledge to develop inhibitors and activators for pharmaceutical purposes. Projects range from cell signaling proteins such as guanylyl cyclases (blood pressure, vision, and bone growth) to beta-lactamases (responsible for the current epidemic antibiotic resistance). The lab group employs state of the art multi-disciplinary biophysical, biochemical, crystallographic, molecular biology, and cell biology techniques.
| Johannes von Lintig, Ph.D. Associate Professor with Tenure, Pharmacology Associate Professor of Pharmacology, Member of the Molecular Pharmacology & Cell Regulation Track.
Carotenoids affect a rich variety of physiological processes in nature and are beneficial for human health, serving as free radical scavengers and filters of phototoxic blue light. These isoprenoid pigments also serve as precursors for retinoids (vitamin A and its derivatives) that are essential for vision, cell proliferation, and embry-onic development. Recently, molecular players in this pathway have been identified and biochemically charac-terized. Mutations in the corresponding genes induce various pathologies in humans, including blindness and the fatal Matthew Wood syndrome. The von Lintig research group has established homologous animal models to study the mechanistic basis of these diseases. The biological studies are accompanied by in vitro struc-ture/function analyses of key proteins of these pathways. By defining a detailed molecular framework of carot-enoid metabolism in health and disease, the research team believes that improved pharmacological agents can be designed and developed to combat and prevent diseases associated with carotenoid metabolism.
| Bingcheng Wang, Ph.D. Professor Professor of Medicine-Nephrology and Pharmacology, Member of the Cancer Therapeutics and Translational Therapeutics Tracks.
The Wang laboratory is interested in the molecular mechanisms driving invasive and metastatic tumor pro-gression responsible for most cancer-related mortality. Their research is focused on Eph receptor tyrosine ki-nases that have been known as essential guidance molecules of cell migration during embryonic development. Studies in the Wang laboratory demonstrate that Eph kinases also critically regulate tumor cell migration and invasion via crosstalk with integrins, Ras/ERK and PI3K/Akt pathways (Nature Cell Biology 3:527, 2001; Cancer Cell 16:9, 2009). The mechanistic insights laid a foundation for the ongoing translational research devoted to the isolation and characterization of small molecules targeting Eph kinases. Multiple lead compounds have been found that could bind Eph kinases and inhibit both Ras/ERK and PI3K/Akt signaling cascades. Preclinical studies are underway to develop the lead compounds into novel therapeutics against tumor dissemination using mouse models of glioma and prostate cancer.
| Vivien Yee, Ph.D Associate Professor Associate Professor of Biochemistry and Pharmacology, Member of the Membrane Structural Biology & Pharmacology Track.
Dr. Yee's laboratory uses X-ray crystallographic methods to determine and analyze the structures of medically important proteins and enzymes with interesting mechanistic questions. Her laboratory combines crystal-lography with modeling and mutagenesis to study several systems. The first of these focuses on serine prote-ases which are central in blood coagulation, where their interest is in enzyme- peptide substrate structures, to provide insight into the effect of clinically relevant polymorphisms and into substrate recognition. They are also studying the prion protein, which is implicated in an intriguing family of neurological diseases, the spongiform encephalopathies. Prion protein structures may be helpful in understanding the structural transformation of the protein that is believed to be a key event in the disease. The Yee group is also investigating the 1.2 million Dal-ton transcarboxylase multienzyme complex. Structures of its large 5s and 12s catalytic subunits serve as mod-els for related mammalian metabolic enzymes, and facilitate speculation on catalytic mechanisms and structural consequences of disease mutations. In collaboration with the Maguire laboratory, studies are underway on the structure of the CorA Mg2+ channel, specifically to determine the structure of the open form of the channel and the structure of CorA homologs.
| Youwei Zhang, Ph.D. Associate Professor Assistant Professor of Pharmacology, Member of the Cancer Therapeutics Track.
Eukaryotic cells have evolved an elaborate network of genome surveillance and repair machinery to insure that DNA replication occurs in an accurate and timely fashion. This surveillance mechanism is termed the S-phase replication checkpoint. The replication checkpoint monitors the progress of replication forks, and when the fork stalls, transmits signals that delay S-phase progression, and maintain the stability of stalled forks so that DNA replication can resume after the initial error is corrected. Two key components of the replication checkpoint are the apical protein kinase, ATR, and its downstream target kinase, Chk1. Replicative stress induces activation of ATR, which then induces activation of Chk1 through phosphorylation at Ser317 and Ser345. Activated Chk1 will activate a cascade of downstream effectors, which will eventually induce cell cycle arrest and damage repair to maintain cell survival, or cell death if the damage is too severe to be repaired. Dr. Zhang’s research group is interested in dissecting the detailed molecular mechanisms underlying the activation of the replication checkpoint, and translating that knowledge into potential anticancer treatment.
| Richard Zigmond, Professor of Neurosciences, Member of the Molecular Pharmacology & Cell Regulation Track.
Dr. Zigmond's lab focuses on adaptive responses of adult neuron's to injury. Due to their suitability for a variety of experimental approaches and to their ability to regenerate after injury, our studies involve the peripheral nervous system, using both sensory and sympathetic neurons. We have two current goals. The first is to examine the mechanisms underlying our recent finding that macrophages enter into peripheral sensory and sympathetic ganglia after axonal damage and promote nerve regeneration. The second is to examine the biochemical changes that underlie diabetic neuropathy. In these latter studies, we are concentrating on our previous findings establishing a role for gp130 cytokines in nerve regeneration and our recent findings that this signaling system is dysregulated in diabetes.