Anatomy

Sean W. Limesand, PhD, is an Associate Professor in the School of Animal and Comparative Biomedical Sciences at the University of Arizona in the College of Agriculture and Life Sciences. He is also a member of the UA’s BIO5 Institute and Department of Obstetrics and Gynecology. Dr. Limesand is nationally and internationally recognized for his work studying fetal endocrinology and metabolism in pregnancy and in pregnancies compromised by pathology such as intrauterine growth restriction and diabetes. His research is focused on defining developmental consequences resulting from a compromised intrauterine environment. Specifically, he is focused on fetal adaptations in insulin secretion and action that when altered in utero create lifelong metabolic complications. Dr. Limesand has lead the charge on prenatal origins of –cell dysfunction as the Principal Investigator for a number of federal and foundation grant awards and published more than 40 peer-reviewed articles on topics related to this research. Keywords: Diabetes, Pregnancy, Perinatal Biology

Public Relevance Statement: Can you imagine having a mouthful of canker sores and cavities? Thousands of head and neck cancer patients suffer these consequences from radiation treatment. The Limesand lab works to prevent these side effects thereby improving patients' quality of life. Clinical Relevance: Radiation therapy for head and neck cancer causes adverse secondary side effects in the normal salivary gland including xerostomia, oral mucositis, malnutrition, and increase oral infections. Although improvements have been made in targeting radiation treatment to the tumor, the salivary glands are often in close proximity to the treatment site. The significant destruction of the oral cavity following radiation therapy results in diminished quality of life and in some cases interruptions in cancer treatment schedules. Research Interests: My research program has its foundation in radiation-induced gland dysfunction; mechanisms of damage, clinical prevention measures, and restoration therapies. Evidence suggests that salivary acinar function is compromised due to apoptosis induced by these treatments and temporary suppression of apoptotic events in salivary glands would have significant benefits to oral health. We utilize a number of techniques in my laboratory including: genetically engineered mouse models, real-time RT/PCR, immunoblotting, immunohistochemistry, primary cultures, siRNA transfections, irradiation, and procedures to quantitate salivary gland physiology. Current project areas: 1. Radiation-induced apoptosis 2. Mechanisms of preserving salivary gland function 3. Identifying the radiosensitivity of salivary gland progenitor cells 4. Restoration of salivary gland function 5. Role of autophagy in radiation-induced loss of function

Dr. Lifshitz is the Director of the Translational Neurotrauma Research Program through the College of Medicine - Phoenix, which brings together clinicians and scientists as faculty to address the pathophysiology and recovery from animal models of acquired neurological injury (e.g. stroke, hemorrhage, concussion). These studies are guided by gaps in clinical knowledge to empower healthcare providers to improve quality of life for survivors. To this end, they use public databases, biorepositories, and animal models to address questions across the lifespan. Specific strengths include inflammation, rehabilitation, puberty, sleep, and neuronal morphology.

Dr. Hay is internationally known for her work in cardiovascular neurobiology and her current studies on the role of sex and sex hormones in the development of hypertension. She has been continuously funded by the NIH and other sources for the past 26 years. She has extensive experience in central renin angiotensin mechanisms, neurophysiology and reactive oxygen and cytosolic calcium neuroimaging and in advancing knowledge related to central mechanisms of neurohumoral control of the circulation. She is a Professor of Physiology at the University of Arizona College of Medicine and maintains active participation in the American Physiological Society, the Society of Neuroscience, AAAS, and has served on numerous editorial boards of prestigious scientific journals and grant review panels for the National Institutes of Health and the National American Heart Association. The primary focus of Dr. Hay’s laboratory is the understanding of the biophysical and cellular mechanisms underlying neurotransmitter modulation of sympathetic outflow and ultimately arterial blood pressure. The scientific questions being asked are: 1) What central neurotransmitter mechanisms are involved in the normal regulation of cardiovascular function? 2) Does the development of some forms of hypertension involve biophysical or molecular alteration in the neurotransmitter mechanisms regulating cardiovascular control? 3) Can these central signal transduction systems, which control sympathetic outflow and ultimately arterial blood pressure, be altered in order to prevent or attenuate the development of some forms of hypertension? 4) Are there gender related differences in some of these mechanisms?Dr. Hay has extensive national experience in university-wide administration and interdisciplinary research program development. Prior to coming to the University of Arizona in 2008 as Executive Vice President and Provost, Dr. Hay was the Vice President for Research for the University of Iowa, where she worked with state and federal lawmakers, private sector representatives, and local community groups to broaden both private and public support for research universities. Dr. Hay, a Texas native, earned her B.A. in psychology from the University of Colorado, Denver, her M.S. in neurobiology from the University of Texas at San Antonio, and her Ph.D. in cardiovascular pharmacology from the University of Texas Health Sciences Center, San Antonio. She trained as a postdoctoral fellow in the Cardiovascular Center at the University of Iowa College of Medicine and in the Department of Molecular Physiology and Biophysics at Baylor College of Medicine in Houston. She was a tenured faculty member of the University of Missouri-Columbia from 1996-2005. Prior to Missouri, she was a faculty member in the Department of Physiology at the University of Texas Health Science Center- San Antonio.

The long-term goal of research in my lab is to understand the molecular mechanisms of muscle contraction. I am especially interested in how contractile proteins of muscle sarcomeres regulate the force and speed of contraction in the heart. The question is important from both basic science and clinical perspectives because mutations in sarcomere proteins of muscle are a leading cause of hypertrophic cardiomyopathy (HCM), the most common cause of sudden cardiac death in the young and a prevalent cause of heart failure in adults. Myosin binding protein-C (MyBP-C) is a muscle regulatory protein that speeds actomyosin cycling kinetics in response to adrenaline (b-adrenergic stimuli) and is one of the two most commonly affected proteins linked to HCM. Currently, the major research focus in my lab is understanding the mechanisms by which cMyBP-C regulates contractile speed and mechanisms by which mutations in cMyBP-C cause disease. In pursuing these interests I have established a variety of approaches to investigate muscle contraction at molecular, cellular, and whole animal levels. Methods include single molecule atomic force microscopy (AFM), mechanical force measurements in permeabilized muscle cells, in vitro motility assays, biochemical enzyme and binding assays, immunofluorescent imaging, knockout/transgenic animal models and the development of a natural large animal model of HCM.

Carol Gregorio, PhD, performs research in her lab that is focused on identifying the components and molecular mechanisms regulating actin architecture in cardiac and skeletal muscle during normal development and disease. Control of actin filament lengths and dynamics is important for cell motility and architecture and is regulated in part by capping proteins that block elongation and depolymerization at both the fast-growing (barbed) and slow-growing (pointed) ends of the filaments. Striated muscle is an ideal model system to test for the functional properties of various actin regulatory proteins due to the precise organization and polarity of cytoskeletal components within repeating sarcomeric units (for example, the ~1 mm long actin filaments are easily resolved by light microscopy). Using this system, she can combine advanced cell biological and biochemical approaches with direct tests of physiological function in live beating muscle cells.The research objectives of the laboratory can be broadly summarized as follows: 1) understanding the cellular mechanisms involved in the assembly, regulation and maintenance of contractile proteins in cardiac muscle in health and disease; 2) deciphering the mechanisms critical for precisely specifying and maintaining the lengths of actin filaments; 3) discovery of novel models of de novo cardiac muscle assembly, with special emphasis on differentiating murine embryonic stem (ES) cells to study all stages of heart muscle development. Actin is an indispensable structural element of cells and is the major component of heart muscle. Changes in actin, caused by genetic mutations, which have been identified in humans, are a frequent cause of several forms of cardiomyopathy. Her lab is determining how genetic defects in this protein affect muscle force generation and muscle contraction, leading to sudden cardiac death.

Hendrikus Granzier, PhD, studies the mechanisms whereby the giant filamentous protein titin (the largest protein known) influence muscle structure and function. His lab has shown that titin functions as a molecular spring that mediates acute responses to changing pathophysiological states of the heart. They also study the role of titin in cardiac disease, using mouse models with specific modifications in the titin gene, including deciphering the mechanisms that are responsible for gender differences in diastolic dysfunction. An additional focus of Dr. Granzier’s lab is on nebulin, a major muscle protein that causes a severe skeletal muscle disease in humans. Based on previous work, they hypothesize that nebulin is a determinant of calcium sensitivity of contractile force. To test this and other concepts, he uses a nebulin knockout approach in the mouse. Research is multi-faceted and uses cutting-edge techniques at levels ranging across the single molecule, single cell, muscle, and the intact heart. His research group is diverse and has brought together individuals from several continents with expertise ranging from physics and chemistry to cell biology and physiology.

Research in my laboratory over the last 30 years has focused on chronic heart failure (CHF), its pathophysiology and the development of new treatments for CHF. We have developed clinically relevant animal models of heart failure that allow us to explore the translational potential of new treatments. Our work initially examined the role of afterload reduction and neurohormal blockade. More recently we have been working with cell-based therapy for CHF using bioengineered scaffolds to prevent left ventricular (LV) remodeling and restore function in the damaged heart. Our most effective scaffold is a biodegradable vicryl mesh with embedded viable neonatal fibroblasts that secrete angiogenic growth factors. This patch increases myocardial blood flow, improves LV systolic function, and reverses LV remodeling if implanted at the time of an acute myocardial infarction. In CHF, this patch still improves myocardial blood flow but does not improve LV function or reverse LV remodeling. Thus, we have an effective delivery system for cell based therapy for CHF that increases myocardial blood flow and provides structural support for new cell growth. We are now focusing on seeding this patch with human inducible pluripotent stem cells in the cardiac lineage, the seeded cardiomyocytes align, communicate, contract in a spontaneous and rhythmic fashion. When implanted in rats with CHF, they improve LV function. We are exploring this patch seeded with human inducible cardiac pluripotent stem cells to treat patients with CHF. Keywords: induced pluripotent stem cells

Current projects include:The Bone, Estrogen and Strength Training (BEST) study, a randomized prospective study of the effects of hormone replacement therapy on bone mineral density, soft tissue composition, and muscle strength in postmenopausal women (National Institutes of Health). The Profile-based Internet-linked Obesity Treatment study (PILOT), a randomized study of internet support for weight maintenance after weight loss in peri-menopausal women (National Institutes of Health). The Trial of Activity for Adolescent Girls (TAAG) study, a multi-center, school-based activity trial designed to prevent the usual decline in physical activity in adolescent girls (National Institutes of Health). The Adequate Calcium Today (ACT) study, a randomized multi-center study of a behavioral intervention to promote healthy eating, calcium intake and bone development in adolescent girls (United States Department of Agriculture). The Healthy Weight in Adolescents study, a randomized, multi-center study of the effects of a science-based curriculum focused on concepts of energy balance on body weight and composition in adolescent boys and girls (United States Department of Agriculture). The KNEE study, a randomized clinical trial of the effects of resistance exercise on disease progression, pain, and functional capacity in osteoarthritis patients (National Institutes of Health). The STRONG study, a randomized clinical trial of the effects of resistance exercise and Remicaid on disease progression, pain, muscle strength and functional capacity in rheumatoid arthritis patients (Centocor, Inc.). Partners for Healthy Active Children, Campañeros Para Niños Sano y Actives, designed to create and implement research-based physical education and nutrition curricula at YMCA after-school programs and Sunnyside District elementary schools, in alignment with the State o Arizona , Health and Physical Activity standards (Carol M. White Physical Education Program CFDA #84.215F). Longitudinal Changes in Hip Geometry, an observational and experimental cohort study of changes in muscle mass, hip structural parameters and hip bone strength in middle-aged and older women in the Women's Healthy Initiative study (National Institutes of Health).

Dr. Garcia is an authority on the genetic basis of inflammatory lung disease (with an emphasis on health disparities) and on the mechanistic basis of lung vascular permeability. Using bench-to-bedside approaches, his lab has explored novel methods to prevent vascular leak and to restore endothelial cell barrier function and vascular integrity. This expertise in lung inflammation and vascular permeability provides a natural linkage to interrogation of lung vascular contribution to the development of lung metastases. Leveraging their genomic expertise, in recent years, Dr. Garcia's lab has identified vascular genes whose products are key participants in inflammatory lung injury that also play a role in cancer development. They have developed lung endothelial inflammatory gene expression profiles as well as diagnostic gene signatures influenced by MYLK and NAMPT that impact lung and breast cancer prognosis. This work with NAMPT led to development of a therapeutic NAMPT neutralizing antibody that has shown promise in treating lung cancer, melanoma, and chronic lymphocytic leukemia. Finally, Dr. Garcia's lab is also interested in the untoward effect of thoracic radiation and has been examining strategies designed to attenuate radiation–induced pneumonits, fibrosis and vascular leak. These collaborative and highly translational cancer research efforts have bolstered the overall mission of the University of Arizona Cancer Center.