Joseph G. Cannon - US grants

nuclear magnetic resonance spectroscopy;

Unaccustomed physical exercise results in delayed-onset muscle soreness, release of muscle enzymes into the circulation and increased myofibrillar protein breakdown. Eccentric exercise, in which muscles are forced to lengthen as they develop tension, is a particularly potent inducer of these responses. In the initial funding period of this grant, we have characterized eccentric exercise-induced changes in host defense factors in humans, specifically activation of neutrophils and production of the cytokine interleukin-1beta. We found highly significant correlations between these defense mechanisms and the muscular responses. Moreover, these parameters were significantly influenced by age and by dietary vitamin E supplementation. In the next 3 years, we propose to determine if the host defense mechanisms do indeed mediate damage or recovery of muscle by studying the responses of young and old mice to eccentric exercise after interventions that alter in vivo levels of cytokines and neutrophils or alter their biological activity. The responses to be measured include changes in muscle membrane permeability, loss of muscle strength (measured in vitro) and the extent of muscle fiber damage (assessed histochemically). The proposal is intended to help develop an understanding of the mechanisms involved in muscle damage and recovery in response to exercise stress. In addition, these studies may lead to new therapies for injury- or age- related deficits in muscle function.

biomedical equipment purchase;

Funds are requested to purchase a Flow Cytometer/Cell Sorter for at least six groups of investigators in the Department of Pathology of the College of Medicine of the University of Florida. The scope of these investigations is very broad and includes: a) analyses of surface antigens, DNA content and kinetic properties of human and murine lymphoma cells, b) detection and quantitation of lymphocyte antigens in prediabetes and endocrine diseases, c) detection of anti-HLA antibodies on human T- lymphocytes and platelets, d) identification of cell surface markers identifying metastic phenotypes and, e) identification and quantitation of Class II molecules on murine splenic B lymphocytes. Although a flow cytometer/cell sorter already exists in our department and is available for these projects, the instrument is reaching obsolescence and is heavily committed to analysis of high priority, hospital-related clinical samples. The lack of ready access to a modern and reliable instrument and a faster, high performance computer is jeopardizing the current efforts of these investigators and those of other researchers with increasing needs for flow cytometry and cell sorting. We have extensive experience with this technology and with the organization and planning of a multi-user laboratory. We also have competent personnel to operate and maintain the instruments. The commitments of the College of Medicine and the Department of Pathology to support our efforts, and the number of well funded projects that require this technology, insure the proper functioning and adequate future operation of the flow cytometry/sorting facility.

Unaccustomed physical exercise results in delayed-onset muscle soreness, release of muscle enzymes into the circulation and increased myofibrillar protein breakdown. Eccentric exercise, in which muscles are forced to lengthen as they develop tension, is a particularly potent inducer of these responses. In the initial funding period of this grant, we have characterized eccentric exercise-induced changes in host defense factors in humans, specifically activation of neutrophils and production of the cytokine interleukin-1beta. We found highly significant correlations between these defense mechanisms and the muscular responses. Moreover, these parameters were significantly influenced by age and by dietary vitamin E supplementation. In the next 3 years, we propose to determine if the host defense mechanisms do indeed mediate damage or recovery of muscle by studying the responses of young and old mice to eccentric exercise after interventions that alter in vivo levels of cytokines and neutrophils or alter their biological activity. The responses to be measured include changes in muscle membrane permeability, loss of muscle strength (measured in vitro) and the extent of muscle fiber damage (assessed histochemically). The proposal is intended to help develop an understanding of the mechanisms involved in muscle damage and recovery in response to exercise stress. In addition, these studies may lead to new therapies for injury- or age- related deficits in muscle function.

The Center for Quantitative Cell Analysis of The Pennsylvania State University seeks funds to purchase a state-of-the-art bench top flow cytometer. The Center is one of the Shared Technology Facilities in the Life Sciences Consortium, providing services for the entire University Park campus. Our existing instrument for flow cytometry (a Coulter EPICS 753) is used to capacity and has become increasingly unreliable due to increased maintenance time. We seek an additional flow cytometer (Becton Dickinson FACSCalibur) to: (a) complete about 50% of our current analyses at lower cost to the user's R01 project; (b) free the existing instrument for those demanding multi-laser or sorting capabilities; (C) provide reliable, rapid, multi-parameter analysis to all users. Eight different investigators will use the new cytometer for over 30 hr/wk.

[unreadable] DESCRIPTION (provided by applicant): The menopausal transition involves dramatic decreases in circulating ovarian steroids and dramatic increases in circulating hypothalamic gonadotropins. The biological consequences of estrogen loss on health problems associated with aging and menopause, such as osteoporosis and cardiovascular disease, have been studied extensively. 1 consequence is that tonic inhibition of inflammatory cytokine synthesis by estradiol is lost. These cytokines, including interleukin-1B (IL-1B), interleukin-6 (IL-6) and tumor necrosis factor-a (TNFa), contribute to bone resorption and development of atherogenic lesions. Although the fundamental influence of estradiol on post-menopausal health is unquestioned, the potential influence of increased gonadotropin concentrations, particularly follicle-stimulating hormone (FSH), has received less attention. This project will investigate potential mechanisms by which FSH may affect skeletal and vascular health, namely by stimulating IL-1B, IL-6 and TNFa secretion and inhibiting the shedding of receptors for these cytokines. These mechanisms will be studied using leukocytes isolated from the peripheral blood of pre-and peri-menopausal women. In addition, the biological significance of these mechanisms will be assessed by comparing plasma FSH, cytokine and cytokine receptor concentrations with circulating markers of bone turnover (N-telopeptide and osteocalcin), bone densities measured by dual energy X-ray absorptionmetry, and indices of vascular health (carotid intimal-medial thickness and pulse wave velocity measured by ultrasound). A better understanding of FSH-mediated mechanisms in peri-and postmenopausal health may lead to new therapies directed at modulation of FSH that can alleviate menopausal health problems without the attendant risks associated with steroid hormone replacement therapy. [unreadable] [unreadable] [unreadable]

DESCRIPTION (provided by applicant): The prevalence of hypertension and cardiovascular disease has increased in recent decades in parallel with increasing obesity. This project explores the hypothesis that a person's physical activity levels influence expression of receptors for leptin, a hormone produced primarily by adipose tissue that increases blood pressure. Leptin also modifies the function of monocytes, cells that play a central role in the pathogenesis of atherosclerosis. Healthy subjects between the ages of 21 and 40 will be assessed for body fat, habitual physical activity levels, aerobic capacity, cardiovascular function, and monocyte leptin receptor expression. The goals of this project are to (a) identify and validate a biomarker (leptin receptor expression on monocytes) that may provide a novel method for determining cardiovascular disease risk and for monitoring the response to exercise intervention;and (b) to determine how leptin affects monocyte function. If physical activity is shown to reduce leptin receptor expression, thus breaking a critical link between fatness and cardiovascular disease, such information can be used as incentive in exercise-based preventive and treatment programs. Less emphasis could be placed on weight loss itself, which is so difficult to attain or maintain, and more emphasis could be placed on the health benefits of exercise, regardless of weight outcomes. PUBLIC HEALTH RELEVANCE: Being overweight puts an individual at greater risk of cardiovascular disease. This project will investigate how fat cells communicate with cells of the immune system to cause high blood pressure and atherosclerosis, and how physical activity disrupts this unhealthy communication.