Andrew Hoffman - US grants

Growth hormone (GH) is essential for normal longitudinal growth and metabolic homeostasis in children. While GH is itself an anabolic hormone, it is believed that most of its activity is mediated by the stimulation of insulin-like growth factors (IGF) or somatomedins. The complex hormonal regulation of GH secretion includes stimulatory (GH-releasing factor, GRF) and inhibitory (somatostatin) hypothalamic control as well as long loop feedback inhibition by the somatomedin peptides. The role of feedback inhibitor would be a unique action for the somatomedins whose major defined physiologic function is that of an anabolic growth factor. Moreover, the presence of insulin receptors on somatotrophic cells suggests that insulin may also play an important direct role in GH homeostasis. This grant will explore 2 major themes in the control of GH synthesis and release using continuous cell culture lines of rat somatotropinoma cells (GH3 cells) and primary cultures of pituitary cells derived from normal rats and from human somatotropinomas: 1) The regulation of GH synthesis by IGF and insulin will be examined by studying the hormonal regulation and ontogeny of IGF and insulin receptors. The ability of somatomedins and insulin to regulate GH secretion and mRNA synthesis will be examined using anti-receptor monoclonal antibodies and by measuring GH released into the medium and intracellular GH mRNA levels. 2) The regulation of IGF synthesis in the pituitary gland and brain will be studied using specific RIAs for the IGFs and RNA probes for each of the somatomedins. These studies will delineate a new feedback role for insulin-like growth factors and will greatly expand our understanding of how IGF, insulin and GRF can regulate pituitary function in normal individuals and in patients with diabetes, acromegaly and hypopituitarism.

Growth hormone (GH) secretion declines during normal aging, resulting in lower serum insulin-like growth factor (IGF)-I levels. Although the physiologic sequelae to this decline in somatotrope function (the "somatopause") are not fully understood, it is likely that many of the catabolic changes seen in normal aging, including osteoporosis, muscle atrophy, and decreased exercise tolerance, are in part caused by the decreased action of the GH-IGF-I axis. Since osteoporosis is a major health problem for women, this proposal will test the effects of GH and IGF-I administration in healthy elderly women to help elucidate the mechanism of the "somatopause". The two specific hypotheses to be tested in this proposal are: 1. GH exerts some of its effects on body composition independent of circulating IGF-I. When GH is administered, circulating GH and IGF-I levels rise, but when IGF-I is infused, GH is suppressed. GH therapy has a number of serious side-effects, including decreased glucose tolerance and the development. of edema and carpal tunnel syndrome, complications which are unlikely to appear with IGF-I therapy. By comparing the effects of GH vs. IGF-I injections, it will be possible to learn which metabolic effects are uniquely exerted by GH, either by itself or through the generation of tissue IGFs. This aim will be accomplished by: A. Brief (6 week) comparative trials of GH vs. IGF-I therapy in elders B. Comparing the effects of IGF-I vs. GH therapy in a placebo-controlled 1 year intervention trial 2. GH or IGF-I therapy will synergize with exercise to increase bone and muscle mass and improve serum lipid profiles. Although exercise will increase muscle mass in healthy elders, a plateau in development occurs after 14 weeks. Since elders do not increase GH secretion during exercise to the levels seen in young subjects, it is likely that adding GH or IGF-I to the exercise regimen at the time of the plateau will further enhance exercise performance and muscle anabolism. Previous studies into the effects of GH on body composition have used methods whose interpretation is obscured by fluid shifts. Since chronic GH therapy in women causes large fluid shifts, investigation of the possibility that GH or IGF-I may have positive effects on body composition will require more sophisticated i and precise methods. Bone density and body composition will be measured by dual energy x-ray absorptiometry. Muscle mass will be evaluated directly by monitoring changes in protein utilization, and V02 max and quality of life indicators will be assessed These studies will provide a rational basis for choosing GH or IGF-I to combat the catabolic effects of aging and to enhance the ability of exercise to increase muscle strength and physical fitness.

[unreadable] DESCRIPTION (provided by applicant): While the vast majority of autosomal genes are expressed from both parental alleles, a small subset of genes, most of which are involved with development, growth and behavior, are expressed from only one allele. These genes are said to be imprinted, as it was initially hypothesized that an epigenetic mark was present on one of the alleles to prevent its transcription. Mutations in imprinted genes are responsible for a number of diseases, including Prader-Willi Syndrome and pseudohypoparathyroidism. The goal of this grant is to discover and explain the underlying mechanisms governing the imprinting of genes. Two specific areas are targeted for intense investigation: 1. Deciphering the Histone Code: It has recently been shown that histones may be modified by acetylation, methylation, phosphorylation, and ubiquitination, and that these modifications may regulate gene transcription. These studies will determine if there is a specific or characteristic histone code that signals to the cell's transcriptional machinery that a gene is imprinted and that only one of the alleles should be transcribed. 2. The Epigenome in Cancer and Development: DNA methylation has been shown to be an important component of the imprinting process, as differentially methylated regions are often associated with gene silencing. Using a novel methylated oligonucleotide approach, it will be possible to add methyl groups to a specific region of a gene and thereby induce specific DNA methylation changes to learn how region-specific methylation can alter the imprinting process. The role of methylation patterns in imprinted genes that have lost imprinting in malignant tissues will also be examined. These aspects of the control of genomic imprinting are closely inter-related and inter-dependent phenomena, and advances in one area will provide new insights into the other mechanisms governing transcriptional control. Ultimately, it will be possible to develop a comprehensive chromatin/DNA model of imprinting. [unreadable] [unreadable]

DESCRIPTION (provided by applicant): This Training Grant, entering its 36th year, has a multidisciplinary faculty from both basic science and clinical departments within Stanford University School of Medicine. The training program is designed to offer postdoctoral trainees a unique and supportive environment in which to learn innovative approaches to the study of Endocrinology, Diabetes and Metabolism. The trainees will pursue research in laboratories where established and cutting edge research programs take advantage of a spectrum of approaches ranging from molecular, cellular, and animal models to human subjects. Advanced molecular and genetic and translational techniques as well as classical clinical protocols and epidemiology are used to develop novel concepts and tools for the study of the physiology, pathophysiology and treatment of diseases of endocrinology, diabetes and metabolism. The training faculty includes 12 investigators from 5 departments- Medicine/Endocrinology, Pediatrics/Endocrinology, Obstetrics/ Gynecology, Urology, and Developmental Biology- whose interests converge on 3 endocrine themes. Theme #1 Hormone Receptors/Signaling Pathways includes projects in the labs of: B. Feldman, D. Feldman, Hsueh, Kim, Kraemer, and Peehl. Theme #2 Genetics/Hormone-Dependent Cancer includes projects in the labs of Chua, B. Feldman, D. Feldman, Hoffman, Hsueh, Kim, Peehl, Reaven, and Stefanick. Theme #3 Diabetes and Cardiovascular Risk included projects in the labs of: McLaughlin, Kim, Kraemer, Reaven, Stefanick, and Wilson. Thus trainees have a wide choice of research projects but within a focus on several major lines of research. This Training Grant has been the core of the Endocrinology teaching program at Stanford providing support for 4 post-doctoral trainees, with either the M.D. or Ph.D. degrees. In addition to research training, the Training Grant, in conjunction with the School of Medicine, provides a rich environment of seminars, courses and conferences as well as core facilities all fostering a stimulating and productive training program with major interaction among trainees and mentors. The Training Grant faculty members are committed to continuing to recruit a diverse group of trainees and to making a strong effort to enlist trainees from under-represented minorities. Programs in the ethics of responsible research, grant writing, critical evaluation of the literature as well as many other courses and seminars enrich the training program. The goal of this Training Grant is to provide 1-2 years of support to promising postdoctoral scholars who will become the future leaders in endocrine research in both academia and in biotechnology.

Project Summary/Abstract Regenerative therapies using stem cells are being explored for treatment of advanced lung diseases such as emphysema. We recently identified an undifferentiated ?fibroblast-like? multipotent stromal cell (LMSC) from lung tissue that expresses the same surface markers (CD44, CD73, CD90, CD105) as multipotent bone marrow stromal cells and displays regenerative capacity following transplantation in mice and sheep with experimental emphysema. LMSCs from adult human lung tissue have elastogenic capacity in vitro, spontaneously form alveolar-like structures in matrigel. and secrete growth factors including FGF2, FGF7, FGF10, and HGF that can promote remodeling. In collaboration with the Production Assistance for Cellular Therapies (PACT) group at the Dana Farber Cancer Institute, we have developed procedures for manufacturing clinical grade LMSCs from biopsy specimens, and designed a biopolymer scaffold to promote lung engraftment of LMSCs following endobronchial administration. These technological advances make autologous LMSC transplantation feasible for human applications, addressing problems of rejection and the need for immunosuppression that are associated with allogeneic transplantation. The objectives of this project are: 1) to complete the preclinical pharmacotoxicology testing required to begin human trials; and 2) initiate Phase 1 trials of autologous LMSC transplantation in emphysema patients awaiting lung transplantation. This trial design will allow us to recover the LMSC-treated organ for histological analysis to characterize responses to LMSC treatment at the cellular level.

? DESCRIPTION (provided by applicant): This Stage 1 Planning Grant will develop an overall vision, roadmap, organizational structure and operational procedures for a centralized Tufts Dental, Oral and Craniofacial Tissue Regeneration Consortium (DOCTRC) Resource Center (RC). At the completion of this 1-Year Stage 1 Grant, the Tufts DOCTRC organizers will have developed detailed plans for establishing interactive, interdisciplinary DOC-RC teams of biologists, bioengineers, clinicians and other technical experts. This effort will be driven by practicing clinicians involved in everyday DOC patient care in order to ensure building a successful RC infrastructure. Academic clinicians, basic scientist engineers, stem cell biologists, developmental biologists, and industrial liaisons also have been included in the proposed Tufts RC in order to ensure a successful outcome. This Stage 1 Planning Grant will set the stage for the 3-year Stage 2 Award that will be used to establish the Tufts Centralized DOCTRC RC, developing a robust infrastructure to deliver uniform, high-quality technical support and research capacities for preclinical studies. The Stage 2 period will also be used to organize, recruit and integrate several Interdisciplinary Translational Project (ITP) teams into the Tufts Centralized RC. Each of these ITP teams will have identified and developed a specific tissue engineering and regenerative medicine (TE/RM) approach for regeneration of a functional DOC tissue that synergizes with the expertise of one of the Tufts DOC-RC teams. Finally, we anticipate submitting a competitive Stage 3 Consortium Stage application, which will utilize the resources developed in Stage 2 to work with the DOC-RCs and the FDA to advance specific TE/RM clinical applications. The Stage 3 Consortium Stage will complete validation, manufacturing and preclinical testing of the most likely to succeed TE/RM products, and develop Investigational New Drugs/Investigational Devices (IND/IDs) for submission to FDA. The outcome of the DOCTRC-TE/RM will be products and associated protocols ready for initiation of Phase I clinical trials.

Project Summary This Training Grant, entering its 41st year, has a multidisciplinary faculty from both basic science and clinical departments within Stanford University School of Medicine. The training program is designed to offer postdoctoral trainees a unique and supportive environment in which to learn innovative approaches to the study of Endocrinology, Diabetes and Metabolism. The trainees will pursue research in laboratories where established and cutting edge research programs take advantage of a spectrum of approaches ranging from molecular, cellular, and animal models to human subjects. Advanced molecular and genetic and translational techniques as well as classical clinical protocols and epidemiology are used to develop novel concepts and tools for the study of the physiology, pathophysiology and treatment of diseases of endocrinology, diabetes and metabolism. The training faculty includes 15 investigators from 5 Departments: Medicine, Pediatrics, Developmental Biology, Chemical & Systems Biology, and Neurosurgery whose interests converge on 4 general endocrine themes. Theme #1 Islet and Beta-cell Biology includes projects in the labs of: Feldman, Seung Kim, Sun Kim, Wilson, McLaughlin and Annes. Theme #2 Genetics/Hormone-Dependent Cancer includes projects in the labs of Chua, Feldman, Hoffman, Kraemer, Annes and Katznelson. Theme #3 Diabetes and Cardiovascular Risk includes projects in the labs of: Kraemer, Teruel, McLaughlin, Sun Kim, Reaven, Stefanick, and Wilson. Theme #4 Endocrine Population Health Sciences and Osteoporosis includes the labs of Wu, Lee, Stefanick, Feldman and Hoffman. Thus trainees have a wide choice of research projects but within a focus on several major lines of research. This Training Grant has been the core of the Endocrinology teaching program at Stanford providing support for 4 post- doctoral trainees, with either the M.D. or Ph.D. degrees. In addition to research training, the Training Grant, in conjunction with the School of Medicine, provides a rich environment of seminars, courses and conferences as well as core facilities all fostering a stimulating and productive training program with major interaction among trainees and mentors. The Training Grant faculty members are committed to continuing to recruit a diverse group of trainees and to making a strong effort to enlist trainees from under-represented minorities. Programs in the ethics of responsible research, grant writing, critical evaluation of the literature as well as many other courses and seminars enrich the training program. The goal of this Training Grant is to provide 1-2 years of support to promising postdoctoral scholars who will become the future leaders in endocrine research in both academia and in biotechnology.