2005 — 2007 |
Buchner, David A |
F32Activity Code Description: To provide postdoctoral research training to individuals to broaden their scientific background and extend their potential for research in specified health-related areas. |
Chemical and Genetic Modifiers of the Protein C Pathway @ Case Western Reserve University
DESCRIPTION (provided by applicant): Venous thrombosis affects approximately 1/1,000 individuals per year. Most cases involve 1 or more complex genetic factors together with a range of environmental triggers. The majority of monogenic cases of familial thrombosis are associated with defects in the protein C (PC) pathway. It would be of tremendous clinical significance to find genes that modulate the penetrance of mutations in the PC pathway. PC knockout zebrafish will be generated from frozen sperm corresponding to 2 previously identified null alleles of PC, identified in a library of DNA from ENU mutagenized zebrafish. These fish will be used in a sensitized genome-wide ENU mutagenesis screen to identify suppressors of the lethal thrombosis. Heritable mutations will be identified by positional cloning. In addition, the PC knockout zebrafish will be used in a second high-throughput screen to identify novel anticoagulants. The strengths of the zebrafish model organism will again be exploited to assay a diverse set of 35,000 small molecule compounds for in vivo rescue of the lethal phenotype. Successfully rescuing compounds can be quickly tested in human plasma coagulation assays and in vivo mouse models to determine their target and evaluate their therapeutic potential.
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1 |
2010 — 2013 |
Buchner, David A |
K01Activity Code Description: For support of a scientist, committed to research, in need of both advanced research training and additional experience. |
Cntnap2 in Diet-Induced Obesity
DESCRIPTION (provided by applicant): Obesity is an increasingly common health problem in the U.S. and throughout the developed world. Approximately two-thirds of the U.S population is currently obese or overweight. While the recent epidemic is being driven primarily by environmental factors, there is strong evidence for unknown genetic factors that significantly contribute to an individual's propensity for weight gain. To better understand these genetic factors, we have studied C57BL/6J and A/J mice which respond differently to a calorie-rich environment. Despite similar physiology under normal conditions, C57BL/6J mice become obese and develop many of the symptoms of metabolic syndrome while A/J mice remain relatively lean. I have mapped a genetic factor that contributes to this strain difference in adiposity to a region on chromosome 6 that contains only a single gene, Cntnap2. There are 2 amino acid residues in CNTNAP2 that differ between C57BL/6J and A/J. These variants may lead to functional differences in the encoded protein in these two strains, thereby contributing to the difference in obesity susceptibility. We propose to study the role of Cntnap2 and a functionally related gene in obesity using approaches that integrate genetics, physiology, and biochemistry. A knockout mouse model will be generated to study the role of Cntnap2 in adiposity and energy balance as well as a number of clinically important comorbidities of obesity. The experiments proposed will greatly contribute to our scientific understanding of the molecular mechanisms underlying obesity and diabetes. Dr. Buchner's prior training has focused on the genetics of complex disease. This proposal aims to complement this training, with additional career development activities in the fields of physiology and mitochondrial biochemistry. This will be attained through additional coursework, hands-on experience with a team of experts in fields relevant to the proposed research, and significant mentoring from Dr. Nadeau and Dr. Charles Hoppel who are internationally recognized experts in their fields of genetics (Nadeau) and mitochondrial biochemistry (Hoppel). In addition to specific metabolism-related training activities, CWRU and the Department of Genetics will provide a rich mentoring environment for career development. Available activities include weekly scientific seminars, journal clubs, postdoctoral training programs, and many others. Another important component of the career development plan will be attending and presenting at national and international research conferences. Conferences will include an annual Keystone Symposium on obesity and diabetes and an annual Mitochondrial Medicine Conference. The mentoring by Drs. Nadeau and Hoppel, and collaborations with a team of accomplished investigators, will provide an exceptional environment to learn new skills and knowledge that will assist Dr. Buchner as he seeks to become a highly productive independent investigator at an academic institution.
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1 |
2013 — 2014 |
Buchner, David A |
K01Activity Code Description: For support of a scientist, committed to research, in need of both advanced research training and additional experience. |
Cntnp2 in Diet-Induced Obesity @ Case Western Reserve University
DESCRIPTION (provided by applicant): Obesity is an increasingly common health problem in the U.S. and throughout the developed world. Approximately two-thirds of the U.S population is currently obese or overweight. While the recent epidemic is being driven primarily by environmental factors, there is strong evidence for unknown genetic factors that significantly contribute to an individual's propensity for weight gain. To better understand these genetic factors, we have studied C57BL/6J and A/J mice which respond differently to a calorie-rich environment. Despite similar physiology under normal conditions, C57BL/6J mice become obese and develop many of the symptoms of metabolic syndrome while A/J mice remain relatively lean. I have mapped a genetic factor that contributes to this strain difference in adiposity to a region on chromosome 6 that contains only a single gene, Cntnap2. There are 2 amino acid residues in CNTNAP2 that differ between C57BL/6J and A/J. These variants may lead to functional differences in the encoded protein in these two strains, thereby contributing to the difference in obesity susceptibility. We propose to study the role of Cntnap2 and a functionally related gene in obesity using approaches that integrate genetics, physiology, and biochemistry. A knockout mouse model will be generated to study the role of Cntnap2 in adiposity and energy balance as well as a number of clinically important comorbidities of obesity. The experiments proposed will greatly contribute to our scientific understanding of the molecular mechanisms underlying obesity and diabetes. Dr. Buchner's prior training has focused on the genetics of complex disease. This proposal aims to complement this training, with additional career development activities in the fields of physiology and mitochondrial biochemistry. This will be attained through additional coursework, hands-on experience with a team of experts in fields relevant to the proposed research, and significant mentoring from Dr. Nadeau and Dr. Charles Hoppel who are internationally recognized experts in their fields of genetics (Nadeau) and mitochondrial biochemistry (Hoppel). In addition to specific metabolism-related training activities, CWRU and the Department of Genetics will provide a rich mentoring environment for career development. Available activities include weekly scientific seminars, journal clubs, postdoctoral training programs, and many others. Another important component of the career development plan will be attending and presenting at national and international research conferences. Conferences will include an annual Keystone Symposium on obesity and diabetes and an annual Mitochondrial Medicine Conference. The mentoring by Drs. Nadeau and Hoppel, and collaborations with a team of accomplished investigators, will provide an exceptional environment to learn new skills and knowledge that will assist Dr. Buchner as he seeks to become a highly productive independent investigator at an academic institution.
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0.931 |
2014 — 2015 |
Buchner, David A |
R03Activity Code Description: To provide research support specifically limited in time and amount for studies in categorical program areas. Small grants provide flexibility for initiating studies which are generally for preliminary short-term projects and are non-renewable. |
Epistatic Regulation of Gene Expression @ Case Western Reserve University
DESCRIPTION (provided by applicant): Obesity and its comorbidities such as type 2 diabetes are a common health problem in the U.S. and throughout the developed world. Approximately one-third of the U.S population is currently obese. There is strong evidence that genetic factors contribute to an individual's propensity for weight gain, however identifying these factors has proven difficult. Part of the difficulty is likely due to complex interactions between genes that modify the phenotypic effects of each gene. Identifying interacting genes is difficult in both humans and in model organisms using traditional genetic techniques. We will to take a novel approach based on using mouse chromosome substitutions strains to characterize and identify these interacting genes. These strains have many advantages that facilitate the identification of genes underlying complex traits including improved reproducibility and simplified genetic crosses and data interpretation due to the partitioning of the genome into non-overlapping segments. We propose to study gene expression in pairwise combinations of the chromosome substitution strains. This will allow us to identify genes with expression patterns that are dependent on non-additive interactions between unlinked loci. This data will then be applied to existing human datasets for which gene expression and genotyping data are available. The mouse epistasis data will be used as a guide to improve statistical power in human studies, and therefore better detect epistasis in humans. Dr. Buchner's training prior to his K01 award had focused on the genetics of complex disease. During the K01 award period, he has complemented this training with additional activities in the fields of physiology, cell biology, an metabolic disease. This R03 proposal now seeks to combine Dr. Buchner's expertise in genetics, physiology, and metabolic disease to distinguish his research from that of his current and former mentors. This proposal will provide novel insights into the genetic architecture of complex traits while laying the groundwork for Dr. Buchner's work as an independent investigator.
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0.931 |
2017 |
Buchner, David A |
R56Activity Code Description: To provide limited interim research support based on the merit of a pending R01 application while applicant gathers additional data to revise a new or competing renewal application. This grant will underwrite highly meritorious applications that if given the opportunity to revise their application could meet IC recommended standards and would be missed opportunities if not funded. Interim funded ends when the applicant succeeds in obtaining an R01 or other competing award built on the R56 grant. These awards are not renewable. |
Molecular Regulation of Pparg Signaling and Adipocyte Function @ Case Western Reserve University
Project Summary Adipocytes serve as the body?s primary site for lipid storage and act as signaling centers to coordinate the physiological response to an organism?s nutritional and metabolic state. Therefore, to understand susceptibility to obesity and type 2 diabetes requires a detailed understanding of the molecules underlying the function of adipocytes. The transcription factor PPAR? is a master regulator of adipogenesis and regulates the transcription of genes involved in glucose transport, lipid metabolism, and a number of adipokines. However, the mechanism by which PPAR? regulates transcription in adipocytes remains incompletely understood. This proposal will improve our understanding of the mechanism of PPAR? transcriptional regulation by studying a novel positive regulator of PPAR? signaling, Zfp407, that was recently identified by our lab. We hypothesize that Zfp407 in adipocytes regulates cell survival by controlling PPAR? signaling as a novel scaffolding cofactor. This hypothesis is based on our preliminary data demonstrating that Zfp407 deficiency in cultured adipocytes broadly reduces the expression of PPAR? target genes while in vivo Zfp407 deficiency in adipocytes greatly reduces fat mass. In Specific Aim 1, we will test whether constitutive and temporal deletion of Zfp407 specifically in adipocytes alters adipocyte survival and function and determine the metabolic consequences. In Specific Aim 2, we will apply genome-wide analysis of transcription factor binding in adipocytes together with biochemical and cell biological approaches to determine the molecular mechanism by which Zfp407 regulates PPAR? activity. Collectively, these studies will improve our mechanistic understanding of adipocyte function and PPAR? signaling, which are together critical for understanding the pathophysiology of metabolic disease and discovering new therapeutic targets.
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0.931 |
2019 — 2021 |
Buchner, David A |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Role of Adipocyte Gene Expression Regulation by Zfp407 in Adipocyte Biology and Metabolic Disease @ Case Western Reserve University
Project Summary Adipocytes serve as the body?s primary site for lipid storage and act as signaling centers to coordinate the physiological response to an organism?s nutritional and metabolic state. A better understand of the molecules underlying adipocyte regulation and function will improve our knowledge of the pathophysiology of obesity and type 2 diabetes, which are associated with altered adipocyte function. This proposal will define the metabolic and molecular effects of a poorly understood transcription factor, Zfp407, that was recently identified by our lab as a critical molecule for adipocyte function and insulin sensitivity. We showed that Zfp407 deficiency has broad effects on adipocyte gene expression and results in reduced fat mass, illustrating the critical role of Zfp407 in adipose biology. However, the detailed physiological significance of Zfp407 and cellular mechanisms underlying them remain poorly understood. We propose three Aims to identify the critical physiological role of Zfp407 in differentiating and mature adipocytes and to determine the molecular mechanism by which Zfp407 controls gene expression in adipocytes. In Specific Aim 1, we will discover the physiological function of Zfp407 in mature adipocytes by testing whether constitutive and temporal deletion of Zfp407 in adipocytes alters adipocyte number, survival, and function and determining the metabolic consequences under normal and obesogenic conditions. In Specific Aim 2, we will elucidate the role and mechanism of Zfp407 in the differentiation of white, brown, and beige adipocytes. In Specific Aim 3, we will determine the molecular mechanism by which Zfp407 regulates the adipocyte transcriptome via PPAR?-dependent and PPAR?-independent mechanisms by combining state-of-the-art genomic approaches such as GRO-Seq and BRIC-Seq with classic biochemical techniques. Collectively, these studies will improve our mechanistic understanding of how the regulation of gene expression controls adipocyte differentiation and function. These data will improve our understanding of the pathophysiology of metabolic disease and may identify new translational opportunities for treating obesity and type 2 diabetes.
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0.931 |