Lipid storage is critical for metabolic homeostasis, and influences components ofthe metabolic syndrome, including visceral obesity, insulin resistance, and dyslipidemia. The objectives are to further elucidate the function of lipin-1 in lipid synthesis, storage, and lipid signaling in adipose tissue and muscle, and to identify novel genes that influence adipose tissue mass and function. Our previous studies demonstrated that lipin-1 is a determinant of adipose tissue development, insulin sensitivity, and energy metabolism. Lipin-I is a phosphatidate phosphatase (PAP) enzyme that converts phosphatidate to diacylglyerol, and accounts for all PAP activity in adipose tissue and muscle. In addition, it is a transcriptional coactivator that influences expression of lipid metabolism genes in liver.
The specific aims are: (1) Determine how lipin-1 modulation of phosphatidate levels regulates adipogenesis and influences insulin sensitivity in skeletal muscle. In the absence of lipin-1, phosphatidate accumulates in tissues, which may activate signal transduction pathways and/or alter mitochondrial or ER membrane properties. We hypothesize that phosphatidate levels determined by lipin-1 influence expression of PPARgamma and adipocyte differentiation, and insulin sensitivity in muscle. We will investigate how dysregulation of lipin-1 and phosphatidate levels contribute to altered metabolism in adipose tissue, muscle, and liver. (2) Evaluate the role of lipin-1 in statin-induced myotoxicity. Human LPINI nonsense mutations cause childhood myopathy, and missense mutations have been associated with statin-induced myopathy. We will test the hypothesis that impaired lipin-1 activity and statin action interact to impair mitochondrial function. We will functionally characterize mutant lipin-1 proteins, evaluate effects of lipin-1 deficiency on statin-induced myotoxicity in the mouse, and evaluate a cohort of subjects with statin-induced myopathy for LPINI mutations. (3) Identify and characterize the molecular function of novel adiposity genes. We hypothesize that genetic variations that alter adiposity in vivo will reveal novel genes in adipose tissue function. We will investigate the function of 7 candidate genes identified by network modeling in the mouse for roles in adipocyte function using in vitro and in vivo methods.

Public Health Relevance

The regulation of fat storage is a key determinant of conditions associated with human disease, including obesity, diabetes, and heart disease. A better understanding ofthe genes and processes involved may contribute to the design of therapeutic intervention.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
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Heart, Lung, and Blood Program Project Review Committee (HLBP)
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University of California Los Angeles
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Zhu, W; Buffa, J A; Wang, Z et al. (2018) Flavin monooxygenase 3, the host hepatic enzyme in the metaorganismal trimethylamine N-oxide-generating pathway, modulates platelet responsiveness and thrombosis risk. J Thromb Haemost 16:1857-1872
Lee, Jessica M; Ong, Jessica R; Vergnes, Laurent et al. (2018) Diet1, bile acid diarrhea, and FGF15/19: mouse model and human genetic variants. J Lipid Res 59:429-438
Miao, Zong; Alvarez, Marcus; Pajukanta, Päivi et al. (2018) ASElux: an ultra-fast and accurate allelic reads counter. Bioinformatics 34:1313-1320
Kurt, Zeyneb; Barrere-Cain, Rio; LaGuardia, Jonnby et al. (2018) Tissue-specific pathways and networks underlying sexual dimorphism in non-alcoholic fatty liver disease. Biol Sex Differ 9:46
Orozco, Luz D; Farrell, Colin; Hale, Christopher et al. (2018) Epigenome-wide association in adipose tissue from the METSIM cohort. Hum Mol Genet 27:1830-1846
Chella Krishnan, Karthickeyan; Kurt, Zeyneb; Barrere-Cain, Rio et al. (2018) Integration of Multi-omics Data from Mouse Diversity Panel Highlights Mitochondrial Dysfunction in Non-alcoholic Fatty Liver Disease. Cell Syst 6:103-115.e7
Freund, Malika Kumar; Burch, Kathryn S; Shi, Huwenbo et al. (2018) Phenotype-Specific Enrichment of Mendelian Disorder Genes near GWAS Regions across 62 Complex Traits. Am J Hum Genet 103:535-552
Pan, David Z; Garske, Kristina M; Alvarez, Marcus et al. (2018) Integration of human adipocyte chromosomal interactions with adipose gene expression prioritizes obesity-related genes from GWAS. Nat Commun 9:1512
Small, Kerrin S; Todor?evi?, Marijana; Civelek, Mete et al. (2018) Regulatory variants at KLF14 influence type 2 diabetes risk via a female-specific effect on adipocyte size and body composition. Nat Genet 50:572-580
Mangul, Serghei; Yang, Harry Taegyun; Strauli, Nicolas et al. (2018) ROP: dumpster diving in RNA-sequencing to find the source of 1 trillion reads across diverse adult human tissues. Genome Biol 19:36

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