This Program Project Grant (PPG) began 35 years ago when we delineated the LDL receptor pathway for control of cholesterol metabolism and showed that defects in the LDL receptor produce Familial Hypercholesterolemia and atherosclerosis. After 35 years, our goals have broadened and the participants have increased, but the focus remains the same: to understand the genetic and molecular basis for regulation of lipid and lipoprotein metabolism and to use this knowledge to prevent and treat lipid-related diseases i.e., atherosclerosis and Metabolic Syndrome. During the last 5 years, we published 164 papers, reporting the following major advances: 1) discovery of Scap as the sensing receptor for membrane cholesterol that controls SREBP processing, thereby determining LDL receptor number and plasma LDL level;2) discovery of mutations in PCSK9 that lower plasma LDL and decrease heart attacks as much as 88%;3) demonstration that PCSK9 functions extracellularly to bind and degrade LDL receptors, an observation that stimulated pharmaceutical companies to develop antibodies that block PCSK9 and lower LDL;4) elucidation of the hydrophobic handoff mechanism for export of LDL-derived cholesterol from lysosomes;5) delineation of the sterol-regulated, ubiquitin-mediated pathway for degradation of HMG CoA reductase and lnsig-1;6) discovery of GOAT, the enzyme that attaches octanoic acid to ghrelin, a covalent modification required for ghrelin's activity in controlling appetite and blod sugar;7) identification of a protein, MIG12, that activates fatty acid synthesis in liver;8) discovery of 25-hydroxycholesterol as an immunoregulatory sterol that links the innate and adaptive immune systems;and 9) elucidation of an LRP1- mediated signaling pathway that protects vascular smooth muscle cells against atherosclerosis. We now apply for a 5-year renewal (Years 36-40) to further study these and related phenomena through an integrated, multidisciplinary approach. We propose to learn more about known molecules and to discover new ones that regulate lipid and lipoprotein metabolism as it relates to disease. We will continue to study these processes at all levels - molecules (i.e., gene, mRNA, protein), cells, experimental animals, and human patients. We will employ multiple approaches - biochemistry, molecular biology, genetics, cell biology, gene-manipulated mice, animal physiology, clinical genetics, and genomics. Such an integrated interdisciplinary approach is possible only through continued support of this PPG.

Public Health Relevance

Disordered fat metabolism lies at the root of two common and devastating diseases in industrialized societies: cardiovascular disease and diabetes. Deep understanding of cholesterol metabolism, much of which resulted from this PPG, has already reduced coronary disease. Further reductions in vascular disease will follow from future advances resulting from studies proposed in this PPG renewal. We have already provided an unprecedented number of novel research tools (>380 different cDNA clones, cell lines, monoclonal and polyclonal antibodies, specialized plasmid constructs, transgenic and knockout mice) to the scientific communitv. and many more will emerge from this renewal.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL020948-38
Application #
8686020
Study Section
Heart, Lung, and Blood Program Project Review Committee (HLBP)
Program Officer
Liu, Lijuan
Project Start
1997-07-15
Project End
2017-06-30
Budget Start
2014-07-01
Budget End
2015-06-30
Support Year
38
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Texas Sw Medical Center Dallas
Department
Genetics
Type
Schools of Medicine
DUNS #
City
Dallas
State
TX
Country
United States
Zip Code
75390
Mitsche, Matthew A; Hobbs, Helen H; Cohen, Jonathan C (2018) Patatin-like phospholipase domain-containing protein 3 promotes transfer of essential fatty acids from triglycerides to phospholipids in hepatic lipid droplets. J Biol Chem 293:6958-6968
Banfi, Serena; Gusarova, Viktoria; Gromada, Jesper et al. (2018) Increased thermogenesis by a noncanonical pathway in ANGPTL3/8-deficient mice. Proc Natl Acad Sci U S A 115:E1249-E1258
Fine, Michael; Schmiege, Philip; Li, Xiaochun (2018) Structural basis for PtdInsP2-mediated human TRPML1 regulation. Nat Commun 9:4192
Linden, Albert G; Li, Shili; Choi, Hwa Y et al. (2018) Interplay between ChREBP and SREBP-1c coordinates postprandial glycolysis and lipogenesis in livers of mice. J Lipid Res 59:475-487
Johnson, Brittany M; DeBose-Boyd, Russell A (2018) Underlying mechanisms for sterol-induced ubiquitination and ER-associated degradation of HMG CoA reductase. Semin Cell Dev Biol 81:121-128
Qi, Xiaofeng; Schmiege, Philip; Coutavas, Elias et al. (2018) Two Patched molecules engage distinct sites on Hedgehog yielding a signaling-competent complex. Science 362:
Engelking, Luke J; Cantoria, Mary Jo; Xu, Yanchao et al. (2018) Developmental and extrahepatic physiological functions of SREBP pathway genes in mice. Semin Cell Dev Biol 81:98-109
Hobbs, Helen H (2018) Science, serendipity, and the single degree. J Clin Invest 128:4218-4223
Muse, Evan D; Yu, Shan; Edillor, Chantle R et al. (2018) Cell-specific discrimination of desmosterol and desmosterol mimetics confers selective regulation of LXR and SREBP in macrophages. Proc Natl Acad Sci U S A 115:E4680-E4689
DeBose-Boyd, Russell A; Ye, Jin (2018) SREBPs in Lipid Metabolism, Insulin Signaling, and Beyond. Trends Biochem Sci 43:358-368

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