2024 Distinguished Scientist Stephen G. Young, MD, FAHA

Stephen G. Young, MD, FAHA
University of California
Los Angeles, CA

Stephen G. Young is an American physician–scientist known for investigating the genetics and molecular physiology of apolipoprotein B, the intravascular processing of triglyceride-rich lipoproteins by lipoprotein lipase, and the role of nuclear lamins in health and disease. Currently, Young is a Distinguished Professor of Medicine and Human Genetics at UCLA, where he has worked closely with two faculty colleagues (Loren G. Fong and Anne P. Beigneux). Young defined the first APOB mutations causing familial hypobetalipoproteinemia. He discovered that GPIHBP1, a protein of capillary endothelial cells, is crucial for the lipolytic processing of triglyceride-rich lipoproteins. GPIHBP1 captures LPL from within the interstitial spaces (where it is secreted by myocytes) and shuttles it across endothelial cells to its site of action within the capillary lumen. In the absence of GPIHBP1, LPL is stranded within the interstitial spaces, resulting in markedly impaired intravascular triglyceride hydrolysis and severe hypertriglyceridemia. Young also demonstrated that the hypertriglyceridemia in the setting of APOA5 deficiency is caused by reduced amounts of LPL inside capillaries. APOA5 functions to suppress the ability of the ANGPTL3/ANGPTL8 complex to detach LPL from its binding sites within capillaries.

Young studied the history of science at Princeton University and obtained a medical degree from Washington University in St. Louis. He trained in internal medicine at UCSF and cardiovascular diseases at UCSD; he is board-certified in both disciplines. He is a member of the National Academy of Sciences, the American Society for Clinical Investigation, and the Association of American Physicians. He is a corresponding member abroad of the Austrian Academy of Sciences and was named an inaugural fellow of the American Society for Biochemistry and Molecular Biology. He received the Jung Price in Medicine and an honorary doctorate in medicine from the University of Gothenburg.