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Chen YQ, Yang Y, Zhen EY, Beyer TP, Li H, Wen Y, Ehsani M, Jackson N, Xie K, Jung H, Scheithauer JL, Kumari A, Birrane G, Russell AM, Balasubramaniam D, Liao Z, Siegel RW, Qian Y, Ploug M, Young SG, Konrad RJ. Carboxyl-terminal sequences in APOA5 are important for suppressing ANGPTL3/8 activity. Proc Natl Acad Sci U S A 2024; 121:e2322332121. [PMID: 38625948 PMCID: PMC11046700 DOI: 10.1073/pnas.2322332121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2023] [Accepted: 03/16/2024] [Indexed: 04/18/2024] Open
Abstract
Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its capacity to inhibit lipoprotein lipase (LPL) catalytic activity and its ability to detach LPL from binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an APOA5 mutation that truncates APOA5 by 35 residues ("APOA5Δ35"). We found that wild-type (WT) human APOA5, but not APOA5Δ35, suppressed ANGPTL3/8's ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C-terminal amino acids ("APOA5Δ40"). Mouse WT-APOA5, but not APOA5Δ40, suppressed ANGPTL3/8's capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT-APOA5, but not APOA5Δ40, increased intracapillary LPL levels and reduced plasma TG levels in Apoa5-/- mice (where TG levels are high and intravascular LPL levels are low). Also, WT-APOA5, but not APOA5Δ40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C-terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.
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Affiliation(s)
- Yan Q. Chen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Eugene Y. Zhen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Thomas P. Beyer
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Hongxia Li
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Yi Wen
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Mariam Ehsani
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Nicholas Jackson
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Katherine Xie
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Hyesoo Jung
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Julia L. Scheithauer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Anni Kumari
- Finsen Laboratory, Centre for Cancer and Organ Diseases, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Gabriel Birrane
- Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Boston, MA02215
| | - Anna M. Russell
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | | | - Zhongping Liao
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Robert W. Siegel
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Yuewei Qian
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
| | - Michael Ploug
- Finsen Laboratory, Centre for Cancer and Organ Diseases, Copenhagen University Hospital-Rigshospitalet, DK-2200Copenhagen N, Denmark
- Finsen Laboratory, Biotech Research and Innovation Centre, University of Copenhagen, DK-2200Copenhagen N, Denmark
| | - Stephen G. Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA90095
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA90095
| | - Robert J. Konrad
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN462585
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