Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins.
Triglyceride-rich lipoproteins (TRLs) are circulating reservoirs of fatty acids used as vital energy sources for peripheral tissues. Lipoprotein lipase (LPL) is a predominant enzyme mediating triglyceride (TG) lipolysis and TRL clearance to provide fatty acids to tissues in animals. Physiological an...
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Public Library of Science (PLoS)
2021-09-01
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| Series: | PLoS Genetics |
| Online Access: | https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1009802&type=printable |
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| author | Sumeet A Khetarpal Cecilia Vitali Michael G Levin Derek Klarin Joseph Park Akhil Pampana John S Millar Takashi Kuwano Dhavamani Sugasini Papasani V Subbaiah Jeffrey T Billheimer Pradeep Natarajan Daniel J Rader |
| author_facet | Sumeet A Khetarpal Cecilia Vitali Michael G Levin Derek Klarin Joseph Park Akhil Pampana John S Millar Takashi Kuwano Dhavamani Sugasini Papasani V Subbaiah Jeffrey T Billheimer Pradeep Natarajan Daniel J Rader |
| author_sort | Sumeet A Khetarpal |
| collection | DOAJ |
| description | Triglyceride-rich lipoproteins (TRLs) are circulating reservoirs of fatty acids used as vital energy sources for peripheral tissues. Lipoprotein lipase (LPL) is a predominant enzyme mediating triglyceride (TG) lipolysis and TRL clearance to provide fatty acids to tissues in animals. Physiological and human genetic evidence support a primary role for LPL in hydrolyzing TRL TGs. We hypothesized that endothelial lipase (EL), another extracellular lipase that primarily hydrolyzes lipoprotein phospholipids may also contribute to TRL metabolism. To explore this, we studied the impact of genetic EL loss-of-function on TRL metabolism in humans and mice. Humans carrying a loss-of-function missense variant in LIPG, p.Asn396Ser (rs77960347), demonstrated elevated plasma TGs and elevated phospholipids in TRLs, among other lipoprotein classes. Mice with germline EL deficiency challenged with excess dietary TG through refeeding or a high-fat diet exhibited elevated TGs, delayed dietary TRL clearance, and impaired TRL TG lipolysis in vivo that was rescued by EL reconstitution in the liver. Lipidomic analyses of postprandial plasma from high-fat fed Lipg-/- mice demonstrated accumulation of phospholipids and TGs harboring long-chain polyunsaturated fatty acids (PUFAs), known substrates for EL lipolysis. In vitro and in vivo, EL and LPL together promoted greater TG lipolysis than either extracellular lipase alone. Our data positions EL as a key collaborator of LPL to mediate efficient lipolysis of TRLs in humans and mice. |
| format | Article |
| id | doaj-art-8f70a22c3e124be3bfe8597898cbddf1 |
| institution | OA Journals |
| issn | 1553-7390 1553-7404 |
| language | English |
| publishDate | 2021-09-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Genetics |
| spelling | doaj-art-8f70a22c3e124be3bfe8597898cbddf12025-08-20T02:17:47ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042021-09-01179e100980210.1371/journal.pgen.1009802Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins.Sumeet A KhetarpalCecilia VitaliMichael G LevinDerek KlarinJoseph ParkAkhil PampanaJohn S MillarTakashi KuwanoDhavamani SugasiniPapasani V SubbaiahJeffrey T BillheimerPradeep NatarajanDaniel J RaderTriglyceride-rich lipoproteins (TRLs) are circulating reservoirs of fatty acids used as vital energy sources for peripheral tissues. Lipoprotein lipase (LPL) is a predominant enzyme mediating triglyceride (TG) lipolysis and TRL clearance to provide fatty acids to tissues in animals. Physiological and human genetic evidence support a primary role for LPL in hydrolyzing TRL TGs. We hypothesized that endothelial lipase (EL), another extracellular lipase that primarily hydrolyzes lipoprotein phospholipids may also contribute to TRL metabolism. To explore this, we studied the impact of genetic EL loss-of-function on TRL metabolism in humans and mice. Humans carrying a loss-of-function missense variant in LIPG, p.Asn396Ser (rs77960347), demonstrated elevated plasma TGs and elevated phospholipids in TRLs, among other lipoprotein classes. Mice with germline EL deficiency challenged with excess dietary TG through refeeding or a high-fat diet exhibited elevated TGs, delayed dietary TRL clearance, and impaired TRL TG lipolysis in vivo that was rescued by EL reconstitution in the liver. Lipidomic analyses of postprandial plasma from high-fat fed Lipg-/- mice demonstrated accumulation of phospholipids and TGs harboring long-chain polyunsaturated fatty acids (PUFAs), known substrates for EL lipolysis. In vitro and in vivo, EL and LPL together promoted greater TG lipolysis than either extracellular lipase alone. Our data positions EL as a key collaborator of LPL to mediate efficient lipolysis of TRLs in humans and mice.https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1009802&type=printable |
| spellingShingle | Sumeet A Khetarpal Cecilia Vitali Michael G Levin Derek Klarin Joseph Park Akhil Pampana John S Millar Takashi Kuwano Dhavamani Sugasini Papasani V Subbaiah Jeffrey T Billheimer Pradeep Natarajan Daniel J Rader Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins. PLoS Genetics |
| title | Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins. |
| title_full | Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins. |
| title_fullStr | Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins. |
| title_full_unstemmed | Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins. |
| title_short | Endothelial lipase mediates efficient lipolysis of triglyceride-rich lipoproteins. |
| title_sort | endothelial lipase mediates efficient lipolysis of triglyceride rich lipoproteins |
| url | https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1009802&type=printable |
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