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Al-Shammari RT, Al-Serri AE, Barhoush SA, Al-Bustan SA. Identification and Characterization of Variants in Intron 6 of the LPL Gene Locus among a Sample of the Kuwaiti Population. Genes (Basel) 2022; 13:genes13040664. [PMID: 35456470 PMCID: PMC9024856 DOI: 10.3390/genes13040664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 11/22/2022] Open
Abstract
Lipoprotein lipase (LPL) is responsible for the hydrolysis of lipoproteins; hence defective LPL is associated with metabolic disorders. Here, we identify certain intronic insertions and deletions (InDels) and single nucleotide polymorphisms (SNPs) in intron 6 of the LPL gene and investigate their associations with different phenotypic characteristics in a cohort of the general Kuwaiti population. Two specific regions of intron 6 of the LPL gene, which contain InDels, were amplified via Sanger sequencing in 729 subjects. Genotypic and allelic frequencies were estimated, and genetic modeling was used to investigate genetic associations of the identified variants with lipid profile, body mass index (BMI), and risk of coronary heart disease (CHD). A total of 16 variants were identified, including 2 InDels, 2 novel SNPs, and 12 known SNPs. The most common variants observed among the population were rs293, rs274, rs295, and rs294. The rs293 “A” insertion showed a significant positive correlation with elevated LDL levels, while rs295 was significantly associated with increased BMI. The rs274 and rs294 variants showed a protective effect of the minor allele with decreased CHD prevalence. These findings shed light on the possible role of LPL intronic variants on metabolic disorders.
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Affiliation(s)
- Reem T. Al-Shammari
- Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait City 13060, Kuwait; (R.T.A.-S.); (S.A.B.)
- Kuwait Medical Genetic Center, Ministry of Health, Kuwait City 70051, Kuwait
| | - Ahmad E. Al-Serri
- Human Genetics Unit, Department of Pathology, Faculty of Medicine, Kuwait University, Kuwait City 46304, Kuwait;
| | - Sahar A. Barhoush
- Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait City 13060, Kuwait; (R.T.A.-S.); (S.A.B.)
| | - Suzanne A. Al-Bustan
- Department of Biological Sciences, Faculty of Science, Kuwait University, Kuwait City 13060, Kuwait; (R.T.A.-S.); (S.A.B.)
- Correspondence: ; Tel.: +965-2498-7130 (ext. 7863)
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Wu SA, Kersten S, Qi L. Lipoprotein Lipase and Its Regulators: An Unfolding Story. Trends Endocrinol Metab 2021; 32:48-61. [PMID: 33277156 PMCID: PMC8627828 DOI: 10.1016/j.tem.2020.11.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 02/07/2023]
Abstract
Lipoprotein lipase (LPL) is one of the most important factors in systemic lipid partitioning and metabolism. It mediates intravascular hydrolysis of triglycerides packed in lipoproteins such as chylomicrons and very-low-density lipoprotein (VLDL). Since its initial discovery in the 1940s, its biology and pathophysiological significance have been well characterized. Nonetheless, several studies in the past decade, with recent delineation of LPL crystal structure and the discovery of several new regulators such as angiopoietin-like proteins (ANGPTLs), glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPIHBP1), lipase maturation factor 1 (LMF1) and Sel-1 suppressor of Lin-12-like 1 (SEL1L), have completely transformed our understanding of LPL biology.
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Affiliation(s)
- Shuangcheng Alivia Wu
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI48105, USA.
| | - Sander Kersten
- Nutrition Metabolism and Genomics group, Wageningen University, Wageningen, The Netherlands
| | - Ling Qi
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI48105, USA; Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48105, USA.
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3
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Radovica I, Fridmanis D, Vaivade I, Nikitina-Zake L, Klovins J. The association of common SNPs and haplotypes in CETP gene with HDL cholesterol levels in Latvian population. PLoS One 2013; 8:e64191. [PMID: 23675527 PMCID: PMC3652817 DOI: 10.1371/journal.pone.0064191] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 04/12/2013] [Indexed: 02/07/2023] Open
Abstract
The heritability of high-density lipoprotein cholesterol (HDL-C) level is estimated at approximately 50%. Recent genome-wide association studies have identified genes involved in regulation of high-density lipoprotein cholesterol (HDL-C) levels. The precise genetic profile determining heritability of HDL-C however are far from complete and there is substantial room for further characterization of genetic profiles influencing blood lipid levels. Here we report an association study comparing the distribution of 139 SNPs from more than 30 genes between groups that represent extreme ends of HDL-C distribution. We genotyped 704 individuals that were selected from Genome Database of Latvian Population. 10 SNPs from CETP gene showed convincing association with low HDL-C levels (rs1800775, rs3764261, rs173539, rs9939224, rs711752, rs708272, rs7203984, rs7205804, rs11076175 and rs9929488) while 34 SNPs from 10 genes were nominally associated (p<0.05) with HDL-C levels. We have also identified haplotypes from CETP with distinct effects on determination of HDL-C levels. Our conclusion: So far the SNPs in CETP gene are identified as the most common genetic factor influencing HDL-C levels in the representative sample from Latvian population.
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Affiliation(s)
- Ilze Radovica
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | | | - Iveta Vaivade
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | | | - Janis Klovins
- Latvian Biomedical Research and Study Centre, Riga, Latvia
- * E-mail:
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Young SG, Davies BSJ, Voss CV, Gin P, Weinstein MM, Tontonoz P, Reue K, Bensadoun A, Fong LG, Beigneux AP. GPIHBP1, an endothelial cell transporter for lipoprotein lipase. J Lipid Res 2011; 52:1869-84. [PMID: 21844202 DOI: 10.1194/jlr.r018689] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Interest in lipolysis and the metabolism of triglyceride-rich lipoproteins was recently reignited by the discovery of severe hypertriglyceridemia (chylomicronemia) in glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1)-deficient mice. GPIHBP1 is expressed exclusively in capillary endothelial cells and binds lipoprotein lipase (LPL) avidly. These findings prompted speculation that GPIHBP1 serves as a binding site for LPL in the capillary lumen, creating "a platform for lipolysis." More recent studies have identified a second and more intriguing role for GPIHBP1-picking up LPL in the subendothelial spaces and transporting it across endothelial cells to the capillary lumen. Here, we review the studies that revealed that GPIHBP1 is the LPL transporter and discuss which amino acid sequences are required for GPIHBP1-LPL interactions. We also discuss the human genetics of LPL transport, focusing on cases of chylomicronemia caused by GPIHBP1 mutations that abolish GPIHBP1's ability to bind LPL, and LPL mutations that prevent LPL binding to GPIHBP1.
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Affiliation(s)
- Stephen G Young
- Department of Medicine, University of California, Los Angeles, CA 90095, USA.
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5
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Mutations in lipoprotein lipase that block binding to the endothelial cell transporter GPIHBP1. Proc Natl Acad Sci U S A 2011; 108:7980-4. [PMID: 21518912 DOI: 10.1073/pnas.1100992108] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
GPIHBP1, a glycosylphosphatidylinositol-anchored protein of capillary endothelial cells, shuttles lipoprotein lipase (LPL) from subendothelial spaces to the capillary lumen. An absence of GPIHBP1 prevents the entry of LPL into capillaries, blocking LPL-mediated triglyceride hydrolysis and leading to markedly elevated triglyceride levels in the plasma (i.e., chylomicronemia). Earlier studies have established that chylomicronemia can be caused by LPL mutations that interfere with catalytic activity. We hypothesized that some cases of chylomicronemia might be caused by LPL mutations that interfere with LPL's ability to bind to GPIHBP1. Any such mutation would provide insights into LPL sequences required for GPIHBP1 binding. Here, we report that two LPL missense mutations initially identified in patients with chylomicronemia, C418Y and E421K, abolish LPL's ability to bind to GPIHBP1 without interfering with LPL catalytic activity or binding to heparin. Both mutations abolish LPL transport across endothelial cells by GPIHBP1. These findings suggest that sequences downstream from LPL's principal heparin-binding domain (amino acids 403-407) are important for GPIHBP1 binding. In support of this idea, a chicken LPL (cLPL)-specific monoclonal antibody, xCAL 1-11 (epitope, cLPL amino acids 416-435), blocks cLPL binding to GPIHBP1 but not to heparin. Also, changing cLPL residues 421 to 425, 426 to 430, and 431 to 435 to alanine blocks cLPL binding to GPIHBP1 without inhibiting catalytic activity. Together, these data define a mechanism by which LPL mutations could elicit disease and provide insights into LPL sequences required for binding to GPIHBP1.
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José Ibáñez A, Peinado-Onsurbe J, Sánchez E, Cerdá-Reverter JM, Prat F. Lipoprotein lipase (LPL) is highly expressed and active in the ovary of European sea bass (Dicentrarchus labrax L.), during gonadal development. Comp Biochem Physiol A Mol Integr Physiol 2008; 150:347-54. [DOI: 10.1016/j.cbpa.2008.04.598] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 04/15/2008] [Accepted: 04/15/2008] [Indexed: 10/22/2022]
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Lindberg A, Olivecrona G. Lipoprotein lipase from rainbow trout differs in several respects from the enzyme in mammals. Gene 2002; 292:213-23. [PMID: 12119116 DOI: 10.1016/s0378-1119(02)00680-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previously we found lipase activity with characteristics similar to lipoprotein lipase (LPL) in tissues from rainbow trout [Biochim. Biophys. Acta 1255 (1995) 205], whereas no equivalent to the related hepatic lipase could be found. An equivalent to apolipoprotein CII was also identified and characterized [Gene 254 (2000) 189]. We present here the full nucleotide sequence for LPL from rainbow trout (Oncorhynchus mykiss) and have investigated some properties of the enzyme. In contrast to what has been found in mammals, LPL mRNA was expressed in livers of adult trout. This indicates that trout LPL carries out functions that hepatic lipase has evolved to take over in mammals. Trout LPL was unstable at 37 degrees C compared with bovine and human LPL. Two sequence differences that may relate to the instability are that trout LPL lacks the disulfide bridge in the C-terminal domain and lacks Pro(258). This residue is conserved in LPL from all mammals and has been shown to be critical for enzyme stability at 37 degrees C. On chromatography on heparin-Sepharose trout and chicken LPL eluted at higher salt concentration than bovine (or other mammalian) LPL. The C-terminal end of LPL has been implied in heparin binding and the higher heparin affinity of the trout and chicken enzymes may be because they have 17 and 15 extra amino acid residues at the C-terminal end, of which three residues are positively charged.
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Affiliation(s)
- Anna Lindberg
- Department of Medical Biosciences, Umeå University, SE-90187 Umeå, Sweden
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Keiper T, Schneider JG, Dugi KA. Novel site in lipoprotein lipase (LPL415–438) essential for substrate interaction and dimer stability. J Lipid Res 2001. [DOI: 10.1016/s0022-2275(20)31567-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Hoffmann MM, Jacob S, Luft D, Schmülling RM, Rett K, März W, Häring HU, Matthaei S. Type I hyperlipoproteinemia due to a novel loss of function mutation of lipoprotein lipase, Cys(239)-->Trp, associated with recurrent severe pancreatitis. J Clin Endocrinol Metab 2000; 85:4795-8. [PMID: 11134145 DOI: 10.1210/jcem.85.12.7069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Lipoprotein lipase (LPL) is the major enzyme responsible for the hydrolysis of triglyceride-rich lipoproteins in plasma. The purpose of this study was to examine the molecular pathogenesis of type I hyperlipoproteinemia in a patient suffering from recurrent severe pancreatitis. Apolipoprotein (apo) CII concentration was normal as well as apo CII-activated LPL in an in vitro assay. In postheparin plasma neither LPL mass nor activity was detectable, whereas hepatic lipase activity was normal. Direct sequencing of all 10 exons of the LPL gene revealed that the patient was homozygous for a hitherto unknown mutation in exon 6, Cys(239)-->Trp. The mutation prevents the formation of the second disulfide bridge of LPL, which is an essential part of the lid covering the catalytic center. Consequently, misfolded LPL is rapidly degraded within the cells, causing the absence of LPL immunoreactive protein in the plasma of this patient. In conclusion, we have identified a novel loss of function mutation in the LPL gene (Cys(239)-->Trp) of a patient with type I hyperlipoproteinemia suffering from severe recurrent pancreatitis. After initiation of heparin therapy (10,000 U/day sc), the patient experienced no more episodes of pancreatitis, although heparin therapy did not affect serum triglyceride levels.
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Affiliation(s)
- M M Hoffmann
- Department of Medicine IV, University of Tübingen, 72076 Tübingen, Germany
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Buscà R, Martínez M, Vilella E, Peinado J, Gelpi JL, Deeb S, Auwerx J, Reina M, Vilaró S. The carboxy-terminal region of human lipoprotein lipase is necessary for its exit from the endoplasmic reticulum. J Lipid Res 1998. [DOI: 10.1016/s0022-2275(20)32569-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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11
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Thorn JA, Needham EW, Mattu RK, Stocks J, Galton DJ. The Ser447–Ter mutation of the lipoprotein lipase gene relates to variability of serum lipid and lipoprotein levels in monozygotic twins. J Lipid Res 1998. [DOI: 10.1016/s0022-2275(20)33904-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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12
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Brumlik MJ, van der Goot FG, Wong KR, Buckley JT. The disulfide bond in the Aeromonas hydrophila lipase/acyltransferase stabilizes the structure but is not required for secretion or activity. J Bacteriol 1997; 179:3116-21. [PMID: 9150203 PMCID: PMC179086 DOI: 10.1128/jb.179.10.3116-3121.1997] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Vibrio and Aeromonas spp. secrete an unusual 35-kDa lipase that shares several properties with mammalian lecithin-cholesterol acyltransferase. The Aeromonas hydrophila lipase contains two cysteine residues that form an intramolecular disulfide bridge. Here we show that changing either of the cysteines to serine does not reduce enzymatic activity, indicating that the disulfide bond is not required for correct folding. However, when either of the cysteines is replaced, the enzyme is more readily denatured by urea and more sensitive to degradation by trypsin than is the wild-type enzyme, evidence that the bridge has an important role in stabilizing the protein's structure. The two mutant proteins with serine-for-cysteine replacements were secreted by Aeromonas salmonicida containing the cloned genes, although the levels of both in the culture supernatants were lower than the level of the wild-type enzyme. When the general secretory pathway was blocked with carbonyl cyanide chlorophenylhydrazone, the cell-associated pools of the mutant enzymes appeared to be degraded, whereas the wild-type pool remained stable. We conclude that reduced extracellular levels of the mutant proteins are the result of their increased sensitivities to proteases encountered inside the cell during export.
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Affiliation(s)
- M J Brumlik
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
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Salinelli S, Lo JY, Mims MP, Zsigmond E, Smith LC, Chan L. Structure-function relationship of lipoprotein lipase-mediated enhancement of very low density lipoprotein binding and catabolism by the low density lipoprotein receptor. Functional importance of a properly folded surface loop covering the catalytic center. J Biol Chem 1996; 271:21906-13. [PMID: 8702993 DOI: 10.1074/jbc.271.36.21906] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We examined the structure-function relationship of human lipoprotein lipase (hLPL) in its ability to enhance the binding and catabolism of very low density lipoproteins (VLDL) in COS cells. Untransfected COS cells did not bind to or catabolize normal VLDL. Expression of wild-type hLPL by transient transfection enhanced binding, uptake, and degradation of the VLDL (a property of LPL that we call bridge function). Heparin pretreatment and a monoclonal antibody ID7 that blocks LDL receptor-binding domain of apoE both inhibited binding, and apoE2/E2 VLDL from a Type III hyperlipidemic subject did not bind. However, LDL did not reduce 125I-VLDL binding to the hLPL-expressing cells, whereas rabbit beta-VLDL was an effective competitor. By contrast, LDL reduced uptake and degradation of 125I-VLDL to the same extent as excess unlabeled VLDL or beta-VLDL. These data suggest that binding occurs by direct interaction of VLDL with LPL but the subsequent catabolism of the VLDL is mediated by the LDL receptor. Mutant hLPLs that were catalytically inactive, S132A, S132D, as well as the partially active mutant, S251T, and S172G, gave normal enhancement of VLDL binding and catabolism, whereas the partially active mutant S172D had markedly impaired capacity for the process; thus, there is no correlation between bridge function and lipolytic activity. A naturally occurring genetic variant hLPL, S447-->Ter, has normal bridge function. The catalytic center of LPL is covered by a 21-amino acid loop that must be repositioned before a lipid substrate can gain access to the active site for catalysis. We studied three hLPL loop mutants (LPL-cH, an enzymatically active mutant with the loop replaced by a hepatic lipase loop; LPL-cP, an enzymatically inactive mutant with the loop replaced by a pancreatic lipase loop; and C216S/C239S, an enzymatically inactive mutant with the pair of Cys residues delimiting the loop substituted by Ser residues) and a control double Cys mutant, C418S/C438S. Two of the loop mutants (LPL-cH and LPL-cP) and the control double Cys mutant C418S/C438S gave normal enhancement of VLDL binding and catabolism, whereas the third loop mutant, C216S/C239S, was completely inactive. We conclude that although catalytic activity and the actual primary sequence of the loop of LPL are relatively unimportant (wild-type LPL loop and pancreatic lipase loops have little sequence similarity), the intact folding of the loop, flanked by disulfide bonds, must be maintained for LPL to express its bridge function.
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Affiliation(s)
- S Salinelli
- Department of Medicine and Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Potenz R, Lo JY, Zsigmond E, Smith LC, Chan L. Human lipoprotein lipase: production in vitro, purification, and generation of polyclonal antibody. Methods Enzymol 1996; 263:319-26. [PMID: 8749018 DOI: 10.1016/s0076-6879(96)63023-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- R Potenz
- Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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