Ioanna Tiniakou1, Zoi Kanaki2, Spiros Georgopoulos2, Angeliki Chroni3, Miranda Van Eck4, Panagiotis Fotakis5, Vassilis I Zannis6, Dimitris Kardassis7. 1. Department of Biochemistry, University of Crete Medical School, 71003 Heraklion, Crete, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Nikolaou Plastira 100, 70013 Heraklion, Crete, Greece. 2. Biomedical Research Foundation, Academy of Athens, Soranou Ephessiou 4, 11527 Athens, Greece. 3. Institute of Biosciences and Applications, National Center for Scientific Research "Demokritos", Patriarchou Grigoriou & Neapoleos 27, 15310, Athens, Greece. 4. Division of Biopharmaceutics, Leiden Academic Centre for Drug Research, Einsteinweg 55, 2333 Leiden, the Netherlands. 5. Department of Biochemistry, University of Crete Medical School, 71003 Heraklion, Crete, Greece; Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston MA 02118, USA. 6. Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston MA 02118, USA. 7. Department of Biochemistry, University of Crete Medical School, 71003 Heraklion, Crete, Greece; Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology - Hellas, Nikolaou Plastira 100, 70013 Heraklion, Crete, Greece. Electronic address: kardasis@imbb.forth.gr.
Abstract
OBJECTIVE: Mutations in human apolipoprotein A-I (apoA-I) are associated with low high-density lipoprotein (HDL) cholesterol levels and pathological conditions such as premature atherosclerosis and amyloidosis. In this study we functionally characterized two natural human apoA-I mutations, L141RPisa and L159RFIN, in vivo. METHODS: We generated transgenic mice expressing either wild-type (WT) or the two mutant forms of human apoA-I on a mouse apoA-I(-/-) background and analyzed for abnormalities in their lipid and lipoprotein profiles. HDL structure and functionality, as well as atherosclerosis development following a 14-week high-fat diet were assessed in these mice. RESULTS: The expression of either apoA-I mutant was associated with markedly reduced serum apoA-I (<10% of WT apoA-I), total and HDL-cholesterol levels (∼20% and ∼7% of WT apoA-I, respectively) and the formation of few small size HDL particles with preβ2 and α3, α4 electrophoretic mobility. HDL particles containing either of the two apoA-I mutants exhibited attenuated anti-oxidative properties as indicated by their inability to prevent low-density lipoprotein oxidation, and by decreased activities of paraoxonase-1 and platelet-activating factor acetylhydrolase. However, the apoA-I(L141R)Pisa or apoA-I(L159R)FIN-containing HDL particles demonstrated increased capacity to promote ATP-Binding Cassette Transporter A1-mediated cholesterol efflux from macrophages. Expression of apoA-I(L141R)Pisa or apoA-I(L159R)FIN mutations in mice was associated with increased diet-induced atherosclerosis compared to either WT apoA-I transgenic or apoA-I(-/-) mice. CONCLUSIONS: These findings suggest that natural apoA-I mutations L141RPisa and L159RFIN affect the biogenesis and the functionality of HDL in vivo and predispose to diet-induced atherosclerosis in the absence of any other genetic defect.
OBJECTIVE: Mutations in humanapolipoprotein A-I (apoA-I) are associated with low high-density lipoprotein (HDL) cholesterol levels and pathological conditions such as premature atherosclerosis and amyloidosis. In this study we functionally characterized two natural humanapoA-I mutations, L141RPisa and L159RFIN, in vivo. METHODS: We generated transgenic mice expressing either wild-type (WT) or the two mutant forms of humanapoA-I on a mouseapoA-I(-/-) background and analyzed for abnormalities in their lipid and lipoprotein profiles. HDL structure and functionality, as well as atherosclerosis development following a 14-week high-fat diet were assessed in these mice. RESULTS: The expression of either apoA-I mutant was associated with markedly reduced serum apoA-I (<10% of WT apoA-I), total and HDL-cholesterol levels (∼20% and ∼7% of WT apoA-I, respectively) and the formation of few small size HDL particles with preβ2 and α3, α4 electrophoretic mobility. HDL particles containing either of the two apoA-I mutants exhibited attenuated anti-oxidative properties as indicated by their inability to prevent low-density lipoprotein oxidation, and by decreased activities of paraoxonase-1 and platelet-activating factor acetylhydrolase. However, the apoA-I(L141R)Pisa or apoA-I(L159R)FIN-containing HDL particles demonstrated increased capacity to promote ATP-Binding Cassette Transporter A1-mediated cholesterol efflux from macrophages. Expression of apoA-I(L141R)Pisa or apoA-I(L159R)FIN mutations in mice was associated with increased diet-induced atherosclerosis compared to either WT apoA-I transgenic or apoA-I(-/-) mice. CONCLUSIONS: These findings suggest that natural apoA-I mutations L141RPisa and L159RFIN affect the biogenesis and the functionality of HDL in vivo and predispose to diet-induced atherosclerosis in the absence of any other genetic defect.
Authors: Sarah Pedretti; Marie-Claude Brulhart-Meynet; Fabrizio Montecucco; Sandrine Lecour; Richard W James; Miguel A Frias Journal: PLoS One Date: 2019-06-20 Impact factor: 3.240