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Normalization of lipoprotein profile during pregnancy in LCAT deficiency
Abstracts / Atherosclerosis 252 (2016) e1ee196
e117
tiveaux 2, K. Ouguerram 1, S. Billon-Crossouard 1, E. M. Croyal 1, M. Che court 3, M. Krempf 3. 1 INRA UMR 1280, Mass Spectrometry Area, Nobe Nantes, France; 2 CRNH, Mass Spectrometry Area, Nantes, France; 3 G and R Laennec Hospital, Endocrinology, Nantes, France
increased lipoprotein-production induced by, e.g., hormones. The findings support a role of ApoO as a likely negative regulator of mitochondrial function that apparently is linked to the onset of NAFLD.
Objectives: Apolipoprotein M (apoM) is a protein mainly associated with HDL and also with LDL and TRL. ApoM is a chaperone of sphingosine-1phosphate (S1P) and could play a role in atherosclerosis prevention. We aimed to study apoM metabolism with stable isotope kinetic study in healthy subjects.
EAS16-0568, LIPOPROTEINS AND LIPID METABOLISM: LIPOPROTEIN METABOLISM. NORMALIZATION OF LIPOPROTEIN PROFILE DURING PREGNANCY IN LCAT DEFICIENCY
Methods: Ten normolipidemic male subjects (Age 37±15 years; BMI 24.4±5.2 kg/m2) received a primed infusion of [2H3]-Leucine (10 mM/kg/ h) for 14h. Enrichment measurements, apos and S1P quantification from hourly plasma samples were performed by LC-MS/MS. PCSK9 was assayed by ELISA. The fractional catabolic rates (FCR) and production rates (PR) of apoM and apoA-I were calculated using mono compartmental models and a multiple compartmental for LDL-apoB100. Results are mean ± SEM and correlations were achieved using the Spearman test. Results: ApoM was mainly recovered in HDL (1.59±0.21 mg/dl) compared to LDL (0.10±0.03 mg/dl) and strongly associated with S1P concentrations (r¼0.742, p¼0.0184 in HDL and r¼0.930, p¼0.0003 in LDL). FCR and PR of apoM-HDL were 0.386±0.073 pool/day and 0.313±0.078 mg/kg/day, respectively, and were correlated with both FCR and PR of apoAI-HDL (r>0.745, p<0.02) and also with HDL-S1P concentrations (r>0.709, p<0.03). FCR and PR of apoM-LDL were 0.175±0.017 pool/day and 0.007±0.001 mg/kg/day and were correlated with apoB100-LDL FCR (r¼0.799, p<0.0071). We did not observe any significant correlation between apoM plasma concentrations (2.91±0.32 mg/gl) and LDL-ApoB100 FCR. PCSK9 and apoM plasma concentrations were significantly correlated (r¼0.703, p¼0.0269). Conclusions: Our kinetic analyses indicate that kinetic parameters of apoM are strongly associated with HDL or LDL turnovers and S1P concentrations.
EAS16-0881, LIPOPROTEINS AND LIPID METABOLISM: LIPOPROTEIN METABOLISM. HEPATOSTEATOSIS AND ESTROGEN INCREASE APOLIPOPROTEIN O PRODUCTION IN THE CHICKEN B. Schmidinger, A. Weijler, W.J. Schneider, M. Hermann. Medical University of Vienna, Department of Medical Biochemistry, Vienna, Austria Objectives: Apolipoprotein O (ApoO) is a recently discovered plasma apolipoprotein that may also play a role in the mitochondrial inner membrane. Possibly due to this complexity, its physiological functions have not been elucidated yet. Methods: To gain insight from a different experimental system, we have investigated the regulation of ApoO levels in an alternative, well-suited model for studies on lipid metabolism, the chicken. qPCR using specific primer pairs and Western blot analysis with our rabbit antisera demonstrated ApoO in the liver of chickens fed a control or a fat-enriched diet, as well as in 2 chicken hepatoma cell lines, LMH and LMH-2A, under conditions of lipid loading by oleic acid treatment. Results: Induced triglyceride accumulation in both the liver and the hepatic cells was associated with significant increases in ApoO mRNA and protein levels. Furthermore, upon treatment for 24 h with estrogen of the estrogen receptor-expressing LMH-2A cells, quantitative analysis of ApoO transcripts and Western blotting revealed significant increases of ApoO expression. Finally, upon estrogen administration to roosters causing hyperlipidemia, higher hepatic levels of both ApoO transcript and protein were observed. Conclusions: Based on these data, we propose that hepatic biosynthesis of ApoO is tightly linked not only to diet-induced hepatosteatosis, but also to
A. Ossoli 1, E. Hanna 2, S. Simonelli 1, R. Mullan 3, S. Chamney 4, J. degli Chestnutt 2, F. Stewart 5, G. Franceschini 6, L. Calabresi 1. 1 Universita Studi di Milano, Pharmacological and Biomolecular Sciences, Milano, Italy; 2 Antrim Hospital- Northern Health and Social Care Trust, Biochemistry, Antrim, United Kingdom; 3 Antrim Hospital- Northern Health and Social Care Trust, Renal Unit, Antrim, United Kingdom; 4 Royal Victoria Hospital, Ophthalmology, Belfast, United Kingdom; 5 Belfast City Hospital- Belfast Health and Social Care Trust, Genetics, Belfast, United Kingdom; 6 degli Studi di Milano, Section of Chemical and Biomolecular Universita Sciences - DeFENS, Milano, Italy Objectives: Subjects with genetic LCAT deficiency show marked alterations in plasmatic lipoprotein profile; among changes, the appearance of an abnormal lipoprotein, Lipoprotein X (LpX), seems to be involved in glomerulosclerosis development. Here we describe the normalization of lipoprotein profile during pregnancy in LCAT deficient woman. Methods: A 29-year-old multigravida woman compound heterozygote with two LCAT gene mutations initially presented with bilateral corneal clouding, greatly reduced HDL-C and proteinuria (113.7 mg/mmol creatinine). Fasting blood was collected at 22 weeks gestation and 14 weeks post-partum to assess possible changes during pregnancy. Results: LCAT activity, cholesterol esterification rate, both undetectable, unesterified/total cholesterol ratio, and LCAT mass remained identical during pregnancy and post-partum. Total cholesterol, HDL-C, phospholipids, apoA-I and apoB increased during pregnancy. Her pregnancy was complicated by an hypertriglyceridaemia (613 mg/dL), which was more severe than is seen with normal physiological changes of pregnancy. Surprisingly, the level of proteinuria significantly improved during pregnancy (13.9 mg/mmol creatinine), despite stopping the ACE inhibitor, but it worsened post partum again (131.6 mg/mmol creatinine). Lipoprotein analysis by FPLC and agarose gel electrophoresis of plasma revealed the presence LpX only in post-partum, whereas this abnormal particle disappeared during pregnancy. Conclusions: LpX is an abnormal lipoprotein particle proposed as a major causative factor in the development of renal disease in carriers of LCAT deficiency. Its disappearance during pregnancy improves proteinuria in this woman and it is probably due to the severe increase of TG that are used, together with phospholipids, to produce VLDL.
EAS16-0439, LIPOPROTEINS AND LIPID METABOLISM: LIPOPROTEIN METABOLISM. CHARGED RESIDUES IN THE C-TERMINAL DOMAIN OF APOLIPOPROTEIN A-I MEDIATE OLIGOMERIZATION P. Weers, V. Narayanaswami, L. Fuentes, J. Horn, R. Ellena, K. Cong. California State University Long Beach, Chemistry and Biochemistry, Long Beach, USA Objectives: Apolipoprotein A-I (apoA-I) is an anti-atherogenic protein circulating in plasma, and is the major protein component of HDL. The Nterminal domain is made of a bundle of amphipathic a-helices, while the structure of the C-terminal (CT) domain is less defined. Lipid-free apoA-I exists as a heterogeneous population of oligomers, and the CT domain may be responsible for self-association. The objective of this study is to identify the residues in apoA-I responsible for oligomerization.
e117
tiveaux 2, K. Ouguerram 1, S. Billon-Crossouard 1, E. M. Croyal 1, M. Che court 3, M. Krempf 3. 1 INRA UMR 1280, Mass Spectrometry Area, Nobe Nantes, France; 2 CRNH, Mass Spectrometry Area, Nantes, France; 3 G and R Laennec Hospital, Endocrinology, Nantes, France
increased lipoprotein-production induced by, e.g., hormones. The findings support a role of ApoO as a likely negative regulator of mitochondrial function that apparently is linked to the onset of NAFLD.
Objectives: Apolipoprotein M (apoM) is a protein mainly associated with HDL and also with LDL and TRL. ApoM is a chaperone of sphingosine-1phosphate (S1P) and could play a role in atherosclerosis prevention. We aimed to study apoM metabolism with stable isotope kinetic study in healthy subjects.
EAS16-0568, LIPOPROTEINS AND LIPID METABOLISM: LIPOPROTEIN METABOLISM. NORMALIZATION OF LIPOPROTEIN PROFILE DURING PREGNANCY IN LCAT DEFICIENCY
Methods: Ten normolipidemic male subjects (Age 37±15 years; BMI 24.4±5.2 kg/m2) received a primed infusion of [2H3]-Leucine (10 mM/kg/ h) for 14h. Enrichment measurements, apos and S1P quantification from hourly plasma samples were performed by LC-MS/MS. PCSK9 was assayed by ELISA. The fractional catabolic rates (FCR) and production rates (PR) of apoM and apoA-I were calculated using mono compartmental models and a multiple compartmental for LDL-apoB100. Results are mean ± SEM and correlations were achieved using the Spearman test. Results: ApoM was mainly recovered in HDL (1.59±0.21 mg/dl) compared to LDL (0.10±0.03 mg/dl) and strongly associated with S1P concentrations (r¼0.742, p¼0.0184 in HDL and r¼0.930, p¼0.0003 in LDL). FCR and PR of apoM-HDL were 0.386±0.073 pool/day and 0.313±0.078 mg/kg/day, respectively, and were correlated with both FCR and PR of apoAI-HDL (r>0.745, p<0.02) and also with HDL-S1P concentrations (r>0.709, p<0.03). FCR and PR of apoM-LDL were 0.175±0.017 pool/day and 0.007±0.001 mg/kg/day and were correlated with apoB100-LDL FCR (r¼0.799, p<0.0071). We did not observe any significant correlation between apoM plasma concentrations (2.91±0.32 mg/gl) and LDL-ApoB100 FCR. PCSK9 and apoM plasma concentrations were significantly correlated (r¼0.703, p¼0.0269). Conclusions: Our kinetic analyses indicate that kinetic parameters of apoM are strongly associated with HDL or LDL turnovers and S1P concentrations.
EAS16-0881, LIPOPROTEINS AND LIPID METABOLISM: LIPOPROTEIN METABOLISM. HEPATOSTEATOSIS AND ESTROGEN INCREASE APOLIPOPROTEIN O PRODUCTION IN THE CHICKEN B. Schmidinger, A. Weijler, W.J. Schneider, M. Hermann. Medical University of Vienna, Department of Medical Biochemistry, Vienna, Austria Objectives: Apolipoprotein O (ApoO) is a recently discovered plasma apolipoprotein that may also play a role in the mitochondrial inner membrane. Possibly due to this complexity, its physiological functions have not been elucidated yet. Methods: To gain insight from a different experimental system, we have investigated the regulation of ApoO levels in an alternative, well-suited model for studies on lipid metabolism, the chicken. qPCR using specific primer pairs and Western blot analysis with our rabbit antisera demonstrated ApoO in the liver of chickens fed a control or a fat-enriched diet, as well as in 2 chicken hepatoma cell lines, LMH and LMH-2A, under conditions of lipid loading by oleic acid treatment. Results: Induced triglyceride accumulation in both the liver and the hepatic cells was associated with significant increases in ApoO mRNA and protein levels. Furthermore, upon treatment for 24 h with estrogen of the estrogen receptor-expressing LMH-2A cells, quantitative analysis of ApoO transcripts and Western blotting revealed significant increases of ApoO expression. Finally, upon estrogen administration to roosters causing hyperlipidemia, higher hepatic levels of both ApoO transcript and protein were observed. Conclusions: Based on these data, we propose that hepatic biosynthesis of ApoO is tightly linked not only to diet-induced hepatosteatosis, but also to
A. Ossoli 1, E. Hanna 2, S. Simonelli 1, R. Mullan 3, S. Chamney 4, J. degli Chestnutt 2, F. Stewart 5, G. Franceschini 6, L. Calabresi 1. 1 Universita Studi di Milano, Pharmacological and Biomolecular Sciences, Milano, Italy; 2 Antrim Hospital- Northern Health and Social Care Trust, Biochemistry, Antrim, United Kingdom; 3 Antrim Hospital- Northern Health and Social Care Trust, Renal Unit, Antrim, United Kingdom; 4 Royal Victoria Hospital, Ophthalmology, Belfast, United Kingdom; 5 Belfast City Hospital- Belfast Health and Social Care Trust, Genetics, Belfast, United Kingdom; 6 degli Studi di Milano, Section of Chemical and Biomolecular Universita Sciences - DeFENS, Milano, Italy Objectives: Subjects with genetic LCAT deficiency show marked alterations in plasmatic lipoprotein profile; among changes, the appearance of an abnormal lipoprotein, Lipoprotein X (LpX), seems to be involved in glomerulosclerosis development. Here we describe the normalization of lipoprotein profile during pregnancy in LCAT deficient woman. Methods: A 29-year-old multigravida woman compound heterozygote with two LCAT gene mutations initially presented with bilateral corneal clouding, greatly reduced HDL-C and proteinuria (113.7 mg/mmol creatinine). Fasting blood was collected at 22 weeks gestation and 14 weeks post-partum to assess possible changes during pregnancy. Results: LCAT activity, cholesterol esterification rate, both undetectable, unesterified/total cholesterol ratio, and LCAT mass remained identical during pregnancy and post-partum. Total cholesterol, HDL-C, phospholipids, apoA-I and apoB increased during pregnancy. Her pregnancy was complicated by an hypertriglyceridaemia (613 mg/dL), which was more severe than is seen with normal physiological changes of pregnancy. Surprisingly, the level of proteinuria significantly improved during pregnancy (13.9 mg/mmol creatinine), despite stopping the ACE inhibitor, but it worsened post partum again (131.6 mg/mmol creatinine). Lipoprotein analysis by FPLC and agarose gel electrophoresis of plasma revealed the presence LpX only in post-partum, whereas this abnormal particle disappeared during pregnancy. Conclusions: LpX is an abnormal lipoprotein particle proposed as a major causative factor in the development of renal disease in carriers of LCAT deficiency. Its disappearance during pregnancy improves proteinuria in this woman and it is probably due to the severe increase of TG that are used, together with phospholipids, to produce VLDL.
EAS16-0439, LIPOPROTEINS AND LIPID METABOLISM: LIPOPROTEIN METABOLISM. CHARGED RESIDUES IN THE C-TERMINAL DOMAIN OF APOLIPOPROTEIN A-I MEDIATE OLIGOMERIZATION P. Weers, V. Narayanaswami, L. Fuentes, J. Horn, R. Ellena, K. Cong. California State University Long Beach, Chemistry and Biochemistry, Long Beach, USA Objectives: Apolipoprotein A-I (apoA-I) is an anti-atherogenic protein circulating in plasma, and is the major protein component of HDL. The Nterminal domain is made of a bundle of amphipathic a-helices, while the structure of the C-terminal (CT) domain is less defined. Lipid-free apoA-I exists as a heterogeneous population of oligomers, and the CT domain may be responsible for self-association. The objective of this study is to identify the residues in apoA-I responsible for oligomerization.