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Al-Mass A, Poursharifi P, Peyot ML, Lussier R, Chenier I, Leung YH, Ghosh A, Oppong A, Possik E, Mugabo Y, Ahmad R, Sladek R, Murthy Madiraju S, Al-Mulla F, Prentki M. Hepatic glycerol shunt and glycerol-3-phosphate phosphatase control liver metabolism and glucodetoxification under hyperglycemia. Mol Metab 2022; 66:101609. [PMID: 36198384 PMCID: PMC9579801 DOI: 10.1016/j.molmet.2022.101609] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 09/30/2022] [Indexed: 12/29/2022] Open
Abstract
OBJECTIVE Glycerol-3-phosphate (Gro3P) phosphatase (G3PP) hydrolyzes Gro3P to glycerol that exits the cell, thereby operating a "glycerol shunt", a metabolic pathway that we identified recently in mammalian cells. We have investigated the role of G3PP and the glycerol shunt in the regulation of glucose metabolism and lipogenesis in mouse liver. METHODS We generated hepatocyte-specific G3PP-KO mice (LKO), by injecting AAV8-TBG-iCre to male G3PPfl/fl mice. Controls received AAV8-TBG-eGFP. Both groups were fed chow diet for 10 weeks. Hyperglycemia (16-20 mM) was induced by glucose infusion for 55 h. Hepatocytes were isolated from normoglycemic mice for ex vivo studies and targeted metabolomics were measured in mice liver after glucose infusion. RESULTS LKO mice showed no change in body weight, food intake, fed and fasted glycemia but had increased fed plasma triglycerides. Hepatic glucose production from glycerol was increased in fasted LKO mice. LKO mouse hepatocytes displayed reduced glycerol production, elevated triglyceride and lactate production at high glucose concentration. Hyperglycemia in LKO mice led to increased liver weight and accumulation of triglycerides, glycogen and cholesterol together with elevated levels of Gro3P, dihydroxyacetone phosphate, acetyl-CoA and some Krebs cycle intermediates in liver. Hyperglycemic LKO mouse liver showed elevated expression of proinflammatory cytokines and M1-macrophage markers accompanied by increased plasma triglycerides, LDL/VLDL, urea and uric acid and myocardial triglycerides. CONCLUSIONS The glycerol shunt orchestrated by G3PP acts as a glucose excess detoxification pathway in hepatocytes by preventing metabolic disturbances that contribute to enhanced liver fat, glycogen storage, inflammation and lipid build-up in the heart. We propose G3PP as a novel therapeutic target for hepatic disorders linked to nutrient excess.
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Affiliation(s)
- Anfal Al-Mass
- Department of Medicine, McGill University, Montréal, QC, Canada,Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Pegah Poursharifi
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Marie-Line Peyot
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Roxane Lussier
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Isabelle Chenier
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Yat Hei Leung
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Anindya Ghosh
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Abel Oppong
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Elite Possik
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Yves Mugabo
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada
| | - Rasheed Ahmad
- Departments of Immunology, Microbiology, Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15462, Kuwait
| | - Robert Sladek
- Department of Medicine, McGill University, Montréal, QC, Canada
| | - S.R. Murthy Madiraju
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada,Corresponding author. CRCHUM, Room R08-418, Tour Viger, 900 rue Saint Denis, Montreal, QC H2X 0A9, Canada.
| | - Fahd Al-Mulla
- Departments of Immunology, Microbiology, Genetics and Bioinformatics, Dasman Diabetes Institute, Dasman 15462, Kuwait
| | - Marc Prentki
- Departments of Nutrition, Biochemistry and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center and CRCHUM, Montréal, QC, Canada,Corresponding author. Biochemistry and Molecular Medicine, Université de Montréal CRCHUM, Room R08-412, Tour Viger, 900 rue Saint Denis Montreal, QC H2X 0A9, Canada.
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Zhao S, Poursharifi P, Mugabo Y, Levens EJ, Vivot K, Attane C, Iglesias J, Peyot ML, Joly E, Madiraju SM, Prentki M. α/β-Hydrolase domain-6 and saturated long chain monoacylglycerol regulate insulin secretion promoted by both fuel and non-fuel stimuli. Mol Metab 2015; 4:940-50. [PMID: 26909310 PMCID: PMC4731734 DOI: 10.1016/j.molmet.2015.09.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 09/21/2015] [Accepted: 09/28/2015] [Indexed: 01/15/2023] Open
Abstract
Objective α/β-Hydrolase domain-6 (ABHD6) is a newly identified monoacylglycerol (MAG) lipase. We recently reported that it negatively regulates glucose stimulated insulin secretion (GSIS) in the β cells by hydrolyzing lipolysis-derived MAG that acts as a metabolic coupling factor and signaling molecule via exocytotic regulator Munc13-1. Whether ABHD6 and MAG play a role in response to all classes of insulin secretagogues, in particular various fuel and non-fuel stimuli, is unknown. Methods Insulin secretion in response to various classes of secretagogues, exogenous MAG and pharmacological agents was measured in islets of mice deficient in ABHD6 specifically in the β cell (BKO). Islet perifusion experiments and determinations of glucose and fatty acid metabolism, cytosolic Ca2+ and MAG species levels were carried out. Results Deletion of ABHD6 potentiated insulin secretion in response to the fuels glutamine plus leucine and α-ketoisocaproate and to the non-fuel stimuli glucagon-like peptide 1, carbamylcholine and elevated KCl. Fatty acids amplified GSIS in control and BKO mice to the same extent. Exogenous 1-MAG amplified insulin secretion in response to fuel and non-fuel stimuli. MAG hydrolysis activity was greatly reduced in BKO islets without changes in total diacylglycerol and triacylglycerol lipase activity. ABHD6 deletion induced insulin secretion independently from KATP channels and did not alter the glucose induced rise in intracellular Ca2+. Perifusion studies showed elevated insulin secretion during second phase of GSIS in BKO islets that was not due to altered cytosolic Ca2+ signaling or because of changes in glucose and fatty acid metabolism. Glucose increased islet saturated long chain 1-MAG species and ABHD6 deletion caused accumulation of these 1-MAG species at both low and elevated glucose. Conclusion ABHD6 regulates insulin secretion in response to fuel stimuli at large and some non-fuel stimuli by controlling long chain saturated 1-MAG levels that synergize with other signaling pathways for secretion. ABHD6 is the major monoacylglycerol (MAG) hydrolase in pancreatic β cells. 1-MAG level is elevated in islets from β cell specific ABHD6-KO mice (BKO). BKO islets show enhanced fuel and non-fuel induced insulin secretion. ABHD6 accessible 1-MAG synergizes with other signals for insulin secretion.
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Key Words
- 1-OG, 1-oleoylglycerol
- 1-PG, 1-palmitoylglycerol
- 1-SG, 1-stearoylglycerol
- ABHD6, α/β-hydrolase domain-6
- ATGL, adipose triglyceride lipase
- BKO, β cell specific ABHD6-knockout
- Carb, carbamylcholine
- Cytosolic Ca2+
- DAG, diacylglycerol
- FFA, free fatty acid
- Flox, flox/flox
- GL/FFA, glycerolipid/ free fatty acid
- GLP1, glucagon-like peptide 1
- GPCR, G-protein coupled receptor
- GSIS, glucose stimulated insulin secretion
- HSL, hormone sensitive lipase
- Insulin secretion
- KO, knockout
- Kic, α-ketoisocaproate
- MAG, monoacylglycerol
- Monoacylglycerol
- OGTT, oral glucose tolerance test
- Pancreatic islets
- ROS, reactive oxygen species
- TG, triacylglycerol
- WT, wild type
- α/β-Hydrolase domain-6
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - S.R. Murthy Madiraju
- Corresponding author. Montreal Diabetes Research Center, CRCHUM, 900 St-Denis (Viger Tower), Rm R08-414, Montreal, QC H1W 4A4, Canada. Tel.: +1 514 890 8000x23610; fax: +1 514 412 7648.
| | - Marc Prentki
- Corresponding author. Montreal Diabetes Research Center, CRCHUM, 900 St-Denis (Viger Tower), Rm R08-412, Montreal, QC H1W 4A4, Canada. Tel.: +1 514 890 8000x23642; fax: +1 514 412 7648.
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Lamontagne J, Jalbert-Arsenault É, Pepin É, Peyot ML, Ruderman NB, Nolan CJ, Joly E, Madiraju SM, Poitout V, Prentki M. Pioglitazone acutely reduces energy metabolism and insulin secretion in rats. Diabetes 2013; 62:2122-9. [PMID: 23378607 PMCID: PMC3661607 DOI: 10.2337/db12-0428] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Our objective was to determine if the insulin-sensitizing drug pioglitazone acutely reduces insulin secretion and causes metabolic deceleration in vivo independently of change in insulin sensitivity. We assessed glucose homeostasis by hyperinsulinemic-euglycemic and hyperglycemic clamp studies and energy expenditure by indirect calorimetry and biotelemetry in male Wistar and obese hyperinsulinemic Zucker diabetic fatty (ZDF) rats 45 min after a single oral dose of pioglitazone (30 mg/kg). In vivo insulin secretion during clamped hyperglycemia was reduced in both Wistar and ZDF rats after pioglitazone administration. Insulin clearance was slightly increased in Wistar but not in ZDF rats. Insulin sensitivity in Wistar rats assessed by the hyperinsulinemic-euglycemic clamp was minimally affected by pioglitazone at this early time point. Pioglitazone also reduced energy expenditure in Wistar rats without altering respiratory exchange ratio or core body temperature. Glucose-induced insulin secretion (GIIS) and oxygen consumption were reduced by pioglitazone in isolated islets and INS832/13 cells. In conclusion, pioglitazone acutely induces whole-body metabolic slowing down and reduces GIIS, the latter being largely independent of the insulin-sensitizing action of the drug. The results suggest that pioglitazone has direct metabolic deceleration effects on the β-cell that may contribute to its capacity to lower insulinemia and antidiabetic action.
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Affiliation(s)
- Julien Lamontagne
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Université de Montréal, Montreal, Quebec, Canada
- Department of Biochemistry, Université de Montréal, Montreal, Quebec, Canada
| | - Élise Jalbert-Arsenault
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Université de Montréal, Montreal, Quebec, Canada
- Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Émilie Pepin
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Université de Montréal, Montreal, Quebec, Canada
- Program of Molecular Biology, Université de Montréal, Montreal, Quebec, Canada
| | - Marie-Line Peyot
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Université de Montréal, Montreal, Quebec, Canada
| | - Neil B. Ruderman
- Departments of Medicine and Physiology and Biophysics, Boston University School of Medicine and Diabetes Unit, Section of Endocrinology, Boston University School of Medicine and Boston Medical Center, Boston, Massachusetts
| | | | - Erik Joly
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Université de Montréal, Montreal, Quebec, Canada
| | - S.R. Murthy Madiraju
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Université de Montréal, Montreal, Quebec, Canada
| | - Vincent Poitout
- Montreal Diabetes Research Center at the CRCHUM and Departments of Medicine, Biochemistry and Nutrition, Université de Montréal, Montreal, Quebec, Canada
| | - Marc Prentki
- Molecular Nutrition Unit and Montreal Diabetes Research Center at the Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM), Université de Montréal, Montreal, Quebec, Canada
- Department of Nutrition, Université de Montréal, Montreal, Quebec, Canada
- Department of Biochemistry, Université de Montréal, Montreal, Quebec, Canada
- Corresponding author: Marc Prentki,
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