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Croteau D, Baka T, Young S, He H, Chambers JM, Qin F, Panagia M, Pimentel DR, Balschi JA, Colucci WS, Luptak I. SGLT2 inhibitor ertugliflozin decreases elevated intracellular sodium, and improves energetics and contractile function in diabetic cardiomyopathy. Biomed Pharmacother 2023; 160:114310. [PMID: 36731341 PMCID: PMC9992115 DOI: 10.1016/j.biopha.2023.114310] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/17/2023] [Accepted: 01/26/2023] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Elevated myocardial intracellular sodium ([Na+]i) was shown to decrease mitochondrial calcium ([Ca2+]MITO) via mitochondrial sodium/calcium exchanger (NCXMITO), resulting in decreased mitochondrial ATP synthesis. The sodium-glucose co-transporter 2 inhibitor (SGLT2i) ertugliflozin (ERTU) improved energetic deficit and contractile dysfunction in a mouse model of high fat, high sucrose (HFHS) diet-induced diabetic cardiomyopathy (DCMP). As SGLT2is were shown to lower [Na+]i in isolated cardiomyocytes, we hypothesized that energetic improvement in DCMP is at least partially mediated by a decrease in abnormally elevated myocardial [Na+]i. METHODS Forty-two eight-week-old male C57BL/6J mice were fed a control or HFHS diet for six months. In the last month, a subgroup of HFHS-fed mice was treated with ERTU. At the end of the study, left ventricular contractile function and energetics were measured simultaneously in isolated beating hearts by 31P NMR (Nuclear Magnetic Resonance) spectroscopy. A subset of untreated HFHS hearts was perfused with vehicle vs. CGP 37157, an NCXMITO inhibitor. Myocardial [Na+]i was measured by 23Na NMR spectroscopy. RESULTS HFHS hearts showed diastolic dysfunction, decreased contractile reserve, and impaired energetics as reflected by decreased phosphocreatine (PCr) and PCr/ATP ratio. Myocardial [Na+]i was elevated > 2-fold in HFHS (vs. control diet). ERTU reversed the impairments in HFHS hearts to levels similar to or better than control diet and decreased myocardial [Na+]i to control levels. CGP 37157 normalized the PCr/ATP ratio in HFHS hearts. CONCLUSIONS Elevated myocardial [Na+]i contributes to mitochondrial and contractile dysfunction in DCMP. Targeting myocardial [Na+]i and/or NCXMITO may be an effective strategy in DCMP and other forms of heart disease associated with elevated myocardial [Na+]i.
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Affiliation(s)
- Dominique Croteau
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - Tomas Baka
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - Sara Young
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - Huamei He
- Physiological NMR Core Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jordan M Chambers
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - Fuzhong Qin
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - Marcello Panagia
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - David R Pimentel
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - James A Balschi
- Physiological NMR Core Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Wilson S Colucci
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA
| | - Ivan Luptak
- Myocardial Biology Unit, Boston University School of Medicine, Boston, MA, USA.
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Atkinson ST, Cale D, Pinder A, Chambers JM, Halse SA, Robson BJ. Substantial long-term loss of alpha and gamma diversity of lake invertebrates in a landscape exposed to a drying climate. Glob Chang Biol 2021; 27:6263-6279. [PMID: 34534383 DOI: 10.1111/gcb.15890] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/30/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
Many regions across the globe are shifting to more arid climates. For shallow lakes, decreasing rainfall volume and timing, changing regional wind patterns and increased evaporation rates alter water regimes so that dry periods occur more frequently and for longer. Drier conditions may affect fauna directly and indirectly through altered physicochemical conditions in lakes. Although many studies have predicted negative effects of such changes on aquatic biodiversity, empirical studies demonstrating these effects are rare. Global warming has caused severe climatic drying in southwestern Australia since the 1970s, so we aimed to determine whether lakes in this region showed impacts on lake hydroperiod, water quality, and α, β and γ diversity of lake invertebrates from 1998 to 2011. Seventeen lakes across a range of salinities were sampled biennially in spring in the Wheatbelt and Great Southern regions of Western Australia. Multivariate analyses were used to identify changes in α, β and γ diversity and examine patterns in physicochemical data. Salinity and average rainfall partially explained patterns in invertebrate richness and assemblage composition. Climatic drying was associated with significant declines in lake depth, increased frequency of dry periods, and reduced α and γ diversity (γ declined from ~300 to ~100 taxa from 1998 to 2011 in the 17 wetlands). In contrast, β diversity remained consistently high, because each lake retained a distinct fauna. Mean α diversity per-lake declined both in lakes that dried and lakes that did not dry out, but lakes which retained a greater proportion of their maximum depth retained more α diversity. Accumulated losses in α diversity caused the decline in γ diversity likely through shrinking habitat area, fewer stepping stones for dispersal and loss of specific habitat types. Biodiversity loss is thus likely from lakes in drying regions globally. Management actions will need to sustain water depth in lakes to prevent biodiversity loss.
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Affiliation(s)
- S T Atkinson
- Harry Butler Institute & Environmental & Conservation Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - D Cale
- Department of Biodiversity, Conservation and Attractions, Bentley, Western Australia, Australia
| | - A Pinder
- Department of Biodiversity, Conservation and Attractions, Bentley, Western Australia, Australia
| | - J M Chambers
- Harry Butler Institute & Environmental & Conservation Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - S A Halse
- Department of Biodiversity, Conservation and Attractions, Bentley, Western Australia, Australia
- Bennelongia Environmental Consultants, Jolimont, Western Australia, Australia
| | - Belinda J Robson
- Harry Butler Institute & Environmental & Conservation Sciences, Murdoch University, Murdoch, Western Australia, Australia
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Goodman JB, Qin F, Morgan RJ, Chambers JM, Croteau D, Siwik DA, Hobai I, Panagia M, Luptak I, Bachschmid M, Tong X, Pimentel DR, Cohen RA, Colucci WS. Redox-Resistant SERCA [Sarco(endo)plasmic Reticulum Calcium ATPase] Attenuates Oxidant-Stimulated Mitochondrial Calcium and Apoptosis in Cardiac Myocytes and Pressure Overload-Induced Myocardial Failure in Mice. Circulation 2020; 142:2459-2469. [PMID: 33076678 DOI: 10.1161/circulationaha.120.048183] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND SERCA [sarco(endo)plasmic reticulum calcium ATPase] is regulated by oxidative posttranslational modifications at cysteine 674 (C674). Because sarcoplasmic reticulum (SR) calcium has been shown to play a critical role in mediating mitochondrial dysfunction in response to reactive oxygen species, we hypothesized that SERCA oxidation at C674 would modulate the effects of reactive oxygen species on mitochondrial calcium and mitochondria-dependent apoptosis in cardiac myocytes. METHODS Adult rat ventricular myocytes expressing wild-type SERCA2b or a redox-insensitive mutant in which C674 is replaced by serine (C674S) were exposed to H2O2 (100 µmol/Lμ). Free mitochondrial calcium concentration was measured in adult rat ventricular myocytes with a genetically targeted fluorescent probe, and SR calcium content was assessed by measuring caffeine-stimulated release. Mice with heterozygous knock-in of the SERCA C674S mutation were subjected to chronic ascending aortic constriction. RESULTS In adult rat ventricular myocytes expressing wild-type SERCA, H2O2 caused a 25% increase in mitochondrial calcium concentration that was associated with a 50% decrease in SR calcium content, both of which were prevented by the ryanodine receptor inhibitor tetracaine. In cells expressing the C674S mutant, basal SR calcium content was decreased by 31% and the H2O2-stimulated rise in mitochondrial calcium concentration was attenuated by 40%. In wild-type cells, H2O2 caused cytochrome c release and apoptosis, both of which were prevented in C674S-expressing cells. In myocytes from SERCA knock-in mice, basal SERCA activity and SR calcium content were decreased. To test the effect of C674 oxidation on apoptosis in vivo, SERCA knock-in mice were subjected to chronic ascending aortic constriction. In wild-type mice, ascending aortic constriction caused myocyte apoptosis, LV dilation, and systolic failure, all of which were inhibited in SERCA knock-in mice. CONCLUSIONS Redox activation of SERCA C674 regulates basal SR calcium content, thereby mediating the pathologic reactive oxygen species-stimulated rise in mitochondrial calcium required for myocyte apoptosis and myocardial failure.
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Affiliation(s)
- Jena B Goodman
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Fuzhong Qin
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Robert J Morgan
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Jordan M Chambers
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Dominique Croteau
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Deborah A Siwik
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Ion Hobai
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Marcello Panagia
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Ivan Luptak
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Markus Bachschmid
- Vascular Biology Unit (M.B., X.T., R.A.C.), Boston University School of Medicine, MA
| | - XiaoYong Tong
- Vascular Biology Unit (M.B., X.T., R.A.C.), Boston University School of Medicine, MA
| | - David R Pimentel
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
| | - Richard A Cohen
- Vascular Biology Unit (M.B., X.T., R.A.C.), Boston University School of Medicine, MA
| | - Wilson S Colucci
- Cardiovascular Medicine Section (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA.,Myocardial Biology Unit (J.B.G.., F.Q., R.J.M., J.M.C., D.C., D.A.S., I.H., M.P., I.L., D.R.P., W.S.C.), Boston University School of Medicine, MA
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