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Ali MA, Gioscia-Ryan R, Yang D, Sutton NR, Tyrrell DJ. Cardiovascular aging: spotlight on mitochondria. Am J Physiol Heart Circ Physiol 2024; 326:H317-H333. [PMID: 38038719 DOI: 10.1152/ajpheart.00632.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/02/2023]
Abstract
Mitochondria are cellular organelles critical for ATP production and are particularly relevant to cardiovascular diseases including heart failure, atherosclerosis, ischemia-reperfusion injury, and cardiomyopathies. With advancing age, even in the absence of clinical disease, mitochondrial homeostasis becomes disrupted (e.g., redox balance, mitochondrial DNA damage, oxidative metabolism, and mitochondrial quality control). Mitochondrial dysregulation leads to the accumulation of damaged and dysfunctional mitochondria, producing excessive reactive oxygen species and perpetuating mitochondrial dysfunction. In addition, mitochondrial DNA, cardiolipin, and N-formyl peptides are potent activators of cell-intrinsic and -extrinsic inflammatory pathways. These age-related mitochondrial changes contribute to the development of cardiovascular diseases. This review covers the impact of aging on mitochondria and links these mechanisms to therapeutic implications for age-associated cardiovascular diseases.
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Affiliation(s)
- Md Akkas Ali
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Rachel Gioscia-Ryan
- Department of Anesthesiology, Michigan Medicine, University of Michigan, Ann Arbor, Michigan, United States
| | - Dongli Yang
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Nadia R Sutton
- Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - Daniel J Tyrrell
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama, United States
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SenthilKumar G, Katunaric B, Zirgibel Z, Lindemer B, Jaramillo-Torres MJ, Bordas-Murphy H, Schulz ME, Pearson PJ, Freed JK. Necessary Role of Ceramides in the Human Microvascular Endothelium During Health and Disease. Circ Res 2024; 134:81-96. [PMID: 38037825 PMCID: PMC10766100 DOI: 10.1161/circresaha.123.323445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 11/10/2023] [Accepted: 11/15/2023] [Indexed: 12/02/2023]
Abstract
BACKGROUND Elevated plasma ceramides and microvascular dysfunction both independently predict adverse cardiac events. Despite the known detrimental effects of ceramide on the microvasculature, evidence suggests that activation of the shear-sensitive, ceramide-forming enzyme NSmase (neutral sphingomyelinase) elicits formation of vasoprotective nitric oxide (NO). Here, we explore a novel hypothesis that acute ceramide formation through NSmase is necessary for maintaining NO signaling within the human microvascular endothelium. We further define the mechanism through which ceramide exerts beneficial effects and discern key mechanistic differences between arterioles from otherwise healthy adults (non-coronary artery disease [CAD]) and patients diagnosed with CAD. METHODS Human arterioles were dissected from discarded surgical adipose tissue (n=166), and vascular reactivity to flow and C2-ceramide was assessed. Shear-induced NO and mitochondrial hydrogen peroxide (H2O2) production were measured in arterioles using fluorescence microscopy. H2O2 fluorescence was assessed in isolated human umbilical vein endothelial cells. RESULTS Inhibition of NSmase in arterioles from otherwise healthy adults induced a switch from NO to NOX-2 (NADPH-oxidase 2)-dependent H2O2-mediated flow-induced dilation. Endothelial dysfunction was prevented by treatment with sphingosine-1-phosphate (S1P) and partially prevented by C2-ceramide and an agonist of S1P-receptor 1 (S1PR1); the inhibition of the S1P/S1PR1 signaling axis induced endothelial dysfunction via NOX-2. Ceramide increased NO production in arterioles from non-CAD adults, an effect that was diminished with inhibition of S1P/S1PR1/S1P-receptor 3 signaling. In arterioles from patients with CAD, inhibition of NSmase impaired the overall ability to induce mitochondrial H2O2 production and subsequently dilate to flow, an effect not restored with exogenous S1P. Acute ceramide administration to arterioles from patients with CAD promoted H2O2 as opposed to NO production, an effect dependent on S1P-receptor 3 signaling. CONCLUSION These data suggest that despite differential downstream signaling between health and disease, NSmase-mediated ceramide formation is necessary for proper functioning of the human microvascular endothelium. Therapeutic strategies that aim to significantly lower ceramide formation may prove detrimental to the microvasculature.
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Affiliation(s)
- Gopika SenthilKumar
- Department of Physiology (G.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center (G.S., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
| | - Boran Katunaric
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
| | - Zachary Zirgibel
- Cardiovascular Center (G.S., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
| | - Brian Lindemer
- Cardiovascular Center (G.S., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
| | - Maria J. Jaramillo-Torres
- Cardiovascular Center (G.S., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
| | - Henry Bordas-Murphy
- Cardiovascular Center (G.S., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
| | - Mary E. Schulz
- Cardiovascular Center (G.S., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
| | - Paul J. Pearson
- Department of Surgery, Division of Cardiothoracic Surgery (P.J.P.), Medical College of Wisconsin, Milwaukee, WI
| | - Julie K. Freed
- Department of Physiology (G.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center (G.S., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
- Department of Anesthesiology (G.S., B.K., Z.Z., B.L., M.J.J.-T., H.B.-M., M.E.S., J.K.F.), Medical College of Wisconsin, Milwaukee, WI
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SenthilKumar G, Katunaric B, Zirgibel Z, Lindemer B, Jaramillo-Torres MJ, Bordas-Murphy H, Schulz ME, Pearson PJ, Freed JK. Necessary Role of Acute Ceramide Formation in The Human Microvascular Endothelium During Health and Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.02.543341. [PMID: 37333082 PMCID: PMC10274701 DOI: 10.1101/2023.06.02.543341] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Background Elevated plasma ceramides independently predict adverse cardiac events and we have previously shown that exposure to exogenous ceramide induces microvascular endothelial dysfunction in arterioles from otherwise healthy adults (0-1 risk factors for heart disease). However, evidence also suggests that activation of the shear-sensitive, ceramide forming enzyme neutral sphingomyelinase (NSmase) enhances vasoprotective nitric oxide (NO) production. Here we explore a novel hypothesis that acute ceramide formation through NSmase is necessary for maintaining NO signaling within the human microvascular endothelium. We further define the mechanism through which ceramide exerts beneficial effects and discern key mechanistic differences between arterioles from otherwise healthy adults and patients with coronary artery disease (CAD). Methods Human arterioles were dissected from otherwise discarded surgical adipose tissue (n=123), and vascular reactivity to flow and C2-ceramide was assessed. Shear-induced NO production was measured in arterioles using fluorescence microscopy. Hydrogen peroxide (H2O2) fluorescence was assessed in isolated human umbilical vein endothelial cells. Results Inhibition of NSmase in arterioles from otherwise healthy adults induced a switch from NO to H2O2-mediated flow-induced dilation within 30 minutes. In endothelial cells, NSmase inhibition acutely increased H2O2 production. Endothelial dysfunction in both models was prevented by treatment with C2-ceramide, S1P, and an agonist of S1P-receptor 1 (S1PR1), while the inhibition of S1P/S1PR1 signaling axis induced endothelial dysfunction. Ceramide increased NO production in arterioles from healthy adults, an effect that was diminished with inhibition of S1P/S1PR1/S1PR3 signaling. In arterioles from patients with CAD, inhibition of NSmase impaired dilation to flow. This effect was not restored with exogenous S1P. Although, inhibition of S1P/S1PR3 signaling impaired normal dilation to flow. Acute ceramide administration to arterioles from patients with CAD also promoted H2O2 as opposed to NO production, an effect dependent on S1PR3 signaling. Conclusion These data suggest that despite key differences in downstream signaling between health and disease, acute NSmase-mediated ceramide formation and its subsequent conversion to S1P is necessary for proper functioning of the human microvascular endothelium. As such, therapeutic strategies that aim to significantly lower ceramide formation may prove detrimental to the microvasculature.
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Affiliation(s)
- Gopika SenthilKumar
- Department of Physiology, Medical College of Wisconsin
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | | | - Zachary Zirgibel
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Brian Lindemer
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Maria J. Jaramillo-Torres
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Henry Bordas-Murphy
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Mary E. Schulz
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
| | - Paul J. Pearson
- Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin
| | - Julie K. Freed
- Department of Physiology, Medical College of Wisconsin
- Cardiovasular Center, Medical College of Wisconsin
- Department of Anesthesiology, Medical College of Wisconsin
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