Increased Mitochondrial Free Ca During Ischemia is Suppressed, but Not Eliminated By, Germline Deletion of the Mitochondrial Ca Uniporter

Overview

Journal Cell Rep

Publisher Cell Press

Specialties Biology
Cell Biology
Molecular Biology

Date 2023 Jul 8

PMID 37421627

Authors

Courtney E Petersen

Junhui Sun

Kavisha Silva

Anna Kosmach

Robert S Balaban

Elizabeth Murphy

Affiliations

Soon will be listed here.

Abstract

Mitochondrial Ca overload is proposed to regulate cell death via opening of the mitochondrial permeability transition pore. It is hypothesized that inhibition of the mitochondrial Ca uniporter (MCU) will prevent Ca accumulation during ischemia/reperfusion and thereby reduce cell death. To address this, we evaluate mitochondrial Ca in ex-vivo-perfused hearts from germline MCU-knockout (KO) and wild-type (WT) mice using transmural spectroscopy. Matrix Ca levels are measured with a genetically encoded, red fluorescent Ca indicator (R-GECO1) using an adeno-associated viral vector (AAV9) for delivery. Due to the pH sensitivity of R-GECO1 and the known fall in pH during ischemia, hearts are glycogen depleted to decrease the ischemic fall in pH. At 20 min of ischemia, there is significantly less mitochondrial Ca in MCU-KO hearts compared with MCU-WT controls. However, an increase in mitochondrial Ca is present in MCU-KO hearts, suggesting that mitochondrial Ca overload during ischemia is not solely dependent on MCU.

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References

Schaefer S, Carr L, Prussel E, Ramasamy R . Effects of glycogen depletion on ischemic injury in isolated rat hearts: insights into preconditioning. Am J Physiol. 1995; 268(3 Pt 2):H935-44. DOI: 10.1152/ajpheart.1995.268.3.H935. View

Femnou A, Kuzmiak-Glancy S, Covian R, Giles A, Kay M, Balaban R . Intracardiac light catheter for rapid scanning transmural absorbance spectroscopy of perfused myocardium: measurement of myoglobin oxygenation and mitochondria redox state. Am J Physiol Heart Circ Physiol. 2017; 313(6):H1199-H1208. PMC: 6148203. DOI: 10.1152/ajpheart.00306.2017. View

Zazueta C, Sosa-Torres M, Correa F . Inhibitory properties of ruthenium amine complexes on mitochondrial calcium uptake. J Bioenerg Biomembr. 2000; 31(6):551-7. DOI: 10.1023/a:1005464927366. View

De Stefani D, Raffaello A, Teardo E, Szabo I, Rizzuto R . A forty-kilodalton protein of the inner membrane is the mitochondrial calcium uniporter. Nature. 2011; 476(7360):336-40. PMC: 4141877. DOI: 10.1038/nature10230. View

Kamer K, Mootha V . The molecular era of the mitochondrial calcium uniporter. Nat Rev Mol Cell Biol. 2015; 16(9):545-53. DOI: 10.1038/nrm4039. View

GUNTER T, Pfeiffer D . Mechanisms by which mitochondria transport calcium. Am J Physiol. 1990; 258(5 Pt 1):C755-86. DOI: 10.1152/ajpcell.1990.258.5.C755. View

Chinopoulos C, Adam-Vizi V . Mitochondrial Ca2+ sequestration and precipitation revisited. FEBS J. 2010; 277(18):3637-51. DOI: 10.1111/j.1742-4658.2010.07755.x. View

Molina R, Qian Y, Wu J, Shen Y, Campbell R, Drobizhev M . Understanding the Fluorescence Change in Red Genetically Encoded Calcium Ion Indicators. Biophys J. 2019; 116(10):1873-1886. PMC: 6531872. DOI: 10.1016/j.bpj.2019.04.007. View

Ruiz-Meana M, Garcia-Dorado D, Miro-Casas E, Abellan A, Soler-Soler J . Mitochondrial Ca2+ uptake during simulated ischemia does not affect permeability transition pore opening upon simulated reperfusion. Cardiovasc Res. 2006; 71(4):715-24. DOI: 10.1016/j.cardiores.2006.06.019. View

10.

Islam M, Takeuchi A, Matsuoka S . Membrane current evoked by mitochondrial Na-Ca exchange in mouse heart. J Physiol Sci. 2020; 70(1):24. PMC: 10717124. DOI: 10.1186/s12576-020-00752-3. View

11.

Kosmach A, Roman B, Sun J, Femnou A, Zhang F, Liu C . Monitoring mitochondrial calcium and metabolism in the beating MCU-KO heart. Cell Rep. 2021; 37(3):109846. PMC: 10461605. DOI: 10.1016/j.celrep.2021.109846. View

12.

Pletneva N, Pletnev V, Shemiakina I, Chudakov D, Artemyev I, Wlodawer A . Crystallographic study of red fluorescent protein eqFP578 and its far-red variant Katushka reveals opposite pH-induced isomerization of chromophore. Protein Sci. 2011; 20(7):1265-74. PMC: 3149199. DOI: 10.1002/pro.654. View

13.

Di Lisa F, Bernardi P . A CaPful of mechanisms regulating the mitochondrial permeability transition. J Mol Cell Cardiol. 2009; 46(6):775-80. DOI: 10.1016/j.yjmcc.2009.03.006. View

14.

Patron M, Tarasenko D, Nolte H, Kroczek L, Ghosh M, Ohba Y . Regulation of mitochondrial proteostasis by the proton gradient. EMBO J. 2022; 41(16):e110476. PMC: 9379554. DOI: 10.15252/embj.2021110476. View

15.

Kwong J, Lu X, Correll R, Schwanekamp J, Vagnozzi R, Sargent M . The Mitochondrial Calcium Uniporter Selectively Matches Metabolic Output to Acute Contractile Stress in the Heart. Cell Rep. 2015; 12(1):15-22. PMC: 4497842. DOI: 10.1016/j.celrep.2015.06.002. View

16.

Bauer T, Murphy E . Role of Mitochondrial Calcium and the Permeability Transition Pore in Regulating Cell Death. Circ Res. 2020; 126(2):280-293. PMC: 8317591. DOI: 10.1161/CIRCRESAHA.119.316306. View

17.

Kamer K, Sancak Y, Mootha V . The uniporter: from newly identified parts to function. Biochem Biophys Res Commun. 2014; 449(4):370-2. DOI: 10.1016/j.bbrc.2014.04.143. View

18.

Arduino D, Perocchi F . Pharmacological modulation of mitochondrial calcium homeostasis. J Physiol. 2018; 596(14):2717-2733. PMC: 6046065. DOI: 10.1113/JP274959. View

19.

Karch J, Bround M, Khalil H, Sargent M, Latchman N, Terada N . Inhibition of mitochondrial permeability transition by deletion of the ANT family and CypD. Sci Adv. 2019; 5(8):eaaw4597. PMC: 6713508. DOI: 10.1126/sciadv.aaw4597. View

20.

Pan X, Liu J, Nguyen T, Liu C, Sun J, Teng Y . The physiological role of mitochondrial calcium revealed by mice lacking the mitochondrial calcium uniporter. Nat Cell Biol. 2013; 15(12):1464-72. PMC: 3852190. DOI: 10.1038/ncb2868. View