Induction of the Ca2+-Dependent Permeability Transition in Liver Mitochondria by α,ω-Hexadecanedioic Acid is Blocked by Inorganic Phosphate in the Presence of Cyclosporin A
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The effect of α,ω-hexadecanedioic acid (HDA) as an inducer of Ca2+-dependent permeability of the inner membrane (pore opening) of isolated rat liver mitochondria was studied in the absence and presence of pore blocker cyclosporin A (CsA) and one of its effective modulator – inorganic phosphate (Pi). It was shown that the addition of HDA at a concentration of 30 µM to Ca2+-loaded mitochondria induces swelling of the organelles, rapid Ca2+ release from the matrix, and almost total drop in Δψ, which indicates the induction of the Ca2+-dependent permeability of the inner membrane. It was found that 1 µM CsA or 1 mM Pi added separately do not affect these effects of HDA. At the same time, in the presence of both CsA and Pi, HDA added to Ca2+-loaded mitochondria does not induce their swelling, Ca2+ release from the matrix, and a drop in Δψ. It is found that unlike HDA, the induction of Ca2+-dependent lipid pore by palmitic acid is not blocked by the combined action of CsA and Pi. On the basis of the obtained data Pi is considered as a blocker of the HDA-induced Ca2+-dependent pore in the presence of CsA. In this case, Pi can not be replaced by a similar permeable anion vanadate. It was established that this effect of Pi was eliminated if mitochondria were incubated with SH-reagents mersalyl (10 nmol/mg protein) and n-ethylmaleimide (200 nmol/mg protein), which are known as Pi-carrier inhibitors. We conclude that the mechanisms of the effects of HDA and palmitic acid as inducers of the Ca2+-dependent permeability of liver mitochondria differ significantly. The Ca2+-dependent effect of HDA can be considered as the formation of a pore sensitive to the combined action of CsA and Pi, while the Ca2+-dependent effect of palmitic acid is the formation of a lipid pore. Possible causes of the blocking action of Pi on the HDA-induced Ca2+-dependent mitochondrial pore are discussed.
Keywords: mitochondrial pore α,ω-hexadecanedioic acid palmitic acid cyclosporin A calcium ions inorganic phosphate
This work was supported by the Ministry of Education and Science of the Russian Federation (project nos. 17.4999.2017/8.9 and 6.5170.2017/8.9), by the Russian Foundation for Basic Research and Moscow Region (project no. 17-44-500584), and by a grant from the Mari State University (project no. 2018-03b).
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Conflict of interests. The authors declare that they have no conflict of interest.
Statement on the welfare of animals. All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.
- 8.Halestrap A.P., Davidson A.M. 1990. Inhibition of Ca2+-induced large-amplitude swelling of liver and heart mitochondria by cyclosporin is probably caused by the inhibitor binding to mitochondrial-matrix peptidyl-prolyl cis–trans isomerase and preventing it interacting with the adenine nucleotide translocase. Biochem. J. 268, 153–160.CrossRefGoogle Scholar
- 10.Bonora M., Bononi A., De Marchi E., Giorgi C., Lebiedzinska M., Marchi S., Patergnani S., Rimessi A., Suski J.M., Wojtala A., Wieckowski M.R., Kroemer G., Galluzzi L., Pinton P. 2013. Role of the c subunit of the FO ATP synthase in mitochondrial permeability transition. Cell. Cycle. 12, 674–683.CrossRefGoogle Scholar
- 13.Halestrap A.P. 2014. The C ring of the F1FO ATP synthase forms the mitochondrial permeability transition pore: A critical appraisal. Front. 4, 234.Google Scholar
- 21.Mironova G.D., Gritsenko E., Gateau-Roesch O., Levrat C., Agafonov A., Belosludtsev K., Prigent A., Muntean D., Dubois M., Ovize M. 2004. Formation of palmitic acid/Ca2+ complexes in the mitochondrial membrane: A possible role in the cyclosporin-insensitive permeability transition. J. Bioenerg. Biomembr. 36, 171–178.CrossRefGoogle Scholar
- 28.Kamo N., Muratsugu M., Hondoh R., Kobatake Y. 1979. Membrane potential of mitochondria measured with an electrode sensitive to tetraphenylphosphonium and reationship between proton electrochemical potential and phosphorylation potential in steady state. J. Membr. Biol. 49, 105–121.CrossRefGoogle Scholar
- 31.Ferreira G.C., Pratt R.D., Pedersen P.L. 1990. Mitochondrial proton/phosphate transporter. An antibody directed against the COOH terminus and proteolytic cleavage experiments new insights about its membrane topology. J. Biol. Chem. 265, 21 202–21 206.Google Scholar
- 32.Samartsev V.N., Chezganova S.A., Polishchuk L.S., Paydyganov A.P., Vidyakina O.V., Zeldi I.P. 2003. Temperature dependence of rat liver mitochondrial respiration with uncoupling of oxidative phosphorylation by fatty acids. Influence of inorganic phosphate. Biochemistry (Moscow). 68, 618–626.CrossRefGoogle Scholar