Faculty Collaboration Database

Anesthetic-induced preconditioning delays opening of mitochondrial permeability transition pore via protein Kinase C-epsilon-mediated pathway. Anesthesiology 2009 Aug;111(2):267-74

Date

07/02/2009

Pubmed ID

19568162

Pubmed Central ID

PMC2744603

DOI

10.1097/ALN.0b013e3181a91957

Scopus ID

2-s2.0-68249162142 (requires institutional sign-in at Scopus site)   68 Citations

Abstract

BACKGROUND: Cardioprotection by volatile anesthetic-induced preconditioning (APC) involves activation of protein kinase C (PKC). This study investigated the importance of APC-activated PKC in delaying mitochondrial permeability transition pore (mPTP) opening.

METHODS: Rat ventricular myocytes were exposed to isoflurane in the presence or absence of nonselective PKC inhibitor chelerythrine or isoform-specific inhibitors of PKC-delta (rottlerin) and PKC-epsilon (myristoylated PKC-epsilon V1-2 peptide), and the mPTP opening time was measured by using confocal microscopy. Ca-induced mPTP opening was measured in mitochondria isolated from rats exposed to isoflurane in the presence and absence of chelerythrine or in mitochondria directly treated with isoflurane after isolation. Translocation of PKC-epsilon was assessed in APC and control cardiomyocytes by Western blotting.

RESULTS: In cardiomyocytes, APC prolonged time necessary to induce mPTP opening (261 +/- 26 s APC vs. 216 +/- 27 s control; P < 0.05), and chelerythrine abolished this delay to 213 +/- 22 s. The effect of isoflurane was also abolished when PKC-epsilon inhibitor was applied (210 +/- 22 s) but not in the presence of PKC-delta inhibitor (269 +/- 31 s). Western blotting revealed translocation of PKC-epsilon toward mitochondria in APC cells. The Ca concentration required for mPTP opening was significantly higher in mitochondria from APC rats (45 +/- 8 microM x mg control vs. 64 +/- 8 microM x mg APC), and APC effect was reversed with chelerythrine. In contrast, isoflurane did not protect directly treated mitochondria.

CONCLUSION: APC induces delay of mPTP opening through PKC-epsilon mediated inhibition of mPTP opening, but not through PKC-delta. These results point to the connection between cytosolic and mitochondrial components of cardioprotection by isoflurane.

Author List

Pravdic D, Sedlic F, Mio Y, Vladic N, Bienengraeber M, Bosnjak ZJ

MESH terms used to index this publication - Major topics in bold

Anesthetics
Animals
Blotting, Western
Enzyme Inhibitors
Image Processing, Computer-Assisted
In Vitro Techniques
Ischemic Preconditioning, Myocardial
Male
Microscopy, Confocal
Mitochondria, Heart
Mitochondrial Membrane Transport Proteins
Myocytes, Cardiac
Permeability
Protein Kinase C-delta
Protein Kinase C-epsilon
Protein Transport
Rats
Rats, Wistar
Signal Transduction