Protein kinase C-ε coimmunoprecipitates with cytochrome oxidase subunit IV and is associated with improved cytochrome-c oxidase activity and cardioprotection

Dehuang Guo, Tiffany Nguyen, Mourad Ogbi, Huda El Sayed Tawfik, Guochun Ma, Qilin Yu, Robert William Caldwell, John A Johnson

Research output: Contribution to journalArticle

51 Citations (Scopus)

Abstract

We have utilized an in situ rat coronary ligation model to establish a PKC-ε cytochrome oxidase subunit IV (COIV) coimmunoprecipitation in myocardium exposed to ischemic preconditioning (PC). Ischemia-reperfusion (I/R) damage and PC protection were confirmed using tetrazolium-based staining methods and serum levels of cardiac troponin I. Homogenates prepared from the regions at risk (RAR) and not at risk (RNAR) for I/R injury were fractionated into cell-soluble (S), 600 g low-speed centrifugation (L), Percoll/Optiprep density gradient-purified mitochondrial (M), and 100,000 g particulate (P) fractions. COIV immunoreactivity and cytochrome-c oxidase activity measurements estimated the percentages of cellular mitochondria in S, L, M, and P fractions to be 0, 55, 29, and 16%, respectively. We observed 18, 3, and 3% of PKC-δ, -ε, and -ζ isozymes in the M fraction under basal conditions. Following PC, we observed a 61% increase in PKC-ε levels in the RAR M fraction compared with the RNAR M fraction. In RAR mitochondria, we also observed a 2.8-fold increase in PKC-ε serine 729 phosphoimmunoreactivity (autophosphorylation), indicating the presence of activated PKC-ε in mitochondria following PC. PC administered before prolonged I/R induced a 1.9-fold increase in the coimmunoprecipitation of COIV, with anti-PKC-ε antisera and a twofold enhancement of cytochrome-c oxidase activity. Our results suggest that PKC-ε may interact with COIV as a component of the cardioprotection in PC. Induction of this interaction may provide a novel therapeutic target for protecting the heart from I/R damage.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume293
Issue number4
DOIs
StatePublished - Oct 1 2007

Fingerprint

Electron Transport Complex IV
Protein Kinase C
Reperfusion Injury
Mitochondria
Ischemia
Ischemic Preconditioning
Troponin I
Centrifugation
Serine
Isoenzymes
Reperfusion
Ligation
Immune Sera
Myocardium
Staining and Labeling
Serum

Keywords

  • Cardiac
  • Coronary ligation
  • Ischemia-reperfusion
  • Mitochondria
  • Oxidative phosphorylation
  • Protein kinase C

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Cite this

Protein kinase C-ε coimmunoprecipitates with cytochrome oxidase subunit IV and is associated with improved cytochrome-c oxidase activity and cardioprotection. / Guo, Dehuang; Nguyen, Tiffany; Ogbi, Mourad; Tawfik, Huda El Sayed; Ma, Guochun; Yu, Qilin; Caldwell, Robert William; Johnson, John A.

In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 293, No. 4, 01.10.2007.

Research output: Contribution to journalArticle

@article{900ca6f0a5f248b7b33dc960aa27e85a,
title = "Protein kinase C-ε coimmunoprecipitates with cytochrome oxidase subunit IV and is associated with improved cytochrome-c oxidase activity and cardioprotection",
abstract = "We have utilized an in situ rat coronary ligation model to establish a PKC-ε cytochrome oxidase subunit IV (COIV) coimmunoprecipitation in myocardium exposed to ischemic preconditioning (PC). Ischemia-reperfusion (I/R) damage and PC protection were confirmed using tetrazolium-based staining methods and serum levels of cardiac troponin I. Homogenates prepared from the regions at risk (RAR) and not at risk (RNAR) for I/R injury were fractionated into cell-soluble (S), 600 g low-speed centrifugation (L), Percoll/Optiprep density gradient-purified mitochondrial (M), and 100,000 g particulate (P) fractions. COIV immunoreactivity and cytochrome-c oxidase activity measurements estimated the percentages of cellular mitochondria in S, L, M, and P fractions to be 0, 55, 29, and 16{\%}, respectively. We observed 18, 3, and 3{\%} of PKC-δ, -ε, and -ζ isozymes in the M fraction under basal conditions. Following PC, we observed a 61{\%} increase in PKC-ε levels in the RAR M fraction compared with the RNAR M fraction. In RAR mitochondria, we also observed a 2.8-fold increase in PKC-ε serine 729 phosphoimmunoreactivity (autophosphorylation), indicating the presence of activated PKC-ε in mitochondria following PC. PC administered before prolonged I/R induced a 1.9-fold increase in the coimmunoprecipitation of COIV, with anti-PKC-ε antisera and a twofold enhancement of cytochrome-c oxidase activity. Our results suggest that PKC-ε may interact with COIV as a component of the cardioprotection in PC. Induction of this interaction may provide a novel therapeutic target for protecting the heart from I/R damage.",
keywords = "Cardiac, Coronary ligation, Ischemia-reperfusion, Mitochondria, Oxidative phosphorylation, Protein kinase C",
author = "Dehuang Guo and Tiffany Nguyen and Mourad Ogbi and Tawfik, {Huda El Sayed} and Guochun Ma and Qilin Yu and Caldwell, {Robert William} and Johnson, {John A}",
year = "2007",
month = "10",
day = "1",
doi = "10.1152/ajpheart.01306.2006",
language = "English (US)",
volume = "293",
journal = "American Journal of Physiology - Heart and Circulatory Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "4",

}

TY - JOUR

T1 - Protein kinase C-ε coimmunoprecipitates with cytochrome oxidase subunit IV and is associated with improved cytochrome-c oxidase activity and cardioprotection

AU - Guo, Dehuang

AU - Nguyen, Tiffany

AU - Ogbi, Mourad

AU - Tawfik, Huda El Sayed

AU - Ma, Guochun

AU - Yu, Qilin

AU - Caldwell, Robert William

AU - Johnson, John A

PY - 2007/10/1

Y1 - 2007/10/1

N2 - We have utilized an in situ rat coronary ligation model to establish a PKC-ε cytochrome oxidase subunit IV (COIV) coimmunoprecipitation in myocardium exposed to ischemic preconditioning (PC). Ischemia-reperfusion (I/R) damage and PC protection were confirmed using tetrazolium-based staining methods and serum levels of cardiac troponin I. Homogenates prepared from the regions at risk (RAR) and not at risk (RNAR) for I/R injury were fractionated into cell-soluble (S), 600 g low-speed centrifugation (L), Percoll/Optiprep density gradient-purified mitochondrial (M), and 100,000 g particulate (P) fractions. COIV immunoreactivity and cytochrome-c oxidase activity measurements estimated the percentages of cellular mitochondria in S, L, M, and P fractions to be 0, 55, 29, and 16%, respectively. We observed 18, 3, and 3% of PKC-δ, -ε, and -ζ isozymes in the M fraction under basal conditions. Following PC, we observed a 61% increase in PKC-ε levels in the RAR M fraction compared with the RNAR M fraction. In RAR mitochondria, we also observed a 2.8-fold increase in PKC-ε serine 729 phosphoimmunoreactivity (autophosphorylation), indicating the presence of activated PKC-ε in mitochondria following PC. PC administered before prolonged I/R induced a 1.9-fold increase in the coimmunoprecipitation of COIV, with anti-PKC-ε antisera and a twofold enhancement of cytochrome-c oxidase activity. Our results suggest that PKC-ε may interact with COIV as a component of the cardioprotection in PC. Induction of this interaction may provide a novel therapeutic target for protecting the heart from I/R damage.

AB - We have utilized an in situ rat coronary ligation model to establish a PKC-ε cytochrome oxidase subunit IV (COIV) coimmunoprecipitation in myocardium exposed to ischemic preconditioning (PC). Ischemia-reperfusion (I/R) damage and PC protection were confirmed using tetrazolium-based staining methods and serum levels of cardiac troponin I. Homogenates prepared from the regions at risk (RAR) and not at risk (RNAR) for I/R injury were fractionated into cell-soluble (S), 600 g low-speed centrifugation (L), Percoll/Optiprep density gradient-purified mitochondrial (M), and 100,000 g particulate (P) fractions. COIV immunoreactivity and cytochrome-c oxidase activity measurements estimated the percentages of cellular mitochondria in S, L, M, and P fractions to be 0, 55, 29, and 16%, respectively. We observed 18, 3, and 3% of PKC-δ, -ε, and -ζ isozymes in the M fraction under basal conditions. Following PC, we observed a 61% increase in PKC-ε levels in the RAR M fraction compared with the RNAR M fraction. In RAR mitochondria, we also observed a 2.8-fold increase in PKC-ε serine 729 phosphoimmunoreactivity (autophosphorylation), indicating the presence of activated PKC-ε in mitochondria following PC. PC administered before prolonged I/R induced a 1.9-fold increase in the coimmunoprecipitation of COIV, with anti-PKC-ε antisera and a twofold enhancement of cytochrome-c oxidase activity. Our results suggest that PKC-ε may interact with COIV as a component of the cardioprotection in PC. Induction of this interaction may provide a novel therapeutic target for protecting the heart from I/R damage.

KW - Cardiac

KW - Coronary ligation

KW - Ischemia-reperfusion

KW - Mitochondria

KW - Oxidative phosphorylation

KW - Protein kinase C

UR - http://www.scopus.com/inward/record.url?scp=35348977705&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=35348977705&partnerID=8YFLogxK

U2 - 10.1152/ajpheart.01306.2006

DO - 10.1152/ajpheart.01306.2006

M3 - Article

VL - 293

JO - American Journal of Physiology - Heart and Circulatory Physiology

JF - American Journal of Physiology - Heart and Circulatory Physiology

SN - 0363-6135

IS - 4

ER -