Faculty Collaboration Database

Reversible blockade of complex I or inhibition of PKCβ reduces activation and mitochondria translocation of p66Shc to preserve cardiac function after ischemia. PLoS One 2014;9(12):e113534

Date

12/02/2014

Pubmed ID

25436907

Pubmed Central ID

PMC4250075

DOI

10.1371/journal.pone.0113534

Scopus ID

2-s2.0-84914689001 (requires institutional sign-in at Scopus site)   26 Citations

Abstract

AIM: Excess mitochondrial reactive oxygen species (mROS) play a vital role in cardiac ischemia reperfusion (IR) injury. P66Shc, a splice variant of the ShcA adaptor protein family, enhances mROS production by oxidizing reduced cytochrome c to yield H2O2. Ablation of p66Shc protects against IR injury, but it is unknown if and when p66Shc is activated during cardiac ischemia and/or reperfusion and if attenuating complex I electron transfer or deactivating PKCβ alters p66Shc activation during IR is associated with cardioprotection.

METHODS: Isolated guinea pig hearts were perfused and subjected to increasing periods of ischemia and reperfusion with or without amobarbital, a complex I blocker, or hispidin, a PKCβ inhibitor. Phosphorylation of p66Shc at serine 36 and levels of p66Shc in mitochondria and cytosol were measured. Cardiac functional variables and redox states were monitored online before, during and after ischemia. Infarct size was assessed in some hearts after 120 min reperfusion.

RESULTS: Phosphorylation of p66Shc and its translocation into mitochondria increased during reperfusion after 20 and 30 min ischemia, but not during ischemia only, or during 5 or 10 min ischemia followed by 20 min reperfusion. Correspondingly, cytosolic p66Shc levels decreased during these ischemia and reperfusion periods. Amobarbital or hispidin reduced phosphorylation of p66Shc and its mitochondrial translocation induced by 30 min ischemia and 20 min reperfusion. Decreased phosphorylation of p66Shc by amobarbital or hispidin led to better functional recovery and less infarction during reperfusion.

CONCLUSION: Our results show that IR activates p66Shc and that reversible blockade of electron transfer from complex I, or inhibition of PKCβ activation, decreases p66Shc activation and translocation and reduces IR damage. These observations support a novel potential therapeutic intervention against cardiac IR injury.

Author List

Yang M, Stowe DF, Udoh KB, Heisner JS, Camara AK

Author

Amadou K. Camara PhD Professor in the Anesthesiology department at Medical College of Wisconsin

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

Amobarbital
Animals
Electron Transport
Electron Transport Complex I
Enzyme Activation
Guinea Pigs
Heart
Mitochondria
Myocardial Ischemia
Protein Kinase C beta
Protein Kinase Inhibitors
Protein Transport
Reperfusion Injury
Shc Signaling Adaptor Proteins