Ischaemic preconditioning preferentially increases protein S-nitrosylation in subsarcolemmal mitochondria

Junhui Sun, Tiffany Nguyen, Angel M. Aponte, Sara Menazza, Mark J. Kohr, David M. Roth, Hemal H. Patel, Elizabeth Murphy, Charles Steenbergen

Research output: Contribution to journalArticle

Abstract

Nitric oxide (NO) and protein S-nitrosylation (SNO) have been shown to play important roles in ischaemic preconditioning (IPC)-induced acute cardioprotection. The majority of proteins that show increased SNO following IPC are localized to the mitochondria, and our recent studies suggest that caveolae transduce acute NO/SNO cardioprotective signalling in IPC hearts. Due to the close association between subsarcolemmal mitochondria (SSM) and the sarcolemma/caveolae, we tested the hypothesis that SSM, rather than the interfibrillar mitochondria (IFM), are major targets for NO/SNO signalling derived from caveolae-associated eNOS. Following either control perfusion or IPC, SSM and IFM were isolated from Langendorff perfused mouse hearts, and SNO was analysed using a modified biotin switch method with fluorescent maleimide fluors. In perfusion control hearts, the SNO content was higher in SSM compared with IFM (1.33 ± 0.19, ratio of SNO content Perf-SSM vs. Perf-IFM), and following IPC SNO content significantly increased preferentially in SSM, but not in IFM (1.72 ± 0.17 and 1.07 ± 0.04, ratio of SNO content IPC-SSM vs. Perf-IFM, and IPC-IFM vs. Perf-IFM, respectively). Consistent with these findings, eNOS, caveolin-3, and connexin-43 were detected in SSM, but not in IFM, and IPC resulted in a further significant increase in eNOS/caveolin-3 levels in SSM. Interestingly, we did not observe an IPC-induced increase in SNO or eNOS/caveolin-3 in SSM isolated from caveolin-3-/- mouse hearts, which could not be protected with IPC. In conclusion, these results suggest that SSM may be the preferential target of sarcolemmal signalling-derived post-translational protein modification (caveolae-derived eNOS/NO/SNO), thus providing an important role in IPC-induced cardioprotection.

Original languageEnglish (US)
Pages (from-to)227-236
Number of pages10
JournalCardiovascular research
Volume106
Issue number2
DOIs
StatePublished - May 1 2015

Keywords

  • Caveolae
  • Ischaemic preconditioning
  • Protein S-nitrosylation
  • Subsarcolemmal and interfibrillar mitochondria

ASJC Scopus subject areas

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

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