SIRT1 in the cardiomyocyte counteracts doxorubicin-induced cardiotoxicity via regulating histone H2AX. Issue 17 (8th March 2022)

• Record Type: Journal Article
• Authors: Kuno, Atsushi; Hosoda, Ryusuke; Tsukamoto, Miki; Sato, Tatsuya; Sakuragi, Hiromi; Ajima, Nami; Saga, Yukika; Tada, Kouhei; Taniguchi, Yoshiki; Iwahara, Naotoshi; Horio, Yoshiyuki
• Is Part Of: Cardiovascular research. Volume 118:Issue 17(2022)
• Page Start: 3360
• Page End: 3373
• Publication Date: 2022-03-08
• Subjects: Doxorubicin cardiotoxicity -- SIRT1 -- Deacetylation -- Histone H2AX -- DNA damage response; Cardiovascular system -- Diseases -- Periodicals; Cardiovascular system -- Periodicals; 616.1
• DOI: 10.1093/cvr/cvac026
• Languages: English
• ISSNs: 0008-6363

Abstract

Abstract: Aims: Cardiotoxicity by doxorubicin predicts worse prognosis of patients. Accumulation of damaged DNA has been implicated in doxorubicin-induced cardiotoxicity. SIRT1, an NAD + -dependent histone/protein deacetylase, protects cells by deacetylating target proteins. We investigated whether SIRT1 counteracts doxorubicin-induced cardiotoxicity by mediating Ser139 phosphorylation of histone H2AX, a critical signal of the DNA damage response. Methods and results: Doxorubicin (5 mg/kg per week, x4) was administered to mice with intact SIRT1 ( Sirt1 f/f ) and mice that lack SIRT1 activity in cardiomyocytes ( Sirt1 f/f ;MHC cre/+ ). Reductions in left ventricular fractional shortening and ejection fraction by doxorubicin treatment were more severe in Sirt1 f/f ;MHC cre/+ than in Sirt1 f/f . Myocardial expression level of type-B natriuretic peptide was 2.5-fold higher in Sirt1 f/f ;MHC cre/+ than in Sirt1 f/f after doxorubicin treatment. Sirt1 f/f ;MHC cre/+ showed larger fibrotic areas and higher nitrotyrosine levels in the heart after doxorubicin treatment. Although doxorubicin-induced DNA damage evaluated by TUNEL staining was enhanced in Sirt1 f/f ;MHC cre/+, the myocardium from Sirt1 f/f ;MHC cre/+ showed blunted Ser139 phosphorylation of H2AX by doxorubicin treatment. In H9c2 cardiomyocytes, SIRT1 knockdown attenuated Ser139 phosphorylation of H2AX, increased DNA damage, and enhanced caspase-3 activation under doxorubicin treatment. Immunostaining revealed that acetylation level of H2AX at Lys5 was higher in hearts from Sirt1 f/f ;MHC cre/+ . In H9c2 cells, acetyl-Lys5-H2AX level was increased by SIRT1 knockdown and reduced by SIRT1 overexpression. Ser139 phosphorylation in response to doxorubicin treatment was blunted in a mutant H2AX with substitution of Lys5 to Gln (K5Q) that mimics acetylated lysine compared with that in wild-type H2AX. Expression of K5Q-H2AX as well as S139A-H2AX, which cannot be phosphorylated at Ser139, augmented doxorubicin-induced caspase-3 activation. Treatment of mice with resveratrol, a SIRT1 activator, attenuated doxorubicin-induced cardiac dysfunction, which was associated with a reduction in acetyl-Lys5-H2AX level and a preserved phospho-Ser139-H2AX level. Conclusion: These findings suggest that SIRT1 counteracts doxorubicin-induced cardiotoxicity by mediating H2AX phosphorylation through its deacetylation in cardiomyocytes. Graphical Abstract: