AIM To investigate the effects of Spectrin β Ⅱ on cardiomyocyte DNA damage and apoptosis induced by palmitic acid (PA).
METHODS Western blot was used to detect the protein levels of Spectrin β Ⅱ in mouse primary cardiomyocytes (MCMs) treated with PA. MCMs were infected with adenovirus expressing independent hairpin shRNA sequences for Spectrin β Ⅱ (Ad-sh-Spectrin β Ⅱ) or control sh-scramble sequence (Ad-sh-scramble). The infection efficiency of the adenovirus was examined by fluorescence microscope and confirmed by Western blot and qPCR. The protein levels of γ-H2AX, an indicator of DNA damage, and apoptotic protein cleaved-caspase 3 were detected by Western blot. Flow cytometry was used to analyze the apoptotic rate.
RESULTS The protein levels of Spectrin β Ⅱ were significantly decreased in MCMs treated with PA (P<0.05). Compared with those in the Ad-sh-scramble group, the protein and mRNA levels of Spectrin β Ⅱ in the Ad-sh-Spectrin β Ⅱ group were significantly decreased (P< 0.05). Compared with those in the Ad-sh-scramble group, the protein levels of γ-H2AX and cleaved-caspase3 were significantly increased (P<0.05) and the apoptotic rate was significantly increased (P<0.05) in the Ad-sh- Spectrin β Ⅱ group after treated with PA.
CONCLUSION Spectrin β Ⅱ knockdown aggravates cardiomyocyte DNA damage and apoptosis induced by palmitic acid.
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