The Effect Of FAT10 Regulate RYR2 In Angiotensin?-induced Cardiac Hypertrophy

Background and objective:Cardiac hypertrophy is often diagnosed in conditions of increased metabolic or hemodynamic stress. Cardiac hypertrophy is characterized by profound changes in size,gene expression, collagen content, and electrical properties that often precipitate progressive heart failure and sudden cardiac death.Ca2+-dependent signaling pathways including Ryanodine receptor 2(RYR2) and its regulatory proteins are considered to play critical roles in adverse cardiac remodeling.The cytokine inducible modifier HLA-F adjacent transcript 10(FAT10) is the only one of Ubiquitin-like modifiers which has been proved to directly mediate proteasomal degradation.We confirmed that FAT10 is a protective factor against apoptosis.Therefore we guess that there are interactions between FAT10 and RYR2 which could prevent cardiomyocytes hypertrophy.The purpose of the present study was to investigate the effects of FAT10 on RYR2 in cardiac hypertrophic induced by Angiotensin?(Ang?). Method:1. The cardiomyocytes were stimulated with Ang? for 48 hours. After that, the mRNA and protein expression of the hypertrophy markers including MYH7, ACTN1, ANF and BNP, were detected by qRT-PCR and Western blot.Meanwhile, cell size was observed by phalloidin-stained technique and laser scanning confocal microscopy.2. The mRNA and protein expression of FAT10 were detected by qRT-PCR and Western blot in hypertrophic cardiomyocytes induced by Ang?.3. NRCM were infected with adenoviral particles carrying Fat10 for 48 hours. Western blot and qRT-PCR were applied to assess the transfection efficiency. After the FAT10 expression restored,the mRNA expression of the hypertrophy markers including ANF and BNP were detected by qRT-PCR.Meanwhile, the RyR2 phosphorylation levels of Ser2814 and protein expression of MYH7 were measured by Western blot. Result:1. We observed a significant elevation in the protein expression of MYH7 and ACTN1 and the mRNA expression of ANF and BNP in the model of cardiomyocytes hypertrophy induced by Ang? compared with the control groups. And besides, the cell area was increased in the intervention group.2. The mRNA and protein expression of FAT10 are decreased in hypertrophic cardiomyocytes induced by Ang?.3. The overexpression of FAT10 results in a rise of protein and mRNA expression of FAT10.Over-expression of FAT10 reduces the mRNA expression of ANF and BNP. Meanwhile, reduces the Phosphorylation of the site Ser2814 on RyR2 and reduces the protein expression of MYH7 in hypertrophic cardiomyocytes stimulated with Ang?. Conclusion:These results suggest that FAT10 overexpression may protect cardiomyocytes from Ang?-induced hypertrophy via reduce phosphorylation of ryanodine receptor.