@article{LI2022, 
author = {Pengjia LI and Weiwei JIA and Jiebei LU and Mingxia MA and Xiuya ZHOU and Ning WANG and Yuan YUAN and Rui GUO and Xiaochen NIU and Xiaohui WANG and Li WANG},
title = {Period 2 protein inhibits cardiomyocyte death induced by β1-adrenoceptor autoantibodies},
year = {2022},
journal = {Journal of Army Medical University},
volume = {44},
number = {9},
pages = {898-905},
keywords = {cardiomyocyte, β1-adrenergic receptor autoantibodies, period 2, circadian rhythm, cell death},
url = {https://www.sciopen.com/article/10.16016/j.2097-0927.202110010},
doi = {10.16016/j.2097-0927.202110010},
abstract = {ObjectiveTo investigate the role of period 2 (Per2) protein in the death of cardiomyocytes induced by β1-adrenergic receptor autoantibodies (β1-AA).MethodsSixteen male SD rats aged 6~8 weeks were randomly divided into active immunization (model) group and control group (n=8). The model group was immunized with the second extracellular loop of beta1-adrenoceptor (β1-AR-ECⅡ), and the control group was injected with Na2CO3 and other solutions. The rat serum was subsequently collected at 8 weeks, followed by the purification of β1-AA. H9c2 cardiomyocyte were selected and randomly divided into control group, β1-AA group, and β1-AR+β1-AA group. Cell viability of each group was detected by CCK-8 assay (n=8). Then H9c2 cells in the control group and β1-AA 1 μmol/L group were synchronized with dexamethasone for 4 h, the expression of Per2 in cardiomyocytes at different circadian time (CT) points was measured by Western blotting, and JTK_CYCLE was used to analyze the circadian rhythm parameters (n=11). Moreover, Per2 in H9c2 cells was knocked down or overexpressed by lentiviral shPer2 and lentiviral Per2, respectively; RT-PCR and Western blotting were performed to detect the changes of Per2 expression (n=6). On the basis of knockdown (n=8) or overexpression (n=10) of Per2, the H9c2 cells were further treated with β1-AA, and the cell survival rate was tested by CCK-8 assay.ResultsCCK-8 assay showed that the survival rate of H9c2 cells was significantly decreased after β1-AA treatment (P<0.05). Western blotting demonstrated that β1-AA remarkably inhibited the rhythmic expression of Per2 protein in the cardiomyocytes (JTK_CYCLE, P>0.05), with the decrease at CT8 and CT16 most obviously (P<0.01). Knockdown of Per2 expression reduced the survival rate of cardiomyocytes, which was further lowered after β1-AA treatment (P<0.001). However, overexpression of Per2 notably reversed the decline in H9c2 survival rate induced by β1-AA (P<0.001).ConclusionPer2 protein inhibits β1-AA induced H9c2 cardiomyocyte death.}
}