Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were ra...Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.展开更多
脑和肌肉芳香烃受体核转运样蛋白1基因(brain and muscle arnt-like 1,Bmal1)是生物钟的核心基因,在机体生命活动中发挥重要调控作用。生物钟的紊乱通常伴随Bmal1的异常表达,进而诱发一系列慢性代谢性疾病。运动可上调Bmal1表达,减缓慢...脑和肌肉芳香烃受体核转运样蛋白1基因(brain and muscle arnt-like 1,Bmal1)是生物钟的核心基因,在机体生命活动中发挥重要调控作用。生物钟的紊乱通常伴随Bmal1的异常表达,进而诱发一系列慢性代谢性疾病。运动可上调Bmal1表达,减缓慢性代谢性疾病的发病进程。本文主要对生物钟Bmal1在慢性代谢性疾病中的作用及其运动干预研究进展进行综述,提出Bmal1在运动改善慢性代谢性疾病中的可能作用机制,以期为运动通过生物钟基因防治慢性代谢性疾病提供新视角。展开更多
文摘Objective To investigate the structural changes of rat thoracic aorta and changes in expression levels of Bmal1 and cyclins in thoracic aorta endothelial cells following heat stress.Methods Twenty male SD rats were randomized equally into control group and heat stress group.After exposure to 32℃for 2 weeks in the latter group,the rats were examined for histopathological changes and Bmal1 expression in the thoracic aorta using HE staining and immunohistochemistry.In the cell experiments,cultured rat thoracic aortic endothelial cells(RTAECs)were incubated at 40℃for 12 h with or without prior transfection with a Bmal1-specific small interfering RNA(si-Bmal1)or a negative sequence.In both rat thoracic aorta and RTAECs,the expressions of Bmal1,the cell cycle proteins CDK1,CDK4,CDK6,and cyclin B1,and apoptosis-related proteins Bax and Bcl-2 were detected using Western blotting.TUNEL staining was used to detect cell apoptosis in rat thoracic aorta,and the changes in cell cycle distribution and apoptosis in RTAECs were analyzed with flow cytometry.Results Compared with the control rats,the rats exposed to heat stress showed significantly increased blood pressures and lowered heart rate with elastic fiber disruption and increased expressions of Bmal1,cyclin B1 and CDK1 in the thoracic aorta(P<0.05).In cultured RTAECs,heat stress caused significant increase of Bmal1,cyclin B1 and CDK1 protein expression levels,which were obviously lowered in cells with prior si-Bmal1 transfection.Bmal1 knockdown also inhibited heat stress-induced increase of apoptosis in RTAECs as evidenced by decreased expression of Bax and increased expression of Bcl-2.Conclusion Heat stress upregulates Bmal1 expression and causes alterations in expressions of cyclins to trigger apoptosis of rat thoracic aorta endothelial cells,which can be partly alleviated by suppressing Bmal1 expression.
文摘脑和肌肉芳香烃受体核转运样蛋白1基因(brain and muscle arnt-like 1,Bmal1)是生物钟的核心基因,在机体生命活动中发挥重要调控作用。生物钟的紊乱通常伴随Bmal1的异常表达,进而诱发一系列慢性代谢性疾病。运动可上调Bmal1表达,减缓慢性代谢性疾病的发病进程。本文主要对生物钟Bmal1在慢性代谢性疾病中的作用及其运动干预研究进展进行综述,提出Bmal1在运动改善慢性代谢性疾病中的可能作用机制,以期为运动通过生物钟基因防治慢性代谢性疾病提供新视角。
