Page 14 - 南京医科大学学报自然科学版

南京医科大学学报（自然科学版） 第42卷第5期
·610 · Journal of Nanjing Medical University（Natural Sciences） 2022年5月

·基础研究·

Bmal1调控T型钙离子通道对慢性心衰室性心律失常昼夜节律

的影响

俞 灏，周子皓，张南南，薛思源，钱智勇，王 垚，邹建刚 *

南京医科大学第一附属医院心血管内科，江苏 南京 210029

［摘 要］ 目的：探究生物钟基因Bmal1调控T型钙离子通道（T⁃type calcium channel，TTCC）对慢性心衰（chronic heart failure，
CHF）室性心律失常（ventricular arrhythmia，VA）昼夜节律的影响及可能的调控机制。方法：采用主动脉缩窄术（TAC）构建
C57BL/6J小鼠慢性心力衰竭模型（CHF），设定假手术对照组（CON）及TTCC抑制剂米贝拉地尔（MIB）治疗组（CHF+MIB）。使
用心脏超声评估各组小鼠心功能，免疫组织化学染色（IHC）及蛋白免疫印迹法（WB）测定心肌TTCC表达。使用程序性电刺激
（PES）诱发室性心律失常（VA），采用WB及实时定量逆转录聚合酶链反应（qRT⁃PCR）检测心肌组织Bmal1、TTCC昼夜节律变
化及关系。使用染色质免疫共沉淀技术（ChIP）揭示Bmal1调控TTCC的分子机制。结果：与CON组相比，CHF小鼠心脏收缩
功能显著降低，心腔扩大且伴有明显心肌肥厚，心肌中TTCC表达量明显增加，行PES检测发现CHF小鼠VA发作率明显增加，
且有昼夜节律差异，使用MIB可一定程度降低CHF小鼠VA的发生。Western blot及qRT⁃PCR结果提示CHF小鼠心肌中Bmal1
及TTCC表达呈昼夜节律性变化，ChIP检测提示Bmal1可直接结合到TTCC启动子区域的E⁃box位点调控TTCC的转录。结论：
CHF小鼠中，TTCC通道重新高表达且呈昼夜节律性，使用MIB可降低CHF小鼠VA发作，Bmal1可通过直接结合TTCC启动子
区域的E⁃box位点调控TTCC的转录。
［关键词］ 室性心律失常；慢性心力衰竭；T型钙离子通道；生物钟
［中图分类号］ R541.7 ［文献标志码］ A ［文章编号］ 1007⁃4368（2022）05⁃610⁃08
doi：10.7655/NYDXBNS20220502

Effect of Bmal1 regulation of T⁃type calcium channel on the circadian rhythm of chronic
heart failure ventricular arrhythmias

*
YU Hao，ZHOU Zihao，ZHANG Nannan，XUE Siyuan，QIAN Zhiyong，WANG Yao，ZOU Jiangang
Department of Cardiology，the First Affiliated Hospital of Nanjing Medical University，Nanjing 210029，China

［Abstract］ Objective：This study aims to Explore the effect of circadian clock gene of brain and muscle ARNT⁃like protein⁃ 1
（Bmal1）regulated T⁃type calcium channel（TTCC）on circadian rhythm of chronic heart failure（CHF）ventricular arrhythmia（VA）and
its possible mechanisms. Methods：The C57BL/6J mice CHF model was established by transverse aortic constriction（TAC）and mice
in control group（CON）were treated with sham operation. Some TAC mice were randomly assigned to receive TTCC inhibitor mibefradil
（MIB）for 2 weeks（CHF+MIB）. Cardiac function was assessed by echocardiographic and the expression level of TTCC was determined
by immune histochemical（IHC）staining and Western blot（WB）. Ventricular arrhythmia（VA）was induced through programmed
electrical stimulation（PES）in each group. The circadian rhythms of Bmal1 and TTCC were detected by WB and real⁃time quantitative
reverse transcription polymerase chain reaction（qRT ⁃ PCR），and the molecular mechanism by which Bmal1 regulated TTCC was
determined by chromatin immunoprecipitation（ChIP）. Results：Compared with CON group，CHF mice had significantly reduced
cardiac systolic function，increased internal diameter accompanied by obvious cardiac hypertrophy. Significantly increased TTCC re⁃
expression level in CHF mice myocardium was detected by IHC staining and WB. PES indicated that VA occurrence was significantly
increased when comparing CHF mice with CON mice. To a certain extent，using MIB could reduce the occurrence of VA in CHF mice.
In addition，VA occurrence appeared circadian rhythm in all three groups（CON，CHF and CHF+MIB）. WB and qRT⁃PCR results

［基金项目］ 国家自然科学基金（81870251）
∗
通信作者（Corresponding author），E⁃mail：jgzou@njmu.edu.cn