Objective

Cardiac hypertrophy is an adaptive response to physiological and pathological stimuli, the latter of which frequently progresses to valvulopathy, heart failure and sudden death. Recent reports revealed that pyroptosis is involved in regulating multiple cardiovascular diseases progression, including cardiac hypertrophy. However, the underlying mechanisms remain poorly understood. This study aims to extensively investigate the regulation of miR-133a-3p on pyroptosis in angiotensin II (Ang II)-induced cardiac hypertrophyin vitro.

Methods

The in vitro model of cardiac hypertrophy was induced by Ang II, which was validated by qPCR combined with measurement of cell surface area by immunofluorescence assay. CCK-8 assay and Hochest33342/PI staining was performed to assess pyroptosis. Dual luciferase reporter system was used to verify the direct interaction between miR-133a-3p and IKKε. The effects of miR-133a-3p/IKKε on pyroptosis activation and cardiac hypertrophy markers (Caspase-1, NLRP3, IL-1β, IL-18, GSDMD, ASC, ANP, BNP and β-MHC) were evaluated by western blot, ELISA and qPCR.

Results

Ang II treatment could induce cardiomyocyte hypertrophy and pyroptosis. The expression of miR-133a-3p was repressed in Ang II-treated HCM cells, and its overexpression could attenuate both pyroptosis and cardiac hypertrophyin vitro. Additionally, IKKε expression was significantly up-regulated in Ang II-induced HCM cells. Dual luciferase reporter system and qPCR validated that miR-133a-3p directly targeted the 3’-UTR of IKKε and suppressed its expression. Moreover, IKKε overexpression impaired the protective function of miR-133a-3p in cardiomyocyte hypertrophy.

Conclusion

Collectively, miR-133a-3p attenuates Ang II induced cardiomyocyte hypertrophy via inhibition of pyroptosis by targeting IKKε. Therefore, miR-133a-3p up-regulation may be a promising strategy for cardiac hypertrophy treatment.

中文翻译：

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miR-133a-3p通过靶向IKKε抑制细胞焦亡激活减弱心肌细胞肥大

客观的

心脏肥大是对生理和病理刺激的适应性反应，后者经常发展为瓣膜病、心力衰竭和猝死。最近的报告表明，细胞焦亡参与调节多种心血管疾病的进展，包括心脏肥大。然而，潜在的机制仍然知之甚少。本研究旨在广泛研究 miR-133a-3p 对体外血管紧张素 II (Ang II) 诱导的心脏肥大中细胞焦亡的调节。

方法

在体外的心脏肥大的模型诱导血管紧张素II，其通过qPCR验证结合通过免疫荧光测定细胞表面积的测量值。进行 CCK-8 测定和 Hochest33342/PI 染色以评估细胞焦亡。双荧光素酶报告系统用于验证 miR-133a-3p 和 IKKε 之间的直接相互作用。通过蛋白质印迹评估 miR-133a-3p/IKKε 对细胞焦亡激活和心脏肥大标志物（Caspase-1、NLRP3、IL-1β、IL-18、GSDMD、ASC、ANP、BNP 和 β-MHC）的影响， ELISA 和 qPCR。

结果

Ang II 治疗可诱导心肌细胞肥大和细胞焦亡。miR-133a-3p 的表达在 Ang II 处理的 HCM 细胞中受到抑制，其过表达可以减轻体外细胞焦亡和心脏肥大。此外，IKKε 表达在 Ang II 诱导的 HCM 细胞中显着上调。双荧光素酶报告系统和 qPCR 验证了 miR-133a-3p 直接靶向 IKKε 的 3'-UTR 并抑制其表达。此外，IKKε 过表达削弱了 miR-133a-3p 在心肌细胞肥大中的保护功能。

结论

总的来说，miR-133a-3p 通过靶向 IKKε 抑制细胞焦亡来减弱 Ang II 诱导的心肌细胞肥大。因此，miR-133a-3p 上调可能是治疗心脏肥大的一种有前景的策略。