ca-circSCN8A Promotes HPASMCs Ferroptosis via LLPS Initiated R-Loop.

IF 6.9 1区 医学 Q1 PERIPHERAL VASCULAR DISEASE
Mengnan Li, Yingying Hao, Xinyue Song, Huiyu Liu, Chi Zhang, Jiaqi Zhang, Hanliang Sun, Xiaodong Zheng, Lixin Zhang, Hang Yu, Cui Ma, Xijuan Zhao, Daling Zhu
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引用次数: 0

Abstract

Background: Ferroptosis has been implicated in pulmonary hypertension (PH), and chromatin-associated RNAs are increasingly recognized as key regulators of this process. However, the detailed mechanism remains unexplored.

Methods: Bioinformatics, Sanger sequencing, and RNase R digestion were used to identify the upregulation of ca-circSCN8A. Functional gain and loss assays were used to unveil the role of ca-circSCN8A in hypoxic redox-dependent ferroptosis in human pulmonary arterial smooth muscle cells and a PH mice model. Interaction between ca-circSCN8A and FUS was detected via RNA immunoprecipitation and pull-down assays. Fluorescence recovery after photobleaching, ChIRP-qPCR, malondialdehyde, reduced glutathione, and glutathione were conducted to explore the potential molecular mechanism.

Results: ca-circSCN8A was identified and confirmed to be upregulated in PH. Its overexpression promoted hypoxia-induced ferroptosis in human pulmonary arterial smooth muscle cells. Under hypoxic conditions, ca-circSCN8A recruited EP300 to facilitate the lactylation of FUS, triggering the formation of a ca-circSCN8A/FUS/EP300 complex via liquid-liquid phase separation. Liquid-liquid phase separation maintained the stability of the R-loop formed by ca-circSCN8A and ferroptosis-related gene SLC7A11 (solute carrier family 7 member 11) promoter that inhibits its transcription, further result in the disruption of the redox homeostasis and causing ferroptosis in human pulmonary arterial smooth muscle cells.

Conclusions: ca-circSCN8A recruits EP300 to promote the lactylation of FUS, thereby driving liquid-liquid phase separation-mediated complex formation with FUS and EP300. This process enables ca-circSCN8A to form an R-loop with the nonhost SLC7A11 promoter, contributing to the regulation of hypoxia-induced ferroptosis in human pulmonary arterial smooth muscle cells. This study provides the first evidence that circRNAs can form R-loops with nonhost genes in a liquid-liquid phase separation-dependent manner. Our findings highlight ca-circSCN8A as a crucial regulator of ferroptosis in hypoxic PH and a potential therapeutic target for PH.

ca-circSCN8A通过LLPS启动R-Loop促进HPASMCs铁下垂。
背景:铁下沉与肺动脉高压(PH)有关,染色质相关rna越来越被认为是这一过程的关键调节因子。然而,详细的机制仍未被探索。方法:采用生物信息学、Sanger测序和RNase R酶切技术鉴定ca-circSCN8A的上调。通过功能得失分析揭示ca-circSCN8A在缺氧氧化还原依赖性人肺动脉平滑肌细胞和PH小鼠模型中的作用。通过RNA免疫沉淀和拉下实验检测ca-circSCN8A和FUS之间的相互作用。通过光漂白后荧光恢复、ChIRP-qPCR、丙二醛、还原性谷胱甘肽和谷胱甘肽等方法探讨其潜在的分子机制。结果:ca-circSCN8A在ph中表达上调,其过表达促进缺氧诱导的人肺动脉平滑肌细胞铁下垂。在缺氧条件下,ca-circSCN8A招募EP300促进FUS的乳酸化,通过液-液相分离触发ca-circSCN8A/FUS/EP300复合物的形成。液液相分离维持了ca-circSCN8A与凋亡相关基因SLC7A11(溶质载体家族7成员11)启动子组成的r环的稳定性,抑制其转录,进一步破坏氧化还原稳态,导致人肺动脉平滑肌细胞发生铁凋亡。结论:ca-circSCN8A招募EP300促进FUS的乳酸化,从而驱动FUS与EP300形成液-液相分离介导的复合物。这一过程使ca-circSCN8A与非宿主SLC7A11启动子形成r环,有助于调节缺氧诱导的人肺动脉平滑肌细胞铁下垂。这项研究提供了第一个证据,证明环状rna可以以液-液相分离依赖的方式与非宿主基因形成r -环。我们的研究结果强调ca-circSCN8A是缺氧PH下铁下垂的关键调节因子,也是PH的潜在治疗靶点。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
Hypertension
Hypertension 医学-外周血管病
CiteScore
15.90
自引率
4.80%
发文量
1006
审稿时长
1 months
期刊介绍: Hypertension presents top-tier articles on high blood pressure in each monthly release. These articles delve into basic science, clinical treatment, and prevention of hypertension and associated cardiovascular, metabolic, and renal conditions. Renowned for their lasting significance, these papers contribute to advancing our understanding and management of hypertension-related issues.
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