Profiling of miR-205/P4HA3 Following Angiotensin II-Induced Atrial Fibrosis: Implications for Atrial Fibrillation.

Zezhou Xiao,Xiao Ling,Jiale Li,Desai Pavan Kumar Reddy,Chuqing Xue,Xiong Chen,Ximao Liu,Shaoyi Zheng

doi:10.3389/fcvm.2021.609300

Zezhou Xiao, Xiao Ling + Show 6 more

Open Access

https://doi.org/10.3389/fcvm.2021.609300

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Abstract

Objective: Atrial fibroblasts are the main component of atrial fibrosis. Data in previous studies proved the implication of miRNAs in AF progression and the association of miR-205 with cancer associated-fibroblasts, while no evidence supported the implication of miR-205 in atrial fibrosis. Therefore, this study aims to explore the effect and mechanism of miR-205/P4HA3 axis on atrial fibrosis.Methods: Angiotensin II (Ang II) was used to induce atrial fibrosis model in rats, which was verified by H&E staining and Masson staining. qRT-PCR and Western blot were applied to measure the expressions of miR-205, P4HA3, collagen I, and α-SMA. The rat atrial fibroblasts were isolated and then subjected to Ang II treatment or cell transfection for determination of cell biological functions using CCK-8, BrdU assay, TUNEL staining, and cell scratch assay. qRT-PCR and Western blot was applied to analyze the expressions of miR-205, P4HA3, collagen I, α-SMA, JNK, and p-JNK in atrial fibroblasts. Dual-luciferase reporter gene assay and RNA immune-precipitation experiment was employed to verify the binding relationship between miR-205 and P4HA3.Results: Ang II induced rats had disordered arrangement of atrial muscles with uneven nuclear sizes and necrotic atrial myocytes, and increased collagen deposition, in which elevated expressions of P4HA3, collagen I, and α-SMA as well as suppressed expression level of miR-205 were found. In vitro, Ang II treatment in atrial fibroblasts with overexpression of P4HA3 facilitated cellular migration and proliferation, with the induction of JNK signaling pathway. However, these trends were reversed after transfection with miR-205 mimic. P4HA3 is a target gene of miR-205.Conclusion: The miR-205/P4HA3 axis is implicated in atrial fibrosis by inhibition of rat fibroblast proliferation and migration and the inactivation of JNK signaling pathway.

Highlights

Atrial fibrillation (AF) has emerged as a growing concern in recent years as it continues to be the most commonly encountered arrhythmia in clinical practice [1, 2]
Angiotensin II (Ang II) was used to induce atrial fibrosis model in rats, which was verified by H&E staining and Masson staining. qRT-PCR and Western blot were applied to measure the expressions of miR-205, P4HA3, collagen I, and α-SMA
The miR-205/P4HA3 axis is implicated in atrial fibrosis by inhibition of rat fibroblast proliferation and migration and the inactivation of JNK signaling pathway

Summary

Introduction

Atrial fibrillation (AF) has emerged as a growing concern in recent years as it continues to be the most commonly encountered arrhythmia in clinical practice [1, 2]. Atrial fibrosis is regarded as the primary substrate that maintains AF, and it is featured by excessive deposition of the extracellular matrix and abnormal proliferation of atrial fibroblasts [4, 5]. These findings emphasize the relationship between AF and atrial fibrosis, revealing the causal influence of tissue fibrosis on the occurrence and persistence of AF remains a crucial challenge. Serving as the major effector hormone of the RAS, Angiotensin II (Ang II) confers a crucial effect on the mediation of atrial fibrosis during AF [7].

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