MicroRNA-182-5p Inhibits Hypertrophic Scar Formation by Inhibiting the Proliferation and Migration of Fibroblasts via SMAD4 Pathway

Abstract

Introduction

Secondary to war wounds, trauma, etc., hypertrophic scar formation is the cause of an excessive proliferation of fibroblasts and accumulation of collagen fibers, which might affect cosmetic appearance, and could cause malignant transformation. miRNAs play an important role in disease regulation via inhibiting post-transcriptional protein translation by targeting and binding to the 3’ UTR region of mRNA. Here we explore the mechanism and interventions of scar formation from the perspective of miRNA.

Methods

Hypertrophic scar-associated differential miRNAs were screened by analyzing sequencing data of normal skin and hypertrophic scar, and verified by RT-qPCR. Signaling pathways that may be influenced by differentially miRNAs were analyzed using KEGG and GO. miRNA mimics were used to explore the effects of miRNAs on SMAD signaling pathway proteins. Dual-luciferase assays were used to explore the targeted binding of miRNAs. The mimics of the miRNA were used to explore the impact of miRNAs on the proliferation, migration, apoptosis and collagen synthesis levels of hypertrophic scar fibroblasts. The scar model of rabbit ear was used to verify the influence of miRNA on wound healing and scar formation in vivo.

Results

Expression of miR-182-5p was found to be considerably decreased in hypertrophic scars and fibroblasts. miR-182-5p was found to act mainly by targeting the 3’UTR region of SMAD4, but not SMAD1 or SMAD3. miR-182-5p overexpression may drastically suppress the proliferation and migration of fibroblasts, accompanied by enhanced apoptosis and reduced collagen fiber synthesis. The overexpression of miR-182-5p in in vivo experiments could effectively inhibit hypertrophic scar formation without affecting the speed and quality of wound healing.

Conclusion

miR-182-5p inhibits hypertrophic scar formation by decreasing the proliferation and migration of fibroblasts via SMAD4 pathway, and is expected to become a novel hypertrophic scar therapeutic target.

Keywords:

• hypertrophic scar
• microRNA
• SMAD4
• fibroblasts

Data Sharing Statement

Further information and requests for reagents may be directed to and will be fulfilled by the Lead Contact: X.X.

Ethics Approval and Consent

This study was performed in compliance with the principles of the Helsinki Declaration and Guidelines for the Care and Use of Laboratory Animals of the Chinese Institute of Health. All procedures using animals were approved by the Animal Research Committee and Ethics Committee of General Hospital of PLA. The use of human skin samples was approved by the Ethics Committee of General Hospital of PLA. We obtained the written informed consent from all the patients participated in this study.

Acknowledgments

Thanks to the involved volunteers who provided tissues for the study. We would like to thank Prof. Minliang Chen for his contribution to this manuscript. We would like to thank Dr. Jiachen Sun for his contribution to the revision of the manuscript.

Author Contributions

X.X. conceptualized the study, designed experiments, critically reviewed the manuscript, reviewed and agreed on all versions of the article before submission and during revision, agreed to take responsibility and be accountable for the contents of the article. M.J. performed experiments, collected, and analyzed the data. All authors contributed to data analysis, drafting or revising the article, have agreed on the journal to which the article will be submitted, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Additional information

Funding

There is no funding to report.