Mettl3 Mediated m6A Methylation Involved in Epithelial-Mesenchymal Transition by Targeting SOCS3/STAT3/SNAI1 in Cigarette Smoking-Induced COPD

Abstract

Purpose

Persistent inflammation and epithelial-mesenchymal transition are essential pathophysiological processes in chronic obstructive pulmonary disease (COPD) and involve airway remodeling. m6A methylation modification was discovered to play an important role in various diseases. Nevertheless, the regulatory role of m6A methylation has not yet been investigated in cigarette smoking-induced COPD. The study aims to explore the regulatory role of m6A methylation in cigarette smoking-induced COPD.

Patients and Methods

In this study, two Gene Expression Omnibus (GEO) datasets were first utilized to analyze the expression profiles of m6A RNA methylation regulators in COPD. We then established a cell model of COPD by exposing human bronchial epithelial cells (HBECs) to cigarette smoke extract (CSE) in vitro and detected the expression of m6A writer Mettl3 and EMT phenotype markers. RNA interference, cycloleucine, RT-qPCR, western blot, MeRIP-sequencing, and cell migration assay were performed to investigate the potential effect of Mettl3 on the EMT process in CSE-induced HBECs.

Results

Our results showed that Mettl3 expression was significantly elevated in cigarette smoking-induced COPD patients and in a cellular model of COPD. Furthermore, Mettl3 silence and cycloleucine treatment inhibited the EMT process of HBECs caused by CSE. Mechanically, Mettl3 silence weakens the m6A methylation of SOCS3 mRNA to enhance the protein expression of SOCS3, inhibiting CSE-induced SOCS3/STAT3/SNAI1 signaling and EMT processes in HBECs.

Conclusion

Our study inferred that Mettl3-mediated m6A RNA methylation modification modulates CSE-induced EMT by targeting SOCS3 mRNA and ultimately serves as a crucial regulator in the emergence of COPD. This conclusion reinforces the regulatory role of m6A methylation in COPD.

Keywords:

• inflammation
• COPD
• MeRIP–sequencing
• cycloleucine

Data Sharing Statement

The dataset used in this study can be obtained from public repositories:

GSE130928 dataset (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE130928);

GSE5058 (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE5058);

Our m6A RNA-sequencing dataset is available in the GEO dataset (GSE209802: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE209802).

Ethical/Institutional Review Board and Ethics Approval Number

The ethical/institutional review board: Medical Ethics Committee of the Second Affiliated Hospital of Fujian Medical University.

Ethics approval number: No. 46 [2016].

Acknowledgments

We thank the funding offered by the Science and Technology Department of Fujian Province (China).

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

Funding for this study came from grants from “the Natural Science Foundation of Fujian, China, grant number 2019J01171”, “Science and Technology Project of Quanzhou, China, grant number 2018Z122” and “Youth Research Project of Fujian Health Commission, grant number 2018-2-25”.