WTAP-Mediated m6A Modification of TRAIL-DR4 Suppresses MH7A Cell Apoptosis

Area of Science:

• Epigenetics and RNA modification
• Molecular mechanisms of autoimmune diseases

Background:

• N6-methyladenosine (m6A) is a crucial RNA modification involved in biological processes like apoptosis and proliferation.
• Wilms tumor 1-associating protein (WTAP) is a key m6A regulator implicated in cell proliferation and apoptosis.
• The role of WTAP in rheumatoid arthritis (RA), characterized by synovial hyperplasia, remains largely unexplored.

Purpose of the Study:

• To investigate the role of WTAP-mediated m6A modification of TNF-related apoptosis-inducing ligand death receptor 4 (TRAIL-DR4) in RA.
• To elucidate the impact of WTAP on cellular processes in RA synovial cells.

Main Methods:

• WTAP overexpression and silencing in MH7A cells using plasmids and small interfering RNAs.
• Assessment of gene and protein expression (WTAP, BCL2, BAX, TRAIL-DR4) via immunofluorescence, RT-qPCR, and Western blot.
• Evaluation of cell viability, cell cycle, apoptosis, and proliferation using CCK-8, flow cytometry, and TEM.
• Verification of TRAIL-DR4 m6A modification and mRNA stability using MeRIP-qPCR and actinomycin D assays.

Main Results:

• WTAP overexpression increased WTAP and BCL2 levels, decreased BAX and TRAIL-DR4 levels, inhibited apoptosis, and promoted cell viability and proliferation in MH7A cells.
• WTAP silencing yielded opposite effects, highlighting WTAP's pro-survival role.
• WTAP was found to promote TRAIL-DR4 m6A modification, reduce TRAIL-DR4 mRNA stability, and subsequently inhibit apoptosis.

Conclusions:

• WTAP-mediated m6A modification of TRAIL-DR4 suppresses apoptosis in RA synovial cells (MH7A).
• This mechanism provides a novel therapeutic target for RA.
• The findings expand the understanding of RA pathophysiology through the lens of m6A alterations.