Stage-specific requirement for METTL3-dependent m⁶A modification during dental pulp stem cell differentiation

Area of Science:

• Stem cell biology
• Epigenetics
• Molecular biology

Background:

• N⁶-methyladenosine (m⁶A) is a key RNA modification influencing cell fate.
• The role of m⁶A in orchestrating stem cell differentiation remains unclear.
• This study investigates m⁶A methylation in dental pulp stem cell (DPSC) differentiation.

Purpose of the Study:

• To elucidate the biological function and mechanism of m⁶A methylation in DPSC differentiation.
• To identify m⁶A targets critical for DPSC mineralization.
• To understand the role of METTL3 in regulating DPSC differentiation via m⁶A.

Main Methods:

• m⁶A-mRNA sequencing to map m⁶A modifications during DPSC differentiation.
• In vivo ectopic transplantation of DPSCs to validate in vitro findings.
• RNA sequencing, RIP, and RNA/protein stability assays to identify and analyze target genes like Noggin (NOG).

Main Results:

• A dynamic m⁶A landscape was observed during DPSC mineralization, enriched in 3' UTRs.
• METTL3 was identified as a key regulator, with its knockdown disrupting differentiation and overexpression enhancing mineralization.
• m⁶A deposition in the 3' UTR of NOG restricted its expression and promoted its degradation by shortening the poly(A) tail in differentiated DPSCs.

Conclusions:

• Dynamic m⁶A signaling plays a crucial role in the temporal control of DPSC differentiation.
• METTL3-mediated m⁶A modification of NOG is essential for DPSC mineralization.
• These findings offer insights into epitranscriptomic regulation in stem cell-based therapies.