The RNA demethylase ALKBH5 promotes osteoblast differentiation by modulating Runx2 mRNA stability

Abstract

AlkB homolog 5 (ALKBH5) has been reported as a key m6A demethylase that is involved in development and diseases; however, the function of ALKBH5 in osteogenesis remains unknown. In this study, we report that ALKBH5 mRNA and protein expression were upregulated during osteoblast differentiation and that ALKBH5 knockdown suppressed osteoblast differentiation, mineralization, and the expression of osteogenic biomarkers. Conversely, ALKBH5 overexpression promoted osteogenesis. Moreover, the expression of wild‐type ALKBH5, but not the m6A‐modified active site mutant ALKBH5, could rescue ALKBH5 knockdown‐induced osteogenesis inhibition. Furthermore, knockdown of ALKBH5 significantly impaired the mRNA stability of the transcription factor Runx2, which plays a key role in osteoblast differentiation. Taken together, our results suggest that ALKBH5 promotes osteogenesis through modulating Runx2 mRNA stability.

Promoting Axon Regeneration By Inhibiting RNA N6-methyladenosine Demethylase ALKBH5

“…Furthermore, our study revealed that H205 is the conserved site of Alkbh5 for RNA demethylase activity in rats, and the mutation of H205A almost completely diminished the m6A modification activity. Similar result were observed for Alkbh5-induced osteoblast differentiation (Feng et al ., 2021), in which the H204A mutation in human Alkbh5 resulted in a complete loss of m6A modification activity (Feng et al, 2014; Zheng et al ., 2013).…”

Role of the Demethylase AlkB Homolog H5 in the Promotion of Dentinogenesis

“…ALKBH5 is a well-known m 6 A demethylase which has extensive involvement in important biological processes ( Geula et al, 2015 ; Zhang et al, 2016 ). Recently, the roles of ALKBH5 in various biological processes have been confirmed, such as cell proliferation, tumor invasion and metastasis, and osteogenesis ( Shen et al, 2020 ; Wang et al, 2020 ; Feng et al, 2021 ; Li et al, 2021 ). Therefore, the current study investigated the role of ALKBH5 in the regulation of odontoblast differentiation by evaluating odontoblast differentiation in mDPC6T cells and in a mouse conditional Alkbh5 knockout model.…”

“…The ALKBH5-protein arginine N-methyltransferase six pathway affects the osteogenic differentiation of bone marrow mesenchymal stem cells ( Li et al, 2021 ). ALKBH5 promotes osteoblast differentiation by regulating the stability of RUNX2 mRNA ( Feng et al, 2021 ). Based on these findings, we hypothesized that m 6 A methylation may be involved in odontoblast differentiation.…”

N6-Methyladenosine RNA Modification: A Potential Regulator of Stem Cell Proliferation and Differentiation

“…ALKBH5 could also dynamically reverse the METTL3-induced m 6 A methylation, and coordinated with METTL3 to regulate osteogenic differentiation via NF-κB signaling ( Yu et al, 2020 ). Additionally, ALKBH5 promoted osteoblast differentiation through modulating Runx2 mRNA stability ( Feng et al, 2021 ). The m 6 A demethylase FTO also possesses a crucial role in BMSCs differentiation, the expression of which was improved during adipocyte differentiation whereas its expression was reduced during osteoblast differentiation, indicating FTO facilitated BMSCs to differentiate into adipocytes compared with osteoblasts ( Shen et al, 2018 ).…”

“…2) The lineage-specific genes are closely associated with stem cells differentiation, which might be the targets of m 6 A modification to enable direct differentiation of stem cells into required lineages. For example, both the writer METTL3, and the erasers FTO and ALKBH5 can target the Runx2 mRNA of BMSCs to regulate osteogenesis, indicating the methylated level of Runx2 mRNA is pivotal for osteogenic differentiation ( Yan et al, 2020 ; Wang J. et al, 2021 ; Feng et al, 2021 ). However, more efforts are needed to determine the key genes associated with the cells differentiation and clarify the potential mechanisms.…”