Activation of ERK/MAPK signaling by MAZ through transcriptional repression of PPP3CA to promote osteoclastogenesis and osteoporosis progression: Functions and mechanisms

Objective

Osteoporosis (OP) is a systemic skeletal disease that contributes to compromised bone strength and increased fracture risk. This paper investigates the functional role of protein phosphatase 3 catalytic subunit α (PPP3CA) in OP and its mechanisms.

Methods

Bioinformatics prediction analysis was performed to identify genes associated with OP and its transcription factor. An OP mouse model was constructed by ovariectomy (OVX). RAW264.7 cells were induced to differentiate into osteoclasts using RANKL for in vitro experiments.

Results

PPP3CA was poorly expressed in the femoral tissues of OVX-induced mice. Overexpression of PPP3CA reduced nuclear factor of activated T cells c1 (NFATC1) and matrix metalloproteinase 9 (MMP9) levels and the extent of extracellular signal-regulated protein kinase (ERK)1/2 phosphorylation. Overexpression of PPP3CA inhibited osteoclast differentiation and OP progression. Myc-associated zinc finger protein (MAZ) was highly expressed in the femoral tissues of OVX-induced mice and inhibited the transcription of PPP3CA by binding to its promoter. MAZ promoted the ERK/mitogen-activated protein kinase (MAPK) pathway and thus promoted osteoclastogenesis. Animal experiments further demonstrated that the MAZ/PPP3CA axis promoted osteoclastogenesis through the ERK/MAPK pathway in vivo.

Conclusion

MAZ promotes osteoclastogenesis and OP progression by activating the ERK/MAPK signaling pathway through transcriptional inhibition of PPP3CA. These findings not only elucidate a novel mechanism driving osteoclastogenesis but also highlight the MAZ/PPP3CA/ERK-MAPK axis as a promising target for innovative therapies aimed at curbing bone resorption and ultimately improving treatment outcomes in OP.