ARG2 knockdown promotes G0/G1 cell cycle arrest and mitochondrial dysfunction in adenomyosis via regulation NF-κB and Wnt/Β-catenin signaling cascades.

Background: Adenomyosis is a common gynecological disease, characterized by overgrowth of endometrial glands and stroma in the myometrium, however its exact pathophysiology still remains uncertain. Emerging evidence has demonstrated the elevated level of arginase 2 (ARG2) in endometriosis and adenomyosis. This study aimed to determine whether ARG2 involved in mitochondrial function and epithelial to mesenchymal transition (EMT) in adenomyosis and its potential underlying mechanisms.

Materials And Methods: RNA interference was used to inhibit ARG2 gene, and then Cell Counting Kit (CCK-8) assay and flow cytometery were performed to detect the cell proliferation capacity, cell cycle, and apoptosis progression, respectively. The mouse adenomyosis model was established and RT-PCR, Western blot analysis, mitochondrial membrane potential (Δψm) detection and mPTP opening evaluation were conducted.

Results: Silencing ARG2 effectively down-regulated its expression at the mRNA and protein levels in endometrial cells, leading to decreased enzyme activity and inhibition of cell viability. Additionally, ARG2 knockdown induced G0/G1 cell cycle arrest, promoted apoptosis, and modulated the expression of cell cycle- and apoptosis-related regulators. Notably, the interference with ARG2 induces apoptosis by mitochondrial dysfunction, ROS production, ATP depletion, decreasing the Bcl-2/Bax ratio, releasing Cytochrome c, and increasing the expression of Caspase-9/-3 and PARP. In vivo study in a mouse model of adenomyosis demonstrated also elevated levels of ARG2 and EMT markers, while siARG2 treatment reversed EMT and modulated inflammatory cytokines. Furthermore, ARG2 knockdown was found to modulate the NF-κB and Wnt/β-catenin signaling pathways in mouse adenomyosis.

Conclusion: Consequently, ARG2 silencing could induce apoptosis through a mitochondria-dependent pathway mediated by ROS, and G0/G1 cell cycle arrest via suppressing NF-κB and Wnt/β-catenin signaling pathways in Ishikawa cells. These findings collectively suggest that ARG2 plays a crucial role in the pathogenesis of adenomyosis and may serve as a potential target for therapeutic intervention.