GPR183 Regulates 7α,25-Dihydroxycholesterol-Induced Oxiapoptophagy in L929 Mouse Fibroblast Cell

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• 7α,25-dihydroxycholesterol (7α,25-DHC) is an oxysterol synthesized by CYP7B1.
• It is expressed under inflammatory conditions in various cell types.

Purpose of the Study:

• To verify that 7α,25-DHC-induced oxiapoptophagy is mediated by apoptosis, oxidative stress, and autophagy in L929 mouse fibroblasts.
• To investigate the role of G-protein-coupled receptor 183 (GPR183) in this process.

Main Methods:

• MTT assays and live/dead cell staining to assess cytotoxicity.
• Analysis of apoptotic markers (caspase-9, caspase-3, PARP) and autophagy biomarkers (beclin-1, LC3).
• Measurement of reactive oxygen species (ROS) and p53 expression.
• Inhibition of GPR183 using a specific antagonist (NIBR189).

Main Results:

• 7α,25-DHC increased cytotoxicity, apoptosis, ROS production, and autophagy in L929 cells.
• Apoptosis involved the intrinsic pathway activation.
• Autophagy markers were upregulated, and Akt phosphorylation was inhibited.
• GPR183 inhibition suppressed 7α,25-DHC-induced oxiapoptophagy, ROS, and autophagy.

Conclusions:

• 7α,25-DHC induces oxiapoptophagy in L929 cells through apoptosis, oxidative stress, and autophagy.
• GPR183 plays a regulatory role in 7α,25-DHC-induced oxiapoptophagy.