Comprehensive Analysis of circRNA and mRNA Revealing Potential Mechanism Underlying Neuroinflammation in BV2 Cells

The significance of circular RNAs (circRNAs) in diabetic complications has been established. However, their role in basal and diabetic states, as well as cognitive dysfunction, requires further investigation.

BV-2 microglial cells were exposed to high glucose (50 mM) and insulin (2 μM) for 48 hours. The levels of interleukin-1beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor- alpha (TNF-α) were assessed through quantitative polymerase chain reaction (qPCR), western blot, and ELISA. CircRNA and messenger RNA (mRNA) sequencing were performed, and the data were analyzed. Differentially expressed circRNAs and mRNAs were identified using qPCR. The circRNA-miRNA interaction was predicted using Miranda and TargetScan software, and their levels were quantified by qPCR.

The results demonstrated a significant increase in mRNA and protein levels of IL-1β, IL-6, and TNF-α in BV2 cells treated with glucose and insulin. Five circRNAs (four upregulated and one downregulated) were identified in both glucose and insulin groups compared to the control. Further qPCR analysis revealed marked increases in the levels of chr17:40159331- 40159711+ and chr2:72800499-72801858- (mmu_circ_0010164) in both treatment groups. Competitive endogenous RNA networks showed significant upregulation of mRNA levels of mitochondrial transcription termination factor 1b (Mterf1b) and G protein subunit gamma 4 (Gng4), accompanied by a decrease in mmu-miR-6918-3p and mmu-miR-7043-3p levels in the glucose and insulin groups compared to the control. Knockdown of mmu_circ_0010164 significantly inhibited the inflammatory response induced by glucose and insulin in BV-2 microglial cells.

These findings indicate that both glucose and insulin can elicit inflammatory responses in BV2 cells through the modulation of mmu_circ_0010164 levels. The underlying mechanism may involve potential downstream targets of mmu_circ_0010164, specifically mmu-miR-7043-3p/Gng4 and mmu-miR-6918-3p/Mterf1b. This provides novel insights into the treatment of glucose-induced neuroinflammation.