miR-194-5p inhibits LPS-induced astrocytes activation by directly targeting neurexophilin 1.

Astrocytes are vitally involved in the development of neurodegenerative diseases and brain cancers. In this work, we investigated the potential ameliorative role of microRNA-194-5p (miR-194-5p) against lipopolysaccharide (LPS)-induced astrocytes activation and the mechanism underneath. Astrocytes were transfected with miR-194-5p mimic or inhibitor and subsequently induced with LPS. Cell proliferation was measured using MTT assay while Transwell assay was used for assessing cell migration. The concentrations of cyclooxygenase 2 (COX2) and cytokines (tumor necrosis factor-α (TNF-α), transforming growth factor β (TGF-β), interleukin (IL)-1β and IL-6) were determined by enzyme-linked immunosorbent assay (ELISA). Gene expression was assessed by quantitative reverse transcription PCR (RT-qPCR) while western blotting was used for quantifying relative protein expression. We found that miR-194-5p, downregulated in LPS-induced astrocytes, significantly inhibited LPS-induced cell proliferation and migration. In addition, miR-194-5p inhibited the release of COX2 and pro-inflammatory cytokines (TNF-α, TGF-β, IL-1β and IL-6). Moreover, the silencing of neurexophilin 1 (NXPH1), an in silico and mechanistically confirmed direct target of miR-194-5p, reverted the anti-inflammatory, anti-proliferative and anti-migratory effects of miR-194-5p. We anticipated that miR-194-5 inhibits the proliferation, invasion, and inflammatory reaction in LPS-induced astrocytes by directly targeting NXPH1. These findings hinted that miR-194-5p/NXPH1 axis exerts vital functions in astrocytes activation and neuroinflammation-associated diseases. This finding will open novel avenues for biomedical and neuroscience research.