Purpose: Cerebral ischemia is related to insufficient blood supply and is characterized by abnormal reactive oxygen species (ROS) production and cell apoptosis. Previous studies have revealed a key role for basic helix-loop-helix family member e40 (Bhlhe40) in oxidative stress and cell apoptosis. This study aimed to investigate the roles of miR-494-3p in cerebral ischemia/reperfusion (I/R) injury. Materials and Methods: A mouse middle cerebral artery occlusion (MCAO/R) model was established to mimic cerebral ischemia in vivo. Brain infarct area was assessed using triphenyl tetrazolium chloride staining. Oxygen-glucose deprivation/reoxygenation (OGD/R) operation was adopted to mimic neuronal injury in vitro. Cell apoptosis was analyzed by flow cytometry. The relationship between miR-494-3p and Bhlhe40 was validated by luciferase reporter and RNA immunoprecipitation assays. Results: Bhlhe40 expression was downregulated both in MCAO/R animal models and OGD/R-induced SH-SY5Y cells. Bhlhe40 overexpression inhibited cell apoptosis and reduced ROS production in SH-SY5Y cells after OGD/R treatment. MiR-494-3p was verified to bind to Bhlhe40 and negatively regulate Bhlhe40 expression. Additionally, cell apoptosis and ROS production in OGD/ R-treated SH-SY5Y cells were accelerated by miR-494-3p overexpression. Rescue experiments suggested that Bhlhe40 could reverse the effects of miR-494-3p overexpression on ROS production and cell apoptosis. Conclusion MiR-494-3p exacerbates brain injury and neuronal injury by regulating Bhlhe40 after I/R.

Objective:To investigate the effect of tofacitinib,a pan-Janus kinase(JAK)inhibitor,on transforming growth factor-beta 1(TGF-β1)-induced fibroblast to myofibroblast transition(FMT)and to explore its mechanism.To provide a theoretical basis for the clinical treatment of connective tissue disease-related interstitial lung disease(CTD-ILD).Methods:(1)Human fetal lung fibroblast 1(HFL-1)were cultured in vitro,and 6 groups were established:DMSO blank control group,TGF-β1 in-duction group,and TGF-β1 with different concentrations of tofacitinib(0.5,1.0,2.0,5.0 μmol/L)drug intervention experimental groups.CCK-8 was used to measure the cell viability,and wound-healing assay was performed to measure cell migration ability.After 48 h of combined treatment,quantitative real-time PCR(RT-PCR)and Western blotting were used to detect the gene and protein expression levels of α-smooth muscle actin(α-SMA),fibronectin(FN),and collagen type Ⅰ(COL1).(2)RT-PCR and enzyme-linked immunosorbnent assay(ELISA)were used to detect the interleukin-6(IL-6)gene and protein expression changes,respectively.(3)DMSO carrier controls,1.0 μmol/L and 5.0 μmol/L tofacitinib were added to the cell culture media of different groups for pre-incubation for 30 min,and then TGF-β1 was added to treat for 1 h,6 h and 24 h.The phosphorylation levels of Smad2/3 and signal transducer and activator of transcription 3(STAT3)protein were detected by Western blotting.Results:(1)Tofacitinib inhibited the viability and migration ability of HFL-1 cells after TGF-β1 induction.(2)The expression of α-SMA,COL1A1 and FN1 genes of HFL-1 in the TGF-β1-induced groups was signifi-cantly up-regulated compared with the blank control group(P＜0.05).Compared with the TGF-β1 in-duction group,α-SMA expression in the 5.0 μmol/L tofacitinib intervention group was significantly inhi-bited(P＜0.05).Compared with the TGF-β1-induced group,FN1 gene was significantly inhibited in each intervention group at a concentration of 0.5-5.0 μmol/L(P＜0.05).Compared with the TGF-β1-induced group,the COL1A1 gene expression in each intervention group did not change significantly.(3)Western blotting results showed that the protein levels of α-SMA and FN1 in the TGF-β1-induced group were significantly higher than those in the control group(P＜0.05),and there was no significant difference in the expression of COL1A1.Compared with the TGF-β1-induced group,the α-SMA protein level in the intervention groups with different concentrations decreased.And the differences between the TGF-β1-induced group and 2.0 μmol/L or 5.0 μmol/L intervention groups were statistically significant(P＜0.05).Compared with the TGF-β1-induced group,the FN1 protein levels in the intervention groups with different concentrations showed a downward trend,but the difference was not statistically sig-nificant.There was no difference in COL1A1 protein expression between the intervention groups com-pared with the TGF-β1-induced group.(4)After TGF-β1 acted on HFL-1 cells for 48 h,the gene ex-pression of the IL-6 was up-regulated and IL-6 in culture supernatant was increased,the intervention with tofacitinib partly inhibited the TGF-β1-induced IL-6 gene expression and IL-6 in culture supernatant.TGF-β1 induced the increase of Smad2/3 protein phosphorylation in HFL-1 cells for 1 h and 6 h,STAT3 protein phosphorylation increased at 1 h,6 h and 24 h,the pre-intervention with tofacitinib inhibited the TGF-β1-induced Smad2/3 phosphorylation at 6 h and inhibited TGF-β1-induced STAT3 phosphorylation at 1 h,6 h and 24 h.Conclusion:Tofacitinib can inhibit the transformation of HFL-1 cells into myofi-broblasts induced by TGF-β1,and the mechanism may be through inhibiting the classic Smad2/3 path-way as well as the phosphorylation of STAT3 induced by TGF-β1,thereby protecting the disease progres-sion of pulmonary fibrosis.