The present study aimed to ascertain the potential roles and mechanisms of action of micro (mi)RNA-22 in ischemic stroke. The results indicated that miRNA-22 expression was downregulated in ischemic stroke rats model, compared with a control group. The downregulation of miRNA-22 upregulated the expression of inflammatory factors [including tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-18]. It could also induce the expression of macrophage inflammatory protein (MIP-2), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS) in the in vitro model. By contrast, the overexpression of miRNA-22 downregulated the expression of inflammatory factors, and suppressed the expression of MIP-2, PGE2, COX-2 and iNOS in the in vitro model. The downregulation of miRNA-22 induced the protein expression of nuclear factor (NF)-κB and phosphorylated-p38 (p-p38) mitogen-activated protein kinase (MAPK) in the in vitro model. By comparison, the overexpression of miRNA-22 suppressed the protein expression of NF-κB and p-p38 in the in vitro model. Typically, LY2228820, the p38 inhibitor (3 nM) would mitigate the pro-inflammatory effects of anti-miRNA-22 in the in vitro model. These results suggested that miRNA-22 can alleviate ischemic stroke-induced inflammation in rats model or vitro model through p38 MAPK/NF-κB pathway suppression.

Accumulating evidence has shown that miR-429 plays an important role in the development and progression of tumour. However, the role of miR-429 in glioblastoma multiforme (GBM) remains largely unknown. The present study is designed to investigate the function of miR-429 in GBM and to explore the molecular mechanism underlying its function. The expression level of miR-429 was detected in GBM tissues and cell lines by quantitative real-time polymerase chain reaction. The effect of overexpression of miR-429 on in vitro cell proliferation, apoptosis and invasion was examined. Western blot analysis was used to detect the influence of miR-429 on the expression of target gene, and Pearson analysis was used to calculate the correlation between the expression of targets gene and the miR-429 in GBM tissues. Our study shows that miR-429 is downregulated in GBM tissues compared with noncancerous tissues (P < .01). In addition, the expression of miR-429 in GBM cell lines is also significantly lower (P < .01). Enforced expression of miR-429 inhibits GBM cells proliferation, induces apoptosis and suppresses invasion and leads to the downregulation of the SOX2 protein. Moreover, the expression level of miR-429 in GBM tissues shows inverse relationship with the expression level of SOX2 protein. Our findings suggest that miR-429 represents a potential tumour-suppressive miRNA and plays an important role in GBM progression by directly targeting SOX2.