Circulating microRNA let­7e is decreased in knee osteoarthritis, accompanied by elevated apoptosis and reduced autophagy.

Knee osteoarthritis (KOA) is a major cause of leg disability in the elderly population. Recently, the expression levels of circulating microRNA (miRNA) let­7e have been reported to be significantly reduced in KOA. The aims of the present study were to assess the feasibility of let­7e as a serum marker for detecting KOA and to explore the underlying mechanisms of its involvement. Based on previous studies and bioinformatics analysis, let­7e may regulate apoptosis and autophagy of articular chondrocytes. A total of 10 patients with KOA and 10 patients with trauma without KOA were recruited to examine the levels of let­7e in peripheral blood. Subsequently, KOA rat models were established, and the levels of let­7e in the cartilage and serum were examined, the expression of apoptotic proteins and autophagy­related proteins in the cartilage were investigated, and apoptotic and autophagic activities of primary cultured chondrocytes were also detected. In patients with KOA, let­7e levels in the peripheral serum were significantly decreased compared with the control group, and this result was confirmed in the peripheral serum and cartilage of KOA rats. In addition, the expression levels of proteins involved in the apoptotic pathway were increased in the cartilage of KOA rats, and apoptotic activity was increased. The expression of autophagy­related proteins beclin 1 and microtubule associated protein 1 light chain 3 ß (LC3B) II/LC3BI in the articular cartilage of KOA rats was lower compared with the controls, and autophagy was decreased. Si­Miao­San (SMS) treatment restored the expression of let­7e and reversed the changes in apoptosis and autophagy. Therefore, the present study provided additional evidence that circulating let­7e may be a potential serum biomarker for the diagnosis and treatment of KOA. Elevated apoptosis levels and decreased autophagy levels of cartilage tissue are involved in KOA, and treatment with SMS may reverse these effects.

[Inhibition effect of hedyotis diffusa wild injection on HL-60 cells and its mechanism].

This study was aimed to explore the inhibition effect and mechanism of hedyotis diffusa wild injection (HDI) on leukemia cell line (HL-60) in vitro. The leukemia cell line HL-60 was used as target cells. The inhibitory effects of HDI on proliferation of HL-60 cells were observed by MTT assay. The positive rate of cell apoptosis and the surface marker of granulocytic differentiation (CD33 and CD15) were measured by flow cytometry. The expressions of anti-apoptosis related gene (survivin and bcl-2) were detected by RT-PCR. The results showed that the growth of HL-60 cells was inhibited by higher concentration of HDI (3.12 - 12.5 ml/L) and inhibited obviously in dose-dependent manner (p < 0.05 or p < 0.01), but not suppressed by low concentration of HDI (1.56 ml/L) in liquid culture system (p > 0.05). The FCM and DNA Ladder results showed that the phenomenon of typical apoptosis did not detected after HL-60 cells were treated with the different concentrations of HDI for 24, 48 and 72 hours respectively. After HL-60 cells were treated with HDI (1.56, 3.12, 6.25 and 12.5 ml/L) for one week, the expression level of CD15 surface marker was all enhanced obviously. When treated with HDI (6.25 ml/L) for 3 weeks, the expression levels of survivin and bcl-2 gene were also decreased obviously by 60% and 44% respectively. It is concluded that HDI can inhibit HL-60 cells in the presence of its higher concentrations. The mechanisms of HDI may induce HL-60 cells differentiation, and suppress the expression of anti-apoptosis related gene (survivin or bcl-2) to inhibit the growth of HL-60 cells.