Résumé
Objective To investigate the effect of long non-coding RNA (lncRNA) alpha-2-macroglobulin antisense RNA 1 (A2M-AS1) targeting microRNA (miR) -106b-5p on oxidized low-density lipoprotein (ox-LDL) -induced injury of human brain microvascular endothelial cells. Methods Human brain microvascular endothelial cells (ox-LDL group) were induced by ox-LDL, normal cultured cells were control group (Ctrl); A2M-AS1 overexpression (pcDNAA2M-AS1 group), empty vector (pcDNA group), miR-106b-5p inhibitor (anti-miR-106b-5p group), negative control (anti-miR-NC group), pcDNA-A2M-AS1 with control mimic NC (miR-NC group), pcDNA-A2M-AS1 with miR-106b-5p mimic (miR-106b-5p mimics group) were transfected into cells and treated with ox-LDL, n = 9. Real-time PCR was used to detect the expression levels of A2M-AS1 and miR-106b-5p; Kits were used to detect malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT)); Flow cytometry and TUNEL detected apoptosis; Dual luciferase reporter gene assay detected A2M-AS1 and miR-106b-5p targeting; Western blotting detected Bcl-2 and Bax protein expression. Results Compared with the Ctrl group, the expression level of A2M-AS1 in the ox-LDL group decreased, and the activity of SOD and CAT and the protein level of Bcl-2 decreased (P<0.05), while the expression level of miR-106b-5p and the level of MDA increased (P<0.05), and the rate of apoptosis and the protein level of Bax increased (P<0.05). Overexpressing A2M-AS1 or interfering with miR-106b-5p decreased the MDA level, apoptosis rate and Bax protein level after ox-LDL-induced cells, and increased SOD, CAT activity and Bcl-2 protein level (P<0.05). A2M-AS1 targeted miR-106b-5p; upregulation of miR-106b-5p reversed the effect of overexpressed lncRNA A2M-AS1 on ox-LDL-induced injury of human brain microvascular endothelial cells (P < 0.05). Conclusion A2M-AS1 attenuates ox-LDL-induced injury of human brain microvascular endothelial cells by targeting miR-106b-5p.
Résumé
Objective To investigate clinical significance and function of microRNA-106b (miR-106b) in retinoblastoma tissues and cells.Methods We detected miR-106b expression in 51 samples of thyroid cancer and the adjacent non-tumor tissues using qRT-PCR.The expression of miR-106b was altered by corresponding vectors in thyroid cancer cells,and then BrdU cell proliferation and flow cytometry assay were performed to examine the proliferation and apoptosis of thyroid cancer cells.Results The expression of miR-106b in thyroid cancer tissues was significantly lower than that in normal tumor-adjacent tissues (0.36±0.029 vs 0.98±0.034,P＝ 0.004).MiR-106b expression in tumor tissues was significantly associated with tumor size and tumor number.MiR-106b was obviously inhibited by miR-106b inhibitor in PTC-I cells (0.96±0.025 vs 0.29±0.032,P＝0.001),and inhibition of miR-106b resulted in significantly increased proliferation (89.33±5.67 vs 136.67±10.33,P＝0.03) and decreased apoptosis (16.33±3.20 vs 7.67±2.45,P＝0.04).On the contrast,over-expression of miR-106b using miR-106b mimics led to significantly decreased proliferation (98.00±4.65 vs 76.33±2.87,P＝0.03) and increased apoptosis (22.54±2.13 vs 32.45±4.34,P＝0.04).Conclusions Decreased expression of miR-106b is correlated with the adverse clinicopathological features of thyroid cancer.MiR-106b can inhibit cell proliferation and apoptosis of thyroid cancer cells,suggesting miR-106b plays a suppressive role in development and progression of thyroid cancer.
Résumé
Neural stem cells (NSCs) proliferation can be influenced by repetitive transcranial magnetic stimulation (rTMS) in vivo via microRNA-106b-25 cluster, but the underlying mechanisms are poorly understood. This study investigated the involvement of microRNA-106b-25 cluster in the proliferation of NSCs after repetitive magnetic stimulation (rMS) in vitro. NSCs were stimulated by rMS (200/400/600/800/1000 pulses per day, with 10 Hz frequency and 50% maximum machine output) over a 3-day period. NSCs proliferation was detected by using ki-67 and EdU staining. Ki-67, p21, p57, cyclinD1, cyclinE, cyclinA, cdk2, cdk4 proteins and miR-106b, miR-93, miR-25 mRNAs were detected by Western blotting and qRT-PCR, respectively. The results showed that rMS could promote NSCs proliferation in a dose-dependent manner. The proportions of ki-67+ and Edu+ cells in 1000 pulses group were 20.65% and 4.00%, respectively, significantly higher than those in control group (9.25%, 2.05%). The expression levels of miR-106b and miR-93 were significantly upregulated in 600-1000 pulses groups compared with control group (P<0.05 or 0.01 for all). The expression levels of p21 protein were decreased significantly in 800/1000 pulses groups, and those of cyclinD1, cyclinA, cyclinE, cdk2 and cdk4 were obviously increased after rMS as compared with control group (P<0.05 or 0.01 for all). In conclusion, our findings suggested that rMS enhances the NSCs proliferation in vitro in a dose-dependent manner and miR-106b/p21/cdks/cyclins pathway was involved in the process.