Effect of fenofibrate on the expression of miR-26a-5p/PTEN in retinal neurons of diabetic mice / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To study the protective effect of fenofibrate on diabetic retinal neurodegeneration and observe its effect on miR-26a-5p and its target gene PTEN in the retinal of diabetic mice.METHODS: Diabetic mice models were established and they were gavaged by fenofibrate. H& E staining and transmission electron microscopy were used to observe the impairments of retinal neurons. Real-time PCR was used to examine the expression of miR-26a-5p, and Western blotting was employed to measure the expression of phosphatase and tensin homologue(PTEN)in the retina of diabetic mice. The expression level of nuclear factor-κB(NF-κB), interleukin-1β(IL-1β)and the morphology of neural tissues were observed.RESULTS: When compared with the diabetic mice, fenofibrate significantly attenuated the damage to retinal ganglion cells and the atrophy of retinal nerve fiber layer. While the level of miR-26a-5p was increased and the levels of PTEN and inflammatory mediators were significantly decreased in the retina of fenofibrate treated diabetic mice, with significant statistical significance(P<0.05).CONCLUSIONS: Fenofibrate protects against diabetic retinal neurodegeneration by upregulating miR-26a-5p and inhibiting PTEN, attenuating the inflammatory response and alleviating retinal cell injury.

Mechanism of miR-26a-5p/cAMP response element binding protein 1 molecular axis regulating osteogenic differentiation of adipose-derived mesenchymal stem cells / 中国修复重建外科杂志

OBJECTIVE@#To investigate the regulatory effects of miR-26a-5p on the osteogenic differentiation of adipose-derived mesenchymal stem cells (ADSCs) by regulating cAMP response element binding protein 1 (CREB1).@*METHODS@#The adipose tissues of four 3-4 weeks old female C57BL/6 mice were collected and the cells were isolated and cultured by digestion separation method. After morphological observation and identification by flow cytometry, the 3rd-generation cells were subjected to osteogenic differentiation induction. At 0, 3, 7, and 14 days after osteogenic differentiation induction, the calcium deposition was observed by alizarin red staining, ALP activity was detected, miR- 26a-5p and CREB1 mRNA expressions were examined by real-time fluorescence quantitative PCR, and CREB1 protein and its phosphorylation (phospho-CREB1, p-CREB1) level were measured by Western blot. After the binding sites between miR-26a-5p and CREB1 was predicted by the starBase database, HEK-293T cells were used to conduct a dual-luciferase reporter gene experiment to verify the targeting relationship (represented as luciferase activity after 48 hours of culture). Finally, miR-26a-p inhibitor (experimental group) and the corresponding negative control (control group) were transfected into ADSCs. Alizarin red staining, ALP activity, real-time fluorescent quantitative PCR (miR-26a-5p) and Western blot [CREB1, p-CREB1, Runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN)] were performed at 7 and 14 days after osteogenic induction culture.@*RESULTS@#The cultured cells were identified as ADSCs. With the prolongation of osteogenic induction culture, the number of calcified nodules and ALP activity significantly increased ( P<0.05). The relative expression of miR-26a-5p in the cells gradually decreased, while the relative expressions of CREB1 mRNA and protein, as well as the relative expression of p-CREB1 protein were increased. The differences were significant between 7, 14 days and 0 day ( P<0.05). There was no significant difference in p-CREB1/CREB1 between different time points ( P>0.05). The starBase database predicted that miR-26a-5p and CREB1 had targeted binding sequences, and the dual-luciferase reporter gene experiment revealed that overexpression of miR-26a-5p significantly suppressed CREB1 wild-type luciferase activity ( P<0.05). After 7 and 14 days of osteogenic induction, compared with the control group, the number of calcified nodules, ALP activity, and relative expressions of CREB1, p-CREB1, OCN, and RUNX2 proteins in the experimental group significantly increased ( P<0.05). There was no significant difference in p-CREB1/CREB1 between the two groups ( P>0.05).@*CONCLUSION@#Knocking down miR-26a-5p promoted the osteogenic differentiation of ADSCs by up-regulating CREB1 and its phosphorylation.

Expression of lncRNA FAM95B1 in glioma and the possible mechanism of its effect on the proliferation and migration of LN382 cells / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探讨lncRNA FAM95B1对胶质瘤细胞增殖和迁移能力的影响并探究其相关作用机制。方法： 选取2018年1月至2020年8月于合肥市第三人民医院行手术治疗的38例胶质瘤患者的胶质瘤组织及癌旁组织标本，利用qPCR检测胶质瘤组织与4种细胞系中FAM95B1的表达水平，以表达最低的胶质瘤LN382细胞为研究对象，转染空载质粒（对照组）或pcDNA3.1-FAM95B1质粒（实验组）。MTT法和划痕实验检测FAM95B1对LN382细胞增殖和迁移能力的影响。生物信息学分析技术和双荧光素酶基因报告实验预测并验证FAM95B1与miR-26a-5p及PTEN之间的相互作用机制，应用qPCR和WB法检测FAM95B1对miR-26a-5p和PTEN表达的影响。结果： FAM95B1在胶质瘤组织中的表达明显低于癌旁组织（P<0.01）。FAM95B1在多种胶质瘤细胞系中的表达均明显低于正常脑胶质细胞（均P<0.01）。过表达FAM95B1可以下调LN382细胞的增殖（P<0.05）和迁移能力（P<0.01）。FAM95B1能够靶向结合miR-26a-5p（P<0.01），miR-26a-5p能够靶向结合PTEN mRNA（P<0.01）。过表达FAM95B1可下调LN382细胞中miR-26a-5p的表达（P<0.01），促进PTEN mRNA的表达（P<0.01）。结论：在胶质瘤组织和细胞系中异常低表达的FAM95B1通过发挥竞争性内源RNA的功能抑制miR-26a-5p的表达而增强PTEN蛋白表达，抑制胶质瘤细胞系LN382的增殖和迁移。

miR-26a-5p protects against myocardial ischemia/reperfusion injury by regulating the PTEN/PI3K/AKT signaling pathway

Reperfusion strategies in acute myocardial infarction (AMI) can cause a series of additional clinical damage, defined as myocardial ischemia/reperfusion (I/R) injury, and thus there is a need for effective therapeutic methods to attenuate I/R injury. miR-26a-5p has been proven to be an essential regulator for biological processes in different cell types. Nevertheless, the role of miR-26a-5p in myocardial I/R injury has not yet been reported. We established an I/R injury model in vitro and in vivo. In vitro, we used cardiomyocytes to simulate I/R injury using hypoxia/reoxygenation (H/R) assay. In vivo, we used C57BL/6 mice to construct I/R injury model. The infarct area was examined by TTC staining. The level of miR-26a-5p and PTEN was determined by bioinformatics methods, qRT-PCR, and western blot. In addition, the viability and apoptosis of cardiomyocytes were separately detected by MTT and flow cytometry. The targeting relationship between miR-26a-5p and PTEN was analyzed by the TargetScan website and luciferase reporter assay. I/R and H/R treatment induced myocardial tissue injury and cardiomyocyte apoptosis, respectively. The results showed that miR-26a-5p was down-regulated in myocardial I/R injury. PTEN was found to be a direct target of miR-26a-5p. Furthermore, miR-26a-5p effectively improved viability and inhibited apoptosis in cardiomyocytes upon I/R injury by inhibiting PTEN expression to activate the PI3K/AKT signaling pathway. miR-26a-5p could protect cardiomyocytes against I/R injury by regulating the PTEN/PI3K/AKT pathway, which offers a potential approach for myocardial I/R injury treatment.