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.

A study on mechanism of lncRNA-mediated SNHG5/miR-26a-5p/MTDH signal axis promoting metastasis of colorectal cancer / 中国癌症杂志

Background and purpose: Long non-coding RNA small nucleolar RNA host gene 5 (lncRNA SNHG5) plays a cancer-promoting role in many cancers, however its effect on colorectal cancer (CRC) and its regulatory mechanism are not clear. This study aimed to explore the mechanism of lncRNA SNHG5/miR-26a-5p/metadherin (MTDH) signal axis promoting metastasis of CRC. Methods: The data of The Cancer Genome Atlas (TCGA) database was analyzed, the abnormal expression of lncRNA in CRC was explored and analyzed the survival. Samples of CRC, paracancerous tissues and complete clinical data of patients who underwent surgical resection from October 2020 to October 2021 were collected. The expression levels of SNHG5 and miR-26a-5p in lncRNA were detected by real-time fluorescence quantitative polymerase chain reaction (RTFQ-PCR), and the expression level of MTDH was detected by immunohistochemistry. The relationship between the relative expression level of lncRNA SNHG5 in CRC and clinicopathological features and survival time was analyzed. The effects of lncRNA SNHG5 on the proliferation, migration and invasion of CRC cells were detected by cell counting kit-8 (CCK-8), clone formation, scratching assays, transwell test and in vivo xenotransplantation. The relationship between CRC cell metastasis, the expression level of epithelial-mesenchymal transition related molecules and lncRNA SNHG5 expression level by Western blot and immunohistochemical detection were explored. The physical interaction between SNHG5 and miR-26a-5p, MTDH and miR-26a-5p was studied by RNA pull-down test, double luciferase reporter gene detection and RNA co-immunoprecipitation. The functional relationship among the three was verified by CCK-8, EdU and transwell experiments. The effect of SNHG5, miR-26a-5p and MTDH expression on migration and invasion related molecules was analyzed by Western blot. Results: The results of TCGA database analysis showed that lncRNA SNHG5 was significantly upregulated in CRC. The results of RTFQ-PCR and immunohistochemistry showed that the levels of lncRNA SNHG5 and MTDH in CRC tissues were significantly upregulated (P＜0.05), the level of miR-26a-5p was decreased (P＜0.05), and the level of MTDH in samples with high expression of SNHG5 was also increased. The expression of lncRNA SNHG5 in CRC tissues with serosa and extraserosal invasion, distant metastasis, lymph node metastasis and TNM stage Ⅲ was significantly higher compared with subserosal invasion, no distant metastasis and lymph node metastasis and TNM stage Ⅰ-Ⅱ (P＜0.05). The results of survival analysis showed that the high expression of lncRNA SNHG5 was significantly correlated with overall survival rate (P＜0.05). Overexpression of lncRNA SNHG5 could enhance the proliferation, clone formation, migration and invasion of CRC cells, promote the growth and lung metastasis of transplanted tumor, increase the relative expression level of Ki-67 proliferation index and vimentin (P＜0.05), and decrease the relative expression level of E-cadherin (P＜0.05). However, the development of CRC cells was inhibited after inhibition of lncRNA SNHG5 expression. RNA pull-down test, double luciferase reporter gene detection and RNA co-immunoprecipitation confirmed the physical interaction between SNHG5 and miR-26a-5p, MTDH and miR-26a-5p. Upregulation of miR-26a-5p or downregulation of MTDH expression in lncRNA SNHG5 overexpressed cells partially reversed the effects of lncRNA SNHG5 on proliferation, migration, invasion and expression of related molecules in CRC cells. Conclusion: LncRNA SNHG5 is upregulated in CRC tissues and cells, and its high expression is related to tumor progression and poor survival. It can be used as a molecular sponge of miR-26a-5p to regulate the expression of MTDH to promote the proliferation and metastasis of SW620 cells.

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 and diagnostic value of plasma exosomes miR - 26a－5p and miR - 151a－3p in tuberculosis / 安徽医科大学学报

Objective @#To study the differential expression and diagnostic value of miR-26a-5p and miR-151a-3p in plasma exosomes of tuberculosis.@*Methods @#Differentially expressed miRNAs ( miR-26a-5p and miR-151a-3p) in tuberculosis exosomes were identified through bioinformatics website．Furthermore，70 tuberculosis patients (tuber- culosis group) and 58 healthy subjects ( healthy control group) were selected for clinical validation : Plasma exo- somes，extracted by differential centrifugation，were identified by Western blot，transmission electron microscopy， nanoparticle tracking analysis．The expression levels of miR-26a-5p and miR-151a-3p in plasma exosome were de- tected by RT-qPCR in the tuberculosis group and the control group．The diagnostic value of miR-26a-5p and miR- 151a-3p in tuberculosis was evaluated by ROC curve. @*Results @#The characteristics of exosomes were identified by transmission electron microscopy，nanoparticle tracking analysis and Western blot，which showed that plasma exo- somes were extracted successfully．In clinical validation，the internal and external parameters were calibrated sim- ultaneously，the expression level of miR-26a-5p in plasma exosome of patients with tuberculosis was lower than that in control group (P＜0. 000 1) ，and the expression level of miR-151a-3p in plasma exosome of patients with tuber- culosis was higher than that in control group (P＜0. 000 1) ，which were consistent with the bioinformatics results. As a diagnostic marker，taking internal reference as the benchmark，the AUC of plasma exosome miR-26a-5p and miR-151a-3p for tuberculosis differentiation was 0. 872 and 0. 709，the AUC of the combined miR-26a-5p and miR- 151a-3p was 0. 915 (P ＜0. 000 1 ) ． Taking external reference as the benchmark ，the AUC of plasma exosomes miR-26a-5p and miR-151a-3p were 0. 829 and 0. 854 respectively ，the AUC of the combined miR-26a-5p and miR-151a-3p was 0. 911 (P＜0. 000 1) ．@*Conclusion @#The expression level of plasma exosome-derived miR-26a- 5p decreases in tuberculosis patients and the expression levelof miR-151a-3p increases，and the clinical diagnostic efficiency of bothis high，which may be a potential biomarker for the diagnosis of tuberculosis.

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.