Expression and regulation of microRNA-29a and microRNA-29c in early diabetic rat cataract formation

Inhibition of miR-29a-3p Alleviates Apoptosis of Lens Epithelial Cells via Upregulation of CAND1

PURPOSE

Accumulated evidence has shown that microRNAs (miRNAs) are closely related to the pathogenesis and progression of senile cataracts. Here we investigate the effect of miR-29a-3p in cataractogenesis and determined the potential molecular mechanism involved.

METHODS

In this study, we constructed a selenite cataract model in rats and obtained the miRNAs related to cataracts by whole transcriptome sequencing. To investigate the effect and mechanism of miR-29a-3p on cataracts, we performed several in vivo and in vitro experiments, including CCK8 assay, flow cytometry, luciferase reporter assay, Edu assay, and western blot analysis.

RESULT

Sequencing data showed downregulation of miR-29a-3p in rats with selenite cataracts. Down-regulation of miR-29a-3p could promote lens epithelial cells (SRA01/04) proliferation and inhibit cell apoptosis, and miR-29a-3p silence could inhibit the development of cataracts. Additionally, CAND1 was a direct target gene for miR-29a-3p.

CONCLUSION

These data demonstrate that miR-29a-3p inhibits apoptosis of lens epithelial cells by regulating CAND1, which may be a potential target for senile cataracts.

Transcriptome sequencing and microRNA-mRNA regulatory network construction in the lens from a Na2SeO3-induced Sprague Dawley rat cataract model

BACKGROUND

A sight-threatening, cataract is a common degenerative disease of the ocular lens. This study aimed to explore the regulatory mechanism of age-related cataract (ARC) formation and progression.

METHODS

Cataracts in Sprague Dawley rats were induced by adopting the method that injected selenite subcutaneously in the nape. We performed high-throughput RNA sequencing technology to identify the mRNA and microRNA(miRNA) expression profiles of the capsular membrane of the lens from Na2SeO3-induced and saline-injected Sprague Dawley rats. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were carried out to forecast the regulatory and functional role of mRNAs in cataracts by DAVID and Metascape. The protein-protein interaction(PPI) network of differentially expressed mRNA(DEmRNAs) was built via the STRING. Target miRNAs of hub genes were predicted by miRBD and TargetScan. Furthermore, differentially expressed miRNA(DEmiRNAs) were selected as hub genes' targets, validated by quantitative real-time polymerase chain reaction(qRT-PCR), and a DEmiRNA-DEmRNA regulatory network was constructed via Cytoscape.

RESULT

In total, 329 DEmRNAs including 40 upregulated and 289 downregulated genes were identified. Forty seven DEmiRNAs including 29 upregulated and 18 downregulated miRNAs were detected. The DEmRNAs are involved in lens development, visual perception, and aging-related biological processes. A protein-protein interaction network including 274 node genes was constructed to explore the interactions of DEmRNAs. Furthermore, a DEmiRNA-DEmRNA regulatory network related to cataracts was constructed, including 8 hub DEmRNAs, and 8 key DEmiRNAs which were confirmed by qRT-PCR analysis.

CONCLUSION

We identified several differentially expressed genes and established a miRNA-mRNA-regulated network in a Na2SeO3-induced Sprague Dawley rat cataract model. These results may provide novel insights into the clinical treatment of cataracts, and the hub DEmRNAs and key DEmiRNAs could be potential therapeutic targets for ARC.

lncRNA TUG1 regulates Smac/DIABLO expression by competitively inhibiting miR-29b and modulates the apoptosis of lens epithelial cells in age-related cataracts

BACKGROUND

As one of the early discovered long non-coding RNAs (lncRNA), taurine upregulation gene 1 ( TUG1 ) has been widely expressed in a variety of tumors. Moreover, it promotes cell proliferation, differentiation, apoptosis, and migration. However, our understanding of its importance in the pathogenesis of cataracts remains limited. This study aimed to explore the mechanism by which lncRNA TUG1 mediates lens epithelial cell apoptosis in age-related cataracts (ARC) by regulating the microRNAs (miR-29b)/second mitochondria-derived activator of caspases axis, and to identify more non-surgical strategies for cataract treatment.

METHODS

The messenger RNA expression levels of TUG1 , miR-29b, and Smac were detected using quantitative real-time polymerase chain reaction in vivo and in vitro . The expression of the Smac protein was analyzed by Western blotting and immunofluorescence. Flow cytometry and cell counting kit-8 assays were used to detect the cell apoptosis and proliferation rates, respectively. The targeted regulatory relationship between lncRNA TUG1 , miR-29b, and Smac was verified by viral vector construction, co-transfection, nuclear and cytoplasmic separation, luciferase reporter assays, and RNA immunoprecipitation.

RESULTS

TUG1 and Smac were expressed at high levels in ARC and HLE-B3 cells treated with 200 μmol/L H 2 O 2 , whereas miR-29b expression was decreased. In vitro cell experiments confirmed that down-regulation of TUG1 could inhibit the apoptosis of lens epithelial cells. Mechanistically, Smac expression was negatively regulated by miR-29b. TUG1 competitively inhibited miR-29b expression and caused greater release of Smac. In addition, miR-29b partially reversed the effects of TUG1 on human lens epithelial cell line cells.

CONCLUSIONS

lncRNA TUG1 increases Smac expression and promotes apoptosis of lens epithelial cells in ARC by competitively inhibiting miR-29b. This mechanism is the cytological basis for ARC formation. Based on these results, the lncRNA TUG1/miR29b/Smac axis may be a new molecular pathway that regulates ARC development.

Knockdown of miR-423-5p simultaneously upgrades the eNOS and VEGFa pathways in ADSCs and improves erectile function in diabetic rats

This study aimed to explore the possibility of miR‐423‐5p modified adipose‐derived stem cell (ADSCs) therapy on streptozotocin (STZ)‐induced diabetes mellitus erectile dysfunction (DMED) rats. MiR‐423‐5p was knocked down in ADSCs. ADSCs, NC‐miR‐ADSCs and miR‐ADSCs were co‐cultured with human umbilical vein endothelial cells (HUVECs). Normal and high glucose media were supplemented. The supernatant and HUVECs were collected for assessment of eNOS and VEGFa expression, cell proliferation, and apoptosis. HUVECs co‐cultured with ADSCs or miR‐ADSCs exhibited higher eNOS and VEGFa protein expression levels compared to DM groups. MiR‐ADSCs enhanced HUVEC proliferation compared to the ADSCs and NC‐miR‐ADSCs. Lower apoptotic rates were observed when HUVECs were co‐cultured with miR‐ADSCs, compared to ADSCs and NC‐miR‐ADSCs. Fifteen male Sprague‐Dawley (SD) rats aged 12 weeks were induced to develop diabetes mellitus by intraperitoneal injection with STZ, and five healthy SD rats were used as normal controls. Eight weeks after developing diabetes, the rats received ADSCs and miR‐ADSCs via injection into the corpora cavernosa, whereas normal controls and DM controls were injected with saline. Erectile function and histological assessment of penile tissues were performed 8 weeks after injection. The ICP/MAP indicated that erectile function was impaired in the DM rats compared with the normal group. Injection of ADSCs and miR‐ADSCs improved erectile function significantly and was associated with the overexpression of eNOS and VEGFa. MiR‐423‐5p knockdown in ADSCs ameliorated high glucose‐mediated damage to HUVECs and improved erectile function in DM rats by inducing eNOS and VEGFa overexpression, indicating that miR‐423‐5p may be a potential target in the treatment of DMED.

MiR-30a inhibits BECN1-mediated autophagy in diabetic cataract

Purpose

To investigate the role of microRNAs in the regulation of autophagy and apoptosis in lens epithelial cells (LECs) during diabetic cataract formation.

Methods

A miRNA microarray study and quantitative real-time PCR were performed to identify the expression of miRNAs in LECs of diabetic cataract. Human LECs were cultured in high glucose conditions as a diabetic cataract model. BECN1 and LC3B were detected by Western blotting and quantitative real-time PCR. The extent of apoptosis was measured using FACSCalibur flow cytometry.

Results

Downregulation of miR-30a was identified in LECs attached to diabetic cataract tissues. By the bioinformatic assay and the luciferase activity assay, BECN1 was found to be a direct target of miR-30a. MiR-30a reduced the BECN1-mediated autophagy activity induced by high glucose in LECs in vitro. The ratio of LECs apoptosis was also decreased.

Conclusion

MiR-30a was involved in the inhibition of autophagy by targeting BECN1 in LECs in human diabetic cataract.

Effects of microRNA-211 on proliferation and apoptosis of lens epithelial cells by targeting SIRT1 gene in diabetic cataract mice

Our study aimed at exploring the effects of miR-211 on the proliferation and apoptosis of lens epithelial cells in diabetic cataract mice by targetting NAD⁺-dependent histone deacetylase sirtulin 1 (SIRT1). Healthy male mice were assigned into normal and diabetic cataract groups. Blood glucose, lens turbidity, and apoptosis were measured. Lens epithelial cells were classified into the normal, blank, negative control (NC), miR-211 mimics, miR-211 inhibitors, siRNA-SIRT1, and miR-211 inhibitors + siRNA-SIRT1 groups. MiR-211, Bcl-2, Bax, p53, and SIRT1 expressions of each group were detected. Cell proliferation, cycle and apoptosis were tested by MTT assay and flow cytometry. MiR-211 can specifically bind to SIRT1 according to the luciferase system. SIRT1 protein concentration was strongly positive in normal mice and weakly positive in diabetic cataract mice. Apoptosis index of diabetic cataract mice was higher than the normal mice. Compared with normal mice, the expressions of miR-211, Bax, and p53 increased in diabetic cataract mice, while the Bcl-2 and SIRT1 expressions decreased. In comparison with the blank and NC groups, the expressions of miR-211, Bax, and p53 increased, while Bcl-2 and SIRT1 expressions decreased, and the proliferation decreased and apoptosis rate increased in the miR-211 mimics and siRNA-SIRT1 groups; the results were contradicting for the miR-211 inhibitor group. MiR-211 could promote apoptosis and inhibit proliferation of lens epithelial cells in diabetic cataract mice by targetting SIRT1.