Overexpression of small ubiquitin‑like modifier 2 ameliorates high glucose‑induced reductions in cardiomyocyte proliferation via the transforming growth factor‑β/Smad pathway

Identification of key genes of diabetic cardiomyopathy in hiPSCs-CMs based on bioinformatics analysis

Diabetic cardiomyopathy (DbCM) is one of the most common vascular complications of diabetes, and can cause heart failure and threaten the life of patients. The pathogenesis is complex, and key genes have not fully identified. In this study, bioinformatics analysis was used to predict DbCM-related gene targets. Published datasets from the NCBI Gene Expression Omnibus with accession numbers GSE62203 and GSE197850 were selected for analysis. Differentially expressed genes (DEGs) were identified by the online tool GEO2R. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the DAVID online database. Protein-protein interaction network construction and hub gene identification were performed using STRING and Cytoscape. We used 30 mM and 1 μM hydrocortisone-stimulated AC16 cells as an in vitro model of diabetic cardiomyopathy. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression levels of hub genes. A total of 73 common DEGs were identified in both datasets, including 47 upregulated and 26 downregulated genes. GO and KEGG pathway enrichment analyses revealed that the DEGs were significantly enriched in metabolism, hypoxia response, apoptosis, cell proliferation regulation, and cytoplasmic and HIF signalling pathways. The top 10 hub genes were LDHA, PGK1, SLC2A1, ENO1, PFKFB3, EGLN1, MYC, PDK1, EGLN3 and BNIP3. In our in vitro study, we found that PGK1, SLC2A1, PFKFB3, EGLN1, MYC, EGLN3 and BNIP3 were upregulated, ENO1 was downregulated, and LDHA was unchanged. Except for PGK1 and ENO1, these hub genes have been previously reported to be involved in DbCM. In summary, we identified DEGs and hub genes and first reported PGK1 and ENO1 in DbCM, which may serve as potential candidate genes for DbCM targeted therapy.

Involvement of long non-coding RNA ZNF503 antisense RNA 1 in diabetic retinopathy and its possible underlying mechanism

ZNF503 antisense RNA 1 (ZNF503-AS1) is a newly identified long non-coding RNA (lncRNA) that regulates retinal pigment epithelium differentiation. To study its role in diabetic retinopathy, we performed RT-qPCR to measure plasma ZNF503-AS1 levels of 298 diabetic patients immediately after the diagnosis, during the follow-up, and at the end of follow-up. Plasma lncRNA ZNF503-AS1 expression in 96 healthy participants was also detected by RT-qPCR. Transforming growth factor beta 1 (TGF-β1) expression after ZNF503-AS1 overexpression was detected by Western blot. Cell proliferation and apoptosis were detected by cell proliferation and apoptosis assays, respectively. We found that ZNF503-AS1 was not differentially expressed in healthy participants and diabetic patients. High plasma lncRNA ZNF503-AS1 level was correlated with a high incidence of diabetic retinopathy. Plasma lncRNA ZNF503-AS1 level was higher in patients with diabetic retinopathy than in patients with other complications (p < 0.05). ZNF503-AS1 overexpression inhibited proliferation, promoted cell apoptosis, and upregulated TGF-β1 expression (p < 0.05). We concluded that ZNF503-AS1 might participate in diabetic retinopathy by activating TGF-β signaling.

Melatonin Alleviates Oxidative Stress Induced by H2O2 in Porcine Trophectodern Cells

Placental oxidative stress has been implicated as a main risk factor for placental dysfunction. Alleviation of oxidative stress and enhancement of antioxidant capacity of porcine trophectoderm (PTr2) cells are effective means to maintaining normal placental function. The present study was conducted to evaluate the protective effect of melatonin (MT) on H₂O₂-induced oxidative damage in PTr2 cells. Our data revealed that pretreatment with MT could significantly improve the decrease in cell viability induced by H₂O₂, and reduce intracellular reactive oxygen species (ROS) levels and the ratio of apoptotic cells. Here, we compared the transcriptomes of untreated versus melatonin-treated PTr2 cells by RNA-seq analysis and found that differentially expressed genes (DEGs) were highly enriched in the Wnt signaling, TGF-beta signaling and mTOR signaling pathways. Moreover, pretreatment with MT upregulated the antioxidant-related genes such as early growth response3 (EGR3), WAP four-disulfide core domain1 (WFDC1), heme oxygenase1 (HMOX1) and vimentin (VIM). These findings reveal that melatonin protects PTr2 cells from H₂O₂-induced oxidative stress damage.

Upregulation of miRNA-23a-3p rescues high glucose-induced cell apoptosis and proliferation inhibition in cardiomyocytes

Maternal hyperglycemia potentially inhibits the development of the fetal heart by suppressing cardiomyocyte proliferation and promoting apoptosis. Different studies have indicated that miRNAs are key regulators of cardiomyocyte proliferation, differentiation, and apoptosis and play a protective role in a variety of cardiovascular diseases. However, the biological function of miRNA-23a in hyperglycemia-related cardiomyocyte injury is not fully understood. The present study investigated the effect of miRNA-23a-3p on cell proliferation and apoptosis in a myocardial injury model induced by high glucose. H9c2 cardiomyocytes were exposed to high glucose to establish an in vitro myocardial injury model and then transfected with miRNA-23a-3p mimics. After miRNA-23a-3p transfection, lens-free microscopy was used to dynamically monitor cell numbers and confluence and calculate the cell cycle duration. CCK-8 and EdU incorporation assays were performed to detect cell proliferation. Flow cytometry was used to measured cell apoptosis. Upregulation of miRNA-23a-3p significantly alleviated high glucose-induced cell apoptosis and cell proliferation inhibition (p < 0.01 and p < 0.0001, respectively). The cell cycle of the miRNA-23a-3p mimics group was significantly shorter than that of the negative control group (p < 0.01). The expression of cell cycle–activating and apoptosis inhibition-associated factors Ccna2, Ccne1, and Bcl-2 was downregulated by high glucose and upregulated by miRNA-23a-3p overexpression in high glucose-injured H9c2 cells. miRNA-23a-3p mimics transfection before high glucose treatment had a significantly greater benefit than transfection after high glucose treatment (p < 0.0001), and the rescue effect of miRNA-23a-3p increased as the concentration increased. This study suggests that miRNA-23a-3p exerted a dose- and time-dependent protective effect on high glucose-induced H9c2 cardiomyocyte injury.