Dataset Information

CircUBXN7 mitigates H/R-induced cell apoptosis and inflammatory response through the miR-622-MCL1 axis.

ABSTRACT:

Background

Hypoxia/reoxygenation (H/R)-mediated apoptosis and inflammation are major causes of tissue injury in acute myocardial infarction (AMI). Exploring the underlying mechanisms of cardiomyocyte injury induced by H/R is important for AMI treatment. Circular RNAs have been demonstrated to paly vital roles in the pathogenesis of AMI. Our study aimed to explore the function of circular RNA UBXN7 (circUBXN7) in regulating H/R-induced cardiomyocyte injury.

Methods

H/R-treated H9c2 cells and a mouse model of AMI were used to investigate the function of circUBXN7 in H/R damage and AMI. The expressions of circUNXN7, miR-622 and MCL1 were analyzed by RT-qPCR. CCK-8 was used for examining cell viability. Cell apoptosis was evaluated with caspase 3 activity and Annexin V/PI staining. MCL1, Bax, Bcl-2 and cleaved-caspase 3 were examined with western blot. ELISA was used to examine the secretion of IL-6, TNF-α and IL-1β.

Results

CircUBXN7 was downregulated in patients and mice with AMI, as well as in H/R-treated cells. Overexpression of circUBXN7 mitigated H/R-mediated apoptosis and secretion of inflammatory factors including IL-6, TNF-α and IL-1β. CircUBXN7 suppressed cell apoptosis and inflammatory reaction induced by H/R via targeting miR-622. MiR-622 targeted MCL1 to restrain its expression in H9c2 cells. Knockdown of MCL1 abrogated circUBXN7-mediated alleviation of apoptosis and inflammation after H/R treatment.

Conclusion

CircUBXN7 mitigates cardiomyocyte apoptosis and inflammatory reaction in H/R injury by targeting miR-622 and maintaining MCL1 expression. Our study provides novel potential therapeutic targets for AMI treatment.

SUBMITTER: Wang S

PROVIDER: S-EPMC8430130 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Breast cancer is the leading cause of cancer-associated deaths among females. In recent decades, microRNAs (miRNAs), a type of short non-coding RNA that regulates gene expression at the post-transcription level, have been reported to participate in the regulation of many hub genes associated with tumorigenesis, tumor progression, and metastasis. However, the precise mechanism by which miRNAs regulate breast cancer metastasis remains poorly discussed, which limits the opportunity for the development of novel, effective therapeutic targets. Here, we aimed to determine the miR-622-related principal regulatory mechanism in cancer. First, we found that miR-622 was significantly related to a poor prognosis in various cancers. By utilizing an integrated miRNA prediction process, we identified 77 promising targets and constructed a protein-protein interaction network. Furthermore, enrichment analyses, including GO and KEGG pathway analyses, were performed to determine the potential function of miR-622, which revealed regulation networks and potential functions of miR-622. Then, we identified a key cluster comprised of six hub genes in the protein-protein interaction network. These genes were further chosen for pan-cancer expression, prognostic and predictive marker analyses based on the TCGA and GEO datasets to mine the potential clinical values of these hub genes. To further validate our bioinformatic results, the regulatory axis of miR-622 and RNF8, one of the hub genes recently reported to promote breast cancer cell EMT process and breast cancer metastasis, was selected as in vitro proof of concept. In vitro, we demonstrated the direct regulation of RNF8 by miR-622 and found that the predicted miR-622-RNF8 axis could regulate RNF8-induced epithelial-mesenchymal transition, cell migration, and cell viability. These results were further demonstrated with rescue experiments. We established a closed-loop miRNA-target-phenotype research model that integrated the bioinformatic analysis of the miRNA target genes and experimental validation of the identified key miRNA-target-phenotype axis. We not only identified the hub target genes of miR-622 in silico but also revealed the regulatory mechanism of miR-622 in breast cancer cell EMT process, viability, and migration in vitro for the first time.

Project description:BackgroundBreast cancer (BC) remains the most prevalent malignancy and the leading cause of cancer death. Circular RNAs (circRNAs) have been discovered to serve as crucial regulators in BC. In the current work, we aimed to study the impact of circRAD18 (hsa_circ_0002453) on BC progression and mechanism governing it.Materials and MethodsThe expression levels of circRAD18, miR-613 and hexokinase 2 (HK2) mRNA were determined by quantitative real-time polymerase chain reaction (qRT-PCR). CircRAD18 identification was performed using RNase R digestion and actinomycin D assay. Cell viability, colony formation, apoptosis, migration, invasion and glycolysis were measured by Cell Counting Kit-8 assay, colony formation assay, flow cytometry, transwell analysis and extracellular acidification rate detection assay, respectively. Western blot was used to assess the levels of E-Cadherin, Vimentin, N-Cadherin and HK2 protein. The targeted interplay between miR-613 and circRAD18 or HK2 was detected by dual-luciferase reporter assay. Xenograft model assay was performed to observe the role of circRAD18 in vivo.ResultsCircRAD18 was highly expressed in BC tissues and cells. CircRAD18 depletion hindered BC cell malignant behaviors, as evidenced by the inhibition in cell viability, colony formation, migration, invasion, epithelial to mesenchymal transition and glycolysis, as well as the promotion in cell apoptosis. CircRAD18 directly interacted with miR-613, and miR-613 mediated the repressive effect of circRAD18 knockdown on BC cell malignant behaviors. Moreover, HK2 was a direct target of miR-613, and circRAD18 positively regulated HK2 expression via sponging miR-613. Additionally, circRAD18 knockdown repressed tumor growth in vivo by miR-613.ConclusionOur current work suggested that circRAD18 silencing suppressed BC cell malignant behaviors in vitro and tumor growth in vivo at least partly via the regulation of the miR-613/HK2 axis, highlighting that circRAD18 might be a promising therapeutic target for BC treatment.