Circular RNA expression alteration and bioinformatics analysis in patients with acute cerebral infarction injury

CircZfp609 contributes to cerebral infarction via sponging miR-145a-5p to regulate BACH1

BACKGROUND

Circular RNAs (circRNA) have been reported to be involved in the progression of cerebral infarction. The purpose of this study was to reveal the role and potential molecular mechanism of circZfp609 (mmu_circ_0001797) in cerebral infarction.

METHODS

C57BL/6J mice was used to construct middle cerebral artery occlusion (MCAO) mice model, and primary mouse astrocytes were treated with oxygen-glucose deprivation/reperfusion (OGD/R) process. The circZfp609, microRNA (miR)-145a-5p and BTB and CNC homology 1 (BACH1) expression levels were detected by quantitative real-time PCR. Cell proliferation and apoptosis were assessed by cell counting kit 8 assay, EdU assay and flow cytometry. Western blot analysis was used to measure protein levels, and ELISA assay was utilized to detect the levels of inflammation factors. Lactate dehydrogenase (LDH) level was measured by LDH Assay Kit. Dual-luciferase reporter assay, RIP assay and RNA pull-down assay were used to evaluate RNA interaction.

RESULTS

CircZfp609 was upregulated in MCAO mice and OGD/R-induced astrocytes. Knockdown of circZfp609 promoted cell proliferation, while suppressed apoptosis and inflammation in OGD/R-induced astrocytes. CircZfp609 served as a sponge for miR-145a-5p, and miR-145a-5p inhibitor reversed the regulation of circZfp609 knockdown on OGD/R-induced astrocyte injury. BACH1 was a target of miR-145a-5p, and its overexpression abolished the inhibition effect of miR-145a-5p on OGD/R-induced astrocyte injury. Besides, circZfp609 downregulation also relieved the brain injury of MCAO mice through miR-145a-5p/BACH1 axis.

CONCLUSION

Our data showed that circZfp609 might promote cerebral infarction by regulating the miR-145a-5p/BACH1 pathway.

Clinical Application of Circular RNAs as Biomarkers in Acute Ischemic Stroke

Despite the substantial improvement in diagnosis and treatment within the last decades, ischemic stroke still represents a challenge, responsible still for a high burden of morbidity and mortality. Among the unmet clinical needs are the difficulties in identifying those subjects with the greatest risk of developing a stroke, the challenges in obtaining a timely diagnosis, the prompt recognition of the different clinical forms of stroke, the assessment of the response to treatments and the prognostic assessment. All these issues might be improved with appropriate smart biomarkers that could better inform clinical management. The present article offers an overview of the potential role of circular RNAs as disease biomarkers in stroke. A systematic approach was adopted to gather all potentially relevant information in order to provide a panoramic view on this class of promising molecules.

FAS-mediated circRNA-miRNA-mRNA Crosstalk Network Regulates Immune Cell Infiltration in Cerebral Infarction

New data are accumulating on the involvement of interaction among circular RNAs (circRNAs), microRNAs (miRNAs/miRs), and messenger RNAs (mRNAs) in cerebral infarction (CI). This study aims to illustrate the GEO database-based identification of a circRNA-miRNA-mRNA crosstalk network underlying immune cell infiltration in CI. The differential analysis suggested that 1696 circRNAs, 1989 miRNAs, and 5550 mRNAs that were differentially expressed in CI samples were retrieved from GEO database. GO and KEGG functional enrichment analyses showed that the differentially expressed mRNAs were mainly associated with common risk factors of CI, such as immune and inflammatory response. Next, the circRNA-miRNA pairs and miRNA-mRNA pairs were predicted, and the circRNA-miRNA-mRNA network was constructed by Cytoscape software. Totally, 436 circRNA-miRNA pairs were obtained through the online database, and 2033 miRNA-mRNA pairs were used to construct the circRNA-miRNA-mRNA crosstalk network. A protein-protein interaction (PPI) network was constructed on the basis of the ceRNA network, followed by key gene identification in the GSE9877 dataset. FAS was identified as the key gene in CI. The constructed FAS-mediated circRNA-miRNA-mRNA crosstalk network included five upregulated circRNAs (hsa_circ_0075341, hsa_circ_0049637, hsa_circ_0001085, hsa_circ_0004808 and hsa_circ_0092337) and five downregulated miRNAs (hsa-miR-92a-2-5p, hsa-miR-1245b-3p, hsa-miR-592, hsa-miR-224-5p, and hsa-miR-30e-3p). Furthermore, the CIBERSORT algorithm indicated that FAS was associated with immune cell infiltration in CI. In conclusion, this study revealed a role for FAS-centered circRNA-miRNA-mRNA crosstalk network in regulating immune cell infiltration of CI, which may be a viable target for CI prevention.

Role of Bioinformatics Analysis in Early Differential Diagnosis of Ovarian Cancer

In order to solve the problem of early differential diagnosis of ovarian cancer, this paper proposes the role of bioinformatics analysis in early differential diagnosis of ovarian cancer. This method uses bioinformatics methods to mine the existing data in the tumor database and obtain tumor-related molecules. It is an efficient method to obtain effective biomarkers, screen signal pathway molecules, and reveal the internal mechanism of tumor occurrence and development. Using this method can greatly improve the efficiency and reliability of screening diagnosis, prognosis, and treatment targets. The results showed that 5821 new lncRNA transcripts and 4611 new lncRNA genes were identified by lncScore from the assembled transcripts. 10 new lncRNA transcripts and 174 new lncRNA genes were found to be differentially expressed in ovarian cancer.

Depletion of mmu_circ_0001751 (circular RNA Carm1) protects against acute cerebral infarction injuries by binding with microRNA-3098-3p to regulate acyl-CoA synthetase long-chain family member 4

Circular RNAs (circRNAs) play a critical role in acute cerebral infarction (ACI). Our research discussed the effect of circ-Carm1 in ACI and its potential molecular mechanisms. Healthy controls and patients with ACI were included in this study. The establishment of an oxygen and glucose deprivation/reoxygenation (OGD/R) model of HT22 cells was conducted to mimic ACI in vitro. Quantitative reverse transcription polymerase chain reaction was conducted to determine mRNA levels extracted from serum and HT22 cell samples, and Western blotting was performed to determine protein levels. Terminal deoxynucleotidyl transferase dUTP nick end labeling and cell counting kit 8 assays were conducted to evaluate cellular functions. Concentrations of Fe²⁺ and malondialdehyde, and levels of transferrin receptor 1, glutathione peroxidase 4, and glutathione were evaluated to determine ferroptosis in OGD/R-induced HT22 cells. The binding relationships between mRNAs and miRNAs were verified. circ-Carm1 was highly expressed in OGD/R-treated HT22 cells. Deficiency of circ-Carm1 restored cell viability and suppressed ferroptosis in OGD/R-induced HT22 cells. miR-3098-3p was predicted to be a target of circ-Carm1. The miR-3098-3p inhibitor partly neutralized the functions of circ-Carm1 in OGD/R-induced HT22 cells. Furthermore, acyl-CoA synthetase long-chain family member 4 (ACSL4) was confirmed to be a downstream target of miR-3098-3p and was elevated in OGD/R-induced HT22 cells. Overexpression of ACSL4 mitigated the functions of miR-3098-3p and accelerated HT22 cell dysfunction. Hence, circ-Carm1 is upregulated in ACI. circ-Carm1 suppression protects HT22 cells from dysfunction by inhibiting ferroptosis. Therefore, inducing circ-Carm1 deficiency may be a promising therapeutic method for ACI.