The Role of Circular RNAs in Ischemic Stroke

Role of O-GlcNAcylation in Central Nervous System Development and Injuries: A Systematic Review

The development of central nervous system (CNS) can form perceptual, memory, and cognitive functions, while injuries to CNS often lead to severe neurological dysfunction and even death. As one of the prevalent post-translational modifications (PTMs), O-GlcNAcylation has recently attracted great attentions due to its functions in regulating the activity, subcellular localization, and stability of target proteins. It has been indicated that O-GlcNAcylation could interact with phosphorylation, ubiquitination, and methylation to jointly regulate the function and activity of proteins. Furthermore, a growing number of studies have suggested that O-GlcNAcylation played an important role in the CNS. During development, O-GlcNAcylation participated in the neurogenesis, neuronal development, and neuronal function. In addition, O-GlcNAcylation was involved in the progress of CNS injuries including ischemic stroke, subarachnoid hemorrhage (SAH), and intracerebral hemorrhage (ICH) and played a crucial role in the improvement of brain damage such as attenuating cognitive impairment, inhibiting neuroinflammation, suppressing endoplasmic reticulum (ER) stress, and maintaining blood-brain barrier (BBB) integrity. Therefore, O-GlcNAcylation showed great promise as a potential target in CNS development and injuries. In this article, we presented a review highlighting the role of O-GlcNAcylation in CNS development and injuries. Hence, on the basis of these properties and effects, intervention with O-GlcNAcylation may be developed as therapeutic agents for CNS diseases.

Analysis of the expression level and predictive value of CLEC16A|miR-654-5p|RARA regulatory axis in the peripheral blood of patients with ischemic stroke based on biosignature analysis

Introduction

Ischemic stroke (IS) is a cerebrovascular disease that can be disabling and fatal, and there are limitations in the clinical treatment and prognosis of IS. It has been reported that changes in the expression profile of circRNAs have been found during injury in ischemic stroke, and circRNAs play an important role in the IS cascade response. However, the specific mechanisms involved in the pathogenesis of IS are not yet fully understood, and thus in-depth studies are needed.

Methods

In this study, one circRNA dataset (GSE161913), one miRNA dataset (GSE60319) and one mRNA dataset (GSE180470) were retrieved from the Gene Expression Omnibus (GEO) database and included, and the datasets were differentially expressed analyzed by GEO2R and easyGEO to get the DEcircRNA, DEmiRNA and DEmRNA, and DEmRNA was enriched using ImageGP, binding sites were predicted in the ENCORI database, respectively, and the competitive endogenous RNA (ceRNA) regulatory network was visualized by the cytoscape software, and then selected by MCC scoring in the cytoHubba plugin Hub genes. In addition, this study conducted a case-control study in which blood samples were collected from stroke patients and healthy medical examiners to validate the core network of ceRNAs constructed by biosignature analysis by real-time fluorescence quantitative qRT-PCR experiments.

Results

A total of 233 DEcircRNAs, 132 DEmiRNAs and 72 DEmRNAs were screened by bioinformatics analysis. circRNA-mediated ceRNA regulatory network was constructed, including 148 circRNAs, 43 miRNAs and 44 mRNAs. Finally, CLEC16A|miR-654-5p|RARA competitive endogenous regulatory axis was selected for validation by qRT-PCR, and the validation results were consistent with the bioinformatics analysis.

Discussion

In conclusion, the present study establishes a new axis of regulation associated with IS, providing new insights into the pathogenesis of IS.

Circ_0059662 exerts a positive role in oxygen-glucose deprivation/reoxygenation-induced SK-N-SH cell injury

Circular RNA (circRNA) is identified as a potential regulator of ischemic stroke (IS) progression. Through GEO database screening, it was found that circ_0059662 was highly expressed in acute IS patients. However, whether circ_0059662 participated in the IS process has not been studied. Oxygen-glucose deprivation/reoxygenation (OGD/R)-induced SK-N-SH cells were established to mimic IS cell models. The expression of circ_0059662, miR-579-3p, and ETS proto-oncogene 1 (ETS1) was measured via quantitative real-time PCR. Cell counting kit 8 assay, EdU assay and flow cytometry were utilized to detect cell proliferation and apoptosis. Western blot was employed to measure protein expression. ELISA was used to detect the levels of inflammation factors, and oxidative stress was determined by assessing SOD activity and MDA level. The relationship between miR-579-3p and circ_0059662 or ETS1 was examined via dual-luciferase reporter assay, RNA pull-down assay and RIP assay. Circ_0059662 was a circular RNA with highly expression in OGD/R-induced SK-N-SH cells. In OGD/R-induced cell injury, circ_0059662 knockdown promoted cell proliferation, and inhibited cell apoptosis, inflammation and oxidative stress. Circ_0059662 served as miR-579-3p sponge to positively regulate ETS1 expression. MiR-579-3p inhibitor and ETS1 overexpression could reverse the inhibition effect of circ_0059662 knockdown on OGD/R-induced cell injury. Besides, MiR-579-3p also could relieve OGD/R-induced SK-N-SH cell apoptosis, inflammation and oxidative stress by targeting ETS1. Our findings indicated that circ_0059662 knockdown alleviated OGD/R-induced SK-N-SH cell injury by sponging miR-579-3p to regulate ETS1 expression.