Circ_0008146 exacerbates ferroptosis via regulating miR-342-5p/ACSL4 axis after cerebral ischemia-reperfusion in mice
Background: Characterized by high incidence, mutilation, and death rate, acute ischemic stroke (AIS) has threatened people's health seriously. Therefore, there is an urge need for early diagnosis and effective treatment of AIS. The purpose of this study was to clarify the regulatory role and potential molecular mechanism of miR-342-5p and circRNA_0008146 in AIS. Materials and Methods: Small RNA sequencing analysis was performed to screen differentially expressed miRNAs between the AIS and control group. Middle cerebral artery occlusion/reperfusion (MCAO/R) models were constructed in C57BL/6J mice. The circRNA_0008146 and miRNA expression levels were detected by quantitative real-time PCR. Assay kits were used to determine Fe2+ levels and assess a battery of oxidative stress indicators, including ROS, MDA, LPO, SOD, and GSH/GSSG. The content of ACSL4 was measured by Western blot. The neurobehavioral manifestation was evaluated using the modified Neurological Severity (mNSS) Score, rotarod test, and corner test. TTC staining was employed to detect cerebral infarction volume. Nissl staining was adapted to detect histological change and neuronal damage. Results: RNA sequencing analysis revealed miR-342-5p was significantly downregulated in the plasma of AIS patients. MiR-342-5p inhibited oxidative stress and RSL3-induced ferroptosis after cerebral ischemic-reperfusion injury in vivo by targeting ferroptosis-related gene ACSL4. CircRNA_0008146 acted as a sponge of miR-342-5p, and overexpression of circRNA_0008146 increased brain damage in stroke mice. CircRNA_0008146 contributed to ferroptosis in cerebral infraction via sponging miR-342-5p to regulate ACSL4. Conclusion: CircRNA_0008146/miR-342-5p/ACSL4 axis regulate ferroptosis after cerebral ischemia-reperfusion, which may be a potential therapeutic target for ischemic stroke. Overall design: miRNA profiles of plasma from 2 acute ischemic stroke patients and 2 healthy controls