LncRNA NEAT1 alleviates ischemic stroke via transcriptional inhibition of NLRP3 mediated by the miR‑10b‑5p/BCL6 axis

• Published in: Acta neurobiologiae experimentalis Vol. 82; no. 1; pp. 12 - 21
• Main Authors: Zhou, Zhi-Wen, Ren, Xiang, Zhou, Wen-Sheng, Li, Ai-Ping, Zheng, Li-Jun
• Format: Journal Article
• Language: English
• Published: Poland Polish Academy of Sciences 01.01.2022
• Subjects: Bcl-6 protein; Cytokines; Damage; Deprivation; Enzyme-linked immunosorbent assay; Gene regulation; Humans; Inflammasomes; Inflammasomes - metabolism; Inflammation; Ischemia; Ischemic Stroke; Microglia; MicroRNAs - genetics; NLR Family, Pyrin Domain-Containing 3 Protein - genetics; NLR Family, Pyrin Domain-Containing 3 Protein - metabolism; Non-coding RNA; Oxygenation; Proteins; Proto-Oncogene Proteins c-bcl-6 - genetics; RNA, Long Noncoding - genetics; RNA, Long Noncoding - metabolism; Stroke
• ISSN: 0065-1400; 1689-0035
• DOI: 10.55782/ane-2022-002

Cerebral ischemic stroke (CIS) is a significant cause of disability and death. Inflammation usually occurs after CIS and accelerates cellular damage. NLRP3 plays a key role in the formation of CIS‑associated inflammasome. Understanding how NLRP3 is regulated bears great importance. We hypothesized that lncRNA NEAT1 can downregulate NLRP3 expression by regulating the miR‑10b‑5p/BCL6 axis, and thus regulate microglia‑driven inflammation. The expression of NEAT1 was analyzed in CIS patients and an in vitro model of oxygen and glucose deprivation/re‑oxygenation (OGD/R). We assessed the levels of pro‑inflammatory cytokines IL‑18 and IL‑1β with ELISA. Interactions between NEAT1/miR‑10b‑5p and miR‑10b‑5p/BCL6 were determined by luciferase assay. The interaction of BCL6 and NLRP3 was identified by ChIP; RNA, and protein levels were evaluated by qRT‑PCR and western blot, respectively. We found that NEAT1 level was decreased in CIS patients and OGD/R treated cells. OGD/R exerted pro‑inflammasome effects by increasing the expression of inflammasome‑associated proteins and ROS and malondialdehyde (MDA) while inhibiting SOD production. This effect was partially antagonized by NEAT1. We bioinformatically identified interactions between NEAT1/miR‑10b‑5p, BCL6/miR‑10b‑5p, and NLRP3‑promoter/BCL6, and validated them by luciferase assay, qRT‑PCR, and ChIP. NEAT1 inhibited miR‑10b‑5p and upregulated BCL6 by ceRNA mechanism and alleviated OGD/R induced cell damage. We also proved that BCL6 was a repressive transcription factor in the regulation of NLRP3 expression. Thus, lncRNA NEAT1 inhibited inflammasome activation by NLRP3 in microglia via the NEAT1/ miR‑10b‑5p/BCL6/NLRP3 regulatory axis, which alleviated deleterious outcomes of ischemic stroke.