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LncRNA HOTAIR/miR-9-5p/FOXP1 axis modulates cerebral ischemia-reperfusion injury via NLRP3 inflammasome activation
Tingting Liu1, Xiaosong Zhu2, Fengjuan Zhuo2
1Department of Vasculocardiology, Linyi People's Hospital, Shandong Second Medical University, Linyi, Shandong 276000, PR China.
Objective:
This study aimed to investigate the association between the HOTAIR-miR-9-5p axis and the inflammatory response in ischemic stroke (IS) and elucidate the underlying molecular mechanisms.
Methods:
Middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) were applied to simulate ischemic/reperfusion conditions in vivo and in vitro. The expression levels of HOTAIR and miR-9-5p in the serum of patients or in the brain tissue of MCAO/R mice were assessed by qRT-PCR, and the secretion levels of IL-1β and IL-18 were analyzed by ELISA. Dual-luciferase reporter assays, RNA-binding protein immunoprecipitation (RIP), and RNA pull-down assays were performed to validate the target relationship. Western blotting was applied to assess the expression of NLRP3, CASP1, and FOXP1. Moreover, MCAO/R mice with intracerebroventricular injection of antagomir-9-5p were used to evaluate the effect of antagomir-9-5p on cerebral ischemia-reperfusion injury (CIRI).
Results:
A significant association was observed between the HOTAIR-miR-9-5p axis and inflammation in both IS patients and MCAO/R mice. HOTAIR was abnormally expressed at a low level, whereas miR-9-5p and the associated protein NLRP3 inflammatory response were increased in the serum of IS patients, as well as in the brain tissue of MCAO/R mice and in SH-SY5Y cells. Mechanistically, miR-9-5p negatively regulated the expression of HOTAIR and FOXP1. Furthermore, HOTAIR was found to regulate NLRP3 expression via the miR-9-5p/FOXP1 pathway. Functional experiments revealed that silencing miR-9-5p protected against cerebral ischemia/reperfusion injury and suppressed NLRP3 inflammasome activation.
Conclusion:
These findings collectively demonstrate that the HOTAIR/miR-9-5p/FOXP1 axis plays a critical role in NLRP3 inflammasome activation following IS, suggesting that its blockade could be a potential therapeutic strategy for ischemic brain injury.
Insights
The HOTAIR/miR-9-5p/FOXP1 axis significantly impacts inflammation in ischemic stroke (IS) by regulating NLRP3 inflammasome activation. Blocking this axis offers a potential therapeutic strategy for ischemic brain injury.
Area of Science:
- Neuroscience
- Molecular Biology
- Immunology
Background:
- Ischemic stroke (IS) is a major cause of disability and mortality worldwide.
- The inflammatory response, particularly NLRP3 inflammasome activation, plays a critical role in the pathogenesis of IS.
- Understanding the molecular mechanisms underlying IS-associated inflammation is crucial for developing effective therapies.
Purpose of the Study:
- To investigate the association between the HOTAIR-miR-9-5p axis and the inflammatory response in IS.
- To elucidate the underlying molecular mechanisms of this association.
- To explore the therapeutic potential of targeting the HOTAIR/miR-9-5p/FOXP1 axis in IS.
Main Methods:
- Establishment of in vivo (MCAO/R) and in vitro (OGD/R) models of ischemic/reperfusion injury.
- Assessment of HOTAIR and miR-9-5p expression levels using qRT-PCR.
- Analysis of IL-1β and IL-18 secretion using ELISA.
- Validation of molecular interactions using dual-luciferase reporter assays, RIP, and RNA pull-down assays.
- Evaluation of protein expression via Western blotting.
- In vivo functional studies using antagomir-9-5p in MCAO/R mice.
Main Results:
- A significant association was found between the HOTAIR-miR-9-5p axis and inflammation in IS patients and MCAO/R mice.
- HOTAIR expression was decreased, while miR-9-5p and NLRP3 were increased in IS.
- miR-9-5p negatively regulated HOTAIR and FOXP1; HOTAIR regulated NLRP3 via the miR-9-5p/FOXP1 pathway.
- Silencing miR-9-5p protected against cerebral ischemia/reperfusion injury and suppressed NLRP3 inflammasome activation.
Conclusions:
- The HOTAIR/miR-9-5p/FOXP1 axis is critically involved in NLRP3 inflammasome activation in IS.
- Targeting this axis represents a promising therapeutic strategy for ischemic brain injury.
- Further research is warranted to translate these findings into clinical applications.
