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Updated: Dec 27, 2025
Evaluating Cell Death Signaling by Immunofluorescence in a Rat Model of Ischemic Stroke
Published on: January 3, 2025
miR-155 Knockdown Protects against Cerebral Ischemia and Reperfusion Injury by Targeting MafB
Li Zhang1,2, Chao Liu2, Chao Huang2
1Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Background:
Studies have elucidated that the variable expression levels of miRNAs influence the inflammatory process in ischemic stroke. Nevertheless, the impact and potential mechanism of miR-155 in cerebral ischemia-reperfusion injury (CIRI) keep to be incompletely known.
Methods:
The levels of miR-155 and MafB were determined via qRT-PCR, western blot, or immunohistochemistry assays in plasma of patients with CIRI, oxygen glucose deprivation/reoxygenation (OGD/R) induced SH-SY5Y cells, and mouse models with middle cerebral artery occlusion (MCAO). The association between miR-155 and MafB was validated via dual-luciferase reporter and western blot assays. Cell viability, apoptosis, invasion, and migration were evaluated through MTT, flow cytometry, Transwell and wound healing assays. Infarction volume was measured in MCAO mouse brain tissues by TTC assay. The expression of inflammatory mediators was measured by ELISA in cells and brain tissues.
Results:
miR-155 level was upregulated whereas MafB was downregulated in the plasma of patients with CIRI, OGD/R-induced SH-SY5Y cells, also as mouse models with MCAO injury. Mechanistically, miR-155 directly targeted 3'UTR of MafB and restrained MafB expression in OGD/R injury SH-SY5Y cells. Downregulation of miR-155 attenuated OGD/R-induced injury through increasing proliferation, inhibiting apoptosis, enhancing invasion and migration abilities, and constraining the expression of inflammatory mediators (IL-1β, IL-6, and TNF-α) and inflammatory enzymes (iNOS and COX-2) in SH-SY5Y cells following OGD/R, while MafB inhibition reversed the protective effects. In vivo, downregulating miR-155 reduced the infarction volume in the MACO mouse brain. Furthermore, miR-155 knockdown inhibited the IL-1β, IL-6, and TNF-α) and inflammatory enzymes (iNOS and COX-2) in SH-SY5Y cells following OGD/R, while MafB inhibition reversed the protective effects.
Conclusion:
Our results suggest that miR-155 knockdown alleviated ischemia-reperfusion injury by targeting MafB to improve the neurological function and inhibit inflammation response, highlighting a novel therapeutic strategist for CIRI.
Insights
Downregulating miR-155 alleviates cerebral ischemia-reperfusion injury (CIRI) by targeting MafB, improving neurological function and reducing inflammation. This highlights miR-155 as a potential therapeutic target for CIRI.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- MicroRNAs (miRNAs) play a role in the inflammatory processes of ischemic stroke.
- The specific role and mechanism of miR-155 in cerebral ischemia-reperfusion injury (CIRI) remain unclear.
Purpose of the Study:
- To investigate the role and mechanism of miR-155 in cerebral ischemia-reperfusion injury (CIRI).
- To explore miR-155 as a potential therapeutic target for CIRI.
Main Methods:
- Quantified miR-155 and MafB levels in patients, cell models (OGD/R), and mouse models (MCAO).
- Validated the interaction between miR-155 and MafB using dual-luciferase and Western blot assays.
- Assessed cell viability, apoptosis, invasion, migration, and inflammatory mediator expression.
Main Results:
- miR-155 was upregulated, while MafB was downregulated in CIRI models.
- miR-155 directly targeted MafB, inhibiting its expression.
- miR-155 knockdown reduced infarct volume and attenuated inflammatory responses in vivo and in vitro.
- MafB inhibition reversed the protective effects of miR-155 knockdown.
Conclusions:
- miR-155 knockdown alleviates CIRI by targeting MafB.
- This mechanism improves neurological function and inhibits inflammation.
- miR-155 presents a novel therapeutic strategy for CIRI.
