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Isolation and Flow Cytometric Assessment of Neuroimmune Interactions in a Mini-Stroke Murine Model
Published on: June 20, 2025
miR-221 Exerts Neuroprotective Effects in Ischemic Stroke by Inhibiting the Proinflammatory Response
1Department of Neurology, Shaanxi Provincial People's Hospital, No. 256 West Friendship Rd, Xi'an, China, 710068.
Background:
Ischemic stroke is clearly affected by microRNAs (miRNAs) due to dysfunction of their regulatory networks. Our clinical data confirmed decreased miR-221 levels in plasma collected from patients with acute ischemia compared with plasma from healthy controls. Therefore, we further aimed to demonstrate the regulatory mechanisms by which miR-221 exerts its neuroprotective effects in acute ischemic brain injury.
Methods:
Middle cerebral artery occlusion (MCAO) was used to establish focal cerebral ischemia in adult male C57BL/6 mice. A miR-221 mimic or a negative mimic control was injected by intracerebroventricular administration 24 h prior to MCAO. After 48 h, cerebral infarction volume and neurological scores were calculated, and to determine the extent of neuroprotection by miR-221, neurobehavioral tests were performed. Quantitative real-time PCR, ELISA, and flow cytometry were also performed to identify the expression of inflammation-related cytokines and chemokines as well as infiltration/activation of various immune cells in the brain.
Results:
The results showed that MCAO mice treated with a miR-221 mimic exhibited significantly decreased cerebral infarction volume and increased amelioration of behavioral deficits. Moreover, the expression of proinflammatory cytokines (TNF-α, MCP-1, VCAM-1, and IL-6) and chemokines (CCL2 and CCL3) was significantly decreased in the miR-221 mimic-treated group. In addition, the flow cytometry data showed that macrophage infiltration and microglial activation were blocked by miR-221 treatment.
Conclusion:
our results indicate that miR-221 could decrease brain damage in the setting of acute ischemic stroke by inhibiting the proinflammatory response, which furthered our understanding of the molecular basis of miR-221 and provided a new potential therapeutic target for the treatment of ischemic stroke .
Insights
MicroRNA-221 (miR-221) shows neuroprotective effects in ischemic stroke by reducing brain damage and inflammation. This study demonstrates miR-221 as a potential therapeutic target for acute ischemic brain injury.
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- MicroRNAs (miRNAs) play a crucial role in regulating networks affected by ischemic stroke.
- Decreased levels of miR-221 were observed in acute ischemic stroke patients compared to healthy controls.
- Understanding miR-221's regulatory mechanisms is key to its neuroprotective potential in ischemic brain injury.
Purpose of the Study:
- To elucidate the neuroprotective mechanisms of miR-221 in acute ischemic brain injury.
- To investigate the impact of miR-221 on inflammation and immune cell activity post-stroke.
- To validate miR-221 as a potential therapeutic target for ischemic stroke.
Main Methods:
- Focal cerebral ischemia was induced in mice using middle cerebral artery occlusion (MCAO).
- Intracerebroventricular administration of miR-221 mimic or control mimic was performed prior to MCAO.
- Cerebral infarction volume, neurological scores, and neurobehavioral tests were assessed; gene and protein expression, immune cell infiltration, and activation were analyzed using qPCR, ELISA, and flow cytometry.
Main Results:
- Treatment with miR-221 mimic significantly reduced cerebral infarction volume and improved behavioral deficits in MCAO mice.
- Expression of pro-inflammatory cytokines (TNF-α, IL-6) and chemokines (CCL2, CCL3) was significantly decreased by miR-221 treatment.
- miR-221 administration effectively blocked macrophage infiltration and microglial activation in the ischemic brain.
Conclusions:
- miR-221 demonstrates significant neuroprotective effects in acute ischemic stroke by suppressing the inflammatory response.
- These findings deepen the understanding of miR-221's molecular basis in stroke pathology.
- miR-221 represents a promising novel therapeutic target for treating ischemic stroke.
