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Updated: Nov 10, 2025
A Preclinical Model to Assess Brain Recovery After Acute Stroke in Rats
Published on: November 6, 2019
MiR-29a Knockout Aggravates Neurological Damage by Pre-polarizing M1 Microglia in Experimental Rat Models of Acute
Fangfang Zhao1,2, Haiping Zhao1,2, Junfen Fan1,2
1Institute of Cerebrovascular Diseases Research and Department of Neurology, Xuanwu Hospital of Capital Medical University, Beijing, China.
Objective:
By exploring the effects of miR-29a-5p knockout on neurological damage after acute ischemic stroke, we aim to deepen understanding of the molecular mechanisms of post-ischemic injury and thus provide new ideas for the treatment of ischemic brain injury.
Methods:
miR-29a-5p knockout rats and wild-type SD rats were subjected to transient middle cerebral artery occlusion (MCAO). miR-29a levels in plasma, cortex, and basal ganglia of ischemic rats, and in plasma and neutrophils of ischemic stroke patients, as well as hypoxic glial cells were detected by real-time PCR. The infarct volume was detected by TTC staining and the activation of astrocytes and microglia was detected by western blotting.
Results:
The expression of miR-29a-5p was decreased in parallel in blood and brain tissue of rat MCAO models. Besides, miR-29a-5p levels were reduced in the peripheral blood of acute stroke patients. Knockout of miR-29a enhanced infarct volume of the MCAO rat model, and miR-29a knockout showed M1 polarization of microglia in the MCAO rat brain. miR-29a knockout in rats after MCAO promoted astrocyte proliferation and increased glutamate release.
Conclusion:
Knockout of miR-29a in rats promoted M1 microglial polarization and increased glutamate release, thereby aggravating neurological damage in experimental stroke rat models.
Insights
Knocking out miR-29a-5p in rats worsened neurological damage after ischemic stroke by increasing microglial activation and glutamate release. This highlights miR-29a-5p
Area of Science:
- Neuroscience
- Molecular Biology
- Genetics
Background:
- Acute ischemic stroke causes significant neurological damage.
- MicroRNAs play crucial roles in regulating cellular responses to injury.
- Understanding the specific roles of microRNAs like miR-29a-5p is vital for developing targeted therapies.
Purpose of the Study:
- To investigate the functional role of miR-29a-5p in the context of acute ischemic stroke.
- To elucidate the molecular mechanisms underlying miR-29a-5p's influence on post-ischemic brain injury.
- To explore miR-29a-5p as a potential therapeutic target for ischemic stroke.
Main Methods:
- Establishment of a transient middle cerebral artery occlusion (MCAO) model in miR-29a-5p knockout and wild-type rats.
- Quantification of miR-29a-5p expression in plasma, brain tissue, and immune cells using real-time PCR.
- Assessment of infarct volume (TTC staining) and glial cell activation (Western blotting) in MCAO models.
Main Results:
- miR-29a-5p expression was significantly decreased in the blood and brain of MCAO rat models and in stroke patients.
- miR-29a-5p knockout exacerbated infarct volume and promoted M1 microglial polarization in the MCAO rat brain.
- Loss of miR-29a-5p led to increased astrocyte proliferation and glutamate release, contributing to heightened neurological damage.
Conclusions:
- miR-29a-5p knockout aggravates neurological damage in experimental stroke models.
- The mechanism involves promoting M1 microglial polarization and increasing glutamate release.
- Targeting miR-29a-5p may offer a novel therapeutic strategy for ischemic brain injury.
