Blockage of p38MAPK in astrocytes alleviates brain damage in a mouse model of embolic stroke through the CX43/AQP4 axis

Background: Cerebral edema, a significant complication arising from acute ischemic stroke (IS), has a critical influence on morbidity and mortality. p38MAPK has been shown to promote neuronal Apoptosis and brain damage. However, the role of the p38MAPK inhibitor SKF-86002 in protecting against ischemic injury and cerebral edema remains unclear.

Methods: Infarct area was examined by TTC staining in middle cerebral artery occlusion (MCAO) mice. Neurological score and brain water content were evaluated. TUNEL and NeuN staining were used to assess neuronal Apoptosis and the survival of neurons. Blood-brain barrier (BBB) permeability was determined by Evans blue. Double immunofluorescence staining detected the colocalization of AQP4 and CX43 in astrocytes. IHC staining revealed CX43 and AQP4 expression. EDU staining detected the proliferation of Oxygen and glucose deprivation/reoxygenation (OGD/R)-treated astrocytes. Levels of oxidative stress markers were determined using commercial kits. ELISA was used to assess the secretion of pro-inflammatory factors. RT-qPCR measured the expression of CX43, AQP4 and pro-inflammatory factors. Western blot analyzed the levels of p-p38/p38, AQP4 and CX43. Co-immunoprecipitation (Co-IP) determined the interaction between CX43 and AQP4.

Results: SKF-86002 attenuated brain damage, edema, and neuronal Apoptosis in MCAO mice. Astrocyte proliferation was suppressed, and oxidative stress and inflammation were alleviated by SKF-86002 treatment. SKF-86002 negatively regulated p38 signaling and the expression of AQP4 and CX43. Additionally, the expression of CX43/AQP4 within astrocytes was modulated by SKF-86002.

Conclusion: In summary, SKF-86002 alleviated IS injury and cerebral edema by inhibiting astrocyte proliferation, oxidative stress and inflammation. This effect was associated with the suppression of CX43/AQP4, suggesting that SKF-86002 shows promise as a novel therapeutic approach for preventing IS.

AQP4; CX43; Cerebral edema; Embolic stroke; SKF-86002; p38MAPK.