Objective To determine whether aquaporin-4 （AQP4） regulates acute lesions, delayed lesions, and the associated microglial activation after cryoinjury to the brain. Methods Brain cryoinjury was applied to AQP4 knockout （KO） and wild-type mice. At 24 h and on days 7 and 14 after cryoinjury, lesion volume, neuronal loss, and densities of microglia and astrocytes were determined, and their changes were compared between AQP4 KO and wild-type mice. Results Lesion volume and neuronal loss in AQP4 KO mice were milder at 24 h following cryoinjury, but worsened on days 7 and 14, compared to those in wild-type mice. Besides, microglial density increased more, and astrocyte proliferation and glial scar formation were attenuated on days 7 and 14 in AQP4 KO mice. Conclusion AQP4 deficiency ameliorates acute lesions, but worsens delayed lesions, perhaps due to the microgliosis in the late phase.
Wen-Zhen Shi Chun-Zhen Zhao Bing Zhao Xiao-Liang Zheng San-Hua Fang Yun-Bi Lu Wei-Ping Zhang Zhong Chen Er-Qing Wei
