Establishment and application of an in vitro neruoinflammation model in astrocytes after ischemic injury / 中华神经医学杂志

ABSTRACT

Objective To establish a in vitro cell model of inflammation following ischemic injury in rat astrocytes, and study the effects of mild hypothermia on the response of astrocytes to ischemia and inflammation. Methods Primary cultured neonatal SD rat astrocytes identified by GFAP immunofluorescence staining were divided into normal control group (C), hypoxia group (H), and hypoxia and leukocyte treatment group (H+W). Hypoxic injury of the cells was induced by exposure to glucose-flee DMEM medium in 5% CO2 and 95% N2 for 4 h, and for leukocyte treatment, the astrocytes were co-cultured with leukocytes isolated from rat blood. The 3 groups of cells were subjected to hypothermia treatments at 37, 34, 32 and 30 ℃, and the cell viability was estimated by lactic dehydrogenase (LDH) release assay and live/dead assay. Results Ischemic injury occurred in the astrocytes after 4 h of hypoxic exposure. Hypoxic treatment of the cells at 37 ℃ resulted in increased LDH release in all the 3 groups, and the increment intensified in the order of groups C, H and H+W. Mild hypothermia at 34 ℃ and 32 ℃ significantly reduced the LDH release in groups H and H+W (P<0.05), but hypothermia at 30 ℃ significantly increased LDH release in comparison with that at 32 ℃ (P<0.05). Conclusion Mild hypothermia can significantly reduce the severity of ischemic and inflammatory injuries in rat astrocytes possibly mediated also by other mechanisms in addition to inhibited astrocyte metabolism due to low temperatures.