Effects of progesterone on the proliferation of neural stem cells in rats with brain trauma / 中国组织工程研究

ABSTRACT

BACKGROUND: Brain trauma can stimulate the proliferation of neural stem cells (NSCs) to some extent, while progesterone can ameliorate the learning and memory function following brain trauma, which can also promote the neurofunctional recovery after brain trauma by stimulating the proliferation of NSCs.OBJECTIVE: To observe the effects of progesterone on the proliferation of NSCs after diffuse brain injury (DBI).DESIGN: Randomized control animal experiment.SETTING: Xinxiang Medical College.MATERIALS Forty-eight healthy male SD rats at 4-5 months with the body mass of 280-330 g were selected.METHODS: The experiment was conducted in Xinxiang Medical College from September 2004 to January 2005. Forty-eight rat models of Marmarou DBI were selected and randomly divided into 4 groups with 12 rats in each group ①Sham-operation group rats were cut open the scalp and then sutured.②Brain trauma group rats were made into animal models of brain trauma.③Dimethyl sulphoxide (DMSO) group rats were given intraperitoneal injection of DMSO at the same volume as progesterone group at one hour after brain trauma and then the same administration was performed daily. ④Progesterone group rats were intraperitoneally injected with 4 mg/kg progesterone at one hour after brain trauma and then the same administration was performed daily. Rats were executed respectively at 3 and 6 days after sham operation or brain trauma operation, and hematoxylin-eosin staining was conducted to observe the morphological changes of cortical neurons in brain. The expressions of nestin in dentate gyrus and hippocampus were detected with immunohistochemical staining.MAIN OUTCOME MEASURES: Observation of histomorphological changes of neurons and detection of the expressions of nestin in hippocampus and dentate gyrus.RESULTS: ①There was no injury in cortical neurons in the sham-operation group, while obvious neuronal injury and loss in cortex of rats were found in the 3-day and 6-day brain trauma groups, and the neuronal injury was significantly severer in brain trauma than in 3-day and 6-day progesterone groups. ②The expressions of nestin in hippocampal CA4 region or dentate gyrus of sham-operation group were in low level or little, and the expression of nestin could be seen occasionally in hippocampal CA4 region. The expressions of nestin in hippocampal CA4 region and dentate gyrus of the brain trauma group significantly increased (P ＜ 0.05), while those in the progesterone group increased more than the brain trauma group remarkably (P ＜ O.05).③There were no differences in neuronal injury and nestin expression between braintrauma group and DMSO group(P ＞ 0.05).CONCLUCION Progesterone for brain trauma may be related with its promoting effects on the proliferation of NSCs.