Study The Difference Of CDKI Between Astrocytes And Neurons

【Objective】Astrocytes and neurons are the predominant cell types found in brain. Recent findings suggest that aberrant reentry of neuronal cells into the cell cycle occurs after cerebral ischemia. But the difference of CDKI between astrocytes and neurons are unclear. In this study, we will investigate the chang of expressions of CDKI on astrocytes and neurons. which will give experiment proves for the study of astrocytes and neurons cell cycle control.【Methods】Ischemia was induced by temporary middle cerebral artery occlusion (MCAo). The experimental rats induced by MCAo were sacrificed on days 1, 3, 7 and 14 after reperfusion. The brain was taken at days 1, 3, 7, 14 after injury, then the P15ink4b and P21cip1of astrocytes and neurons were detected by flow cytometry.【Results】Compared with that of the control group, the expression of P15ink4b in astrocytes was remarkably downregulated on the ischemic side of cerebral cortex after 3, 7 and 14days of cerebral ischemia reperfusion ( P < 0.05). The expression of P15ink4b in neurons was remarkably downregulated on the ischemic side of cerebral cortex after 14 days of cerebral ischemia ( P < 0.05). The P15ink4b expression in astrocytes was remarkably downregulated than that in neurons ( P < 0.05). Compared with that of the controls, the expression of P21cip1 in astrocytes was remarkably down-regulated on the ischemic side of cerebral cortex after3, 7 and 14days of cerebral ischemia reperfusion ( P < 0.05). The expression of P21cip1 in neurons was remarkably down-regulated on the ischemic side of cerebral cortex after3, 7 and 14days of cerebral ischemia reperfusion ( P < 0.05). The P21cip1expression was no marked difference between astrocytes and neurons ( P > 0.05).【Conclusion】Astrocytes and neurons have a different downregulation of expression of P15ink4b after MCAo in rats. The P15ink4b expression in astrocytes was more remarkably downregulated than that in neurons. Astrocytes and neurons have a downregulation of expression of P21cip1. The P21cip1expression was no marked difference between astrocytes and neurons. downregulation of expression of P15ink4b and P21cip1 may be not only related to the proliferation of astrocytes, but also participate in the apoptosis process in neurons after focal cerebral ischemia.