Progesterone regulates COX-2 and Caspase-3 expressions in hippocampal neurons in rats after traumatic brain injury by NF-?B signaling pathway / 第三军医大学学报

ABSTRACT

Objective To investigate the effect of nuclear factor-?B(NF-?B) on the regulation of cyclooxygenase-2(COX-2) and Caspase-3 in hippocampal neurons after traumatic brain injury(TBI) in rats,and explore the neuroprotective effect and the possible mechanism of progesterone(PROG) in hippocampal neurons after TBI.Methods Forty-five male Spraque-Dawley rats were randomly divided into 3 groups: sham-operated group(n=15),TBI group(n=15) and PROG-treated group(n=15,intraperitoneal injection of PROG 16 mg/kg in 1 and 6 h after injury).The rat model of TBI was duplicated with the improved Feeney's method.The rats were sacrificed in 24 h after injury and their brain was resected.Nissl staining,immunohistochemical staining and Western blot assay for NF-?B,COX-2 and Caspase-3 was used to observe the changes of positive cell numbers and protein levels in the hippocampal neurons.Results The numbers of immunoreactive neurons to NF-?B(24.0?2.5),COX-2(35.9?2.7) and Caspase-3(25.1?2.7) were significantly increased in the hippocampus at 24 h after TBI when compared with the positive neuron numbers of NF-?B(1.9?0.9),COX-2(1.5?0.7) and Caspase-3(1.8?0.8) in sham group.After the treatment of PROG,the positive cell number of NF-?B(14.2?1.8),COX-2(16.6?2.7),Caspase-3(11.2?2.4) was reduced obviously as compared with the TBI group(P