Pan Feng, Chen An-min, Guo Feng-jin, Zhu Cheng-liang
Department of Orthopaedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhonghua Wai Ke Za Zhi. 2006 Dec 15;44(24):1708-12.
To investigate the effect of tacrolimus on expression of heat shock protein 70 (HSP 70) after spinal cord injuries (SCI) in rats and the relationship between expression of HSP 70 and apoptosis of neural cells.
Seventy-two male rats were divided randomly into three groups: the sham-operation group, the injury group and the group treated with tacrolimus, and the latter two groups were SCI with a weight-drop impactor at the T(10) vertebrae level (10 g weight was dropped from a 4.0 cm height). The tacrolimus group was injected with tacrolimus 5 minutes after SCI, while the other groups received 0.9% saline likewise. The inclined plate and BBB (Basso, Beattie and Bresnahan) scales were used to evaluate hindlimb neurological function. The expression of HSP 70 mRNA after SCI was detected by using reverse transcription polymerase chain reactions (RT-PCR) and immunohistochemistry staining was performed to determine the protein expression of HSP 70 and Caspase-3. The apoptosis of neural cells was assessed with the terminal deoxynucleotidyl transferase-mediated deoxyuredine triphosphate-digoxin nick end labeling (TUNEL) method.
Compared with the injury group, the expression of HSP 70 was significantly higher in the tacrolimus group, and the peak expression of HSP 70 mRNA and protein was respectively observed at 6, 24 h after SCI. Caspase-3-positive or TUNEL-positive cells were significantly less in the tacrolimus group than in the injury group. Neurological function score of the tacrolimus group was significantly better than that of the injury group.
Tacrolimus may inhibit activity of Caspase-3, attenuate apoptosis of neural cells and ameliorate neurological function recovery after SCI by inducing high expression of HSP 70.
探讨他克莫司对大鼠脊髓损伤（SCI）后热休克蛋白70（HSP 70）表达的影响以及HSP 70表达与神经细胞凋亡之间的关系。
将72只雄性大鼠随机分为三组：假手术组、损伤组和他克莫司治疗组，后两组于T10椎体水平用重物打击法造成SCI（10 g重物从4.0 cm高度落下）。他克莫司组在SCI后5分钟注射他克莫司，其他组同样注射0.9%生理盐水。采用斜板试验和BBB（Basso、Beattie和Bresnahan）评分评估后肢神经功能。采用逆转录聚合酶链反应（RT-PCR）检测SCI后HSP 70 mRNA的表达，并进行免疫组织化学染色以确定HSP 70和Caspase-3的蛋白表达。用末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸-地高辛缺口末端标记（TUNEL）法评估神经细胞凋亡。
与损伤组相比，他克莫司组HSP 70的表达显著升高，HSP 70 mRNA和蛋白的表达峰值分别在SCI后6、24小时出现。他克莫司组Caspase-3阳性或TUNEL阳性细胞明显少于损伤组。他克莫司组的神经功能评分明显优于损伤组。
他克莫司可能通过诱导HSP 70的高表达抑制Caspase-3的活性，减轻神经细胞凋亡，改善SCI后的神经功能恢复。
