摘要
目的研究应用cAMP衍生物特异性激活Epac2/Akt信号通路在哺乳动物脊髓损伤中的病理和生理机制。方法 96只成年健康雌性SD大鼠,完全随机分为4组(n=24),A、B、C组均采用改良Allen重物打击法制备大鼠脊髓损伤模型。A组给予8-CPT-2'-O-Me-cAMP 0.5 mg/(kg·d)、B组给予等量10%(体积分数)DMSO、C组给予8-CPT-2'-O-Me-cAMP 0.5 mg/(kg·d)加LY294002 0.2 mg/(kg·d)各7 d。D组为正常对照组。各组分别于1、2、3、4周采用BBB评分法评估大鼠后肢功能恢复情况,各时间点取材行HE染色、免疫荧光、实时荧光定量PCR检测脊髓细胞标志物(Nestin、NF200、GFAP)和通路因子(Epac2、Akt)的表达。结果 A组大鼠在术后1～4周BBB评分持续升高,均高于B、C组(P<0.01),低于D组(P<0.01)。在1、2、3周,A组Epac2 mRNA表达与C组Epac2 mRNA表达差异无意义,但高于B组(P<0.01)和D组(P<0.01)。A组Akt mRNA表达高于B、C、D组(P<0.01)。A组Nestin、NF200 mRNA表达在各期均高于B、C、D组(P<0.01)。A、B、C组GFAP mRNA表达差异无统计学意义。HE染色可见A、B、C组造模后脊髓组织结构疏松,有大量空洞形成。免疫荧光染色并进行积分光密度值分析,其结果与实时荧光定量PCR检测结果相符。结论在哺乳动物脊髓损伤后应用cAMP衍生物能够特异性激活Epac2/Akt通路,促使神经干细胞分化和神经细胞增殖,有助于脊髓修复。
Objective To investigate the underlying mechanism of cAMP derivative（8-CPT-2＇-O-Me- cAMP） in the physiology and pathology of spinal cord injury （SCI）. Methods Ninety-six adult healthy female Sprague-Dawley rats were randomly divided into 4 groups （ n = 24）. The rats from groups A, B and C were in- flicted to SCI models with a modified Allen＇ s method. The rats were subjected to administer the derivative of 0.5 mg/（kg . d） in group A, 10% DMSO at equal volume in group B, and the derivative and LY294002 of 0.2 mg/（kg d） in group C respectively for 7 d. The rats in groups D served as normal control. Locomotor activity was evaluated by using the Basso-Beattie-Bresnahan （BBB） score test at 1,2, 3 and 4 weeks postoper- increase in the postoperative 1 to 4 weeks and were significantly higher than those in groups B and C （P 〈 0. 01 ）, but were lower than that in group D （P 〈0. 01 ）. In the postoperative 1st to 3th weeks, the mRNA ex- pression of Epac2 in group A was significantly higher than that of group B （P 〈 0. 01 ） and group D （ P 〈 0. 01 ）, but was not different with that of group C. The mRNA expression of Akt in group A was significantly higher than those of groups B, C and D （ all P 〈 0. 01 ）. The mRNA expression of Nestin and NF200 in group A were significantly higher than those of groups B, C and D （ P 〈 0. 01 ） at 1 to 4 weeks. There was nodifference in GFAP mRNA expression among groups A, B and C. The similar changes were found by immuno- fluorescence analysis. A lot of cavities were observed in spinal cord tissues by HE staining in groups A, B and C. Conclusion The derivative of cAMP activates the Epac2/Akt pathway to induce neural stem cells to proliferate and differentiate into neurons, and thus enhances the healing, of SCI in rats.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2012年第24期2493-2497,共5页
Journal of Third Military Medical University
基金
全军医学科学技术研究"十一五"计划课题(06MA081)~~
