Objective To investigate the anti-chronic stress effect of bone marrow mesenchymal stem cell (BMSCs) transplantation in rats with spinal cord injury.Methods Forty-eight adult SD rats were divided into control group,model group and treatment group according to the random number table,with 16 rats each.In model and treatment groups,lower thoracic (T10) spinal cord injury were constructed using the modified Allen's method.In control group,only laminectomy was performed.After 7 days,100 μl Hank's buffer suspension containing 1.0 × 106 BMSCs was injected into the subarachnoid space of L4-5 intervertebral space of rats in control group and treatment group.While in model group,only the equal volume of Hank's buffer was used.Basso-Beattie-Bresnahan (BBB) scale was performed to evaluate hindlimb motor function in rats.At postoperative 14 and 28 days,blood samples were collected to measure adrenocorticotropic hormone (ACTH),norepinephrine (NE),epinephrine (E) and corticosterone (CORT) using the ELISA method;brains were harvested for the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor proteins GluR1 and GluR2 immunohistochemical staining.Results After injury,BBB scores in model and treatment groups were similar,but both were lower than that in control group (P ＜ 0.05).After BMSCs transplantation,BBB score in treatment group [21 d:(9.85 ± 0.82)points and 28 d:(11.23 ±0.68)points] improved continuously compared to model group [21 d:(8.42 ± 0.39) points and 28 d:(8.84 ± 0.25) points],but all were lower than that in control group [(21.00 ±0.00)points,P ＜0.05].ACTH contents in model and treatment groups at 14d [(104.80±6.16) and (98.50 ± 4.07) pg/ml] and 28 d [(101.40±2.33) and (96.50± 2.28) pg/ml] were higher than those in control group [(90.40 ± 1 1.36) and (83.20 ± 5.22) pg/ml] (P ＜ 0.05).CORT contents in model and treatment groups [(44.40 ± 1.44) and (43.30 ± 1.17) ng/ml] was lower than that in control group [(48.20 ± 2.27) ng/ml] at 14 d,but were found to be elevated [(70.40 ± 1.90) and (61.40 ± 1.83) ng/ml] compared to control group [(46.40 ± 1.49) ng/ml] at 28 d (P ＜ 0.05).Meanwhile,the CORT content in treatment group was lower than that in model group (P ＜ 0.05).Changes in NE and E contents among the groups were similar with ACTH.Immunohistochemical staining suggested the amounts of GluR1 and GluR2 positive cells in treatment group lowered compared to control group (P ＜ 0.05),but increased in model group compared to control group (P ＜ 0.05).Conclusion BMSCs transplantation can improve the hindlimb motor function,contribute to reducing the secretion of stress-related hormones ACTH,CORT,NE and E,and down-regulate the expression of AMPA receptor proteins GluR1 and GluR2 in rats with spinal cord injury,suggesting a potential role in antichronic stress.%目的 观察骨髓间充质干细胞(BMSCs)移植对脊髓损伤大鼠的潜在抗慢性应激作用. 方法 48只成年SD大鼠按随机数字表法分为对照组、模型组、治疗组,每组16只.对照组仅做T10椎板切除术,模型组和治疗组采用改良Allen法制造大鼠T10脊髓损伤模型.造模后7d,对照组、治疗组于L4-5水平向蛛网膜下腔注射100μl含1.0×106 BMSCs的Hank缓冲液的混悬液,模型组注射等量Hank缓冲液.术前、术后BBB评分评估大鼠后肢运动功能.移植后14,28 d采集各组新鲜血液,ELISA法检测血浆促肾上腺皮质激素(ACTH)、去甲肾上腺素(NE)、肾上腺素(E)及血清皮质酮(CORT)含量;取脑组织,行免疫组织化学染色检测海马、杏仁核区α-氨基羟甲基恶唑丙酸(AMPA)受体蛋白谷氨酸受体1(GluR1)和谷氨酸受体2(GluR2)的表达.结果 造模后,模型组、治疗组BBB评分差异无统计学意义,但两者均低于对照组(P＜0.05).BMSCs移植后,治疗组大鼠BBB评分较模型组持续增高,移植后21,28 d治疗组[(9.85±0.82)分、(11.23±0.68)分]和模型组[(8.42±0.39)分、(8.84±0.25)分]均低于对照组[(21.00±0.00)分、(21.00 ±0.00)分](P＜0.05).移植后14,28 d ACTH浓度模型组[(104.80±6.16) pg/ml、(101.40 ±2.33) pg/ml]和治疗组[(98.50±4.07) pg/ml、(96.50±2.28) pg/ml]均高于对照组[(90.40±11.36)pg/ml、(83.20 ±5.22) pg/ml] (P ＜0.05);移植后14 d CORT浓度模型组、治疗组[(44.40±1.44) ng/ml、(43.30±1.17) ng/ml]均低于对照组(48.20±2.27) ng/ml (P ＜0.05),28d时模型组、治疗组[(70.40±1.90) ng/ml、(61.40±1.83) ng/ml]均高于对照组(46.40±1.49) ng/ml(P＜0.05);治疗组均低于模型组(P＜0.05);三组NE、E浓度的变化趋势与ACTH浓度变化趋势相似.移植后14,28 d GluR1、GluR2阳性细胞数治疗组与模型组比较,总体呈下降趋势(P＜0.05);模型组与对照组比较,总体呈上升趋势(P＜0.05);治疗组与对照组比较,总体呈下降趋势(P＜0.05). 结论 BMSCs移植可下调应激相关激素ACTH、CORT、NE和E的分泌,以及海马、杏仁核区AMPA通道受体蛋白GluR1、GluR2的表达,表现出潜在的抗慢性应激作用,从而促进脊髓损伤后大鼠的后肢运动功能恢复.
展开▼
