牙髓干细胞移植治疗缺氧缺血性脑损伤新生大鼠远期行为学及环磷酸腺苷反应元件结合蛋白的变化

Effects of dental pulp stem cell transplantation on the long-term behavior and cAMP response element binding protein in neonatal rats with hypoxic ischemic brain damage

背景:环磷酸腺苷反应元件结合蛋白(c AMP response element binding protein,CREB)是影响记忆存储的关键蛋白,与长期记忆密切相关,研究牙髓干细胞侧脑室移植远期行为学及CREB的变化机制可为缺氧缺血性脑损伤的治疗提供新思路。目的:观察人牙髓干细胞移植对缺氧缺血性脑损伤新生大鼠远期行为学以及CREB表达的影响,为缺氧缺血性脑损伤的治疗提供科学的理论依据。方法:36只健康7 d龄SD大鼠随机等分为正常组、缺氧缺血性脑损伤组和人牙髓干细胞组。采用经典的Rice法建立新生大鼠缺氧缺血性脑损伤模型,造模后24 h后,人牙髓干细胞组经侧脑室注入2μL人牙髓干细胞(浓度为1.5×106μL-1),正常组和缺氧缺血性脑损伤组分别注射等量生理盐水。结果与结论:人牙髓干细胞组大鼠平均觅水时间、平均逃避潜伏期及平均逃避距离亦显著短于缺氧缺血性脑损伤组(P<0.01),但其平均觅水时间、逃避潜伏期及距离均长于正常组(P<0.01);尼氏染色结果示人牙髓干细胞组海马CA1区细胞排列较规则,细胞数量较多,显著多于缺氧缺血性脑损伤组,但仍少于正常组(P<0.05);免疫组织化学染色结果示人牙髓干细胞组CREB阳性细胞数亦显著多于缺氧缺血性脑损伤组,但仍显著少于正常组(P<0.01)。提示人牙髓干细胞移植可通过促进海马CA1区CREB的表达,改善缺氧缺血性脑损伤新生大鼠远期学习记忆能力,从而修复新生大鼠缺氧缺血性脑损伤。

BACKGROUND： c AMP response element binding protein（CREB） is a key protein of memory, which is closely related to long-term memory. It will provide a new way for the treatment of hypoxic ischemic brain damage（HIBD） to study the effects of dental pulp stem cells transplantation on the long-term behavior and CREB protein via the lateral ventricle in neonatal HIBD rats.OBJECTIVE： To observe the changes in long-term behavior and CREB protein expression in neonatal HIBD rats after human dental pulp stem cell transplantation, thereby providing scientific evidence for clinical treatment of neonatal HIBD. METHODS： Thirty-six healthy 7-day-old Sprague-Dawley rats were randomly divided into normal, HIBD and cell transplantation group. The hypoxic ischemic brain damage models were established in the brain damage and cell transplantation groups. Twenty-four hours after HIBD, human dental pulp stem cells were injected into the left lateral cerebral ventricle of rats in the cell transplantation group, totally 3×10^6 living cells. Equal volume of normal saline was injected into the left lateral cerebral ventricle of rats in the normal control and HIBD groups. RESULTS AND CONCLUSION： The average time to seek water, the average escape latency and escape distance of the human dental pulp stem cells group were significantly shorter than those of hypoxic ischemic brain injury group（P〈0.01）, but longer than those in the normal group（P〈0.01）. Nissl staining showed that the cells in the hippocampal CA1 region in human dental pulp stem cells group were more regular, the number of cells was significantly higher than that of hypoxic ischemic brain injury group, but still significantly less than that in the normal group（P〈0.05）. Immunohistochemical staining results showed that the number of CREB positive cells in human dental pulp stem cells group was significantly higher than those in HIBD group, but still significantly less than those in the normal group（P〈0.01）. It is suggested that human dental pulp stem cells transplantation could promote the expression of CREB protein in the hippocampal CA1 region, to improve the long-term learning and memory ability of hypoxic ischemic neonatal rats, and thus repair HIBD.