摘要
BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE： To observe changes in nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, and interleukin-8 （IL-8） expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS： Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS： A total of 62 Wister rats were randomly assigned to control （n = 18）, model （n = 22, SCI ＋ PBS）, and transplantation （n = 22, SCI ＋ MSCs） groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine （BrdU）-Iabeled MSCs （24 hours before injection） were intravascularly transplanted. MAIN OUTCOME MEASURES： The rats were evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation. RESULTS： A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group （P 〈 0.05）, which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks （P 〈 0.05）, but IL-8 levels remained unchanged （P 〉 0.05）. CONCLUSION： MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.
BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE： To observe changes in nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, and interleukin-8 （IL-8） expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS： Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS： A total of 62 Wister rats were randomly assigned to control （n = 18）, model （n = 22, SCI ＋ PBS）, and transplantation （n = 22, SCI ＋ MSCs） groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine （BrdU）-Iabeled MSCs （24 hours before injection） were intravascularly transplanted. MAIN OUTCOME MEASURES： The rats were evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation. RESULTS： A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group （P 〈 0.05）, which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks （P 〈 0.05）, but IL-8 levels remained unchanged （P 〉 0.05）. CONCLUSION： MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.
基金
the National Natural Science Foundation of China, No. 30671041
30870642
