title: Systematic review and meta-analysis of efficacy of mesenchymal stem cells on locomotor recovery in animal models of traumatic brain injury.
abstract: BACKGROUND
  The therapeutic potential of mesenchymal stem cells (MSCs) for traumatic brain injury (TBI) is attractive. Conducting systematic review and meta-analyses based on data from animal studies can be used to inform clinical trial design. To conduct a systematic review and meta-analysis to (i) systematically review the literatures describing the effect of MSCs therapy in animal models of TBI, (ii) determine the estimated effect size of functional locomotor recovery after experimental TBI, and (iii) to provide empirical evidence of biological factors associated with greater efficacy.
  
  
  METHODS
  We conducted a systematic search of PubMed, EMBASE, and Web of Science and hand searched related references. Studies were selected if they reported the efficacy of MSCs in animal models of TBI. Two investigators independently assessed the identified studies. We extracted the details of individual study characteristics from each publication, assessed study quality, evaluated the effect sizes of MSCs treatment, and performed stratified meta-analysis and meta-regression, to assess the influence of study design on the estimated effect size. The presence of small effect sizes was investigated using funnel plots and Egger's tests.
  
  
  RESULTS
  Twenty-eight eligible controlled studies were identified. The study quality was modest. Between-study heterogeneity was large. Meta-analysis showed that MSCs exert statistically significant positive effects on sensorimotor and neurological motor function. For sensorimotor function, maximum effect size in studies with a quality score of 5 was found in the weight-drop impact injury TBI model established in male SD rats, to which syngeneic umbilical cord-derived MSCs intracerebrally at cell dose of (1-5)×10(6) was administered r 6 hours following TBI, using ketamine as anesthetic agent. For neurological motor function, effect size was maximum for studies with a quality score of 5, in which the weight-drop impact injury TBI models of the female Wistar rats were adopted, with administration syngeneic bone marrow-derived MSCs intravenously at cell dose of 5×10(6) at 2 months after TBI, using sevofluorane as anesthetic agent.
  
  
  CONCLUSIONS
  We conclude that MSCs therapy may improve locomotor recovery after TBI. However, additional well-designed and well-reported animal studies are needed to guide further clinical studies.
authors.affiliation: Department of Integrated Chinese and Western Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan, 410011, PR China. pengweijun1987@gmail.com.
authors.forename: Weijun
authors.initials: W
authors.lastname: Peng
authors.affiliation: Department of Pathology, Development and Regeneration Key Laboratory of Sichuan Province, Chengdu Medical College, Chengdu, Sichuan, 610500, PR China. lucysunmoon@126.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Integrated Chinese and Western Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan, 410011, PR China. 921191689@qq.com.
authors.forename: Chenxia
authors.initials: C
authors.lastname: Sheng
authors.affiliation: Department of Integrated Chinese and Western Medicine, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, Hunan, 410011, PR China. ericwangzhe@126.com.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Institute of Integrated Medicine, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, Hunan, 410008, PR China. 3130748102@qq.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Institute of Integrated Medicine, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, Hunan, 410008, PR China. chzxysm@yahoo.com.
authors.forename: Chunhu
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Institute of Integrated Medicine, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, Hunan, 410008, PR China. 1973240230@qq.com.
authors.forename: Rong
authors.initials: R
authors.lastname: Fan
mesh_terms: D000818:Animals; D001930:Brain Injuries / Q000628:therapy*; D064987:Cell- and Tissue-Based Therapy / Q000379:methods*; D004195:Disease Models, Animal; D005260:Female; D008124:Locomotion / Q000502:physiology*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology; D009043:Motor Activity / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D020127:Recovery of Function