title: Integration of donor mesenchymal stem cell-derived neuron-like cells into host neural network after rat spinal cord transection.
abstract: Functional deficits following spinal cord injury (SCI) primarily attribute to loss of neural connectivity. We therefore tested if novel tissue engineering approaches could enable neural network repair that facilitates functional recovery after spinal cord transection (SCT). Rat bone marrow-derived mesenchymal stem cells (MSCs), genetically engineered to overexpress TrkC, receptor of neurotrophin-3 (NT-3), were pre-differentiated into cells carrying neuronal features via co-culture with NT-3 overproducing Schwann cells in 3-dimensional gelatin sponge (GS) scaffold for 14 days in vitro. Intra-GS formation of MSC assemblies emulating neural network (MSC-GS) were verified morphologically via electron microscopy (EM) and functionally by whole-cell patch clamp recording of spontaneous post-synaptic currents. The differentiated MSCs still partially maintained prototypic property with the expression of some mesodermal cytokines. MSC-GS or GS was then grafted acutely into a 2 mm-wide transection gap in the T9-T10 spinal cord segments of adult rats. Eight weeks later, hindlimb function of the MSC-GS-treated SCT rats was significantly improved relative to controls receiving the GS or lesion only as indicated by BBB score. The MSC-GS transplantation also significantly recovered cortical motor evoked potential (CMEP). Histologically, MSC-derived neuron-like cells maintained their synapse-like structures in vivo; they additionally formed similar connections with host neurites (i.e., mostly serotonergic fibers plus a few corticospinal axons; validated by double-labeled immuno-EM). Moreover, motor cortex electrical stimulation triggered c-fos expression in the grafted and lumbar spinal cord cells of the treated rats only. Our data suggest that MSC-derived neuron-like cells resulting from NT-3-TrkC-induced differentiation can partially integrate into transected spinal cord and this strategy should be further investigated for reconstructing disrupted neural circuits.
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, Guangdong, 510080, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, Guangdong, 510080, China.
authors.forename: Xue-Cheng
authors.initials: XC
authors.lastname: Qiu
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, Guangdong, 510080, China.
authors.forename: Yuan-Huan
authors.initials: YH
authors.lastname: Ma
authors.affiliation: Department of Human Anatomia, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Duan
authors.affiliation: Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Yuan-Feng
authors.initials: YF
authors.lastname: Chen
authors.affiliation: Department of Human Anatomia, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Huai-Yu
authors.initials: HY
authors.lastname: Gu
authors.affiliation: Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Jun-Mei
authors.initials: JM
authors.lastname: Wang
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.
authors.forename: Eng-Ang
authors.initials: EA
authors.lastname: Ling
authors.affiliation: Department of Electron Microscope, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China.
authors.forename: Jin-Lang
authors.initials: JL
authors.lastname: Wu
authors.affiliation: Department of Anatomy and State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; GHM Institute of CNS Regeneration, Jinan University, Guangzhou, 510632, China.
authors.forename: Wutian
authors.initials: W
authors.lastname: Wu
authors.affiliation: Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, Guangdong, 510080, China; Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China; Institute of Spinal Cord Injury, Sun Yat-sen University, Guangzhou, 510120, China; Co-innovation Center of Neuroregeneration, Jiangsu, 226019, China. Electronic address: zengysh@mail.sysu.edu.cn.
authors.forename: Yuan-Shan
authors.initials: YS
authors.lastname: Zeng
mesh_terms: D000818:Animals; D018920:Coculture Techniques; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D009415:Nerve Net; D009474:Neurons / Q000166:cytology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D055647:Rats, Transgenic; D013116:Spinal Cord / Q000601:surgery*
keywords: Mesenchymal stem cells; Neural network; Neurotrophin-3; Spinal cord injury; Three-dimensional scaffold; TrkC