Transplantation of hypoxic preconditioned neural stem cells benefits functional recovery via enhancing neurotrophic secretion after spinal cord injury in rats

• Published in: Journal of cellular biochemistry 2018-06, Vol.119 (6), p.4339-4351
• Main Authors: Fan, Wei‐li, Liu, Peng, Wang, Guan, Pu, Jun‐gang, Xue, Xin, Zhao, Jian‐hua
• Format: Article
• Language: English
• Subjects: Brain; Brain-derived neurotrophic factor; Central nervous system; Engraftment; Enzyme-linked immunosorbent assay; Exposure; Flow cytometry; Fluorescence; Glial cell line-derived neurotrophic factor; Growth factors; Hypersensitivity; Hypoxia; hypoxic preconditioning; Immunofluorescence; In vivo methods and tests; Injuries; Magnetic resonance imaging; Neural stem cells; Neuronal-glial interactions; neurotrophic factors; Preconditioning; Rats; Recovery; Recovery of function; Rodents; Spinal cord injuries; spinal cord injury; Staining; Stem cells; Strategy; Transplantation
• ISSN: 0730-2312; 1097-4644
• DOI: 10.1002/jcb.26397

Spinal cord injury (SCI) is a debilitating, costly, and common pathological condition that affects the function of central nervous system (CNS). To date, there are few promising therapeutic strategies available for SCI. To look for a suitable therapeutic strategy, we have developed a sublethal hypoxic preconditioning procedure using Fluorescence‐activated cell sorting (FACS) analysis, LDH releasing, and cell viability assays in vitro. Meanwhile, we have examined the benefits of neural stem cells (NSCs) transplantation prior to hypoxic preconditioning on functional recovery and potential mechanism via MRI screening, H&E, and Nissl staining, immunofluorescence staining and Elisa assays. Our data showed that transplantation of hypoxic prconditioned NSCs could enhance neuronal survival, especially 5‐TH+ and ChAT+ neurons, in the injured spinal cord to reinforce functional benefits. The hypoxia exposure upregulated HIF‐1α, neurotrophic and growth factors including neurotrophin‐3 (NT‐3), glial cell‐derived neurotrophic factor (GDNF), and brain‐derived neurotrophic factor (BDNF) in vitro and in vivo. Furthermore, functional recovery, including locomotor and hypersensitivities to mechanical and thermal stimulation assessed via behavioral and sensory tests, improved significantly in rats with engraftment of NSCs after hypoxia exposure from day 14 post‐SCI, compared with the control and N‐NSCs groups. In short, the approach employed in this study could result in functional recovery via upregulating neurotrophic and growth factors, which implies that hypoxic preconditioning strategy could serve as an effective and feasible strategy for cell‐based therapy in the treatment of SCI in rats. The transplantation of NSCs after hypoxic preconditioning enhances local resident neuronal survival after SCI in rats. Hypoxia exposure up‐regulated HIF‐1α and neurotrophic/growth factors in NSCs, including neurotrophin‐3 (NT‐3), glial cell‐derived neurotrophic factor (GDNF), and brain‐derived neurotrophic factor (BDNF). The transplantation of NSCs prior to hypoxic preconditioning enhances secretion of neurotrophic factors to reinforce functional recovery in rats after SCI.