Repeated injections of human umbilical cord blood-derived mesenchymal stem cells significantly promotes functional recovery in rabbits with spinal cord injury of two noncontinuous segments

Abstract

BackgroundSpinal cord injuries (SCIs) are sustained by an increasing number of patients each year worldwide. The treatment of SCIs has long been a hard nut to crack for doctors around the world. Mesenchymal stem cells (MSCs) have shown benefits for the repair of SCI and recovery of function. Our present study aims to investigate the effects of intravenously infused human umbilical cord blood-derived MSCs (hUCB-MSCs) on functional recovery after subacute spinal cord compression injury of two noncontinuous segments. In addition, we compared the effects of single infusion and repeated intravenous (i.v.) injections on the recovery of spinal cord function.MethodsA total of 43 adult rabbits were randomly divided into four groups: control, single injection (SI), repeated injection at a 3-day (3RI) or repeated injection at a 7-day interval (7RI) groups. Non-immunosuppressed rabbits in the transplantation groups were infused with either a single complete dose or three divided doses of 2 × 106 hUCB-MSCs (3-day or 7-day intervals) on the first day post decompression. Behavioural scores and somatosensory evoked potentials (SEPs) were used to evaluate hindlimb functional recovery. The survival and differentiation of the transplanted human cells and the activation of the host glial and inflammatory reaction in the injured spinal cord were studied by immunohistochemical staining.ResultsOur results showed that hUCB-MSCs survived, proliferated, and primarily differentiated into oligodendrocytes in the injured area. Treatment with hUCB-MSCs reduced the extent of astrocytic activation, increased axonal preservation, potentially promoted axonal regeneration, decreased the number of Iba-1+ and TUNEL+ cells, increased the amplitude and decreased the onset latency of SEPs and significantly promoted functional improvement. However, these effects were more pronounced in the 3RI group compared with the SI and 7RI groups.ConclusionsOur results suggest that treatment with i.v. injected hUCB-MSCs after subacute spinal cord compression injury of two noncontinuous segments can promote functional recovery through the differentiation of hUCB-MSCs into specific cell types and the enhancement of anti-inflammatory, anti-astrogliosis, anti-apoptotic and axonal preservation effects. Furthermore, the recovery was more pronounced in the rabbits repeatedly injected with cells at 3-day intervals. The results of this study may provide a novel and useful treatment strategy for the transplantation treatment of SCI.Electronic supplementary materialThe online version of this article (10.1186/s13287-018-0879-0) contains supplementary material, which is available to authorized users.

HiPSC-Derived NSCs Effectively Promote The Functional Recovery of Acute Spinal Cord Injury in Mice

“…A positive effect of the huMSC treatment on function was observed, but the difference was not statistically signi cant. The results differed from other studies [43,44] . These opposing results are potentially attributed to the time of transplantation.…”

Mesenchymal Stem Cell Therapy for Spinal Cord Contusion: A Comparative Study on Small and Large Animal Models

“…MSCs can mediate anatomical improvement in the subacute phase after SCI through anti-inflammatory activity, glial scar reduction, and cell bridging effects [50,60]. Our results suggest that MSCs are able to prevent secondary injury by contributing to astroglia suppression, consistent with the results of other studies of MSC transplantation in SCI [61][62][63]. We observed greater reduction of astroglial activation caudally from the injury epicenter after AD-MSCs application compared to other sources of MSCs and the control groups.…”

SDF-1/CXCR4 Axis-mediated Migration of Systematically Transplanted Bone Marrow Mesenchymal Stem Cells Towards the Injured Spinal Cord in a Rat Model

“…Less invasive techniques suited for the clinical application need to be developed. Trials by intravenous injections of MSCs in rodents were widely reported [44][45][46][47][48]. Cultured rat and human MSCs have been shown to migrate into sites of brain injury after cerebral ischemia when transplanted intravenously in rats [49].…”

“…No previously reported study has tracked MSCs that were intravenously transplanted into the spinal cord in living animals; to date, only histological assessments have con rmed the fate of stem cells after their systemic transplantation [27,[44][45][46][47][48]. These studies did not evaluate the survival, proliferation, and migration of transplanted cells.…”