Bone marrow stromal cell transplantation preserves gammaaminobutyric acid receptor function in the injured spinal cord

Stem cell-derived exosomes as a cell free therapy against spinal cord injury

Recent evidence suggests that stem cell therapy has beneficial effects on spinal cord injury. It was subsequently established that these beneficial effects may be mediated through release of paracrine factors, a kind of extracellular vesicle known as exosomes. Stem cell-secreted nano-sized exosomes have shown great potential to reduce apoptosis and inflammation, enhance angiogenesis, and improve functional behavioral recovery following spinal cord injury. This review summarizes current knowledge about the influence of exosomes derived from stem cells on spinal cord protection and regeneration with their molecular mechanisms after injury.

Rehabilitative Training in Animal Models of Spinal Cord Injury

Rehabilitative motor training is currently one of the most widely used approaches to promote moderate recovery following injuries of the central nervous system. Such training is generally applied in the clinical setting, whereas it is not standard in preclinical research. This is a concern as it is becoming increasingly apparent that neuroplasticity enhancing treatments require training or some form of activity as a co-therapy to promote functional recovery. Despite the importance of training and the many open questions regarding its mechanistic consequences, its use in preclinical animal models is rather limited. Here we review approaches, findings and challenges when training is applied in animal models of spinal cord injury, and we suggest recommendations to facilitate the integration of training using an appropriate study design, into pre-clinical studies.

Treadmill exercise with bone marrow stromal cells transplantation potentiates recovery of locomotor function after spinal cord injury in rats

Transplantation of bone marrow stromal cells (BMSCs) is regarded as a promising candidate for the spinal cord injury (SCI). In the present study, we investigated whether treadmill exercise potentiate the effect of BM-SCs transplantation on the functional recovery in the SCI rats. The spinal cord contusion injury applied at the T9–T10 level using the impactor. Cultured BMSCs were transplanted into the lesion at 1 week after SCI induction. Treadmill exercise was conducted for 6 weeks. Basso-Beattie-Bresnahan (BBB) scale for locomotor function was determined. Sprouting axons in the lesion cavity were detected by immunofluorescence staining for neurofilament-200. Brain-derived neurotrophic factor (BDNF) and synapsin-I expressions were analyzed using western blotting. BMSCs transplantation improved BBB score and increased expressions of neurofilament-200, BDNF, and synapsin-I in the SCI rats. Treadmill exercise potentiated the improving effect of BMSCs transplantation on BBB score in the SCI rats. This potentiating effect of treadmill exercise could be ascribed to the enhancement of BDNF expression in the SCI rats.

Comprehensive Analysis of MILE Gene Expression Data Set Advances Discovery of Leukaemia Type and Subtype Biomarkers

Large collections of data in studies on cancer such as leukaemia provoke the necessity of applying tailored analysis algorithms to ensure supreme information extraction. In this work, a custom-fit pipeline is demonstrated for thorough investigation of the voluminous MILE gene expression data set. Three analyses are accomplished, each for gaining a deeper understanding of the processes underlying leukaemia types and subtypes. First, the main disease groups are tested for differential expression against the healthy control as in a standard case-control study. Here, the basic knowledge on molecular mechanisms is confirmed quantitatively and by literature references. Second, pairwise comparison testing is performed for juxtaposing the main leukaemia types among each other. In this case by means of the Dice coefficient similarity measure the general relations are pointed out. Moreover, lists of candidate main leukaemia group biomarkers are proposed. Finally, with this approach being successful, the third analysis provides insight into all of the studied subtypes, followed by the emergence of four leukaemia subtype biomarkers. In addition, the class enhanced DEG signature obtained on the basis of novel pipeline processing leads to significantly better classification power of multi-class data classifiers. The developed methodology consisting of batch effect adjustment, adaptive noise and feature filtration coupled with adequate statistical testing and biomarker definition proves to be an effective approach towards knowledge discovery in high-throughput molecular biology experiments.

Neuroprotective Effects of Bone Marrow Mesenchymal Stem Cells on Bilateral Common Carotid Arteries Occlusion Model of Cerebral Ischemia in Rat

Cell therapy is the most advanced treatment of the cerebral ischemia, nowadays. Herein, we discuss the neuroprotective effects of bone marrow mesenchymal stem cells (BMSCs) on rat hippocampal cells following intravenous injection of these cells in an ischemia-reperfusion model. Adult male Wistar rats were divided into 5 groups: control, sham (surgery without blockage of common carotid arteries), ischemia (common carotid arteries were blocked for 30 min prior to reperfusion), vehicle (7 days after ischemia PBS was injected via the tail vein), and treatment (injections of BMSC into the tail veins 7 days after ischemia). We performed neuromuscular and vestibulomotor function tests to assess behavioral function and, finally, brains were subjected to hematoxylin and eosin (H&E), anti-Brdu immunohistochemistry, and TUNEL staining. The ischemia group had severe apoptosis. The group treated with BMSCs had a lower mortality rate and also had significant improvement in functional recovery (P < 0.001). Ischemia-reperfusion for 30 min causes damage and extensive neuronal death in the hippocampus, especially in CA1 and CA3 regions, leading to several functional and neurological deficits. In conclusion, intravenous injection of BMSCs can significantly decrease the number of apoptotic neurons and significantly improve functional recovery, which may be a beneficial treatment method for ischemic injuries.

Autologous bone marrow mononuclear cell transplant and surgical decompression in a dog with chronic spinal cord injury

OBJECTIVES

In dogs with deep analgesia caused by acute spinal cord injury from thoracolumbar disk herniation, autologous bone marrow mononuclear cell transplant may improve recovery. The purpose of the present study was to evaluate autologous bone marrow mononuclear cell transplant in a dog that had paraplegia and deep analgesia caused by chronic spinal cord injury.

MATERIALS AND METHODS

Autologous bone marrow mononuclear cell transplant was performed in a dog having paraplegia and analgesia for 3 years that was caused by a chronic spinal cord injury secondary to Hansen type I thoracolumbar disk herniation. Functional recovery was evaluated with electrophysiologic studies and the Texas Spinal Cord Injury Scale.

RESULTS

Somatosensory evoked potentials were absent before transplant but were detected after transplant. Functional improvement was noted (Texas Spinal Cord Injury Scale: before transplant, 0; after transplant, 6). No adverse events were observed.

CONCLUSIONS

Autologous bone marrow mononuclear cell transplant into the subarachnoid space may be a safe and beneficial treatment for chronic spinal cord injury in dogs.

Combined Bone Mesenchymal Stem Cell and Olfactory Ensheathing Cell Transplantation Promotes Neural Repair Associated With CNTF Expression in Traumatic Brain-Injured Rats

This study examined the role of bone mesenchymal stem cell (BMSC) and olfactory ensheathing cell (OEC) cografting on neural function and underlying molecular mechanisms in acute stage of traumatic brain injury (TBI) rats. Eighty Sprague-Dawley (SD) female rats were randomly divided into five groups (n = 16 per category): sham operated group (Sham), weight-drop-induced TBI group (TBI), BMSC transplantation group (BMSC), OEC transplantation group (OEC), and cotransplantation group (CO). Eight rats were randomly selected from each group for behavioral and morphological assessment. Another category (n = 8 rats) was employed in the genetic expression detection. BMSCs were isolated from GFP mice and identified by CD44 antibody. OECs were isolated from the SD rats, identified by P75 antibody and labeled by Hoechst 33342. They were then transplanted into the surrounding tissue of the epicenter of TBI rats. The result of neurological severity scores revealed that BMSC or OEC transplantation alone and BMSC and OEC cografting significantly ameliorated the neurological deficits of TBI rats. Quantitative immunohistochemical analysis showed that graft-recipient animals possessed dramatically more neurons and regenerated axons and smaller amounts of astrocytes than controls 14 days posttransplantation (p < 0.05). However, the expressional level of ciliary neurotrophic factor significantly decreased in the cografting group as determined by RT-PCR (p < 0.05), and the Janus kinase/signal transducer and activator of transcription pathway was significantly activated at 7 days after cell transplantation (p < 0.05). This study is the first to report the role of cotransplantation of BMSCs and OECs in the therapy of TBI and explore its potential molecular mechanisms, therefore providing the important morphological and molecular biological evidence for the clinical application of BMSC and/or OEC transplantation in TBI.

Canine bone marrow stromal cells promote functional recovery in mice with spinal cord injury

Regenerative therapy has begun to be clinically applied in humans and dogs to treat neurological disorders, such as spinal cord injury (SCI). Here, we show the therapeutic potential of transplantation of cultured canine bone marrow stromal cells (BMSCs) into mice with SCI. Canine BMSC transplantation therapy was performed, immediately after the spinal cord was injured. Canine BMSC therapy enhanced functional recovery of the hind limbs in mice with SCI. Nestin-positive cells were observed only in the lesion of mice with SCI that received BMSCs. These results suggest that canine BMSCs promote functional recovery in mice with SCI and that migration of nestin-positive cells may contribute to the efficacy of the BMSC treatment.

Immunological characteristics of human umbilical cord mesenchymal stem cells and the therapeutic effects of their transplantion on hyperglycemia in diabetic rats

Islet transplantation involves the transplantation of pancreatic islets from the pancreas of a donor to another individual. It has proven to be an effective method for the treatment of type 1 diabetes. However, islet transplantation is hampered by immune rejection, as well as the shortage of donor islets. Human umbilical cord Wharton's jelly-derived mesenchymal stem cells (HUMSCs) are an ideal cell source for use in transplantation due to their biological characteristics and their use does not provoke any ethical issues. In this study, we investigated the immunological characteristics of HUMSCs and their effects on lymphocyte proliferation and the secretion of interferon (IFN)-γ, and explored whether direct cell-to-cell interactions and soluble factors, such as IFN-γ were important for balancing HUMSC-mediated immune regulation. We transplanted HUMSCs into diabetic rats to investigate whether these cells can colonize in vivo and differentiate into pancreatic β-cells, and whether the hyperglycemia of diabetic rats can be improved by transplantation. Our results revealed that HUMSCs did not stimulate the proliferation of lymphocytes and did not induce allogeneic or xenogeneic immune cell responses. qRT-PCR demonstrated that the HUMSCs produced an immunosuppressive isoform of human leukocyte antigen (HLA-I) and did not express HLA-DR. Flow cytometry revealed that the HUMSCs did not express immune response-related surface antigens such as, CD40, CD40L, CD80 and CD86. IFN-γ secretion by human peripheral blood lymphocytes was reduced when the cells were co-cultured with HUMSCs. These results suggest that HUMSCs are tolerated by the host in an allogeneic transplant. We transplanted HUMSCs into diabetic rats, and the cells survived in the liver and pancreas. Hyperglycemia of the diabetic rats was improved and the destruction of pancreatic cells was partly repaired by HUMSC transplantation. Hyperglycemic improvement may be related to the immunomodulatory effects of HUMSCs. However, the exact mechanisms involved remain to be further clarified.

Effects of polyethylene glycol administration and bone marrow stromal cell transplantation therapy in spinal cord injury mice

Bone marrow stromal cell (BMSC) transplantation has been reported as treatments that promote functional recovery after spinal cord injury (SCI) in humans and animals. Polyethylene glycol (PEG) has been also reported as treatments that promote functional recovery after spinal cord injury (SCI) in humans and animals. Therefore, administration of PEG combined with BMSC transplantation may improve outcomes compared with BMSC transplantation only in SCI model mice. SCI mice were divided into a control-group, BMSC-group, PEG-group and BMSC+PEG-group. BMSC transplantation and PEG administration were performed immediately after surgery. Compared to the control-group, PEG- and BMSC+PEG-groups showed significant locomotor functional recovery 4 weeks after therapy. We observed no significant differences among the groups. In the BMSC- and BMSC+PEG-groups, immunohistochemistry showed that many neuronal cells aggressively migrated toward the glial scar from the region rostral of the lesion site. In the control- and PEG-groups, the boundary of the injured regions was covered with astrocytes, and a few neuronal cells were migrated toward the glial scar. We conclude that combined BMSC transplantation with PEG treatment showed no synergistic effects on locomotor functional recovery or beneficial cellular events. Further studies may improve the effect of the treatment, including modification of the timing of BMSC transplantation.

123 I-Iomazenil Single Photon Emission Computed Tomography Visualizes Recovery of Neuronal Integrity by Bone Marrow Stromal Cell Therapy in Rat Infarct Brain

Background and Purpose—

This study was aimed to assess whether 123 I-iomazenil (IMZ) single photon emission computed tomography can serially monitor the effects of bone marrow stromal cell (BMSC) transplantation on neuronal integrity in infarct brain of rats.

Methods—

The BMSCs were harvested from green fluorescent protein–transgenic rats and were cultured. The rats were subjected to permanent middle cerebral artery occlusion. Their motor function was serially quantified throughout the experiments. The BMSCs or vehicle was stereotactically transplanted into the ipsilateral striatum at 7 days after the insult. Using small-animal single photon emission computed tomography/computed tomography apparatus, the 123 I-IMZ uptake was serially measured at 6 and 35 days after the insult. Finally, fluorescence immunohistochemistry was performed to evaluate the distribution of engrafted cells and their phenotypes.

Results—

The distribution of 123 I-IMZ was markedly decreased in the ipsilateral neocortex at 6 days postischemia. The vehicle-transplanted animals did not show a significant change at 35 days postischemia. However, BMSC transplantation significantly improved the distribution of 123 I-IMZ in the peri-infarct neocortex as well as motor function. The engrafted BMSCs were densely distributed around cerebral infarct, and some of them expressed neuronal nuclear antigen and γ-aminobutyric acid type-A receptor.

Conclusions—

The present findings strongly suggest that the BMSCs may enhance functional recovery by improving the neuronal integrity in the peri-infarct area, when directly transplanted into the infarct brain at clinically relevant timing. 123 I-IMZ single photon emission computed tomography may be a promising modality to scientifically prove the beneficial effects of BMSC transplantation on the host brain in clinical situation.

Autotransplanting of bone marrow-derived mononuclear cells for complete cases of canine paraplegia and loss of pain perception, secondary to intervertebral disc herniation

OBJECTIVES

Severe intervertebral disc herniation causes complete paraplegia and loss of pain sensation in canines. The prognosis is poor, even when decompression surgery is performed immediately after onset. Studies suggest that bone marrow-derived mononuclear cells will regenerate the injured spinal cord and restore neurologic function. This study was conducted to assess the clinical efficacy of bone marrow-derived mononuclear cell autotransplanting in severe cases of canine intervertebral disc herniation.

MATERIALS AND METHODS

Eighty-two dogs (miniature dachshunds) with severe thoracolumbar intervertebral disc herniation were used. All had intervertebral disc herniation accompanied by paraplegia and loss of pain perception. In 36 dogs, bone marrow-derived mononuclear cells were autotransplanted to the lesioned spinal cord immediately after decompression surgery. Bone marrow was collected from the proximal humerus and subjected to density gradient centrifugation to isolate the bone marrow-derived mononuclear cells. The remaining 46 dogs (receiving surgical treatment only) were assigned as controls. Therapeutic efficacy was compared based on the rate of ambulatory recovery.

RESULTS

Ambulatory recovery was observed in 88.9% and 56.5% of animals in the bone marrow-derived mononuclear cells and control groups, and a significant difference was found. No complications were found in bone marrow-derived mononuclear cells group.

CONCLUSIONS

Bone marrow-derived mononuclear cell transplanting revealed a significant increase in the recovery rate and, as has been reported in rats and humans, bone marrow-derived mononuclear cell autotransplanting shows efficacy in canines as well.

Therapeutic effects of intra-arterial delivery of bone marrow stromal cells in traumatic brain injury of rats--in vivo cell tracking study by near-infrared fluorescence imaging

BACKGROUND

A noninvasive and effective route of cell delivery should be established to yield maximal therapeutic effects for central nervous system (CNS) disorders.

OBJECTIVE

To elucidate whether intra-arterial delivery of bone marrow stromal cells (BMSCs) significantly promotes functional recovery in traumatic brain injury (TBI) in rats.

METHODS

Rat BMSCs were transplanted through the ipsilateral internal carotid artery 7 days after the onset of cortical freezing injury. The BMSCs were labeled with fluorescent dye, and in vivo optical imaging was employed to monitor the behaviors of cells for 4 weeks after transplantation. Motor function was assessed for 4 weeks, and the transplanted BMSCs were examined using immunohistochemistry.

RESULTS

In vivo optical imaging and histologic analysis clearly demonstrated that the intra-arterially injected BMSCs were engrafted during the first pass without systemic circulation, and the transplanted BMSCs started to migrate from the cerebral capillary bed to the injured CNS tissue within 3 hours. Intra-arterial BMSC transplantation significantly promoted functional recovery after cortical freezing injury. A subgroup of BMSCs expressed the phenotypes of neurons, astrocytes, and endothelial cells around the injured neocortex 4 weeks after transplantation.

CONCLUSION

Intra-arterial transplantation may be a valuable option for prompt, noninvasive delivery of BMSCs to the injured CNS tissue, enhancing functional recovery after TBI. In vivo optical imaging may provide important information on the intracerebral behaviors of donor cells by noninvasive, serial visualization.

Autologous bone marrow stromal cell transplantation for central nervous system disorders - recent progress and perspective for clinical application

There is increasing evidence that the transplanted BMSC significantly promote functional recovery after CNS damage in the animal models of various kinds of CNS disorders, including cerebral infarct, traumatic brain injury and spinal cord injury. However, there are several shortages of information when considering clinical application of BMSC transplantation for patients with CNS disorders. In this review, therefore, we discuss what we should clarify to establish cell transplantation therapy as the scientifically proven entity in clinical situation and describe our recent works for this purpose. The BMSC have the ability to alter their gene expression profile and phenotype in response to the surrounding circumstances and to protect the neurons by producing some neurotrophic factors. They also promote neurite extension and rebuild the neural circuits in the injured CNS. The BMSC can be expanded in vitro using the animal serum-free medium. Pharmacological modulation may accelerate the in vitro proliferation of the BMSC. Using in vivo optical imaging technique, the transplanted BMSC can non-invasively be tracked in the living animals for at least 8 weeks after transplantation. It is urgent issues to develop clinical imaging technique to track the transplanted cells in the CNS and evaluate the therapeutic significance of BMSC transplantation in order to establish it as a definite therapeutic strategy in clinical situation in the future.

A systematic review of cellular transplantation therapies for spinal cord injury

Cell transplantation therapies have become a major focus in pre-clinical research as a promising strategy for the treatment of spinal cord injury (SCI). In this article, we systematically review the available pre-clinical literature on the most commonly used cell types in order to assess the body of evidence that may support their translation to human SCI patients. These cell types include Schwann cells, olfactory ensheathing glial cells, embryonic and adult neural stem/progenitor cells, fate-restricted neural/glial precursor cells, and bone-marrow stromal cells. Studies were included for review only if they described the transplantation of the cell substrate into an in-vivo model of traumatic SCI, induced either bluntly or sharply. Using these inclusion criteria, 162 studies were identified and reviewed in detail, emphasizing their behavioral effects (although not limiting the scope of the discussion to behavioral effects alone). Significant differences between cells of the same "type" exist based on the species and age of donor, as well as culture conditions and mode of delivery. Many of these studies used cell transplantations in combination with other strategies. The systematic review makes it very apparent that cells derived from rodent sources have been the most extensively studied, while only 19 studies reported the transplantation of human cells, nine of which utilized bone-marrow stromal cells. Similarly, the vast majority of studies have been conducted in rodent models of injury, and few studies have investigated cell transplantation in larger mammals or primates. With respect to the timing of intervention, nearly all of the studies reviewed were conducted with transplantations occurring subacutely and acutely, while chronic treatments were rare and often failed to yield functional benefits.

Effect of biodegradable fibrin scaffold on survival, migration, and differentiation of transplanted bone marrow stromal cells after cortical injury in rats

Object

In this study the authors' aim was to assess whether fibrin matrix could act as an injectable, valuable scaffold in bone marrow stromal cell (BMSC) transplantation for injured CNS tissue.

Methods

Both clotting time and 3D structure of fibrin matrix were analyzed with various concentrations of fibrinogen and CaCl2. The BMSCs were harvested from green fluorescent protein–transgenic mice and cultured. A cortical lesion was produced in rats by application of a very cold rod to the right cerebral hemisphere. The BMSCs, fibrin matrix, or BMSC–fibrin matrix complex was transplanted into the lesion though a small bur hole 7 days after the insult. Using immunohistochemical analysis, the authors evaluated the survival, migration, and differentiation of the transplanted cells 4 weeks after transplantation.

Results

Based on in vitro observations, the concentrations of fibrinogen and CaCl2 were fixed at 2.5 mg/ml and 2 μM in animal experiments, respectively. Fibrin matrix almost completely disappeared 4 weeks after transplantation. However, immunohistochemical analysis revealed that fibrin matrix exclusively enhanced the retention of the transplanted cells within the lesion, migration toward the lesion boundary zone, and differentiation into the neurons and perivascular cells.

Conclusions

Injectable fibrin matrix enhanced the survival, migration, and differentiation of the BMSCs transplanted into the cortical lesion in rats. The authors believe that it is one of the promising candidates for a potential, minimally invasive scaffold for CNS disorders. The present findings strongly suggest that such a strategy of tissue engineering could be a therapeutic option for CNS regeneration in patients with CNS injuries.

Treatment of rat spinal cord injury with a Rho-kinase inhibitor and bone marrow stromal cell transplantation

In light of reports that the administration of fasudil, a Rho-kinase inhibitor, improved rats locomotor abilities following spinal cord injury, we hypothesized that combining fasudil with another type of therapy, such as stem cell transplantation, might further improve the level of locomotor recovery. Bone marrow stromal cells (BMSCs) are readily available for stem cell therapy. In the present study, we examined whether fasudil combined with BMSC transplantation would produce synergistic effects on recovery. Adult female Sprague-Dawley rats were subjected to spinal cord contusion injury at the T10 vertebral level using an IH impactor (200 Kdyn). Immediately after contusion, they were administrated fasudil intrathecally for 4 weeks. GFP rat-derived BMSCs (2.5x10(6)) were injected into the lesion site 14 days after contusion. Locomotor recovery was assessed for 9 weeks with BBB scoring. Sensory tests were conducted at 8 weeks. Biotinylated dextran amine (BDA) was injected into the sensory-motor cortex at 9 weeks. In addition to an untreated control group, the study also included a fasudil-only group and a BMSC-only group in order to compare the effects of combined therapy vs. single-agent therapy. Animals were perfused transcardially 11 weeks after contusion, and histological examinations were performed. The combined therapy group showed statistically better locomotor recovery than the untreated control group at 8 and 9 weeks after contusion. Neither of the two single-agent treatments improved open field locomotor function. Sensory tests showed no statistically significant difference by treatment. Histological and immunohistochemical studies provided some supporting evidence for better locomotor recovery following combined therapy. The average area of the cystic cavity was significantly smaller in the fasudil+BMSC group than in the control group. The number of 5-HT nerve fibers was significantly higher in the fasudil+BMSC group than in the control group on the rostral side of the lesion site. BDA-labeled fibers on the caudal side of the lesion epicenter were observed only in the fasudil+BMSC group. On the other hand, only small numbers of GFP-labeled grafted cells remained 9 weeks after transplantation, and these were mainly localized at the site of injection. Double immunofluorescence studies showed no evidence of differentiation of grafted BMSCs into glial cells or neurons. The Rho-kinase inhibitor fasudil combined with BMSC transplantation resulted in better locomotor recovery than occurred in the untreated control group. However, the data failed to demonstrate significant synergism from combined therapy compared with the levels of recovery following single-agent treatment.

Synergistic effects of granulocyte-colony stimulating factor on bone marrow stromal cell transplantation for mice cerebral infarct

This study was aimed to assess whether ex vivo treatment with granulocyte-colony stimulating factor (G-CSF) modifies biological properties of bone marrow stromal cells (BMSC) and enhances functional recovery by BMSC transplantation into infarct brain. Immunohistochemistry was conducted to characterize the cultured BMSC. The pharmacological effects of G-CSF on their proliferation, cell cycle, and growth factor production were precisely analyzed, using FACS and ELISA techniques. Non-treated or G-CSF treated BMSC were stereotactically transplanted into the mice brain subjected to cerebral infarct, and its effects on functional and histological aspects were evaluated. The BMSC expressed the receptor for G-CSF. Treatment with 0.1muM of G-CSF significantly enhanced the proliferation of BMSC by increasing their population in S phase, and increased their production of SDF-1alpha, HGF, and NGF. When transplanted into infarct brain, G-CSF treated BMSC significantly improved motor function as early as 2 weeks after transplantation, whereas non-treated BMSC did 4 weeks after transplantation. These findings strongly suggest that G-CSF may enhance the proliferation and growth factor production of the cultured BMSC and accelerate functional restoration by BMSC transplantation. Such pharmacological "activation" of the BMSC may contribute to successful clinical application of BMSC transplantation therapy for ischemic stroke.

Reduction of cystic cavity, promotion of axonal regeneration and sparing, and functional recovery with transplanted bone marrow stromal cell–derived Schwann cells after contusion injury to the adult rat spinal cord

Object

The authors previously reported that Schwann cells (SCs) could be derived from bone marrow stromal cells (BMSCs) in vitro and that they promoted axonal regeneration of completely transected rat spinal cords in vivo. The aim of the present study is to evaluate the efficacy of transplanted BMSC-derived SCs (BMSC-SCs) in a rat model of spinal cord contusion, which is relevant to clinical spinal cord injury.

Methods

Bone marrow stromal cells were cultured as plastic-adherent cells from the bone marrow of GFPtransgenic rats. The BMSC-SCs were derived from BMSCs in vitro with sequential treatment using beta-mercaptoethanol, all-trans-retinoic acid, forskolin, basic fibroblast growth factor, platelet derived–growth factor, and heregulin. Schwann cells were cultured from the sciatic nerve of neonatal, GFP-transgenic rats. Immunocytochemical analysis and the reverse transcriptase–polymerase chain reaction were performed to characterize the BMSC-SCs. For transplantation, contusions with the New York University impactor were delivered at T-9 in 10- to 11-week-old male Wistar rats. Four groups of rats received injections at the injury site 7 days postinjury: the first received BMSCSCs and matrigel, a second received peripheral SCs and matrigel, a third group received BMSCs and matrigel, and a fourth group received matrigel alone. Histological and immunohistochemical studies, electron microscopy, and functional assessments were performed to evaluate the therapeutic effects of BMSC-SC transplantation.

Results

Immunohistochemical analysis and reverse transcriptase–polymerase chain reaction revealed that BMSC-SCs have characteristics similar to SCs not only in their morphological characteristics but also in their immunocytochemical phenotype and genotype. Histological examination revealed that the area of the cystic cavity was significantly reduced in the BMSC-SC and SC groups compared with the control rats. Immunohistochemical analysis showed that transplanted BMSCs, BMSC-SCs, and SCs all maintained their original phenotypes. The BMSC-SC and SC groups had a larger number of tyrosine hydroxilase–positive fibers than the control group, and the BMSC-SC group had more serotonin-positive fibers than the BMSC or control group. The BMSC-SC group showed significantly better hindlimb functional recovery than in the BMSC and control group. Electron microscopy revealed that transplanted BMSC-SCs existed in association with the host axons.

Conclusions

Based on their findings, the authors concluded that BMSC-SC transplantation reduces the size of the cystic cavity, promotes axonal regeneration and sparing, results in hindlimb functional recovery, and can be a useful tool for spinal cord injury as a substitute for SCs.

Cell therapy for spinal cord regeneration

This review presents a summary of the various types of cellular therapy used to treat spinal cord injury. The inhibitory environment and loss of axonal connections after spinal cord injury pose many obstacles to regenerating the lost tissue. Cellular therapy provides a means of restoring the cells lost to the injury and could potentially promote functional recovery after such injuries. A wide range of cell types have been investigated for such uses and the advantages and disadvantages of each cell type are discussed along with the research studying each cell type. Additionally, methods of delivering cells to the injury site are evaluated. Based on the current research, suggestions are given for future investigation of cellular therapies for spinal cord regeneration.