Cell transplantation for the treatment of spinal cord injury - bone marrow stromal cells and choroid plexus epithelial cells

hBcl2 overexpression in BMSCs enhances resistance to myelin debris-induced apoptosis and facilitates neuroprotection after spinal cord injury in rats

After spinal cord injury (SCI), the accumulation of myelin debris at the lesion exacerbates cell death and hinders axonal regeneration. Transplanted bone marrow mesenchymal stem cells (BMSCs) have been proven to be beneficial for SCI repair, but they are susceptible to apoptosis. It remains unclear whether this apoptotic process is influenced by myelin debris. Here, we constructed rat BMSCs overexpressing human B-cell lymphoma 2 (hBcl2) alone (hBcl2 group), BMSCs overexpressing hBcl2 with an endoplasmic reticulum-anchored segment (hBcl2-cb) (cb group), and a negative control group (NC group) for transplantation in this study. Immunocytochemistry staining validated the successful expression of hBcl2 in BMSCs within the hBcl2 group and cb group. All BMSCs from each group exhibited the ability to phagocytize myelin debris. Nevertheless, only BMSCs derived from the hBcl2 group exhibited heightened resistance to apoptosis and maintained prolonged viability for up to 5 days when exposed to myelin debris. Notably, overexpression of hBcl2 protein, rather than its endoplasmic reticulum-anchored counterpart, significantly enhanced the resistance of BMSCs against myelin debris-induced apoptosis. This process appeared to be associated with the efficient degradation of myelin debris through the Lamp1+ lysosomal pathway in the hBcl2 group. In vivo, the hBcl2 group exhibited significantly higher numbers of surviving cells and fewer apoptotic BMSCs compared to the cb and NC groups following transplantation. Furthermore, the hBcl2 group displayed reduced GFAP+ glial scarring and greater preservation of NF200+ axons in the lesions of SCI rats. Our results suggest that myelin debris triggers apoptosis in transplanted BMSCs, potentially elucidating the low survival rate of these cells after SCI. Consequently, the survival rate of transplanted BMSCs is improved by hBcl2 overexpression, leading to enhanced preservation of axons within the injured spinal cord.

The Neuronal Regeneration of Adult Zebrafish After Spinal Cord Injury Is Enhanced by Transplanting Optimized Number of Neural Progenitor Cells

Cell transplantation is commonly used to study the regeneration and repair of the nervous system in animals. However, a technical platform used to evaluate the optimum number of transplanted cells in the recipient’s spinal cord is little reported. Therefore, to develop such platform, we used a zebrafish model, which has transparent embryos, and transgenic line huORFZ, which generates green fluorescent protein (GFP)-expressing cells in the central nervous system under hypoxic stress. After GFP-expressing cells, also termed as hypoxia-responsive recovering cells, were obtained from hypoxia-exposed huORFZ embryos, we transplanted these GFP-(+) cells into the site of spinal cord injury (SCI) in adult wild-type zebrafish, followed by assessing the relationship between number of transplanted cells and the survival rate of recipients. When 100, 300, 500, and 1,000 GFP-(+) donor cells were transplanted into the lesion site of SCI-treated recipients, we found that recipient adult zebrafish transplanted with 300 donor cells had the highest survival rate. Those GFP-(+) donor cells could undergo proliferation and differentiation into neuron in recipients. Furthermore, transplantation of GFP-(+) cells into adult zebrafish treated with SCI was able to enhance the neuronal regeneration of recipients. In contrast, those fish transplanted with over 500 cells showed signs of inflammation around the SCI site, resulting in higher mortality. In this study, we developed a technological platform for transplanting cells into the lesion site of SCI-treated adult zebrafish and defined the optimum number of successfully transplanted cells into recipients, as 300, and those GFP-(+) donor cells could enhance recipient’s spinal cord regeneration. Thus, we provided a practical methodology for studying cell transplantation therapy in neuronal regeneration of zebrafish after SCI.

Mesenchymal stem cells in chemotherapy-induced peripheral neuropathy: A new challenging approach that requires further investigations

Chemotherapeutic drugs may disrupt the nervous system and cause chemotherapy-induced peripheral neuropathy (CIPN) as side effects. There are no completely successful medications for the prevention or treatment of CIPN. Many drugs such as tricyclic antidepressants and anticonvulsants have been used for symptomatic treatment of CIPN. Unfortunately, these drugs often give only partial relief or have dose-limiting side effects. Thus, the treatment of CIPN becomes a challenge because of failure to regenerate and repair the injured neurons. Mesenchymal stem cell (MSC) therapy is a new attractive approach for CIPN. Evidence has demonstrated that MSCs play important roles in reducing oxidative stress, neuroinflammation, and apoptosis, as well as mediating axon regeneration after nerve damage in several experimental studies and some clinical trials. We will briefly review the pathogenesis of CIPN, traditional therapies used and their drawbacks as well as therapeutic effects of MSCs, their related mechanisms, future challenges for their clinical application, and the additional benefit of their combination with pharmacological agents. MSCs-based therapies may provide a new therapeutic strategy for patients suffering from CIPN where further investigations are required for studying their exact mechanisms. Combined therapy with pharmacological agents can provide another promising option for enhancing MSC therapy success while limiting its adverse effects.

Treatment of the bone marrow stromal stem cell supernatant by nasal administration-a new approach to EAE therapy

Introduction

Multiple sclerosis (MS) is one of the most common autoimmune diseases of the central nervous system (CNS). CNS has its own unique structural and functional features, while the lack of precision regulatory element with high specificity as therapeutic targets makes the development of disease treatment in the bottleneck. Recently, the immunomodulation and neuroprotection capabilities of bone marrow stromal stem cells (BMSCs) were shown in experimental autoimmune encephalomyelitis (EAE). However, the administration route and the safety evaluation limit the application of BMSC. In this study, we investigated the therapeutic effect of BMSC supernatant by nasal administration.

Methods

In the basis of the establishment of the EAE model, the BMSC supernatant were treated by nasal administration. The clinical score and weight were used to determine the therapeutic effect. The demyelination of the spinal cord was detected by LFB staining. ELISA was used to detect the expression of inflammatory factors in serum of peripheral blood. Flow cytometry was performed to detect pro-inflammatory cells in the spleen and draining lymph nodes.

Results

BMSC supernatant by nasal administration can alleviate B cell-mediated clinical symptoms of EAE, decrease the degree of demyelination, and reduce the inflammatory cells infiltrated into the central nervous system; lessen the antibody titer in peripheral bloods; and significantly lower the expression of inflammatory factors. As a new, non-invasive treatment, there are no differences in the therapeutic effects between BMSC supernatant treated by nasal route and the conventional applications, i.e. intraperitoneal or intravenous injection.

Conclusions

BMSC supernatant administered via the nasal cavity provide new sights and new ways for the EAE therapy.

The rate of fluid shear stress is a potent regulator for the differentiation of mesenchymal stem cells

We have previously demonstrated that the rate of fluid shear stress (ΔSS) can manipulate the fate of mesenchymal stem cells (MSCs) to osteogenic or chondrogenic cells. However, whether ΔSS is comparable to other two means of induction medium and substrate stiffness that have been proven to be potent in differentiation control is unknown. In this study, we subjected MSCs to 1-7 days of osteogenic or chondrogenic chemical induction, or 1-4 days of 37 or 86 kPa of substrate stiffness induction, followed by 20 min of Fast ΔSS (0-0') or Slow ΔSS (0-2'), which is a laminar FSS that linearly increased from 0 to 10 dyn/cm ² in 0 (Fast) or 2 min (Slow) and maintained at 10 dyn/cm ² for a total of 20 min. We found that 20 min of ΔSS could compete with 5 days' chemical and 2 days' substrate stiffness inductions. Our study confirmed that ΔSS is a powerful tool to control the differentiation of MSCs, which stressed the possible application in MSCs linage specification.

Hypoxic preconditioned bone mesenchymal stem cells ameliorate spinal cord injury in rats via improved survival and migration

The unique hypoxic inflammatory microenvironment observed in the spinal cord following spinal cord injury (SCI) limits the survival and efficacy of transplanted bone mesenchymal stem cells (BMSCs). The aim of the present study was to determine whether hypoxic preconditioning (HP) increased the therapeutic effects of BMSC on SCI. BMSCs were pretreated with cobalt chloride (CoCl2) in vitro, and the proliferative apoptotic and migratory abilities of these hypoxic BMSCs (H‑BMSCs) were assessed. BMSCs and H‑BMSCs derived from green fluorescent protein (GFP) rats were transplanted into SCI rats in vivo. The neurological function, histopathology, inflammation, and number and migration of transplanted cells were examined. HP significantly enhanced BMSC migration (increased hypoxia inducible factor 1α and C‑X‑C motif chemokine receptor 4 expression) and tolerance to apoptotic conditions (decreased caspase‑3 and increased B‑cell lymphoma 2 expression) in vitro. In vivo, H‑BMSC transplantation significantly improved neurological function, decreased spinal cord damage and suppressed the inflammatory response associated with microglial activation. The number of GFP‑positive cells in the SCI core and peripheral region of H‑BMSC animals was increased compared with that in those of BMSC animals, suggesting that HP may increase the survival and migratory abilities of BMSCs and highlights their therapeutic potential for SCI.

Hypoxia induces senescence of bone marrow mesenchymal stem cells via altered gut microbiota

Systemic chronic hypoxia is a feature of many diseases and may influence the communication between bone marrow (BM) and gut microbiota. Here we analyse patients with cyanotic congenital heart disease (CCHD) who are experiencing chronic hypoxia and characterize the association between bone marrow mesenchymal stem cells (BMSCs) and gut microbiome under systemic hypoxia. We observe premature senescence of BMSCs and abnormal d-galactose accumulation in patients with CCHD. The hypoxia that these patients experience results in an altered diversity of gut microbial communities, with a remarkable decrease in the number of Lactobacilli and a noticeable reduction in the amount of enzyme-degraded d-galactose. Replenishing chronic hypoxic rats with Lactobacillus reduced the accumulation of d-galactose and restored the deficient BMSCs. Together, our findings show that chronic hypoxia predisposes BMSCs to premature senescence, which may be due to gut dysbiosis and thus induced d-galactose accumulation.

Systemic chronic hypoxia is a feature of many diseases and may influence the communication between bone marrow and gut microbiota. Here, the authors show that chronic hypoxia predisposes bone marrow stem cells to premature senescence, which may be due to gut dysbiosis and gut microbiota-derived d-galactose accumulation.

Bone marrow mesenchymal stem cells (BMSCs) improved functional recovery of spinal cord injury partly by promoting axonal regeneration

Spinal cord injury (SCI) disrupts the spinal cord and results in the loss of sensory and motor function below the lesion site. The treatment of SCI became a challenge because the injured neurons fail to axon regenerate and repair after injury. Promoting axonal regeneration plays a key role in the treatment strategies for SCI. It would meet the goal of reconstruction the injured spinal cord and improving the functional recovery. Bone marrow mesenchymal stem cells (BMSCs) are attractive therapeutic potential cell sources for SCI, and it could rebuild the injured spinal cord through neuroprotection, neural regeneration and remyelinating. Evidence has demonstrated that BMSCs play important roles in mediating axon regeneration, and glial scar formation after SCI in animal experiments and some clinical trials. We reviewed the role of BMSCs in regulating axon regeneration and glial scar formation after SCI. BMSCs based therapies may provide a therapeutic potential for the injured spinal cord by promoting axonal regeneration and repair.

A cellular spinal cord scaffold seeded with rat adipose‑derived stem cells facilitates functional recovery via enhancing axon regeneration in spinal cord injured rats

Spinal cord injury (SCI), usually resulting in severe sensory and motor deficits, is a major public health concern. Adipose-derived stem cells (ADSCs), one type of adult stem cell, are free from ethical restriction, easily isolated and enriched. Therefore, ADSCs may provide a feasible cell source for cell-based therapies in treatment of SCI. The present study successfully isolated rat ADSCs (rADSCs) from Sprague-Dawley male rats and co-cultured them with acellular spinal cord scaffolds (ASCs). Then, a rat spinal cord hemisection model was built and rats were randomly divided into 3 groups: SCI only, ASC only, and ASC + ADSCs. Furthermore, behavioral tests were conducted to evaluate functional recovery. Hematoxylin & Eosin staining and immunofluorence were carried out to assess histopathological remodeling. In addition, biotinylated dextran amines anterograde tracing was employed to visualize axon regeneration. The data demonstrated that harvested cells, which were positive for cell surface antigen cluster of differentiation (CD) 29, CD44 and CD90 and negative for CD4, detected by flow cytometry analysis, held the potential to differentiate into osteocytes and adipocytes. Rats that received transplantation of ASCs seeded with rADSCs benefited greatly in functional recovery through facilitation of histopathological rehabilitation, axon regeneration and reduction of reactive gliosis. rADSCs co-cultured with ASCs may survive and integrate into the host spinal cord on day 14 post-SCI.

Blood-brain barrier and foetal-onset hydrocephalus, with a view on potential novel treatments beyond managing CSF flow

Despite decades of research, no compelling non-surgical therapies have been developed for foetal hydrocephalus. So far, most efforts have pointed to repairing disturbances in the cerebrospinal fluid (CSF) flow and to avoid further brain damage. There are no reports trying to prevent or diminish abnormalities in brain development which are inseparably associated with hydrocephalus. A key problem in the treatment of hydrocephalus is the blood–brain barrier that restricts the access to the brain for therapeutic compounds or systemically grafted cells. Recent investigations have started to open an avenue for the development of a cell therapy for foetal-onset hydrocephalus. Potential cells to be used for brain grafting include: (1) pluripotential neural stem cells; (2) mesenchymal stem cells; (3) genetically-engineered stem cells; (4) choroid plexus cells and (5) subcommissural organ cells. Expected outcomes are a proper microenvironment for the embryonic neurogenic niche and, consequent normal brain development.

The choroid plexus as a site of damage in hemorrhagic and ischemic stroke and its role in responding to injury

While the impact of hemorrhagic and ischemic strokes on the blood–brain barrier has been extensively studied, the impact of these types of stroke on the choroid plexus, site of the blood-CSF barrier, has received much less attention. The purpose of this review is to examine evidence of choroid plexus injury in clinical and preclinical studies of intraventricular hemorrhage, subarachnoid hemorrhage, intracerebral hemorrhage and ischemic stroke. It then discusses evidence that the choroid plexuses are important in the response to brain injury, with potential roles in limiting damage. The overall aim of the review is to highlight deficiencies in our knowledge on the impact of hemorrhagic and ischemic strokes on the choroid plexus, particularly with reference to intraventricular hemorrhage, and to suggest that a greater understanding of the response of the choroid plexus to stroke may open new avenues for brain protection.