Bone Marrow Stromal Cells for Repair of the Spinal Cord: Towards Clinical Application

A case report: The first show phenomenon in the treatment of spinal cord injury with Regentime procedure using autologous bone marrow-derived stem cells

Key Clinical Message

Promising outcomes are shown in this case report using the Regentime procedure and autologous stem cells to treat spinal cord injury. The observed "First Show Phenomenon" provides valuable insights into the therapy's potential for spinal cord injury.

Abstract

This case report demonstrates "the first show phenomenon" following Regentime stem cell therapy applied to a spinal cord injury patient. A 40-year-old gentleman sustained a ballistic injury at the level of T9, resulting in complete bilateral motor and sensory loss from T9 and below. He was treated with autologous bone marrow-derived mononuclear stem cells injected into his spinal canal 2.5 years after his injury. Follow-up during the first-week posttransplantation showed early symptom improvement termed "the first show phenomenon." He regained sensation to light touch in his lower limbs by the end of week 1 and reported no serious implications or complications.

The Effects of the Combination of Mesenchymal Stromal Cells and Nanofiber-Hydrogel Composite on Repair of the Contused Spinal Cord

A bone marrow-derived mesenchymal stromal cell (MSC) transplant and a bioengineered nanofiber-hydrogel composite (NHC) have been shown to stimulate nervous tissue repair in the contused spinal cord in rodent models. Here, these two modalities were combined to assess their repair effects in the contused spinal cord in adult rats. Cohorts of contused rats were treated with MSC in NHC (MSC-NHC), MSC in phosphate-buffered saline (MSC-PBS), NHC, or PBS injected into the contusion site at 3 days post-injury. One week after injury, there were significantly fewer CD68+ cells in the contusion with MSC-NHC and NHC, but not MSC-PBS. The reduction in CD86+ cells in the injury site with MSC-NHC was mainly attributed to NHC. One and eight weeks after injury, we found a greater CD206+/CD86+ cell ratio with MSC-NHC or NHC, but not MSC-PBS, indicating a shift from a pro-inflammatory towards an anti-inflammatory milieu in the injury site. Eight weeks after injury, the injury size was significantly reduced with MSC-NHC, NHC, and MSC-PBS. At this time, astrocyte, and axon presence in the injury site was greater with MSC-NHC compared with MSC-PBS. We did not find a significant effect of NHC on MSC transplant survival, and hind limb function was similar across all groups. However, we did find fewer macrophages at 1 week post-injury, more macrophages polarized towards a pro-regenerative phenotype at 1 and 8 weeks after injury, and reduced injury volume, more astrocytes, and more axons at 8 weeks after injury in rats with MSC-NHC and NHC alone compared with MSC-PBS; these findings were especially significant between rats with MSC-NHC and MSC-PBS. The data support further study in the use of an NHC-MSC combination transplant in the contused spinal cord.

Therapeutic Potential of Mesenchymal Stem Cells (MSCs) and MSC-Derived Extracellular Vesicles for the Treatment of Spinal Cord Injury

Spinal cord injury (SCI) is a life-threatening condition that leads to permanent disability with partial or complete loss of motor, sensory, and autonomic functions. SCI is usually caused by initial mechanical insult, followed by a cascade of several neuroinflammation and structural changes. For ameliorating the neuroinflammatory cascades, MSC has been regarded as a therapeutic agent. The animal SCI research has demonstrated that MSC can be a valuable therapeutic agent with several growth factors and cytokines that may induce anti-inflammatory and regenerative effects. However, the therapeutic efficacy of MSCs in animal SCI models is inconsistent, and the optimal method of MSCs remains debatable. Moreover, there are several limitations to developing these therapeutic agents for humans. Therefore, identifying novel agents for regenerative medicine is necessary. Extracellular vesicles are a novel source for regenerative medicine; they possess nucleic acids, functional proteins, and bioactive lipids and perform various functions, including damaged tissue repair, immune response regulation, and reduction of inflammation. MSC-derived exosomes have advantages over MSCs, including small dimensions, low immunogenicity, and no need for additional procedures for culture expansion or delivery. Certain studies have demonstrated that MSC-derived extracellular vesicles (EVs), including exosomes, exhibit outstanding chondroprotective and anti-inflammatory effects. Therefore, we reviewed the principles and patho-mechanisms and summarized the research outcomes of MSCs and MSC-derived EVs for SCI, reported to date.

Implantation of nanofibrous silk scaffolds seeded with bone marrow stromal cells promotes spinal cord regeneration (6686 words)

Spinal cord injury (SCI) is a common pathology often resulting in permanent loss of sensory, motor, and autonomic function. Numerous studies in which stem cells have been transplanted in biomaterial scaffolds into animals have demonstrated their considerable potential for recovery from SCI. In the present study, a three-dimensional porous silk fibroin (SF) scaffold with a mean pore size of approximately 383 μm and nanofibrous structure was fabricated, the silk scaffold enabling the enhanced attachment and proliferation of bone marrow stromal cells (BMSCs). Investigation of its therapeutic potential was conducted by implantation of the nanofibrous SF scaffold seeded with BMSCs into a transected spinal cord model. Recovery of the damaged spinal cord was significantly improved after 2 months, compared with a non-nanofibrous scaffold, in combination with decreased glial fibrillary acidic protein (GFAP) expression and improved axonal regeneration at the site of injury. Furthermore, elevated Basso-Beattie-Bresnahan (BBB) scores indicated greatly improved hindlimb movement. Together, these results demonstrate that transplantation of neural scaffolds consisting of nanofibrous SF and BMSCs is an attractive strategy for the promotion of functional recovery following SCI.

Safety and efficacy of bone marrow derived-mesenchymal stem cells transplantation in patients with amyotrophic lateral sclerosis

Stem cell-based treatments have emerged as potentially effective approaches to delay the progression of amyotrophic lateral sclerosis (ALS). This study was designed as a single-center, prospective, and open-label study without a placebo control group to assess the safety and efficacy of concurrent intrathecal (IT) and intravenous (IV) administration of autologous bone marrow-derived mesenchymal stem cells (BM-MSCs) in patients with ALS. Autologous BM-MSCs were isolated and expanded under standard conditions. Fifteen patients were neurologically examined before BM-MSCs transplantation (1 × 10 ⁶ cells/kg BW) to evaluate the rate of pre-treatment disease progression. To assess the safety and efficacy, patients were examined at 1, 3, and 6 months following the treatment with BM-MSCs. Adverse reactions were assessed, and the clinical outcome was determined by the evaluation of the ALS functional rating scale-revised (ALSFRS-R) and forced vital capacity (FVC). No serious adverse reaction was observed after combined IT and IV administration of BM-MSCs. The mean ALSFRS-R and FVC values remained stable during the first 3 months of the treatment. However, a significant reduction in ALSFRS-R and FVC levels was observed in these patients 6 months after BM-MSCs administration. Our study revealed that the concurrent IT and IV application of BM-MSCs in patients with ALS is a safe procedure. Furthermore, our data indicate a temporary delay in the progression of ALS after a single combined IT and IV administration of BM-MSCs. Further studies are required to explore if the repeated applications of BM-MSCs could prolong survival and delay the progression of ALS.

An Overview of Mesenchymal Stem Cell-based Therapy Mediated by Noncoding RNAs in the Treatment of Neurodegenerative Diseases

Mesenchymal stem cells (MSCs) have become a promising tool for neurorestorative therapy of neurodegenerative diseases (NDDs), which are mainly characterized by the progressive and irreversible loss of neuronal structure and function in the central or peripheral nervous system. Recently, studies have reported that genetic manipulation mediated by noncoding RNAs (ncRNAs) can increase survival and neural regeneration of transplanted MSCs, offering a new strategy for clinical translation. In this review, we summarize the potential role and regulatory mechanism of two major types of ncRNAs, including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), during the neurogenesis of MSCs with gene expression profile analyses. We also overview the realization of MSC-based therapy mediated by ncRNAs in the treatment of spinal cord injury, stroke, Alzheimer's disease and peripheral nerve injury. It is expected that ncRNAs will become promising therapeutic targets for NDD on stem cells, while the underlying mechanisms require further exploration.

Elucidating the Pivotal Neuroimmunomodulation of Stem Cells in Spinal Cord Injury Repair

Spinal cord injury (SCI) is a distressing incident with abrupt onset of the motor as well as sensory dysfunction, and most often, the injury occurs as result of high-energy or velocity accidents as well as contact sports and falls in the elderly. The key challenges associated with nerve repair are the lack of self-repair as well as neurotrophic factors and primary and secondary neuronal apoptosis, as well as factors that prevent the regeneration of axons locally. Neurons that survive the initial traumatic damage may be lost due to pathogenic activities like neuroinflammation and apoptosis. Implanted stem cells are capable of differentiating into neural cells that replace injured cells as well as offer local neurotrophic factors that aid neuroprotection, immunomodulation, axonal sprouting, axonal regeneration, and remyelination. At the microenvironment of SCI, stem cells are capable of producing growth factors like brain-derived neurotrophic factor and nerve growth factor which triggers neuronal survival as well as axonal regrowth. Although stem cells have proven to be of therapeutic value in SCI, the major disadvantage of some of the cell types is the risk for tumorigenicity due to the contamination of undifferentiated cells prior to transplantation. Local administration of stem cells via either direct cellular injection into the spinal cord parenchyma or intrathecal administration into the subarachnoid space is currently the best transplantation modality for stem cells during SCI.

Mesenchymal Stem Cells in Treatment of Spinal Cord Injury and Amyotrophic Lateral Sclerosis

Preclinical and clinical studies with various stem cells, their secretomes, and extracellular vesicles (EVs) indicate their use as a promising strategy for the treatment of various diseases and tissue defects, including neurodegenerative diseases such as spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS). Autologous and allogenic mesenchymal stem cells (MSCs) are so far the best candidates for use in regenerative medicine. Here we review the effects of the implantation of MSCs (progenitors of mesodermal origin) in animal models of SCI and ALS and in clinical studies. MSCs possess multilineage differentiation potential and are easily expandable in vitro. These cells, obtained from bone marrow (BM), adipose tissue, Wharton jelly, or even other tissues, have immunomodulatory and paracrine potential, releasing a number of cytokines and factors which inhibit the proliferation of T cells, B cells, and natural killer cells and modify dendritic cell activity. They are hypoimmunogenic, migrate toward lesion sites, induce better regeneration, preserve perineuronal nets, and stimulate neural plasticity. There is a wide use of MSC systemic application or MSCs seeded on scaffolds and tissue bridges made from various synthetic and natural biomaterials, including human decellularized extracellular matrix (ECM) or nanofibers. The positive effects of MSC implantation have been recorded in animals with SCI lesions and ALS. Moreover, promising effects of autologous as well as allogenic MSCs for the treatment of SCI and ALS were demonstrated in recent clinical studies.

Comparative Analysis of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells between Preeclampsia and Normal Pregnant Women

Preeclampsia is a syndrome characterized by deterioration of either the maternal condition or the fetal condition. The adverse intrauterine environment made by preeclampsia results into intrauterine growth restriction and increased risk of a variety of diseases in future life. Given the adverse environment of fetal circulation made in the preeclamptic condition, and the role of mesenchymal stem cell (MSC) as a multipotent progenitor cell, we hypothesized that MSCs derived from human umbilical cord blood (hUCB-MSCs) obtained from preeclampsia are adversely altered or affected compared with normal pregnancy. The aim of this study was to analyze the biological characteristics and compare the functional abilities and gene expression patterns of hUCB-MSCs originating from pregnant women with and without severe preeclampsia. hUCB-MSCs were isolated and cultured from 28 pregnant women with severe preeclampsia and 30 normal pregnant women. hUCB-MSCs obtained from women with preeclampsia were less proliferative and more senescent and had lower telomerase activity and higher ROS activity than cells from women with normal pregnancy. In addition, many senescence-related differentially expressed genes (DEGs) were identified by analysis of microarray gene expression profiles and significantly associated with the Gene Ontology term cell aging. In conclusion, hUCB-MSCs obtained from women with preeclampsia showed the poorly proliferative, more senescent, and decreased telomerase activity, and these characters may be related with functional impairment of MSC from preeclampsia compared with cells from normal pregnancy.

Protective effect of brain-derived neurotrophic factor and neurotrophin-3 overexpression by adipose-derived stem cells combined with silk fibroin/chitosan scaffold in spinal cord injury

Objectives: Spinal cord injury (SCI) is a most debilitating traumatic injury, and cytotherapy is a promising alternative treatment strategy. Here we investigated the effect and mechanism of adipose-derived stem/stromal cells (ASCs) with overexpressing brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) (BDNF-NT3) in combination with silk fibroin/chitosan scaffold (SFCS) in SCI.Methods: Female Sprague-Dawley rats were used as an SCI model. SFCS,SFCS and ASCs, or ASCs overexpressing NT3, BDNF, and BDNF-NT3 were implanted into SCI rats. Basso, Beattie, and Bresnahan score, pathological changes, and spinal cord tissue and nerve fiber morphology were observed and assayed. GAP-43, GFAP, and caspase-3 expression was determined using immunohistochemistry and western blotting.Results: Smoother spinal cords, less scar tissue, and lower inflammatory activity were found in the SFCS, SFCS and ASCs, ASCs with NT3, BDNF, and BDNF-NT3 overexpression treatment than in the untreated SCI rat groups. Increasing formation of nerve fibers was observed in the above groups in order. GAP-43 expression significantly increased, while GFAP and caspase-3 expression significantly decreased. These results indicated obvious alleviation in pathological changes and BDNF-NT3 overexpression in ASCs combined with SFCS treatment in SCI rats.Conclusion: Thus, BDNF-NT3 overexpression from ASCs with SFCS had synergistic neuroprotective effects on SCI and may be a treatment option for SCI.

Engineering biomaterial microenvironments to promote myelination in the central nervous system

Promoting remyelination and/or minimizing demyelination are key therapeutic strategies under investigation for diseases and injuries like multiple sclerosis (MS), spinal cord injury, stroke, and virus-induced encephalopathy. Myelination is essential for efficacious neuronal signaling. This myelination process is originated by oligodendrocyte progenitor cells (OPCs) in the central nervous system (CNS). Resident OPCs are capable of both proliferation and differentiation, and also migration to demyelinated injury sites. OPCs can then engage with these unmyelinated or demyelinated axons and differentiate into myelin-forming oligodendrocytes (OLs). However this process is frequently incomplete and often does not occur at all. Biomaterial strategies can now be used to guide OPC and OL development with the goal of regenerating healthy myelin sheaths in formerly damaged CNS tissue. Growth and neurotrophic factors delivered from such materials can promote proliferation of OPCs or differentiation into OLs. While cell transplantation techniques have been used to replace damaged cells in wound sites, they have also resulted in poor transplant cell viability, uncontrollable differentiation, and poor integration into the host. Biomaterial scaffolds made from extracellular matrix (ECM) mimics that are naturally or synthetically derived can improve transplanted cell survival, support both transplanted and endogenous cell populations, and direct their fate. In particular, stiffness and degradability of these scaffolds are two parameters that can influence the fate of OPCs and OLs. The future outlook for biomaterials research includes 3D in vitro models of myelination / remyelination / demyelination to better mimic and study these processes. These models should provide simple relationships of myelination to microenvironmental biophysical and biochemical properties to inform improved therapeutic approaches.

Spinal Cord Injury: Animal Models, Imaging Tools and the Treatment Strategies

Spinal cord injury (SCI) often leads to irreversible neuro-degenerative changes with life-long consequences. While there is still no effective therapy available, the results of past research have led to improved quality of life for patients suffering from partial or permanent paralysis. In this review we focus on the need, importance and the scientific value of experimental animal models simulating SCI in humans. Furthermore, we highlight modern imaging tools determining the location and extent of spinal cord damage and their contribution to early diagnosis and selection of appropriate treatment. Finally, we focus on available cellular and acellular therapies and novel combinatory approaches with exosomes and active biomaterials. Here we discuss the efficacy and limitations of adult mesenchymal stem cells which can be derived from bone marrow, adipose tissue or umbilical cord blood and its Wharton's jelly. Special attention is paid to stem cell-derived exosomes and smart biomaterials due to their special properties as a delivery system for proteins, bioactive molecules or even genetic material.

Cortical AAV-CNTF Gene Therapy Combined with Intraspinal Mesenchymal Precursor Cell Transplantation Promotes Functional and Morphological Outcomes after Spinal Cord Injury in Adult Rats

Ciliary neurotrophic factor (CNTF) promotes survival and enhances long-distance regeneration of injured axons in parts of the adult CNS. Here we tested whether CNTF gene therapy targeting corticospinal neurons (CSN) in motor-related regions of the cerebral cortex promotes plasticity and regrowth of axons projecting into the female adult F344 rat spinal cord after moderate thoracic (T10) contusion injury (SCI). Cortical neurons were transduced with a bicistronic adeno-associated viral vector (AAV1) expressing a secretory form of CNTF coupled to mCHERRY (AAV-CNTF^mCherry) or with control AAV only (AAV-GFP) two weeks prior to SCI. In some animals, viable or nonviable F344 rat mesenchymal precursor cells (rMPCs) were injected into the lesion site two weeks after SCI to modulate the inhibitory environment. Treatment with AAV-CNTF^mCherry, as well as with AAV-CNTF^mCherry combined with rMPCs, yielded functional improvements over AAV-GFP alone, as assessed by open-field and Ladderwalk analyses. Cyst size was significantly reduced in the AAV-CNTF^mCherry plus viable rMPC treatment group. Cortical injections of biotinylated dextran amine (BDA) revealed more BDA-stained axons rostral and alongside cysts in the AAV-CNTF^mCherry versus AAV-GFP groups. After AAV-CNTF^mCherry treatments, many sprouting mCherry-immunopositive axons were seen rostral to the SCI, and axons were also occasionally found caudal to the injury site. These data suggest that CNTF has the potential to enhance corticospinal repair by transducing parent CNS populations.

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

Background

Spinal 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.

Methods

A 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.

Results

Our 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.

Conclusions

Our 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 material

The online version of this article (10.1186/s13287-018-0879-0) contains supplementary material, which is available to authorized users.

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.

Article Commentary: Stem Cell Research in Cell Transplantation: An Analysis of Geopolitical Influence by Publications

One of the fastest growing fields in researching treatments for neurodegenerative and other disorders is the use of stem cells. These cells are naturally occurring and can be obtained from three different stages of an organism's life: embryonic, fetal, and adult. In the US, political doctrine has restricted use of federal funds for stem cells, enhancing research towards an adult source. In order to determine how this legislation may be represented by the stem cell field, a retrospective analysis of stem cell articles published in the journal Cell Transplantation over a 2-year period was performed. Cell Transplantation is considered a translational journal from preclinical to clinical, so it was of interest to determine the publication outcome of stem cell articles 6 years after the US regulations. The distribution of the source of stem cells was found to be biased towards the adult stage, but relatively similar over the embryonic and fetal stages. The fetal stem cell reports were primarily neural in origin, whereas the adult stem cell ones were predominantly mesenchymal and used mainly in neural studies. The majority of stem cell studies published in Cell Transplantation were found to fall under the umbrella of neuroscience research. American scientists published the most articles using stem cells with a bias towards adult stem cells, supporting the effect of the legislation, whereas Europe was the leading continent with a bias towards embryonic and fetal stem cells, where research is “controlled” but not restricted. Japan was also a major player in the use of stem cells. Allogeneic transplants (where donor and recipient are the same species) were the most common transplants recorded, although the transplantation of human-derived stem cells into rodents was the most common specific transplantation performed. This demonstrates that the use of stem cells is an increasingly important field (with a doubling of papers between 2005 and 2006), which is likely to develop into a major therapeutic area over the next few decades and that funding restrictions can affect the type of research being performed.

Molecular mechanisms of brain-derived neurotrophic factor in neuro-protection: Recent developments

Neuronal cell injury, as a consequence of acute or chronic neurological trauma, is a significant cause of mortality around the world. On a molecular level, the condition is characterized by widespread cell death and poor regeneration, which can result in severe morbidity in survivors. Potential therapeutics are of major interest, with a promising candidate being brain-derived neurotrophic factor (BDNF), a ubiquitous agent in the brain which has been associated with neural development and may facilitate protective and regenerative effects following injury. This review summarizes the available information on the potential benefits of BDNF and the molecular mechanisms involved in several pathological conditions, including hypoxic brain injury, stroke, Alzheimer's disease and Parkinson's disease. It further explores the methods in which BDNF can be applied in clinical and therapeutic settings, and the potential challenges to overcome.

A Method for Reconstruction of Severely Damaged Spinal Cord using Autologous Hematopoietic Stem Cells and Platelet-rich Protein as a Biological Scaffold

Introduction:

There have been attempts to alter the prognosis of severe spinal cord injury in different centers, but none of which have reliably altered the outcome. Some trials use stem cells (SCs) that produced widely differing results. We hereby add our experience in our center of a surgical reconstruction of the damaged spinal cord using a mixture of SCs and Platelet-Rich Protein (PRP) with fibrin coated as a biological scaffold.

Materials and Methods:

Four cases of severely damaged spinal cord have been operated for neurolysis and reconstruction of the spinal cord using SCs and platelet-rich protein (PRP) with fibrin coated harvested from the peripheral circulation of the patient. PRP serves to maintain the position of the SCs. One milliliter suspension contains an average of 2.8 × 10⁶ of autologous hematopoietic SCs. Patients were intraoperatively monitored by somatosensory evoked potential, motor evoked potentials, and delta wave. They are clinically followed postoperatively and electromyogram was repeated every 2 weeks. Magnetic resonance imaging (MRI) was repeated regularly. The patients are followed up for a period between 2 and 3 years.

Results:

One patient demonstrated motor and objective sensory improvement (P = 0.05), two other patients reported subjective sensory improvement, and the fourth one remained without any improvement (P = 0.1). None of these patients demonstrated any sign of deterioration or complication either on the surgery or on implanting of the SCs. MRI clearly proved that the inserted biological scaffold remained in place of reconstruction.

Conclusion:

SCs may play a role in restoring spinal cord functions. However, the unsolved problems of the use of SCs and related ethical issues should be addressed.

Transplantation of bone mesenchymal stem cells promotes angiogenesis and improves neurological function after traumatic brain injury in mouse

Traumatic brain injury (TBI) has emerged as a leading cause of mortality and morbidity worldwide. Transplantation of bone mesenchymal stem cells (BMSCs) has emerged as a promising treatment for various central nervous system diseases. This study aims to evaluate the effect of BMSCs transplantation by intravenous injection on neurological function and angiogenesis of the TBI mice. C57BL/6 male mice were randomly divided into four groups: control, sham, TBI, and BMSC. Functional neurological evaluation was performed 1, 4, 7, 14, and 21 days after TBI using neurological severity scores. The impairment of learning and memory in mice was evaluated 14 days after TBI by Morris water maze experiment. Mice were sacrificed 14 days after TBI, and then brain sections were stained by terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling staining to assess brain neuronal apoptosis. Immunohistochemistry was conducted to evaluate caspase-3 activity and identify vascular distribution and microvessel density. Protein and mRNA levels of vascular endothelial growth factor (VEGF) and angiogenin-1 (Ang-1) in brain tissues were analyzed by Western blot and quantitative real-time polymerase chain reaction, respectively. BMSCs transplantation promoted recovery of neurological function, ameliorated impairment of learning and memory, attenuated neuronal apoptosis, and diminished caspase-3 activation in mice after TBI. Also, BMSCs transplantation upregulated expressions of VEGF and Ang-1 and promoted the formation of microvessels in brain tissues after TBI. Our study demonstrated the important role of BMSCs transplantation in TBI mouse and indicated that the underlying mechanism was through promoting angiogenesis and improving neurological function. This provides a novel and effective strategy for cell-based therapy in the treatment of TBI.

G-CSF and hypoxic conditioning improve the proliferation, neural differentiation and migration of canine bone marrow mesenchymal stem cells

Transplantation using bone marrow mesenchymal stem cells (BMSCs) is emerging as a potential regenerative therapy after ischemic attacks in the brain. However, it has been questioned because very few transplanted BMSCs are detected homing to and survived in the ischemic region. Improving the cell viability and migration ability under the complex ischemic condition seems very important. The aim of our study is to identify whether hypoxic condition and granulocyte colony-stimulating factor (G-CSF) could improve the cell survival and migration ability of transplanted cells or hypoxic condition could promote BMSC's neural differentiation. BMSCs were treated under either normoxic (21% O₂) or hypoxic (1% O₂) (HP-BMSCs) conditions, no significant apoptosis was observed in hypoxic precondition (HP) group, our study confirmed that HP improves BMSCs proliferation and migration. Meanwhile, neural induction of BMSCs under hypoxic condition exhibited significant superior results than normoxic condition. Additionally, the addition of G-CSF in HP-BMSCs culture media promoted HP efficiency on BMSCs. These findings shed light on novel efficient strategy on the prosperity of BMSCs. Hypoxic preconditioning and cultured with G-CSF may become a promising therapeutics for cell-based therapy in the treatments of ischemia stroke.

Bone Marrow Stromal Cell Intraspinal Transplants Fail to Improve Motor Outcomes in a Severe Model of Spinal Cord Injury

Bone marrow stromal cells (BMSCs) have been reported to exert potential neuroprotective properties in models of neurotrauma, although precise mechanisms underlying their benefits are poorly understood. Despite this lack of knowledge, several clinical trials have been initiated using these cells. To determine whether local mechanisms mediate BMSC neuroprotective actions, we grafted allogeneic BMSCs to sites of severe, compressive spinal cord injury (SCI) in Sprague-Dawley rats. Cells were administered 48 h after the original injury. Additional animals received allogeneic MSCs that were genetically modified to secrete brain-derived neurotrophic factor (BDNF) to further determine whether a locally administered neurotrophic factor provides or extends neuroprotection. When assessed 2 months post-injury in a clinically relevant model of severe SCI, BMSC grafts with or without BDNF secretion failed to improve motor outcomes. Thus, allogeneic grafts of BMSCs do not appear to act through local mechanisms, and future clinical trials that acutely deliver BMSCs to actual sites of injury within days are unlikely to be beneficial. Additional studies should address whether systemic administration of BMSCs alter outcomes from neurotrauma.

Transplantation of adipose derived mesenchymal stem cells for acute thoracolumbar disc disease with no deep pain perception in dogs

Thirty-four dogs with no deep pain perception due to acute thoracolumbar intervertebral disc disease underwent decompression surgery within 1 week of diagnosis. All dogs underwent hemilaminectomy. Adipose derived mesenchymal stem cells (AD-MSCs) were transplanted into the injured spinal cord parenchyma for the AD-MSCs transplant dogs. Long-term outcome was evaluated at the end of the follow-up period (> 6 months). AD-MSCs combination treatment showed better recovery outcomes compared to decompression surgery alone. These results indicate that this stem cell therapy is a potential therapeutic strategy to overcome the limitations of treatment for spinal cord injury in clinical medicine.

The New Role of CD163 in the Differentiation of Bone Marrow Stromal Cells into Vascular Endothelial-Like Cells

Bone marrow stromal cells (BMSCs) can differentiate into vascular endothelial cells (VECs). It is regarded as an important solution to cure many diseases, such as ischemic diseases and diabetes. However, the mechanisms underlying BMSC differentiation into VECs are not well understood. Recent reports showed that CD163 expression was associated with angiogenesis. In this study, overexpression of CD163 in BMSCs elevated the protein level of the endothelial-associated markers CD31, Flk-1, eNOS, and VE-cadherin, significantly increased the proportion of Alexa Fluor 488-acetylated-LDL-positive VECs, and promoted angiogenesis on Matrigel. Furthermore, we demonstrated that CD163 acted downstream homeobox containing 1 (Hmbox1) and upstream fibroblast growth factor 2 (FGF-2). These data suggested that CD163 was involved in Hmbox1/CD163/FGF-2 signal pathway in BMSC differentiation into vascular endothelial-like cells. We found a new signal pathway and a novel target for further investigating the gene control of BMSC differentiation into a VEC lineage.

Classic Studies on the Potential of Stem Cell Neuroregeneration

The 1990s and 2000s were the beginning of an exciting time period for developmental neuroscience and neural stem cell research. By better understanding brain plasticity and the birth of new neurons in the adult brain, contrary to established dogma, hope for therapy from devastating neurological diseases was generated. The potential for stem cells to provide functional recovery in humans remains to be further tested and to further move into the clinical trial realm. The future certainly has great promise on stem cells to assist in alleviation of difficult-to-treat neurologic disorders. This article reviews classic studies of the 1990s and 2000s that paved the way for the advances of today, which can in turn lead to tomorrow's therapies.

Bone Marrow Stromal Cells Combined with a Honeycomb Collagen Sponge Facilitate Neurite Elongation in Vitro and Neural Restoration in the Hemisected Rat Spinal Cord

In the last decade, researchers and clinicians have reported that transplantation of bone marrow stromal cells (BMSCs) promotes functional recovery after brain or spinal cord injury (SCI). However, an appropriate scaffold designed for the injured spinal cord is needed to enhance the survival of transplanted BMSCs and to promote nerve regeneration. We previously tested a honeycomb collagen sponge (HC), which when applied to the transected spinal cord allowed bridging of the gap with nerve fibers. In this study, we examined whether the HC implant combined with rat BMSCs increases nerve regeneration in vitro and enhances functional recovery in vivo. We first evaluated the neurite outgrowth of rat dorsal root ganglion (DRG) explants cultured on HC with or without BMSCs in vitro. Regeneration of neurites from the DRGs was increased by BMSCs combined with HC scaffolds. In the in vivo study, 3-mm-long HC scaffolds with or without BMSCs were implanted into the hemisected rat thoracic spinal cord. Four weeks after the procedure, rats implanted with HC scaffolds containing BMSCs displayed better motor and sensory recovery than those implanted with HC scaffolds only. Histologically, more CGRP-positive sensory fibers at the implanted site and 5-HT-positive serotonergic fibers contralateral to the implanted site were observed in spinal cords receiving BMSCs. Furthermore, more rubrospinal neurons projected distally to the HC implant containing BMSCs. Our study indicates that the application of BMSCs in a HC scaffold in the injured spinal cord directly promoted sensory nerve and rubrospinal tract regeneration, thus resulting in functional recovery.

The role of brain-derived neurotrophic factor in bone marrow stromal cell-mediated spinal cord repair

The ability of intraspinal bone marrow stromal cell (BMSC) transplants to elicit repair is thought to result from paracrine effects by secreted trophic factors including brain-derived neurotrophic factor (BDNF). Here we used gene therapy to increase or silence BDNF production in BMSCs to investigate the role of BDNF in BMSC-mediated neuroprotection. In a spinal cord organotypic culture, BMSC-conditioned medium significantly enhanced spinal motoneuron survival by 64% compared with culture medium only. Only conditioned medium of BDNF-hypersecreting BMSCs sustained this neuroprotective effect. In a rat model of spinal cord contusion, a BDNF-dependent neuroprotective effect was confirmed; only with a subacute transplant of BDNF-hypersecreting BMSCs were significantly more spared motoneurons found at 4 weeks postinjury compared with vehicle controls. Spared nervous tissue volume was improved by 68% with both control BMSCs and BDNF-hypersecreting BMSCs. In addition, blood vessel density in the contusion with BDNF-hypersecreting BMSCs was 35% higher compared with BMSC controls and sixfold higher compared with vehicle controls. BDNF-silenced BMSCs did not survive the first week of transplantation, and no neuroprotective effect was found at 4 weeks after transplantation. Together, our data broaden our understanding of the role of BDNF in BMSC-mediated neuroprotection and successfully exploit BDNF dependency to enhance anatomical spinal cord repair.

Biohybrid hematopoietic niche for expansion of hematopoietic stem/progenitor cells by using geometrically controlled fibrous layers

Biohybrid hematopoietic niche for expansion of hematopoietic stem/progenitor cells.

Modulation properties of factors released by bone marrow stromal cells on activated microglia: an in vitro study

In the present paper we develop a new non-cell based (cell-free) therapeutic approach applied to BV2 microglial cells and spinal cord derived primary microglia (PM) using conditioned media from rat bone marrow stromal cells (BMSCs-CM). First we collected conditioned media (CM) from either naive or injured rat spinal cord tissue (SCI-CM, inflammatory stimulation agent) and from rat bone marrow stromal cells (BMSCs-CM, therapeutic immunomodulation agent). They were both subsequently checked for the presence of chemokines and growth, neurotrophic and neural migration factors using proteomics analysis. The data clearly showed that rat BMSCs-CM contain in vitro growth factors, neural migration factors, osteogenic factors, differentiating factors and immunomodulators, whereas SCI-CM contain chemokines, chemoattractant factors and neurotrophic factors. Afterwards we determined whether the BMSCs-CM affect chemotactic activity, NO production, morphological and pro-apoptotic changes of either BV2 or PM cells once activated with SCI-CM. Our results confirm the anti-migratory and NO-inhibitory effects of BMSCs-CM on SCI-CM-activated microglia with higher impact on primary microglia. The cytotoxic effect of BMSCs-CM occurred only on SCI-CM-stimulated BV2 cells and PM, not on naive BV2 cells, nor on PM. Taken together, the molecular cocktail found in BMSCs-CM is favorable for immunomodulatory properties.

A prospective randomized double-blind clinical trial using a combination of olfactory ensheathing cells and Schwann cells for the treatment of chronic complete spinal cord injuries

The aim of this prospective randomized double-blind clinical study is to examine the benefits of using olfactory ensheathing cells (OECs) combined with or without Schwann cells (SCs) in treating chronic complete spinal cord injuries (SCIs). This would offer patients a better alternative for neurological functional recovery. According to the initial design, 28 eligible participants with cervical chronic complete SCI were recruited and randomly allocated into four groups of seven participants each. The neurological assessments were to be performed according to the American Spinal Injury Association (ASIA) and International Association of Neurorestoratology (IANR) Functional Rating Scales, in combination with electrophysiological tests, for example, electromyography (EMG) and paraspinal somatosensory evoked potentials (PSSEPs). Here we have summarized the data from seven patients; three patients received an OEC intraspinal transplantation, one underwent SC implantation, and one received a combination of OECs and SCs. The remaining two patients were used as controls. The scores were evaluated independently by at least two neurologists in a blinded fashion for comparing the neurological functional changes during pre- and post-cell transplantation (6-month follow-up). All patients who received OECs, SCs alone, and a combination of them showed functional improvement. Mild fever occurred in one of the patients with OEC transplant that subsided after symptomatic treatments. All treated patients except one showed improvement in the electrophysiological tests. The functional improvement rate comprises 5/5 (100%) in the treated group, but 0/2 (0%) in the control group (p = 0.008). These preliminary findings show that transplanting OECs, SCs, or a combination of them is well tolerated and that they have beneficial effects in patients. Thus, further studies in larger patient cohorts are warranted to assess the benefits and risks of these intervention strategies. This manuscript is published as part of the IANR special issue of Cell Transplantation.

Co-culture of bone marrow-derived mesenchymal stem cells overexpressing lipocalin 2 with HK-2 and HEK293 cells protects the kidney cells against cisplatin-induced injury

Conditioned medium of mesenchymal stem cells (MSCs) is now being used for its cytoprotective effects, especially when the cells are equipped with cytoprotective factors to strengthen them against unfavorable microenvironments. Overexpression of Lcn2 in MSCs mimics in vivo kidney injury. Hence, unraveling how Lcn2-engineered MSCs affect kidney cells has been investigated. Cisplatin treated HK-2 or HEK293 kidney cells were co-cultivated with Lcn2 overexpressing MSCs in upper and lower chambers of transwell plates. Proliferation, apoptosis, and expression of growth factors and cytokines were assessed in the kidney cells. Co-cultivation with the MSCs-Lcn2 not only inhibited cisplatin-induced cytotoxicity in the HK-2 and HEK293 cells, but increased proliferation rate, prevented cisplatin-induced apoptosis, and increased expression of growth factors and the amount of antioxidants in the kidney cells. Thus Lcn2-engineered MSCs can ameliorate and repair injured kidney cells in vitro, which strongly suggests there are beneficial effects of the MSCs-Lcn2 in cell therapy of kidney injury.

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.

17β-estradiol protects human eyelid-derived adipose stem cells against cytotoxicity and increases transplanted cell survival in spinal cord injury

Stem cell transplantation represents a promising strategy for the repair of spinal cord injury (SCI). However, the low survival rate of the grafted cells is a major obstacle hindering clinical success because of ongoing secondary injury processes, which includes excitotoxicity, inflammation and oxidative stress. Previous studies have shown that 17b-estradiol (E2) protects several cell types against cytotoxicity. Thus, we examined the effects of E2 on the viability of human eyelid adipose-derived stem cells (hEASCs) in vitro with hydrogen peroxide (H₂O₂)-induced cell model and in vivo within a rat SCI model. Our results showed that E2 protected hEASCs against H₂O₂-induced cell death in vitro, and enhanced the survival of grafted hEASCs in vivo by reducing apoptosis. Additionally, E2 also enhanced the secretion of growth factors by hEASCs, thereby making the local microenvironment more conducive for tissue regeneration. Overall, E2 administration enhanced the therapeutic efficacy of hEASCs transplantation and facilitated motor function recovery after SCI. Hence, E2 administration may be an intervention of choice for enhancing survival of transplanted hEASCs after SCI.

A comparison of the behavioral and anatomical outcomes in sub-acute and chronic spinal cord injury models following treatment with human mesenchymal precursor cell transplantation and recombinant decorin

This study assessed the potential of highly purified (Stro-1(+)) human mesenchymal precursor cells (hMPCs) in combination with the anti-scarring protein decorin to repair the injured spinal cord (SC). Donor hMPCs isolated from spinal cord injury (SCI) patients were transplanted into athymic rats as a suspension graft, alone or after previous treatment with, core (decorin(core)) and proteoglycan (decorin(pro)) isoforms of purified human recombinant decorin. Decorin was delivered via mini-osmotic pumps for 14 days following sub-acute (7 day) or chronic (1 month) SCI. hMPCs were delivered to the spinal cord at 3 weeks or 6 weeks after the initial injury at T9 level. Behavioral and anatomical analysis in this study showed statistically significant improvement in functional recovery, tissue sparing and cyst volume reduction following hMPC therapy. The combination of decorin infusion followed by hMPC therapy did not improve these measured outcomes over the use of cell therapy alone, in either sub-acute or chronic SCI regimes. However, decorin infusion did improve tissue sparing, reduce spinal tissue cavitation and increase transplanted cell survivability as compared to controls. Immunohistochemical analysis of spinal cord sections revealed differences in glial, neuronal and extracellular matrix molecule expression within each experimental group. hMPC transplanted spinal cords showed the increased presence of serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted hMPCs for up to 2 months; however, no evidence of hMPC transdifferentiation into neuronal or glial phenotypes. The number of hMPCs was dramatically reduced overall, and no transplanted cells were detected at 8 weeks post-injection using lentiviral GFP labeling and human nuclear antigen antibody labeling. The presence of recombinant decorin in the cell transplantation regimes delayed in part the loss of donor cells, with small numbers remaining at 2 months after transplantation. In vitro co-culture experiments with embryonic dorsal root ganglion explants revealed the growth promoting properties of hMPCs. Decorin did not increase axonal outgrowth from that achieved by hMPCs. We provide evidence for the first time that (Stro-1(+)) hMPCs provide: i) an advantageous source of allografts for stem cell transplantation for sub-acute and chronic spinal cord therapy, and (ii) a positive host microenvironment that promotes tissue sparing/repair that subsequently improves behavioral outcomes after SCI. This was not measurably improved by recombinant decorin treatment, but does provide important information for the future development and potential use of decorin in contusive SCI therapy.

Bone marrow stromal cells inhibit caspase-12 expression in rats with spinal cord injury

The mechanisms underlying the potentially beneficial effect of bone marrow stem cells (BMSCs) on spinal cord injury (SCI) are unknown. Therefore, the aim of the present study was to explore the protective effect of BMSCs in rats with SCI. A total of 45 adult male Sprague-Dawley rats were randomly divided into three groups; the SCI group (n=15), the BMSC group (n=15) and the sham-operation group (n=15). In the SCI and BMSC treatment groups, a modified Allen’s weight-drop technique was used to induce SCI. The BMSC treatment group received an injection of BMSCs using a microneedle into the epicenter of the spinal cord 24 h after injury. Rats in the sham-operation group were not subjected to SCI; however, the corresponding vertebral laminae were removed. Seven days after transplantation, a rapid recovery was observed in the Basso, Beattie and Bresnahan (BBB) scores of the BMSC treatment group, whereas the BBB scores in the SCI group remained low (P<0.05). Caspase-12 expression in the SCI group was increased compared with that in the sham-operation group, whereas caspase-12 expression was attenuated 24 h after transplantation in the BMSC treatment group (P<0.05). In conclusion, the transplantation of BMSCs may improve locomotor function and attenuate caspase-12 expression following SCI. Therefore, it is likely to be an effective strategy for preventing severe injury of the spinal cord.

Human Mesenchymal Precursor Cells (Stro-1+) from Spinal Cord Injury Patients Improve Functional Recovery and Tissue Sparing in an Acute Spinal Cord Injury Rat Model

This study aimed to determine the potential of purified (Stro-1+) human mesenchymal precursor cells (hMPCs) to repair the injured spinal cord (SC) after transplantation into T-cell-deficient athymic RNU nude rats following acute moderate contusive spinal cord injury (SCI). hMPCs were isolated from the bone marrow (BM) stroma of SCI patients and transplanted as a suspension graft in medium [with or without immunosuppression using cyclosporin A (CsA)]. Extensive anatomical analysis shows statistically significant improvement in functional recovery, tissue sparing, and cyst reduction. We provide quantitative assessment of supraspinal projections in combination with functional outcomes. hMPC-transplanted animals consistently achieved mean BBB scores of 15 at 8 weeks postinjury. Quantitative histological staining revealed that graft-recipient animals possessed more intact spinal tissue and reduced cyst formation than controls. Fluorogold (FG) retrograde tracing revealed sparing/regeneration of supraspinal and local propriospinal axonal pathways, but no statistical differences were observed compared to controls. Immunohistochemical analysis revealed increased serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted donor hMPCs 2 weeks posttransplantation, but no evidence of hMPC transdifferentiation was seen. Although hMPCs initially survive at 2 weeks posttransplantation, their numbers were dramatically reduced and no cells were detected at 8 weeks posttransplantation using retroviral/lentiviral GFP labeling and a human nuclear antigen (HNA) antibody. Additional immunosuppression with CsA did not improve hMPC survival or their ability to promote tissue sparing or functional recovery. We propose Stro-1+-selected hMPCs provide (i) a reproducible source for stem cell transplantation for SC therapy and (ii) a positive host microenvironment resulting in the promotion of tissue sparing/repair that subsequently improves behavioral outcomes after SCI. Our results provide a new candidate for consideration as a stem cell therapy for the repair of traumatic CNS injury.

Clinical application of olfactory ensheathing cells in the treatment of spinal cord injury

OBJECTIVES

To investigate the safety and therapeutic efficacy of autologous olfactory ensheathing cell (OEC) transplantation in cervical spinal cord injury (SCI).

METHODS

Patients with cervical SCI of >6 months' duration were treated with autologous OECs, injected into the area surrounding the SCI under magnetic resonance imaging guidance, twice a week for 4 weeks. Patients were evaluated before treatment and at 3, 6, 12 and 24 months post-treatment, using the American Spinal Injury Association (ASIA) Impairment Scale, the ASIA sensory and motor score and the Functional Independence Measure (FIM) score.

RESULTS

Eight patients were recruited to the study. Three months after treatment, ASIA and FIM scores had improved significantly compared with pretreatment, though by 1 year no further significant improvements in the ASIA score were seen. The return of substantial sensation and motor activity in various muscles below the injury level was observed in three patients during follow-up. In addition, bladder function was restored in two patients. There were no serious complications postoperatively or during the follow-up period.

CONCLUSIONS

This study provides preliminary evidence of the safety and possible efficacy of autologous OEC transplantation.

Long-term outcome of olfactory ensheathing cell therapy for patients with complete chronic spinal cord injury

The neurorestorative effect of the parenchymal transplantation of olfactory ensheathing cells (OECs) for cord trauma remains clinically controversial. The aim of this article is to study the long-term result of OECs for patients with complete chronic spinal cord injury (SCI). One hundred and eight patients suffered from complete chronic SCI were followed up successfully within the period of 3.47 ± 1.12 years after OEC therapy. They were divided into two groups based on the quality and quantity of their rehabilitative training: group A (n = 79) in sufficient rehabilitation (or active movement-target enhancement-neurorehabilitation therapy, AMTENT) and group B (n = 29) in insufficient rehabilitation. All patients were assessed by using the American Spinal Injury Association (ASIA) standard and the International Association of Neurorestoratology Spinal Cord Injury Functional Rating Scale (IANR-SCIFRS). Thirty-one patients were evaluated by the tests of magnetic resonance imaging (MRI), electromyography (EMG), and paravertebral sensory evoked potential (PVSEP). We found the following. 1) According to ASIA and IANR-SCIFRS assessment for all 108 patients, averaged motor scores increased from 37.79 ± 18.45 to 41.25 ± 18.18 (p < 0.01), light touch scores from 50.32 ± 24.71 to 55.90 ± 24.46 (p < 0.01), pin prick scores from 50.53 ± 24.92 to 54.53 ± 24.62 (p < 0.01); IANR-SCIFRS scores increased from 19.32 ± 9.98 to 23.12 ± 10.30 (p < 0.01). 2) The score changes in terms of motor, light touch, pin prick, and IANR-SCIFRS in group A were remarkably different (all p < 0.01). The score changes in group B were remarkably different in terms of motor (p < 0.05) and IANR-SCIFRS (p < 0.01), but not light touch or pin prick (p > 0.05). 3) Comparing group A with group B, the increased scores in terms of motor, light touch, and pin prick were remarkably different (all p < 0.01), but not IANR-SCIFRS (p > 0.05). 4) Fourteen of 108 patients (12.96%) became ASIA B from ASIA A; 18 of 108 (16.67%) became ASIA C from ASIA A. Nine of them (8.33%) improved their walk ability or made them rewalk by using a walker with or without assistance; 12 of 84 men (14.29%) improved their sex function. 5) MRI examinations were taken for 31 patients; there were no neoplasm, bleeding, swelling, cysts, neural tissue destruction or infection (abscess) or any other pathological changes in or around OEC transplant sites. 6) EMG examinations were done on 31 patients; 29 showed improvement and the remaining 2 had no change. PVSEP tests were performed in 31 patients; 28 showed improvements and the remaining 3 had no change. 7) No deterioration or complications were observed in our patients within the follow-up period. Our data suggest OEC therapy is safe and can improve neurological functions for patients with complete chronic SCI and ameliorate their quality of life; the AMTENT most likely plays a critical role in enhancing functional recovery after cell-based neurorestorotherapy.

Immediate intraportal transplantation of human bone marrow mesenchymal stem cells prevents death from fulminant hepatic failure in pigs

The effectiveness of human bone marrow mesenchymal stem cell (hBMSC) transplantation to treat acute and chronic liver injury has been demonstrated in animal models and in a few nonrandomized clinical trials. However, no studies have investigated hBMSC transplantation in the treatment of fulminant hepatic failure (FHF), especially in large animal (pig) models. The aim of this study was to demonstrate the safety, effectiveness, and underlying mechanism of hBMSC transplantation for treating FHF in pigs through the intraportal route. Human BMSCs (3 × 10(7) ) were transplanted into pigs with FHF via the intraportal route or peripheral vein immediately after D-galactosamine injection, and a sham group underwent intraportal transplantation (IPT) without cells (IPT, peripheral vein transplantation [PVT], and control groups, respectively, n = 15 per group). All of the animals in the PVT and control groups died of FHF within 96 hours. In contrast, 13 of 15 animals in the IPT group achieved long-term survival (>6 months). Immunohistochemistry demonstrated that transplanted hBMSC-derived hepatocytes in surviving animals were widely distributed in the hepatic lobules and the liver parenchyma from weeks 2 to 10. Thirty percent of the hepatocytes were hBMSC-derived. However, the number of transplanted cells decreased significantly at week 15. Only a few single cells were scattered in the regenerated liver lobules at week 20, and the liver tissues exhibited a nearly normal structure.

CONCLUSION

Immediate IPT of hBMSCs is a safe and effective treatment for FHF. The transplanted hBMSCs may quickly participate in liver regeneration via proliferation and transdifferentiation into hepatocytes during the initial stage of FHF. This method can possibly be used in future clinical therapy.

Bone Marrow Stromal Cell-Mediated Tissue Sparing Enhances Functional Repair after Spinal Cord Contusion in Adult Rats

Bone marrow stromal cell (BMSC) transplantation has shown promise for repair of the spinal cord. We showed earlier that a BMSC transplant limits the loss of spinal nervous tissue after a contusive injury. Here, we addressed the premise that BMSC-mediated tissue sparing underlies functional recovery in adult rats after a contusion of the thoracic spinal cord. Our results reveal that after 2 months BMSCs had elicited a significant increase in spared tissue volumes and in blood vessel density in the contusion epicenter. A strong functional relationship existed between spared tissue volumes and blood vessel density. BMSC-transplanted rats exhibited significant improvements in motor, sensorimotor, and sensory functions, which were strongly correlated with spared tissue volumes. Retrograde tracing revealed that rats with BMSCs had twice as many descending brainstem neurons with an axon projecting beyond the contused spinal cord segment and these correlated strongly with the improved motor/sensorimotor functions but not sensory functions. Together, our data indicate that tissue sparing greatly contributes to BMSC-mediated functional repair after spinal cord contusion. The preservation/formation of blood vessels and sparing/regeneration of descending brainstem axons may be important mediators of the BMSC-mediated anatomical and functional improvements.

Tissue engineered regeneration of completely transected spinal cord using human mesenchymal stem cells

The present study employed a combinatorial strategy using poly(D,L-lactide-co-glycolide) (PLGA) scaffolds seeded with human mesenchymal stem cells (hMSCs) to promote cell survival, differentiation, and neurological function in a completely transected spinal cord injury (SCI) model. The SCI model was prepared by complete removal of a 2-mm length of spinal cord in the eighth-to-ninth spinal vertebra, a procedure that resulted in bilateral hindlimb paralysis. PLGA scaffolds 2 mm in length without hMSCs (control) or with different numbers of hMSCs (1 × 10(5), 2 × 10(4), and 4 × 10(3)) were fitted into the completely transected spinal cord. Rats implanted with hMSCs received Basso-Beattie-Bresnahan scores for hindlimb locomotion of about 5, compared with ~2 for animals in the control group. The amplitude of motor-evoked potentials (MEPs) averaged 200-300 μV in all hMSC-implanted SCR model rats. In contrast, the amplitude of MEPs in control group animals averaged 135 μV at 4 weeks and then declined to 100 μV at 8 weeks. These results demonstrate functional recovery in a completely transected SCI model under conditions that exclude self-recovery. hMSCs were detected at the implanted site 4 and 8 weeks after transplantation, indicating in vivo survival of implanted hMSCs. Immunohistochemical staining revealed differentiation of implanted hMSCs into nerve cells, and immunostained images showed clear evidence for axonal regeneration only in hMSC-seeded PLGA scaffolds. Collectively, our results indicate that hMSC-seeded PLGA scaffolds induced nerve regeneration in a completely transected SCI model, a finding that should have significant implications for the feasibility of therapeutic and clinical hMSC-delivery using three-dimensional scaffolds, especially in the context of complete spinal cord transection.

Transplantation of hypoxia preconditioned bone marrow mesenchymal stem cells enhances angiogenesis and neurogenesis after cerebral ischemia in rats

Hypoxic preconditioning of stem cells and neural progenitor cells has been tested for promoting cell survival after transplantation. The present investigation examined the hypothesis that hypoxic preconditioning of bone marrow mesenchymal stem cells (BMSCs) could not only enhance their survival but also reinforce regenerative properties of these cells. BMSCs from eGFP engineered rats or pre-labeled with BrdU were pre-treated with normoxia (20% O(2), N-BMSCs) or sub-lethal hypoxia (0.5% O(2). H-BMSCs). The hypoxia exposure up-regulated HIF-1α and trophic/growth factors in BMSCs, including brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), vascular endothelial growth factor (VEGF) and its receptor FIK-1, erythropoietin (EPO) and its receptor EPOR, stromal derived factor-1 (SDF-1) and its CXC chemokine receptor 4 (CXCR4). Meanwhile, many pro-inflammatory cytokines/chemokines were down-regulated in H-BMSCs. N-BMSCs or H-BMSCs were intravenously injected into adult rats 24h after 90-min middle cerebral artery occlusion. Comparing to N-BMSCs, transplantation of H-BMSCs showed greater effect of suppressing microglia activity in the brain. Significantly more NeuN-positive and Glut1-positive cells were seen in the ischemic core and peri-infarct regions of the animals received H-BMSC transplantation than that received N-BMSCs. Some NeuN-positive and Glut-1-positive cells showed eGFP or BrdU immunoflourescent reactivity, suggesting differentiation from exogenous BMSCs into neuronal and vascular endothelial cells. In Rotarod test performed 15days after stroke, animals received H-BMSCs showed better locomotion recovery compared with stroke control and N-BMSC groups. We suggest that hypoxic preconditioning of transplanted cells is an effective means of promoting their regenerative capability and therapeutic potential for the treatment of ischemic stroke.

Plasticity of human menstrual blood stem cells derived from the endometrium

Stem cells can be obtained from women's menstrual blood derived from the endometrium. The cells display stem cell markers such as Oct-4, SSEA-4, Nanog, and c-kit (CD117), and have the potent ability to differentiate into various cell types, including the heart, nerve, bone, cartilage, and fat. There has been no evidence of teratoma, ectopic formation, or any immune response after transplantation into an animal model. These cells quickly regenerate after menstruation and secrete many growth factors to display recurrent angiogenesis. The plasticity and safety of the acquired cells have been demonstrated in many studies. Menstrual blood-derived stem cells (MenSCs) provide an alternative source of adult stem cells for research and application in regenerative medicine. Here we summarize the multipotent properties and the plasticities of MenSCs and other endometrial stem cells from recent studies conducted both in vitro and in vivo.

Comparison of canine umbilical cord blood-derived mesenchymal stem cell transplantation times: involvement of astrogliosis, inflammation, intracellular actin cytoskeleton pathways, and neurotrophin-3

Canine mesenchymal stem cells (cMSCs) derived from umbilical cord blood represent a potentially useful source of stem cells for therapy. The aim of this study was to compare the effects of different transplantation times of cMSCs after spinal cord injury (SCI). A total of 21 dogs were subjected to SCI by balloon-induced compression of the first lumbar vertebrae for 12 h. Of the 21 dogs, 12 were divided into four groups of three according to the time of stem cell (1 × 10(6)) transplantation at the injury site: control no treatment, 12 h, 1 week, and 2 weeks. The remaining 9 animals were negative harvest (HA) time controls for each treatment group (n = 3). Olby and Tarlov scores were used to evaluate functional recovery of the hindlimbs. Markers for neuronal regeneration (Tuj-1, nestin, MAP2, and NF-M), astrogliosis (GALC, GFAP, and pSTAT3), signal molecules for actin cytoskeleton (RhoA, Cdc42, and Rac1), inflammation (COX-2), and neurotrophins (NT-3) were evaluated by Western blot analysis. Scores of the 1-week transplantation group showed significant improvement compared to controls. Hematoxylin and eosin (H&E) staining revealed less fibrosis at the injury site in the 1-week transplantation group compared to other groups and immunohistochemistry showed increased expression of neuronal markers. Furthermore, in both 1-week and 2-week transplantation groups, Tuj-1, nestin, MAP2, NF-M, NT-3, and GFAP increased, but pSTAT3, GALC, and COX2 decreased. RhoA decreased and Rac1 and Cdc42 increased in the 1-week transplantation group. In conclusion, transplantation of cMSCs 1 week after SCI was more effective in improving clinical signs and neuronal regeneration and reducing fibrosis formation compared to the other transplantation times evaluated. Subsequently, these data may contribute to the optimization of timing for MSC transplantation used as a therapeutic modality.

Botanical Drugs and Stem Cells

The potential to generate virtually any differentiated cell type from stem cells offers the possibility of creating new sources of cells for regenerative medicine. To realize this potential, it will be essential to control stem cell differentiation. Chinese herbal medicine is a major aspect of traditional Chinese medicine and is a rich source of unique chemicals. As such, individual herbs or extracts may play a role in the proliferation and differentiation of stem cells. In this review, we discuss some of the Chinese herbal medicines that are used to treat human diseases such as neuronal degenerative diseases, cardiovascular diseases, and osteoporosis. We also describe the relationship between Chinese herbal medicines and stem cell regulation.

Treat the graft to improve the regenerative ability of the host

The staggering number of publications featuring the use of stem cells has revolutionized regenerative medicine research. Preclinical studies indicate that allogeneic human mesenchymal stem cells (MSCs) may be useful for the treatment of several clinical disorders, including sepsis, acute renal failure, acute myocardial infarction, and more recently, acute lung injury (ALI). However, considerable success would not be obtained in clinical trials due to poor survival of transplanted cells under the influence of inflammatory conditions. Despite robust approaches like cellular reprogramming, scaffolds and conditioned media have been tested to overcome this problem; however the success rate of these approaches remain questionable. Recently, pretreatment of bioactive compounds in vitro have been shown to suppress cell apoptosis and promote cell survival. Quite likely a similar phenomenon can take place in vivo. Based on such studies, we hypothesize that MSCs derived from human post-natal tissues could be conditioned and prepared for targeted disease therapy. Depending on the disease condition, the MSCs could be treated prior to delivery with appropriate bioactive compounds to allow them survive longer and perform a better role as biocatalyst. The advantage of this approach could be the tailor made availability of MSCs preconditioned with appropriate bioactive compounds for disease specific therapy. Therefore, the choice of suitable bioactive molecule is likely to enhance the efficacy of targeted stem cell therapy and preconditioning may provide a novel strategy in maximizing biological and functional properties of MSCs.

Experimental reconstruction of the injured spinal cord

Injury to the spinal cord, with its pathological sequelae, results in a permanent neurological deficit. With currently available tools at hand, there is very little that clinicians can do to treat such a condition with the view of helping patients with spinal cord injury (SCI). On the other hand, in the last 20 years experimental research has brought new insights into the pathophysiology of spinal cord injury; we can divide the time course into 3 phases: primary injury (the time of traumatic impact and the period immediately afterwards), the secondary phase (cell death, inflammation, ischemia), and the chronic phase (scarring, demyelination, cyst formation). Increased knowledge about the pathophysiology of SCI can stimulate the development of new therapeutic modalities and approaches, which may be feasible in the future in clinical practice. Some of the most promising experimental therapies include: neurotrophic factors, enzymes and antibodies against inhibitory molecules (such as Nogo), activated macrophages, stem cells and bridging scaffolds. Their common goal is to reconstitute the damaged tissue in order to recover the lost function. In the current review, we focus on some of the recent developments in experimental SCI research.

Suspension matrices for improved Schwann-cell survival after implantation into the injured rat spinal cord

Trauma to the spinal cord produces endogenously irreversible tissue and functional loss, requiring the application of therapeutic approaches to achieve meaningful restoration. Cellular strategies, in particular Schwann-cell implantation, have shown promise in overcoming many of the obstacles facing successful repair of the injured spinal cord. Here, we show that the implantation of Schwann cells as cell suspensions with in-situ gelling laminin:collagen matrices after spinal-cord contusion significantly enhances long-term cell survival but not proliferation, as well as improves graft vascularization and the degree of axonal in-growth over the standard implantation vehicle, minimal media. The use of a matrix to suspend cells prior to implantation should be an important consideration for achieving improved survival and effectiveness of cellular therapies for future clinical application.