Human umbilical cord blood stem cells and brainderived neurotrophic factor for optic nerve injury: a biomechanical evaluation

Treatment for optic nerve injury by brain-derived neurotrophic factor or the transplantation of human umbilical cord blood stem cells has gained progress, but analysis by biomechanical indicators is rare. Rabbit models of optic nerve injury were established by a clamp. At 7 days after injury, the vitreous body received a one-time injection of 50 μg brain-derived neurotrophic factor or 1 × 10^6 human umbilical cord blood stem cells. After 30 days, the maximum load, maximum stress, maximum strain, elastic limit load, elastic limit stress, and elastic limit strain had clearly improved in rabbit models of optical nerve injury after treatment with brain-derived neurotrophic factor or human umbilical cord blood stem cells. The damage to the ultrastructure of the optic nerve had also been reduced. These findings suggest that human umbilical cord blood stem cells and brain-derived neurotrophic factor effectively repair the injured optical nerve, improve biomechanical properties, and contribute to the recovery after injury.

Substance P combined with epidermal stem cells promotes wound healing and nerve regeneration in diabetes mellitus

Exogenous substance P accelerates wound healing in diabetes,but the mechanism remains poorly understood.Here,we established a rat model by intraperitoneally injecting streptozotocin.Four wounds（1.8 cm diameter） were drilled using a self-made punch onto the back,bilateral to the vertebral column,and then treated using amniotic membrane with epidermal stem cells and/or substance P around and in the middle of the wounds.With the combined treatment the wound-healing rate was 100% at 14 days.With prolonged time,type I collagen content gradually increased,yet type III collagen content gradually diminished.Abundant protein gene product 9.5-and substance P-immunoreactive nerve fibers regenerated.Partial nerve fiber endings extended to the epidermis.The therapeutic effects of combined substance P and epidermal stem cells were better than with amniotic membrane and either factor alone.Our results suggest that the combination of substance P and epidermal stem cells effectively contributes to nerve regeneration and wound healing in diabetic rats.

Nerve growth factor promotes in vitro proliferation of neural stem cells from tree shrews

Neural stem cells promote neuronal regeneration and repair of brain tissue after injury,but have limited resources and proliferative ability in vivo.We hypothesized that nerve growth factor would promote in vitro proliferation of neural stem cells derived from the tree shrews,a primate-like mammal that has been proposed as an alternative to primates in biomedical translational research.We cultured neural stem cells from the hippocampus of tree shrews at embryonic day 38,and added nerve growth factor（100 μg/L） to the culture medium.Neural stem cells from the hippocampus of tree shrews cultured without nerve growth factor were used as controls.After 3 days,fluorescence microscopy after DAPI and nestin staining revealed that the number of neurospheres and DAPI/nestin-positive cells was markedly greater in the nerve growth factor-treated cells than in control cells.These findings demonstrate that nerve growth factor promotes the proliferation of neural stem cells derived from tree shrews.

Human umbilical cord blood-derived stem cells and brain-derived neurotrophic factor protect injured optic nerve:viscoelasticity characterization

The optic nerve is a viscoelastic solid-like biomaterial.Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury.We hypothesized that stress relaxation and creep properties of the optic nerve change after injury.Moreover,human brain-derived neurotrophic factor or umbilical cord blood-derived stem cells may restore these changes to normal.To validate this hypothesis,a rabbit model of optic nerve injury was established using a clamp approach.At 7 days after injury,the vitreous body received a one-time injection of 50 μg human brain-derived neurotrophic factor or 1 × 106 human umbilical cord blood-derived stem cells.At 30 days after injury,stress relaxation and creep properties of the optic nerve that received treatment had recovered greatly,with pathological changes in the injured optic nerve also noticeably improved.These results suggest that human brain-derived neurotrophic factor or umbilical cord blood-derived stem cell intervention promotes viscoelasticity recovery of injured optic nerves,and thereby contributes to nerve recovery.

Combined use of Y-tube conduits with human umbilical cord stem cells for repairing nerve bifurcation defects

Given the anatomic complexity at the bifurcation point of a nerve trunk,enforced suturing between stumps can lead to misdirection of nerve axons,thereby resulting in adverse consequences.We assumed that Y-tube conduits injected with human umbilical cord stem cells could be an effective method to solve such problems,but studies focused on the best type of Y-tube conduit remain controversial.Therefore,the present study evaluated the applicability and efficacy of various types of Y-tube conduits containing human umbilical cord stem cells for treating rat femoral nerve defects on their bifurcation points.At 12 weeks after the bridging surgery that included treatment with different types of Y-tube conduits,there were no differences in quadriceps femoris muscle weight or femoral nerve ultrastructure.However,the Y-tube conduit group with longer branches and a short trunk resulted in a better outcome according to retrograde labeling and electrophysiological analysis.It can be concluded from the study that repairing a mixed nerve defect at its bifurcation point with Y-tube conduits,in particular those with long branches and a short trunk,is effective and results in good outcomes.

Fasudil hydrochloride differentiates bone marrow mesenchymal stem cells into neurons via notch signaling

BACKGROUND： Notch signaling regulates bone marrow mesenchymal stem cell （MSC） proliferation, differentiation, and apoptosis, Notch signaling and Rho kinase signaling exhibit a crosstalk phenomenon with JAK/STAT, and both participate in the neuronal dendritic spine development. Inhibition of RhoA/Rho kinase signaling may regulate MSC differentiation into neuronal-like cells. OBJECTIVE： To investigate the effect of Notch1 signaling on the differentiation of rat MSCs into neurons induced by fasudil hydrochloride （C14H17N3O2S-HCI）, a Rho kinase inhibitor, through a siRNA approach. DESIGN, TIME AND SETTING： An in vitro cytological experiment was performed in the Cell Laboratory of Henan Academy of Medical and Pharmaceutical Sciences between December 2007 and May 2009. MATERIALS： MSCs were obtained from Wistar rat femoral bone, fasudil hydrochloride was provided by -Tianjin Chase Sun Pharmaceutical Co., Ltd. Rn-notchl-siRNa, negative control siRNA （Cy3 label） and Rn-MAPK1 control siRNA were provided by QIAGEN, Coloqne, German. METHODS： The cultured MSCs were divided into non-transfected, transfected group （transfected with Rn-Notchl-siRNA）, positive control （transfected with Rn-MAPK-1 control siRNA）, and negative control （transfected with negative control siRNA） groups. Fasudil hydrochloride was applied to induce MSCs to differentiate into neurons. MAIN OUTCOME MEASURES： The fluorescence expression by the transfected MSCs was observed under an inverted fluorescence microscope; the expression of Notch1 mRNA, Hesl mRNA, and MAPK1 mRNA in MSCs was detected by reverse transcription polymerase chain reaction; the expression of Notch1 protein, nestin, neurofilament M, and glial fibrillary acidic protein was detected by immunocytochemistry. The viability of MSCs was detected by tetrazolium bromide assay. RESULTS： MSC fluorescence increased following a 72-hour siRNA transfection, with transfection efficiencies of up to （0.91 ± 0.04）; the Notch1 mRNA and Hesl mRNA expressed by transfected MSCs was significantly decreased （P 〈 0.05） compared with non-transfected cells. Fasudil hydrochloride induced MSCs to differentiate into neurons with greater efficiency in the transfected group （P 〈 0.05）. CONCLUSION： Fasudil hydrochloride induces rat MSCs to differentiate into neurons; inhibition of Notch1 signaling and Hesl expression may jointly promote the differentiation of MSCs into neurons.

Stem cells:a promising candidate to treat neurological disorders

Neurologic impairments are usually irreversible as a result of limited regeneration in the central nervous system.Therefore,based on the regenerative capacity of stem cells,transplantation therapies of various stem cells have been tested in basic research and preclinical trials,and some have shown great prospects.This manuscript overviews the cellular and molecular characteristics of embryonic stem cells,induced pluripotent stem cells,neural stem cells,retinal stem/progenitor cells,mesenchymal stem/stromal cells,and their derivatives in vivo and in vitro as sources for regenerative therapy.These cells have all been considered as candidates to treat several major neurological disorders and diseases,owing to their self-renewal capacity,multi-directional differentiation,neurotrophic properties,and immune modulation effects.We also review representative basic research and recent clinical trials using stem cells for neurodegenerative diseases,including Parkinson＇s disease,Alzheimer＇s disease,and age-related macular degeneration,as well as traumatic brain injury and glioblastoma.In spite of a few unsuccessful cases,risks of tumorigenicity,and ethical concerns,most results of animal experiments and clinical trials demonstrate efficacious therapeutic effects of stem cells in the treatment of nervous system disease.In summary,these emerging findings in regenerative medicine are likely to contribute to breakthroughs in the treatment of neurological disorders.Thus,stem cells are a promising candidate for the treatment of nervous system diseases.

Bone marrow mesenchymal stem cells transplantation promotes the release of endogenous erythropoietin after ischemic stroke

This study investigated whether bone marrow mesenchymal stem cell（BMSC） transplantation protected ischemic cerebral injury by stimulating endogenous erythropoietin. The model of ischemic stroke was established in rats through transient middle cerebral artery occlusion. Twenty-four hours later, 1 × 106 human BMSCs（h BMSCs） were injected into the tail vein. Fourteen days later, we found that h BMSCs promoted the release of endogenous erythropoietin in the ischemic region of rats. Simultaneously, 3 μg/d soluble erythropoietin receptor（s EPOR） was injected into the lateral ventricle, and on the next 13 consecutive days. s EPOR blocked the release of endogenous erythropoietin. The neurogenesis in the subventricular zone was less in the h BMSCs ＋ s EPOR group than in the h BMSCs ＋ heat-denatured s EPOR group. The adhesive-removal test result and the modified Neurological Severity Scores（m NSS） were lower in the h BMSCs ＋ s EPOR group than in the heat-denatured s EPOR group. The adhesive-removal test result and m NSS were similar between the h BMSCs ＋ heat-denatured s EPOR group and the h BMSCs ＋ s EPOR group. These findings confirm that BMSCs contribute to neurogenesis and improve neurological function by promoting the release of endogenous erythropoietin following ischemic stroke.

Denervated hippocampus provides a favorable microenvironment for neuronal differentiation of endogenous neural stem cells

Fimbria-fornix transection induces both exogenous and endogenous neural stem cells to differentiate into neurons in the hippocampus.This indicates that the denervated hippocampus provides an environment for neuronal differentiation of neural stem cells.However,the pathways and mechanisms in this process are still unclear.Seven days after fimbria fornix transection,our reverse transcription polymerase chain reaction,western blot assay,and enzyme linked immunosorbent assay results show a significant increase in ciliary neurotrophic factor m RNA and protein expression in the denervated hippocampus.Moreover,neural stem cells derived from hippocampi of fetal（embryonic day 17） Sprague-Dawley rats were treated with ciliary neurotrophic factor for 7 days,with an increased number of microtubule associated protein-2-positive cells and decreased number of glial fibrillary acidic protein-positive cells detected.Our results show that ciliary neurotrophic factor expression is up-regulated in the denervated hippocampus,which may promote neuronal differentiation of neural stem cells in the denervated hippocampus.

Correlation between receptor-interacting protein 140 expression and directed differentiation of human embryonic stem cells into neural stem cells

Overexpression of receptor-interacting protein 140（RIP140） promotes neuronal differentiation of N2 a cells via extracellular regulated kinase 1/2（ERK1/2） signaling.However,involvement of RIP140 in human neural differentiation remains unclear.We found both RIP140 and ERK1/2 expression increased during neural differentiation of H1 human embryonic stem cells.Moreover,RIP140 negatively correlated with stem cell markers Oct4 and Sox2 during early stages of neural differentiation,and positively correlated with the neural stem cell marker Nestin during later stages.Thus,ERK1/2 signaling may provide the molecular mechanism by which RIP140 takes part in neural differentiation to eventually affect the number of neurons produced.

Stem cell transplantation for repair of sciatic nerve injury

Three articles regarding transplantation of umbilical cord mesenchmal stem cells alone or in combination with Schwann cells and feridex and polylysine complex-labeled bone marrow stromal cell transplantation （MRI tracing） for repair of sciatic nerve injury were reported in Neural Regeneration

Editor's Choice--Umbilical cord mesenchymal stem cell transplantation for the treatment of peripheral nerve injury

Schwann cells are the predominant seed cells for cell transplantation in the treatment of peripheral nerve injury. However, the source of Schwann cells is limited and amplification remains difficult. Studies have shown that mesenchymal stem cells, an alternative cell type, can be used for transplantation treatment of peripheral nerve defects. Umbilical cord mesenchymal stem cells are pluripotent stem cells derived from newborn umbilical cord tissues.

Differentiation of Wharton's jelly mesenchymal stem cells into neurons in alginate scaffold

Alginate scaffold has been considered as an appropriate biomaterial for promoting the differentiation of embryonic stem cells toward neuronal cell lineage. We hypothesized that alginate scaffold is suitable for culturing Wharton’s jelly mesenchymal stem cells（WJMSCs） and can promote the differentiation of WJMSCs into neuron-like cells. In this study, we cultured WJMSCs in a three-dimensional scaffold fabricated by 0.25% alginate and 50 m M Ca Cl2 in the presence of neurogenic medium containing 10 μM retinoic acid and 20 ng/m L basic fibroblast growth factor. These cells were also cultured in conventional two-dimensional culture condition in the presence of neurogenic medium as controls. After 10 days, immunofluorescence staining was performed for detecting β-tubulin（marker for WJMSCs-differentiated neuron） and CD271（motor neuron marker）. β-Tubulin and CD271 expression levels were significantly greater in the WJMSCs cultured in the three-dimensional alginate scaffold than in the conventional two-dimensional culture condition. These findings suggest that three-dimensional alginate scaffold cell culture system can induce neuronal differentiation of WJMSCs effectively.

Umbilical cord-derived mesenchymal stem cell transplantation combined with hyperbaric oxygen treatment for repair of traumatic brain injury

Transplantation of umbilical cord-derived mesenchymal stem cells（UC-MSCs） for repair of traumatic brain injury has been used in the clinic. Hyperbaric oxygen（HBO） treatment has long been widely used as an adjunctive therapy for treating traumatic brain injury. UC-MSC transplantation combined with HBO treatment is expected to yield better therapeutic effects on traumatic brain injury. In this study, we established rat models of severe traumatic brain injury by pressurized fluid（2.5–3.0 atm impact force）. The injured rats were then administered UC-MSC transplantation via the tail vein in combination with HBO treatment. Compared with monotherapy, aquaporin 4 expression decreased in the injured rat brain, but growth-associated protein-43 expression, calaxon-like structures, and CM-Dil-positive cell number increased. Following combination therapy, however, rat cognitive and neurological function significantly improved. UC-MSC transplantation combined with HBO therapyfor repair of traumatic brain injury shows better therapeutic effects than monotherapy and significantly promotes recovery of neurological functions.

Propofol promotes spinal cord injury repair by bone marrow mesenchymal stem cell transplantation

Propofol is a neuroprotective anesthetic. Whether propofol can promote spinal cord injury repair by bone marrow mesenchymal stem cells remains poorly understood. We used rats to investigate spinal cord injury repair using bone marrow mesenchymal stem cell transplantation combined with propofol administration via the tail vein. Rat spinal cord injury was clearly alleviated; a large number of newborn non-myelinated and myelinated nerve fibers appeared in the spinal cord, the numbers of CM-Dil-labeled bone marrow mesenchymal stem cells and fluorogold-labeled nerve fibers were increased and hindlimb motor function of spinal cord-injured rats was markedly improved. These improvements were more prominent in rats subjected to bone marrow mesenchymal cell transplantation combined with propofol administration than in rats receiving monotherapy. These results indicate that propofol can enhance the therapeutic effects of bone marrow mesenchymal stem cell transplantation on spinal cord injury in rats.

Neural differentiation of choroid plexus epithelial cells:role of human traumatic cerebrospinal fluid

As the key producer of cerebrospinal fluid（CSF）,the choroid plexus（CP） provides a unique protective system in the central nervous system.CSF components are not invariable and they can change based on the pathological conditions of the central nervous system.The purpose of the present study was to assess the effects of non-traumatic and traumatic CSF on the differentiation of multipotent stem-like cells of CP into the neural and/or glial cells.CP epithelial cells were isolated from adult male rats and treated with human non-traumatic and traumatic CSF.Alterations in m RNA expression of Nestin and microtubule-associated protein（MAP2）,as the specific markers of neurogenesis,and astrocyte marker glial fibrillary acidic protein（GFAP） in cultured CP epithelial cells were evaluated using quantitative real-time PCR.The data revealed that treatment with CSF（non-traumatic and traumatic） led to increase in m RNA expression levels of MAP2 and GFAP.Moreover,the expression of Nestin decreased in CP epithelial cells treated with non-traumatic CSF,while treatment with traumatic CSF significantly increased its m RNA level compared to the cells cultured only in DMEM/F12 as control.It seems that CP epithelial cells contain multipotent stem-like cells which are inducible under pathological conditions including exposure to traumatic CSF because of its compositions.

Nanotechnology and bio-functionalisation for peripheral nerve regeneration

There is a high clinical demand for new smart biomaterials, which stimulate neuronal cell proliferation, migration and increase cell-material interaction to facilitate nerve regeneration across these critical-sized defects. This article briefly reviews several up-to-date published studies using Arginine-Glycine-Aspartic acid peptide sequence, nanocomposite based on polyhedral oligomeric silsesquioxane nanoparticle and nanofibrous scaffolds as promising strategies to enhance peripheral nerve regeneration by influencing cellular behaviour such as attachment, spreading and proliferation. The aim is to establish the potent manipulations, which are simple and easy to employ in the clinical conditions for nerve regeneration and repair.

Human umbilical cord Wharton's Jelly-derived mesenchymal stem cells differentiation into nerve-like cells

Background The two most basic properties of mesenchymal stem cells （MSCs） are the capacities to selfrenew indefinitely and differentiate into multiple cells and tissue types. The cells from human umbilical cord Wharton＇ s Jelly have properties of MSCs and represent a rich source of primitive cells. This study was conducted to explore the possibility of inducing human umbilical cord Wharton＇ s Jelly-derived MSCs to differentiate into nerve-like cells.Methods MSCs were cultured from the Wharton＇ s Jelly taken from human umbilical cord of babies delivered after full-term normal labor. Salvia miltiorrhiza and [3-mercaptoethanol were used to induce the human umbilical cord-derived MSCs to differentiate The expression of neural protein markers was shown by immunocytochemistry. The induction process was monitored by phase contrast microscopy, electron microscopy （EM）, and laser scanning confocal microscopy （LSCM） . The pleiotrophin and nestin genes were measured by reverse transcription-polymerase chain reaction （RT-PCR）.Results MSCs in the Wharton＇ s Jelly were easily attainable and could be maintained and expanded in culture. They were positive for markers of MSCs, but negative for markers of hematopoietic cells and graft-versus-host disease （GVHD）-related cells. Treatment with Salvia mihiorrhiza caused Wharton＇ s Jelly cells to undergo profound morphological changes. The induced MSCs developed rounded cell bodies with multiple neurite-like extensions. Eventually they developed processes that formed networks reminiscent of primary cultures of neurons. Salvia mihiorrhiza and β-mercaptoethanol also induced MSCs to express nestin, β-tubulin Ⅲ, neurofilament （NF） and glial fibrillary acidic protein （GFAP）. It was confirmed by RT-PCR that MSCs could express pleiotrophin both before and after induction by Salvia miltiorrhiza. The expression was markedly enhanced after induction and the nestin gene was also expressed.Conclusions MSCs could be isolated from human umbilical cord Wharton＇ s Jelly. They were capable ofdifferentiating into nerve-like cells using Salvia miltiorrhiza or 15-mercaptoethanol. The induced MSCs not only underwent morphologic changes, but also expressed the neuron-related genes and neuronal cell markers. They may represent an alternative source of stem cells for central nervous system cell transplantation.