Hypoxia-preconditioned bone marrow-derived mesenchymal stem cells protect neurons from cardiac arrest-induced pyroptosis

Cardiac arrest can lead to severe neurological impairment as a result of inflammation,mitochondrial dysfunction,and post-cardiopulmonary resuscitation neurological damage.Hypoxic preconditioning has been shown to improve migration and survival of bone marrow–derived mesenchymal stem cells and reduce pyroptosis after cardiac arrest,but the specific mechanisms by which hypoxia-preconditioned bone marrow–derived mesenchymal stem cells protect against brain injury after cardiac arrest are unknown.To this end,we established an in vitro co-culture model of bone marrow–derived mesenchymal stem cells and oxygen–glucose deprived primary neurons and found that hypoxic preconditioning enhanced the protective effect of bone marrow stromal stem cells against neuronal pyroptosis,possibly through inhibition of the MAPK and nuclear factor κB pathways.Subsequently,we transplanted hypoxia-preconditioned bone marrow–derived mesenchymal stem cells into the lateral ventricle after the return of spontaneous circulation in an 8-minute cardiac arrest rat model induced by asphyxia.The results showed that hypoxia-preconditioned bone marrow–derived mesenchymal stem cells significantly reduced cardiac arrest–induced neuronal pyroptosis,oxidative stress,and mitochondrial damage,whereas knockdown of the liver isoform of phosphofructokinase in bone marrow–derived mesenchymal stem cells inhibited these effects.To conclude,hypoxia-preconditioned bone marrow–derived mesenchymal stem cells offer a promising therapeutic approach for neuronal injury following cardiac arrest,and their beneficial effects are potentially associated with increased expression of the liver isoform of phosphofructokinase following hypoxic preconditioning.

Microvesicles derived from mesenchymal stem cells: A promising therapeutic strategy for acute respiratory distress syndrome-related pulmonary fibrosis?

Pulmonary fibrosis significantly contributes to the pathogenesis of acute respiratory distress syndrome(ARDS),markedly increasing patient mortality.Despite the established anti-fibrotic effects of mesenchymal stem cells(MSCs),numerous challenges hinder their clinical application.A recent study demon-strated that microvesicles(MVs)from MSCs(MSC-MVs)could attenuate ARDS-related pulmonary fibrosis and enhance lung function via hepatocyte growth factor mRNA transcription.This discovery presents a promising strategy for managing ARDS-associated pulmonary fibrosis.This article initially examines the safety and efficacy of MSCs from both basic science and clinical perspectives,subsequently exploring the potential and obstacles of employing MSC-MVs as a novel therapeutic approach.Additionally,it provides perspectives on future research into the application of MSC-MVs in ARDS-associated pulmonary fi-brosis.

Microvesicles derived from mesenchymal stem cells inhibit acute respiratory distress syndrome-related pulmonary fibrosis in mouse partly through hepatocyte growth factor

BACKGROUND Pulmonary fibrosis is one of the main reasons for the high mortality rate among acute respiratory distress syndrome(ARDS)patients.Mesenchymal stromal cell-derived microvesicles(MSC-MVs)have been shown to exert antifibrotic effects in lung diseases.AIM To investigate the effects and mechanisms of MSC-MVs on pulmonary fibrosis in ARDS mouse models.METHODS MSC-MVs with low hepatocyte growth factor(HGF)expression(siHGF-MSC-MVs)were obtained via lentivirus transfection and used to establish the ARDS pulmonary fibrosis mouse model.Following intubation,respiratory mechanics-related indicators were measured via an experimental small animal lung function tester.Homing of MSC-MVs in lung tissues was investigated by near-infrared live imaging.Immunohistochemical,western blotting,ELISA and other methods were used to detect expression of pulmonary fibrosis-related proteins and to compare effects on pulmonary fibrosis and fibrosis-related indicators.RESULTS The MSC-MVs gradually migrated and homed to damaged lung tissues in the ARDS model mice.Treatment with MSC-MVs significantly reduced lung injury and pulmonary fibrosis scores.However,low expression of HGF(siHGF-MSC-MVs)significantly inhibited the effects of MSC-MVs(P<0.05).Compared with the ARDS pulmonary fibrosis group,the MSC-MVs group exhibited suppressed expression of type I collagen antigen,type III collagen antigen,and the proteins transforming growth factor-βandα-smooth muscle actin,whereas the siHGF-MVs group exhibited significantly increased expression of these proteins.In addition,pulmonary compliance and the pressure of oxygen/oxygen inhalation ratio were significantly lower in the MSC-MVs group,and the effects of the MSC-MVs were significantly inhibited by low HGF expression(all P<0.05).CONCLUSION MSC-MVs improved lung ventilation functions and inhibited pulmonary fibrosis in ARDS mice partly via HGF mRNA transfer.

Mesenchymal stem cells derived from human placenta suppress allogeneic umbilical cord blood lymphocyte proliferation

Human placenta-derived mononuclear cells （MNC） were isolated by a Percoll density gradient and cultured in mesenchymal stem cell （MSC） maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblastlike morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitro differentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic and chondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was a homogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105, CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and m-smooth muscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class Ⅰ major histocompatibility complex （MHC-I）, but they did not express MHC-Ⅱ molecules. Additionally these cells could suppress umbilical cord blood （UCB） lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. This strongly implies that they may have potential application in allograft transplantation. Since placenta and UCB are homogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells （HSC） from UCB to reduce the potential graft-versus-host disease （GVHD） in recipients.

Evaluating Wharton’s jelly-derived stem cell therapy in autism:Insights from a case study

Autism spectrum disorder(ASD)is a complex neurodevelopmental disorder affecting over 2%of the global population,marked by social communication deficits and repetitive behaviors.Kabatas et al explored the efficacy and safety of Wharton’s jelly-derived mesenchymal stem cell(WJ-MSC)therapy in a 4-year-old child with ASD.Using the childhood autism rating scale and Denver II develop-mental screening test,significant improvements were seen after six WJ-MSC sessions,with no adverse events over 2 years.Despite promising results,the study’s single-case design limits generalizability.Larger,multi-center trials are needed to validate the findings and assess long-term effects of WJ-MSC therapy in ASD.

Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.

Transplantation of mesenchymal stem cells from human umbilical cord versus human umbilical cord blood for peripheral nerve regeneration

BACKGROUND： Mesenchymal stem cells （MSCs） appear to be a good alternative to Schwann cells in the treatment of peripheral nerve injury. Fetal stem cells, like umbilical cord blood （UCB） and umbilical cord （UC） stem cells, have several advantages over adult stem cells. OBJECTIVE： To assess the effects of UC-derived MSCs （UCMSCs） and UCB-derived MSCs （UCBMSCs） in repair of sciatic nerve defects. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was performed at the laboratory of Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from July to December 2009. MATERIALS： UCMSCs were provided by the Research Institute of Biotechnology, Dongguk University. UCBMSCs were provided by the Laboratory of Stem Cells and Tumor Biology, College of Veterinary Medicine, Seoul National University. Dulbecco＇s modified Eagle＇s medium （DMEM） was purchased from Gibco-BRL, USA. METHODS： Seven-week-old Sprague-Dawley rats were randomly and evenly divided into three groups： DMEM, UCBMSCs, and UCMSCs. A 10-mm defect in the left sciatic nerve was constructed in all rats. DMEM （15 μL） containing 1×10^6 UCBMSCs or UCMSCs was injected into the gap between nerve stumps, with the surrounding epineurium as a natural conduit. For the DMEM group, simple DMEM was injected. MAIN OUTCOME MEASURES： At 7 weeks after sciatic nerve dissection, dorsal root ganglia neurons were labeled by fluorogold retrograde labeling. At 8 weeks, electrophysiology and histomorphometry were performed. At 2, 4, 6, and 8 weeks after surgery, sciatic nerve function was evaluated using gait analysis. RESULTS： The UCBMSCs group and the UCMSCs group exhibited similar sciatic nerve function and electrophysiological indices, which were better than the DMEM group, as measured by gait analysis （P 〈 0.05）. Fluorogold retrograde labeling of sciatic nerve revealed that the UCBMSCs group demonstrated a higher number of labeled neurons; however, the differences were not significant. Histomorphometric indices were similar in the UCBMSCs and UCMSCs groups, and total axon counts, particularly axon density （P 〈 0.05）, were significantly greater in the UCBMSCs and UCMSCs groups than in the DMEM group. CONCLUSION： Transplanting either UCBMSCs or UCMSCs into axotomized sciatic nerves could accelerate and promote sciatic nerve regeneration over 8 weeks. Both treatments had similar effects on nerve regeneration.

Differentiation and tumorigenicity of neural stem cells from human cord blood mesenchymal stem cells

BACKGROUND： Mesenchymal stem cells （MSCs） are capable of differentiating into a variety of tissues and exhibit low immunogenicity. OBJECTIVE： To investigate isolation and in vitro cultivation methods of human cord blood MSCs, to observe expression of neural stem cell （NSC） marker mRNA under induction, and to detect tumorigenicity in animals. DESIGN, TIME AND SETTING： A cell biological, in vitro trial and a randomized, controlled, in vivo experiment were performed at the Department of Neurology, Daping Hospital at the Third Military Medical University of Chinese PLA from August 2006 to May 2008. MATERIALS： Umbilical cord blood was collected from full-term-delivery fetus at the Department of Gynecology and Obstetrics of Daping Hospital, China. Eighteen BALB/C nu/nu nude mice were randomly assigned to three groups： back subcutaneous, cervical subcutaneous, and control, with 6 mice in each group. METHODS： Monocytes were isolated from heparinized human cord blood samples by density gradient centrifugation and then adherent cultivated in vitro to obtain MSC clones. After the cord blood MSCs were cultured for 7 days with nerve growth factor and retinoic acid to induce differentiation into NSCs, the cells （adjusted density of 1 × 10^7/mL） were prepared into cell suspension. In the back subcutaneous and cervical subcutaneous groups, nude mice were hypodermically injected with a 0.5-mL cell suspension into the back and cervical regions, respectively. In the control group, nude mice received a subcutaneous injection of 0.5 mL physiological saline into the back or cervical regions, respectively. MAIN OUTCOME MEASURES： Cellular morphology was observed by inverted microscopy, cultured cord blood MSCs were examined by flow cytometry, expression of nestin and musashi-1 mRNA was detected by reverse-transcriptase polymerase chain reaction prior to and after induction, and tumorigenicity following cord blood MSC transplantation was assayed by hematoxylin-eosin staining. RESULTS： Following adherent cultivation, the majority of cord blood monocytes became rhombic and strongly expressed CD29, but not CD34, CD1 la, or CD11 b. These results supported previously known characteristics of cord blood MSCs. Following differentiation induction, nestin and musashi-1 were expressed on the surface of NSCs, exhibiting strongest expression at 48 hours, and subsequently reducing expression. Cultured cord blood MSCs were not tumorigenic in the nude mice. Cellular morphology displayed no malignant changes between the control and subcutaneous groups. CONCLUSION： MSCs can be isolated from human cord blood, efficiently expanded under culture conditions, differentiated into NSCs following induction, and display no tumorigenicity in nude mice.

Prospects for the therapeutic development of umbilical cord bloodderived mesenchymal stem cells

Umbilical cord blood(UCB)is a primitive and abundant source of mesenchymal stem cells(MSCs).UCB-derived MSCs have a broad and efficient therapeutic capacity to treat various diseases and disorders.Despite the high latent selfrenewal and differentiation capacity of these cells,the safety,efficacy,and yield of MSCs expanded for ex vivo clinical applications remains a concern.However,immunomodulatory effects have emerged in various disease models,exhibiting specific mechanisms of action,such as cell migration and homing,angiogenesis,anti-apoptosis,proliferation,anti-cancer,anti-fibrosis,anti-inflammation and tissue regeneration.Herein,we review the current literature pertaining to the UCB-derived MSC application as potential treatment strategies,and discuss the concerns regarding the safety and mass production issues in future applications.

Methods to produce induced pluripotent stem cell-derived mesenchymal stem cells: Mesenchymal stem cells from induced pluripotent stem cells

Mesenchymal stem cells(MSCs)have received significant attention in recent years due to their large potential for cell therapy.Indeed,they secrete a wide variety of immunomodulatory factors of interest for the treatment of immune-related disorders and inflammatory diseases.MSCs can be extracted from multiple tissues of the human body.However,several factors may restrict their use for clinical applications:the requirement of invasive procedures for their isolation,their limited numbers,and their heterogeneity according to the tissue of origin or donor.In addition,MSCs often present early signs of replicative senescence limiting their expansion in vitro,and their therapeutic capacity in vivo.Due to the clinical potential of MSCs,a considerable number of methods to differentiate induced pluripotent stem cells(iPSCs)into MSCs have emerged.iPSCs represent a new reliable,unlimited source to generate MSCs(MSCs derived from iPSC,iMSCs)from homogeneous and well-characterized cell lines,which would relieve many of the above mentioned technical and biological limitations.Additionally,the use of iPSCs prevents some of the ethical concerns surrounding the use of human embryonic stem cells.In this review,we analyze the main current protocols used to differentiate human iPSCs into MSCs,which we classify into five different categories:MSC Switch,Embryoid Body Formation,Specific Differentiation,Pathway Inhibitor,and Platelet Lysate.We also evaluate common and method-specific culture components and provide a list of positive and negative markers for MSC characterization.Further guidance on material requirements to produce iMSCs with these methods and on the phenotypic features of the iMSCs obtained is added.The information may help researchers identify protocol options to design and/or refine standardized procedures for large-scale production of iMSCs fitting clinical demands.

Therapeutic effects of menstrual blood-derived endometrial stem cells on mouse models of streptozotocin-induced type 1 diabetes

BACKGROUND Type 1 diabetes(T1D),a chronic metabolic and autoimmune disease,seriously endangers human health.In recent years,mesenchymal stem cell(MSC)transplantation has become an effective treatment for diabetes.Menstrual bloodderived endometrial stem cells(MenSC),a novel MSC type derived from the decidual endometrium during menstruation,are expected to become promising seeding cells for diabetes treatment because of their noninvasive collection procedure,high proliferation rate and high immunomodulation capacity.AIM To comprehensively compare the effects of MenSC and umbilical cord-derived MSC(UcMSC)transplantation on T1D treatment,to further explore the potential mechanism of MSC-based therapies in T1D,and to provide support for the clinical application of MSC in diabetes treatment.METHODS A conventional streptozotocin-induced T1D mouse model was established,and the effects of MenSC and UcMSC transplantation on their blood glucose and serum insulin levels were detected.The morphological and functional changes in the pancreas,liver,kidney,and spleen were analyzed by routine histological and immunohistochemical examinations.Changes in the serum cytokine levels in the model mice were assessed by protein arrays.The expression of target proteins related to pancreatic regeneration and apoptosis was examined by western blot.RESULTS MenSC and UcMSC transplantation significantly improved the blood glucose and serum insulin levels in T1D model mice.Immunofluorescence analysis revealed that the numbers of insulin+and CD31+cells in the pancreas were significantly increased in MSC-treated mice compared with control mice.Subsequent western blot analysis also showed that vascular endothelial growth factor(VEGF),Bcl2,Bcl-xL and Proliferating cell nuclear antigen in pancreatic tissue was significantly upregulated in MSC-treated mice compared with control mice.Additionally,protein arrays indicated that MenSC and UcMSC transplantation significantly downregulated the serum levels of interferonγand tumor necrosis factorαand upregulated the serum levels of interleukin-6 and VEGF in the model mice.Additionally,histological and immunohistochemical analyses revealed that MSC transplantation systematically improved the morphologies and functions of the liver,kidney,and spleen in T1D model mice.CONCLUSION MenSC transplantation significantly improves the symptoms in T1D model mice and exerts protective effects on their main organs.Moreover,MSC-mediated angiogenesis,antiapoptotic effects and immunomodulation likely contribute to the above improvements.Thus,MenSC are expected to become promising seeding cells for clinical diabetes treatment due to their advantages mentioned above.

Human umbilical cord blood-derived mesenchymal stem cells promote regeneration of crush-injured rat sciatic nerves

Several studies have demonstrated that human umbilical cord blood-derived mesenchymal stem cells can promote neural regeneration following brain injury. However, the therapeutic effects of human umbilical cord blood-derived mesenchymal stem cells in guiding peripheral nerve regeneration remain poorly understood. This study was designed to investigate the effects of human umbilical cord blood-derived mesenchymal stem cells on neural regeneration using a rat sciatic nerve crush injury model. Human umbilical cord blood-derived mesenchymal stem cells （1 ~ 106） or a PBS control were injected into the crush-injured segment of the sciatic nerve. Four weeks after cell injection, brain-derived neurotrophic factor and tyrosine kinase receptor B mRNA expression at the lesion site was increased in comparison to control. Furthermore, sciatic function index, Fluoro Gold-labeled neuron counts and axon density were also significantly increased when compared with control. Our results indicate that human umbilical cord blood-derived mesenchvmal stem cells promote the functinnal r~.RcJv^rv nf P.n I^h-inillr^4 ~r^i~tit, n^r~e

Similarities and differences between mesenchymal stem/progenitor cells derived from various human tissues

BACKGROUND Mesenchymal stromal/stem cells (MSCs) constitute a promising tool in regenerative medicine and can be isolated from different human tissues. However, their biological properties are still not fully characterized. Whereas MSCs from different tissue exhibit many common characteristics, their biological activity and some markers are different and depend on their tissue of origin. Understanding the factors that underlie MSC biology should constitute important points for consideration for researchers interested in clinical MSC application. AIM To characterize the biological activity of MSCs during longterm culture isolated from: bone marrow (BM-MSCs), adipose tissue (AT-MSCs), skeletal muscles (SMMSCs), and skin (SK-MSCs). METHODS MSCs were isolated from the tissues, cultured for 10 passages, and assessed for: phenotype with immunofluorescence and flow cytometry, multipotency with differentiation capacity for osteo-, chondro-, and adipogenesis, stemness markers with qPCR for mRNA for Sox2 and Oct4, and genetic stability for p53 and c-Myc;27 bioactive factors were screened using the multiplex ELISA array, and spontaneous fusion involving a co-culture of SM-MSCs with BM-MSCs or AT-MSCs stained with PKH26 (red) or PKH67 (green) was performed. RESULTS All MSCs showed the basic MSC phenotype;however, their expression decreased during the follow-up period, as confirmed by fluorescence intensity. The examined MSCs express CD146 marker associated with proangiogenic properties;however their expression decreased in AT-MSCs and SM-MSCs, but was maintained in BM-MSCs. In contrast, in SK-MSCs CD146 expression increased in late passages. All MSCs, except BM-MSCs, expressed PW1, a marker associated with differentiation capacity and apoptosis. BM-MSCs and AT-MSCs expressed stemness markers Sox2 and Oct4 in long-term culture. All MSCs showed a stable p53 and c-Myc expression. BM-MSCs and AT-MSCs maintained their differentiation capacity during the follow-up period. In contrast, SK-MSCs and SM-MSCs had a limited ability to differentiate into adipocytes. BM-MSCs and AT-MSCs revealed similarities in phenotype maintenance, capacity for multilineage differentiation, and secretion of bioactive factors. Because AT-MSCs fused with SM-MSCs as effectively as BM-MSCs, AT-MSCs may constitute an alternative source for BM-MSCs. CONCLUSION Long-term culture affects the biological activity of MSCs obtained from various tissues. The source of MSCs and number of passages are important considerations in regenerative medicine.

Functional recovery and microenvironmental alterations in a rat model of spinal cord injury following human umbilical cord blood-derived mesenchymal stem cells transplantation

BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE： To observe changes in nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, and interleukin-8 （IL-8） expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS： Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS： A total of 62 Wister rats were randomly assigned to control （n = 18）, model （n = 22, SCI ＋ PBS）, and transplantation （n = 22, SCI ＋ MSCs） groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine （BrdU）-Iabeled MSCs （24 hours before injection） were intravascularly transplanted. MAIN OUTCOME MEASURES： The rats were evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation. RESULTS： A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group （P 〈 0.05）, which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks （P 〈 0.05）, but IL-8 levels remained unchanged （P 〉 0.05）. CONCLUSION： MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.

Mesenchymal Stromal Cells Derived from Human Embryonic Stem Cells, Fetal Limb and Bone Marrow Share a Common Phenotype but Are Transcriptionally and Biologically Different

Mesenchymal stromal cells (MSCs) can be obtained from several sources and the significant differences in their properties make it crucial to investigate the differentiation potential of MSCs from different sources to determine the optimal source of MSCs. We investigated if this biological heterogeneity in MSCs from different sources results in different mechanisms for their differentiation. In this study, we compared the gene expression patterns of phenotypically defined MSCs derived from three ontogenically different sources: Embryonic stem cells (hES-MSCs), Fetal limb (Flb-MSCs) and Bone Marrow (BM-MSCs). Differentially expressed genes between differentiated cells and undifferentiated controls were compared across the three MSC sources. We found minimal overlap (5% - 16%) in differentially expressed gene sets among the three sources. Flb-MSCs were similar to BM-MSCs based on differential gene expression patterns. Pathway analysis of the differentially expressed genes using Ingenuity Pathway Analysis (IPA) revealed a large variation in the canonical pathways leading to MSC differentiation. The similar canonical pathways among the three sources were lineage specific. The Flb-MSCs showed maximum overlap of canonical pathways with the BM-MSCs, indicating that the Flb-MSCs are an intermediate source between the less specialised hES-MSC source and the more specialised BM-MSC source. The source specific pathways prove that MSCs from the three ontogenically different sources use different biological pathways to obtain similar differentiation outcomes. Thus our study advocates the understanding of biological pathways to obtain optimal sources of MSCs for various clinical applications.

Neuronal-like differentiation of bone marrow-derived mesenchymal stem cells induced by striatal extracts from a rat model of Parkinson's disease

A rat model of Parkinson＇s disease was established by 6-hydroxydopamine injection into the medial forebrain bundle. Bone marrow-derived mesenchymal stem cells （BMSCs） were isolated from the femur and tibia, and were co-cultured with 10% and 60% lesioned or intact striatal extracts. The results showed that when exposed to lesioned striatal extracts, BMSCs developed bipolar or multi-polar morphologies, and there was an increase in the percentage of cells that expressed glial fibrillary acidic protein （GFAP）, nestin and neuron-specific enolase （NSE）. Moreover, the percentage of NSE-positive cells increased with increasing concentrations of lesioned striatal extracts. However, intact striatal extracts only increased the percentage of GFAP-positive cells. The findings suggest that striatal extracts from Parkinson＇s disease rats induce BMSCs to differentiate into neuronal-like cells in vitro.

Safety and effect of umbilical cord blood -derived mesenchymal stem cells on apoptosis of human cardiomyocytes

Objective To study the safety and effect of the umbilical cord blood （UCB）-derived mesenchymal stem cells （MSCs） on apoptosis of human cardiomyocytes （HCM）. Methods UCB was collected at the time of delivery with informed consent obtained from 10 donors. The UCB-derived MSCs were treated with 5-azaserube （5-AZA） and were further induced to differentiate into cardiomyocytes. Telomerase activity, G-banding patterns of chromosomal karyotypes, tumor formation in nude mice, RT-PCR, and the effect of inhibiting apoptosis of HCM were investigated. Results MSCs derived from UCB were differentiated into cardiomyocytes in vitro, which possessed telomerase activity after 5-AZA induction, and no abnormal chromosomal karyotypes were observed. Expression of p53, cyclin A, cdk2, ~3 -actin, C-fos, h-TERT and c-myc were similar in MSCs before and after 5-AZA treatment. There was no tumor formation in nude mice after injection of UCB-derived MSCs. UCB-derived MSCs significantly inhibited apoptosis of HCM. Conclusion UCB-derived MSCs are a valuable, safe and effective source of cell-transplantation treatment .

Immunomodulatory properties of dental tissue-derived mesenchymal stem cells: Implication in disease and tissue regeneration

Mesenchymal stem cells(MSCs)are considered as an attractive tool for tissue regeneration and possess a strong immunomodulatory ability.Dental tissuederived MSCs can be isolated from different sources,such as the dental pulp,periodontal ligament,deciduous teeth,apical papilla,dental follicles and gingiva.According to numerous in vitro studies,the effect of dental MSCs on immune cells might depend on several factors,such as the experimental setting,MSC tissue source and type of immune cell preparation.Most studies have shown that the immunomodulatory activity of dental MSCs is strongly upregulated by activated immune cells.MSCs exert mostly immunosuppressive effects,leading to the dampening of immune cell activation.Thus,the reciprocal interaction between dental MSCs and immune cells represents an elegant mechanism that potentially contributes to tissue homeostasis and inflammatory disease progression.Although the immunomodulatory potential of dental MSCs has been extensively investigated in vitro,its role in vivo remains obscure.A few studies have reported that the MSCs isolated from inflamed dental tissues have a compromised immunomodulatory ability.Moreover,the expression of some immunomodulatory proteins is enhanced in periodontal disease and even shows some correlation with disease severity.MSC-based immunomodulation may play an essential role in the regeneration of different dental tissues.Therefore,immunomodulation-based strategies may be a very promising tool in regenerative dentistry.

Transplantation of human umbilical cord blood mesenchymal stem cells to treat a rat model of traumatic brain injury

In the present study, human umbilical cord blood mesenchymal stem cells were injected into a rat model of traumatic brain injury via the tail vein. Results showed that 5-bromodeoxyuridine-labeled cells aggregated around the injury site, surviving up to 4 weeks post-transplantation. In addition, transplantation-related death did not occur, and neurological functions significantly improved. Histological detection revealed attenuated pathological injury in rat brain tissues following human umbilical cord blood mesenchymal stem cell transplantation. In addition, the number of apoptotic cells decreased. Immunohistochemistry and in situ hybridization showed increased expression of brain-derived neurotrophic factor, nerve growth factor, basic fibroblast growth factor, and vascular endothelial growth factor, along with increased microvessel density in surrounding areas of brain injury. Results demonstrated migration of transplanted human umbilical cord blood mesenchymal stem cells into the lesioned boundary zone of rats, as well as increased angiogenesis and expression of related neurotrophic factors in the lesioned boundary zone.

Therapeutic potential of menstrual blood stem cells in treating acute liver failure

BACKGROUND Acute liver failure(ALF)is a significant and complex hepatic insult that may rapidly progress to life-threatening conditions.Recently,menstrual blood stem cells(MenSCs)have been identified as a group of easily accessible mesenchymal stem cells with the advantages of non-invasive acquisition,low immunogenicity,a greater capacity of self-renewal and multi-lineage differentiation,making them promising candidates for stem cell-based therapy to revolutionize the treatment strategies for liver failure.AIM To investigate the therapeutic potential of MenSCs for treating ALF in pigs and to dynamically trace the biodistribution of transplanted cells.METHODS MenSCs were labeled in vitro with PKH26,a lipophilic fluorescent dye.The treatment group received immediate transplantation of PKH26-labelled MenSCs(2.5×106/kg)via the portal vein after D-galactosamine injection,and the control group underwent sham operation.The survival time,liver function,and hepatic pathological changes were compared between the two groups.Three major organs(liver,lungs and spleen)were extracted from animals and imaged directly with the In vivo Imaging System(IVIS)at the predetermined time points.The regions of interest were drawn to quantify the cell uptake in different organs.RESULTS The labelling procedure did not affect the morphology,viability or multipotential differentiation of MenSCs.Biochemical analysis showed that the levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),total bilirubin(TBIL)and prothrombin time(PT)measured at selected time points 24 h after transplantation were significantly decreased in the treatment group(P<0.05).The survival time of ALF animals was prolonged in the treatment group compared with the control group(75.75±5.11 h vs 53.75±2.37 h,log rank,P<0.001).The liver pathological tissue in the MenSC treatment group showed obviously increased numbers of remaining hepatocytes and a comparatively slight necrotic degree and area.In addition,the IVIS imaging revealed that PKH26-positive MenSCs were clearly retained in the liver initially and then diffused through the systemic circulation.Interestingly,the signal intensity in the liver increased obviously at 36 h,which corresponded to the biochemical result that liver function deteriorated most rapidly at 24-36 h.CONCLUSION Our study demonstrates the therapeutic efficacy and homing ability of transplanted MenSCs in a large animal model of ALF and suggests that MenSC transplantation could be a promising strategy for treating ALF.