Cord Blood Stem Cells: A Review of Potential Neurological Applications

Cartilage Regeneration Using Human Umbilical Cord Blood Derived Mesenchymal Stem Cells: A Systematic Review and Meta-Analysis

Background and Objectives: Human umbilical-cord-blood-derived mesenchymal stem cells (hUCB-MSCs) have recently been used in clinical cartilage regeneration procedures with the expectation of improved regeneration capacity. However, the number of studies using hUCB-MSCs is still insufficient, and long-term follow-up results after use are insufficient, indicating the need for additional data and research. We have attempted to prove the efficacy and safety of hUCB-MSC treatment in a comprehensive analysis by including all subjects with knee articular cartilage defect or osteoarthritis who have undergone cartilage repair surgery using hUCB-MSCs. We conducted a meta-analysis and demonstrated efficacy and safety based on a systematic review. Materials and Methods: This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. For this study, we searched the PubMed, Embase, Web of Science, Scopus, and Cochrane Library literature databases up to June 2022. A total of seven studies were included, and quality assessment was performed for each included study using the Newcastle−Ottawa Quality Assessment Scale. Statistical analysis was performed on the extracted pooled clinical outcome data, and subgroup analyses were completed. Results: A total of 570 patients were included in the analysis. In pooled analysis, the final follow-up International Knee Documentation Committee (IKDC) score showed a significant increase (mean difference (MD), −32.82; 95% confidence interval (CI), −38.32 to −27.32; p < 0.00001) with significant heterogeneity (I2 = 93%, p < 0.00001) compared to the preoperative score. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores at final follow-up were significantly decreased (MD, 30.73; 95% CI, 24.10−37.36; p < 0.00001) compared to the preoperative scores, with significant heterogeneity (I2 = 95%, p < 0.00001). The visual analog scale (VAS) score at final follow-up was significantly decreased (MD, 4.81; 95% CI, 3.17−6.46; p < 0.00001) compared to the preoperative score, with significant heterogeneity (I2 = 98%, p < 0.00001). Two studies evaluated the modified Magnetic Resonance Observation of Cartilage Repair Tissue (M-MOCART) score and confirmed sufficient improvement. In a study analyzing a group treated with bone marrow aspiration concentrate (BMAC), there was no significant difference in clinical outcome or M-MOCART score, and the post-treatment International Cartilage Repair Society (ICRS) grade increased. Conclusion: This analysis demonstrated the safety, efficacy, and quality of repaired cartilage following hUCB-MSC therapy. However, there was no clear difference in the comparison with BMAC. In the future, comparative studies with other stem cell therapies or cartilage repair procedures should be published to support the superior effect of hUCB-MSC therapy to improve treatment of cartilage defect or osteoarthritis.

Stem cells: a comprehensive review of origins and emerging clinical roles in medical practice

Stem cells are types of cells that have unique ability to self-renew and to differentiate into more than one cell lineage. They are considered building blocks of tissues and organs. Over recent decades, they have been studied and utilized for repair and regenerative medicine. One way to classify these cells is based on their differentiation capacity. Totipotent stem cells can give rise to any cell of an embryo but also to extra-embryonic tissue as well. Pluripotent stem cells are limited to any of the three embryonic germ layers; however, they cannot differentiate into extra-embryonic tissue. Multipotent stem cells can only differentiate into one germ line tissue. Oligopotent and unipotent stem cells are seen in adult organ tissues that have committed to a cell lineage. Another way to differentiate these cells is based on their origins. Stem cells can be extracted from different sources, including bone marrow, amniotic cells, adipose tissue, umbilical cord, and placental tissue. Stem cells began their role in modern regenerative medicine in the 1950's with the first bone marrow transplantation occurring in 1956. Stem cell therapies are at present indicated for a range of clinical conditions beyond traditional origins to treat genetic blood diseases and have seen substantial success. In this regard, emerging use for stem cells is their potential to treat pain states and neurodegenerative diseases such as Parkinson's and Alzheimer's disease. Stem cells offer hope in neurodegeneration to replace neurons damaged during certain disease states. This review compares stem cells arising from these different sources of origin and include clinical roles for stem cells in modern medical practice.

Exploring the Role of Stem Cell Therapy in Treating Neurodegenerative Diseases: Challenges and Current Perspectives

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Several human neurological disorders, such as Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, Huntington’s disease, spinal cord injury, multiple sclerosis, and brain stroke, are caused by the injury to neurons or glial cells. The recent years have witnessed the successful generation of neurons and glia cells driving efforts to develop stem-cell-based therapies for patients to combat a broad spectrum of human neurological diseases. The inadequacy of suitable cell types for cell replacement therapy in patients suffering from neurological disorders has hampered the development of this promising therapeutic approach. Attempts are thus being made to reconstruct viable neurons and glial cells from different stem cells, such as embryonic stem cells, mesenchymal stem cells, and neural stem cells. Dedicated research to cultivate stem cell-based brain transplantation therapies has been carried out. We aim at compiling the breakthroughs in the field of stem cell-based therapy for the treatment of neurodegenerative maladies, emphasizing the shortcomings faced, victories achieved, and the future prospects of the therapy in clinical settings.

Determinants of the intention to donate umbilical cord blood in pregnant women

Background and Objectives

Umbilical cord blood (UCB) donation is a behaviour promoted by many countries' health systems. However, UCB donation is not a widespread behaviour among expectant mothers, and little is known about the reasons that may lead to it. The aim of the present study was to analyse the contribution of Theory of Planned Behaviour (TPB) variables among both primiparous and multiparous women in predicting intention to donate UCB.

Materials and Methods

Three hundred seventy‐six expectant mothers completed questionnaires that captured sociodemographic data, parity, previous donation, attitudes, subjective norms, perceived behavioural control (PBC) and intention to donate UCB. Multigroup analysis structural equation modelling was conducted using Mplus (version 8.02).

Results

Multigroup path analyses showed that intentions were strongly predicted by subjective norms and moderately predicted by positive attitudes and PBC in both primiparous and multiparous women. TPB constructs explained 71% of the variance in intentions for both groups.

Conclusions

Future interventions to increase intention to donate among primiparous and multiparous women could primarily consider the influence of partner and significant others in determining positive intentions and secondarily target increasing positive attitudes and perceptions of control.

Umbilical cord blood CD34+ cells administration improved neurobehavioral status and alleviated brain injury in a mouse model of cerebral palsy

PURPOSE

Cerebral palsy (CP) is the most common neuromuscular disease in children, and currently, there is no cure. Several studies have reported the benefits of umbilical cord blood (UCB) cell treatment for CP. However, these studies either examined the effects of UCB cell fraction with a short experimental period or used neonatal rat models for a long-term study which displayed an insufficient immunological reaction and clearance of human stem cells. Here, we developed a CP model by hypoxia-ischemic injury (HI) using immunodeficient mice and examined the effects of human UCB CD34⁺ hematopoietic stem cells (HSCs) on CP therapy over a period of 8 weeks.

METHODS

Sixty postnatal day-9 (P9) mouse pups were randomly divided into 4 groups (n = 15/group) as follows: (1) sham operation (control group), (2) HI-induced CP model, (3) CP model with CD34⁺ HSC transplantation, and (4) CP model with CD34^- cell transplantation. Eight weeks after insult, the sensorimotor performance was analyzed by rotarod treadmill, gait dynamic, and open field assays. The pathological changes in brain tissue of mice were determined by HE staining, Nissl staining, and MBP immunohistochemistry of the hippocampus in the mice.

RESULTS

HI brain injury in mice pups resulted in significant behavioral deficits and loss of neurons. Both CD34⁺ HSCs and CD34^- cells improved the neurobehavioral statuses and alleviated the pathological brain injury. In comparison with CD34^- cells, the CD34⁺ HSC compartments were more effective.

CONCLUSION

These findings indicate that CD34⁺ HSC transplantation was neuroprotective in neonatal mice and could be an effective therapy for CP.

Exploring the relationship between umbilical blood cord donation and the impact of social distance on altruism and trust

Allogeneic umbilical cord blood (UCB) donation is a pro-social behaviour directed to strangers that has a certain cost for the donor. Although the promotion of such behaviour is an important goal for many countries' health systems, little is known about the reasons that would lead to it. With this study, we explored how the impact of social closeness on altruism and trust could be related to UCB donation in a sample of new-mothers (N = 167). Participants played hypothetical Dictator and Trust games with socially close (e.g., parents) or distant (e.g., strangers) others. They donated more money to parents and siblings compared to cousins, friends and strangers and they trusted more parents, siblings and friends than cousins and strangers. Interestingly, the lower the impact of social closeness on altruism (i.e., generosity towards socially distant others), the higher the intention and the actual probability of UCB donation. A mediation analysis has shown that the relationship between social closeness on altruism and UCB donation was mediated by objective intention to donate (i.e., having followed all the procedures needed). These findings show that other-oriented motivations towards distant others might have important practical implications in identifying the targets of interventions for the promotion of UCB donation.

Human colorectal cancer derived-MSCs promote tumor cells escape from senescence via P53/P21 pathway

PURPOSE

The purpose of this study was to evaluate effect of MSCs on CRC cell.

METHODS

in this study the MSC was isolated from CRC tissue, its effect on CRC cells was investigated in vivo and vitro, and the underlying mechanism was investigated.

RESULTS

In this study we found that MSC-CM could promote colorectal cancer cells escape from senescence both in vitro and in vivo. Further research we demonstrated that MSC-CM acted in colorectal cancer cells senescence through P53/P21 pathway. Next we found that MSC-CM regulate P53 via posttranscription method.

CONCLUSION

Collectively, these results reveal that MSCs can help colorectal cancer cells defend against senescence through P53/P21 pathway, which may be a new strategy for colorectal cancer therapy.

A Randomized, Placebo-Controlled Trial of Human Umbilical Cord Blood Mesenchymal Stem Cell Infusion for Children With Cerebral Palsy

Cerebral palsy (CP) is a common disability which results in permanent chronic motor disability appearing in early childhood. Recently human umbilical cord blood mesenchymal stem cell (hUCB-MSC) infusion has emerged as a promising therapeutic strategy for CP, and the treatment efficacy remains to be confirmed by clinical trials. All 54 patients received basic rehabilitation as a background treatment. The infusion group comprising 27 patients received 4 infusions of hUCB-MSCs (intravenous infusions at a fixed dose of 5 × 10⁷) and basic rehabilitation treatment, whereas 27 patients in the control group received 0.9% normal saline and basic rehabilitation treatment. Several indices were tested from baseline up to 24 months posttreatment regarding efficacy and safety evaluations, including the gross motor function measurement 88 (GMFM-88) scores, the comprehensive function assessment (CFA), lab tests, electroencephalogram (EEG), routine magnetic resonance imaging (MRI), and adverse events. The changes in the total proportion of GMFM-88 and total scores of CFA in the hUCB-MSC infusion group were significantly higher than that in control group at 3, 6, 12, 24 months posttreatment. Less diffuse slow waves were noticed after hUCB-MSC infusion in patients with slowing of EEG background rhythms at baseline. Based on the routine MRI exams, improvements in cerebral structures were rare after treatment. Serious adverse events were not observed during the whole study period. The results of the study indicated that hUCB-MSC infusion with basic rehabilitation was safe and effective in improving gross motor and comprehensive functions in children with CP.

A New Approach to Cerebral Palsy Treatment: Discussion of the Effective Components of Umbilical Cord Blood and its Mechanisms of Action

Cerebral palsy (CP) includes a group of persistent non-progressive disorders affecting movement, muscle tone, and/or posture. The total economic loss during the life-span of an individual with CP places a heavy financial burden on such patients and their families worldwide; however, a complete cure is still lacking. Umbilical cord blood (UCB)-based interventions are emerging as a scientifically plausible treatment and possible cure for CP. Stem cells have been used in many experimental CP animal models and achieved good results. Compared with other types of stem cells, those from UCB have advantages in terms of treatment safety and efficacy, ethics, non-neoplastic proliferation, accessibility, ease of preservation, and regulation of immune responses, based on findings in animal models and clinical trials. Currently, the use of UCB-based interventions for CP is limited as the components of UCB are complex and possess different therapeutic mechanisms. These can be categorized by three aspects: homing and neuroregeneration, trophic factor secretion, and neuroprotective effects. Our review summarizes the features of active components of UCB and their therapeutic mechanism of action. This review highlights current research findings and clinical evidence regarding UCB that contribute to treatment suggestions, inform decision-making for therapeutic interventions, and help to direct future research.

Motivating Cord Blood Donation with Information and Behavioral Nudges

Umbilical cord blood is a source of hematopoietic stem cells essential to treat life-threatening diseases, such as leukemia and lymphoma. However, only a very small percentage of parents donate upon delivery. The decision to donate the cord blood occurs at a very specific time and when parents likely experience emotional, informational, and decisional overloads; these features of cord blood donation make it different from other pro-social activities. In collaboration with an OB-GYN clinic in Milan, Italy, we conducted the first randomized controlled trial that applies tools from behavioral science to foster cord blood donation, and quantified the gains that informational and behavioral "nudges" can achieve. We found that information and "soft" commitments increased donations; approaching expecting parents closer to the delivery date and providing them with multiple reminders, moreover, had the strongest impact. However, a significant portion of women who expressed consent to donate could not do so because of organizational constraints. We conclude that simple, non-invasive behavioral interventions that address information gaps and procrastination, and that increase the salience of the activity can substantially enhance altruistic donations of cord blood, especially when coupled with organizational support.

Transplantation of Human Umbilical Cord Blood Mononuclear Cells Attenuated Ischemic Injury in MCAO Rats via Inhibition of NF-κB and NLRP3 Inflammasome

Accumulated evidence displayed that transplantation of stem cells may be a promising approach for the treatment of neurological disorders. However, the underlying mechanisms remain to be well elucidated. Moreover, some investigators cannot reproduce similar results as the previous. The present results showed that transplantation of fresh human umbilical cord blood mononuclear cells (cbMNCs) attenuated ischemic damage in middle cerebral artery occlusion (MCAO) rats, accompanied with improvement of neurologic deficits, learning and memory function. The increase in neovascularization and related molecules such as vascular endothelial growth factor (VEGF), Angiopoietin-1 (Ang-1) and endothelium-specific receptor tyrosine kinase 2 (Tie-2) in the injured brain was observed in cbMNCs-treated rats. Moreover, nuclear factor-κB (NF-κB) activation and nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome were also inhibited by the cells graft, resulting in reduction in cleaved caspase-1 and mature interleukin-1β (IL-1β) content. These results suggested that the protective actions of the cells on the cerebral ischemia may be related to inhibition of NF-κB pathway and NLRP3 inflammasome.

The Role of Stem Cells in the Treatment of Cerebral Palsy: a Review

Cerebral palsy (CP) is a neuromuscular disease due to injury in the infant's brain. The CP disorder causes many neurologic dysfunctions in the patient. Various treatment methods have been used for the management of CP disorder. However, there has been no absolute cure for this condition. Furthermore, some of the procedures which are currently used for relief of symptoms in CP cause discomfort or side effects in the patient. Recently, stem cell therapy has attracted a huge interest as a new therapeutic method for treatment of CP. Several investigations in animal and human with CP have demonstrated positive potential of stem cell transplantation for the treatment of CP disorder. The ultimate goal of this therapeutic method is to harness the regenerative capacity of the stem cells causing a formation of new tissues to replace the damaged tissue. During the recent years, there have been many investigations on stem cell therapy. However, there are still many unclear issues regarding this method and high effort is needed to create a technology as a perfect treatment. This review will discuss the scientific background of stem cell therapy for cerebral palsy including evidences from current clinical trials.

Systemic human CD34(+) cells populate the brain and activate host mechanisms to counteract nigrostriatal degeneration

AIM

Here we investigated the neuroprotective potential of systemic CD34(+) human cord blood cells (hCBCs) in a 6-hydroxydopamine rat model of Parkinson's disease.

METHODS

Purified CD34(+) hCBCs were intravenously administered to rats subjected to 6-hydroxydopamine 24 h earlier, and behavioral and immunohistological analysis performed.

RESULTS

CD34(+) hCBC administration significantly prevented host nigrostriatal degeneration inducing behavioral recovery in treated rats. Although donor hCBCs did not differentiate into neural phenotypes, they stimulated the production of new neuroblasts and angiogenesis, and reduced gliosis in recipient animals. Importantly, surviving donor hCBCs were identified, and their tissue distribution pattern correlated with the observed therapeutic effects.

CONCLUSION

Peripherally applied CD34(+) hCBCs can migrate into brain tissues and elicit host-based protective mechanisms to support the survival of midbrain dopamine neurons.

Stem cell transplantation for treating spinal cord injury: A literature comparison between studies of stem cells obtained from various sources

OBJECTIVE:

To identify global research trends of stem cell transplantation for treating spinal cord injury using a bibliometric analysis of the Web of Science.

DATA RETRIEVAL:

We performed a bibliometric analysis of data retrievals for stem cell transplantation for treating spinal cord injury from 2002 to 2011 using the Web of Science.

SELECTION CRITERIA:

Inclusion criteria: (a) peer-reviewed articles on stem cell transplantation for treating spinal cord injury that were published and indexed in the Web of Science; (b) type of articles: original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items; and (c) year of publication: 2002–2011. Exclusion criteria: (a) articles that required manual searching or telephone access; (b) documents that were not published in the public domain; and (c) a number of corrected papers from the total number of articles.

MAIN OUTCOME MEASURES:

(1) Annual publication output; (2) distribution according to country; (3) distribution according to institution; (4) distribution according to journals; (5) distribution according to funding agencies; and (6) top cited articles over the last 10 years.

RESULTS:

Bone marrow mesenchymal stem cells and embryonic stem cells have been widely used for treating spinal cord injury. In total, 191 studies of bone marrow mesenchymal stem cell transplantation and 236 studies of embryonic stem cell transplantation for treating spinal cord injury appeared in the Web of Science from 2002 to 2011, and almost half of which were derived from American or Japanese authors and institutes. The number of studies of stem cell transplantation for treating spinal cord injury has gradually increased over the past 10 years. Most papers on stem cell transplantation for treating spinal cord injury appeared in journals with a particular focus on stem cell research, such as Stem Cells and Cell Transplantation. Although umbilical cord blood stem cells and adipose-derived stem cells have been studied for treating spinal cord injury, the number of published papers was much smaller, with only 21 and 17 records, respectively, in the Web of Science.

CONCLUSION:

Based on our analysis of the literature and research trends, we found that stem cells transplantation obtained from various sources have been studied for treating spinal cord injury; however, it is difficult for researchers to reach a consensus on this theme.

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 mesenchymal stem cells promote the functional recovery of crush-injured sciatic nerves.

Retraction: The effect of anticoagulant choice on collection of cord blood

"The effect of anticoagulant choice on collection of cord blood" by M. Badowski, C. Shultz and D.T. Harris. Transfusion. First published online: June 12, 2014. The above article, published online on June 12, 2014 on Wiley Online Library (wileyonlinelibrary.com), has been withdrawn for legal reasons by agreement between the authors, the journal Editor in Chief, Paul M. Ness, MD, the AABB, and Wiley Periodicals, Inc. The withdrawal has been agreed due to violation of a research agreement between the Cord Blood Registry, which commissioned the article, and the authors.

REFERENCE

Badowski M, Shultz C and Harris DT. The effect of anticoagulant choice on collection of cord blood. Transfusion. 2014. doi: 10.1111/trf.12744. First published online: 12 JUN 2014.

Intrathecal injection of human umbilical cord blood stem cells attenuates spinal cord ischaemic compromise in rats

OBECTIVES

Spinal cord ischaemia with resulting paraplegia remains a devastating and unpredictable complication after thoraco-abdominal aortic surgery. With the advent of stem cell therapy and its potential to induce nervous tissue regeneration processes, the interest in the use of these cells as a treatment for neurological disorders has increased. Human stem cells, derived from the umbilical cord, are one of the strong candidates used in cell therapy for spinal cord injury because of weak immunogenicity and ready availability. We sought to evaluate the use of human umbilical cord blood stem cells (HUCBSCs) to attenuate the neurological effects of spinal cord ischaemia induced by high thoracic aorta occlusion.

METHODS

Forty Wistar rats were randomized to receive intrathecal injection of 10 µl phosphate buffered saline (PBS) solution containing 1 × 10(4) HUCBSCs, 30 min before (Tpre group: n = 10) and 30 min after (Tpos group: n = 10) descending thoracic aorta occlusion by intraluminal balloon during 12 min. Control groups received only PBS solution (Cpre group: n = 10; and Cpos group: n = 10). During a 28-day observational period, motor function was assessed by a functional grading scale (Basso, Beattie and Bresnahan). Segments of thoracolumbar spinal cord specimens were analysed for histological and immunohistochemical assessment for detection and quantification of human haematopoietic cells (CD45(+)) and apoptosis (transferase-mediated deoxyuridine triphosphate-biotin nick-end labelling).

RESULTS

Overall mortality was 12 animals (30%). Therefore, the observational sample was composed of 28 animals. All groups showed similar incidence of paraplegia and mortality. The mean motor function scores showed no difference during time between the animals of each group, excepting for the Tpos group, which improved from 8.14 (±8.6) to 14.28 (±9.8) (P < 0.01). A treatment-by-time interaction was detected among animals that received HUCBSCs 30 min after ischaemia, with BBB scores higher from Days 14 to 28 compared with the first observational day with statistical difference (P = 0.01). Number of viable neurons was higher in the Tpos group (P = 0.14) and the incidence of apoptosis was lower in the same animals (P = 0.048), but showed no difference with its respective control. We confirmed the presence of CD45(+) cells 4 weeks after intrathecal injection in both therapeutic groups but mainly in the Tpos group.

CONCLUSIONS

Intrathecal transplantation of HUCBSCs is feasible, and it improved spinal cord function, when they were delivered 30 min after spinal cord ischaemia, in a model of endovascular descending thoracic aorta occlusion in rats. Human umbilical cord blood is one of the potentially useful sources of stem cells for therapy of spinal cord ischaemia.

Humoral activity of cord blood-derived stem/progenitor cells: implications for stem cell-based adjuvant therapy of neurodegenerative disorders

Background

Stem/progenitor cells (SPCs) demonstrate neuro-regenerative potential that is dependent upon their humoral activity by producing various trophic factors regulating cell migration, growth, and differentiation. Herein, we compared the expression of neurotrophins (NTs) and their receptors in specific umbilical cord blood (UCB) SPC populations, including lineage-negative, CD34⁺, and CD133⁺ cells, with that in unsorted, nucleated cells (NCs).

Methods and Results

The expression of NTs and their receptors was detected by QRT-PCR, western blotting, and immunofluorescent staining in UCB-derived SPC populations (i.e., NCs vs. lineage-negative, CD34⁺, and CD133⁺ cells). To better characterize, global gene expression profiles of SPCs were determined using genome-wide RNA microarray technology. Furthermore, the intracellular production of crucial neuro-regenerative NTs (i.e., BDNF and NT-3) was assessed in NCs and lineage-negative cells after incubation for 24, 48, and 72 h in both serum and serum-free conditions. We discovered significantly higher expression of NTs and NT receptors at both the mRNA and protein level in lineage-negative, CD34⁺, and CD133⁺ cells than in NCs. Global gene expression analysis revealed considerably higher expression of genes associated with the production and secretion of proteins, migration, proliferation, and differentiation in lineage-negative cells than in CD34⁺ or CD133⁺ cell populations. Notably, after short-term incubation under serum-free conditions, lineage-negative cells and NCs produced significantly higher amounts of BDNF and NT-3 than under steady-state conditions. Finally, conditioned medium (CM) from lineage-negative SPCs exerted a beneficial impact on neural cell survival and proliferation.

Conclusions

Collectively, our findings demonstrate that UCB-derived SPCs highly express NTs and their relevant receptors under steady-state conditions, NT expression is greater under stress-related conditions and that CM from SPCs favorable influence neural cell proliferation and survival. Understanding the mechanisms governing the characterization and humoral activity of subsets of SPCs may yield new therapeutic strategies that might be more effective in treating neurodegenerative disorders.

Electrophysiological characterisation of human umbilical cord blood-derived mesenchymal stem cells induced by olfactory ensheathing cell-conditioned medium

Umbilical cord blood-derived marrow stromal cells (UCB-MSCs) with high proliferation capacity and immunomodulatory properties are considered to be a good candidate for cell-based therapies. But until now, little work has been focused on the differentiation of UCB-MSCs. In this work, UCB-MSCs were demonstrated to be negative for CD34 and CD45 expression but positive for CD90 and CD105 expression. The gate values of UCB-MSCs for CD90 and CD105 were 99.3 and 98.6 %, respectively. Two weeks after treatment, the percentage of neuron-like cells differentiated from UCB-MSCs was increased to 84 ± 12 % in the experimental group [treated with olfactory ensheathing cells (OECs)-conditioned medium] and they were neuron-specific enolase positive; few neuron-like cells were found in the control group (without OECs-conditioned medium). Using whole-cell recording, sodium and potassium currents were recorded in UCB-MSCs after differentiation by OECs. Thus, human UCB-MSCs could be differentiated to neural cells by secreted secretion from OECs and exhibited electrophysiological properties similar to mature neurons after 2 weeks post-induction. These results imply that OECs can be used as a new strategy for stem cell differentiation and provide an alternative neurogenesis pathway for generating sufficient numbers of neural cells for cell therapy.

Comparative proteomic analysis of endothelial cells progenitor cells derived from cord blood- and peripheral blood for cell therapy

Vasculopathy due to ischemia in damaged tissues is a major cause of morbidity and mortality. To treat these conditions, endothelial progenitor cells (EPCs) from various sources, such as umbilical cord or peripheral blood, have been the focus of the regenerative medicine field due to their proliferative and vasculogenic activities. However, the fundamental, molecular-level differences between EPCs obtained from different cellular sources have rarely been studied. In this study, we established endothelial progenitor cells derived from cord blood- and peripheral blood (CB- and PB-EPCs) and investigated their fundamental differences at the cellular and molecular levels through a combination of stem cell biology techniques and proteomic analysis. Our results suggest that specifically up-regulated factors such as STMIN 1, CFL 1, PARK 7, NME 1, GLO 1, HSP 27 and PRDX 2 in CB-EPCs as key elements that could be functionally active in ischemic regions. We also discussed functional behaviors important for inducing and maintaining long-lasting blood vessels under ischemic conditions. As a result, CB-EPCs retained a higher anti-oxidant and migration ability than PB-EPCs in vitro. Furthermore, CB-EPCs retained a higher therapeutic efficacy than PB-EPCs in a hindlimb ischemic disease model. The up-regulated expression pattern of STMIN 1, CFL 1, PARK 7, NME 1, GLO 1, HSP 27 and PRDX 2 was confirmed under several conditions in vitro and in vivo, indicating that the up-regulation of these molecules in CB-EPCs may be critical to the mechanism of healing in ischemic conditions and that CB-EPCs may be more appropriate for inducing neo-vessels. Thus, these results may aid in predetermining which cell sources will be of value for cell-based therapies of pathological conditions and identify several candidate molecules that may be involved in the therapeutic mechanism for ischemia.

Effects of intravenous administration of human umbilical cord blood stem cells in 3-acetylpyridine-lesioned rats

Cerebellar ataxias include a heterogeneous group of infrequent diseases characterized by lack of motor coordination caused by disturbances in the cerebellum and its associated circuits. Current therapies are based on the use of drugs that correct some of the molecular processes involved in their pathogenesis. Although these treatments yielded promising results, there is not yet an effective therapy for these diseases. Cell replacement strategies using human umbilical cord blood mononuclear cells (HuUCBMCs) have emerged as a promising approach for restoration of function in neurodegenerative diseases. The aim of this work was to investigate the potential therapeutic activity of HuUCBMCs in the 3-acetylpyridine (3-AP) rat model of cerebellar ataxia. Intravenous administered HuUCBMCs reached the cerebellum and brain stem of 3-AP ataxic rats. Grafted cells reduced 3-AP-induced neuronal loss promoted the activation of microglia in the brain stem, and prevented the overexpression of GFAP elicited by 3-AP in the cerebellum. In addition, HuUCBMCs upregulated the expression of proteins that are critical for cell survival, such as phospho-Akt and Bcl-2, in the cerebellum and brain stem of 3-AP ataxic rats. As all these effects were accompanied by a temporal but significant improvement in motor coordination, HuUCBMCs grafts can be considered as an effective cell replacement therapy for cerebellar disorders.

Intravenous administration of human umbilical cord blood-mononuclear cells dose-dependently relieve neurologic deficits in rat intracerebral hemorrhage model

Human umbilical cord blood (HUCB) is now considered as a valuable source for stem cell-based therapies. Previous studies showed that intravascular injection of the HUCB significantly improves neurological functional recovery in a model of intracerebral hemorrhage (ICH). To extend these findings, we examined the behavioral recovery and injured volume in the presence of increasing doses of human umbilical cord blood derived mononuclear cells (HUC-MCs) after intracerebral hemorrhage in rats. The experimental ICH was induced by intrastriatal administration of bacterial collagenase IV in adult rats. One day after the surgery, the rats were randomly divided into 4 groups to receive intravenously either BrdU positive human UC-MCs (4 × 10(6), 8 × 10(6) and 16 × 10(6) cells in 1 ml saline, n=10, respectively) as treated groups or the same amount of saline as lesion group (n=10). There was also one group (control n=10) that received only the vehicle solution of collagenase. The animals were evaluated for 14 days with modified limb placing and corner turn tests. The transplanted human UC-MCs were also detected by immunohistochemistry with labeling of BrdU. Two weeks after infusion, there was a significant recovery in the behavioral performance when 4 × 10(6) or more UC-MCs were delivered (P<0.05-0.001). Injured volume measurements disclosed an inverse relationship between UC-MCs dose and damage reaching significance at the higher UC-MCs doses. Moreover, human UC-MCs were localized by immunohistochemistry only in the injured area. Intravenously transplanted UC-MCs can accelerate the neurological function recovery of ICH rat and diminish the striatum lesion size by demonstrating a dose relationship between them.

Ensheathing cell-conditioned medium directs the differentiation of human umbilical cord blood cells into aldynoglial phenotype cells

Despite their similarities to bone marrow precursor cells (PC), human umbilical cord blood (HUCB) PCs are more immature and, thus, they exhibit greater plasticity. This plasticity is evident by their ability to proliferate and spontaneously differentiate into almost any cell type, depending on their environment. Moreover, HUCB-PCs yield an accessible cell population that can be grown in culture and differentiated into glial, neuronal and other cell phenotypes. HUCB-PCs offer many potential therapeutic benefits, particularly in the area of neural replacement. We sought to induce the differentiation of HUCB-PCs into glial cells, known as aldynoglia. These cells can promote neuronal regeneration after lesion and they can be transplanted into areas affected by several pathologies, which represents an important therapeutic strategy to treat central nervous system damage. To induce differentiation to the aldynoglia phenotype, HUCB-PCs were exposed to different culture media. Mononuclear cells from HUCB were isolated and purified by identification of CD34 and CD133 antigens, and after 12 days in culture, differentiation of CD34+ HUCB-PCs to an aldynoglia phenotypic, but not that of CD133+ cells, was induced in ensheathing cell (EC)-conditioned medium. Thus, we demonstrate that the differentiation of HUCB-PCs into aldynoglia cells in EC-conditioned medium can provide a new source of aldynoglial cells for use in transplants to treat injuries or neurodegenerative diseases.

The dose-response effect of acute intravenous transplantation of human umbilical cord blood cells on brain damage and spatial memory deficits in neonatal hypoxia-ischemia

Despite the beneficial effects of cell-based therapies on brain repair shown in most studies, there has not been a consensus regarding the optimal dose of human umbilical cord blood cells (HUCBC) for neonatal hypoxia-ischemia (HI). In this study, we compared the long-term effects of intravenous administration of HUCBC at three different doses on spatial memory and brain morphological changes after HI in newborn Wistar rats. In addition, we tested whether the transplanted HUCBC migrate to the injured brain after transplantation. Seven-day-old animals underwent right carotid artery occlusion and were exposed to 8% O(2) inhalation for 2 h. After 24 h, randomly selected animals were assigned to four different experimental groups: HI rats administered with vehicle (HI+vehicle), HI rats treated with 1×10(6) (HI+low-dose), 1×10(7) (HI+medium-dose), and 1×10(8) (HI+high-dose) HUCBC into the jugular vein. A control group (sham-operated) was also included in this study. After 8 weeks of transplantation, spatial memory performance was assessed using the Morris water maze (MWM), and subsequently, the animals were euthanized for brain morphological analysis using stereological methods. In addition, we performed immunofluorescence and polymerase chain reaction (PCR) analyses to identify HUCBC in the rat brain 7 days after transplantation. The MWM test showed a significant spatial memory recovery at the highest HUCBC dose compared with HI+vehicle rats (P<0.05). Furthermore, the brain atrophy was also significantly lower in the HI+medium- and high-dose groups compared with the HI+vehicle animals (P<0.01; 0.001, respectively). In addition, HUCBC were demonstrated to be localized in host brains by immunohistochemistry and PCR analyses 7 days after intravenous administration. These results revealed that HUCBC transplantation has the dose-dependent potential to promote robust tissue repair and stable cognitive improvement after HI brain injury.

Therapeutic potential of umbilical cord blood stem cells on brain damage of a model of stroke

INTRODUCTION

Human cord blood-derived stem cells are a rich source of stem cells as well as precursors. With regard to the researchers have focused on the therapeutic potential of stem cell in the neurological disease such as stroke, the aim of this study was the investiga-tion of the therapeutic effects of human cord blood-derived stem cells in cerebral ischemia on rat.

METHODS

This study was carried out on young rats. Firstly, to create a laboratory model of ischemic stroke, carotid artery of animals was occluded for 30 minutes. Then, umbilical cord blood cells were isolated and labeled using bromodeoxyuridine and 2×10(5) cells were injected into the experimental group via the tail vein. Rats with hypoxic condi-tions were used as a sham group. A group of animals did not receive any injection or sur-geries were used as a control.

RESULTS

Obtained results were evaluated based on behavioral responses and immunohistochemistry, with emphasis on areas of putamen and caudate nucleus in the control, sham and experimental groups. Our results indicated that behavioral recovery was observed in the experimental group compared to the either the sham or the control group. However, histological studies demonstrated a low percent of tissue injury in the experimental group in comparison with the sham group.

CONCLUSION

Stem cell transplantation is beneficial for the brain tissue reparation after hypoxic ischemic cell death.

Transplantation of mononuclear cells from human umbilical cord blood promotes functional recovery after traumatic spinal cord injury in Wistar rats

Cell transplantation is a promising experimental treatment for spinal cord injury. The aim of the present study was to evaluate the efficacy of mononuclear cells from human umbilical cord blood in promoting functional recovery when transplanted after a contusion spinal cord injury. Female Wistar rats (12 weeks old) were submitted to spinal injury with a MASCIS impactor and divided into 4 groups: control, surgical control, spinal cord injury, and one cell-treated lesion group. Mononuclear cells from umbilical cord blood of human male neonates were transplanted in two experiments: a) 1 h after surgery, into the injury site at a concentration of 5 x 10⁶ cells diluted in 10 µL 0.9% NaCl (N = 8-10 per group); b) into the cisterna magna, 9 days after lesion at a concentration of 5 x 10⁶ cells diluted in 150 µL 0.9% NaCl (N = 12-14 per group). The transplanted animals were immunosuppressed with cyclosporin-A (10 mg/kg per day). The BBB scale was used to evaluate motor behavior and the injury site was analyzed with immunofluorescent markers to label human transplanted cells, oligodendrocytes, neurons, and astrocytes. Spinal cord injury rats had 25% loss of cord tissue and cell treatment did not affect lesion extension. Transplanted cells survived in the injured area for 6 weeks after the procedure and both transplanted groups showed better motor recovery than the untreated ones (P < 0.05). The transplantation of mononuclear cells from human umbilical cord blood promoted functional recovery with no evidence of cell differentiation.

Umbilical cord blood: lessons learned and lingering challenges after more than 20 years of basic and clinical research

During the last 23 years, cord blood research has played important roles both in experimental and clinical hematology. Cord blood-derived hematopoietic stem and progenitor cells have been shown to possess particular biological features and their study has been very important in our understanding of hematopoietic development. Today, >20,000 umbilical cord blood (UCB) transplants have been performed worldwide and ∼460,000 UCB units are being stored in >47 UCB banks worldwide. Here a brief overview on some of the most relevant issues regarding cord blood research is presented.

Lessons from genetically altered mesenchymal stem cells (MSCs): candidates for improved MSC-directed myocardial repair

The regenerative and reparative potential of mesenchymal stem cells (MSCs) make them attractive candidates for numerous cell-directed therapies. The variant degree of tissue repair by transplanted MSCs has been assessed in several published reports. There are many gaps in the knowledge of MSC biology and the underlying reasons for their disparate effectiveness in tissue repair. This review examines successful preclinical models of MSC-directed repair, particularly of myocardial repair, in an attempt to shed light into the events dictating MSC therapeutic efficacy. The reparative advantage of genetically altered MSCs will be described. This overview will elucidate possible molecular mechanisms that can influence MSC engraftment, differentiation, self-renewal, and ultimately increase wound repair.

Intracerebroventricular administration of human umbilical cord blood cells delays disease progression in two murine models of motor neuron degeneration

The lack of effective drug therapies for motor neuron diseases (MND), and in general for all the neurodegenerative disorders, has increased the interest toward the potential use of stem cells. Among the cell therapy approaches so far tested in MND animal models, systemic injection of human cord blood mononuclear cells (HuCB-MNCs) has proven to reproducibly increase, although modestly, the life span of SOD1G93A mice, a model of familial amyotrophic lateral sclerosis (ALS), even if only few transplanted cells were found in the damaged areas. In attempt to improve the potential efficacy of these cells in the central nervous system, we examined the effect and distribution of Hoechst 33258-labeled HuCB-MNCs after a single bilateral intracerberoventricular injection in two models of motor neuron degeneration, the transgenic SOD1G93A and wobbler mice. HuCB-MNCs significantly ameliorated symptoms progression in both mouse models and prolonged survival in SOD1G93A mice. They were localized in the lateral ventricles, even 4 months after administration. However, HuCB-MNCs were not found in the spinal cord ventral horns. This evidence strengthens the hypothesis that the beneficial role of transplanted cells is not due to cell replacement but is rather associated with the production and release of circulating protective factors that may act both at the central and/or peripheral levels. In particular, we show that HuCB-MNCs release a series of cytokines and chemokines with antiinflammatory properties that could be responsible of the functional improvement of mouse models of motor neuron degenerative disorders.

Tissue regeneration potential in human umbilical cord blood

Regenerative medicine is the process of creating functional tissue with the aid of stem cells, to repair loss of organ function. Possible targets for regenerative medicine include orthopaedic, cardiac, hepatic, pancreatic and central nervous system (CNS) applications. Umbilical cord blood (CB) has established itself as a legitimate source for haematopoietic stem cell transplantation. It is also considered an accessible and less immunogenic source for mesenchymal, unrestricted somatic and for other stem cells with pluri/multipotent properties. The latter are capable of differentiating into a wide variety of cell types including bone, cartilage, cardiomyocytes and neural. They also possess protective abilities that may contribute to tissue repair even if in vitro differentiation is excluded. In view of the absence of treatment for many devastating diseases, the elucidation of non-haematopoietic applications for CB will facilitate the development of pioneering relevant cell therapy approaches. This review focusses on current studies using human CB-derived cells for regenerative medicine.

Could autologous cord blood stem cell transplantation treat cerebral palsy?

The young human brain is highly plastic and thus early brain lesions can lead to aberrant development of connectivity and mapping of functions. This is why initially in cerebral palsy only subtle changes in spontaneous movements are seen after the time of lesion, followed by a progressive evolution of a movement disorder over many months and years. Thus we propose that interventions to treat cerebral palsy should be initiated as soon as possible in order to restore the nervous system to the correct developmental trajectory. One such treatment might be autologous stem cell transplantation either intracerebrally or intravenously. All babies come with an accessible supply of stem cells, the umbilical cord, which can supply cells that could theoretically replace missing neural cell types, or act indirectly by supplying trophic support or modulating inflammatory responses to hypoxia/ischaemia. However, for such radical treatment to be proposed, it is necessary to be able to detect and accurately predict the outcomes of brain injury from a very early age. This article reviews our current understanding of perinatal injuries that lead to cerebral palsy, how well modern imaging might predict outcomes, what stem cells are yielded from umbilical cord blood and experimental models of brain repair using stem cells.

Molecular mediators of mesenchymal stem cell biology

Mesenchymal stem cells (MSCs) have the ability to self-renew and differentiate into multiple lineages making them an appropriate candidate for stem cell therapy. In spite of achieving considerable success in preclinical models, limited success has been achieved in clinical settings with MSCs. A major impediment that is faced is low survival of MSCs in injured tissues following implantation. In order to enhance the reparative properties of MSCs, it is vital to understand the molecular signals that regulate MSC survival and self-renewal. This review assimilates information that characterizes MSCs and mentions their utilization in myocardial infarction therapy. Additionally, our attempt herein is to gather pertinent published information regarding the role of canonical Wnt and BMP signaling in regulating the potential of MSCs to self-renew, proliferate, differentiate, and survive.

Efficient generation of multipotent mesenchymal stem cells from umbilical cord blood in stroma-free liquid culture

Background

Haematopoiesis is sustained by haematopoietic (HSC) and mesenchymal stem cells (MSC). HSC are the precursors for blood cells, whereas marrow, stroma, bone, cartilage, muscle and connective tissues derive from MSC. The generation of MSC from umbilical cord blood (UCB) is possible, but with low and unpredictable success. Here we describe a novel, robust stroma-free dual cell culture system for long-term expansion of primitive UCB-derived MSC.

Methods and Findings

UCB-derived mononuclear cells (MNC) or selected CD34⁺ cells were grown in liquid culture in the presence of serum and cytokines. Out of 32 different culture conditions that have been tested for the efficient expansion of HSC, we identified one condition (DMEM, pooled human AB serum, Flt-3 ligand, SCF, MGDF and IL-6; further denoted as D7) which, besides supporting HSC expansion, successfully enabled long-term expansion of stromal/MSC from 8 out of 8 UCB units (5 MNC-derived and 3 CD34⁺ selected cells). Expanded MSC displayed a fibroblast-like morphology, expressed several stromal/MSC-related antigens (CD105, CD73, CD29, CD44, CD133 and Nestin) but were negative for haematopoietic cell markers (CD45, CD34 and CD14). MSC stemness phenotype and their differentiation capacity in vitro before and after high dilution were preserved throughout long-term culture. Even at passage 24 cells remained Nestin⁺, CD133⁺ and >95% were positive for CD105, CD73, CD29 and CD44 with the capacity to differentiate into mesodermal lineages. Similarly we show that UCB derived MSC express pluripotency stem cell markers despite differences in cell confluency and culture passages.

Further, we generated MSC from peripheral blood (PB) MNC of 8 healthy volunteers. In all cases, the resulting MSC expressed MSC-related antigens and showed the capacity to form CFU-F colonies.

Conclusions

This novel stroma-free liquid culture overcomes the existing limitation in obtaining MSC from UCB and PB enabling so far unmet therapeutic applications, which might substantially affect clinical practice.

An Efficient Approach to Isolation and Characterization of Pre- and Postnatal Umbilical Cord Lining Stem Cells for Clinical Applications

There have been various forms of mesenchymal stem cell-like (MSC-like) cells isolated from umbilical cords (UCs). The isolation of umbilical cord lining stem cells (ULSCs) may be of great value for those interested in a possible treatment to several disease/disorders. Unlike umbilical cord blood cells, these cells are unique because they can be expanded to therapeutically relevant numbers and cryopreserved for several different uses. Here we efficiently isolate stem cells from a small segment of pre- and postnatal UCs, and obtain therapeutically relevant amounts of ULSCs within 3 weeks. We demonstrate their growth potential and characterize them using immunocytochemistry, flow cytometry, and RT-PCR. In addition, we differentiate ULSCs into multiple lineages. Pre- and postnatal ULSCs are morphologically similar to mesenchymal stem cells (MSCs) and easily expand to greater than 70 population doublings. They express pluripotent markers Oct4 and nanog at the protein and RNA level. Flow cytometry demonstrates that they express markers indicative of MSCs in addition to high SSEA-4 expression. ULSCs are easily differentiated into osteogenic, adipogenic, chondrogenic, cardiogenic, and neurogenic cells. Pre- and postnatal ULSCs are characteristically similar in respect to their growth, marker expression, and plasticity, demonstrating they are highly conserved throughout development. ULSCs have phenotypic and genotypic properties of MSCs. These studies demonstrate the therapeutic potential of an otherwise discarded tissue. They are a perfect HLA match for the donor and an excellent match for immediate family members; therefore, they may serve as a therapeutic cell source.

Human umbilical cord blood stem cells: rational for use as a neuroprotectant in ischemic brain disease

The use of stem cells for reparative medicine was first proposed more than three decades ago. Hematopoietic stem cells from bone marrow, peripheral blood and human umbilical cord blood (CB) have gained major use for treatment of hematological indications. CB, however, is also a source of cells capable of differentiating into various non-hematopoietic cell types, including neural cells. Several animal model reports have shown that CB cells may be used for treatment of neurological injuries. This review summarizes the information available on the origin of CB-derived neuronal cells and the mechanisms proposed to explain their action. The potential use of stem/progenitor cells for treatment of ischemic brain injuries is discussed. Issues that remain to be resolved at the present stage of preclinical trials are addressed.

Human umbilical cord blood-derived mesenchymal stem cells improve neuropathology and cognitive impairment in an Alzheimer's disease mouse model through modulation of neuroinflammation

Human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSC) have a potential therapeutic role in the treatment of neurological disorders, but their current clinical usage and mechanism of action has yet to be ascertained in Alzheimer's disease (AD). Here we report that hUCB-MSC transplantation into amyloid precursor protein (APP) and presenilin1 (PS1) double-transgenic mice significantly improved spatial learning and memory decline. Furthermore, amyloid-β peptide (Aβ) deposition, β-secretase 1 (BACE-1) levels, and tau hyperphosphorylation were dramatically reduced in hUCB-MSC transplanted APP/PS1 mice. Interestingly, these effects were associated with reversal of disease-associated microglial neuroinflammation, as evidenced by decreased microglia-induced proinflammatory cytokines, elevated alternatively activated microglia, and increased anti-inflammatory cytokines. These findings lead us to suggest that hUCB-MSC produced their sustained neuroprotective effect by inducing a feed-forward loop involving alternative activation of microglial neuroinflammation, thereby ameliorating disease pathophysiology and reversing the cognitive decline associated with Aβ deposition in AD mice.

Reprogramming of active and repressive histone modifications following nuclear transfer with rabbit mesenchymal stem cells and adult fibroblasts

Following nuclear transfer (NT) the epigenetic state of a donor nucleus must be reprogrammed to an embryonic one. To evaluate the efficiency of nuclear reprogramming, we monitored the levels of histone H3 di/tri-methylated on lysine 4 (H3K4m2/3), a marker for transcriptionally active/permissive euchromatin, and of histone H3 tri-methylated on lysine 27 (H3K27m3), a modification associated with facultative heterochromatin, in embryos cloned using rabbit mesenchymal stem cells (MSC) and adult fibroblasts (RAF) isolated from the same animals. In vivo fertilized, in vitro cultured embryos served as controls. H3K27m3 was undetectable in all stages of control embryos except for weak staining in a few blastocyst cells. A similar situation was found in all NT embryos irrespective of the type of donor cells used, although both MSC and RAF stained substantially for H3K27m3. H3K4m2/3 levels were very high in one- and two-cell control embryos, but then decreased to reach a minimum at the eight-cell stage, and finally increased again to initial levels at the morula and blastocyst stage. Reprogramming of H3K4m2/3 differed remarkably among the different types NT embryos as well as between NT embryos and control embryos, and was apparently dependent on the type of donor cells. Interestingly, abnormal reprogramming of H3K4m2/3 was observed in NT embryos derived from both MSC and RAF, donor cell types with markedly different proliferation capacity. Our study demonstrates that the repressive chromatin modification, H3K27m3, is faithfully reprogrammed in NT embryos derived from MSC or RAF, while reprogramming of the activating chromatin modification, H3K4m2/3, is quite variable and does not reflect the situation observed in control embryos derived by fertilization.

Late outgrowth endothelial cells derived from Wharton jelly in human umbilical cord reduce neointimal formation after vascular injury: involvement of pigment epithelium-derived factor

OBJECTIVE

The number of endothelial progenitor cells (EPCs) that can be obtained from adult bone marrow and peripheral blood to treat cardiovascular diseases is limited. The goal was to examine the endothelial potential of Wharton jelly in human umbilical cord (WJC)-derived stem cells and evaluate their potential to affect neointimal formation after vascular injury.

METHODS AND RESULTS

Mesenchymal cells (MCs) were isolated from WJC and cultured in endothelial growth medium. Differentiation into late outgrowth endothelial cells (WJC-OECs) was demonstrated by incorporation of acetylated low-density lipoprotein and expression of the endothelial-specific markers. Transplantation of these cells into wire-injured femoral arteries in mice led to rapid reendothelialization. At 4 weeks after injury, the neointima/media area ratio was reduced and strong expression of pigment epithelium-derived factor (PEDF) compared to saline-or MC- or cord blood-OEC-treated mice. WJC-OECs-conditioned medium has an extremely strong capacity to inhibit the migration and proliferation of smooth muscle cells. The effects were inhibited by neutralizing antibody for PEDF and by siRNA silencing of PEDF.

CONCLUSIONS

We firstly demonstrated the presence of a cell population within WJC that has the potential to differentiate into OECs. Transplantation of WJC-OECs may play a crucial role in reestablishing endothelial integrity in injured vessels, thereby inhibiting neointimal hyperplasia. These findings have implications for a novel and practical cell-based therapy for vascular diseases.