Umbilical cord blood mesenchymal stem cells

Autologous umbilical cord blood mononuclear cell therapy for hypoplastic left heart syndrome: a nonrandomized control trial of the efficacy and safety of intramyocardial injections

BACKGROUND

Preliminary phase I clinical trial results revealed that autologous umbilical cord blood-derived mononuclear cells (UCB-MNCs) preserved right ventricular cardiac function. To establish the efficacy of intramyocardial injections of an autologous UCB-MNC product at the time of stage II palliation surgery in patients with hypoplastic left heart syndrome (HLHS).

METHODS

A phase IIb, multicenter, open-label, nonrandomized study was conducted. Ninety-five children (fifty treated and forty-five controls) with HLHS and its variants, a history of stage I palliation surgery, and planned stage II palliation surgery at less than thirteen months were enrolled. We assessed coprimary efficacy endpoints for changes in right ventricular cardiac function through fractional area changes and longitudinal and circumferential strain, both in the short term (three months) and long term (twelve months). Second, we assessed changes in biomarkers of cardiac injury. Safety endpoints included severe adverse events (SAEs), changes in overall health through vital signs, and cumulative hospitalization.

RESULTS

Assessment of our coprimary efficacy endpoints revealed an unfavorable change in longitudinal cardiac strain in the treatment group compared with an improvement in strain in the control group (unadjusted p =.032) in the short term. No differences were observed between the groups in terms of other coprimary efficacy endpoints in the short or long term. A secondary assessment of biomarkers of cardiac injury revealed higher troponin T levels in the treatment group at three and six hours postsurgery. Regarding safety, no deaths related to the administered product or delivery procedure were reported. The treatment group presented a greater incidence (20%) of at least one SAE than the control group at three months (p =.048). Additionally, no statistically significant differences were found for the other safety endpoints.

CONCLUSION

Intramyocardial injections of autologous UCB-MNC products into the right ventricular myocardium during stage II palliation surgery failed to enhance cardiac function in patients with hypoplastic left heart syndrome. REGISTERED ON CLINICALTRIALS.GOV: Registered on ClinicalTrials.gov (NCT03779711) on 12/04/2018; URL: https://clinicaltrials.gov/ct2/show/NCT0377971 .

Effect of mesenchymal stem cells and melatonin on experimentally induced peripheral nerve injury in rats

Injury of a peripheral nerve (PNI) leads to both ischemic and inflammatory alterations. Sciatic nerve injury (SNI) represents the most widely used model for PNI. Mesenchymal stem cell-based therapy (MSCs) has convenient properties on PNI by stimulating the nerve regeneration. Melatonin has cytoprotective activity. The neuroprotective characteristics of MSCs and melatonin separately or in combination remain a knowledge need. In the rats-challenged SNI, therapeutic roles of intralesional MSCs and intraperitoneal melatonin injections were evaluated by functional assessment of peripheral nerve regeneration by walking track analysis involving sciatic function index (SFI) and two electrophysiological tests, electromyography and nerve conduction velocity, as well as measurement of antioxidant markers in serum, total antioxidant capacity (TAC) and malondialdehyde, and mRNA expression of brain derived neurotrophic factor (BDNF) in nerve tissues in addition to the histopathological evaluation of nerve tissue. Both individual and combination therapy with MSCs and melatonin therapies could effectively ameliorate this SNI and promote its regeneration as evidenced by improving the SFI and two electrophysiological tests and remarkable elevation of TAC with decline in lipid peroxidation and upregulation of BDNF levels. All of these led to functional improvement of the damaged nerve tissues and good recovery of the histopathological sections of sciatic nerve tissues suggesting multifactorial synergistic approach of the concurrent usage of melatonin and MSCs in PNI. The combination regimen has the most synergistic neuro-beneficial effects in PNI that should be used as therapeutic option in patients with PNI to boost their quality of life.

Preclinical Studies and Clinical Prospects of Wharton's Jelly-Derived MSC for Treatment of Acute Radiation Syndrome

Purpose of Review

Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) have received widespread attention from researchers owing to the remarkable benefits offered by these cells over other stem cells. The primitive nature of WJ-MSCs, ease of isolation, differentiation ability, and immuno-modulatory nature make these cells superior to bone marrow MSCs and ideal to treat various human ailments. This review explores ability of WJ-MSCs to mitigate acute radiation syndrome caused by planned or unplanned radiation exposure.

Recent Findings

Recent reports suggest that WJ-MSCs home to damaged tissues in irradiated host and mitigate radiation induced damage to radiosensitive tissues such as hematopoietic and gastrointestinal systems. WJ-MSCs and conditioned media were found to protect mice from radiation induced mortality and also prevent radiation dermatitis. Local irradiation-induced lung toxicity in mice was significantly reduced by CXCR4 over-expressing WJ-MSCs.

Summary

Emerging evidences support safety and effectiveness of WJ-MSCs for treatment of acute radiation syndrome and lung injury after planned or accidental exposure. Additionally, conditioned media collected after culturing WJ-MSCs can also be used for mitigation of radiation dermatitis. Clinical translation of these findings would be possible after careful evaluation of resilience, effectiveness, and molecular mechanism of action of xenogeneic WJ-MSCs in non-human primates.

Stem Cell Therapy for Neonatal Hypoxic-Ischemic Encephalopathy: A Systematic Review of Preclinical Studies

Neonatal hypoxic-ischemic encephalopathy (HIE) is an important cause of mortality and morbidity in the perinatal period. This condition results from a period of ischemia and hypoxia to the brain of neonates, leading to several disorders that profoundly affect the daily life of patients and their families. Currently, therapeutic hypothermia (TH) is the standard of care in developing countries; however, TH is not always effective, especially in severe cases of HIE. Addressing this concern, several preclinical studies assessed the potential of stem cell therapy (SCT) for HIE. With this systematic review, we gathered information included in 58 preclinical studies from the last decade, focusing on the ones using stem cells isolated from the umbilical cord blood, umbilical cord tissue, placenta, and bone marrow. Outstandingly, about 80% of these studies reported a significant improvement of cognitive and/or sensorimotor function, as well as decreased brain damage. These results show the potential of SCT for HIE and the possibility of this therapy, in combination with TH, becoming the next therapeutic approach for HIE. Nonetheless, few preclinical studies assessed the combination of TH and SCT for HIE, and the existent studies show some contradictory results, revealing the need to further explore this line of research.

Allogeneic human umbilical cord Wharton's jelly stem cells increase several-fold the expansion of human cord blood CD34+ cells both in vitro and in vivo

Background

The transplantation of human umbilical cord blood (UCB) CD34+ cells has been successfully used to treat hematological disorders but one major limitation has been the low cell numbers available. Mesenchymal stem cells (MSCs) lying within the bone marrow in vivo behave like a scaffold on which CD34+ cells interact and proliferate. We therefore evaluated the use of allogeneic MSCs from the human UC Wharton’s jelly (hWJSCs) as stromal support for the ex vivo expansion of CD34+ cells.

Methods

We performed an in-depth evaluation of the primitiveness, migration, adhesion, maturation, mitochondrial behavior, and pathway mechanisms of this platform using conventional assays followed by the evaluation of engraftment potential of the expanded CD34+ cells in an in vivo murine model.

Results

We demonstrate that hWJSCs and its conditioned medium (hWJSC-CM) support the production of significantly high fold changes of CD34+, CD34+CD133+, CD34+CD90+, CD34+ALDH+, CD34+CD45+, and CD34+CD49f+ cells after 7 days of interaction when compared to controls. In the presence of hWJSCs or hWJSC-CM, the CD34+ cells produced significantly more primitive CFU-GEMM colonies, HoxB4, and HoxA9 gene expression and lower percentages of CD34+CXCR4+ cells. There were also significantly higher N-cadherin+ cell numbers and increased cell migration in transwell migration assays. The CD34+ cells expanded with hWJSCs had significantly lower mitochondrial mass, mitochondrial membrane potential, and oxidative stress. Green Mitotracker-tagged mitochondria from CD34+ cells were observed lying within red CellTracker-tagged hWJSCs under confocal microscopy indicating mitochondrial transfer via tunneling nanotubes. CD34+ cells expanded with hWJSCs and hWJSC-CM showed significantly reduced oxidative phosphorylation (ATP6VIH and NDUFA10) and increased glycolytic (HIF-1a and HK-1) pathway-related gene expression. CD34+ cells expanded with hWJSCs for 7 days showed significant greater CD45+ cell chimerism in the bone marrow of primary and secondary irradiated mice when transplanted intravenously.

Conclusions

In this report, we confirmed that allogeneic hWJSCs provide an attractive platform for the ex vivo expansion of high fold numbers of UCB CD34+ cells while keeping them primitive. Allogeneic hWJSCs are readily available in abundance from discarded UCs, can be easily frozen in cord blood banks, thawed, and then used as a platform for UCB-HSC expansion if numbers are inadequate.

Potentials of Differentiated Human Cord Blood-Derived Unrestricted Somatic Stem Cells in Treatment of Liver Cirrhosis

OBJECTIVES

Liver transplantation is the well-known treatment for chronic liver diseases; however, postoperative complications and lack of donors continue to be limitations with this treatment. Investigating new modalities for treatment of chronic liver illness is a must. In the present study, we aimed to clarify the effects of an in vitro hepatocyte-differentiated human unrestricted somatic stem cell transplant as a new cell-based therapy in an experimental model of chronic liver failure.

MATERIALS AND METHODS

Human umbilical cord blood-derived unrestricted somatic stem cells were isolated, cultured, propagated, and characterized. Cells were directed to differentiate into hepatocyte-like cells. An animal model of carbon tetrachloride cirrhotic liver failure was prepared, and the human in vitro differentiated unrestricted somatic stem cells were transplanted into the experimental model. Animals that did not receive transplant served as the pathologic control group. Animals were euthanized 12 weeks after transplant, and liver functions and histopathology were assessed.

RESULTS

Compared with the pathologic control group, the transplant group showed improvements in levels of alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin. Histopathologic examination of the transplant group also showed improvements in hydropic degeneration and fibrosis.

CONCLUSIONS

The use of unrestricted somatic stem cells, isolated and propagated from cord blood and then differentiated into hepatocyte-like cells, improved both fibrosis and normal function of cirrhotic livers. These cells could be considered as a line of cell-based therapy in cases of chronic liver disease.

Current Status of Canine Umbilical Cord Blood-Derived Mesenchymal Stem Cells in Veterinary Medicine

Stem cell therapy has prompted the expansion of veterinary medicine both experimentally and clinically, with the potential to contribute to contemporary treatment strategies for various diseases and conditions for which limited or no therapeutic options are presently available. Although the application of various types of stem cells, such as bone marrow-derived mesenchymal stem cells (BM-MSCs), adipose tissue-derived mesenchymal stem cells (AT-MSCs), and umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), has promising potential to improve the health of different species, it is crucial that the benefits and drawbacks are completely evaluated before use. Umbilical cord blood (UCB) is a rich source of stem cells; nonetheless, isolation of mesenchymal stem cells (MSCs) from UCB presents technical challenges. Although MSCs have been isolated from UCB of diverse species such as human, equine, sheep, goat, and canine, there are inherent limitations of using UCB from these species for the expansion of MSCs. In this review, we investigated canine UCB (cUCB) and compared it with UCB from other species by reviewing recent articles published from February 2003 to June 2017 to gain an understanding of the limitations of cUCB in the acquisition of MSCs and to determine other suitable sources for the isolation of MSCs from canine. Our review indicates that cUCB is not an ideal source of MSCs because of insufficient volume and ethical issues. However, canine reproductive organs discarded during neutering may help broaden our understanding of effective isolation of MSCs. We recommend exploring canine reproductive and adipose tissue rather than UCB to fulfill the current need in veterinary medicine for the well-designed and ethically approved source of MSCs.

Optimal Dose and Timing of Umbilical Stem Cells Treatment in Pulmonary Arterial Hypertensive Rats

PURPOSE

Pulmonary arterial hypertension (PAH) is a fatal disease which is characterized by an increase in pulmonary arterial pressure leading to increases in right ventricular afterload. Human umbilical cord blood derived-mesenchymal stem cells (hUCB-MSCs) administered via the jugular vein have been previously shown to improve PAH by reversal treatment. However, the effect of low dosage and transfusion timing of hUCB-MSCs on PAH has not yet been clearly established. Obviously, low dosage treatment can lead to a reduction in costs. This is the first study on early transfusion effect.

MATERIALS AND METHODS

This study was divided into two parts. The first part is an investigation of dose-dependent effect. hUCB-MSCs were administered into 3 groups of rats (UA: 3×10⁶ cells, UB: 1.5×10⁶ cells, UC: 3×10⁵ cells) via the external jugular vein at week 1 after monocrotaline (MCT) injection. The second part is a search for optimal treatment timing in 3×10⁵ cells dose of hUCB-MSCs administered at day 1 for UD group (low dose of hUCB-MSCs at day 1), at day 1 and week 1 for the UE group (dual transfusion of low dose of hUCB-MSCs at day 1 and week 1) and at 1 week for the UF group (reversal treatment of low dose hUCB-MSC at week 1) after MCT injection.

RESULTS

The administration of 3×10⁵ hUCB-MSCs was as effective as the 3×10⁶ dose in decreasing mean right ventricle (RV) pressure and pulmonary pathological changes. Early treatment with hUCB-MSCs improved mean RV pressure, pulmonary pathological changes and heart collagen 3 protein expression levels in PAH.

CONCLUSION

Low-dose early treatment of hUCB-MSCs is as effective as a high dose treatment of hUCB-MSCs in improving PAH although dual or reversal treatment is still more effective.

Freezing of Fresh Wharton's Jelly From Human Umbilical Cords Yields High Post-Thaw Mesenchymal Stem Cell Numbers for Cell-Based Therapies

Some cord blood banks freeze entire pieces of UC (mixed cord, MC) which after post-thaw yields mixed heterogeneous populations of mesenchymal stem cells (MSCs) from all its microanatomical compartments. Freezing of such entire tissues results in sub-optimal post-thaw cell recovery because of poor cryoprotectant diffusion and intracellular ice-formation, heat and water transport issues, and damage to intercellular junctions. To develop a simple method of harvesting pure homogeneous MSCs for cord blood banks, we compared the post-thaw behavior of three groups of frozen UC tissues: (i) freshly harvested WJ without cell separation; (ii) MSCs isolated from WJ (WJSC); and (iii) MC, WJ, and WJSC produced high post-thaw cell survival rates (93.52 ± 6.12% to 90.83 ± 4.51%) and epithelioid monolayers within 24 h in primary culture whereas post-thaw MC explants showed slow growth with mixed epithelioid and fibroblastic cell outgrowths after several days. Viability and proliferation rates of post-thawed WJ and hWJSC were significantly greater than MC. Post-thaw WJ and WJSC produced significantly greater CD24(+) and CD108(+) fluorescence intensities and significantly lower CD40(+) contaminants. Post-thaw WJ and WJSC produced significantly lesser annexin-V-positive and sub-G1 cells and greater degrees of osteogenic and chondrogenic differentiation compared to MC. qRT-PCR analysis of post-thaw MC showed significant decreases in anti-apoptotic gene expression (SURVIVIN, BCL2) and increases in pro-apoptotic (BAX) and cell cycle regulator genes (P53, P21, ROCK 1) compared to WJ and WJSC. We conclude that freezing of fresh WJ is a simple and reliable method of generating large numbers of clinically utilizable MSCs for cell-based therapies.

Immortalisation with hTERT Impacts on Sulphated Glycosaminoglycan Secretion and Immunophenotype in a Variable and Cell Specific Manner

Background

Limited options for the treatment of cartilage damage have driven the development of tissue engineered or cell therapy alternatives reliant on ex vivo cell expansion. The study of chondrogenesis in primary cells is difficult due to progressive cellular aging and senescence. Immortalisation via the reintroduction of the catalytic component of telomerase, hTERT, could allow repeated, longitudinal studies to be performed while bypassing senescent phenotypes.

Methods

Three human cell types: bone marrow-derived stromal cells (BMA13), embryonic stem cell-derived (1C6) and chondrocytes (OK3) were transduced with hTERT (BMA13H, 1C6H and OK3H) and proliferation, surface marker expression and tri-lineage differentiation capacity determined. The sulphated glycosaminoglycan (sGAG) content of the monolayer and spent media was quantified in maintenance media (MM) and pro-chondrogenic media (PChM) and normalised to DNA.

Results

hTERT expression was confirmed in transduced cells with proliferation enhancement in 1C6H and OK3H cells but not BMA13H. All cells were negative for leukocyte markers (CD19, CD34, CD45) and CD73 positive. CD14 was expressed at low levels on OK3 and OK3H and HLA-DR on BMA13 (84.8%). CD90 was high for BMA13 (84.9%) and OK3 (97.3%) and moderate for 1C6 (56.7%), expression was reduced in BMA13H (33.7%) and 1C6H (1.6%). CD105 levels varied (BMA13 87.7%, 1C6 8.2%, OK3 43.3%) and underwent reduction in OK3H (25.1%). 1C6 and BMA13 demonstrated osteogenic and adipogenic differentiation but mineralised matrix and lipid accumulation appeared reduced post hTERT transduction. Chondrogenic differentiation resulted in increased monolayer-associated sGAG in all primary cells and 1C6H (p<0.001), and BMA13H (p<0.05). In contrast OK3H demonstrated reduced monolayer-associated sGAG in PChM (p<0.001). Media-associated sGAG accounted for ≥55% (PChM-1C6) and ≥74% (MM-1C6H).

Conclusion

In conclusion, hTERT transduction could, but did not always, prevent senescence and cell phenotype, including differentiation potential, was affected in a variable manner. As such, these cells are not a direct substitute for primary cells in cartilage regeneration research.

Chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in vitro

Different therapeutic techniques have been developed for regeneration of articular cartilage injuries, but none has provided an optimal solution to their treatment. Human umbilical cord blood-mesenchymal Stem Cells (HUCB-MSCs) have been considered as promising alternative cell source for cartilage repair.

OBJECTIVES

Examining the success rate of MSCs isolation from HUCB as well as chondrogenic differentiation potential of HUCB-MSCs in vitro.

MATERIALS AND METHODS

32 UCB samples were collected, in addition to 5 bone marrow (BM) and 5 peripheral blood (PB) samples, taken as reference controls. Samples were used for mononuclear cells isolation from which MSCs were expanded under complete aseptic conditions, were verified morphologically and through the presence of CD44 and CD105, and absence of CD34.

RESULTS

Success rate of UCB-MSCs isolation was (25%), a rate that was lower than those of PB (40%) and BM (80%). Accordingly, certain input parameters have been recommended for successful MSCs isolation from UCB. On selecting samples in which recommended parameters were fulfilled, success rate was increased to 72%. This was together with providing optimal experiment conditions; mainly type of expansion medium, success rate reached 80%. Then, successfully expanded MSCs were subjected to chondrogenic differentiation by culturing in pelleted micromass system in presence of transforming growth factor beta-1 and chondrogenic medium devoid of fetal bovine serum to evaluate their ability to undergo chondrogenesis. Differentiation was verified microscopically using special stains, and proved by reverse transcriptase-polymerase chain reaction for expression of aggrecan and collagen II genes. In conclusion, in vitro differentiation into chondrocytes is possible from HUCB-MSCs.

An experimental approach to the generation of human embryonic stem cells equivalents

Recently, particular attention has been paid to the human embryonic stem cells (hESC) in the context of their potential application in regenerative medicine; however, ethical concerns prevent their clinical application. Induction of pluripotency in somatic cells seems to be a good alternative for hESC recruitment regarding its potential use in tissue regeneration, disease modeling, and drug screening. Since Yamanaka's team in 2006 restored pluripotent state of somatic cells for the first time, a significant progress has been made in the area of induced pluripotent stem cells (iPSC) generation. Here, we review the current state of knowledge in the issue of techniques applied to establish iPSC. Somatic cell nuclear transfer, cell fusion, cell extracts reprogramming, and techniques of direct reprogramming are described. Retroviral and lentiviral transduction are depicted as ways of cell reprogramming with the use of integrating vectors. Contrary to them, adenoviruses, plasmids, single multiprotein expression vectors, and PiggyBac transposition systems are examples of non-integrative vectors used in iPSC generation protocols. Furthermore, reprogramming with the delivery of specific proteins, miRNA or small chemical compounds are presented. Finally, the changes occurring during the reprogramming process are described. It is concluded that subject to some limitations iPSC could become equivalents for hESC in regenerative medicine.

Stem Cell Banking for Regenerative and Personalized Medicine

Regenerative medicine, tissue engineering and gene therapy offer the opportunity to treat and cure many of today’s intractable afflictions. These approaches to personalized medicine often utilize stem cells to accomplish these goals. However, stem cells can be negatively affected by donor variables such as age and health status at the time of collection, compromising their efficacy. Stem cell banking offers the opportunity to cryogenically preserve stem cells at their most potent state for later use in these applications. Practical stem cell sources include bone marrow, umbilical cord blood and tissue, and adipose tissue. Each of these sources contains stem cells that can be obtained from most individuals, without too much difficulty and in an economical fashion. This review will discuss the advantages and disadvantages of each stem cell source, factors to be considered when contemplating banking each stem cell source, the methodology required to bank each stem cell source, and finally, current and future clinical uses of each stem cell source.

Tropism of avian influenza A (H5N1) virus to mesenchymal stem cells and CD34+ hematopoietic stem cells

The presence of abnormal hematologic findings such as lymphopenia, thrombocytopenia, and pancytopenia were diagnosed in severe cases of avian influenza A H5N1. Whether direct viral dissemination to bone marrow (BM) cells causes this phenomenon remains elusive. We explore the susceptibility of the two stem cell types; hematopoietic stem cells (HSCs) and mesenchymal stromal cells (MSCs) isolated from human BM cells or cord blood, to infection with avian H5N1 viruses. For the first time, we demonstrated that the H5N1 virus could productively infect and induce cell death in both human stem cell types. In contrast, these activities were not observed upon human influenza virus infection. We also determined whether infection affects the immunomodulatory function of MSCs. We noted a consequent dysregulation of MSC-mediated immune modulation as observed by high cytokine and chemokine production in H5N1 infected MSCs and monocytes cocultures. These findings provide a better understanding of H5N1 pathogenesis in terms of broad tissue tropism and systemic spread.

Role of CD271 enrichment in the isolation of mesenchymal stromal cells from umbilical cord blood

Isolation of mesenchymal stromal cells (MSCs) from the umbilical cord blood (UCB) has a success rate of 25% and is frequently contaminated by osteoclast-like cells (OLCs). CD271 is a well-known marker for the enrichment of bone marrow (BM) MSCs. We have assessed the effect of CD271 isolation on the isolation rate of MSCs from UCB. Twenty-one samples of UCB were collected. Ten samples of UCB and five of BM underwent CD271 isolation using magnetic activated cell sorting. The other 11 UCB samples were used as the control. The isolated cells were cultured and MSC isolation was confirmed with respect to morphology, flow cytometry, adipogenic and osteogenic differentiation potentials. CD271-positive UCB cells did not show outgrowth despite 54.5% MSCs isolation in the non-enriched portion. No OLC was noted in the CD271-enriched group, but 66% of the non-enriched samples were contaminated. All the CD271-positive BM cells formed MSC colonies. Although the per cent of CD271+ cells showed no difference between BM-mononuclear cells (MNCs) and UCB-MNCs, the haematopoietic marker, CD45, was found in a higher percentage of CD271-positive UCB-MNCs. The results of our study indicate that, although CD271 is a valuable marker for enrichment of MSCs from BM, it does not contribute to isolation of MSCs from UCB. In this source, most of the CD271+ cells are from haematopoietic origin, and possibly the process of isolation may eliminate the very low frequent MSCs and the isolation therefore fails.

Parameters that influence the isolation of multipotent mesenchymal stromal cells from human umbilical cord blood

BACKGROUND AND OBJECTIVES

Umbilical cord blood is an important source of stem cells. However, isolating multipotent mesenchymal stromal cells (MSCs) from umbilical cord blood presents methodological challenges. We compared the effectiveness of six approaches to improve the success rate of MSC isolation and proliferation from umbilical cord blood.

METHODS

Thirty umbilical cord blood units underwent investigation. In 10 samples, MNCs from each sample were divided into four groups to test the effect of negative immunodepletion (NI) alone (group A); NI plus basic fibroblastic growth factor (bFGF) supplementation together (group B); bFGF supplementation alone (group C); and culture with neither NI nor bFGF (group D). The cells of each group were isolated from 10mL of umbilical cord blood. For investigating the effect of sample volume (group E) and MesenCult Proliferation Kits (group F), cells were isolated from 45±2ml. MSCs were identified on the basis of morphological, flow cytometric and differentiation potential characteristics.

RESULTS

In groups of A-D, one week after the initial seeding, the cells showed a rounded appearance, and in the fourth week, many of them died. MSCs outgrowth was seen in 40% of the samples from group F, and this yield was further enhanced to 60% in cultures done with the MesenCult Proliferation Kit (group F). The fibroblast-like cells expanded rapidly and showed features of MSCs.

CONCLUSION

Sample volume was the parameter that showed the greatest influence on the isolation yield of MSCs from umbilical cord blood. This could be further enhanced by adding the MesenCult Proliferation Kit.

Transplantation of cord blood mesenchymal stem cells as spheroids enhances vascularization

Despite promising results from the therapeutic use of stem cells for treating ischemic diseases, the poor survival of cells transplanted into ischemic regions is one of the major problems that undermine the efficacy of stem cell therapy. Cord blood mononuclear cells (CBMNCs) are an alternative source of mesenchymal stem cells (MSCs) without disadvantages, such as the painful and invasive harvesting procedure, of MSCs derived from bone marrow or adipose tissue. In the present study, we investigated whether the angiogenic efficacy of cord blood mesenchymal stem cells (CBMSCs) can be enhanced by grafting as spheroids in a mouse hindlimb ischemia model. Human CBMSC (hCBMSC) spheroids were prepared by using the hanging-drop method. Mouse hindlimb ischemia was induced by excising the femoral artery and its branches. After surgery, the animals were divided into no-treatment, dissociated hCBMSC, and spheroid hCBMSC groups (n=8 per group) and received corresponding hCBMSC treatments. After surgery, the ischemic hindlimbs were monitored for 4 weeks, and then, the ischemic hindlimb muscles were harvested for histological analysis. Apoptotic signaling, angiogenesis-related signal pathways, and blood vessel formation were investigated in vitro and/or in vivo. The transplantation of hCBMSCs as spheroids into mouse ischemic hindlimbs significantly improved the survival of the transplanted cells by suppressing apoptotic signaling while activating antiapoptotic signaling. Furthermore, the transplantation of hCBMSCs as spheroids significantly increased the number of microvessels and smooth muscle α-actin-positive vessels in the ischemic limbs of mice, and attenuated limb loss and necrosis. Human CBMNC can be considered an alternative source of MSC, and spheroid-based hCBMSC delivery can be considered a simple and effective strategy for enhancing the therapeutic efficacy of hCBMSCs.

Human umbilical cord Wharton's jelly mesenchymal stem cells do not transform to tumor-associated fibroblasts in the presence of breast and ovarian cancer cells unlike bone marrow mesenchymal stem cells

Human bone marrow mesenchymal stem cells (hBMMSCs) were shown to transform into tumor-associated fibroblasts (TAFs) when in the vicinity of breast cancer tumors and played an important role in tumor enhancement and metastasis. In early human development MSCs migrating from the yolk sac and aorta-gonad-mesonephros (AGM) via the umbilical cord to the placenta and back to the fetal bone marrow were shown to get trapped in the gelatinous Wharton's jelly of the umbilical cord. The common origin of the Wharton's jelly MSCs and the finally homed hBMMSCs prompted us to evaluate whether hWJSCs are also involved in TAF transformation. hWJSCs and hBMMSCs were grown in the presence of breast and ovarian cancer cell conditioned medium (MDA-TCM, TOV-TCM) for 30 days. No changes were observed in the hWJSCs but the hBMMSCs transformed from short to thin long fibroblasts, their proliferation rates increased and CD marker expression decreased. The transformed hBMMSCs showed positive staining for the tumor-associated markers FSP, VEGF, EGF, and Tn-C. Real-time PCR and multiplex luminex bead analysis showed upregulation of TAF-related genes (FSP, FAP, Tn-C, Tsp-1, EGF, bFGF, IL-6, α-SMA, VEGF, and TGF-β) for hBMMSCs with low expression for hWJSCs. The luciferase assay showed that hWJSCs previously exposed to MDA-TCM or TOV-TCM had no stimulatory growth effect on luciferase-tagged MDA or TOV cells unlike hBMMSCs. The results confirmed that hWJSCs do not transform to the TAF phenotype and may therefore not be associated with enhanced growth of solid tumors making them a safe MSC for cell based therapies.

Therapeutic potential of transplanted placental mesenchymal stem cells in treating Chinese miniature pigs with acute liver failure

BACKGROUND

Stem cell-based therapy to treat liver diseases is a focus of current research worldwide. So far, most such studies depend on rodent hepatic failure models. The purpose of this study was to isolate mesenchymal stem cells from human placenta (hPMSCs) and determine their therapeutic potential for treating Chinese experimental miniature pigs with acute liver failure (ALF).

METHODS

hPMSCs were isolated and analyzed for their purity and differentiation potential before being employed as the donor cells for transplantation. ALF models of Chinese experimental miniature pigs were established and divided into four groups: no cell transplantation; hPMSCs transplantation via the jugular vein; X-ray-treated hPMSCs transplantation via the portal vein; and hPMSCs transplantation via the portal vein. The restoration of biological functions of the livers receiving transplantation was assessed via a variety of approaches such as mortality rate determination, serum biochemical analysis, and histological, immunohistochemical, and genetic analysis.

RESULTS

hPMSCs expressed high levels of CD29, CD73, CD13, and CD90, had adipogenic, osteogenic, and hepatic differentiation potential. They improved liver functions in vivo after transplantation into the D-galactosamine-injured pig livers as evidenced by the fact that ALT, AST, ALP, CHE, TBIL, and TBA concentrations returned to normal levels in recipient ALF pigs. Meanwhile, histological data revealed that transplantation of hPMSCs via the portal vein reduced liver inflammation, decreased hepatic denaturation and necrosis, and promoted liver regeneration. These ameliorations were not found in the other three groups. The result of 7-day survival rates suggested that hPMSCs transplantation via the portal vein was able to significantly prolong the survival of ALF pigs compared with the other three groups. Histochemistry and RT-PCR results confirmed the presence of transplanted human cells in recipient pig livers (Groups III, IV).

CONCLUSIONS

Our data revealed that hPMSCs could not only differentiate into hepatocyte-like cells in vitro and in vivo, but could also prolong the survival time of ALF pigs. Regarding the transplantation pathways, the left branch of the portal vein inside the liver was superior to the jugular vein pathway. Thus, hPMSCs transplantation through the portal vein by B-ultrasonography may represent a superior approach for treating liver diseases.

Human umbilical cord Wharton's jelly stem cells and its conditioned medium support hematopoietic stem cell expansion ex vivo

Bone marrow mesenchymal stromal cells (BMMSCs) have been used as feeder support for the ex vivo expansion of hematopoietic stem cells (HSCs) but have the limitations of painful harvest, morbidity, and risk of infection to the patient. This prompted us to explore the use of human umbilical cord Wharton's jelly MSCs (hWJSCs) and its conditioned medium (hWJSC-CM) for ex vivo expansion of HSCs in allogeneic and autologous settings because hWJSCs can be harvested in abundance painlessly, are proliferative, hypoimmunogenic, and secrete a variety of unique proteins. In the presence of hWJSCs and hWJSC-CM, HSCs put out pseudopodia-like outgrowths and became highly motile. Time lapse imaging showed that the outgrowths helped them to migrate towards and attach to the upper surfaces of hWJSCs and undergo proliferation. After 9 days of culture in the presence of hWJSCs and hWJSC-CM, MTT, and Trypan blue assays showed significant increases in HSC numbers, and FACS analysis generated significantly greater numbers of CD34(+) cells compared to controls. hWJSC-CM produced the highest number of colonies (CFU assay) and all six classifications of colony morphology typical of hematopoiesis were observed. Proteomic analysis of hWJSC-CM showed significantly greater levels of interleukins (IL-1a, IL-6, IL-7, and IL-8), SCF, HGF, and ICAM-1 compared to controls suggesting that they may be involved in the HSC multiplication. We propose that cord blood banks freeze autologous hWJSCs and umbilical cord blood (UCB) from the same umbilical cord at the same time for the patient for future ex vivo HSC expansion and cell-based therapies.

Transplantation of umbilical cord-derived mesenchymal stem cells as a novel strategy to protect the central nervous system: technical aspects, preclinical studies, and clinical perspectives

The prevention of perinatal neurological disabilities remains a major challenge for public health, and no neuroprotective treatment to date has proven clinically useful in reducing the lesions leading to these disabilities. Efforts are, therefore, urgently needed to test other neuroprotective strategies including cell therapies. Although stem cells have raised great hopes as an inexhaustible source of therapeutic products that could be used for neuroprotection and neuroregeneration in disorders affecting the brain and spinal cord, certain sources of stem cells are associated with potential ethical issues. The human umbilical cord (hUC) is a rich source of stem and progenitor cells including mesenchymal stem cells (MSCs) derived either from the cord or from cord blood. hUC MSCs (hUC-MSCs) have several advantages as compared to other types and sources of stem cells. In this review, we will summarize the most recent findings regarding the technical aspects and the preclinical investigation of these promising cells in neuroprotection and neuroregeneration, and their potential use in the developing human brain. However, extensive studies are needed to optimize the administration protocol, safety parameters, and potential preinjection cell manipulations before designing a controlled trial in human neonates.

Cord stem-cell transplantation in Ontario: do we need a public bank?

It has been 21 years since the first successful use of umbilical cord blood as a source of donor cells for hematopoietic stem cell transplantation (HSCT). Over those years, cord blood transplantation (CBT) has shown marked success as an effective modality in the treatment of children and adults with hematologic malignancies, marrow failure, immunodeficiency, hemoglobinopathy, and inherited metabolic diseases. Furthermore, transplantation without full human leukocyte antigen (HLA) matching is possible and, despite a lower incidence of graft-versus-host disease, graft-versus-leukemia effect is preserved. More than 20,000 cbts have been performed worldwide. Ontario is the most populated province in Canada, and its cbt numbers have increased dramatically in recent years, but most of the umbilical cord blood units are purchased from unrelated international registries. There is no public cord bank in Ontario, but there is a private cord banking option, and notably, Ontario has the largest number of live births in Canada [approximately 40% of all Canadian live births per year occur in Ontario (Statistics Canada, 2007)]. In this brief review, the pros and cons of private and public cord banking and the feasibility of starting an Ontario public cord bank are discussed.

A rapid, simple, and reproducible method for the isolation of mesenchymal stromal cells from Wharton's jelly without enzymatic treatment

The co-infusion of mesenchymal stromal cells (MSCs) with hematopoietic stem cells could improve the hematopoietic engraftment after cord blood transplant. Adult bone marrow is the major source of MSCs for cell therapy. However, bone marrow aspiration involves an invasive procedure and, in the case of a cord blood transplant, requires the use of a third party. The umbilical cord matrix, called Wharton's jelly (WJ), was previously shown to be a valuable source of MSCs. However, the process of cell separation is not standardized and needs to be optimized. In this study, we focused on the efficiency of the isolation procedure and expansion of cells from WJ MSCs isolated from human full-term umbilical cords. MSCs were isolated from the WJ without enzyme digestion or dissection. The procedure was based only on the plastic adhesion capacities of MSCs. Briefly, umbilical cord segments of 5-10 cm were cut longitudinally and plated with the WJ onto a plastic surface for 5 days in an appropriate culture medium. After removing the cord segment, the culture was pursued until subconfluency. The number of cells and their phenotypes, clonogenic capacities, differentiation capacities, immunomodulation, and hematopoietic supportive functions were evaluated. Using this method, we were able to isolate MSCs from all human umbilical cords analyzed (n = 50). We obtained a mean of 1.4 × 10(8) cells at the second passage and >7 × 10(9) cells at the third. The expanded cells expressed characteristic markers and presented typical functional properties of MSCs such as differentiation capacities, immunologic properties, and hematopoietic supportive functions. In conclusion, we have established a simple, rapid, and reproducible protocol to isolate abundant MSCs from short segments of umbilical cords.

Biological characteristics of stem cells from foetal, cord blood and extraembryonic tissues

Foetal stem cells (FSCs) can be isolated during gestation from many different tissues such as blood, liver and bone marrow as well as from a variety of extraembryonic tissues such as amniotic fluid and placenta. Strong evidence suggests that these cells differ on many biological aspects such as growth kinetics, morphology, immunophenotype, differentiation potential and engraftment capacity in vivo. Despite these differences, FSCs appear to be more primitive and have greater multi-potentiality than their adult counterparts. For example, foetal blood haemopoietic stem cells proliferate more rapidly than those found in cord blood or adult bone marrow. These features have led to FSCs being investigated for pre- and post-natal cell therapy and regenerative medicine applications. The cells have been used in pre-clinical studies to treat a wide range of diseases such as skeletal dysplasia, diaphragmatic hernia and respiratory failure, white matter damage, renal pathologies as well as cancers. Their intermediate state between adult and embryonic stem cells also makes them an ideal candidate for reprogramming to the pluripotent status.

Derivation efficiency, cell proliferation, freeze-thaw survival, stem-cell properties and differentiation of human Wharton's jelly stem cells

Human mesenchymal stem cells (MSC) are non-controversial multipotent stem cells. Their presence in umbilical cord blood (UCB) has been debated in some studies and others report low counts per cord blood unit and poor proliferation rates. On the other hand, Wharton's jelly of human umbilical cords appears to be a rich source of human MSC. This study derived 13 human Wharton's jelly stem cell (WJSC) lines from 13 human umbilical cords (100%) and recovered 4.7 +/- 0.2 x 10(6) live WJSC/cm of cord before culture. Complex culture medium produced greater proliferation rates of the WJSC in culture compared with simple medium. The mean population doubling times were 24.47 +/- 0.33 to 26.25 +/- 0.50 h in complex medium. The stem-cell markers of the WJSC were retained for at least 10 passages in both media. After programmed machine freezing, the thaw-survival rates of WJSC were 85-90% and they could be differentiated into neurons. Given the high derivation efficiency, availability of large numbers of fresh live cells, high expansion capabilities, prolonged maintenance of stem-cell properties and differentiation potential, it is proposed that human WJSC may be frozen at the same time as UCB in cord blood banks for regenerative medicine purposes.

Human dental follicle precursor cells of wisdom teeth: isolation and differentiation towards osteoblasts for implants with and without scaffolds

The human dental follicle is a developmental precursor for essential periodontal tissues such as periodontal ligament and root development. These cells can be expected to differentiate into several lineages, since they are derived from mesoderm. Especially the differentiation towards the osteogenic lineage could be interesting for tissue regeneration with or without growing on scaffold biomaterials in autologous transplantation for reconstruction of large bone defects and incorporation of teeth implants.

Here we demonstrate a fast and efficient method to isolate stem cells out of the dental follicle of wisdom teeth and their more determined lineage specific commitment into the osteogenic direction.

Typical markers confirmed the stem cell character of the isolated and differentiated cells and the successful differentiation has been verified in addition after lineage specific induction using corresponding stainings. In order to evaluate the quality of the cells microbiological investigations were performed and showed that all samples contained microbial species. Pre‐treatment of patients with antibiotics reduced the number of microorganisms to a minimum but did not suffice to eliminate all bacteria. The predominantly found species were gram‐positive cocci being either catalase‐positive and oxidase‐negative or catalase‐ and oxidase‐negative. Most microorganisms belonged to the families of Streptococcaceae and Staphylococcaceae. During cultivation of the stem cells, the contamination with microorganisms could be easily suppressed by usage of standard cell culture conditions with penicillin and streptomycin.

A comprehensive review on mesenchymal stem cell growth and senescence

In recent years mesenchymal stem cells (MSCs) have generated a great deal of excitement as an attractive alternative to embryonic stem cells (ESCs) in cell-based regenerative medicine. In contrast to cells of embryonic origin, however, the clinical application of MSCs is heavily restricted by their finite ability of self-renewal, in which they resemble the rest of the somatic cells. Yet the mechanisms controlling MSC proliferation and senescence remain unclear. This review summarizes recent advances in our understanding of the factors affecting MSC expansion in vitro and discusses the pattern of their senescence with particular emphasis on the role of telomere shortening, activation of effectory pathways, and oxidative stress. The issues associated with MSC growth and senescence will be shown in the context of other somatic cells, and all of the parallels and disparities will be delineated precisely.

Cord blood--an alternative source for bone regeneration

Bone regeneration is one of the best investigated pathways in mesenchymal stromal cell (MSC) biology. Therefore strong efforts have been made to introduce tissue engineering and cell therapeutics as an alternative treatment option for patients with bone defects. This review of the literature gives an overview of MSC biology aiming for clinical application including advantages but also specific challenges and problems which are associated with cord blood derived stromal cell (CB-MSC) as a source for bone regeneration. The use of postnatal CB-MSC is ethically uncomplicated and requires no invasive harvesting procedure. Moreover, most data document a high osteogenic potential of CB-MCS and also low immunoreactivity compared with other MSC types. The expression profile of CB-MSC during osteogenic differentiation shows similarities to that of other MSC types. Within the umbilical cord different MSC types have been characterized which are potent to differentiate into osteoblasts. In contrast to a large number of in vitro investigations there are only few in vivo studies available so far.

Xenotransplantation of Human Umbilical Cord Blood Mononuclear Cells to Rats with D-Galactosamine-Induced Hepatitis

Cord blood is an attractive cell source in regenerative medicine and represents an alternative to bone marrow. The aim of this study was to investigate whether human umbilical cord blood mononuclear (HUCBM) cells might be valuable in hepatic regenerative medicine. HUCBM cells differentiated in vitro into hepatocytes, as suggested by expression of albumin, cytokeratin-18, glutamine synthetase, α-fetoprotein, and cytochrome P450 3A4 at both mRNA and protein levels in a time-dependent fashion. In contrast, the hematopoietic phenotype was gradually lost, as demonstrated by disappearance of CD45 expression. The regenerative potential of HUCBM cells was tested by using a human-to-rat xenotransplant model in which HUCBM cells were intraportally injected into rats with D-galactosamine-induced hepatitis. Liver histology and biochemical markers of hepatic damage were determined. Presence of human cells was detected in blood and liver of both control and D-galactosamine-treated animals. Cell transplantation produced an improvement in both the histological damage and liver function, as demonstrated by plasma values of alkaline phosphatase, γ-glutamyl transferase, lactate dehydrogenase, and total and direct bilirubins. Results obtained suggest that HUCBM cells are capable of hepatic engraftment in this human-to-rat xenotransplant model and that transplantation of HUCBM cells may be a suitable therapy for liver disease.