New Simple and Rapid Method for Purification of Mesenchymal Stem Cells from the Human Umbilical Cord Wharton Jelly

Emerging of a new CD3+CD31HCD184+ tang cell phenothype in Sjögren’s syndrome induced by microencapsulated human umbilical cord matrix-derived multipotent stromal cells

Background

Sjögren’s syndrome (SS) is an autoimmune disease hallmarked by infiltration and destruction of exocrine glands. Currently, there is no therapy that warrants full recovery of the affected tissues. Umbilical cord-derived multipotent stromal cells, microincapsulated in an endotoxin-free alginate gel (CpS-hUCMS), were shown to modulate the inflammatory activity of PBMCs in SS patients in vitro, through release of soluble factors (TGFβ1, IDO1, IL6, PGE2, VEGF). These observations led us to set up the present study, aimed at defining the in vitro effects of CpS-hUCMS on pro- and anti-inflammatory lymphocyte subsets involved in the pathogenesis of SS.

Methods and results

Peripheral blood mononuclear cells (PBMCs) upon collection from SS patients and matched healthy donors, were placed in co-culture with CpS-hUCMS for five days. Cellular proliferation and T- (Tang, Treg) and B- (Breg, CD19+) lymphocyte subsets were studied by flow cytometry, while Multiplex, Real-Time PCR, and Western Blotting techniques were employed for the analysis of transcriptome and secretome. IFNγ pre-treated hUCMS were assessed with a viability assay and Western Blotting analysis before co-culture. After five days co-culture, CpS-hUCMS induced multiple effects on PBMCs, with special regard to decrease of lymphocyte proliferation, increase of regulatory B cells and induction of an angiogenic T cell population with high expression of the surface marker CD31, that had never been described before in the literature.

Conclusion

We preliminarily showed that CpS-hUCMS can influence multiple pro- and anti-inflammatory pathways that are deranged in SS. In particular, Breg raised and a new Tang phenothype CD3+CD31HCD184+ emerged. These results may considerably expand our knowledge on multipotent stromal cell properties and may open new therapeutic avenues for the management of this disease, by designing ad hoc clinical studies.

Co-microencapsulation of human umbilical cord-derived mesenchymal stem and pancreatic islet-derived insulin producing cells in experimental type 1 diabetes

INTRODUCTION

Post-partum umbilical cord Wharton Jelly-derived adult mesenchymal stem cells (hUCMS) hold anti-inflammatory and immunosuppressive properties. Human pancreatic islet-derived progenitor cells (hIDC) may de-differentiate, and subsequently re-differentiate into insulin producing cells. The two cell types share common molecules that facilitate their synergistic interaction and possibly crosstalk, likely useful for the cell therapy of type 1 diabetes (T1D).

MATERIALS AND METHODS

Upon microencapsulation in sodium alginate (AG), hUCMS and hIDC were able to form cell co-aggregates that looked well integrated and viable. We then grafted microencapsulated hUCMS/hIDC co-aggregates into non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice, and observed an acquired ability of cells to produce and store hormones. Finally, we transplanted these biohybrid constructs into NOD mice with recent onset, spontaneous overt diabetes, observing a decline of blood glucose levels.

RESULTS

In vitro, we have shown that hUCMS inhibited proliferation of allogeneic polymorphonuclear blood cells from patients with T1D, while promoting expansion of FoxP3⁺ Tregs. Reversal of hyperglycemia in diabetic NODs seems to suggest that hUCMS and hIDC, upon co-microencapsulation, anatomically and functionally synergized to accomplish two goals: maintain tracer insulin output by hIDC, while exploting the immunoregulatory properties of hUCMS.

CONCLUSION

We have gathered preliminary evidence that the two adult stem cell types within AG microcapsules, may synergistically promote tracer insulin production, while "freezing" the autoimmune disease process, and help reversal of the recent onset hyperglycemia in a spontaneous, autoimmune rodent model of diabetes, the NOD mouse, with no need for pharmacologic immunosuppression.

Antioxidant pretreatment enhances umbilical cord derived stem cells survival in response to thermal stress in vitro

Aim: Pretreatment of stem cells with antioxidants accelerates their ability to counter oxidative stress and is associated with the overall therapeutic outcome of their transplantation. Material & methods: Wharton Jelly derived mesenchymal stem cells (WJMSCs) were cultured and pretreated with various doses of antioxidants; Vitamin C (Vit C), Vitamin E (Vit E), Vitamin D3 (Vit D3) and their Cocktail, followed by exposure to in vitro heat injury. Assessment of WJMSCs survival, paracrine release, in vitro wound healing and expression of angiogenic and survival markers was conducted. Results: The results displayed an enhanced survival of WJMSCs especially in the case of Cocktail priming. Conclusion: Our data suggest that antioxidant pretreatment of WJMSCs strengthens the endurance of the cells, within stress conditions.

Differentiation of Human Mesenchymal Stem Cells from Wharton's Jelly Towards Neural Stem Cells Using A Feasible and Repeatable Protocol

The transplantation of neural stem cells (NSCs) capable of regenerating to the cells of the central nervous system (CNS) is a promising strategy in the treatment of CNS diseases and injury. As previous studies have highlighted mesenchymal stem cells (MSCs) as a source of NSCs, this study aimed to develop a feasible, efficient, and reproducible method for the neural induction of MSCs isolated from Wharton's jelly (hWJ-MSCs). We induced neural differentiation in a monolayer culture using epidermal growth factor, basic fibroblast growth factor, N2, and B27 supplements. This resulted in a homogenous population of proliferating cells that expressed certain neural markers at both the protein and mRNA levels. Flow cytometry and immunocytochemistry confirmed the expression of neural markers: nestin, sex-determining region Y (SRY) box 1 and 2 (SOX1 and SOX2), microtubule-associated protein 2 (MAP2), and glial fibrillary acidic protein (GFAP). The qRT-PCR analysis revealed significantly enhanced expression of nestin and MAP2 in differentiated cells. This study confirms that it is possible to generate NSCs-like cells from hWJ-MSCs in a 2D culture using a practical method. However, the therapeutic effectiveness of such differentiated cells should be extended to confirm the terminal differentiation ability and electrophysiological properties of neurons derived from them.

Adipose Stem Cell Translational Applications: From Bench-to-Bedside

During the last five years, there has been a significantly increasing interest in adult adipose stem cells (ASCs) as a suitable tool for translational medicine applications. The abundant and renewable source of ASCs and the relatively simple procedure for cell isolation are only some of the reasons for this success. Here, we document the advances in the biology and in the innovative biotechnological applications of ASCs. We discuss how the multipotential property boosts ASCs toward mesenchymal and non-mesenchymal differentiation cell lineages and how their character is maintained even if they are combined with gene delivery systems and/or biomaterials, both in vitro and in vivo.

Ultrastructural analysis of human umbilical cord derived MSCs at undifferentiated stage and during osteogenic and adipogenic differentiation

Mesenchymal stem cells (MSCs) are considered as an important tool for regenerative medicine and experimental treatments. Unveiling the ultrastructural changes during the differentiation of MSCs might help us to understand the nature of the process and to develop novel therapeutic approaches. For this purpose, human umbilical cord (hUC) was chosen as MSC source. In the first place, MSCs were isolated from sub-amniotic, intervascular and perivascular areas of hUC by enzymatic and tissue explant method to determine the most favorable region of hUC and technique for further processing. Therefore, microscopic and growth kinetics analyses showed that there was no clear difference in the morphologies and proliferation rates among the hUC-MSC groups. Flow cytometric analysis showed that CD44 and CD90 MSC markers were highly expressed, while CD34 and CD45 hematopoietic stem cells markers were expressed at low degree. Because our preliminary results showed that there was no conspicuous superiority among the hUC-MSCs groups, whole UC was utilized as a source, and tissue explant method was applied to isolate MSCs for further differentiation analysis. At the 1^st and 3^rd week of osteogenic and adipogenic differentiation, ultrastructural analysis showed an increase in the number of secondary lysosomes in comparison with the undifferentiated status. Increase in the mitochondrial content was also detected at the 1^st week of adipogenic differentiation. Consequently, ultrastructural changes including increase in the number of mitochondria and secondary lysosomes during the adipogenic and osteogenic differentiation could be attributed to the switch in energy metabolism of the MSCs and increment in the lysosomal activity respectively.

Surface Hydrophilicity of Poly(l-Lactide) Acid Polymer Film Changes the Human Adult Adipose Stem Cell Architecture

Current knowledge indicates that the molecular cross-talk between stem cells and biomaterials guides the stem cells’ fate within a tissue engineering system. In this work, we have explored the effects of the interaction between the poly(l-lactide) acid (PLLA) polymer film and human adult adipose stem cells (hASCs), focusing on the events correlating the materials’ surface characteristics and the cells’ plasma membrane. hASCs were seeded on films of pristine PLLA polymer and on a PLLA surface modified by the radiofrequency plasma method under oxygen flow (PLLA+O₂). Comparative experiments were performed using human bone-marrow mesenchymal stem cells (hBM-MSCs) and human umbilical matrix stem cells (hUCMSCs). After treatment with oxygen-plasma, the surface of PLLA films became hydrophilic, whereas the bulk properties were not affected. hASCs cultured on pristine PLLA polymer films acquired a spheroid conformation. On the contrary, hASCs seeded on PLLA+O₂ film surface maintained the fibroblast-like morphology typically observed on tissue culture polystyrene. This suggests that the surface hydrophilicity is involved in the acquisition of the spheroid conformation. Noteworthy, the oxygen treatment had no effects on hBM-MSC and hUCMSC cultures and both stem cells maintained the same shape observed on PLLA films. This different behavior suggests that the biomaterial-interaction is stem cell specific.

Human Umbilical Cord Wharton Jelly-Derived Adult Mesenchymal Stem Cells, in Biohybrid Scaffolds, for Experimental Skin Regeneration

The ultimate goal for skin tissue engineering is to regenerate skin lesions to allow the full restoration of morphological and functional properties as what they were before injury. To this end, we have assembled a new prototype of a biomimetic human umbilical cord adult mesenchymal stem cell (hUCMS)/fibrin-based scaffold. We have fully characterized the proposed dermal equivalent (DE) in vitro, to assess morphological, functional, and biological properties of the encased cells. We transplanted DE subcutaneously into immunocompetent rodents, to verify its full biocompatibility. Finally, we studied DE graft effects on full-thickness wounds, in immunocompetent mice to demonstrate its capability to drive the healing process in the absence of significant scarring tissue. The excellent outcome of these in vivo studies fuels hope that this new approach, based on a biohybrid DE, may be applied to the operative treatment of skin lesions (i.e., diabetic foot ulcers and burns) in man.

Design of a nanocomposite substrate inducing adult stem cell assembly and progression toward an Epiblast-like or Primitive Endoderm-like phenotype via mechanotransduction

This work shows that the active interaction between human umbilical cord matrix stem cells and Poly (l-lactide)acid (PLLA) and PLLA/Multi Walled Carbon Nanotubes (MWCNTs) nanocomposite films results in the stem cell assembly as a spheroid conformation and affects the stem cell fate transition. We demonstrated that spheroids directly respond to a tunable surface and the bulk properties (electric, dielectric and thermal) of plain and nanocomposite PLLA films by triggering a mechanotransduction axis. This stepwise process starts from tethering of the cells' focal adhesion proteins to the surface, together with the adherens junctions between cells. Both complexes transmit traction forces to F-Actin stress fibres that link Filamin-A and Myosin-IIA proteins, generating a biological scaffold, with increased stiffening conformation from PLLA to PLLA/MWCNTs, and enable the nucleoskeleton proteins to boost chromatin reprogramming processes. Herein, the opposite expression of NANOG and GATA6 transcription factors, together with other lineage specification related proteins, steer spheroids toward an Epiblast-like or Primitive Endoderm-like lineage commitment, depending on the absence or presence of 1 wt% MWCNTs, respectively. This work represents a pioneering effort to create a stem cell/material interface that can model the stem cell fate transition under growth culture conditions.

Efficacy and safety of human mesenchymal stromal cells in healing of critical-size bone defects in immunodeficient rats

To evaluate the preclinical efficacy and safety of human mesenchymal stem cells (hMSC) rapidly expanded in growth medium for clinical use with human serum and recombinant growth factors, we conducted a controlled, randomized trial of plasma clots with hMSC vs. plasma clots only in critical segmental femoral defects in rnu/rnu immunodeficient rats. X-ray, microCT and histomorphometrical evaluation were performed at 8 and 16 weeks. MSC were obtained from healthy volunteers and patients with lymphoid malignancy. Human MSC survived in the defect for the entire duration of the trial. MSC from healthy volunteers, in contrast to hMSC from cancer patients, significantly improved bone healing at 8, but not 16 weeks. However, at 16 weeks, hMSC significantly improved vasculogenesis in residual defect. We conclude that hMSC from healthy donors significantly contributed to the healing of bone defects at 8 weeks and to the vascularisation of residual connective tissue for up to 16 weeks. We found the administration of hMSC to be safe, as no adverse reaction to human cells at the site of implantation and no evidence of migration of hMSC to distant organs was detected.

c-Met inhibitors attenuate tumor growth of small cell hypercalcemic ovarian carcinoma (SCCOHT) populations

A cellular model (SCCOHT-1) of the aggressive small cell hypercalcemic ovarian carcinoma demonstrated constitutive chemokine and growth factor production including HGF. A simultaneous presence of c-Met in 41% SCCOHT-1 cells suggested an autocrine growth mechanism. Expression of c-Met was also observed at low levels in the corresponding BIN-67 cell line (6.5%) and at high levels in ovarian adenocarcinoma cells (NIH:OVCAR-3 (84.4%) and SK-OV-3 (99.3%)). Immunohistochemistry of c-Met expression in SCCOHT tumors revealed a heterogeneous distribution between undetectable levels and 80%. Further characterization of SCCOHT-1 and BIN-67 cells by cell surface markers including CD90 and EpCAM demonstrated similar patterns with differences to the ovarian adenocarcinoma cells. HGF stimulation of SCCOHT-1 cells was associated with c-Met phosphorylation at Tyr1349 and downstream Thr202/Tyr204 phosphorylation of p44/42 MAP kinase. This HGF-induced signaling cascade was abolished by the c-Met inhibitor foretinib. Cell cycle analysis after foretinib treatment demonstrated enhanced G2 accumulation and increasing apoptosis within 72 h. Moreover, the IC50 of foretinib revealed 12.4 nM in SCCOHT-1 cells compared to 411 nM and 481 nM in NIH:OVCAR-3 and SK-OV-3 cells, respectively, suggesting potential therapeutic effects. Indeed, SCCOHT-1 and BIN-67 tumor xenografts in NODscid mice exhibited an approximately 10-fold and 5-fold reduced tumor size following systemic application of foretinib, respectively. Furthermore, foretinib-treated tumors revealed a significantly reduced vascularization and little if any c-Met-mediated signal transduction. Similar findings of reduced proliferative capacity and declined tumor size were observed after siRNA-mediated c-Met knock-down in SCCOHT-1 cells demonstrating that in vivo inhibition of these pathways contributed to an attenuation of SCCOHT tumor growth.

Human Umbilical Cord-Derived Mesenchymal Stromal Cells Improve Left Ventricular Function, Perfusion, and Remodeling in a Porcine Model of Chronic Myocardial Ischemia

: Stem cell therapy has emerged as a new strategy for treatment of ischemic heart disease. Although umbilical cord-derived mesenchymal stromal cells (UC-MSCs) have been used preferentially in the acute ischemia model, data for the chronic ischemia model are lacking. In this study, we investigated the effect of UC-MSCs originated from Wharton's jelly in the treatment of chronic myocardial ischemia in a porcine model induced by ameroid constrictor. Four weeks after ameroid constrictor placement, the surviving animals were divided randomly into two groups to undergo saline injection (n = 6) or UC-MSC transplantation (n = 6) through the left main coronary artery. Two additional intravenous administrations of UC-MSCs were performed in the following 2 weeks to enhance therapeutic effect. Cardiac function and perfusion were examined just before and at 4 weeks after intracoronary transplantation. The results showed that pigs with UC-MSC transplantation exhibited significantly greater left ventricular ejection fraction compared with control animals (61.3% ± 1.3% vs. 50.3% ± 2.0%, p < .05). The systolic thickening fraction in the infarcted left ventricular wall was also improved (41.2% ± 3.3% vs. 46.2% ± 2.3%, p < .01). Additionally, the administration of UC-MSCs promoted collateral development and myocardial perfusion. The indices of fibrosis and apoptosis were also significantly reduced. Immunofluorescence staining showed clusters of CM-DiI-labeled cells in the border zone, some of which expressed von Willebrand factor. These results suggest that UC-MSC treatment improves left ventricular function, perfusion, and remodeling in a porcine model with chronic myocardial ischemia.

SIGNIFICANCE

Ischemic heart disease is the leading cause of death worldwide. Many patients with chronic myocardial ischemia are not suitable for surgery and have no effective drug treatment; they are called "no-option" patients. This study finds that umbilical cord-derived mesenchymal stromal cells transplanted by intracoronary delivery combined with two intravenous administrations was safe and could significantly improve left ventricular function, perfusion, and remodeling in a large-animal model of chronic myocardial ischemia, which provides a new choice for the no-option patients. In addition, this study used clinical-grade mesenchymal stem cells with delivery and assessment methods commonly used clinically to facilitate further clinical transformation.

Current View on Osteogenic Differentiation Potential of Mesenchymal Stromal Cells Derived from Placental Tissues

Mesenchymal stromal cells (MSC) isolated from human term placental tissues possess unique characteristics, including their peculiar immunomodulatory properties and their multilineage differentiation potential. The osteogenic differentiation capacity of placental MSC has been widely disputed, and continues to be an issue of debate. This review will briefly discuss the different MSC populations which can be obtained from different regions of human term placenta, along with their unique properties, focusing specifically on their osteogenic differentiation potential. We will present the strategies used to enhance osteogenic differentiation potential in vitro, such as through the selection of subpopulations more prone to differentiate, the modification of the components of osteo-inductive medium, and even mechanical stimulation. Accordingly, the applications of three-dimensional environments in vitro and in vivo, such as non-synthetic, polymer-based, and ceramic scaffolds, will also be discussed, along with results obtained from pre-clinical studies of placental MSC for the regeneration of bone defects and treatment of bone-related diseases.

The effect of bisphosphonates on the endothelial differentiation of mesenchymal stem cells

The contribution of the local stem cell niche to providing an adequate vascular framework during healing cannot be overemphasized. Bisphosphonates (BPs) are known to have a direct effect on the local vasculature, but their effect on progenitor cell differentiation is unknown. This in vitro study evaluated the effect(s) of various BPs on the differentiation of human placental mesenchymal stem cells (pMSCs) along the endothelial lineage and their subsequent functional and morphogenic capabilities. pMSC multipotency was confirmed by successful differentiation into cells of both the osteogenic and endothelial lineages, as demonstrated by positive Alizarin Red S staining and Ac-LDL uptake. pMSC differentiation in the presence of non-cytotoxic BP concentrations showed that nitrogen containing BPs had a significant inhibitory effect on cell migration and endothelial marker gene expression, as well as compromised endothelial differentiation as demonstrated using von Willebrand factor immunofluorescence staining and tube formation assay. This in vitro study demonstrated that at non-cytotoxic levels, nitrogen-containing BPs inhibit differentiation of pMSCs into cells of an endothelial lineage and affect the downstream functional capability of these cells supporting a multi-modal effect of BPs on angiogenesis as pathogenic mechanism contributing to bone healing disorders such as bisphosphonate related osteonecrosis of the jaws (BRONJ).

Restoration of t cell substes of patients with type 1 diabetes mellitus by microencapsulated human umbilical cord Wharton jelly-derived mesenchymal stem cells: An in vitro study

Human umbilical cord Wharton jelly-derived mesenchymal stem cells (hUCMS) might apply to treating chronic autoimmune disorders, as already shown for Sjögren's syndrome, including type 1 diabetes mellitus (T1D). Since naked hUCMS grafts encountered restraints, we enveloped hUCMS, within immunoisolatory microcapsules (CpS-hUCMS), made of our endotoxin-free, clinical grade alginate. We then examined the vitro effects of interferon (IFN)-γ-pretreated CpS-hUCMS on Th17 and Treg of T1D patients (n=15) and healthy controls (n=10). Peripheral blood mononuclear cells (PBMCs) were co-cultured with PBMC/CpS-hUCMS: lymphocyte proliferation was assessed by carboxyfluorescein succinimidyl esther (CFSE) dilution assay, and phenotypic analysis of regulatory and effector Tc was also performed. Cytokine expression was performed by bead array and qPCR on IFN-γ-pretreated hUCMS before PBMCs co-culture. CpS-hUCMS restored a correct Treg/Th17 ratio, relevant to the T1D disease process. In summary, we have preliminarily developed a new biohybrid system, associated with immunoregulatory properties, that is ready for in vivo application.

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

Alginate scaffold has been considered as an appropriate biomaterial for promoting the differentiation of embryonic stem cells toward neuronal cell lineage. We hypothesized that alginate scaffold is suitable for culturing Wharton's jelly mesenchymal stem cells (WJMSCs) and can promote the differentiation of WJMSCs into neuron-like cells. In this study, we cultured WJMSCs in a three-dimensional scaffold fabricated by 0.25% alginate and 50 mM CaCl₂ in the presence of neurogenic medium containing 10 μM retinoic acid and 20 ng/mL basic fibroblast growth factor. These cells were also cultured in conventional two-dimensional culture condition in the presence of neurogenic medium as controls. After 10 days, immunofluorescence staining was performed for detecting β-tubulin (marker for WJMSCs-differentiated neuron) and CD271 (motor neuron marker). β-Tubulin and CD271 expression levels were significantly greater in the WJMSCs cultured in the three-dimensional alginate scaffold than in the conventional two-dimensional culture condition. These findings suggest that three-dimensional alginate scaffold cell culture system can induce neuronal differentiation of WJMSCs effectively.

ATP-binding cassette proteins BCRP, MRP1 and P-gp expression and localization in the human umbilical cord

1. The umbilical cord is a direct conduit to the fetus hence transporters could have roles in partitioning substances between the maternal-placental-fetal units. Here we determined the expression and localization of the ATP-Binding Cassette (ABC) transporters BCRP (ABCG2), P-gp (ABCB1) and MRP1 (ABCC1) in human umbilical cords. 2. The mRNA for BCRP and MRP1 was detected in 25/25 samples, but P-gp was detected in only 5/25. ABC transporter mRNA expression relative to 18S was 25.6 ± 0.3, 26.5 ± 0.6 and 22.2 ± 0.2 cycles for BCRP, MRP1 and P-gp respectively. 3. Using a subset of 10 umbilical cords, BCRP protein was present in all samples (immunoblot) with positive correlation between mRNA and proteins (p = 0.07, r = 0.62) and between immunoblotting and immunohistochemistry (IHC) (p = 0.03, r = 0.67). P-gp protein was observed in 4/10 samples by both immunoblot and IHC, with no correlation between mRNA and protein (p = 0.45, r = 0.55) or immunoblotting and IHC (p = 0.2, r = 0.72), likely due to small sample size. MRP1 protein was not observed. 4. Localization of BCRP and P-gp proteins was to Wharton's jelly with no specific staining in arterial or venous endothelia. 5. Understanding ABC transporter expression in the umbilical cord may be useful for determining fetal exposures to xenobiotics if functional properties can be defined.

Antibody Arrays for Quality Control of Mesenchymal Stem Cells

Quality control of mesenchymal stem cells is an important step before their clinical use in regenerative therapy. Among various characteristics of mesenchymal stem cells, reproducibility of population compositions should be analyzed according to characteristics, such as stem cell contents and differentiation stages. Such characterization may be possible by assessing the expression of several surface markers. Here we report our attempts to utilize antibody arrays for analyzing surface markers expressed in mesenchymal stem cell populations in a high-throughput manner. Antibody arrays were fabricated using a glass plate on which a micropatterned alkanethiol monolayer was formed. Various antibodies against surface markers including CD11b, CD31, CD44, CD45, CD51, CD73, CD90, CD105, and CD254 were covalently immobilized on the micropatterned surface in an array format to obtain an antibody array. To examine the feasibility of the array, cell binding assays were performed on the array using a mouse mesenchymal stem cell line. Our results showed that cell binding was observed on the arrayed spots with immobilized antibodies which exhibited reactivity to the cells in flow cytometry. It was further found that the density of cells attached to antibody spots was correlated to the mean fluorescent channel recorded in flow cytometry. These results demonstrate that data obtained by cell binding assays on the antibody array are comparable to those by the conventional flow cytometry, while throughput of the analysis is much higher with the antibody array-based method than flow cytometry. Accordingly, we concluded that the antibody array provides a high-throughput analytical method useful for the quality control of mesenchymal stem cells.

Cellular therapies based on stem cells and their insulin-producing surrogates: a 2015 reality check

Stem cell technology has recently gained a substantial amount of interest as one method to create a potentially limitless supply of transplantable insulin-producing cells to treat, and possibly cure diabetes mellitus. In this review, we summarize the state-of-the art of stem cell technology and list the potential sources of stem cells that have been shown to be useful as insulin-expressing surrogates. We also discuss the milestones that have been reached and those that remain to be addressed to generate bona fide beta cell-similar, insulin-producing surrogates. The caveats, limitations, and realistic expectations are also considered for current and future technology. In spite of the tremendous technical advances realized in the past decade, especially in the field of reprogramming adult somatic cells to become stem cells, the state-of-the art still relies on lengthy and cumbersome in vitro culture methods that yield cell populations that are not particularly glucose-responsive when transplanted into diabetic hosts. Despite the current impediments toward clinical translation, including the potential for immune rejection, the availability of technology to generate patient-specific reprogrammable stem cells has, and will be critical for, important insights into the genetics, epigenetics, biology, and physiology of insulin-producing cells in normal and pathologic states. This knowledge could accelerate the time to reach the desired breakthrough for safe and efficacious beta cell surrogates.

Human mesenchymal stroma/stem cells exchange membrane proteins and alter functionality during interaction with different tumor cell lines

To analyze effects of cellular interaction between human mesenchymal stroma/stem cells (MSC) and different cancer cells, direct co-cultures were performed and revealed significant growth stimulation of the tumor populations and a variety of protein exchanges. More than 90% of MCF-7 and primary human HBCEC699 breast cancer cells as well as NIH:OVCAR-3 ovarian adenocarcinoma cells acquired CD90 proteins during MSC co-culture, respectively. Furthermore, SK-OV-3 ovarian cancer cells progressively elevated CD105 and CD90 proteins in co-culture with MSC. Primary small cell hypercalcemic ovarian carcinoma cells (SCCOHT-1) demonstrated undetectable levels of CD73 and CD105; however, both proteins were significantly increased in the presence of MSC. This co-culture-mediated protein induction was also observed at transcriptional levels and changed functionality of SCCOHT-1 cells by an acquired capability to metabolize 5'cAMP. Moreover, exchange between tumor cells and MSC worked bidirectional, as undetectable expression of epithelial cell adhesion molecule (EpCAM) in MSC significantly increased after co-culture with SK-OV-3 or NIH:OVCAR-3 cells. In addition, a small population of chimeric/hybrid cells appeared in each MSC/tumor cell co-culture by spontaneous cell fusion. Immune fluorescence demonstrated nanotube structures and exosomes between MSC and tumor cells, whereas cytochalasin-D partially abolished the intercellular protein transfer. More detailed functional analysis of FACS-separated MSC and NIH:OVCAR-3 cells after co-culture revealed the acquisition of epithelial cell-specific properties by MSC, including increased gene expression for cytokeratins and epithelial-like differentiation factors. Vice versa, a variety of transcriptional regulatory genes were down-modulated in NIH:OVCAR-3 cells after co-culture with MSC. Together, these mutual cellular interactions contributed to functional alterations in MSC and tumor cells.

Evaluation of sericin as a fetal bovine serum-replacing cryoprotectant during freezing of human mesenchymal stromal cells and human osteoblast-like cells

A reliable, cryoprotective, xeno-free medium suitable for different cell types is highly desirable in regenerative medicine. There is danger of infection or allergic reaction with the use of fetal bovine serum (FBS), making it problematic for medical applications. The aim of the present study was to develop an FBS-free cryoprotective medium for human mesenchymal stromal cells (hMSCs; primary cells) and immortalized human osteoblasts (SAOS-2 cell line). Furthermore, we endeavored to eliminate or reduce the presence of dimethyl sulfoxide (DMSO) in the medium. Sericin, a sticky protein derived from the silkworm cocoon, was investigated as a substitute for FBS and DMSO in the freezing medium. Cell viability (24 hours after thawing, both hMSC and SAOS-2) and colony-forming ability (2 weeks after thawing, only for hMSCs) were both determined. The FBS-free medium with 1% sericin in 10% DMSO was found to be a suitable freezing medium for primary hMSCs, in contrast to immortalized human osteoblasts. Surprisingly, the storage of hMSCs in a cultivation medium with only 10% DMSO also provided satisfactory results. Any drop in DMSO concentration led to significantly worse survival of cells, with little improvement in hMSC survival in the presence of sericin. Thus, sericin may substitute for FBS in the freezing medium for primary hMSCs, but cannot substitute for DMSO.

Karyotype stability of human umbilical cord-derived mesenchymal stem cells during in vitro culture

The aim of this study was to investigate whether the chromosomes of human umbilical cord-derived mesenchymal stem cells (hUCMSCs) change following in vitro culture for several generations. In the present study, umbilical cords from two healthy infants following cesarean delivery were collected aseptically and hUCMSCs were isolated by digestion with collagenase and trypsin, and then cultured in vitro. hUCMSCs with fibroblastic morphology were presented from the human umbilical cord tissue after 7 days of adherent culture. When cultured for 6 passages in vitro, the hUCMSCs maintained a stable spindle-shaped morphology. Cells reached the logarithmic growth phase after 3–4 days of culture. In addition, CD13, CD29, CD44, CD90 and CD105 were highly expressed in generations P3-P6. The expression of CD31, CD34, CD45 and HLA-DR was negative. Furthermore, karyotype analysis revealed a normal diploid karyotype with 46 chromosomes and no abnormal changes were found in chromosome structure. These findings suggest that when cultured for 6 passages in vitro, hUCMSCs maintain a stable immunophenotype and chromosome structure, which provides an experimental basis for the safety of hUCMSC cytotherapy.

Stem cells for pancreatic β-cell replacement in diabetes mellitus: actual perspectives

PURPOSE OF REVIEW

Type 1 and type 2 diabetes mellitus represent a widespread metabolic disorder, related to autoimmune β-cell destruction and insulin resistance, leading to β-cell dysfunction, respectively, that are associated with severe chronic complications with irreversible multiorgan morphological and functional damage. Conventional treatment, based on exogenous insulin or oral agents may control and delay but not prevent the disease complications, which has lead, so far, to a steady increase in mortality and morbidity. β-Cell substitution cell therapy, initially pursued by whole pancreatic and isolated islet transplantation, with scarce and limited efficiency, now is looking at the new technologies for cell and molecular therapy for diabetes, based on stem cells.

RECENT FINDINGS

Pancreatic endocrine cells regeneration might replenish the destroyed β-cell pool, with neogenerated β-cell derived from pancreatic and extrapancreatic stem cell sources. Additionally, embryonic or adult stem cells derived from different cell lineages, and able to differentiate into β-like cell elements, may not only restore the original insulin secretory patterns but also exert the immunomodulatory effects aimed at interrupting the β-cell-directed autoimmune destruction vicious cycle.

SUMMARY

These new strategies may, one day, provide for the final cure of diabetes mellitus.

Transplantation of umbilical cord blood-derived cells for novel indications in regenerative therapy or immune modulation: a scoping review of clinical studies

Although used mainly for transplantation of hematopoietic stem cells in the treatment of blood disorders, umbilical cord blood (UCB)-based therapies are now being used increasingly for novel applications in nonhematopoietic diseases and as a form of cellular regenerative therapy or immune modulation. We performed a systematic scoping review by searching Medline, EMBASE, and the Cochrane Library for published articles, and we searched www.clinicaltrials.com and the World Health Organization International Clinical Trials Registry Platform to describe the breadth of published studies and ongoing clinical activity in umbilical cord-based cellular therapy for regenerative therapy and immune modulation. The most commonly published area of expertise in the use of UCB-derived cellular transplantation for novel indications is for neurological disorders and this remains the most active area of study in ongoing registered trials. An increasingly broad range of disorders, however, are reflected in ongoing registered trials, which suggests greater activity, interest, and investment in UCB-derived cellular therapy. Interestingly, adult patients compose the majority of patients reported in published reports and registered ongoing clinical studies continue to enroll predominantly adult subjects. Geographically, Asian countries appear most active in UCB-derived cellular therapy and our analysis of ongoing studies suggests this trend will likely continue. Regular assessment of published and ongoing activity in UCB transplantation for emerging novel indications will be critical for informing UCB banking establishments and funding agencies to guide changes in banking practices related to emerging trends in cell therapy.

Impact of passing mesenchymal stem cells through smaller bore size needles for subsequent use in patients for clinical or cosmetic indications

Background

Numerous preclinical and clinical studies have investigated the regenerative potential and the trophic support of mesenchymal stem cells (MSCs) following their injection into a target organ. Clinicians favor the use of smallest bore needles possible for delivering MSCs into vascular organs like heart, liver and spleen. There has been a concern that small needle bore sizes may be detrimental to the health of these cells and reduce the survival and plasticity of MSCs.

Methods

In this report, we aimed to investigate the smallest possible bore size needle which would support the safe delivery of MSCs into various tissues for different clinical or cosmetic applications. To accomplish this we injected cells via needle sizes 24, 25 and 26 G attached to 1 ml syringe in the laboratory and collected the cells aseptically. Control cells were ejected via 1 ml syringe without any needle. Thereafter, the needle ejected cells were cultured and characterized for their morphology, attachment, viability, phenotypic expression, differentiation potential, cryopreservation and in vivo migration abilities. In the second phase of the study, cells were injected via 26 G needle attached to 1 ml syringe for 10 times.

Results

Similar phenotypic and functional characteristics were observed between ejected and control group of cells. MSCs maintained their cellular and functional properties after single and multiple injections.

Conclusions

This study proves that 26 G bore size needles can be safely used to inject MSCs for clinical/therapeutics purposes.

Mesenchymal stem or stromal cells from amnion and umbilical cord tissue and their potential for clinical applications

Mesenchymal stem or stromal cells (MSC) have proven to offer great promise for cell-based therapies and tissue engineering applications, as these cells are capable of extensive self-renewal and display a multilineage differentiation potential. Furthermore, MSC were shown to exhibit immunomodulatory properties and display supportive functions through parakrine effects. Besides bone marrow (BM), still today the most common source of MSC, these cells were found to be present in a variety of postnatal and extraembryonic tissues and organs as well as in a large variety of fetal tissues. Over the last decade, the human umbilical cord and human amnion have been found to be a rich and valuable source of MSC that is bio-equivalent to BM-MSC. Since these tissues are discarded after birth, the cells are easily accessible without ethical concerns.

Early experiences with stem cells in treating chronic wounds

This review provides a thorough and clear discussion on the outcomes of stem cells in treating chronic wounds. With recent technological developments that now allow isolation and culture of stem cells, researchers are able to perform vigorous studies on somatic or adult stem cells. Human and animal stem cell studies are discussed with a focus on the basic process of stem cells in wound healing and the authors' first-hand clinical experience with stem cells used for chronic wound healing.

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.

Minced umbilical cord fragments as a source of cells for orthopaedic tissue engineering: an in vitro study

A promising approach for musculoskeletal repair and regeneration is mesenchymal-stem-cell- (MSC-)based tissue engineering. The aim of the study was to apply a simple protocol based on mincing the umbilical cord (UC), without removing any blood vessels or using any enzymatic digestion, to rapidly obtain an adequate number of multipotent UC-MSCs. We obtained, at passage 1 (P1), a mean value of 4, 2 × 10⁶ cells (SD 0,4) from each UC. At immunophenotypic characterization, cells were positive for CD73, CD90, CD105, CD44, CD29, and HLA-I and negative for CD34 and HLA-class II, with a subpopulation negative for both HLA-I and HLA-II. Newborn origin and multilineage potential toward bone, fat, cartilage, and muscle was demonstrated. Telomere length was similar to that of bone-marrow (BM) MSCs from young donors. The results suggest that simply collecting UC-MSCs at P1 from minced umbilical cord fragments allows to achieve a valuable population of cells suitable for orthopaedic tissue engineering.