ALBERT

Description: ABSTRACT 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 24h 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. This article is protected by copyright. All rights reserved

Description: The infants of mothers with gestational diabetes mellitus (GDM) have an increased risk of metabolic and cardiovascular disease. It has been difficult to study the direct effects of maternal hyperglycemia on the fetus because of inaccessibility of fetal tissues. The development of tissues that simulate the function of fetal organs using stem cell technology provides an unprecedented opportunity to study this disorder. Stem cells in the Wharton's jelly of the umbilical cord (hWJSCs) possess unique properties that are different from other stem cells. They are primitive, present in large numbers, non-tumorigenic, hypoimmunogenic, tumoricidal and carry a genetic signature that represents the fetus. They are multipotent but their differentiation into functional pancreatic and cardiovascular tissues has been challenging. We have been able to reprogram hWJSCs from normal and GDM cords into induced pluripotent stem cells (iPSCs) from which a variety of functional fetal tissues including insulin-producing and cardiovascular tissues could be derived. Such tissues from reprogrammed hWJSCs of normal and GDM cords that physiologically and genetically mimic the fetus of the diabetic or non-diabetic mother are an ideal platform to study the effects of glucose, the Zika virus and other harmful agents on the fetus. The immature stemness phenotype of hWJSCs, easy accessibility, availability in large numbers without the need for propagation and lower risk of accumulation of epigenetic mutations make them the most attractive candidate over other umbilical cord cell types for reprogramming. Additionally, some of their beneficial genes may be retained in memory in the iPSCs derived from them. This article is protected by copyright. All rights reserved

Description: 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. J. Cell. Biochem. 113: 1886–1895, 2012. © 2012 Wiley Periodicals, Inc.

Description: Umbilical cord mesenchymal stem cells (MSCs) have been shown to inhibit breast cancer cell growth but it is not known whether this effect is specific to only breast cancer cells. We compared the effects of human Wharton's jelly stem cell (hWJSC) extracts [conditioned medium (hWJSC-CM) and cell lysate (hWJSC-CL)] on breast adenocarcinoma (MDA-MB-231), ovarian carcinoma (TOV-112D), and osteosarcoma (MG-63) cells. The cells were treated with either hWJSC-CM (50%) or hWJSC-CL (15 µg/ml) for 48–72 h and changes in cell morphology, proliferation, cycle, gene expression, migration, and cell death studied. All three cancer cell lines showed cell shrinkage, blebbing, and vacuolations with hWJSC-CL and hWJSC-CM compared to controls. MTT and BrdU assays showed inhibition of cell growth by 2–6% and 30–60%, while Transwell migration assay showed inhibition by 20–26% and 31–46% for hWJSC-CM and hWJSC-CL, respectively, for all three cancer cell lines. Cell cycle assays showed increases in sub-G1 and G2/M phases for all three cancer cell lines suggestive of apoptosis and metaphase arrest. AnnexinV-FITC and TUNEL positive cells seen in TOV-112D and MDA-MB-231 suggested that inhibition was via apoptosis while the presence of anti-BECLIN1 and anti-LC3B antibodies seen with MG-63 indicated autophagy. Upregulation of pro-apoptotic BAX and downregulation of anti-apoptotic BCL2 and SURVIVIN genes were observed in all three cancer cell lines and additionally the autophagy genes (ATG5, ATG7, and BECLIN1) were upregulated in MG-63 cells. hWJSCs possess tumor inhibitory properties that are not specific to breast cancer cells alone and these effects are mediated via agents in its extracts. J. Cell. Biochem. 113: 2027–2039, 2012. © 2012 Wiley Periodicals, Inc.

Description: ABSTRACT Several groups have reported that human umbilical cord Wharton's jelly stem cells (hWJSCs) possess unique tumoricidal properties against many cancers. However, the exact mechanisms as to how hWJSCs inhibit tumor growth are not known. Recent evidence suggests that exposure of cancer cells to high hydrogen peroxide (H 2 O 2 ) levels from H 2 O 2 -releasing drugs causes their death. We therefore explored whether the tumoricidal effect of hWJSCs on lymphoma cells was mediated via H 2 O 2 . We first exposed lymphoma cells to six different molecular weight cut-off (MWCO) concentrates of hWJSC-conditioned medium (hWJSC-CM) (3, 5, 10, 30, 50, 100 kDa) for 48h. Since the 3kDa-MWCO concentrate showed the greatest cell inhibition we then investigated whether the tumoricidal effect of the specific 3kDa-MWCO concentrate on two different lymphoma cell lines (Ramos and Toledo) was mediated via accumulation of H 2 O 2 . We used a battery of assays (MTT, propidium iodide, mitochondria membrane potential, apoptosis, cell cycle, oxidative stress enzymes, hydrogen peroxide, mitochondrial superoxide, hydroxyl radical, peroxynitrile anion and lipid peroxidation) to test this mechanism. The hWJSC-CM-3kDa MWCO concentrate significantly decreased cell viability and mitochondrial membrane potential and increased cell death and apoptosis in both lymphoma cell lines. There were significant increases in superoxide dismutase with concomitant decreases in glutathione peroxidase, catalase and thioredoxin peroxidase activities. H 2 O 2 levels, mitochondrial superoxide, hydroxyl radical, peroxynitrile anion and lipid peroxidation were also significantly increased in both lymphoma cell lines. The results suggested that the hWJSC-CM-3kDa MWCO concentrate regulates cellular H 2 O 2 leading to a tumoricidal effect and may thus be a promising anti-lymphoma agent. This article is protected by copyright. All rights reserved

Description: Human Wharton's jelly stem cells (hWJSCs) were shown to inhibit the growth of human mammary carcinomas. It is not known whether cell-free secretions or lysates of hWJSCs do the same on different cancers. They may be less controversial than cells to regulatory bodies for clinical application. We examined the influence of hWJSC conditioned medium (hWJSC-CM) and cell-free lysate (hWJSC-CL) on two osteosarcoma cell lines (MG-63, SKES-1) in vitro and on human mammary carcinomas in immunodeficient mice. When exposed to hWJSC-CL, increased vacuolations in MG-63 and increased membrane fragmentation in SKES-1 cells were observed, with greater cell death in SKES-1. Exposure of SKES-1 and MG-63 cells to hWJSC-CL showed significant decreases in cell proliferation of 46.48 ± 6.66% and 24.32 ± 5.67% respectively compared to controls. MG-63 and SKES-1 cells were annexin V-FITC positive and SKES-1 TUNEL positive following treatment with hWJSC-CM and hWJSC-CL. MG-63 cells were positive and SKES-1 cells negative for anti-BECLIN-1 and anti-LC3B following treatment with hWJSC-CM and hWJSC-CL. RT-PCR showed that the pro-apoptotic BAX gene and the autophagy-related ATG-5 and BECLIN-1 genes were up-regulated while the anti-apoptotic BCL2 and SURVIVIN genes were down-regulated in MG-63 and SKES-1 cells treated with hWJSC-CM and hWJSC-CL. Injections of hWJSCs and hWJSC-CM into mammary carcinomas in immunodeficient mice resulted in decreased tumor sizes and weights of 24.86 ± 6.05% to 37.03 ± 5.91% and 47.14 ± 7.36% to 55.09 ± 5.87% respectively at 6 weeks compared to controls. hWJSC-CM and hWJSC-CL inhibit mammary carcinoma and osteosarcoma cells via apoptosis and autophagy. J. Cell. Biochem. © 2012 Wiley Periodicals, Inc.

Description: Keloids are firm rubbery growths that grow beyond the boundaries of human wounds and their treatment has met with limited success. Their properties and growth behavior have not been properly characterized and it has been suggested that a benign neoplastic stem cell-like phenotype in an altered cytokine microenvironment drives their uncontrolled cell proliferation. Modification of the stem cell niche may be an attractive approach to its prevention. We studied the growth behavior, stemness and tumorigenic characteristics of keloid cells in prolonged culture. Since human Wharton's jelly stem cells (hWJSCs) secrete high levels of cytokines and have anti-tumorigenic properties we explored its role on the inhibition of keloid growth in vitro . Keloid cells grew readily in both adherent and sphere culture and expressed high levels of mesenchymal CD and tumor-associated fibroblast (TAF) markers up to passage 10. When they were exposed to repeat doses of hWJSC conditioned medium (hWJSC-CM) and lysate (hWJSC-CL) every 72 h up to 9 days their growth was inhibited with a reduction in CD and TAF marker expression. On days 3, 6 and 9 treated keloid cells showed linear decreases in cell proliferation (BrdU), increases in Annexin V-FITC and TUNEL-positive cells, interruptions of the cell cycle and inhibition of migration in scratch-wound assays. Immunocytochemistry and qRT-PCR confirmed a significant downregulation of TAF and anti-apoptotic-related gene (SURVIVIN) expression and upregulation of autophagy-related (BAX, ATG5, ATG7, BECLIN-1) gene expression. The results suggest that hWJSCs or molecules secreted by them may be of therapeutic value in the treatment of keloids. J. Cell. Biochem. © 2013 Wiley Periodicals, Inc.

Description: Wound healing is a major problem in diabetic patients and current methods of treatment have met with limited success. Since skin cell renewal is under the control of mesenchymal stem cells (MSCs) treatment of wounds has been attempted with the application of exogenous bone marrow MSCs (hBMMSCs). However, hBMMSCs have the limitations of painful harvest, low cell numbers and short-lived stemness properties unlike MSCs from the Wharton's jelly of human umbilical cords (hWJSCs). Since nanoscaffolds provide three dimensional architectural patterns that mimic in vivo stem cell niches and aloe vera has antibacterial properties we evaluated the use of an aloe vera-polycaprolactone (AV/PCL) nanoscaffold impregnated with green fluorescent protein (GFP)-labeled hWJSCs (GFP-hWJSCs + AV/PCL) or its conditioned medium (hWJSC-CM + AV/PCL) for healing of excisional and diabetic wounds. In skin fibroblast scratch-wound assays exposed to GFP-hWJSCs + AV/PCL or hWJSC-CM + AV/PCL, fibroblasts migrated significantly faster from edges of scratches into vacant areas together with increased secretion of collagen I and III, elastin, fibronectin, superoxide dismutase and metalloproteinase-1 (MMP-1) compared to controls. After one application of GFP-hWJSCs + AV/PCL or hWJSC-CM + AV/PCL excisional and diabetic wounds in mice showed rapid wound closure, reepithelialization and increased numbers of sebaceous glands and hair follicles compared to controls. The same wounds exposed to GFP-hWJSCs + AV/PCL or hWJSC-CM + AV/PCL also showed positive keratinocyte markers (cytokeratin, involucrin, filaggrin) and increased expression of ICAM-1, TIMP-1 and VEGF-A compared to controls. AV/PCL nanoscaffolds in combination with hWJSCs appear to have synergistic benefits for wound healing. J. Cell. Biochem. © 2013 Wiley Periodicals, Inc.

Description: Wound healing is a major problem in diabetic patients and current treatments have met with limited success. We evaluated the treatment of excisional and diabetic wounds using a stem cell isolated from the human umbilical cord Wharton's jelly (hWJSC) that shares unique properties with embryonic and adult mesenchymal stem cells. hWJSCs are non-controversial, available in abundance, hypo-immunogenic, non-tumorigenic, differentiate into keratinocytes and secrete important molecules for tissue repair. When human skin fibroblasts (CCD) in conventional scratch-wound assays were exposed to hWJSC-conditioned medium (hWJSC-CM) the fibroblasts at the wound edges migrated and completely covered the spaces by day 2 compared to controls. The number of invaded cells, cell viability, total collagen, elastin and fibronectin levels were significantly greater in the hWJSC-CM treatment arm compared to controls ( p  〈 0.05). When a single application of green fluorescent protein (GFP)-labelled hWJSCs (GFP-hWJSCs) or hWJSC-CM was administered to full-thickness murine excisional and diabetic wounds, healing rates were significantly greater compared to controls ( p  〈 0.05). Wound biopsies collected at various time points showed the presence of green GFP-labelled hWJSCs, positive human keratinocyte markers (cytokeratin, involucrin, filaggrin) and expression of ICAM-1, TIMP-1 and VEGF-A. On histology, the GFP-hWJSCs and hWJSC-CM treated wounds showed reepithelialisation, increased vascularity and cellular density and increased sebaceous gland and hair follicle numbers compared to controls. hWJSCs showed increased expression of several miRNAs associated with wound healing compared to CCDs. Our studies demonstrated that hWJSCs enhance healing of excisional and diabetic wounds via differentiation into keratinocytes and release of important molecules. J. Cell. Biochem. © 2013 Wiley Periodicals, Inc.