IntroductionAdipose-derived stem cells (ADSCs) have been isolated, expanded, and applied in the treatment of many diseases. ADSCs have also been used to treat injured articular cartilage. However, there is controversy regarding the treatment efficiency. We considered that ADSC transplantation with activated platelet-rich plasma (PRP) may improve injured articular cartilage compared with that of ADSC transplantation alone. In this study, we determined the role of PRP in ADSC transplantation to improve the treatment efficiency.MethodsADSCs were isolated and expanded from human adipose tissue. PRP was collected and activated from human peripheral blood. The effects of PRP were evaluated in vitro and in ADSC transplantation in vivo. In vitro, the effects of PRP on ADSC proliferation, differentiation into chondrogenic cells, and inhibition of angiogenic factors were investigated at three concentrations of PRP (10%, 15% and 20%). In vivo, ADSCs pretreated with or without PRP were transplanted into murine models of injured articular cartilage.ResultsPRP promoted ADSC proliferation and differentiation into chondrogenic cells that strongly expressed collagen II, Sox9 and aggrecan. Moreover, PRP inhibited expression of the angiogenic factor vascular endothelial growth factor. As a result, PRP-pretreated ADSCs improved healing of injured articular cartilage in murine models compared with that of untreated ADSCs.ConclusionPretreatment of ADSCs with PRP is a simple method to efficiently apply ADSCs in cartilage regeneration. This study provides an important step toward the use of autologous ADSCs in the treatment of injured articular cartilage.

BackgroundBreast cancer stem cells (BCSCs) are the source of breast tumors. Compared with other cancer cells, cancer stem cells show high resistance to both chemotherapy and radiotherapy. Targeting of BCSCs is thus a potentially promising and effective strategy for breast cancer treatment. Differentiation therapy represents one type of cancer stem-cell-targeting therapy, aimed at attacking the stemness of cancer stem cells, thus reducing their chemo- and radioresistance. In a previous study, we showed that down-regulation of CD44 sensitized BCSCs to the anti-tumor agent doxorubicin. This study aimed to determine if CD44 knockdown caused BCSCs to differentiate into breast cancer non-stem cells (non-BCSCs).MethodsWe isolated a breast cancer cell population (CD44+CD24- cells) from primary cultures of malignant breast tumors. These cells were sorted into four sub-populations based on their expression of CD44 and CD24 surface markers. CD44 knockdown in the BCSC population was achieved using small hairpin RNA lentivirus particles. The differentiated status of CD44 knock-down BCSCs was evaluated on the basis of changes in CD44+CD24- phenotype, tumorigenesis in NOD/SCID mice, and gene expression in relation to renewal status, metastasis, and cell cycle in comparison with BCSCs and non-BCSCs.ResultsKnockdown of CD44 caused BCSCs to differentiate into non-BCSCs with lower tumorigenic potential, and altered the cell cycle and expression profiles of some stem cell-related genes, making them more similar to those seen in non-BCSCs.ConclusionsKnockdown of CD44 is an effective strategy for attacking the stemness of BCSCs, resulting in a loss of stemness and an increase in susceptibility to chemotherapy or radiation. The results of this study highlight a potential new strategy for breast cancer treatment through the targeting of BCSCs.

BackgroundMesenchymal stem cells (MSCs) are an attractive source of stem cells for clinical applications. These cells exhibit a multilineage differentiation potential and strong capacity for immune modulation. Thus, MSCs are widely used in cell therapy, tissue engineering, and immunotherapy. Because of important advantages, umbilical cord blood-derived MSCs (UCB-MSCs) have attracted interest for some time. However, the applications of UCB-MSCs are limited by the small number of recoverable UCB-MSCs and fetal bovine serum (FBS)-dependent expansion methods. Hence, this study aimed to establish a xenogenic and allogeneic supplement-free expansion protocol.MethodsUCB was collected to prepare activated platelet-rich plasma (aPRP) and mononuclear cells (MNCs). aPRP was applied as a supplement in Iscove modified Dulbecco medium (IMDM) together with antibiotics. MNCs were cultured in complete IMDM with four concentrations of aPRP (2, 5, 7, or 10%) or 10% FBS as the control. The efficiency of the protocols was evaluated in terms of the number of adherent cells and their expansion, the percentage of successfully isolated cells in the primary culture, surface marker expression, and in vitro differentiation potential following expansion.ResultsThe results showed that primary cultures with complete medium containing 10% aPRP exhibited the highest success, whereas expansion in complete medium containing 5% aPRP was suitable. UCB-MSCs isolated using this protocol maintained their immunophenotypes, multilineage differentiation potential, and did not form tumors when injected at a high dose into athymic nude mice.ConclusionThis technique provides a method to obtain UCB-MSCs compliant with good manufacturing practices for clinical application.

Because of self-renewal, strong proliferation in vitro, abundant sources for isolation, and a high differentiation capacity, mesenchymal stem cells are suggested to be potentially therapeutic for liver fibrosis/cirrhosis. In this study, we evaluated the treatment effects of mouse bone marrow-derived mesenchymal stem cells (BM-MSCs) on mouse liver cirrhosis induced by carbon tetrachloride. Portal and tail vein transplantations were examined to evaluate the effects of different injection routes on the liver cirrhosis model at 21 days after transplantation. BM-MSCs transplantation reduced aspartate aminotransferase/alanine aminotransferase levels at 21 days after injection. Furthermore, BM-MSCs induced positive changes in serum bilirubin and albumin and downregulated expression of integrins (600- to 7000-fold), transforming growth factor, and procollagen-α1 compared with the control group. Interestingly, both injection routes ameliorated inflammation and liver cirrhosis scores. All mice in treatment groups had reduced inflammation scores and no cirrhosis. In conclusion, transplantation of BM-MSCs via tail or portal veins ameliorates liver cirrhosis in mice. Notably, there were no differences in treatment effects between tail and portal vein administrations. In consideration of safety, we suggest transfusion of bone marrow-derived mesenchymal stem cells via a peripheral vein as a potential method for liver fibrosis treatment.