The high demand of human placenta-derived mesenchymal stem cells (hPDMSCs) for therapeutic applications requires reproducible production of large numbers of well-characterized cells under well-controlled conditions. However, no method for fast hPDMSCs proliferation has yet been reported. In the present study, the feasibility of using a stirred bioreactor system to expand hPDMSCs was examined. hPDMSCs were cultured either in stirred bioreactors or in tissue culture flasks (T-flasks) for 5 days. Total cell density and several parameters of physical microenvironments were monitored in the two culture systems every 24 h. The maintenance of the antigenic phenotype of hPDMSCs before and after culturing in the stirred bioreactor system was cytometrically assessed. Data suggested that the physical microenvironment in the stirred bioreactors was much more favorable than that of the T-flasks. At the end of 144 h culturing, the total cell number was increased 1.73 times from the T-flasks to the stirred bioreactors. In addition, hPDMSCs could maintain their antigenic phenotype when cultured in stirred bioreactors. These results provide the initial assessment for large-scale hPDMSCs production using suspension culture bioreactors.

Mesenchymal stem cells (MSCs) are potential and optimal stem cells in clinical cell therapy, and fetal bovine serum (FBS) is widely used for expansion of MSCs, despite the risks of infectious disease transmission and immunological reaction of the xenogenic origin. This study was designed to compare human four blood group cord blood serum (CBS) with FBS in culturing human placenta-derived mesenchymal stem cells (hPDMSCs), which were derived from four blood group donors. The expansion medium included: 10% FBS, 10% A-CBS, 10% B-CBS, 10% O-CBS, and 10% AB-CBS. Cumulative population doubling, generation time, fold expansion rates and differentiation capacity, cell cycle, and immunophenotype were also assessed. The results showed that fold expansion rate and cumulative population doubling of hPDMSCs significantly increased during long-term MSC expansion in CBS medium, but the generation time decreased compared with FBS. CBS might be an effective supplement for stem cells expand rapidly ex vivo. Cell cycle and differentiation assays showed that most of the hPDMSCs expanding in the presence of CBS were in stationary phase, which was the characteristic of stem cells, and they retained their ability to differentiate into chondrogenic and endothelial cells. By comparing these four blood groups of CBS, we found that there was no significant difference among different blood groups in culturing hPDMSCs, which were isolated from different blood group donors. So CBS may be an optimal replacement to avoid the risks of FBS application in expansion of stem cell for clinical cell therapy and tissue engineering.

Apoptosis and necrosis of intestinal epithelial cells (IECs), induced by ischemia-reperfusion (I/R) injury, can lead to dysfunction of the intestinal barrier, which could cause multiple organ dysfunction syndromes. Mesenchymal stem cells (MSCs) have the potential of providing protective effects on damaged IECs via paracrine action. This study investigated whether hypoxia can enhance the protective effect of placental-derived MSCs (pMSCs) on H2O2-treated-caco2 cells, and explored the possible mechanism. The pMSCs isolated by tissue culture were fibroblast-like, positive for CD73, CD90 and CD105 and can differentiate into chondrocytes and endothelial cells. Five days after treatment with H2O2, the numbers of living caco2 cells significantly decreased. More live H2O2-treated-caco2 cells were observed in pMSCs hypoxia culture medium (pMSCs-HCM) than pMSCs normoxia culture medium (pMSCs-NCM), and the application of a specific antibody that blocked insulin-like growth factor-1 (IGF-1) leads to a significant decrease of the protective effect of pMSCs-HCM. Hypoxia can promote IGF-1 expression of pMSCs at mRNA and protein levels, and caco2 stably expressed IGF-1 receptor. Knocking down IGF-1 expression in pMSCs by siRNA resulted in a significant attenuation of the increase in apoptosis of H2O2-treated-caco2 cultured in pMSCs-HCM. In conclusion, hypoxia can increase the protective effect of pMSCs on H2O2-treated-caco2 cells via a promotion of their paracrine actions, and the key cytokine involved is IGF-1.

BackgroundThe present study was designed to determine whether Allium ursinum L (ramson) could inhibit the proliferation of human AGS gastric cancer cells. Furthermore, we attempted to determine whether this inhibition could occur by targeting regulatory elements of the cell cycle.MethodsFlow cytometry was used to observe apoptosis and the cell cycle in AGS cell lines treated or not treated with ramson watery extract. Proteins related to the cell cycle were detected by Western blotting. Caspase activity was measured using a colorimetric assay kit according to the manufacturer’s instructions.ResultsRamson watery extract induced apoptosis and G2/M phase arrest in AGS cells. Western blotting showed that cyclin B was inhibited by ramson watery extract. However, G1 phase-related proteins remain unchanged after treatment.ConclusionOur results indicate that ramson effectively sup pressed proliferation and induced apoptosis and G2/M arrest in AGS cells by regulating elements of the cell cycle.

The present study aimed to investigate the role of lumican in mice with endotoxin-induced acute renal failure (ARF). Lumican transgenic mice and wild-type mice were injected with lipopolysaccharide (LPS; 10 mg/kg) to establish a model of ARF. The mice were sacrificed at 24 h and the blood and renal tissue samples were collected. The value of serum creatinine (SCr) and blood urea nitrogen (BUN) were measured to determine renal function. An ELISA was used to determined the concentrations of renal cytokines, including tumor necrosis factor (TNF)α, interleukin (IL)-6, IL-4 and IL-10. The protein expression levels of Toll-like receptor (TLR4) and nuclear factor (NF)κB in renal tissues were assessed using western blot analysis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was performed to monitor apoptosis of renal tissue. Light microscopy and electron microscopy were used to observe structural changes in the renal tissues. Following the administration of LPS, the SCr and BUN values of mice in the lumican transgenic group were higher compared with those in the control group. The expression levels of renal TLR4, NFκB, TNFα, IL-6, IL-4 and IL-10 were upregulated in the lumican transgenic mice compared with those in the wild-type control group. Apoptosis was detected predominantly on the renal tubule. There was a significant difference in the optical density of apoptotic bodies between the control mice and the lumican transgenic mice. Light and electron microscopy demonstrated more severe renal tissue injury in the lumican transgenic mice compared with that in the control mice. In conclusion, LPS may cause excessive apoptosis in the renal tubular cells via the TLR4 signal transduction pathway, a decrease in the number of renal tubular cells and ARF. Lumican may be important in mice with LPS-induced ARF.