Effects Of Human Mesenchymal Stem Cells Research Articles

Temporal patterns and distribution of pyroptosis-related molecules and effects of human mesenchymal stem cells on pyroptosis following cerebral ischemia/reperfusion in rats

ObjectivesPyroptosis is a new type of programmed cell death that has a strong proinflammatory effect. The present study investigated the dynamic changes of pyroptosis-related molecules and the effect of mesenchymal stem cells (MSCs) on pyroptosis following cerebral ischemia/reperfusion (I/R). Materials and MethodsThe temporal pattern and cellular distribution of caspase-1, Gasdermin D and E (GSDMD and GSDME) in the peri-infarct area, and the effect of human MSCs on GSDMD, IL-1β, IL-18, Lactate dehydrogenase (LDH) and neurological function were studied in a rat model of transient focal cerebral ischemia. ResultsThe expression of caspase-1 mRNA increased with time, with a protein level of pro-caspase-1 comparable to its mRNA level, while the level of cleaved-caspase-1 protein peaked at 48 h following I/R. Increased levels of GSDMD mRNA and protein were also observed, with a peak level at 24 h. There were no significant changes in GSDME mRNA or protein expression after I/R. In regards to changes in the number of cells expressing GSDMD after I/R, that for neurons was more significant than those for microglia and astrocytes. The modified neurological severity score discrepancy and the expression of GSDMD showed no significant differences within 24 h following I/R between the MSC- and NS-treated groups, but MSCs treatment promoted the secretion of IL-1β, IL-18 and LDH. ConclusionsIn the early stage of cerebral infarction in rats, there were dynamic changes in pyroptosis-related molecules (caspase-1 and GSDMD), but MSCs showed no effect on the levels of GSDMD or neurological function.

Human mesenchymal stem cells promote tumor growth via MAPK pathway and metastasis by epithelial mesenchymal transition and integrin \u03b15 in hepatocellular carcinoma

Mesenchymal stem cells (MSCs) appear to be a potential vehicle for anticancer drugs due to their excellent tumor tropism ability. However, the interactions between MSCs and hepatocellular carcinoma (HCC) are quite controversial and the underlying mechanisms are ambiguous. In this study, an investigation was conducted into the effect of human MSCs (hMSCs) on tumor proliferation and metastasis both in xenograft and orthotopic models. It was discovered that hMSCs could promote tumor growth though activating mitogen-activated protein kinase (MAPK) signaling pathway and promote metastasis by epithelial mesenchymal transition (EMT) in vivo. To test whether hMSCs could induce immunosuppressive effects, the expression of the Natural killer (NK) cell marker CD56 was measured by immunohistochemical staining and the expression of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured by qRT-PCR. It was found out that CD56 expression significantly decreased, while TNF-α and IL-6 expression increased in the hMSCs-treated tissues. Mechanistically, RNA sequencing was performed, which led to a discovery that integrin α5 (ITGA5) was over-expressed in hMSCs-treated HCC. ITGA5 siRNAs blocked the hMSCs-induced migration and invasion of HCC, while over-expression of ITGA5 promoted the migration and invasion ability in HCC-hMSCs, indicating that the expression of ITGA5 is associated with hMSCs-induced tumor metastasis. These findings suggest that hMSCs may play a vital role in HCC proliferation and metastasis and could be identified as a putative therapeutic target in HCC.

Abstract 129: Human Mesenchymal Stem Cells Augment Contractile Function of Human Engineered Cardiac Tissues

Mesenchymal stem cells (MSC) have demonstrated efficacy for improving cardiomyocyte (CM) function in vitro, in vivo and in clinical trials, but the mechanism of this enhancement remains elusive. The objective of this study was to test the hypothesis that human engineered cardiac tissues (hECT) offer a viable model system to investigate the effects of human MSC on CM contractile function. Human CM (hCM) were produced from embryonic stem cells (hESC, H7 line) using a small-molecule based differentiation approach. Blebbistatin and BMP4 were added to hESC suspended in StemPro34 differentiation media for 24 h, followed by BMP4 and Activin A to day 4.5, followed by addition of IWR-1 Wnt inhibitor for at least 4 days. To create hECT, approximately 1 million hCM were mixed with 2.0 mg/ml bovine type I collagen and 0.9 mg/ml Matrigel, and pipetted into a mold fabricated from polydimethylsiloxane with integrated cantilever end-posts. To model hMSC cell therapy, two types of hECT were created: hCM-only control hECT, and hMSC-CM hybrid hECT containing hCM mixed with 5-10% of human bone marrow-derived MSC. Over several days in culture, the hECT self-assembled and started beating; end-post deflection was tracked in real time to compute twitch force using beam theory. Human CMs were produced with high efficiency (>70% cTnT+) with a predominantly ventricular phenotype (MLC2v+). Resulting hECTs exhibited spontaneous beating (1.3±0.4 Hz), cellular alignment, registered sarcomeres, and expression of cardiac specific genes cTnT, α-MHC, β-MHC and SERCA2a. After 11±2 days in culture, developed stress (force/area) was over 10-fold higher in hMSC-CM hybrid tissues (0.27±0.048 mN/mm 2 ) compared to hCM-only controls (0.02±0.006 mN/mm 2 ; p=0.04, n=5 per group). This reflected significantly greater twitch force (0.11±0.004 mN vs 0.033±0.016 mN, p=0.016) and smaller cross-sectional area (0.19±0.12 mm 2 vs 0.49±0.10 mm 2 ; p=0.003) in hMSC-CM hybrid vs hCM-only hECT. In conclusion, human ECT offer a novel system to study MSC-CM interactions. The findings suggest hMSC supplementation improves contractility compared to CM-only hECT. Investigating the mechanisms of hMSC-mediated enhancement of hECT function may yield insights into MSC-based therapies for cardiac regeneration.

Growth Inhibitory Effect of Palatine Tonsil-derived Mesenchymal Stem Cells on Head and Neck Squamous Cell Carcinoma Cells

ObjectivesMesenchymal stem cells (MSCs) play an important role in the development and growth of tumor cells. However, the effect of human MSCs on the growth of human tumors is not well understood. The purpose of this study is to confirm the growth effect of palatine tonsil-derived MSCs (TD-MSCs) on head and neck squamous cell carcinoma (HNSCC) cell lines and to elucidate the mechanism of their action.MethodsTD-MSCs were isolated from patient with chronic tonsillitis and tonsillar hypertrophy. Two human HNSCC cell lines (PNUH-12 and SNU-899) were studied and cocultured with isolated palatine tonsil-derived MSC. The growth inhibitory effect of MSCs on HNSCC cell lines was tested through methylthiazolyldiphenyl-tetrazolium (MTT) assay. The apoptosis induction effect of MSCs on cell lines was assessed with flow cytometry and reverse transcriptase (RT)-PCR.ResultsPalatine tonsil-derived MSCs exhibited a growth inhibitory effect on both cell lines. Cell cycle analysis showed an accumulation of tumor cells predominantly in G0/G1 phase with an increase in concentration of TD-MSCs, which was confirmed by increased mRNA expression of cell cycle negative regulator p21. Apoptosis of tumor cells increased significantly as concentration of cocultured TD-MSCs increased. Additionally, mRNA expression of caspase 3 was upregulated with increased concentration of TD-MSCs.ConclusionTD-MSCs have a potential growth inhibitory effect on HNSCC cell lines in vitro by inducing apoptotic cell death and G1 phase arrest of cell lines.

Isolation and ex vivo expansion of human umbilical cord blood-derived CD34+ stem cells and their cotransplantation with or without mesenchymal stem cells

Umbilical cord blood (UCB) contains a high number of primitive progenitor cells, allowing UCB to be used as a source of hematopoietic progenitors for clinical transplantation. However the rate of UCB CD34+ stem cells graft is low. Mesenchymal stem cells (MSCs) have been implicated in playing an important role in hematopoietic stem cell engraftment.In this study we examined the effect of human MSC on engraftment of human UCB-derived CD34+ cells in irradiated Balb/c mice.Human UCB CD34+ cells were obtained from full-term normal deliveries by using an immunomagnetic separation technique and MSC were isolated by standard methodology from human bone marrow. Isolated CD34+ cells were cultured in Stemline Hematopoietic stem cell expansion medium supplemented with 100 ng/ml stem cell factor (SCF), and 100 ng/ml thrombopoietin (TPO) in 24-well plates and incubated at 37°C in a fully humidified atmosphere with 5% CO2, and maintained over 3 weeks and half the medium was exchanged twice a week. Irradiated (7 Gy) Balb/c mice were transplanted intravenously with 0·1 × 106 to 10 × 106 human UCB CD34+ cells in the presence or absence of 0·5 × 106 and 1 × 106 human bone marrow-derived MSC. After 11 days, in each group, the spleen was dissected and colony assay performed. Hematoxilin and eosin staining of the spleen colony was performed, and UCB CD34+ cells labeled with super paramagnetic iron oxide (SPIO). After establishing the presence of colonies in spleen, Prussian blue staining was performed.Flow cytometry assay showed that up to 90% purity of CD34+ cells and 96% for MSC. After 3 weeks the cell numbers showed a 1000-fold increase in CD34+. Cotransplantation of low doses of UCB CD34+ cells (0·2 × 106 and 0·3 × 106) and MSC (0·5 × 106 and 1 × 106) resulted in a significant increase in colony forming unit spleen, in comparison with engraftment of UCB CD34+ stem cells without MSC after 11 days (p<0·01).In conclusion the results showed that two cytokines (SCF, TPO) were sufficient for expansion of UCB CD34+ cells and cotransplantation of MSC with UCB CD34+ cells, promoting engraftment of UCB CD34+ cells.