Comparative profiling of exosomal miRNAs in human adult peripheral and umbilical cord blood plasma by deep sequencing.

Aim: To assess differential expression profiles of miRNAs in exosomes derived from human peripheral blood (PB) and umbilical cord blood (UCB). Materials & methods: Small RNA sequencing was performed to characterize the miRNA expression in plasma exosomes processed from UCB of five healthy newborns and PB of five normal adult volunteers, and differentially expressed miRNAs were further analyzed. Results: A total of 65 exosomal miRNAs, including 46 upregulated and 19 downregulated, showed differential expression between UCB and PB. Target genes of these miRNAs were mainly enriched in signaling pathways associated with pregnancy, cancers, cell mobility and nervous system. Conclusion: Exosomal miRNAs may have essential roles in the biological functions of UCB, suggesting the therapeutic and biomarker potentials of exosomes in UCB.

Double labelling of human umbilical cord mesenchymal stem cells with Gd-DTPA and PKH26 and the influence on biological characteristics of hUCMSCs.

The aim of this study was to determine whether double labelling of human umbilical cord mesenchymal stem cells (hUCMSCs) with gadolinium-diethylene triamine penta-acetic acid (Gd-DTPA) and PKH26 influences their biological characteristics. A tissue adherence technique was used to separate and purify the hUCMSCs and flow cytometry was performed to detect the surface markers expressed on them. Gd-DTPA and PKH26 were used to label the stem cells and MRI and fluorescence microscopy were used to detect the double-labelled hUCMSCs. A MTT assay was used to delineate the growth curve. Transmission electron microscopy (TEM) and atomic force microscopy were used to demonstrate the ultrastructural features of the hUCMSCs. Flow cytometry showed that hUCMSCs highly expressed CD29, CD90, CD44 and CD105. No expression of CD31, CD34 and CD45 was detected. Very low expression of HLA-DR and CD40 was detected. Atomic force microscopy showed these cells were long, spindle shaped, and the cytoplasm and nucleus had clear boundaries. After double labelling, TEM showed Gd particles aggregated in the cytoplasm in a cluster pattern. The proliferation activity, cell cycle, apoptosis and differentiation of the stem cells were not influenced by double labelling. Thus a tissue adherence technique is helpful to separate and purify hUCMSCs effectively; and Gd-DTPA and PKH26 are promising tracers in the investigation of migration and distribution of hUCMSCs in vivo.

Analysis of feasibility of in vitro nuclear magnetic resonance tracking human umbilical cord mesenchymal stem cells by Gd-DTPA labeled.

OBJECTIVE: Three different kinds of transfection reagents were used to mediate the transfection of gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) into human umbilical-cord-derived mesenchymal stem cells (hUCMSCs). The efficacy of different transfection reagents and the feasibility of NMR tracer in vitro of magnetized stem cells were estimated. METHODS: After purification by tissue explants adherent method, the biological characteristics of hUCMSCs in vitro were identified by subculture and amplification. Calcium phosphate, Effectene and liposome2000 were used to transfect Gd-DTPA-labeled hUCMSCs respectively, and cell counting was used to mediate the transfection of Gd-DTPA into hUCMSCs, which were then induced to lipoblast and osteoblast in vitro. The determination of the transfection activities of the transfection reagents was conducted by measuring the magnetic resonance imaging (MRI) signal intensity of the Gd-DTPA-labeled cells and the concentration of gadolinium ion in the cells. Furthermore, the relationship between the signal intensity of Gd-DTPA-labeled hUCMSCsMRI, cell subculture and generations was studied. RESULTS: Primary cells were obtained by tissue explants adherent for two weeks. The cells displayed a long spindle form and grew in swirl. After two passage generations, the cellular morphology became more homogeneous. The result detected by the flow cytometer showed that CD29C, D44, CD90, and CD105 were highly expressed, while no CD45, CD40, and HLA-DR expression was detected in the third generation cells. Directional induction in vitro caused the differentiation into lipoblast and osteoblast. After transfected by calcium phosphate, Effectene and liposome 2000, the signal intensity of stem cells was 2281.2±118.8, 2031.9±59.7 and 1887.4±40.8 measured by MRI. Differences between these three groups were statistically significant (P<0.05). The concentrations of gadolinium ion in three groups of stem cells were 0.178±0.009mg/L, 0.158±0.003mg/L and 0.120±0.002mg/L respectively, examined by inductively coupled plasma atomic emission spectrometry. No significant differences were found among these three groups (P<0.05). The proliferation and differentiation abilities of the Gd-DTPA-labeled stem cells were not affected. A minimum 5×10(4) Gd-DTPA-labeled stem cells could be traced with MRI in vitro and presented in high signal. The trace duration time in vitro was about 12days. CONCLUSIONS: Tissue explants adherent method can be availably applied to purify hUCMSCs. The Effectene method was proved to have the best transfection effect. The proliferation ability and differentiation potency of Gd-DTPA-labeled hUCMSCs were not affected, and the NMR of labeled stem cells in vitro was proved to be feasible.

Human umbilical cord-derived mesenchymal stem cells inhibit proliferation but maintain survival of Jurkat leukemia cells in vitro by activating Notch signaling.

OBJECTIVE: To investigate the effects of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) on the proliferation and survival of Jurkat leukemia cells in vitro and explore the possible mechanism. METHODS: Jurkat leukemia cells were co-cultured with hUC-MSCs isolated from human umbilical cord tissues by plastic adherence at a ratio of 10:1. The proliferation and survival of the co-cultured Jurkat cells, separated by immunomagnetic bead cell sorting on day 4, were evaluated by flow cytometry. Western blotting was performed to evaluate the activation of Notch signaling in the co-cultured Jurkat cells. RESULTS: Jurkat leukemia cells co-cultured with hUC-MSCs for 4 days showed a lowered proliferation rate and cell cycle arrest at G0/G1 phase with a reduction in the cell apoptotic rate. Notch signaling pathway was activated in the co-cultured Jurkat cells as evidenced by an increased cellular expression of HES-1. CONCLUSION: Co-culture with hUC-MSCs can inhibit the proliferation of Jurkat leukemia cells in vitro and protect the cells from apoptosis by activating Notch signaling, indicating a potential shielding effect of MSCs on leukemia cells.

XRCC1 polymorphisms are associated with cervical cancer risk and response to chemotherapy: a systematic review and meta-analysis.

BACKGROUND: Functional single nucleotide polymorphisms of x-ray repair cross-complementing protein 1 (XRCC1) have been suspected to contribute to uterine cervical cancer risk for a long time; however, most previous case-control studies were small sized and biased. Additionally, recent studies suggested that XRCC1 polymorphisms could be a biomarker of response to platinum-based chemotherapy. METHODS: A comprehensive search was conducted to retrieve eligible studies and odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to measure association strength. RESULTS: A total of 13 studies were identified and analyzed. We found that the Arg194Trp polymorphism (Trp vs. Arg, OR=1.342, 95% CI: 1.176) was associated with increased risk of cervical cancer, while no significant association was found with Arg280His (His vs. Arg, OR=1.059, 95% CI: 0.863, 1.299) or Arg399Gln (Gln vs. Arg, OR=1.144, 95% CI: 0.938, 1.394). As for response to platinum- based chemotherapy, the variant XRCC1 399Gln allele (Gln vs. Arg, OR=0.345, 95% CI: 0.163, 0.729) was linked with a poor response; however, the Arg194Trp polymorphism (TrpArg vs. ArgArg, OR=6.421, 95% CI: 1.573, 26.205) predicted a good response. CONCLUSION: The Arg194Trp polymorphism of XRCC1 increases risk of cervical cancer; the variant 399Gln allele predicts poor response to platinum-based chemotherapy, while the Arg194Trp polymorphism indicates a good response.