搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

Mobile elements are important evolutionary forces that challenge genomic integrity. Long interspersed element-1 (L1,also known as LINE-1) is the only autonomous transposon still active in the human genome. It displays an unusual pattern of evolution,with,at any given time,a single active L1 lineage amplifying to thousands of copies before getting replaced by a new lineage,likely under pressure of host restriction factors,which act notably by silencing L1 expression during early embryogenesis. Here,we demonstrate that in human embryonic stem (hES) cells,KAP1 (KRAB [Kruppel-associated box domain]-associated protein 1),the master cofactor of KRAB-containing zinc finger proteins (KRAB-ZFPs) previously implicated in the restriction of endogenous retroviruses,represses a discrete subset of L1 lineages predicted to have entered the ancestral genome between 26.8 million and 7.6 million years ago. In mice,we documented a similar chronologically conditioned pattern,albeit with a much contracted time scale. We could further identify an L1-binding KRAB-ZFP,suggesting that this rapidly evolving protein family is more globally responsible for L1 recognition. KAP1 knockdown in hES cells induced the expression of KAP1-bound L1 elements,but their younger,human-specific counterparts (L1Hs) were unaffected. Instead,they were stimulated by depleting DNA methyltransferases,consistent with recent evidence demonstrating that the PIWI-piRNA (PIWI-interacting RNA) pathway regulates L1Hs in hES cells. Altogether,these data indicate that the early embryonic control of L1 is an evolutionarily dynamic process and support a model in which newly emerged lineages are first suppressed by DNA methylation-inducing small RNA-based mechanisms before KAP1-recruiting protein repressors are selected. View Publication

B-cell functions in antitumor immunity are not well understood. In this study,we evaluated the role of B cells in the development of antitumor immunity using Friend murine leukemia virus gag-expressing mouse EL-4 (EL-4 gag),D5 mouse melanoma,or MCA304 mouse sarcoma cells. To screen tumors for susceptibility to B-cell-deficient immune environments,spleen cells from naive C57BL/6 [wild-type (WT)] and B-cell knockout (BKO) mice were cultured with irradiated tumor cells in vitro. When cells were stimulated with EL-4 gag or D5 (but not MCA304 tumors),IFN-gamma production from CD8 T cells and natural killer cells was markedly decreased in WT compared with BKO cultures. IFN-gamma production was correlated with CD40 ligand expression on the tumor and inversely with interleukin-10 (IL-10) production by B cells. Sorted WT B cells produced more IL-10 than CD40 knockout (CD40KO) B cells when cocultured with EL-4 gag or D5 (but not MCA304). IFN-gamma production by BKO cells was reduced by the addition of sorted naive WT B cells (partially by CD40KO B cells) or recombinant mouse IL-10. In vivo tumor progression mirrored in vitro studies in that WT mice were unable to control tumor growth whereas EL-4 gag and D5 tumors (but not MCA304) were eliminated in BKO mice. Robust in vivo antitumor CTLs developed only in BKO tumor-challenged mice. Our studies provide the first mechanistic basis for the concept that B-cell depletion could therapeutically enhance antitumor immune responses to certain tumors by decreasing IL-10 production from B cells. View Publication

CONTEXT: The osteoanabolic properties of PTH may be due to increases in the number and maturity of circulating osteogenic cells. Hypoparathyroidism is a useful clinical model because this hypothesis can be tested by administering PTH. OBJECTIVE: The objective of the study was to characterize circulating osteogenic cells in hypoparathyroid subjects during 12 months of PTH (1-84) administration. DESIGN: Osteogenic cells were characterized using flow cytometry and antibodies against osteocalcin,an osteoblast-specific protein product,and stem cell markers CD34 and CD146. Changes in bone formation from biochemical markers and quadruple-labeled transiliac crest bone biopsies (0 and 3 month time points) were correlated with measurements of circulating osteogenic cells. SETTING: The study was conducted at a clinical research center. PATIENTS: Nineteen control and 19 hypoparathyroid patients were included in the study. INTERVENTION: Intervention included the administration of PTH (1-84). RESULTS: Osteocalcin-positive cells were lower in hypoparathyroid subjects than controls (0.7 ± 0.1 vs. 2.0 ± 0.1%; P textless 0.0001),with greater coexpression of the early cell markers CD34 and CD146 among the osteocalcin-positive cells in the hypoparathyroid subjects (11.0 ± 1.0 vs. 5.6 ± 0.7%; P textless 0.001). With PTH (1-84) administration,the number of osteogenic cells increased 3-fold (P textless 0.0001),whereas the coexpression of the early cell markers CD34 and CD146 decreased. Increases in osteogenic cells correlated with circulating and histomorphometric indices of osteoblast function: N-terminal propeptide of type I procollagen (R(2) = 0.4,P ≤ 0.001),bone-specific alkaline phosphatase (R(2) = 0.3,P textless 0.001),osteocalcin (R(2) = 0.4,P textless 0.001),mineralized perimeter (R(2) = 0.5,P textless 0.001),mineral apposition rate (R(2) = 0.4,P = 0.003),and bone formation rate (R(2) = 0.5,P textless 0.001). CONCLUSIONS: It is likely that PTH stimulates bone formation by stimulating osteoblast development and maturation. Correlations between circulating osteogenic cells and histomorphometric indices of bone formation establish that osteoblast activity is being identified by this methodology. View Publication

BACKGROUND Emerging evidence of antibody-independent functions,as well as the clinical efficacy of anti-CD20 depleting therapies,helped to reassess the contribution of B cells during multiple sclerosis (MS) pathogenesis. OBJECTIVE To investigate whether CD19+ B cells may share expression of the serine-protease granzyme-B (GzmB),resembling classical cytotoxic CD8+ T lymphocytes,in the peripheral blood from relapsing-remitting MS (RRMS) patients. METHODS In this study,104 RRMS patients during different treatments and 58 healthy donors were included. CD8,CD19,Runx3,and GzmB expression was assessed by flow cytometry analyses. RESULTS RRMS patients during fingolimod (FTY) and natalizumab (NTZ) treatment showed increased percentage of circulating CD8+GzmB+ T lymphocytes when compared to healthy volunteers. An increase in circulating CD19+GzmB+ B cells was observed in RRMS patients during FTY and NTZ therapies when compared to glatiramer (GA),untreated RRMS patients,and healthy donors but not when compared to interferon-$\beta$ (IFN). Moreover,regarding Runx3,the transcriptional factor classically associated with cytotoxicity in CD8+ T lymphocytes,the expression of GzmB was significantly higher in CD19+Runx3+-expressing B cells when compared to CD19+Runx3- counterparts in RRMS patients. CONCLUSIONS CD19+ B cells may exhibit cytotoxic behavior resembling CD8+ T lymphocytes in MS patients during different treatments. In the future,monitoring cytotoxic" subsets might become an accessible marker for investigating MS pathophysiology and even for the development of new therapeutic interventions." View Publication

Preclinical in vitro models provide an essential tool to study cancer cell biology as well as aid in translational research,including drug target identification and drug discovery efforts. For any model to be clinically relevant,it needs to recapitulate the biology and cell heterogeneity of the primary tumor. We recently developed and described a conditional reprogramming (CR) cell technology that addresses many of these needs and avoids the deficiencies of most current cancer cell lines,which are usually clonal in origin. Here,we used the CR cell method to generate a collection of patient-derived cell cultures from non-small cell lung cancers (NSCLC). Whole exome sequencing and copy number variations are used for the first time to address the capability of CR cells to keep their tumor-derived heterogeneity. Our results indicated that these primary cultures largely maintained the molecular characteristics of the original tumors. Using a mutant-allele tumor heterogeneity (MATH) score,we showed that CR cells are able to keep and maintain most of the intra-tumoral heterogeneity,suggesting oligoclonality of these cultures. CR cultures therefore represent a pre-clinical lung cancer model for future basic and translational studies. View Publication

Small intestinal CD103(+) dendritic cells (DCs) have the selective ability to promote de novo generation of regulatory T cells via the production of retinoic acid (RA). Considering that aldehyde dehydrogenase (ALDH) activity controls the production of RA,we used a flow cytometry-based assay to measure ALDH activity at the single-cell level and to perform a comprehensive analysis of the RA-producing DC populations present in lymphoid and nonlymphoid mouse tissues. RA-producing DCs were primarily of the tissue-derived,migratory DC subtype and can be readily found in the skin and in the lungs as well as in their corresponding draining lymph nodes. The RA-producing skin-derived DCs were capable of triggering the generation of regulatory T cells,a finding demonstrating that the presence of RA-producing,tolerogenic DCs is not restricted to the intestinal tract as previously thought. Unexpectedly,the production of RA by skin DCs was restricted to CD103(-) DCs,indicating that CD103 expression does not constitute a universal" marker for RA-producing mouse DCs. Finally View Publication

BACKGROUND Glioblastoma (GBM) is the most common and aggressive form of primary brain tumor. Although numerous postoperative therapeutic strategies have already been developed,including radiotherapy,tumors inevitably recur after several years of treatment. The coinhibitory molecule B7-H4 negatively regulates T cell immune responses and promotes immune escape. Exosomes mediate intercellular communication and initiate immune evasion in the tumor microenvironment (TME). OBJECTIVE This study aimed to determine whether B7-H4 is upregulated by radiation and loaded into exosomes,thus contributing to immunosuppression and enhancing tumor growth. METHODS Iodixanol density-gradient centrifugation and flow cytometry were used to verify exosomal B7-H4. Na{\{i}}ve T cells were differentiated into Th1 cells with or without exosomes. T cell-secreted cytokines and markers of T cell subsets were measured. Mechanistically the roles of B7-H4 and ALIX in GBM were analyzed using databases and tissue samples. Co-immunoprecipitation and pull-down assays were used to tested the direct interactions between ATM and ALIX or STAT3. In vitro ATM kinase assays western blotting and site-directed mutation were used to assess ATM-mediated STAT3 phosphorylation. Finally the contribution of exosomal B7-H4 to immunosuppression and tumor growth was investigated in vivo. RESULTS Exosomes from irradiated GBM cells decreased the anti-tumor immune response of T cell in vitro and in vivo via delivered B7-H4. Mechanistically irradiation promoted exosome biogenesis by increasing the ATM-ALIX interaction. Furthermore the ATM-phosphorylated STAT3 was found to directly binds to the B7-H4 promoter to increase its expression. Finally the radiation-induced increase in exosomal B7-H4 induced FoxP3 expression during Th1 cell differentiation via the activated STAT1 pathway. In vivo exosomal B7-H4 decreased the radiation sensitivity of GBM cells and reduced the survival of GBM mice model. CONCLUSION This study showed that radiation-enhanced exosomal B7-H4 promoted immunosuppression and tumor growth hence defining a direct link between irradiation and anti-tumor immune responses. Our results suggest that co-administration of radiotherapy with anti-B7-H4 therapy could improve local tumor control and identify exosomal B7-H4 as a potential tumor biomarker." View Publication

The coding region determinant-binding protein/insulin-like growth factor II mRNA-binding protein (CRD-BP/IMP1) is an RNA-binding protein specifically recognizing c-myc,leader 3' IGF-II and tau mRNAs,and the H19 RNA. CRD-BP/IMP1 is predominantly expressed in embryonal tissues but is de novo activated and/or overexpressed in various human neoplasias. To address the question of whether CRD-BP/IMP1 expression characterizes certain cell types displaying distinct proliferation and/or differentiation properties (i.e. stem cells),we isolated cell subpopulations from human bone marrow,mobilized peripheral blood,and cord blood,all sources known to contain stem cells,and monitored for its expression. CRD-BP/IMP1 was detected only in cord blood-derived CD34(+) stem cells and not in any other cell type of either adult or cord blood origin. Adult BM CD34(+) cells cultured in the presence of 5'-azacytidine expressed de novo CRD-BP/IMP1,suggesting that epigenetic modifications may be responsible for its silencing in adult non-expressing cells. Furthermore,by applying the short interfering RNA methodology in MCF-7 cells,we observed,subsequent to knocking down CRD-BP/IMP1,decreased c-myc expression,increased IGF-II mRNA levels,and reduced cell proliferation rates. These data 1) suggest a normal role for CRD-BP/IMP1 in pluripotent stem cells with high renewal capacity,like the CB CD34(+) cells,2) indicate that altered methylation may directly or indirectly affect its expression in adult cells,3) imply that its de novo activation in cancer cells may affect the expression of c-Myc and insulin-like growth factor II,and 4) indicate that the inhibition of CRD-BP/IMP1 expression might affect cancer cell proliferation. View Publication

The purpose of this study is to characterize the microRNA (miRNA) expression profiles of induced pluripotent stem (iPS) cells and retinal pigment epithelium (RPE) derived from induced pluripotent stem cells (iPS-RPE). MiRNAs have been demonstrated to play critical roles in both maintaining pluripotency and facilitating differentiation. Gene expression networks accountable for maintenance and induction of pluripotency are linked and share components with those networks implicated in oncogenesis. Therefore,we hypothesize that miRNA expression profiling will distinguish iPS cells from their iPS-RPE progeny. To identify and analyze differentially expressed miRNAs,RPE was derived from iPS using a spontaneous differentiation method. MiRNA microarray analysis identified 155 probes that were statistically differentially expressed between iPS and iPS-RPE cells. Up-regulated miRNAs including miR-181c and miR-129-5p may play a role in promoting differentiation,while down-regulated miRNAs such as miR-367,miR-18b,and miR-20b are implicated in cell proliferation. Subsequent miRNA-target and network analysis revealed that these miRNAs are involved in cellular development,cell cycle progression,cell death,and survival. A systematic interrogation of temporal and spatial expression of iPS-RPE miRNAs and their associated target mRNAs will provide new insights into the molecular mechanisms of carcinogenesis,eye differentiation and development. View Publication

STUDY QUESTION Can human embryonic stem cell-derived trophoblastic spheroids be used to study the early stages of implantation? SUMMARY ANSWER We generated a novel human embryonic stem cell-derived trophoblastic spheroid model mimicking human blastocysts in the early stages of implantation. WHAT IS KNOWN ALREADY Both human embryos and choriocarcinoma cell line derived spheroids can attach onto endometrial cells and are used as models to study the early stages of implantation. However,human embryos are limited and the use of cancer cell lines for spheroid generation remains sub-optimal for research. STUDY DESIGN,SIZE,DURATION Experimental induced differentiation of human embryonic stem cells into trophoblast and characterization of the trophoblast. PARTICIPANTS/MATERIALS,SETTING,METHODS Trophoblastic spheroids (BAP-EB) were generated by inducing differentiation of a human embryonic stem cell line,VAL3 cells with bone morphogenic factor-4,A83-01 (a TGF-$\$),and PD173074 (a FGF receptor-3 inhibitor) after embryoid body formation. The expressions of trophoblastic markers and hCG levels were studied by real-time PCR and immunohistochemistry. BAP-EB attachment and invasion assays were performed on different cell lines and primary endometrial cells. MAIN RESULTS AND THE ROLE OF CHANCE After 48 h of induced differentiation,the BAP-EB resembled early implanting human embryos in terms of size and morphology. The spheroids derived from embryonic stem cells (VAL3),but not from several other cell lines studied,possessed a blastocoel-like cavity. BAP-EB expressed several markers of trophectoderm of human blastocysts on Day 2 of induced differentiation. In the subsequent days of differentiation,the cells of the spheroids differentiated into trophoblast-like cells expressing trophoblastic markers,though at levels lower than that in the primary trophoblasts or in a choriocarcinoma cell line. On Day 3 of induced differentiation,BAP-EB selectively attached onto endometrial epithelial cells,but not other non-endometrial cell lines or an endometrial cell line that had lost its epithelial character. The attachment rates of BAP-EB was significantly higher on primary endometrial epithelial cells (EEC) taken from 7 days after hCG induction of ovulation (hCG+7 day) when compared with that from hCG+2 day. The spheroids also invaded through Ishikawa cells and the primary endometrial stromal cells in the co-culture. LIMITATIONS,REASONS FOR CAUTION The attachment rates of BAP-EB were compared between EEC obtained from Day 2 and Day 7 of the gonadotrophin stimulated cycle,but not the natural cycles. WIDER IMPLICATIONS OF THE FINDINGS BAP-EB have the potential to be used as a test for predicting endometrial receptivity in IVF cycles and provide a novel approach to study early human implantation,trophoblastic cell differentiation and trophoblastic invasion into human endometrial cells. View Publication

Raloxifene reduces bone loss and prevents vertebral fractures in postmenopausal women. Its skeletal effects are mediated by estrogen receptors (ER) and their modulation of paracrine osteoblastic factors. Receptor activator of nuclear factor-kappa B ligand is essential for osteoclasts and enhances bone resorption,whereas osteoprotegerin (OPG) neutralizes receptor activator of nuclear factor-kappa B ligand. Here,we assessed the effects of raloxifene on OPG production in human osteoblasts (hOB). Raloxifene enhanced gene expression of ER-alpha and progesterone receptor. Moreover,raloxifene increased OPG mRNA levels and protein secretion by hOB in a dose- and time-dependent fashion by 2- to 4-fold with a maximum effect at 10(-7) M and after 72 h (P textless 0.001). Treatment with the ER antagonist ICI 182,780 abrogated the effects of raloxifene on OPG production. Moreover,raloxifene enhanced osteoblastic differentiation markers,type 1 collagen secretion,and alkaline phosphatase activity by 3- and 2-fold,respectively (P textless 0.001). In addition,raloxifene inhibited expression of the bone-resorbing cytokine IL-6 by 25-45% (P textless 0.001). In conclusion,our data suggest that raloxifene stimulates OPG production and inhibits IL-6 production by hOB. Because OPG production increases with osteoblastic maturation,enhancement of OPG production by raloxifene could be related to its stimulatory effects on osteoblastic differentiation. View Publication

MEK/ERK signaling plays a crucial role in a diverse set of cellular functions including cell proliferation,differentiation and survival,and recently has been reported to negatively regulate mouse embryonic stem cell (mESC) self-renewal by antagonizing STAT3 activity. However,its role in human ESCs (hESCs) remains unclear. Here we investigated the functions of MEK/ERK in controlling hESC activity. We demonstrated that MEK/ERK kinases were targets of fibroblast growth factor (FGF) pathway in hESCs. Surprisingly,we found that,in contrast to mESCs,high basal MEK/ERK activity was required for maintaining hESCs in an undifferentiated state. Inhibition of MEK/ERK activity by specific MEK inhibitors PD98059 and U0126,or by RNA interference,rapidly caused the loss of self-renewal capacity. We also showed that MEK/ERK signaling cooperated with phosphoinositide 3-kinase (PI3K)/AKT signaling in maintaining hESC pluripotency. However,MEK/ERK signaling had little or no effect on regulating hESC proliferation and survival,in contrast to PI3K/AKT signaling. Taken together,these findings reveal the unique and crucial role of MEK/ERK signaling in the determination of hESC cell fate and expand our understanding of the molecular mechanisms behind the FGF pathway maintenance of hESC pluripotency. Importantly,these data make evident the striking differences in the control of self-renewal between hESCs and mESCs. View Publication