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

OBJECTIVES Kidney disease is emerging as a critical medical problem worldwide. Because of limited treatment options for the damaged kidney,stem cell treatment is becoming an alternative therapeutic approach. Of many possible human stem cell sources,pluripotent stem cells are most attractive due to their self-renewal and pluripotent capacity. However,little is known about the derivation of renal lineage cells from human pluripotent stem cells (hPSCs). In this study,we developed a novel protocol for differentiation of nephron progenitor cells (NPCs) from hPSCs in a serum- and feeder-free system. MATERIALS AND METHODS We designed step-wise protocols for differentiation of human pluripotent stem cells toward primitive streak,intermediate mesoderm and NPCs by recapitulating normal nephrogenesis. Expression of key marker genes was examined by RT-PCR,real time RT-PCR and immunocytochemistry. Each experiment was independently performed three times to confirm its reproducibility. RESULTS After modification of culture period and concentration of exogenous factors,hPSCs can differentiate into NPCs that markedly express specific marker genes such as SIX2,GDNF,HOXD11,WT1 and CITED1 in addition to OSR1,PAX2,SALL1 and EYA1. Moreover,NPCs possess the potential of bidirectional differentiation into both renal tubular epithelial cells and glomerular podocytes in defined culture conditions. In particular,approximately 70% of SYN-positive cells were obtained from hPSC-derived NPCs after podocytes induction. NPCs can also form in vitro tubule-like structures in three dimensional culture systems. CONCLUSIONS Our novel protocol for hPSCs differentiation into NPCs can be useful for producing alternative sources of cell replacement therapy and disease modeling for human kidney diseases. View Publication

Human embryonic stem cells (hESCs) are pluripotent cells derived from the embryo at the blastocyst stage. Their embryonic origin confers upon them the capacity to proliferate indefinitely in vitro while maintaining the capacity to differentiate into a large variety of cell types. Based on these properties of self-renewal and pluripotency,hESCs represent a unique source to generate a large quantity of certain specialized cell types with clinical interest for transplantation-based therapy. However,hESCs are usually grown in culture conditions using fetal bovine serum and mouse embryonic fibroblasts,two components that are not compatible with clinical applications. Consequently,the possibility to expand hESCs in serum-free and in feeder-free culture conditions is becoming a major challenge to deliver the clinical promises of hESCs. Here,we describe the basic principles of growing hESCs in a chemically defined medium (CDM) devoid of serum and feeders. View Publication

Renal lineages including kidney are derived from intermediate mesoderm,which are differentiated from a subset of caudal undifferentiated mesoderm. The inductive mechanisms of mammalian intermediate mesoderm and renal lineages are still poorly understood. Mouse embryonic stem cells (mESCs) can be a good in vitro model to reconstitute the developmental pathway of renal lineages and to analyze the mechanisms of the sequential differentiation. We examined the effects of Activin A and retinoic acid (RA) on the induction of intermediate mesoderm from mESCs under defined,serum-free,adherent,monolayer culture conditions. We measured the expression level of intermediate mesodermal marker genes and examined the developmental potential of the differentiated cells into kidney using an ex vivo transplantation assay. Adding Activin A followed by RA to mESC cultures induced the expression of marker genes and proteins for intermediate mesoderm,odd-skipped related 1 (Osr1) and Wilm’s Tumor 1 (Wt1). These differentiated cells integrated into laminin-positive tubular cells and Pax2-positive renal cells in cultured embryonic kidney explants. We demonstrated that intermediate mesodermal marker expression was also induced by RA receptor (RAR) agonist,but not by retinoid X receptor (RXR) agonists. Furthermore,the expression of these markers was decreased by RAR antagonists. We directed the differentiation of mESCs into intermediate mesoderm using Activin A and RA and revealed the role of RAR signaling in this differentiation. These methods and findings will improve our understanding of renal lineage development and could contribute to the regenerative medicine of kidney. View Publication

The aim of the present study is to clarify the functional expression and physiological role in neural progenitor cells (NPCs) of carnitine/organic cation transporter OCTN1/SLC22A4,which accepts the naturally occurring food-derived antioxidant ergothioneine (ERGO) as a substrate in vivo. Real-time PCR analysis revealed that mRNA expression of OCTN1 was much higher than that of other organic cation transporters in mouse cultured cortical NPCs. Immunocytochemical analysis showed colocalization of OCTN1 with the NPC marker nestin in cultured NPCs and mouse embryonic carcinoma P19 cells differentiated into neural progenitor-like cells (P19-NPCs). These cells exhibited time-dependent [(3)H]ERGO uptake. These results demonstrate that OCTN1 is functionally expressed in murine NPCs. Cultured NPCs and P19-NPCs formed neurospheres from clusters of proliferating cells in a culture time-dependent manner. Exposure of cultured NPCs to ERGO or other antioxidants (edaravone and ascorbic acid) led to a significant decrease in the area of neurospheres with concomitant elimination of intracellular reactive oxygen species. Transfection of P19-NPCs with small interfering RNA for OCTN1 markedly promoted formation of neurospheres with a concomitant decrease of [(3)H]ERGO uptake. On the other hand,exposure of cultured NPCs to ERGO markedly increased the number of cells immunoreactive for the neuronal marker βIII-tubulin,but decreased the number immunoreactive for the astroglial marker glial fibrillary acidic protein (GFAP),with concomitant up-regulation of neuronal differentiation activator gene Math1. Interestingly,edaravone and ascorbic acid did not affect such differentiation of NPCs,in contrast to the case of proliferation. Knockdown of OCTN1 increased the number of cells immunoreactive for GFAP,but decreased the number immunoreactive for βIII-tubulin,with concomitant down-regulation of Math1 in P19-NPCs. Thus,OCTN1-mediated uptake of ERGO in NPCs inhibits cellular proliferation via regulation of oxidative stress,and also promotes cellular differentiation by modulating the expression of basic helix-loop-helix transcription factors via an unidentified mechanism different from antioxidant action. View Publication

Human pluripotent stem cells (hPSCs) and their differentiated derivatives represent valuable tools for studying development,modeling diseases,and advancing cell therapy. Recent improvements in genome engineering allow for precise modifications of hPSCs,further enhancing their utility in basic and translational research. Here we describe a Recombinase-Mediated Cassette Exchange (RMCE) platform in hPSCs that allows for the highly efficient,rapid,and specific integration of transgenes. The RCME-mediated DNA integration process is nearly 100% efficient,without negatively affecting the pluripotency or karyotypic stability of hPSCs. Taking advantage of this convenient system,we first established a dual inducible expression system based on the Tet-On and Cumate-On systems,allowing for the inducible expression of two transgenes independently. Secondly,we incorporated a Tet-on inducible system,driving the expression of three genes simultaneously. However,two genes also contain independent degron sequences,allowing for precise control over the expression of each gene individually. We demonstrated the utility of these systems in hPSCs,as well as their functionality after differentiation into cells that were representative of the three germ layers. Lastly,we used the triple inducible system to investigate the lineage commitment induced by the pancreatic transcription factors NKX6.1 and PDX1. We found that controlled dual expression,but not individual expression,biases hPSC embryoid body differentiation towards the pancreatic lineage by inducing the expression of the NeuroD program. In sum,we describe a novel genetic engineering platform that allows for the efficient and fast integration of any desired transgene(s) in hPSCs using RMCE. We anticipate that the ability to modulate the expression of three transgenes simultaneously will further accelerate discoveries using stem cell technology. View Publication

Human embryonic stem cells,because of their unique combination of long-term self-renewal properties and pluripotency,are providing new avenues of investigation of stem cell biology and human development and show promise in providing a new source of human cells for transplantation therapies and pharmaceutical testing. Current methods of propagating these cells using combinations of mouse fibroblast feeder cultures and bovine serum components are inexpensive and,in general,useful. However,the systematic investigation of the regulation of self-renewal and the production of safer sources of cells for transplantation depends on the elimination of animal products and the use of defined culture conditions. Both goals are served by the development of serum-free culture methods for human embryonic stem cells. View Publication

Mice deficient in early B cell factor (EBF) are blocked at the progenitor B cell stage prior to immunoglobulin gene rearrangement. The EBF-dependent block in B cell development occurs near the onset of B-lineage commitment,which raises the possibility that EBF may act instructively to specify the B cell fate from uncommitted,multipotential progenitor cells. To test this hypothesis,we transduced enriched hematopoietic progenitor cells with a retroviral vector that coexpressed EBF and the green fluorescent protein (GFP). Mice reconstituted with EBF-expressing cells showed a near complete absence of T lymphocytes. Spleen and peripheral blood samples were textgreater95 and 90% GFP+EBF+ mature B cells,respectively. Both NK and lymphoid-derived dendritic cells were also significantly reduced compared with control-transplanted mice. These data suggest that EBF can restrict lymphopoiesis to the B cell lineage by blocking development of other lymphoid-derived cell pathways. View Publication