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

Human stem cells are powerful tools by which to investigate molecular mechanisms of cell growth and differentiation under normal and pathological conditions. Hedgehog signaling,the dysregulation of which causes several pathologies,such as congenital defects and cancer,is involved in several cell differentiation processes and interferes with adipocyte differentiation of rodent cells. The present study was aimed at investigating the effect of Hedgehog pathway modulation on adipocyte phenotype using different sources of human mesenchymal cells,such as bone marrow stromal cells and human multipotent adipose-derived stem cells. We bring evidence that Hedgehog signaling decreases during human adipocyte differentiation. Inhibition of this pathway is not sufficient to trigger adipogenesis,but activation of Hedgehog pathway alters adipocyte morphology as well as insulin sensitivity. Analysis of glycerol-3-phosphate dehydrogenase activity and expression of adipocyte marker genes indicate that activation of Hedgehog signaling by purmorphamine impairs adipogenesis. In sharp contrast to reports in rodent cells,the maturation process,but not the early steps of human mesenchymal stem cell differentiation,is affected by Hedgehog activation. Hedgehog interferes with adipocyte differentiation by targeting CCAAT enhancer-binding protein alpha and peroxisome proliferator-activated receptor (PPAR) gamma2 expression,whereas PPARgamma1 level remains unaffected. Although Hedgehog pathway stimulation does not modify the total number of adipocytes,adipogenesis appears dramatically impaired,with reduced lipid accumulation,a decrease in adipocyte-specific markers,and acquisition of an insulin-resistant phenotype. This study indicates that a decrease in Hedgehog signaling is necessary but not sufficient to trigger adipocyte differentiation and unveils a striking difference in the adipocyte differentiation process between rodent and human mesenchymal stem cells. View Publication

Human induced pluripotent stem cells (iPSCs) can give rise to multiple cell types and hold great promise in regenerative medicine and disease-modeling applications. We have developed a reliable two-step protocol to generate human mammary-like organoids from iPSCs. Non-neural ectoderm-cell-containing spheres,referred to as mEBs,were first differentiated and enriched from iPSCs using MammoCult medium. Gene expression profile analysis suggested that mammary gland function-associated signaling pathways were hallmarks of 10-day differentiated mEBs. We then generated mammary-like organoids from 10-day mEBs using 3D floating mixed gel culture and a three-stage differentiation procedure. These organoids expressed common breast tissue,luminal,and basal markers,including estrogen receptor,and could be induced to produce milk protein. These results demonstrate that human iPSCs can be directed in vitro toward mammary lineage differentiation. Our findings provide an iPSC-based model for studying regulation of normal mammary cell fate and function as well as breast disease development. View Publication

In the adult human,mesenchymal stem cells (MSCs) resident in bone marrow retain the capacity to proliferate and differentiate along multiple connective tissue lineages,including cartilage. In this study,culture-expanded human MSCs (hMSCs) of 60 human donors were induced to express the morphology and gene products of chondrocytes. Chondrogenesis was induced by culturing hMSCs in micromass pellets in the presence of a defined medium that included 100 nM dexamethasone and 10 ng/ml transforming growth factor-beta(3) (TGF-beta(3)). Within 14 days,cells secreted an extracellular matrix incorporating type II collagen,aggrecan,and anionic proteoglycans. hMSCs could be further differentiated to the hypertrophic state by the addition of 50 nM thyroxine,the withdrawal of TGF-beta(3),and the reduction of dexamethasone concentration to 1 nM. Increased understanding of the induction of chondrogenic differentiation should lead to further progress in defining the mechanisms responsible for the generation of cartilaginous tissues,their maintenance,and their regeneration. View Publication

Here we describe a protocol for generating 3D human intestinal tissues (called organoids) in vitro from human pluripotent stem cells (hPSCs). To generate intestinal organoids,pluripotent stem cells are first differentiated into FOXA2(+)SOX17(+) endoderm by treating the cells with activin A for 3 d. After endoderm induction,the pluripotent stem cells are patterned into CDX2(+) mid- and hindgut tissue using FGF4 and WNT3a. During this patterning step,3D mid- or hindgut spheroids bud from the monolayer epithelium attached to the tissue culture dish. The 3D spheroids are further cultured in Matrigel along with prointestinal growth factors,and they proliferate and expand over 1-3 months to give rise to intestinal tissue,complete with intestinal mesenchyme and epithelium comprising all of the major intestinal cell types. To date,this is the only method for efficiently directing the differentiation of hPSCs into 3D human intestinal tissue in vitro. View Publication

Human induced pluripotent stem cells (iPSCs) have been generated with varied efficiencies from multiple tissues. Yet,acquiring donor cells is,in most instances,an invasive procedure that requires laborious isolation. Here we present a detailed protocol for generating human iPSCs from exfoliated renal epithelial cells present in urine. This method is advantageous in many circumstances,as the isolation of urinary cells is simple (30 ml of urine are sufficient),cost-effective and universal (can be applied to any age,gender and race). Moreover,the entire procedure is reasonably quick--around 2 weeks for the urinary cell culture and 3-4 weeks for the reprogramming--and the yield of iPSC colonies is generally high--up to 4% using retroviral delivery of exogenous factors. Urinary iPSCs (UiPSCs) also show excellent differentiation potential,and thus represent a good choice for producing pluripotent cells from normal individuals or patients with genetic diseases,including those affecting the kidney. View Publication

T-cell genome engineering holds great promise for cell-based therapies for cancer,HIV,primary immune deficiencies,and autoimmune diseases,but genetic manipulation of human T cells has been challenging. Improved tools are needed to efficiently knock out" genes and "knock in" targeted genome modifications to modulate T-cell function and correct disease-associated mutations. CRISPR/Cas9 technology is facilitating genome engineering in many cell types� View Publication

Hematopoiesis is a carefully controlled process that is regulated by complex networks of transcription factors that are,in part,controlled by signals resulting from ligand binding to cell-surface receptors. To further understand hematopoiesis,we have compared gene expression profiles of human erythroblasts,megakaryocytes,B cells,cytotoxic and helper T cells,natural killer cells,granulocytes,and monocytes using whole genome microarrays. A bioinformatics analysis of these data was performed focusing on transcription factors,immunoglobulin superfamily members,and lineage-specific transcripts. We observed that the numbers of lineage-specific genes varies by 2 orders of magnitude,ranging from 5 for cytotoxic T cells to 878 for granulocytes. In addition,we have identified novel coexpression patterns for key transcription factors involved in hematopoiesis (eg,GATA3-GFI1 and GATA2-KLF1). This study represents the most comprehensive analysis of gene expression in hematopoietic cells to date and has identified genes that play key roles in lineage commitment and cell function. The data,which are freely accessible,will be invaluable for future studies on hematopoiesis and the role of specific genes and will also aid the understanding of the recent genome-wide association studies. View Publication

RNA-targeting CRISPR-Cas13 proteins have recently emerged as a powerful platform to modulate gene expression outcomes. However,protein and CRISPR RNA (crRNA) delivery in human cells can be challenging with rapid crRNA degradation yielding transient knockdown. Here we compare several chemical RNA modifications at different positions to identify synthetic crRNAs that improve RNA targeting efficiency and half-life in human cells. We show that co-delivery of modified crRNAs and recombinant Cas13 enzyme in ribonucleoprotein (RNP) complexes can alter gene expression in primary CD4+ and CD8+ T cells. This system represents a robust and efficient method to modulate transcripts without genetic manipulation. View Publication