Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Embryo-derived tissues, such as umbilical cord (UC), can represent attractive sources of mesenchymal stem cells because their use is not related to any ethical issue. Abundant experimental evidence has already shown that Wharton's jelly contains cells able to differentiate in vitro into adipocytes, chondrocytes, osteocytes and neurons. Human UCs were obtained from term caesarean deliveries and processed within 24 h. Cells derived from the Wharton's jelly expressing mesenchymal markers, such as CD105, but not KDR and CD31 antigens, have been selected by positive and negative immunoseparation. These cells were characterized by an elongated shape and a good proliferation rate. Moreover, they were, at least in part, of fetal origin, as demonstrated by the expression of Sry mRNA. The expression of Myf5 and MyoD was detected after 7 and 11 days of in vitro myogenic induction, respectively. At two weeks from cell injection in the tibialis anterior muscle, previously damaged with bupivacaine, skeletal muscle appeared completely repaired and transplanted cells were present in the muscle for two weeks and differentiated into skeletal muscle cells, as demonstrated by the co-localization of HLA 1 and sarcomeric tropomyosine antigens. These observations provide the first demonstration that CD105(+)/CD31(-)/KDR(-) cells are able not only to differentiate in vivo towards the myogenic lineage, but also to contribute to the muscle regenerative process.
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PMID:CD105(+) cells from Wharton's jelly show in vitro and in vivo myogenic differentiative potential. 1708 12

To detect endothelial progenitor cells in human umbilical veins and isolated endothelial cells, the authors examined protein and mRNA expression levels of cell surface markers for endothelial progenitor cells in human umbilical veins before and after trypsin treatment and at different passages of the isolated endothelial cells. CD133(+) (2.14 +/- 0.57 per mm) and KDR(+) (35.74 +/- 8.28 per mm) cells were observed in the intima of umbilical veins. The amounts of CD133(+), KDR(+), CD34(+), and CD105(+) cells decreased in the intima after trypsin treatment, whereas the percent of CD133(+) and KDR(+)cells in the media did not change significantly. Moreover, similar protein and mRNA expression levels of CD133 and KDR were detected in the umbilical veins before and after trypsin treatment. In the isolated cells from umbilical veins, the percent of CD133(+) and CD34(+) cells in P1 was 3.43% +/- 3.85%, which was higher than those in P3 (0.17% +/- 0.21%, p = 0.005) and P6 (0.14% +/- 0.18%, p = .001). The mRNA expression levels of CD133 and CD105 were down-regulated in later passages compared to those in P1, whereas the expression level of KDR was up-regulated in late passages. Thus it is suggested that endothelial progenitor cells reside in the distinct zone (e.g., initma and media) of human umbilical veins, and retain the capacity of differentiation to endothelial cells in vitro.
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PMID:Validation of endothelial progenitor cells in human umbilical veins and the isolated endothelial cells. 1757 8

The stromal-vascular fraction (SVF) of human adipose tissue contains, among other cell types, mesenchymal stem cells and precursors of adipocyte and endothelial cells. Here we show that, in addition, the nonhematopoietic fraction of the SVF has hematopoietic activity, since all types of hematopoietic colony-forming units (CFUs) developed when cultured in methylcellulose-based medium. This hematopoietic activity was restricted to the CD45(-)CD105(+) cell subset, well correlated with KDR(+) cell content, and increased after culture with a combination of early-acting hematopoietic cytokines. Most of the CD45(-)KDR(+)CD105(+) cells were nonadherent and did not express CD31, and this subset included both CD34(-) and CD34(+) cells. Moreover, these nonadherent cells migrated in response to KDR gradient, and when they were cultured in the presence of both hematopoietic and endothelial growth factors, a wave of CFUs was followed by a wave of mixed colonies comprising adherent elongated and nonadherent round hematopoietic cells. These mixed hematopoietic-endothelial (Hem-End) colonies were able to generate secondary Hem-End colonies and exhibited both hematopoietic and endothelial activity, as demonstrated by in vitro functional assays. These findings demonstrate for the first time the existence of primitive mesodermal progenitors within the SVF of human adipose tissue that exhibit in vitro hematopoietic and hemangioblastic activities, susceptible to being used in cell therapy and basic cell research. Disclosure of potential conflicts of interest is found at the end of this article.
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PMID:IFATS collection: Identification of hemangioblasts in the adult human adipose tissue. 1845 Aug 25

The successful differentiation of human embryonic stem cells (hESCs) to fibrochondrocyte-like cells and characterization of these differentiated cells is a critical step toward tissue engineering of musculoskeletal fibrocartilages (e.g., knee meniscus, temporomandibular joint disc, and intervertebral disc). In this study, growth factors and primary cell cocultures were applied to hESC embryoid bodies (EBs) for 3 weeks and evaluated for their effect on the synthesis of critical fibrocartilage matrix components: glycosaminoglycans (GAG) and collagens (types I, II, and VI). Changes in surface markers (CD105, CD44, SSEA, PDGFR alpha) after the differentiation treatments were also analyzed. The study was conducted in three phases: (1) examination of growth factors (TGF-beta 3, BMP-2, BMP-4, BMP-6, PDGF-BB, sonic hedgehog protein); (2) comparison of two cocultures (primary chondrocytes or fibrochondrocytes); and (3) the combination of the most effective growth factor and coculture regimen. TGF-beta 3 with BMP-4 yielded EBs positive for collagens I, II, and VI, with up to 6.7- and 4.8-fold increases in GAG and collagen, respectively. Analysis of cell surface markers showed a significant increase in CD44 with the TGF-beta 3 + BMP-4 treatment compared to the controls. Coculture with fibrochondrocytes resulted in up to a 9.8-fold increase in collagen II production. The combination of the growth factors BMP-4 + TGF-beta 3 with the fibrochondrocyte coculture led to an increase in cell proliferation and GAG production compared to either treatment alone. This study determined two powerful treatments for inducing fibrocartilaginous differentiation of hESCs and provides a foundation for using flow cytometry to purify these differentiated cells.
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PMID:Fibrochondrogenesis of hESCs: growth factor combinations and cocultures. 1845 97

The ability to subfractionate minor cellular subsets by multiparameter flow cytometry and to evaluate such cells for functional properties has been used to ascertain lineal relationships and detail developmental hierarchies in the hematopoietic system for more than 20 years. However, steady advances in technology combined with the use of novel cell surface markers continues to redefine the developmental landscape as novel subpopulations are purified and characterized. We recently used such an approach to stage progenitor cell hierarchy involved in myeloid development with the use of two markers, Slamf1 and Endoglin that have recently been shown to be associated with hematopoietic stem cells. Here, we provide additional characterization of these cellular subsets to further refine their developmental potential. Little or no alterations in lineage potential were observed in these subsets when evaluated in a BCL2 transgenic setting or in response to various growth factor combinations, although BCL2 significantly enhanced their in vitro readout. Gene expression patterns of functionally opposing transcription factors that are known to play key roles for the appropriate development into separate myeloid lineages were associated with the functional activity of prospectively isolated subsets. Multiple genes traditionally associated with early lymphopoiesis were observed in early candidate granulocyte/monocyte, but not early megakaryocytic and/or erythroid progenitor cells. When functionally evaluated, such early granulocyte/monocyte precursors displayed a latent lymphoid activity, which was pronounced in subsets bearing high expression of the tyrosine kinase receptor FLT3.
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PMID:Deciphering developmental stages of adult myelopoiesis. 1846 20

Human embryonic stem cells (hESCs) are to be considered as a valuable source for regenerative medicine because of their capacity to differentiate into all cell types. We have developed an efficient culture system to differentiate hECSs into endothelial cells without the formation of embryoid bodies Establishing appropriate culture conditions with a cocktail of growth factors allowed us to differentiate hESCs directly to endothelial primary culture with about 50% efficiency. CD31 immunomagnetic cell sorting was used to purify derived endothelium from the primary culture of hESCs. Isolated endothelial cells expressed immunological markers (vWF, CD105), specific genes (VE-cadherin, KDR, GATA-2, GATA-3, eNOS), and formed cord-like structures on collagen matrix and in Matrigel assay. During differentiation to endothelial lineage promoter regions of the genes involved in specific cell fate determination and homeostasis (GATA-2,-3, and eNOS) underwent intensive hypomethylation which correlated with the gene expression. Overall our data demonstrate that direct differentiation of hESCs leads to endothelial cells that acquire epigenetic patterning similar to the functional endothelial cells of the organism.
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PMID:Efficient differentiation of hESCs into endothelial cells in vitro is secured by epigenetic changes. 1881 42

Human endometrium is a highly regenerative tissue undergoing more than 400 cycles of growth, differentiation, and shedding during a woman's reproductive years. Endometrial regeneration is likely mediated by adult stem/progenitor cells. This study investigated key stem cell properties of individual clonogenic epithelial and stromal cells obtained from human endometrium. Single-cell suspensions of endometrial epithelial or stromal cells were obtained from hysterectomy tissues from 15 women experiencing normal menstrual cycles, and were cultured at clonal density (10 cells/cm(2)) or limiting dilution. The adult stem cell properties-self-renewal, high proliferative potential, and differentiation of single epithelial and stromal cells-were assessed by harvesting individual colonies and undertaking serial clonal culture, serial passaging, and culture in differentiation-induction media, respectively. Lineage differentiation markers were examined by RT-PCR, immunocytochemistry, and flow cytometry. Rare single human endometrial EpCAM(+) epithelial cells and EpCAM(-) stromal cells demonstrated self-renewal by serially cloning >3 times and underwent >30 population doublings over 4 mo in culture. Clonally derived epithelial cells differentiated into cytokeratin(+) gland-like structures in three dimensional culture. Single stromal cells were multipotent, as their progeny differentiated into smooth muscle cells, adipocytes, chondrocytes, and osteoblasts. Stromal clones expressed mesenchymal stem cell (MSC) markers ITGB1 (CD29), CD44, NT5E (CD73), THY1 (CD90), ENG (CD105), PDGFRB (CD140B), MCAM (CD146) but not endothelial or hemopoietic markers PECAM1 (CD31), CD34, PTPRC (CD45). Adult human endometrium contains rare epithelial progenitors and MSCs, likely responsible for its immense regenerative capacity, which may also have critical roles in the development of endometriosis and endometrial cancer. Human endometrium may provide a readily available source of MSCs for cell-based therapies.
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PMID:Isolation and culture of epithelial progenitors and mesenchymal stem cells from human endometrium. 1922 91

1p19q LOH has been shown to predict radio- and chemosensitivity and prolonged survival in oligodendrogliomas (OLs). We have recently shown that magnetic resonance perfusion-weighted imaging (MR-PWI) may be useful in predicting the histopathological grade or cytogenetic type of oligodendroglial neoplasms. MR-PWI allows noninvasive determination of relative tumor blood volume (rTBV), which may reflect the degree of neoplastic angiogenesis and metabolism. The present study was aimed to correlate rTBV to the angiogenic markers and EGFR expression in oligodendroglial tumors with 1p/19q LOH or 1p LOH (Group 1) and 1p19q intact alleles or 19q LOH (Group 2), respectively. In WHO grade II neoplasms, Group 1 showed significantly greater rTBV than Group 2 (P = 0.013). However, the differences between Group 1 and Group 2 were not significant in grade III tumors. Probe-based real-time RT-PCR analyses showed that 12% of Group 2 high-grade tumors with intact 1p19q exhibited dramatic EGFR overexpression (designated EGFR-high). Grade III neoplasms showed a significantly higher rTBV than grade II neoplasms. Group 1 tumors showed significantly higher rTBV than Group 2 tumors, independent of the EGFR-high subtype. Real-time RT-PCR analyses showed increased expression of VEGF, CD31 and CD105 in Group 1 tumors as compared to Group 2 tumors, excluding the EGFR-high subtype. Multivariable linear regression analysis showed a significant association of rTBV with 1p19q LOH, and expression of EGFR and VEGF. Therefore, the combined use of extensive molecular profiling and advanced MR imaging modalities may improve the accuracy of tumor grading, provide prognostic information, and has the potential to influence treatment decisions.
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PMID:Magnetic resonance perfusion-weighted imaging defines angiogenic subtypes of oligodendroglioma according to 1p19q and EGFR status. 1935 63

In the human fetal kidney (HFK) self-renewing stem cells residing in the metanephric mesenchyme (MM)/blastema are induced to form all cell types of the nephron till 34(th) week of gestation. Definition of useful markers is crucial for the identification of HFK stem cells. Because wilms' tumor, a pediatric renal cancer, initiates from retention of renal stem cells, we hypothesized that surface antigens previously up-regulated in microarrays of both HFK and blastema-enriched stem-like wilms' tumor xenografts (NCAM, ACVRIIB, DLK1/PREF, GPR39, FZD7, FZD2, NTRK2) are likely to be relevant markers. Comprehensive profiling of these putative and of additional stem cell markers (CD34, CD133, c-Kit, CD90, CD105, CD24) in mid-gestation HFK was performed using immunostaining and FACS in conjunction with EpCAM, an epithelial surface marker that is absent from the MM and increases along nephron differentiation and hence can be separated into negative, dim or bright fractions. No marker was specifically localized to the MM. Nevertheless, FZD7 and NTRK2 were preferentially localized to the MM and emerging tubules (<10% of HFK cells) and were mostly present within the EpCAM(neg) and EpCAM(dim) fractions, indicating putative stem/progenitor markers. In contrast, single markers such as CD24 and CD133 as well as double-positive CD24(+)CD133(+) cells comprise >50% of HFK cells and predominantly co-express EpCAM(bright), indicating they are mostly markers of differentiation. Furthermore, localization of NCAM exclusively in the MM and in its nephron progenitor derivatives but also in stroma and the expression pattern of significantly elevated renal stem/progenitor genes Six2, Wt1, Cited1, and Sall1 in NCAM(+)EpCAM(-) and to a lesser extent in NCAM(+)EpCAM(+) fractions confirmed regional identity of cells and assisted us in pinpointing the presence of subpopulations that are putative MM-derived progenitor cells (NCAM(+)EpCAM(+)FZD7(+)), MM stem cells (NCAM(+)EpCAM(-)FZD7(+)) or both (NCAM(+)FZD7(+)). These results and concepts provide a framework for developing cell selection strategies for human renal cell-based therapies.
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PMID:Expression of stem cell markers in the human fetal kidney. 1969 31

Dental pulp is a heterogeneous microenviroment where unipotent progenitor and pluripotent mesenchymal stem cells cohabit. In this study we investigated whether human dental pulp stromal (stem) cells (DP-SCs) committed to the angiogenic fate. DP-SCs showed the specific mesenchymal immunophenotypical profile positive for CD29, CD44, CD73, CD105, CD166 and negative for CD14, CD34, CD45, in accordance with that reported for bone marrow-derived SCs. The Oct-4 expression in DP-SCs, evaluated through RT-PCR analysis, increased in relation with the number of the passages in cell culture and decreased after angiogenic induction. In agreement with their multipotency, DP-SCs differentiated toward osteogenic and adipogenic commitments. In angiogenic experiments, differentiation of DP-SCs, through vascular endothelial growth factor (VEGF) induction, was evaluated by in vitro matrigel assay and by cytometric analysis. Accordingly, endothelial-specific markers like Flt-1 and KDR were basally expressed and they increased after exposure to VEGF together with the occurrence of ICAM-1 and von Willebrand factor positive cells. In addition, VEGF-induced DP-SCs maintained endothelial cell-like features when cultured in a 3-D fibrin mesh, displaying focal organization into capillary-like structures. The DP-SC angiogenic potential may prove a remarkable tool for novel approaches to developing tissue-engineered vascular grafts which are useful when vascularization of ischemic tissues is required.
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PMID:Angiogenic potential of human dental pulp stromal (stem) cells. 1982 86


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