Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Testicular germ cell tumours (TGCTs), the most frequent solid tumour of the young men, originate from the primitive germ cells. They share some pluripotency stem-cell markers which may help to distinguish between seminoma, the most frequent TGCTs and non-seminoma tumours, such as embryonal carcinoma, teratocarcinoma or choriocarcinoma. Due probably to the propensity of seminoma to apoptosis, only two cell lines originated from pure testicular seminoma, TCam-2 and JKT-1 have been up to now, established, maintained and proposed as representative models of human testicular seminoma. However, both seem, following recent reports, to be able to drift. Thus, the molecular signature of embryonic stem-cell markers of the JKT-1 cells cultured in our laboratory, were studied by RT-PCR, Western blot and immunofluorescence (IF). JKT-1 cells analysed after 30 passages, expressed placenta alkaline phosphatase but not alphafoetoprotein (alphaFP) nor beta-human chorionic gonadotropin. JKT-1 cells also expressed markers of pluripotency such as NANOG and OCT3/4 and more specific seminoma markers, such as AP2gamma and HIWI. However, protein expression of OCT3/4 and AP2y was weak and these JKT-1 cells expressed SOX2, a marker of embryonal carcinoma and did not express c-KIT usually expressed in most seminoma. Possible derivation through in vitro culture conditions was supported by looking at later passages (61) which showed a decrease of NANOG and HIWI protein expression. JKT-1 cells express a signature of markers which is still near from the one express by seminoma cells, allowing carcinogenetic studies. However, because of their great ability to drift as shown for TCam-2, it is recommended to verify and to precise this molecular signature before reporting functional results.
 ...
PMID:Expression of embryonic stem cell markers in cultured JKT-1, a cell line derived from a human seminoma. 1922 8

Embryo-derived stem cells hold enormous potential for producing cell-based transplantation therapies, allowing high-throughput drug screening and delineating early embryonic development. However, potential clinical applications must first be tested for safety and efficacy in preclinical animal models. Due to physiological and genetic parity to humans, the domestic dog is widely used as a clinically relevant animal model for cardiovascular, neurodegenerative, orthopedic, and oncologic diseases. Therefore, we established numerous putative canine embryonic stem cell (cESC) lines by immunodissection of the inner cell mass (ICM), which we termed OVC.ID.1-23, and by explant outgrowths from whole canine blastocysts, named OVC.EX.1-16. All characterized lines were immunopositive for OCT4, SOX2, NANOG, SSEA-3, and SSEA-4; displayed high telomerase and alkaline phosphatase (ALP) activities; and were maintained in this state up to 37 passages ( approximately 160 days). Colonies from OVC.EX lines showed classic domed hESC-like morphology surrounded by a ring of fibroblast-like cells, whereas all OVC.ID lines exhibited a mixed cell colony of tightly packed cESCs surrounded by a GATA6+/CDX2- hypoblast-derived support layer. Spontaneous serum-only differentiation without feeder layers demonstrated a strong lineage selection associated with the colony niche type, and not the isolation method. Upon differentiation, cESC lines formed embryoid bodies (EB) comprised of cells representative of all germinal layers, and differentiated into cell types of each layer. Canine ESC lines such as these have the potential to identify differences between embryonic stem cell line derivations, and to develop or to test cell-based transplantation therapies in the dog before attempting human clinical trials.
 ...
PMID:Characterization of canine embryonic stem cell lines derived from different niche microenvironments. 1932 15

For reasons that are unclear the production of embryonic stem cells from ungulates has proved elusive. Here, we describe induced pluripotent stem cells (iPSC) derived from porcine fetal fibroblasts by lentiviral transduction of 4 human (h) genes, hOCT4, hSOX2, hKLF4, and hc-MYC, the combination commonly used to create iPSC in mouse and human. Cells were cultured on irradiated mouse embryonic fibroblasts (MEF) and in medium supplemented with knockout serum replacement and FGF2. Compact colonies of alkaline phosphatase-positive cells emerged after approximately 22 days, providing an overall reprogramming efficiency of approximately 0.1%. The cells expressed porcine OCT4, NANOG, and SOX2 and had high telomerase activity, but also continued to express the 4 human transgenes. Unlike human ESC, the porcine iPSC (piPSC) were positive for SSEA-1, but negative for SSEA-3 and -4. Transcriptional profiling on Affymetrix (porcine) microarrays and real time RT-PCR supported the conclusion that reprogramming to pluripotency was complete. One cell line, ID6, had a normal karyotype, a cell doubling time of approximately 17 h, and has been maintained through >220 doublings. The ID6 line formed embryoid bodies, expressing genes representing all 3 germ layers when cultured under differentiating conditions, and teratomas containing tissues of ectoderm, mesoderm, and endoderm origin in nude mice. We conclude that porcine somatic cells can be reprogrammed to form piPSC. Such cell lines derived from individual animals could provide a means for testing the safety and efficacy of stem cell-derived tissue grafts when returned to the same pigs at a later age.
 ...
PMID:Derivation of induced pluripotent stem cells from pig somatic cells. 1954

Mouse embryonic stem cells (mESCs) have played a key role in the newly emerging fields of stem cell research. The traditional derivation and culture of mESCs have been based on the use of mouse embryonic fibroblasts (MEFs) treated with exogenous leukemia inhibitory factor (LIF). However, the rapid senescence of MEFs, coupled with the high cost of LIF, has significantly hampered the widespread use of mESCs in stem cell research. Thus, we present a novel exogenous LIF-free culture system for general mESCs applications, comprising fibroblast-like cells derived from the rabbit spleen (RSFs). We demonstrated that mESCs cultured on RSFs (mESCs-RSFs) maintained all mESC features after prolonged LIF-free culture, including alkaline phosphatase, cell surface markers (SSEA-1), molecular markers (OCT-4, NANOG, TERT, REX-1), karyotype, and pluripotency. The high expression level of both LIF and WNT3A in the RSFs may account for their ability to maintain mESCs without exogenous LIF. Moreover, this exogenous LIF-free culture system was verified to be of microbiological quality through analysis with electron transmission microscopy.
 ...
PMID:Establishment of an exogenous LIF-free culture system for mouse embryonic stem cells. 1975 Nov 13

Four continuous human embryonic stem cell lines (SC1, SC2, SC3 and SC4), derived from the blastocysts has been described. The cell lines were cultivated on mitotically inactivated human feeder cells. The cell lines SC1 and SC2 have passed through 150 population doublings and the cell lines SC3 and SC4 -- near 120 populations doublings, which exceeds Hayflick limit sufficiently. These cell lines maintain high activity of alkaline phosphatase, expression of transcription factor OCT-4 and cell surface antigens (SSEA-4, TRA-1-60 and TRA-1-81), confirming their ESC status and human specificity. Immunofluorescent detection of antigens, characteristic of ectoderm, endoderm and mesoderm confirms the ability of these cells to retain their pluripotency under in vitro condition. PCR analysis revealed expression of six genes specific for pluripotent cells (OCT-4, NANOG, DPPA3/STELLA, TDGF/CRIPTO and LEFTYA). Correlation between the level of proliferative activity and the character of DNA-bound fluorescent staining was found. Fluorescent dyes, Hoechst 33342 and PI, produced diffuse staining of the nuclei in slowly proliferating cells of the SC1 and SC2 lines. In contrast, in actively proliferating cells of the SC3 and SC4 lines, the clear staining of the nuclei was observed. Upon changing the cultivation condition, proliferative activity of SC3 and SC4 lines decreased and became similar to that of SC1 and SC2 lines. The character of the fluorescent staining of all these lines was also shown to be similar. These results show that quality of the fluorescent staining with Hoechst 33342 and PI reflects the level of proliferation. Possible causes and mechanisms of this feature of human ESC are discussed.
 ...
PMID:[The characters and specific features of new human embryonic stem cells lines]. 1976 48

Somatic cells can be reprogrammed into induced pluripotent stem (iPS) cells by enforced expression of transcription factors. Using serial live imaging of human fibroblasts undergoing reprogramming, we identified distinct colony types that morphologically resemble embryonic stem (ES) cells yet differ in molecular phenotype and differentiation potential. By analyzing expression of pluripotency markers, methylation at the OCT4 and NANOG promoters and differentiation into teratomas, we determined that only one colony type represents true iPS cells, whereas the others represent reprogramming intermediates. Proviral silencing and expression of TRA-1-60, DNMT3B and REX1 can be used to distinguish the fully reprogrammed state, whereas alkaline phosphatase, SSEA-4, GDF3, hTERT and NANOG are insufficient as markers. We also show that reprogramming using chemically defined medium favors formation of fully reprogrammed over partially reprogrammed colonies. Our data define molecular markers of the fully reprogrammed state and highlight the need for rigorous characterization and standardization of putative iPS cells.
 ...
PMID:Live cell imaging distinguishes bona fide human iPS cells from partially reprogrammed cells. 1989 51

The majority of human embryonic stem cell (hESC) lines have been derived and grown using mouse or human feeder cells, or using Matrigel, an animal derivative rich in extracellular matrix (ECM) proteins. However, reliance on feeder layers and animal products limits the manipulation and clinical application of hESC. Alternatively, human fibroblasts produce an ECM which could be employed to coated plates and be easily sterilized. We have shown that hESC grown on this matrix and in the presence of medium conditioned by fibroblast cells maintain markers of pluripotency, including expression of cell surface proteins (SSEA3, SSEA4, TRA-1-60, TRA-1-81), alkaline phosphatase activity, and specific intracellular markers (NANOG, OCT, REX1). Moreover, hESC cultured on this novel human-derived ECM display a normal karyotype. This growth system reduces exposure of hESC to feeder layers and animal ingredients, thereby limiting the risk of pathogenic contamination and additionally facilitating manipulation of hESCs.
 ...
PMID:Growth of human embryonic stem cells using derivates of human fibroblasts. 1990 71

The periodontal ligament (PDL) comprises adult stem cells, which are responsible for periodontal tissue regeneration. In the present study, we investigated the specific profile of the stem cells in the human PDL. Microscopic analysis demonstrated that PDL cells showed a fibroblastic appearance, forming flat and loose aggregates. PDL cells expressed embryonic stem cell-associated antigens (SSEA-1, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81, OCT4, NANOG, SOX2, and REX1, and alkaline phosphatase activity), as well as conventional mesenchymal stem cell markers. When PDL cells were cultured in the presence of all-trans-retinoic acid, the numbers of SSEA-3+ and SSEA-4+ PDL cells were significantly decreased, while that of SSEA-1+ was increased. SSEA-4+ PDL cells showed a greater telomere length and growth rate. SSEA-4+ PDL cells exhibited the potential to generate specialized cells derived from three embryonic germ layers: mesodermal (adipocytes, osteoblasts, and chondrocytes), ectodermal (neurons), and endodermal (hepatocytes) lineages. Our findings demonstrated that SSEA-4, a major antigen to distinguish human embryonic stem cells, could also be used to identify multipotent stem cells in the PDL. Hence, SSEA-4+ human PDL cells appear to be a promising source of stem cells for regenerative medicine.
 ...
PMID:Isolation of multipotent stem cells in human periodontal ligament using stage-specific embryonic antigen-4. 1994 9

Here, we describe the derivation of a novel human embryonic stem cell (hESC) line, Endeavour-2 (E-2), propagated on human fetal fibroblasts (HFF) in a serum-replacement media. The inner cell mass (ICM) was manually dissected from the blastocyst without using immunodissection and, therefore, antibodies from animal sources. A total of 20 embryos were thawed and cultured, eight embryos were hatched, and five ICMs were obtained. They were transferred onto HFF used as feeder layer, and one colony representing the initial cell proliferation of a new hESC line, E-2, was obtained. The newly emerged hESC colony was passaged first by physical dissection and subsequently by enzymatic dissociation. E-2 has been in culture for over 6 months and has been shown to possess typical features of a pluripotent hESC line including expression of stem cell surface markers (SSEA4, TRA-160, and integrin alpha-6), intracellular alkaline phosphatase, and pluripotency gene markers, OCT4 and NANOG. This hESC line shows lineage-specific differentiation into various representative cell types expressing markers characteristic of the three somatic germ layers under both in vitro and in vivo conditions. E-2 line shows a normal karyotype (46 XX) and has been successfully cryopreserved and thawed several times using slow-freezing procedures. E-2 adds to the repertoire of existing hESC lines for research and development purposes in the field of regenerative medicine.
 ...
PMID:Derivation of a new human embryonic stem cell line, Endeavour-2, and its characterization. 2017 1

Activin/Nodal signaling is required for maintaining pluripotency and self-renewal of mouse epiblast stem cells and human embryonic stem cells (hESC). In this study, we investigated whether this signaling mechanism is also operative in cultured epiblasts derived from Days 10.5-12 pig embryos. Pig epiblast stem cell lines (pEpiSC) were established on mouse feeder layers and medium supplemented with basic fibroblast growth factor (bFGF). pEpiSC express the core pluripotency factors OCT4 (or POU5F1), NANOG, SOX2, and NODAL, but they do not express REX1 or alkaline phosphatase activity. Blocking leukemia inhibitory factor (LIF)/JAK/STAT3 pathway by adding the specific JAK I inhibitor 420099 and an anti-LIF antibody over 3 passages did not affect pluripotency of pEpiSC. In contrast, cells grown with the Alk-5 inhibitor SB431542, which blocks Activin/Nodal pathway, differentiated readily toward the neural lineage. pEpiSC are pluripotent, as established by their differentiation potential to ectoderm, mesoderm, and endoderm. These cells can be induced to differentiate toward trophectoderm and to germ cell precursors in response to bone morphogenetic protein 4 (BMP-4). In conclusion, our study demonstrates that pig epiblasts express the core pluripotency genes and that the capacity for maintaining self-renewal in pEpiSC depends on Activin/Nodal signaling. This study provides further evidence that maintenance of pluripotency via Activin/Nodal signal is conserved in mammals.
 ...
PMID:Pig epiblast stem cells depend on activin/nodal signaling for pluripotency and self-renewal. 2021 Jun 27


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>