A mesoderm-inducing factor is produced by a Xenopus cell line

Development ◽  
1987 ◽  
Vol 99 (1) ◽  
pp. 3-14 ◽  
Author(s):  
J.C. Smith
Keyword(s):  
Cell Line ◽  
Culture Medium ◽  
Cell Types ◽  
Active Principle ◽  
Relative Molecular Mass ◽  
Mesoderm Induction ◽  
Vertebrate Development ◽  
Animal Pole ◽  
Heat Stable

Inductive interactions play a major role in the diversification of cell types during vertebrate development. These interactions have been extensively studied in amphibian embryos (usually Xenopus laevis) where the earliest is mesoderm induction, in which an equatorial mesodermal rudiment is induced from the animal hemisphere under the influence of a signal from the vegetal hemisphere. The molecular basis of mesoderm induction is unknown, although Tiedemann has isolated a protein from 9- to 13-day chick embryos that has the properties one would expect of a mesoderm-inducing factor. However, the relevance of this molecule to the events of early amphibian development is unclear, and it is a matter of some importance to discover a Xenopus mesoderm-inducing factor. In this paper I show that the Xenopus XTC cell line secretes mesoderm-inducing activity into the culture medium. Isolated animal pole regions cultured in XTC- conditioned medium differentiate into muscle and notochord, while controls form ‘atypical epidermis’. Three different cell lines - XL, XL177 and KR - secrete no such activity. Preliminary characterization of the XTC mesoderm-inducing activity indicates that the active principle is heat stable, trypsin sensitive, nondialysable, and has an apparent relative molecular mass of about 16000. Work is in progress to characterize the activity further and to discover whether the mesoderm-inducing factor is also present in normal embryos.

scholarly journals Characterization of four novel ras-like genes expressed in a human teratocarcinoma cell line.

1990 ◽  
Vol 10 (4) ◽  
pp. 1793-1798 ◽  
Author(s):  
G T Drivas ◽  
A Shih ◽  
E Coutavas ◽  
M G Rush ◽  
P D'Eustachio
Keyword(s):  
Cell Line ◽  
Cdna Library ◽  
Human Cell ◽  
Genomic Dna ◽  
Oligonucleotide Probe ◽  
Cell Types ◽  
Ras Gene ◽  
Teratocarcinoma Cell ◽  
Coding Sequences

A mixed-oligonucleotide probe was used to identify four ras-like coding sequences in a human teratocarcinoma cDNA library. Two of these sequences resembled the rho genes, one was closely related to H-, K-, and N-ras, and one shared only the four sequence domains that define the ras gene superfamily. Homologs of the four genes were found in genomic DNA from a variety of mammals and from chicken. The genes were transcriptionally active in a range of human cell types.

Characterization of four novel ras-like genes expressed in a human teratocarcinoma cell line

1990 ◽  
Vol 10 (4) ◽  
pp. 1793-1798
Author(s):  
G T Drivas ◽  
A Shih ◽  
E Coutavas ◽  
M G Rush ◽  
P D'Eustachio
Keyword(s):  
Cell Line ◽  
Cdna Library ◽  
Human Cell ◽  
Genomic Dna ◽  
Oligonucleotide Probe ◽  
Cell Types ◽  
Ras Gene ◽  
Teratocarcinoma Cell ◽  
Coding Sequences

A mixed-oligonucleotide probe was used to identify four ras-like coding sequences in a human teratocarcinoma cDNA library. Two of these sequences resembled the rho genes, one was closely related to H-, K-, and N-ras, and one shared only the four sequence domains that define the ras gene superfamily. Homologs of the four genes were found in genomic DNA from a variety of mammals and from chicken. The genes were transcriptionally active in a range of human cell types.

Characterization of a 58 kDa cis-Golgi protein in pancreatic exocrine cells

1992 ◽  
Vol 103 (2) ◽  
pp. 321-333 ◽  
Author(s):  
U. Lahtinen ◽  
B. Dahllof ◽  
J. Saraste
Keyword(s):  
Secretory Pathway ◽  
Cell Types ◽  
Pancreatic Acinar Cells ◽  
Relative Molecular Mass ◽  
Cell Fractionation ◽  
Charge Heterogeneity ◽  
Exocrine Cells ◽  
Pancreatic Exocrine ◽  
Golgi Protein

We have studied the biochemical characteristics and localization of a 58 kDa cis-Golgi marker protein (p58) in rat pancreatic exocrine cells. The protein remained associated with membranes after extraction at alkaline pH and was largely resistant to proteases, added to intact microsomes. By electrophoresis p58 could be resolved into two bands which in two-dimensional gels separated into several charge variants around pI 5.5. This size and charge heterogeneity of p58 did not appear to be due to acylation, glycosylation or phosphorylation. In non-reduced gels p58 migrated as two kinetically related, high relative molecular mass forms, apparently corresponding to disulfide-linked homo-dimers and -hexamers. Immuno-electron microscopy localized p58 to both the fenestrated cis-Golgi cisternae and small Golgi vesicles or buds as well as large, pleiomorphic structures, scattered throughout the cells and associated with distinct smooth ER (endoplasmic reticulum) clusters. These findings correlated with cell fractionation results showing the concentration of p58 in two microsomal subfractions, banding at intermediate densities between the rough ER and trans-Golgi in sucrose gradients. Our results indicate that p58 is a major component of pre- and cis-Golgi elements and could be part of the transport machinery that operates in these membranes. Together with results obtained with other cell types, these observations suggest that the peripheral smooth ER clusters are involved in the early stages of the secretory pathway in the pancreatic acinar cells.

scholarly journals Purification and Characterization of Chondroitin 4-Sulfotransferase from the Culture Medium of a Rat Chondrosarcoma Cell Line

1999 ◽  
Vol 274 (4) ◽  
pp. 2456-2463 ◽  
Author(s):  
Shinobu Yamauchi ◽  
Yukie Hirahara ◽  
Hiroaki Usui ◽  
Yoshiko Takeda ◽  
Megumi Hoshino ◽  
...  
Keyword(s):  
Cell Line ◽  
Culture Medium ◽  
Purification And Characterization ◽  
Chondrosarcoma Cell ◽  
Chondrosarcoma Cell Line

scholarly journals Characterization of a complement-fragment-C5a-stimulated calcium-influx mechanism in U937 monocytic cells

1993 ◽  
Vol 295 (3) ◽  
pp. 679-684 ◽  
Author(s):  
P N Monk ◽  
L J Partridge
Keyword(s):  
Cell Line ◽  
Pertussis Toxin ◽  
Inositol Phosphates ◽  
Calcium Influx ◽  
Cell Types ◽  
U937 Cells ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Monocytic Cells

The mechanism by which complement fragment C5a elevates intracellular Ca2+ ([Ca2+]i) levels in two cell types, a monocytic cell line, U937, and neutrophils, has been investigated by the use of fluorometric and radiometric techniques. In U937 cells the influx of extracellular Ca2+ can be distinguished from the release of intracellular Ca2+ stores in terms of dose-responsiveness to C5a and sensitivity to pertussis-toxin poisoning. This suggests that the mechanism of Ca2+ influx in these cells is at least partially independent of both the production of inositol phosphates and elevation of internal Ca2+ concentration. The C5a-stimulated influx of 45Ca2+ into U937 cells is inhibited by a series of metal ions (Zn2+ > Co2+ > Mn2+ > Sr2+ approximately equal to Ni2+ > La3+). The stimulated influx of Ca2+ into neutrophils is inhibited differently (Ni2 >> Co2+ > Zn2+ approximately equal to La3+ > Mn2+ approximately equal to Sr2+), is less sensitive to C5a and both the influx of extracellular Ca2+ and the release of intracellular stores are equally sensitive to pertussis toxin treatment. Taken together these results indicate that [Ca2+]i is controlled in U937 monocytes by mechanisms distinct from those which appear to operate in other myeloid cells, such as neutrophils, stimulated with C5a and formylpeptide.

Cl− transport in an immortalized human epithelial cell line (NCM460) derived from the normal transverse colon

1998 ◽  
Vol 275 (4) ◽  
pp. C1048-C1057 ◽  
Author(s):  
Jasminder Sahi ◽  
Selvaraj G. Nataraja ◽  
Thomas J. Layden ◽  
Jay L. Goldstein ◽  
M. P. Moyer ◽  
...  
Keyword(s):  
Cell Line ◽  
Channel Blocker ◽  
Human Colon ◽  
Cell Types ◽  
Epithelial Cell Line ◽  
Transmembrane Conductance Regulator ◽  
Cyclic Monophosphate ◽  
Heat Stable ◽  
Colonic Crypts ◽  
Dependent Protein

Cells of a newly described, immortalized, epithelial, human transverse colonic cell line, NCM460, reach ∼90% confluence on plastic and develop transepithelial resistances of 120–250 Ω ⋅ cm2 on porous substrates. Its utility as a model for the transverse human colon was validated by comparing second messenger-mediated Cl− transport, using the fluorescent probe 6-methoxy-quinolyl acetoethyl ester, in NCM460 cells and colonocytes isolated from human transverse crypts. Basal Cl− influx was increased ( P < 0.01) by PGE1 (1 μM), forskolin (1 μM), 8-bromoadenosine 3′5′-cyclic monophosphate (100 μM), heat-stable Escherichia colienterotoxin (STa; 1 μM), 8-bromoguanosine 3′5′-cyclic monophosphate (100 μM), histamine (1 μM), and phorbol 12,13-dibutyrate (1 μM) in both cell types. The Cl− channel blocker diphenylamine 2-carboxylic acid (50 μM) and the Na+-K+-2Cl−cotransport inhibitor furosemide (1 μM), but not the K+ channel blocker Ba2+ (3 mM), inhibited these Cl− permeabilities. These cells possess transcripts for cystic fibrosis transmembrane conductance regulator, Na+-K+-2Cl−cotransporter, STa receptor, and intestine-specific cGMP-dependent protein kinase II. Thus cAMP-, cGMP-, and Ca2+-dependent secretagogues act on NCM460 and primary colonocytes to stimulate Cl− transport. This validates the utility of NCM460 as a model for transverse colonic crypts and is the first demonstration of a colonic cell line whose origin is known.

Ultrastructural Study of a differentiating human colon carcinoma cell line

1990 ◽  
Vol 48 (3) ◽  
pp. 208-209
Author(s):  
Sylvie Polak-Charcon ◽  
Mehrdad Hekmati ◽  
Yehuda Ben Shaul
Keyword(s):  
Cell Line ◽  
Morphological Changes ◽  
Secretory Granules ◽  
Human Colon ◽  
Cell Types ◽  
Culture Conditions ◽  
Morphological Evidence ◽  
Human Colon Carcinoma Cell ◽  
Colon Cell

The epithelium of normal human colon mucosa “in vivo” exhibits a gradual pattern of differentiation as undifferentiated stem cells from the base of the crypt of “lieberkuhn” rapidly divide, differentiate and migrate toward the free surface. The major differentiated cell type of the intestine observed are: absorptive cells displaying brush border, goblet cells containing mucous granules, Paneth and endocrine cells containing dense secretory granules. These different cell types are also found in the intestine of the 13-14 week old embryo.We present here morphological evidence showing that HT29, an adenocarcinoma of the human colon cell line, can differentiate into various cell types by changing the growth and culture conditions and mimic morphological changes found during development of the intestine in the human embryo.HT29 cells grown in tissue-culture dishes in DMEM and 10% FCS form at late confluence a multilayer of morphologically undifferentiated cell culture covered with irregular microvilli, and devoid of tight junctions (Figs 1-3).

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