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排序方式: 共有288条查询结果,搜索用时 15 毫秒
1.
Control of type IV collagen production in rat mammary epithelial and myoepithelial-like cells 总被引:1,自引:0,他引:1
M J Warburton R Kimbell P S Rudland S A Ferns R Barraclough 《Journal of cellular physiology》1986,128(1):76-84
A rat mammary myoepithelial-like cell line (Rama 401) produces 3.5 times more type IV collagen than a mammary epithelial cell line (Rama 25), as measured by the formation of protein hydroxyproline. However, using quantitative "dot" hybridization techniques, the level of poly (A)-containing mRNA hybridizing to a type IV collagen cDNA probe is only 50% higher in Rama 401 cells than in Rama 25 cells. The total amount of hydroxyproline synthesized per cell by the two cell lines is similar. However, in the Rama 25 cells approximately 70% of the hydroxyproline is found as free hydroxyproline against 13% for Rama 401 cells. When Rama 25 cells are grown on collagen gels, they accumulate 2.5-fold more type IV collagen. However, type IV collagen mRNA levels are only 30% higher in Rama 25 cells grown on collagen. The total amount of hydroxyproline synthesized is the same as cells grown on plastic, whereas the extent of collagen degradation is reduced from 71% to 30% in cells grown on collagen gels. No degradation of type IV collagen can be detected in the culture medium of Rama 25 cells. These results indicate that the increased accumulation of type IV collagen in Rama 401 cells is not due to increased synthesis but to a decreased rate of intracellular degradation, and that for Rama 25 cells, the extracellular matrix modulates type IV collagen production by regulating the rate of intracellular collagen degradation. 相似文献
2.
Philip S. Rudland Christine M. Hughes Sharon A. Ferns Michael J. Warburton 《In vitro cellular & developmental biology. Plant》1989,25(1):23-36
Summary Parenchymal organoidal structures that were obtained from collagenase digestion of reduction mammoplasty specimens of apparently
normal human breasts have been grown in short-term primary cultures, either on plastic or on floating gels of polymerized
rat-tail collagen. Three morphologically distinct major cell types are readily observed in both systems: cuboidal cells, which
occupy apical positions on collagen gels; larger, epithelioid, or basal cells on gels; and elongated cells which penetrate
into the gel. In addition, a fourth cell type, that of a large, flat cell, is observed less readily by phase contrast microscopy
on the surface of cultures grown on plastic. Immunofluorescent and immunocytochemical staining of cultures on plastic or histologic
sections of cultures on gels have been undertaken with antisera and other histochemical reagents that stain the different
parenchymal cell types in vivo. Thus antisera to epithelial membrane antigen(s), monoclonal antibodies (MABs) to the defatted
mammary milk fat globule membrane, peanut lectin, and keratin MAB LE61, which preferentially stain the epithelial cells of
ducts in vivo, also stain the cuboidal/apical cells in vitro. The large, flat cells are stained intensely by the first three
reagents but not by the last one. Antisera to collagen IV, laminin, fibronectin, actin, keratin MAB LP34, MABs to the common
acute lymphoblastic leukemia antigen, and MAB LICR-LON-23.10, which showed enhanced staining for the ductal myoepithelial
cells in vivo, also stain the epithelioid/elongated cells in vitro. However, the effect of the last four reagents is reduced
considerably in most elongated cells, and MAB LP34 stains the large, flat cells intensely. Heterogeneous cells of intermediate
morphologies and staining patterns between the cuboidal/flat cells and large epithelioid cells have also been identified.
The results suggest that the cuboidal cells and large, flat cells are related to mammary epithelial cells, whereas the large
epithelioid/elongated cells have some characteristics of myoepithelial cells, and that intermediate forms may exist in culture
between the two parenchymal cell types.
This work was supported in part by the Ludwig Institute for Cancer Research and the Cancer and Polio Research Fund. Dr. M.
J. Warburton is supported by the Cancer Research Campaign. 相似文献
3.
We have broadly defined the DNA regions regulating esterase6 activity in
several life stages and tissue types of D. melanogaster using P-
element-mediated transformation of constructs that contain the esterase6
coding region and deletions or substitutions in 5' or 3' flanking DNA.
Hemolymph is a conserved ancestral site of EST6 activity in Drosophila and
the primary sequences regulating its activity lie between -171 and -25 bp
relative to the translation initiation site: deletion of these sequences
decrease activity approximately 20-fold. Hemolymph activity is also
modulated by four other DNA regions, three of which lie 5' and one of which
lies 3' of the coding region. Of these, two have positive and two have
negative effects, each of approximately twofold. Esterase6 activity is
present also in two male reproductive tract tissues; the ejaculatory bulb,
which is another ancestral activity site, and the ejaculatory duct, which
is a recently acquired site within the melanogaster species subgroup.
Activities in these tissues are at least in part independently regulated:
activity in the ejaculatory bulb is conferred by sequences between -273 and
-172 bp (threefold decrease when deleted), while activity in the
ejaculatory duct is conferred by more distal sequences between -844 and
-614 bp (fourfold decrease when deleted). The reproductive tract activity
is further modulated by two additional DNA regions, one in 5' DNA (-613 to
-284 bp; threefold decrease when deleted) and the other in 3' DNA (+1860 to
+2731 bp; threefold decrease when deleted) that probably overlaps the
adjacent esteraseP gene. Collating these data with previous studies
suggests that expression of EST6 in the ancestral sites is mainly regulated
by conserved proximal sequences while more variable distal sequences
regulate expression in the acquired ejaculatory duct site.
相似文献
4.
Litman GW; Rast JP; Shamblott MJ; Haire RN; Hulst M; Roess W; Litman RT; Hinds- Frey KR; Zilch A; Amemiya CT 《Molecular biology and evolution》1993,10(1):60-72
Immunoglobulins are encoded by a large multigene system that undergoes
somatic rearrangement and additional genetic change during the development
of immunoglobulin-producing cells. Inducible antibody and antibody-like
responses are found in all vertebrates. However, immunoglobulin possessing
disulfide-bonded heavy and light chains and domain-type organization has
been described only in representatives of the jawed vertebrates. High
degrees of nucleotide and predicted amino acid sequence identity are
evident when the segmental elements that constitute the immunoglobulin gene
loci in phylogenetically divergent vertebrates are compared. However, the
organization of gene loci and the manner in which the independent elements
recombine (and diversify) vary markedly among different taxa. One striking
pattern of gene organization is the "cluster type" that appears to be
restricted to the chondrichthyes (cartilaginous fishes) and limits
segmental rearrangement to closely linked elements. This type of gene
organization is associated with both heavy- and light-chain gene loci. In
some cases, the clusters are "joined" or "partially joined" in the germ
line, in effect predetermining or partially predetermining, respectively,
the encoded specificities (the assumption being that these are expressed)
of the individual loci. By relating the sequences of transcribed gene
products to their respective germ-line genes, it is evident that, in some
cases, joined-type genes are expressed. This raises a question about the
existence and/or nature of allelic exclusion in these species. The
extensive variation in gene organization found throughout the vertebrate
species may relate directly to the role of intersegmental
(V<==>D<==>J) distances in the commitment of the individual
antibody-producing cell to a particular genetic specificity. Thus, the
evolution of this locus, perhaps more so than that of others, may reflect
the interrelationships between genetic organization and function.
相似文献
5.
Distribution of entactin in the basement membrane of the rat mammary gland. Evidence for a non-epithelial origin 总被引:4,自引:0,他引:4
M J Warburton P Monaghan S A Ferns P S Rudland N Perusinghe A E Chung 《Experimental cell research》1984,152(1):240-254
Entactin, a sulfated glycoprotein with a molecular weight (MW) of about 150 kD, is present in vascular basement membranes and in the interstitial connective tissue of the mammary glands of virgin rats. It does not appear to be present in the basement membrane surrounding the mammary ductal system. However, in lactating mammary glands entactin is also present in the basement membrane region surrounding the secretory alveoli. Ultrastructural localisation of entactin reveals that it is present on the basal surface of epithelial cells, with patchy staining in the lamina lucida and lamina densa. Entactin also appears to be associated with interstitial collagen fibres. Mammary fibroblastic cells in culture are able to produce entactin, whereas mammary epithelial and myoepithelial cells, which synthesise the basement membrane proteins laminin and type IV collagen, fail to synthesise entactin. 相似文献
6.
Ghazizadeh Hamideh Rezaei Majid Avan Amir Fazilati Mohammad Pasdar Alireza Tavallaie Shima Kazemi Elham Seyedi Seyed Mohammad Reza Ferns Gordon A. Azimi-Nezhad Mohsen Ghayour-Mobarhan Majid 《Molecular biology reports》2020,47(2):867-875
Molecular Biology Reports - Metabolic syndrome (MetS) is associated with a pro-inflammatory state and endothelial dysfunction that places subjects with MetS at a higher risk of atherosclerosis.... 相似文献
7.
Reza Jafarzadeh-Esfehani Seyed Mostafa Parizadeh Amirsaeed Sabeti Aghabozorgi Negar Yavari Ariane Sadr-Nabavi Seyed Alireza Parizadeh Maryam Ghandehari Afsane Javanbakht Afsaneh Rezaei-Kalat Seyed Mahdi Hassanian Mohammad Vojdanparast Gordon A. Ferns Majid Khazaei Amir Avan 《Journal of cellular physiology》2020,235(10):6393-6403
Venous and arterial thrombosis are conditions that have a considerable burden if left untreated. The hypoxia-induced by the occluded vessel can disrupt the circulation of any organ, the cornerstone of treating thrombosis is rapid diagnosis and appropriate treatment. Diagnosis of thrombosis may be made by using laboratory tests or imaging techniques in individuals who have clinical manifestations of a thrombotic event. The use of serum micro ribonucleic acids (RNAs) has recently been applied to the diagnosis of thrombosis. These small RNA molecules are emerging as new diagnostic markers but have had very limited applications in vascular disease. Most of the articles provided various microRNAs with different levels of accuracy. However, there remains a lack of an appropriate panel of the most specific microRNA in the literature. The purpose of the present review was to summarize the existing data on the use of microRNAs as a diagnostic biomarker for venous thrombosis. 相似文献
8.
Schistosomiasis vector snails are subjected to extreme seasonal changes, particularly in ephemeral rivers and lentic waterbodies. In the tropics, aestivation is one of the adaptive strategies for survival and is used by snails in times of extremely high temperatures and desiccation. Aestivation therefore plays an important role in maintaining the transmission of schistosomiasis. This review assesses the possible impacts of climate change on the temporal and spatial distribution of schistosomiasis-transmitting snails with special emphasis on aestivation, and discusses the effect of schistosome infection on aestivation ability. The impacts of parasite development on snails, as well as physiological changes, are discussed with reference to schistosomiasis transmission. This review shows that schistosome-infected snails have lower survival rates during aestivation, and that those that survive manage to get rid of the infection. In general, snail aestivation ability is poor and survival chances diminish with time. Longer dry periods result in fewer, as well as uninfected, snails. However, the ability of the surviving snails to repopulate the habitats is high. 相似文献
9.
Suhad M. Bahijri Hanan A. Jambi Rajaa M. Al Raddadi Gordon Ferns Jaakko Tuomilehto 《PloS one》2016,11(4)
BackgroundType 2 (T2DM) is believed to be common in Saudi Arabia, but data are limited. In this population survey, we determined the prevalence of T2DM and prediabetes.ResultsAge and sex standardized prevalence of prediabetes was 9.0% (95% CI 7.5–10.5); 9.4% (7.1–11.8) in men and 8.6% (6.6–10.6) in women. For DM it was 12.1% (10.7–13.5); 12.9% (10.7–13.5) in men and 11.4% (9.5–13.3) in women. The prevalence based on World Population as standard was 18.3% for DM and 11.9% for prediabetes. The prevalence of DM and prediabetes increased with age. Of people aged ≥50 years 46% of men and 44% of women had DM. Prediabetes and DM were associated with various measures of adiposity. DM was also associated with and family history of dyslipidemia in women, cardiovascular disease in men, and with hypertension, dyslipidemia and family history of diabetes in both sexes.DiscussionAge was the strongest predictor of DM and prediabetes followed by obesity. Of people aged 50 years or over almost half had DM and another 10–15% had prediabetes leaving only a small proportion of people in this age group with normoglycemia. Since we did not use an oral glucose tolerance test the true prevalence of DM and prediabetes is thus likely to be even higher than reported here. These results demonstrate the urgent need to develop primary prevention strategies for type 2 diabetes in Saudi Arabia. 相似文献
10.
Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase
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Sharon C Mithoe Christina Ludwig Michiel JC Pel Mara Cucinotta Alberto Casartelli Malick Mbengue Jan Sklenar Paul Derbyshire Silke Robatzek Corné MJ Pieterse Ruedi Aebersold Frank LH Menke 《EMBO reports》2016,17(3):441-454
Pattern recognition receptors (PRRs) play a key role in plant and animal innate immunity. PRR binding of their cognate ligand triggers a signaling network and activates an immune response. Activation of PRR signaling must be controlled prior to ligand binding to prevent spurious signaling and immune activation. Flagellin perception in Arabidopsis through FLAGELLIN‐SENSITIVE 2 (FLS2) induces the activation of mitogen‐activated protein kinases (MAPKs) and immunity. However, the precise molecular mechanism that connects activated FLS2 to downstream MAPK cascades remains unknown. Here, we report the identification of a differentially phosphorylated MAP kinase kinase kinase that also interacts with FLS2. Using targeted proteomics and functional analysis, we show that MKKK7 negatively regulates flagellin‐triggered signaling and basal immunity and this requires phosphorylation of MKKK7 on specific serine residues. MKKK7 attenuates MPK6 activity and defense gene expression. Moreover, MKKK7 suppresses the reactive oxygen species burst downstream of FLS2, suggesting that MKKK7‐mediated attenuation of FLS2 signaling occurs through direct modulation of the FLS2 complex. 相似文献