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1.
In this study, we applied specific blocking antibodies for integrin α6 or β1 subunit, and evaluated the in vitro effects of
integrins α6β1 on the adhesion, chemotaxis and migration of hepatocellular carcinoma (HCC) cell line SMMC-7721 to type IV
collagen. The adhesion force and cell migration, as measured by a micropipette aspiration system and Boyden chamber assay
respectively, was dramatically reduced when either integrin subunits was blocked. The chemotaxis, as determined using a dual-micropipette
system, was only affected by the antibody against β1 subunit. This study suggests that integrin α6β1 is an important cell
surface receptor that mediates the adhesion of SMMC-7721 to type IV collagen. But the α6 subunit has minimal effect on pseudopod
formation in response to type IV collagen. Therefore, the integrin α6β1-mediated cell migration is, at least in part, through
the regulation on the cell adhesion step. 相似文献
2.
Epigenetic activation of α4, β2 and β6 integrins involved in cell migration in trichostatin A-treated Hep3B cells 总被引:4,自引:0,他引:4
Summary The epigenetic modulation by histone deacetylase (HDAC) inhibitors including trichostatin A (TSA) has been known to block
cell proliferation, induce apoptosis and inhibit cell migration in human cancer cells that represents the potential therapeutic
agents for cancers and fibrosis. However, more than 55% of Hep3B cells remained alive after our initial study of 100 nM TSA
treatment. To further study the epigenetic modulation and the biological function of newly activated genes by HDAC inhibitor
involved in HCC progression and metastasis, we profiled 23 integrin genes including 15α and 8β in TSA-treated Hep3B cells.
Six integrins including three down-regulated α6, α10, β8 and three significant up-regulated α4, β2, β6 integrins were revealed
after semi-quantitative RT-PCR. To confirm the epigenetic modulation and explore their biological functions, we selected the
three significantly up-regulated integrins for confirmation of protein up-regulation, hyperacetylated-histones by ChIP assays,
and functional inhibition by specific neutralizing antibodies of integrins. Our results indicated that epigenetic modulation
in TSA-treated Hep3B cells up-regulated new integrins including α4, β2 and β6 and reduced migration activities by specific
neutralizing antibodies to 61.3%, 42.4% and 34.5%, respectively. Our novel findings provided a better understanding of the
epigenetic modulation of integrins and suggested that targeting the epigenetic up-regulated integrins to abrogate the migration
activity might be a promising strategy to prevent HCC progression. 相似文献
3.
Integrin expression in developing human salivary glands 总被引:1,自引:1,他引:0
The development and complete differentiation of salivary glands is a complex process that involves a large number of co-ordinated
events. Little is known about the molecular basis for salivary gland development. However, we have reported previously that
integrins appear to play a role. Integrins are heterodimeric transmembrane receptors consisting of one α and one β subunit
that play a pivotal role in the interaction of cells with the extracellular matrix. Such interactions regulate the organisation
of cells of tissues and organs during development as well as cell proliferation and differentiation. Using immunohistochemistry
and Western and Northern blot analysis, we mapped the localisation and expression of integrins β1, β3 and β4 in human salivary
glands obtained from foetuses ranging from weeks 4–24 of gestation and compared it with adult salivary glands. Integrin β1
first appeared during the canalisation stage and during the differentiation stage. A message first appeared at week 6 of development.
The expression of β4 integrin protein and message was observed only in the late stage of differentiation. Integrin β3 was
not detected in the developing glands; however, integrins β1, β3 and β4 were all expressed in adult salivary gland tissues.
The data suggest that integrins, particularly β1, have a role to play in salivary gland development and differentiation. 相似文献
4.
Evolution of the Integrin α and β Protein Families 总被引:4,自引:0,他引:4
Hughes AL 《Journal of molecular evolution》2001,52(1):63-72
A phylogenetic analysis of vertebrate and invertebrate α integrins supported the hypothesis that two major families of vertebrate
α integrins originated prior to the divergence of deuterostomes and protostomes. These two families include, respectively,
the αPS1 and αPS2 integrins of Drosophila melanogaster, and each family has duplicated repeatedly in vertebrates but not in Drosophila. In contrast, a third family (including αPS3) has duplicated in Drosophila but is absent from vertebrates. Vertebrate αPS1 and αPS2 family members are found on human chromosomes 2, 12, and 17. Linkage
of these family members may have been conserved since prior to the origin of vertebrates, and the two genes duplicated simultaneously.
A phylogenetic analysis of β integrins did not clearly resolve whether vertebrate β integrin genes duplicated prior to the
origin of vertebrates, although it suggested that at least the gene encoding vertebrate β4 may have done so. In general, the
phylogeny of neither α nor β integrins showed a close correspondence with patterns of α–β heterodimer formation or other functional
characteristics. One major exception to this trend involved αL, αM, αX, and αD, a monophyletic group of immune cell-expressed
α integrins, which share a number of common functional characteristics and have evolved in coordinated fashion with their
β integrin partners.
Received: 22 June 2000 / Accepted: 11 September 2000 相似文献
5.
The integrin α6β1 modulation of PI3K and Cdc42 activities induces dynamic filopodium formation in human platelets 总被引:5,自引:0,他引:5
Summary Platelets are an ideal model for studying a rapid morphological change in response to various signal transduction systems.
Morphological changes via the activation of integrin αIIbβ3 in platelets have been investigated intensively. In contrast,
activation via integrin α6β1 is less well studied. Here, we provide the first biochemical evidence that integrins α6β1 and
αIIbβ3 of platelets are associated with different membrane proteins. We also demonstrate that platelets activated by integrin
α6β1 show dynamic change by actively forming filopodia and never fully spreading over a period of more than an hour. In addition,
platelets activated by integrin α6β1 are different from those activated by integrin αIIbβ3 in terms of cell–substrate contact
and in their distribution pattern of actin, Arp2/3 and various phosphotyrosine proteins. The morphological appearance of platelets
produced through integrin α6β1 activation is highly dependent on PI3 kinase (PI3K) but less dependent on Src kinase. Suppression
of PI3K activity in integrin α6β1 activated platelets induces an increase in Cdc42 activity and more filopodium formation.
However, both Cdc42 and PI3K activity are higher in platelets activated by integrin α6β1 than in those activated by integrin
αIIbβ3. Taken together, this study demonstrates that the signals induced by integrin α6β1 modulate at the level of PI3K and
Cdc42 activity to allow platelets to actively form filopodia. 相似文献
6.
George K. Koukoulis Ismo Virtanen Roland Moll Vito Quaranta Victor E. Gould 《Virchows Archiv. B, Cell pathology including molecular pathology》1993,63(1):373-383
Cryosections of normal colon (NC), tubular and villous adenomas (TA, VA), and variably differentiated colon adenocarcinomas
(CA) were immunostained with monoclonal antibodies to α1−6 and αv, and β1−4 integrin subunits; select samples were stained for cytokeratin (Ck) 20 and villin. In NC, α2 staining was strongest in crypt cells; α1,3 and αv, and β1,3 and β4, and Ck 20 and villin predominated in superficial enterocytes. In TA and VA, monolayered glands showed integrin, Ck 20 and
villin patterns that differed slightly from both crypt and superficial enterocytes. Complex glands in VA showed decreased
integrin staining and basal polarization; Ck 20 and villin were strong only in luminal cells. CA showed overall weaker integrin
staining than adenomas. Regardless of invasion depth, well formed malignant glands mimicked TA; pleomorphic glands mimicked
VA with focal basal integrin polarization and solid clusters displayed scanty integrins, uneven Ck 20, and villin in occasional
cells. Diverse integrins in crypt compared with superficial enterocytes reflect changing adhesive requirements as cells migrate
and terminally differentiate. Decreasing expression and altered distribution of integrins, Ck 20 and villin noted in TA, VA,
and in CA of increasing grade indicate that certain adhesive and cytoskeletal features more closely relate to glandular architecture
than to depth of invasion. 相似文献
7.
A. Makrigiannakis M. Karamouti G. Petsas N. Makris G. Nikas A. Antsaklis 《Histochemistry and cell biology》2009,132(2):159-167
Pinopodes represent the morphological and integrins, the biomollecular markers of endometrial receptivity. We studied using
scanning electron microscopy, the expression of pinopodes on tubal samples and their corresponding endometria, from 21 women
of reproductive age (7 from proliferative phase, 7 from day LH +5 and 7 from day LH +7). In addition, we examined the immunohistochemical
staining of integrins αvβ3, αvβ5 and their ligands, fibronectin (FN) and osteopontin (OPN) in the same tubal epithelium samples.
Pinopodes were detected on the tubal epithelium exclusively during day LH +7, coincident with their formation in the endometrium
and synchronous to αvβ3 sharp increase in the oviduct epithelium, suggesting a regulation similar to the endometrium. In contrast,
αvβ5, FN and OPN remained unchanged during the cycle. These results show for the first time the formation of pinopodes in
the tubal epithelium at the time of endometrial receptivity and correlate it with the upregulation of the intact dimmer αvβ3
in the tubes. 相似文献
8.
Daisei Miyamoto Takao Ueno Sachiko Takashima Kazuhide Ohta Toshio Miyawaki Takashi Suzuki Yasuo Suzuki 《Glycoconjugate journal》1997,14(3):379-388
A new monoclonal antibody (TU-1) directed against the Galα1-4Galβ1-4Glc residue of the Gb3Cer/CD77 antigen was prepared by
the hybridoma technique following immunization of mice with an emulsion composed of monophosphoryl lipid A, trehalose dimycolate,
and Gb3Cer isolated from porcine erythrocytes. TU-1 showed reactivity towards Gb3Cer and lyso-Gb3Cer (Galα1-4Galβ1-4Glcβ1-1′Sph),
although the reactivity towards lyso-Gb3Cer was about 10-fold lower than that to Gb3Cer. But it did not react with other structurally-related
glycolipids, such as LacCer (Galβ1-4Glcβ1-1′Cer), Gg3Cer, Gg4Cer, Gb4Cer (GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1′Cer), galactosylparagloboside
(Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer), sulfatide (HSO3-3Galβ1-1′Cer), other gangliosides (GM3, GM2, GM1a, GD1a and
GT1b), or P1 antigen (Galα1-4Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer) among neutral glycolipids prepared from P1 phenotype red
blood cells. Furthermore, TU-1 reacted with viable lymphoma cells, such as human Burkitt lymphoma cell line, Daudi, and Epstein-Barr
virus (EBV)-transformed B cells by the immunofluorescence method, and also with germinal centre B cells in human tonsil and
vessel endothelial cells in human thymus histochemically. These results indicate that TU-1 is a monoclonal antibody directed
against Gb3Cer/CD77 antigen and can be utilized as a diagnostic reagent for Burkitt's lymphoma and also for detection of the
blood group Pk antigen in glycolipid extracts of erythrocytes. Abbreviations: ATL, adult T-cell leukaemia; BSA, bovine serum
albumin; Cer, ceramide; DPPC, L-α-dipalmitoylphosphatidylcholine; EBV, Epstein-Barr virus; FCS, fetal calf serum; GalCer,
Galβ1-1′Cer; GlcCer, Glcβ1-1′Cer; LacCer, Galβ1-4Glcβ1-1′Cer; Gb3Cer, Galα1-4Galβ1-4Glcβ1-1′Cer; Iyso-Gb3Cer, Galα1-4Galβ1-4Glc1-1′Sph;
Gb4Cer, GalNAcβ1-3Galα1-4Galβ1-4Glc1-1′Cer; galactosylparagloboside, Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer; Gg3Cer, GalNAcβ1-4Galβ1-4Glcβ1-1′Cer;
Gg4Cer, Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1′Cer; GM3, Neu5Acα2-3Galβ1-4Glcβ1-1′Cer; GM2, GalNAcβ1-4(Neu5Acα2-3) Galβ1-4Glcβ1-1′Cer;
GM1a, Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GD1a, Neu5Acα2-3Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GD1b,
Galβ1-3GalNAcβ1-4(Neu5Acα2-8Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GT1b, Neu5Acα2-3Galβ1-3GalNAcβ1-4(Neu5Acα2-8Neu5Acα2-3) Galβ1-4Glcβ1-1′Cer;
HRP, horseradish peroxidase; LDH, lactate dehydrogenase; MAb, monoclonal antibody; MPL, monophosphoryl lipid A; P1 antigen,
Galα1-4Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer; PVP, polyvinylpyrolidone; Sph, sphingosine; sulfatide, HSO3-Galβ1-1′Cer; TDM,
trehalose dimycolate; TLC, thin-layer chromatography
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
9.
Vainionpää N Bützow R Hukkanen M Jackson DG Pihlajaniemi T Sakai LY Virtanen I 《Cell and tissue research》2007,328(2):317-328
The endothelial cells of blood vessels assemble basement membranes that play a role in vessel formation, maintenance and function,
and in the migration of inflammatory cells. However, little is known about the distribution of basement membrane constituents
in lymphatic vessels. We studied the distribution of basement membrane proteins in lymphatic vessels of normal human skin,
digestive tract, ovary and, as an example of tumours with abundant lymphatics, ovarian carcinomas. Basement membrane proteins
were localized by immunohistochemistry with monoclonal antibodies, whereas lymphatic capillaries were detected with antibodies
to the lymphatic vessel endothelial hyaluronan receptor-1, LYVE-1. In skin and ovary, fibrillar immunoreactivity for the laminin
α4, β1, β2 and γ1 chains, type IV and XVIII collagens and nidogen-1 was found in the basement membrane region of the lymphatic
endothelium, whereas also heterogeneous reactivity for the laminin α5 chain was detected in the digestive tract. Among ovarian
carcinomas, intratumoural lymphatic vessels were found especially in endometrioid carcinomas. In addition to the laminin α4,
β1, β2 and γ1 chains, type IV and XVIII collagens and nidogen-1, carcinoma lymphatics showed immunoreactivity for the laminin
α5 chain and Lutheran glycoprotein, a receptor for the laminin α5 chain. In normal lymphatic capillaries, the presence of
primarily α4 chain laminins may therefore compromise the formation of endothelial basement membrane, as these truncated laminins
lack one of the three arms required for efficient network assembly. The localization of basement membrane proteins adjacent
to lymphatic endothelia suggests a role for these proteins in lymphatic vessels. The distribution of the laminin α5 chain
and Lutheran glycoprotein proposes a difference between normal and carcinoma lymphatic capillaries. 相似文献
10.
Ismo Virtanen Jouni Lohi Taneli Tani Hannu Sariola Robert E. Burgeson Veli-Pekka Lehto 《The Histochemical journal》1996,28(9):643-650
Summary In recent studies, the α2 chain of laminin (Ln) has been suggested to be the only laminin α chain expressed in mouse and human
thymus. We have now used chain-specific monoclonal antibodies and indirect immunofluorescence microscopy to study the expression
of laminin chains in samples of foetal and 6-year-old human thymus. The subepithelial basement membrane of the capsule of
foetal 16- to 18-week thymus presented a bright immunoreactivity for Ln α1, α3, β1, β3 and γ1 chains but not for α2 chain,
suggesting the expression of laminins-1 and-5. Most cortical and medullary epithelial cells, including Hassall's corpuscles,
however, lacked laminin immunoreactivity. Immunoreactivity for Ln β2 chain was only seen in basal laminae of larger blood
vessels. In thymic specimens from 6-year-old children, immunoreactivity for the laminin α1, α3, β1, β3 and γ1 chains was invariably
found in subepithelial basement membrane of the capsule and that for laminin α2 chain was now also distinct but more heterogeneous.
Furthermore, the thymic subepithelial basement membrane of the capsule at all stages showed immunore-activity for collagen
type VII, forming the anchoring fibres in epithelial basement membranes. The subcapsular thymic epithelium also showed immunoreactivity
for the BP 230 antigen and β4 integrin subunit, both components of hemidesmosomes. The present results show that the thymic subepithelial basement membrane
of the capsule presents properties which are commonly seen in stratified and combined epithelia, and are compatible with suggestions
of the antigenic similarity of thymic epithelial cells and keratinocytes. 相似文献
11.
Integrins are cell adhesion receptors that are evolutionary old and that play important roles during developmental and pathological
processes. The integrin family is composed of 24 αβ heterodimeric members that mediate the attachment of cells to the extracellular
matrix (ECM) but that also take part in specialized cell-cell interactions. Only a subset of integrins (8 out of 24) recognizes
the RGD sequence in the native ligands. In some ECM molecules, such as collagen and certain laminin isoforms, the RGD sequences
are exposed upon denaturation or proteolytic cleavage, allowing cells to bind these ligands by using RGD-binding receptors.
Proteolytic cleavage of ECM proteins might also generate fragments with novel biological activity such as endostatin, tumstatin,
and endorepellin. Nine integrin chains contain an αI domain, including the collagen-binding integrins α1β1, α2β1, α10β1, and
α11β1. The collagen-binding integrins recognize the triple-helical GFOGER sequence in the major collagens, but their ability
to recognize these sequences in vivo is dependent on the fibrillar status and accessibility of the interactive domains in
the fibrillar collagens. The current review summarizes some basic facts about the integrin family including a historical perspective,
their structure, and their ligand-binding properties. 相似文献
12.
Summary Platelet-derived growth factor (PDGF) and transforming growth factor beta-1(TGF-β1) were tested separately or together for
the ability to stimulate migration of human aortic vascular smooth muscle cells (VSMC). PDGF (10 ng/ml) stimulated migration
of VSMC over a 48-h period. TGF-β1 (10 ng/ml) had no effect on migration during the same period. VSMC exposed simultaneously
to both TGF-β1 and PDGF exhibited diminished migration (50%) when compared to cells treated only with PDGF. Cells that migrated
in the presence of PDGF possessed short actin cables that extended from cellular processes at the leading edge of migrating
cells; focal adhesions containing the αvβ3/β5 integrins localized to the same region. Cells grown in the presence of TGF-β1 exhibited long, intensely stained actin filaments
that spanned the entire length of the cell and were similar to untreated control VSMC. Focal adhesions containing αvβ3/β5 distributed evenly on the basal surface in both TGF-β1-treated cells and control cultures. Cellular responses to PDGF were
mitigated when TGF-β1 was present in the culture medium. VSMC grown in the presence of both PDGF and TGF-β1 exhibited elongated
actin filaments that were similar to nonmotile TGF-β1-treated cultures. Concomitant exposure of VSMC to PDGF and TGF-β1 resulted
in focal adhesions that distributed evenly on the lower cell surface. This study suggests that TGF-β1 can partially reverse
the stimulatory effect of PDGF on VSMC migration in vitro by modifying the actin cytoskeleton and the distribution of the α
vβ3/β5 integrins. 相似文献
13.
P. Ofner R. L. Vena N. J. Barowsky R. M. Singer A. H. Tashjian Jr. 《In vitro cellular & developmental biology. Plant》1977,13(6):378-388
Summary Since the designation of the human MA 160 line as prostatic epithelial cells has been questioned and the possibility of HeLa
cross contamination raised, this comparative study of C19-radiosteroid transformation in MA 160 and HeLa monolayer cultures was done to determine whether these cells possess the distinguishing
features of reductive and oxidative androgen metabolism expected in male and female genital organs, respectively. We compared
the radiometabolite patterns produced by incubating [14C]testosterone (300nM) and [3H]testosterone (3nm) and 5α-dihydrotestosterone (17β-hydroxy-5α-androstan-3-one) with cultures of prostatic MA 160 and HeLa Parent, TCRC-1, TCRC-2
and ATC 229 cells. C19-Radiosteroid metabolite patterns from MA 160 cell incubations also were compared with patterns generated by MA 196 fibroblasts
from abdomnal skin of the same donor. MA 160 cells metabolized radiotestosterone predominantly to 5α-dihydrotestosterone,
5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol. The diol epimers were the principal metabolites of 5α-dihydrotestosterone
radiosubstrate. In contrast, radiotestosterone metabolism by MA 196 and HeLa Parent, TCRC-1 and TCRC-2 cells was overwhelmingly
to the 17-oxosteroids 4-androstene-3,17-dione and androsterone. Another pathway was operative in HeLa 229 and, to a minor
extent, in TCRC-1, which converted radiotestosterone to 4-androstene-3α,17β-diol and 5α-androstane-3α,17β-dol, with little
formation of 5α-dihydrotestosterone. MA 160 cells thus metabolize radiotestosterone preponderantly to 5α-reduced 17β-hydroxysteroids
as expected for prostatic epithelial cells, whereas HeLa cells show heterogeneity in metabolizing the labeled hormone by the
alternative 17-oxosteroid and Δ4 pathways.
This work was supported by Public Health Service Research Grants CA 13417 and CA 12924 from the National Cancer Institute,
AM 11011 from the National Institute of Arthritis, Metabolism and Digestive Diseases, and by appropriations of the Commonwealth
of Massachusetts, Item No. 4532-9003-01. 相似文献
14.
Michael Hadjiargyrou Zaven Kaprielian Nobuo Kato Paul H. Patterson 《Journal of neurochemistry》1996,67(6):2505-2513
Abstract: The cell surface glycoprotein CD9 is a member of a group of proteins known as the "tetraspan" or "transmembrane 4 superfamily." Previous work with non-neural cells has shown that CD9 associates in cis with integrins and small GTP-binding proteins on the cell surface. To extend our recent findings showing that perturbation of CD9 alters Schwann cell adhesion, proliferation, and migration, as well as neurite outgrowth in sympathetic neurons, we have searched for CD9-associated proteins in S-16 Schwann cells. We demonstrate here that CD9 is specifically coprecipitated from S-16 cell extracts by antibodies against integrins α3, α6, and β1. In addition, double immunofluorescence labeling and co-capping experiments indicate that CD9 is specifically colocalized with these integrins on the cell membrane of S-16 Schwann cells. 相似文献
15.
Using human endothelial cells, we define a mechanism that accounts for the induction of interleukin 8 (IL-8) by protein I/IIf, an adhesin from Streptococcus mutans serotype f. We report that protein I/IIf interactions with endothelial cells increased the tyrosine phosphorylation of three cellular components with relative mass of 145 000, 125 000 and 70 000 in endothelial cells. These proteins were identified as phospholipase Cγ (PLCγ), focal adhesion kinase (FAK) and paxillin after immunoprecipitation with monoclonal antibodies (mAbs) and immunoblotting with antiphosphotyrosine mAbs. These results suggested that β1 integrins could be one of the components implicated in the modulin activity of protein I/IIf. By incubating protein I/IIf with either purified α5β1 integrins or with α5β1 integrins overexpressing CHO cells, we demonstrated that α5β1 integrins act as cell receptors for protein I/IIf. We also showed that protein I/IIf interactions with α5β1 integrins lead to IL-8 secretion. Using specific inhibitors, we demonstrated that protein I/IIf-induced IL-8 release involves mitogen-activated protein kinases (MAPKs), and that PLCγ and PKC also seem to contribute to protein I/IIf stimulation. However, PI-3K activation is not involved in IL-8 release. Altogether, these results indicate that, after binding to α5β1 integrins, protein I/IIf induces IL-8 release by activating the MAPKs signalling pathways. 相似文献
16.
Novel oligosaccharide has suppressive activity against human leukemia cell proliferation 总被引:1,自引:0,他引:1
Hosomi O Misawa Y Takeya A Matahira Y Sugahara K Kubohara Y Yamakura F Kudo S 《Glycoconjugate journal》2009,26(2):189-198
Various oligosaccharides containing galactose(s) and one glucosamine (or N-acetylglucosamine) residues with β1–4, α1–6 and β1–6 glycosidic bond were synthesized; Galβ1–4GlcNH2, Galα1–6GlcNH2, Galα1–6GlcNAc, Galβ1–6GlcNH2, Galβ1–4Galβ1–4GlcNH2 and Galβ1–4Galβ1–4GlcNAc. Galα1–6GlcNH2 (MelNH2) and glucosamine (GlcNH2) had a suppressive effect on the proliferation of K562 cells, but none of the other saccharides tested containing GlcNAc
showed this effect. On the other hand, the proliferation of the human normal umbilical cord fibroblast was suppressed by none
of the saccharides other than GlcNH2. Adding Galα1–6GlcNH2 or glucosamine to the culture of K562 cell, the cell number decreased strikingly after 72 h. Staining the remaining cells
with Cellstain Hoechst 33258, chromatin aggregation was found in many cells, indicating the occurrence of cell death. Furthermore,
all of the cells were stained with Galα1–6GlcNH-FITC (MelNH-FITC). Neither the control cells nor the cells incubated with
glucosamine were stained. On the other hand, when GlcNH-FITC was also added to cell cultures, some of them incubated with
Galα1–6GlcNH2 were stained. The difference in the stainability of the K562 cells by Galα1–6GlcNH-FITC and GlcNH-FITC suggests that the
intake of Galα1–6GlcNH2 and the cell death induced by this saccharide is not same as those of glucosamine. The isolation of the Galα1–6GlcNH2 binding protein was performed by affinity chromatography (melibiose-agarose) and LC-MS/MS, and we identified the human heterogeneous
ribonucleoprotein (hnRNP) A1 (34.3 kDa) isoform protein (30.8 kDa). The hnRNP A1 protein was also detected from the eluate(s)
of the MelNH-agarose column by the immunological method (anti-hnRNP-A1 and HRP-labeled anti-mouse IgG (γ) antibodies). 相似文献
17.
18.
19.
Menghang Xia Sunil P. Sreedharan Paul Dazin Caroline H. Damsky Edward J. Goetzl 《Journal of cellular biochemistry》1996,61(3):452-458
Human T lymphoblastoma cells of the CD4+ 8+ Tsup-1 line, that express alpha4 and alpha5 but not alpha6 integrins of the beta1 family, and CD4+ human blood T cells bind vasoactive intestinal peptide (VIP) with high affinity, leading to increased adherence, secretion of matrix metalloproteinases (MMPs), and chemotaxis. VIP-enhanced adherence of T cells to fibronectin was inhibited significantly by neutralizing monoclonal antibodies to beta1 > alpha4 >> alpha5, but not to alpha6. Antibodies to beta1 and alpha4 suppressed to a similarly significant extent VIP stimulation of both MMP-dependent T cell chemotaxis through fibronectin-enriched Matrigel and T cell degradation of 3H-type IV collagen in the Matrigel, without affecting VIP-evoked secretion of MMP by suspensions of T cells. The lesser inhibition of VIP-enhanced adherence of T cells to fibronectin by anti-alpha5 antibody, than antibodies to beta1 or alpha4 chains, was associated with lesser or no suppression of MMP-dependent T cell chemotaxis through Matrigel and T cell degradation of type IV collagen in the Matrigel in response to VIP. Specific beta1 integrins thus mediate interactions of stimulated T cells with basement membranes, including adherence, localized digestion by MMPs, and chemotactic passage, that promote entry of T cells into extravascular tissues. © 1996 Wiley-Liss, Inc. 相似文献
20.
Peter R. Andreana Przemyslaw Kowal Adam J. Janczuk Peng George Wang 《Glycoconjugate journal》2003,20(2):107-118
Galactose oxidase (EC 1.1.3.9, GAO) was used to convert the C-6′ OH of Galβ(1 → 4)Glcβ–OBn (5) to the corresponding hydrated
aldehyde (7). Chemical modification, through dehydratative coupling and reductive amination, gave rise to a small library
of Galβ(1 → 4)Glcβ–OBn analogues (9a–f, 10, 11). UDP-[6-3H]Gal studies indicated that α1,3-galactosyltransferase recognized the C-6′ modified Galβ(1 → 4)Glcβ–OBn analogues (9a–f,
10, 11). Preparative scale reactions ensued, utilizing a single enzyme UDP-Gal conversion as well as a dual enzymatic system
(GalE and α1,3GalT), taking full advantage of the more economical UDP-Glc, giving rise to compounds 6, 15–22. Galα(1 → 3)Galβ(1
→ 4)Glcβ–OBn trisaccharide (6) was produced on a large scale (2 g) and subjected to the same chemoenzymatic modification as
stated above to produce C-6″ modified derivatives (23–30). An ELISA bioassay was performed utilizing human anti-αGal antibodies
to study the binding affinity of the derivatized epitopes (6, 15–30). Modifications made at the C-6′ position did not alter
the IgG antibody's ability to recognize the unnatural epitopes. Modifications made at the C-6″ position resulted in significant
or complete abrogation of recognition. The results indicate that the C-6′ OH of the αGal trisaccharide epitope is not mandatory
for antibody recognition. Published in 2004.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献