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Query: UNIPROT:P10145 (
IL-8
)
23,849
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The purpose of this article is to present the current state of knowledge regarding the structure and functions of articular cartilage. Articular cartilage is constructed with hyaline cartilage tissue. It is composed of chondrocytes located in lacunae and the extracellular matrix. The chondrial matrix contains water, collagen, proteglycans, non-collagenous matrix proteins, and lipids. Articular cartilage is devided into four zones - superficial, intermediate, deep, and calcified - on the basic of morphology, the orientation of collagen fiber, and the proteoglycan content. The dominant collagen of this tissue is Type II collagen, which, together with smaller quantities of other collagens (i.e. Types IX and XII), forms a network of fibers, with large, aggregating proteoglycans and smaller, non-aggregating proteoglycans. Proteoglycans are proteins that contain covalently attached glycosaminoglycans (GAGs), with water between them. The large aggregating proteoglycans, called "aggrecans", form aggregates that bind hyaluronic acid, and together with collagen they are responsible for the mechanical properties of cartilage. The smallnonaggregating proteoglycans, decorin and fibromodulin, limit the formation of collagen fibres. Other proteins in the cartilage matrix - chondrocalcin and the N-propetide of Type II collagen - participate in fiber formation. Yet other proteins - chondronectin,
fibronectin
, vitronectin and thrombospondin - take part in the interaction between the chondrocytes and the matrix. Cartilage oligomeric matrix protein (COMP) prevents the vascularization of the cartilage and, perhaps, is responsible for the repair process. The proteins known as Cart-1 and CEP-68 participate in chondrogenesis, while tenascin and Mgp are considered to be cartilage calcification inhibitors. Apart from the structural elements, chondrocytes produce substances that fulfill purely physiological functions: enzymes and cytokines. The enzymes - which include metalloproteinases, adamalysins, serine and cysteine proteases and their inhibitors - participate in cartilage matrix reconstruction. The cytokines - IL-1, TNF-alfa, IL-6,
IL-8
, and LIF - stimulate the chondrocytes to produce an increased amount of enzymes, while IL-4 inhibits this process. Human articular chondrocytes exibit the constitutive expression of class I molecules of the major histocompatibility complex (MHC), molecules regulating the activation of the complement, and after activation (e.g. under the influence of IFN-alfa, IL-1, TNF-a or in the course of arthritis), also MHC class II and ICAM-1 intracellular adhesion molecules. Numerous studies have shown that chondrocytes also have tissue-specific antigens, which induce the production of antibodies in patients with cartilage grafts, as well as those with rheumatoid arthritis and osteoarthritis. Some of these antibodies react with type II collagen, others are directed against other proteins i.e. anchorin CII and CH65. the role of these diverse molecules, which are present in cartilage cells and separated from the immune system by the matrix, remains unclear.
...
PMID:The morphology and selected biological properties of articular cartilage. 1798 77
Mechanical ventilation plays a central role in the pathogenesis of bronchopulmonary dysplasia. However, the mechanisms by which excessive stretch of fetal or neonatal type II epithelial cells contributes to lung injury are not well defined. In these investigations, isolated embryonic day 19 fetal rat type II epithelial cells were cultured on substrates coated with
fibronectin
and exposed to 5% or 20% cyclic stretch to simulate mechanical forces during lung development or lung injury, respectively. Twenty percent stretch of fetal type II epithelial cells increased necrosis, apoptosis, and proliferation compared with control, unstretched samples. By ELISA and real-time PCR (qRT-PCR), 20% stretch increased secretion of
IL-8
into the media and
IL-8
gene expression and inhibited IL-10 release. Interestingly, administration of recombinant IL-10 before 20% stretch did not affect cell lysis but significantly reduced apoptosis and
IL-8
release compared with stretched samples without IL-10. Collectively, our studies suggest that IL-10 may play an important role in protection of fetal type II epithelial cells from injury secondary to stretch.
...
PMID:Interleukin-10 protects cultured fetal rat type II epithelial cells from injury induced by mechanical stretch. 1806 56
Cytokines, such as granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin (IL)-8 attract neutrophils into inflammatory sites. During emigration from the blood neutrophils interact with extracellular matrix proteins such as
fibronectin
.
Fibronectin
provides beta2-integrin co-stimulation, allowing GM-CSF and
IL-8
to activate nuclear factor (NF)-kappaB, an effect that does not occur in suspension. We tested the hypothesis that exposure of mice to fever-like temperatures abrogates neutrophil recruitment and NF-kappaB activation in a mouse model of skin inflammation. Mice that were exposed to 40 degrees C for 1 hour showed strongly reduced GM-CSF- and
IL-8
-induced neutrophilic skin inflammation. In vitro heat exposure did not interfere with neutrophil adhesion or spreading on
fibronectin
but strongly inhibited migration toward both cytokines. Using specific inhibitors, we found that PI3-K/Akt was pivotal for neutrophil migration and that heat down-regulated this pathway. Furthermore, neutrophils on
fibronectin
showed abrogated NF-kappaB activation in response to GM-CSF and
IL-8
after heat. In vivo heat exposure of mice followed by ex vivo stimulation of isolated bone marrow neutrophils confirmed these results. Finally, less NF-kappaB activation was seen in the inflammatory lesions of mice exposed to fever-like temperatures as demonstrated by in situ hybridization for IkappaBalpha mRNA. These new findings suggest that heat may have anti-inflammatory effects in neutrophil-dependent inflammation.
...
PMID:Short-term heat exposure inhibits inflammation by abrogating recruitment of and nuclear factor-{kappa}B activation in neutrophils exposed to chemotactic cytokines. 1818 71
Fibroblast growth factors interact with appropriate endothelial cell (EC) surface receptors and initiate intracellular signal cascades, which participate in modulating blood vessel growth. EC, upon exposure to basic fibroblast growth factors (bFGFs) undergo profound functional alterations, which depend on their actual sensitivity and involve gene expression and de novo protein synthesis. We investigated the effects of bFGF on signaling pathways of EA.hy926 cells in different environments. EC were cultured under normal gravity (1 g) and simulated microgravity (micro g) using a three-dimensional (3D) clinostat. Microgravity induced early and late apoptosis, extracellular matrix proteins, endothelin-1 (ET-1) and TGF-beta(1) expression. Microgravity reduced eNOS mRNA within 24 h. Moreover, a six- to eightfold higher amount of IL-6 and
IL-8
was secreted within 24 h micro g. In addition, microgravity induced a duplication of NF-kappaB p50, while p65 was quadrupled. At 1 g, bFGF application (4 h) reduced ET-1, TGF-beta(1) and eNOS gene expression. After 24 h, bFGF enhanced
fibronectin
, VEGF, Flk-1, Flt-1, the release of IL-6,
IL-8
, and TGF-beta(1). Furthermore, bFGF promoted apoptosis, reduced NFkB p50, but enhanced NFkB p65. After 4 h micro g, bFGF decreased TGF-beta(1), eNOS, and ET-1 gene expression. After 24 h micro g, bFGF elevated
fibronectin
, Flk-1 and Flt-1 protein, and reduced IL-6 and
IL-8
compared with vehicle treated micro g cultures. In micro g, bFGF enhanced NF-KappaB p50 by 50%, Bax by 25% and attenuated p65, activation of caspase-3 and annexin V-positive cells. bFGF differently changes intracellular signals in ECs depending whether it is applied under microgravity or normal gravity conditions. In microgravity, bFGF contributes to protect the EC from apoptosis.
...
PMID:Effects of basic fibroblast growth factor on endothelial cells under conditions of simulated microgravity. 1825 36
Neutrophil directional migration in response to chemical gradients, also known as chemotaxis, is one of the key phenomena in the immune responses against bacterial infection. To better study neutrophils chemotaxis, several in vitro assays have been developed that replicate chemotactic gradients around neutrophils isolated from whole blood. One drawback for most of these assays is the lengthy processing of blood required for neutrophils isolation, which can alter the responsiveness of neutrophils compared to the in vivo conditions. To address this limitation, we have designed a microfluidic chip for chemotaxis studies which can use neutrophils isolated on the chip, directly from whole blood. We have tested three different cell adhesion molecules as substrates for neutrophil isolation (P-selectin, E-selectin and
fibronectin
) and found average capture efficiencies of 20-40 neutrophils/mm2 at optimized concentrations. Subsequent analysis of neutrophil migration in chemoattractant gradients of N-formyl-methyl-leucyl-phenylalanine (fMLP) or
Interleukin-8
(
IL-8
) shows higher average velocities over E-selectin as compared to the P-selectin. Our microfluidic assay uses just a drop of whole blood (<10 microL) for neutrophil isolation and provides a robust platform to perform chemotaxis assays in the competing environment of different chemokines.
...
PMID:Neutrophil migration assay from a drop of blood. 1902 68
Among proteases, metalloproteases are implicated in tissue remodeling, as shown in numerous diseases including allergy. ADAMs (A Disintegrin And Metalloprotease) metalloproteases are implicated in physiologic processes such as cytokine and growth factor shedding, cell migration, adhesion, or repulsion. Our aim was to measure ADAM-12 expression in airway epithelium and to define its role during the allergic response. To raise this question, we analyzed the ADAM-12 expression ex vivo after allergen exposure in patients with allergic rhinitis and in vitro in cultured primary human airway epithelial cells (AEC). Clones of BEAS-2B cells transfected with the full-length form of ADAM-12 were generated to study the consequences of ADAM-12 up-regulation on AEC function. After allergen challenge, a strong increase of ADAM-12 expression was observed in airway epithelium from patients with allergic rhinitis but not from control subjects. In contrast with the other HB-epidermal growth factor sheddases, ADAM-10 and -17, TNF-alpha in vitro increased the expression of ADAM-12 by AEC, an effect amplified by IL-4 and IL-13. Up-regulation of ADAM-12 in AEC increased the expression of alpha3 and alpha4 integrins and to the modulation of cell migration on
fibronectin
but not on collagen. Moreover, overexpression of ADAM-12 in BEAS-2B enhanced the secretion of CXCL1 and
CXCL8
and their capacity to recruit neutrophils. CD47 was strongly decreased by ADAM-12 overexpression, a process associated with a reduced adhesion of neutrophils. These effects were mainly dependent on epidermal growth factor receptor activation. In summary, ADAM-12 is produced during allergic reaction by AEC and might increase neutrophil recruitment within airway mucosa.
...
PMID:Role of A disintegrin and metalloprotease-12 in neutrophil recruitment induced by airway epithelium. 1921 76
The Staphylococcus aureus
fibronectin
(Fn) -binding protein A (FnBPA) is involved in bacterium-endothelium interactions which is one of the crucial events leading to infective endocarditis (IE). We previously showed that the sole expression of S. aureus FnBPA was sufficient to confer to non-invasive Lactococcus lactis bacteria the capacity to invade human endothelial cells (ECs) and to launch the typical endothelial proinflammatory and procoagulant responses that characterize IE. In the present study we further questioned whether these bacterium-EC interactions could be reproduced by single or combined FnBPA sub-domains (A, B, C or D) using a large library of truncated FnBPA constructs expressed in L. lactis. Significant invasion of cultured ECs was found for L. lactis expressing the FnBPA subdomains CD (aa 604-877) or A4(+16) (aa 432-559). Moreover, this correlates with the capacity of these fragments to elicit in vitro a marked increase in EC surface expression of both ICAM-1 and VCAM-1 and secretion of the
CXCL8
chemokine and finally to induce a tissue factor-dependent endothelial coagulation response. We thus conclude that (sub)domains of the staphylococcal FnBPA molecule that express Fn-binding modules, alone or in combination, are sufficient to evoke an endothelial proinflammatory as well as a procoagulant response and thus account for IE severity.
...
PMID:Contribution of (sub)domains of Staphylococcus aureus fibronectin-binding protein to the proinflammatory and procoagulant response of human vascular endothelial cells. 1927 11
Moraxella catarrhalis, a major nasopharyngeal pathogen of the human respiratory tract, is exposed to rapid and prolonged downshifts of environmental temperature when humans breathe cold air. In the present study, we show that a 26 degrees C cold shock up-regulates the expression of UspA1, a major adhesin and putative virulence factor of M. catarrhalis, by prolonging messenger RNA half-life. Cold shock promotes M. catarrhalis adherence to upper respiratory tract cells via enhanced binding to
fibronectin
, an extracellular matrix component that mediates bacterial attachment. Exposure of M. catarrhalis to 26 degrees C increases the outer membrane protein-mediated release of the proinflammatory cytokine
interleukin 8
in pharyngeal epithelial cells. Furthermore, cold shock at 26 degrees C enhances the binding of salivary immunoglobulin A on the surface of M. catarrhalis. These data indicate that cold shock at a physiologically relevant temperature of 26 degrees C affects the nasopharyngeal host-pathogen interaction and may contribute to M. catarrhalis virulence.
...
PMID:Physiologic cold shock increases adherence of Moraxella catarrhalis to and secretion of interleukin 8 in human upper respiratory tract epithelial cells. 1983 76
Thymic stromal lymphopoietin (TSLP) is highly expressed by bronchial epithelial cells and skin keratinocytes in allergic diseases. TSLP acts as a master switch for allergic inflammation through the activation of dendritic cells and mast cells for initiating inflammatory type 2 T-helper lymphocyte responses. To elucidate the immunological cascades of epithelium/keratinocyte-eosinophil-mediated allergic inflammation, we examined the modulating effects of TSLP on human eosinophils. Expression of TSLP receptor complex was detected by RT-PCR, flow cytometry, and Western blot. Adhesion molecules, cytokine, and chemokines were quantitated by flow cytometry or ELISA. Intracellular signal transduction molecules were measured by Western blot and flow cytometry. We observed that human eosinophils constitutively expressed functional heterodimeric TSLP receptor complex comprising TSLP-binding chain TSLPR and IL-7Ralpha chain. TSLP could significantly delay eosinophil apoptosis, up-regulate cell surface expression of adhesion molecule CD18 and intercellular adhesion molecule-1, but down-regulate L-selectin, enhance eosinophil adhesion onto
fibronectin
, and induce the release of inflammatory cytokine IL-6 and chemokines
CXCL8
, CXCL1, and CCL2 (all P < 0.05). All these effects were concentration dependent and TSLP specific. TSLP regulated the above effects through the activation of extracellular signal-regulated protein kinase, p38 mitogen-activated protein kinase, and NF-kappaB signaling pathway, but not signal transducer and activator of transcription 5 and 3, which were usually activated in other effector cells upon TSLP stimulation. Collectively, the above findings elucidate the proallergic mechanisms of TSLP via the activation of distinct intracellular signaling pathways in eosinophils.
...
PMID:Thymic stromal lymphopoietin induces chemotactic and prosurvival effects in eosinophils: implications in allergic inflammation. 1984 4
The function of neutrophils in the inflammatory response is modulated by contact with ECM proteins. We have now investigated the effect of collagen type I on secretion of the cytokine
IL-8
by human neutrophils in vitro. Collagen type I inhibited the secretion of
IL-8
from neutrophils maintained under basal conditions or stimulated with fMLF. This effect was accompanied by down-regulation of
IL-8
mRNA, and it appeared to be specific to collagen type I among ECM proteins, in that it was not observed with
fibronectin
or laminin. The inhibitory effect of collagen type I on
IL-8
secretion was dependent on collagen concentration and cell density. It was also abolished in the presence of antibodies to integrin alpha2beta1 but was not affected by antibodies to integrin alpha5beta1 or beta4. Our results thus suggest that collagen type I inhibits the secretion of
IL-8
by human neutrophils in a selective manner and that this effect is mediated by the interaction of collagen with integrin alpha2beta1.
...
PMID:Integrin-mediated inhibition of interleukin-8 secretion from human neutrophils by collagen type I. 1999 41
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