interleukin-8 and Hypertrophy

We developed a novel multi-torsional mechanical stretch stress loading device for ligamentum flavum cells and evaluated its influence on the development of ligamentum flavum hypertrophy, a common cause of lumbar spinal canal stenosis.. Stretch strength of the device was optimized by applying 5% and 15% MSS loads for 24, 48, and 72 h. A cytotoxicity assay of human ligamentum flavum cells was performed and the results were compared to control (0% stress). Inflammatory markers (interleukin [IL]-6, IL-8), vascular endothelial growth factor [VEGF], and extracellular matrix (ECM)-regulating cytokines (matrix metalloproteinase [MMP]-1, MMP-3 and MMP-9, and tissue inhibitor of metalloproteinase [TIMP]-1 and TIMP-2) were quantified via enzyme-linked immunosorbent assay.. Using our multi-torsional mechanical stretch stress loading device, 5% stress for 24 hour was optimal for ligamentum flavum cells. Under this condition, the IL-6 and IL-8 levels, VEGF level, and MMP-1, MMP-3, and TIMP-2 were significantly increased, compared to the control.. Using the novel multi-torsional mechanical stretch stress loading device we confirmed that, mechanical stress enhances the production of inflammatory cytokines and angiogenic factors, and altered the expression of ECM-regulating enzymes, possibly triggering ligamentum flavum hypertrophy.

Topics: Cytokines; Humans; Hypertrophy; Interleukin-6; Interleukin-8; Ligamentum Flavum; Lumbar Vertebrae; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Spinal Stenosis; Stress, Mechanical; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-2; Vascular Endothelial Growth Factor A

To explore how systemic factors that modify knee osteoarthritis risk are connected to 'whole-joint' structural changes by evaluating the effects of high-fat diet and wheel running exercise on synovial fluid (SF) metabolomics.. Male mice were fed a defined control or high-fat (60% kcal fat) diet from 6 to 52 weeks of age, and half the animals were housed with running wheels from 26 to 52 weeks of age (n = 9-13 per group). Joint tissue structure and osteoarthritis pathology were evaluated by histology and micro-computed tomography. Systemic metabolic and inflammatory changes were evaluated by body composition, glucose tolerance testing, and serum biomarkers. SF metabolites were analyzed by high performance-liquid chromatography mass spectrometry. We built correlation-based network models to evaluate the connectivity between systemic and local metabolic biomarkers and osteoarthritis structural pathology within each experimental group.. High-fat diet caused moderate osteoarthritis, including cartilage pathology, synovitis and increased subchondral bone density. In contrast, voluntary exercise had a negligible effect on these joint structure components. 1,412 SF metabolite features were detected, with high-fat sedentary mice being the most distinct. Diet and activity uniquely altered SF metabolites attributed to amino acids, lipids, and steroids. Notably, high-fat diet increased network connections to systemic biomarkers such as interleukin-1β and glucose intolerance. In contrast, exercise increased local joint-level network connections, especially among subchondral bone features and SF metabolites.. Network mapping showed that obesity strengthened SF metabolite links to blood glucose and inflammation, whereas exercise strengthened SF metabolite links to subchondral bone structure.

Topics: Animals; Biomarkers; Chemokine CCL2; Chondrocytes; Diet, High-Fat; Glucose Intolerance; Hypertrophy; Interleukin-10; Interleukin-1beta; Interleukin-8; Leptin; Metabolomics; Mice, Inbred C57BL; Osteoarthritis; Physical Conditioning, Animal; Stifle; Synovial Fluid; X-Ray Microtomography

Defensins and chemokines are an essential part of the immune response mechanisms in the head and neck mucosa. This work investigates their correlation and their expression pattern in tonsillar disease. Forty-four tonsil tissue samples were obtained from patients who underwent tonsillectomy between 1998 and 1999 for chronic tonsillitis with (n =9) and without (n =25) inflammatory infiltrates and hyperplasia of the tonsil (n =10). Defensin (hBD-1, hBD-2, HNP-1 and HNP-4) and chemokine (RANTES, eotaxin, eotaxin-2, MCP-3, MCP-4 and IL-8) mRNA expressions were analyzed by SQRT-PCR. HNP-4 and eotaxin-2 expressions were positively correlated (P <0.05) in the acute tonsillitis group. HBD-2 and MCP-3 expressions were positively correlated in the hyperplastic tonsils group. Within all groups together, HNP-4 and RANTES expressions were highly positively correlated (P <0.01), and HNP-1 and hBD-2 were positively correlated with IL-8 expressions. Immunohistochemistry demonstrated eotaxin-1 as well as IL-8 production to be predominantly located within the lymphoid follicles and submucosa. RANTES production was shown in the epithelial lining and perivascular tissue. The expression of hBD-1 and hBD-2 was limited to the epithelial lining. Our data support an association between the innate and acquired immune systems on the defensin-chemokine level. The finding of positively correlated hBD-2 and IL-8 expression is biologically relevant because of the proximity of hBD-2 (epithelium) and IL-8 (submucosa) release, as well as the synergistic support of the Th1 system. In addition, our data suggest RANTES as a first-line mediator of perivascular leukocyte recruitment.

Topics: alpha-Defensins; Chemokine CCL11; Chemokine CCL5; Chemokines; Chemokines, CC; Chronic Disease; Defensins; Humans; Hypertrophy; Immunohistochemistry; Interleukin-8; Palatine Tonsil; Polymerase Chain Reaction; Tonsillitis

The proinflammatory chemokine interleukin-8 (IL-8) induces chondrocyte hypertrophy. Moreover, chondrocyte hypertrophy develops in situ in osteoarthritic (OA) articular cartilage and promotes dysregulated matrix repair and calcification. Growth plate chondrocyte hypertrophy is associated with expression of the type III sodium-dependent inorganic phosphate (Pi) cotransporter phosphate transporter/retrovirus receptor 1 (PiT-1). This study was undertaken to test the hypothesis that IL-8 promotes chondrocyte hypertrophy by modulating chondrocyte PiT-1 expression and sodium-dependent Pi uptake, and to assess differential roles in this activity.. The selective IL-8 receptor CXCR1 and the promiscuous chemokine receptor CXCR2 were used. Human knee OA cartilage, cultured normal bovine knee chondrocytes, and immortalized human articular chondrocytic CH-8 cells were transfected with CXCR1/CXCR2 chimeric receptors in which the 40-amino acid C-terminal cytosolic tail domains were swapped and site mutants of a CXCR1-specific region were generated.. Up-regulated PiT-1 expression was detected in OA cartilage. IL-8, but not IL-1 or the CXCR2 ligand growth-related oncogene alpha, induced PiT-1 expression and increased sodium-dependent Pi uptake by >40% in chondrocytes. The sodium/phosphate cotransport inhibitor phosphonoformic acid blocked IL-8-induced chondrocyte hypertrophic differentiation. Signaling mediated by kinase Pyk-2 was essential for IL-8 induction of PitT-1 expression and Pi uptake. Signaling through the TSYT(346-349) region of the CXCR1 cytosolic tail, a region divergent from the CXCR2 cytosolic tail, was essential for IL-8 to induce Pi uptake.. Our results link low-grade IL-8-mediated cartilaginous inflammation in OA to altered chondrocyte differentiation and disease progression through PiT-1 expression and sodium-dependent Pi uptake mediated by CXCR1 signaling.

Topics: Cartilage, Articular; Cell Differentiation; Cells, Cultured; Chondrocytes; Focal Adhesion Kinase 2; Humans; Hypertrophy; Interleukin-8; Osteoarthritis; Phosphate Transport Proteins; Phosphates; Protein-Tyrosine Kinases; Receptors, Interleukin-8A; Recombinant Proteins; Sodium; Up-Regulation

Foci of chondrocyte hypertrophy that commonly develop in osteoarthritic (OA) cartilage can promote dysregulated matrix repair and pathologic calcification in OA. The closely related chemokines IL-8/CXCL8 and growth-related oncogene alpha (GROalpha)/CXCL1 and their receptors are up-regulated in OA cartilage chondrocytes. Because these chemokines regulate leukocyte activation through p38 mitogen-activated protein kinase signaling, a pathway implicated in chondrocyte hypertrophic differentiation, we tested whether IL-8 and GROalpha promote chondrocyte hypertrophy. We observed that normal human and bovine primary articular chondrocytes expressed both IL-8Rs (CXCR1, CXCR2). IL-8 and the selective CXCR2 ligand GROalpha (10 ng/ml) induced tissue inhibitor of metalloproteinase-3 expression, markers of hypertrophy (type X collagen and MMP-13 expression, alkaline phosphatase activity), as well as matrix calcification. IL-8 and the selective CXCR2 ligand GROalpha also induced increased transamidation activity of chondrocyte transglutaminases (TGs), enzymes up-regulated in chondrocyte hypertrophy that have the potential to modulate differentiation and calcification. Under these conditions, p38 mitogen-activated protein kinase pathway signaling mediated induction of both type X collagen and TG activity. Studies using mouse knee chondrocytes lacking one of the two known articular chondrocyte-expressed TG isoenzymes (TG2) demonstrated that TG2 was essential for murine GROalpha homologue KC-induced TG activity and critically mediated induction by KC of type X collagen, matrix metalloproteinase-13, alkaline phosphatase, and calcification. In conclusion, IL-8 and GROalpha induce articular chondrocyte hypertrophy and calcification through p38 and TG2. Our results suggest a novel linkage between inflammation and altered differentiation of articular chondrocytes. Furthermore, CXCR2 and TG2 may be sites for intervention in the pathogenesis of OA.

Topics: Animals; Cartilage, Articular; Cattle; Cell Differentiation; Cells, Cultured; Chemokine CXCL1; Chemokines; Chemokines, CXC; Chemotactic Factors; Chondrocytes; Cytokines; GTP-Binding Proteins; Humans; Hypertrophy; Intercellular Signaling Peptides and Proteins; Interleukin-8; Ligands; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Protein Glutamine gamma Glutamyltransferase 2; Transglutaminases

Implantation of abraded polyethylene intramammary devices (IMD) for six months in the mammary glands of cows resulted in macroscopic and microscopic pathological changes in udder tissue. These changes were characterised by hyperplasia and metaplasia of the epithelial cells and hypertrophy of the subepithelial connective tissue examined by light and electron microscopy (EM). Quarters containing IMDs also had increased numbers of neutrophils and macrophages in the subepithelial stroma compared with control quarters. IMDs recovered six months after implantation were shown by transmission and scanning EM to be covered with plaque and cells. These cells were mainly macrophages, although other leucocytes were also present. In vitro culture of recovered IMDs in the presence of lipopolysaccharide resulted in the release of neutrophil chemotactic factor, or factors, and interleukin-1. Some quarters with IMDs also had concurrent infections at the time of slaughter. In these cases both the pathological changes seen in the tissues and the release of soluble mediators following in vitro culture of the IMDs were significantly increased compared with sterile quarters containing IMD.

Topics: Animals; Cattle; Cattle Diseases; Chemotactic Factors; Epithelium; Female; Hyperplasia; Hypertrophy; Interleukin-1; Interleukin-2; Interleukin-8; Interleukins; Mammary Glands, Animal; Metaplasia; Microscopy, Electron; Neutrophils; Prostheses and Implants