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MCP-1 Secretion (mcp-1 + secretion)
Selected AbstractsCobalt ions induce chemokine secretion in primary human osteoblasts,JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 7 2009J.M. Queally Abstract Chemokines are major regulators of the inflammatory response and have been shown to play an important role in periprosthetic osteolysis. Titanium particles have previously been shown to induce IL-8 and MCP-1 secretion in osteoblasts. These chemokines result in the chemotaxis and activation of neutrophils and macrophages, respectively. Despite a resurgence in the use of cobalt-chromium-molybdenum alloys in metal-on-metal arthroplasty, cobalt and chromium ion toxicity in the periprosthetic area has been insufficiently studied. In this study we investigate the in vitro effect of cobalt ions on primary human osteoblast activity. We demonstrate that cobalt ions rapidly induce the protein secretion of IL-8 and MCP-1 in primary human osteoblasts. This elevated chemokine secretion is preceded by an increase in the transcription of the corresponding chemokine gene. Using a Transwell migration chemotaxis assay we also demonstrate that the chemokines secreted are capable of inducing neutrophil and macrophage migration. Furthermore, cobalt ions significantly inhibit osteoblast function as demonstrated by reduced alkaline phosphatase activity and calcium deposition. In aggregate these data demonstrate that cobalt ions can activate transcription of the chemokine genes IL-8 and MCP-1 in primary human osteoblasts. Cobalt ions are not benign and may play an important role in the pathogenesis of osteolysis by suppressing osteoblast function and stimulating the production and secretion of chemokines that attract inflammatory and osteoclastic cells to the periprosthetic area. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 855,864, 2009 [source] Hepatocyte growth factor induction of macrophage chemoattractant protein-1 and osteophyte-inducing factors in osteoarthritisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2007Berno Dankbar Abstract In osteoarthritis (OA), hepatocyte growth factor (HGF) is supposed to play a role in cartilage repair. Because the development of osteophytes is a major characteristic of OA and thought to be part of an attempted repair process, the purpose of this study was to determine whether HGF may be involved in osteophyte formation. HGF levels in synovial fluids from 41 patients assessed by enzyme immunosorbant assay were correlated with disease severity and osteophyte formation, evaluated by anteroposterior weight-bearing radiographs. Detection of HGF, c-Met, and CD68 in cartilage and synovial tissues was assessed by immunohistochemistry. Effects of HGF on the secretion of TGF-,1 and BMP-2 by chondrocytes, fibroblast-like synovial cells (FLS), and macrophages as well as HGF-induced secretion of MCP-1 by FLS and chondrocytes were determined by ELISA. HGF was detected in all synovial fluids and concentrations correlated highly with disease severity and osteophyte formation (p,<,0.001). Immunohistochemistry revealed weak synovial staining for HGF, whereas increasing numbers of HGF expressing chondrocytes were detected depending on disease severity. In addition, an increased number of macrophages in synovial specimens was observed, which was likewise severity dependent. In a series of subsequent in vitro studies, HGF remarkable induced MCP-1 secretion by FLS in a dose-dependent manner. No effect on TGF-,1 and BMP-2 secretion by FLS and chondrocytes was evident upon HGF stimulation, whereas secretion of these growth factors by PMA-differentiated THP-1 cells was significantly increased by HGF. The results indicate that HGF may facilitate osteophyte development by promoting MCP-1-mediated entry of monocytes/macrophages into the OA-affected joint and/or by stimulating macrophage-derived growth factors. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:569,577, 2007 [source] Effects of interleukin 18 on injury and activation of human proximal tubular epithelial cellsNEPHROLOGY, Issue 1 2007DONG LIANG SUMMARY: Background/Aims: Injury and activation of tubular proximal epithelial cells (TEC) play central roles in renal tubulointerstitial fibrosis (TIF), but its mechanisms remain obscure. Interleukin 18 (IL-18) is overproduced during chronic kidney diseases (CKD), but how IL-18 affects the biological behaviour of TEC is not clear. The aim of the present study is to reveal the role of IL-18 in renal TIF. Methods: The expressions of IL-18 and IL-18 receptor in TEC were detected by immunohistochemical staining in vivo and by reverse transcriptase polymerase chain reaction (RT-PCR) in vitro. TEC line (HK-2 cells) were incubated without or with IL-18. Cell proliferation and cell cycle were evaluated by methyl thiazolyl tetrazolium assay and flow cytometric analysis, respectively. Cell apoptosis was assessed by Hoechst 33258 staining. Expression of ,-smooth muscle actin was evaluated by RT-PCR, immunocytochemical staining and flow cytometric analysis, respectively. Type I collagen, fibronectin, MCP-1 and RANTES in cultured supernatants were measured by enzyme-linked immunosorbent assay. Results: IL-18 expression in TEC increased significantly in CKD state. IL-18 receptor was constitutively expressed in normal proximal TEC, and its expression increased strongly in CKD state. Proliferation and cell cycle of HK-2 cells were not affected by IL-18. Cell apoptosis, ,-smooth muscle actin expression, type I collagen and fibronectin production as well as MCP-1 secretion were promoted by IL-18 in dosage- and/or time-dependent manners, but RANTES secretion was not affected. Conclusion: IL-18 may play a crucial role in the process of TIF by promoting TEC injury and activation, and could be a target of the therapeutic approaches against TIF. [source] Atorvastatin Decreases C-Reactive Protein-Induced Inflammatory Response in Pulmonary Artery Smooth Muscle Cells by Inhibiting Nuclear Factor-,B PathwayCARDIOVASCULAR THERAPEUTICS, Issue 1 2010Jie Li C-reactive protein (CRP) is well-known inflammatory marker, and recognized as a risk predictor of pulmonary arterial diseases. Although statins have a beneficial effect in animal models and patients with pulmonary arterial hypertension (PAH), the underlying mechanisms of their actions have less been investigated. The aims of this study was to examined the effects of CRP on expressions of interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1), and the possible mechanisms of atorvastatin on CRP-induced IL-6 and MCP-1 production in cultured human pulmonary artery smooth muscle cells (PASMCs). In a preliminary study, the human PASMCs were stimulated by a variety of concentrations of CRP (5,200 ,g/mL) at different time points (0, 3, 6, 9, 12, 18 and 24 h) for the purpose of determining the dose- and time-dependent effects of CRP on inflammatory response of the cells. Then, the cells were pre-incubated for 2 h with atorvastatin (0.1,10 ,mol/L) in the presence of CRP. The supernatant levels of both IL-6 and MCP-1 secretion were examined by ELISA. The cellular mRNA expressions of IL-6 and MCP-1 and nuclear factor-,B (NF-,B) activity were determined by real-time reverse transcription and polymerase chain reaction (RT-PCR) and electrophoretic mobility shift assay (EMSA), respectively. CRP resulted in elevated IL-6 and MCP-1 secretion and mRNA expression in a dose- and time-dependent manner. In addition, CRP also significantly activated the NF-,B pathway. Preincubation with 0.1,10 ,mol/L of atorvastatin significantly decreased the secretions of IL-6 and MCP-1 induced by CRP. Moreover, 10 ,mol/L of atorvastatin completely abrogated CRP-induced increase in IL-6 and MCP-1 by attenuating the activation of NF-,B. The present study demonstrated that inhibiting effect of atorvastatin on CRP-induced inflammatory response in cultured PASMCs was associated with NF-,B pathway. This pathway might represent a promising target for controlling CRP-induced inflammatory response in pulmonary arterial diseases. [source] | ||||||||||