Effects Of FKN On P38MAPK Activation And NF-κB Expression In Human PBMC And The Role Of Syk

Background:Recent research has shown that inflammation plays a key role in atherogenesis. CX3CL1 (fractalkine), the only member of the subclass of chemokines, is a known chemotactic factor for monocytes /macrophages as well as NK cells and T lymphocytes. In several pathologies, excessive production of CX3CL1 at specific sites leads primarily to monocyte/macrophage recruitment, which causes tissue and vascular damage. TNF-αand MMPS are prototypic inflammatory mediators produced by various cell types, including mast cells, macrophages, lymphocytes, and fibroblasts. Elevated serum levels of TNF-αand MMPS are associated with the pathophysiology of atherogenesis.Despite their clinical relevance, the mechanisms underlying monocyte/macrophage chemotaxis to CX3CL1 remain poorly documented. The present report addresses this issue and identifies cell signaling crucial for this process. Using the MonoMac6 cell line in response to soluble CX3CL1, Cambien et al. have identified PI3K and members of the MAPK family, ERK1/2, p38MAPK, and JNK1, as signaling components required for cell adhesion to fibronectin. Activation of Src and phosphorylation of Syk tyrosine kinases downstream of CX3CR1 have also been reported, although a putative functional role for these enzymes in any CX3CL1-induced cell response has not been investigated.Syk is a non-receptor protein tyrosine kinase, it is located in the cytoplasm, with two SH-2 domain and an SH-1 domain. Syk can be expressed in all hematopoietic cells . Jabril-Cuenod, etc. [5] reported, Syk and Ras-Raf-MAPK signaling cascade is closely related to some process. Mitogen-activated protein kinase (MAPK) cascade signal transduction pathway exists in all eukaryotes, in the process of signal transduction it occupys a very important position, it was considered closely collected with cell proliferation, differentiation or apoptosis is closely related to regulation of cell signal transduction pathway, extracellular signal is caused by cell proliferation, differentiation, such as the common means of nuclear reaction or aggregation points. P38 is an important MAPK family members, the pilot confirmed that for the MAPK family of p38-mediated inflammation is reflected as the most important factor.Nuclear transcription factor kappaB (nuclear factor-kappaB, NF-кB),founded in 1986, is a polypeptide complex subunit composition of the protein family, widespread in the eukaryotes. as the hub of Signal transduction pathway, it is closely related to the immune, tumorigenesis, development, regulation of apoptosis. At the same time, NF-кB as a transcription factor, present in monocytes, vascular endothelial and vascular smooth muscle cells in the regulation of cell gene transcription.as one of the key factors,it is involved in regulation and controlling of many inflammatory response and the expression of genes .Objective:(1) Effects of FKN on p38MAPK activation and NF-КB Expression (2) to study the relevance of the effect of FKN on expression of the NF-КB in mononuclear cells in mononuclear cells and the p38MAPK signal transduction pathway; (3), the effects of spleen tyrosine kinase (Syk ) in the Effects of FKN on p38MAPK activation and NF-КB Expression.Methods:(1)Peripheral blood monocytes(PBMC) were isolated from fresh blood of healthy volunteers by Ficoll-Paque gradient centrifugation;(2) The extractive PBMC were div-ided into four groups :control group,FKN group, FKN + p38MAPK inhibitor (SB203580) group, FKN + Syk inhibitor (piceatannol) group..Each group was divided into two shares. an application of Western blot (Western blot) methods for semi-quantitative p38MAPK phosphorylation; a used immunoblotting (Western blot) was detected in PBMC culture medium NF-КB content.Result: (1)The expressions of p38MAPK and NF-КB of FKN group was increased compared with the control group . (2)The expressions of p38MAPK and NF-КB of FKN + p38MAPK inhibitor (SB203580) groupwere decreased compared with the FKN group.(3)The expression of p38MAPK of FKN + Syk inhibitor (piceatannol) group was decreased compared with the FKN group.(4)The expressions of NF-КB of FKN+Piceatannol(Syk inhibitor) group were increased compared with the FKN group.Conclusion: (1)FKN/CX3CR1 increases the expression of NF-КB in Peripheral blood monocytes as one of the mechanism of contributing to the progression of atherosclerosis. (2)p38MAPK plays an important role during the expression of NF-КB in FKN-induced. FKN/CX3CR1 probably initiates intracellular signal transduction mechanism through the process that FKN/CX3CR1 activates the p38MAPK and then improves the expression of NF-КB. (3)Spleen tyrosine kinase (Syk) plays an important role during the process that Peripheral blood monocytes synthesize p38MAPK induced by FKN/CX3CR1. FKN/CX3CR1 perhaps initiates intracellular signal conductive mechanism through the process that FKN/CX3CR1 activates the p38MAPK by Syk and then improves the expression of NF-КB.