Claudin-1 functions as a major constituent of the limited junction complexes and regulate the permeability of epithelia, which takes on an essential part in the formation of impermeable barriers (37,38). become reversed in the presence of SR-A1 antibody. The induction of cleaved caspase-3 and claudin-1 in Caco-2 cells was also suppressed when Clofibric Acid SR-A1 antibody pre-treatment. Conclusions Pre-treatment with SR-A1 antibody can inhibit inflammatory response in LPS-induced macrophages inside a NF-B dependent Clofibric Acid manner. Pre-treatment with SR-A1 antibody also inhibits M1 phenotype manifestation of macrophages, and attenuates the pro-apoptotic effect on colonic epithelial cells and disruption of intestinal barrier integrity induced by macrophages. LPS group) (NF-B p-p56 manifestation was mainly found in the cell nuclei, and NF-B p-p56 manifestation was upregulated after LPS activation (P 0.05), which however was significantly inhibited in the presence of SR-A1 antibody pre-treatment. These findings show pre-treatment with SR-A1 antibody may up-regulate anti-inflammatory cytokines and down-regulate inflammatory cytokines secreted by Natural264.7 cells inside a NF-B pathway dependent manner. Open in a separate window Number 2 NF-B p-p65 manifestation in Natural264.7 cells with different treatments. NF-B p-p65 manifestation was determined Clofibric Acid by immunofluorescence staining. Nuclei were stained with DAPI, and green transmission displayed NF-B p-p65 (100). Data are offered as the mean SEM (*, P 0.05 the expression of p-ERK1/2, JNK and p-JNK increased significantly after LPS stimulation (P 0.05). However, only the improved p-JNK expression could be inhibited in the presence of SR-A1 antibody (P 0.05 LPS group). We also recognized the manifestation of SR-A1 by Western blotting, which indicated that SR-A1 was present in Natural 264.7 cells. Open in a separate window Number 3 Manifestation of proliferation related protein in Natural264.7 cells with different treatments. Protein expression was recognized by Western blotting. Data are offered as mean SEM (*, P 0.05 LPS group) (untreated cells experienced homogeneous nuclei, but Caco-2 cells co-cultured with RAW264.7 cells with LPS and IFN- treatment exhibited more condensed nuclei and apoptotic bodies after DAPI staining. SR-A1 antibody pre-treatment could attenuate the pro-apoptotic effect of macrophages on Caco-2 cells, which was shown by less condensed nuclei and less apoptotic body in cells. Open in a separate window Number 6 SR-A1 antibody pre-treatment attenuates the pro-apoptotic effect of Natural264.7 cells on Caco-2 cells in the co-culture system. Caco-2 in different groups were stained with DAPI and photographed under a ?uorescence microscope (100). Red arrow: condensed nuclei and apoptotic body in Caco-2 cells. Data are offered as mean SEM (*, P 0.05 LPS + IFN- group). SEM, standard error of the mean; LPS, lipopolysaccharide; SR-A1, A1 scavenger receptor. Conversation As the first-line defense in the lamina propria of mucosa, intestinal macrophages contribute to the integrity of intestinal barrier. On one hand, intestinal macrophages can get rid of invading pathogens though secreting cytokines and chemokines; on the other hand, intestinal macrophages are tolerant toward commensal microbiota though down-regulating acknowledgement receptors (20,21). Macrophages have different subtypes that can orchestrate or counteract swelling, including pro-in?ammatory M1 macrophages and anti-in?ammatory M2 macrophages. Macrophages of different phenotypes have been investigated in many inflammation-associated diseases, including IBD. In CD individuals, intestinal macrophages, especially a large number of CD68+ macrophages, usually migrate through the thickened mucosa to the submucosa. In UC individuals, macrophages usually infiltrate the intestinal mucous coating (22,23). However, the exact mechanism underlying the part of human being macrophages in the pathogenesis of IBD is still poorly understood. In order to protect from the invasion of pathogens in the process of mucosal immune, macrophages secrete a variety of cytokines and exert strong anti-bactericidal effect via PRRs. SR-A1, as one of PRRs, is definitely a type II membrane glycoprotein and may form homotrimers, including in the progression of innate immunity, cell apoptosis and proliferation (24). SR-A1 is mainly indicated in macrophages, monocytes, dendritic cells, clean muscle mass cells and endothelial cells, and may form complexes with additional PRRS, exerting synergistic effects within the inflammatory response (25,26). Early studies show SR-A1 implicates in the pathogenesis of atherosclerosis, by mediating endocytotic effect of foam cells on RGS5 low-density lipoprotein (27). Upon the cytomegalovirus exposure, SR-A1, coordinating with Toll-like receptor 3/9, may induce the THP-1 cells to express IL-12p35, IFN- and TNF, triggering pro-inflammatory response (28). In the present study, the mRNA manifestation of.