Luteolin, a flavonoid found in high concentrations in celery and green pepper, has been shown to reduce production of proinflammatory mediators in LPS-stimulated macrophages, fibroblasts, and intestinal epithelial cells. Because excessive production of proinflammatory cytokines by activated brain microglia can cause behavioral pathology and neurodegeneration, we sought to determine whether luteolin also regulates microglial cell production of a prototypic inflammatory cytokine, IL-6. Pretreatment of primary murine microlgia and BV-2 microglial cells with luteolin inhibited LPS-stimulated IL-6 production at both the mRNA and protein levels. To determine how luteolin inhibited IL-6 production in microglia, EMSAs were performed to establish the effects of luteolin on LPS-induced binding of transcription factors to the NF-B and activator protein-1 (AP-1) sites on the IL-6 promoter. Whereas luteolin had no effect on the LPS-induced increase in NF-B DNA binding activity, it markedly reduced AP-1 transcription factor binding activity. Consistent with this finding, luteolin did not inhibit LPS-induced degradation of I B-␣ but inhibited JNK phosphorylation. To determine whether luteolin might have similar effects in vivo, mice were provided drinking water supplemented with luteolin for 21 days and then they were injected i.p. with LPS. Luteolin consumption reduced LPS-induced IL-6 in plasma 4 h after injection. Furthermore, luteolin decreased the induction of IL-6 mRNA by LPS in hippocampus but not in the cortex or cerebellum. Taken together, these data suggest luteolin inhibits LPS-induced IL-6 production in the brain by inhibiting the JNK signaling pathway and activation of AP-1 in microglia. Thus, luteolin may be useful for mitigating neuroinflammation.cytokines ͉ flavonoids ͉ MAPK ͉ brain ͉ neuroinflammation

Collectins are a family of C‐type lectins with two characteristic structures, collagen like domains and carbohydrate recognition domains. They recognize carbohydrate antigens on microorganisms and act as host‐defense. Here we report the cloning and characterization of a novel collectin CL‐K1. RT‐PCR analyses showed CL‐K1 mRNA is present in all organs. The deduced amino acid sequence and the data from immunostaining of CL‐K1 cDNA expressing CHO cells revealed that CL‐K1 is expressed as a secreted protein. CL‐K1 is found in blood by immunoblotting and partial amino acid analyses. CL‐K1 showed Ca2+‐dependent sugar binding activity of fucose and weakly mannose but not N‐acetyl‐galactosamine, N‐acetyl‐glucosamine, or maltose, though mannose‐binding lectin (MBL) containing similar amino acid motif. CL‐K1 can recognize specially several bacterial saccharides due to specific sugar‐binding character. Elucidation of the role of two ancestor collectins of CL‐K1 and CL‐L1 could lead to see the biological function of collectin family.

A dysregulated overexpression of inflammatory mediators by microglia may facilitate cognitive aging and neurodegeneration. Considerable evidence suggests the flavonoid luteolin has antiinflammatory effects, but its ability to inhibit microglia, reduce inflammatory mediators, and improve hippocampal-dependent learning and memory in aged mice is unknown. In initial studies, pretreatment of BV-2 microglia with luteolin inhibited the induction of inflammatory genes and the release of inflammatory mediators after lipopolysaccharide (LPS) stimulation. Supernatants from LPS-stimulated microglia caused discernible death in Neuro.2a cells. However, treating microglia with luteolin prior to LPS reduced neuronal cell death caused by conditioned supernatants, indicating luteolin was neuroprotective. In subsequent studies, adult (3-6 mo) and aged (22-24 mo) mice were fed control or luteolin (20 mg/d)-supplemented diet for 4 wk and spatial working memory was assessed as were several inflammatory markers in the hippocampus. Aged mice fed control diet exhibited deficits in spatial working memory and expression of inflammatory markers in the hippocampus indicative of increased microglial cell activity. Luteolin consumption improved spatial working memory and restored expression of inflammatory markers in the hippocampus compared with that of young adults. Luteolin did not affect either spatial working memory or inflammatory markers in young adults. Taken together, the current findings suggest dietary luteolin enhanced spatial working memory by mitigating microglial-associated inflammation in the hippocampus. Therefore, luteolin consumption may be beneficial in preventing or treating conditions involving increased microglial cell activity and inflammation.

This study demonstrates that consumption of cocoa powder by pigs can contribute to gut health by enhancing the abundance ofLactobacillusandBifidobacteriumspecies and modulating markers of localized intestinal immunity.

The number of older adults with HIV-1 disease is increasing but little is known about how age influences behavioral deficits associated with HIV-1 infection. The purpose of this study was to determine in a murine model if aging influenced sickness behavior following central injection of HIV-1 gp120. In initial studies, behavioral deficits induced by acute and repeated intracerebroventricular (ICV) injection of gp120 were greater in aged mice than in adults. Furthermore, repeated ICV injection of gp120 increased hippocampal levels of IL-1β and IL-6 mRNA in aged mice but not in adults. To determine if IL-6, which is elevated in aged brain, affects expression of the gp120-binding target, CCR5, microglia (BV-2 cell line) were incubated with increasing concentrations of IL-6. Cell surface expression of CCR5 was increased by IL-6 in a dosedependent manner. Additionally, IL-6 increased gp120-dependent chemotaxis. These results suggest that aging increases the sensitivity of mice to behavioral deficits caused by ICV gp120, perhaps by increasing expression of CCR5 and augmenting production of cytokines.

No abstract

Ossabaw pigs manifested a dyslipidemic and inflammatory profile accompanied by early-stage atherosclerosis when fed a WD compared with an HHD, which was moderately reduced by atorvastatin therapy. This phenotype presents a translational model to examine mechanistic pathways of whole food-based dietary patterns on atherosclerosis development.

Collectin placenta 1 (CL-P1), a recently discovered scavenger receptor, mediates the uptake of oxidized low density lipoprotein and microbes. In this study, we investigated CL-P1-mediated binding and ingestion of yeast-derived zymosan bioparticles using Chinese hamster ovary (CHO) cells stably expressing human CL-P1 (CHO/CL-P1) and human vascular endothelial cells constitutively expressed CL-P1. The uptake of zymosan by CHO/CL-P1 was dependent upon the level of CL-P1 expressed on the membrane and was inhibited by cytochalasin D and wortmannin. The binding of zymosan was also inhibited by ligands of other scavenger receptors such as poly(I) and dextran sulfate. Real time reverse transcription-PCR analyses showed that other scavenger receptors, namely LOX-1, Stabilin-2, or macrophage receptor with collagenous structure (MARCO), were not expressed in human umbilical vein endothelial cells isolated from different individuals. Nonopsonic zymosan ingestion was inhibited in three primary cultured vascular endothelial cells, including different human umbilical vein endothelial cells from nine individuals treated with CL-P1 small interfering RNAs, although small interfering RNAs of other scavenger receptors had no effect on zymosan uptake in these cells. Furthermore, we confirmed that CL-P1 is expressed in human and murine vascular endothelial layers. Our results demonstrated that CL-P1 predominantly mediated phagocytosis for fungi in vascular endothelia.Scavenger receptors are integral membrane proteins consisting at least eight different subclasses (Class A to Class H), with little amino acid sequence homology, that bind to a wide variety of ligands, including modified or oxidized low density lipoproteins (oxLDLs), 2 apoptotic cells, and microbial pathogens (1). Among these ligands, oxLDLs are considered to have an important role in interactions with endothelial cells, macrophages, and smooth muscle cells in the development of atherosclerosis according to Ross's response-to-injury hypothesis (2, 3). Vascular endothelial cells express several distinct scavenger receptors, such as SR-BI (4 -6), LOX-1 (7), SREC (8), FEEL-1/stabilin-1, and FEEL-2/stabilin-2 (9).Using placental cDNA, we recently identified CL-P1 (10), a type II transmembrane protein with a coiled-coil, a collagenlike domain, and a carbohydrate recognition domain (CRD) and showed it to be a scavenger receptor, in addition to its role as a collectin (Colec12). This molecule resembles a Class A scavenger receptor (SR-A) in its structure except for the replacement of the cysteine-rich domain by a CRD (11). CL-P1 can bind to oxLDL without interacting with other modified LDLs such as acetyl-LDL. Interestingly, we found that CL-P1 expression in HUVECs was up-regulated after the induction of oxidative stress in vitro and was increased in aortic endothelia in a rat ischemia-reperfusion model (12). Another reported finding on the ability of CL-P1 to mediate the binding of yeast, as well as Gram-negative and -positive bacteria in CL-P1-transfected CHO cells, strongly ...