ABSTRACT
Atherosclerosis is an arterial inflammatory disease. The circulating level of the C-C chemokine ligand (CCL4) is increased in atherosclerotic patients. This study aimed to investigate whether CCL4 inhibition could retard the progression of atherosclerosis. In ApoE knockout mice, CCL4 antibody treatment reduced circulating interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α levels and improved lipid profiles accompanied with upregulation of the liver X receptor. CCL4 inhibition reduced the atheroma areas and modified the progression of atheroma plaques, which consisted of a thicker fibrous cap with a reduced macrophage content and lower matrix metalloproteinase-2 and -9 expressions, suggesting the stabilization of atheroma plaques. Human coronary endothelial cells (HCAECs) and macrophages were stimulated with TNF-α or oxidized LDL (ox-LDL). The induced expression of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) were attenuated by the CCL4 antibody or CCL4 si-RNA. CCL4 inhibition reduced the adhesiveness of HCAECs, which is an early sign of atherogenesis. CCL4 blockade reduced the activity of metalloproteinase-2 and -9 and the production of TNF-α and IL-6 in stimulated macrophages. The effects of CCL4 inhibition on down-regulating adhesion and inflammation proteins were obtained through the nuclear factor kappa B (NFκB) signaling pathway. The direct inhibition of CCL4 stabilized atheroma and reduced endothelial and macrophage activation. CCL4 may be a novel therapeutic target for modulating atherosclerosis.
Subject(s)
Atherosclerosis/metabolism , Chemokine CCL4/antagonists & inhibitors , Adhesiveness , Animals , Atherosclerosis/physiopathology , Cell Adhesion/physiology , Chemokine CCL4/metabolism , Endothelial Cells/metabolism , Humans , Inflammation/pathology , Intercellular Adhesion Molecule-1/metabolism , Interleukin-6/metabolism , Ligands , Lipoproteins, LDL/metabolism , Liver X Receptors/metabolism , Macrophage Activation/physiology , Macrophages/metabolism , Male , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout, ApoE , NF-kappa B/metabolism , Plaque, Atherosclerotic/metabolism , Plaque, Atherosclerotic/pathology , Tumor Necrosis Factor-alpha/metabolism , Vascular Cell Adhesion Molecule-1/metabolismABSTRACT
BACKGROUND: Excessive eosinophil airway infiltration is a clinically critical condition in some cases. Eosinophilic pneumonia (EP) is a pulmonary condition involving eosinophil infiltration of the lungs. Although several chemokines, including eotaxin-1 (CCL11), RANTES (CCL5) and macrophage inflammatory protein 1ß (MIP-1ß or CCL4), have been detected in bronchoalveolar lavage fluid (BALF) from patients with EP, the pathophysiological mechanisms underlying EP, including potential relationships between eosinophils and CCL4, have not been fully elucidated. OBJECTIVE: To examine the involvement of CCL4 in eosinophilic airway inflammation. METHODS: We analysed supernatants of activated eosinophils and BALF from 16 patients with eosinophilic pneumonia (EP). Further, we examined the effects of CCL4 on eosinophil functions in vitro and those of anti-CCL4 neutralizing antibody in an in vivo model. RESULTS: We found that purified human eosinophils stimulated with IL-5 predominantly secreted CCL4 and that patients with EP had elevated CCL11 and CCL4 levels in BALF compared with samples from individuals without EP. Because CCL4 levels were more strongly correlated with eosinophil count and expression of eosinophil granule proteins than CCL11, in vitro experiments using purified eosinophils concentrated on the former chemokine. Interestingly, CCL4 acted as a chemoattractant for eosinophils. In a mouse model, administration of a CCL4-neutralizing antibody attenuated eosinophilic airway infiltration and airway hyperresponsiveness. CONCLUSIONS AND CLINICAL RELEVANCE: Overall, these findings highlight an important role of CCL4 in the mechanisms underlying eosinophil recruitment into the airway and may provide a novel insight into this potential therapeutic target.
Subject(s)
Chemokine CCL4/immunology , Eosinophils/immunology , Pulmonary Eosinophilia/immunology , Animals , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/pharmacology , Chemokine CCL4/antagonists & inhibitors , Disease Models, Animal , Eosinophils/pathology , Humans , Mice , Mice, Inbred BALB C , Pulmonary Eosinophilia/pathologyABSTRACT
Sepsis is a systemic inflammatory response to infection, accounting for the most common cause of death in intensive care units. Here, we report that peripheral administration of the hypothalamic neuropeptide orexin improves the survival of mice with lipopolysaccharide (LPS) induced endotoxin shock, a well-studied septic shock model. The effect is accompanied by a suppression of excessive cytokine production and an increase of catecholamines and corticosterone. We found that peripherally administered orexin penetrates the blood-brain barrier under endotoxin shock, and that central administration of orexin also suppresses the cytokine production and improves the survival, indicating orexin's direct action in the central nervous system (CNS). Orexin helps restore body temperature and potentiates cardiovascular function in LPS-injected mice. Pleiotropic modulation of inflammatory response by orexin through the CNS may constitute a novel therapeutic approach for septic shock.
Subject(s)
Blood-Brain Barrier/drug effects , Body Temperature Regulation/drug effects , Bradycardia/drug therapy , Orexins/pharmacology , Shock, Septic/drug therapy , Animals , Blood-Brain Barrier/immunology , Blood-Brain Barrier/metabolism , Body Temperature Regulation/immunology , Bradycardia/chemically induced , Bradycardia/immunology , Bradycardia/mortality , Chemokine CCL3/antagonists & inhibitors , Chemokine CCL3/genetics , Chemokine CCL3/immunology , Chemokine CCL4/antagonists & inhibitors , Chemokine CCL4/genetics , Chemokine CCL4/immunology , Disease Models, Animal , Gene Expression Regulation , Humans , Injections, Subcutaneous , Interferon-gamma/antagonists & inhibitors , Interferon-gamma/genetics , Interferon-gamma/immunology , Interleukin-17/antagonists & inhibitors , Interleukin-17/genetics , Interleukin-17/immunology , Lipopolysaccharides , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Shock, Septic/chemically induced , Shock, Septic/immunology , Shock, Septic/mortality , Survival Analysis , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunologyABSTRACT
An elevated level of macrophage inflammatory protein-1beta (MIP-1beta) induced by IL-1beta has been correlated with chronic hepatic inflammatory disease. However, molecular mechanism of IL-1beta-induced MIP-1beta expression in hepatic cells is obscure. Previously, we reported the mechanism of the anti-hepatitis B virus (HBV) activity of helioxanthin (HE-145). Here, we demonstrated that HE-145 inhibited IL-1beta-induced MIP-1beta expression in a dose-dependent manner in Huh7 cells. To understand the mode of action of HE-145, we first examined how IL-1beta induced MIP-1beta expression at the molecular level. Using selective inhibitors, we found that JNK and p38 pathways participated in IL-1beta-induced MIP-1beta expression. HE-145 specifically suppressed IL-1beta-induced c-jun mRNA and protein expression and prevented c-jun-mediated AP-1 DNA-binding activity, whereas it had no effect on IL-1beta-induced activation of JNK, p38 and ATF2. Further studies indicated that HE-145 may downregulate c-jun mRNA expression directly at transcriptional level without requirement of de novo protein synthesis. Mutational analysis and supershift assays indicated that IL-1beta stimulated c-jun and CREB1 binding to the essential AP-1/CRE site of the MIP-1beta promoter. The inhibitory effect of HE-145 on IL-1beta-induced MIP-1beta promoter activity was completely reversed by overexpressing c-jun. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay consistently revealed that HE-145 reduced c-jun binding to the AP-1/CRE site in vitro and in vivo. Our results established a major role for c-jun in IL-1beta-induced MIP-1beta expression in hepatic cells. The reduction in IL-1beta-induced c-jun expression and subsequent binding of the c-jun/CREB1 complex to AP-1/CRE site mainly contributed to the inhibitory action of HE-145 on IL-1beta-induced MIP-1beta production.
