ABSTRACT
Focal segmental glomerulosclerosis (FSGS) is a scarring process associated with chronic low-grade inflammation ascribed to toll-like receptor (TLR) activation and monocyte migration. We developed synthetic, small-molecule lecinoxoids, VB-201 and VB-703, that differentially inhibit TLR-2- and TLR-4-mediated activation and monocyte migration. The efficacy of anti-inflammatory lecinoxoid treatment on FSGS development was explored using a 5/6 nephrectomy rat model. Five-sixths of nephrectomized rats were treated with lecinoxoids VB-201, VB-703 or PBS, for 7 weeks. Upon sacrifice, albumin/creatinine ratio, glomerulosclerosis, fibrosis-related gene expression and the number of glomerular and interstitial monocyte were evaluated. Treatment of nephrectomized rats with lecinoxoids ameliorated glomerulosclerosis. The percentage of damaged glomeruli, glomerular sclerosis and glomeruli fibrotic score was significantly reduced following VB-201 and VB-703 treatment. VB-703 attenuated the expression of fibrosis hallmark genes collagen, fibronectin (FN) and transforming growth factor ß (TGF-ß) in kidneys and improved albumin/creatinine ratio with higher efficacy than did VB-201, but only VB-201 significantly reduced the number of glomerular and interstitial monocytes. These results indicate that treatment with TLR-2, and more prominently, TLR-4 antagonizing lecinoxioids, is sufficient to significantly inhibit FSGS. Moreover, inhibiting monocyte migration can also contribute to treatment of FSGS. Our data demonstrate that targeting TLR-2-TLR-4 and/or monocyte migration directly affects the priming phase of fibrosis and may consequently perturb disease parthogenesis.
Subject(s)
Glomerulosclerosis, Focal Segmental/drug therapy , Glycerophosphates/pharmacology , Glycerylphosphorylcholine/pharmacology , Pyridinium Compounds/pharmacology , Animals , Blood Cells/drug effects , Collagen/metabolism , Disease Models, Animal , Fibronectins/metabolism , Glomerulosclerosis, Focal Segmental/metabolism , Glomerulosclerosis, Focal Segmental/pathology , Kidney/drug effects , Kidney/physiology , Macrophages/drug effects , Male , Monocytes/drug effects , Nephrectomy , Podocytes/drug effects , Podocytes/pathology , Random Allocation , Rats , Rats, Sprague-Dawley , Toll-Like Receptor 2/antagonists & inhibitors , Toll-Like Receptor 4/antagonists & inhibitors , Transforming Growth Factor beta/metabolismABSTRACT
Binding of chemokines to their cognate receptors on monocytes instigates a cascade of events that directs these cells to migrate to sites of inflammation and cancerous tissues. Although targeting of selected chemokine receptors on monocytes exhibited preclinical efficacy, attempts to translate these studies to the clinic have failed thus far, possibly due to redundancy of the target receptor. We reveal that motile sperm domain-containing protein 2 (MOSPD2), a protein with a previously unknown function, regulates monocyte migration in vitro. This protein was found to be expressed on the cytoplasmic membrane of human monocytes. Silencing or neutralizing MOSPD2 in monocytes restricted their migration when induced by different chemokines. Mechanistically, silencing MOSPD2 inhibited signaling events following chemokine receptor ligation. When tested for expression in other immune cell subsets, MOSPD2 was apparent also, though less abundantly, in neutrophils, but not in lymphocytes. Thus, in the presence of neutralizing Abs, neutrophil migration was inhibited to some extent whereas lymphocyte migration remained intact. In view of these results, we suggest MOSPD2 as a potential target protein for treating diseases in which monocyte and neutrophil accumulation is correlated with pathogenesis.
Subject(s)
Inflammation/immunology , Membrane Proteins/metabolism , Monocytes/physiology , Neutrophils/physiology , Receptors, Chemokine/metabolism , Antibodies, Neutralizing/metabolism , Cell Movement/drug effects , Cell Movement/genetics , Cells, Cultured , Chemokines/metabolism , Humans , Inflammation/therapy , Membrane Proteins/genetics , Membrane Proteins/immunology , Molecular Targeted Therapy , Protein Binding , RNA Interference , RNA, Small Interfering/genetics , Receptors, Chemokine/genetics , Receptors, Chemokine/immunology , Signal Transduction/drug effects , Signal Transduction/geneticsABSTRACT
BACKGROUND AND AIMS: Previous studies demonstrated that toll-like receptors 4 and 2 (TLR-4 and TLR-2), which are expressed on liver-resident Kupffer, hepatic stellate cells, and circulating monocytes, play a role in nonalcoholic fatty liver disease. Lecinoxoids are oxidized phospholipids that antagonize TLR-2- and TLR-4-mediated activation of innate immune cells and inhibit monocyte migration. In this study, we tested the effect of two functionally different lecinoxoids on the development of nonalcoholic steatohepatitis and liver fibrosis in a mouse model. METHODS: Two-day-old C57BL/6 mice were injected with streptozotocin and fed a high-fat diet from Week 4 after birth. At Week 6 post-birth, lecinoxoids VB-201 or VB-703 were given orally, once daily, for 3 weeks. Telmisartan was administered orally, once daily, for 3 weeks, as positive control. At experiment conclusion, biochemical indices were evaluated. HE stain and quantitative PCR were used to determine the extent of steatosis and steatohepatitis, and Sirius red stain was used to assess liver fibrosis. RESULTS: Treatment with lecinoxoids did not alter the concentration of blood glucose, liver triglycerides, or steatosis compared with solvent-treated mice. However, whereas VB-201 inhibited the development of fibrosis and, to some extent, liver inflammation, VB-703 significantly lessened both liver inflammation and fibrosis. CONCLUSIONS: This study indicates that using lecinoxoids to antagonize TLR-2, and more prominently TLR-4, is sufficient to significantly inhibit nonalcoholic steatohepatitis and liver fibrosis. Inhibiting monocyte migration with lecinoxoids that are relatively weak TLR-4 antagonists may alter liver fibrosis and to some extent nonalcoholic steatohepatitis.
Subject(s)
Cytokines/drug effects , Diabetes Mellitus, Experimental/metabolism , Diet, High-Fat , Glycerophosphates/pharmacology , Glycerylphosphorylcholine/pharmacology , Liver Cirrhosis/metabolism , Liver/drug effects , Non-alcoholic Fatty Liver Disease/metabolism , Pyridinium Compounds/pharmacology , Animals , Antihypertensive Agents/pharmacology , Benzimidazoles/pharmacology , Benzoates/pharmacology , Blood Glucose , Blotting, Western , Cell Movement/drug effects , Cytokines/metabolism , Dendritic Cells , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Hepatic Stellate Cells/metabolism , Humans , Inflammation , Kupffer Cells/metabolism , Liver/metabolism , Liver/pathology , Mice , Mice, Inbred C57BL , Monocytes/drug effects , Phospholipids/pharmacology , Real-Time Polymerase Chain Reaction , Telmisartan , Toll-Like Receptor 2/antagonists & inhibitors , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/antagonists & inhibitors , Toll-Like Receptor 4/metabolism , Triglycerides/metabolismABSTRACT
Oxidized phospholipids (Ox-PLs) are generated in abundance at sites of inflammation. Recent studies have indicated that Ox-PLs may also exhibit anti-inflammatory activities. In this study, we investigated the beneficial effect of VB-201, a pure synthetic Ox-PL analog that we synthesized, on the development of a central nervous system (CNS) autoimmune inflammatory disease, in vivo. Oral administration of VB-201 ameliorated the severity of experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein (MOG) peptide MOG35-55, and restrained the encephalogenicity of MOG35-55-specific T-cells. Our data presents a novel prospect for the role of Ox-PL analogs in CNS inflammatory diseases.
