piperidines and Sclerosis

Rimonabant (SR141716) is a specific antagonist of the cannabinoid-1 receptor. Activation of the receptor initiates multiple effects on central nervous system function, metabolism, and body weight. The hypothesis that rimonabant has protective effects against vascular disease associated with the metabolic syndrome was tested using JCR:LA-cp rats. JCR:LA-cp rats are obese if they are cp/cp, insulin resistant, and exhibit associated micro- and macrovascular disease with end-stage myocardial and renal disease. Treatment of obese rats with rimonabant (10 mg.kg(-1).day(-1), 12-24 wk of age) caused transient reduction in food intake for 2 wk, without reduction in body weight. However, by 4 wk, there was a modest, sustained reduction in weight gain. Glycemic control improved marginally compared with controls, but at the expense of increased insulin concentration. In contrast, rimonabant normalized fasting plasma triglyceride and reduced plasma plasminogen activator inhibitor-1 and acute phase protein haptoglobin in cp/cp rats. Furthermore, these changes were accompanied by reduced postprandial intestinal lymphatic secretion of apolipoprotein B48, cholesterol, and haptoglobin. While macrovascular dysfunction and ischemic myocardial lesion frequency were unaffected by rimonabant treatment, both microalbuminuria and glomerular sclerosis were substantially reduced. In summary, rimonabant has a modest effect on body weight in freely eating obese rats and markedly reduces plasma triglyceride levels and microvascular disease, in part due to changes in intestinal metabolism, including lymphatic secretion of apolipoprotein B48 and haptoglobin. We conclude that rimonabant improves renal disease and intestinal lipid oversecretion associated with an animal model of the metabolic syndrome that appears to be independent of hyperinsulinemia or macrovascular dysfunction.

Topics: Animals; Biomarkers; Blood Vessels; Body Weight; Cannabinoid Receptor Antagonists; Disease Models, Animal; Eating; Inflammation; Insulin Resistance; Intestinal Mucosa; Kidney Diseases; Kidney Glomerulus; Lipid Metabolism; Male; Metabolic Syndrome; Myocardial Ischemia; Piperidines; Prediabetic State; Pyrazoles; Rats; Rats, Mutant Strains; Renal Circulation; Rimonabant; Sclerosis; Thrombosis

Halofuginone is a drug that has been shown to have an antifibrotic property in vitro and in vivo. Whereas halofuginone shows promise as a therapeutic agent for a variety of diseases including scleroderma, liver cirrhosis, cystic fibrosis, and certain types of cancer, the mechanism of action remains unknown. Using the tight skin mouse (TSK) model for scleroderma, we evaluated the ability of halofuginone to inhibit spontaneous development of dermal fibrosis. We found that administration of a low dose of halofuginone both in adult and newborn animals for 60 d prevented the development of cutaneous hyperplasia (dermal fibrosis). In vitro halofuginone was found to reduce the amount of collagen synthesized by fibroblasts. This effect was due to a reduction in the promoter activity of the type-I collagen genes as treatment of fibroblast cultures with 10(-8) M halofuginone reduced the level of alpha2(I) collagen message detectible by northern blot and greatly reduced the activity of a reporter construct under control of the -3200 to +54 bp alpha2(I) collagen promoter. In addition, analysis of transforming growth factor beta signaling pathways in fibroblasts revealed that halofuginone inhibited transforming-growth-factor-beta-induced upregulation of collagen protein and activity of the alpha2(I) collagen promoter. Further we found that halofuginone blocked the phosphorylation and subsequent activation of Smad3 after transforming growth factor beta stimulation. Apparently the inhibitory property was specific to Smad3 as there was no inhibitory effect on the activation of Smad2 after stimulation with transforming growth factor beta. Our results demonstrate that halofuginone is a specific inhibitor of type-I collagen synthesis and may elicit its effect via interference with the transforming growth factor beta signaling pathway.

Topics: Animals; Cells, Cultured; Collagen; Collagen Type I; DNA-Binding Proteins; Fibroblasts; Gene Expression; Hyperplasia; Male; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Mice, Mutant Strains; Piperidines; Quinazolines; Quinazolinones; Receptors, Transforming Growth Factor beta; Sclerosis; Signal Transduction; Skin; Skin Diseases; Smad3 Protein; Trans-Activators; Transforming Growth Factor beta

In chronic graft-versus-host disease (cGvHD), skin fibrosis, contractures, and an increase in collagen content form the hallmark. We report a successful treatment of a cGvHD patient by topical application of halofuginone, an inhibitor of collagen alpha1(I) gene expression.. Halofuginone-containing ointment was applied daily on the left side of the neck and shoulder of a cGvHD patient. Collagen alpha1(I) gene expression and collagen content in skin biopsy specimens were evaluated by in situ hybridization and sirius red staining, respectively.. After 3 and 6 months, a marked reduction in skin collagen synthesis was observed, accompanied with increase neck rotation on the treated side. After cessation of treatment, the sclerosis, skin tightness, and collagen alpha1(I) gene expression returned to baseline level. No adverse effects were observed, and no plasma levels of halofuginone could be detected.. Halofuginone may provide a promising novel and safe therapy for cGvHD patients.

Topics: Administration, Topical; Adult; Animals; Collagen; Gene Expression; Graft vs Host Disease; Humans; Male; Neck; Piperidines; Protein Synthesis Inhibitors; Quinazolines; Quinazolinones; Rabbits; Range of Motion, Articular; Sclerosis; Skin; Skin Transplantation