Bensaid M, Gary-Bobo M, Esclangon A, Maffrand J P, Le Fur G, Oury-Donat F, Soubrié P
CNS Research Department, Sanofi-Synthélabo Recherche, Montpellier, France.
Mol Pharmacol. 2003 Apr;63(4):908-14. doi: 10.1124/mol.63.4.908.
This study investigates the effects of SR141716, a selective CB(1) receptor antagonist that reduces food intake and body weight of rodents, on Acrp30 mRNA expression in adipose tissue. Acrp30, a plasma protein exclusively expressed and secreted by adipose tissue, has been shown to induce free fatty acid oxidation, hyperglycemia and hyperinsulinemia decrease, and body weight reduction. We report that N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR141716) treatment once daily (10 mg/kg/d, i.p.) from 2 to 14 days reduced body weight and stimulated Acrp30 mRNA expression in adipose tissue of obese Zucker (fa/fa) rats. In parallel, the hyperinsulinemia associated with this animal model was reduced by SR141716 treatment. In cultured mouse adipocytes (3T3 F442A), SR141716 (25 to 100 nM) also induced an overexpression of Acrp30 mRNA and protein. In addition, in adipose tissue of CB(1)-receptor knockout mice, SR141716 had no effect on Acrp30 mRNA expression, demonstrating a CB(1) receptor mediating effect. Furthermore, RT-PCR analysis revealed that rat adipose tissue and 3T3 F442A adipocytes expressed CB(1) receptor mRNA. Relative quantification of this expression revealed an up-regulation (3- to 4-fold) of CB(1) receptor mRNA expression in adipose tissue of obese (fa/fa) rats and in differentiated 3T3 F442A adipocytes compared with lean rats and undifferentiated adipocytes, respectively. Western blot analysis revealed the presence of CB(1) receptors in 3T3 F442A adipocytes, and their expression was up-regulated in differentiated cells. These results show that SR141716 stimulated Acrp30 mRNA expression in adipose tissue by an effect on adipocytes, and reduced hyperinsulinemia in obese (fa/fa) rats. These hormonal regulations may participate in the body weight reduction induced by SR141716 and suggest a role of metabolic regulation in the antiobesity effect of SR141716.
本研究调查了选择性CB(1)受体拮抗剂SR141716对脂肪组织中Acrp30 mRNA表达的影响，该拮抗剂可减少啮齿动物的食物摄入量和体重。Acrp30是一种仅由脂肪组织表达和分泌的血浆蛋白，已被证明可诱导游离脂肪酸氧化、降低高血糖和高胰岛素血症，并减轻体重。我们报告，从第2天至第14天每天一次（10 mg/kg/d，腹腔注射）给予盐酸N-(哌啶-1-基)-5-(4-氯苯基)-1-(2,4-二氯苯基)-4-甲基-1H-吡唑-3-甲酰胺(SR141716)可减轻肥胖Zucker(fa/fa)大鼠的体重，并刺激其脂肪组织中Acrp30 mRNA的表达。同时，SR141716治疗可减轻与该动物模型相关的高胰岛素血症。在培养的小鼠脂肪细胞(3T3 F442A)中，SR141716(25至100 nM)也可诱导Acrp30 mRNA和蛋白的过表达。此外，在CB(1)受体基因敲除小鼠的脂肪组织中，SR141716对Acrp30 mRNA表达无影响，表明存在CB(1)受体介导的效应。此外，RT-PCR分析显示大鼠脂肪组织和3T3 F442A脂肪细胞表达CB(1)受体mRNA。该表达的相对定量显示，与瘦大鼠和未分化脂肪细胞相比，肥胖(fa/fa)大鼠脂肪组织和分化的3T3 F442A脂肪细胞中CB(1)受体mRNA表达上调（3至4倍）。蛋白质印迹分析显示3T3 F442A脂肪细胞中存在CB(1)受体，且其表达在分化细胞中上调。这些结果表明，SR141716通过对脂肪细胞的作用刺激脂肪组织中Acrp30 mRNA的表达，并减轻肥胖(fa/fa)大鼠的高胰岛素血症。这些激素调节可能参与了SR141716诱导的体重减轻，并提示代谢调节在SR141716的抗肥胖作用中发挥作用。
