Kratzer Adelheid, Buchebner Marlene, Pfeifer Thomas, Becker Tatjana M, Uray Georg, Miyazaki Makoto, Miyazaki-Anzai Shinobu, Ebner Birgit, Chandak Prakash G, Kadam Rajendra S, Calayir Emine, Rathke Nora, Ahammer Helmut, Radovic Branislav, Trauner Michael, Hoefler Gerald, Kompella Uday B, Fauler Guenter, Levi Moshe, Levak-Frank Sanja, Kostner Gerhard M, Kratky Dagmar
Institute of Molecular Biology and Biochemistry, Center of Molecular Medicine, Medical University of Graz, Harrachgasse 21/3, 8010 Graz, Austria.
J Lipid Res. 2009 Feb;50(2):312-26. doi: 10.1194/jlr.M800376-JLR200. Epub 2008 Sep 23.
Liver X receptors (LXRs) are important regulators of cholesterol and lipid metabolism. LXR agonists have been shown to limit the cellular cholesterol content by inducing reverse cholesterol transport, increasing bile acid production, and inhibiting intestinal cholesterol absorption. Most of them, however, also increase lipogenesis via sterol regulatory element-binding protein-1c (SREBP1c) and carbohydrate response element-binding protein activation resulting in hypertriglyceridemia and liver steatosis. We report on the antiatherogenic properties of the steroidal liver X receptor agonist N,N-dimethyl-3beta-hydroxy-cholenamide (DMHCA) in apolipoprotein E (apoE)-deficient mice. Long-term administration of DMHCA (11 weeks) significantly reduced lesion formation in male and female apoE-null mice. Notably, DMHCA neither increased hepatic triglyceride (TG) levels in male nor female apoE-deficient mice. ATP binding cassette transporter A1 and G1 and cholesterol 7alpha-hydroxylase mRNA abundances were increased, whereas SREBP1c mRNA expression was unchanged in liver, and even decreased in macrophages and intestine. Short-term treatment revealed even higher changes on mRNA regulation. Our data provide evidence that DMHCA is a strong candidate as therapeutic agent for the treatment or prevention of atherosclerosis, circumventing the negative side effects of other LXR agonists.
肝脏X受体(LXRs)是胆固醇和脂质代谢的重要调节因子。LXR激动剂已被证明可通过诱导胆固醇逆向转运、增加胆汁酸生成以及抑制肠道胆固醇吸收来限制细胞内胆固醇含量。然而,它们中的大多数还会通过固醇调节元件结合蛋白-1c(SREBP1c)和碳水化合物反应元件结合蛋白的激活来增加脂肪生成,从而导致高甘油三酯血症和肝脏脂肪变性。我们报道了甾体类肝脏X受体激动剂N,N-二甲基-3β-羟基胆酰胺(DMHCA)在载脂蛋白E(apoE)缺陷小鼠中的抗动脉粥样硬化特性。长期给予DMHCA(11周)可显著减少雄性和雌性apoE基因敲除小鼠的病变形成。值得注意的是,DMHCA在雄性和雌性apoE缺陷小鼠中均未增加肝脏甘油三酯(TG)水平。肝脏中ATP结合盒转运体A1和G1以及胆固醇7α-羟化酶的mRNA丰度增加,而SREBP1c的mRNA表达在肝脏中未发生变化,在巨噬细胞和肠道中甚至下降。短期治疗显示mRNA调节方面的变化更大。我们的数据提供了证据,表明DMHCA作为治疗或预防动脉粥样硬化的治疗剂是一个有力的候选药物,可避免其他LXR激动剂的负面副作用。