Abstract：
METHODS: Alcoholic liver disease (ALD) is a global public health concern. Nobiletin, a polymethoxyflavone abundant in citrus fruits, enhances circadian rhythms and ameliorates diet-induced hepatic steatosis, but its influences on ALD are unknown. This study investigates the role of brain and muscle Arnt-like protein-1 (Bmal1), a key regulator of the circadian clock, in nobiletin-alleviated ALD.
RESULTS: This study uses chronic ethanol feeding plus an ethanol binge to establish ALD models in Bmal1flox/flox and Bmal1 liver-specific knockout (Bmal1LKO) mice. Nobiletin mitigates ethanol-induced liver injury (alanine aminotransferase [ALT]), glucose intolerance, hepatic apoptosis, and lipid deposition (triglyceride [TG], total cholesterol [TC]) in Bmal1flox/flox mice. Nobiletin fails to modulated liver injury (ALT, aspartate aminotransferase [AST]), apoptosis, and TG accumulation in Bmal1LKO mice. The expression of lipogenic genes (acetyl-CoA carboxylase alpha [Acaca], fatty acid synthase [Fasn]) and fatty acid oxidative genes (carnitine pamitoyltransferase [Cpt1a], cytochrome P450, family 4, subfamily a, polypeptide 10 [Cyp4a10], and cytochrome P450, family4, subfamily a, polypeptide 14 [Cyp4a14]) is inhibited, and the expression of proapoptotic genes (Bcl2 inteacting mediator of cell death [Bim]) is enhanced by ethanol in Bmal1flox/flox mice. Nobiletin antagonizes the expression of these genes in Bmal1flox/flox mice and not in Bmal1LKO mice. Nobiletin activates protein kinase B (PKB, also known as AKT) phosphorylation, increases the levels of the carbohydrate response element binding protein (ChREBP), ACC1, and FASN, and reduces the level of sterol-regulatory element binding protein 1 (SREBP1) and phosphorylation of ACC1 in a Bmal1-dependent manner.
CONCLUSIONS: Nobiletin alleviates ALD by increasing the expression of genes involved in fatty acid oxidation by increasing AKT phosphorylation and lipogenesis in a Bmal1-dependent manner.
RESULTS: This study uses chronic ethanol feeding plus an ethanol binge to establish ALD models in Bmal1flox/flox and Bmal1 liver-specific knockout (Bmal1LKO) mice. Nobiletin mitigates ethanol-induced liver injury (alanine aminotransferase [ALT]), glucose intolerance, hepatic apoptosis, and lipid deposition (triglyceride [TG], total cholesterol [TC]) in Bmal1flox/flox mice. Nobiletin fails to modulated liver injury (ALT, aspartate aminotransferase [AST]), apoptosis, and TG accumulation in Bmal1LKO mice. The expression of lipogenic genes (acetyl-CoA carboxylase alpha [Acaca], fatty acid synthase [Fasn]) and fatty acid oxidative genes (carnitine pamitoyltransferase [Cpt1a], cytochrome P450, family 4, subfamily a, polypeptide 10 [Cyp4a10], and cytochrome P450, family4, subfamily a, polypeptide 14 [Cyp4a14]) is inhibited, and the expression of proapoptotic genes (Bcl2 inteacting mediator of cell death [Bim]) is enhanced by ethanol in Bmal1flox/flox mice. Nobiletin antagonizes the expression of these genes in Bmal1flox/flox mice and not in Bmal1LKO mice. Nobiletin activates protein kinase B (PKB, also known as AKT) phosphorylation, increases the levels of the carbohydrate response element binding protein (ChREBP), ACC1, and FASN, and reduces the level of sterol-regulatory element binding protein 1 (SREBP1) and phosphorylation of ACC1 in a Bmal1-dependent manner.
CONCLUSIONS: Nobiletin alleviates ALD by increasing the expression of genes involved in fatty acid oxidation by increasing AKT phosphorylation and lipogenesis in a Bmal1-dependent manner.
摘要：
方法：酒精性肝病（ALD）是全球公共卫生问题。诺美林,柑橘类水果中丰富的多甲氧基黄酮，增强昼夜节律，改善饮食诱导的肝脂肪变性，但它对ALD的影响是未知的。这项研究调查了大脑和肌肉Arnt样蛋白1（Bmal1）的作用，生物钟的关键调节器，在诺比林缓解的ALD中。
结果：本研究使用慢性乙醇喂养加乙醇暴饮暴食，在Bmal1flox/flox和Bmal1肝脏特异性敲除（Bmal1LKO）小鼠中建立ALD模型。Nobiletin缓解乙醇诱导的肝损伤（丙氨酸转氨酶[ALT]），葡萄糖不耐受,肝细胞凋亡,和脂质沉积(甘油三酯[TG]，总胆固醇[TC]）在Bmal1flox/flox小鼠中。诺比林不能调节肝损伤（ALT，天冬氨酸氨基转移酶[AST]），凋亡，和TG在Bmal1LKO小鼠中的积累。脂肪生成基因的表达（乙酰辅酶A羧化酶α[Acaca]，脂肪酸合成酶[Fasn]）和脂肪酸氧化基因（肉碱棕榈酰转移酶[Cpt1a]，细胞色素P450家族4亚家族a,多肽10[Cyp4a10]，和细胞色素P450，家族4，亚家族，多肽14[Cyp4a14])被抑制，在Bmal1flox/flox小鼠中，乙醇增强了促凋亡基因（Bcl2细胞死亡的相互作用介质[Bim]）的表达。Nobiletin在Bmal1flox/flox小鼠中拮抗这些基因的表达，而在Bmal1LKO小鼠中没有。Nobiletin激活蛋白激酶B（PKB，也称为AKT）磷酸化，增加碳水化合物反应元件结合蛋白（ChREBP）的水平，ACC1和FASN,并以Bmal1依赖性方式降低固醇调节元件结合蛋白1（SREBP1）的水平和ACC1的磷酸化。
结论：Nobiletin通过以Bmal1依赖性方式增加AKT磷酸化和脂肪生成来增加参与脂肪酸氧化的基因表达，从而减轻ALD。
结果：本研究使用慢性乙醇喂养加乙醇暴饮暴食，在Bmal1flox/flox和Bmal1肝脏特异性敲除（Bmal1LKO）小鼠中建立ALD模型。Nobiletin缓解乙醇诱导的肝损伤（丙氨酸转氨酶[ALT]），葡萄糖不耐受,肝细胞凋亡,和脂质沉积(甘油三酯[TG]，总胆固醇[TC]）在Bmal1flox/flox小鼠中。诺比林不能调节肝损伤（ALT，天冬氨酸氨基转移酶[AST]），凋亡，和TG在Bmal1LKO小鼠中的积累。脂肪生成基因的表达（乙酰辅酶A羧化酶α[Acaca]，脂肪酸合成酶[Fasn]）和脂肪酸氧化基因（肉碱棕榈酰转移酶[Cpt1a]，细胞色素P450家族4亚家族a,多肽10[Cyp4a10]，和细胞色素P450，家族4，亚家族，多肽14[Cyp4a14])被抑制，在Bmal1flox/flox小鼠中，乙醇增强了促凋亡基因（Bcl2细胞死亡的相互作用介质[Bim]）的表达。Nobiletin在Bmal1flox/flox小鼠中拮抗这些基因的表达，而在Bmal1LKO小鼠中没有。Nobiletin激活蛋白激酶B（PKB，也称为AKT）磷酸化，增加碳水化合物反应元件结合蛋白（ChREBP）的水平，ACC1和FASN,并以Bmal1依赖性方式降低固醇调节元件结合蛋白1（SREBP1）的水平和ACC1的磷酸化。
结论：Nobiletin通过以Bmal1依赖性方式增加AKT磷酸化和脂肪生成来增加参与脂肪酸氧化的基因表达，从而减轻ALD。
