Rui Jiang1, Yujia Zhou2, Sufan Wang2, Nengzhi Pang2, Yuanling Huang2, Mingtong Ye2, Ting Wan2, Yun Qiu2, Lei Pei2, Xuye Jiang2, Yufeng Huang3, Hainan Yang3, Wenhua Ling2, Xufeng Li4, Zhenfeng Zhang5, Lili Yang6. 1. Department of Nutrition, Guangdong Provincial Key Laboratory of Food, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, People's Republic of China; Nutrition Clinic, The Maternal & Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi Zhuang Autonomous Region 530003, People's Republic of China. 2. Department of Nutrition, Guangdong Provincial Key Laboratory of Food, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, People's Republic of China. 3. Department of Radiology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong Province 510260, People's Republic of China. 4. Department of Radiology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong Province 510260, People's Republic of China. Electronic address: lixufeng@gzhmu.edu.cn. 5. Department of Radiology, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong Province 510260, People's Republic of China. Electronic address: zhangzhf@gzhmu.edu.cn. 6. Department of Nutrition, Guangdong Provincial Key Laboratory of Food, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, People's Republic of China. Electronic address: yangll7@mail.sysu.edu.cn.
Abstract
AIMS: Increasing nicotinamide adenine dinucleotide (NAD+) by Nicotinamide riboside (NR) provides protective benefits in multiple disorders. However, the role of NR on liver fibrosis is unclear. We performed in vivo and in vitro experiments to test the hepatic protective effects of NR against liver fibrosis and the underlying mechanisms. MATERIALS AND METHODS: Mice were injected with CCl4 to establish liver fibrosis model. NR was given by gavage to explore the hepatic protection of NR. LX-2 cells were given a TGF-β stimulation ± NR, the activation of LX-2 cells and the acetylation of Smads were analyzed. To further confirm the role of Sirt1 on the protective pathway of NR, we knockdown Sirt1 in LX-2 cells. KEY FINDINGS: We found NR could prevent liver fibrosis and reverse the existing liver fibrosis. NR inhibited the activation of LX-2 cells induced by TGF-β, activated Sirt1 and deacetylated Smad2/3. Sirt1 knockdown diminished the inhibiting effect of NR on LX-2 cells activation, and increased expressions of acetylated Smads. In conclusion, NR could prevent liver fibrosis via suppressing activation of hepatic stellate cells (HSCs). This protective effect was mediated by regulating the acetylation of Smads signaling pathway. SIGNIFICANCE: NR protected mice against liver fibrosis induced by CCl4. NR suppressed activation of hepatic stellate cells induced by TGF-β. NR protects liver fibrosis via increasing the activity of Sirt1 and decreasing the expression of P300, resulting in the deacetylation of Smads in stellate cells.
AIMS: Increasing nicotinamide adenine dinucleotide (NAD+) by Nicotinamide riboside (NR) provides protective benefits in multiple disorders. However, the role of NR on liver fibrosis is unclear. We performed in vivo and in vitro experiments to test the hepatic protective effects of NR against liver fibrosis and the underlying mechanisms. MATERIALS AND METHODS:Mice were injected with CCl4 to establish liver fibrosis model. NR was given by gavage to explore the hepatic protection of NR. LX-2 cells were given a TGF-β stimulation ± NR, the activation of LX-2 cells and the acetylation of Smads were analyzed. To further confirm the role of Sirt1 on the protective pathway of NR, we knockdown Sirt1 in LX-2 cells. KEY FINDINGS: We found NR could prevent liver fibrosis and reverse the existing liver fibrosis. NR inhibited the activation of LX-2 cells induced by TGF-β, activated Sirt1 and deacetylated Smad2/3. Sirt1 knockdown diminished the inhibiting effect of NR on LX-2 cells activation, and increased expressions of acetylated Smads. In conclusion, NR could prevent liver fibrosis via suppressing activation of hepatic stellate cells (HSCs). This protective effect was mediated by regulating the acetylation of Smads signaling pathway. SIGNIFICANCE: NR protected mice against liver fibrosis induced by CCl4. NR suppressed activation of hepatic stellate cells induced by TGF-β. NR protects liver fibrosis via increasing the activity of Sirt1 and decreasing the expression of P300, resulting in the deacetylation of Smads in stellate cells.
Authors: Alex Claveria-Cabello; Leticia Colyn; Maria Arechederra; Jesus M Urman; Carmen Berasain; Matias A Avila; Maite G Fernandez-Barrena Journal: Cells Date: 2020-10-19 Impact factor: 6.600