title: Liver Fibrosis Can Be Induced by High Salt Intake through Excess Reactive Oxygen Species (ROS) Production.
abstract: High salt intake has been known to cause hypertension and other side effects. However, it is still unclear whether it also affects fibrosis in the mature or developing liver. This study demonstrates that high salt exposure in mice (4% NaCl in drinking water) and chick embryo (calculated final osmolality of the egg was 300 mosm/L) could lead to derangement of the hepatic cords and liver fibrosis using H&E, PAS, Masson, and Sirius red staining. Meanwhile, Desmin immunofluorescent staining of mouse and chick embryo livers indicated that hepatic stellate cells were activated after the high salt exposure. pHIS3 and BrdU immunohistological staining of mouse and chick embryo livers indicated that cell proliferation decreased; as well, TUNEL analyses indicated that cell apoptosis increased in the presence of high salt exposure. Next, dihydroethidium staining on the cultured chick hepatocytes indicated the excess ROS was generated following high salt exposure. Furthermore, AAPH (a known inducer of ROS production) treatment also induced the liver fibrosis in chick embryo. Positive Nrf2 and Keap1 immunohistological staining on mouse liver suggested that Nrf2/Keap1 signaling was involved in high salt induced ROS production. Finally, the CCK8 assay was used to determine whether or not the growth inhibitory effect induced by high salt exposure can be rescued by antioxidant vitamin C. Meanwhile, the RT-PCR result indicated that the Nrf2/Keap1 downsteam genes including HO-1, NQO-1, and SOD2 were involved in this process. In sum, these experiments suggest that high salt intake would lead to high risk of liver damage and fibrosis in both adults and developing embryos. The pathological mechanism may be the result from an imbalance between oxidative stress and the antioxidant system.
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Guang
authors: G
authors: Wang
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Cheung-kwan
authors: CK
authors: Yeung
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Wing-Yan
authors: WY
authors: Wong
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Nuan
authors: N
authors: Zhang
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Yi-fan
authors: YF
authors: Wei
authors: Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University , Guangzhou 510006, China.
authors: Jing-li
authors: JL
authors: Zhang
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Yu
authors: Y
authors: Yan
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Ching-yee
authors: CY
authors: Wong
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Jun-jie
authors: JJ
authors: Tang
authors: Division of Cell and Developmental Biology, University of Dundee , Dundee DD1 5EH, United Kingdom.
authors: Manli
authors: M
authors: Chuai
authors: Key Laboratory for Regenerative Medicine of the Ministry of Education, School of Biomedical Sciences, Chinese University of Hong Kong , Shatin, Hong Kong, China.
authors: Kenneth Ka Ho
authors: KK
authors: Lee
authors: Institute of Vascular Biological Sciences, Guangdong Pharmaceutical University , Guangzhou 510006, China.
authors: Li-jing
authors: LJ
authors: Wang
authors: Division of Histology and Embryology, Key Laboratory for Regenerative Medicine of the Ministry of Education, Medical College, Jinan University , Guangzhou 510632, China.
authors: Xuesong
authors: X
authors: Yang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D002642:Chick Embryo; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D022781:Hepatocytes / Q000166:cytology / Q000378:metabolism; D006801:Humans; D000072019:Kelch-Like ECH-Associated Protein 1; D008103:Liver Cirrhosis / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012965:Sodium Chloride / Q000009:adverse effects* / Q000032:analysis / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D003598:Cytoskeletal Proteins; C117301:Keap1 protein, mouse; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; D017382:Reactive Oxygen Species; D012965:Sodium Chloride
keywords: ROS; chick embryos; high salt; liver fibrosis; mouse