Liver Cholesterol Overload Aggravates Obstructive Cholestasis by Inducing Oxidative Stress and Premature Death in Mice

Nonalcoholic steatohepatitis is one of the leading causes of liver disease. Dietary factors determine the clinical presentation of steatohepatitis and can influence the progression of related diseases. Cholesterol has emerged as a critical player in the disease and hence consumption of cholesterol-enriched diets can lead to a progressive form of the disease. The aim was to investigate the impact of liver cholesterol overload on the progression of the obstructive cholestasis in mice subjected to bile duct ligation surgery. Mice were fed with a high cholesterol diet for two days and then were subjected to surgery procedure; histological, biochemical, and molecular analyses were conducted to address the effect of cholesterol in liver damage. Mice under the diet were more susceptible to damage. Results show that cholesterol fed mice exhibited increased apoptosis and oxidative stress as well as reduction in cell proliferation. Mortality following surgery was higher in HC fed mice. Liver cholesterol impairs the repair of liver during obstructive cholestasis and aggravates the disease with early fatal consequences; these effects were strongly associated with oxidative stress.This work was supported by grants of the CONACYT 252942, 236558, and 166042, CONACYT Fronteras de la Ciencia 1320, Asociación Mexicana de Hepatología, and SEP-PRODEP-913026-1461211, Universidad Autónoma Metropolitana Iztapalapa, by grants SAF-2011-23031 and SAF-2012-34831 from Plan Nacional de I+D, Spain, Fundació la Marató de TV3, La Mutua Madrileña, PI11/0325 (META) Grant from the Instituto Salud Carlos III, by the support of CIBEREHD, and by the Center Grant P50-AA-11999 from Research Center for Liver and Pancreatic Diseases funded by NIAAA/NIH.Peer Reviewe

GDF11 restricts aberrant lipogenesis and changes in mitochondrial structure and function in human hepatocellular carcinoma cells

Growth differentiation factor 11 (GDF11) has been characterized as a key regulator of differentiation in cells that retain stemness features. Recently, it has been reported that GDF11 exerts tumor‐suppressive properties in hepatocellular carcinoma cells, decreasing clonogenicity, proliferation, spheroid formation, and cellular function, all associated with a decrement in stemness features, resulting in mesenchymal to epithelial transition and loss of aggressiveness. The aim of the present work was to investigate the mechanism associated with the tumor‐suppressive properties displayed by GDF11 in liver cancer cells. Hepatocellular carcinoma‐derived cell lines were exposed to GDF11 (50 ng/ml), RNA‐seq analysis in Huh7 cell line revealed that GDF11 exerted profound transcriptomic impact, which involved regulation of cholesterol metabolic process, steroid metabolic process as well as key signaling pathways, resembling endoplasmic reticulum‐related functions. Cholesterol and triglycerides determination in Huh7 and Hep3B cells treated with GDF11 exhibited a significant decrement in the content of these lipids. The mTOR signaling pathway was downregulated, and this was associated with a reduction in key proteins involved in the mevalonate pathway. In addition, real‐time metabolism assessed by Seahorse technology showed abridged glycolysis as well as glycolytic capacity, closely related to an impaired oxygen consumption rate and decrement in adenosine triphosphate production. Finally, transmission electron microscopy revealed mitochondrial abnormalities, such as cristae disarrangement, consistent with metabolic changes. Results provide evidence that GDF11 impairs cancer cell metabolism targeting lipid homeostasis, glycolysis, and mitochondria function and morphology.This study was partially funded by a grant from the Consejo Nacionalde Ciencia y Tecnología (CONACYT): CB252942, Fronteras de laCiencia1320, Apoyo al Fortalecimiento y Desarrollo de la Infra-estructura 2013205941 and 2017280788, and Universidad Autonoma Metropolitana. We thank the confocal core unit of the Universidad Autonoma Metropolitana Iztapalapa. SH, MGR, ASN arescholarship holders from Conacyt. We acknowledge the support fromgrants: PID2019111669RB, and SAF201785877R from PlanNacional de IþD, Spain, and by the CIBEREHD; the center grantP50AA011999 Southern California Research Center for ALPD andCirrhosis funded by the National Institute on Alcohol Abuse andAlcoholism/National Institutes of Health (NIH); as well as supportfrom AGAUR of the Generalitat de Catalunya SGR20171112,European Cooperation in Science & Technology (COST) ACTIONCA17112 Prospective European DrugInduced Liver Injury Network,and the Fundación BBVA. RED Nacional 2018102799Tdeenfermedades metabólicas y Cáncer y Proyecto 201916/31 DeFundacion Marató TV3Peer reviewe