1. The Propensity of the Human Liver to Form Large Lipid Droplets Is Associated with PNPLA3 Polymorphism, Reduced INSIG1 and NPC1L1 Expression and Increased Fibrogenetic Capacity
- Author
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Monica Mischitelli, Gianluca Mennini, Massimo Rossi, Antonio Molinaro, Flaminia Ferri, Maria Eva Argenziano, Alessandro Corsi, Mara Riminucci, Quirino Lai, Sergio Morini, Alfredo Cantafora, G. Spadetta, Eugenio Gaudio, Francesco Pugliese, Guido Carpino, Simona Parisse, Simone Carotti, and Stefano Ginanni Corradini
- Subjects
single nucleotide ,0301 basic medicine ,Male ,lipid droplets ,NPC1L1 ,Hepacivirus ,medicine.disease_cause ,polymorphism ,chemistry.chemical_compound ,0302 clinical medicine ,Fibrosis ,Non-alcoholic Fatty Liver Disease ,Lipid droplet ,Biology (General) ,Spectroscopy ,large droplet macrovesicular steatosis ,Intracellular Signaling Peptides and Proteins ,General Medicine ,Middle Aged ,Computer Science Applications ,Chemistry ,Liver ,030211 gastroenterology & hepatology ,Female ,lipids (amino acids, peptides, and proteins) ,hepatic stellate cells ,Adult ,medicine.medical_specialty ,QH301-705.5 ,Hepatitis C virus ,cholesterol ,fibrosis ,INSIG-1 ,liver donor ,NAFLD ,PNPLA3 ,adult ,aged ,female ,gene expression regulation ,hepacivirus ,hepatocytes ,humans ,intracellular signaling peptides and proteins ,lipase ,liver ,male ,membrane proteins ,membrane transport proteins ,middle aged ,non-alcoholic fatty liver disease ,retrospective studies ,Polymorphism, Single Nucleotide ,Catalysis ,Article ,Inorganic Chemistry ,03 medical and health sciences ,Internal medicine ,medicine ,Humans ,Physical and Theoretical Chemistry ,Molecular Biology ,QD1-999 ,Aged ,Retrospective Studies ,Cholesterol ,Organic Chemistry ,Membrane Proteins ,Membrane Transport Proteins ,Lipid metabolism ,Lipase ,medicine.disease ,Transplantation ,030104 developmental biology ,Endocrinology ,chemistry ,Gene Expression Regulation ,Hepatic stellate cell ,Hepatocytes ,Steatosis - Abstract
In nonalcoholic steatohepatitis animal models, an increased lipid droplet size in hepatocytes is associated with fibrogenesis. Hepatocytes with large droplet (Ld-MaS) or small droplet (Sd-MaS) macrovesicular steatosis may coexist in the human liver, but the factors associated with the predominance of one type over the other, including hepatic fibrogenic capacity, are unknown. In pre-ischemic liver biopsies from 225 consecutive liver transplant donors, we retrospectively counted hepatocytes with Ld-MaS and Sd-MaS and defined the predominant type of steatosis as involving ≥50% of steatotic hepatocytes. We analyzed a donor Patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 polymorphism, hepatic expression of proteins involved in lipid metabolism by RT-PCR, hepatic stellate cell (HSC) activation by α-SMA immunohistochemistry and, one year after transplantation, histological progression of fibrosis due to Hepatitis C Virus (HCV) recurrence. Seventy-four livers had no steatosis, and there were 98 and 53 with predominant Ld-MaS and Sd-MaS, respectively. In linear regression models, adjusted for many donor variables, the percentage of steatotic hepatocytes affected by Ld-MaS was inversely associated with hepatic expression of Insulin Induced Gene 1 (INSIG-1) and Niemann-Pick C1-Like 1 gene (NPC1L1) and directly with donor PNPLA3 variant M, HSC activation and progression of post-transplant fibrosis. In humans, Ld-MaS formation by hepatocytes is associated with abnormal PNPLA3-mediated lipolysis, downregulation of both the intracellular cholesterol sensor and cholesterol reabsorption from bile and increased hepatic fibrogenesis.
- Published
- 2021