Quantitative Lipid Profiling Reveals Major Differences between Liver Organoids with Normal PiM and Deficient PiZ Variants of Alpha-1-antitrypsin

• Published in: International journal of molecular sciences 2023-08, Vol.24 (15), p.12472
• Main Authors: Pérez-Luz, Sara, Lalchandani, Jaanam, Matamala, Nerea, Barrero, Maria Jose, Gil-Martín, Sara, Saz, Sheila Ramos-Del, Varona, Sarai, Monzón, Sara, Cuesta, Isabel, Justo, Iago, Marcacuzco, Alberto, Hierro, Loreto, Garfia, Cristina, Gomez-Mariano, Gema, Janciauskiene, Sabina, Martínez-Delgado, Beatriz
• Format: Article
• Language: English
• Subjects: AAT aggregates; alpha 1-Antitrypsin - genetics; alpha 1-Antitrypsin Deficiency - complications; alpha 1-Antitrypsin Deficiency - genetics; alpha-1 antitrypsin (AAT); alpha-1 antitrypsin deficiency (AATD); Analysis; Cardiolipin; Cholesterol; Cytochrome; Gene expression; Genes; Genetic aspects; Humans; lipid accumulation; Lipids; Liver; Liver cirrhosis; Liver Cirrhosis - etiology; Liver diseases; liver organoids; Medical research; Medicine, Experimental; Metabolism; Mutation; Organoids; Patients; Physiological aspects; Polymerization; Polymers; Proteins; Transcription factors; Triglycerides
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms241512472

Different mutations in the gene result in alpha-1 antitrypsin (AAT) deficiency and in an increased risk for the development of liver diseases. More than 90% of severe deficiency patients are homozygous for Z (Glu342Lys) mutation. This mutation causes Z-AAT polymerization and intrahepatic accumulation which can result in hepatic alterations leading to steatosis, fibrosis, cirrhosis, and/or hepatocarcinoma. We aimed to investigate lipid status in hepatocytes carrying Z and normal M alleles of the gene. Hepatic organoids were developed to investigate lipid alterations. Lipid accumulation in HepG2 cells overexpressing Z-AAT, as well as in patient-derived hepatic organoids from Pi*MZ and Pi*ZZ individuals, was evaluated by Oil-Red staining in comparison to HepG2 cells expressing M-AAT and liver organoids from Pi*MM controls. Furthermore, mass spectrometry-based lipidomics analysis and transcriptomic profiling were assessed in Pi*MZ and Pi*ZZ organoids. HepG2 cells expressing Z-AAT and liver organoids from Pi*MZ and Pi*ZZ patients showed intracellular accumulation of AAT and high numbers of lipid droplets. These latter paralleled with augmented intrahepatic lipids, and in particular altered proportion of triglycerides, cholesterol esters, and cardiolipins. According to transcriptomic analysis, Pi*ZZ organoids possess many alterations in genes and cellular processes of lipid metabolism with a specific impact on the endoplasmic reticulum, mitochondria, and peroxisome dysfunction. Our data reveal a relationship between intrahepatic accumulation of Z-AAT and alterations in lipid homeostasis, which implies that liver organoids provide an excellent model to study liver diseases related to the mutation of the gene.