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Poole B, Oshins R, Huo Z, Aranyos A, West J, Duarte S, Clark VC, Beduschi T, Zarrinpar A, Brantly M, Khodayari N. Sirtuin3 promotes the degradation of hepatic Z alpha-1 antitrypsin through lipophagy. Hepatol Commun 2024; 8:e0370. [PMID: 38285890 PMCID: PMC10830086 DOI: 10.1097/hc9.0000000000000370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/01/2023] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Alpha-1 antitrypsin deficiency (AATD) is a genetic disease caused by misfolding and accumulation of mutant alpha-1 antitrypsin (ZAAT) in the endoplasmic reticulum of hepatocytes. Hepatic ZAAT aggregates acquire a toxic gain-of-function that impacts the endoplasmic reticulum which is theorized to cause liver disease in individuals with AATD who present asymptomatic until late-stage cirrhosis. Currently, there is no treatment for AATD-mediated liver disease except liver transplantation. In our study of mitochondrial RNA, we identified that Sirtuin3 (SIRT3) plays a role in the hepatic phenotype of AATD. METHODS Utilizing RNA and protein analysis in an in vitro AATD model, we investigated the role of SIRT3 in the pathophysiology of AATD-mediated liver disease while also characterizing our novel, transgenic AATD mouse model. RESULTS We show lower expression of SIRT3 in ZAAT-expressing hepatocytes. In contrast, the overexpression of SIRT3 increases hepatic ZAAT degradation. ZAAT degradation mediated by SIRT3 appeared independent of proteasomal degradation and regular autophagy pathways. We observed that ZAAT-expressing hepatocytes have aberrant accumulation of lipid droplets, with ZAAT polymers localizing on the lipid droplet surface in a direct interaction with Perilipin2, which coats intracellular lipid droplets. SIRT3 overexpression also induced the degradation of lipid droplets in ZAAT-expressing hepatocytes. We observed that SIRT3 overexpression induces lipophagy by enhancing the interaction of Perilipin2 with HSC70. ZAAT polymers then degrade as a consequence of the mobilization of lipids through this process. CONCLUSIONS In this context, SIRT3 activation may eliminate the hepatic toxic gain-of-function associated with the polymerization of ZAAT, providing a rationale for a potential novel therapeutic approach to the treatment of AATD-mediated liver disease.
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Affiliation(s)
- Brittney Poole
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Regina Oshins
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Zhiguang Huo
- Department of Biostatistics, College of Public Health, University of Florida, Gainesville, Florida, USA
| | - Alek Aranyos
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Jesse West
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Sergio Duarte
- Department of Surgery, Division of Transplantation and Hepatobiliary Surgery, University of Florida, Gainesville, Florida, USA
| | - Virginia C. Clark
- Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, University of Florida, Gainesville, Florida, USA
| | - Thiago Beduschi
- Department of Surgery, Division of Transplantation and Hepatobiliary Surgery, University of Florida, Gainesville, Florida, USA
| | - Ali Zarrinpar
- Department of Surgery, Division of Transplantation and Hepatobiliary Surgery, University of Florida, Gainesville, Florida, USA
| | - Mark Brantly
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, Florida, USA
| | - Nazli Khodayari
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, Florida, USA
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Perez-Luz S, Matamala N, Gomez-Mariano G, Janciauskiene S, Martínez-Delgado B. NAFLD and AATD Are Two Diseases with Unbalanced Lipid Metabolism: Similarities and Differences. Biomedicines 2023; 11:1961. [PMID: 37509601 PMCID: PMC10377048 DOI: 10.3390/biomedicines11071961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/04/2023] [Accepted: 07/07/2023] [Indexed: 07/30/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a type of steatosis commonly associated with obesity, dyslipidemia, hypertension, and diabetes. Other diseases such as inherited alpha-1 antitrypsin deficiency (AATD) have also been related to the development of liver steatosis. The primary reasons leading to hepatic lipid deposits can be genetic and epigenetic, and the outcomes range from benign steatosis to liver failure, as well as to extrahepatic diseases. Progressive hepatocellular damage and dysregulated systemic immune responses can affect extrahepatic organs, specifically the heart and lungs. In this review, we discuss the similarities and differences between the molecular pathways of NAFLD and AATD, and the putative value of hepatic organoids as novel models to investigate the physio pathological mechanisms of liver steatosis.
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Affiliation(s)
- Sara Perez-Luz
- Molecular Genetics Unit, Institute of Rare Diseases Research (IIER), Institute of Health Carlos III (ISCIII), 28220 Madrid, Spain
| | - Nerea Matamala
- Molecular Genetics Unit, Institute of Rare Diseases Research (IIER), Institute of Health Carlos III (ISCIII), 28220 Madrid, Spain
| | - Gema Gomez-Mariano
- Molecular Genetics Unit, Institute of Rare Diseases Research (IIER), Institute of Health Carlos III (ISCIII), 28220 Madrid, Spain
| | - Sabina Janciauskiene
- Department of Respiratory Medicine and Infectious Diseases, Biomedical Research in Endstage and Obstructive Lung Disease Hannover BREATH, Member of the German Center for Lung Research DZL, Hannover Medical School, 30625 Hannover, Germany
| | - Beatriz Martínez-Delgado
- Molecular Genetics Unit, Institute of Rare Diseases Research (IIER), Institute of Health Carlos III (ISCIII), 28220 Madrid, Spain
- CIBER de Enfermedades Raras, Instituto de Salud Carlos III, CIBERER U758, 28029 Madrid, Spain
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