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Padova G, Prudente S, Vinciguerra F, Sudano D, Baratta R, Bellacchio E, Trischitta V, Vallone A, Sciacca L, Frittitta L. The novel loss of function Ile354Val mutation in PPARG causes familial partial lipodystrophy. Acta Diabetol 2020; 57:589-596. [PMID: 31863320 DOI: 10.1007/s00592-019-01462-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/25/2019] [Indexed: 01/21/2023]
Abstract
AIMS Familial partial lipodystrophy (FPLD) is a rare autosomal dominant disorder, mostly due to mutations in lamin A (LMNA) or in peroxisome proliferator-activated receptor gamma (PPARG) genes. In the present study, we aimed to identify and functionally characterize the genetic defect underlying FPLD in an Italian family presenting with several affected individuals in three consecutive generations. METHODS Mutational screening by direct Sanger sequencing has been carried out on both LMNA and PPARG genes. In silico analyses and functional in vitro studies on transfected cell lines have been also performed to evaluate the biological impact of the identified mutation. RESULTS We identified a novel PPARG missense mutation (i.e., PPARγ2 Ile354Val) segregating with FPLD in the study family. In silico analyses and in vitro experiments showed that probably altering the PPARγ2 ligand binding domain conformation, the Ile354Val aminoacid change leads to a significant reduction (i.e., ~ 30-35%) of transcriptional activity in the mutant receptor, with no evidences of a dominant negative effect on the wild-type receptor. CONCLUSIONS Our present data extend the spectrum of PPARG mutations responsible for FPLD3 and reinforce the notion that even loss of function mutations affecting transcriptional activity to an extent lower than that observed in the case of haploinsufficiency are able to cause a severe FPLD3 phenotype.
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Affiliation(s)
| | - Sabrina Prudente
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Federica Vinciguerra
- Endocrine Section, Department of Clinical and Experimental Medicine, University of Catania, Via Palermo 636, 95122, Catania, Italy
| | - Dora Sudano
- Endocrine Section, Department of Clinical and Experimental Medicine, University of Catania, Via Palermo 636, 95122, Catania, Italy
| | | | - Emanuele Bellacchio
- Bioinformatics Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Research Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Vincenzo Trischitta
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
- Department of Experimental Medicine, "Sapienza" University, Rome, Italy
| | | | - Laura Sciacca
- Endocrinology Unit, Garibaldi Hospital, Catania, Italy
- Endocrine Section, Department of Clinical and Experimental Medicine, University of Catania, Via Palermo 636, 95122, Catania, Italy
| | - Lucia Frittitta
- Endocrinology Unit, Garibaldi Hospital, Catania, Italy.
- Endocrine Section, Department of Clinical and Experimental Medicine, University of Catania, Via Palermo 636, 95122, Catania, Italy.
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Abstract
Nonalcoholic fatty liver disease (NAFLD) affects one-third of the population and two-thirds of patients with obesity or type 2 diabetes (T2DM). Its more aggressive form is known as nonalcoholic steatohepatitis (NASH) and is characterized by hepatocyte necrosis, inflammation and often fibrosis. The presence of fibrosis indicates a more aggressive course and may lead to cirrhosis. Premature mortality in NASH is related to both hepatic (cirrhosis and hepatocellular carcinoma) and extra-hepatic complications, largely cardiovascular disease (CVD). Many therapeutic agents have been tested, but still none approved specifically for NASH. Treatment of NAFLD includes aggressive management of diabetes and cardiovascular risk factors, although the role of controlling hyperglycemia per se in patients with T2DM and NASH remains unknown. Agents tested with some success in non-diabetic patients with NASH include pioglitazone, liraglutide, vitamin E and to a lesser degree, pentoxiphylline. In patients with T2DM and NASH only pioglitazone has shown to significantly improve liver histology, with only a handful of patients with diabetes having been studied with other modalities. This review focuses on available agents for NASH to assist clinicians in the management of these complex patients. Many novel compounds are being studied and will likely make combination therapy for NASH a reality in the future.
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Affiliation(s)
- Diana Barb
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA; Division of Endocrinology, Diabetes and Metabolism at Malcom Randall Veterans Affairs Medical Center, Gainesville, FL, USA
| | - Paola Portillo-Sanchez
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA; Division of Endocrinology, Diabetes and Metabolism at Malcom Randall Veterans Affairs Medical Center, Gainesville, FL, USA
| | - Kenneth Cusi
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Florida College of Medicine, Gainesville, FL, USA; Division of Endocrinology, Diabetes and Metabolism at Malcom Randall Veterans Affairs Medical Center, Gainesville, FL, USA.
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Portillo-Sanchez P, Cusi K. Treatment of Nonalcoholic Fatty Liver Disease (NAFLD) in patients with Type 2 Diabetes Mellitus. Clin Diabetes Endocrinol 2016; 2:9. [PMID: 28702244 PMCID: PMC5471954 DOI: 10.1186/s40842-016-0027-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/28/2016] [Indexed: 02/08/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is believed to be the most common chronic liver disease, affecting at least one-third of the population worldwide. The more aggressive form is known as nonalcoholic steatohepatitis (NASH) and characterized by hepatocyte necrosis and inflammation. The presence of fibrosis is not uncommon. Fibrosis indicates a more aggressive course and patients with NASH that are at high-risk of cirrhosis and premature mortality, as well as at increased risk of hepatocellular carcinoma (HCC). Patients with type 2 diabetes mellitus (T2DM) are at the highest risk for the development of NASH, even in the setting of normal plasma aminotransferase levels. The presence of dysfunctional adipose tissue in most overweight and obese subjects, combined with insulin resistance, hyperglycemia, and atherogenic dyslipidemia, contribute to their increased cardiovascular risk. Many therapeutic agents have been tested for the treatment of NASH but few studies have focused in patients with T2DM. At the present moment, the only FDA-approved agents that in controlled studies have shown to significantly improve liver histology in patients with diabetes are pioglitazone and liraglutide. Current research efforts are centering on the mechanisms for intrahepatic triglyceride accumulation and for the development of steatohepatitis, the role of mitochondrial dysfunction in NASH, and the impact of improving glycemic control per se on the natural history of the disease. This brief review summarizes our current knowledge on the pharmacological agents available for the treatment of NASH to assist healthcare providers in the management of these challenging patients.
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Affiliation(s)
- Paola Portillo-Sanchez
- Division of Endocrinology, Diabetes and Metabolism, University of Florida, 1600 SW Archer Road, room H-2, Gainesville, FL 32610 USA
| | - Kenneth Cusi
- Division of Endocrinology, Diabetes and Metabolism, University of Florida, 1600 SW Archer Road, room H-2, Gainesville, FL 32610 USA
- Division of Endocrinology, Diabetes, and Metabolism, Malcom Randall Veterans Affairs Medical Center, Gainesville, FL 32608 USA
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