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Rodriguez AJ, Mastronardi CA, Paz-Filho GJ. New advances in the treatment of generalized lipodystrophy: role of metreleptin. Ther Clin Risk Manag 2015; 11:1391-400. [PMID: 26396524 PMCID: PMC4577254 DOI: 10.2147/tcrm.s66521] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Recombinant methionyl human leptin or metreleptin is a synthetic leptin analog that has been trialed in patients with leptin-deficient conditions, such as leptin deficiency due to mutations in the leptin gene, hypothalamic amenorrhea, and lipodystrophy syndromes. These syndromes are characterized by partial or complete absence of adipose tissue and hormones derived from adipose tissue, most importantly leptin. Patients deficient in leptin exhibit a number of severe metabolic abnormalities such as hyperglycemia, hypertriglyceridemia, and hepatic steatosis, which can progress to diabetes mellitus, acute pancreatitis, and hepatic cirrhosis, respectively. For the management of these abnormalities, multiple therapies are usually required, and advanced stages may be progressively difficult to treat. Following many successful trials, the US Food and Drug Administration approved metreleptin for the treatment of non-HIV-related forms of generalized lipodystrophy. Leptin replacement therapy with metreleptin has, in many cases, reversed these metabolic complications, with improvements in glucose-insulin-lipid homeostasis, and regression of fatty liver disease. Besides being effective, a daily subcutaneous administration of metreleptin is generally safe, but the causal association between metreleptin and immune complications (such as lymphoma) is still unclear. Moreover, further investigation is needed to elucidate mechanisms by which metreleptin leads to the development of anti-leptin antibodies. Herein, we review clinical aspects of generalized lipodystrophy and the pharmacological profile of metreleptin. Further, we examine studies that assessed the safety and efficacy of metreleptin, and outline some clinical perspectives on the drug.
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Affiliation(s)
| | - Claudio A Mastronardi
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
| | - Gilberto J Paz-Filho
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia
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Abstract
Congenital generalized lipodystrophy (CGL) is a heterogeneous autosomal recessive disorder characterized by a near complete lack of adipose tissue from birth and, later in life, the development of metabolic complications, such as diabetes mellitus, hypertriglyceridaemia and hepatic steatosis. Four distinct subtypes of CGL exist: type 1 is associated with AGPAT2 mutations; type 2 is associated with BSCL2 mutations; type 3 is associated with CAV1 mutations; and type 4 is associated with PTRF mutations. The products of these genes have crucial roles in phospholipid and triglyceride synthesis, as well as in the formation of lipid droplets and caveolae within adipocytes. The predominant cause of metabolic complications in CGL is excess triglyceride accumulation in the liver and skeletal muscle owing to the inability to store triglycerides in adipose tissue. Profound hypoleptinaemia further exacerbates metabolic derangements by inducing a voracious appetite. Patients require psychological support, a low-fat diet, increased physical activity and cosmetic surgery. Aside from conventional therapy for hyperlipidaemia and diabetes mellitus, metreleptin replacement therapy can dramatically improve metabolic complications in patients with CGL. In this Review, we discuss the molecular genetic basis of CGL, the pathogenesis of the disease's metabolic complications and therapeutic options for patients with CGL.
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Affiliation(s)
- Nivedita Patni
- Division of Paediatric Endocrinology, Department of Paediatrics, Department of Internal Medicine, Centre for Human Nutrition, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8537, USA
| | - Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8537, USA
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Schrauwen I, Szelinger S, Siniard AL, Kurdoglu A, Corneveaux JJ, Malenica I, Richholt R, Van Camp G, De Both M, Swaminathan S, Turk M, Ramsey K, Craig DW, Narayanan V, Huentelman MJ. A Frame-Shift Mutation in CAV1 Is Associated with a Severe Neonatal Progeroid and Lipodystrophy Syndrome. PLoS One 2015; 10:e0131797. [PMID: 26176221 PMCID: PMC4503302 DOI: 10.1371/journal.pone.0131797] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/05/2015] [Indexed: 12/20/2022] Open
Abstract
A 3-year-old female patient presenting with an unknown syndrome of a neonatal progeroid appearance, lipodystrophy, pulmonary hypertension, cutis marmorata, feeding disorder and failure to thrive was investigated by whole-genome sequencing. This revealed a de novo, heterozygous, frame-shift mutation in the Caveolin1 gene (CAV1) (p.Phe160X). Mutations in CAV1, encoding the main component of the caveolae in plasma membranes, cause Berardinelli-Seip congenital lipodystrophy type 3 (BSCL). Although BSCL is recessive, heterozygous carriers either show a reduced phenotype of partial lipodystrophy, pulmonary hypertension, or no phenotype. To investigate the pathogenic mechanisms underlying this syndrome in more depth, we performed next generation RNA sequencing of peripheral blood, which showed several dysregulated pathways in the patient that might be related to the phenotypic progeroid features (apoptosis, DNA repair/replication, mitochondrial). Secondly, we found a significant down-regulation of known Cav1 interaction partners, verifying the dysfunction of CAV1. Other known progeroid genes and lipodystrophy genes were also dysregulated. Next, western blotting of lysates of cultured fibroblasts showed that the patient shows a significantly decreased expression of wild-type CAV1 protein, demonstrating a loss-of-function mutation, though her phenotype is more severe that other heterozygotes with similar mutations. This phenotypic variety could be explained by differences in genetic background. Indications for this are supported by additional rare variants we found in AGPAT2 and LPIN1 lipodystrophy genes. CAV1, AGPAT2 and LPIN1 all play an important role in triacylglycerol (TAG) biosynthesis in adipose tissue, and the defective function in different parts of this pathway, though not all to the same extend, could contribute to a more severe lipoatrophic phenotype in this patient. In conclusion, we report, for the first time, an association of CAV1 dysfunction with a syndrome of severe premature aging and lipodystrophy. This may contribute to a better understanding of the aging process and pathogenic mechanisms that contribute to premature aging.
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Affiliation(s)
- Isabelle Schrauwen
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Szabolcs Szelinger
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Ashley L. Siniard
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Ahmet Kurdoglu
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Jason J. Corneveaux
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Ivana Malenica
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Ryan Richholt
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Guy Van Camp
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Matt De Both
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Shanker Swaminathan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Mari Turk
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - David W. Craig
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
| | - Matthew J. Huentelman
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ, United States of America
- * E-mail:
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Abstract
Lipodystrophy syndromes comprise a group of rare, heterogeneous disorders characterized by progressive loss of fat tissue, mainly from subcutaneous compartment and occasionally affecting visceral fat. Lipoatrophy may be partial, localized, or generalized. The latter cases are usually accompanied by metabolic-related disorders, including insulin resistance, diabetes mellitus, hyperlipemia, progressive hepatic disease and anabolic state. Treatment for lipodystrophy has increased interest in recent years because a new lipoatrophic population-patients who have HIV-associated lipodystrophy--is much more numerous than the whole number of patients affected by classic lipodystrophy entities.
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Affiliation(s)
- Pedro Herranz
- Department of Dermatology, La Paz University Hospital, Universidad Autónoma, Paseo Castellana 261, 28046 Madrid, Spain.
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