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Simha V, Lanza IR, Dasari S, Klaus KA, Le Brasseur N, Vuckovic I, Laurenti MC, Cobelli C, Port JD, Nair KS. Impaired Muscle Mitochondrial Function in Familial Partial Lipodystrophy. J Clin Endocrinol Metab 2022; 107:346-362. [PMID: 34614176 PMCID: PMC8764358 DOI: 10.1210/clinem/dgab725] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Indexed: 01/04/2023]
Abstract
CONTEXT Familial partial lipodystrophy (FPL), Dunnigan variety is characterized by skeletal muscle hypertrophy and insulin resistance besides fat loss from the extremities. The cause for the muscle hypertrophy and its functional consequences is not known. OBJECTIVE To compare muscle strength and endurance, besides muscle protein synthesis rate between subjects with FPL and matched controls (n = 6 in each group). In addition, we studied skeletal muscle mitochondrial function and gene expression pattern to help understand the mechanisms for the observed differences. METHODS Body composition by dual-energy X-ray absorptiometry, insulin sensitivity by minimal modelling, assessment of peak muscle strength and fatigue, skeletal muscle biopsy and calculation of muscle protein synthesis rate, mitochondrial respirometry, skeletal muscle transcriptome, proteome, and gene set enrichment analysis. RESULTS Despite increased muscularity, FPL subjects did not demonstrate increased muscle strength but had earlier fatigue on chest press exercise. Decreased mitochondrial state 3 respiration in the presence of fatty acid substrate was noted, concurrent to elevated muscle lactate and decreased long-chain acylcarnitine. Based on gene transcriptome, there was significant downregulation of many critical metabolic pathways involved in mitochondrial biogenesis and function. Moreover, the overall pattern of gene expression was indicative of accelerated aging in FPL subjects. A lower muscle protein synthesis and downregulation of gene transcripts involved in muscle protein catabolism was observed. CONCLUSION Increased muscularity in FPL is not due to increased muscle protein synthesis and is likely due to reduced muscle protein degradation. Impaired mitochondrial function and altered gene expression likely explain the metabolic abnormalities and skeletal muscle dysfunction in FPL subjects.
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MESH Headings
- Absorptiometry, Photon
- Adult
- Aged
- Female
- Gene Expression Profiling
- Humans
- Lipodystrophy, Familial Partial/genetics
- Lipodystrophy, Familial Partial/metabolism
- Lipodystrophy, Familial Partial/pathology
- Lipodystrophy, Familial Partial/physiopathology
- Male
- Middle Aged
- Mitochondria, Muscle/metabolism
- Mitochondria, Muscle/pathology
- Muscle Strength/physiology
- Muscle, Skeletal/cytology
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Physical Endurance/physiology
- Proteolysis
- Young Adult
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Affiliation(s)
- Vinaya Simha
- Divisions of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
| | - Ian R Lanza
- Divisions of Endocrinology, Mayo Clinic, Rochester, MN 55905, USA
| | - Surendra Dasari
- Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN 55905, USA
| | | | - Nathan Le Brasseur
- Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA
| | - Ivan Vuckovic
- Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN 55905, USA
| | | | | | - John D Port
- Radiology, Mayo Clinic, Rochester, MN 55905, USA
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Varlet AA, Helfer E, Badens C. Molecular and Mechanobiological Pathways Related to the Physiopathology of FPLD2. Cells 2020; 9:cells9091947. [PMID: 32842478 PMCID: PMC7565540 DOI: 10.3390/cells9091947] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/15/2022] Open
Abstract
Laminopathies are rare and heterogeneous diseases affecting one to almost all tissues, as in Progeria, and sharing certain features such as metabolic disorders and a predisposition to atherosclerotic cardiovascular diseases. These two features are the main characteristics of the adipose tissue-specific laminopathy called familial partial lipodystrophy type 2 (FPLD2). The only gene that is involved in FPLD2 physiopathology is the LMNA gene, with at least 20 mutations that are considered pathogenic. LMNA encodes the type V intermediate filament lamin A/C, which is incorporated into the lamina meshwork lining the inner membrane of the nuclear envelope. Lamin A/C is involved in the regulation of cellular mechanical properties through the control of nuclear rigidity and deformability, gene modulation and chromatin organization. While recent studies have described new potential signaling pathways dependent on lamin A/C and associated with FPLD2 physiopathology, the whole picture of how the syndrome develops remains unknown. In this review, we summarize the signaling pathways involving lamin A/C that are associated with the progression of FPLD2. We also explore the links between alterations of the cellular mechanical properties and FPLD2 physiopathology. Finally, we introduce potential tools based on the exploration of cellular mechanical properties that could be redirected for FPLD2 diagnosis.
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Affiliation(s)
- Alice-Anaïs Varlet
- Marseille Medical Genetics (MMG), INSERM, Aix Marseille University, 13005 Marseille, France;
| | - Emmanuèle Helfer
- Centre Interdisciplinaire de Nanoscience de Marseille (CINAM), CNRS, Aix Marseille University, 13009 Marseille, France
- Correspondence: (E.H.); (C.B.); Tel.: +33-6-60-30-28-91 (E.H.); +33-4-91-78-68-94 (C.B.)
| | - Catherine Badens
- Marseille Medical Genetics (MMG), INSERM, Aix Marseille University, 13005 Marseille, France;
- Correspondence: (E.H.); (C.B.); Tel.: +33-6-60-30-28-91 (E.H.); +33-4-91-78-68-94 (C.B.)
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Vasandani C, Li X, Sekizkardes H, Adams-Huet B, Brown RJ, Garg A. Diagnostic Value of Anthropometric Measurements for Familial Partial Lipodystrophy, Dunnigan Variety. J Clin Endocrinol Metab 2020; 105:5810271. [PMID: 32193531 PMCID: PMC7202860 DOI: 10.1210/clinem/dgaa137] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 03/18/2020] [Indexed: 01/17/2023]
Abstract
CONTEXT Familial partial lipodystrophy, Dunnigan variety (FPLD2) is a rare autosomal dominant disorder resulting from LMNA causal variants, which is characterized by loss of subcutaneous fat from the extremities and predisposition to metabolic complications. The diagnostic value of various anthropometric measurements for FPLD2 remains unknown. OBJECTIVE To determine specificity and sensitivity of anthropometric measurements for the diagnosis of FPLD2. METHODS We measured skinfold thickness and regional body fat by dual energy X-ray absorptiometry (DXA) in 50 adult females and 6 males with FPLD2 at UT Southwestern and compared their data with the sex- and age-matched controls from the National Health and Nutrition Examination Survey (NHANES) 1999-2010. We further compared data from 1652 unaffected females from the Dallas Heart Study and 23 females with FPLD2 from the National Institutes of Health with the NHANES data. RESULTS The DXA-derived lower limb fat (%) had the best specificity (0.995) and sensitivity (1.0) compared with the upper limb fat, truncal fat, the ratio of lower limb to truncal fat, and triceps skinfold thickness for adult females with FPLD2. The lower limb fat below 1st percentile of NHANES females had a false-positive rate of 0.0054 and a false negative rate of 0. The diagnostic value of anthropometric parameters could not be determined for males with FPLD2 due to small sample size. CONCLUSIONS The lower limb fat (%) is the best objective anthropometric measure for diagnosing FPLD2 in females. Women with below the 1st percentile lower limb fat should undergo genetic testing for FPLD2, especially if they have metabolic complications.
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Affiliation(s)
- Chandna Vasandani
- The Division of Nutrition and Metabolic Diseases and the Center for Human Nutrition, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Xilong Li
- Department of Population and Data Sciences, UT Southwestern Medical Center, Dallas, Texas
| | - Hilal Sekizkardes
- National Institute of Child Health and Human Development, National Institutes of Health, Bathesda, Maryland
| | - Beverley Adams-Huet
- Department of Population and Data Sciences, UT Southwestern Medical Center, Dallas, Texas
| | - Rebecca J Brown
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Abhimanyu Garg
- The Division of Nutrition and Metabolic Diseases and the Center for Human Nutrition, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
- Correspondence: Abhimanyu Garg, M.D., Division of Nutrition and Metabolic Diseases, Department of Internal Medicine and the Center for Human Nutrition, 5323 Harry Hines Boulevard, Dallas, TX 75390-8537. E-mail:
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Akinci B, Unlu SM, Celik A, Simsir IY, Sen S, Nur B, Keskin FE, Saydam BO, Ozdemir NK, Yurekli BS, Ergur BU, Sonmez M, Atik T, Arslan A, Demir T, Altay C, Tunc UA, Arkan T, Gen R, Eren E, Akinci G, Yilmaz AA, Bilen H, Ozen S, Celtik A, Erdeve SS, Cetinkaya S, Onay H, Sarioglu S, Oral EA. Renal complications of lipodystrophy: A closer look at the natural history of kidney disease. Clin Endocrinol (Oxf) 2018; 89:65-75. [PMID: 29722904 PMCID: PMC5999575 DOI: 10.1111/cen.13732] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/02/2018] [Accepted: 04/24/2018] [Indexed: 01/21/2023]
Abstract
OBJECTIVES Lipodystrophy syndromes are a group of heterogeneous disorders characterized by adipose tissue loss. Proteinuria is a remarkable finding in previous reports. STUDY DESIGN In this multicentre study, prospective follow-up data were collected from 103 subjects with non-HIV-associated lipodystrophy registered in the Turkish Lipodystrophy Study Group database to study renal complications in treatment naïve patients with lipodystrophy. METHODS Main outcome measures included ascertainment of chronic kidney disease (CKD) by studying the level of proteinuria and the estimated glomerular filtration rate (eGFR). Kidney volume was measured. Percutaneous renal biopsies were performed in 9 patients. RESULTS Seventeen of 37 patients with generalized and 29 of 66 patients with partial lipodystrophy had CKD characterized by proteinuria, of those 12 progressed to renal failure subsequently. The onset of renal complications was significantly earlier in patients with generalized lipodystrophy. Patients with CKD were older and more insulin resistant and had worse metabolic control. Increased kidney volume was associated with poor metabolic control and suppressed leptin levels. Renal biopsies revealed thickening of glomerular basal membranes, mesangial matrix abnormalities, podocyte injury, focal segmental sclerosis, ischaemic changes and tubular abnormalities at various levels. Lipid vacuoles were visualized in electron microscopy images. CONCLUSIONS CKD is conspicuously frequent in patients with lipodystrophy which has an early onset. Renal involvement appears multifactorial. While poorly controlled diabetes caused by severe insulin resistance may drive the disease in some cases, inherent underlying genetic defects may also lead to cell autonomous mechanisms contributory to the pathogenesis of kidney disease.
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Affiliation(s)
- Baris Akinci
- Division of Endocrinology, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | | | - Ali Celik
- Division of Nephrology, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Ilgin Yildirim Simsir
- Division of Endocrinology, Department of Internal Medicine, Ege University, Izmir, Turkey
| | - Sait Sen
- Department of Pathology, Ege University, Izmir, Turkey
| | - Banu Nur
- Division of Pediatric Genetics, Department of Pediatrics, Akdeniz University, Antalya, Turkey
| | - Fatma Ela Keskin
- Division of Endocrinology, Department of Internal Medicine, Istanbul University, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
| | - Basak Ozgen Saydam
- Division of Endocrinology, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | | | - Banu Sarer Yurekli
- Division of Endocrinology, Department of Internal Medicine, Ege University, Izmir, Turkey
| | | | - Melda Sonmez
- Koc University, School of Medicine, Istanbul, Turkey
| | - Tahir Atik
- Division of Pediatric Genetics, Department of Pediatrics, Ege University, Izmir, Turkey
| | - Atakan Arslan
- Department of Radiology, Dokuz Eylul University, Izmir, Turkey
| | - Tevfik Demir
- Division of Endocrinology, Department of Internal Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Canan Altay
- Department of Radiology, Dokuz Eylul University, Izmir, Turkey
| | - Ulku Aybuke Tunc
- Division of Endocrinology, Karabuk State Hospital, Karabuk, Turkey
| | - Tugba Arkan
- Division of Endocrinology, Kocaeli Training Hospital, Kocaeli, Turkey
| | - Ramazan Gen
- Division of Endocrinology, Department of Internal Medicine, Mersin University, Mersin, Turkey
| | - Erdal Eren
- Division of Pediatric Endocrinology, Department of Pediatrics, Uludag University, Bursa, Turkey
| | - Gulcin Akinci
- Division of Pediatric Neurology, Dr. Behcet Uz Children’s Hospital, Izmir, Turkey
| | - Aslihan Arasli Yilmaz
- Division of Pediatric Endocrinology, Dr. Sami Ulus Obstetrics and Gynecology, Children’s Health and Disease Training and Research Hospital, Ankara, Turkey
| | - Habip Bilen
- Division of Endocrinology, Department of Internal Medicine, Ataturk University, Erzurum, Turkey
| | - Samim Ozen
- Division of Pediatric Endocrinology, Department of Pediatrics, Ege University, Izmir, Turkey
| | - Aygul Celtik
- Division of Nephrology, Department of Internal Medicine, Ege University, Izmir, Turkey
| | - Senay Savas Erdeve
- Division of Pediatric Endocrinology, Dr. Sami Ulus Obstetrics and Gynecology, Children’s Health and Disease Training and Research Hospital, Ankara, Turkey
| | - Semra Cetinkaya
- Division of Pediatric Endocrinology, Dr. Sami Ulus Obstetrics and Gynecology, Children’s Health and Disease Training and Research Hospital, Ankara, Turkey
| | - Huseyin Onay
- Division of Pediatric Genetics, Department of Pediatrics, Ege University, Izmir, Turkey
| | - Sulen Sarioglu
- Department of Pathology, Dokuz Eylul University, Izmir, Turkey
| | - Elif Arioglu Oral
- Division of Endocrinology and Metabolism, Brehm Center for Diabetes Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
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Fernández-Pombo A, Ossandon-Otero JA, Guillín-Amarelle C, Sánchez-Iglesias S, Castro AI, González-Méndez B, Rodríguez-García S, Rodriguez-Cañete L, Casanueva FF, Araújo-Vilar D. Bone mineral density in familial partial lipodystrophy. Clin Endocrinol (Oxf) 2018; 88:44-50. [PMID: 29078011 DOI: 10.1111/cen.13504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [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: 05/20/2017] [Revised: 10/15/2017] [Accepted: 10/17/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Type 1 and type 2 familial partial lipodystrophies (FPLD) are characterized by the loss or increase in subcutaneous fat in certain body regions, as well as metabolic disorders. Higher muscle volume and mass have also been described. However, so far, possible bone involvement has not been studied. The aim of this study was to evaluate bone mineral density (BMD) in patients with type 1 and type 2 FPLD. METHODS A total of 143 women were selected and distributed into three groups (17 women with FPLD2, 82 women with FPLD1 and 44 nonlipodystrophic obese female controls). A thorough history and physical examination were carried out on all subjects, as well as the measurement of anthropometric features. BMD along with fat and fat-free mass (FFM) were determined by DXA (dual-energy X-ray absorptiometry). Statistical analyses, primarily using the χ2 , ANOVA and ANCOVA tests, were performed, using age, height, fat and FFM as covariables. RESULTS After eliminating the possible influences of age, height, fat and FFM, we observed that there were no significant differences in total BMD between patients with FPLD and the control group, showing total BMD values of 1.092 ± 0.037 g/cm2 in the FPLD2 group, 1.158 ± 0.013 g/cm2 in the FPLD1 group and 1.173 ± 0.018 g/cm2 in the control group (P = .194). Similarly, no significant differences were found in segmental BMD. CONCLUSIONS Unlike in other types of laminopathy in which bone is affected, in the case of FPLD, there are no differences in BMD compared to nonlipodystrophic subjects.
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Affiliation(s)
- Antía Fernández-Pombo
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
- Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Santiago de Compostela, Spain
| | - Javier A Ossandon-Otero
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Cristina Guillín-Amarelle
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
- Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Santiago de Compostela, Spain
| | - Sofía Sánchez-Iglesias
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Ana I Castro
- Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Madrid, Spain
| | - Blanca González-Méndez
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Silvia Rodríguez-García
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Leticia Rodriguez-Cañete
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Felipe F Casanueva
- Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y la Nutrición (CIBERobn), Madrid, Spain
| | - David Araújo-Vilar
- UETeM-Molecular Pathology Group, Department of Medicine, IDIS-CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
- Division of Endocrinology and Nutrition, University Clinical Hospital of Santiago de Compostela, Santiago de Compostela, Spain
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Ajluni N, Meral R, Neidert AH, Brady GF, Buras E, McKenna B, DiPaola F, Chenevert TL, Horowitz JF, Buggs-Saxton C, Rupani AR, Thomas PE, Tayeh MK, Innis JW, Omary MB, Conjeevaram H, Oral EA. Spectrum of disease associated with partial lipodystrophy: lessons from a trial cohort. Clin Endocrinol (Oxf) 2017; 86:698-707. [PMID: 28199729 PMCID: PMC5395301 DOI: 10.1111/cen.13311] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/18/2017] [Accepted: 02/10/2017] [Indexed: 12/29/2022]
Abstract
CONTEXT Partial lipodystrophy (PL) is associated with metabolic co-morbidities but may go undiagnosed as the disease spectrum is not fully described. OBJECTIVE The objective of the study was to define disease spectrum in PL using genetic, clinical (historical, morphometric) and laboratory characteristics. DESIGN Cross-sectional evaluation. PARTICIPANTS Twenty-three patients (22 with familial, one acquired, 78·3% female, aged 12-64 years) with PL and non-alcoholic fatty liver disease (NAFLD). MEASUREMENTS Genetic, clinical and laboratory characteristics, body composition indices, liver fat content by magnetic resonance imaging (MRI), histopathological and immunofluorescence examinations of liver biopsies. RESULTS Seven patients displayed heterozygous pathogenic variants in LMNA. Two related patients had a heterozygous, likely pathogenic novel variant of POLD1 (NM002691·3: c.3199 G>A; p.E1067K). Most patients had high ratios (>1·5) of percentage fat trunk to percentage fat legs (FMR) when compared to reference normals. Liver fat quantified using MR Dixon method was high (11·3 ± 6·3%) and correlated positively with haemoglobin A1c and triglycerides while leg fat by dual-energy X-ray absorptiometry (DEXA) correlated negatively with triglycerides. In addition to known metabolic comorbidities; chronic pain (78·3%), hypertension (56·5%) and mood disorders (52·2%) were highly prevalent. Mean NAFLD Activity Score (NAS) was 5 ± 1 and 78·3% had fibrosis. LMNA-immunofluorescence staining from select patients (including one with the novel POLD1 variant) showed a high degree of nuclear atypia and disorganization. CONCLUSIONS Partial lipodystrophy is a complex multi-system disorder. Metabolic parameters correlate negatively with extremity fat and positively with liver fat. DEXA-based FMR may prove useful as a diagnostic tool. Nuclear disorganization and atypia may be a common biomarker even in the absence of pathogenic variants in LMNA.
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Affiliation(s)
- Nevin Ajluni
- Brehm Center for Diabetes Research and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Rasimcan Meral
- Brehm Center for Diabetes Research and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Adam H. Neidert
- Brehm Center for Diabetes Research and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Graham F. Brady
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Eric Buras
- Brehm Center for Diabetes Research and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
| | - Barbara McKenna
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Frank DiPaola
- Division of Pediatric Gastroenterology, University of Michigan, Ann Arbor, MI, USA
| | | | | | - Colleen Buggs-Saxton
- Pediatric Endocrinology, Children’s Hospital of Michigan, Wayne School of Medicine, Detroit, MI, USA
| | - Amit R. Rupani
- Departments of Pediatrics and Communicable Diseases and Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Peedikayil E. Thomas
- Departments of Pediatrics and Communicable Diseases and Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Marwan K. Tayeh
- Departments of Pediatrics and Communicable Diseases and Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Jeffrey W. Innis
- Departments of Pediatrics and Communicable Diseases and Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - M. Bishr Omary
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Hari Conjeevaram
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Elif A. Oral
- Brehm Center for Diabetes Research and Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI, USA
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Garg A, Agarwal AK. Lipodystrophies: disorders of adipose tissue biology. Biochim Biophys Acta 2009; 1791:507-13. [PMID: 19162222 PMCID: PMC2693450 DOI: 10.1016/j.bbalip.2008.12.014] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/26/2008] [Accepted: 12/23/2008] [Indexed: 11/15/2022]
Abstract
The adipocytes synthesize and store triglycerides as lipid droplets surrounded by various proteins and phospholipids at its surface. Recently, the molecular basis of some of the genetic syndromes of lipodystrophies has been elucidated and some of these genetic loci have been found to contribute to lipid droplet formation in adipocytes. The two main types of genetic lipodystrophies are congenital generalized lipodystrophy (CGL) and familial partial lipodystrophy (FPL). So far, three CGL loci: 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2), Berardinelli-Seip Congenital Lipodystrophy 2 (BSCL2) and caveolin 1 (CAV1) and four FPL loci: lamin A/C (LMNA), peroxisome proliferator-activated receptor gamma (PPARG), v-AKT murine thymoma oncogene homolog 2 (AKT2) and zinc metalloprotease (ZMPSTE24), have been identified. AGPAT2 plays a critical role in the synthesis of glycerophospholipids and triglycerides required for lipid droplet formation. Another protein, seipin (encoded by BSCL2 gene), has been found to induce lipid droplet fusion. CAV1 is an integral component of caveolae and might contribute towards lipid droplet formation. PPARgamma and AKT2 play important role in adipogenesis and lipid synthesis. In this review, we discuss and speculate about the contribution of various lipodystrophy genes and their products in the lipid droplet formation.
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Affiliation(s)
- Abhimanyu Garg
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA.
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Villena JA, Choi CS, Wang Y, Kim S, Hwang YJ, Kim YB, Cline G, Shulman GI, Sul HS. Resistance to high-fat diet-induced obesity but exacerbated insulin resistance in mice overexpressing preadipocyte factor-1 (Pref-1): a new model of partial lipodystrophy. Diabetes 2008; 57:3258-66. [PMID: 18835937 PMCID: PMC2584131 DOI: 10.2337/db07-1739] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 09/17/2008] [Indexed: 01/07/2023]
Abstract
OBJECTIVE White adipose tissue is a critical regulator of whole-body glucose metabolism. Preadipocyte factor-1 (Pref-1) is a secreted protein that inhibits adipocyte differentiation, both in vitro and in vivo. In this study, we have investigated the effects of Pref-1 overexpression on whole-body glucose homeostasis and its contribution to the development of insulin resistance. RESEARCH DESIGN AND METHODS To gain insight into the role of Pref-1 on the onset of insulin resistance and type 2 diabetes, we measured body composition and whole-body insulin-stimulated glucose metabolism during a hyperinsulinemic-euglycemic clamp in Pref-1 transgenic and wild-type control mice fed a high-fat diet. RESULTS Mice overexpressing Pref-1 were resistant to high-fat diet-induced obesity, as reflected by a marked reduction in adipose tissue mass. However, Pref-1-overexpressing mice were severely insulin resistant, mainly because of a reduction in insulin-stimulated glucose uptake in skeletal muscle and adipose tissue. The aggravated insulin resistance was associated with impaired insulin signaling and increased diacylglycerol content in skeletal muscle. CONCLUSIONS Mice overexpressing Pref-1 are insulin resistant despite being protected from diet-induced obesity and may provide a new rodent model for the study of lipodystrophic disorders.
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Affiliation(s)
- Josep A Villena
- Department of Nutritional Science and Toxicology, University of California, Berkeley, CA, USA
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Caron M, Auclair M, Donadille B, Béréziat V, Guerci B, Laville M, Narbonne H, Bodemer C, Lascols O, Capeau J, Vigouroux C. Human lipodystrophies linked to mutations in A-type lamins and to HIV protease inhibitor therapy are both associated with prelamin A accumulation, oxidative stress and premature cellular senescence. Cell Death Differ 2007; 14:1759-67. [PMID: 17612587 DOI: 10.1038/sj.cdd.4402197] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Lipodystrophic syndromes associated with mutations in LMNA, encoding A-type lamins, and with HIV antiretroviral treatments share several clinical characteristics. Nuclear alterations and prelamin A accumulation have been reported in fibroblasts from patients with LMNA mutations and adipocytes exposed to protease inhibitors (PI). As genetically altered lamin A maturation also results in premature ageing syndromes with lipodystrophy, we studied prelamin A expression and senescence markers in cultured human fibroblasts bearing six different LMNA mutations or treated with PIs. As compared to control cells, fibroblasts with LMNA mutations or treated with PIs had nuclear shape abnormalities and reduced proliferative activity that worsened with increasing cellular passages. They exhibited prelamin A accumulation, increased oxidative stress, decreased expression of mitochondrial respiratory chain proteins and premature cellular senescence. Inhibition of prelamin A farnesylation prevented cellular senescence and oxidative stress. Adipose tissue samples from patients with LMNA mutations or treated with PIs also showed retention of prelamin A, overexpression of the cell cycle checkpoint inhibitor p16 and altered mitochondrial markers. Thus, both LMNA mutations and PI treatment result in accumulation of farnesylated prelamin A and oxidative stress that trigger premature cellular senescence. These alterations could participate in the pathophysiology of lipodystrophic syndromes and lead to premature ageing complications.
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Affiliation(s)
- M Caron
- INSERM U680, Université Pierre et Marie Curie-Paris 6, Faculté de Médecine, Site Saint-Antoine, 27 rue Chaligny, 75571 Paris Cedex 12, France.
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Spuler S, Kalbhenn T, Zabojszcza J, van Landeghem FKH, Ludtke A, Wenzel K, Koehnlein M, Schuelke M, Lüdemann L, Schmidt HH. Muscle and nerve pathology in Dunnigan familial partial lipodystrophy. Neurology 2007; 68:677-83. [PMID: 17325275 DOI: 10.1212/01.wnl.0000255939.73424.f8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To characterize muscle and nerve pathology in Dunnigan familial partial lipodystrophy (FPLD). METHODS We used conventional histology, immunohistochemistry, messenger RNA (mRNA) expression, gene sequencing, and clinical studies of 13 patients with neuromuscular involvement. RESULTS The clinical findings consisted of muscle hypertrophy (12/13), severe myalgias (9/13), and multiple nerve entrapment syndromes (8/13). Skeletal muscle histology demonstrated marked Type 1 and 2 muscle fiber hypertrophy and nonspecific myopathic changes, whereas numerous paranodal myelin swellings (tomacula) were found in sural nerve biopsies. We found that myostatin mRNA expression was reduced in patients with FPLD vs controls. We sequenced the myostatin gene in our subjects, but found no mutations. We then investigated whether or not SMAD, the intracellular mediator of myostatin signaling, might be impaired in patients with FPLD. We found that in FPLD muscle, a large number of SMAD molecules adhered to the nuclear membrane and were not found within the nucleus, compared with normal muscle or muscle from a patient with a non-FPLD lamin A/C disease. CONCLUSION The myopathy and neuropathy associated with Dunnigan familial partial lipodystrophy are distinct from other lamin A/C disorders. We hypothesize that the lipodystrophy-associated mutation interferes with SMAD signaling, linking this type of lipodystrophy to the phenotypically similar myostatin deficiency.
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Affiliation(s)
- S Spuler
- Muscle Research Group, Department of Neurology, Medical Faculty of the Charité, Berlin, Germany.
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Capeau J, Magré J, Lascols O, Caron M, Béréziat V, Vigouroux C. [Primary lipodystrophies]. Ann Endocrinol (Paris) 2007; 68:10-20. [PMID: 17320032 DOI: 10.1016/j.ando.2006.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 12/15/2006] [Accepted: 12/15/2006] [Indexed: 11/30/2022]
Abstract
Primary lipodystrophies represent a heterogeneous group of very rare diseases with a prevalence of less than 1 case for 100.000, inherited or acquired, caracterized by a loss of body fat either generalized or localized (lipoatrophy). In some forms, lipoatrophy is associated with a selective hypertrophy of other fat depots. Clinical signs of insulin resistance are often present: acanthosis nigricans, signs of hyperandrogenism. All lipodystrophies are associated with dysmetabolic alterations with insulin resistance, altered glucose tolerance or diabetes and hypertriglyceridemia leading to a risk of acute pancreatitis. Chronic complications are those resulting from diabetes involving the retina, kidney and nerves, cardiovascular complications and steatotic liver lesions that could result in cirrhosis. Genetic forms of generalized lipodystrophy (or Berardinelli-Seip syndrome) result, in most cases, from recessive mutations in one of two genes: either BSCL2 coding seipin or BSCL1 coding AGPAT2, an acyl-transferase involved in triglyceride synthesis. Acquired generalized lipodystrophy (Lawrence syndrome) is of unknown origin but is sometimes associated with signs of autoimmunity. Partial lipodystrophies can be familial with dominant transmission. Heterozygous mutations have been identified in the LMNA gene encoding nuclear lamin A/C belonging to the nuclear lamina, or in PPARG encoding the adipogenic transcription factor PPARgamma. Some less typical lipodystrophies, associated with signs of premature aging, have been linked to mutations in LMNA or in the ZMPSTE24 gene encoding the protease responsible for the maturation of prelamin A into lamin A. Acquired partial lipodystrophy (Barraquer-Simons syndrome) is characterized by cephalothoracic fat loss. Its aetiology is unknown but mutations in LMNB2, encoding the lamina protein lamin B2, could represent susceptibility factors. Highly active antiretroviral treatments for HIV infection are currently the most frequent cause of acquired secondary lipodystrophic syndromes. The genetic diagnosis is performed in specialized laboratories and, in the most severe forms, antenatal diagnosis could be proposed. Treatment of diabetes, dyslipidemia and complications involves the classical intervention strategies. Insulino-sensitizing drugs are useful. Therapeutic trials with recombinant human leptin in patients with very low leptin levels reported good results with respect to the metabolic and liver alterations. The prognosis is linked to the precocity and severity of the diabetic, cardiovascular and liver complications.
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Affiliation(s)
- J Capeau
- Inserm, U680, 75012 Paris, France.
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Gubanova NV, Kiseleva EV. [Structural organization and function of nuclear envelope]. Tsitologiia 2007; 49:257-69. [PMID: 17657938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Higher-eukaryotic membrane compartmentalization of different processes provides the control of functional activity in cells. The nuclear envelope that consists of outer and inner nuclear membranes, lamina, and nuclear pore complexes is one of the most significant and complex cell compartments. It separates DNA replication and transcription in the nucleus from RNA translation in the cytoplasm and regulates the nuclear-cytoplasmic transport of different molecules. This review describes and discusses the structural organization and biochemical composition of different nuclear envelope components (except nuclear pore complexes, which were discussed in our previous review) as well as its dynamics during mitosis in vitro and in vivo. Special attention is given to the role of lamina in a group of human genetic diseases, collectively referred to as laminopathies.
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