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Romano MMD, Sapalo AT, Guidorizzi NR, Moreira HT, Inês PAC, Kalil LC, Foss MC, de Paula FJA. Echocardiographic Alterations of Cardiac Geometry and Function in Patients with Familial Partial Lipodystrophy. Arq Bras Cardiol 2024; 121:e20230442. [PMID: 38922260 PMCID: PMC11216334 DOI: 10.36660/abc.20230442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 02/06/2024] [Accepted: 03/13/2024] [Indexed: 06/27/2024] Open
Abstract
BACKGROUND Cardiomyopathy associated with partial lipodystrophy (PL) has not been well described yet. OBJECTIVE To characterize cardiac morphology and function in PL. METHODS Patients with familial PL and controls were prospectively assessed by transthoracic echocardiography and with speckle-tracking echocardiography (global longitudinal strain, GLS). The relationship between echocardiographic variables and PL diagnosis was tested with regression models, considering the effect of systolic blood pressure (SBP). Significance level of 5% was adopted. RESULTS Twenty-nine patients with PL were compared to 17 controls. They did not differ in age (p=0.94), gender or body mass index (p= 0.05). Patients with PL had statistically higher SBP (p=0.02) than controls. Also, PL patients had higher left atrial dimension (37.3 ± 4.4 vs. 32.1 ± 4.3 mm, p= 0.001) and left atrial (30.2 ± 7.2 vs. 24.9 ± 9.0 mL/m2,p=0.02), left ventricular (LV) mass (79.3 ± 17.4 vs. 67.1 ± 19.4, p=0.02), and reduced diastolic LV parameters (E' lateral, p= 0.001) (E' septal, p= 0.001), (E/E' ratio, p= 0.02). LV ejection fraction (64.7 ± 4.6 vs. 62.2 ± 4.4 %, p= 0.08) and GLS were not statistically different between groups (-17.1 ± 2.7 vs. -18.0 ± 2.0 %, p= 0.25). There was a positive relationship of left atrium (β 5.6, p<0.001), posterior wall thickness, (β 1.3, p=0.011), E' lateral (β -3.5, p=0.002) and E' septal (β -3.2, p<0.001) with PL diagnosis, even after adjusted for SBP. CONCLUSION LP patients have LV hypertrophy, left atrial enlargement, and LV diastolic dysfunction although preserved LVEF and GLS. Echocardiographic parameters are related to PL diagnosis independent of SBP.
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Affiliation(s)
- Minna Moreira Dias Romano
- Universidade de São PauloCentro de Cardiologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilCentro de Cardiologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
| | - André Timóteo Sapalo
- Universidade de São PauloCentro de Cardiologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilCentro de Cardiologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
| | - Natália Rossin Guidorizzi
- Universidade de São PauloCentro de Cardiologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilCentro de Cardiologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
| | - Henrique Turin Moreira
- Universidade de São PauloCentro de Cardiologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilCentro de Cardiologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
| | - Paula Ananda Chacon Inês
- Universidade de São PauloCentro de Cardiologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilCentro de Cardiologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
| | - Lucas Candelária Kalil
- Universidade de São PauloCentro de Cardiologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilCentro de Cardiologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
| | - Maria Cristina Foss
- Universidade de São PauloDivisão de Endocrinologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilDivisão de Endocrinologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
| | - Francisco José Albuquerque de Paula
- Universidade de São PauloDivisão de Endocrinologia da Faculdade de Medicina de Ribeirão PretoSão PauloBrasilDivisão de Endocrinologia da Faculdade de Medicina de Ribeirão Preto – Universidade de São Paulo (USP), São Paulo – Brasil
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Fourman LT, Lima JG, Simha V, Cappa M, Alyaarubi S, Montenegro R, Akinci B, Santini F. A rapid action plan to improve diagnosis and management of lipodystrophy syndromes. Front Endocrinol (Lausanne) 2024; 15:1383318. [PMID: 38952397 PMCID: PMC11215967 DOI: 10.3389/fendo.2024.1383318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 05/13/2024] [Indexed: 07/03/2024] Open
Abstract
Introduction Lipodystrophy syndromes are rare diseases that can present with a broad range of symptoms. Delays in diagnosis are common, which in turn, may predispose to the development of severe metabolic complications and end-organ damage. Many patients with lipodystrophy syndromes are only diagnosed after significant metabolic abnormalities arise. Prompt action by clinical teams may improve disease outcomes in lipodystrophy syndromes. The aim of the Rapid Action Plan is to serve as a set of recommendations from experts that can support clinicians with limited experience in lipodystrophy syndromes. Methods The Rapid Action Plan was developed using insights gathered through a series of advisory meetings with clinical experts in lipodystrophy syndromes. A skeleton template was used to facilitate interviews. A consensus document was developed, reviewed, and approved by all experts. Results Lipodystrophy is a clinical diagnosis. The Rapid Action Plan discusses tools that can help diagnose lipodystrophy syndromes. The roles of clinical and family history, physical exam, patient and family member photos, routine blood tests, leptin levels, skinfold measurements, imaging studies, and genetic testing are explored. Additional topics such as communicating the diagnosis to the patients/families and patient referrals are covered. A set of recommendations regarding screening and monitoring for metabolic diseases and end-organ abnormalities is presented. Finally, the treatment of lipodystrophy syndromes is reviewed. Discussion The Rapid Action Plan may assist clinical teams with the prompt diagnosis and holistic work-up and management of patients with lipodystrophy syndromes, which may improve outcomes for patients with this rare disease.
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Affiliation(s)
- Lindsay T. Fourman
- Metabolism Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
| | - Josivan Gomes Lima
- Hospital Universitário Onofre Lopes, Departamento de Clinica Medica, Universidade Federal do Rio Grande do Norte, Natal, Brazil
| | - Vinaya Simha
- Division of Endocrinology, Mayo Clinic, Rochester, MN, United States
| | - Marco Cappa
- Research Area for Innovative Therapies in Endocrinopathies Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy
| | - Saif Alyaarubi
- Pediatric Endocrinology, Oman Medical Specialty Board, Muscat, Oman
| | - Renan Montenegro
- Brazilian Group for the Study of Inherited and Acquired Lipodystrophies (BRAZLIPO), Clinical Research Unit, Walter Cantidio University Hospital, Federal University of Ceará/Ebserh, Fortaleza, Brazil
| | - Baris Akinci
- Dokuz Eylul University Health Campus Technopark (DEPARK), Dokuz Eylul University, Izmir, Türkiye
- Department of Research Programs, Technological Research, Izmir Biomedicine and Genome Center (IBG), Izmir, Türkiye
| | - Ferruccio Santini
- Obesity and Lipodystrophy Center, Endocrinology Unit, University Hospital of Pisa, Pisa, Italy
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Cecchetti C, D’Apice MR, Morini E, Novelli G, Pizzi C, Pagotto U, Gambineri A. Case Report: An Atypical Form of Familial Partial Lipodystrophy Type 2 Due to Mutation in the Rod Domain of Lamin A/C. Front Endocrinol (Lausanne) 2021; 12:675096. [PMID: 33953703 PMCID: PMC8092436 DOI: 10.3389/fendo.2021.675096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/29/2021] [Indexed: 11/30/2022] Open
Abstract
Purpose Familial partial lipodystrophy type 2 (FPLD2) patients generally develop a wide variety of severe metabolic complications. However, they are not usually affected by primary cardiomyopathy and conduction system disturbances, although a few cases of FPLD2 and cardiomyopathy have been reported in the literature. These were all due to amino-terminal heterozygous lamin A/C mutations, which are considered as new forms of overlapping syndromes. Methods and Results Here we report the identification of a female patient with FPLD2 due to a heterozygous missense variant c.604G>A in the exon 3 of the LMNA gene, leading to amino acid substitution (p.Glu202Lys) in the central alpha-helical rod domain of lamin A/C with a high propensity to form coiled-coil dimers. The patient's cardiac evaluations that followed the genetic diagnosis revealed cardiac rhythm disturbances which were promptly treated pharmacologically. Conclusions This report supports the idea that there are "atypical forms" of FPLD2 with cardiomyopathy, especially when a pathogenic variant affects the lamin A/C head or alpha-helical rod domain. It also highlights how increased understanding of the genotype-phenotype correlation could help clinicians to schedule personalized monitoring of the lipodystrophic patient, in order to prevent uncommon but possible devastating manifestations, including arrhythmias and sudden death.
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Affiliation(s)
- Carolina Cecchetti
- Division of Endocrinology and Diabetes Prevention and Care, Department of Medical and Surgical Sciences (DIMEC), Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | | | - Elena Morini
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
| | - Giuseppe Novelli
- Laboratory of Medical Genetics, Tor Vergata Hospital, Rome, Italy
- Department of Biomedicine and Prevention, University of Rome “Tor Vergata”, Rome, Italy
| | - Carmine Pizzi
- Unit of Cardiology, Department of Specialistic, Diagnostic and Experimental Medicine, Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Uberto Pagotto
- Division of Endocrinology and Diabetes Prevention and Care, Department of Medical and Surgical Sciences (DIMEC), Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Alessandra Gambineri
- Division of Endocrinology and Diabetes Prevention and Care, Department of Medical and Surgical Sciences (DIMEC), Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
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Östlund C, Hernandez-Ono A, Shin JY. The Nuclear Envelope in Lipid Metabolism and Pathogenesis of NAFLD. BIOLOGY 2020; 9:biology9100338. [PMID: 33076344 PMCID: PMC7602593 DOI: 10.3390/biology9100338] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023]
Abstract
Simple Summary The liver is a major organ regulating lipid metabolism and a proper liver function is essential to health. Nonalcoholic fatty liver disease (NAFLD) is a condition with abnormal fat accumulation in the liver without heavy alcohol use. NAFLD is becoming one of the most common liver diseases with the increase in obesity in many parts of the world. There is no approved cure for the disease and a better understanding of disease mechanism is needed for effective prevention and treatment. The nuclear envelope, a membranous structure that surrounds the cell nucleus, is connected to the endoplasmic reticulum where the vast majority of cellular lipids are synthesized. Growing evidence indicates that components in the nuclear envelope are involved in cellular lipid metabolism. We review published studies with various cell and animal models, indicating the essential roles of nuclear envelope proteins in lipid metabolism. We also discuss how defects in these proteins affect cellular lipid metabolism and possibly contribute to the pathogenesis of NAFLD. Abstract Nonalcoholic fatty liver disease (NAFLD) is a burgeoning public health problem worldwide. Despite its tremendous significance for public health, we lack a comprehensive understanding of the pathogenic mechanisms of NAFLD and its more advanced stage, nonalcoholic steatohepatitis (NASH). Identification of novel pathways or cellular mechanisms that regulate liver lipid metabolism has profound implications for the understanding of the pathology of NAFLD and NASH. The nuclear envelope is topologically connected to the ER, where protein synthesis and lipid synthesis occurs. Emerging evidence points toward that the nuclear lamins and nuclear membrane-associated proteins are involved in lipid metabolism and homeostasis. We review published reports that link these nuclear envelope proteins to lipid metabolism. In particular, we focus on the recent work demonstrating the essential roles for the nuclear envelope-localized torsinA/lamina-associated polypeptide (LAP1) complex in hepatic steatosis, lipid secretion, and NASH development. We also discuss plausible pathogenic mechanisms by which the loss of either protein in hepatocytes leads to hepatic dyslipidemia and NASH development.
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Affiliation(s)
- Cecilia Östlund
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; (C.Ö.); (A.H.-O.)
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Antonio Hernandez-Ono
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; (C.Ö.); (A.H.-O.)
| | - Ji-Yeon Shin
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; (C.Ö.); (A.H.-O.)
- Correspondence: ; Tel.: +1-212-305-4088
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Resende ATP, Martins CS, Bueno AC, Moreira AC, Foss-Freitas MC, de Castro M. Phenotypic diversity and glucocorticoid sensitivity in patients with familial partial lipodystrophy type 2. Clin Endocrinol (Oxf) 2019; 91:94-103. [PMID: 30954027 DOI: 10.1111/cen.13984] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/19/2019] [Accepted: 04/03/2019] [Indexed: 01/07/2023]
Abstract
UNLABELLED Familial partial lipodystrophy type 2 (FPLD2) is characterized by insulin resistance, adipose atrophy of the extremities and central obesity. Due to the resemblance with Cushing's syndrome, we hypothesized a putative role of glucocorticoid in the pathogenesis of metabolic abnormalities in FPLD2. OBJECTIVE To evaluate the phenotypic heterogeneity and glucocorticoid sensitivity in FPLD2 patients exhibiting the p.R482W or p.R644C LMNA mutations. DESIGN, PATIENTS AND MEASUREMENTS Prospective study with FPLD2 patients (n = 24) and controls (n = 24), who underwent anthropometric, body composition, metabolic profile and adipokines/cytokine plasma measurements. Plasma and salivary cortisol were measured in basal conditions and after 0.25, 0.5 and 1.0 mg of dexamethasone (DEX) given at 23:00 hours. Glucocorticoid receptor (GR) and 11βHSD isoforms expression were assessed by qPCR. RESULTS Familial partial lipodystrophy type 2 individuals presented increased waist and neck circumferences, decreased hip circumference, peripheral skinfold thickness and fat mass. Patients presented increased HOMA-IR, triglycerides, TNF-α, IL-1β, IL-6 and IL-10, and decreased adiponectin and leptin plasma levels. FPLD2 patients showed decreased ability to suppress the HPA axis compared with controls after 0.5 mg DEX. The phenotype was more pronounced in patients harbouring the p.R482W LMNA mutation. GRβ overexpression in PBMC was observed in female patients compared with female controls. CONCLUSIONS Familial partial lipodystrophy type 2 patients exhibited anthropometric, clinical and biochemical phenotypic heterogeneity related to LMNA mutation sites and to gender. LMNA mutations affecting both lamin A and lamin C lead to more severe phenotype. FPLD2 patients also showed blunted HPA axis response to DEX, probably due to the association of increased levels of proinflammatory cytokines with GRβ overexpression leading to a more severe phenotype in female.
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Affiliation(s)
- Ana Teresa Prata Resende
- Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Clarissa Silva Martins
- Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Ana Carolina Bueno
- Department of Pediatrics, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Ayrton Custódio Moreira
- Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Maria Cristina Foss-Freitas
- Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Margaret de Castro
- Department of Internal Medicine, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
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Mathur SK, Tiwari P, Gupta S, Gupta N, Nimesh S, Medicherla KM, Suravajhala P. Genetics of Lipodystrophy: Can It Help in Understanding the Pathophysiology of Metabolic Syndrome? Biomolecules 2018; 8:E47. [PMID: 29986445 PMCID: PMC6163883 DOI: 10.3390/biom8030047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/21/2018] [Accepted: 06/22/2018] [Indexed: 12/18/2022] Open
Abstract
Understanding phenotypes and their genetic determinants for metabolic syndrome (MetS) has been quite challenging. With the advent of systems genomic approaches, there is a need to decipher methods for identification and evaluating the functional role of phenotypic traits associated with complex diseases, such as MetS. The monogenic syndromes of lipodystrophy are well understood, but the molecular pathophysiology of insulin resistance (IR) underpinning the obesity, diabetes mellitus, and dyslipidemia is not well deciphered. In this commentary, we argue the role of pathophysiology of MetS, and its effects into possible understanding of genetic determinants associated with lipodystrophy-mediated diabetes mellitus.
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Affiliation(s)
| | - Pradeep Tiwari
- Department of Biotechnology and Bioinformatics, Birla Institute of Scientific Research, Statue Circle, Jaipur 302001, India.
| | - Sonal Gupta
- Department of Biotechnology and Bioinformatics, Birla Institute of Scientific Research, Statue Circle, Jaipur 302001, India.
| | - Nidhi Gupta
- Department of Biotechnology, IIS University, Mansarovar, Jaipur 302020, India.
| | - Surendra Nimesh
- Department of Biotechnology, Central University of Rajasthan, Bandarsindri, N.H. 8, Kishangarh 305801, India.
| | - Krishna Mohan Medicherla
- Department of Biotechnology and Bioinformatics, Birla Institute of Scientific Research, Statue Circle, Jaipur 302001, India.
| | - Prashanth Suravajhala
- Department of Biotechnology and Bioinformatics, Birla Institute of Scientific Research, Statue Circle, Jaipur 302001, India.
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Ernszt D, Banfai K, Kellermayer Z, Pap A, Lord JM, Pongracz JE, Kvell K. PPARgamma Deficiency Counteracts Thymic Senescence. Front Immunol 2017; 8:1515. [PMID: 29163553 PMCID: PMC5681731 DOI: 10.3389/fimmu.2017.01515] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/26/2017] [Indexed: 12/30/2022] Open
Abstract
Thymic senescence contributes to increased incidence of infection, cancer and autoimmunity at senior ages. This process manifests as adipose involution. As with other adipose tissues, thymic adipose involution is also controlled by PPARgamma. This is supported by observations reporting that systemic PPARgamma activation accelerates thymic adipose involution. Therefore, we hypothesized that decreased PPARgamma activity could prevent thymic adipose involution, although it may trigger metabolic adverse effects. We have confirmed that both human and murine thymic sections show marked staining for PPARgamma at senior ages. We have also tested the thymic lobes of PPARgamma haplo-insufficient and null mice. Supporting our working hypothesis both adult PPARgamma haplo-insufficient and null mice show delayed thymic senescence by thymus histology, thymocyte mouse T-cell recombination excision circle qPCR and peripheral blood naive T-cell ratio by flow-cytometry. Delayed senescence showed dose-response with respect to PPARgamma deficiency. Functional immune parameters were also evaluated at senior ages in PPARgamma haplo-insufficient mice (null mice do not reach senior ages due to metabolic adverse affects). As expected, sustained and elevated T-cell production conferred oral tolerance and enhanced vaccination efficiency in senior PPARgamma haplo-insufficient, but not in senior wild-type littermates according to ELISA IgG measurements. Of note, humans also show increased oral intolerance issues and decreased protection by vaccines at senior ages. Moreover, PPARgamma haplo-insufficiency also exists in human known as a rare disease (FPLD3) causing metabolic adverse effects, similar to the mouse. When compared to age- and metabolic disorder-matched other patient samples (FPLD2 not affecting PPARgamma activity), FPLD3 patients showed increased human Trec (hTrec) values by qPCR (within healthy human range) suggesting delayed thymic senescence, in accordance with mouse results and supporting our working hypothesis. In summary, our experiments prove that systemic decrease of PPARgamma activity prevents thymic senescence, albeit with metabolic drawbacks. However, thymic tissue-specific PPARgamma antagonism would likely solve the issue.
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Affiliation(s)
- David Ernszt
- Faculty of Pharmacy, Department of Pharmaceutical Biotechnology, University of Pecs, Pecs, Hungary.,Szentagothai Research Center, University of Pecs, Pecs, Hungary
| | - Krisztina Banfai
- Faculty of Pharmacy, Department of Pharmaceutical Biotechnology, University of Pecs, Pecs, Hungary.,Szentagothai Research Center, University of Pecs, Pecs, Hungary
| | - Zoltan Kellermayer
- Faculty of Medicine, Department of Immunology and Biotechnology, University of Pecs, Pecs, Hungary
| | - Attila Pap
- Faculty of Medicine, Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Janet M Lord
- College of Medical and Dental Sciences, Institute of Inflammation and Aging, University of Birmingham, Birmingham, United Kingdom
| | - Judit E Pongracz
- Faculty of Pharmacy, Department of Pharmaceutical Biotechnology, University of Pecs, Pecs, Hungary.,Szentagothai Research Center, University of Pecs, Pecs, Hungary
| | - Krisztian Kvell
- Faculty of Pharmacy, Department of Pharmaceutical Biotechnology, University of Pecs, Pecs, Hungary.,Szentagothai Research Center, University of Pecs, Pecs, Hungary
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Abstract
PURPOSE OF REVIEW Adipose tissue (AT) houses both innate and adaptive immune systems that are crucial for preserving AT function and metabolic homeostasis. In this review, we summarize recent information regarding progression of obesity-associated AT inflammation and insulin resistance. We additionally consider alterations in AT distribution and the immune system in males vs. females and among different racial populations. RECENT FINDINGS Innate and adaptive immune cell-derived inflammation drives insulin resistance both locally and systemically. However, new evidence also suggests that the immune system is equally vital for adipocyte differentiation and protection from ectopic lipid deposition. Furthermore, roles of anti-inflammatory immune cells such as regulatory T cells, "M2-like" macrophages, eosinophils, and mast cells are being explored, primarily due to promise of immunotherapeutic applications. Both immune responses and AT distribution are strongly influenced by factors like sex and race, which have been largely underappreciated in the field of metabolically-associated inflammation, or meta-flammation. More studies are required to recognize factors that switch inflammation from controlled to uncontrolled in obesity-associated pathogenesis and to integrate the combined effects of meta-flammation and immunometabolism. It is critical to recognize that the AT-associated immune system can be alternately beneficial and destructive; therefore, simply blocking immune responses early in obesity may not be the best clinical approach. The dearth of information on gender and race-associated disparities in metabolism, AT distribution, and the immune system suggest that a greater understanding of such differences will be critical to develop personalized treatments for obesity and the associated metabolic dysfunction.
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Affiliation(s)
- Madhur Agrawal
- Department of Microbiology, Boston University School of Medicine, 72 East Concord Street L-516, Boston, MA, 02118, USA
| | - Philip A Kern
- Department of Medicine, Division of Endocrinology, University of Kentucky, Lexington, KY, USA
| | - Barbara S Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, 72 East Concord Street L-516, Boston, MA, 02118, USA.
- Department of Pathology, Boston University School of Medicine, Boston, MA, USA.
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, MA, USA.
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Crux NB, Elahi S. Human Leukocyte Antigen (HLA) and Immune Regulation: How Do Classical and Non-Classical HLA Alleles Modulate Immune Response to Human Immunodeficiency Virus and Hepatitis C Virus Infections? Front Immunol 2017; 8:832. [PMID: 28769934 PMCID: PMC5513977 DOI: 10.3389/fimmu.2017.00832] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/30/2017] [Indexed: 12/13/2022] Open
Abstract
The genetic factors associated with susceptibility or resistance to viral infections are likely to involve a sophisticated array of immune response. These genetic elements may modulate other biological factors that account for significant influence on the gene expression and/or protein function in the host. Among them, the role of the major histocompatibility complex in viral pathogenesis in particular human immunodeficiency virus (HIV) and hepatitis C virus (HCV), is very well documented. We, recently, added a novel insight into the field by identifying the molecular mechanism associated with the protective role of human leukocyte antigen (HLA)-B27/B57 CD8+ T cells in the context of HIV-1 infection and why these alleles act as a double-edged sword protecting against viral infections but predisposing the host to autoimmune diseases. The focus of this review will be reexamining the role of classical and non-classical HLA alleles, including class Ia (HLA-A, -B, -C), class Ib (HLA-E, -F, -G, -H), and class II (HLA-DR, -DQ, -DM, and -DP) in immune regulation and viral pathogenesis (e.g., HIV and HCV). To our knowledge, this is the very first review of its kind to comprehensively analyze the role of these molecules in immune regulation associated with chronic viral infections.
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Affiliation(s)
- Nicole B Crux
- Faculty of Medicine and Dentistry, Department of Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Medicine and Dentistry, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Shokrollah Elahi
- Faculty of Medicine and Dentistry, Department of Dentistry, University of Alberta, Edmonton, AB, Canada.,Faculty of Medicine and Dentistry, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
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Monteiro L, Foss-Freitas MC, Navarro A, Pereira F, Coeli F, Carneseca E, Júnior RM, Foss M. Evaluation of Dietary Intake, Leisure-Time Physical Activity, and Metabolic Profile in Women with Mutation in the LMNA Gene. J Am Coll Nutr 2017; 36:248-252. [PMID: 28443701 DOI: 10.1080/07315724.2016.1262299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Familial partial lipodystrophy (FPL) is a rare genetic disorder characterized by selective lack of subcutaneous fat, which is associated with insulin-resistant diabetes. The Dunnigan variety (FPLD2) is caused by several missense mutations in the lamin A/C (LMNA) gene, most of which are typically located in exon 8 at the codon position 482. OBJECTIVE The aim of this study was to assess and compare the dietary intake, leisure-time physical activity (LTPA), and biochemical measurements (glucose, A1C, and plasma lipids) in women with FPLD2 and without (control group, CG) and to examine the associations between dietary intake and biochemical measurements (BM). METHODS LTPA was measured with a questionnaire and metabolic equivalent (MET) hours per week (hours/week) were calculated. Dietary intake by the 3-day recall method and clinical laboratory parameters were collected. RESULTS Characteristics of women with FPLD2: 35.8 ± 13.9 years, fat mass = 10 ± 2.3 kg and fat free mass = 41.4 ± 4.5 kg (p < 0.05). Women with FPLD2 showed a smaller intake of energy (kcal), lipids, and carbohydrates and a large intake of protein (p < 0.01) compared to CG. Comparing the 2 groups in terms of LTPA, 78% of women with FPLD2 performed insufficient physical activity. In addition, they had a higher levels of glucose, A1C, and triglycerides (TG) and lower levels of high-density lipoprotein (HDL). There was no correlation between dietary intake and biochemical measurements. CONCLUSIONS Women with FPLD2 have a lower intake of energy (kcal), lipids, and carbohydrates and greater changes in biochemical measurements. Because this is a rare disease, future studies are needed with encouragement of the practice of physical activity and of healthy eating habits, preventing the onset of diseases.
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Affiliation(s)
- Luciana Monteiro
- a Division of Endocrinology, Department of Internal Medicine , Medical School of Ribeirão Preto, University of São Paulo , São Paulo , BRAZIL
| | - Maria Cristina Foss-Freitas
- a Division of Endocrinology, Department of Internal Medicine , Medical School of Ribeirão Preto, University of São Paulo , São Paulo , BRAZIL
| | - Anderson Navarro
- b Division of Nutrition and Metabolism, Department of Internal Medicine , Medical School of Ribeirão Preto, University of São Paulo , São Paulo , BRAZIL
| | - Francisco Pereira
- a Division of Endocrinology, Department of Internal Medicine , Medical School of Ribeirão Preto, University of São Paulo , São Paulo , BRAZIL
| | - Fernanda Coeli
- a Division of Endocrinology, Department of Internal Medicine , Medical School of Ribeirão Preto, University of São Paulo , São Paulo , BRAZIL
| | - Estela Carneseca
- c Institute of Education and Research, Foundation Institution Pio XII-Cancer Hospital of Barretos , São Paulo , BRAZIL
| | - Renan Montenegro Júnior
- d Department of Community Health, Service of Endocrinology and Diabetes , University Hospital Walter Cantídio, Fortaleza Medical School, Ceará University , Fortaleza , Ceará , BRAZIL
| | - Milton Foss
- a Division of Endocrinology, Department of Internal Medicine , Medical School of Ribeirão Preto, University of São Paulo , São Paulo , BRAZIL
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Malashicheva A, Bogdanova M, Zabirnyk A, Smolina N, Ignatieva E, Freilikhman O, Fedorov A, Dmitrieva R, Sjöberg G, Sejersen T, Kostareva A. Various lamin A/C mutations alter expression profile of mesenchymal stem cells in mutation specific manner. Mol Genet Metab 2015; 115:118-27. [PMID: 25982065 DOI: 10.1016/j.ymgme.2015.04.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/27/2015] [Accepted: 04/28/2015] [Indexed: 12/31/2022]
Abstract
Various mutations in LMNA gene, encoding for nuclear lamin A/C protein, lead to laminopathies and contribute to over ten human disorders, mostly affecting tissues of mesenchymal origin such as fat tissue, muscle tissue, and bones. Recently it was demonstrated that lamins not only play a structural role providing communication between extra-nuclear structures and components of cell nucleus but also control cell fate and differentiation. In our study we assessed the effect of various LMNA mutations on the expression profile of mesenchymal multipotent stem cells (MMSC) during adipogenic and osteogenic differentiation. We used lentiviral approach to modify human MMSC with LMNA-constructs bearing mutations associated with different laminopathies--G465D, R482L, G232E, R527C, and R471C. The impact of various mutations on MMSC differentiation properties and expression profile was assessed by colony-forming unit analysis, histological staining, expression of the key differentiation markers promoting adipogenesis and osteogenesis followed by the analysis of the whole set of genes involved in lineage-specific differentiation using PCR expression arrays. We demonstrate that various LMNA mutations influence the differentiation efficacy of MMSC in mutation-specific manner. Each LMNA mutation promotes a unique expression pattern of genes involved in a lineage-specific differentiation and this pattern is shared by the phenotype-specific mutations.
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Affiliation(s)
- Anna Malashicheva
- Almazov Federal Medical Research Centre, St. Petersburg, Russia; St. Petersburg State University, St. Petersburg, Russia; ITMO University, Institute of translational Medicine, St. Petersburg, Russia
| | - Maria Bogdanova
- Almazov Federal Medical Research Centre, St. Petersburg, Russia; St. Petersburg State University, St. Petersburg, Russia
| | | | - Natalia Smolina
- Almazov Federal Medical Research Centre, St. Petersburg, Russia; Department of Woman and Child Health, Centre for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Elena Ignatieva
- Almazov Federal Medical Research Centre, St. Petersburg, Russia
| | | | - Anton Fedorov
- Almazov Federal Medical Research Centre, St. Petersburg, Russia
| | | | - Gunnar Sjöberg
- Department of Woman and Child Health, Centre for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Thomas Sejersen
- Department of Woman and Child Health, Centre for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Anna Kostareva
- Almazov Federal Medical Research Centre, St. Petersburg, Russia; Department of Woman and Child Health, Centre for Molecular Medicine, Karolinska Institute, Stockholm, Sweden; ITMO University, Institute of translational Medicine, St. Petersburg, Russia.
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Abstract
Most diabetes is polygenic in etiology, with (type 1 diabetes, T1DM) or without (type 2 diabetes, T2DM) an autoimmune basis. Genetic counseling for diabetes generally focuses on providing empiric risk information based on family history and/or the effects of maternal hyperglycemia on pregnancy outcome. An estimated one to five percent of diabetes is monogenic in nature, e.g., maturity onset diabetes of the young (MODY), with molecular testing and etiology-based treatment available. However, recent studies show that most monogenic diabetes is misdiagnosed as T1DM or T2DM. While efforts are underway to increase the rate of diagnosis in the diabetes clinic, genetic counselors and clinical geneticists are in a prime position to identify monogenic cases through targeted questions during a family history combined with working in conjunction with diabetes professionals to diagnose and assure proper treatment and familial risk assessment for individuals with monogenic diabetes.
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Affiliation(s)
- Stephanie A Stein
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, Maryland
| | - Kristin L Maloney
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, Maryland ; Program in Genetics and Genomic Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Toni I Pollin
- Department of Medicine, Division of Endocrinology, Diabetes & Nutrition, University of Maryland School of Medicine, Baltimore, Maryland ; Program in Genetics and Genomic Medicine, University of Maryland School of Medicine, Baltimore, Maryland ; Department of Epidemiology & Public Health, University of Maryland School of Medicine, Baltimore, Maryland
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Kuznetsov SA, Mankani MH, Robey PG. In vivo formation of bone and haematopoietic territories by transplanted human bone marrow stromal cells generated in medium with and without osteogenic supplements. J Tissue Eng Regen Med 2013; 7:226-35. [PMID: 22052864 PMCID: PMC3276737 DOI: 10.1002/term.515] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Revised: 05/25/2011] [Accepted: 09/14/2011] [Indexed: 12/30/2022]
Abstract
Autologous transplantation of human bone marrow stromal cells (BMSCs) has been successfully used for bone reconstruction. However, in order to advance this approach into the mainstream of bone tissue engineering, the conditions for BMSC cultivation and transplantation must be optimized. In a recent report, cultivation with dexamethasone (Dex) significantly increased bone formation by human BMSCs in vivo. Based on this important conclusion, we analysed the data accumulated by our laboratory, where human BMSCs have been routinely generated using media both with and without a combination of two osteogenic supplements: Dex at 10(-8) m and ascorbic acid phosphate (AscP) at 10(-4) m. Our data demonstrate that for 22/24 donors, BMSC strains propagated with and without Dex/AscP formed similar amounts of bone in vivo. Thus, human BMSCs do not appear to need to be induced to osteogenic differentiation ex vivo prior to transplantation. Similarly, for 12/14 donors, BMSC strains cultured with and without Dex/AscP formed haematopoietic territories to a comparable extent. While Dex/AscP did not increase bone formation, they significantly stimulated BMSC in vitro proliferation without affecting the number of BMSC colonies formed by the colony-forming units-fibroblasts. We conclude that for the substantial majority of donors, Dex/AscP have no effect on the ability of BMSCs to form bone and myelosupportive stroma in vivo. However, due to increased BMSC proliferation, the total osteogenic population obtained from a single marrow sample is larger after cultivation with Dex/AscP than without them. Secondary to increased BMSC proliferation, Dex/AscP may stimulate bone formation if BMSCs and/or the transplantation system are less than optimal. Published 2011. This article is a U.S. Government work and is in the public domain in the USA.
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Affiliation(s)
- Sergei A Kuznetsov
- Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892–4370, USA.
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15
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Min JY, Cho JS, Lee KJ, Park JB, Min KB. Thigh circumference and low ankle brachial index in US adults: results from the National Health and Nutrition Examination Survey 1999-2004. Int J Cardiol 2012; 163:40-5. [PMID: 23164588 DOI: 10.1016/j.ijcard.2012.10.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 08/29/2012] [Accepted: 10/28/2012] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Recent studies have suggested that smaller thighs are a disadvantage for health and survival, but the association of thigh circumference with atherosclerosis remains uncertain. The purpose of this study was to investigate the association between thigh circumference and peripheral arterial disease (PAD), as measured by ankle brachial index (ABI). METHODS This study used data from the National Health and Nutrition Examination Survey (1999-2004), in which participants' ABI and thigh circumference were measured simultaneously. A total of 5716 participants (2959 men and 2757 women) were included in the final analysis. A diagnosis of PAD was determined on the basis of ABI <0.9. RESULTS The overall prevalence of PAD in this sample was 6.6%. Thigh circumference of those with PAD was 50.1cm compared to 52.2 cm for those without PAD (p < 0.0001). After adjusting for potential covariates, the prevalence of PAD generally decreased as thigh circumference increased up to 55 cm. In the first quantile (smallest thigh circumference), men and women had as much as a 4.8-fold (95% CI, 2.28-10.29) and a 3-fold (95% CI, 1.45-6.18) increased risk of PAD, respectively. Above 55 cm, PAD was no longer related to thigh circumference. CONCLUSIONS Small thigh circumference may be associated with PAD, as measured by ABI.
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Affiliation(s)
- Jin-Young Min
- Institute of Health and Environment, Seoul National University, Seoul, Republic of Korea
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Monteiro LZ, Foss-Freitas MC, Júnior Montenegro RM, Foss MC. Body fat distribution in women with familial partial lipodystrophy caused by mutation in the lamin A/C gene. Indian J Endocrinol Metab 2012; 16:136-138. [PMID: 22276265 PMCID: PMC3263183 DOI: 10.4103/2230-8210.91209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Familial partial lipodystrophy (FPLD), Dunnigan variety, is an autosomal dominant disorder caused due to missense mutations in the lamin A/C (LMNA) gene encoding nuclear lamina proteins. Patients with FPLD are predisposed to metabolic complications of insulin resistance such as diabetes. We sought to evaluate and compare body fat distribution with dual-emission X-ray absorptiometry in women with and without FPLD and identify densitometric, clinical and metabolic features.
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Affiliation(s)
- Luciana Z. Monteiro
- Department of Medicine, Divisions of Endocrinology and Metabolism, Ribeirão Preto Medical School, São Paulo University, Brazil
| | - Maria C. Foss-Freitas
- Department of Medicine, Divisions of Endocrinology and Metabolism, Ribeirão Preto Medical School, São Paulo University, Brazil
| | - Renan M. Júnior Montenegro
- Department of Community Health, Service of Endocrinology and Diabetes, University Hospital Walter Cantídio, Fortaleza Medical School, Ceará University, Brazil
| | - Milton C. Foss
- Department of Medicine, Divisions of Endocrinology and Metabolism, Ribeirão Preto Medical School, São Paulo University, Brazil
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Garg A. Clinical review#: Lipodystrophies: genetic and acquired body fat disorders. J Clin Endocrinol Metab 2011; 96:3313-25. [PMID: 21865368 PMCID: PMC7673254 DOI: 10.1210/jc.2011-1159] [Citation(s) in RCA: 353] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 07/28/2011] [Indexed: 12/14/2022]
Abstract
CONTEXT Lipodystrophies are heterogeneous, genetic or acquired disorders characterized by selective loss of body fat and predisposition to insulin resistance. The extent of fat loss determines the severity of associated metabolic complications such as diabetes mellitus, hypertriglyceridemia, and hepatic steatosis. EVIDENCE ACQUISITION AND SYNTHESIS Both original and review articles were found via PubMed search reporting on clinical features and management of various types of lipodystrophies and were integrated with the author's knowledge of the field. CONCLUSION The autosomal recessive congenital generalized lipodystrophy and autosomal dominant familial partial lipodystrophy (FPL) are the two most common types of genetic lipodystrophies. Mutations in AGPAT2, BSCL2, CAV1, and PTRF have been reported in congenital generalized lipodystrophy and in LMNA, PPARG, AKT2, and PLIN1 in FPL. CIDEC is the disease gene for autosomal recessive, FPL and LMNA and ZMPSTE24 for autosomal recessive, mandibuloacral dysplasia-associated lipodystrophy. Recently, an autosomal recessive autoinflammatory lipodystrophy syndrome was reported to be due to PSMB8 mutation. Molecular genetic bases of many rare forms of genetic lipodystrophies remain to be elucidated. The most prevalent subtype of acquired lipodystrophy currently occurs with prolonged duration of protease inhibitor-containing, highly-active antiretroviral therapy in HIV-infected patients. The acquired generalized and partial lipodystrophies are mainly autoimmune in origin and display complement abnormalities. Localized lipodystrophies occur due to drug or vaccine injections, pressure, panniculitis, and other unknown reasons. The current management includes cosmetic surgery and early identification and treatment of metabolic and other complications with diet, exercise, hypoglycemic drugs, and lipid-lowering agents.
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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 at Dallas, Dallas, Texas 75390-8537, USA.
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Ensling M, Steinmann W, Whaley-Connell A. Hypoglycemia: A Possible Link between Insulin Resistance, Metabolic Dyslipidemia, and Heart and Kidney Disease (the Cardiorenal Syndrome). Cardiorenal Med 2011; 1:67-74. [PMID: 22258467 DOI: 10.1159/000322886] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Resistance to insulin metabolic signaling in adipose tissue contributes to the lipid abnormalities in obese, hyperinsulinemic, insulin-resistant patients who develop the cardiorenal syndrome. These same metabolic dyslipidemic abnormalities can be found in conditions of caloric energy restriction with decreased adiposity or normal insulin levels, such as anorexia, starvation or non-diabetic kidney disease. In this review, we assess hypoglycemia as an alternative physiological explanation for the biochemical and lipid findings in conditions of insulin resistance (IR). Therefore, PubMed databases (1961-2010) were searched for articles on the effect of hypoglycemia and starvation on non-esterified fatty acid (NEFA) elevation and abnormalities in insulin signaling in muscles as well as abnormal kidney metabolism. The search included articles on NEFA and their role in triglyceride (TG) and high-density lipoprotein (HDL) metabolism, as well as kidney and heart disease. Available studies support that hypoglycemia increases NEFA generation from adipose tissue. Elevated levels of NEFA induce increased plasma levels of TG and decreased levels of HDL cholesterol, and may cause direct kidney and myocardial damage. IR of adipose and skeletal muscle tissue, and the elevation in insulin levels in obese, insulin-resistant patients could be explained by an adaptation to their carbohydrate intake. These molecular abnormalities in insulin metabolic signaling can also be found in hypoglycemia or starvation. In conclusion, IR of adipose tissue cannot fully explain the lipid abnormalities observed in the cardiorenal syndrome. Decreased blood glucose levels (e.g. hypoglycemia) occur frequently in patients at risk for this syndrome. Hypoglycemia-induced increases in NEFA levels can promote lipid abnormalities that contribute to IR and the cardiorenal syndrome.
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19
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Subramanyam L, Simha V, Garg A. Overlapping syndrome with familial partial lipodystrophy, Dunnigan variety and cardiomyopathy due to amino-terminal heterozygous missense lamin A/C mutations. Clin Genet 2009; 78:66-73. [PMID: 20041886 DOI: 10.1111/j.1399-0004.2009.01350.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Familial partial lipodystrophy, Dunnigan variety (FPLD) is a well-recognized autosomal dominant disorder due to heterozygous missense mutations in lamin A/C (LMNA) gene. Most of the FPLD patients harbor mutations in the C-terminal of the lamin A/C and do not develop cardiomyopathy. On the other hand, affected subjects from three FPLD pedigrees with heterozygous R28W, R60G and R62G LMNA mutations in the amino-terminal had associated cardiomyopathy presenting as premature onset of congestive heart failure, dilated cardiomyopathy and conduction system disturbances. We report three new FPLD pedigrees presenting with cardiomyopathy associated with heterozygous LMNA mutations in the amino-terminal region. Two of them had previously reported R60G and R62G mutations and one has a novel D192V mutation. Affected subjects belonging to the pedigree with heterozygous R62G mutation had atrial fibrillation and required pacemaker implantation. The affected subjects from the other pedigrees with R60G and D192V mutations developed severe cardiomyopathy requiring defibrillator implantation and cardiac transplantation before 30 years of age in some and premature death in the fourth decade in others. Thus, our report provides further evidence of association of a multisystem dystrophy syndrome in FPLD patients harboring amino-terminal mutations in LMNA. Increased understanding of the genotype-phenotype association might help devise clinical strategies aimed at preventing devastating manifestations of cardiomyopathy including heart failure, arrhythmias and sudden death. Furthermore, the underlying molecular mechanisms by which these amino-terminal mutations cause lipodystrophy as well as cardiomyopathy remain to be understood.
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Affiliation(s)
- L Subramanyam
- Department of Internal Medicine, Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-8537, USA
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Klupa T, Szopa M, Skupien J, Wojtyczek K, Cyganek K, Kowalska I, Malecki MT. LMNA gene mutation search in Polish patients: new features of the heterozygous Arg482Gln mutation phenotype. Endocrine 2009; 36:518-23. [PMID: 19859838 DOI: 10.1007/s12020-009-9265-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Accepted: 09/18/2009] [Indexed: 01/28/2023]
Abstract
Mutations of the LMNA gene have been shown to cause an autosomal dominant form of insulin resistance with familial partial lipodystrophy (PLD), frequently accompanied by diabetes. LMNA mutations are considered to be a rare cause of monogenic diabetes; however, they are probably sometimes misdiagnosed as type 2 diabetes (T2DM). We examined whether skin fold thickness measurements may be an effective screening procedure to select individuals with T2DM for molecular testing of the LMNA gene. We also aimed to search for mutations in diabetic patients with evident clinical features of lipodystrophy. Skin fold measurements were performed in 249 not pre-selected T2DM patients. The sum of two trunk skin fold measurements divided by the sum of two peripheral was obtained. Men with a skin fold ratio above 2.5 and women above 1.5 were selected for further molecular analysis of the LMNA gene by direct sequencing. We also examined eight patients presenting typical clinical features of lipodystrophy. We selected 16 patients with T2DM on the basis of skin fold measurements. LMNA gene sequencing in this group revealed no mutation that could be attributable to diabetic phenotype. However, in the group of subjects with apparent lipodystrophic phenotype, we identified one Arg482Gln mutation. This female, diagnosed with diabetes at the age of 51 years, was characterized by insulin resistance but, unlike previously reported LMNA Arg48Gln mutation carriers, she was not overweight. The patient also presented with chronic kidney disease and pulmonary fibrosis that could potentially be a part of the phenotype related to the identified LMNA mutation. We did not find the evidence that screening based on skin fold measurements alone could be an efficient approach to select T2DM patients for molecular testing of the LMNA gene; the presence of features typical for laminopathy seems to be required for such testing. A clinical picture related to the LMNA Arg482Gln mutation may be more diversified than it was previously considered and include low BMI and pulmonary fibrosis.
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Affiliation(s)
- Tomasz Klupa
- Department of Metabolic Diseases, Jagiellonian University, Medical College, 15 Kopernika Street, 31-501 Krakow, Poland
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Davies BSJ, Fong LG, Yang SH, Coffinier C, Young SG. The posttranslational processing of prelamin A and disease. Annu Rev Genomics Hum Genet 2009; 10:153-74. [PMID: 19453251 DOI: 10.1146/annurev-genom-082908-150150] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Human geneticists have shown that some progeroid syndromes are caused by mutations that interfere with the conversion of farnesyl-prelamin A to mature lamin A. For example, Hutchinson-Gilford progeria syndrome is caused by LMNA mutations that lead to the accumulation of a farnesylated version of prelamin A. In this review, we discuss the posttranslational modifications of prelamin A and their relevance to the pathogenesis and treatment of progeroid syndromes.
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Affiliation(s)
- Brandon S J Davies
- Department of Medicine, University of California, Los Angeles, California 90095, USA.
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Collet-Gaudillat C, Billon-Bancel A, Beressi JP. Long-term improvement of metabolic control with pioglitazone in a woman with diabetes mellitus related to Dunnigan syndrome: A case report. DIABETES & METABOLISM 2009; 35:151-4. [DOI: 10.1016/j.diabet.2009.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 12/19/2008] [Accepted: 01/04/2009] [Indexed: 10/21/2022]
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Abstract
Lipases are acyl hydrolases that represent a diverse group of enzymes present in organisms ranging from prokaryotes to humans. This article focuses on an evolutionarily related family of extracellular lipases that include lipoprotein lipase, hepatic lipase and endothelial lipase. As newly synthesized proteins, these lipases undergo a series of co- and post-translational maturation steps occurring in the endoplasmic reticulum, including glycosylation and glycan processing, and protein folding and subunit assembly. This article identifies and discusses mechanisms that direct early and late events in lipase folding and assembly. Lipase maturation employs the two general chaperone systems operating in the endoplasmic reticulum, as well as a recently identified lipase-specific chaperone termed lipase maturation factor 1. We propose that the two general chaperone systems act in a coordinated manner early in lipase maturation in order to help create partially folded monomers; lipase maturation factor 1 then facilitates final monomer folding and subunit assembly into fully functional homodimers. Once maturation is complete, the lipases exit the endoplasmic reticulum and are secreted to extracellular sites, where they carry out a number of functions related to lipoprotein and lipid metabolism.
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Affiliation(s)
- Mark H Doolittle
- VA Greater Los Angeles, Healthcare System, 11301 Wilshire Blvd, Bldg 113, Rm 312, Los Angeles, CA 90073, USA, Tel.: +1 661 433 6349
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Scazzocchio B, Varì R, D'Archivio M, Santangelo C, Filesi C, Giovannini C, Masella R. Oxidized LDL impair adipocyte response to insulin by activating serine/threonine kinases. J Lipid Res 2009; 50:832-45. [PMID: 19136667 DOI: 10.1194/jlr.m800402-jlr200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Oxidized LDL (oxLDL) increase in patients affected by type-2 diabetes, obesity, and metabolic syndrome. Likewise, insulin resistance, an impaired responsiveness of target tissues to insulin, is associated with those pathological conditions. To investigate a possible causal relationship between oxLDL and the onset of insulin resistance, we evaluated the response to insulin of 3T3-L1 adipocytes treated with oxLDL. We observed that oxLDL inhibited glucose uptake (-40%) through reduced glucose transporter 4 (GLUT4) recruitment to the plasma membrane (-70%), without affecting GLUT4 gene expression. These findings were associated to the impairment of insulin signaling. Specifically, in oxLDL-treated cells insulin receptor (IR) substrate-1 (IRS-1) was highly degraded likely because of the enhanced Ser(307)phosphorylation. This process was largely mediated by the activation of the inhibitor of kappaB-kinase beta (IKKbeta) and the c-Jun NH(2)-terminal kinase (JNK). Moreover, the activation of IKKbeta positively regulated the nuclear content of nuclear factor kappaB (NF-kappaB), by inactivating the inhibitor of NF-kappaB (IkappaBalpha). The activated NF-kappaB further impaired per se GLUT4 functionality. Specific inhibitors of IKKbeta, JNK, and NF-kappaB restored insulin sensitivity in adipocytes treated with oxLDL. These data provide the first evidence that oxLDL, by activating serine/threonine kinases, impaired adipocyte response to insulin affecting pathways involved in the recruitment of GLUT4 to plasma membranes (PM). This suggests that oxLDL might participate in the development of insulin resistance.
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Affiliation(s)
- Beatrice Scazzocchio
- Department of Veterinary Public Health and Food Safety, Istituto Superiore di Sanità, Rome, Italy
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Boorsma W, Snijder MB, Nijpels G, Guidone C, Favuzzi AMR, Mingrone G, Kostense PJ, Heine RJ, Dekker JM. Body composition, insulin sensitivity, and cardiovascular disease profile in healthy Europeans. Obesity (Silver Spring) 2008; 16:2696-701. [PMID: 18927552 DOI: 10.1038/oby.2008.433] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To assess whether insulin sensitivity can explain the associations of leg-fat mass (LFM) and trunk-fat mass (TFM) with the cardiovascular disease (CVD) risk profile in healthy European men and women. METHODS AND PROCEDURES We studied 142 healthy men and women of a multicenter European study on insulin sensitivity, aged 30-60 years, from the centres in Hoorn, the Netherlands and Rome, Italy. Whole-body dual-energy X-ray absorptiometry (DXA) was used to determine fat and lean soft tissue mass in the trunk and legs. Fasting glucose, insulin, and lipid levels were measured. Insulin sensitivity (M/I-ratio) was measured during a euglycemic-hyperinsulinemic clamp. Associations between fat distribution and CVD risk factors were studied with linear regression analyses with adjustment for other body compartments, and subsequent adjustment for insulin sensitivity. RESULTS In men, larger LFM was significantly and independently associated with lower triglyceride levels (TGs) and higher high-density lipoprotein (HDL) cholesterol (P < 0.10) and tended to be associated also with lower low-density lipoprotein (LDL) cholesterol, and lower fasting insulin levels. In women, larger LFM was associated with favorable values of all CVD risk factors, although the associations were not statistically significant. In both sexes, larger TFM was independently and significantly associated with unfavorable values of most CVD risk factors, and most associations did not markedly change after adjustment for insulin sensitivity. DISCUSSION In a relatively young and healthy European population, larger LFM is associated with a lower and TFM with a higher cardiovascular and metabolic risk, which can not be explained by insulin sensitivity.
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Affiliation(s)
- Wiebe Boorsma
- EMGO Institute, VU University Medical Center, Amsterdam, The Netherlands
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Enumeration of the colony-forming units-fibroblast from mouse and human bone marrow in normal and pathological conditions. Stem Cell Res 2008; 2:83-94. [PMID: 19383412 DOI: 10.1016/j.scr.2008.07.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 07/03/2008] [Accepted: 07/31/2008] [Indexed: 01/14/2023] Open
Abstract
Bone marrow stromal cell populations, containing a subset of multipotential skeletal stem cells, are increasingly contemplated for use in tissue engineering and stem cell therapy, whereas their involvement in the pathogenetic mechanisms of skeletal disorders is far less recognized. We compared the concentrations of stromal clonogenic cells, colony forming units-fibroblast (CFU-Fs), in norm and pathology. Initially, culture conditions were optimized by demonstrating that fetal bovine serum heat inactivation could significantly repress colony formation. Using non-heat-inactivated fetal bovine serum, the concentration of CFU-Fs (colony-forming efficiency, CFE) ranged from 3.5 +/- 1.0 to 11.5 +/- 4.0 per 1 x 10(5) nucleated cells in five inbred mouse strains. In four transgenic lines with profound bone involvement, CFE was either significantly reduced or increased compared to wild-type littermates. In normal human donors, CFE decreased slightly with age and averaged 52.2 +/- 4.1 for children and 32.3 +/- 3.0 for adults. CFE was significantly altered in patients with several skeletal, metabolic, and hematological disorders: reduced in congenital generalized lipodystrophy, achondroplasia (SADDAN), pseudoachondroplasia, and Paget disease of bone and elevated in alcaptonuria and sickle cell anemia. Our findings indicate that under appropriate culture conditions, CFE values may provide useful insights into bone/bone marrow pathophysiology.
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Coffinier C, Hudon SE, Lee R, Farber EA, Nobumori C, Miner JH, Andres DA, Spielmann HP, Hrycyna CA, Fong LG, Young SG. A potent HIV protease inhibitor, darunavir, does not inhibit ZMPSTE24 or lead to an accumulation of farnesyl-prelamin A in cells. J Biol Chem 2008; 283:9797-804. [PMID: 18230615 DOI: 10.1074/jbc.m709629200] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
HIV protease inhibitors (HIV-PIs) are key components of highly active antiretroviral therapy, but they have been associated with adverse side effects, including partial lipodystrophy and metabolic syndrome. We recently demonstrated that a commonly used HIV-PI, lopinavir, inhibits ZMPSTE24, thereby blocking lamin A biogenesis and leading to an accumulation of prelamin A. ZMPSTE24 deficiency in humans causes an accumulation of prelamin A and leads to lipodystrophy and other disease phenotypes. Thus, an accumulation of prelamin A in the setting of HIV-PIs represents a plausible mechanism for some drug side effects. Here we show, with metabolic labeling studies, that lopinavir leads to the accumulation of the farnesylated form of prelamin A. We also tested whether a new and chemically distinct HIV-PI, darunavir, inhibits ZMPSTE24. We found that darunavir does not inhibit the biochemical activity of ZMPSTE24, nor does it lead to an accumulation of farnesyl-prelamin A in cells. This property of darunavir is potentially attractive. However, all HIV-PIs, including darunavir, are generally administered with ritonavir, an HIV-PI that is used to block the metabolism of other HIV-PIs. Ritonavir, like lopinavir, inhibits ZMPSTE24 and leads to an accumulation of prelamin A.
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Affiliation(s)
- Catherine Coffinier
- Department of Medicine and Human Genetics, David Geffen School of Medicine, University of California-Los Angeles, 695 Charles E. Young Drive South, Los Angeles, CA 90095, USA.
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Coffinier C, Hudon SE, Farber EA, Chang SY, Hrycyna CA, Young SG, Fong LG. HIV protease inhibitors block the zinc metalloproteinase ZMPSTE24 and lead to an accumulation of prelamin A in cells. Proc Natl Acad Sci U S A 2007; 104:13432-7. [PMID: 17652517 PMCID: PMC1948915 DOI: 10.1073/pnas.0704212104] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
HIV protease inhibitors (HIV-PIs) target the HIV aspartyl protease, which cleaves the HIV gag-pol polyprotein into shorter proteins required for the production of new virions. HIV-PIs are a cornerstone of treatment for HIV but have been associated with lipodystrophy and other side effects. In both human and mouse fibroblasts, we show that HIV-PIs caused an accumulation of prelamin A. The prelamin A in HIV-PI-treated fibroblasts migrated more rapidly than nonfarnesylated prelamin A, comigrating with the farnesylated form of prelamin A that accumulates in ZMPSTE24-deficient fibroblasts. The accumulation of farnesyl-prelamin A in response to HIV-PI treatment was exaggerated in fibroblasts heterozygous for Zmpste24 deficiency. HIV-PIs inhibited the endoproteolytic processing of a GFP-prelamin A fusion protein. The HIV-PIs did not affect the farnesylation of HDJ-2, nor did they inhibit protein farnesyltransferase in vitro. HIV-PIs also did not inhibit the activities of the isoprenyl-cysteine carboxyl methyltransferase ICMT or the prenylprotein endoprotease RCE1 in vitro, but they did inhibit ZMPSTE24 (IC(50): lopinavir, 18.4 +/- 4.6 microM; tipranavir, 1.2 +/- 0.4 microM). We conclude that the HIV-PIs inhibit ZMPSTE24, leading to an accumulation of farnesyl-prelamin A. The inhibition of ZMPSTE24 by HIV-PIs could play a role in the side effects of these drugs.
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Affiliation(s)
- Catherine Coffinier
- *Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095; and
- To whom correspondence may be addressed. E-mail: , , , or
| | - Sarah E. Hudon
- Department of Chemistry, Purdue University, West Lafayette, IN 47907
| | - Emily A. Farber
- *Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095; and
| | - Sandy Y. Chang
- *Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095; and
| | - Christine A. Hrycyna
- Department of Chemistry, Purdue University, West Lafayette, IN 47907
- To whom correspondence may be addressed. E-mail: , , , or
| | - Stephen G. Young
- *Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095; and
- To whom correspondence may be addressed. E-mail: , , , or
| | - Loren G. Fong
- *Department of Medicine/Division of Cardiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095; and
- To whom correspondence may be addressed. E-mail: , , , or
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Pessler-Cohen D, Pekala PH, Kovsan J, Bloch-Damti A, Rudich A, Bashan N. GLUT4 repression in response to oxidative stress is associated with reciprocal alterations in C/EBP alpha and delta isoforms in 3T3-L1 adipocytes. Arch Physiol Biochem 2006; 112:3-12. [PMID: 16754198 DOI: 10.1080/13813450500500399] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Insulin responsiveness of adipocytes is acquired during normal adipogenesis, and is essential for maintaining whole-body insulin sensitivity. Differentiated adipocytes exposed to oxidative stress become insulin resistant, exhibiting decreased expression of genes like the insulin-responsive glucose transporter GLUT4. Here we assessed the effect of oxidative stress on DNA binding capacity of C/EBP isoforms known to participate in adipocyte differentiation, and determine the relevance for GLUT4 gene regulation. By electrophoretic mobility shift assay, nuclear proteins from oxidized adipocytes exhibited decreased binding of C/EBPalpha-containing dimers to a DNA oligonucleotide harboring the C/EBP binding sequence from the murine GLUT4 promoter. C/EBPdelta-containing dimers were increased, while C/EBPbeta-dimers were unchanged. These alterations were mirrored by a 50% decrease and a 2-fold increase in the protein content of C/EBPalpha and C/EBPdelta, respectively. In oxidized cells, GLUT4 protein and mRNA levels were decreased, and a GLUT4 promoter segment containing the C/EBP binding site partially mediated oxidative stress-induced repression of a reported gene. The antioxidant lipoic acid protected against oxidation-induced decrease in GLUT4 and C/EBPalpha mRNA, but did not prevent the increase in C/EBPdelta mRNA. We propose that oxidative stress induces adipocyte insulin resistance partially by affecting the expression of C/EBPalpha and delta, resulting in altered C/EBP-dimer composition potentially occupying the GLUT4 promoter.
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Affiliation(s)
- Dorit Pessler-Cohen
- Department of Clinical Biochemistry, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Young SG, Fong LG, Michaelis S. Prelamin A, Zmpste24, misshapen cell nuclei, and progeria--new evidence suggesting that protein farnesylation could be important for disease pathogenesis. J Lipid Res 2005; 46:2531-58. [PMID: 16207929 DOI: 10.1194/jlr.r500011-jlr200] [Citation(s) in RCA: 177] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prelamin A undergoes multistep processing to yield lamin A, a structural protein of the nuclear lamina. Prelamin A terminates with a CAAX motif, which triggers farnesylation of a C-terminal cysteine (the C of the CAAX motif), endoproteolytic release of the last three amino acids (the AAX), and methylation of the newly exposed farnesylcysteine residue. In addition, prelamin A is cleaved a second time, releasing 15 more residues from the C terminus (including the farnesylcysteine methyl ester), generating mature lamin A. This second cleavage step is carried out by an endoplasmic reticulum membrane protease, ZMPSTE24. Interest in the posttranslational processing of prelamin A has increased with the recognition that certain progeroid syndromes can be caused by mutations that lead to an accumulation of farnesyl-prelamin A. Recently, we showed that a key cellular phenotype of these progeroid disorders, misshapen cell nuclei, can be ameliorated by inhibitors of protein farnesylation, suggesting a potential strategy for treating these diseases. In this article, we review the posttranslational processing of prelamin A, describe several mouse models for progeroid syndromes, explain the mutations underlying several human progeroid syndromes, and summarize recent data showing that misshapen nuclei can be ameliorated by treating cells with protein farnesyltransferase inhibitors.
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Affiliation(s)
- Stephen G Young
- Division of Cardiology, Department of Internal Medicine, University of California, Los Angeles, CA 90095, USA.
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Abstract
The nuclear envelope separates the chromosomes from cytoplasm in eukaryotic cells and consists of three main domains: inner and outer nuclear membranes and nuclear pore complexes. The inner nuclear membrane maintains close associations with the underlying chromatin and nuclear lamina. For many years, the nuclear envelope was thought to function mainly as an architectural stabilizer of the nucleus, participating in assembly and disassembly processes during mitosis. However, recent findings demonstrate that nuclear envelope proteins are involved in fundamental nuclear functions, such as gene transcription and DNA replication, and that inherited or de novo mutated proteins cause human diseases, termed "nuclear envelopathies." These findings emphasize the importance of understanding the functions of this cellular domain, in both physiologic and pathologic states. To date, mutations in the genes encoding the nuclear envelope proteins emerin, MAN1, lamin A/C, and lamin B receptor were found to cause nuclear envelopathies. The diseases that are caused by mutations in LMNA gene are collectively called "laminopathies." Nuclear envelopathies have diverse clinical phenotypes, ranging from cardiac and skeletal myopathies to partial lipodystrophy, peripheral neuropathy, and premature aging. This raises the question of how do such ubiquitously expressed proteins give rise to tissue-specific disease phenotypes. One possible explanation is the involvement of nuclear envelope proteins in the regulation of gene transcription, a novel mechanism that has been the focus of research in our lab in recent years. In this review, we describe recent discoveries in the field of nuclear envelopathies and discuss current proposed pathophysiological mechanisms underlying these diseases.
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Affiliation(s)
- Raz Somech
- Sheba Cancer Research Center, Institute of Hematology, The Chaim Sheba Medical Center and Sackler School of Medicine, Tel-Aviv University, Israel
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Freedland ES. Role of a critical visceral adipose tissue threshold (CVATT) in metabolic syndrome: implications for controlling dietary carbohydrates: a review. Nutr Metab (Lond) 2004; 1:12. [PMID: 15530168 PMCID: PMC535537 DOI: 10.1186/1743-7075-1-12] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Accepted: 11/05/2004] [Indexed: 12/25/2022] Open
Abstract
There are likely many scenarios and pathways that can lead to metabolic syndrome. This paper reviews mechanisms by which the accumulation of visceral adipose tissue (VAT) may contribute to the metabolic syndrome, and explores the paradigm of a critical VAT threshold (CVATT). Exceeding the CVATT may result in a number of metabolic disturbances such as insulin resistance to glucose uptake by cells. Metabolic profiles of patients with visceral obesity may substantially improve after only modest weight loss. This could reflect a significant reduction in the amount of VAT relative to peripheral or subcutaneous fat depots, thereby maintaining VAT below the CVATT. The CVATT may be unique for each individual. This may help explain the phenomena of apparently lean individuals with metabolic syndrome, the so-called metabolically normal weight (MONW), as well as the obese with normal metabolic profiles, i.e., metabolically normal obese (MNO), and those who are "fit and fat." The concept of CVATT may have implications for prevention and treatment of metabolic syndrome, which may include controlling dietary carbohydrates. The identification of the CVATT is admittedly difficult and its anatomical boundaries are not well-defined. Thus, the CVATT will continue to be a work in progress.
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Affiliation(s)
- Eric S Freedland
- Boston University School of Medicine, 5 Bessom Street, No, 318, Marblehead, MA 01945, USA.
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Abstract
Type II diabetes is a common, complex and heterogeneous group of disorders of growing public health concern. Paradoxically, rare monogenic forms of diabetes mellitus have been the most informative regarding diabetes pathophysiology to date. We discuss disappointing results of genetic approaches thus far, emphasizing the genetic heterogeneity underlying the common phenotypic endpoint of elevated blood glucose level and the phenotypic misclassification in large studies resulting from this admixture and from the obligatory use of epidemiological or clinical surrogate measures. We suggest that novel approaches that take explicit account of the phenotypic, environmental and genetic complexities of type II diabetes are needed and discuss some principles that might underlie such approaches.
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Affiliation(s)
- A B Jenkins
- Department of Biomedical Science, University of Wollongong, Wollongong, NSW
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Nagy GS, Tsiodras S, Martin LD, Avihingsanon A, Gavrila A, Hsu WC, Karchmer AW, Mantzoros CS. Human immunodeficiency virus type 1-related lipoatrophy and lipohypertrophy are associated with serum concentrations of leptin. Clin Infect Dis 2003; 36:795-802. [PMID: 12627366 DOI: 10.1086/367859] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2002] [Accepted: 12/04/2002] [Indexed: 11/03/2022] Open
Abstract
The relationship between the adipocyte-derived hormone leptin, insulin resistance, and fat redistribution in patients with human immunodeficiency virus (HIV) infection has not been established. We classified a cohort of HIV type 1 (HIV-1)-infected patients with >or=6 months of antiretroviral exposure as having no lipodystrophy (51 patients [43% of the cohort]), lipoatrophy (23 patients [19% of the cohort]), mixed lipodystrophy (29 patients [24% of the cohort]), or lipohypertrophy (17 patients [14% of the cohort]), on the basis of physical examination, anthropometric measurements, and the findings of dual-emission x-ray absorptiometry and computed tomography. Measurements of insulin resistance were higher for patients with each category of lipodystrophy, compared with those observed for patients with no lipodystrophy (P<.001). Mean leptin levels (+/- standard deviation) were lowest in patients with lipoatrophy (1.76+/-1.20 ng/mL), highest in patients with lipohypertrophy (9.10+/-6.86 ng/mL), and significantly different from those in patients without lipodystrophy (3.14+/-2.30 ng/mL; both P<.01). In this cohort of antiretroviral-experienced HIV-infected patients, a low serum level of leptin was independently associated with insulin resistance in patients with lipoatrophy, after controlling for total and regional body fat.
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Affiliation(s)
- G Sonia Nagy
- Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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Hegele RA, Kraw ME, Ban MR, Miskie BA, Huff MW, Cao H. Elevated serum C-reactive protein and free fatty acids among nondiabetic carriers of missense mutations in the gene encoding lamin A/C (LMNA) with partial lipodystrophy. Arterioscler Thromb Vasc Biol 2003; 23:111-6. [PMID: 12524233 DOI: 10.1161/01.atv.0000047460.27435.b8] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Dunnigan-type familial partial lipodystrophy (FPLD) due to mutant LMNA is a monogenic form of insulin resistance. Affected subjects, especially women, are at increased risk of early coronary heart disease (CHD). Although common insulin resistance is associated with several biochemical perturbations, including elevated C-reactive protein (CRP), the biochemical profile in subjects with mutant LMNA is incompletely defined. METHODS AND RESULTS We studied 35 nondiabetic adult FPLD subjects (of whom 24 were women) with either the LMNA R482Q or R482W missense mutations and 51 matched normal first-degree relatives (of whom 27 were women). Compared with normal controls, LMNA mutation carriers had significantly higher plasma insulin and more dyslipidemia, higher mean triglycerides and lower HDL cholesterol, significantly higher nonesterified free fatty acids and CRP, and significantly lower leptin and adiponectin than controls. Subgroup analyses showed that these differences were more pronounced in women. Other biomarkers such as resistin, fibrinogen, and plasminogen activator inhibitor-1 were not different between groups. CONCLUSIONS LMNA mutations in nondiabetic patients with FPLD are associated with several metabolic and biochemical changes, particularly in women. The unfavorable profile might contribute to the increased susceptibility to CHD seen in LMNA mutation carriers.
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Affiliation(s)
- Robert A Hegele
- Blackburn Cardiovascular Genetics Laboratory and Vascular Biology Research Group, Robarts Research Institute, London, Ontario, Canada.
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Hegele RA, Cao H, Frankowski C, Mathews ST, Leff T. PPARG F388L, a transactivation-deficient mutant, in familial partial lipodystrophy. Diabetes 2002; 51:3586-90. [PMID: 12453919 DOI: 10.2337/diabetes.51.12.3586] [Citation(s) in RCA: 217] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Autosomal dominant familial partial lipodystrophy (FPLD) due to mutant LMNA encoding nuclear lamin A/C is characterized by adipose tissue repartitioning together with multiple metabolic disturbances, including insulin resistance and dyslipidemia. There is emerging evidence that some rare mutations in peroxisome proliferator-activated receptor-gamma (PPAR-gamma), encoded by PPARG, might be associated with human lipodystrophy. We report a three-generation Canadian kindred ascertained based upon partial lipodystrophy, with a normal LMNA gene sequence. Candidate gene sequencing showed that all four affected subjects were heterozygous for a novel T-->A mutation at PPARG nucleotide 1164 in exon 5 that predicted substitution of phenylalanine at codon 388 by leucine (F388L). The mutation was absent from normal family members and normal unrelated subjects, and altered a highly conserved residue within helix 8 of the predicted ligand-binding pocket of PPAR-gamma. The mutant receptor had significantly decreased basal transcriptional activity and impaired stimulation by a synthetic ligand. The germline transmission of a transactivation-deficient mutation in PPARG suggests that autosomal dominant partial lipodystrophy is genetically heterogeneous. Our findings are consistent with the idea that mutant PPARG can underlie the partial lipodystrophy phenotype.
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Affiliation(s)
- Robert A Hegele
- Blackburn Cardiovascular Genetics Laboratory, Robarts Research Institute, 406-100 Perth Drive, London, Ontario, Canada N6A 5K8.
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37
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Abstract
Both type 2 diabetes mellitus (T2DM) and insulin resistance are complex traits in which multiple gene effects and metabolic and environmental factors combine to contribute to the overall pathogenesis of these conditions. This complexity has complicated the search for susceptibility genes and has led to different but complementary approaches being used for the detection of gene effects. These include the study of monogenic cases of insulin resistance and T2DM, association studies of candidate genes and genome-wide scans. The peroxisome proliferator-activated receptor gamma (PPARgamma) and calpain-10 (CAPN10) genes have recently been identified as T2DM susceptibility genes, and the lessons learnt from these studies are helping to shape future strategies to search for additional susceptibility genes in T2DM and insulin resistance.
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Affiliation(s)
- E A McIntyre
- School of Clinical Medical Sciences, University of Newcastle upon Tyne, UK
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38
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Ceddia RB, Koistinen HA, Zierath JR, Sweeney G. Analysis of paradoxical observations on the association between leptin and insulin resistance. FASEB J 2002; 16:1163-76. [PMID: 12153984 DOI: 10.1096/fj.02-0158rev] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Obesity is commonly associated with the development of insulin resistance and diabetes in humans and rodents. Insulin resistance and diabetes are observed in lipoatrophic individuals or rodent models of lipoatrophy. Here we focus on the role of leptin, the product of the obesity (ob) gene, in the development of insulin resistance and diabetes associated with obesity and lipoatrophy. We review the reported effects of leptin on whole body glucose metabolism and compare and contrast these with direct effects on skeletal muscle, fat and liver. This summary of paradoxical observations on the effects of leptin on glucose homeostasis and the ability of leptin to induce or improve insulin resistance suggests that a complex interplay exists between direct peripheral and centrally mediated effects of the hormone. Evidence suggesting that leptin acts as a mediator of insulin release from pancreatic beta cells is reviewed. Finally, intracellular signaling mechanisms stimulated by both leptin and insulin are discussed, with potential points of cross-talk suggested.
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Lewis GF, Carpentier A, Adeli K, Giacca A. Disordered fat storage and mobilization in the pathogenesis of insulin resistance and type 2 diabetes. Endocr Rev 2002; 23:201-29. [PMID: 11943743 DOI: 10.1210/edrv.23.2.0461] [Citation(s) in RCA: 744] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The primary genetic, environmental, and metabolic factors responsible for causing insulin resistance and pancreatic beta-cell failure and the precise sequence of events leading to the development of type 2 diabetes are not yet fully understood. Abnormalities of triglyceride storage and lipolysis in insulin-sensitive tissues are an early manifestation of conditions characterized by insulin resistance and are detectable before the development of postprandial or fasting hyperglycemia. Increased free fatty acid (FFA) flux from adipose tissue to nonadipose tissue, resulting from abnormalities of fat metabolism, participates in and amplifies many of the fundamental metabolic derangements that are characteristic of the insulin resistance syndrome and type 2 diabetes. It is also likely to play an important role in the progression from normal glucose tolerance to fasting hyperglycemia and conversion to frank type 2 diabetes in insulin resistant individuals. Adverse metabolic consequences of increased FFA flux, to be discussed in this review, are extremely wide ranging and include, but are not limited to: 1) dyslipidemia and hepatic steatosis, 2) impaired glucose metabolism and insulin sensitivity in muscle and liver, 3) diminished insulin clearance, aggravating peripheral tissue hyperinsulinemia, and 4) impaired pancreatic beta-cell function. The precise biochemical mechanisms whereby fatty acids and cytosolic triglycerides exert their effects remain poorly understood. Recent studies, however, suggest that the sequence of events may be the following: in states of positive net energy balance, triglyceride accumulation in "fat-buffering" adipose tissue is limited by the development of adipose tissue insulin resistance. This results in diversion of energy substrates to nonadipose tissue, which in turn leads to a complex array of metabolic abnormalities characteristic of insulin-resistant states and type 2 diabetes. Recent evidence suggests that some of the biochemical mechanisms whereby glucose and fat exert adverse effects in insulin-sensitive and insulin-producing tissues are shared, thus implicating a diabetogenic role for energy excess as a whole. Although there is now evidence that weight loss through reduction of caloric intake and increase in physical activity can prevent the development of diabetes, it remains an open question as to whether specific modulation of fat metabolism will result in improvement in some or all of the above metabolic derangements or will prevent progression from insulin resistance syndrome to type 2 diabetes.
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Affiliation(s)
- Gary F Lewis
- Department of Medicine, Division of Endocrinology, University of Toronto, Canada M5G 2C4.
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40
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Abstract
Functional genomics, commonly applied to the genes and enzymes involved in metabolism of chemicals, can also be applied to enzymes involved in the metabolism of nutrients. Although in its infancy, genomics can be used to determine relationships between nutrition and toxicology, drug metabolism, and cancer.
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Affiliation(s)
- F P Guengerich
- Department of Biochemistry, Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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41
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Abstract
Severely obese children are even more likely to have mutations in obesity genes than are severely obese adults. Thus, investigators searching for obesity genes commonly focus on children, with the result that many human obesity genes were first identified in studies of children. Although the development of obesity depends on living in an obesity-promoting environment, it also is influenced strongly by individual genetic composition. Thus, the discovery of new obesity genes provides new opportunities to identify causes of severe obesity. Finally, identification of individual causes of obesity may, in the future, provide for a safe, effective, and individualized treatment recommendation for each obese person.
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Affiliation(s)
- N A Warden
- Department of Pediatrics, University of California Davis Medical Center, Sacramento, California, USA.
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