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Bhandari R, Armenian SH, McCormack S, Natarajan R, Mostoufi-Moab S. Diabetes in childhood cancer survivors: emerging concepts in pathophysiology and future directions. Front Med (Lausanne) 2023; 10:1206071. [PMID: 37675136 PMCID: PMC10478711 DOI: 10.3389/fmed.2023.1206071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/10/2023] [Indexed: 09/08/2023] Open
Abstract
With advancements in cancer treatment and supportive care, there is a growing population of childhood cancer survivors who experience a substantial burden of comorbidities related to having received cancer treatment at a young age. Despite an overall reduction in the incidence of most chronic health conditions in childhood cancer survivors over the past several decades, the cumulative incidence of certain late effects, in particular diabetes mellitus (DM), has increased. The implications are significant, because DM is a key risk factor for cardiovascular disease, a leading cause of premature death in childhood cancer survivors. The underlying pathophysiology of DM in cancer survivors is multifactorial. DM develops at younger ages in survivors compared to controls, which may reflect an "accelerated aging" phenotype in these individuals. The treatment-related exposures (i.e., chemotherapy, radiation) that increase risk for DM in childhood cancer survivors may be more than additive with established DM risk factors (e.g., older age, obesity, race, and ethnicity). Emerging research also points to parallels in cellular processes implicated in aging- and cancer treatment-related DM. Still, there remains marked inter-individual variability regarding risk of DM that is not explained by demographic and therapeutic risk factors alone. Recent studies have highlighted the role of germline genetic risk factors and epigenetic modifications that are associated with risk of DM in both the general and oncology populations. This review summarizes our current understanding of recognized risk factors for DM in childhood cancer survivors to help inform targeted approaches for disease screening, prevention, and treatment. Furthermore, it highlights the existing scientific gaps in understanding the relative contributions of individual therapeutic exposures and the mechanisms by which they exert their effects that uniquely predispose this population to DM following cancer treatment.
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Affiliation(s)
- Rusha Bhandari
- Department of Pediatrics, City of Hope, Duarte, CA, United States
- Department of Population Sciences, City of Hope, Duarte, CA, United States
| | - Saro H. Armenian
- Department of Pediatrics, City of Hope, Duarte, CA, United States
- Department of Population Sciences, City of Hope, Duarte, CA, United States
| | - Shana McCormack
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Rama Natarajan
- Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA, United States
| | - Sogol Mostoufi-Moab
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, United States
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2
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Chang CS, Yu SS, Ho LC, Chao SH, Chou TY, Shao AN, Kao LZ, Chang CY, Chen YH, Wu MS, Tsai PJ, Maeda N, Tsai YS. Inguinal Fat Compensates Whole Body Metabolic Functionality in Partially Lipodystrophic Mice with Reduced PPARγ Expression. Int J Mol Sci 2023; 24:3904. [PMID: 36835312 PMCID: PMC9966317 DOI: 10.3390/ijms24043904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/08/2023] [Accepted: 02/08/2023] [Indexed: 02/17/2023] Open
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) gene mutations in humans and mice lead to whole-body insulin resistance and partial lipodystrophy. It is unclear whether preserved fat depots in partial lipodystrophy are beneficial for whole-body metabolic homeostasis. We analyzed the insulin response and expression of metabolic genes in the preserved fat depots of PpargC/- mice, a familial partial lipodystrophy type 3 (FPLD3) mouse model resulting from a 75% decrease in Pparg transcripts. Perigonadal fat of PpargC/- mice in the basal state showed dramatic decreases in adipose tissue mass and insulin sensitivity, whereas inguinal fat showed compensatory increases. Preservation of inguinal fat metabolic ability and flexibility was reflected by the normal expression of metabolic genes in the basal or fasting/refeeding states. The high nutrient load further increased insulin sensitivity in inguinal fat, but the expression of metabolic genes became dysregulated. Inguinal fat removal resulted in further impairment of whole-body insulin sensitivity in PpargC/- mice. Conversely, the compensatory increase in insulin sensitivity of the inguinal fat in PpargC/- mice diminished as activation of PPARγ by its agonists restored insulin sensitivity and metabolic ability of perigonadal fat. Together, we demonstrated that inguinal fat of PpargC/- mice plays a compensatory role in combating perigonadal fat abnormalities.
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Affiliation(s)
- Cherng-Shyang Chang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Shang-Shiuan Yu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Li-Chun Ho
- School of Medicine, College of Medicine, I-Shou University, Kaohsiung 824, Taiwan
- Division of General Medicine, Department of Internal Medicine, E-DA Hospital, Kaohsiung 824, Taiwan
| | - Shu-Hsin Chao
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Ting-Yu Chou
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Institute of Molecular Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Ai-Ning Shao
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Ling-Zhen Kao
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Chia-Yu Chang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Yu-Hsin Chen
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Ming-Shan Wu
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Pei-Jane Tsai
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Nobuyo Maeda
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
- Clinical Medicine Research Center, National Cheng Kung University Hospital, Tainan 704, Taiwan
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Iizaka T, Kodama E, Mikura K, Iida T, Imai H, Hashizume M, Kigawa Y, Sugisawa C, Tadokoro R, Endo K, Otsuka F, Isoda M, Ebihara K, Ishibashi S, Nagasaka S. Clinical characteristics and efficacy of pioglitazone in a Japanese patient with familial partial lipodystrophy due to peroxisome proliferator-activated receptor γ gene mutation. Endocr J 2023; 70:69-76. [PMID: 36171144 DOI: 10.1507/endocrj.ej22-0140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Familial partial lipodystrophy (FPLD) 3 is a rare genetic disorder caused by peroxisome proliferator-activated receptor γ gene (PPARG) mutations. Most cases have been reported in Western patients. Here, we describe a first pedigree of FPLD 3 in Japanese. The proband was a 51-year-old woman. She was diagnosed with fatty liver at age 32 years, dyslipidemia at age 37 years, and diabetes mellitus at age 41 years. Her body mass index was 18.5 kg/m2, and body fat percentage was 19.2%. On physical examination, she had less subcutaneous fat in the upper limbs than in other sites. On magnetic resonance imaging, atrophy of subcutaneous adipose tissue was seen in the upper limbs and lower legs. Fasting serum C-peptide immunoreactivity was high (3.4 ng/mL), and the plasma glucose disappearance rate was low (2.07%/min) on an insulin tolerance test, both suggesting apparent insulin resistance. The serum total adiponectin level was low (2.3 μg/mL). Mild fatty liver was seen on abdominal computed tomography. On genetic analysis, a P495L mutation in PPARG was identified. The same mutation was also seen in her father, who had non-obese diabetes mellitus, and FPLD 3 was diagnosed. Modest increases in body fat and serum total adiponectin were seen with pioglitazone treatment. Attention should be paid to avoid overlooking lipodystrophy syndromes even in non-obese diabetic patients if they show features of insulin resistance.
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Affiliation(s)
- Toru Iizaka
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Eriko Kodama
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Kentaro Mikura
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Tatsuya Iida
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Hideyuki Imai
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Mai Hashizume
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Yasuyoshi Kigawa
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Chiho Sugisawa
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Rie Tadokoro
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Kei Endo
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Fumiko Otsuka
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
| | - Masayo Isoda
- Division of Endocrinology and Metabolism, Jichi Medical University, Tochigi 329-0498, Japan
| | - Ken Ebihara
- Division of Endocrinology and Metabolism, Jichi Medical University, Tochigi 329-0498, Japan
| | - Shun Ishibashi
- Division of Endocrinology and Metabolism, Jichi Medical University, Tochigi 329-0498, Japan
| | - Shoichiro Nagasaka
- Division of Diabetes, Metabolism and Endocrinology, Showa University Fujigaoka Hospital, Kanagawa 227-8501, Japan
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Tang H, Zeng Q, Tang T, Wei Y, Pu P. Kaempferide improves glycolipid metabolism disorder by activating PPARγ in high-fat-diet-fed mice. Life Sci 2021; 270:119133. [PMID: 33508298 DOI: 10.1016/j.lfs.2021.119133] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/14/2021] [Accepted: 01/19/2021] [Indexed: 12/13/2022]
Abstract
AIMS Kaempferide (Ka, 3,5,7-trihydroxy-4'-methoxyflavone), an active ingredient of Tagetes erecta L., has been demonstrated to possess many pharmacological effects, including antioxidant, anti-inflammation, anticancer and antihypertension in previous study. However, there is no evidence of Ka on metabolic disorder in former studies. This study investigated the effects of Ka on glycolipid metabolism and explored the underlying mechanisms of action in vivo and vitro. MATERIALS AND METHODS The mouse model of glycolipid metabolism disorder was induced by high-fat diet (HFD). The effects of Ka were evaluated on bodyweight, lipid metabolism and glucose metabolism. Hypolipidemic effect was examined by blood sample analysis. The hypoglycemic effect was detected by several indicators, like blood glucose, serum insulin, HOMA index and intraperitoneal glucose tolerance tests (IPGTT). The signaling pathways of lipid metabolism (PPARγ/LXRα/ABCA1) and glucose metabolism (PPARγ/PI3K/AKT) were evaluated using Real-Time PCR and Western blot. The primary culture of hepatocyte was prepared to confirm the target of Ka by co-culturing with PPARγ agonist or inhibitor. KEY FINDINGS The HFD mice developed obesity, hyperlipidemia, hyperglycemia and insulin resistance. Administration of Ka at a dose of 10 mg/kg.BW for 16 weeks effectively attenuated these changes. Further studies revealed the hypolipidemic and hypoglycemic effects of Ka depended on the activation of PPARγ/LXRα/ABCA1 and PPARγ/PI3K/AKT pathways, respectively. The primary hepatocyte test, co-cultured with PPARγ agonists or inhibitors, further confirmed the above signaling pathway and key protein. SIGNIFICANCE These results suggested that Ka played an important role in improving glycolipid metabolism disorder. These favorable effects were causally associated with anti-obesity. The underlying mechanisms might have to do with the activation of the PPARγ and its downstream signaling pathway. Our study helped to understand the pharmacological actions of Ka, and played a role for Ka in the effective treatment of obesity, diabetes, nonalcoholic hepatitis and other metabolic diseases.
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Affiliation(s)
- Heng Tang
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, No.1 Youyi Road, Yuanjiagang, Yuzhong District, Chongqing 400042, China
| | - Qingfu Zeng
- Department of Vascular Surgery, The Second Affiliated Hospital of Nanchang University, No. 1, Minde Road, Donghu District, Nanchang City, Jiangxi Province 330006, China
| | - Ting Tang
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, No.1 Youyi Road, Yuanjiagang, Yuzhong District, Chongqing 400042, China
| | - Yunjie Wei
- Department of Cardiology, Hubei Shiyan Taihe hospital, Hubei, China
| | - Peng Pu
- Department of Cardiology, The First Affiliated Hospital of Chongqing Medical University, No.1 Youyi Road, Yuanjiagang, Yuzhong District, Chongqing 400042, China.
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Lambadiari V, Kountouri A, Maratou E, Liatis S, Dimitriadis GD, Karpe F. Case Report: Metreleptin Treatment in a Patient With a Novel Mutation for Familial Partial Lipodystrophy Type 3, Presenting With Uncontrolled Diabetes and Insulin Resistance. Front Endocrinol (Lausanne) 2021; 12:684182. [PMID: 34168618 PMCID: PMC8217860 DOI: 10.3389/fendo.2021.684182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Familial partial lipodystrophy type 3 (FPLD3) is a very rare autosomal dominant genetic disorder which is caused by mutations in the peroxisome proliferator activated receptor gamma (PPARG) gene. It is characterized by a partial loss of adipose tissue leading to subnormal leptin secretion and metabolic complications. Metreleptin, a synthetic analogue of human leptin, is an effective treatment for generalized lipodystrophies, but the evidence for efficacy in patients with FPLD3 is scarce. CASE PRESENTATION We present a 61-year-old woman, initially misdiagnosed as type 1 diabetes since the age of 29, with severe insulin resistance, who gradually displayed a more generalized form of lipoatrophy and extreme hypertriglyceridemia, hypertension and multiple manifestations of cardiovascular disease. She was found to carry a novel mutation leading to PPARGGlu157Gly variant. After six months of metreleptin treatment, HbA1c decreased from 10 to 7.9% and fasting plasma triglycerides were dramatically reduced from 2.919 mg/dl to 198 mg/dl. CONCLUSIONS This case highlights the importance of early recognition of FPLD syndromes otherwise frequently observed as difficult-to-classify and manages diabetes cases, in order to prevent cardiovascular complications. Metreleptin may be an effective treatment for FPLD3.
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Affiliation(s)
- Vaia Lambadiari
- Second Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
- *Correspondence: Vaia Lambadiari,
| | - Aikaterini Kountouri
- Second Department of Internal Medicine, Medical School, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Eirini Maratou
- Department of Clinical Biochemistry, Medical School, National and Kapodistrian University of Athens, Attikon University Hospital, Athens, Greece
| | - Stavros Liatis
- First Department of Propaedeutic and Internal Medicine, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital, Athens, Greece
| | - George D. Dimitriadis
- Medical School, Sector of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford and National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), Oxford University Hospital Trusts, Oxford, United Kingdom
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6
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Lim K, Haider A, Adams C, Sleigh A, Savage DB. Lipodistrophy: a paradigm for understanding the consequences of "overloading" adipose tissue. Physiol Rev 2020; 101:907-993. [PMID: 33356916 DOI: 10.1152/physrev.00032.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Lipodystrophies have been recognized since at least the nineteenth century and, despite their rarity, tended to attract considerable medical attention because of the severity and somewhat paradoxical nature of the associated metabolic disease that so closely mimics that of obesity. Within the last 20 yr most of the monogenic subtypes have been characterized, facilitating family genetic screening and earlier disease detection as well as providing important insights into adipocyte biology and the systemic consequences of impaired adipocyte function. Even more recently, compelling genetic studies have suggested that subtle partial lipodystrophy is likely to be a major factor in prevalent insulin-resistant type 2 diabetes mellitus (T2DM), justifying the longstanding interest in these disorders. This progress has also underpinned novel approaches to treatment that, in at least some patients, can be of considerable therapeutic benefit.
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Affiliation(s)
- Koini Lim
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Afreen Haider
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Claire Adams
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Alison Sleigh
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - David B Savage
- Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
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Malandrino N, Reynolds JC, Brychta RJ, Chen KY, Auh S, Gharib AM, Startzell M, Cochran EK, Brown RJ. Visceral fat does not contribute to metabolic disease in lipodystrophy. Obes Sci Pract 2019; 5:75-82. [PMID: 30847226 PMCID: PMC6381384 DOI: 10.1002/osp4.319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 12/05/2018] [Accepted: 12/06/2018] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVES Lipodystrophies are characterized by regional or generalized loss of adipose tissue and severe metabolic complications. The role of visceral adipose tissue (VAT) in the development of metabolic derangements in lipodystrophy is unknown. The study aim was to investigate VAT contribution to metabolic disease in lipodystrophy versus healthy controls. METHODS Analysis of correlations between VAT volume and biomarkers of metabolic disease in 93 patients and 93 age/sex-matched healthy controls. RESULTS Patients with generalized lipodystrophy (n = 43) had lower VAT compared with matched controls, while those with partial lipodystrophy (n = 50) had higher VAT versus controls. Both groups with lipodystrophy had lower leg fat mass versus controls (p < 0.05 for all; unpaired t-test). In both generalized and partial lipodystrophy, there was no correlation between VAT and glucose, triglycerides or high-density lipoprotein cholesterol (p > 0.05 for all; Spearman correlation). In controls matched to patients with generalized or partial lipodystrophy, VAT correlated with glucose (R = 0.42 and 0.36), triglycerides (R = 0.36 and 0.60) and high-density lipoprotein cholesterol (R = -0.34 and -0.64) (p < 0.05 for all; Spearman correlation). CONCLUSIONS In contrast to healthy controls, metabolic derangements in lipodystrophy did not correlate with VAT volume. These data suggest that, in lipodystrophy, impaired peripheral subcutaneous fat deposition may exert a larger effect than VAT accumulation on the development of metabolic complications. Interventions aimed at increasing functional subcutaneous adipose tissue may provide metabolic benefit.
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Affiliation(s)
- N. Malandrino
- Diabetes, Endocrinology, and Obesity BranchNIDDK, NIHBethesdaMDUSA
| | - J. C. Reynolds
- Radiology and Imaging Sciences DepartmentClinical Center, NIHBethesdaMDUSA
| | - R. J. Brychta
- Diabetes, Endocrinology, and Obesity BranchNIDDK, NIHBethesdaMDUSA
| | - K. Y. Chen
- Diabetes, Endocrinology, and Obesity BranchNIDDK, NIHBethesdaMDUSA
| | - S. Auh
- Office of the DirectorNIDDK, NIHBethesdaMDUSA
| | - A. M. Gharib
- Biomedical and Metabolic Imaging BranchNIDDK, NIHBethesdaMDUSA
| | - M. Startzell
- Diabetes, Endocrinology, and Obesity BranchNIDDK, NIHBethesdaMDUSA
| | - E. K. Cochran
- Diabetes, Endocrinology, and Obesity BranchNIDDK, NIHBethesdaMDUSA
| | - R. J. Brown
- Diabetes, Endocrinology, and Obesity BranchNIDDK, NIHBethesdaMDUSA
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Piché ME, Parry SA, Karpe F, Hodson L. Chylomicron-Derived Fatty Acid Spillover in Adipose Tissue: A Signature of Metabolic Health? J Clin Endocrinol Metab 2018; 103:25-34. [PMID: 29099975 PMCID: PMC5761493 DOI: 10.1210/jc.2017-01517] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/27/2017] [Indexed: 12/29/2022]
Abstract
Context and Objectives Spillover of fatty acids (FAs) into the plasma nonesterified fatty acid (NEFA) pool, because of an inability of adipose tissue (AT) to accommodate sufficient fat uptake, has been suggested to contribute to obesity-related insulin resistance. Using specific labeling techniques, we compared the proportion of spillover-derived NEFA across a range of adiposity. Participants and Methods Seventy-one healthy men and women were fed a mixed meal (40 g fat) containing [U13C]palmitate to assess the contribution of chylomicron-derived spillover FAs. To investigate subcutaneous abdominal-specific spillover, arteriovenous difference and stable-isotope methodologies were used in substudy (six men, six women). Results Chylomicron-derived FA spillover was higher in individuals with a BMI <25 kg/m2 (n = 18) compared with those with a BMI ≥25 kg/m2 (n = 53) (22.2 ± 1.6% vs 18.6 ± 0.7%, P = 0.02). Women had higher chylomicron-derived FA spillover than age- and BMI-matched men (21.9 ± 1.1% vs 15.0 ± 1.6%, P = 0.001). Assessing spillover across subcutaneous abdominal AT showed higher proportions in women than in men (28.5 ± 6.1% vs 9.9 ± 1.3%, P = 0.01). Conclusion There is a considerable degree of spillover FA into the systemic NEFA pool in the postprandial state; this process is greater and more dynamic in lean individuals and women. Contrary to general perception, spillover of chylomicron-derived FA into systemic circulation is a physiologically normal feature most easily observed in people with a higher capacity for clearance of plasma triglycerides, but does not appear to be a pathway providing excess NEFA in obesity.
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Affiliation(s)
- Marie-Eve Piché
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
- Quebec Heart and Lung Institute, Laval University, Quebec G1V 4G5, Canada
| | - Siôn A. Parry
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford University Hospital Trusts, Oxford OX3 9DU, United Kingdom
| | - Leanne Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LE, United Kingdom
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9
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Single-Nucleotide Polymorphism of PPARγ, a Protein at the Crossroads of Physiological and Pathological Processes. Int J Mol Sci 2017; 18:ijms18020361. [PMID: 28208577 PMCID: PMC5343896 DOI: 10.3390/ijms18020361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 01/24/2017] [Accepted: 02/01/2017] [Indexed: 01/28/2023] Open
Abstract
Genome polymorphisms are responsible for phenotypic differences between humans and for individual susceptibility to genetic diseases and therapeutic responses. Non-synonymous single-nucleotide polymorphisms (nsSNPs) lead to protein variants with a change in the amino acid sequence that may affect the structure and/or function of the protein and may be utilized as efficient structural and functional markers of association to complex diseases. This study is focused on nsSNP variants of the ligand binding domain of PPARγ a nuclear receptor in the superfamily of ligand inducible transcription factors that play an important role in regulating lipid metabolism and in several processes ranging from cellular differentiation and development to carcinogenesis. Here we selected nine nsSNPs variants of the PPARγ ligand binding domain, V290M, R357A, R397C, F360L, P467L, Q286P, R288H, E324K, and E460K, expressed in cancer tissues and/or associated with partial lipodystrophy and insulin resistance. The effects of a single amino acid change on the thermodynamic stability of PPARγ, its spectral properties, and molecular dynamics have been investigated. The nsSNPs PPARγ variants show alteration of dynamics and tertiary contacts that impair the correct reciprocal positioning of helices 3 and 12, crucially important for PPARγ functioning.
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10
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Prieur X, Le May C, Magré J, Cariou B. Congenital lipodystrophies and dyslipidemias. Curr Atheroscler Rep 2015; 16:437. [PMID: 25047893 DOI: 10.1007/s11883-014-0437-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Lipodystrophies are rare acquired and genetic disorders characterized by the selective loss of adipose tissue. One key metabolic feature of patients with congenital inherited lipodystrophy is hypertriglyceridemia. The precise mechanisms by which the lack of adipose tissue causes dyslipidemia remain largely unknown. In recent years, new insights have arisen from data obtained in vitro in adipocytes, yeast, drosophila, and very recently in several genetically modified mouse models of generalized lipodystrophy. A common metabolic pathway involving accelerated lipolysis and defective energy storage seems to contribute to the dyslipidemia associated with congenital generalized lipodystrophy syndromes, although the pathophysiological changes may vary with the nature of the mutation involved. Therapeutic management of dyslipidemia in patients with lipodystrophy is primarily based on specific approaches using recombinant leptin therapy. Preclinical studies suggest a potential efficacy of thiazolidinediones that remains to be assessed in dedicated clinical trials.
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Affiliation(s)
- Xavier Prieur
- INSERM U1087-CNRS UMR 6291, L'institut du Thorax, 8 quai Moncousu, 44007, Nantes Cedex 1, France,
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11
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Jin D, Sun J, Huang J, He Y, Yu A, Yu X, Yang Z. TNF-α reduces g0s2 expression and stimulates lipolysis through PPAR-γ inhibition in 3T3-L1 adipocytes. Cytokine 2014; 69:196-205. [PMID: 24993166 DOI: 10.1016/j.cyto.2014.06.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 05/22/2014] [Accepted: 06/04/2014] [Indexed: 01/04/2023]
Abstract
Tumor necrosis factor-α (TNF-α) is a multifunctional cytokine that acts as a mediator of obesity-linked insulin resistance (IR). It is commonly accepted that macrophage-derived TNF-α acts in a paracrine manner on adjacent adipocytes, induces lipolysis, which contributes to obesity-linked hyperglycemia. Several studies suggested that G0/G1 switch gene 2 (g0s2) was up-regulated during adipogenesis, and its protein could be degraded in response to TNF-α stimulation. The aim of the present work was to investigate the transcriptional regulation of g0s2 by TNF-α stimulation. In this study, 3T3-L1 pre-adipocytes were differentiated, and treated with TNF-α for 24h. The effects of TNF-α on lipolysis and lipase expression were then examined. Our results revealed that TNF-α exerted dose- and time-dependent lipolytic effects, which could be partially reversed by overexpression of g0s2 and peroxisome proliferator-activated receptor-γ (ppar-γ). In addition, TNF-α treatment significantly reduced the expression of adiponectin, ppar-γ, hormone-sensitive Lipase (hsl), adipose triglyceride lipase (atgl) as well as ATGL co-factors. Interestingly, TNF-α significantly decreased adiponectin and PPAR-γ protein levels, while treatment with the proteasomal inhibitor MG-132 maintained PPAR-γ levels. Degradation of PPAR-γ almost completely abolished the binding of PPAR-γ to the g0s2 promoter in adipocytes treated with TNF-α. We propose that proteasomal degradation of PPAR-γ and the reduction of g0s2 content are permissive for prolonged TNF-α induced lipolysis.
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Affiliation(s)
- Dan Jin
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
| | - Jun Sun
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Jing Huang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yiduo He
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - An Yu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Xiaoling Yu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Zaiqing Yang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, PR China.
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12
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Lori C, Pasquo A, Montanari R, Capelli D, Consalvi V, Chiaraluce R, Cervoni L, Loiodice F, Laghezza A, Aschi M, Giorgi A, Pochetti G. Structural basis of the transactivation deficiency of the human PPARγ F360L mutant associated with familial partial lipodystrophy. ACTA ACUST UNITED AC 2014; 70:1965-76. [DOI: 10.1107/s1399004714009638] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 04/29/2014] [Indexed: 11/11/2022]
Abstract
The peroxisome proliferator-activated receptors (PPARs) are transcription factors that regulate glucose and lipid metabolism. The role of PPARs in several chronic diseases such as type 2 diabetes, obesity and atherosclerosis is well known and, for this reason, they are the targets of antidiabetic and hypolipidaemic drugs. In the last decade, some rare mutations in human PPARγ that might be associated with partial lipodystrophy, dyslipidaemia, insulin resistance and colon cancer have emerged. In particular, the F360L mutant of PPARγ (PPARγ2 residue 388), which is associated with familial partial lipodystrophy, significantly decreases basal transcriptional activity and impairs stimulation by synthetic ligands. To date, the structural reason for this defective behaviour is unclear. Therefore, the crystal structure of PPARγ F360L together with the partial agonist LT175 has been solved and the mutant has been characterized by circular-dichroism spectroscopy (CD) in order to compare its thermal stability with that of the wild-type receptor. The X-ray analysis showed that the mutation induces dramatic conformational changes in the C-terminal part of the receptor ligand-binding domain (LBD) owing to the loss of van der Waals interactions made by the Phe360 residue in the wild type and an important salt bridge made by Arg357, with consequent rearrangement of loop 11/12 and the activation function helix 12 (H12). The increased mobility of H12 makes the binding of co-activators in the hydrophobic cleft less efficient, thereby markedly lowering the transactivation activity. The spectroscopic analysis in solution and molecular-dynamics (MD) simulations provided results which were in agreement and consistent with the mutant conformational changes observed by X-ray analysis. Moreover, to evaluate the importance of the salt bridge made by Arg357, the crystal structure of the PPARγ R357A mutant in complex with the agonist rosiglitazone has been solved.
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Auclair M, Vigouroux C, Boccara F, Capel E, Vigeral C, Guerci B, Lascols O, Capeau J, Caron-Debarle M. Peroxisome proliferator-activated receptor-γ mutations responsible for lipodystrophy with severe hypertension activate the cellular renin-angiotensin system. Arterioscler Thromb Vasc Biol 2013; 33:829-38. [PMID: 23393388 DOI: 10.1161/atvbaha.112.300962] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Inactivating peroxisome proliferator-activated receptor-γ (PPARγ) mutations lead to a syndrome of familial partial lipodystrophy (FPLD3) associated with early-onset severe hypertension. PPARγ can repress the vascular renin-angiotensin system (RAS) and angiotensin II receptor 1 expression. We evaluated the relationships between PPARγ inactivation and cellular RAS using FPLD3 patients' cells and human vascular smooth muscle cells expressing mutant or wild-type PPARγ. Approach and Results- We identified 2 novel PPARG mutations, R165T and L339X, located in the DNA and ligand-binding domains of PPARγ, respectively in 4 patients from 2 FPLD3 families. In cultured skin fibroblasts and peripheral blood mononuclear cells from the 4 patients and healthy controls, we compared markers of RAS activation, oxidative stress, and inflammation, and tested the effect of modulators of PPARγ and angiotensin II receptor 1. We studied the impact of the 2 mutations on the transcriptional activity of PPARγ and on the vascular RAS in transfected human vascular smooth muscle cells. Systemic RAS was not altered in patients. However, RAS markers were overexpressed in patients' fibroblasts and peripheral blood mononuclear cells, as in vascular cells expressing mutant PPARγ. Angiotensin II-mediated mitogen-activated protein kinase activity increased in patients' fibroblasts, consistent with RAS constitutive activation. Patients' cells also displayed oxidative stress and inflammation. PPARγ activation and angiotensin II receptor 1 mRNA silencing reversed RAS overactivation, oxidative stress, and inflammation, arguing for a role of angiotensin II receptor 1 in these processes. CONCLUSIONS Two novel FPLD3-linked PPARG mutations are associated with a defective transrepression of cellular RAS leading to cellular dysfunction, which might contribute to the specific FPLD3-linked severe hypertension.
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Affiliation(s)
- Martine Auclair
- INSERM UMRS938, Centre de Recherche Saint Antoine, Paris, France
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14
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Virtue S, Masoodi M, Velagapudi V, Tan CY, Dale M, Suorti T, Slawik M, Blount M, Burling K, Campbell M, Eguchi N, Medina-Gomez G, Sethi JK, Orešič M, Urade Y, Griffin JL, Vidal-Puig A. Lipocalin prostaglandin D synthase and PPARγ2 coordinate to regulate carbohydrate and lipid metabolism in vivo. PLoS One 2012; 7:e39512. [PMID: 22792179 PMCID: PMC3390315 DOI: 10.1371/journal.pone.0039512] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 05/22/2012] [Indexed: 12/15/2022] Open
Abstract
Mice lacking Peroxisome Proliferator-Activated Receptor γ2 (PPARγ2) have unexpectedly normal glucose tolerance and mild insulin resistance. Mice lacking PPARγ2 were found to have elevated levels of Lipocalin prostaglandin D synthase (L-PGDS) expression in BAT and subcutaneous white adipose tissue (WAT). To determine if induction of L-PGDS was compensating for a lack of PPARγ2, we crossed L-PGDS KO mice to PPARγ2 KO mice to generate Double Knock Out mice (DKO). Using DKO mice we demonstrated a requirement of L-PGDS for maintenance of subcutaneous WAT (scWAT) function. In scWAT, DKO mice had reduced expression of thermogenic genes, the de novo lipogenic program and the lipases ATGL and HSL. Despite the reduction in markers of lipolysis in scWAT, DKO mice had a normal metabolic rate and elevated serum FFA levels compared to L-PGDS KO alone. Analysis of intra-abdominal white adipose tissue (epididymal WAT) showed elevated expression of mRNA and protein markers of lipolysis in DKO mice, suggesting that DKO mice may become more reliant on intra-abdominal WAT to supply lipid for oxidation. This switch in depot utilisation from subcutaneous to epididymal white adipose tissue was associated with a worsening of whole organism metabolic function, with DKO mice being glucose intolerant, and having elevated serum triglyceride levels compared to any other genotype. Overall, L-PGDS and PPARγ2 coordinate to regulate carbohydrate and lipid metabolism.
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Affiliation(s)
- Sam Virtue
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Mojgan Masoodi
- Elsie Widdowson Laboratory, Medical Research Council Human Nutrition Research, Cambridge, United Kingdom
| | | | - Chong Yew Tan
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Martin Dale
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Tapani Suorti
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Marc Slawik
- Department of Medicine Innenstadt, Endocrinology/Diabetes University Hospital, Munich, Germany
| | - Margaret Blount
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Keith Burling
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Mark Campbell
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
| | | | - Gema Medina-Gomez
- Departamento de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Madrid, Spain
| | - Jaswinder K. Sethi
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
| | - Matej Orešič
- VTT Technical Research Centre of Finland, Espoo, Finland
| | | | - Julian L. Griffin
- Department of Biochemistry, Medical Research Council Human Nutrition Research, Cambridge, United Kingdom
| | - Antonio Vidal-Puig
- University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Cambridge, United Kingdom
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Rodriguez-Cuenca S, Carobbio S, Velagapudi VR, Barbarroja N, Moreno-Navarrete JM, Tinahones FJ, Fernandez-Real JM, Orešič M, Vidal-Puig A. Peroxisome proliferator-activated receptor γ-dependent regulation of lipolytic nodes and metabolic flexibility. Mol Cell Biol 2012; 32:1555-65. [PMID: 22310664 PMCID: PMC3318581 DOI: 10.1128/mcb.06154-11] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Accepted: 01/28/2012] [Indexed: 12/15/2022] Open
Abstract
Optimal lipid storage and mobilization are essential for efficient adipose tissue. Nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) regulates adipocyte differentiation and lipid deposition, but its role in lipolysis and dysregulation in obesity is not well defined. This investigation aimed to understand the molecular impact of dysfunctional PPARγ on the lipolytic axis and to explore whether these defects are also confirmed in common forms of human obesity. For this purpose, we used the P465L PPARγ mouse as a model of dysfunctional PPARγ that recapitulates the human pparγ mutation (P467L). We demonstrated that defective PPARγ impairs catecholamine-induced lipolysis. This abnormal lipolytic response is exacerbated by a state of positive energy balance in leptin-deficient ob/ob mice. We identified the protein kinase A (PKA) network as a PPARγ-dependent regulatory node of the lipolytic response. Specifically, defective PPARγ is associated with decreased basal expression of prkaca (PKAcatα) and d-akap1, the lipase genes Pnplaz (ATGL) and Lipe (HSL), and lipid droplet protein genes fsp27 and adrp in vivo and in vitro. Our data indicate that PPARγ is required for activation of the lipolytic regulatory network, dysregulation of which is an important feature of obesity-induced insulin resistance in humans.
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Affiliation(s)
- Sergio Rodriguez-Cuenca
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Stefania Carobbio
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | | | - Nuria Barbarroja
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
- Hospital Virgen de la Victoria, CIBERobn Fisiopatología de la Obesidad y Nutrición, Malaga, Spain
| | - Jose Maria Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomédica de Girona, CIBERobn Fisiopatología de la Obesidad y Nutrición, Girona, Spain
| | - Francisco Jose Tinahones
- Hospital Virgen de la Victoria, CIBERobn Fisiopatología de la Obesidad y Nutrición, Malaga, Spain
| | - Jose Manuel Fernandez-Real
- Department of Diabetes, Endocrinology and Nutrition, Institut d'Investigació Biomédica de Girona, CIBERobn Fisiopatología de la Obesidad y Nutrición, Girona, Spain
| | - Matej Orešič
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Antonio Vidal-Puig
- Department of Clinical Biochemistry, Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
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16
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Frayn KN, Humphreys SM. Metabolic characteristics of human subcutaneous abdominal adipose tissue after overnight fast. Am J Physiol Endocrinol Metab 2012; 302:E468-75. [PMID: 22167523 PMCID: PMC3287351 DOI: 10.1152/ajpendo.00527.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Subcutaneous abdominal adipose tissue is one of the largest fat depots and contributes the major proportion of circulating nonesterified fatty acids (NEFA). Little is known about aspects of human adipose tissue metabolism in vivo other than lipolysis. Here we collated data from 331 experiments in 255 healthy volunteers over a 23-year period, in which subcutaneous abdominal adipose tissue metabolism was studied by measurements of arterio-venous differences after an overnight fast. NEFA and glycerol were released in a ratio of 2.7:1, different (P < 0.001) from the value of 3.0 that would indicate no fatty acid re-esterification. Fatty acid re-esterification was 10.2 ± 1.4%. Extraction of triacylglycerol (TG) (fractional extraction 5.7 ± 0.4%) indicated intravascular lipolysis by lipoprotein lipase, and this contributed 21 ± 3% of the glycerol released. Glucose uptake (fractional extraction 2.6 ± 0.3%) was partitioned around 20-25% for provision of glycerol 3-phosphate and 30% into lactate production. There was release of lactate and pyruvate, with extraction of the ketone bodies 3-hydroxybutyrate and acetoacetate, although these were small numerically compared with TG and glucose uptake. NEFA release (expressed per 100 g tissue) correlated inversely with measures of fat mass (e.g., with BMI, r(s) = -0.24, P < 0.001). We examined within-person variability. Systemic NEFA concentrations, NEFA release, fatty acid re-esterification, and adipose tissue blood flow were all more consistent within than between individuals. This picture of human adipose tissue metabolism in the fasted state should contribute to a greater understanding of adipose tissue physiology and pathophysiology.
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Affiliation(s)
- Keith N Frayn
- Oxford Centre for Diabetes, Endocrinology & Metabolism, Churchill Hospital, Oxford OX3 7LJ, UK.
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17
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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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18
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Affiliation(s)
- Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, U.K.
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19
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Götz AA, Vidal-Puig A, Rödel HG, de Angelis MH, Stoeger T. Carbon-nanoparticle-triggered acute lung inflammation and its resolution are not altered in PPARγ-defective (P465L) mice. Part Fibre Toxicol 2011; 8:28. [PMID: 21933390 PMCID: PMC3197489 DOI: 10.1186/1743-8977-8-28] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 09/20/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The alveolar macrophage (AM) - first line of innate immune defence against pathogens and environmental irritants - constitutively expresses peroxisome-proliferator activated receptor γ (PPARγ). PPARγ ligand-induced activation keeps the AM quiescent, and thereby contributes to combat invaders and resolve inflammation by augmenting the phagocytosis of apoptotic neutrophils and inhibiting an excessive expression of inflammatory genes. Because of these presumed anti-inflammatory functions of PPARγ we tested the hypothesis, whether reduced functional receptor availability in mutant mice resulted in increased cellular and molecular inflammatory response during acute inflammation and/or in an impairment of its resolution. METHODS To address this hypothesis we examined the effects of a carbon-nanoparticle (CNP) lung challenge, as surrogate for non-infectious environmental irritants, in a murine model carrying a dominant-negative point mutation in the ligand-binding domain of PPARγ (P465L/wt). Animals were instilled intratracheally with Printex 90 CNPs and bronchoalveolar lavage (BAL) was gained 24 h or 72 h after instillation to investigate its cellular and protein composition. RESULTS Higher BAL cell numbers - due to higher macrophage counts - were found in mutants irrespective of treatment. Neutrophil numbers in contrast were slightly lower in mutants. Intratracheal CNP instillation resulted in a profound recruitment of inflammatory neutrophils into the alveolus, but genotype related differences at acute inflammation (24 h) and resolution (72 h) were not observed. There were no signs for increased alveolar-capillary membrane damage or necrotic cell death in mutants as determined by BAL protein and lactate-dehydrogenase content. Pro-inflammatory macrophage-derived cytokine osteopontin was higher, but galectin-3 lower in female mutants. CXCL5 and lipocalin-2 markers, attributed to epithelial cell stimulation did not differ. CONCLUSIONS Despite general genotype-related differences, we had to reject our hypothesis of an increased CNP induced lung inflammation and an impairment of its resolution in PPARγ defective mice. Although earlier studies showed ligand-induced activation of nuclear receptor PPARγ to promote resolution of lung inflammation, its reduced activity did not provide signs of resolution impairment in the settings investigated here.
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Affiliation(s)
- Alexander A Götz
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg/Munich, D-85764, Germany
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Level 4, Institute of Metabolic Science, Box 289, NIHR Cambridge Biomedical Research Centre Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Heiko G Rödel
- Laboratory of Experimental and Comparative Ethology, University of Paris 13, F-93430, Villetaneuse, France
| | - Martin Hrabé de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg/Munich, D-85764, Germany
| | - Tobias Stoeger
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg/Munich, D-85764, Germany
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20
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Hooper AJ, Adams LA, Burnett JR. Genetic determinants of hepatic steatosis in man. J Lipid Res 2011; 52:593-617. [PMID: 21245030 DOI: 10.1194/jlr.r008896] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatic steatosis is one of the most common liver disorders in the general population. The main cause of hepatic steatosis is nonalcoholic fatty liver disease (NAFLD), representing the hepatic component of the metabolic syndrome, which is characterized by type 2 diabetes, obesity, and dyslipidemia. Insulin resistance and excess adiposity are considered to play key roles in the pathogenesis of NAFLD. Although the risk factors for NAFLD are well established, the genetic basis of hepatic steatosis is largely unknown. Here we review recent progress on genomic variants and their association with hepatic steatosis and discuss the potential impact of these genetic studies on clinical practice. Identifying the genetic determinants of hepatic steatosis will lead to a better understanding of the pathogenesis and progression of NAFLD.
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Affiliation(s)
- Amanda J Hooper
- Department of Core Clinical Pathology and Biochemistry, Royal Perth Hospital, Perth, Australia
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21
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Differential modulatory effects of rosiglitazone and pioglitazone on white adipose tissue in db/db mice. Life Sci 2010; 87:405-10. [DOI: 10.1016/j.lfs.2010.08.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 07/07/2010] [Accepted: 08/07/2010] [Indexed: 11/21/2022]
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Abstract
Insulin resistance is a major factor in the pathogenesis of type 2 diabetes and underpins the strong association between obesity and diabetes. Paradoxically, the metabolic consequences of having 'too much' fat (obesity) are remarkably similar to those of having 'too little' fat (lipodystrophy): a finding that has generated considerable interest in a rare disease. In both cases, excess energy accumulates as lipid in ectopic sites such as the liver (fatty liver) and skeletal muscle, where it plays a central role in the pathogenesis of insulin resistance, dyslipidemia and type 2 diabetes. Human lipodystrophies are characterised by a total or partial deficiency of body fat, and may be inherited or acquired in origin. Genetically engineered mice with generalised lipodystrophy manifest many of the features of the human disorder, including hyperphagia, fatty liver, hypertriglyceridaemia, insulin resistance and type 2 diabetes, providing a useful tractable model of the human disorder. Partial lipodystrophy, which causes similar, albeit milder, metabolic problems in humans has been more difficult to mimic in the mouse. This review discusses key translational studies in mice with generalised lipodystrophy, including fat transplantation and the use of recombinant leptin replacement therapy. These studies have been instrumental in advancing our understanding of the underlying molecular pathogenesis of ectopic lipid accumulation and insulin resistance, and have prompted the initiation and subsequent adoption of leptin replacement therapy in human lipodystrophies. This review also considers the possible reasons for the apparent difficulties in generating mouse models of partial lipodystrophy, such as interspecies differences in the distribution of fat depots and the apparent lack of sexual dimorphism in fat mass and distribution in mice compared with the dramatic differences present in adult humans.
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Affiliation(s)
- David B Savage
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
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Nohara A, Kobayashi J, Mabuchi H. Retinoid X receptor heterodimer variants and cardiovascular risk factors. J Atheroscler Thromb 2009; 16:303-18. [PMID: 19672026 DOI: 10.5551/jat.no786] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Nuclear receptors are transcription factors that can be activated by specific ligands. Recent progress has shown that retinoid X receptor (RXR) and its heterodimerization partners, including peroxisome proliferator-activated receptors, regulate many important genes involved in energy homeostasis and atherosclerosis, and should be promising therapeutic targets of metabolic syndrome. RXR heterodimers regulate a number of complex cellular processes, and genetic studies of RXR heterodimers have provided important clinical information in addition to knowledge gained from basic research. Genetic variants of RXR heterodimers were screened and investigated, and some variants were shown to have a considerable impact on metabolic disorders, including phenotypic components of familial combined hyperlipidemia. The combined efforts of basic and clinical science regarding nuclear receptors have achieved significant progress in unraveling the inextricably linked control system of energy expenditure, lipid and glucose homeostasis, inflammation, and atherosclerosis.This review summarizes the current understanding regarding RXR heterodimers based on their human genetic variants, which will provide new clues to uncover the background of multifactorial disease, such as metabolic syndrome or familial combined hyperlipidemia.
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Affiliation(s)
- Atsushi Nohara
- Departments of Lipidology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
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