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Treiber G, Guilleux A, Huynh K, Bonfanti O, Flaus-Furmaniuk A, Couret D, Mellet N, Bernard C, Le-Moullec N, Doray B, Jéru I, Maiza JC, Domun B, Cogne M, Meilhac O, Vigouroux C, Meikle PJ, Nobécourt E. Lipoatrophic diabetes in familial partial lipodystrophy type 2: From insulin resistance to diabetes. Diabetes Metab 2023; 49:101409. [PMID: 36400409 DOI: 10.1016/j.diabet.2022.101409] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/17/2022]
Abstract
AIM Subjects with Familial Partial Lipodystrophy type 2 (FPLD2) are at high risk to develop diabetes. To better understand the natural history and variability of this disease, we studied glucose tolerance, insulin response to an oral glucose load, and metabolic markers in the largest cohort to date of subjects with FPLD2 due to the same LMNA variant. METHODS A total of 102 patients aged > 18 years, with FPLD2 due to the LMNA 'Reunionese' variant p.(Thr655Asnfs*49) and 22 unaffected adult relatives with normal glucose tolerance (NGT) were enrolled. Oral Glucose Tolerance Tests (OGTT) with calculation of derived insulin sensitivity and secretion markers, and measurements of HbA1c, C-reactive protein, leptin, adiponectin and lipid profile were performed. RESULTS In patients with FPLD2: 65% had either diabetes (41%) or prediabetes (24%) despite their young age (median: 39.5 years IQR 29.0-50.8) and close-to-normal BMI (median: 25.5 kg/m2 IQR 23.1-29.4). Post-load OGTT values revealed insulin resistance and increased insulin secretion in patients with FPLD2 and NGT, whereas patients with diabetes were characterized by decreased insulin secretion. Impaired glucose tolerance with normal fasting glucose was present in 86% of patients with prediabetes. Adiponectin levels were decreased in all subjects with FPLD2 and correlated with insulin sensitivity markers. CONCLUSIONS OGTT reveals early alterations of glucose and insulin metabolism in patients with FPLD2, and should be systematically performed before excluding a diagnosis of prediabetes or diabetes to adapt medical care. Decreased adiponectin is an early marker of the disease. Adiponectin replacement therapy warrants further study in FPLD2.
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Affiliation(s)
- Guillaume Treiber
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France; University of La Réunion, INSERM, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Plateforme CYROI, Saint-Denis de, La Réunion, France
| | - Alice Guilleux
- Centre d'Investigation Clinique - Epidémiologie Clinique (CIC-EC) U1410 INSERM, Centre Hospitalo-Universitaire de la Réunion, La Réunion, France
| | - Kevin Huynh
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Oriane Bonfanti
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France
| | - Ania Flaus-Furmaniuk
- Department of Endocrinology, Diabetes and Nutrition, Felix-Guyon, Centre Hospitalo-Universitaire de la Réunion, Saint-Denis, La Réunion, France
| | - David Couret
- University of La Réunion, INSERM, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Plateforme CYROI, Saint-Denis de, La Réunion, France; Neurocritical Care Unit, Centre Hospitalo-Universitaire de la Réunion, University of La Réunion, BP 350, Saint Pierre, 97448, la Réunion, France
| | - Natalie Mellet
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Céline Bernard
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France
| | - Nathalie Le-Moullec
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France
| | - Berenice Doray
- Genetic Department, Felix-Guyon, Centre Hospitalo-Universitaire de la Réunion, Saint-Denis, La Réunion, France
| | - Isabelle Jéru
- Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, AP-HP, Pitié-Salpêtrière Hospital, Department of Medical Genetics, DMU BioGeM, Paris, France
| | - Jean-Christophe Maiza
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France
| | - Bhoopendrasing Domun
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France
| | - Muriel Cogne
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France
| | - Olivier Meilhac
- University of La Réunion, INSERM, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Plateforme CYROI, Saint-Denis de, La Réunion, France
| | - Corinne Vigouroux
- Sorbonne Université, Inserm UMR S938, Saint-Antoine Research Centre, Institute of Cardiometabolism and Nutrition, AP-HP, Saint-Antoine Hospital, Genetics, Molecular Biology and Endocrinology Departments, National Reference Centre for Rare Diseases of Insulin Secretion and Insulin Sensitivity (PRISIS), Paris, France
| | - Peter J Meikle
- Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia; Baker Department of Cardiometabolic Health, University of Melbourne, Melbourne, Victoria, Australia; Baker Department of Cardiovascular Research Translation and Implementation, La Trobe University, Bundoora, Victoria, Australia
| | - Estelle Nobécourt
- Department of Endocrinology, Diabetes and Nutrition, GHSR, Centre Hospitalo-Universitaire de la Réunion, Saint-Pierre, La Réunion, France; University of La Réunion, INSERM, UMR 1188 Diabète Athérothrombose Thérapies Réunion Océan Indien (DéTROI), Plateforme CYROI, Saint-Denis de, La Réunion, France; Centre d'Investigation Clinique - Epidémiologie Clinique (CIC-EC) U1410 INSERM, Centre Hospitalo-Universitaire de la Réunion, La Réunion, France.
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Chu KY, Mellet N, Thai LM, Meikle PJ, Biden TJ. Short-term inhibition of autophagy benefits pancreatic β-cells by augmenting ether lipids and peroxisomal function, and by countering depletion of n-3 polyunsaturated fatty acids after fat-feeding. Mol Metab 2020; 40:101023. [PMID: 32504884 PMCID: PMC7322075 DOI: 10.1016/j.molmet.2020.101023] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 04/29/2020] [Accepted: 05/14/2020] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Investigations of autophagy in β-cells have usually focused on its homeostatic function. More dynamic roles in inhibiting glucose-stimulated insulin secretion (GSIS), potentially involving remodelling of cellular lipids, have been suggested from in vitro studies but not evaluated in vivo. METHODS We employed temporally-regulated deletion of the essential autophagy gene, Atg7, in β-cells. Mice were fed chow or high-fat diets (HFD), in conjunction with deletion of Atg7 for the last 3 weeks (short-term model) or 9 weeks (long-term model). Standard in vivo metabolic phenotyping was undertaken, and 450 lipid species in islets quantified ex vivo using mass spectroscopy (MS). MIN6 cells were also employed for lipidomics and secretory interventions. RESULTS β-cell function was impaired by inhibiting autophagy in the longer-term, but conversely improved by 3-week deletion of Atg7, specifically under HFD conditions. This was accompanied by augmented GSIS ex vivo. Surprisingly, the HFD had minimal effect on sphingolipid and neutral lipid species, but modulated >100 phospholipids and ether lipids, and markedly shifted the profile of polyunsaturated fatty acid (PUFA) sidechains from n3 to n6 forms. These changes were partially countered by Atg7 deletion, consistent with an accompanying upregulation of the PUFA elongase enzyme, Elovl5. Loss of Atg7 separately augmented plasmalogens and alkyl lipids, in association with increased expression of Lonp2, a peroxisomal chaperone/protease that facilitates maturation of ether lipid synthetic enzymes. Depletion of PUFAs and ether lipids was also observed in MIN6 cells chronically exposed to oleate (more so than palmitate). GSIS was inhibited by knocking down Dhrs7b, which encodes an enzyme of peroxisomal ether lipid synthesis. Conversely, impaired GSIS due to oleate pre-treatment was selectively reverted by Dhrs7b overexpression. CONCLUSIONS A detrimental increase in n6:n3 PUFA ratios in ether lipids and phospholipids is revealed as a major response of β-cells to high-fat feeding. This is partially reversed by short-term inhibition of autophagy, which results in compensatory changes in peroxisomal lipid metabolism. The short-term phenotype is linked to improved GSIS, in contrast to the impairment seen with the longer-term inhibition of autophagy. The balance between these positive and negative inputs could help determine whether β-cells adapt or fail in response to obesity.
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Affiliation(s)
- Kwan Yi Chu
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
| | - Natalie Mellet
- Baker Heart and Diabetes Institute, PO Box 6492, Melbourne, Vic, 3004, Australia
| | - Le May Thai
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia
| | - Peter J Meikle
- Baker Heart and Diabetes Institute, PO Box 6492, Melbourne, Vic, 3004, Australia.
| | - Trevor J Biden
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW, 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, The University of New South Wales, Sydney, NSW, Australia.
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Chu KY, O'Reilly L, Mellet N, Meikle PJ, Bartley C, Biden TJ. Oleate disrupts cAMP signaling, contributing to potent stimulation of pancreatic β-cell autophagy. J Biol Chem 2018; 294:1218-1229. [PMID: 30518550 DOI: 10.1074/jbc.ra118.004833] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/19/2018] [Indexed: 12/12/2022] Open
Abstract
Autophagy is critical for maintaining cellular function via clearance of excess nutrients and damaged organelles. In pancreatic β-cells, it helps counter the endoplasmic reticulum (ER) stress that impairs insulin secretory capacity during Type 2 diabetes. Chronic exposure of β-cells to saturated fatty acids (FAs) such as palmitate stimulates ER stress and modulates autophagy, but the effects of unsaturated FAs such as oleate, which are also elevated during obesity, are less well understood. We therefore treated MIN6 cells and mouse islets for 8-48 h with either palmitate or oleate, and then monitored autophagic flux, signaling pathways, lysosomal biology, and phospholipid profiles. Compared with palmitate, oleate more effectively stimulated both autophagic flux and clearance of autophagosomes. The flux stimulation occurred independently of ER stress, nutrient-sensing (mTOR) and signaling pathways (protein kinases A, C, and D). Instead the mechanism involved the exchange factor directly activated by cAMP 2 (EPAC2). Oleate reduced cellular cAMP, and its effects on autophagic flux were reproduced or inhibited, respectively, by Epac2 knockdown or activation. Oleate also increased lysosomal acidity and increased phospholipid saturation, consistent with improved autophagosomal fusion with lysosomes. We conclude that a potent stimulation of autophagy might help explain the known benefits of unsaturated FAs in countering the toxicity of saturated FAs in β-cells during obesity and lipid loading.
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Affiliation(s)
- Kwan Yi Chu
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010; St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, NSW 2052
| | - Liam O'Reilly
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010
| | - Natalie Mellet
- Baker IDI Heart and Diabetes Institute, Prahran, Victoria 3004, Australia
| | - Peter J Meikle
- Baker IDI Heart and Diabetes Institute, Prahran, Victoria 3004, Australia
| | - Clarissa Bartley
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010
| | - Trevor J Biden
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010; St. Vincent's Clinical School, Faculty of Medicine, UNSW Sydney, NSW 2052.
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