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We evaluated the role of the p66Shc redox adaptor protein in pancreatic β-cell insulin resistance that develops under lipotoxic conditions and with excess body fat. Prolonged exposure to palmitate in vitro or the presence of overweight/obesity augmented p66Shc expression levels and caused an impaired ability of exogenous insulin to increase cellular insulin content and secreted C-peptide levels in INS-1E cells and human and murine islets. In INS-1E cells, p66Shc knockdown resulted in enhanced insulin-induced augmentation of insulin content and C-peptide secretion and prevented the ability of palmitate to impair these effects of insulin. Conversely, p66Shc overexpression impaired insulin-induced augmentation of insulin content and C-peptide secretion in both the absence and presence of palmitate. Under lipotoxic condition, the effects of p66Shc are mediated by a p53-induced increase in p66Shc protein levels and JNK-induced p66Shc phosphorylation at Ser36 and appear to involve the phosphorylation of the ribosomal protein S6 kinase at Thr389 and of insulin receptor substrate 1 at Ser307, resulting in the inhibition of insulin-stimulated protein kinase B phosphorylation at Ser473. Thus, the p66Shc protein mediates the impaired β-cell function and insulin resistance induced by saturated fatty acids and excess body fat.

Elevated saturated fatty acid deposition in the heart results in insulin resistance, stress kinase activation, and increased cardiovascular risk in humans. The viability of human cardiac progenitor cells (hCPC) is essential for myocardium homeostasis. This study investigates the ability of palmitate, a saturated fatty acid, to impair insulin signaling in hCPC isolated from right auricle biopsies, and the potential protective effects of oleate, a mono-unsaturated fatty acid. hCPC were found to express both insulin receptor (IR) isoforms, IR-A and IR-B, with higher IR-A:IR-B ratio. Exposure of hCPC to 100 nM insulin for 15 min induced Akt (S473) phosphorylation (p In conclusion, oleate prevents the palmitate-induced abnormalities in insulin signaling in hCPC, largely by counteracting p38 MAPK and JNK activation. Hence, oleate supplementation might limit lipotoxicity, thus contributing to cardiac protection. Disclosure R.Doria: None. F.Giorgino: Advisory Panel; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk, Consultant; Lilly Diabetes, Sanofi, Research Support; Lilly Diabetes, Roche Diabetes Care, Takeda Pharmaceutical Company Limited. L.Laviola: Advisory Panel; Lilly Diabetes, Novo Nordisk, Roche Diabetes Care, Sanofi, Speaker's Bureau; A. Menarini Diagnostics, Abbott Diabetes, Medtronic, Terumo Corporation. I.Calderoni: None. C.Caccioppoli: None. V.Genchi: None. G.Santarpino: None. A.Leonardini: None. A.Natalicchio: Consultant; Novo Nordisk, Other Relationship; AstraZeneca, Lilly Diabetes, Sanofi. S.Perrini: None. A.Cignarelli: None.

Dysfunction of visceral and epicardial adipose tissue may alter heart performance and promote adverse cardiovascular outcomes in obesity and diabetes. We assessed whether the secretome from abdominal visceral (AV) and epicardial (E) adipose stem cells (ASC) and from AV mature adipocytes might affect the viability of human cardiac progenitor cells (hCPC) in human obesity, and the effects of dapagliflozin (DAPA) , a selective SGLT-2 inhibitor. ASC and mature adipocytes were isolated from AV and E adipose tissue biopsies of obese (Ob) and non-obese subjects, respectively. hCPC were isolated from right auricle biopsies of non-Ob, non-diabetic donors. hCPC were pretreated with uM DAPA for 24 h or left untreated, and then exposed to the conditioned media (CM) of AV-ASC, E-ASC, and AV mature adipocytes. The CM of AV-ASC, E-ASC, and AV mature adipocytes induced apoptosis, assessed by ELISA for cytoplasmic oligonucleosomes, in hCPC after 24 h (p In conclusion, in human obesity, the secretome of both AV and E ASC and mature adipocytes induces stress kinase activation in hCPC and impairs their viability and functionality, and these effects can be counteracted by SGLT-2 inhibitors directly acting on the hCPC. Disclosure G.Palma: None. F.Giorgino: Advisory Panel; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk, Consultant; Lilly Diabetes, Sanofi, Research Support; Lilly Diabetes, Roche Diabetes Care, Takeda Pharmaceutical Company Limited. S.Perrini: None. C.Caccioppoli: None. R.Doria: None. V.Genchi: None. G.Santarpino: None. A.Cignarelli: None. A.Natalicchio: Consultant; Novo Nordisk, Other Relationship; AstraZeneca, Lilly Diabetes, Sanofi. L.Laviola: Advisory Panel; Lilly Diabetes, Novo Nordisk, Roche Diabetes Care, Sanofi, Speaker's Bureau; A. Menarini Diagnostics, Abbott Diabetes, Medtronic, Terumo Corporation. A.Pezzolla: None.

Irisin is a hormone secreted by skeletal muscle following exercise or excess of saturated fatty acids (SFAs) , able to improve metabolic homeostasis and promote energy expenditure. Serum irisin levels are reduced in type 2 diabetes (T2D) , while exogenous irisin administration improves glycemic control in diabetic mice. We have previously demonstrated that irisin protects human and rodent β-cells and pancreatic islets from SFAs-induced apoptosis, increases insulin biosynthesis and glucose-stimulated insulin secretion (GSIS) , and promotes β-cell proliferation, both in vitro and in vivo in healthy wild-type mice. Irisin may also restore the defective GSIS and reduce the high rate of apoptosis that are characteristic of islets from T2D patients. However, the β-cellular effects of irisin administration to diabetic mice are still unknown. 6 weeks-old C57Bl/6 mice (n = 8) were fed a high-fat diet (HFD, 60% of energy deriving from fat) for weeks and then intraperitoneally injected with streptozotocin (STZ, 100 mg/Kg) to induce diabetes. 4 standard diet (SD) -fed mice were used as control. HFD/STZ mice were then treated with 0.5 μg/g irisin (n = 4) or vehicle (n = 4) for 14 days. Glucose tolerance, glycemia, insulinemia, body weight, pancreatic islet architecture and function were assessed throughout the study. As expected, compared to SD mice, HFD/STZ mice showed higher glycemia and body weight, glucose intolerance, and reduced GSIS; in addition, HFD/STZ mice showed reduced islet volume (-78%) , β-cell area (-35%) , and insulin content (-60%) , while increased α-cell area (+54%) . Irisin administration significantly restored glycemia (-31%) , body weight (-13%) , glucose tolerance (-27%, AUC) , GSIS (+23%, AUC) , islet volume (+61%) , β-cell (+34%) and α-cell (-49%) areas, and insulin content (+36%) . Of note, irisin treatment induced a 9-fold increase in β-cell proliferation rate. These results show for the first time that irisin can restore β-cell functional mass when administered in vivo to diabetic mice. Disclosure N.Marrano: None. G.Biondi: None. A.Borrelli: None. L.Roberto: None. A.Cignarelli: None. S.Perrini: None. L.Laviola: Advisory Panel; Lilly Diabetes, Novo Nordisk, Roche Diabetes Care, Sanofi, Speaker's Bureau; A. Menarini Diagnostics, Abbott Diabetes, Medtronic, Terumo Corporation. F.Giorgino: Advisory Panel; AstraZeneca, Boehringer Ingelheim International GmbH, Novo Nordisk, Consultant; Lilly Diabetes, Sanofi, Research Support; Lilly Diabetes, Roche Diabetes Care, Takeda Pharmaceutical Company Limited. A.Natalicchio: Consultant; Novo Nordisk, Other Relationship; AstraZeneca, Lilly Diabetes, Sanofi. Funding EU – ESF PON R&I 2014-20, AIM

Endothelial progenitor cells (EPCs) are key for angiogenic responses in multiple tissues and mediate a coordinate augmentation of the capillary network as adipose tissue (AT) expands in response to positive energy balance. However, isolation and culture of EPCs from human AT has been difficult. Here we describe a new method for obtaining well-characterized EPCs from human AT. Subcutaneous and visceral AT specimens (approximately 1-2 g) were obtained from 10-20 obese subjects by needle biopsy of abdominal subcutaneous AT and removal of omental AT fragments during abdominal surgery, respectively. Human EPCs were isolated from both the digested (SVCI) and undigested (SVCII) stromal vascular fractions of AT by anti-CD31 beads. After 5 days of in vitro culture, EPCs from SVCII exhibited an endothelial-like cobblestone morphology as compared to EPCs from SVCI. Flow cytometry analysis showed that the percentage of CD31+ and CD144+ cells was much higher in the SVCII compared to SVCI fraction (SVCII: CD31 97.9±2.9%, CD144 93.3±4.7%; SVCI: CD31 4.0±1.2%, CD144 3.8±0.7%). Immunofluorescence staining demonstrated that CD31+ EPCs from SVCII expressed Von Willebrand Factor (vWF) and VE-cadherin. Additionally, significantly higher mRNA and protein levels of CD31, E-selectin, e-NOS, VEGFR, and CD34 were found in CD31+ EPCs from SVCII than in control cells (CD31- cells from SVCI). EPCs from SVCII maintained the expression of endothelial markers (CD144 mRNA and protein levels) up to the fourth cell passage. Lastly, CD31+ EPCs from SVCII, but not control cells, were able to form tubes in 3D scaffolds (Matrigel) resembling capillary structures, as well as to incorporate acetylated LDL in vitro. Thus, we have successfully isolated EPCs with high proliferative potential and specific functional properties from the human AT. This will potentially increase our understanding of AT biology particularly in relation to altered expansion of distinct AT depots in human obesity. Disclosure C. Caccioppoli: None. S. Perrini: None. V. Genchi: None. R. Doria: None. G. Palma: None. A. Cignarelli: None. A. Natalicchio: Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Sanofi. L. Laviola: Advisory Panel; Self; A. Menarini Diagnostics, Abbott, AstraZeneca, Lilly Diabetes, Novo Nordisk Inc., Roche Diabetes Care, Sanofi-Aventis, Speaker’s Bureau; Self; Boehringer Ingelheim International GmbH, Medtronic. F. Giorgino: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Novo Nordisk, Roche Diabetes Care, Sanofi, Research Support; Self; Lilly Diabetes, Roche Diabetes Care.

Bariatric surgery and consequent weight loss improve metabolic and anthropometric parameters in obese subjects. However, a detailed assessments about the impact of bariatric surgery on quality of life (QoL), body image perception, and sex life is lacking. The aim of this study was to assess the QoL, body image satisfaction and sexual function in 389 female patients with obesity (age 40±10 years, pre-surgery weight 120.4±17.7 kg) before and at least 6 months after bariatric surgery (60% sleeve gastrectomy, 40% gastric bypass). All participants were asked to complete the following online self-report questionnaires seven days before and six months after bariatric surgery: the Body Uneasiness Test (BUT) to assess self-perception of body image, the Short Form-12 (SF-12) to QoL as per the physical (PCS) and mental (MCS) domains, and the Female Sexual Function Index (FSFI) to screen for sexual dysfunctions in women. After bariatric surgery, patients lost 44.5±16.5 kg (p Disclosure L. Di gioia: None. A. Natalicchio: Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Sanofi. L. Laviola: Advisory Panel; Self; A. Menarini Diagnostics, Abbott, AstraZeneca, Lilly Diabetes, Novo Nordisk Inc., Roche Diabetes Care, Sanofi-Aventis, Speaker’s Bureau; Self; Boehringer Ingelheim International GmbH, Medtronic. A. Bertolino: None. F. Giorgino: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Novo Nordisk, Roche Diabetes Care, Sanofi, Research Support; Self; Lilly Diabetes, Roche Diabetes Care. S. Perrini: None. A. Braun: None. E. Rossi: None. F. Giordano: None. F. Guarini: None. E. Siciliano: None. A. Cignarelli: None. A. Leonardini: None.

Myocardial ectopic lipid deposition has been associated with insulin resistance and cardiovascular risk. Palmitate, one of the most abundant saturated fatty acids, has been shown to impair insulin signaling in multiple cell types. Human cardiac progenitor cells (CPC) represent a compartment of multipotent stem cells essential for constant tissue repair and renewal in the adult heart. In this study, the ability of palmitate to impair insulin signaling, and the modulatory effects of oleate, a mono-unsaturated fatty acid, on palmitate-induced abnormalities were investigated in human CPC isolated from control subjects undergoing cardiac surgery. Human CPC express insulin receptor (IR), as assessed by quantitative RT-PCR and immunoblotting. Specifically, in human CPC both IR isoforms, A (IR-A) and B (IR-B), were identified, and IR-A was more expressed than IR-B. Exposure of human CPC to 100 nM insulin for 15 minutes resulted in increased Akt and p44/p42 MAPK phosphorylation (p In conclusion, oleate prevents some of the palmitate-induced impairments in insulin signaling in human CPC, thus contributing to cardiac protection from lipotoxicity-induced metabolic alterations. Disclosure R. Doria: None. F. Giorgino: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Novo Nordisk, Roche Diabetes Care, Sanofi, Research Support; Self; Lilly Diabetes, Roche Diabetes Care. C. Caccioppoli: None. R. Schipani: None. V. Genchi: None. A. Leonardini: None. A. Natalicchio: Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Sanofi. S. Perrini: None. A. Cignarelli: None. L. Laviola: Advisory Panel; Self; A. Menarini Diagnostics, Abbott, AstraZeneca, Lilly Diabetes, Novo Nordisk Inc., Roche Diabetes Care, Sanofi-Aventis, Speaker’s Bureau; Self; Boehringer Ingelheim International GmbH, Medtronic.

Irisin is a hormone secreted by skeletal muscle following physical activity or excess of saturated fatty acids, able to promote energy expenditure and improve metabolic homeostasis. Serum irisin levels are reduced in type 2 diabetes (T2D), while exogenous irisin administration improves glycemic control in diabetic mice. We have previously demonstrated that irisin promotes beta-cell viability and insulin secretory function. This study investigated serum irisin levels in T2D patients according to their antidiabetes treatment. 127 T2D patients were enrolled and stratified by antidiabetes therapy: diet only (17); metformin only (met, 37); met plus sulfonylureas (5); met plus pioglitazone (7); met plus GLP-1 receptor agonists (GLP-1RAs, 31); met plus DPP-4 inhibitors (DPP-4i, 15); and met plus SGLT2 inhibitors (SGLT2i, 15). The control group included 36 sex-, and BMI-matched subjects without diabetes. T2D patients showed lower irisin levels than controls (21.5 [10.1-50.8] vs. 29.1 [14.1-43.5] ng/mL, P In conclusion, in T2D GLP-1-based therapies significantly increase serum irisin to levels comparable to those of nondiabetic subjects, possibly through GLP-1 receptor-mediated stimulation of irisin release by skeletal muscle cells. Irisin may thus represent a new factor in the mechanism of action of GLP-1-based therapies. Disclosure A. Natalicchio: Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Sanofi. S. Perrini: None. L. Laviola: Advisory Panel; Self; A. Menarini Diagnostics, Abbott, AstraZeneca, Lilly Diabetes, Novo Nordisk Inc., Roche Diabetes Care, Sanofi-Aventis, Speaker’s Bureau; Self; Boehringer Ingelheim International GmbH, Medtronic. F. Giorgino: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Novo Nordisk, Roche Diabetes Care, Sanofi, Research Support; Self; Lilly Diabetes, Roche Diabetes Care. N. Marrano: None. G. Biondi: None. A. Montedoro: None. G. Le grazie: None. L. Di gioia: None. F. Guarini: None. A. Borrelli: None. A. Cignarelli: None. Funding European Union–European Social Fund; PON R&I (2014-2020); AIM (1810057)

Pasireotide is a new-generation somatostatin analog used for the treatment of acromegaly, Cushing’s disease and neuroendocrine tumors. However, due to its high affinity for somatostatin receptors (SSTR) 2 and 5, highly expressed in enteroendocrine- and pancreatic β-cells, it can reduce insulin, GLP-1 and GIP release and increase glucagonemia, causing marked hyperglycemia in some patients. The diabetogenic effects of pasireotide are significantly reduced in vivo by the co-administration of liraglutide or vildagliptin. The aim of this study was to evaluate the effects of pasireotide on β-cell survival and function, and the ability of molecules with known beneficial action on β-cells (incretin-based drugs and irisin, a myokine with β-cellular trophic properties) to prevent these effects. In INS-1E cells, both acute and chronic administration of pasireotide 10-50 nM reduced glucose-induced insulin secretion by 30% and 50% respectively and proinsulin mRNA levels by 20%, without altering cellular insulin content. Furthermore, pasireotide induced apoptosis in INS-1E cells and human pancreatic islets. Pretreatment with both incretin-based drugs (exendin-4, lixisenatide, liraglutide, saxagliptin) and irisin prevented pasireotide-induced apoptosis in INS-1E cells. In addition, pasireotide increased the protein levels of SSTR2 (2-fold) but not of SSTR5. Among the protective molecules examined, only irisin was able to prevent this increase. In conclusion, pasireotide can induce hyperglycemia and diabetes via direct effects on β-cells, resulting in reduced insulin secretory capacity and survival. Both GLP-1 receptor agonists and DPP-4 inhibitors and irisin can reduce the proapoptotic effects of pasireotide, acting through partially different molecular mechanisms. These results demonstrate for the first time a functional antagonism between SSTR2/5 activation and incretin-based drugs or irisin in pancreatic β-cells. Disclosure A. Natalicchio: Consultant; Self; AstraZeneca, Novo Nordisk Inc., Sanofi-Aventis. G. Biondi: None. N. Marrano: None. L. Vincenti: None. A. Cignarelli: None. S. Perrini: None. L. Laviola: Advisory Panel; Self; Abbott, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk Inc., Roche Diabetes Care, Sanofi-Aventis. Speaker’s Bureau; Self; Abbott, Medtronic. F. Giorgino: Advisory Panel; Self; AstraZeneca, Eli Lilly and Company, Novo Nordisk Inc., Roche Diabetes Care, Sanofi. Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., LifeScan, Inc., MedImmune, Merck Sharp & Dohme Corp., Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Development Centre Europe Ltd. Funding Novartis

This study aimed to assess whether the secretome from abdominal visceral (AV) and epicardial (E) adipose stem cells (ASC), ASC-derived mature adipocytes, and isolated AV mature adipocytes may affect the viability of cardiac progenitor cells (CPC) in human obesity, and whether dapagliflozin (DAPA) may reduce the proapoptotic effects in injured CPC. ASC were isolated from AV and E adipose tissue biopsies of nondiabetic subjects with varying levels of BMI and used before and after differentiation into adipocytes in vitro. CPC were isolated from right auricle biopsies of non-obese (Ob) subjects, preincubated in the presence or absence of 10 uM DAPA, and exposed or not to conditioned media (CM) of AV-ASC, E-ASC, AV-ASC-derived adipocytes and isolated AV mature adipocytes. The CM of AV-ASC and differentiated adipocytes from Ob subjects induced CPC apoptosis after 4-8-24 h (p In conclusion, the secretome of adipose cells from Ob subjects impairs insulin action and viability of the CPC, and these effects can be counteracted by DAPA. Disclosure S. Porro: None. S. Perrini: None. C. Caccioppoli: None. R. Doria: None. V. Genchi: None. R. Schipani: None. A. Cignarelli: None. A. Natalicchio: Consultant; Self; AstraZeneca, Novo Nordisk Inc., Sanofi-Aventis. L. Laviola: Advisory Panel; Self; Abbott, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk Inc., Roche Diabetes Care, Sanofi-Aventis. Speaker’s Bureau; Self; Abbott, Medtronic. F. Giorgino: Advisory Panel; Self; AstraZeneca, Eli Lilly and Company, Novo Nordisk Inc., Roche Diabetes Care, Sanofi. Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., LifeScan, Inc., MedImmune, Merck Sharp & Dohme Corp., Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Development Centre Europe Ltd.

Irisin is a hormone secreted by skeletal muscle following physical activity and excess of saturated fatty acids, able to improve metabolic homeostasis and promote energy expenditure. In a previous study, we have demonstrated that, in beta-cells, irisin promotes proliferation and glucose-stimulated insulin secretion (GSIS), increases insulin content levels, and reduces lipotoxicity-induced apoptosis. The aim of this study was to evaluate the effects of irisin on the function and survival of pancreatic islets isolated from patients with type 2 diabetes mellitus (T2DM), characterized by reduced ability to secrete insulin and high levels of apoptosis, and to investigate the molecular mechanisms underlying this action. Pancreatic islets isolated from T2DM patients (n=7) and nondiabetic subjects (ND) (n=3), as well as INS-1E cells, were exposed to 100 nM irisin for different times. GSIS, insulin content, apoptosis and cytoplasmic calcium levels were measured by ELISA assays; the activation of the main mediators of beta-cell intracellular signalling (AKT, CREB and PKA) was evaluated by immunoblotting. Irisin increased GSIS approximately 2-fold (p In conclusion, the myokine irisin is able to increase the secretory function and survival of human pancreatic islets and to improve the functional defects typical of the T2DM islets. The mechanisms underlying the secretagogue effects of irisin in the T2DM islets do not apparently involve the known signaling machinery of this novel hormone. Disclosure N. Marrano: None. A. Natalicchio: Consultant; Self; AstraZeneca, Novo Nordisk Inc., Sanofi-Aventis. G. Biondi: None. A. Cignarelli: None. L. Vincenti: None. L.G. Lupo: None. S. Perrini: None. L. Laviola: Advisory Panel; Self; Abbott, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Novo Nordisk Inc., Roche Diabetes Care, Sanofi-Aventis. Speaker’s Bureau; Self; Abbott, Medtronic. F. Giorgino: Advisory Panel; Self; AstraZeneca, Eli Lilly and Company, Novo Nordisk Inc., Roche Diabetes Care, Sanofi. Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., LifeScan, Inc., MedImmune, Merck Sharp & Dohme Corp., Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Development Centre Europe Ltd. Funding European Union (AIM1810057)

Physical exercise may profoundly affect glucose variability (GV) in insulinopenic diabetes leading to both hypo- and hyperglycemia and feeling of discomfort reported by the patients after work out. Even if combined training reportedly reduces GV, an ideal training protocol is still not established in these patients. The aim of this study was to evaluate the effects of different combinations of continuous aerobic exercise (CON) and high intensity interval training (HIIT) on GV during a 24-h period after work out. A cross-over study was conducted on 14 outpatients [male 50%, mean age 31.9 (8.1) y, BMI 22.1 (2.5) Kg/m2] with either T1D (n=10) or LADA (n=4) on continuous subcutaneous insulin infusion (CSII) therapy [4 (3.9) y]. Data from flash glucose monitoring were collected for 72 h before work out. After different sequences of HIIT and CON work out (HIIT followed by CON, HIIT-CON; and CON followed by HIIT, CON-HIIT), 24-h glucose profiles were acquired. Several indices of GV and predictors of hypo-/hyperglycemia were analyzed. Indices of GV revealed no statistically significant difference when compared to baseline GV [mean -0.38 (1.85) vs. -0.43 (1.66); SD 0.02 (1.06) vs. -0.04 (0.94); CONGA: -0.18 (1.63) vs. -0.36 (1.69); MAG -0.12 (0.44) vs. -0.21 (0.47); MAGE 0.73 (1.65) vs. 1.11 (0.84); LBGI: 1.28 (6.83) vs. 1.71 (5.43); HBGI -0.18 (5.34) vs. -1.03 (4.89); HIIT-CON delta vs. baseline and CON-HIIT delta vs. baseline, respectively]. Moreover, time spent in 180 mg/dl 24 h after either HIIT-CON or CON-HIIT training was comparable to baseline [for 180 mg/dl: baseline 27.2% (22.7), HIIT-CON 22.6% (21.1), CON-HIIT 22.2% (16.8)]. The comparison between HIIT-CON and CON-HIIT also showed no differences in GV. Thus, a standardized combined work out (either HIIT-CON or CON-HIIT) avoids late glycemic fluctuations and dangerous hypo-/hyperglycemia in T1D and LADA patients on CSII therapy. Disclosure A. Cignarelli: Consultant; Self; Eli Lilly and Company. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., Novo Nordisk A/S. G. Lisco: None. L. Di Gioia: None. A. Natalicchio: Other Relationship; Self; Novo Nordisk Inc., Sanofi-Aventis. S. Perrini: None. L. Laviola: Advisory Panel; Self; Abbott, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc. Board Member; Self; AstraZeneca, Roche Diabetes Care, Sanofi-Aventis. Speaker's Bureau; Self; Medtronic, Mundipharma, Takeda Pharmaceutical Company Limited. F. Giorgino: Advisory Panel; Self; Aegerion Pharmaceuticals, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, MedImmune, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Roche Diabetes Care, Sanofi. Consultant; Self; Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Pharmaceutical Company Limited. Other Relationship; Self; AstraZeneca, Eli Lilly and Company, Sanofi.

Insulin, acting in an autocrine manner, promotes β-cell survival and growth and its own biosynthesis and secretion. Prolonged exposure of β-cells to high levels of saturated fatty acids (SFAs) impairs insulin signaling, reducing the ability of insulin to promote its release. The p66Shc protein is an inducer of cellular oxidative stress and apoptosis, and its mRNA levels are increased in pancreatic islets from overweight/obese subjects. Here we evaluated the role of p66Shc in pancreatic β-cell insulin resistance (IR) occurring in obesity and lipotoxic conditions. Insulin effects on its own content and C-peptide secretion were studied in pancreatic islets from overweight/obese (BMI ≥25 kg/m2) compared to lean (BMI In conclusion, the protein p66Shc exerts an inhibitory effect on β-cell insulin signaling and can mediate the ability of SFAs and excess body fat to cause β-cell IR, which results in both reduced survival and impaired secretory function. Disclosure L. Dipaola: None. A. Natalicchio: Other Relationship; Self; Novo Nordisk Inc., Sanofi-Aventis. G. Biondi: None. N. Marrano: None. M. Bugliani: None. A. Cignarelli: Consultant; Self; Eli Lilly and Company. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., Novo Nordisk A/S. S. Perrini: None. P. Marchetti: None. L. Laviola: Advisory Panel; Self; Abbott, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc. Board Member; Self; AstraZeneca, Roche Diabetes Care, Sanofi-Aventis. Speaker's Bureau; Self; Medtronic, Mundipharma, Takeda Pharmaceutical Company Limited. F. Giorgino: Advisory Panel; Self; Aegerion Pharmaceuticals, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, MedImmune, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Roche Diabetes Care, Sanofi. Consultant; Self; Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Pharmaceutical Company Limited. Other Relationship; Self; AstraZeneca, Eli Lilly and Company, Sanofi.

Elevated circulating levels of saturated fatty acids (SFA; e.g., palmitate) are associated with increased cardiovascular risk in diabetes. In contrast, monounsaturated fatty acids (e.g., oleate) prevent the toxic effects of SFA in multiple cell types. The viability of cardiac progenitor cells (CPC) is essential for myocardial tissue homeostasis. In this study, the ability of palmitate and oleate to induce apoptosis and autophagy, as well as the effects of oleate on the palmitate-induced damage, were investigated in human CPC isolated from right auricle biopsies. Palmitate, but not oleate, induced apoptosis in a dose- and time-dependent manner in human CPC, as assessed by caspase-3 cleavage and ELISA assay for cytoplasmic oligonucleosomes (p In conclusion, oleate prevents the palmitate-induced increase in apoptosis and autophagy of human CPC by counteracting the activation of p38 MAPK and JNK. Hence, oleate supplementation might limit the lipotoxic damage of human heart by preserving the viability of myocardial progenitors. Disclosure R. Doria: None. R. Schipani: None. C. Caccioppoli: None. M. Incalza: None. A. Leonardini: None. A. Natalicchio: Other Relationship; Self; Novo Nordisk Inc., Sanofi-Aventis. S. Perrini: None. A. Cignarelli: Consultant; Self; Eli Lilly and Company. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., Novo Nordisk A/S. L. Laviola: Advisory Panel; Self; Abbott, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc. Board Member; Self; AstraZeneca, Roche Diabetes Care, Sanofi-Aventis. Speaker's Bureau; Self; Medtronic, Mundipharma, Takeda Pharmaceutical Company Limited. F. Giorgino: Advisory Panel; Self; Aegerion Pharmaceuticals, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, MedImmune, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Roche Diabetes Care, Sanofi. Consultant; Self; Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Pharmaceutical Company Limited. Other Relationship; Self; AstraZeneca, Eli Lilly and Company, Sanofi.

Insulin regulates the development and metabolism of adipose tissue (AT) by activating its tyrosine kinase receptor in this tissue. The insulin receptor (IR) consists of two isoforms, a short isoform (IR-A) with prevalent mitogenic property and a long isoform (IR-B) with prevalent metabolic activity. We investigated the expression of IR-A and IR-B in human AT and adipocyte precursors. Biopsies of abdominal subcutaneous AT (S-AT) and visceral AT (V-AT) were obtained from subjects with different BMI. Adipose-derived stem cells (ASC) were also isolated from both AT depots, and were analyzed before and after differentiation into adipocytes (dASC). mRNA levels of IR-A were 2-fold and 3-fold higher compared to IR-B in S-AT and V-AT, respectively. Total IR and IR-A mRNA levels were also 2-fold higher in S-ASC compared to V-ASC. Accordingly, S-ASC exhibited a greater insulin-induced Akt phosphorylation (4-fold) as compared to V-ASC. IR-A expression displayed a positive correlation with BMI in S-ASC (r = 0.50; p = 0.04) but not in V-ASC, in which an inverse correlation was noted (r = -0.66; p = 0.01). Adipocyte differentiation in the presence of human insulin was associated with increased mRNA expression of IR-A in both S-dASC (3-fold) and V-dASC (2.8-fold), and of total IR (5-fold) and IR-B (2-fold) only in S-dASC. Moreover, S-dASC showed higher IR-A mRNA expression (2.5-fold) when compared to V-dASC, similarly to S-ASC and S-AT. In V-dASC, but not in S-dASC, the extent of lipogenesis assessed by oil-Red-O staining was positively correlated with basal expression of total IR (r = 0.94; p = 0.04), while adipogenesis measured by Nile red fluorescent staining showed a correlation with the pAkt/pErk ratio (r = 0.95; p < 0.01). In conclusion, expression of total IR, IR-A and IR-B differs in relation to the stage of tissue development (ASC, dASC, AT) and in a depot-related manner (S vs. V). IR-A appears to be the prevalent IR isoform in human AT and adipocyte precursors and to be particularly involved in the expansion of S-AT in human obesity. Disclosure V. Genchi: None. A. Cignarelli: Consultant; Self; Eli Lilly and Company. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., Novo Nordisk A/S. S. Perrini: None. S. Porro: None. C. Caccioppoli: None. A. Natalicchio: Other Relationship; Self; Novo Nordisk Inc., Sanofi-Aventis. L. Laviola: Advisory Panel; Self; Abbott, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc. Board Member; Self; AstraZeneca, Roche Diabetes Care, Sanofi-Aventis. Speaker's Bureau; Self; Medtronic, Mundipharma, Takeda Pharmaceutical Company Limited. F. Giorgino: Advisory Panel; Self; Aegerion Pharmaceuticals, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, MedImmune, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Roche Diabetes Care, Sanofi. Consultant; Self; Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Pharmaceutical Company Limited. Other Relationship; Self; AstraZeneca, Eli Lilly and Company, Sanofi.

Increased abdominal visceral adipose tissue (VAT) is associated with cardiovascular risk in metabolically unhealthy subjects. The viability of cardiac progenitor cells (CPC) is essential for myocardial tissue turnover. This study aimed to assess whether the secretome of visceral adipose stem cells (ASC) and ASC-derived mature adipocytes may affect the viability and insulin signaling of CPC in human obesity. ASC were isolated from VAT biopsies of nondiabetic subjects with varying levels of BMI and used before and after differentiation into adipocytes in vitro. CPC isolated from right auricle biopsies of healthy non-obese subjects were exposed or not to conditioned media (CM) of ASC or ASC-derived adipocytes. Apoptosis was assessed by caspase-3 cleavage and ELISA for oligonucleosomes, and insulin signaling by immunoblotting analysis of Akt Ser473 phosphorylation. The CM of ASC isolated from obese subjects (Ob-ASC) induced CPC apoptosis in a time-dependent manner (4-8-24 h) (p0.05 vs. control CPC). Similarly to Ob-ASC, exposure of CPC to the CM of ASC-derived adipocytes from obese subjects also induced apoptosis and inhibited insulin-mediated Akt phosphorylation (p0.05 vs. control CPC). In conclusion, human obesity is associated with the secretion of factors from visceral ASC that impair insulin action in CPC and CPC survival. This property is retained in ASC-derived adipocytes, providing a potential link between expansion of VAT and development of myocardial dysfunction. Disclosure S. Porro: None. S. Perrini: None. C. Caccioppoli: None. R. Doria: None. V. Genchi: None. A. Cignarelli: Consultant; Self; Eli Lilly and Company. Speaker's Bureau; Self; Merck Sharp & Dohme Corp., Novo Nordisk A/S. A. Natalicchio: Other Relationship; Self; Novo Nordisk Inc., Sanofi-Aventis. L. Laviola: Advisory Panel; Self; Abbott, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc. Board Member; Self; AstraZeneca, Roche Diabetes Care, Sanofi-Aventis. Speaker's Bureau; Self; Medtronic, Mundipharma, Takeda Pharmaceutical Company Limited. F. Giorgino: Advisory Panel; Self; Aegerion Pharmaceuticals, AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, MedImmune, Merck Sharp & Dohme Corp., Novo Nordisk A/S, Roche Diabetes Care, Sanofi. Consultant; Self; Roche Diabetes Care, Sanofi. Research Support; Self; Eli Lilly and Company, LifeScan, Inc., Takeda Pharmaceutical Company Limited. Other Relationship; Self; AstraZeneca, Eli Lilly and Company, Sanofi.

Extra virgin olive oil (EVOO) is one of the major components of the Mediterranean diet and is appreciated worldwide because of its nutritional benefits in metabolic diseases, including type 2 diabetes. In addition to high levels of fatty acids, EVOO contains significant amounts of micronutrients such as polyphenolic compounds that may positively influence the metabolic status. In this study, we have evaluated the effects of such EVOO polyphenolic compounds on beta-cell function and survival. INS-1E cells were exposed to different doses (10-50-100 microM) of the main polyphenols of EVOO for 24 h. Under these conditions, glucose-stimulated insulin secretion (GSIS), insulin content, proinsulin mRNA expression and cellular apoptosis were evaluated. At the concentration of 10 microM, which is closest to that in EVOO, hydroxytyrosol, tyrosol and apigenin augmented proinsulin mRNA levels and insulin content; moreover, apigenin and luteolin enhanced GSIS. On the other hand, vanillic acid and vanillin were pro-apoptotic for beta-cells, even if they increased GSIS. Finally, ferulic and sinapic acids significantly worsened GSIS. Furthermore, although most of the polyphenol compounds at the concentration of 50 microM did not induce apoptosis, some of them (e.g., caffeic, vanillic and ferulic acids) caused a marked reduction in proinsulin gene expression. At the concentration of 100 microM, most polyphenolic compounds caused a reduction in proinsulin mRNA levels and enhanced apoptosis. In conclusion, this study, comparing for the first time the effects of the main polyphenols contained in EVOO, shows that, at low concentrations, hydroxytyrosol, tyrosol, luteolin and apigenin exert positive effects on both the function and survival of beta-cells, suggesting that EVOO enriched with these compounds may improve insulin secretion and promote glycemic control in type 2 diabetic patients. Disclosure A. Natalicchio: None. R. Spagnuolo: None. N. Marrano: None. G. Biondi: None. L. Dipaola: None. A. Cignarelli: Advisory Panel; Self; Aegerion Pharmaceuticals. Consultant; Self; Roche Diagnostics Corporation, Eli Lilly and Company. S. Perrini: None. L. Laviola: Advisory Panel; Self; AstraZeneca, Animas Corporation. Speaker's Bureau; Self; A. Menarini Diagnostics. Advisory Panel; Self; Boehringer Ingelheim GmbH, Eli Lilly and Company. Speaker's Bureau; Self; Medtronic, Merck Sharp & Dohme Corp.. Advisory Panel; Self; Novo Nordisk Inc., Roche Diabetes Care Health and Digital Solutions, Sanofi-Aventis, Takeda Development Centre Europe Ltd. F. Giorgino: Consultant; Self; Abbott, AstraZeneca, Boehringer Ingelheim GmbH. Research Support; Self; Eli Lilly and Company, Johnson & Johnson Services, Inc.. Consultant; Self; MedImmune, Merck Sharp & Dohme Corp., Roche Diabetes Care Health and Digital Solutions, Sanofi. Research Support; Self; Takeda Development Centre Europe Ltd..

Physiological tissue turnover in the heart requires proper activation and viability of multipotent cardiac progenitor cells (CPCs). A defective CPC compartment, in terms of CPC number and maturation capacity, contributes to diabetes- and hyperglycemia-related heart failure in humans. GLP-1-based therapies, including the DPP-4 inhibitors, improve cardiac function in vivo and ameliorate myocardial and endothelial dysfunction in vitro. Pioglitazone has also demonstrated pleiotropic anti-oxidant and anti-atherogenic effects. The aim of this study was to evaluate the effects of alogliptin and pioglitazone, alone or in combination, on the viability of human CPCs exposed to 0.25 mM palmitate for 16 h. Human CPCs were obtained from patients undergoing cardiac surgery for coronary artery bypass grafting and/or valve surgery. Exposure of human CPCs to both alogliptin (10 µM) and pioglitazone (10 µM) for 16 h resulted in Akt, but not Erk, activation. Exposure to palmitate was associated with increased human CPC apoptosis and autophagy evaluated by ELISA assay and LC3-II immunoblotting, respectively (p In conclusion, palmitate induces apoptosis and autophagy in human CPCs, and alogliptin and pioglitazone, as well as their combination, prevent the effects of palmitate, likely through enhancement of pro-survival pathways. Hence, DPP-4 inhibitors and thiazolidinediones, alone or in combination, may limit the lipotoxic damage of the human heart by preserving the viability of myocardial progenitor cells. Disclosure M. Incalza: None. R. D'Oria: None. C. Caccioppoli: None. A. Leonardini: None. R. Schipani: None. A. Cignarelli: Advisory Panel; Self; Aegerion Pharmaceuticals. Consultant; Self; Roche Diagnostics Corporation, Eli Lilly and Company. A. Natalicchio: None. S. Perrini: None. V. Margari: None. D. Paparella: None. L. Laviola: Advisory Panel; Self; AstraZeneca, Animas Corporation. Speaker's Bureau; Self; A. Menarini Diagnostics. Advisory Panel; Self; Boehringer Ingelheim GmbH, Eli Lilly and Company. Speaker's Bureau; Self; Medtronic, Merck Sharp & Dohme Corp.. Advisory Panel; Self; Novo Nordisk Inc., Roche Diabetes Care Health and Digital Solutions, Sanofi-Aventis, Takeda Development Centre Europe Ltd. F. Giorgino: Consultant; Self; Abbott, AstraZeneca, Boehringer Ingelheim GmbH. Research Support; Self; Eli Lilly and Company, Johnson & Johnson Services, Inc.. Consultant; Self; MedImmune, Merck Sharp & Dohme Corp., Roche Diabetes Care Health and Digital Solutions, Sanofi. Research Support; Self; Takeda Development Centre Europe Ltd..

Activators of peroxisome proliferator–activated receptor (PPAR)γ have been studied intensively for their insulin-sensitizing properties and antidiabetic effects. Recently, a specific PPARδ activator (GW501516) was reported to attenuate plasma glucose and insulin levels when administered to genetically obese ob/ob mice. This study was performed to determine whether specific activation of PPARδ has direct effects on insulin action in skeletal muscle. Specific activation of PPARδ using two pharmacological agonists (GW501516 and GW0742) increased glucose uptake independently of insulin in differentiated C2C12 myotubes. In cultured primary human skeletal myotubes, GW501516 increased glucose uptake independently of insulin and enhanced subsequent insulin stimulation. PPARδ agonists increased the respective phosphorylation and expression of AMP-activated protein kinase 1.9-fold (P < 0.05) and 1.8-fold (P < 0.05), of extracellular signal–regulated kinase 1/2 mitogen-activated protein kinase (MAPK) 2.2-fold (P < 0.05) and 1.7-fold (P < 0.05), and of p38 MAPK 1.2-fold (P < 0.05) and 1.4-fold (P < 0.05). Basal and insulin-stimulated protein kinase B/Akt was unaltered in cells preexposed to PPARδ agonists. Preincubation of myotubes with the p38 MAPK inhibitor SB203580 reduced insulin- and PPARδ-mediated increase in glucose uptake, whereas the mitogen-activated protein kinase kinase inhibitor PD98059 was without effect. PPARδ agonists reduced mRNA expression of PPARδ, sterol regulatory element binding protein (SREBP)-1a, and SREBP-1c (P < 0.05). In contrast, mRNA expression of PPARγ, PPARγ coactivator 1, GLUT1, and GLUT4 was unaltered. Our results provide evidence to suggest that PPARδ agonists increase glucose metabolism and promote gene regulatory responses in cultured human skeletal muscle. Moreover, we provide biological validation of PPARδ as a potential target for antidiabetic therapy.

We determined whether protein kinase C (PKC) isoforms are redistributed and phosphorylated in response to acute exercise in skeletal muscle. Muscle biopsies were obtained from six healthy subjects (four women, two men; age 25 +/- 1 years) before, during, and after 60 min of one-leg cycle ergometry at approximately 70% VO(2peak). Exercise for 30 and 60 min was associated with a three- and fourfold increase in PKC-zeta/lambda abundance and a four- and threefold increase in phosphorylation, respectively, in total membranes (P0.05) and a decrease in PKC-zeta/lambda phosphorylation in cytosolic fractions. During exercise recovery, PKC-zeta/lambda abundance and phosphorylation remained elevated. PKC-zeta/lambda abundance and phosphorylation were increased in nonexercised muscle upon cessation of exercise, indicating a systemic response may contribute to changes in PKC abundance and phosphorylation. Exercise did not change PKC-delta or -epsilon abundance or phosphorylation in either the cytosolic or total membrane fraction. In conclusion, exercise is associated with an isoform-specific effect on PKC. PKC-zeta/lambda are candidate PKC isoforms that may play a role in the regulation of exercise-related changes in metabolic and gene-regulatory responses.

In this study, we evaluated the activation of various insulin signaling molecules in human fat in vivo and compared signaling reactions in visceral and subcutaneous fat depots. Paired abdominal omental and subcutaneous fat biopsies were obtained from nonobese subjects with normal insulin sensitivity under basal conditions and 6 and 30 min following administration of intravenous insulin. Insulin receptor phosphorylation was more intense and rapid and insulin receptor protein content was greater in omental than in subcutaneous adipose tissue (P < 0.05). Insulin-induced phosphorylation of Akt also occurred to a greater extent and earlier in omental than in subcutaneous fat (P < 0.05) in the absence of significant changes in Akt protein content. Accordingly, phosphorylation of the Akt substrate glycogen synthase kinase-3 was more responsive to insulin stimulation in omental fat. Protein content of extracellular signal–regulated kinase (ERK)-1/2 was threefold higher in omental than in subcutaneous fat (P < 0.05), and ERK phosphorylation showed an early 6-min peak in omental fat, in contrast with a more gradual increase observed in subcutaneous fat. In conclusion, the adipocyte insulin signaling system of omental fat shows greater and earlier responses to insulin than that of subcutaneous fat. These findings may contribute to explain the biological diversity of the two fat depots.

Dehydroepiandrosterone (DHEA) has been shown to modulate glucose utilization in humans and animals, but the mechanisms of DHEA action have not been clarified. We show that DHEA induces a dose- and time-dependent increase in glucose transport rates in both 3T3-L1 and human adipocytes with maximal effects at 2 h. Exposure of adipocytes to DHEA does not result in changes of total GLUT4 and GLUT1 protein levels. However, it does result in significant increases of these glucose transporters in the plasma membrane. In 3T3-L1 adipocytes, DHEA increases tyrosine phosphorylation of insulin receptor substrate (IRS)-1 and IRS-2 and stimulates IRS-1- and IRS-2-associated phosphatidylinositol (PI) 3-kinase activity with no effects on either insulin receptor or Akt phosphorylation. In addition, DHEA causes significant increases of cytosolic Ca(2+) concentrations and a parallel activation of protein kinase C (PKC)-beta(2). The effects of DHEA are abrogated by pretreatment of adipocytes with PI 3-kinase and phospholipase C gamma inhibitors, as well as by inhibitors of Ca(2+)-dependent PKC isoforms, including a specific PKC-beta inhibitor. Thus, DHEA increases glucose uptake in both human and 3T3-L1 adipocytes by stimulating GLUT4 and GLUT1 translocation to the plasma membrane. PI 3-kinase, phospholipase C gamma, and the conventional PKC-beta(2) seem to be involved in DHEA effects.