Integrative transcriptomic analysis of pancreatic islets from patients with prediabetes/type 2 diabetes

To identify new transcriptomic alterations in pancreatic islets associated with metabolic dysfunctions in people with prediabetes (PD)/type 2 diabetes (T2D).Fil: Mencucci, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Flores, Luis Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Abba, Martín Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; ArgentinaFil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; Argentin

Chronological appearance of endocrine and metabolic dysfunctions induced by an unhealthy diet in rats

Background and Objectives: The work was aimed to determine the chronological sequence of events triggered by a fructose-rich diet (FRD) (10% w/v in the drinking water) in normal rats. Material and Methods: Serum parameters, liver and islet markers of metabolism, inflammation and oxidative stress were determined weekly for 21 days. Results: At the end of the first week, rats fed with a FRD showed an early increase in circulating triglycerides, fat liver deposit, and enzymatic activity of liver glucokinase and glucose-6-phosphate dehydrogenase (G6P-DH). After two weeks of such a diet, liver glucose-6-phosphatase (G6Pase) activity and liver oxidative stress markers were significantly increased. Liver sterol regulatory element-binding protein 1c (SREBP1c) mRNA also increased in the second week while their target genes fatty acid synthase (FAS) and glycerol-3-phosphate dehydrogenase (GPAT) enhanced their expression at the third week. Liver and pancreatic inflammation markers also enhanced their gene expression in the last week of treatment. Whereas both control and FRD rats remained normoglycemic throughout the entire period of treatment, blood insulin levels were significantly higher in FRD animals at the third week, thereby evidencing an insulin-resistant state (higher HOMA-IR, HOMA-B and HIS indexes). Pancreatic islets isolated from rats fed with a FRD for 3 weeks also increased glucose-induced insulin secretion (8.3 and 16.7 mM). Conclusions: FRD induces asynchronous changes involving early hypertriglyceridemia together with intrahepatic lipid deposit and metabolic disturbances from week one, followed by enhanced liver oxidative stress, liver and pancreas inflammation, pancreatic β-cell dysfunction, and peripheral insulin-resistance registered at the third week. Knowledge of time-course adaptation mechanisms involved in our rat model could be helpful in developing appropriate strategies to prevent the progression from prediabetes to Type 2 diabetes (T2D) triggered by unhealthy diets.Fil: Castro, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Villagarcía, Hernán Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Román, Carolina Lisi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Flores, Luis Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Schinella, Guillermo Raúl. Universidad Nacional de La Plata; Argentina. Universidad Nacional Arturo Jauretche; ArgentinaFil: Massa, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Francini, Flavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; Argentin

Habitat Associations and Relative Densities of Rodent Populations in Cultivated Areas of Central Argentina

Small mammals were livetrapped during 12 months in crop fields and weedy borders at 18 sites in central Argentina. A total of 1,652 mammals of 14 species was captured during3 3,060 trap-nights. Six species of rodents comprised \u3e 95% of captures. Periodically disturbed fields of crops were dominated by Calomys musculinus and C. laucha, and to a lesser extent Mus musculus. A second group composed of Akodon azarae, Bolomys obscures, and Oligoryzomys flavescens primarily inhabited the more stable, weedy borders of cultivated fields. Peaks in relative densities of C. musculinus, C. laucha, and M . musculus were observed in summer and early autumn ,and populations declined to low numbers in winter, following harvest. In contrast, maxima for A. azarae, B . obscures, and O. flavescens were in late autumn and early winter ,and numbers never declined to low values seen for the other species. These characteristic differences in habitat associations and relative densities of pampas rodents may reflect colonizing potential, as both Calomys and Mus potentially are highly opportunistic genera

Reproductive Characteristics of Rodent Assemblages in Cultivated Regions of Central Argentina

Small mammals were trapped for 2 years at 16 localities on the central-Argentine pampa. Six species (Akodon azarae, Calomys musculinus, C. laucha, Bolomys obscurus, Oligory-zomys flavescens and Mus musculus) accounted for \u3e95% of captures. The major breeding season, as assessed by pregnancies, was September or October through April or May. Mild weather in late autumn and winter of the second season resulted in a relatively longer breeding season during the 2nd year of the study. Females of all six species comprised significantly 50% of captures during the height of the breeding season. For most species, there was a negative correlation between embryo size and embryos per pregnancy; females with large embryos were poorly represented. C. musculinus had the longest breeding season; C. musculinus and Mus had the highest number of embryos per pregnancy; the two species of Calomys and Oligoryzomys had the highest percentages of pregnant females during the breeding season. The predominance of animals of smaller mass classes during the winter is thought to represent seasonal weight loss rather than juvenile recruitmen

Impaired endocrine-metabolic homeostasis: Underlying mechanism of its induction by unbalanced diet

To characterize the intrinsic mechanism by which sucrose induces β-cell dysfunction. Normal rats received for 3 weeks a standard diet supplemented with 10% sucrose in the drinking water (high sucrose (HS)) with/out an antioxidant agent (R/S α-lipoic acid). We measured plasma glucose, insulin, triglyceride, leptin, and lipid peroxidation levels; homeostasis model assessment (HOMA)-insulin resistance (HOMA-IR) and HOMA for β-cell function (HOMA-β) indexes were also determined. Insulin secretion, β-cell apoptosis, intracellular insulin and leptin mediators, and oxidative stress (OS) markers were also measured in islets isolated from each experimental group. HS rats had increased plasma triglyceride, insulin, leptin, and lipid peroxidation (OS marker) levels associated with an insulin-resistant state. Their islets developed an initial compensatory increase in glucose-induced insulin secretion and mRNA and protein levels of β-cell apoptotic markers. They also showed a significant decrease in mRNA and protein levels of insulin and leptin signaling pathway mediators. Uncoupling protein 2 (UCP2), peroxisome proliferator-activated receptor (PPAR)-α and -δ mRNA and protein levels were increased whereas mRNA levels of Sirtuin-1 (Sirt-1), glutathione peroxidase, and catalase were significantly lower in these animals. Development of all these endocrine-metabolic abnormalities was prevented by co-administration of R/S a-lipoic acid together with sucrose. OS may be actively involved in the mechanism by which unbalanced/unhealthy diet induces β-cell dysfunction. Since metabolic-endocrine dysfunctions recorded in HS rats resembled those measured in human pre-diabetes, knowledge of its molecular mechanism could help to develop appropriate strategies to prevent the progression of this metabolic state toward type 2 diabetes (T2D).Fil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Román, Carolina Lisi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); ArgentinaFil: Flores, Luis Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Endocrinología Experimental y Aplicada (i); Argentin

Islet adaptive changes to fructose-induced insulin resistance: β-cell mass, glucokinase, glucose metabolism, and insulin secretion

β-Cell mass, hexokinase/glucokinase (HK/GK) activity, glucose metabolism and insulin secretion were studied in the islets of rats with fructose-induced insulin resistance (IR). Normal male Wistar rats were fed a standard commercial diet and water without (control, C) or with 10% fructose-rich diet (FRD) for 3 weeks. Blood glucose (strips), triglyceride (commercial kit), and insulin (RIA) levels were measured at the time of death. Glucose-induced insulin release, glucose metabolism (14CO2 and 3H2O production from d-[U-14C]- and d-[5-3H]-glucose) and HK/GK activity (G-6-P production), transcription (RT-PCR), protein expression (Western blot), and cellular compartmentalization were measured in isolated islets (collagenase digestion). FRD rats presented normoglycemia but impaired glucose tolerance, hypertriglyceridemia, hyperinsulinemia, and increased HOMA-IR index. In these rats, β-cell mass decreased significantly by 33%, with a 44% increase in the percentage of apoptotic cells. Glucose-induced insulin release and islet glucose metabolism were higher in FRD rats. While GK activity (total and cytosolic fraction) and protein expression were significantly higher in FRD islets, HK showed no change in any of these parameters. Our results demonstrate that the changes induced by dietary-induced IR upon β-cell function and mass are strongly conditional on the nutrient model used. In our model (intact animals with impaired glucose tolerance), GK activity increases through mechanisms previously shown only in vitro or under highly hyperglycemic conditions. Such an increase plays a pivotal role in the adaptive increased release of insulin in response to IR, even in the presence of marked β-cell mass reduction.Fil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Borelli, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Raschia, Maria Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: del Zotto, Hector Herminio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Endocrinología Experimental y Aplicada; Argentin

Role of Islet Glucokinase, Glucose Metabolism, and Insulin Pathway in the Enhancing Effect of Islet Neogenesis-Associated Protein on Glucose-Induced Insulin Secretion

Objective: To demonstrate the role of islet glucokinase, glucose metabolism, and intracellular insulin mediators in the enhancing effect of islet neogenesis-associated protein pentadecapeptide (INGAP-PP) on glucoseinduced insulin secretion. Methods: Islets from normal rats were cultured for 4 days in the absence or presence of 10 μg/mL INGAP-PP, with/without Wortmannin or LY294002. Islets were incubated with different glucose concentrations to measure insulin secretion and content, hexokinase and glucokinase activity, glucose oxidation and utilization, glucokinase, insulin receptor, insulin receptor substrate (IRS)-1/2, and PI3K concentration and phosphorylation. Results: The INGAP-PP significantly increased insulin release at high but not at low glucose concentration, glucokinase activity, glucose metabolism, glucokinase, insulin receptor, IRS-2 and PI3K protein concentration, insulin receptor and IRS-1/2 tyrosine phosphorylation, and the association of p85 with IRS-1. Wortmannin and LY294002 blocked INGAP-PP effect on insulin secretion and glucokinase protein levels in a dosedependent manner. Conclusions: The enhancing effect of INGAP-PP on glucose-induced insulin release could be partly ascribed to its effect on glucokinase activity and glucose metabolism and is mainly mediated by the PI3K/AKT pathway. These results, together with the low hypoglycemia risk associated with the use of INGAP-PP, offer a new alternative for diabetes prevention and treatment.Fil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico la Plata. Centro de Endocrinologia Experimental y Aplicada (i); Argentina. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; ArgentinaFil: Román, Carolina Lisi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico la Plata. Centro de Endocrinologia Experimental y Aplicada (i); Argentina. Universidad del Aconcagua. Facultad de Cs.Medicas; ArgentinaFil: Barbosa Sampaio, Helena C.. Universidade Estadual Do Campinas. Instituto de Biologia; BrasilFil: Boschero, Antonio C.. Universidade Estadual Do Campinas. Instituto de Biologia; BrasilFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico la Plata. Centro de Endocrinologia Experimental y Aplicada (i); Argentina. Universidad del Aconcagua. Facultad de Ciencias Médicas; Argentin

INGAP-PP effects on β-cell mass and function are related to its positive effect on islet angiogenesis and VEGFA production

Our aim was to determine whether islet angiogenesis and VEGFA production/release participate in the mechanism by which INGAP-PP enhances β-cell function and mass. We used two models: a) in vivo (normal rats injected with INGAP-PP for 10 days) and b) in vitro (normal islets cultured for 4 days with INGAP-PP, VEGFA, Rapamycin, and the specific VEGF-Receptor inhibitor, SU5416). INGAP-PP administration enhanced insulin secretion, β-cell mass, islet vascularization, and angiogenesis without affecting glucose homeostasis. Normal islets cultured with INGAP-PP and VEGFA increased insulin and VEGFA secretion while apoptosis decreased. INGAP-PP-induced effects were prevented by both Rapamycin and SU5416. INGAP-PP effects on β-cell mass and function were significantly associated with a positive effect on islet angiogenesis and VEGFA production/release. VEGF-A possibly potentiates INGAP-PP effect through mTORC pathway.Fil: Román, Carolina Lisi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: del Zotto, Hector Herminio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; ArgentinaFil: Flores, Luis Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Endocrinología Experimental y Aplicada. Universidad Nacional de la Plata. Facultad de Cs.médicas. Centro de Endocrinología Experimental y Aplicada; Argentin

Islet neogenesis-associated protein (INGAP)-positive cell mass, β-cell mass, and insulin secretion: their relationship during the fetal and neonatal periods

Objectives: To study the chronological appearance of pancreatic islet neogenesis–associated protein (INGAP)-positive cells and its correlation with the increase in β-cell mass and function in fetal and neonatal rats. Methods: Normal Wistar rat embryos (E) at gestational days 15, 17, and 19 (E15, E17, E19) and 7-day-old postnatal rats (P7) were humanely killed to determine body and pancreas weight; blood glucose; glucose and arginine-induced insulin secretion; real-time polymerase chain reaction of Pdx1 and Ngn3; quantitative immunomorphometric analysis of β-cell replication and apoptosis rate, cytokeratin and INGAP cell mass, and Pdx-1– and Ngn3-positive cells. Results: Body and pancreas weight increased with age (P7 > E19 > E17 > E15; P < 0.05). Neonates had higher blood glucose concentrations than embryos (P < 0.05). We recorded a simultaneous and significant age-dependent trend of increase in the number of β- and Pdx-1-positive cells, β- and cytokeratin-positive cell mass and β-cell capacity to release insulin in response to glucose and arginine, and decreased β-cell apoptotic rate. These changes closely paralleled the increase in INGAP-positive cell mass. Conclusions: These findings suggest that INGAP exerts a positive modulatory effect on β-cell mass and its secretory function in fetal and neonatal rats, thus becoming a new component in the multifactorial regulation of such processes.Fil: Madrid, Viviana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); ArgentinaFil: Borelli, Maria Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); ArgentinaFil: Maiztegui, Barbara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); ArgentinaFil: Flores, Luis Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); ArgentinaFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); ArgentinaFil: del Zotto, Hector Herminio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnológico La Plata. Centro de Endocrinologia Experimental y Aplicada (i); Argentin