Developmental programming of aging of isolated pancreatic islet glucose-stimulated insulin secretion in female offspring of mothers fed low-protein diets in pregnancy and/or lactation

2012 ◽  
Vol 3 (6) ◽  
pp. 483-488 ◽  
Author(s):  
S. Morimoto ◽  
T. C. Sosa ◽  
L. Calzada ◽  
L. A. Reyes-Castro ◽  
E. Díaz-Díaz ◽  
...  

Diabetes predisposition is determined by pancreatic islet insulin secretion and insulin resistance. We studied female rat offspring exposed to low-protein maternal diet (50% control protein diet) in pregnancy and/or lactation at postnatal days 36, 110 and 450. Rats were fed either control 20% casein diet (C) or restricted diet (R – 10% casein) during pregnancy. After delivery, mothers received either C or R diet until weaning to provide four offspring groups: CC, RR, CR and RC (first letter denoting maternal pregnancy diet and the second lactation diet). Serum glucose, insulin and homeostatic model assessment (HOMA) were measured. Pancreatic islets were isolated and in vitro insulin secretion quantified in low glucose (5 mM) and high glucose (11 mM). Serum glucose, insulin and HOMA were similar in all groups at 36 and 110 postnatal days. HOMA was only higher in RR at 450 postnatal days. Only CC demonstrated differences in glucose sensitivity of β-cells to high and low doses at the three ages studied. At 36 days, RR, CR and RC and at 450 days RR and RC groups did not show glucose-stimulated insulin secretion differences between low and high glucose. Aging-associated glucose-stimulated insulin secretion loss was affected by maternal dietary history, indicating that developmental programming must be considered a major factor in aging-related development of predisposition to later-life dysfunctional insulin metabolism. Female offspring islets’ insulin secretion was higher than previously reported in males.

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 2162-P
Author(s):  
STEPHAN NIEUWOUDT ◽  
RUTH MCDOWELL ◽  
HUI ZHANG ◽  
JOHN P. KIRWAN

2019 ◽  
Vol 10 (8) ◽  
pp. 5018-5031 ◽  
Author(s):  
Shin Sato ◽  
Toshio Norikura ◽  
Yuuka Mukai

Quercetin intake during lactation causes long-term alterations in inflammation and autophagy flux in the kidneys of high-fructose-diet-fed adult female offspring exposed to maternal normal- or low-protein diets.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Jing Duan ◽  
Xian-Ling Qian ◽  
Jun Li ◽  
Xing-Hua Xiao ◽  
Xiang-Tong Lu ◽  
...  

Background. Diabetes is a progressive metabolic disease characterized by hyperglycemia. Functional impairment of islet β cells can occur to varying degrees. This impairment can initially be compensated for by proliferation and metabolic changes of β cells. Cell division control protein 42 (Cdc42) and the microRNA (miRNA) miR-29 have important roles in β-cell proliferation and glucose-stimulated insulin secretion (GSIS), which we further explored using the mouse insulinoma cell line MIN6. Methods. Upregulation and downregulation of miR-29a and Cdc42 were accomplished using transient transfection. miR-29a and Cdc42 expression was detected by real-time PCR and western blotting. MIN6 proliferation was detected using a cell counting kit assay. GSIS under high-glucose (20.0 mM) or basal-glucose (5.0 mM) stimulation was detected by enzyme-linked immunosorbent assay. The miR-29a binding site in the Cdc42 mRNA 3′-untranslated region (UTR) was determined using bioinformatics and luciferase reporter assays. Results. miR-29a overexpression inhibited proliferation (P<0.01) and GSIS under high-glucose stimulation (P<0.01). Cdc42 overexpression promoted proliferation (P<0.05) and GSIS under high-glucose stimulation (P<0.05). miR-29a overexpression decreased Cdc42 expression (P<0.01), whereas miR-29a downregulation increased Cdc42 expression (P<0.01). The results showed that the Cdc42 mRNA 3′-UTR is a direct target of miR-29a in vitro. Additionally, Cdc42 reversed miR-29a-mediated inhibition of proliferation and GSIS (P<0.01). Furthermore, miR-29a inhibited β-catenin expression (P<0.01), whereas Cdc42 promoted β-catenin expression (P<0.01). Conclusion. By negatively regulating Cdc42 and the downstream molecule β-catenin, miR-29a inhibits MIN6 proliferation and insulin secretion.


2012 ◽  
Vol 302 (11) ◽  
pp. E1431-E1439 ◽  
Author(s):  
Adriana Rodríguez-Trejo ◽  
María Guadalupe Ortiz-López ◽  
Elena Zambrano ◽  
María de los Ángeles Granados-Silvestre ◽  
Carmen Méndez ◽  
...  

Maternal low-protein diets (LP) impair pancreatic β-cell development, resulting in later-life failure and susceptibility to type 2 diabetes (T2D). We hypothesized that intrauterine and/or postnatal developmental programming seen in this situation involve altered β-cell structure and relative time course of expression of genes critical to β-cell differentiation and growth. Pregnant Wistar rats were fed either control (C) 20% or restricted (R) 6% protein diets during pregnancy (1st letter) and/or lactation (2nd letter) in four groups: CC, RR, RC, and CR. At postnatal days 7 and 21, we measured male offspring β-cell fraction, mass, proliferation, aggregate number, and size as well as mRNA level for 13 key genes regulating β-cell development and function in isolated islets. Compared with CC, pre- and postnatal LP (RR) decreased β-cell fraction, mass, proliferation, aggregate size, and number and increased Hnf1a, Hnf4a, Pdx1, Isl1, Rfx6, and Slc2a2 mRNA levels. LP only in pregnancy (RC) also decreased β-cell fraction, mass, proliferation, aggregate size, and number and increased Hnf1a, Hnf4a, Pdx1, Rfx6, and Ins mRNA levels. Postnatal LP offspring (CR) showed decreased β-cell mass but increased β-cell fraction, aggregate number, and Hnf1a, Hnf4a, Rfx6, and Slc2a2 mRNA levels. We conclude that LP in pregnancy sets the trajectory of postnatal β-cell growth and differentiation, whereas LP in lactation has smaller effects. We propose that LP promotes differentiation through upregulation of transcription factors that stimulate differentiation at the expense of proliferation. This results in a decreased β-cell reserve, which can contribute to later-life predisposition to T2D.


2020 ◽  
Author(s):  
Ada Admin ◽  
Kung-Hsien Ho ◽  
Xiaodun Yang ◽  
Anna B. Osipovich ◽  
Over Cabrera ◽  
...  

The microtubule cytoskeleton of pancreatic islet β-cells regulates glucose-stimulated insulin secretion (GSIS). We have reported that the microtubule-mediated movement of insulin vesicles away from the plasma membrane limits insulin secretion. High glucose-induced remodeling of microtubule network facilitates robust GSIS. This remodeling involves disassembly of old microtubules and nucleation of new microtubules. Here, we examine the mechanisms whereby glucose stimulation decreases microtubule lifetimes in β-cells. Using real-time imaging of photoconverted microtubules, we demonstrate that high levels of glucose induce rapid microtubule disassembly preferentially in the periphery of individual β-cells, and this process is mediated by the phosphorylation of microtubule-associated protein tau. Specifically, high glucose induces tau hyper-phosphorylation via glucose-responsive kinases GSK3, PKA, PKC, and CDK5. This causes dissociation of tau from and subsequent destabilization of microtubules. Consequently, tau-knockdown in mouse islet β-cells facilitates microtubule turnover, causing increased basal insulin secretion, depleting insulin vesicles from the cytoplasm, and impairing GSIS. More importantly, tau-knockdown uncouples microtubule destabilization from glucose stimulation. These findings suggest that tau suppresses peripheral microtubules turning-over to restrict insulin over-secretion at basal conditions and preserve the insulin pool that can be released in following stimulation; high glucose promotes tau phosphorylation to enhance microtubule disassembly to acutely enhance GSIS.


Endocrinology ◽  
2011 ◽  
Vol 152 (10) ◽  
pp. 3614-3621 ◽  
Author(s):  
Laila R. B. Santos ◽  
Eduardo Rebelato ◽  
Maria Fernanda R. Graciano ◽  
Fernando Abdulkader ◽  
Rui Curi ◽  
...  

Positive acute effects of fatty acids (FA) on glucose-stimulated insulin secretion (GSIS) and reactive oxygen species (ROS) formation have been reported. However, those studies mainly focused on palmitic acid actions, and reports on oleic acid (OA) are scarce. In this study, the effect of physiological OA levels on β-cell function and the mechanisms involved were investigated. Analyses of insulin secretion, FA and glucose oxidation, and ROS formation showed that, at high glucose concentration, OA treatment increases GSIS in parallel with increased ROS content. At high glucose, OA oxidation was increased, accompanied by a suppression of glucose oxidation. Using approaches for protein knockdown of FA receptor G protein-coupled receptor 40 (GPR40) and of p47PHOX, a reduced nicotinamide adenine dinucleotide phosphate [NAD(P)H] oxidase component, we observed that GPR40 does not mediate OA effects on ROS formation and GSIS. However, in p47PHOX knockdown islets, OA-induced ROS formation and the inhibitory effect of OA on glucose metabolism was abolished. Similar results were obtained by pharmacological inhibition of protein kinase C, a known activator of NAD(P)H oxidase. Thus, ROS derived from OA metabolism via NAD(P)H oxidase are an inhibitor of glucose oxidation. Put together, these results indicate that OA acts as a modulator of glucose oxidation via ROS derived from its own metabolism in β-cells.


2020 ◽  
Author(s):  
Brit H Boehmer ◽  
Stephanie R Wesolowski ◽  
Laura D Brown ◽  
Paul J Rozance

ABSTRACT Background Growth-restricted fetuses have attenuated glucose-stimulated insulin secretion (GSIS), smaller pancreatic islets, less pancreatic β-cells, and less pancreatic vascularization compared with normally growing fetuses. Infusion of leucine into normal late-gestation fetal sheep potentiates GSIS, as well as increases pancreatic islet size, the proportion of the pancreas and islet comprising β-cells, and pancreatic and islet vascularity. In addition, leucine stimulates hepatocyte growth factor (HGF ) mRNA expression in islet endothelial cells isolated from normal fetal sheep. Objective We hypothesized that a 9-d leucine infusion would potentiate GSIS and increase pancreatic islet size, β-cells, and vascularity in intrauterine fetal growth restriction (IUGR) fetal sheep. We also hypothesized that leucine would stimulate HGF mRNA in islet endothelial cells isolated from IUGR fetal sheep. Methods Late-gestation Columbia-Rambouillet IUGR fetal sheep (singleton or twin) underwent surgeries to place vascular sampling and infusion catheters. Fetuses were randomly allocated to receive a 9-d leucine infusion to achieve a 50–100% increase in leucine concentrations or a control saline infusion. GSIS was measured and pancreas tissue was processed for histologic analysis. Pancreatic islet endothelial cells were isolated from IUGR fetal sheep and incubated with supplemental leucine. Data were analyzed by mixed-models ANOVA; Student, Mann-Whitney, or a paired t test; or a test of equality of proportions. Results Chronic leucine infusion in IUGR fetuses did not affect GSIS, islet size, the proportion of the pancreas comprising β-cells, or pancreatic or pancreatic islet vascularity. In isolated islet endothelial cells from IUGR fetuses, HGF mRNA expression was not affected by supplemental leucine. Conclusions IUGR fetal sheep islets are not responsive to a 9-d leucine infusion with respect to insulin secretion or any histologic features measured. This is in contrast to the response in normally growing fetuses. These results are important when considering nutritional strategies to prevent the adverse islet and β-cell consequences in IUGR fetuses.


2021 ◽  
Author(s):  
Casey J. Bauchle ◽  
Kristen E. Rohli ◽  
Cierra K. Boyer ◽  
Vidhant Pal ◽  
Jonathan V. Rocheleau ◽  
...  

The defining feature of pancreatic islet β-cell function is the precise coordination of changes in blood glucose levels with insulin secretion to regulate systemic glucose homeostasis. While ATP has long been heralded as a critical metabolic coupling factor to trigger insulin release, glucose-derived metabolites have been suggested to further amplify fuel-stimulated insulin secretion. The mitochondrial export of citrate and isocitrate through the citrate-isocitrate carrier (CIC) has been suggested to initiate a key pathway that amplifies glucose-stimulated insulin secretion, though the physiological significance of β-cell CIC to glucose homeostasis has not been established. Here, we generated constitutive and adult CIC β-cell knockout mice and demonstrate these animals have normal glucose tolerance, similar responses to diet-induced obesity, and identical insulin secretion responses to various fuel secretagogues. Glucose-stimulated NADPH production was impaired in β-cell CIC KO islets, whereas glutathione reduction was retained. Furthermore, suppression of the downstream enzyme, cytosolic isocitrate dehydrogenase, Idh1, inhibited insulin secretion in wild type islets, but failed to impact β-cell function in β-cell CIC KO islets.<b> </b>Our data demonstrate that the mitochondrial citrate-isocitrate carrier is not required for glucose-stimulated insulin secretion, and that additional complexities exist for the role of Idh1 and NADPH in the regulation of β-cell function.


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