Science.gov

Sample records for differentially alter glucose

  1. Docosahexaenoyl ethanolamide improves glucose uptake and alters endocannabinoid system gene expression in proliferating and differentiating C2C12 myoblasts

    PubMed Central

    Kim, Jeffrey; Carlson, Morgan E.; Watkins, Bruce A.

    2014-01-01

    Skeletal muscle is a major storage site for glycogen and a focus for understanding insulin resistance and type-2-diabetes. New evidence indicates that overactivation of the peripheral endocannabinoid system (ECS) in skeletal muscle diminishes insulin sensitivity. Specific n-6 and n-3 polyunsaturated fatty acids (PUFA) are precursors for the biosynthesis of ligands that bind to and activate the cannabinoid receptors. The function of the ECS and action of PUFA in skeletal muscle glucose uptake was investigated in proliferating and differentiated C2C12 myoblasts treated with either 25 μM of arachidonate (AA) or docosahexaenoate (DHA), 25 μM of EC [anandamide (AEA), 2-arachidonoylglycerol (2-AG), docosahexaenoylethanolamide (DHEA)], 1 μM of CB1 antagonist NESS0327, and CB2 inverse agonist AM630. Compared to the BSA vehicle control cell cultures in both proliferating and differentiated myoblasts those treated with DHEA, the EC derived from the n-3 PUFA DHA, had higher 24 h glucose uptake, while AEA and 2-AG, the EC derived from the n-6 PUFA AA, had lower basal glucose uptake. Adenylyl cyclase mRNA was higher in myoblasts treated with DHA in both proliferating and differentiated states while those treated with AEA or 2-AG were lower compared to the control cell cultures. Western blot and qPCR analysis showed higher expression of the cannabinoid receptors in differentiated myoblasts treated with DHA while the opposite was observed with AA. These findings indicate a compensatory effect of DHA and DHEA compared to AA-derived ligands on the ECS and associated ECS gene expression and higher glucose uptake in myoblasts. PMID:24711795

  2. Moderate amounts of fructose- or glucose-sweetened beverages do not differentially alter metabolic health in male and female adolescents123

    PubMed Central

    Heden, Timothy D; Liu, Ying; Park, Young-Min; Nyhoff, Lauryn M; Winn, Nathan C; Kanaley, Jill A

    2014-01-01

    .05). Conclusions: Moderate amounts of HF- or HG-sweetened beverages for 2 wk did not have differential effects on fasting or postprandial cholesterol, triacylglycerol, glucose, or hepatic insulin clearance in weight-stable, physically active adolescents. This trial was registered at clinicaltrials.gov as NCT02058914. PMID:25030782

  3. Green tea, black tea, and epigallocatechin modify body composition, improve glucose tolerance, and differentially alter metabolic gene expression in rats fed a high-fat diet.

    PubMed

    Chen, Nora; Bezzina, Rebecca; Hinch, Edward; Lewandowski, Paul A; Cameron-Smith, David; Mathai, Michael L; Jois, Markandeya; Sinclair, Andrew J; Begg, Denovan P; Wark, John D; Weisinger, Harrison S; Weisinger, Richard S

    2009-11-01

    The mechanisms of how tea and epigallocatechin-3-gallate (EGCG) lower body fat are not completely understood. This study investigated long-term administration of green tea (GT), black tea (BT), or isolated EGCG (1 mg/kg per day) on body composition, glucose tolerance, and gene expression related to energy metabolism and lipid homeostasis; it was hypothesized that all treatments would improve the indicators of metabolic syndrome. Rats were fed a 15% fat diet for 6 months from 4 weeks of age and were supplied GT, BT, EGCG, or water. GT and BT reduced body fat, whereas GT and EGCG increased lean mass. At 16 weeks GT, BT, and EGCG improved glucose tolerance. In the liver, GT and BT increased the expression of genes involved in fatty acid synthesis (SREBP-1c, FAS, MCD, ACC) and oxidation (PPAR-alpha, CPT-1, ACO); however, EGCG had no effect. In perirenal fat, genes that mediate adipocyte differentiation were suppressed by GT (Pref-1, C/EBP-beta, and PPAR-gamma) and BT (C/EBP-beta), while decreasing LPL, HSL, and UCP-2 expression; EGCG increased expression of UCP-2 and PPAR-gamma genes. Liver triacylglycerol content was unchanged. The results suggest that GT and BT suppressed adipocyte differentiation and fatty acid uptake into adipose tissue, while increasing fat synthesis and oxidation by the liver, without inducing hepatic fat accumulation. In contrast, EGCG increased markers of thermogenesis and differentiation in adipose tissue, while having no effect on liver or muscle tissues at this dose. These results show novel and separate mechanisms by which tea and EGCG may improve glucose tolerance and support a role for these compounds in obesity prevention. PMID:19932867

  4. A Differential Dielectric Affinity Glucose Sensor

    PubMed Central

    Huang, Xian; Leduc, Charles; Ravussin, Yann; Li, Siqi; Davis, Erin; Song, Bing; Li, Dachao; Xu, Kexin; Accili, Domenico; Wang, Qian; Leibel, Rudolph; Lin, Qiao

    2013-01-01

    A continuous glucose monitor with a differential dielectric sensor implanted within the subcutaneous tissue that determines the glucose in the interstitial fluid is presented. The device, created using microelectromechanical systems (MEMS) technology, consists of sensing and reference modules that are identical in design and placed in close proximity. Each module contains a microchamber housing a pair of capacitive electrodes residing on the device substrate and embedded in a suspended, perforated polymer diaphragm. The microchambers, enclosed in semi-permeable membranes, are filled with either a polymer solution that has specific affinity to glucose or a glucose-insensitive reference solution. To accurately determine the glucose concentration, changes in the permittivity of the sensing and the reference solutions induced by changes in glucose concentration are measured differentially. In vitro characterization demonstrated the sensor capable of measuring glucose concentrations from 0 to 500 mg/dL with resolution and accuracy of ∼1.7 μg/dL and ∼1.74 mg/dL, respectively. In addition, device drift was reduced to 1.4% (uncontrolled environment) and 11% (5 °C of temperature variation) of that from non-differential measurements, indicating significant stability improvements. Preliminary animal testing demonstrated that the differential sensor accurately tracks glucose concentration in blood. This sensor can potentially be used clinically as a subcutaneously implanted continuous monitoring device in diabetic patients. PMID:24220675

  5. Dietary fructose and glucose differentially affect lipid and glucose homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Absorbed glucose and fructose differ in that glucose largely escapes first pass removal by the liver, whereas fructose does not, resulting in different metabolic effects of these two monosaccharides. In short-term controlled feeding studies, dietary fructose significantly increases postprandial trig...

  6. Dietary fructose and glucose differentially affect lipid and glucose homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Absorbed glucose and fructose differ in that glucose largely escapes first-pass removal by the liver, whereas fructose does not, resulting in different metabolic effects of these 2 monosaccharides. In short-term controlled feeding studies, dietary fructose significantly increases postprandial trigly...

  7. A MEMS differential viscometric sensor for affinity glucose detection in continuous glucose monitoring.

    PubMed

    Huang, Xian; Li, Siqi; Davis, Erin; Leduc, Charles; Ravussin, Yann; Cai, Haogang; Song, Bing; Li, Dachao; Accili, Domenico; Leibel, Rudolph; Wang, Qian; Lin, Qiao

    2013-05-01

    Micromachined viscometric affinity glucose sensors have been previously demonstrated using vibrational cantilever and diaphragm. These devices featured a single glucose detection module that determines glucose concentrations through viscosity changes of glucose-sensitive polymer solutions. However, fluctuations in temperature and other environmental parameters might potentially affect the stability and reliability of these devices, creating complexity in their applications in subcutaneously implanted continuous glucose monitoring (CGM). To address these issues, we present a MEMS differential sensor that can effectively reject environmental disturbances while allowing accurate glucose detection. The sensor consists of two magnetically driven vibrating diaphragms situated inside microchambers filled with a boronic-acid based glucose-sensing solution and a reference solution insensitive to glucose. Glucose concentrations can be accurately determined by characteristics of the diaphragm vibration through differential capacitive detection. Our in-vitro and preliminary in-vivo experimental data demonstrate the potential of this sensor for highly stable subcutaneous CGM applications. PMID:23956499

  8. A MEMS differential viscometric sensor for affinity glucose detection in continuous glucose monitoring

    NASA Astrophysics Data System (ADS)

    Huang, Xian; Li, Siqi; Davis, Erin; Leduc, Charles; Ravussin, Yann; Cai, Haogang; Song, Bing; Li, Dachao; Accili, Domenico; Leibel, Rudolph; Wang, Qian; Lin, Qiao

    2013-05-01

    Micromachined viscometric affinity glucose sensors have been previously demonstrated using vibrational cantilever and diaphragm. These devices featured a single glucose detection module that determines glucose concentrations through viscosity changes of glucose-sensitive polymer solutions. However, fluctuations in temperature and other environmental parameters might potentially affect the stability and reliability of these devices, creating complexity in their applications in subcutaneously implanted continuous glucose monitoring (CGM). To address these issues, we present a MEMS differential sensor that can effectively reject environmental disturbances while allowing accurate glucose detection. The sensor consists of two magnetically driven vibrating diaphragms situated inside microchambers filled with a boronic-acid based glucose-sensing solution and a reference solution insensitive to glucose. Glucose concentrations can be accurately determined by characteristics of the diaphragm vibration through differential capacitive detection. Our in vitro and preliminary in vivo experimental data demonstrate the potential of this sensor for highly stable subcutaneous CGM applications.

  9. A MEMS differential viscometric sensor for affinity glucose detection in continuous glucose monitoring

    PubMed Central

    Huang, Xian; Li, Siqi; Davis, Erin; Leduc, Charles; Ravussin, Yann; Cai, Haogang; Song, Bing; Li, Dachao; Accili, Domenico; Leibel, Rudolph; Wang, Qian; Lin, Qiao

    2013-01-01

    Micromachined viscometric affinity glucose sensors have been previously demonstrated using vibrational cantilever and diaphragm. These devices featured a single glucose detection module that determines glucose concentrations through viscosity changes of glucose-sensitive polymer solutions. However, fluctuations in temperature and other environmental parameters might potentially affect the stability and reliability of these devices, creating complexity in their applications in subcutaneously implanted continuous glucose monitoring (CGM). To address these issues, we present a MEMS differential sensor that can effectively reject environmental disturbances while allowing accurate glucose detection. The sensor consists of two magnetically driven vibrating diaphragms situated inside microchambers filled with a boronic-acid based glucose-sensing solution and a reference solution insensitive to glucose. Glucose concentrations can be accurately determined by characteristics of the diaphragm vibration through differential capacitive detection. Our in-vitro and preliminary in-vivo experimental data demonstrate the potential of this sensor for highly stable subcutaneous CGM applications. PMID:23956499

  10. Alterations in glucose kinetics induced by pentobarbital anesthesia

    SciTech Connect

    Lang, C.H.; Bagby, G.J.; Hargrove, D.M.; Hyde, P.M.; Spitzer, J.J. )

    1987-12-01

    Because pentobarbital is often used in investigations related to carbohydrate metabolism, the in vivo effect of this drug on glucose homeostasis was studied. Glucose kinetics assessed by the constant intravenous infusion of (6-{sup 3}H)- and (U-{sup 14}C)glucose, were determined in three groups of catheterized fasted rats: conscious, anesthetized and body temperature maintained, and anesthetized but body temperature not maintained. After induction of anesthesia, marked hypothermia developed in rats not provided with external heat. Anesthetized rats that developed hypothermia showed a decrease in mean arterial blood pressure (25%) and heart rate (40%). Likewise, the plasma lactate concentration and the rates of glucose appearance, recycling, and metabolic clearance were reduced by 30-50% in the hypothermic anesthetized rats. Changes in whole-body carbohydrate metabolism were prevented when body temperature was maintained. Because plasma pentobarbital levels were similar between the euthermic and hypothermic rats during the first 2 h of the experiment, the rapid reduction in glucose metabolism in this latter group appears related to the decrease in body temperature. The continuous infusion of epinephrine produced alterations in glucose kinetics that were not different between conscious animals and anesthetized rats with body temperature maintained. Thus pentobarbital-anesthetized rats became hypothermic when kept at room temperature and exhibited marked decreases in glucose metabolism. Such changes were absent when body temperature was maintained during anesthesia.

  11. Proximity to Delivery Alters Insulin Sensitivity and Glucose Metabolism in Pregnant Mice.

    PubMed

    Musial, Barbara; Fernandez-Twinn, Denise S; Vaughan, Owen R; Ozanne, Susan E; Voshol, Peter; Sferruzzi-Perri, Amanda N; Fowden, Abigail L

    2016-04-01

    In late pregnancy, maternal insulin resistance occurs to support fetal growth, but little is known about insulin-glucose dynamics close to delivery. This study measured insulin sensitivity in mice in late pregnancy at day 16 (D16) and near term at D19. Nonpregnant (NP) and pregnant mice were assessed for metabolite and hormone concentrations, body composition by DEXA, tissue insulin signaling protein abundance by Western blotting, glucose tolerance and utilization, and insulin sensitivity using acute insulin administration and hyperinsulinemic-euglycemic clamps with [(3)H]glucose infusion. Whole-body insulin resistance occurred in D16 pregnant dams in association with basal hyperinsulinemia, insulin-resistant endogenous glucose production, and downregulation of several proteins in hepatic and skeletal muscle insulin signaling pathways relative to NP and D19 values. Insulin resistance was less pronounced at D19, with restoration of NP insulin concentrations, improved hepatic insulin sensitivity, and increased abundance of hepatic insulin signaling proteins. At D16, insulin resistance at whole-body, tissue, and molecular levels will favor fetal glucose acquisition, while improved D19 hepatic insulin sensitivity will conserve glucose for maternal use in anticipation of lactation. Tissue sensitivity to insulin, therefore, alters differentially with proximity to delivery in pregnant mice, with implications for human and other species. PMID:26740602

  12. PROXIMITY TO DELIVERY ALTERS INSULIN SENSITIVITY AND GLUCOSE METABOLISM IN PREGNANT MICE

    PubMed Central

    Musial, Barbara; Fernandez-Twinn, Denise S.; Vaughan, Owen R.; Ozanne, Susan E.; Voshol, Peter; Sferruzzi-Perri, Amanda N.; Fowden, Abigail L.

    2016-01-01

    In late pregnancy, maternal insulin resistance occurs to support fetal growth but little is known about insulin-glucose dynamics close to delivery. This study measured insulin sensitivity in mice in late pregnancy, day (D) 16, and near term, D19, (term 20.5D). Non-pregnant (NP) and pregnant mice were assessed for metabolite and hormone concentrations, body composition by dual energy X-ray absorptiometry, tissue insulin signalling protein abundance by Western blotting, glucose tolerance and utilisation, and insulin sensitivity using acute insulin administration and hyperinsulinaemic-euglycaemic clamps with 3H-glucose infusion. Whole body insulin resistance occurred in D16 pregnant dams in association with basal hyperinsulinaemia, insulin-resistant endogenous glucose production and downregulation of several proteins in hepatic and skeletal muscle insulin signalling pathways relative to NP and D19 values. Insulin resistance was less pronounced at D19 with restoration of NP insulin concentrations, improved hepatic insulin sensitivity and increased abundance of hepatic insulin signalling proteins. At D16, insulin resistance at whole body, tissue and molecular levels will favour fetal glucose acquisition while improved D19 hepatic insulin sensitivity will conserve glucose for maternal use in anticipation of lactation. Tissue sensitivity to insulin, therefore, alters differentially with proximity to delivery in pregnant mice with implications for human and other species. PMID:26740602

  13. Artificial sweeteners induce glucose intolerance by altering the gut microbiota.

    PubMed

    Suez, Jotham; Korem, Tal; Zeevi, David; Zilberman-Schapira, Gili; Thaiss, Christoph A; Maza, Ori; Israeli, David; Zmora, Niv; Gilad, Shlomit; Weinberger, Adina; Kuperman, Yael; Harmelin, Alon; Kolodkin-Gal, Ilana; Shapiro, Hagit; Halpern, Zamir; Segal, Eran; Elinav, Eran

    2014-10-01

    Non-caloric artificial sweeteners (NAS) are among the most widely used food additives worldwide, regularly consumed by lean and obese individuals alike. NAS consumption is considered safe and beneficial owing to their low caloric content, yet supporting scientific data remain sparse and controversial. Here we demonstrate that consumption of commonly used NAS formulations drives the development of glucose intolerance through induction of compositional and functional alterations to the intestinal microbiota. These NAS-mediated deleterious metabolic effects are abrogated by antibiotic treatment, and are fully transferrable to germ-free mice upon faecal transplantation of microbiota configurations from NAS-consuming mice, or of microbiota anaerobically incubated in the presence of NAS. We identify NAS-altered microbial metabolic pathways that are linked to host susceptibility to metabolic disease, and demonstrate similar NAS-induced dysbiosis and glucose intolerance in healthy human subjects. Collectively, our results link NAS consumption, dysbiosis and metabolic abnormalities, thereby calling for a reassessment of massive NAS usage. PMID:25231862

  14. Alteration of the regional cerebral glucose metabolism in healthy subjects by glucose loading.

    PubMed

    Ishibashi, Kenji; Wagatsuma, Kei; Ishiwata, Kiichi; Ishii, Kenji

    2016-08-01

    High plasma glucose (PG) levels can reduce fluorine-18-labeled fluorodeoxyglucose ((18) F-FDG) uptake, especially in the Alzheimer's disease (AD)-related regions. This fact is supported by studies showing that the resting-state activity in diabetes can be altered in the default mode network (DMN)-related regions, which considerably overlap with the AD-related regions. In order to expand the current knowledge, we aimed to investigate the relationship between increasing PG levels and the regional cerebral metabolic rates for glucose (CMRglc ) as a direct index of brain activity. We performed dynamic (18) F-FDG positron emission tomography with arterial blood sampling once each in the fasting and glucose-loading conditions on 12 young, healthy volunteers without cognitive impairment or insulin resistance. The absolute CMRglc values were calculated for the volume-of-interest (VOI) analysis, and normalized CMRglc maps were generated for the voxelwise analysis. The normalized measurement is known to have smaller intersubject variability than the absolute measurement, and may, thus, lead to greater statistical power. In VOI analysis, no regional difference in the CMRglc was found between the two conditions. In exploratory voxelwise analysis, however, significant clusters were identified in the precuneus, posterior cingulate, lateral parietotemporal, and medial prefrontal regions where the CMRglc decreased upon glucose loading (P < 0.05, corrected). These regions include the representative components of both the DMN and AD pathology. Taken together with the previous knowledge on the relationships between the DMN, AD, and diabetes, it may be inferred that glucose loading induces hypometabolism in the AD-related and DMN-related regions. Hum Brain Mapp 37:2823-2832, 2016. © 2016 Wiley Periodicals, Inc. PMID:27061859

  15. The effect of glucose concentration on insulin-induced 3T3-L1 adipose cell differentiation.

    PubMed

    Gagnon, A; Sorisky, A

    1998-03-01

    We examined the effect of glucose concentration on insulin-induced 3T3-L1 adipose cell differentiation. Oil Red O staining of neutral lipid, cellular triglyceride mass, and glycerol phosphate dehydrogenase (GPDH) activity, were greater in 3T3-L1 cells cultured at 5 mM vs. 25 mM glucose. GPDH activity was 2- to 4-fold higher at 5 mM vs. 25 mM glucose over a range of insulin concentrations (0.1 to 100 nM). Insulin-stimulated tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) was 1.7-fold greater, and insulin-stimulated phosphoinositide 3-kinase association with IRS-1 was 2.3-fold higher, at 5 mM vs. 25 mM glucose. These effects of glucose were not caused by alterations in IRS-1 mass or cell-surface insulin binding. In preadipose cells at 5 mM glucose, expression of the leukocyte antigen-related (LAR) protein tyrosine phosphatase (negative regulator of insulin signaling) was 63% of the level at 25 mM glucose. Our data demonstrate that glucose concentration affects insulin-induced 3T3-L1 adipose cell differentiation as well as differentiation-directed insulin signaling pathways. Alterations in LAR expression potentially may be involved in modulating these responses. PMID:9545023

  16. Fructose Alters Intermediary Metabolism of Glucose in Human Adipocytes and Diverts Glucose to Serine Oxidation in the One–Carbon Cycle Energy Producing Pathway

    PubMed Central

    Varma, Vijayalakshmi; Boros, László G.; Nolen, Greg T.; Chang, Ching-Wei; Wabitsch, Martin; Beger, Richard D.; Kaput, Jim

    2015-01-01

    Increased consumption of sugar and fructose as sweeteners has resulted in the utilization of fructose as an alternative metabolic fuel that may compete with glucose and alter its metabolism. To explore this, human Simpson-Golabi-Behmel Syndrome (SGBS) preadipocytes were differentiated to adipocytes in the presence of 0, 1, 2.5, 5 or 10 mM of fructose added to a medium containing 5 mM of glucose representing the normal blood glucose concentration. Targeted tracer [1,2-13C2]-d-glucose fate association approach was employed to examine the influence of fructose on the intermediary metabolism of glucose. Increasing concentrations of fructose robustly increased the oxidation of [1,2-13C2]-d-glucose to 13CO2 (p < 0.000001). However, glucose-derived 13CO2 negatively correlated with 13C labeled glutamate, 13C palmitate, and M+1 labeled lactate. These are strong markers of limited tricarboxylic acid (TCA) cycle, fatty acid synthesis, pentose cycle fluxes, substrate turnover and NAD+/NADP+ or ATP production from glucose via complete oxidation, indicating diminished mitochondrial energy metabolism. Contrarily, a positive correlation was observed between glucose-derived 13CO2 formed and 13C oleate and doses of fructose which indicate the elongation and desaturation of palmitate to oleate for storage. Collectively, these results suggest that fructose preferentially drives glucose through serine oxidation glycine cleavage (SOGC pathway) one-carbon cycle for NAD+/NADP+ production that is utilized in fructose-induced lipogenesis and storage in adipocytes. PMID:26087138

  17. Chlorogenic acid differentially affects postprandial glucose and glucose-dependent insulinotropic polypeptide response in rats.

    PubMed

    Tunnicliffe, Jasmine M; Eller, Lindsay K; Reimer, Raylene A; Hittel, Dustin S; Shearer, Jane

    2011-10-01

    Regular coffee consumption significantly lowers the risk of type 2 diabetes (T2D). Coffee contains thousands of compounds; however, the specific component(s) responsible for this reduced risk is unknown. Chlorogenic acids (CGA) found in brewed coffee inhibit intestinal glucose uptake in vitro. The objective of this study was to elucidate the mechanisms by which CGA acts to mediate blood glucose response in vivo. Conscious, unrestrained, male Sprague-Dawley rats were chronically catheterized and gavage-fed a standardized meal (59% carbohydrate, 25% fat, 12% protein), administered with or without CGA (120 mg·kg(-1)), in a randomized crossover design separated by a 3-day washout period. Acetaminophen was co-administered to assess the effects of CGA on gastric emptying. The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were measured. GLP-1 response in the presence of glucose and CGA was further examined, using the human colon cell line NCI-H716. Total area under the curve (AUC) for blood glucose was significantly attenuated in rats fed CGA (p < 0.05). Despite this, no differences in plasma insulin or nonesterified fatty acids were observed, and gastric emptying was not altered. Plasma GIP response was blunted in rats fed CGA, with a lower peak concentration and AUC up to 180 min postprandially (p < 0.05). There were no changes in GLP-1 secretion in either the in vivo or in vitro study. In conclusion, CGA treatment resulted in beneficial effects on blood glucose response, with alterations seen in GIP concentrations. Given the widespread consumption and availability of coffee, CGA may be a viable prevention tool for T2D. PMID:21977912

  18. Implications of Hydrogen Sulfide in Glucose Regulation: How H2S Can Alter Glucose Homeostasis through Metabolic Hormones

    PubMed Central

    Pichette, Jennifer

    2016-01-01

    Diabetes and its comorbidities continue to be a major health problem worldwide. Understanding the precise mechanisms that control glucose homeostasis and their dysregulation during diabetes are a major research focus. Hydrogen sulfide (H2S) has emerged as an important regulator of glucose homeostasis. This is achieved through its production and action in several metabolic and hormone producing organs including the pancreas, liver, and adipose. Of importance, H2S production and signaling in these tissues are altered during both type 1 and type 2 diabetes mellitus. This review first examines how H2S is produced both endogenously and by gastrointestinal microbes, with a particular focus on the altered production that occurs during obesity and diabetes. Next, the action of H2S on the metabolic organs with key roles in glucose homeostasis, with a particular focus on insulin, is described. Recent work has also suggested that the effects of H2S on glucose homeostasis goes beyond its role in insulin secretion. Several studies have demonstrated important roles for H2S in hepatic glucose output and adipose glucose uptake. The mechanism of H2S action on these metabolic organs is described. In the final part of this review, future directions examining the roles of H2S in other metabolic and glucoregulatory hormone secreting tissues are proposed. PMID:27478532

  19. Implications of Hydrogen Sulfide in Glucose Regulation: How H2S Can Alter Glucose Homeostasis through Metabolic Hormones.

    PubMed

    Pichette, Jennifer; Gagnon, Jeffrey

    2016-01-01

    Diabetes and its comorbidities continue to be a major health problem worldwide. Understanding the precise mechanisms that control glucose homeostasis and their dysregulation during diabetes are a major research focus. Hydrogen sulfide (H2S) has emerged as an important regulator of glucose homeostasis. This is achieved through its production and action in several metabolic and hormone producing organs including the pancreas, liver, and adipose. Of importance, H2S production and signaling in these tissues are altered during both type 1 and type 2 diabetes mellitus. This review first examines how H2S is produced both endogenously and by gastrointestinal microbes, with a particular focus on the altered production that occurs during obesity and diabetes. Next, the action of H2S on the metabolic organs with key roles in glucose homeostasis, with a particular focus on insulin, is described. Recent work has also suggested that the effects of H2S on glucose homeostasis goes beyond its role in insulin secretion. Several studies have demonstrated important roles for H2S in hepatic glucose output and adipose glucose uptake. The mechanism of H2S action on these metabolic organs is described. In the final part of this review, future directions examining the roles of H2S in other metabolic and glucoregulatory hormone secreting tissues are proposed. PMID:27478532

  20. Altered glucose metabolism in mouse and humans conceived by IVF.

    PubMed

    Chen, Miaoxin; Wu, Linda; Zhao, Junli; Wu, Fang; Davies, Michael J; Wittert, Gary A; Norman, Robert J; Robker, Rebecca L; Heilbronn, Leonie K

    2014-10-01

    In vitro fertilization (IVF) may influence the metabolic health of children. However, in humans, it is difficult to separate out the relative contributions of genetics, environment, or the process of IVF, which includes ovarian stimulation (OS) and embryo culture. Therefore, we examined glucose metabolism in young adult humans and in adult male C57BL/6J mice conceived by IVF versus natural birth under energy-balanced and high-fat-overfeeding conditions. In humans, peripheral insulin sensitivity, as assessed by hyperinsulinemic-euglycemic clamp (80 mU/m(2)/min), was lower in IVF patients (n = 14) versus control subjects (n = 20) after 3 days of an energy-balanced diet (30% fat). In response to 3 days of overfeeding (+1,250 kcal/day, 45% fat), there was a greater increase in systolic blood pressure in IVF versus controls (P = 0.02). Mice conceived after either OS alone or IVF weighed significantly less at birth versus controls (P < 0.01). However, only mice conceived by IVF displayed increased fasting glucose levels, impaired glucose tolerance, and reduced insulin-stimulated Akt phosphorylation in the liver after 8 weeks of consuming either a chow or high-fat diet (60% fat). Thus, OS impaired fetal growth in the mouse, but only embryo culture resulted in changes in glucose metabolism that may increase the risk of the development of metabolic diseases later in life, in both mice and humans. PMID:24760136

  1. Altered glucose kinetics in diabetic rats during Gram-negative infection

    SciTech Connect

    Lang, C.H.; Dobrescu, C.; Bagby, G.J.; Spitzer, J.J. )

    1987-08-01

    The present study examined the purported exacerbating effect of sepsis on glucose metabolism in diabetes. Diabetes was induced in rats by an intravenous injection of 70 or 45 mg/kg streptozotocin. The higher dose produced severe diabetes, whereas the lower dose of streptozotocin produced a miler, latent diabetes. After a chronic diabetic state had developed for 4 wk, rats had catheters implanted and sepsis induced by intraperitoneal injections of live Escherichia coli. After 24 h of sepsis the blood glucose concentration was unchanged in nondiabetics and latent diabetics, but glucose decreased from 15 to 8 mM in the septic severe diabetic group. This decrease in blood glucose was not accompanied by alterations in the plasma insulin concentration. Glucose turnover, assessed by the constant intravenous infusion of (6-{sup 3}H)- and (U-{sup 14}C)glucose, was elevated in the severe diabetic group, compared with either latent diabetics or nondiabetics. Sepsis increased the rate of glucose disappearance in nondiabetic rats but had no effect in either group of diabetic animals. Sepsis also failed to alter the insulinogenic index, used to estimate the insulin secretory capacity, in diabetic rats. Thus the present study suggests that the imposition of nonlethal Gram-negative sepsis on severe diabetic animals does not further impair glucose homeostasis and that the milder latent diabetes was not converted to a more severe diabetic state by the septic challenge.

  2. High glucose suppresses embryonic stem cell differentiation into neural lineage cells.

    PubMed

    Yang, Penghua; Shen, Wei-bin; Reece, E Albert; Chen, Xi; Yang, Peixin

    2016-04-01

    Abnormal neurogenesis occurs during embryonic development in human diabetic pregnancies and in animal models of diabetic embryopathy. Our previous studies in a mouse model of diabetic embryopathy have implicated that high glucose of maternal diabetes delays neurogenesis in the developing neuroepithelium leading to neural tube defects. However, the underlying process in high glucose-impaired neurogenesis is uncharacterized. Neurogenesis from embryonic stem (ES) cells provides a valuable model for understanding the abnormal neural lineage development under high glucose conditions. ES cells are commonly generated and maintained in high glucose (approximately 25 mM glucose). Here, the mouse ES cell line, E14, was gradually adapted to and maintained in low glucose (5 mM), and became a glucose responsive E14 (GR-E14) line. High glucose induced the endoplasmic reticulum stress marker, CHOP, in GR-E14 cells. Under low glucose conditions, the GR-E14 cells retained their pluripotency and capability to differentiate into neural lineage cells. GR-E14 cell differentiation into neural stem cells (Sox1 and nestin positive cells) was inhibited by high glucose. Neuron (Tuj1 positive cells) and glia (GFAP positive cells) differentiation from GR-E14 cells was also suppressed by high glucose. In addition, high glucose delayed GR-E14 differentiation into neural crest cells by decreasing neural crest markers, paired box 3 (Pax3) and paired box 7 (Pax7). Thus, high glucose impairs ES cell differentiation into neural lineage cells. The low glucose adapted and high glucose responsive GR-E14 cell line is a useful in vitro model for assessing the adverse effect of high glucose on the development of the central nervous system. PMID:26940741

  3. Circulating endothelial progenitor cells in women with gestational alterations of glucose tolerance.

    PubMed

    Penno, Giuseppe; Pucci, Laura; Lucchesi, Daniela; Lencioni, Cristina; Iorio, Maria Carla; Vanacore, Renato; Storti, Eugenia; Resi, Veronica; Di Cianni, Graziano; Del Prato, Stefano

    2011-07-01

    Endothelial progenitor cells (EPCs) play a role in angiogenesis during pregnancy. The aim of this study was to evaluate circulating EPCs in pregnant women with gestational alterations of glucose tolerance. Glucose tolerance, insulin sensitivity and β-cell function were derived from oral glucose tolerance tests in 23 women with normal glucose tolerance (NGT), 18 with gestational impaired glucose tolerance (GIGT) and 24 with gestational diabetes mellitus (GDM). Circulating cells expressing CD34 in combination with CD133, kinase insert domain receptor (KDR) or both were quantified by flow cytometry. Women with GIGT and GDM had lower CD34(+)KDR(+) and CD34(+)CD133( +)KDR(+) cells at 27±3.2 weeks' gestation compared with NGT (ANOVA p<0.02 for both). CD34(+)KDR(+) and CD34(+)CD133(+)KDR(+) cells were inversely correlated with the area-under-the-glucose-curve (p<0.005, for both) and positively to insulin secretion-sensitivity index (p<0.05, for both). Alterations of glucose tolerance during pregnancy are associated with a decrease in EPCs. Hyperglycaemia might exert a direct effect on depletion of EPCs. PMID:21653675

  4. Phloretin promotes adipocyte differentiation in vitro and improves glucose homeostasis in vivo.

    PubMed

    Shu, Gang; Lu, Nai-Sheng; Zhu, Xiao-Tong; Xu, Yong; Du, Min-Qing; Xie, Qiu-Ping; Zhu, Can-Jun; Xu, Qi; Wang, Song-Bo; Wang, Li-Na; Gao, Ping; Xi, Qian-Yun; Zhang, Yong-Liang; Jiang, Qing-Yan

    2014-12-01

    Adipocyte dysfunction is associated with many metabolic diseases such as obesity, insulin resistance and diabetes. Previous studies found that phloretin promotes 3T3-L1 cells differentiation, but the underlying mechanisms for phloretin's effects on adipogenesis remain unclear. In this study, we demonstrated that phloretin enhanced the lipid accumulation in porcine primary adipocytes in a time-dependent manner. Furthermore, phloretin increased the utilization of glucose and nonesterified fatty acid, while it decreased the lactate output. Microarray analysis revealed that genes associated with peroxisome proliferator-activated receptor-γ (PPARγ), mitogen-activated protein kinase and insulin signaling pathways were altered in response to phloretin. We further confirmed that phloretin enhanced expression of PPARγ, CAAT enhancer binding protein-α (C/EBPα) and adipose-related genes, such as fatty acids translocase and fatty acid synthase. In addition, phloretin activated the Akt (Thr308) and extracellular signal-regulated kinase, and therefore, inactivated Akt targets protein. Wortmannin effectively blocked the effect of phloretin on Akt activity and the protein levels of PPARγ, C/EBPα and fatty acid binding protein-4 (FABP4/aP2). Oral administration of 5 or 10 mg/kg phloretin to C57BL BKS-DB mice significantly decreased the serum glucose level and improved glucose tolerance. In conclusion, phloretin promotes the adipogenesis of porcine primary preadipocytes through Akt-associated signaling pathway. These findings suggested that phloretin might be able to increase insulin sensitivity and alleviate the metabolic diseases. PMID:25283330

  5. Alteration of de novo glucose production contributes to fasting hypoglycaemia in Fyn deficient mice.

    PubMed

    Yang, Yingjuan; Tarabra, Elena; Yang, Gong-She; Vaitheesvaran, Bhavapriya; Palacios, Gustavo; Kurland, Irwin J; Pessin, Jeffrey E; Bastie, Claire C

    2013-01-01

    Previous studies have demonstrated that glucose disposal is increased in the Fyn knockout (FynKO) mice due to increased insulin sensitivity. FynKO mice also display fasting hypoglycaemia despite decreased insulin levels, which suggested that hepatic glucose production was unable to compensate for the increased basal glucose utilization. The present study investigates the basis for the reduction in plasma glucose levels and the reduced ability for the liver to produce glucose in response to gluconeogenic substrates. FynKO mice had a 5-fold reduction in phosphoenolpyruvate carboxykinase (PEPCK) gene and protein expression and a marked reduction in pyruvate, pyruvate/lactate-stimulated glucose output. Remarkably, de novo glucose production was also blunted using gluconeogenic substrates that bypass the PEPCK step. Impaired conversion of glycerol to glucose was observed in both glycerol tolerance test and determination of the conversion of (13)C-glycerol to glucose in the fasted state. α-glycerol phosphate levels were reduced but glycerol kinase protein expression levels were not changed. Fructose-driven glucose production was also diminished without alteration of fructokinase expression levels. The normal levels of dihydroxyacetone phosphate and glyceraldehyde-3-phosphate observed in the FynKO liver extracts suggested normal triose kinase function. Fructose-bisphosphate aldolase (aldolase) mRNA or protein levels were normal in the Fyn-deficient livers, however, there was a large reduction in liver fructose-6-phosphate (30-fold) and fructose-1,6-bisphosphate (7-fold) levels as well as a reduction in glucose-6-phosphate (2-fold) levels. These data suggest a mechanistic defect in the allosteric regulation of aldolase activity. PMID:24312371

  6. Apelin Controls Fetal and Neonatal Glucose Homeostasis and Is Altered by Maternal Undernutrition.

    PubMed

    Mayeur, Sylvain; Wattez, Jean-Sébastien; Lukaszewski, Marie-Amélie; Lecoutre, Simon; Butruille, Laura; Drougard, Anne; Eberlé, Delphine; Bastide, Bruno; Laborie, Christine; Storme, Laurent; Knauf, Claude; Vieau, Didier; Breton, Christophe; Lesage, Jean

    2016-03-01

    The adequate control of glucose homeostasis during both gestation and early postnatal life is crucial for the development of the fetoplacental unit and adaptive physiological responses at birth. Growing evidences indicate that apelin and its receptor, APJ, which are expressed across a wide range of tissues, exert important roles in glucose homeostasis in adults. However, little is known about the function of the apelinergic system during gestation. In this study, we evaluated the activity of this system in rats, the role of apelin in fetal and neonatal glucose homeostasis, and its modulation by maternal food restriction. We found that 1) the apelinergic system was expressed at the fetoplacental interface and in numerous fetal tissues, 2) ex vivo, the placenta released high amounts of apelin in late gestation, 3) intravenous apelin injection in mothers increased the transplacental transport of glucose, and 4) intraperitoneal apelin administration in neonates increased glucose uptake in lung and muscle. Maternal food restriction drastically reduced apelinemia in both mothers and growth-restricted fetuses and altered the expression of the apelinergic system at the fetoplacental interface. Together, our data demonstrate that apelin controls fetal and neonatal glucose homeostasis and is altered by fetal growth restriction induced by maternal undernutrition. PMID:26631739

  7. Chromium supplementation alters the glucose and lipid metabolism of feedlot cattle during the receiving period

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crossbreed steers (n = 20; 235 ± 4 kg) were fed 53 d during a receiving period to determine if supplementing chromium (Cr; KemTRACE®brand Chromium Propionate 0.04%, Kemin Industries) would alter the glucose or lipid metabolism of newly received cattle. Chromium premixes were supplemented to add 0 (C...

  8. Chromium supplementation alters both glucose and lipid metabolism in feedlot cattle during the receiving period

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crossbred steers (n = 20; 235 +/- 4 kg) were fed 53 days during a receiving period to determine if supplementing chromium (Cr; KemTRACE®brandChromium Propionate 0.04%, Kemin Industries) would alter the glucose or lipid metabolism of newly received cattle. Chromium premixes were supplemented to add 0...

  9. Striatal GABA receptor alterations in hypoxic neonatal rats: role of glucose, oxygen and epinephrine treatment.

    PubMed

    Anju, T R; Binoy, J; Anitha, M; Paulose, C S

    2012-03-01

    Hypoxia in neonates disrupts the oxygen flow to the brain, essentially starving the brain and preventing it from performing vital biochemical processes important for central nervous system development. Hypoxia results in a permanent brain damage by gene and receptor level alterations mediated through neurotransmitters. The present study evaluated GABA, GABAA, GABAB receptor functions and gene expression changes in glutamate decarboxylase in the corpus striatum of hypoxic neonatal rats and the treatment groups with glucose, oxygen and epinephrine. Since GABA is the principal neurotransmitter involved in hypoxic ventilatory decline, the alterations in its level under hypoxic stress points to an important aspect of respiratory control. Following hypoxic stress, a significant decrease in total GABA, GABAA and GABAB receptors function and GAD expression was observed in the striatum, which accounts for the ventilator decline. Hypoxic rats treated with glucose alone and with oxygen showed a reversal of the receptor alterations and changes in GAD to near control. Being a source of immediate energy, glucose can reduce the ATP-depletion-induced changes in GABA and oxygenation helps in overcoming reduction in oxygen supply. Treatment with oxygen alone and epinephrine was not effective in reversing the altered receptor functions. Thus, our study point to the functional role of GABA receptors in mediating ventilatory response to hypoxia and the neuroprotective role of glucose treatment. This has immense significance in the proper management of neonatal hypoxia for a better intellect in the later stages of life. PMID:22089934

  10. Alteration in plasma glucose levels in Japanese encephalitis patients.

    PubMed

    Tandon, Apurva; Singh, Aditi; Atrishi, Ekta; Saxena, S K; Mathur, Asha

    2002-02-01

    A unique factor, human T cell hypoglycaemic factor (hTCHF), has been shown to produce hypoglycaemia during the convalescent stage in the plasma of patients with Japanese encephalitis virus (JEV) infection. The present study was undertaken to investigate the ability of T cells from fresh peripheral blood mononuclear cells (PBMC) of such patients to produce hTCHF. The PBMC, as well as the individual subpopulations, were cultured for 24 h and the culture supernatants (CS) were assayed for hypoglycaemic activity. The activity was observed in the CD8+ T cells. The hypoglycaemia in JE-confirmed patients coincided with the gradual rise in circulating glucagon level, with no significant alterations in insulin, growth hormone and cortisol levels. The hTCHF was purified by ion exchange chromatography and the purified protein was observed as a approximately 25 kDa band on SDS-PAGE. Secretory hTCHF in the sera of patients and T cell CS was present in 88% of convalescent serum samples. We conclude that during the convalescent stage of JEV infection, a unique factor, hTCHF, is secreted by activated CD8+ T cells from patients and that this is responsible for the development of hypoglycaemia. PMID:12059908

  11. Low glucose level and low pH alter the electrochemical function of human parietal pleura.

    PubMed

    Kouritas, V K; Hatzoglou, C; Foroulis, C N; Hevas, A; Gourgoulianis, K I; Molyvdas, P A

    2007-08-01

    The aim of the present study was to investigate whether low glucose and pH level, which are usually measured in complicated pleural effusions, alter the electrochemical function of healthy human parietal pleura. Parietal pleural pieces were stripped from 66 patients during thoracic surgery and were mounted in Ussing chambers. Krebs' solutions containing different glucose levels (0, 40 and 100 mg) and balanced at different pH levels (7.4, 7.3 and 7.2) were added to the pleural cavity surface of the pieces. Transmesothelial potential difference was measured at various time-points as an electrophysiological variable and transmesothelial resistance (R(TM)) was calculated using Ohm's law. When normal-glucose Krebs at pH 7.45 was used, R(TM) remained unchanged over time, but when low-glucose Krebs was used, R(TM) decreased. Krebs without glucose caused the greatest decrease in R(TM). Use of low-pH Krebs decreased R(TM). The lower the pH of the Krebs, the faster the decrease in R(TM) and the greater the effect. The decrease in R(TM) was greater with low-pH than with low-glucose Krebs. Low glucose and low pH caused an additive decrease in R(TM). Low glucose concentration and low pH cause alteration of the electrochemical function of human parietal pleura and could act as agents that lead to further exudate progression. PMID:17666558

  12. METHYLMERCURY IMPAIRS NEURONAL DIFFERENTIATION BY ALTERING NEUROTROPHIN SIGNALING.

    EPA Science Inventory

    In previous in vivo studies, we observed that developmental exposure to CH3Hg can alter neocortical morphology and neurotrophin signaling. Using primed PC12 cells as a model system for neuronal differentiation, we examined the hypothesis that the developmental effects of CH3Hg ma...

  13. Experimental type II diabetes and related models of impaired glucose metabolism differentially regulate glucose transporters at the proximal tubule brush border membrane.

    PubMed

    Chichger, Havovi; Cleasby, Mark E; Srai, Surjit K; Unwin, Robert J; Debnam, Edward S; Marks, Joanne

    2016-06-01

    What is the central question of this study? Although SGLT2 inhibitors represent a promising treatment for patients suffering from diabetic nephropathy, the influence of metabolic disruption on the expression and function of glucose transporters is largely unknown. What is the main finding and its importance? In vivo models of metabolic disruption (Goto-Kakizaki type II diabetic rat and junk-food diet) demonstrate increased expression of SGLT1, SGLT2 and GLUT2 in the proximal tubule brush border. In the type II diabetic model, this is accompanied by increased SGLT- and GLUT-mediated glucose uptake. A fasted model of metabolic disruption (high-fat diet) demonstrated increased GLUT2 expression only. The differential alterations of glucose transporters in response to varying metabolic stress offer insight into the therapeutic value of inhibitors. SGLT2 inhibitors are now in clinical use to reduce hyperglycaemia in type II diabetes. However, renal glucose reabsorption across the brush border membrane (BBM) is not completely understood in diabetes. Increased consumption of a Western diet is strongly linked to type II diabetes. This study aimed to investigate the adaptations that occur in renal glucose transporters in response to experimental models of diet-induced insulin resistance. The study used Goto-Kakizaki type II diabetic rats and normal rats rendered insulin resistant using junk-food or high-fat diets. Levels of protein kinase C-βI (PKC-βI), GLUT2, SGLT1 and SGLT2 were determined by Western blotting of purified renal BBM. GLUT- and SGLT-mediated d-[(3) H]glucose uptake by BBM vesicles was measured in the presence and absence of the SGLT inhibitor phlorizin. GLUT- and SGLT-mediated glucose transport was elevated in type II diabetic rats, accompanied by increased expression of GLUT2, its upstream regulator PKC-βI and SGLT1 protein. Junk-food and high-fat diet feeding also caused higher membrane expression of GLUT2 and its upstream regulator PKC

  14. Ethanol induced impairment of glucose metabolism involves alterations of GABAergic signaling in pancreatic β-cells.

    PubMed

    Wang, Shuanglian; Luo, Yan; Feng, Allen; Li, Tao; Yang, Xupeng; Nofech-Mozes, Roy; Yu, Meng; Wang, Changhui; Li, Ziwei; Yi, Fan; Liu, Chuanyong; Lu, Wei-Yang

    2014-12-01

    Alcohol overindulgence is a risk factor of type 2 diabetes mellitus. However, the mechanisms by which alcohol overindulgence damages glucose metabolism remain unclear. Pancreatic islet β-cells are endowed with type-A γ-aminobutyric acid receptor (GABAAR) mediated autocrine signaling mechanism, which regulates insulin secretion and fine-tunes glucose metabolism. In neurons GABAAR is one of the major targets for alcohol. This study investigated whether ethanol alters glucose metabolism by affecting GABAAR signaling in pancreatic β-cells. Blood glucose level of test mice was measured using a blood glucose meter. Insulin secretion by the pancreatic β-cell line INS-1 cells was examined using a specific insulin ELISA kit. Whole-cell patch-clamp recording was used to evaluate GABA-elicited current in INS-1 cells. Western blot and immunostaining were used to measure the expression of GABAAR subunits in mouse pancreatic tissues or in INS-1 cells. Intraperitoneal (i.p.) administration of ethanol (3.0g/kg body weight) to mice altered glucose metabolism, which was associated with decreased expression of GABAAR α1- and δ- subunits on the surface of pancreatic β-cells. Acute treatment of cultured INS-1cells with ethanol (60mM) decreased the GABA-induced current and reduced insulin secretion. In contrast, treating INS-1 cells with GABA (100μM) largely prevented the ethanol-induced reduction of insulin release. Importantly, pre-treating mice with GABA (i.p., 1.5mg/kg body weight) partially reversed ethanol-induced impairment of glucose homeostasis in mice. Our data suggest a novel role of pancreatic GABA signaling in protecting pancreatic islet β-cells from ethanol-induced dysfunction. PMID:25456265

  15. Glucose metabolism during fasting is altered in experimental porphobilinogen deaminase deficiency.

    PubMed

    Collantes, María; Serrano-Mendioroz, Irantzu; Benito, Marina; Molinet-Dronda, Francisco; Delgado, Mercedes; Vinaixa, María; Sampedro, Ana; Enríquez de Salamanca, Rafael; Prieto, Elena; Pozo, Miguel A; Peñuelas, Iván; Corrales, Fernando J; Barajas, Miguel; Fontanellas, Antonio

    2016-04-01

    Porphobilinogen deaminase (PBGD) haploinsufficiency (acute intermittent porphyria, AIP) is characterized by neurovisceral attacks when hepatic heme synthesis is activated by endogenous or environmental factors including fasting. While the molecular mechanisms underlying the nutritional regulation of hepatic heme synthesis have been described, glucose homeostasis during fasting is poorly understood in porphyria. Our study aimed to analyse glucose homeostasis and hepatic carbohydrate metabolism during fasting in PBGD-deficient mice. To determine the contribution of hepatic PBGD deficiency to carbohydrate metabolism, AIP mice injected with a PBGD-liver gene delivery vector were included. After a 14 h fasting period, serum and liver metabolomics analyses showed that wild-type mice stimulated hepatic glycogen degradation to maintain glucose homeostasis while AIP livers activated gluconeogenesis and ketogenesis due to their inability to use stored glycogen. The serum of fasted AIP mice showed increased concentrations of insulin and reduced glucagon levels. Specific over-expression of the PBGD protein in the liver tended to normalize circulating insulin and glucagon levels, stimulated hepatic glycogen catabolism and blocked ketone body production. Reduced glucose uptake was observed in the primary somatosensorial brain cortex of fasted AIP mice, which could be reversed by PBGD-liver gene delivery. In conclusion, AIP mice showed a different response to fasting as measured by altered carbohydrate metabolism in the liver and modified glucose consumption in the brain cortex. Glucose homeostasis in fasted AIP mice was efficiently normalized after restoration of PBGD gene expression in the liver. PMID:26908609

  16. Altered insulin response to glucose in weight-losing cancer patients.

    PubMed

    Rofe, A M; Bourgeois, C S; Coyle, P; Taylor, A; Abdi, E A

    1994-01-01

    Cancer cachexia and the underlying metabolic disturbances are due in part to either altered insulin release and action. Glucose intolerance in cancer patients is frequently observed but the nature of the insulin response is not usually described. The aim of this study was to investigate the insulin response in fasted, weigh-losing cancer patients following an oral glucose load (75 g). All cancer patients (n = 35) showed glucose intolerance. Three types of response were identified; those with an increased insulin: glucose ratio (I:G) at 60 min, (average 12.3, n = 13), those with a normal I:G (average 7.2 n = 7) and those with a decrease I:G (average 4.2, n = 15). Fasting plasma glucose concentrations were normal in all groups prior to the glucose tolerance test. However, patients with the lowest I:G also had the lowest fasting plasma insulin concentrations, the lowest plasma albumin concentrations and the highest plasma triglyceride concentrations. Those patients with an abnormal insulin response (either high or low I:G) had significantly greater weight loss (16% for low I:G group, 13% for the high I:G) compared to the normal responders (8%). Plasma fatty acid concentrations were increased in all cancer patients and decreased appropriately after glucose administration, indicating that lipolysis remained sensitive to the action of insulin. It is concluded that weight loss in cancer is associated with glucose intolerance and an abnormal insulin response, and that this response is indicative of either insulin resistance (high I:G) or decreased pancreatic function (low I:G). These findings suggest a role for insulin replacement therapy in the latter group of patients. PMID:8010722

  17. Continuous Monitoring of Glucose in Subcutaneous Tissue Using Microfabricated Differential Affinity Sensors

    PubMed Central

    Huang, Xian; Leduc, Charles; Ravussin, Yann; Li, Siqi; Davis, Erin; Song, Bing; Wang, Qian; Accili, Domenico; Leibel, Rudolph; Lin, Qiao

    2012-01-01

    Objective We describe miniaturized differential glucose sensors based on affinity binding between glucose and a synthetic polymer. The sensors possess excellent resistance to environmental disturbances and can potentially allow wireless measurements of glucose concentrations within interstitial fluid in subcutaneous tissue for long-term, stable continuous glucose monitoring (CGM). Methods The sensors are constructed using microelectromechanical systems (MEMS) technology and exploit poly(N-hydroxy-ethyl acrylamide-ran-3-acrylamidophenylboronic acid) (PHEAA-ran-PAAPBA), a glucose-binding polymer with excellent specificity, reversibility, and stability. Two sensing approaches have been investigated, which respectively, use a pair of magnetically actuated diaphragms and perforated electrodes to differentially measure the glucose-binding-induced changes in the viscosity and permittivity of the PHEAA-ran-PAAPBA solution with respect to a reference, glucose-unresponsive polymer solution. Results In vivo characterization of the MEMS affinity sensors were performed by controlling blood glucose concentrations of laboratory mice by exogenous glucose and insulin administration. The sensors experienced an 8–30 min initialization period after implantation and then closely tracked commercial capillary glucose meter readings with time lags ranging from 0–15 min during rapid glucose concentration changes. Clarke error grid plots obtained from sensor calibration suggest that, for the viscometric and dielectric sensors, respectively, approximately 95% (in the hyperglycemic range) and 84% (ranging from hypoglycemic to hyperglycemic glucose concentrations) of measurement points were clinically accurate, while 5% and 16% of the points were clinically acceptable. Conclusions The miniaturized MEMS sensors explore differential measurements of affinity glucose recognition. In vivo testing demonstrated excellent accuracy and stability, suggesting that the devices hold the potential to

  18. Population differentiation in Daphnia alters community assembly in experimental ponds.

    PubMed

    Pantel, Jelena H; Leibold, Mathew A; Juenger, Thomas E

    2011-03-01

    Most studies of community assembly ignore how genetic differentiation within species affects their colonization and extinction. However, genetic differentiation in ecologically relevant traits may be substantial enough to alter the colonization and extinction processes that drive community assembly. We measured significant molecular genetic and quantitative trait differentiation among three Daphnia pulex × pulicaria populations in southwestern Michigan ponds and investigated whether this differentiation could alter the assembly of pond zooplankton communities in experimental mesocosms. In this study, we monitored the invasion success of different D. pulex × pulicaria populations after their introduction into an established zooplankton community. We also monitored the invasion success of a diverse array of zooplankton species into different D. pulex × pulicaria populations. Zooplankton community composition depended on the D. pulex × pulicaria source population. Daphnia pulex × pulicaria from one population failed to invade zooplankton communities, while those from other populations successfully invaded similar communities. If population differentiation in other species plays a role in community assembly similar to that demonstrated in our study, assembly may be more sensitive to evolutionary processes than has been previously generally considered. PMID:21460540

  19. Increased maternal nighttime cortisol concentrations in late gestation alter glucose and insulin in the neonatal lamb

    PubMed Central

    Antolic, Andrew; Feng, Xiaodi; Wood, Charles E; Richards, Elaine M; Keller-Wood, Maureen

    2015-01-01

    Previous studies in our laboratory have shown that a modest chronic increase in maternal cortisol concentrations impairs maternal glucose metabolism and increases the incidence of perinatal stillbirth. The dramatic outcomes prevented our ability to study the effects of maternal hypercortisolemia on neonatal growth, glucose metabolism, and hypothalamo–pituitary–adrenal axis response. Therefore, we developed a model in which pregnant ewes are infused for 12 h/day at 0.5 mg·kg–1·day–1 from day 115 of gestation until delivery (˜145), elevating nighttime plasma cortisol concentrations. This pattern of elevation of cortisol mimics that in patients with elevated evening cortisol concentrations, as in Cushing’s syndrome or chronic depression. Plasma cortisol, glucose, insulin, and electrolytes were measured during pregnancy and postpartum in control and cortisol-infused ewes and their postnatal lambs for the first 14 days after delivery. Neonatal growth and plasma ACTH, aldosterone, renin activity, and electrolytes, and organ weights at 14 days of age were also measured. Infusion of cortisol increased maternal plasma cortisol during pregnancy but not postpartum, and did not alter neonatal ACTH or cortisol. Although maternal glucose and insulin concentrations were not changed by the maternal infusion of cortisol, neonatal plasma glucose was increased and plasma insulin was decreased compared to those in the control group. Neonatal ponderal index and kidney weight were reduced, left ventricular wall thickness was increased, and plasma sodium and creatinine were increased after maternal cortisol infusion. These results suggest that excess maternal cortisol concentrations in late gestation alter growth, glucose and insulin regulation, and organ maturation in the neonate. PMID:26371232

  20. Corticosterone alters materno-fetal glucose partitioning and insulin signalling in pregnant mice.

    PubMed

    Vaughan, O R; Fisher, H M; Dionelis, K N; Jefferies, E C; Higgins, J S; Musial, B; Sferruzzi-Perri, A N; Fowden, A L

    2015-03-01

    Glucocorticoids affect glucose metabolism in adults and fetuses, although their effects on materno-fetal glucose partitioning remain unknown. The present study measured maternal hepatic glucose handling and placental glucose transport together with insulin signalling in these tissues in mice drinking corticosterone either from day (D) 11 to D16 or D14 to D19 of pregnancy (term = D21). On the final day of administration, corticosterone-treated mice were hyperinsulinaemic (P < 0.05) but normoglycaemic compared to untreated controls. In maternal liver, there was no change in glycogen content or glucose 6-phosphatase activity but increased Slc2a2 glucose transporter expression in corticosterone-treated mice, on D16 only (P < 0.05). On D19, but not D16, transplacental (3) H-methyl-d-glucose clearance was reduced by 33% in corticosterone-treated dams (P < 0.05). However, when corticosterone-treated animals were pair-fed to control intake, aiming to prevent the corticosterone-induced increase in food consumption, (3) H-methyl-d-glucose clearance was similar to the controls. Depending upon gestational age, corticosterone treatment increased phosphorylation of the insulin-signalling proteins, protein kinase B (Akt) and glycogen synthase-kinase 3β, in maternal liver (P < 0.05) but not placenta (P > 0.05). Insulin receptor and insulin-like growth factor type I receptor abundance did not differ with treatment in either tissue. Corticosterone upregulated the stress-inducible mechanistic target of rapamycin (mTOR) suppressor, Redd1, in liver (D16 and D19) and placenta (D19), in ad libitum fed animals (P < 0.05). Concomitantly, hepatic protein content and placental weight were reduced on D19 (P < 0.05), in association with altered abundance and/or phosphorylation of signalling proteins downstream of mTOR. Taken together, the data indicate that maternal glucocorticoid excess reduces fetal growth partially by altering placental glucose transport and mTOR signalling. PMID:25625347

  1. Alterations of hippocampal glucose metabolism by even versus uneven medium chain triglycerides

    PubMed Central

    McDonald, Tanya S; Tan, Kah Ni; Hodson, Mark P; Borges, Karin

    2014-01-01

    Medium chain triglycerides (MCTs) are used to treat neurologic disorders with metabolic impairments, including childhood epilepsy and early Alzheimer's disease. However, the metabolic effects of MCTs in the brain are still unclear. Here, we studied the effects of feeding even and uneven MCTs on brain glucose metabolism in the mouse. Adult mice were fed 35% (calories) of trioctanoin or triheptanoin (the triglycerides of octanoate or heptanoate, respectively) or a matching control diet for 3 weeks. Enzymatic assays and targeted metabolomics by liquid chromatography tandem mass spectrometry were used to quantify metabolites in extracts from the hippocampal formations (HFs). Both oils increased the levels of β-hydroxybutyrate, but no other significant metabolic alterations were observed after triheptanoin feeding. The levels of glucose 6-phosphate and fructose 6-phosphate were increased in the HF of mice fed trioctanoin, whereas levels of metabolites further downstream in the glycolytic pathway and the pentose phosphate pathway were reduced. This indicates that trioctanoin reduces glucose utilization because of a decrease in phosphofructokinase activity. Trioctanoin and triheptanoin showed similar anticonvulsant effects in the 6 Hz seizure model, but it remains unknown to what extent the anticonvulsant mechanism(s) are shared. In conclusion, triheptanoin unlike trioctanoin appears to not alter glucose metabolism in the healthy brain. PMID:24169853

  2. Modification of collagen IV by glucose or methylglyoxal alters distinct mesangial cell functions.

    PubMed

    Pozzi, Ambra; Zent, Roy; Chetyrkin, Sergei; Borza, Corina; Bulus, Nada; Chuang, Peale; Chen, Dong; Hudson, Billy; Voziyan, Paul

    2009-10-01

    Diabetic nephropathy (DN) affects both glomerular cells and the extracellular matrix (ECM), yet the pathogenic mechanisms involving cell-matrix interactions are poorly understood. Glycation alters integrin-dependent cell-ECM interactions, and perturbation of these interactions results in severe renal pathology in diabetic animals. Here, we investigated how chemical modifications of the ECM by hyperglycemia and carbonyl stress, two major features of the diabetic milieu, affect mesangial cell functions. Incubation of collagen IV with pathophysiological levels of either the carbonyl compound methylglyoxal (MGO) or glucose resulted in modification of arginine or lysine residues, respectively. Mouse mesangial cells plated on MGO-modified collagen IV showed decreased adhesion and migration. Cells plated on glucose-modified collagen IV showed reduced proliferation and migration and increased collagen IV production. Inhibiting glucose-mediated oxidative modification of collagen IV lysine residues rescued the alterations in cell growth, migration, and collagen synthesis. We propose that diabetic ECM affects mesangial cell functions via two distinct mechanisms: modification of arginine residues by MGO inhibits cell adhesion, whereas oxidative modification of lysine residues by glucose inhibits cell proliferation and increases collagen IV production. These mechanisms may contribute to mesangial cell hypertrophy and matrix expansion in DN. PMID:19608705

  3. Modification of Collagen IV by Glucose or Methylglyoxal Alters Distinct Mesangial Cell Functions

    PubMed Central

    Pozzi, Ambra; Zent, Roy; Chetyrkin, Sergei; Borza, Corina; Bulus, Nada; Chuang, Peale; Chen, Dong; Hudson, Billy

    2009-01-01

    Diabetic nephropathy (DN) affects both glomerular cells and the extracellular matrix (ECM), yet the pathogenic mechanisms involving cell-matrix interactions are poorly understood. Glycation alters integrin-dependent cell-ECM interactions, and perturbation of these interactions results in severe renal pathology in diabetic animals. Here, we investigated how chemical modifications of the ECM by hyperglycemia and carbonyl stress, two major features of the diabetic milieu, affect mesangial cell functions. Incubation of collagen IV with pathophysiological levels of either the carbonyl compound methylglyoxal (MGO) or glucose resulted in modification of arginine or lysine residues, respectively. Mouse mesangial cells plated on MGO-modified collagen IV showed decreased adhesion and migration. Cells plated on glucose-modified collagen IV showed reduced proliferation and migration and increased collagen IV production. Inhibiting glucose-mediated oxidative modification of collagen IV lysine residues rescued the alterations in cell growth, migration, and collagen synthesis. We propose that diabetic ECM affects mesangial cell functions via two distinct mechanisms: modification of arginine residues by MGO inhibits cell adhesion, whereas oxidative modification of lysine residues by glucose inhibits cell proliferation and increases collagen IV production. These mechanisms may contribute to mesangial cell hypertrophy and matrix expansion in DN. PMID:19608705

  4. Alterations of hippocampal glucose metabolism by even versus uneven medium chain triglycerides.

    PubMed

    McDonald, Tanya S; Tan, Kah Ni; Hodson, Mark P; Borges, Karin

    2014-01-01

    Medium chain triglycerides (MCTs) are used to treat neurologic disorders with metabolic impairments, including childhood epilepsy and early Alzheimer's disease. However, the metabolic effects of MCTs in the brain are still unclear. Here, we studied the effects of feeding even and uneven MCTs on brain glucose metabolism in the mouse. Adult mice were fed 35% (calories) of trioctanoin or triheptanoin (the triglycerides of octanoate or heptanoate, respectively) or a matching control diet for 3 weeks. Enzymatic assays and targeted metabolomics by liquid chromatography tandem mass spectrometry were used to quantify metabolites in extracts from the hippocampal formations (HFs). Both oils increased the levels of β-hydroxybutyrate, but no other significant metabolic alterations were observed after triheptanoin feeding. The levels of glucose 6-phosphate and fructose 6-phosphate were increased in the HF of mice fed trioctanoin, whereas levels of metabolites further downstream in the glycolytic pathway and the pentose phosphate pathway were reduced. This indicates that trioctanoin reduces glucose utilization because of a decrease in phosphofructokinase activity. Trioctanoin and triheptanoin showed similar anticonvulsant effects in the 6 Hz seizure model, but it remains unknown to what extent the anticonvulsant mechanism(s) are shared. In conclusion, triheptanoin unlike trioctanoin appears to not alter glucose metabolism in the healthy brain. PMID:24169853

  5. Corticosterone alters materno-fetal glucose partitioning and insulin signalling in pregnant mice

    PubMed Central

    Vaughan, O R; Fisher, H M; Dionelis, K N; Jefferies, E C; Higgins, J S; Musial, B; Sferruzzi-Perri, A N; Fowden, A L

    2015-01-01

    Glucocorticoids affect glucose metabolism in adults and fetuses, although their effects on materno-fetal glucose partitioning remain unknown. The present study measured maternal hepatic glucose handling and placental glucose transport together with insulin signalling in these tissues in mice drinking corticosterone either from day (D) 11 to D16 or D14 to D19 of pregnancy (term = D21). On the final day of administration, corticosterone-treated mice were hyperinsulinaemic (P < 0.05) but normoglycaemic compared to untreated controls. In maternal liver, there was no change in glycogen content or glucose 6-phosphatase activity but increased Slc2a2 glucose transporter expression in corticosterone-treated mice, on D16 only (P < 0.05). On D19, but not D16, transplacental 3H-methyl-d-glucose clearance was reduced by 33% in corticosterone-treated dams (P < 0.05). However, when corticosterone-treated animals were pair-fed to control intake, aiming to prevent the corticosterone-induced increase in food consumption, 3H-methyl-d-glucose clearance was similar to the controls. Depending upon gestational age, corticosterone treatment increased phosphorylation of the insulin-signalling proteins, protein kinase B (Akt) and glycogen synthase-kinase 3β, in maternal liver (P < 0.05) but not placenta (P > 0.05). Insulin receptor and insulin-like growth factor type I receptor abundance did not differ with treatment in either tissue. Corticosterone upregulated the stress-inducible mechanistic target of rapamycin (mTOR) suppressor, Redd1, in liver (D16 and D19) and placenta (D19), in ad libitum fed animals (P < 0.05). Concomitantly, hepatic protein content and placental weight were reduced on D19 (P < 0.05), in association with altered abundance and/or phosphorylation of signalling proteins downstream of mTOR. Taken together, the data indicate that maternal glucocorticoid excess reduces fetal growth partially by altering placental glucose transport and mTOR signalling. Key

  6. Altered Skeletal Muscle Fatty Acid Handling in Subjects with Impaired Glucose Tolerance as Compared to Impaired Fasting Glucose.

    PubMed

    Goossens, Gijs H; Moors, Chantalle C M; Jocken, Johan W E; van der Zijl, Nynke J; Jans, Anneke; Konings, Ellen; Diamant, Michaela; Blaak, Ellen E

    2016-03-01

    Altered skeletal muscle fatty acid (FA) metabolism contributes to insulin resistance. Here, we compared skeletal muscle FA handling between subjects with impaired fasting glucose (IFG; n = 12 (7 males)) and impaired glucose tolerance (IGT; n = 14 (7 males)) by measuring arterio-venous concentration differences across forearm muscle. [²H₂]-palmitate was infused intravenously, labeling circulating endogenous triacylglycerol (TAG) and free fatty acids (FFA), whereas [U-(13)C]-palmitate was incorporated in a high-fat mixed-meal, labeling chylomicron-TAG. Skeletal muscle biopsies were taken to determine muscle TAG, diacylglycerol (DAG), FFA, and phospholipid content, their fractional synthetic rate (FSR) and degree of saturation, and gene expression. Insulin sensitivity was assessed using a hyperinsulinemic-euglycemic clamp. Net skeletal muscle glucose uptake was lower (p = 0.018) and peripheral insulin sensitivity tended to be reduced (p = 0.064) in IGT as compared to IFG subjects. Furthermore, IGT showed higher skeletal muscle extraction of VLDL-TAG (p = 0.043), higher muscle TAG content (p = 0.025), higher saturation of FFA (p = 0.004), lower saturation of TAG (p = 0.017) and a tendency towards a lower TAG FSR (p = 0.073) and a lower saturation of DAG (p = 0.059) versus IFG individuals. Muscle oxidative gene expression was lower in IGT subjects. In conclusion, increased liver-derived TAG extraction and reduced lipid turnover of saturated FA, rather than DAG content, in skeletal muscle accompany the more pronounced insulin resistance in IGT versus IFG subjects. PMID:26985905

  7. Polychlorinated biphenyl 126 exposure in L6 myotubes alters glucose metabolism: a pilot study.

    PubMed

    Mauger, Jean-François; Nadeau, Lucien; Caron, Audrey; Chapados, Natalie Ann; Aguer, Céline

    2016-04-01

    Polychlorinated biphenyls (PCBs) are increasingly recognized as metabolic disruptors. Due to its mass, skeletal muscle is the major site of glucose disposal. While muscle mitochondrial dysfunction and oxidative stress have been shown to play a central role in metabolic disease development, no studies to date have investigated the effect of PCB exposure on muscle energy metabolism and oxidative stress. In this pilot study, we tested the effect of exposure to PCB126 in L6 myotubes (from 1 to 2500 nM for 24 h) on mitochondrial function, glucose metabolism, and oxidative stress. Exposure to PCB126 had no apparent effect on resting, maximal, and proton leak-dependent oxygen consumption rate in intact L6 myotubes. However, basal glucose uptake and glycolysis were inhibited by 20-30 % in L6 myotubes exposed to PCB126. Exposure to PCB126 did not appear to alter skeletal muscle anti-oxidant defense or oxidative stress. In conclusion, our study shows for the first time that exposure to a dioxin-like PCB adversely affects skeletal muscle glucose metabolism. Given the importance of skeletal muscle in the maintenance of glucose homeostasis, PCB126 could play an important role in the development of metabolic disorders. PMID:26936477

  8. Restraint Stress Impairs Glucose Homeostasis Through Altered Insulin Signalling in Sprague-Dawley Rat.

    PubMed

    Morakinyo, Ayodele O; Ajiboye, Kolawole I; Oludare, Gabriel O; Samuel, Titilola A

    2016-01-01

    The study investigated the potential alteration in the level of insulin and adiponectin, as well as the expression of insulin receptors (INSR) and glucose transporter 4 GLUT-4 in chronic restraint stress rats. Sprague-Dawley rats were randomly divided into two groups: the control group and stress group in which the rats were exposed to one of the four different restraint stressors; 1 h, twice daily for a period of 7 days (S7D), 14 days (S14D) and 28 days (S28D). Glucose tolerance and insulin sensitivity were evaluated following the final stress exposure. ELISA were performed to assess the level of insulin and adiponectin as well as expression of INSR and GLUT4 protein in skeletal muscle. Plasma corticosterone level was also determined as a marker of stress exposure. Restraint stress for 7 days caused transient glucose intolerance, while S14D rats demonstrated increased glucose intolerance and insulin insensitivity. However, restraint stress for 28 days had no effect on glucose tolerance, but did cause an increase in glucose response to insulin challenge. The serum level of adiponectin was significantly (p< 0.05) lower compared with the control value while insulin remained unchanged except at in S28D rats that had a significant (p<0.05) increase. The expression of INSR and GLUT4 receptors were significantly (p< 0.05) decreased in the skeletal muscle of restraint stress exposed rats. There was a significant (p< 0.05) increase in the plasma corticosterone level of the stress rats compared with their control counterparts. Restraint stress caused glucose intolerance and insulin insensitivity in male Sprague-Dawley rats, which becomes accommodated with prolonged exposure and was likely related to the blunted insulin signalling in skeletal muscle. PMID:27574760

  9. Wavelength-modulated differential photothermal radiometry: theory and experimental applications to glucose detection in water.

    PubMed

    Mandelis, Andreas; Guo, Xinxin

    2011-10-01

    A differential photothermal radiometry method, wavelength-modulated differential photothermal radiometry (WM-DPTR), has been developed theoretically and experimentally for noninvasive, noncontact biological analyte detection, such as blood glucose monitoring. WM-DPTR features analyte specificity and sensitivity by combining laser excitation by two out-of-phase modulated beams at wavelengths near the peak and the base line of a prominent and isolated mid-IR analyte absorption band (here the carbon-oxygen-carbon bond in the pyran ring of the glucose molecule). A theoretical photothermal model of WM-DPTR signal generation and detection has been developed. Simulation results on water-glucose phantoms with the human blood range (0-300 mg/dl) glucose concentration demonstrated high sensitivity and resolution to meet wide clinical detection requirements. The model has also been validated by experimental data of the glucose-water system obtained using WM-DPTR. PMID:22181185

  10. Wavelength-modulated differential photothermal radiometry: Theory and experimental applications to glucose detection in water

    NASA Astrophysics Data System (ADS)

    Mandelis, Andreas; Guo, Xinxin

    2011-10-01

    A differential photothermal radiometry method, wavelength-modulated differential photothermal radiometry (WM-DPTR), has been developed theoretically and experimentally for noninvasive, noncontact biological analyte detection, such as blood glucose monitoring. WM-DPTR features analyte specificity and sensitivity by combining laser excitation by two out-of-phase modulated beams at wavelengths near the peak and the base line of a prominent and isolated mid-IR analyte absorption band (here the carbon-oxygen-carbon bond in the pyran ring of the glucose molecule). A theoretical photothermal model of WM-DPTR signal generation and detection has been developed. Simulation results on water-glucose phantoms with the human blood range (0-300 mg/dl) glucose concentration demonstrated high sensitivity and resolution to meet wide clinical detection requirements. The model has also been validated by experimental data of the glucose-water system obtained using WM-DPTR.

  11. High glucose induces adipogenic differentiation of muscle-derived stem cells

    PubMed Central

    Aguiari, Paola; Leo, Sara; Zavan, Barbara; Vindigni, Vincenzo; Rimessi, Alessandro; Bianchi, Katiuscia; Franzin, Chiara; Cortivo, Roberta; Rossato, Marco; Vettor, Roberto; Abatangelo, Giovanni; Pozzan, Tullio; Pinton, Paolo; Rizzuto, Rosario

    2008-01-01

    Regeneration of mesenchymal tissues depends on a resident stem cell population, that in most cases remains elusive in terms of cellular identity and differentiation signals. We here show that primary cell cultures derived from adipose tissue or skeletal muscle differentiate into adipocytes when cultured in high glucose. High glucose induces ROS production and PKCβ activation. These two events appear crucial steps in this differentiation process that can be directly induced by oxidizing agents and inhibited by PKCβ siRNA silencing. The differentiated adipocytes, when implanted in vivo, form viable and vascularized adipose tissue. Overall, the data highlight a previously uncharacterized differentiation route triggered by high glucose that drives not only resident stem cells of the adipose tissue but also uncommitted precursors present in muscle cells to form adipose depots. This process may represent a feed-forward cycle between the regional increase in adiposity and insulin resistance that plays a key role in the pathogenesis of diabetes mellitus. PMID:18212116

  12. Non-invasive Glucose Measurements Using Wavelength Modulated Differential Photothermal Radiometry (WM-DPTR)

    NASA Astrophysics Data System (ADS)

    Guo, X.; Mandelis, A.; Zinman, B.

    2012-11-01

    Wavelength-modulated differential laser photothermal radiometry (WM-DPTR) is introduced for potential development of clinically viable non-invasive glucose biosensors. WM-DPTR features unprecedented glucose-specificity and sensitivity by combining laser excitation by two out-of-phase modulated beams at wavelengths near the peak and the baseline of a prominent and isolated mid-IR glucose absorption band. Measurements on water-glucose phantoms (0 to 300 mg/dl glucose concentration) demonstrate high sensitivity to meet wide clinical detection requirements ranging from hypoglycemia to hyperglycemia. The measurement results have been validated by simulations based on fully developed WM-DPTR theory. For sensitive and accurate glucose measurements, the key is the selection and tight control of the intensity ratio and the phase shift of the two laser beams.

  13. Wavelength-modulated differential laser photothermal radiometry for blood glucose measurements

    NASA Astrophysics Data System (ADS)

    Guo, X.; Mandelis, A.; Matvienko, A.; Sivagurunathan, K.; Zinman, B.

    2010-03-01

    A Wavelength-Modulated Differential Laser Photothermal Radiometer (WM-DPTR) technique was used for non-invasive blood glucose monitoring in the mid-IR range, where the prominent absorption peak is glucose specific and isolated from other interfering peaks in human blood. The WM-DPTR method consists of the out-of-phase modulated excitation at two discrete wavelengths 9.5 μm and 10.4 μm (near the peak and the baseline of glucose absorption), generated from two quantum cascade lasers (QCL) and the differential emission detection through a thermal-wave upconversion process via a HgCdZnTe (MCZT) detector (2-5 μm). The differential method suppresses the background signal and reduces source-detection interference, thus enhancing glucose detection sensitivity. The results from aqueous glucose phantom (0-440 mg/dl) measurements demonstrate that both amplitude and phase of the WM-DPTR signal can be used for glucose detection. The dynamic range and the sensitivity of the glucose detection are influenced greatly by the laser intensity ratio and modulation frequency. The optimal intensity ratio for high sensitivity is ~1. Other laser intensity ratios increase dynamic range but reduce sensitivity. Sensitivity increases with frequency.

  14. High glucose-induced proteome alterations in hepatocytes and its possible relevance to diabetic liver disease.

    PubMed

    Chen, Jing-Yi; Chou, Hsiu-Chuan; Chen, You-Hsuan; Chan, Hong-Lin

    2013-11-01

    Hyperglycemia can cause several abnormalities in liver cells, including diabetic liver disease. Previous research has shown that high blood glucose levels can damage liver cells through glycoxidation. However, the detailed molecular mechanisms underlying the effects of high blood glucose on the development of diabetic liver disease have yet to be elucidated. In this study, we cultured a liver cell line (Chang liver cell) in mannitol-balanced 5.5 mM, 25 mM and 100 mM d-glucose media and evaluated protein expression and redox regulation. We identified 141 proteins that showed significant changes in protein expression and 29 proteins that showed significant changes in thiol reactivity, in response to high glucose concentration. Several proteins involved in transcription-control, signal transduction, redox regulation and cytoskeleton regulation showed significant changes in expression, whereas proteins involved in protein folding and gene regulation displayed changes in thiol reactivity. Further analyses of clinical plasma specimens confirmed that the proteins AKAP8L, galectin-3, PGK 1, syntenin-1, Abin 2, aldose reductase, CD63, GRP-78, GST-pi, RXR-gamma, TPI and vimentin showed type 2 diabetic liver disease-dependent alterations. In summary, in this study we used a comprehensive hepatocyte-based proteomic approach to identify changes in protein expression and to identify redox-associated diabetic liver disease markers induced by high glucose concentration. Some of the identified proteins were validated with clinical samples and are presented as potential targets for the prognosis and diagnosis of diabetic liver disease. PMID:24011924

  15. Noninvasive glucose detection in human skin using wavelength modulated differential laser photothermal radiometry.

    PubMed

    Guo, Xinxin; Mandelis, Andreas; Zinman, Bernard

    2012-11-01

    Noninvasive glucose monitoring will greatly improve diabetes management. We applied Wavelength-Modulated Differential Laser Photothermal Radiometry (WM-DPTR) to noninvasive glucose measurements in human skin in vitro in the mid-infrared range. Glucose measurements in human blood serum diffused into a human skin sample (1 mm thickness from abdomen) in the physiological range (21-400 mg/dl) demonstrated high sensitivity and accuracy to meet wide clinical detection requirements. It was found that the glucose sensitivity could be tuned by adjusting the intensity ratio and phase difference of the two laser beams in the WM-DPTR system. The measurement results demonstrated the feasibility of the development of WM-DPTR into a clinically viable noninvasive glucose biosensor. PMID:23162736

  16. Noninvasive glucose detection in human skin using wavelength modulated differential laser photothermal radiometry

    PubMed Central

    Guo, Xinxin; Mandelis, Andreas; Zinman, Bernard

    2012-01-01

    Noninvasive glucose monitoring will greatly improve diabetes management. We applied Wavelength-Modulated Differential Laser Photothermal Radiometry (WM-DPTR) to noninvasive glucose measurements in human skin in vitro in the mid-infrared range. Glucose measurements in human blood serum diffused into a human skin sample (1 mm thickness from abdomen) in the physiological range (21-400 mg/dl) demonstrated high sensitivity and accuracy to meet wide clinical detection requirements. It was found that the glucose sensitivity could be tuned by adjusting the intensity ratio and phase difference of the two laser beams in the WM-DPTR system. The measurement results demonstrated the feasibility of the development of WM-DPTR into a clinically viable noninvasive glucose biosensor. PMID:23162736

  17. Use of anesthesia dramatically alters the oral glucose tolerance and insulin secretion in C57Bl/6 mice.

    PubMed

    Windeløv, Johanne A; Pedersen, Jens; Holst, Jens J

    2016-06-01

    Evaluation of the impact of anesthesia on oral glucose tolerance in mice. Anesthesia is often used when performing OGTT in mice to avoid the stress of gavage and blood sampling, although anesthesia may influence gastrointestinal motility, blood glucose, and plasma insulin dynamics. C57Bl/6 mice were anesthetized using the following commonly used regimens: (1) hypnorm/midazolam repetitive or single injection; (2) ketamine/xylazine; (3) isoflurane; (4) pentobarbital; and (5) A saline injected, nonanesthetized group. Oral glucose was administered at time 0 min and blood glucose measured in the time frame -15 to +150 min. Plasma insulin concentration was measured at time 0 and 20 min. All four anesthetic regimens resulted in impaired glucose tolerance compared to saline/no anesthesia. (1) hypnorm/midazolam increased insulin concentrations and caused an altered glucose tolerance; (2) ketamine/xylazine lowered insulin responses and resulted in severe hyperglycemia throughout the experiment; (3) isoflurane did not only alter the insulin secretion but also resulted in severe hyperglycemia; (4) pentobarbital resulted in both increased insulin secretion and impaired glucose tolerance. All four anesthetic regimens altered the oral glucose tolerance, and we conclude that anesthesia should not be used when performing metabolic studies in mice. PMID:27255361

  18. Characterization of glucose-related metabolic pathways in differentiated rat oligodendrocyte lineage cells.

    PubMed

    Amaral, Ana I; Hadera, Mussie G; Tavares, Joana M; Kotter, Mark R N; Sonnewald, Ursula

    2016-01-01

    Although oligodendrocytes constitute a significant proportion of cells in the central nervous system (CNS), little is known about their intermediary metabolism. We have, therefore, characterized metabolic functions of primary oligodendrocyte precursor cell cultures at late stages of differentiation using isotope-labelled metabolites. We report that differentiated oligodendrocyte lineage cells avidly metabolize glucose in the cytosol and pyruvate derived from glucose in the mitochondria. The labelling patterns of metabolites obtained after incubation with [1,2-(13)C]glucose demonstrated that the pentose phosphate pathway (PPP) is highly active in oligodendrocytes (approximately 10% of glucose is metabolized via the PPP as indicated by labelling patterns in phosphoenolpyruvate). Mass spectrometry and magnetic resonance spectroscopy analyses of metabolites after incubation of cells with [1-(13)C]lactate or [1,2-(13)C]glucose, respectively, demonstrated that anaplerotic pyruvate carboxylation, which was thought to be exclusive to astrocytes, is also active in oligodendrocytes. Using [1,2-(13)C]acetate, we show that oligodendrocytes convert acetate into acetyl CoA which is metabolized in the tricarboxylic acid cycle. Analysis of labelling patterns of alanine after incubation of cells with [1,2-(13)C]acetate and [1,2-(13)C]glucose showed catabolic oxidation of malate or oxaloacetate. In conclusion, we report that oligodendrocyte lineage cells at late differentiation stages are metabolically highly active cells that are likely to contribute considerably to the metabolic activity of the CNS. PMID:26352325

  19. TCDD alters medial epithelial cell differentiation during palatogenesis

    SciTech Connect

    Abbott, B.D.; Birnbaum, L.S. )

    1989-06-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a widely distributed, persistent environmental contaminant that is teratogenic in mice, where it induces hydronephrosis and cleft palate. The incidence of clefting has been shown to be dose dependent after exposure on either gestation Day (GD) 10 or 12, although the embryo is more susceptible on GD 12. TCDD-exposed palatal shelves meet but do not fuse, and programmed cell death of the medial epithelial cells is inhibited. The mechanism of action through which TCDD alters the program of medial cell development has not been examined in earlier studies, and it is not known whether the mechanism is the same regardless of the dose or developmental stage of exposure. In this study, C57BL/6N mice, a strain sensitive to TCDD, were dosed orally on GD 10 or 12 with 0, 6, 12, 24, or 30 micrograms/kg body wt, in 10 ml corn oil/kg. Embryonic palatal shelves were examined on GD 14, 15, or 16. The degree of palatal closure, epithelial surface morphology, and cellular ultrastructure, the incorporation of (3H)TdR, the expression of EGF receptors, and the binding of 125I-EGF were assessed. After exposure on GD 10 or 12, TCDD altered the differentiation pathway of the medial epithelial cells. The palatal shelves were of normal size and overall morphology, but fusion of the medial epithelia of the opposing shelves did not occur. TCDD prevented programmed cell death of the medial peridermal cells. The expression of EGF receptors by medial cells continued through Day 16 and the receptors were able to bind ligand. The medial cells differentiated into a stratified, squamous, keratinizing epithelium. The shift in phenotype to an oral-like epithelium occurred after exposure on either GD 10 or 12. At the lower dose (6 micrograms/kg), fewer cleft palates were produced, but those shelves which did respond had a fully expressed shift in differentiation.

  20. Glucose-induced alterations of cytosolic free calcium in cultured rat tail artery vascular smooth muscle cells.

    PubMed Central

    Barbagallo, M; Shan, J; Pang, P K; Resnick, L M

    1995-01-01

    We have previously suggested that hyperglycemia per se may contribute to diabetic hypertensive and vascular disease by altering cellular ion content. To more directly investigate the potential role of glucose in this process, we measured cytosolic free calcium in primary cultures of vascular smooth muscle cells isolated from Sprague-Dawley rat tail artery before and after incubation with 5 (basal), 10, 15, and 20 mM glucose. Glucose significantly elevated cytosolic free calcium in a dose- and time-dependent manner, from 110.0 +/- 5.4 to 124.5 +/- 9.0, 192.7 +/- 20.4, and 228.4 +/- 21.9 nM at 5, 10, 15, and 20 mM glucose concentrations, respectively. This glucose-induced cytosolic free calcium elevation was also specific, no change being observed after incubation with equivalent concentrations of L-glucose or mannitol. This glucose effect was also dependent on extracellular calcium and pH, since these calcium changes were inhibited in an acidotic or a calcium-free medium, or by the competitive calcium antagonist lanthanum. We conclude that ambient glucose concentrations within clinically observed limits may alter cellular calcium ion homeostasis in vascular smooth muscle cells. We suggest that these cellular ionic effects of hyperglycemia may underlie the predisposition to hypertension and vascular diseases among diabetic subjects and/or those with impaired glucose tolerance. PMID:7860758

  1. Preweaning cocaine exposure alters brain glucose metabolic rates following repeated amphetamine administration in the adult rat.

    PubMed

    Melnick, Susan M; Torres-Reveron, Annelyn; Dow-Edwards, Diana L

    2004-10-15

    Developmental cocaine exposure produces long-term alterations in function of many neuronal circuits. This study examined glucose metabolic rates following repeated amphetamine administration in adult male and female rats pretreated with cocaine during postnatal days (PND) 11-20. PND11-20 cocaine increased the response to amphetamine in many components of the motor system and the dorsal caudate-putamen, in particular, and decreased the metabolic response in the hypothalamus. While amphetamine alone produced widespread increases in metabolism, there were no cocaine-related effects in the mesolimbic, limbic or sensory structures. These data suggest that a brief cocaine exposure during development can alter ontogeny and result in abnormal neuronal responses to repeated psychostimulant administration in adulthood. PMID:15464226

  2. Effect of altered eating pattern on serum fructosamine: total protein ratio and plasma glucose level.

    PubMed

    Ch'ng, S L; Cheah, S H; Husain, R; Duncan, M T

    1989-05-01

    The effect of alteration of eating pattern during Ramadan on body mass index (BMI), serum fructosamine: total protein ratio (F/TP), and glucose level in 18 healthy male Asiatic Moslems were studied. The results showed a significant decrease (p less than 0.025) in F/TP at the second week of Ramadan in 11 subjects who experienced continuous decrease in BMI throughout Ramadan. The remaining 7 subjects showed no significant changes in BMI and F/TP. No evidence of hypoglycaemia was observed in the subjects during the study. Serum fructosamine: total protein ratio in subjects with altered eating pattern preferably should be interpreted along with the change in body mass index. PMID:2774480

  3. Heterogeneity in multicell spheroids induced by alterations in the external oxygen and glucose concentration

    SciTech Connect

    Freyer, J.P.

    1981-01-01

    Multicell tumor spheroids are currently being used as in vitro models for investigations of tumor therapy, based on the concept that spheroids exhibit many of the growth characteristics and cell subpopulations of tumors in vivo. At present, the factors which regulate cell proliferation, clonogenicity and viability in spheroids are unknown, as are the effects of alterations in these critical factors on therapeutic results. The symmetrical structure of the EMT6/Ro spheroid and the ease of manipulating the external environment are key features of this spheroid system which are used to investigate the role of oxygen and glucose in the control of spheroid growth and the development of cell subpopulations. A technique is developed for selectivity dissociating a spheroid population into fractions of cells originating from known locations in the spheroid structure. Characterization of these cell subpopulations demonstrates that outer cells are similar to an exponential cell population, while inner region cells are not proliferating and have a reduced cell volume and clonogenic capacity. Oxygen and glucose concentrations at critical depths in the spheroid were determined. It is concluded that the oxygen and glucose supply to cells in spheroids is critical in determining the initial onset of central necrosis. 217 references, 32 figures, 15 tables. (ACR)

  4. Alterations in glucose and protein metabolism in animals subjected to simulated microgravity

    NASA Astrophysics Data System (ADS)

    Mondon, C. E.; Rodnick, K. J.; Dolkas, C. B.; Azhar, S.; Reaven, G. M.

    1992-09-01

    Reduction of physical activity due to disease or environmental restraints, such as total bed rest or exposure to spaceflight, leads to atrophy of skeletal muscle and is frequently accompanied by alterations in food intake and the concentration of metabolic regulatory hormones such as insulin. Hindlimb suspension of laboratory rats, as a model for microgravity, also shows marked atrophy of gravity dependent muscles along with a reduced gain in body weight. Suspended rats exhibit enhanced sensitivity to insulin-induced glucose uptake when compared with normal control rats and resistance to insulin action when compared with control rats matched similarly for reduced body weight gain. These changes are accompanied by decreased insulin binding and tyrosine kinase activity in soleus but not plantaris muscle, unchanged glucose uptake by perfused hindlimb and decreased sensitivity but not responsiveness to insulin-induced suppression of net proteolysis in hindlimb skeletal muscle. These findings suggest that loss of insulin sensitivity during muscle atrophy is associated with decreased insulin binding and tyrosine kinase activity in atrophied soleus muscle along with decreased sensitivity to the effects of insulin on suppressing net protein breakdown but not on enhancing glucose uptake by perfused hindlimb.

  5. Alterations in glucose and protein metabolism in animals subjected to simulated microgravity

    NASA Technical Reports Server (NTRS)

    Mondon, C. E.; Rodnick, K. J.; Azhar, S.; Reaven, G. M.; Dolkas, C. B.

    1992-01-01

    Reduction of physical activity due to disease or environmental restraints, such as total bed rest or exposure to spaceflight, leads to atrophy of skeletal muscle and is frequently accompanied by alterations in food intake and the concentration of metabolic regulatory hormones such as insulin. Hindlimb suspension of laboratory rats, as a model for microgravity, also shows marked atrophy of gravity-dependent muscles along with a reduced gain in body weight. Suspended rats exhibit enhanced sensitivity to insulin-induced glucose uptake when compared with normal control rats and resistance to insulin action when compared with control rats matched similarly for reduced body weight gain. These changes are accompanied by decreased insulin binding and tyrosine kinase activity in soleus but not plantaris muscle, unchanged glucose uptake by perfused hindlimb and decreased sensitivity but not responsiveness to insulin-induced suppression of net proteolysis in hindlimb skeletal muscle. These findings suggest that loss of insulin sensitivity during muscle atrophy is associated with decreased insulin binding and tyrosine kinase activity in atrophied soleus muscle along with decreased sensitivity to the effects of insulin on suppressing net protein breakdown but not on enhancing glucose uptake by perfused hindlimb.

  6. Immune Alterations in Male and Female Mice after 2-Deoxy-D-Glucose Administration

    NASA Technical Reports Server (NTRS)

    Dreau, Didier; Morton, Darla S.; Foster, Mareva; Swiggett, Jeanene P.; Sonnenfeld, Gerald

    1995-01-01

    Administration of 2-deoxy-D-glucose (2-DG), an analog of glucose which inhibits glycolysis by competitive antagonism for phosphohexose isomerase, results in acute periods of intracellular glucoprivation and hyperglycemia resulting in hyperphagia. In addition to these changes in the carbohydrate metabolism, injection of 2-DG results in alterations of both the endocrine and neurological systems as suggested by modifications in oxytocin and glucocorticoid levels and norepinephrine production. Moreover, alterations of the immune response, such as a decrease in the in vitro proliferation of splenocytes after mitogen-stimulation, were observed in mice injected with 2-DG. Sex, genotype and environment are among the factors that may modulate effects of catecholamines and hypothalamo-pituitary-adrenal axis on these immune changes. Sexual dimorphism in immune function resulting from the effects of sex hormones on immune effector cells has been shown in both animals and humans. These observations have important implications, especially with regard to higher incidence of many autoimmune diseases in females. Evidence exists that reproductive hormones influence the immune system and increase the risk of immunologically related disorders in both animals and humans. Indeed, immunological responses in stressful situations may also be confounded by fluctuations of sex hormones especially in females. Lymphocyte distribution, cytoldne production, and the ability of lymphocyte to proliferate in vitro were analyzed in male and female mice to determine if sex influenced 2-DG immunomodulation. In addition, the influence of hormones, especially sex hormones, on these changes were evaluated.

  7. Differentiation of the insulin-sensitive glucose transporter in 3T3-L1 adipocytes

    SciTech Connect

    Frost, S.C.; Baly, D.L.; Cushman, S.W.; Lane, M.D.; Simpson, I.A.

    1986-05-01

    3T3-L1 fibroblasts differentiate in culture to resemble adipocytes both morphologically and biochemically. Insulin-sensitive glucose transport, as measured by 2-deoxy-(1-/sup 14/C)- glucose uptake in the undifferentiated cell is small (2X). In contrast, the rate of glucose transport in fully differentiated cells is elevated 15-fold over basal in the presence of insulin. To determine if this is due to an increase in the number of transporters/cell or accessibility to the transporters, the number of transporters was measured in subcellular fractions over differentiation using a /sup 3/H-cytochalasin B binding assay. The increase in the rate of insulin-sensitive glucose transport directly parallels an increase in the number of transporters which reside in an insulin-responsive intracellular compartment. This observation was confirmed by identifying the transporters by immunoblotting using an antibody generated against the human erythrocyte transporter. The molecular weight of this transporter increases over differentiation from a single band of 40kDa to a heterogeneous triplet of 40, 44 and 48kDa. These data suggest that the transporter undergoes differential processing and that the functional, insulin-responsive transporter may be different from the insulin-insensitive (basal) transporter.

  8. Resistance to chemotherapy is associated with altered glucose metabolism in acute myeloid leukemia

    PubMed Central

    SONG, KUI; LI, MIN; XU, XIAOJUN; XUAN, LI; HUANG, GUINIAN; LIU, QIFA

    2016-01-01

    Altered glucose metabolism has been described as a cause of chemoresistance in multiple tumor types. The present study aimed to identify the expression profile of glucose metabolism in drug-resistant acute myeloid leukemia (AML) cells and provide potential strategies for the treatment of drug-resistant AML. Bone marrow and serum samples were obtained from patients with AML that were newly diagnosed or had relapsed. The messenger RNA expression of hypoxia inducible factor (HIF)-1α, glucose transporter (GLUT)1, and hexokinase-II was measured by quantitative polymerase chain reaction. The levels of LDH and β subunit of human F1-F0 adenosine triphosphate synthase (β-F1-ATPase) were detected by enzyme-linked immunosorbent and western blot assays. The HL-60 and HL-60/ADR cell lines were used to evaluate glycolytic activity and effect of glycolysis inhibition on cellular proliferation and apoptosis. Drug-resistant HL-60/ADR cells exhibited a significantly increased level of glycolysis compared with the drug-sensitive HL-60 cell line. The expression of HIF-1α, hexokinase-II, GLUT1 and LDH were increased in AML patients with no remission (NR), compared to healthy control individuals and patients with complete remission (CR) and partial remission. The expression of β-F1-ATPase in patients with NR was decreased compared with the expression in the CR group. Treatment of HL-60/ADR cells with 2-deoxy-D-glucose or 3-bromopyruvate increased in vitro sensitivity to Adriamycin (ADR), while treatment of HL-60 cells did not affect drug cytotoxicity. Subsequent to treatment for 24 h, apoptosis in these two cell lines showed no significant difference. However, glycolytic inhibitors in combination with ADR increased cellular necrosis. These findings indicate that increased glycolysis and low efficiency of oxidative phosphorylation may contribute to drug resistance. Targeting glycolysis is a viable strategy for modulating chemoresistance in AML. PMID:27347147

  9. Differential diagnosis of altered mind/body perception.

    PubMed

    Gabbard, G O; Twemlow, S W; Jones, F C

    1982-11-01

    Considerable confusion exists in the psychiatric literature concerned with states of consciousness in which there is an altered perception of the mind/body relationship; related but different terms are often used interchangeably, with a lack of definitional rigor. The purpose of this paper is to bring clarity to this group of related phenomena by differentiating out-of-body experience (OBE) from depersonalization, autoscopic phenomena and schizophrenic body distortions (such as boundary loss), which are the principal entities with which the syndrome may be confused. The problem of variable definition of the syndromes is compounded by the fact that some studies deal with psychiatric or medical patients, others focus on nonpatients, and still others deal with both groups. The fact that some groups of persons with experiences of altered mind/body perception do not define themselves as patients, do not seek treatment, and may not need treatment underscores the need for clarification. Following an explication of the different syndromes and their characteristics, we will briefly consider treatment implications. PMID:7146229

  10. The Brain-to-Pancreatic Islet Neuronal Map Reveals Differential Glucose Regulation From Distinct Hypothalamic Regions.

    PubMed

    Rosario, Wilfredo; Singh, Inderroop; Wautlet, Arnaud; Patterson, Christa; Flak, Jonathan; Becker, Thomas C; Ali, Almas; Tamarina, Natalia; Philipson, Louis H; Enquist, Lynn W; Myers, Martin G; Rhodes, Christopher J

    2016-09-01

    The brain influences glucose homeostasis, partly by supplemental control over insulin and glucagon secretion. Without this central regulation, diabetes and its complications can ensue. Yet, the neuronal network linking to pancreatic islets has never been fully mapped. Here, we refine this map using pseudorabies virus (PRV) retrograde tracing, indicating that the pancreatic islets are innervated by efferent circuits that emanate from the hypothalamus. We found that the hypothalamic arcuate nucleus (ARC), ventromedial nucleus (VMN), and lateral hypothalamic area (LHA) significantly overlap PRV and the physiological glucose-sensing enzyme glucokinase. Then, experimentally lowering glucose sensing, specifically in the ARC, resulted in glucose intolerance due to deficient insulin secretion and no significant effect in the VMN, but in the LHA it resulted in a lowering of the glucose threshold that improved glucose tolerance and/or improved insulin sensitivity, with an exaggerated counter-regulatory response for glucagon secretion. No significant effect on insulin sensitivity or metabolic homeostasis was noted. Thus, these data reveal novel direct neuronal effects on pancreatic islets and also render a functional validation of the brain-to-islet neuronal map. They also demonstrate that distinct regions of the hypothalamus differentially control insulin and glucagon secretion, potentially in partnership to help maintain glucose homeostasis and guard against hypoglycemia. PMID:27207534

  11. Using meta-differential evolution to enhance a calculation of a continuous blood glucose level.

    PubMed

    Koutny, Tomas

    2016-09-01

    We developed a new model of glucose dynamics. The model calculates blood glucose level as a function of transcapillary glucose transport. In previous studies, we validated the model with animal experiments. We used analytical method to determine model parameters. In this study, we validate the model with subjects with type 1 diabetes. In addition, we combine the analytic method with meta-differential evolution. To validate the model with human patients, we obtained a data set of type 1 diabetes study that was coordinated by Jaeb Center for Health Research. We calculated a continuous blood glucose level from continuously measured interstitial fluid glucose level. We used 6 different scenarios to ensure robust validation of the calculation. Over 96% of calculated blood glucose levels fit A+B zones of the Clarke Error Grid. No data set required any correction of model parameters during the time course of measuring. We successfully verified the possibility of calculating a continuous blood glucose level of subjects with type 1 diabetes. This study signals a successful transition of our research from an animal experiment to a human patient. Researchers can test our model with their data on-line at https://diabetes.zcu.cz. PMID:27393799

  12. Differential thermal wave radiometry for noninvasive blood glucose monitoring: feasibility analysis

    NASA Astrophysics Data System (ADS)

    Telenkov, Sergey A.

    2004-04-01

    Blood glucose monitoring is essential for management of diabetes especially for those patients who requires regular insulin injections. A reliable noninvasive technique may eliminate inconvenience associated with frequent skin puncture to draw blood for measurement by a standard meter. Laser-induced thermal waves in tissue and detection of resulting IR response may provide a valuable approach to development of noninvasive glucose sensor. The present report analyzes radiometric response of tissue at the two wavelengths in mid-IR spectral band with phase-sensitive detection to evaluate feasibility of differential phase radiometry for noninvasive glucose monitoring. Sensitivity of the differential phase method is computed using two models of laser-tissue interaction: homogeneous light absorption and a discrete chromophore heating.

  13. Interruptin B induces brown adipocyte differentiation and glucose consumption in adipose-derived stem cells

    PubMed Central

    KAEWSUWAN, SIREEWAN; PLUBRUKARN, ANUCHIT; UTSINTONG, MALEERUK; KIM, SEOK-HO; JEONG, JIN-HYUN; CHO, JIN GU; PARK, SANG GYU; SUNG, JONG-HYUK

    2016-01-01

    Interruptin B has been isolated from Cyclosorus terminans, however, its pharamcological effect has not been fully identified. In the present study, the effects of interruptin B, from C. terminans, on brown adipocyte differentiation and glucose uptake in adipose-derived stem cells (ASCs) were investigated. The results revealed that interruptin B dose-dependently enhanced the adipogenic differentiation of ASCs, with an induction in the mRNA expression levels of peroxisome proliferator-activated receptor (PPAR)-α and PPAR-γ. In addition, interruptin B efficiently increased the number and the membrane potential of mitochondria and upregulated the mRNA expression levels of uncoupling protein (UCP)-1 and cyclooxygenase (COX)-2, which are all predominantly expressed in brown adipocytes. Interruptin B increased glucose consumption in differentiated ASCs, accompanied by the upregulation in the mRNA expression levels of glucose transporter (GLUT)-1 and GLUT-4. The computational analysis of molecular docking, a luciferase reporter assay and surface plasmon resonance confirmed the marked binding affinity of interruptin B to PPAR-α and PPAR-γ (KD values of 5.32 and 0.10 µM, respectively). To the best of our knowledge, the present study is the first report to show the stimulatory effects of interruptin B on brown adipocyte differentiation and glucose uptake in ASCs, through its role as a dual PPAR-α and PPAR-γ ligand. Therefore, interruptin B could be further developed as a therapeutic agent for the treatment of diabetes. PMID:26781331

  14. Impact of streptozotocin on altering normal glucose homeostasis during insulin testing in diabetic rats compared to normoglycemic rats

    PubMed Central

    Qinna, Nidal A; Badwan, Adnan A

    2015-01-01

    Streptozotocin (STZ) is currently the most used diabetogenic agent in testing insulin and new antidiabetic drugs in animals. Due to the toxic and disruptive nature of STZ on organs, apart from pancreas, involved in preserving the body’s normal glucose homeostasis, this study aims to reassess the action of STZ in inducing different glucose response states in diabetic rats while testing insulin. Diabetic Sprague-Dawley rats induced with STZ were classified according to their initial blood glucose levels into stages. The effect of randomizing rats in such a manner was investigated for the severity of interrupting normal liver, pancreas, and kidney functions. Pharmacokinetic and pharmacodynamic actions of subcutaneously injected insulin in diabetic and nondiabetic rats were compared. Interruption of glucose homeostasis by STZ was challenged by single and repeated administrations of injected insulin and oral glucose to diabetic rats. In diabetic rats with high glucose (451–750 mg/dL), noticeable changes were seen in the liver and kidney functions compared to rats with lower basal glucose levels. Increased serum levels of recombinant human insulin were clearly indicated by a significant increase in the calculated maximum serum concentration and area under the concentration–time curve. Reversion of serum glucose levels to normal levels pre- and postinsulin and oral glucose administrations to STZ diabetic rats were found to be variable. In conclusion, diabetic animals were more responsive to insulin than nondiabetic animals. STZ was capable of inducing different levels of normal glucose homeostasis disruption in rats. Both pharmacokinetic and pharmacodynamic actions of insulin were altered when different initial blood glucose levels of STZ diabetic rats were selected for testing. Such findings emphasize the importance of selecting predefined and unified glucose levels when using STZ as a diabetogenic agent in experimental protocols evaluating new antidiabetic agents

  15. Alterations in cortical GABAB receptors in neonatal rats exposed to hypoxic stress: role of glucose, oxygen, and epinephrine resuscitation.

    PubMed

    Anju, T R; Abraham, Pretty Mary; Antony, Sherin; Paulose, C S

    2010-10-01

    Hypoxia in neonates can cause permanent brain damage by gene and receptor level alterations mediated through changes in neurotransmitters. The present study evaluated GABA(B) receptor alterations, gene expression changes in glutamate decarboxylase and hypoxia-inducible factor 1A in the cerebral cortex of hypoxic neonatal rats and the resuscitation groups with glucose, oxygen, and epinephrine. Under hypoxic stress, a significant decrease in total GABA and GABA(B) receptors, GABA(B) and GAD gene expression was observed in the cerebral cortex, which accounts for the respiratory inhibition. Hypoxia-inducible factor 1A was upregulated under hypoxia to maintain body homeostasis. Hypoxic rats supplemented with glucose alone and with oxygen showed a reversal of the receptor alterations and changes in GAD and HIF-1A to near control. Being a source of immediate energy, glucose can reduce the ATP-depletion-induced changes in GABA and oxygenation, which helps in encountering hypoxia. Resuscitation with oxygen alone and epinephrine was less effective in reversing the receptor alterations. Thus, our study suggests that reduction in the GABA(B) receptors functional regulation during hypoxia plays an important role in cortical damage. Resuscitation with glucose alone and glucose and oxygen to hypoxic neonatal rats helps in protecting the brain from severe hypoxic damage. PMID:20473556

  16. βIII-Tubulin alters glucose metabolism and stress response signaling to promote cell survival and proliferation in glucose-starved non-small cell lung cancer cells.

    PubMed

    Parker, Amelia L; Turner, Nigel; McCarroll, Joshua A; Kavallaris, Maria

    2016-08-01

    Non-small cell lung cancer (NSCLC) survival rates are dismal and high βIII-tubulin expression is associated with chemotherapy drug resistance and tumor aggressiveness in this disease. Mounting evidence supports a role for βIII-tubulin in promoting cell survival in the harsh tumor microenvironment, which is characterized by poor nutrient supply. This study aimed to investigate the role of βIII-tubulin in glucose stress response signaling and the survival and proliferation of NSCLC cells. This study revealed that βIII-tubulin regulates cellular metabolism and glucose stress response signaling in NSCLC cells to promote cell survival and proliferation in glucose starvation. βIII-Tubulin decreases the reliance of cells on glycolytic metabolism, priming them to cope with variable nutrient supply present within the tumor microenvironment. βIII-Tubulin protects cells from endoplasmic reticulum (ER) stress and reduces both basal and glucose starvation-induced autophagy to maintain cell survival and proliferation. βIII-Tubulin enables rapid Akt activation in response to glucose starvation and co-immunoprecipitates with the master regulator of the ER stress response GRP78. Furthermore, suppression of βIII-tubulin delays the association of GRP78 with Akt in response to glucose starvation with the potential to influence Akt activation and ER homeostasis under these conditions. Together these results identify that βIII-tubulin regulates glucose metabolism and alters glucose starvation stress signaling to promote cell proliferation and survival in NSCLC cells. This elucidates a hitherto unknown role for this microtubule protein and provides insight into correlations between high βIII-tubulin expression and poor patient outcome in this disease. PMID:27207668

  17. Differential Geometric Analysis of Alterations in MH α-Helices

    PubMed Central

    Hischenhuber, Birgit; Havlicek, Hans; Todoric, Jelena; Höllrigl-Binder, Sonja; Schreiner, Wolfgang; Knapp, Bernhard

    2013-01-01

    Antigen presenting cells present processed peptides via their major histocompatibility (MH) complex to the T cell receptors (TRs) of T cells. If a peptide is immunogenic, a signaling cascade can be triggered within the T cell. However, the binding of different peptides and/or different TRs to MH is also known to influence the spatial arrangement of the MH α-helices which could itself be an additional level of T cell regulation. In this study, we introduce a new methodology based on differential geometric parameters to describe MH deformations in a detailed and comparable way. For this purpose, we represent MH α-helices by curves. On the basis of these curves, we calculate in a first step the curvature and torsion to describe each α-helix independently. In a second step, we calculate the distribution parameter and the conical curvature of the ruled surface to describe the relative orientation of the two α-helices. On the basis of four different test sets, we show how these differential geometric parameters can be used to describe changes in the spatial arrangement of the MH α-helices for different biological challenges. In the first test set, we illustrate on the basis of all available crystal structures for (TR)/pMH complexes how the binding of TRs influences the MH helices. In the second test set, we show a cross evaluation of different MH alleles with the same peptide and the same MH allele with different peptides. In the third test set, we present the spatial effects of different TRs on the same peptide/MH complex. In the fourth test set, we illustrate how a severe conformational change in an α-helix can be described quantitatively. Taken together, we provide a novel structural methodology to numerically describe subtle and severe alterations in MH α-helices for a broad range of applications. © 2013 Wiley Periodicals, Inc. PMID:23703160

  18. Applications of ultrasensitive wavelength-modulated differential photothermal radiometry to noninvasive glucose detection in blood serum.

    PubMed

    Guo, Xinxin; Mandelis, Andreas; Zinman, Bernard

    2013-12-01

    Wavelength-Modulated Differential Laser Photothermal Radiometry (WM-DPTR) has been designed for noninvasive glucose measurements in the mid-infrared (MIR) range. Glucose measurements in human blood serum in the physiological range (20-320 mg/dl) with predicted error <10.3 mg/dl demonstrated high sensitivity and accuracy to meet wide clinical detection requirements, ranging from hypoglycemia to hyperglycemia. The glucose sensitivity and specificity of WM-DPTR stem from the subtraction of the simultaneously measured signals from two excitation laser beams at wavelengths near the peak and the baseline of the strongest interference-free glucose absorption band in the MIR range. It was found that the serum glucose sensitivity and measurement precision strongly depend on the tunability and stability of the intensity ratio and the phase shift of the two laser beams. This level of accuracy was favorably compared to other MIR techniques. WM-DPTR has shown excellent potential to be developed into a clinically viable noninvasive glucose biosensor. PMID:22930666

  19. Transgenerational glucose intolerance with Igf2/H19 epigenetic alterations in mouse islet induced by intrauterine hyperglycemia.

    PubMed

    Ding, Guo-Lian; Wang, Fang-Fang; Shu, Jing; Tian, Shen; Jiang, Ying; Zhang, Dan; Wang, Ning; Luo, Qiong; Zhang, Yu; Jin, Fan; Leung, Peter C K; Sheng, Jian-Zhong; Huang, He-Feng

    2012-05-01

    Gestational diabetes mellitus (GDM) has been shown to be associated with high risk of diabetes in offspring. However, the mechanisms involved and the possibilities of transgenerational transmission are still unclear. We intercrossed male and female adult control and first-generation offspring of GDM (F1-GDM) mice to obtain the second-generation (F2) offspring in four groups: C♂-C♀, C♂-GDM♀, GDM♂-C♀, and GDM♂-GDM♀. We found that birth weight significantly increased in F2 offspring through the paternal line with impaired glucose tolerance (IGT). Regardless of birth from F1-GDM with or without IGT, high risk of IGT appeared as early as 3 weeks in F2 offspring and progressed through both parental lineages, especial the paternal line. IGT in male offspring was more obvious than that in females, with parental characteristics and sex-specific transmission. In both F1 and F2 offspring of GDM, the expression of imprinted genes Igf2 and H19 was downregulated in pancreatic islets, caused by abnormal methylation status of the differentially methylated region, which may be one of the mechanisms for impaired islet ultrastructure and function. Furthermore, altered Igf2 and H19 gene expression was found in sperm of adult F1-GDM, regardless of the presence of IGT, indicating that changes of epigenetics in germ cells contributed to transgenerational transmission. PMID:22447856

  20. Immune alterations in male and female mice after 2-deoxy-D-glucose administration

    NASA Technical Reports Server (NTRS)

    Dreau, D.; Morton, D. S.; Foster, M.; Swiggett, J. P.; Sonnenfeld, G.

    1997-01-01

    Administration of 2-deoxy-D-glucose (2-DG) induces acute cellular glucoprivation. In the current study, we examined differences in immune parameters after 2-DG administration in both sexes. Male and female BDF1 mice were injected three times, 48 h apart, either with a saline solution (control group) or with 2-DG in saline (500 mg/kg). Two hours after the last injection, blood and spleens were collected. Plasma levels of interleukin-1beta, and interferon-gamma levels were measured. Additionally, the levels of the specific leukocyte antigens CD3, CD4, CD8, T cell receptor (TCR) alpha/beta, I-Ad, and H-2Ld/H-2Db were evaluated by flow cytometry on both blood and spleen cells. The blastogenic response of leukocytes from both tissues to mitogens was assessed. Levels of glucose, corticosterone, testosterone, progesterone, 17beta-estradiol, follicle-stimulating hormone, and luteinizing hormone were also determined. Increases in the percentage of cells bearing TCR alpha/beta and I-Ad in the blood and H-2Ld/H-2Db in the spleen were observed in the 2-DG-treated group for both sexes. In contrast, higher corticosterone and IL-1beta plasma concentrations, as well as higher percentages of splenocytes bearing TCR alpha/beta and I-Ad, and lower mitogen-induced proliferation of mature T splenocytes (79%) were observed in female but not in male mice injected with 2-DG compared with those injected with saline (p < 0.05). Taken together, these results suggest that female mice are more sensitive than male mice to immune alterations induced by 2-DG administration.

  1. Fetal rat metabonome alteration by prenatal caffeine ingestion probably due to the increased circulatory glucocorticoid level and altered peripheral glucose and lipid metabolic pathways

    SciTech Connect

    Liu, Yansong; Xu, Dan; Feng, Jianghua; Kou, Hao; Liang, Gai; Yu, Hong; He, Xiaohua; Zhang, Baifang; Chen, Liaobin; Magdalou, Jacques; Wang, Hui

    2012-07-15

    The aims of this study were to clarify the metabonome alteration in fetal rats after prenatal caffeine ingestion and to explore the underlying mechanism pertaining to the increased fetal circulatory glucocorticoid (GC). Pregnant Wistar rats were daily intragastrically administered with different doses of caffeine (0, 20, 60 and 180 mg/kg) from gestational days (GD) 11 to 20. Metabonome of fetal plasma and amniotic fluid on GD20 were analyzed by {sup 1}H nuclear magnetic resonance-based metabonomics. Gene and protein expressions involved in the GC metabolism, glucose and lipid metabolic pathways in fetal liver and gastrocnemius were measured by real-time RT-PCR and immunohistochemistry. Fetal plasma metabonome were significantly altered by caffeine, which presents as the elevated α- and β‐glucose, reduced multiple lipid contents, varied apolipoprotein contents and increased levels of a number of amino acids. The metabonome of amniotic fluids showed a similar change as that in fetal plasma. Furthermore, the expressions of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD-2) were decreased, while the level of blood GC and the expressions of 11β-HSD-1 and glucocorticoid receptor (GR) were increased in fetal liver and gastrocnemius. Meanwhile, the expressions of insulin-like growth factor 1 (IGF-1), IGF-1 receptor and insulin receptor were decreased, while the expressions of adiponectin receptor 2, leptin receptors and AMP-activated protein kinase α2 were increased after caffeine treatment. Prenatal caffeine ingestion characteristically change the fetal metabonome, which is probably attributed to the alterations of glucose and lipid metabolic pathways induced by increased circulatory GC, activated GC metabolism and enhanced GR expression in peripheral metabolic tissues. -- Highlights: ► Prenatal caffeine ingestion altered the metabonome of IUGR fetal rats. ► Caffeine altered the glucose and lipid metabolic pathways of IUGR fetal rats. ► Prenatal caffeine

  2. Interruptin B induces brown adipocyte differentiation and glucose consumption in adipose-derived stem cells.

    PubMed

    Kaewsuwan, Sireewan; Plubrukarn, Anuchit; Utsintong, Maleeruk; Kim, Seok-Ho; Jeong, Jin-Hyun; Cho, Jin Gu; Park, Sang Gyu; Sung, Jong-Hyuk

    2016-03-01

    Interruptin B has been isolated from Cyclosorus terminans, however, its pharamcological effect has not been fully identified. In the present study, the effects of interruptin B, from C. terminans, on brown adipocyte differentiation and glucose uptake in adipose‑derived stem cells (ASCs) were investigated. The results revealed that interruptin B dose‑dependently enhanced the adipogenic differentiation of ASCs, with an induction in the mRNA expression levels of peroxisome proliferator‑activated receptor (PPAR)‑α and PPAR‑γ. In addition, interruptin B efficiently increased the number and the membrane potential of mitochondria and upregulated the mRNA expression levels of uncoupling protein (UCP)‑1 and cyclooxygenase (COX)‑2, which are all predominantly expressed in brown adipocytes. Interruptin B increased glucose consumption in differentiated ASCs, accompanied by the upregulation in the mRNA expression levels of glucose transporter (GLUT)‑1 and GLUT‑4. The computational analysis of molecular docking, a luciferase reporter assay and surface plasmon resonance confirmed the marked binding affinity of interruptin B to PPAR‑α and PPAR‑γ (KD values of 5.32 and 0.10 µm, respectively). To the best of our knowledge, the present study is the first report to show the stimulatory effects of interruptin B on brown adipocyte differentiation and glucose uptake in ASCs, through its role as a dual PPAR‑α and PPAR‑γ ligand. Therefore, interruptin B could be further developed as a therapeutic agent for the treatment of diabetes. PMID:26781331

  3. Aberrant TGFβ Signaling Contributes to Altered Trophoblast Differentiation in Preeclampsia.

    PubMed

    Xu, Jing; Sivasubramaniyam, Tharini; Yinon, Yoav; Tagliaferro, Andrea; Ray, Jocelyn; Nevo, Ori; Post, Martin; Caniggia, Isabella

    2016-02-01

    TGFβ has been implicated in preeclampsia, but its intracellular signaling via phosphorylated mothers against decapentaplegic (SMADs) and SMAD-independent proteins in the placenta remains elusive. Here we show that TGFβ receptor-regulated SMAD2 was activated (Ser(465/467) phosphorylation) in syncytiotrophoblast and proliferating extravillous trophoblast cells of first-trimester placenta, whereas inhibitory SMAD7 located primarily to cytotrophoblast cells. SMAD2 phosphorylation decreased with advancing gestation, whereas SMAD7 expression increased and shifted to syncytiotrophoblasts toward term. Additionally, we found that the TGFβ SMAD-independent signaling via partitioning defective protein 6 (PARD6)/Smad ubiquitylation regulatory factor was activated at approximately 10-12 weeks of gestation in cytotrophoblast and extravillous trophoblast cells comprising the anchoring column. Placentae from early-onset, but not late-onset, preeclampsia exhibited elevated SMAD2 phosphorylation and SMAD7 levels. Whereas PARD6 expression increased and SMURF1 levels decreased in preeclamptic placentae, their association increased. SMAD2 phosphorylation by TGFβ in villous explants and BeWo cells resulted in a reduction of Glial cell missing-1 (GCM1) and fusogenic protein syncytin-1 while increasing cell cycle regulators cyclin E-1 (CCNE1) and cyclin-dependent kinase 4. SMAD7 abrogated the proliferative effects of TGFβ. CCNE1 levels were increased in preeclamptic placentae, whereas GCM1 was markedly reduced. In addition, TGFβ treatment increased the association of PARD6 and SMURF1 and down-regulated Ras homolog gene family, member A (RHOA) GTPase in JEG3 cells. In a wound assay, TGFβ treatment increased the association of PARD6 and SMURF1 and triggered JEG3 cell migration through increased cellular protrusions. Taken together, our data indicate that TGFβ signaling via both SMAD2/7 and PARD6/SMURF1 pathways plays a role in trophoblast growth and differentiation. Altered SMAD

  4. Differential Responses of Plasma Adropin Concentrations To Dietary Glucose or Fructose Consumption In Humans.

    PubMed

    Butler, Andrew A; St-Onge, Marie-Pierre; Siebert, Emily A; Medici, Valentina; Stanhope, Kimber L; Havel, Peter J

    2015-01-01

    Adropin is a peptide hormone encoded by the Energy Homeostasis Associated (ENHO) gene whose physiological role in humans remains incompletely defined. Here we investigated the impact of dietary interventions that affect systemic glucose and lipid metabolism on plasma adropin concentrations in humans. Consumption of glucose or fructose as 25% of daily energy requirements (E) differentially affected plasma adropin concentrations (P < 0.005) irrespective of duration, sex or age. Glucose consumption reduced plasma adropin from 3.55 ± 0.26 to 3.28 ± 0.23 ng/ml (N = 42). Fructose consumption increased plasma adropin from 3.63 ± 0.29 to 3.93 ± 0.34 ng/ml (N = 45). Consumption of high fructose corn syrup (HFCS) as 25% E had no effect (3.43 ± 0.32 versus 3.39 ± 0.24 ng/ml, N = 26). Overall, the effect of glucose, HFCS and fructose on circulating adropin concentrations were similar to those observed on postprandial plasma triglyceride concentrations. Furthermore, increases in plasma adropin levels with fructose intake were most robust in individuals exhibiting hypertriglyceridemia. Individuals with low plasma adropin concentrations also exhibited rapid increases in plasma levels following consumption of breakfasts supplemented with lipids. These are the first results linking plasma adropin levels with dietary sugar intake in humans, with the impact of fructose consumption linked to systemic triglyceride metabolism. In addition, dietary fat intake may also increase circulating adropin concentrations. PMID:26435060

  5. Immobilized glucose oxidase--catalase and their deactivation in a differential-bed loop reactor.

    PubMed

    Prenosil, J E

    1979-01-01

    Glucose oxidase containing catalase was immobilized with a copolymer of phenylenediamine and glutaraldehyde on pumice and titania carrier to study the enzymatic oxidation of glucose in a differential-bed loop reactor. The reaction rate was found to be first order with respect to the concentration of limiting oxygen substrate, suggesting a strong external mass-transfer resistance for all the flow rates used. The partial pressure of oxygen was varied from 21.3 up to 202.6 kPa. The use of a differential-bed loop reactor for the determination of the active enzyme concentration in the catalyst with negligible internal pore diffusion resistance is shown. Catalyst deactivation was studied, especially with respect to the presence of catalase. It is believed that the hydrogen peroxide formed in the oxidation reaction deactivates catalase first; if an excess of catalase is present, the deactivation of glucose oxidase remains small. The mathematical model subsequently developed adequately describes the experimental results. PMID:427262

  6. The Glucose Sensor ChREBP Links De Novo Lipogenesis to PPARγ Activity and Adipocyte Differentiation.

    PubMed

    Witte, Nicole; Muenzner, Matthias; Rietscher, Janita; Knauer, Miriam; Heidenreich, Steffi; Nuotio-Antar, Alli M; Graef, Franziska A; Fedders, Ronja; Tolkachov, Alexander; Goehring, Isabel; Schupp, Michael

    2015-11-01

    Reduced de novo lipogenesis in adipose tissue, often observed in obese individuals, is thought to contribute to insulin resistance. Besides trapping excess glucose and providing for triglycerides and energy storage, endogenously synthesized lipids can function as potent signaling molecules. Indeed, several specific lipids and their molecular targets that mediate insulin sensitivity have been recently identified. Here, we report that carbohydrate-response element-binding protein (ChREBP), a transcriptional inducer of glucose use and de novo lipogenesis, controls the activity of the adipogenic master regulator peroxisome proliferator-activated receptor (PPAR)γ. Expression of constitutive-active ChREBP in precursor cells activated endogenous PPARγ and promoted adipocyte differentiation. Intriguingly, ChREBP-constitutive-active ChREBP expression induced PPARγ activity in a fatty acid synthase-dependent manner and by trans-activating the PPARγ ligand-binding domain. Reducing endogenous ChREBP activity by either small interfering RNA-mediated depletion, exposure to low-glucose concentrations, or expressing a dominant-negative ChREBP impaired differentiation. In adipocytes, ChREBP regulated the expression of PPARγ target genes, in particular those involved in thermogenesis, similar to synthetic PPARγ ligands. In summary, our data suggest that ChREBP controls the generation of endogenous fatty acid species that activate PPARγ. Thus, increasing ChREBP activity in adipose tissue by therapeutic interventions may promote insulin sensitivity through PPARγ. PMID:26181104

  7. Altered Brain Response to Drinking Glucose and Fructose in Obese Adolescents.

    PubMed

    Jastreboff, Ania M; Sinha, Rajita; Arora, Jagriti; Giannini, Cosimo; Kubat, Jessica; Malik, Saima; Van Name, Michelle A; Santoro, Nicola; Savoye, Mary; Duran, Elvira J; Pierpont, Bridget; Cline, Gary; Constable, R Todd; Sherwin, Robert S; Caprio, Sonia

    2016-07-01

    Increased sugar-sweetened beverage consumption has been linked to higher rates of obesity. Using functional MRI, we assessed brain perfusion responses to drinking two commonly consumed monosaccharides, glucose and fructose, in obese and lean adolescents. Marked differences were observed. In response to drinking glucose, obese adolescents exhibited decreased brain perfusion in brain regions involved in executive function (prefrontal cortex [PFC]) and increased perfusion in homeostatic appetite regions of the brain (hypothalamus). Conversely, in response to drinking glucose, lean adolescents demonstrated increased PFC brain perfusion and no change in perfusion in the hypothalamus. In addition, obese adolescents demonstrated attenuated suppression of serum acyl-ghrelin and increased circulating insulin level after glucose ingestion; furthermore, the change in acyl-ghrelin and insulin levels after both glucose and fructose ingestion was associated with increased hypothalamic, thalamic, and hippocampal blood flow in obese relative to lean adolescents. Additionally, in all subjects there was greater perfusion in the ventral striatum with fructose relative to glucose ingestion. Finally, reduced connectivity between executive, homeostatic, and hedonic brain regions was observed in obese adolescents. These data demonstrate that obese adolescents have impaired prefrontal executive control responses to drinking glucose and fructose, while their homeostatic and hedonic responses appear to be heightened. Thus, obesity-related brain adaptations to glucose and fructose consumption in obese adolescents may contribute to excessive consumption of glucose and fructose, thereby promoting further weight gain. PMID:27207544

  8. Iris as a reflector for differential absorption low-coherence interferometry to measure glucose level in the anterior chamber

    NASA Astrophysics Data System (ADS)

    Zhou, Yong; Zeng, Nan; Ji, Yanhong; Li, Yao; Dai, Xiangsong; Li, Peng; Duan, Lian; Ma, Hui; He, Yonghong

    2011-01-01

    We present a method of glucose concentration detection in the anterior chamber with a differential absorption optical low-coherent interferometry (LCI) technique. Back-reflected light from the iris, passing through the anterior chamber twice, was selectively obtained with the LCI technique. Two light sources, one centered within (1625 nm) and the other centered outside (1310 nm) of a glucose absorption band were used for differential absorption measurement. In the eye model and pig eye experiments, we obtained a resolution glucose level of 26.8 mg/dL and 69.6 mg/dL, respectively. This method has a potential application for noninvasive detection of glucose concentration in aqueous humor, which is related to the glucose concentration in blood.

  9. Withdrawal of dietary phytoestrogens in adult male rats affects hypothalamic regulation of food intake, induces obesity and alters glucose metabolism.

    PubMed

    Andreoli, María Florencia; Stoker, Cora; Rossetti, María Florencia; Alzamendi, Ana; Castrogiovanni, Daniel; Luque, Enrique H; Ramos, Jorge Guillermo

    2015-02-01

    The absence of phytoestrogens in the diet during pregnancy has been reported to result in obesity later in adulthood. We investigated whether phytoestrogen withdrawal in adult life could alter the hypothalamic signals that regulate food intake and affect body weight and glucose homeostasis. Male Wistar rats fed from conception to adulthood with a high phytoestrogen diet were submitted to phytoestrogen withdrawal by feeding a low phytoestrogen diet, or a high phytoestrogen-high fat diet. Withdrawal of dietary phytoestrogens increased body weight, adiposity and energy intake through an orexigenic hypothalamic response characterized by upregulation of AGRP and downregulation of POMC. This was associated with elevated leptin and T4, reduced TSH, testosterone and estradiol, and diminished hypothalamic ERα expression, concomitant with alterations in glucose tolerance. Removing dietary phytoestrogens caused manifestations of obesity and diabetes that were more pronounced than those induced by the high phytoestrogen-high fat diet intake. PMID:25486512

  10. NEONATAL CHIORDECONE EXPOSURE ALTERS BEHAVIORAL SEX DIFFERENTIATION IN FEMALE HAMSTERS

    EPA Science Inventory

    The present study was designed in order to determine if exposure to the weakly estrogenic pesticide Chlordecone during a critical period of behavioral sex differentiation of the brain could masculinize and defeminize the behavior of female hamsters.

  11. Keratin 8/18 regulation of glucose metabolism in normal versus cancerous hepatic cells through differential modulation of hexokinase status and insulin signaling

    SciTech Connect

    Mathew, Jasmin; Loranger, Anne; Gilbert, Stéphane; Faure, Robert; Marceau, Normand

    2013-02-15

    As differentiated cells, hepatocytes primarily metabolize glucose for ATP production through oxidative phosphorylation of glycolytic pyruvate, whereas proliferative hepatocellular carcinoma (HCC) cells undergo a metabolic shift to aerobic glycolysis despite oxygen availability. Keratins, the intermediate filament (IF) proteins of epithelial cells, are expressed as pairs in a lineage/differentiation manner. Hepatocyte and HCC (hepatoma) cell IFs are made solely of keratins 8/18 (K8/K18), thus providing models of choice to address K8/K18 IF functions in normal and cancerous epithelial cells. Here, we demonstrate distinctive increases in glucose uptake, glucose-6-phosphate formation, lactate release, and glycogen formation in K8/K18 IF-lacking hepatocytes and/or hepatoma cells versus their respective IF-containing counterparts. We also show that the K8/K18-dependent glucose uptake/G6P formation is linked to alterations in hexokinase I/II/IV content and localization at mitochondria, with little effect on GLUT1 status. In addition, we find that the insulin-stimulated glycogen formation in normal hepatocytes involves the main PI-3 kinase-dependent signaling pathway and that the K8/K18 IF loss makes them more efficient glycogen producers. In comparison, the higher insulin-dependent glycogen formation in K8/K18 IF-lacking hepatoma cells is associated with a signaling occurring through a mTOR-dependent pathway, along with an augmentation in cell proliferative activity. Together, the results uncover a key K8/K18 regulation of glucose metabolism in normal and cancerous hepatic cells through differential modulations of mitochondrial HK status and insulin-mediated signaling.

  12. Differential effect of saturated and polyunsaturated fatty acids on hepatic glucose metabolism in humans.

    PubMed

    Clore, John N; Stillman, Julie S; Li, Jing; O'Keefe, Stephen J D; Levy, James R

    2004-08-01

    Prolonged infusions of lipid and heparin that achieve high physiological free fatty acid (FFA) concentrations inhibit hepatic (and peripheral) insulin sensitivity in humans. These infusions are composed largely of polyunsaturated fatty acids (PUFA; linoleic and linolenic). It is not known whether fatty acid composition per se affects hepatic glucose metabolism in humans. To address this issue, we examined the impact of enteral infusions of either palm oil (48% palmitic, 35% oleic, and 8% linoleic acids) or safflower oil (6% palmitic, 12% oleic, 74% linoleic acids) in 14 obese nondiabetic subjects. (2)H(2)O was administered to determine the contribution of gluconeogenesis to endogenous glucose production (EGP), and a primed continuous infusion of [6,6-(2)H]glucose was administered to assess glucose appearance. As a result of the lipid infusions, plasma FFA concentrations increased significantly in both the palm oil (507.5 +/- 47.4 to 939.3 +/- 61.3 micromol/l, P < 0.01) and safflower oil (588.2.0 +/- 43.0 to 857.8 +/- 68.7 micromol/l, P < 0.01) groups after 4 h. EGP was similar at baseline (12.4 +/- 1.8 vs. 11.2 +/- 1.0 micromol x kg FFM(-1) x min(-1)). During a somatostatin-insulin clamp, the glucose infusion rate was significantly lower (AUC glucose infusion rate 195.8 +/- 50.7 vs. 377.8 +/- 38.0 micromol/kg FFM, P < 0.01), and rates of EGP were significantly higher (10.7 +/- 1.4 vs. 6.5 +/- 1.5 micromol x kg FFM(-1) x min(-1), P < 0.01) after palm oil compared with safflower oil, respectively. Baseline rates of gluconeogenesis and glycogenolysis were also similar. However, after lipid infusion, rates of glycogenolysis were suppressed by safflower oil but not by palm oil. Thus these studies demonstrate, for the first time in humans, a differential effect of saturated fatty acids and PUFA on hepatic glucose metabolism. PMID:15082421

  13. Different alterations in the insulin-stimulated glucose uptake in the athlete's heart and skeletal muscle.

    PubMed Central

    Nuutila, P; Knuuti, M J; Heinonen, O J; Ruotsalainen, U; Teräs, M; Bergman, J; Solin, O; Yki-Järvinen, H; Voipio-Pulkki, L M; Wegelius, U

    1994-01-01

    Physical training increases skeletal muscle insulin sensitivity. Since training also causes functional and structural changes in the myocardium, we compared glucose uptake rates in the heart and skeletal muscles of trained and untrained individuals. Seven male endurance athletes (VO2max 72 +/- 2 ml/kg/min) and seven sedentary subjects matched for characteristics other than VO2max (43 +/- 2 ml/kg/min) were studied. Whole body glucose uptake was determined with a 2-h euglycemic hyperinsulinemic clamp, and regional glucose uptake in femoral and arm muscles, and myocardium using 18F-fluoro-2-deoxy-D-glucose and positron emission tomography. Glucose uptake in the athletes was increased by 68% in whole body (P < 0.0001), by 99% in the femoral muscles (P < 0.01), and by 62% in arm muscles (P = 0.06), but it was decreased by 33% in the heart muscle (P < 0.05) as compared with the sedentary subjects. The total glucose uptake rate in the heart was similar in the athletes and control subjects. Left ventricular mass in the athletes was 79% greater (P < 0.001) and the meridional wall stress smaller (P < 0.001) as estimated by echocardiography. VO2max correlated directly with left ventricular mass (r = 0.87, P < 0.001) and inversely with left ventricular wall stress (r = -0.86, P < 0.001). Myocardial glucose uptake correlated directly with the rate-pressure product (r = 0.75, P < 0.02) and inversely with left ventricular mass (r = -0.60, P < 0.05) or with the whole body glucose disposal (r = -0.68, P < 0.01). Thus, in athletes, (a) insulin-stimulated glucose uptake is enhanced in the whole body and skeletal muscles, (b) whereas myocardial glucose uptake per muscle mass is reduced possibly due to decreased wall stress and energy requirements or the use of alternative fuels, or both. Images PMID:8182160

  14. Smurf1 inhibits osteoblast differentiation, bone formation and glucose homeostasis through Serine 148

    PubMed Central

    Shimazu, Junko; Wei, Jianwen; Karsenty, Gerard

    2016-01-01

    Summary The E3 ubiquitin ligase Smurf1 targets the master regulator of osteoblast differentiation Runx2, for degradation yet the function of Smurf1 if any during osteoblast differentiation in vivo is ill-defined. Here we show that Smurf1 prevents osteoblast differentiation by decreasing Runx2 accumulation in osteoblasts. Remarkably, mice harboring a substitution-mutation at serine 148 (S148) in Smurf1 that prevents its phosphorylation by AMPK (Smurf1ki/ki) display an equally severe premature osteoblast differentiation phenotype as Smurf1−/− mice, a high bone mass and are also hyperinsulinemic and hypoglycemic. Consistent with the fact that Smurf1 targets the insulin receptor for degradation, there is in Smurf1ki/ki mice an increase in insulin signaling in osteoblasts that triggers a rise in the circulating levels of osteocalcin, a hormone that favors insulin secretion. These results identify Smurf1 as a determinant of osteoblast differentiation during development, of bone formation and glucose homeostasis post-natally and demonstrate the necessity of S148 for these functions. PMID:27052174

  15. Fat intake leads to differential response of rat adipocytes to glucose, insulin and ascorbic acid.

    PubMed

    Garcia-Diaz, Diego F; Campion, Javier; Arellano, Arianna V; Milagro, Fermin I; Moreno-Aliaga, Maria J; Martinez, J Alfredo

    2012-04-01

    Antioxidant-based treatments have emerged as novel and interesting approaches to counteract fat accumulation in obesity and associated metabolic disturbances. Adipocytes from rats that were fed on chow or high-fat diet (HFD) for 50 d were isolated (primary adipocytes) and incubated (72 h) on low (LG; 5.6 mmol/L) or high (HG; 25 mmol/L) glucose levels, in the presence or absence of 1.6 nmol/L insulin and 200 μmol/L vitamin C (VC). Adipocytes from HFD-fed animals presented lower insulin-induced glucose uptake, lower lactate and glycerol release, and lower insulin-induced secretion of some adipokines as compared with controls. HG treatment restored the blunted response to insulin regarding apelin secretion in adipocytes from HFD-fed rats. VC treatment inhibited the levels of nearly all variables, irrespective of the adipocytes' dietary origin. The HG treatment reduced adipocyte viability, and VC protected from this toxic effect, although more drastically in control adipocytes. Summing up, in vivo chow or HFD intake determines a differential response to insulin and glucose treatments that appears to be dependent on the insulin-resistance status of the adipocytes, while VC modifies some responses from adipocytes independently of the previous dietary intake of the animals. PMID:22454546

  16. Differential Responses of Plasma Adropin Concentrations To Dietary Glucose or Fructose Consumption In Humans

    PubMed Central

    Butler, Andrew A.; St-Onge, Marie-Pierre; Siebert, Emily A.; Medici, Valentina; Stanhope, Kimber L.; Havel, Peter J.

    2015-01-01

    Adropin is a peptide hormone encoded by the Energy Homeostasis Associated (ENHO) gene whose physiological role in humans remains incompletely defined. Here we investigated the impact of dietary interventions that affect systemic glucose and lipid metabolism on plasma adropin concentrations in humans. Consumption of glucose or fructose as 25% of daily energy requirements (E) differentially affected plasma adropin concentrations (P < 0.005) irrespective of duration, sex or age. Glucose consumption reduced plasma adropin from 3.55 ± 0.26 to 3.28 ± 0.23 ng/ml (N = 42). Fructose consumption increased plasma adropin from 3.63 ± 0.29 to 3.93 ± 0.34 ng/ml (N = 45). Consumption of high fructose corn syrup (HFCS) as 25% E had no effect (3.43 ± 0.32 versus 3.39 ± 0.24 ng/ml, N = 26). Overall, the effect of glucose, HFCS and fructose on circulating adropin concentrations were similar to those observed on postprandial plasma triglyceride concentrations. Furthermore, increases in plasma adropin levels with fructose intake were most robust in individuals exhibiting hypertriglyceridemia. Individuals with low plasma adropin concentrations also exhibited rapid increases in plasma levels following consumption of breakfasts supplemented with lipids. These are the first results linking plasma adropin levels with dietary sugar intake in humans, with the impact of fructose consumption linked to systemic triglyceride metabolism. In addition, dietary fat intake may also increase circulating adropin concentrations. PMID:26435060

  17. Effects of high glucose on mesenchymal stem cell proliferation and differentiation

    SciTech Connect

    Li Yuming; Schilling, Tatjana; Benisch, Peggy; Zeck, Sabine; Meissner-Weigl, Jutta; Schneider, Doris; Limbert, Catarina; Seufert, Jochen; Kassem, Moustapha; Schuetze, Norbert; Jakob, Franz Ebert, Regina

    2007-11-09

    High glucose (HG) concentrations impair cellular functions and induce apoptosis. Exposition of mesenchymal stem cells (MSC) to HG was reported to reduce colony forming activity and induce premature senescence. We characterized the effects of HG on human MSC in vitro using telomerase-immortalized MSC (hMSC-TERT) and primary MSC (hMSC). HG (25 mM) enhanced hMSC-TERT proliferation in long-term studies in contrast to hMSC where proliferation was unchanged. Thioredoxin-interacting protein, which is involved in apoptosis regulation, was stimulated by glucose in hMSC-TERT. However, apoptosis was not influenced by HG in both cell types. MSC treatment with HG favored osteogenic differentiation. MSC are resistant to HG toxicity, depending on the stemness of MSC. Proliferation and osteogenic differentiation are stimulated by HG. Effects of HG on the transient amplifying compartment of MSC may differ from those in mature cells. Further research is needed to unravel the molecular mechanisms of HG resistance of MSC.

  18. Transplantation Dose Alters the Differentiation Program of Hematopoietic Stem Cells.

    PubMed

    Brewer, Casey; Chu, Elizabeth; Chin, Mike; Lu, Rong

    2016-05-24

    Hematopoietic stem cell (HSC) transplantation is the most prevalent stem cell therapy, but it remains a risky procedure. To improve this treatment, it is important to understand how transplanted stem cells rebuild the blood and immune systems and how this process is impacted by transplantation variables such as the HSC dose. Here, we find that, in the long term following transplantation, 70%-80% of donor-HSC-derived clones do not produce all measured blood cell types. High HSC doses lead to more clones that exhibit balanced lymphocyte production, whereas low doses produce more T-cell-specialized clones. High HSC doses also produce significantly higher proportions of early-differentiating clones compared to low doses. These complex differentiation behaviors uncover the clonal-level regeneration dynamics of hematopoietic regeneration and suggest that transplantation dose can be exploited to improve stem cell therapy. PMID:27184851

  19. Early alterations in soleus GLUT-4, glucose transport, and glycogen in voluntary running rats

    NASA Technical Reports Server (NTRS)

    Henriksen, Erik J.; Halseth, Amy E.

    1994-01-01

    Voluntary wheel running (WR) by juvenile female rats was used as a noninterventional model of soleus muscle functional overload to study the regulation of insulin-stimulated glucose transport activity by the glucose transporter (GLUT-4 isoform) protein level and glycogen concentration. Soleus total protein content was significantly greater (+18%;P greater than 0.05) than in age-matched controls after 1 wk of WR, and this hypertrophic response continued in weeks 2-4 (+24-32%). GLUT-4 protein was 39% greater than in controls in 1-wk WR soleus, and this adaptation was accompanied by a similar increase in in vitro insulin-stimulated glucose transport activity(+29%). After 2 and 4 wk of WR, however, insulin-stimulated glucose transport activity had returned to control levels, despite a continued elevation (+25-28%) of GLUT-4 protein. At these two time points, glycogen concentration was significantly enhanced in WR soleus (+21-42%), which coincided with significant reductions in glycogen synthase activity ratios (-23 to-41%). These results indicate that, in this model of soleus muscle functional overload, the GLUT-4 protein level may initially regulate insulin-stimulated glucose transport activity in the absence of changes in other modifying factors. However,this regulation of glucose transport activity by GLUT-4 protein may be subsequently overridden by elevated glycogen concentration.

  20. Foregut Exclusion Disrupts Intestinal Glucose Sensing and Alters Portal Nutrient and Hormonal Milieu

    PubMed Central

    Pal, Atanu; Rhoads, David B.

    2015-01-01

    The antidiabetes effects of Roux-en-Y gastric bypass (RYGB) are well-known, but the underlying mechanisms remain unclear. Isolating the proximal small intestine, and in particular its luminal glucose sensors, from the nutrient stream has been proposed as a critical change, but the pathways involved are unclear. In a rodent model, we tested the effects of isolating and then stimulating a segment of proximal intestine using glucose analogs to examine their impact on glucose absorption (Gabsorp) and hormone secretion after a glucose bolus into the distal jejunum. Analogs selective for sodium-glucose cotransporter (SGLT) family members and the sweet taste receptor were tested, and measurements of the portosystemic gradient were used to determine Gabsorp and hormone secretion, including GLP-1. Proximal intestinal isolation reduced Gabsorp and GLP-1 secretion. Stimulation of the glucose-sensing protein SGLT3 increased Gabsorp and GLP-1 secretion. These effects were abolished by vagotomy. Sweet taste receptor stimulation only increased GLP-1 secretion. This study suggests a novel role for SGLT3 in coordinating intestinal function, as reflected by the concomitant modulation of Gabsorp and GLP-1 secretion, with these effects being mediated by the vagus nerve. Our findings provide potential mechanistic insights into foregut exclusion in RYGB and identify SGLT3 as a possible antidiabetes therapeutic target. PMID:25576062

  1. Foregut exclusion disrupts intestinal glucose sensing and alters portal nutrient and hormonal milieu.

    PubMed

    Pal, Atanu; Rhoads, David B; Tavakkoli, Ali

    2015-06-01

    The antidiabetes effects of Roux-en-Y gastric bypass (RYGB) are well-known, but the underlying mechanisms remain unclear. Isolating the proximal small intestine, and in particular its luminal glucose sensors, from the nutrient stream has been proposed as a critical change, but the pathways involved are unclear. In a rodent model, we tested the effects of isolating and then stimulating a segment of proximal intestine using glucose analogs to examine their impact on glucose absorption (Gabsorp) and hormone secretion after a glucose bolus into the distal jejunum. Analogs selective for sodium-glucose cotransporter (SGLT) family members and the sweet taste receptor were tested, and measurements of the portosystemic gradient were used to determine Gabsorp and hormone secretion, including GLP-1. Proximal intestinal isolation reduced Gabsorp and GLP-1 secretion. Stimulation of the glucose-sensing protein SGLT3 increased Gabsorp and GLP-1 secretion. These effects were abolished by vagotomy. Sweet taste receptor stimulation only increased GLP-1 secretion. This study suggests a novel role for SGLT3 in coordinating intestinal function, as reflected by the concomitant modulation of Gabsorp and GLP-1 secretion, with these effects being mediated by the vagus nerve. Our findings provide potential mechanistic insights into foregut exclusion in RYGB and identify SGLT3 as a possible antidiabetes therapeutic target. PMID:25576062

  2. Changing climate cues differentially alter zooplankton dormancy dynamics across latitudes.

    PubMed

    Jones, Natalie T; Gilbert, Benjamin

    2016-03-01

    In seasonal climates, dormancy is a common strategy that structures biodiversity and is necessary for the persistence of many species. Climate change will likely alter dormancy dynamics in zooplankton, the basis of aquatic food webs, by altering two important hatching cues: mean temperatures during the ice-free season, and mean day length when lakes become ice free. Theory suggests that these changes could alter diversity, hatchling abundances and phenology within lakes, and that these responses may diverge across latitudes due to differences in optimal hatching cues and strategies. To examine the role of temperature and day length on hatching dynamics, we collected sediment from 25 lakes across a 1800 km latitudinal gradient and exposed sediment samples to a factorial combination of two photoperiods (12 and 16 h) and two temperatures (8 and 12 °C) representative of historical southern (short photoperiod, warm) and northern (long photoperiod, cool) lake conditions. We tested whether sensitivity to these hatching cues varies by latitudinal origin and differs among taxa. Higher temperatures advanced phenology for all taxa, and these advances were greatest for cladocerans followed by copepods and rotifers. Although phenology differed among taxa, the effect of temperature did not vary with latitude. The latitudinal origin of the egg bank influenced egg abundance and hatchling abundance and diversity, with these latter effects varying with taxa, temperature and photoperiod. Copepod hatchling abundances peaked at mid-latitudes in the high temperature and long photoperiod treatments, whereas hatchling abundances of other zooplankton were greatest at low latitudes and high temperature. The overall diversity of crustacean zooplankton (copepods and cladocerans) also reflected distinct responses of each taxa to our treatments, with the greatest diversity occurring at mid-latitudes (~56 °N) in the shorter photoperiod treatment. Our results demonstrate that hatching cues

  3. Antitumor and chemosensitizing action of dichloroacetate implicates modulation of tumor microenvironment: A role of reorganized glucose metabolism, cell survival regulation and macrophage differentiation

    SciTech Connect

    Kumar, Ajay; Kant, Shiva; Singh, Sukh Mahendra

    2013-11-15

    Targeting of tumor metabolism is emerging as a novel therapeutic strategy against cancer. Dichloroacetate (DCA), an inhibitor of pyruvate dehydrogenase kinase (PDK), has been shown to exert a potent tumoricidal action against a variety of tumor cells. The main mode of its antineoplastic action implicates a shift of glycolysis to oxidative metabolism of glucose, leading to generation of cytotoxic reactive oxygen intermediates. However, the effect of DCA on tumor microenvironment, which in turn regulates tumor cell survival; remains speculative to a large extent. It is also unclear if DCA can exert any modulatory effect on the process of hematopoiesis, which is in a compromised state in tumor-bearing hosts undergoing chemotherapy. In view of these lacunas, the present study was undertaken to investigate the so far unexplored aspects with respect to the molecular mechanisms of DCA-dependent tumor growth retardation and chemosensitization. BALB/c mice were transplanted with Dalton's lymphoma (DL) cells, a T cell lymphoma of spontaneous origin, followed by administration of DCA with or without cisplatin. DCA-dependent tumor regression and chemosensitization to cisplatin was found to be associated with altered repertoire of key cell survival regulatory molecules, modulated glucose metabolism, accompanying reconstituted tumor microenvironment with respect to pH homeostasis, cytokine balance and alternatively activated TAM. Moreover, DCA administration also led to an alteration in the MDR phenotype of tumor cells and myelopoietic differentiation of macrophages. The findings of this study shed a new light with respect to some of the novel mechanisms underlying the antitumor action of DCA and thus may have immense clinical applications. - Highlights: • DCA modulates tumor progression and chemoresistance. • DCA alters molecules regulating cell survival, glucose metabolism and MDR. • DCA reconstitutes biophysical and cellular composition of tumor microenvironment.

  4. Locomotion in Lymphocytes is Altered by Differential PKC Isoform Expression

    NASA Technical Reports Server (NTRS)

    Sundaresan, A.; Risin, D.; Pellis, N. R.

    1999-01-01

    Lymphocyte locomotion is critical for proper elicitation of the immune response. Locomotion of immune cells via the interstitium is essential for optimal immune function during wound healing, inflammation and infection. There are conditions which alter lymphocyte locomotion and one of them is spaceflight. Lymphocyte locomotion is severely inhibited in true spaceflight (true microgravity) and in rotating wall vessel culture (modeled microgravity). When lymphocytes are activated prior to culture in modeled microgravity, locomotion is not inhibited and the levels are comparable to those of static cultured lymphocytes. When a phorbol ester (PMA) is used in modeled microgravity, lymphocyte locomotion is restored by 87%. This occurs regardless if PMA is added after culture in the rotating wall vessel or during culture. Inhibition of DNA synthesis also does not alter restoration of lymphocyte locomotion by PMA. PMA is a direct activator of (protein kinase C) PKC . When a calcium ionophore, ionomycin is used it does not possess any restorative properties towards locomotion either alone or collectively with PMA. Since PMA brings about restoration without help from calcium ionophores (ionomycin), it is infer-red that calcium independent PKC isoforms are involved. Changes were perceived in the protein levels of PKC 6 where levels of the protein were downregulated at 24,72 and 96 hours in untreated rotated cultures (modeled microgravity) compared to untreated static (1g) cultures. At 48 hours there is an increase in the levels of PKC & in the same experimental set up. Studies on transcriptional and translational patterns of calcium independent isoforms of PKC such as 8 and E are presented in this study.

  5. Diabetes alters the blood glucose response to ketamine in streptozotocin-diabetic rats

    PubMed Central

    Chen, Huayong; Li, Li; Xia, Hui

    2015-01-01

    Ketamine is a commonly used short-acting anesthetic and recently attempted to treat pain which is a complication of diabetes. In this study we investigated the effect of ketamine on glucose levels of normal rats and diabetic rats. The results showed that no significance between the glucose levels in ketamine treatment group and saline treatment group at all time points was observed in normal rats. Ketamine did not produce hyperglycemia in normal fasted rats. However, ketamine dose dependently elevated glucose in diabetic rats from 80 mg/kg to 120 mg/kg at 1 hour after injection. The glucose did not return to the levels before treatment in streptozotocin (STZ) induced diabetic rats. Insulin revealed a powerful potency in decreasing glucose levels in diabetic rats. Ketamine did not induce acute hyperglycemia any more after diabetic rats pretreated with insulin. Serum corticosterone was significantly increased in all treatment groups including saline group after 1 hour treatment compared with baseline values. Then the corticosterone declined in both saline treatment groups. However, ketamine induced a more significant increase in corticosterone at 1 hour after injection compared with that of saline control group of diabetic rats. And no decline trend of corticosterone was observed after ketamine treatment 2 hours. Insulin did not reduce the elevated corticosterone level induced by ketamine either. The results suggested that the diabetic rats had a risk of hyperglycaemia when they were treated with ketamine. Pretreatment with insulin is a good symptomatic treatment for hyperglycaemia induced by ketamine. PMID:26379948

  6. Diabetes alters the blood glucose response to ketamine in streptozotocin-diabetic rats.

    PubMed

    Chen, Huayong; Li, Li; Xia, Hui

    2015-01-01

    Ketamine is a commonly used short-acting anesthetic and recently attempted to treat pain which is a complication of diabetes. In this study we investigated the effect of ketamine on glucose levels of normal rats and diabetic rats. The results showed that no significance between the glucose levels in ketamine treatment group and saline treatment group at all time points was observed in normal rats. Ketamine did not produce hyperglycemia in normal fasted rats. However, ketamine dose dependently elevated glucose in diabetic rats from 80 mg/kg to 120 mg/kg at 1 hour after injection. The glucose did not return to the levels before treatment in streptozotocin (STZ) induced diabetic rats. Insulin revealed a powerful potency in decreasing glucose levels in diabetic rats. Ketamine did not induce acute hyperglycemia any more after diabetic rats pretreated with insulin. Serum corticosterone was significantly increased in all treatment groups including saline group after 1 hour treatment compared with baseline values. Then the corticosterone declined in both saline treatment groups. However, ketamine induced a more significant increase in corticosterone at 1 hour after injection compared with that of saline control group of diabetic rats. And no decline trend of corticosterone was observed after ketamine treatment 2 hours. Insulin did not reduce the elevated corticosterone level induced by ketamine either. The results suggested that the diabetic rats had a risk of hyperglycaemia when they were treated with ketamine. Pretreatment with insulin is a good symptomatic treatment for hyperglycaemia induced by ketamine. PMID:26379948

  7. Queens become workers: pesticides alter caste differentiation in bees

    PubMed Central

    dos Santos, Charles F.; Acosta, André L.; Dorneles, Andressa L.; dos Santos, Patrick D. S.; Blochtein, Betina

    2016-01-01

    Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies. PMID:27530246

  8. Queens become workers: pesticides alter caste differentiation in bees.

    PubMed

    Dos Santos, Charles F; Acosta, André L; Dorneles, Andressa L; Dos Santos, Patrick D S; Blochtein, Betina

    2016-01-01

    Bees are important for the world biodiversity and economy because they provide key pollination services in forests and crops. However, pesticide use in crops has adversely affected (decreased) queen production because of increased mortality among larvae. Here, we demonstrated that in vitro-reared queens of a neotropical social bee species (Plebeia droryana) also showed high larval mortality after exposure to an organophosphate pesticide (chlorpyrifos) via larval food. Moreover, most of the surviving larvae that were destined to develop into queens became workers more likely because they ate less food than expected without pesticide skewing thus caste differentiation in this bee species. This adverse effect has not been previously reported for any other social insects, such as honeybees or bumblebees. Queens are essential for breeding and colony growth. Therefore, if our data are applicable to other pantropical social bee species across the globe, it is likely that these bees are at a serious risk of failure to form new colonies. PMID:27530246

  9. Differential CYP 2D6 Metabolism Alters Primaquine Pharmacokinetics

    PubMed Central

    Potter, Brittney M. J.; Xie, Lisa H.; Vuong, Chau; Zhang, Jing; Zhang, Ping; Duan, Dehui; Luong, Thu-Lan T.; Bandara Herath, H. M. T.; Dhammika Nanayakkara, N. P.; Tekwani, Babu L.; Walker, Larry A.; Nolan, Christina K.; Sciotti, Richard J.; Zottig, Victor E.; Smith, Philip L.; Paris, Robert M.; Read, Lisa T.; Li, Qigui; Pybus, Brandon S.; Sousa, Jason C.; Reichard, Gregory A.

    2015-01-01

    Primaquine (PQ) metabolism by the cytochrome P450 (CYP) 2D family of enzymes is required for antimalarial activity in both humans (2D6) and mice (2D). Human CYP 2D6 is highly polymorphic, and decreased CYP 2D6 enzyme activity has been linked to decreased PQ antimalarial activity. Despite the importance of CYP 2D metabolism in PQ efficacy, the exact role that these enzymes play in PQ metabolism and pharmacokinetics has not been extensively studied in vivo. In this study, a series of PQ pharmacokinetic experiments were conducted in mice with differential CYP 2D metabolism characteristics, including wild-type (WT), CYP 2D knockout (KO), and humanized CYP 2D6 (KO/knock-in [KO/KI]) mice. Plasma and liver pharmacokinetic profiles from a single PQ dose (20 mg/kg of body weight) differed significantly among the strains for PQ and carboxy-PQ. Additionally, due to the suspected role of phenolic metabolites in PQ efficacy, these were probed using reference standards. Levels of phenolic metabolites were highest in mice capable of metabolizing CYP 2D6 substrates (WT and KO/KI 2D6 mice). PQ phenolic metabolites were present in different quantities in the two strains, illustrating species-specific differences in PQ metabolism between the human and mouse enzymes. Taking the data together, this report furthers understanding of PQ pharmacokinetics in the context of differential CYP 2D metabolism and has important implications for PQ administration in humans with different levels of CYP 2D6 enzyme activity. PMID:25645856

  10. Metabolism of Fructooligosaccharides in Lactobacillus plantarum ST-III via Differential Gene Transcription and Alteration of Cell Membrane Fluidity.

    PubMed

    Chen, Chen; Zhao, Guozhong; Chen, Wei; Guo, Benheng

    2015-11-01

    Although fructooligosaccharides (FOS) can selectively stimulate the growth and activity of probiotics and beneficially modulate the balance of intestinal microbiota, knowledge of the molecular mechanism for FOS metabolism by probiotics is still limited. Here a combined transcriptomic and physiological approach was used to survey the global alterations that occurred during the logarithmic growth of Lactobacillus plantarum ST-III using FOS or glucose as the sole carbon source. A total of 363 genes were differentially transcribed; in particular, two gene clusters were induced by FOS. Gene inactivation revealed that both of the clusters participated in the metabolism of FOS, which were transported across the membrane by two phosphotransferase systems (PTSs) and were subsequently hydrolyzed by a β-fructofuranosidase (SacA) in the cytoplasm. Combining the measurements of the transcriptome- and membrane-related features, we discovered that the genes involved in the biosynthesis of fatty acids (FAs) were repressed in cells grown on FOS; as a result, the FA profiles were altered by shortening of the carbon chains, after which membrane fluidity increased in response to FOS transport and utilization. Furthermore, incremental production of acetate was observed in both the transcriptomic and the metabolic experiments. Our results provided new insights into gene transcription, the production of metabolites, and membrane alterations that could explain FOS metabolism in L. plantarum. PMID:26319882

  11. Metabolism of Fructooligosaccharides in Lactobacillus plantarum ST-III via Differential Gene Transcription and Alteration of Cell Membrane Fluidity

    PubMed Central

    Chen, Chen; Zhao, Guozhong

    2015-01-01

    Although fructooligosaccharides (FOS) can selectively stimulate the growth and activity of probiotics and beneficially modulate the balance of intestinal microbiota, knowledge of the molecular mechanism for FOS metabolism by probiotics is still limited. Here a combined transcriptomic and physiological approach was used to survey the global alterations that occurred during the logarithmic growth of Lactobacillus plantarum ST-III using FOS or glucose as the sole carbon source. A total of 363 genes were differentially transcribed; in particular, two gene clusters were induced by FOS. Gene inactivation revealed that both of the clusters participated in the metabolism of FOS, which were transported across the membrane by two phosphotransferase systems (PTSs) and were subsequently hydrolyzed by a β-fructofuranosidase (SacA) in the cytoplasm. Combining the measurements of the transcriptome- and membrane-related features, we discovered that the genes involved in the biosynthesis of fatty acids (FAs) were repressed in cells grown on FOS; as a result, the FA profiles were altered by shortening of the carbon chains, after which membrane fluidity increased in response to FOS transport and utilization. Furthermore, incremental production of acetate was observed in both the transcriptomic and the metabolic experiments. Our results provided new insights into gene transcription, the production of metabolites, and membrane alterations that could explain FOS metabolism in L. plantarum. PMID:26319882

  12. Diabetes Alters the Expression and Translocation of the Insulin-Sensitive Glucose Transporters 4 and 8 in the Atria

    PubMed Central

    Maria, Zahra; Campolo, Allison R.; Lacombe, Veronique A.

    2015-01-01

    Although diabetes has been identified as a major risk factor for atrial fibrillation, little is known about glucose metabolism in the healthy and diabetic atria. Glucose transport into the cell, the rate-limiting step of glucose utilization, is regulated by the Glucose Transporters (GLUTs). Although GLUT4 is the major isoform in the heart, GLUT8 has recently emerged as a novel cardiac isoform. We hypothesized that GLUT-4 and -8 translocation to the atrial cell surface will be regulated by insulin and impaired during insulin-dependent diabetes. GLUT protein content was measured by Western blotting in healthy cardiac myocytes and type 1 (streptozotocin-induced, T1Dx) diabetic rodents. Active cell surface GLUT content was measured using a biotinylated photolabeled assay in the perfused heart. In the healthy atria, insulin stimulation increased both GLUT-4 and -8 translocation to the cell surface (by 100% and 240%, respectively, P<0.05). Upon insulin stimulation, we reported an increase in Akt (Th308 and s473 sites) and AS160 phosphorylation, which was positively (P<0.05) correlated with GLUT4 protein content in the healthy atria. During diabetes, active cell surface GLUT-4 and -8 content was downregulated in the atria (by 70% and 90%, respectively, P<0.05). Akt and AS160 phosphorylation was not impaired in the diabetic atria, suggesting the presence of an intact insulin signaling pathway. This was confirmed by the rescued translocation of GLUT-4 and -8 to the atrial cell surface upon insulin stimulation in the atria of type 1 diabetic subjects. In conclusion, our data suggest that: 1) both GLUT-4 and -8 are insulin-sensitive in the healthy atria through an Akt/AS160 dependent pathway; 2) GLUT-4 and -8 trafficking is impaired in the diabetic atria and rescued by insulin treatment. Alterations in atrial glucose transport may induce perturbations in energy production, which may provide a metabolic substrate for atrial fibrillation during diabetes. PMID:26720696

  13. Slowly digestible starch diets alter proximal glucosidase activity and glucose absorption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrase-isomaltase (Si) and maltase-glucoamylase (Mgam) are mucosal glucosidases required for digestion of starch to glucose. Ablation of maltase-Mgam reduces in vivo starch digestion. We tested whether slowly digestible starch diets induce changes in glucosidase activities. Rice starch was encaps...

  14. Altered baseline brain activity differentiates regional mechanisms subserving biological and psychological alterations in obese men

    PubMed Central

    Zhang, Bin; Tian, Derun; Yu, Chunshui; Li, Meng; Zang, Yufeng; Liu, Yijun; Walter, Martin

    2015-01-01

    Obesity as a chronic disease is a major factor for insulin resistance and Type 2 diabetes, which has become a global health problem. In the present study, we used resting state functional MRI to investigate the amplitude of low frequency fluctuations of spontaneous signal during both hunger and satiety states in 20 lean and 20 obese males. We found that, before food intake, obese men had significantly greater baseline activity in the precuneus and lesser activity in dorsal anterior cingulate cortex (dACC) relative to lean subjects. Furthermore, after food intake, obese males had significantly lesser activity in dACC than lean males. We further found a significant positive correlation between precuneus activation and hunger ratings before food intake, while dACC activity was negatively correlated with plasma insulin levels before and after food intake. These results indicated that both precuneus and dACC may play an important role in eating behavior. While precuneus rather seemed to mediate subjective satiety, dACC levels rather reflected indirect measures of glucose utilization. PMID:26099208

  15. Altered baseline brain activity differentiates regional mechanisms subserving biological and psychological alterations in obese men.

    PubMed

    Zhang, Bin; Tian, Derun; Yu, Chunshui; Li, Meng; Zang, Yufeng; Liu, Yijun; Walter, Martin

    2015-01-01

    Obesity as a chronic disease is a major factor for insulin resistance and Type 2 diabetes, which has become a global health problem. In the present study, we used resting state functional MRI to investigate the amplitude of low frequency fluctuations of spontaneous signal during both hunger and satiety states in 20 lean and 20 obese males. We found that, before food intake, obese men had significantly greater baseline activity in the precuneus and lesser activity in dorsal anterior cingulate cortex (dACC) relative to lean subjects. Furthermore, after food intake, obese males had significantly lesser activity in dACC than lean males. We further found a significant positive correlation between precuneus activation and hunger ratings before food intake, while dACC activity was negatively correlated with plasma insulin levels before and after food intake. These results indicated that both precuneus and dACC may play an important role in eating behavior. While precuneus rather seemed to mediate subjective satiety, dACC levels rather reflected indirect measures of glucose utilization. PMID:26099208

  16. Dietary patterns in men and women are simultaneously determinants of altered glucose metabolism and bone metabolism.

    PubMed

    Langsetmo, Lisa; Barr, Susan I; Dasgupta, Kaberi; Berger, Claudie; Kovacs, Christopher S; Josse, Robert G; Adachi, Jonathan D; Hanley, David A; Prior, Jerilynn C; Brown, Jacques P; Morin, Suzanne N; Davison, Kenneth S; Goltzman, David; Kreiger, Nancy

    2016-04-01

    We hypothesized that diet would have direct effects on glucose metabolism with direct and indirect effects on bone metabolism in a cohort of Canadian adults. We assessed dietary patterns (Prudent [fruit, vegetables, whole grains, fish, and legumes] and Western [soft drinks, potato chips, French fries, meats, and desserts]) from a semiquantitative food frequency questionnaire. We used fasting blood samples to measure glucose, insulin, homeostatic model assessment insulin resistance (HOMA-IR), 25-hydroxyvitamin D (25OHD), parathyroid hormone, bone-specific alkaline phosphatase (a bone formation marker), and serum C-terminal telopeptide (CTX; a bone resorption marker). We used multivariate regression models adjusted for confounders and including/excluding body mass index. In a secondary analysis, we examined relationships through structural equations models. The Prudent diet was associated with favorable effects on glucose metabolism (lower insulin and HOMA-IR) and bone metabolism (lower CTX in women; higher 25OHD and lower parathyroid hormone in men). The Western diet was associated with deleterious effects on glucose metabolism (higher glucose, insulin, and HOMA-IR) and bone metabolism (higher bone-specific alkaline phosphatase and lower 25OHD in women; higher CTX in men). Body mass index adjustment moved point estimates toward the null, indicating partial mediation. The structural equation model confirmed the hypothesized linkage with strong effects of Prudent and Western diet on metabolic risk, and both direct and indirect effects of a Prudent diet on bone turnover. In summary, a Prudent diet was associated with lower metabolic risk with both primary and mediated effects on bone turnover, suggesting that it is a potential target for reducing fracture risk. PMID:27001278

  17. Chronic levodopa treatment alters basal and dopamine agonist-stimulated cerebral glucose utilization

    SciTech Connect

    Engber, T.M.; Susel, Z.; Kuo, S.; Chase, T.N. )

    1990-12-01

    The effect of chronic levodopa administration on the functional activity of the basal ganglia and its output regions was evaluated by means of the 2-deoxyglucose (2-DG) autoradiographic technique in rats with a unilateral 6-hydroxydopamine lesion of the nigrostriatal pathway. The rates of local cerebral glucose utilization were studied under basal conditions as well as in response to challenge with a selective D1 or D2 dopamine-receptor agonist. Levodopa (100 mg/kg/d, i.p.) was administered for 19 d either continuously via infusion with an osmotic pump or intermittently by twice-daily injections. Following a 3-d washout, glucose utilization was found to be decreased by both levodopa regimens in the nucleus accumbens; intermittent levodopa also decreased glucose utilization in the entopeduncular nucleus, subthalamic nucleus, ventrolateral thalamus, ventromedial thalamus, ventroposterolateral thalamus, and lateral habenula. In control (lesioned and treated chronically with saline) rats, the D1 agonist SKF 38393 (5 mg/kg, i.v.) increased 2-DG uptake in the substantia nigra pars reticulata and entopeduncular nucleus ipsilateral to the lesion by 84% and 56%, respectively. Both continuous and intermittent levodopa blunted the SKF 38393-induced elevation in glucose metabolism in the substantia nigra pars reticulata, while intermittent levodopa also attenuated the increase in the entopeduncular nucleus. The D2 agonist quinpirole (0.4 mg/kg, i.v.) did not increase glucose utilization in any brain region in control animals; following intermittent levodopa treatment, however, quinpirole increased 2-DG uptake by 64% in the subthalamic nucleus and by 39% in the deep layers of the superior colliculus on the ipsilateral side.

  18. GLUCOSE METABOLITE PATTERNS AS MARKERS OF FUNCTIONAL DIFFERENTIATION IN FRESHLY ISOLATED AND CULTURED MOUSE MAMMARY EPITHELIAL CELLS

    SciTech Connect

    Emerman, J.T.; Bartley, J.C.; Bissell, M.J.

    1980-06-01

    In the mammary gland of nonruminant animals, glucose is utilized in a characteristic and unique way during lactation. We have measured the incorporation of glucose carbon from [U-{sup 14}C] glucose into intermediary metabolites and metabolic products in mammary epithelial cells from virgin, pregnant, and lactating mice and demonstrate that glucose metabolite patterns can be used to recognize stages of differentiated function. For these cells, the rates of synthesis of glycogen and lactose, the ratio of lactate to alanine, and the ratio of citrate to malate were important parameters in identifying the degree of expression of differentiation. We further show that these patterns can be used as markers to determine the differentiated state of cultured mammary epithelial cells. Cells maintained on plastic substrates lose their distinctive glucose metabolite patterns while those on floating collagen gels do not. Cells from pregnant mice have a pattern similar to freshly isolated cells from pregnant mice. The pattern of cells from lactating mice is different from that of the cells of origin, and resembles that of the cells from pregnant mice. Our findings suggest that the floating collagen gels under the culture conditions used in these experiments provide an environment for the functional expression of the pregnant state, while additional factors are needed for the expression of the lactating state.

  19. Glucose metabolite patterns as markers of functional differentiation in freshly isolated and cultured mouse mammary epithelial cells

    SciTech Connect

    Emerman, J.T.; Bartley, J.C.; Bissel, M.J.

    1981-01-01

    In the mammary gland of non-ruminant animals, glucose is utilized in a characteristic and unique way during lacation. By measuring the incorporation of glucose carbon from (U-/sup 14/C)glucose into intermediary metabolitees and metabolic products in mammary epithelia cells from virgin, pregnant, and lacating mice, we domonstrate that glucose metabolite patterns can be used to recognize stages of differentiated function. For these cells, the rates of synthesis of glycogen and lactose, the ratio of lactate to alanine, and the ratio of citrate to malate are important parameters in identifying the degree of expression of differentiation. We further show that these patterns can be used as markers to determine the differentiated state of cultured mammary epithelial cells. Cells maintained on plastic substrates lose their distinctive glucose metabolite patterns while those on floating collagen gels do not. Cells isolated from pregnant mice and cultured on collagen gels have a pattern similar to that of their freshly isolated counter-parts. When isolated from lacating mice, the metabolite patterns of cells cultured on collagen gels are different from that of the cells of origin, and resembles that of freshly isolated cells from pregnant mice. Our findings suggest that the floating collagen gels under the culture conditions used in these experiments provide an environment for the functional expression of the pregnant state, while additional factors are needed for the expression of the lactating state.

  20. Alterations in Glucose Metabolism on Cognition: A Possible Link Between Diabetes and Dementia.

    PubMed

    González-Reyes, Rodrigo E; Aliev, Gjumrakch; Ávila-Rodrigues, Marco; Barreto, George E

    2016-01-01

    The use of the carbohydrate glucose as an energetic source is essential for an adequate function of the human body. The complex regulation of this molecule involves the coordinated action of various organs such as pancreas, liver and brain. Any disruption of this physiological balance may result in a dangerous compromise of general metabolic activities increasing the possibility of developing T1DM, T2DM and possibly AD. Astrocytes convert glucose into lactate and transfer it to neurons. This lactate is essential for neuronal metabolism and for various processes including the formation of synapses, dendrites and the expression of genes involved in memory. The brain is highly susceptible to variations in glucose blood levels, and both hypoglycemia and hyperglycemia can be dangerous. Pathological hyperglycemia induces changes in plasmatic osmotic pressure, mitochondrial production of free radicals, oxidative stress and activation of neuronal apoptosis, among others. Both AD and diabetes are chronic diseases having age as an important risk factor. As the brain ages, it seems to become much more susceptible to cellular damage induced by excess of circulating glucose and this could explain the appearance of cognitive changes observed in some patients with diabetes. Excessive circulation of pro-inflammatory agents has been observed in insulin resistance and is likely that some of these mediators may cross the bloodbrain barrier and induce abnormal neuroinflammation. GSK-3 is overexpressed in diabetes and also has been reported to regulate tau phosphorylation and production of Aβ peptides in the brain. Currently, diabetes (hyperglycemia) is considered as a risk factor for the development of AD. A novel therapeutic approach, using intranasal insulin and anti-diabetic medications in patients suffering from AD is being explored and is discussed in this review. PMID:26648470

  1. Association of Urinary Metal Profiles with Altered Glucose Levels and Diabetes Risk: A Population-Based Study in China

    PubMed Central

    Feng, Wei; Cui, Xiuqing; Liu, Bing; Liu, Chuanyao; Xiao, Yang; Lu, Wei; Guo, Huan; He, Meian; Zhang, Xiaomin; Yuan, Jing; Chen, Weihong; Wu, Tangchun

    2015-01-01

    Background Elevated heavy metals and fasting plasma glucose (FPG) levels were both associated with increased risk of cardiovascular diseases. However, studies on the associations of heavy metals and essential elements with altered FPG and diabetes risk were limited or conflicting. The objective of this study was to evaluate the potential associations of heavy metals and essential trace elements with FPG and diabetes risk among general Chinese population. Methods We conducted a cross-sectional study to investigate the associations of urinary concentrations of 23 metals with FPG, impaired fasting glucose (IFG) and diabetes among 2242 community-based Chinese adults in Wuhan. We used the false discovery rate (FDR) method to correct for multiple hypothesis tests. Results After adjusting for potential confounders, urinary aluminum, titanium, cobalt, nickel, copper, zinc, selenium, rubidium, strontium, molybdenum, cadmium, antimony, barium, tungsten and lead were associated with altered FPG, IFG or diabetes risk (all P< 0.05); arsenic was only dose-dependently related to diabetes (P< 0.05). After additional adjustment for multiple testing, titanium, copper, zinc, selenium, rubidium, tungsten and lead were still significantly associated with one or more outcomes (all FDR-adjusted P< 0.05). Conclusions Our results suggest that multiple metals in urine are associated with FPG, IFG or diabetes risk. Because the cross-sectional design precludes inferences about causality, further prospective studies are warranted to validate our findings. PMID:25874871

  2. Adolescents with Mild Stunting Show Alterations in Glucose and Insulin Metabolism

    PubMed Central

    da Luz Santos, Carla Danusa; Clemente, Ana Paula Grotti; Martins, Vinicius José Baccin; Albuquerque, Maria Paula; Sawaya, Ana Lydia

    2010-01-01

    Purpose. To evaluate glucose and insulin profiles in adolescents with mild stunting and overweight in order to assess the possibility of increased predisposition to diabetes. Subjects and Methods. The study population consisted of 66 pubertal adolescents classified as mildly stunted (height-for-age z scores ≥−2 and <−1) or of normal stature, as well as overweight (body mass index ≥85th percentile) or normal weight. Beta-cell function and insulin resistance were evaluated according to the homeostasis model assessment (HOMA). Results. In the group with mild stunting, glucose, insulin, and HOMA-IR levels were significantly higher in overweight adolescents compared with those of normal weight, whereas HOMA-B levels were significantly lower. Adolescents with mild stunting showed significantly higher accumulations of body and abdominal fat than their normal stature counterparts. Conclusions. The presence of mild stunting was associated with higher levels of glucose and insulin, diminished function of beta cells, and increased insulin resistance. These results reinforce the need for intervention in adolescents with mild stunting. PMID:21318152

  3. Local release of masitinib alters in vivo implantable continuous glucose sensor performance.

    PubMed

    Avula, M; Jones, D; Rao, A N; McClain, D; McGill, L D; Grainger, D W; Solzbacher, F

    2016-03-15

    Continuous glucose monitoring (CGM) sensors are often advocated as a clinical solution to improve long-term glycemic control in the context of diabetes. Subcutaneous sensor inflammatory response, fouling and fibrous encapsulation resulting from the host foreign body response (FBR) reduce sensor sensitivity to glucose, eventually resulting in sensor performance compromise and device failure. Several combination device strategies load CGM sensors with drug payloads that release locally to tissue sites to mitigate FBR-mediated sensor failure. In this study, the mast cell-targeting tyrosine kinase inhibitor, masitinib, was released from degradable polymer microspheres delivered from the surfaces of FDA-approved human commercial CGM needle-type implanted sensors in a rodent subcutaneous test bed. By targeting the mast cell c-Kit receptor and inhibiting mast cell activation and degranulation, local masitinib penetration around the CGM to several hundred microns sought to reduce sensor fibrosis to extend CGM functional lifetimes in subcutaneous sites. Drug-releasing and control CGM implants were compared in murine percutaneous implant sites for 21 days using direct-wire continuous glucose reporting. Drug-releasing implants exhibited no significant difference in CGM fibrosis at implant sites but showed relatively stable continuous sensor responses over the study period compared to blank microsphere control CGM implants. PMID:26402593

  4. Blueberries improve glucose tolerance and lipid handling without altering body composition in obese postmenopausal mice

    PubMed Central

    Elks, Carrie M.; Terrebonne, Jennifer D.; Ingram, Donald K.; Stephens, Jacqueline M.

    2014-01-01

    Objective Metabolic syndrome (MetS) risk increases significantly during menopause and remains elevated post-menopause. Several botanicals, including blueberries (BB), have been shown to delay MetS progression, but few studies have been conducted in postmenopausal animal models. Here, we examined the effects of BB supplementation on obese postmenopausal mice using a chemically-induced menopause model. Design and Methods After induction of menopause, mice were fed a high-fat diet or the same diet supplemented with 4% BB powder for 12 weeks. Body weight and body composition were measured, and mice were subjected to glucose and insulin tolerance tests. Serum triglycerides and adiponectin were measured, and liver histology and hepatic gene expression were assessed. Results: Menopausal and BB-supplemented mice had significantly higher body weights and fat mass than control mice, while menopausal mice had impaired glucose tolerance and higher serum triglycerides when compared with control and BB-supplemented mice. Menopausal mice also had hepatic steatosis that was prevented by BB supplementation and correlated with expression of genes involved in hepatic fatty acid oxidation. Conclusions We conclude that BB supplementation prevents the glucose intolerance and hepatic steatosis that occur in obese postmenopausal mice, and that these effects are independent of body weight. PMID:25611327

  5. Effects of High Glucose on Cell Viability and Differentiation in Primary Cultured Schwann Cells: Potential Role of ERK Signaling Pathway.

    PubMed

    Liu, Di; Liang, Xiaochun; Zhang, Hong

    2016-06-01

    Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes mellitus and hyperglycemia is considered to be the major factor in the development and progression of DPN. Because of the contribution of Schwann cells (SCs) to the pathology of DPN, we investigated the effects of high glucose on cell proliferation, apoptosis and differentiation in primary cultured SCs. Cell Counting Kit-8 (CCK-8) assay and Hoechst staining showed that high glucose inhibited SCs proliferation and increased apoptosis ratio in time and concentration dependent manner. Western blot and real-time quantitative PCR analysis revealed that the major myelin proteins and genes expressions including P0, MAG and Krox-20, were downregulated time dependently in SCs exposed to high glucose from 48 to 96 h. To further elucidate the underlying pathogenic mechanisms, we also explored the role of ERK signaling pathway in high glucose induced SC injury, which has been proved to drive demyelination of peripheral nerves. The western blot analysis showed that compared with control group phosphorylation level of ERK was increased by 14.3 % in SCs exposed to high glucose for 72 h (P < 0.01). Using immunocytochemistry analysis, we observed that the ERK specific inhibitor U0126 blocked the ERK activation induced by high glucose and reversed the inhibitory effect of high glucose on P0 expression. Taken together, these results suggest that high glucose can cause damage in primary cultured SCs and may exert the inhibitory effect on SC differentiation and myelination through ERK signaling activation. PMID:26915107

  6. Protection against Myocardial Ischemia-Reperfusion Injury at Onset of Type 2 Diabetes in Zucker Diabetic Fatty Rats Is Associated with Altered Glucose Oxidation

    PubMed Central

    Povlsen, Jonas Agerlund; Løfgren, Bo; Dalgas, Christian; Birkler, Rune Isak Dupont; Johannsen, Mogens; Støttrup, Nicolaj Brejnholt; Bøtker, Hans Erik

    2013-01-01

    Background Inhibition of glucose oxidation during initial reperfusion confers protection against ischemia-reperfusion (IR) injury in the heart. Mitochondrial metabolism is altered with progression of type 2 diabetes (T2DM). We hypothesized that the metabolic alterations present at onset of T2DM induce cardioprotection by metabolic shutdown during IR, and that chronic alterations seen in late T2DM cause increased IR injury. Methods Isolated perfused hearts from 6 (prediabetic), 12 (onset of T2DM) and 24 (late T2DM) weeks old male Zucker diabetic fatty rats (ZDF) and their age-matched heterozygote controls were subjected to 40 min ischemia/120 min reperfusion. IR injury was assessed by TTC-staining. Myocardial glucose metabolism was evaluated by glucose tracer kinetics (glucose uptake-, glycolysis- and glucose oxidation rates), myocardial microdialysis (metabolomics) and tissue glycogen measurements. Results T2DM altered the development in sensitivity towards IR injury compared to controls. At late diabetes ZDF hearts suffered increased damage, while injury was decreased at onset of T2DM. Coincident with cardioprotection, oxidation of exogenous glucose was decreased during the initial and normalized after 5 minutes of reperfusion. Metabolomic analysis of citric acid cycle intermediates demonstrated that cardioprotection was associated with a reversible shutdown of mitochondrial glucose metabolism during ischemia and early reperfusion at onset of but not at late type 2 diabetes. Conclusions The metabolic alterations of type 2 diabetes are associated with protection against IR injury at onset but detrimental effects in late diabetes mellitus consistent with progressive dysfunction of glucose oxidation. These findings may explain the variable efficacy of cardioprotective interventions in individuals with type 2 diabetes. PMID:23704975

  7. Cell Walls of Saccharomyces cerevisiae Differentially Modulated Innate Immunity and Glucose Metabolism during Late Systemic Inflammation

    PubMed Central

    Baurhoo, Bushansingh; Ferket, Peter; Ashwell, Chris M.; de Oliviera, Jean; Zhao, Xin

    2012-01-01

    Background Salmonella causes acute systemic inflammation by using its virulence factors to invade the intestinal epithelium. But, prolonged inflammation may provoke severe body catabolism and immunological diseases. Salmonella has become more life-threatening due to emergence of multiple-antibiotic resistant strains. Mannose-rich oligosaccharides (MOS) from cells walls of Saccharomyces cerevisiae have shown to bind mannose-specific lectin of Gram-negative bacteria including Salmonella, and prevent their adherence to intestinal epithelial cells. However, whether MOS may potentially mitigate systemic inflammation is not investigated yet. Moreover, molecular events underlying innate immune responses and metabolic activities during late inflammation, in presence or absence of MOS, are unknown. Methods and Principal Findings Using a Salmonella LPS-induced systemic inflammation chicken model and microarray analysis, we investigated the effects of MOS and virginiamycin (VIRG, a sub-therapeutic antibiotic) on innate immunity and glucose metabolism during late inflammation. Here, we demonstrate that MOS and VIRG modulated innate immunity and metabolic genes differently. Innate immune responses were principally mediated by intestinal IL-3, but not TNF-α, IL-1 or IL-6, whereas glucose mobilization occurred through intestinal gluconeogenesis only. MOS inherently induced IL-3 expression in control hosts. Consequent to LPS challenge, IL-3 induction in VIRG hosts but not differentially expressed in MOS hosts revealed that MOS counteracted LPS's detrimental inflammatory effects. Metabolic pathways are built to elucidate the mechanisms by which VIRG host's higher energy requirements were met: including gene up-regulations for intestinal gluconeogenesis (PEPCK) and liver glycolysis (ENO2), and intriguingly liver fatty acid synthesis through ATP citrate synthase (CS) down-regulation and ATP citrate lyase (ACLY) and malic enzyme (ME) up-regulations. However, MOS host's lower energy

  8. Cigarette smoke alters primary human bronchial epithelial cell differentiation at the air-liquid interface

    PubMed Central

    Schamberger, Andrea C.; Staab-Weijnitz, Claudia A.; Mise-Racek, Nikica; Eickelberg, Oliver

    2015-01-01

    The differentiated human airway epithelium consists of different cell types forming a polarized and pseudostratified epithelium. This is dramatically altered in chronic obstructive pulmonary disease (COPD), characterized by basal and goblet cell hyperplasia, and squamous cell metaplasia. The effect of cigarette smoke on human bronchial epithelial cell (HBEC) differentiation remains to be elucidated. We analysed whether cigarette smoke extract (CSE) affected primary (p)HBEC differentiation and function. pHBEC were differentiated at the air-liquid interface (ALI) and differentiation was quantified after 7, 14, 21, or 28 days by assessing acetylated tubulin, CC10, or MUC5AC for ciliated, Clara, or goblet cells, respectively. Exposure of differentiating pHBEC to CSE impaired epithelial barrier formation, as assessed by resistance measurements (TEER). Importantly, CSE exposure significantly reduced the number of ciliated cells, while it increased the number of Clara and goblet cells. CSE-dependent cell number changes were reflected by a reduction of acetylated tubulin levels, an increased expression of the basal cell marker KRT14, and increased secretion of CC10, but not by changes in transcript levels of CC10, MUC5AC, or FOXJ1. Our data demonstrate that cigarette smoke specifically alters the cellular composition of the airway epithelium by affecting basal cell differentiation in a post-transcriptional manner. PMID:25641363

  9. Methyl-ß-cyclodextrin alters adipokine gene expression and glucose metabolism in swine adipose tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was designed to determine if metabolic stress as induced by methyl-ß-cyclodextrin (MCD) can alter cytokine expression in neonatal swine adipose tissue explants. Subcutaneous adipose tissue explants (100 ± 10 mg) were prepared from 21 day old pigs. Explants were incubated in medium 199 s...

  10. Dynamic changes in glucose metabolism accompanying the expression of the neural phenotype after differentiation in PC12 cells.

    PubMed

    Waki, A; Yano, R; Yoshimoto, M; Sadato, N; Yonekura, Y; Fujibayashi, Y

    2001-03-01

    To assess what properties of glucose metabolism are most closely related to expression of the neural phenotype, some parameters of glucose metabolism in PC12 cells before (tumor-type) and after differentiation (neuron-type) were investigated. Neuron-type cells exhibited a 2.7-fold higher level of [3H]DG retention than tumor-type cells, accompanied by a higher glucose transport rate and higher levels of hexokinase activity. [14C]CO2 production from [U-14C]glucose in neuron-type was also more than four-times greater than that in tumor-type cells. The levels of [14C]carbon in macromolecules from [14C]glucose in neuron-type cells were also much higher (10.6-fold) than those in tumor-type cells, and the levels of incorporation of [14C]carbon were almost as high as those of [14C]CO2. From the metabolite analysis, amino acids appeared to be the major compounds converted from glucose. On the other hand, the uptakes of [35S]methionine-[35S]cysteine and [3H]uridine in neuron-type cells were lower than those in tumor-type cells. Following depolarization with 50 mM potassium, [14C]CO2 production increased, but the retention of [14C]carbon was not changed in neuron-type cells. The largest change accompanied by acquisition of the neural phenotype was carbon incorporation into the macromolecules derived from glucose. This property may be important for the expression of the neural phenotype as well as the higher levels of both glucose uptake and oxygen consumption. PMID:11245818

  11. GPR17 gene disruption does not alter food intake or glucose homeostasis in mice

    PubMed Central

    Mastaitis, Jason; Min, Soo; Elvert, Ralf; Kannt, Aimo; Xin, Yurong; Ochoa, Francisca; Gale, Nicholas W.; Valenzuela, David M.; Murphy, Andrew J.; Yancopoulos, George D.; Gromada, Jesper

    2015-01-01

    G protein-coupled receptor 17 (GPR17) was recently reported to be a Foxo1 target in agouti-related peptide (AGRP) neurons. Intracerebroventricular injection of GPR17 agonists induced food intake, whereas administration of an antagonist to the receptor reduced feeding. These data lead to the conclusion that pharmacological modulation of GPR17 has therapeutic potential to treat obesity. Here we report that mice deficient in Gpr17 (Gpr17−/−) have similar food intake and body weight compared with their wild-type littermates. Gpr17−/− mice have normal hypothalamic Agrp mRNA expression, AGRP plasma levels, and metabolic rate. GPR17 deficiency in mice did not affect glucose homeostasis or prevent fat-induced insulin resistance. These data do not support a role for GPR17 in the control of food intake, body weight, or glycemic control. PMID:25624481

  12. Alterations of glucose-dependent insulinotropic polypeptide (GIP) during cold acclimation.

    PubMed

    Irwin, N; Francis, J M E; Flatt, P R

    2011-02-25

    Cold acclimation is initially associated with shivering thermogenesis in skeletal muscle followed by adaptive non-shivering thermogenesis, particularly in brown adipose tissue (BAT). In response, hyperphagia occurs to meet increased metabolic demand and thermoregulation. The present study investigates the effects of cold (4 ± 1 °C) acclimation and hyperphagia on circulating and intestinal levels of gastric inhibitory polypeptide (GIP) in rats. Pair fed animals were used as additional controls in some experiments. Cold acclimation for 42 days significantly (p<0.01) increased daily food intake. There was no corresponding change in body weight. However, body weights of pair fed cold exposed rats were significantly (p<0.01) reduced compared to controls and ad libitum fed cold exposed rats. By day 42, non-fasting plasma glucose was increased (p<0.05) by chronic cold exposure regardless of food intake. Corresponding plasma insulin concentrations were significantly (p<0.01) lower in pair fed cold exposed rats. Circulating GIP levels were elevated (p<0.05) in ad libitum fed cold acclimated rats on days 18 and 24, but returned to normal levels by the end of the study. The glycaemic response to oral glucose was improved (p<0.01) in all cold exposed rats, with significantly (p<0.05) elevated GIP responses in ad libitum fed rats and significantly (p<0.05) reduced insulin responses in pair fed rats. In keeping with this, insulin sensitivity was enhanced (p<0.05) in cold exposed rats compared to controls. By the end of the study, cold acclimated rats had significantly (p<0.01) increased BAT mass and intestinal concentrations of GIP and GLP-1 compared to controls, independent of food intake. These data indicate that changes in the secretion and actions of GIP may be involved in the metabolic adaptations to cold acclimation in rats. PMID:21146561

  13. Alteration of blood glucose levels in the rat following exposure to hyperbaric oxygen.

    PubMed

    Eynan, Mirit; Mullokandov, Michael; Krinsky, Nitzan; Biram, Adi; Arieli, Yehuda

    2015-09-01

    Findings regarding blood glucose level (BGL) on exposure to hyperbaric oxygen (HBO) are contradictory. We investigated the influence of HBO on BGL, and of BGL on latency to central nervous system oxygen toxicity (CNS-OT). The study was conducted on five groups of rats: Group 1, exposure to oxygen at 2.5 atmospheres absolute (ATA), 90 min/day for 7 days; Group 2, exposure to oxygen once a week from 2 to 6 ATA in increments of 1 ATA/wk, for a period of time calculated as 60% of the latency to CNS-OT (no convulsions); Group 3, exposure to 6 ATA breathing a gas mixture with a pO2 of 0.21; Group 4, received 10 U/kg insulin to induce hypoglycemia before exposure to HBO; Group 5, received 33% glucose to induce hyperglycemia before exposure to HBO. Blood samples were drawn before and after exposures for measurement of BGL. No change was observed in BGL after exposure to oxygen at 2.5 ATA, 90 min/day for 7 days. BGL was significantly elevated after exposure to oxygen at 6 ATA until the appearance of convulsions, and following exposure to 4, 5, and 6 ATA without convulsions (P < 0.01). No change was observed in BGL after exposure to 6 ATA breathing a gas mixture with a pO2 of 0.21. Hypoglycemia shortened latency to CNS oxygen toxicity, whereas hyperglycemia had no effect. Our results demonstrate an influence of HBO exposure on elevation of BGL, starting at 4 ATA. This implies that BGL may serve as a marker for the generation of CNS-OT. PMID:26183474

  14. Inhibition of GSK-3 induces differentiation and impaired glucose metabolism in renal cancer.

    PubMed

    Pal, Krishnendu; Cao, Ying; Gaisina, Irina N; Bhattacharya, Santanu; Dutta, Shamit K; Wang, Enfeng; Gunosewoyo, Hendra; Kozikowski, Alan P; Billadeau, Daniel D; Mukhopadhyay, Debabrata

    2014-02-01

    Glycogen synthase kinase-3 (GSK-3), a constitutively active serine/threonine kinase, is a key regulator of numerous cellular processes ranging from glycogen metabolism to cell-cycle regulation and proliferation. Consistent with its involvement in many pathways, it has also been implicated in the pathogenesis of various human diseases, including type II diabetes, Alzheimer disease, bipolar disorder, inflammation, and cancer. Consequently, it is recognized as an attractive target for the development of new drugs. In the present study, we investigated the effect of both pharmacologic and genetic inhibition of GSK-3 in two different renal cancer cell lines. We have shown potent antiproliferative activity of 9-ING-41, a maleimide-based GSK-3 inhibitor. The antiproliferative activity is most likely caused by G(0)-G(1) and G(2)-M phase arrest as evident from cell-cycle analysis. We have established that inhibition of GSK-3 imparted a differentiated phenotype in renal cancer cells. We have also shown that GSK-3 inhibition induced autophagy, likely as a result of imbalanced energy homeostasis caused by impaired glucose metabolism. In addition, we have demonstrated the antitumor activity of 9-ING-41 in two different subcutaneous xenograft renal cell carcinoma tumor models. To our knowledge, this is the first report describing autophagy induction due to GSK-3 inhibition in renal cancer cells. PMID:24327518

  15. A monocrystal graphene domain biosensor array with differential output for real-time monitoring of glucose and normal saline.

    PubMed

    Shi, Junjie; Li, Xin; Chen, Qian; Gao, Kun; Song, Hui; Guo, Shixi; Li, Quanfu; Fang, Ming; Liu, Weihua; Liu, Hongzhong; Wang, Xiaoli

    2015-05-01

    A biosensor array with differential output based on a monocrystal graphene domain is proposed to realize high resolution measurements. The differential output structure can eliminate the noise that comes from graphene crystal orientation and grain boundary, as well as the fluctuation that comes from the contact resistance and experiment process, so as to improve resolution in the lower concentration. We have fabricated a high quality monocrystal graphene domain that has millimeter size by the chemical vapor deposition method. Two identical graphene ribbons that are cut from the same domain are used as field effect transistor source-to-drain channels for the reference and the test of differential output, respectively. The experimental results show that the source-to-drain current has a fast response shorter than 0.5 second in glucose, normal saline and pH buffer solutions of different concentrations. Sensitivity increases exponentially with the increase of concentration of the tested liquid and the high resolution range is 0.01-2 wt% in glucose and 0.0009-0.018 wt% in saline, and the highest resolutions of glucose and saline are 0.01 wt% and 0.0009 wt%, respectively. We have fabricated a 1 × 4 array structure with differential outputs that pave the way for rapidly detecting ultra-low concentration of analytes. PMID:25853238

  16. A monocrystal graphene domain biosensor array with differential output for real-time monitoring of glucose and normal saline

    NASA Astrophysics Data System (ADS)

    Shi, Junjie; Li, Xin; Chen, Qian; Gao, Kun; Song, Hui; Guo, Shixi; Li, Quanfu; Fang, Ming; Liu, Weihua; Liu, Hongzhong; Wang, Xiaoli

    2015-04-01

    A biosensor array with differential output based on a monocrystal graphene domain is proposed to realize high resolution measurements. The differential output structure can eliminate the noise that comes from graphene crystal orientation and grain boundary, as well as the fluctuation that comes from the contact resistance and experiment process, so as to improve resolution in the lower concentration. We have fabricated a high quality monocrystal graphene domain that has millimeter size by the chemical vapor deposition method. Two identical graphene ribbons that are cut from the same domain are used as field effect transistor source-to-drain channels for the reference and the test of differential output, respectively. The experimental results show that the source-to-drain current has a fast response shorter than 0.5 second in glucose, normal saline and pH buffer solutions of different concentrations. Sensitivity increases exponentially with the increase of concentration of the tested liquid and the high resolution range is 0.01-2 wt% in glucose and 0.0009-0.018 wt% in saline, and the highest resolutions of glucose and saline are 0.01 wt% and 0.0009 wt%, respectively. We have fabricated a 1 × 4 array structure with differential outputs that pave the way for rapidly detecting ultra-low concentration of analytes.

  17. DNA Demethylation Rescues the Impaired Osteogenic Differentiation Ability of Human Periodontal Ligament Stem Cells in High Glucose

    PubMed Central

    Liu, Zhi; Chen, Tian; Sun, Wenhua; Yuan, Zongyi; Yu, Mei; Chen, Guoqing; Guo, Weihua; Xiao, Jingang; Tian, Weidong

    2016-01-01

    Diabetes mellitus, characterized by abnormally high blood glucose levels, gives rise to impaired bone remodeling. In response to high glucose (HG), the attenuated osteogenic differentiation capacity of human periodontal ligament stem cells (hPDLSCs) is associated with the loss of alveolar bone. Recently, DNA methylation was reported to affect osteogenic differentiation of stem cells in pathological states. However, the intrinsic mechanism linking DNA methylation to osteogenic differentiation ability in the presence of HG is still unclear. In this study, we found that diabetic rats with increased DNA methylation levels in periodontal ligaments exhibited reduced bone mass and density. In vitro application of 5-aza-2′-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to decrease DNA methylation levels in hPDLSCs, rescued the osteogenic differentiation capacity of hPDLSCs under HG conditions. Moreover, we demonstrated that the canonical Wnt signaling pathway was activated during this process and, under HG circumstances, the 5-aza-dC-rescued osteogenic differentiation capacity was blocked by Dickkopf-1, an effective antagonist of the canonical Wnt signaling pathway. Taken together, these results demonstrate for the first time that suppression of DNA methylation is able to facilitate the osteogenic differentiation capacity of hPDLSCs exposed to HG, through activation of the canonical Wnt signaling pathway. PMID:27273319

  18. DNA Demethylation Rescues the Impaired Osteogenic Differentiation Ability of Human Periodontal Ligament Stem Cells in High Glucose.

    PubMed

    Liu, Zhi; Chen, Tian; Sun, Wenhua; Yuan, Zongyi; Yu, Mei; Chen, Guoqing; Guo, Weihua; Xiao, Jingang; Tian, Weidong

    2016-01-01

    Diabetes mellitus, characterized by abnormally high blood glucose levels, gives rise to impaired bone remodeling. In response to high glucose (HG), the attenuated osteogenic differentiation capacity of human periodontal ligament stem cells (hPDLSCs) is associated with the loss of alveolar bone. Recently, DNA methylation was reported to affect osteogenic differentiation of stem cells in pathological states. However, the intrinsic mechanism linking DNA methylation to osteogenic differentiation ability in the presence of HG is still unclear. In this study, we found that diabetic rats with increased DNA methylation levels in periodontal ligaments exhibited reduced bone mass and density. In vitro application of 5-aza-2'-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to decrease DNA methylation levels in hPDLSCs, rescued the osteogenic differentiation capacity of hPDLSCs under HG conditions. Moreover, we demonstrated that the canonical Wnt signaling pathway was activated during this process and, under HG circumstances, the 5-aza-dC-rescued osteogenic differentiation capacity was blocked by Dickkopf-1, an effective antagonist of the canonical Wnt signaling pathway. Taken together, these results demonstrate for the first time that suppression of DNA methylation is able to facilitate the osteogenic differentiation capacity of hPDLSCs exposed to HG, through activation of the canonical Wnt signaling pathway. PMID:27273319

  19. Anterior-posterior and lateral hemispheric alterations in cortical glucose utilization in Alzheimer's disease

    SciTech Connect

    Friedland, T.F.; Budinger, T.F.; Jaqust, W.J.; Yano, Y.; Huesman, R.H.; Knittel, B.; Koss, E.; Ober, B.A.

    1984-01-01

    The anatomical and chemical features of Alzheimer's disease (AD) are not distributed evenly throughout the brain. However, the nature of this focality has not been well established in vivo. Dynamic studies using the Donner 280-Crystal Positron Tomograph with (F-18)2-fluorodeoxyglucose were performed in 17 subjects meeting current research criteria for AD, and in 7 healthy age-matched control subjects. Glucose metabolic rates in the temporal-parietal cortex are 27% lower in AD than in controls. Ratios of activity density reveal consistently lower metabolic rates in temporal-parietal than frontal cortex in the AD group, while healthy aged subjects have equal metabolic rates in the two areas. Similar findings have been reported by other laboratories. A major finding is a striking lateral asymmetry of cortical metabolism in AD which does not favor either hemisphere. (The asymmetry is 13% in the AD group, 3% in controls, p<.005.) This has not been previously reported in AD. The consistency with which anterior-posterior metabolic differences are found in AD suggests that the focality of the metabolic changes may be used to develop a noninvasive diagnostic test for the disorder. The metabolic asymmetry in AD may be compared to the clinical and pathological asymmetry found in Creutzfeldt-Jakob disease, and may represent an additional link between AD and the subacute spongiform encephalopathies.

  20. Altered cerebral blood flow and glucose metabolism in patients with liver disease and minimal encephalopathy

    SciTech Connect

    Lockwood, A.H.; Yap, E.W.; Rhoades, H.M.; Wong, W.H. )

    1991-03-01

    We measured CBF and the CMRglc in normal controls and in patients with severe liver disease and evidence for minimal hepatic encephalopathy using positron emission tomography. Regions were defined in frontal, temporal, parietal, and visual cortex; the thalamus; the caudate; the cerebellum; and the white matter along with a whole-slice value obtained at the level of the thalamus. There was no difference in whole-slice CBF and CMRglc values. Individual regional values were normalized to the whole-slice value and subjected to a two-way repeated measures analysis of variance. When normalized CBF and CMRglc values for regions were compared between groups, significant differences were demonstrated (F = 5.650, p = 0.00014 and F = 4.58, p = 0.0073, respectively). These pattern differences were due to higher CBF and CMRglc in the cerebellum, thalamus, and caudate in patients and lower values in the cortex. Standardized coefficients extracted from a discriminant function analysis permitted correct group assignment for 95.5% of the CBF studies and for 92.9% of the CMRglc studies. The similarity of the altered pattern of cerebral metabolism and flow in our patients to that seen in rats subjected to portacaval shunts or ammonia infusions suggests that this toxin may alter flow and metabolism and that this, in turn, causes the clinical expression of encephalopathy.

  1. Altered TNF-Alpha, Glucose, Insulin and Amino Acids in Islets Langerhans Cultured in a Microgravity Model System

    NASA Technical Reports Server (NTRS)

    Tobin, Brian W.; Leeper-Woodford, Sandra K.; Hashemi, Brian B.; Smith, Scott M.; Sams, Clarence F.

    2001-01-01

    The present studies were designed to determine effects of a microgravity model system upon lipopolysaccharide (LPS) stimulated tumor necrosis factor alpha (TNF-alpha) activity and indices of insulin and fuel homeostasis of pancreatic islets of Langerhans. Islets (1726+/-1 17,150 u IEU) from Wistar Furth rats were treated as: 1) HARV (High Aspect Ratio Vessel cell culture) , 2) HARV plus LPS, 3) static culture, 4) static culture plus LPS. TNF-alpha (L929 cytotoxicity assay) was significantly increased in LPS-induced HARV and static cultures, yet the increase was more pronounced in the static culture group (p<0.05). A decrease in insulin concentration was demonstrated in the LPS stimulated HARV culture (p<0.05). We observed a greater glucose concentration and increased disappearance of arginine in islets cultured in HARVs. While nitrogenous compound analysis indicated a ubiquitous reliance upon glutamine in all experimental groups, arginine was converted to ornithine at a two-fold greater rate in the islets cultured in the HARV microgravity model system (p<0.05). These studies demonstrate alterations in LPS induced TNF-alpha production of pancreatic islets of Langerhans, favoring a lesser TNF activity in the HARV. These alterations in fuel homeostasis may be promulgated by gravity averaged cell culture methods or by three dimensional cell assembly.

  2. Genetic alterations of differentiated thyroid carcinoma in iodine-rich and iodine-deficient countries.

    PubMed

    Vuong, Huy Gia; Kondo, Tetsuo; Oishi, Naoki; Nakazawa, Tadao; Mochizuki, Kunio; Inoue, Tomohiro; Tahara, Ippei; Kasai, Kazunari; Hirokawa, Mitsuyoshi; Tran, Thong Minh; Katoh, Ryohei

    2016-08-01

    BRAF V600E mutation, RET rearrangements, and RAS mutations are the common genetic alterations in differentiated thyroid carcinomas derived from follicular thyroid cells. However, the relationship between these alterations and iodine intake is still controversial. To clarify the influence of iodine intake on the occurrence of differentiated thyroid carcinomas, we performed molecular analyses for two differentiated carcinomas, papillary thyroid carcinomas (PTCs) and follicular thyroid carcinomas (FTCs), from an iodine-rich country (Japan) and an iodine-deficient country (Vietnam). We examined 120 PTCs (67 Japanese and 53 Vietnamese) and 74 FTCs (51 Japanese and 23 Vietnamese). We carried out allele-specific polymerase chain reaction (AS-PCR) for BRAF V600E, PCR and direct sequencing for RAS mutations (codon 12, 13, and 61 in NRAS, HRAS, and KRAS), and RT-PCR for RET/PTC1 and RET/PTC3. BRAF V600E was present in 55/67 (82.1%) Japanese PTCs and 44/53 (83%) Vietnamese PTCs. RET/PTC1 was identified in only one PTC from each country, and no samples had RET/PTC3. NRAS mutation was found in 17/51 (33.3%) Japanese FTCs and 4/23 (17.4%) Vietnamese FTCs. NRAS mutation was cited in codon 61 (20 cases) and codon 12 (one case). None of FTCs had KRAS or HRAS mutations. There were no significant differences in the prevalence of BRAF V600E, RET/PTC, or RAS mutations between the two countries. Our study showed no differences in genetic alterations of thyroid cancers from iodine-rich and iodine-deficient countries, possibly suggesting that iodine intake might not affect the genetic alterations of differentiated thyroid cancer. PMID:27264674

  3. Glucose-dependent insulinotropic polypeptide (GIP) dose-dependently reduces osteoclast differentiation and resorption.

    PubMed

    Mabilleau, Guillaume; Perrot, Rodolphe; Mieczkowska, Aleksandra; Boni, Sébastien; Flatt, Peter R; Irwin, Nigel; Chappard, Daniel

    2016-10-01

    A role for glucose-dependent insulinotropic polypeptide (GIP) in controlling bone resorption has been suspected. However uncertainty remains to identify whether GIP act directly on osteoclasts. The aim of the present study were (i) to identify in different osteoclast differentiation models (human peripheral blood mononuclear cells-PBMC, murine bone marrow macrophage-BMM and murine Raw 264.7 cells) whether GIP was capable of reducing osteoclast formation and resorption; (ii) ascertain whether the highly potent GIP analogue N-AcGIP was capable of inducing a response at lower concentrations and (iii) to decipher the molecular mechanisms responsible for such effects. [d-Ala(2)]-GIP dose-dependently reduced osteoclast formation at concentration as low as 1nM in human PBMC and 10nM in murine BMM cultures. Furthermore, [d-Ala(2)]-GIP also reduced the extent of osteoclast resorption at concentration as low as 1nM in human PBMC and murine BMM cultures. The mechanism of action of [d-Ala(2)]-GIP appeared to be mediated by reduction in intracellular calcium concentration and oscillation that subsequently inhibited calcineurin activity and NFATc1 nuclear translocation. The potency of the highly potent N-AcGIP was determined and highlighted an effect on osteoclast formation and resorption at concentration ten times lower than observed with [d-Ala(2)]-GIP in vitro. Furthermore, N-AcGIP was also capable of reducing the number of osteoclast in ovariectomized mice as well as the circulating level of type I collagen C-telopeptide. Pharmacological concentrations required for reducing osteoclast formation and resorption provide the impetus to design and exploit enzymatically stable GIP analogues for the treatment of bone resorption disorders in humans. PMID:27451082

  4. Osmolarity and glucose differentially regulate aldose reductase activity in cultured mouse podocytes.

    PubMed

    Lewko, Barbara; Latawiec, Elżbieta; Maryn, Anna; Barczyńska, Anna; Pikuła, Michał; Zieliński, Maciej; Rybczyńska, Apolonia

    2011-01-01

    Podocyte injury is associated with progression of many renal diseases, including diabetic nephropathy. In this study we examined whether aldose reductase (AR), the enzyme implicated in diabetic complications in different tissues, is modulated by high glucose and osmolarity in podocyte cells. AR mRNA, protein expression, and activity were measured in mouse podocytes cultured in both normal and high glucose and osmolarity for 6 hours to 5 days. Hyperosmolarity acutely stimulated AR expression and activity, with subsequent increase of AR expression but decrease of activity. High glucose also elevated AR protein level; however, this was not accompanied by respective enzyme activation. Furthermore, high glucose appeared to counteract the osmolarity-dependent activation of AR. In conclusion, in podocytes AR is modulated by high glucose and increased osmolarity in a different manner. Posttranslational events may affect AR activity independent of enzyme protein amount. Activation of AR in podocytes may be implicated in diabetic podocytopathy. PMID:22253613

  5. Arsenic trioxide alters the differentiation of mouse embryonic stem cell into cardiomyocytes.

    PubMed

    Rebuzzini, Paola; Cebral, Elisa; Fassina, Lorenzo; Alberto Redi, Carlo; Zuccotti, Maurizio; Garagna, Silvia

    2015-01-01

    Chronic arsenic exposure is associated with increased morbidity and mortality for cardiovascular diseases. Arsenic increases myocardial infarction mortality in young adulthood, suggesting that exposure during foetal life correlates with cardiac alterations emerging later. Here, we investigated the mechanisms of arsenic trioxide (ATO) cardiomyocytes disruption during their differentiation from mouse embryonic stem cells. Throughout 15 days of differentiation in the presence of ATO (0.1, 0.5, 1.0 μM) we analysed: the expression of i) marker genes of mesoderm (day 4), myofibrillogenic commitment (day 7) and post-natal-like cardiomyocytes (day 15); ii) sarcomeric proteins and their organisation; iii) Connexin 43 and iv) the kinematics contractile properties of syncytia. The higher the dose used, the earlier the stage of differentiation affected (mesoderm commitment, 1.0 μM). At 0.5 or 1.0 μM the expression of cardiomyocyte marker genes is altered. Even at 0.1 μM, ATO leads to reduction and skewed ratio of sarcomeric proteins and to a rarefied distribution of Connexin 43 cardiac junctions. These alterations contribute to the dysruption of the sarcomere and syncytium organisation and to the impairment of kinematic parameters of cardiomyocyte function. This study contributes insights into the mechanistic comprehension of cardiac diseases caused by in utero arsenic exposure. PMID:26447599

  6. Arsenic trioxide alters the differentiation of mouse embryonic stem cell into cardiomyocytes

    PubMed Central

    Rebuzzini, Paola; Cebral, Elisa; Fassina, Lorenzo; Alberto Redi, Carlo; Zuccotti, Maurizio; Garagna, Silvia

    2015-01-01

    Chronic arsenic exposure is associated with increased morbidity and mortality for cardiovascular diseases. Arsenic increases myocardial infarction mortality in young adulthood, suggesting that exposure during foetal life correlates with cardiac alterations emerging later. Here, we investigated the mechanisms of arsenic trioxide (ATO) cardiomyocytes disruption during their differentiation from mouse embryonic stem cells. Throughout 15 days of differentiation in the presence of ATO (0.1, 0.5, 1.0 μM) we analysed: the expression of i) marker genes of mesoderm (day 4), myofibrillogenic commitment (day 7) and post-natal-like cardiomyocytes (day 15); ii) sarcomeric proteins and their organisation; iii) Connexin 43 and iv) the kinematics contractile properties of syncytia. The higher the dose used, the earlier the stage of differentiation affected (mesoderm commitment, 1.0 μM). At 0.5 or 1.0 μM the expression of cardiomyocyte marker genes is altered. Even at 0.1 μM, ATO leads to reduction and skewed ratio of sarcomeric proteins and to a rarefied distribution of Connexin 43 cardiac junctions. These alterations contribute to the dysruption of the sarcomere and syncytium organisation and to the impairment of kinematic parameters of cardiomyocyte function. This study contributes insights into the mechanistic comprehension of cardiac diseases caused by in utero arsenic exposure. PMID:26447599

  7. Differential control of glucoregulatory hormone response and glucose metabolism by NMDA and kainate.

    PubMed

    Yousef, K A; Tepper, P G; Molina, P E; Abumrad, N N; Lang, C H

    1994-01-14

    The aim of the present study was to elucidate the effect of kainate and N-methyl-D-aspartate (NMDA), two different excitatory amino acid (EAA) agonists, on glucoregulatory hormone production and whole body glucose metabolism. Rates of hepatic glucose production (HGP) and peripheral glucose utilization (GU) were assessed in overnight fasted, catheterized, conscious rats using [3-3H]glucose. At the highest dose of kainate examined (16 mg/kg), glucose levels increased 97% after 1 h; thereafter, glucose fell towards basal values but was still elevated 25% at the end of the 3 h experiment. This hyperglycemia resulted from a rapid increase in HGP that exceeded an increased rate of GU. Both HGP and GU were elevated 86% throughout the final 2 h of the experiment. NMDA induced changes in glucose flux that were qualitatively similar, yet of smaller magnitude and of shorter duration, than those produced by kainate. Kainate-induced increases in glucose metabolism were associated with an early transient hyperinsulinemia followed by a period of insulinopenia, and sustained increases in the plasma concentrations of glucagon, corticosterone, epinephrine and norepinephrine. In contrast, sustained increases in glucagon and catecholamines, as well as the late hypoinsulinemia were not detected in NMDA-treated rats. Adrenergic blockade attenuated the kainate- but not the NMDA-induced increase in glucose metabolism. These results indicate that EAA agonists that bind preferentially to different receptor subtypes produce qualitatively similar changes in glucose metabolism. Whereas the increased HGP in kainate-injected rats was associated with sustained elevations in glucagon, catecholamines and corticosterone, NMDA only transiently elevated circulating glucocorticoid levels, suggesting a different mechanism of action. These data, support the involvement of EAA in various aspects of glucoregulation. PMID:8156383

  8. Alteration of NCoR Corepressor Splicing in Mice Causes Increased Body Weight and Hepatosteatosis without Glucose Intolerance

    PubMed Central

    Goodson, Michael L.; Young, Briana M.; Snyder, Chelsea A.; Schroeder, Amy C.

    2014-01-01

    Alternative mRNA splicing is an important means of diversifying function in higher eukaryotes. Notably, both NCoR and SMRT corepressors are subject to alternative mRNA splicing, yielding a series of distinct corepressor variants with highly divergent functions. Normal adipogenesis is associated with a switch in corepressor splicing from NCoRω to NCoRδ, which appears to help regulate this differentiation process. We report here that mimicking this development switch in mice by a splice-specific whole-animal ablation of NCoRω is very different from a whole-animal or tissue-specific total NCoR knockout and produces significantly enhanced weight gain on a high-fat diet. Surprisingly, NCoRω−/− mice are protected against diet-induced glucose intolerance despite enhanced adiposity and the presence of multiple additional, prodiabetic phenotypic changes. Our results indicate that the change in NCoR splicing during normal development both helps drive normal adipocyte differentiation and plays a key role in determining a metabolically appropriate storage of excess calories. We also conclude that whole-gene “knockouts” fail to reveal how important gene products are customized, tailored, and adapted through alternative mRNA splicing and thus do not reveal all the functions of the protein products of that gene. PMID:25182530

  9. Cardiac-Specific Disruption of GH Receptor Alters Glucose Homeostasis While Maintaining Normal Cardiac Performance in Adult Male Mice.

    PubMed

    Jara, Adam; Liu, Xingbo; Sim, Don; Benner, Chance M; Duran-Ortiz, Silvana; Qian, Yanrong; List, Edward O; Berryman, Darlene E; Kim, Jason K; Kopchick, John J

    2016-05-01

    GH is considered necessary for the proper development and maintenance of several tissues, including the heart. Studies conducted in both GH receptor null and bovine GH transgenic mice have demonstrated specific cardiac structural and functional changes. In each of these mouse lines, however, GH-induced signaling is altered systemically, being decreased in GH receptor null mice and increased in bovine GH transgenic mice. Therefore, to clarify the direct effects GH has on cardiac tissue, we developed a tamoxifen-inducible, cardiac-specific GHR disrupted (iC-GHRKO) mouse line. Cardiac GH receptor was disrupted in 4-month-old iC-GHRKO mice to avoid developmental effects due to perinatal GHR gene disruption. Surprisingly, iC-GHRKO mice showed no difference vs controls in baseline or postdobutamine stress test echocardiography measurements, nor did iC-GHRKO mice show differences in longitudinal systolic blood pressure measurements. Interestingly, iC-GHRKO mice had decreased fat mass and improved insulin sensitivity at 6.5 months of age. By 12.5 months of age, however, iC-GHRKO mice no longer had significant decreases in fat mass and had developed glucose intolerance and insulin resistance. Furthermore, investigation via immunoblot analysis demonstrated that iC-GHRKO mice had appreciably decreased insulin stimulated Akt phosphorylation, specifically in heart and liver, but not in epididymal white adipose tissue. These changes were accompanied by a decrease in circulating IGF-1 levels in 12.5-month-old iC-GHRKO mice. These data indicate that whereas the disruption of cardiomyocyte GH-induced signaling in adult mice does not affect cardiac function, it does play a role in systemic glucose homeostasis, in part through modulation of circulating IGF-1. PMID:27035649

  10. Stromal-epithelial interactions in aging and cancer: Senescent fibroblasts alter epithelial cell differentiation

    SciTech Connect

    Parrinello, Simona; Coppe, Jean-Philippe; Krtolica, Ana; Campisi, Judith

    2004-07-14

    Cellular senescence suppresses cancer by arresting cells at risk for malignant tumorigenesis. However, senescent cells also secrete molecules that can stimulate premalignant cells to proliferate and form tumors, suggesting the senescence response is antagonistically pleiotropic. We show that premalignant mammary epithelial cells exposed to senescent human fibroblasts in mice irreversibly lose differentiated properties, become invasive and undergo full malignant transformation. Moreover, using cultured mouse or human fibroblasts and non-malignant breast epithelial cells, we show that senescent fibroblasts disrupt epithelial alveolar morphogenesis, functional differentiation, and branching morphogenesis. Further, we identify MMP-3 as the major factor responsible for the effects of senescent fibroblasts on branching morphogenesis. Our findings support the idea that senescent cells contribute to age-related pathology, including cancer, and describe a new property of senescent fibroblasts--the ability to alter epithelial differentiation--that might also explain the loss of tissue function and organization that is a hallmark of aging.

  11. Stromal-epithelial interactions in aging and cancer: senescent fibroblasts alter epithelial cell differentiation

    PubMed Central

    Parrinello, Simona; Coppe, Jean-Philippe; Krtolica, Ana; Campisi, Judith

    2016-01-01

    Summary Cellular senescence suppresses cancer by arresting cells at risk of malignant tumorigenesis. However, senescent cells also secrete molecules that can stimulate premalignant cells to proliferate and form tumors, suggesting the senescence response is antagonistically pleiotropic. We show that premalignant mammary epithelial cells exposed to senescent human fibroblasts in mice irreversibly lose differentiated properties, become invasive and undergo full malignant transformation. Moreover, using cultured mouse or human fibroblasts and non-malignant breast epithelial cells, we show that senescent fibroblasts disrupt epithelial alveolar morphogenesis, functional differentiation and branching morphogenesis. Furthermore, we identify MMP-3 as the major factor responsible for the effects of senescent fibroblasts on branching morphogenesis. Our findings support the idea that senescent cells contribute to age-related pathology, including cancer, and describe a new property of senescent fibroblasts – the ability to alter epithelial differentiation – that might also explain the loss of tissue function and organization that is a hallmark of aging. PMID:15657080

  12. Selective estrogen receptor modulators differentially alter the immune response of gilthead seabream juveniles.

    PubMed

    Rodenas, M C; Cabas, I; García-Alcázar, A; Meseguer, J; Mulero, V; García-Ayala, A

    2016-05-01

    17α-ethynylestradiol (EE2), a synthetic estrogen used in oral contraceptives and hormone replacement therapy, tamoxifen (Tmx), a selective estrogen-receptor modulator used in hormone replacement therapy, and G1, a G protein-coupled estrogen receptor (GPER) selective agonist, differentially increased the hepatic vitellogenin (vtg) gene expression and altered the immune response in adult gilthead seabream (Sparus aurata L.) males. However, no information exists on the effects of these compounds on the immune response of juveniles. This study aims, for the first time, to investigate the effects of the dietary intake of EE2, Tmx or G1 on the immune response of gilthead seabream juveniles and the capacity of the immune system of the specimens to recover its functionality after ceasing exposures (recovery period). The specimens were immunized with hemocyanin in the presence of aluminium adjuvant 1 (group A) or 120 (group B) days after the treatments ceased (dpt). The results indicate that EE2 and Tmx, but not G1, differentially promoted a transient alteration in hepatic vtg gene expression. Although all three compounds did not affect the production of reactive oxygen intermediates, they inhibited the induction of interleukin-1β (il1b) gene expression after priming. Interestingly, although Tmx increased the percentage of IgM-positive cells in both head kidney and spleen during the recovery period, the antibody response of vaccinated fish varied depending on the compound used and when the immunization was administered. Taken together, our results suggest that these compounds differentially alter the capacity of fish to respond to infection during ontogeny and, more interestingly, that the adaptive immune response remained altered to an extent that depends on the compound. PMID:27012396

  13. An analogue of atrial natriuretic peptide (C-ANP4-23) modulates glucose metabolism in human differentiated adipocytes.

    PubMed

    Ruiz-Ojeda, Francisco Javier; Aguilera, Concepción María; Rupérez, Azahara Iris; Gil, Ángel; Gomez-Llorente, Carolina

    2016-08-15

    The present study was undertaken to investigate the effects of C-atrial natriuretic peptide (C-ANP4-23) in human adipose-derived stem cells differentiated into adipocytes over 10 days (1 μM for 4 h). The intracellular cAMP, cGMP and protein kinase A levels were determined by ELISA and gene and protein expression were determined by qRT-PCR and Western blot, respectively, in the presence or absence of C-ANP4-23. The levels of lipolysis and glucose uptake were also determined. C-ANP4-23 treatment significantly increased the intracellular cAMP levels and the gene expression of glucose transporter type 4 (GLUT4) and protein kinase, AMP-activated, alpha 1 catalytic subunit (AMPK). Western blot showed a significant increase in GLUT4 and phosphor-AMPKα levels. Importantly, the adenylate cyclase inhibitor SQ22536 abolished these effects. Additionally, C-ANP4-23 increased glucose uptake by 2-fold. Our results show that C-ANP4-23 enhances glucose metabolism and might contribute to the development of new peptide-based therapies for metabolic diseases. PMID:27181211

  14. Impact of elvitegravir on human adipocytes: Alterations in differentiation, gene expression and release of adipokines and cytokines.

    PubMed

    Moure, Ricardo; Domingo, Pere; Gallego-Escuredo, José M; Villarroya, Joan; Gutierrez, Maria Del Mar; Mateo, Maria G; Domingo, Joan C; Giralt, Marta; Villarroya, Francesc

    2016-08-01

    Elvitegravir is a recently developed integrase inhibitor used for antiretroviral treatment of HIV infection. Secondary effects, including disturbances in lipid metabolism and, ultimately, in adipose tissue distribution and function, are common concerns associated with antiretroviral treatments. Here, we provide the first study of the effects of elvitegravir (in comparison with efavirenz, a non-nucleoside analog inhibitor of reverse transcriptase; and raltegravir, another integrase inhibitor) on human adipocyte differentiation, gene expression and secretion of adipokines and cytokines. Elvitegravir impaired adipogenesis and adipocyte metabolism in human SGBS adipocytes in a concentration-dependent manner (delaying acquisition of adipocyte morphology and reducing the expression of adipogenesis marker genes such as PPARγ, glucose transporter GLUT4, lipoprotein lipase, and the adipokines adiponectin and leptin). Compared with efavirenz, the effects of elvitegravir were similar but tended to occur at higher concentrations than those elicited by efavirenz, or were somewhat less intense than those caused by efavirenz at similar concentration. Elvitegravir tended to cause a more moderate induction of pro-inflammatory cytokines than efavirenz. Efavirenz induced a marked concentration-dependent increase in interleukin-8 expression and release whereas elvitregravir had little effect. Raltegravir had totally neutral actions of adipogenesis, adipocyte metabolism-related gene expression and release of adipokines and cytokines. In conclusion, elvitegravir alters adipocyte differentiation and function and promotes induction of pro-inflammatory cytokines similarly to efavirenz, but several effects were less intense. Further assessment of lipid metabolism and adipose tissue function in patients administered elvitegravir-based regimes is advisable considering that totally neutral effects of elvitegravir on lipid homeostasis cannot be anticipated from the current study in

  15. Alteration of protein prenylation promotes spermatogonial differentiation and exhausts spermatogonial stem cells in newborn mice

    PubMed Central

    Diao, Fan; Jiang, Chen; Wang, Xiu-Xing; Zhu, Rui-Lou; Wang, Qiang; Yao, Bing; Li, Chao-Jun

    2016-01-01

    Spermatogenesis in adulthood depends on the successful neonatal establishment of the spermatogonial stem cell (SSC) pool and gradual differentiation during puberty. The stage-dependent changes in protein prenylation in the seminiferous epithelium might be important during the first round of spermatogenesis before sexual maturation, but the mechanisms are unclear. We have previous found that altered prenylation in Sertoli cells induced spermatogonial apoptosis in the neonatal testis, resulting in adult infertility. Now we further explored the role of protein prenylation in germ cells, using a conditional deletion of geranylgeranyl diphosphate synthase (Ggpps) in embryonic stage and postmeiotic stage respectively. We observed infertility of Ggpps−/− Ddx4-Cre mice that displayed a Sertoli-cell-only syndrome phenotype, which resulted from abnormal spermatogonial differentiation and SSC depletion during the prepubertal stage. Analysis of morphological characteristics and cell-specific markers revealed that spermatogonial differentiation was enhanced from as early as the 7th postnatal day in the first round of spermatogenesis. Studies of the molecular mechanisms indicated that Ggpps deletion enhanced Rheb farnesylation, which subsequently activated mTORC1 and facilitated spermatogonial differentiation. In conclusion, the prenylation balance in germ cells is crucial for spermatogonial differentiation fate decision during the prepubertal stage, and the disruption of this process results in primary infertility. PMID:27374985

  16. Simulated microgravity alters multipotential differentiation of rat mesenchymal stem cells in association with reduced telomerase activity

    NASA Astrophysics Data System (ADS)

    Sun, Lianwen; Gan, Bo; Fan, Yubo; Xie, Tian; Hu, Qinghua; Zhuang, Fengyuan

    Microgravity is one of the most important characteristics in space flight. Exposure to microgravity results in extensive physiological changes in humans. Bone loss is one of the changes with serious consequences; however, the mechanism retains unclear. As the origin of osteoprogenitors, mesenchymal stem cells (MSCs) may play an important role in it. After cultured under simulated microgravity (in a rotary cell culture system, RCCS), MSCs were stained using oil red O to identify adipocytes. The mRNA level of bone morphogenetic protein (BMP)-2 and peroxisome proliferators-activated receptor (PPAR) γ2 was determined by RT-PCR. Otherwise, MSCs were induced to osteogenic differentiation after microgravity culture, and then the activity of alkaline phosphatase (ALP) was determined by PNPP and the content of osteocalcin (OC) by ELISA. Furthermore, the telomerase activity in MSCs was measured by TRAP. The results showed that simulated microgravity inhibited osteoblastic differentiation and induced adipogenic differentiation accompanied by the change of gene expression of BMP-2 and PPARγ2 in MSCs. Meanwhile, the telomerase activity decreased significantly in MSCs under simulated microgravity. The reduced bone formation in space flight may partly be due to the altered potential differentiation of MSCs associated with telomerase activity which plays a key role in regulating the lifespan of cell proliferation and differentiation. Therefore, telomerase activation/replacement may act as a potential countermeasure for microgravity-induced bone loss.

  17. The progression from a lower to a higher invasive stage of bladder cancer is associated with severe alterations in glucose and pyruvate metabolism

    SciTech Connect

    Conde, Vanessa R.; Oliveira, Pedro F.; Ramalhosa, Elsa; Pereira, José A.; Alves, Marco G.; Silva, Branca M.

    2015-07-01

    Cancer cells present a particular metabolic behavior. We hypothesized that the progression of bladder cancer could be accompanied by changes in cells glycolytic profile. We studied two human bladder cancer cells, RT4 and TCCSUP, in which the latter represents a more invasive stage. The levels of glucose, pyruvate, alanine and lactate in the extracellular media were measured by Proton Nuclear Magnetic Resonance. The protein expression levels of glucose transporters 1 (GLUT1) and 3 (GLUT3), monocarboxylate transporter 4 (MCT4), phosphofructokinase-1 (PFK1), glutamic-pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) were determined. Our data showed that glucose consumption and GLUT3 levels were similar in both cell lines, but TCCSUP cells displayed lower levels of GLUT1 and PFK expression. An increase in pyruvate consumption, concordant with the higher levels of lactate and alanine production, was also detected in TCCSUP cells. Moreover, TCCSUP cells presented lower protein expression levels of GPT and LDH. These results illustrate that bladder cancer progression is associated with alterations in cells glycolytic profile, namely the switch from glucose to pyruvate consumption in the more aggressive stage. This may be useful to develop new therapies and to identify biomarkers for cancer progression. - Highlights: • Metabolic phenotype of less and high invasive bladder cancer cells was studied. • Bladder cancer progression involves alterations in cells glycolytic profile. • More invasive bladder cancer cells switch from glucose to pyruvate consumption. • Our results may help to identify metabolic biomarkers of bladder cancer progression.

  18. Genetic engineering to enhance the Ehrlich pathway and alter carbon flux for increased isobutanol production from glucose by Saccharomyces cerevisiae.

    PubMed

    Kondo, Takashi; Tezuka, Hironori; Ishii, Jun; Matsuda, Fumio; Ogino, Chiaki; Kondo, Akihiko

    2012-05-31

    The production of higher alcohols by engineered bacteria has received significant attention. The budding yeast, Saccharomyces cerevisiae, has considerable potential as a producer of higher alcohols because of its capacity to naturally fabricate fusel alcohols, in addition to its robustness and tolerance to low pH. However, because its natural productivity is not significant, we considered a strategy of genetic engineering to increase production of the branched-chain higher alcohol isobutanol, which is involved in valine biosynthesis. Initially, we overexpressed 2-keto acid decarboxylase (KDC) and alcohol dehydrogenase (ADH) in S. cerevisiae to enhance the endogenous activity of the Ehrlich pathway. We then overexpressed Ilv2, which catalyzes the first step in the valine synthetic pathway, and deleted the PDC1 gene encoding a major pyruvate decarboxylase with the intent of altering the abundant ethanol flux via pyruvate. Through these engineering steps, along with modification of culture conditions, the isobutanol titer of S. cerevisiae was elevated 13-fold, from 11 mg/l to 143 mg/l, and the yield was 6.6 mg/g glucose, which is higher than any previously reported value for S. cerevisiae. PMID:22342368

  19. Oxidative Stress in Mouse Sperm Impairs Embryo Development, Fetal Growth and Alters Adiposity and Glucose Regulation in Female Offspring

    PubMed Central

    Lane, Michelle; McPherson, Nicole O.; Fullston, Tod; Spillane, Marni; Sandeman, Lauren; Kang, Wan Xian; Zander-Fox, Deirdre L.

    2014-01-01

    Paternal health cues are able to program the health of the next generation however the mechanism for this transmission is unknown. Reactive oxygen species (ROS) are increased in many paternal pathologies, some of which program offspring health, and are known to induce DNA damage and alter the methylation pattern of chromatin. We therefore investigated whether a chemically induced increase of ROS in sperm impairs embryo, pregnancy and offspring health. Mouse sperm was exposed to 1500 µM of hydrogen peroxide (H2O2), which induced oxidative damage, however did not affect sperm motility or the ability to bind and fertilize an oocyte. Sperm treated with H2O2 delayed on-time development of subsequent embryos, decreased the ratio of inner cell mass cells (ICM) in the resulting blastocyst and reduced implantation rates. Crown-rump length at day 18 of gestation was also reduced in offspring produced by H2O2 treated sperm. Female offspring from H2O2 treated sperm were smaller, became glucose intolerant and accumulated increased levels of adipose tissue compared to control female offspring. Interestingly male offspring phenotype was less severe with increases in fat depots only seen at 4 weeks of age, which was restored to that of control offspring later in life, demonstrating sex-specific impacts on offspring. This study implicates elevated sperm ROS concentrations, which are common to many paternal health pathologies, as a mediator of programming offspring for metabolic syndrome and obesity. PMID:25006800

  20. Operant licking for intragastric sugar infusions: Differential reinforcing actions of glucose, sucrose and fructose in mice.

    PubMed

    Sclafani, Anthony; Ackroff, Karen

    2016-01-01

    Intragastric (IG) flavor conditioning studies in rodents indicate that isocaloric sugar infusions differ in their reinforcing actions, with glucose and sucrose more potent than fructose. Here we determined if the sugars also differ in their ability to maintain operant self-administration by licking an empty spout for IG infusions. Food-restricted C57BL/6J mice were trained 1 h/day to lick a food-baited spout, which triggered IG infusions of 16% sucrose. In testing, the mice licked an empty spout, which triggered IG infusions of different sugars. Mice shifted from sucrose to 16% glucose increased dry licking, whereas mice shifted to 16% fructose rapidly reduced licking to low levels. Other mice shifted from sucrose to IG water reduced licking more slowly but reached the same low levels. Thus IG fructose, like water, is not reinforcing to hungry mice. The more rapid decline in licking induced by fructose may be due to the sugar's satiating effects. Further tests revealed that the Glucose mice increased their dry licking when shifted from 16% to 8% glucose, and reduced their dry licking when shifted to 32% glucose. This may reflect caloric regulation and/or differences in satiation. The Glucose mice did not maintain caloric intake when tested with different sugars. They self-infused less sugar when shifted from 16% glucose to 16% sucrose, and even more so when shifted to 16% fructose. Reduced sucrose self-administration may occur because the fructose component of the disaccharide reduces its reinforcing potency. FVB mice also reduced operant licking when tested with 16% fructose, yet learned to prefer a flavor paired with IG fructose. These data indicate that sugars differ substantially in their ability to support IG self-administration and flavor preference learning. The same post-oral reinforcement process appears to mediate operant licking and flavor learning, although flavor learning provides a more sensitive measure of sugar reinforcement. PMID:26485294

  1. Functional differentiation of human jejunum and ileum: A comparison of the handling of glucose, peptides, and amino acids

    PubMed Central

    Silk, D. B. A.; Webb, Joan P. W.; Lane, Annette E.; Clark, M. L.; Dawson, A. M.

    1974-01-01

    The characteristics of glucose, glycine, L-alanine, and glycyl-L-alanine absorption from the jejunum and ileum have been compared in normal human subjects. A perfusion technique has been used, and correct positioning of the perfusion tube has been confirmed by measuring the differential jejunal and ileal handling of bicarbonate. Glucose and glycine were absorbed faster from the jejunum than from the ileum of all subjects studied, and L-alanine was absorbed faster from the jejunum than from the ileum in five out of six subjects studied. In contrast, the dipeptide glycyl-L-alanine was absorbed at comparable rates from the jejunum and ileum. Higher concentrations of free amino acids were detected in the luminal contents aspirated during the ileal dipeptide perfusions. These results emphasize the importance of oligopeptide transport in the absorption of protein digestion products, especially in the human ileum, and the practical implications of these findings are discussed. PMID:4852103

  2. Differential expression of receptors for advanced glycation end-products in peritoneal mesothelial cells exposed to glucose degradation products

    PubMed Central

    LAI, K N; LEUNG, J C K; CHAN, L Y Y; LI, F F K; TANG, S C W; LAM, M F; TSE, K C; YIP, T P; CHAN, T M; WIESLANDER, A; VLASSARA, H

    2004-01-01

    Autoclaving peritoneal dialysate fluid (PDF) degrades glucose into glucose degradation products (GDPs) that impair peritoneal mesothelial cell functions. While glycation processes leading to formation of advanced glycation end-products (AGE) were viewed commonly as being mediated by glucose present in the PDF, recent evidence indicates that certain GDPs are even more powerful inducers of AGE formation than glucose per se. In the present study, we examined the expression and modulation of AGE receptors on human peritoneal mesothelial cells (HPMC) cultured with GDPs, conventional PDF or PDF with low GDP content. HPMC cultured with GDPs differentially modulated AGE receptors (including RAGE, AGE–R1, AGE–R2 and AGE–R3) expression in a dose-dependent manner. At subtoxic concentrations, GDPs increased RAGE mRNA expression in HPMC. 2-furaldehyde (FurA), methylglyoxal (M-Glx) and 3,4-dideoxy-glucosone-3-Ene (3,4-DGE) increased the expression of AGE–R1 and RAGE, the receptors that are associated with toxic effects. These three GDPs up-regulated the AGE synthesis by cultured HPMC. In parallel, these GDPs also increased the expression of vascular endothelial growth factor (VEGF) in HPMC. PDF with lower GDP content exerted less cytotoxic effect than traditional heat-sterilized PDF. Both PDF preparations up-regulated the protein expression of RAGE and VEGF. However, the up-regulation of VEGF in HPMC following 24-h culture with conventional PDF was higher than values from HPMC cultured with PDF containing low GDP. We have demonstrated, for the first time, that in addition to RAGE, other AGE receptors including AGE–R1, AGE–R2 and AGE–R3 are expressed on HPMC. Different GDPs exert differential regulation on the expression of these receptors on HPMC. The interactions between GDPs and AGE receptors may bear biological relevance to the intraperitoneal homeostasis and membrane integrity. PMID:15544624

  3. Time-Course of Alterations in Myocardial Glucose Utilization in the Zucker Diabetic Fatty (ZDF) Rat with Correlation to Gene Expression of Glucose Transporters: A Small Animal PET Investigation

    PubMed Central

    Shoghi, Kooresh I.; Gropler, Robert J.; Sharp, Terry; Herrero, Pilar; Fettig, Nicole; Su, Yi; Mitra, Mayurranjan S.; Kovacs, Attila; Finck, Brian N.; Welch, Michael J.

    2010-01-01

    Objective Diabetic cardiomyopathy is associated with abnormalities in glucose metabolism. We evaluated myocardial glucose metabolism in a rodent model of Type 2 Diabetes (T2D), namely the Zucker Diabetic Rat (ZDF), and validated PET measures of glucose uptake against gene and protein expression of glucose transporters. Methods Six lean and ZDF rat underwent small animal PET imaging at the age of 14 weeks and at the age of 19 weeks. The imaging protocol consisted of a 60-minute dynamic acquisition with 18FDG (0.5–0.8mCi). Dynamic images were reconstructed using filtered back projection (FBP) with a 2.5 zoom on the heart and 40 frames per imaging session. PET measures of myocardial glucose uptake rate (MGUp) and utilization were determined with an input function derived by the Hybrid Image- Blood Sampling (HIBS) algorithm on recovery-corrected anterolateral myocardial regions of interest. Following the PET imaging session at week 19, hearts were extracted for gene and protein expression analysis of GLUT1 and GLUT4. The dependence of MGUp on gene expression of GLUT1 and GLUT4 was characterized by multiple-regression analysis. Results Compared to lean littermate control rats, MGUp was significantly depressed in ZDF rats at both week 14 and week 19 (P<0.006). Moreover, lean rats at week 19 displayed significantly higher MGUp than week 14 (P=0.007). Consistent with diminished MGUp, gene expression of GLUT4 was significantly (P=0.004) lower in ZDF rats. Finally, MGUp significantly (P=0.0003) correlated with gene expression of GLUT4. Conclusions Using small animal PET, we confirmed alterations in myocardial glucose utilization and validated PET measure of MGUp against gene and protein expression of glucose transporters in the diabetic heart of an animal model of T2D. PMID:18632819

  4. Lead Exposure Disrupts Global DNA Methylation in Human Embryonic Stem Cells and Alters Their Neuronal Differentiation

    PubMed Central

    Senut, Marie-Claude; Sen, Arko; Cingolani, Pablo; Shaik, Asra; Land, Susan J.; Ruden, Douglas M.

    2014-01-01

    Exposure to lead (Pb) during childhood can result in learning disabilities and behavioral problems. Although described in animal models, whether Pb exposure also alters neuronal differentiation in the developing brains of exposed children is unknown. Here, we investigated the effects of physiologically relevant concentrations of Pb (from 0.4 to 1.9μM) on the capacity of human embryonic stem cells (hESCs) to progress to a neuronal fate. We found that neither acute nor chronic exposure to Pb prevented hESCs from generating neural progenitor cells (NPCs). NPCs derived from hESCs chronically exposed to 1.9μM Pb throughout the neural differentiation process generated 2.5 times more TUJ1-positive neurons than those derived from control hESCs. Pb exposure of hESCs during the stage of neural rosette formation resulted in a significant decrease in the expression levels of the neural marker genes PAX6 and MSI1. Furthermore, the resulting NPCs differentiated into neurons with shorter neurites and less branching than control neurons, as assessed by Sholl analysis. DNA methylation studies of control, acutely treated hESCs and NPCs derived from chronically exposed hESCs using the Illumina HumanMethylation450 BeadChip demonstrated that Pb exposure induced changes in the methylation status of genes involved in neurogenetic signaling pathways. In summary, our study shows that exposure to Pb subtly alters the neuronal differentiation of exposed hESCs and that these changes could be partly mediated by modifications in the DNA methylation status of genes crucial to brain development. PMID:24519525

  5. Lead exposure disrupts global DNA methylation in human embryonic stem cells and alters their neuronal differentiation.

    PubMed

    Senut, Marie-Claude; Sen, Arko; Cingolani, Pablo; Shaik, Asra; Land, Susan J; Ruden, Douglas M

    2014-05-01

    Exposure to lead (Pb) during childhood can result in learning disabilities and behavioral problems. Although described in animal models, whether Pb exposure also alters neuronal differentiation in the developing brains of exposed children is unknown. Here, we investigated the effects of physiologically relevant concentrations of Pb (from 0.4 to 1.9μM) on the capacity of human embryonic stem cells (hESCs) to progress to a neuronal fate. We found that neither acute nor chronic exposure to Pb prevented hESCs from generating neural progenitor cells (NPCs). NPCs derived from hESCs chronically exposed to 1.9μM Pb throughout the neural differentiation process generated 2.5 times more TUJ1-positive neurons than those derived from control hESCs. Pb exposure of hESCs during the stage of neural rosette formation resulted in a significant decrease in the expression levels of the neural marker genes PAX6 and MSI1. Furthermore, the resulting NPCs differentiated into neurons with shorter neurites and less branching than control neurons, as assessed by Sholl analysis. DNA methylation studies of control, acutely treated hESCs and NPCs derived from chronically exposed hESCs using the Illumina HumanMethylation450 BeadChip demonstrated that Pb exposure induced changes in the methylation status of genes involved in neurogenetic signaling pathways. In summary, our study shows that exposure to Pb subtly alters the neuronal differentiation of exposed hESCs and that these changes could be partly mediated by modifications in the DNA methylation status of genes crucial to brain development. PMID:24519525

  6. Alcohol alters DNA Methylation Patterns and Inhibits Neural Stem Cell Differentiation

    PubMed Central

    Zhou, Feng C.; Balaraman, Yokesh; Teng, MingXiang; Liu, Yunlong; Singh, Robindra; Nephew, Kenneth P.

    2010-01-01

    Background Potential epigenetic mechanisms underlying fetal alcohol syndrome (FAS) include alcohol-induced alterations of methyl metabolism, resulting in aberrant patterns of DNA methylation and gene expression during development. Having previously demonstrated an essential role for epigenetics in neural stem cell (NSC) development and that inhibiting DNA methylation prevents NSC differentiation, here we investigated the effect of alcohol exposure on genome-wide DNA methylation patterns and NSC differentiation. Methods NSCs in culture were treated with or without a 6-hr 88mM (“binge-like”) alcohol exposure and examined at 48 hrs, for migration, growth, and genome-wide DNA methylation. The DNA methylation was examined using DNA-methylation immunoprecipitation (MeDIP) followed by microarray analysis. Further validation was performed using Independent Sequenom analysis. Results NSC differentiated in 24 to 48 hrs with migration, neuronal expression, and morphological transformation. Alcohol exposure retarded the migration, neuronal formation, and growth processes of NSC, similar to treatment with the methylation inhibitor 5-aza-cytidine. When NSC departed from the quiescent state, a genome-wide diversification of DNA methylation was observed—that is, many moderately methylated genes altered methylation levels and became hyper- and hypomethylated. Alcohol prevented many genes from such diversification, including genes related to neural development, neuronal receptors, and olfaction, while retarding differentiation. Validation of specific genes by Sequenom analysis demonstrated that alcohol exposure prevented methylation of specific genes associated with neural development [cutl2 (cut-like 2), Igf1 (insulin-like growth factor 1), Efemp1 (epidermal growth factor-containing fibulin-like extracellular matrix protein 1), and Sox 7 (SRY-box containing gene 7)]; eye development, Lim 2 (lens intrinsic membrane protein 2); the epigenetic mark Smarca2 (SWI/SNF related

  7. REST/NRSF Knockdown Alters Survival, Lineage Differentiation and Signaling in Human Embryonic Stem Cells

    PubMed Central

    Thakore-Shah, Kaushali; Koleilat, Tasneem; Jan, Majib; John, Alan; Pyle, April D.

    2015-01-01

    REST (RE1 silencing transcription factor), also known as NRSF (neuron-restrictive silencer factor), is a well-known transcriptional repressor of neural genes in non-neural tissues and stem cells. Dysregulation of REST activity is thought to play a role in diverse diseases including epilepsy, cancer, Down’s syndrome and Huntington’s disease. The role of REST/NRSF in control of human embryonic stem cell (hESC) fate has never been examined. To evaluate the role of REST in hESCs we developed an inducible REST knockdown system and examined both growth and differentiation over short and long term culture. Interestingly, we have found that altering REST levels in multiple hESC lines does not result in loss of self-renewal but instead leads to increased survival. During differentiation, REST knockdown resulted in increased MAPK/ERK and WNT signaling and increased expression of mesendoderm differentiation markers. Therefore we have uncovered a new role for REST in regulation of growth and early differentiation decisions in human embryonic stem cells. PMID:26690059

  8. No Islet Cell Hyperfunction, but Altered Gut-Islet Regulation and Postprandial Hypoglycemia in Glucose-Tolerant Patients 3 Years After Gastric Bypass Surgery.

    PubMed

    Dirksen, Carsten; Eiken, Aleksander; Bojsen-Møller, Kirstine N; Svane, Maria S; Martinussen, Christoffer; Jørgensen, Nils B; Holst, Jens J; Madsbad, Sten

    2016-09-01

    Postprandial hyperinsulinemia characterizes Roux-en-Y gastric bypass (RYGB) and sometimes leads to reactive hypoglycemia. We prospectively evaluated changes in beta cell function in seven RYGB-operated patients with a median follow-up of 2.9 years with hyperglycemic clamps and oral glucose tolerance tests (OGTTs). Three years after RYGB, weight loss was 26 % and insulin sensitivity had improved. Insulin secretion during clamp experiments was largely unchanged compared to before surgery. In contrast, insulin secretion in response to the OGTTs doubled when evaluated by the disposition index and 2-h plasma glucose declined to a mean of 3.3 ± 0.3 mmol/l postoperatively. Our findings indicate that intrinsic beta cell function remains unchanged in glucose-tolerant patients even years after RYGB, while altered gut-islet regulation drive risk of postprandial hyperinsulinemic hypoglycemia. PMID:27138601

  9. Differential regulation of two distinct families of glucose transporter genes in Trypanosoma brucei.

    PubMed Central

    Bringaud, F; Baltz, T

    1993-01-01

    A tandemly arranged multigene family encoding putative hexose transporters in Trypanosoma brucei has been characterized. It is composed of two 80% homologous groups of genes called THT1 (six copies) and THT2 (five copies). When Xenopus oocytes are microinjected with in vitro-transcribed RNA from a THT1 gene, they express a glucose transporter with properties similar to those of the trypanosome bloodstream-form protein(s). This THT1-encoded transport system for glucose differs from the human erythrocyte-type glucose transporter by its moderate sensitivity to cytochalasin B and its capacity to transport D-fructose. These properties suggest that the trypanosomal transporter may be a good target for antitrypanosomal drugs. mRNA analysis revealed that expression of these genes was life cycle stage dependent. Bloodstream forms express 40-fold more THT1 than THT2. In contrast, procyclic trypanosomes express no detectable THT1 but demonstrate glucose-dependent expression of THT2. Images PMID:8423781

  10. Alterations in blood glucose and plasma glucagon concentrations during deep brain stimulation in the shell region of the nucleus accumbens in rats

    PubMed Central

    Diepenbroek, Charlene; van der Plasse, Geoffrey; Eggels, Leslie; Rijnsburger, Merel; Feenstra, Matthijs G. P.; Kalsbeek, Andries; Denys, Damiaan; Fliers, Eric; Serlie, Mireille J.; la Fleur, Susanne E.

    2013-01-01

    Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is an effective therapy for obsessive compulsive disorder (OCD) and is currently under investigation as a treatment for eating disorders. DBS of this area is associated with altered food intake and pharmacological treatment of OCD is associated with the risk of developing type 2 diabetes. Therefore we examined if DBS of the NAc-shell (sNAc) influences glucose metabolism. Male Wistar rats were subjected to DBS, or sham stimulation, for a period of 1 h. To assess the effects of stimulation on blood glucose and glucoregulatory hormones, blood samples were drawn before, during and after stimulation. Subsequently, all animals were used for quantitative assessment of Fos immunoreactivity in the lateral hypothalamic area (LHA) using computerized image analysis. DBS of the sNAc rapidly increased plasma concentrations of glucagon and glucose while sham stimulation and DBS outside the sNAc were ineffective. In addition, the increase in glucose was dependent on DBS intensity. In contrast, the DBS-induced increase in plasma corticosterone concentrations was independent of intensity and region, indicating that the observed DBS-induced metabolic changes were not due to corticosterone release. Stimulation of the sNAc with 200 μA increased Fos immunoreactivity in the LHA compared to sham or 100 μA stimulated animals. These data show that DBS of the sNAc alters glucose metabolism in a region- and intensity- dependent manner in association with neuronal activation in the LHA. Moreover, these data illustrate the need to monitor changes in glucose metabolism during DBS-treatment of OCD patients. PMID:24339800

  11. Alterations in blood glucose and plasma glucagon concentrations during deep brain stimulation in the shell region of the nucleus accumbens in rats.

    PubMed

    Diepenbroek, Charlene; van der Plasse, Geoffrey; Eggels, Leslie; Rijnsburger, Merel; Feenstra, Matthijs G P; Kalsbeek, Andries; Denys, Damiaan; Fliers, Eric; Serlie, Mireille J; la Fleur, Susanne E

    2013-01-01

    Deep brain stimulation (DBS) of the nucleus accumbens (NAc) is an effective therapy for obsessive compulsive disorder (OCD) and is currently under investigation as a treatment for eating disorders. DBS of this area is associated with altered food intake and pharmacological treatment of OCD is associated with the risk of developing type 2 diabetes. Therefore we examined if DBS of the NAc-shell (sNAc) influences glucose metabolism. Male Wistar rats were subjected to DBS, or sham stimulation, for a period of 1 h. To assess the effects of stimulation on blood glucose and glucoregulatory hormones, blood samples were drawn before, during and after stimulation. Subsequently, all animals were used for quantitative assessment of Fos immunoreactivity in the lateral hypothalamic area (LHA) using computerized image analysis. DBS of the sNAc rapidly increased plasma concentrations of glucagon and glucose while sham stimulation and DBS outside the sNAc were ineffective. In addition, the increase in glucose was dependent on DBS intensity. In contrast, the DBS-induced increase in plasma corticosterone concentrations was independent of intensity and region, indicating that the observed DBS-induced metabolic changes were not due to corticosterone release. Stimulation of the sNAc with 200 μA increased Fos immunoreactivity in the LHA compared to sham or 100 μA stimulated animals. These data show that DBS of the sNAc alters glucose metabolism in a region- and intensity- dependent manner in association with neuronal activation in the LHA. Moreover, these data illustrate the need to monitor changes in glucose metabolism during DBS-treatment of OCD patients. PMID:24339800

  12. Cocoa and Whey Protein Differentially Affect Markers of Lipid and Glucose Metabolism and Satiety.

    PubMed

    Campbell, Caroline L; Foegeding, E Allen; Harris, G Keith

    2016-03-01

    Food formulation with bioactive ingredients is a potential strategy to promote satiety and weight management. Whey proteins are high in leucine and are shown to decrease hunger ratings and increase satiety hormone levels; cocoa polyphenolics moderate glucose levels and slow digestion. This study examined the effects of cocoa and whey proteins on lipid and glucose metabolism and satiety in vitro and in a clinical trial. In vitro, 3T3-L1 preadipocytes were treated with 0.5-100 μg/mL cocoa polyphenolic extract (CPE) and/or 1-15 mM leucine (Leu) and assayed for lipid accumulation and leptin production. In vivo, a 6-week clinical trial consisted of nine panelists (age: 22.6 ± 1.7; BMI: 22.3 ± 2.1) consuming chocolate-protein beverages once per week, including placebo, whey protein isolate (WPI), low polyphenolic cocoa (LP), high polyphenolic cocoa (HP), LP-WPI, and HP-WPI. Measurements included blood glucose and adiponectin levels, and hunger ratings at baseline and 0.5-4.0 h following beverage consumption. At levels of 50 and 100 μg/mL, CPE significantly inhibited preadipocyte lipid accumulation by 35% and 50%, respectively, and by 22% and 36% when combined with 15 mM Leu. Leu treatment increased adipocyte leptin production by 26-37%. In the clinical trial, all beverages significantly moderated blood glucose levels 30 min postconsumption. WPI beverages elicited lowest peak glucose levels and HP levels were significantly lower than LP. The WPI and HP beverage treatments significantly increased adiponectin levels, but elicited no significant changes in hunger ratings. These trends suggest that combinations of WPI and cocoa polyphenols may improve markers of metabolic syndrome and satiety. PMID:26987021

  13. Letm1, the mitochondrial Ca2+/H+ antiporter, is essential for normal glucose metabolism and alters brain function in Wolf-Hirschhorn syndrome.

    PubMed

    Jiang, Dawei; Zhao, Linlin; Clish, Clary B; Clapham, David E

    2013-06-11

    Mitochondrial metabolism, respiration, and ATP production necessitate ion transport across the inner mitochondrial membrane. Leucine zipper-EF-hand containing transmembrane protein 1 (Letm1), one of the genes deleted in Wolf-Hirschhorn syndrome, encodes a putative mitochondrial Ca(2+)/H(+) antiporter. Cellular Letm1 knockdown reduced Ca(2+)mito uptake, H(+)mito extrusion and impaired mitochondrial ATP generation capacity. Homozygous deletion of Letm1 in mice resulted in embryonic lethality before day 6.5 of embryogenesis and ~50% of the heterozygotes died before day 13.5 of embryogenesis. The surviving heterozygous mice exhibited altered glucose metabolism, impaired control of brain ATP levels, and increased seizure activity. We conclude that loss of Letm1 contributes to the pathology of Wolf-Hirschhorn syndrome in humans and may contribute to seizure phenotypes by reducing glucose oxidation and other specific metabolic alterations. PMID:23716663

  14. Homeostatic effect of p-chloro-diphenyl diselenide on glucose metabolism and mitochondrial function alterations induced by monosodium glutamate administration to rats.

    PubMed

    Quines, Caroline B; Rosa, Suzan G; Chagas, Pietro M; da Rocha, Juliana T; Dobrachinski, Fernando; Carvalho, Nélson R; Soares, Félix A; da Luz, Sônia C Almeida; Nogueira, Cristina W

    2016-01-01

    The metabolic syndrome is a group of metabolic alterations considered a worldwide public health problem. Organic selenium compounds have been reported to have many different pharmacological actions, such as anti-hypercholesterolemic and anti-hyperglycemic. The aim of this study was to evaluate the effect of p-chloro-diphenyl diselenide (p-ClPhSe)2, an organic selenium compound, in a model of obesity induced by monosodium glutamate (MSG) administration in rats. The rats were treated during the first ten postnatal days with MSG and received (p-ClPhSe)2 (10 mg/kg, intragastrically) from 45th to 51 th postnatal day. Glucose, lipid and lactate levels were determined in plasma of rats. Glycogen levels and activities of tyrosine aminotransferase, hexokinase, citrate synthase and glucose-6-phosphatase (G-6-Pase) were determined in livers of rats. Renal G-6-Pase activity was also determined. The purine content [Adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate] and mitochondrial functionality in the liver were also investigated. p-(ClPhSe)2 did not alter the reduction in growth performance and in the body weight caused by MSG but reduced epididymal fat deposition of rats. p-(ClPhSe)2 restored glycemia, triglycerides, cholesterol and lactate levels as well as the glucose metabolism altered in rats treated with MSG. p-(ClPhSe)2 restored hepatic mitochondrial dysfunction and the decrease in citrate synthase activity and ATP and ADP levels caused by MSG in rats. In summary, (p-ClPhSe)2 had homeostatic effects on glucose metabolism and mitochondrial function alterations induced by MSG administration to rats. PMID:26293481

  15. Glucose concentration alters dissolved oxygen levels in liquid cultures of Beauveria bassiana and affects formation and bioefficacy of blastospores.

    PubMed

    Mascarin, Gabriel Moura; Jackson, Mark A; Kobori, Nilce Naomi; Behle, Robert W; Dunlap, Christopher A; Delalibera Júnior, Ítalo

    2015-08-01

    The filamentous fungus Beauveria bassiana is an economically important pathogen of numerous arthropod pests and is able to grow in submerged culture as filaments (mycelia) or as budding yeast-like blastospores. In this study, we evaluated the effect of dissolved oxygen and high glucose concentrations on blastospore production by submerged cultures of two isolates of B. bassiana, ESALQ1432 and GHA. Results showed that maintaining adequate dissolved oxygen levels coupled with high glucose concentrations enhanced blastospore yields by both isolates. High glucose concentrations increased the osmotic pressure of the media and coincided with higher dissolved oxygen levels and increased production of significantly smaller blastospores compared with blastospores produced in media with lower concentrations of glucose. The desiccation tolerance of blastospores dried to less than 2.6 % moisture was not affected by the glucose concentration of the medium but was isolate dependent. Blastospores of isolate ESALQ1432 produced in media containing 140 g glucose L(-1) showed greater virulence toward whitefly nymphs (Bemisia tabaci) as compared with blastospores produced in media containing 40 g glucose L(-1). These results suggest a synergistic effect between glucose concentration and oxygen availability on changing morphology and enhancing the yield and efficacy of blastospores of B. bassiana, thereby facilitating the development of a cost-effective production method for this blastospore-based bioinsecticide. PMID:25947245

  16. Altered expression and editing of miRNA-100 regulates iTreg differentiation

    PubMed Central

    Negi, Vinny; Paul, Deepanjan; Das, Sudipta; Bajpai, Prashant; Singh, Suchita; Mukhopadhyay, Arijit; Agrawal, Anurag; Ghosh, Balaram

    2015-01-01

    RNA editing of miRNAs, especially in the seed region, adds another layer to miRNA mediated gene regulation which can modify its targets, altering cellular signaling involved in important processes such as differentiation. In this study, we have explored the role of miRNA editing in CD4+ T cell differentiation. CD4+ T cells are an integral component of the adaptive immune system. Naïve CD4+ T cells, on encountering an antigen, get differentiated either into inflammatory subtypes like Th1, Th2 or Th17, or into immunosuppressive subtype Treg, depending on the cytokine milieu. We found C-to-U editing at fifth position of mature miR-100, specifically in Treg. The C-to-U editing of miR-100 is functionally associated with at least one biologically relevant target change, from MTOR to SMAD2. Treg cell polarization by TGFβ1 was reduced by both edited and unedited miR-100 mimics, but percentage of Treg in PBMCs was only reduced by edited miR-100 mimics, suggesting a model in which de-repression of MTOR due to loss of unedited mir-100, promotes tolerogenic signaling, while gain of edited miR-100 represses SMAD2, thereby limiting the Treg. Such delicately counterbalanced systems are a hallmark of immune plasticity and we propose that miR-100 editing is a novel mechanism toward this end. PMID:26209130

  17. Altered expression and editing of miRNA-100 regulates iTreg differentiation.

    PubMed

    Negi, Vinny; Paul, Deepanjan; Das, Sudipta; Bajpai, Prashant; Singh, Suchita; Mukhopadhyay, Arijit; Agrawal, Anurag; Ghosh, Balaram

    2015-09-18

    RNA editing of miRNAs, especially in the seed region, adds another layer to miRNA mediated gene regulation which can modify its targets, altering cellular signaling involved in important processes such as differentiation. In this study, we have explored the role of miRNA editing in CD4(+) T cell differentiation. CD4(+) T cells are an integral component of the adaptive immune system. Naïve CD4(+) T cells, on encountering an antigen, get differentiated either into inflammatory subtypes like Th1, Th2 or Th17, or into immunosuppressive subtype Treg, depending on the cytokine milieu. We found C-to-U editing at fifth position of mature miR-100, specifically in Treg. The C-to-U editing of miR-100 is functionally associated with at least one biologically relevant target change, from MTOR to SMAD2. Treg cell polarization by TGFβ1 was reduced by both edited and unedited miR-100 mimics, but percentage of Treg in PBMCs was only reduced by edited miR-100 mimics, suggesting a model in which de-repression of MTOR due to loss of unedited mir-100, promotes tolerogenic signaling, while gain of edited miR-100 represses SMAD2, thereby limiting the Treg. Such delicately counterbalanced systems are a hallmark of immune plasticity and we propose that miR-100 editing is a novel mechanism toward this end. PMID:26209130

  18. Melanoma-derived factors alter the maturation and activation of differentiated tissue-resident dendritic cells.

    PubMed

    Hargadon, Kristian M; Bishop, Johnathan D; Brandt, John P; Hand, Zachary C; Ararso, Yonathan T; Forrest, Osric A

    2016-01-01

    Dendritic cells (DCs) are key regulators of host immunity that are capable of inducing either immune tolerance or activation. In addition to their well-characterized role in shaping immune responses to foreign pathogens, DCs are also known to be critical for the induction and maintenance of anti-tumor immune responses. Therefore, it is important to understand how tumors influence the function of DCs and the quality of immune responses they elicit. Although the majority of studies in this field to date have utilized either immortalized DC lines or DC populations that have been generated under artificial conditions from hematopoietic precursors in vitro, we wished to investigate how tumors impact the function of already differentiated, tissue-resident DCs. Therefore, we used both an ex vivo and in vivo model system to assess the influence of melanoma-derived factors on DC maturation and activation. In ex vivo studies with freshly isolated splenic DCs, we demonstrate that the extent to which DC maturation and activation are altered by these factors correlates with melanoma tumorigenicity, and we identify partial roles for tumor-derived transforming growth factor (TGF)β1 and vascular endothelial growth factor (VEGF)-A in the altered functionality of DCs. In vivo studies using a lung metastasis model of melanoma also demonstrate tumorigenicity-dependent alterations to the function of lung-resident DCs, and skewed production of proinflammatory cytokines and chemokines by these tumor-altered cells is associated with recruitment of an immune infiltrate that may ultimately favor tumor immune escape and outgrowth. PMID:26010746

  19. Differential Tiam1/Rac1 activation in hippocampal and cortical neurons mediates differential spine shrinkage in response to oxygen/glucose deprivation

    PubMed Central

    Blanco-Suárez, Elena; Fiuza, Maria; Liu, Xun; Chakkarapani, Elavazhagan; Hanley, Jonathan G

    2014-01-01

    Distinct neuronal populations show differential sensitivity to global ischemia, with hippocampal CA1 neurons showing greater vulnerability compared to cortical neurons. The mechanisms that underlie differential vulnerability are unclear, and we hypothesize that intrinsic differences in neuronal cell biology are involved. Dendritic spine morphology changes in response to ischemic insults in vivo, but cell type-specific differences and the molecular mechanisms leading to such morphologic changes are unexplored. To directly compare changes in spine size in response to oxygen/glucose deprivation (OGD) in cortical and hippocampal neurons, we used separate and equivalent cultures of each cell type. We show that cortical neurons exhibit significantly greater spine shrinkage compared to hippocampal neurons. Rac1 is a Rho-family GTPase that regulates the actin cytoskeleton and is involved in spine dynamics. We show that Rac1 and the Rac guanine nucleotide exchange factor (GEF) Tiam1 are differentially activated by OGD in hippocampal and cortical neurons. Hippocampal neurons express more Tiam1 than cortical neurons, and reducing Tiam1 expression in hippocampal neurons by shRNA enhances OGD-induced spine shrinkage. Tiam1 knockdown also reduces hippocampal neuronal vulnerability to OGD. This work defines fundamental differences in signalling pathways that regulate spine morphology in distinct neuronal populations that may have a role in the differential vulnerability to ischemia. PMID:25248834

  20. Differential Response of Human Hepatocyte Chromatin to HDAC Inhibitors as a Function of Microenvironmental Glucose Level.

    PubMed

    Felisbino, Marina Barreto; Alves da Costa, Thiago; Gatti, Maria Silvia Viccari; Mello, Maria Luiza Silveira

    2016-10-01

    Diabetes is a complex multifactorial disorder characterized by chronic hyperglycemia due to impaired insulin secretion. Recent observations suggest that the complexity of the disease cannot be entirely accounted for genetic predisposition and a compelling argument for an epigenetic component is rapidly emerging. The use of histone deacetylase inhibitor (HDACi) in clinical setting is an emerging area of investigation. In this study, we have aimed to understand and compare the response of hepatocyte chromatin to valproic acid (VPA) and trichostatin A (TSA) treatments under normoglycemic or hyperglycemic conditions to expand our knowledge about the consequences of HDACi treatment in a diabetes cell model. Under normoglycemic conditions, these treatments promoted chromatin remodeling, as assessed by image analysis and H3K9ac and H3K9me2 abundance. Simultaneously, H3K9ac marks shifted to the nuclear periphery accompanied by HP1 dissociation from the heterochromatin and a G1 cell cycle arrest. More striking changes in the cell cycle progression and mitotic ratios required drastic treatment. Under hyperglycemic conditions, high glucose per se promoted chromatin changes similar to those promoted by VPA and TSA. Nonetheless, these results were not intensified in cells treated with HDACis under hyperglycemic conditions. Despite the absence of morphological changes being promoted, HDACi treatment seems to confer a physiological meaning, ameliorating the cellular hyperglycemic state through reduction of glucose production. These observations allow us to conclude that the glucose level to which the hepatocytes are subjected affects how chromatin responds to HDACi and their action under high-glucose environment might not reflect on chromatin remodeling. J. Cell. Physiol. 231: 2257-2265, 2016. © 2016 Wiley Periodicals, Inc. PMID:26888775

  1. Trypanosoma cruzi cells undergo an alteration in protein N-glycosylation upon differentiation

    SciTech Connect

    Engel, J.C.; Parodi, A.J.

    1985-08-25

    Trypanosoma cruzi epimastigotes (insect gut stage) incubated with (U- UC)glucose synthesized Man9GlcNAc2-P-P-dolichol as practically the sole dolichol-P-P derivative. On the other hand, amastigotes (intracellular stage) of the same parasite synthesized four to five times more Man7GlcNAc2-P-P-dolichol than Man9GlcNAc2-P-P-dolichol. Evidence is presented indicating that, whereas in epimastigotes only Man9GlcNAc2 was transferred to proteins, in amastigotes both Man7GlcNAc2 and Man9GlcNAc2 were transferred in direct proportion to their respective amounts bound to dolichol-P-P. The change in the mechanism of protein N-glycosylation could be observed upon in vitro differentiation of amastigotes to epimastigotes. The dissimilar size of the main oligosaccharides transferred to proteins in epimastigotes and amastigotes was responsible for differences in two structural features of high mannose-type oligosaccharides present in mature glycoproteins of both forms of the parasite, namely the average size of the compounds and the structure of the main species of some isomer oligosaccharides.

  2. Aqueous glucose measurement using differential absorption-based frequency domain optical coherence tomography at wavelengths of 1310 nm and 1625 nm

    NASA Astrophysics Data System (ADS)

    John, Pauline; Manoj, Murali; Sujatha, N.; Vasa, Nilesh J.; Rao, Suresh R.

    2015-07-01

    This work presents a combination of differential absorption technique and frequency domain optical coherence tomography for detection of glucose, which is an important analyte in medical diagnosis of diabetes. Differential absorption technique is used to detect glucose selectively in the presence of interfering species especially water and frequency domain optical coherence tomography (FDOCT) helps to obtain faster acquisition of depth information. Two broadband super-luminescent diode (SLED) sources with centre wavelengths 1586 nm (wavelength range of 1540 to 1640 nm) and 1312 nm (wavelength range of 1240 to 1380 nm) and a spectral width of ≍ 60 nm (FWHM) are used. Preliminary studies on absorption spectroscopy using various concentrations of aqueous glucose solution gave promising results to distinguish the absorption characteristics of glucose at two wavelengths 1310 nm (outside the absorption band of glucose) and 1625 nm (within the absorption band of glucose). In order to mimic the optical properties of biological skin tissue, 2% and 10% of 20% intralipid with various concentrations of glucose (0 to 4000 mg/dL) was prepared and used as sample. Using OCT technique, interference spectra were obtained using an optical spectrum analyzer with a resolution of 0.5 nm. Further processing of the interference spectra provided information on reflections from the surfaces of the cuvette containing the aqueous glucose sample. Due to the absorption of glucose in the wavelength range of 1540 nm to 1640 nm, a trend of reduction in the intensity of the back reflected light was observed with increase in the concentration of glucose.

  3. Altered Proliferation and Differentiation Properties of Primary Mammary Epithelial Cells from BRCA1 Mutation Carriers

    PubMed Central

    Burga, Laura N.; Tung, Nadine M.; Troyan, Susan L.; Bostina, Mihnea; Konstantinopoulos, Panagiotis A.; Fountzilas, Helena; Spentzos, Dimitrios; Miron, Alexander; Yassin, Yosuf A.; Lee, Bernard T.; Wulf, Gerburg M.

    2011-01-01

    Female BRCA1 mutation carriers have a nearly 80% probability of developing breast cancer during their life-time. We hypothesized that the breast epithelium at risk in BRCA1 mutation carriers harbors mammary epithelial cells (MEC) with altered proliferation and differentiation properties. Using a three-dimensional culture technique to grow MECs ex vivo, we found that the ability to form colonies, an indication of clonality, was restricted to the aldehyde dehydrogenase 1–positive fraction in MECs but not in HCC1937 BRCA1-mutant cancer cells. Primary MECs from BRCA1 mutation carriers (n = 9) had a 28% greater ability for clonal growth compared with normal controls (n= 6; P = 0.006), and their colonies were significantly larger. Colonies in controls and BRCA1 mutation carriers stained positive for BRCA1 by immunohistochemistry, and 79% of the examined single colonies from BRCA1 carriers retained heterozygosity for BRCA1 (ROH). Colonies from BRCA1 mutation carriers frequently showed high epidermal growth factor receptor (EGFR) expression (71% EGFR positive versus 44% in controls) and were negative for estrogen receptor (ERα; 32% ER negative, 44% mixed, 24% ER positive versus 90% ER positive in controls). Expression of CK14 and p63 were not significantly different. Microarray studies revealed that colonies from BRCA1-mutant PMECs anticipate expression profiles found in BRCA1-related tumors, and that the EGFR pathway is up-regulated. We conclude that BRCA1 haploin-sufficiency leads to an increased ability for clonal growth and proliferation in the PMECs of BRCA1 mutation carriers, possibly as a result of EGFR pathway activation. These altered growth and differentiation properties may render BRCA1-mutant PMECs vulnerable to transformation and predispose to the development of ER-negative, EGFR-positive breast cancers. PMID:19190334

  4. Endoplasmic Reticulum Stress, Unfolded Protein Response and Altered T Cell Differentiation in Necrotizing Enterocolitis

    PubMed Central

    Lu, Peng; Struijs, Marie-Chantal; Mei, Jiaping; Witte-Bouma, Janneke; Korteland-van Male, Anita M.; de Bruijn, Adrianus C. J. M.; van Goudoever, Johannes B.; Renes, Ingrid B.

    2013-01-01

    Background Endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) play important roles in chronic intestinal inflammation. Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in preterm infants and is characterized by acute intestinal inflammation and necrosis. The objective of the study is to investigate the role of ER stress and the UPR in NEC patients. Methods Ileal tissues from NEC and control patients were obtained during surgical resection and/or at stoma closure. Splicing of XBP1 was detected using PCR, and gene expression was quantified using qPCR and Western blot. Results Splicing of XBP1 was only detected in a subset of acute NEC (A-NEC) patients, and not in NEC patients who had undergone reanastomosis (R-NEC). The other ER stress and the UPR pathways, PERK and ATF6, were not activated in NEC patients. A-NEC patients showing XBP1 splicing (A-NEC-XBP1s) had increased mucosal expression of GRP78, CHOP, IL6 and IL8. Similar results were obtained by inducing ER stress and the UPR in vitro. A-NEC-XBP1s patients showed altered T cell differentiation indicated by decreased mucosal expression of RORC, IL17A and FOXP3. A-NEC-XBP1s patients additionally showed more severe morphological damage and a worse surgical outcome. Compared with A-NEC patients, R-NEC patients showed lower mucosal IL6 and IL8 expression and higher mucosal FOXP3 expression. Conclusions XBP1 splicing, ER stress and the UPR in NEC are associated with increased IL6 and IL8 expression levels, altered T cell differentiation and severe epithelial injury. PMID:24194940

  5. Glucose levels affect LL-37 expression in monocyte-derived macrophages altering the Mycobacterium tuberculosis intracellular growth control.

    PubMed

    Montoya-Rosales, Alejandra; Castro-Garcia, Pamela; Torres-Juarez, Flor; Enciso-Moreno, Jose Antonio; Rivas-Santiago, Bruno

    2016-08-01

    Diabetes mellitus (DM)-2 patients have an increased susceptibility to develop pulmonary tuberculosis; this is partly due to the impairment of the innate immunity because of their higher glucose concentrations. In the present study, we determined the effect of the glucose concentrations in the LL-37 expression in infected and non-infected macrophages. Our results showed that the increasing glucose concentrations correlates with the low cathelicidin expression in non-infected cells, however in Mycobacterium tuberculosis infected cells, LL-37 expression was substantially increased in higher glucose concentrations, nevertheless the mycobacterial burden also increased, this phenomena can be associated with the cathelicidin immunomodulatory activity. Further evaluation for LL-37 needs to be done to determine whether this peptide can be used as a biomarker of tuberculosis progression in DM2 patients. PMID:27263098

  6. Differential effects of temperature and glucose on glycogenolytic enzymes in tissues of rainbow trout (Oncorhynchus mykiss).

    PubMed

    Bolinger, Mark T; Rodnick, Kenneth J

    2014-05-01

    The pathways and regulatory mechanisms of glycogenolysis remain relatively unexplored in non-mammalian vertebrates, especially poikilotherms. We studied the temperature sensitivity and inhibition of glycogenolytic enzymes in liver, ventricle, and white muscle of rainbow trout acclimated to 14 °C. Glycogen phosphorylase (GP) and acid α-glucosidase (GAA) activities were measured in homogenates of tissues at physiological temperatures (4, 14, and 24 °C), and in the presence of allosteric inhibitor, glucose. Higher GP versus GAA activity in all three tissues suggested a predominance of phosphorolytic glycogenolysis over the lysosomal glucosidic pathway. GP activities at 14 °C were ~2-fold higher in the ventricle and white muscle versus the liver and selectively increased by AMP in striated muscle. Conversely, the activities of GAA and lysosomal marker acid phosphatase were 8- to 10-fold higher in the liver compared with the ventricle and white muscle. Thermal sensitivity (Q10) was increased for GP in all tissues below 14 °C and decreased in striated muscle in the absence of AMP above 14 °C. GAA had lower Q10 values than GP below 14 °C, and, unlike GP, Q10s for GAA were not different between tissues or affected by temperature. Both GP (in the absence of AMP) and GAA were inhibited by glucose in a dose-dependent manner, with the lowest IC50 values observed in the white muscle (1.4 and 6.3 mM, respectively). In conclusion, despite comparatively low kinetic potential, lysosomal GAA might facilitate glycogenolysis at colder body temperatures in striated muscle and intracellular glucose could limit phosphorolytic and glucosidic glycogenolysis in multiple tissues of the rainbow trout. PMID:24704523

  7. Reducing dietary fat from a meal increases the bioavailability of exogenous carbohydrate without altering plasma glucose concentration.

    PubMed

    Knuth, Nicolas D; Shrivastava, Cara R; Horowitz, Jeffrey F

    2009-01-01

    The primary goal of this study was to determine the acute glycemic and endocrine responses to the reduction of fat content from a meal. On three separate occasions, nine overweight subjects (body mass index = 30 +/- 1 kg/m(2); 5 men, 4 women) consumed 1) a control meal ( approximately 800 kcal; 100 g of carbohydrate, 31 g of fat, and 30 g of protein), 2) a low-fat meal ( approximately 530 kcal; 100 g of carbohydrate, 1 g of fat, and 30 g of protein), or 3) a low-fat meal plus lipid infusion [same meal as low-fat meal, but the total energy provided was the same as control (800 kcal), with the "missing" fat ( approximately 30 g) provided via an intravenous lipid infusion]. All three meals contained [(13)C]glucose (3 mg/kg body wt) to assess the bioavailability of ingested glucose. During the 5-h period after each meal, we measured the recovery of [(13)C]glucose in plasma, plasma glucose, and insulin concentrations. We also measured plasma concentration of the gastrointestinal peptides: glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and peptide YY(3-36) (PYY(3-36)). The recovery of the ingested [(13)C]glucose in the hour after ingestion was greater (P < 0.05) after the low-fat than after the control meal [area under the curve (AUC): 1,206 +/- 252 and 687 +/- 161 microM.h, respectively]. However, removing dietary fat from the meal did not affect the plasma concentration of glucose or insulin. Importantly, [(13)C]glucose recovery was not different during the low-fat and lipid infusion trials (AUC: 1,206 +/- 252 and 1,134 +/- 247 microM.h, respectively), indicating that the accelerated delivery of exogenous glucose found after removing fat from the meal is due exclusively to the reduction of fat in the gastrointestinal tract. In parallel with these findings, the reduction in fat calories from the meal reduced plasma concentration of GIP, GLP-1, and PYY(3-36). In summary, these data suggest that removing fat from the diet expedited

  8. Intra-uterine undernutrition amplifies age-associated glucose intolerance in pigs via altered DNA methylation at muscle GLUT4 promoter.

    PubMed

    Wang, Jun; Cao, Meng; Yang, Mei; Lin, Yan; Che, Lianqiang; Fang, Zhengfeng; Xu, Shengyu; Feng, Bin; Li, Jian; Wu, De

    2016-08-01

    The present study aimed to investigate the effect of maternal malnutrition on offspring glucose tolerance and the epigenetic mechanisms involved. In total, twelve primiparous Landrace×Yorkshire gilts were fed rations providing either 100 % (control (CON)) or 75 % (undernutrition (UN)) nutritional requirements according to the National Research Council recommendations, throughout gestation. Muscle samples of offspring were collected at birth (dpn1), weaning (dpn28) and adulthood (dpn189). Compared with CON pigs, UN pigs showed lower serum glucose concentrations at birth, but showed higher serum glucose and insulin concentrations as well as increased area under the blood glucose curve during intravenous glucose tolerance test at dpn189 (P<0·05). Compared with CON pigs, GLUT-4 gene and protein expressions were decreased at dpn1 and dpn189 in the muscle of UN pigs, which was accompanied by increased methylation at the GLUT4 promoter (P<0·05). These alterations in methylation concurred with increased mRNA levels of DNA methyltransferase (DNMT) 1 at dpn1 and dpn28, DNMT3a at dpn189 and DNMT3b at dpn1 in UN pigs compared with CON pigs (P<0·05). Interestingly, although the average methylation levels at the muscle GLUT4 promoter were decreased at dpn189 compared with dpn1 in pigs exposed to a poor maternal diet (P<0·05), the methylation differences in individual CpG sites were more pronounced with age. Our results indicate that in utero undernutrition persists to silence muscle GLUT4 likely through DNA methylation during the ageing process, which may lead to the amplification of age-associated glucose intolerance. PMID:27265204

  9. The rs340874 PROX1 type 2 diabetes mellitus risk variant is associated with visceral fat accumulation and alterations in postprandial glucose and lipid metabolism.

    PubMed

    Kretowski, Adam; Adamska, Edyta; Maliszewska, Katarzyna; Wawrusiewicz-Kurylonek, Natalia; Citko, Anna; Goscik, Joanna; Bauer, Witold; Wilk, Juliusz; Golonko, Anna; Waszczeniuk, Magdalena; Lipinska, Danuta; Hryniewicka, Justyna; Niemira, Magdalena; Paczkowska, Magdalena; Ciborowski, Michal; Gorska, Maria

    2015-03-01

    Large-scale meta-analyses of genome-wide association studies have recently confirmed that the rs340874 single-nucleotide polymorphism in PROX1 gene is associated with fasting glycemia and type 2 diabetes mellitus; however, the mechanism of this link was not well established. The aim of our study was to evaluate the functional/phenotypic differences related to rs340874 PROX1 variants. The study group comprised 945 subjects of Polish origin (including 634 with BMI > 25) without previously known dysglycemia. We analyzed behavioral patterns (diet, physical activity), body fat distribution and glucose/fat metabolism after standardized meals and during the oral glucose tolerance test. We found that the carriers of the rs340874 PROX1 CC genotype had higher nonesterified fatty acids levels after high-fat meal (p = 0.035) and lower glucose oxidation (p = 0.014) after high-carbohydrate meal in comparison with subjects with other PROX1 genotypes. Moreover, in subjects with CC variant, we found higher accumulation of visceral fat (p < 0.02), but surprisingly lower daily food consumption (p < 0.001). We hypothesize that lipid metabolism alterations in subjects with the PROX1 CC genotype may be a primary cause of higher glucose levels after glucose load, since the fatty acids can inhibit insulin-stimulated glucose uptake by decreasing carbohydrate oxidation. Our observations suggest that the PROX1 variants have pleiotropic effect on disease pathways and it seem to be a very interesting goal of research on prevention of obesity and type 2 diabetes mellitus. The study may help to understand the mechanisms of visceral obesity and type 2 diabetes mellitus risk development. PMID:25601634

  10. (18)F-FDG-PET imaging of rat spinal cord demonstrates altered glucose uptake acutely after contusion injury.

    PubMed

    von Leden, Ramona E; Selwyn, Reed G; Jaiswal, Shalini; Wilson, Colin M; Khayrullina, Guzal; Byrnes, Kimberly R

    2016-05-16

    Spinal cord injury (SCI) results in an acute reduction in neuronal and glial cell viability, disruption in axonal tract integrity, and prolonged increases in glial activity and inflammation, all of which can influence regional metabolism and glucose utilization. To date, the understanding of glucose uptake and utilization in the injured spinal cord is limited. Positron emission tomography (PET)-based measurements of glucose uptake may therefore serve as a novel biomarker for SCI. This study aimed to determine the acute and sub-acute glucose uptake pattern after SCI to determine its potential as a novel non-invasive tool for injury assessment and to begin to understand the glucose uptake pattern following acute SCI. Briefly, adult male Sprague-Dawley rats were subjected to moderate contusion SCI, confirmed by locomotor function and histology. PET imaging with [(18)F] Fluorodeoxyglucose (FDG) was performed prior to injury and at 6 and 24h and 15days post-injury (dpi). FDG-PET imaging revealed significantly depressed glucose uptake at 6h post-injury at the lesion epicenter that returned to sham/naïve levels at 24h and 15 dpi after moderate injury. FDG uptake at 15 dpi was likely influenced by a combination of elevated glial presence and reduced neuronal viability. These results show that moderate SCI results in acute depression in glucose uptake followed by an increase in glucose uptake that may be related to neuroinflammation. This acute and sub-acute uptake, which is dependent on cellular responses, may represent a therapeutic target. PMID:27084688

  11. 18F-FDG-PET imaging of rat spinal cord demonstrates altered glucose uptake acutely after contusion injury

    PubMed Central

    von Leden, Ramona E.; Selwyn, Reed G.; Jaiswal, Shalini; Wilson, Colin M.; Khayrullina, Guzal; Byrnes, Kimberly R.

    2016-01-01

    Spinal cord injury (SCI) results in an acute reduction in neuronal and glial cell viability, disruption in axonal tract integrity, and prolonged increases in glial activity and inflammation, all of which can influence regional metabolism and glucose utilization. To date, the understanding of glucose uptake and utilization in the injured spinal cord is limited. Positron emission tomography (PET)-based measurements of glucose uptake may therefore serve as a novel bio-marker for SCI. This study aimed to determine the acute and sub-acute glucose uptake pattern after SCI to determine its potential as a novel non-invasive tool for injury assessment and to begin to understand the glucose uptake pattern following acute SCI. Briefly, adult male Sprague-Dawley rats were subjected to moderate contusion SCI, confirmed by locomotor function and histology. PET imaging with [18F]Fluorodeoxyglucose (FDG) was performed prior to injury and at 6 and 24 hours and 15 days post-injury (dpi). FDG-PET imaging revealed significantly depressed glucose uptake at 6 hours post-injury at the lesion epicenter that returned to sham/naïve levels at 24 hours and 15 dpi after moderate injury. FDG uptake at 15 dpi was likely influenced by a combination of elevated glial presence and reduced neuronal viability. These results show that moderate SCI results in acute depression in glucose uptake followed by an increase in glucose uptake that may be related to neuroinflammation. This acute and sub-acute uptake, which is dependent on cellular responses, may represent a therapeutic target. PMID:27084688

  12. Vorinostat differentially alters 3D nuclear structure of cancer and non-cancerous esophageal cells

    PubMed Central

    Nandakumar, Vivek; Hansen, Nanna; Glenn, Honor L.; Han, Jessica H.; Helland, Stephanie; Hernandez, Kathryn; Senechal, Patti; Johnson, Roger H.; Bussey, Kimberly J.; Meldrum, Deirdre R.

    2016-01-01

    The histone deacetylase (HDAC) inhibitor vorinostat has received significant attention in recent years as an ‘epigenetic’ drug used to treat solid tumors. However, its mechanisms of action are not entirely understood, particularly with regard to its interaction with the aberrations in 3D nuclear structure that accompany neoplastic progression. We investigated the impact of vorinostat on human esophageal epithelial cell lines derived from normal, metaplastic (pre-cancerous), and malignant tissue. Using a combination of novel optical computed tomography (CT)-based quantitative 3D absorption microscopy and conventional confocal fluorescence microscopy, we show that subjecting malignant cells to vorinostat preferentially alters their 3D nuclear architecture relative to non-cancerous cells. Optical CT (cell CT) imaging of fixed single cells showed that drug-treated cancer cells exhibit significant alterations in nuclear morphometry. Confocal microscopy revealed that vorinostat caused changes in the distribution of H3K9ac-marked euchromatin and H3K9me3-marked constitutive heterochromatin. Additionally, 3D immuno-FISH showed that drug-induced expression of the DNA repair gene MGMT was accompanied by spatial relocation toward the center of the nucleus in the nuclei of metaplastic but not in non-neoplastic cells. Our data suggest that vorinostat’s differential modulation of 3D nuclear architecture in normal and abnormal cells could play a functional role in its anti-cancer action. PMID:27503568

  13. Vorinostat differentially alters 3D nuclear structure of cancer and non-cancerous esophageal cells.

    PubMed

    Nandakumar, Vivek; Hansen, Nanna; Glenn, Honor L; Han, Jessica H; Helland, Stephanie; Hernandez, Kathryn; Senechal, Patti; Johnson, Roger H; Bussey, Kimberly J; Meldrum, Deirdre R

    2016-01-01

    The histone deacetylase (HDAC) inhibitor vorinostat has received significant attention in recent years as an 'epigenetic' drug used to treat solid tumors. However, its mechanisms of action are not entirely understood, particularly with regard to its interaction with the aberrations in 3D nuclear structure that accompany neoplastic progression. We investigated the impact of vorinostat on human esophageal epithelial cell lines derived from normal, metaplastic (pre-cancerous), and malignant tissue. Using a combination of novel optical computed tomography (CT)-based quantitative 3D absorption microscopy and conventional confocal fluorescence microscopy, we show that subjecting malignant cells to vorinostat preferentially alters their 3D nuclear architecture relative to non-cancerous cells. Optical CT (cell CT) imaging of fixed single cells showed that drug-treated cancer cells exhibit significant alterations in nuclear morphometry. Confocal microscopy revealed that vorinostat caused changes in the distribution of H3K9ac-marked euchromatin and H3K9me3-marked constitutive heterochromatin. Additionally, 3D immuno-FISH showed that drug-induced expression of the DNA repair gene MGMT was accompanied by spatial relocation toward the center of the nucleus in the nuclei of metaplastic but not in non-neoplastic cells. Our data suggest that vorinostat's differential modulation of 3D nuclear architecture in normal and abnormal cells could play a functional role in its anti-cancer action. PMID:27503568

  14. Acute hyperglycemia alters von Willebrand factor but not the fibrinolytic system in elderly subjects with normal or impaired glucose tolerance.

    PubMed

    Coppola, Ludovico; Coppola, Antonino; Grassia, Antonio; Mastrolorenzo, Luigia; Lettieri, Biagio; De Lucia, Domenico; De Nanzio, Annarita; Gombos, Giorgio

    2004-10-01

    To assess whether acute hyperglycemia affects fibrinolytic balance in elderly subjects with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT), 40 non-obese elderly subjects (20 NGT, age 68 +/- 8 years; and 20 IGT, age 69 +/- 11 years) were studied. On two experimental days, randomly allocated and spaced 1 week apart, plasma concentrations of glucose, insulin, fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor type 1 and von Willebrand factor (vWF) were measured in each subject at baseline (0) and 30, 60, 90, 120 min after the ingestion of 75 g glucose or a similarly sweet dose of aspartame (250 mg) (control test). In both NGT and IGT elderly subjects, tissue plasminogen activator, plasminogen activator inhibitor type 1 and fibrinogen plasma levels did not significantly change after both oral aspartame and glucose load. In IGT subjects, vWF plasmatic levels decreased after glucose (not aspartame) oral load, reaching the minimum level at 90 min after load (82.7 +/- 7.8 versus 93.7 +/- 10.2, P <0.01). These results demonstrate that acute hyperglycemia does not modify plasma fibrinolysis in elderly subjects. The decrease of plasma concentration of vWF in IGT elderly subjects requires cautious interpretation and further extensive investigations. PMID:15613917

  15. Glucose metabolism in diabetic blood vessels

    SciTech Connect

    Brown, B.J.; Crass, M.F. III

    1986-03-05

    Since glycolysis appears to be coupled to active ion transport in vascular smooth muscle, alterations in glucose metabolism may contribute to cellular dysfunction and angiopathy in diabetes. Uptake and utilization of glucose were studied in perfused blood vessels in which pulsatile flow and perfusion pressure were similar to those measured directly in vivo. Thoracic aortae isolated from 8-wk alloxan diabetic (D) and nondiabetic control rabbits were cannulated, tethered, and perfused with oxygenated buffer containing 7 or 25 mM glucose and tracer amounts of glucose-U/sup -14/ C. Norepinephrine (NE) (10/sup -6/ M) and/or insulin (I) (150 ..mu..U/ml) and albumin (0.2%) were added. NE-induced tension development increased glucose uptake 39% and /sup 14/CO/sub 2/ and lactate production 2.3-fold. With 7 mM glucose, marked decreases in glucose uptake (74%), /sup 14/CO/sub 2/ (68%), lactate (30%), total tissue glycogen (75%), and tissue phospholipids (70%) were observed in D. Addition of I or elevation of exogenous glucose to 25 mM normalized glucose uptake, but had differential effects on the pattern of substrate utilization. Thus, in D, there was a marked depression of vascular glucose metabolism that was partially reversed by addition of low concentrations of insulin or D levels of glucose.

  16. Mature adipocyte proteome reveals differentially altered protein abundances between lean, overweight and morbidly obese human subjects.

    PubMed

    Benabdelkamel, Hicham; Masood, Afshan; Almidani, Ghaith M; Alsadhan, Abdulmajeed A; Bassas, Abdulelah F; Duncan, Mark W; Alfadda, Assim A

    2015-02-01

    Overweight (OW) and obese individuals are considered to be graded parts of the scale having increasing weight as a common feature. They may not, however, be part of the same continuum and may differ metabolically. In this study we applied an untargeted proteomic approach to compare protein abundances in mature adipocytes derived from the subcutaneous adipose tissue of overweight and morbidly obese female subjects to those of lean age matched controls. Mature adipocytes were isolated from liposuction samples of abdominal subcutaneous adipose tissue collected from both lean (L; n = 7, 23.3 ± 0.4 kg/m(2); mean BMI ± SD), overweight (OW; n = 8, 27.9 ± 0.6 kg/m(2); mean BMI ± SD) and morbidly obese (MOB; n = 7, 44.8 ± 3.8 kg/m(2); mean BMI ± SD) individuals. Total protein extracts were then compared by two-dimensional difference in gel electrophoresis (2D DIGE). One hundred and ten differentially expressed protein spots (i.e., fitting the statistical criteria ANOVA test, p < 0.05; fold-change ≥1.5) were detected, and of these, 89 were identified by MALDI-TOF mass spectrometry. Of these, 66 protein spots were common to both groups whereas 23 were unique to the MOB group. Significant differences were evident in the abundances of key proteins involved in glucose and lipid metabolism, energy regulation, cytoskeletal structure and redox control signaling pathways. Differences in the abundance of some chaperones were also evident. The differentially abundant proteins were investigated using Ingenuity Pathway Analysis (IPA) to establish their associations with known biological functions. The network identified in the OW group with the highest score relates to-: cell-to-cell signaling and interaction; in contrast, in the MOB group the major interacting pathways are associated with lipid metabolism, small molecule biochemistry and cancer. The differences in abundance of the differentially regulated proteins were validated by

  17. X-ray induced alterations in the differentiation and mineralization potential of murine preosteoblastic cells

    NASA Astrophysics Data System (ADS)

    Hu, Yueyuan; Lau, Patrick; Baumstark-Khan, Christa; Hellweg, Christine E.; Reitz, Günther

    2012-05-01

    To evaluate the effects of ionizing radiation (IR) on murine preosteoblastic cell differentiation, we directed OCT-1 cells to the osteoblastic lineage by treatment with a combination of β-glycerophosphate (β-GP), ascorbic acid (AA), and dexamethasone (Dex). In vitro mineralization was evaluated based on histochemical staining and quantification of the hydroxyapatite content of the extracellular bone matrix. Expression of mRNA encoding Runx2, transforming growth factor β1 (TGF-β1), osteocalcin (OCN), and p21CDKN1A was analyzed. Exposure to IR reduced the growth rate and diminished cell survival of OCT-1 cells under standard conditions. Notably, calcium content analysis revealed that deposition of mineralized matrix increased significantly under osteogenic conditions after X-ray exposure in a time-dependent manner. In this study, higher radiation doses exert significant overall effects on TGF-β1, OCN, and p21CDKN1A gene expression, suggesting that gene expression following X-ray treatment is affected in a dose-dependent manner. Additionally, we verified that Runx2 was suppressed within 24 h after irradiation at 2 and 4 Gy. Although further studies are required to verify the molecular mechanism, our observations strongly suggest that treatment with IR markedly alters the differentiation and mineralization process of preosteoblastic cells.

  18. Mitochondrial (Dys)function in Adipocyte (De)differentiation and Systemic Metabolic Alterations

    PubMed Central

    De Pauw, Aurélia; Tejerina, Silvia; Raes, Martine; Keijer, Jaap; Arnould, Thierry

    2009-01-01

    In mammals, adipose tissue, composed of BAT and WAT, collaborates in energy partitioning and performs metabolic regulatory functions. It is the most flexible tissue in the body, because it is remodeled in size and shape by modifications in adipocyte cell size and/or number, depending on developmental status and energy fluxes. Although numerous reviews have focused on the differentiation program of both brown and white adipocytes as well as on the pathophysiological role of white adipose tissues, the importance of mitochondrial activity in the differentiation or the dedifferentiation programs of adipose cells and in systemic metabolic alterations has not been extensively reviewed previously. Here, we address the crucial role of mitochondrial functions during adipogenesis and in mature adipocytes and discuss the cellular responses of white adipocytes to mitochondrial activity impairment. In addition, we discuss the increase in scientific knowledge regarding mitochondrial functions in the last 10 years and the recent suspicion of mitochondrial dysfunction in several 21st century epidemics (ie, obesity and diabetes), as well as in lipodystrophy found in HIV-treated patients, which can contribute to the development of new therapeutic strategies targeting adipocyte mitochondria. PMID:19700756

  19. Altered Transcriptional Control Networks with Trans-Differentiation of Isogenic Mutant-KRas NSCLC Models

    PubMed Central

    Haley, John A.; Haughney, Elizabeth; Ullman, Erica; Bean, James; Haley, John D.; Fink, Marc Y.

    2014-01-01

    Background: The capacity of cancer cells to undergo epithelial mesenchymal trans-differentiation has been implicated as a factor driving metastasis, through the acquisition of enhanced migratory/invasive cell programs and the engagement of anti-apoptotic mechanisms promoting drug and radiation resistance. Our aim was to define molecular signaling changes associated with mesenchymal trans-differentiation in two KRas mutant NSCLC models. We focused on central transcription and epigenetic regulators predicted to be important for mesenchymal cell survival. Experimental design: We have modeled trans-differentiation and cancer stemness in inducible isogenic mutant-KRas H358 and A549 non-small cell lung cell backgrounds. As expected, our models show mesenchymal-like tumor cells acquire novel mechanisms of cellular signaling not apparent in their epithelial counterparts. We employed large-scale quantitative phosphoproteomic, proteomic, protein–protein interaction, RNA-Seq, and network function prediction approaches to dissect the molecular events associated with the establishment and maintenance of the mesenchymal state. Results: Gene-set enrichment and pathway prediction indicated BMI1, KDM5B, RUNX2, MYC/MAX, NFκB, LEF1, and HIF1 target networks were significantly enriched in the trans-differentiation of H358 and A549 NSCLC models. Physical overlaps between multiple networks implicate NR4A1 as an overlapping control between TCF and NFκB pathways. Enrichment correlations also indicated marked decrease in cell cycling, which occurred early in the EMT process. RNA abundance time course studies also indicated early expression of epigenetic and chromatin regulators within 8–24 h, including CITED4, RUNX3, CMBX1, and SIRT4. Conclusion: Multiple transcription and epigenetic pathways where altered between epithelial and mesenchymal tumor cell states, notably the polycomb repressive complex-1, HP1γ, and BAF/Swi-Snf. Network analysis suggests redundancy in the activation

  20. Coffee Consumption, Newly Diagnosed Diabetes, and Other Alterations in Glucose Homeostasis: A Cross-Sectional Analysis of the Longitudinal Study of Adult Health (ELSA-Brasil)

    PubMed Central

    Yarmolinsky, James; Mueller, Noel T.; Duncan, Bruce B.; Bisi Molina, Maria del Carmen; Goulart, Alessandra C.; Schmidt, Maria Inês

    2015-01-01

    Introduction Observational studies have reported fairly consistent inverse associations between coffee consumption and risk of type 2 diabetes, but this association has been little investigated with regard to lesser degrees of hyperglycemia and other alterations in glucose homeostasis. Additionally, the association between coffee consumption and diabetes has been rarely investigated in South American populations. We examined the cross-sectional relationships of coffee intake with newly diagnosed diabetes and measures of glucose homeostasis, insulin sensitivity, and insulin secretion, in a large Brazilian cohort of middle-aged and elderly individuals. Methods We used baseline data from 12,586 participants of the Longitudinal Study of Adult Health (ELSA-Brasil). Logistic regression analyses were performed to examine associations between coffee consumption and newly diagnosed diabetes. Analysis of covariance was used to assess coffee intake in relation to two-hour glucose from an oral glucose tolerance test, fasting glucose, glycated hemoglobin, fasting and –2-hour postload insulin and measures of insulin sensitivity. Results We found an inverse association between coffee consumption and newly diagnosed diabetes, after adjusting for multiple covariates [23% and 26% lower odds of diabetes for those consuming coffee 2–3 and >3 times per day, respectively, compared to those reporting never or almost never consuming coffee, (p = .02)]. An inverse association was also found for 2-hour postload glucose [Never/almost never: 7.57 mmol/L, ≤1 time/day: 7.48 mmol/L, 2-3 times/day: 7.22 mmol/L, >3 times/day: 7.12 mol/L, p<0.0001] but not with fasting glucose concentrations (p = 0.07). Coffee was additionally associated with 2-hour postload insulin [Never/almost never: 287.2 pmol/L, ≤1 time/day: 280.1 pmol/L, 2–3 times/day: 275.3 pmol/L, >3 times/day: 262.2 pmol/L, p = 0.0005) but not with fasting insulin concentrations (p = .58). Conclusion Our present study provides

  1. Phloretin promotes adipocyte differentiation in vitro and improves glucose homeostasis in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adipocyte dysfunction is associated with many metabolic diseases such as obesity, insulin resistance and diabetes. Previous studies found that phloretin promotes 3T3-L1 cells differentiation, but the underlying mechanisms for phloretin's effects on adipogenesis remain unclear. In this study, we demo...

  2. Fucoxanthin exerts differing effects on 3T3-L1 cells according to differentiation stage and inhibits glucose uptake in mature adipocytes

    SciTech Connect

    Kang, Seong-Il; Ko, Hee-Chul; Shin, Hye-Sun; Kim, Hyo-Min; Hong, Youn-Suk; Lee, Nam-Ho; Kim, Se-Jae

    2011-06-17

    Highlights: {yields} Fucoxanthin enhances 3T3-L1 adipocyte differentiation at an early stage. {yields} Fucoxanthin inhibits 3T3-L1 adipocyte differentiation at intermediate and late stages. {yields} Fucoxanthin attenuates glucose uptake by inhibiting the phosphorylation of IRS in mature 3T3-L1 adipocytes. {yields} Fucoxanthin exerts its anti-obesity effect by inhibiting the differentiation of adipocytes at both intermediate and late stages, as well as glucose uptake in mature adipocytes. -- Abstract: Progression of 3T3-L1 preadipocyte differentiation is divided into early (days 0-2, D0-D2), intermediate (days 2-4, D2-D4), and late stages (day 4 onwards, D4-). In this study, we investigated the effects of fucoxanthin, isolated from the edible brown seaweed Petalonia binghamiae, on adipogenesis during the three differentiation stages of 3T3-L1 preadipocytes. When fucoxanthin was applied during the early stage of differentiation (D0-D2), it promoted 3T3-L1 adipocyte differentiation, as evidenced by increased triglyceride accumulation. At the molecular level, fucoxanthin increased protein expression of peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}), CCAAT/enhancer-binding protein {alpha} (C/EBP{alpha}), sterol regulatory element-binding protein 1c (SREBP1c), and aP2, and adiponectin mRNA expression, in a dose-dependent manner. However, it reduced the expression of PPAR{gamma}, C/EBP{alpha}, and SREBP1c during the intermediate (D2-D4) and late stages (D4-D7) of differentiation. It also inhibited the uptake of glucose in mature 3T3-L1 adipocytes by reducing the phosphorylation of insulin receptor substrate 1 (IRS-1). These results suggest that fucoxanthin exerts differing effects on 3T3-L1 cells of different differentiation stages and inhibits glucose uptake in mature adipocytes.

  3. An acute bout of whole body passive hyperthermia increases plasma leptin, but does not alter glucose or insulin responses in obese type 2 diabetics and healthy adults.

    PubMed

    Rivas, Eric; Newmire, Dan E; Crandall, Craig G; Hooper, Philip L; Ben-Ezra, Vic

    2016-07-01

    Acute and chronic hyperthermic treatments in diabetic animal models repeatedly improve insulin sensitivity and glycemic control. Therefore, the purpose of this study was to test the hypothesis that an acute 1h bout of hyperthermic treatment improves glucose, insulin, and leptin responses to an oral glucose challenge (OGTT) in obese type 2 diabetics and healthy humans. Nine obese (45±7.1% fat mass) type 2 diabetics (T2DM: 50.1±12y, 7.5±1.8% HbA1c) absent of insulin therapy and nine similar aged (41.1±13.7y) healthy non-obese controls (HC: 33.4±7.8% fat mass, P<0.01; 5.3±0.4% HbA1c, P<0.01) participated. Using a randomized design, subjects underwent either a whole body passive hyperthermia treatment via head-out hot water immersion (1h resting in 39.4±0.4°C water) that increased internal temperature above baseline by ∆1.6±0.4°C or a control resting condition. Twenty-four hours post treatments, a 75g OGTT was administered to evaluate changes in plasma glucose, insulin, C-peptide, and leptin concentrations. Hyperthermia itself did not alter area under the curve for plasma glucose, insulin, or C-peptide during the OGTT in either group. Fasting absolute and normalized (kg·fat mass) plasma leptin was significantly increased (P<0.01) only after the hyperthermic exposure by 17% in T2DM and 24% in HC groups (P<0.001) when compared to the control condition. These data indicate that an acute hyperthermic treatment does not improve glucose tolerance 24h post treatment in moderate metabolic controlled obese T2DM or HC individuals. PMID:27264884

  4. Altered differentiation and paracrine stimulation of mammary epithelial cell proliferation by conditionally activated Smoothened

    PubMed Central

    Visbal, Adriana P.; LaMarca, Heather L.; Villanueva, Hugo; Toneff, Michael J.; Li, Yi; Rosen, Jeffrey M.; Lewis, Michael T.

    2011-01-01

    The Hedgehog (Hh) signaling network is critical for patterning and organogenesis in mammals, and has been implicated in a variety of cancers. Smoothened (Smo), the gene encoding the principal signal transducer, is overexpressed frequently in breast cancer, and constitutive activation in MMTV-SmoM2 transgenic mice caused alterations in mammary gland morphology, increased proliferation, and changes in stem/progenitor cell number. Both in transgenic mice and in clinical specimens, proliferative cells did not usually express detectable Smo, suggesting the hypothesis that Smo functioned in a non-cell autonomous manner to stimulate proliferation. Here, we employed a genetically tagged mouse model carrying a Cre-recombinase-dependent conditional allele of constitutively active Smo (SmoM2) to test this hypothesis. MMTV-Cre- or adenoviral-Cre-mediated SmoM2 expression in the luminal epithelium, but not in the myoepithelium, was required for the hyper-proliferative phenotypes. High levels of proliferation were observed in cells adjacent or in close-proximity to Smo expressing cells demonstrating that SmoM2 expressing cells were stimulating proliferation via a paracrine or juxtacrine mechanism. In contrast, Smo expression altered luminal cell differentiation in a cell-autonomous manner. SmoM2 expressing cells, purified by fluorescence activated cell sorting (FACS) via the genetic fluorescent tag, expressed high levels of Ptch2, Gli1, Gli2, Jag2 and Dll-1, and lower levels of Notch4 and Hes6, in comparison to wildtype cells. These studies provide insight into the mechanism of Smo activation in the mammary gland and its possible roles in breast tumorigenesis. In addition, these results also have potential implications for the interpretation of proliferative phenotypes commonly observed in other organs as a consequence of hedgehog signaling activation. PMID:21276786

  5. Regional homogeneity alterations differentiate between tremor dominant and postural instability gait difficulty subtypes of Parkinson's disease.

    PubMed

    Jiang, Siming; Wang, Min; Zhang, Li; Yuan, Yongsheng; Tong, Qing; Ding, Jian; Wang, Jianwei; Xu, Qinrong; Zhang, Kezhong

    2016-03-01

    Parkinson's disease (PD) can be classified into the tremor dominant (TD) subtype and the postural instability gait difficulty (PIGD) subtype, which present with different clinical courses and prognoses. However, the symptom-specific intrinsic neural mechanisms underlying the subtypes of PD still remain elusive. In the current study, we utilized resting-state fMRI (rs-fMRI) combined with the regional homogeneity (ReHo) method to investigate the modulations of neural activity in 13 patients with predominantly PIGD (p-PIGD) and 15 patients with predominantly TD (p-TD) in the resting state. Compared with healthy controls, the p-PIGD and the p-TD groups both displayed ReHo changes in the default mode network (DMN). By contrast, the p-TD group exhibited more ReHo alterations in the cerebellum involved in the cerebello-thalamo-cortical (CTC) loops, whilst the p-PIGD group in extensive cortical and sub-cortical areas, including the frontal, parietal, occipital, temporal, limbic lobes, basal ganglia and thalamus, which are involved in the striatal-thalamo-cortical (STC) loops. Direct comparison between the two groups showed significant ReHo alterations in the primary visual cortex. Our findings underscore the differential involvement of the STC and CTC circuits underlying the two subtypes of PD. Moreover, relatively widespread neural activity abnormality, especially in the motor-related regions as well as the visual network, is apparently a characteristic feature of PIGD symptoms. This study could shed light on the underlying pathophysiology and clinical heterogeneity of PD presentation. PMID:26666253

  6. Glucose-dependent insulinotropic peptide: differential effects on hepatic artery vs. portal vein endothelial cells.

    PubMed

    Ding, Ke-Hong; Zhong, Qing; Xu, Jianrui; Isales, Carlos M

    2004-05-01

    Glucose-dependent insulinotropic peptide (GIP) has been reported to have opposing effects on splanchnic blood flow. GIP infusion in dogs results in an increase in portal vein circulation but a drop in hepatic artery blood flow. In an effort to evaluate whether these different responses were related to intrinsic differences in GIP effects, we isolated canine hepatic artery (HAEC) and portal vein endothelial cells (PVEC). We report that there are differences in GIP activation of the signal transduction pathways in these two cell types. GIP stimulates secretion of endothelin-1 (ET-1), a potent vasoconstrictor, from HAEC (EC50 0.28 nM) but not from PVEC. This effect could be abolished by preventing a rise in intracellular calcium, demonstrating the calcium dependence of GIP-induced ET-1 secretion from HAEC. The GIP effect was specific, as a GIP receptor antagonist blocked it. In contrast, GIP stimulated nitric oxide production from PVEC (EC50 0.09 nM) but not from HAEC. Taken together, our data demonstrate distinct differences in GIP effects on HAEC from those on PVEC. We conclude that differences in GIP stimulation of ET-1 vs. nitric oxide production in different vascular beds may account for some of the observed differences in its physiological effects. PMID:14709420

  7. The RUNX2 Transcription Factor Negatively Regulates SIRT6 Expression to Alter Glucose Metabolism in Breast Cancer Cells.

    PubMed

    Choe, Moran; Brusgard, Jessica L; Chumsri, Saranya; Bhandary, Lekhana; Zhao, Xianfeng Frank; Lu, Song; Goloubeva, Olga G; Polster, Brian M; Fiskum, Gary M; Girnun, Geoffrey D; Kim, Myoung Sook; Passaniti, Antonino

    2015-10-01

    Activation of genes promoting aerobic glycolysis and suppression of mitochondrial oxidative phosphorylation is one of the hallmarks of cancer. The RUNX2 transcription factor mediates breast cancer (BC) metastasis to bone and is regulated by glucose availability. But, the mechanisms by which it regulates glucose metabolism and promotes an oncogenic phenotype are not known. RUNX2 expression in luminal BC cells correlated with lower estrogen receptor-α (ERα) levels, anchorage-independent growth, expression of glycolytic genes, increased glucose uptake, and sensitivity to glucose starvation, but not to inhibitors of oxidative phosphorylation. Conversely, RUNX2 knockdown in triple-negative BC cells inhibited mammosphere formation and glucose dependence. RUNX2 knockdown resulted in lower LDHA, HK2, and GLUT1 glycolytic gene expression, but upregulation of pyruvate dehydrogenase-A1 (PDHA1) mRNA and enzymatic activity, which was consistent with lower glycolytic potential. The NAD-dependent histone deacetylase, SIRT6, a known tumor suppressor, was a critical regulator of these RUNX2-mediated metabolic changes. RUNX2 expression resulted in elevated pAkt, HK2, and PDHK1 glycolytic protein levels that were reduced by ectopic expression of SIRT6. RUNX2 also repressed mitochondrial oxygen consumption rates (OCR), a measure of oxidative phosphorylation (respiration). Overexpression of SIRT6 increased respiration in RUNX2-positive cells, but knockdown of SIRT6 in cells expressing low RUNX2 decreased respiration. RUNX2 repressed SIRT6 expression at both the transcriptional and post-translational levels and endogenous SIRT6 expression was lower in malignant BC tissues or cell lines that expressed high levels of RUNX2. These results support a hypothesis whereby RUNX2-mediated repression of the SIRT6 tumor suppressor regulates metabolic pathways that promote BC progression. PMID:25808624

  8. Sepsis does not alter red blood cell glucose metabolism or Na+ concentration: A 2H-, 23Na-NMR study

    SciTech Connect

    Hotchkiss, R.S.; Song, S.K.; Ling, C.S.; Ackerman, J.J.; Karl, I.E. )

    1990-01-01

    The effects of sepsis on intracellular Na+ concentration ((Na+)i) and glucose metabolism were examined in rat red blood cells (RBCs) by using 23Na- and 2H-nuclear magnetic resonance (NMR) spectroscopy. Sepsis was induced in 15 halothane-anesthetized female Sprague-Dawley rats by using the cecal ligation and perforation technique; 14 control rats underwent cecal manipulation without ligation. The animals were fasted for 36 h, but allowed free access to water. At 36 h postsurgery, RBCs were examined by 23Na-NMR by using dysprosium tripolyphosphate as a chemical shift reagent. Human RBCs from 17 critically ill nonseptic patients and from 7 patients who were diagnosed as septic were also examined for (Na+)i. Five rat RBC specimens had (Na+)i determined by both 23Na-NMR and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). For glucose metabolism studies, RBCs from septic and control rats were suspended in modified Krebs-Henseleit buffer containing (6,6-2H2)glucose and examined by 2H-NMR. No significant differences in (Na+)i or glucose utilization were found in RBCs from control or septic rats. There were no differences in (Na+)i in the two groups of patients. The (Na+)i determined by NMR spectroscopy agreed closely with measurements using ICP-AES and establish that 100% of the (Na+)i of the RBC is visible by NMR. Glucose measurements determined by 2H-NMR correlated closely (correlation coefficient = 0.93) with enzymatic analysis. These studies showed no evidence that sepsis disturbed RBC membrane function or metabolism.

  9. The five glucose-6-phosphatase paralogous genes are differentially regulated by insulin alone or combined with high level of amino acids and/or glucose in trout hepatocytes.

    PubMed

    Lucie, Marandel; Weiwei, Dai; Stéphane, Panserat; Sandrine, Skiba-Cassy

    2016-04-01

    A recent analysis of the newly sequenced rainbow trout (Oncorhynchus mykiss) genome suggested that duplicated gluconeogenic g6pc paralogues, fixed in this genome after the salmonid-specific 4th whole genome duplication, may have a role in the setting up of the glucose-intolerant phenotype in this carnivorous species. This should be due to the sub- or neo-functionalization of their regulation. In the present short communication we thus addressed the question of the regulation of these genes by insulin, hormone involved in the glucose homeostasis, and its interaction with glucose and amino acids in vitro. The stimulation of trout hepatocytes with insulin revealed an atypical up-regulation of g6pcb2 ohnologues and confirmed the sub- or neo-functionalization of the five g6pc genes at least at the regulatory level. Intriguingly, when hepatocytes were cultured with high levels of glucose and/or AAs in presence of insulin, most of the g6pc paralogues were up-regulated. It strongly suggested a cross-talk between insulin and nutrients for the regulation of these genes. Moreover these results strengthened the idea that g6pc duplicated genes may significantly contribute to the setting up of the glucose-intolerant phenotype in trout via their atypical regulation by insulin alone or in interaction with nutrients. These findings open new perspectives to better understand in vivo glucose-intolerant phenotype in trout fed a high carbohydrate diet. PMID:26896939

  10. Irradiation alters the differentiation potential of bone marrow mesenchymal stem cells

    PubMed Central

    WANG, YU; ZHU, GUOYING; WANG, JIANPING; CHEN, JUNXIANG

    2016-01-01

    Bone injury following radiotherapy has been confirmed by epidemiological and animal studies. However, the underlying mechanism remains to be elucidated and no preventive or curative solution has been identified for this bone loss. The present study aimed to investigate the irradiation-altered osteogenesis and adipogenesis of bone marrow mesenchymal stem cells (BMSCs). BMSCs were derived and exposed to γ-irradiation at doses of 0, 0.25, 0.5, 1, 2, 5 and 10 Gy. Cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide assay, and clonal expansion in vitro was detected by colony forming unit assessment. The osteogenic differentiation ability was demonstrated by alkaline phosphatase (ALP) activity, ALP staining and mineralization alizarin red staining, and the adipogenic differentiation ability was determined using Oil O red staining. The osteogenesis-associated genes, RUNX2, ALP, osteocalcin (OCN) and adipogenesis-associated genes, PPAR-γ and C/EBPα, were detected using reverse transcription-quantitative polymerase chain reaction analyses. The protein expression levels of RUNX2, ALP and PPAR-γ were detected using western blotting. Compared with the control, significant decreases in the proliferation, ALP activity and mineralization ability of the BMSCs were observed in the γ-irradiation group, with a high level of correlation with the exposure dose. However, no significant changes were observed in the area of Oil red O positive staining. The mRNA levels of RUNX2, ALP and OCN were decreased (P<0.05), however, no significant changes were observed in the levels of C/EBPα and PPAR-γ. The protein expression levels of RUNX2 and ALP were decreased in the irradiated BMSCs, however, no significant difference was observed in the protein expression of PPAR-γ. Irradiation inhibited the osteogenic and adipogenic ability of the BMSCs, and the osteogenic differentiation was decreased. The results of the present study provided evidence

  11. Prenatal methamphetamine differentially alters myocardial sensitivity to ischemic injury in male and female adult hearts.

    PubMed

    Rorabaugh, Boyd R; Seeley, Sarah L; Bui, Albert D; Sprague, Lisanne; D'Souza, Manoranjan S

    2016-02-15

    Methamphetamine is one of the most common illicit drugs abused during pregnancy. The neurological effects of prenatal methamphetamine are well known. However, few studies have investigated the potential effects of prenatal methamphetamine on adult cardiovascular function. Previous work demonstrated that prenatal cocaine exposure increases sensitivity of the adult heart to ischemic injury. Methamphetamine and cocaine have different mechanisms of action, but both drugs exert their effects by increasing dopaminergic and adrenergic receptor stimulation. Thus the goal of this study was to determine whether prenatal methamphetamine also worsens ischemic injury in the adult heart. Pregnant rats were injected with methamphetamine (5 mg·kg(-1)·day(-1)) or saline throughout pregnancy. When pups reached 8 wk of age, their hearts were subjected to ischemia and reperfusion by means of a Langendorff isolated heart system. Prenatal methamphetamine had no significant effect on infarct size, preischemic contractile function, or postischemic recovery of contractile function in male hearts. However, methamphetamine-treated female hearts exhibited significantly larger infarcts and significantly elevated end-diastolic pressure during recovery from ischemia. Methamphetamine significantly reduced protein kinase Cε expression and Akt phosphorylation in female hearts but had no effect on these cardioprotective proteins in male hearts. These data indicate that prenatal methamphetamine differentially affects male and female sensitivity to myocardial ischemic injury and alters cardioprotective signaling proteins in the adult heart. PMID:26683901

  12. Differential splicing and glycosylation of Apoer2 alters synaptic plasticity and fear learning

    PubMed Central

    Wasser, Catherine R.; Masiulis, Irene; Durakoglugil, Murat S.; Lane-Donovan, Courtney; Xian, Xunde; Beffert, Uwe; Agarwala, Anandita; Hammer, Robert E.; Herz, Joachim

    2015-01-01

    Apoer2 is an essential receptor in the central nervous system that binds to the apolipoprotein ApoE. Various splice variants of Apoer2 are produced. We showed that Apoer2 lacking exon 16, which encodes the O-linked sugar (OLS) domain, altered the proteolytic processing and abundance of Apoer2 in cells and synapse number and function in mice. In cultured cells expressing this splice variant, extracellular cleavage of OLS-deficient Apoer2 was reduced, consequently preventing γ-secretase-dependent release of the intracellular domain of Apoer2. Mice expressing Apoer2 lacking the OLS domain had increased Apoer2 abundance in the brain, hippocampal spine density, and glutamate receptor abundance, but decreased synaptic efficacy. Mice expressing a form of Apoer2 lacking the OLS domain and containing an alternatively spliced cytoplasmic tail region that promotes glutamate receptor signaling showed enhanced hippocampal long-term potentiation (LTP), a phenomenon associated with learning and memory. However, these mice did not display enhanced spatial learning in the Morris water maze, and cued fear conditioning was reduced. Reducing the expression of the mutant Apoer2 allele so that the abundance of the protein was similar to that of Apoer2 in wild-type mice normalized spine density, hippocampal LTP, and cued fear learning. These findings demonstrated a role for ApoE receptors as regulators of synaptic glutamate receptor activity and established differential receptor glycosylation as a potential regulator of synaptic function and memory. PMID:25429077

  13. Mouse embryonic stem cells irradiated with γ-rays differentiate into cardiomyocytes but with altered contractile properties.

    PubMed

    Rebuzzini, Paola; Fassina, Lorenzo; Mulas, Francesca; Bellazzi, Riccardo; Redi, Carlo Alberto; Di Liberto, Riccardo; Magenes, Giovanni; Adjaye, James; Zuccotti, Maurizio; Garagna, Silvia

    2013-08-30

    Embryonic stem cells (ESCs) for their derivation from the inner cell mass of a blastocyst represent a valuable in vitro model to investigate the effects of ionizing radiation on early embryonic cellular response. Following irradiation, both human and mouse ESCs (mESCs) maintain their pluripotent status and the capacity to differentiate into embryoid bodies and to form teratomas. Although informative of the maintenance of a pluripotent status, these studies never investigated the capability of irradiated ESCs to form specific differentiated phenotypes. Here, for the first time, 5Gy-irradiated mESCs were differentiated into cardiomyocytes, thus allowing the analysis of the long-term effects of ionizing radiations on the differentiation potential of a pluripotent stem cell population. On treated mESCs, 96h after irradiation, a genome-wide expression analysis was first performed in order to determine whether the treatment influenced gene expression of the surviving mESCs. Microarrays analysis showed that only 186 genes were differentially expressed in treated mESCs compared to control cells; a quarter of these genes were involved in cellular differentiation, with three main gene networks emerging, including cardiogenesis. Based on these results, we differentiated irradiated mESCs into cardiomyocytes. On day 5, 8 and 12 of differentiation, treated cells showed a significant alteration (qRT-PCR) of the expression of marker genes (Gata-4, Nkx-2.5, Tnnc1 and Alpk3) when compared to control cells. At day 15 of differentiation, although the organization of sarcomeric α-actinin and troponin T proteins appeared similar in cardiomyocytes differentiated from either mock or treated cells, the video evaluation of the kinematics and dynamics of the beating cardiac syncytium evidenced altered contractile properties of cardiomyocytes derived from irradiated mESCs. This alteration correlated with significant reduction of Connexin 43 foci. Our results indicate that mESCs populations

  14. Metabolomic analysis of long-term spontaneous exercise in mice suggests increased lipolysis and altered glucose metabolism when animals are at rest.

    PubMed

    Monleon, Daniel; Garcia-Valles, Rebeca; Morales, Jose Manuel; Brioche, Thomas; Olaso-Gonzalez, Gloria; Lopez-Grueso, Raul; Gomez-Cabrera, Mari Carmen; Viña, Jose

    2014-11-15

    Exercise has been associated with several beneficial effects and is one of the major modulators of metabolism. The working muscle produces and releases substances during exercise that mediate the adaptation of the muscle but also improve the metabolic flexibility of the complete organism, leading to adjustable substrate utilization. Metabolomic studies on physical exercise are scarce and most of them have been focused on the effects of intense exercise in professional sportsmen. The aim of our study was to determine plasma metabolomic adaptations in mice after a long-term spontaneous exercise intervention study (18 mo). The metabolic changes induced by long-term spontaneous exercise were sufficient to achieve complete discrimination between groups in the principal component analysis scores plot. We identified plasma indicators of an increase in lipolysis (elevated unsaturated fatty acids and glycerol), a decrease in glucose and insulin plasma levels and in heart glucose consumption (by PET), and altered glucose metabolism (decreased alanine and lactate) in the wheel running group. Collectively these data are compatible with an increase in skeletal muscle insulin sensitivity in the active mice. We also found an increase in amino acids involved in catecholamine synthesis (tyrosine and phenylalanine), in the skeletal muscle pool of creatine phosphate and taurine, and changes in phospholipid metabolism (phosphocholine and choline in lipids) between the sedentary and the active mice. In conclusion, long-term spontaneous wheel running induces significant plasma and tissue (heart) metabolic responses that remain even when the animal is at rest. PMID:25190738

  15. Extracellular Protease Inhibition Alters the Phenotype of Chondrogenically Differentiating Human Mesenchymal Stem Cells (MSCs) in 3D Collagen Microspheres

    PubMed Central

    Han, Sejin; Li, Yuk Yin; Chan, Barbara Pui

    2016-01-01

    Matrix remodeling of cells is highly regulated by proteases and their inhibitors. Nevertheless, how would the chondrogenesis of mesenchymal stem cells (MSCs) be affected, when the balance of the matrix remodeling is disturbed by inhibiting matrix proteases, is incompletely known. Using a previously developed collagen microencapsulation platform, we investigated whether exposing chondrogenically differentiating MSCs to intracellular and extracellular protease inhibitors will affect the extracellular matrix remodeling and hence the outcomes of chondrogenesis. Results showed that inhibition of matrix proteases particularly the extracellular ones favors the phenotype of fibrocartilage rather than hyaline cartilage in chondrogenically differentiating hMSCs by upregulating type I collagen protein deposition and type II collagen gene expression without significantly altering the hypertrophic markers at gene level. This study suggests the potential of manipulating extracellular proteases to alter the outcomes of hMSC chondrogenesis, contributing to future development of differentiation protocols for fibrocartilage tissues for intervertebral disc and meniscus tissue engineering. PMID:26760956

  16. Alteration of carbohydrates metabolism and midgut glucose absorption in Gromphadorhina portentosa after subchronic exposure to imidacloprid and fenitrothion.

    PubMed

    Sawczyn, Tomasz; Dolezych, Bogdan; Klosok, Marcin; Augustyniak, Maria; Stygar, Dominika; Buldak, Rafal J; Kukla, Michal; Michalczyk, Katarzyna; Karcz-Socha, Iwona; Zwirska-Korczala, Krystyna

    2012-01-01

    This study was undertaken to test the hypothesis that following exposure to insecticides, changes take place in the metabolism of carbohydrates and absorption in the midgut of insects. The Madagascar hissing cockroach (Gromphadorhina portentosa) was chosen for the experiment as a model organism, due to it being easy to breed and its relatively large alimentary tract, which was important when preparing the microperfusion midgut bioassay. In each group of cockroaches treated with imidacloprid and fenitrothion, absorption of glucose, expressed as the area under the curve (AUC), was elevated compared to the control group. Glucose in the hemolymph of the examined insects was present in a vestigial amount, often below the threshold of determination, so the determinable carbohydrate indices were: hemolymph trehalose concentration and fat body glycogen content. The level of trehalose found in the hemolymph of insects when exposed to fenitrothion, and irrespective of the level of concentration mixed into food, were significantly lower when comparing to the control samples. Imidacloprid acted analogically with one exception at the concentration of 10 mg·kg(-1) dry food where trehalose concentration did not differ from the control values. Coupling with fat body glycogen concentration was less visible and appeared only at the concentrations of 5 and 10 mg imidacloprid·kg(-1) dry food. As described in this study changes in the sugar distribution and midgut glucose absorption indicate that insects cover the increased energy needs induced by insecticides; also at the gastrointestinal tract level. The result indicates that the midgut glucose absorption parameters could be considered as a non-specific biomarker of insecticide toxicity. PMID:22702824

  17. Partial Inhibition of Adipose Tissue Lipolysis Improves Glucose Metabolism and Insulin Sensitivity Without Alteration of Fat Mass

    PubMed Central

    Girousse, Amandine; Tavernier, Geneviève; Valle, Carine; Moro, Cedric; Mejhert, Niklas; Dinel, Anne-Laure; Houssier, Marianne; Roussel, Balbine; Besse-Patin, Aurèle; Combes, Marion; Mir, Lucile; Monbrun, Laurent; Bézaire, Véronic; Prunet-Marcassus, Bénédicte; Waget, Aurélie; Vila, Isabelle; Caspar-Bauguil, Sylvie; Louche, Katie; Marques, Marie-Adeline; Mairal, Aline; Renoud, Marie-Laure; Galitzky, Jean; Holm, Cecilia; Mouisel, Etienne; Thalamas, Claire; Viguerie, Nathalie; Sulpice, Thierry; Burcelin, Rémy; Arner, Peter; Langin, Dominique

    2013-01-01

    When energy is needed, white adipose tissue (WAT) provides fatty acids (FAs) for use in peripheral tissues via stimulation of fat cell lipolysis. FAs have been postulated to play a critical role in the development of obesity-induced insulin resistance, a major risk factor for diabetes and cardiovascular disease. However, whether and how chronic inhibition of fat mobilization from WAT modulates insulin sensitivity remains elusive. Hormone-sensitive lipase (HSL) participates in the breakdown of WAT triacylglycerol into FAs. HSL haploinsufficiency and treatment with a HSL inhibitor resulted in improvement of insulin tolerance without impact on body weight, fat mass, and WAT inflammation in high-fat-diet–fed mice. In vivo palmitate turnover analysis revealed that blunted lipolytic capacity is associated with diminution in FA uptake and storage in peripheral tissues of obese HSL haploinsufficient mice. The reduction in FA turnover was accompanied by an improvement of glucose metabolism with a shift in respiratory quotient, increase of glucose uptake in WAT and skeletal muscle, and enhancement of de novo lipogenesis and insulin signalling in liver. In human adipocytes, HSL gene silencing led to improved insulin-stimulated glucose uptake, resulting in increased de novo lipogenesis and activation of cognate gene expression. In clinical studies, WAT lipolytic rate was positively and negatively correlated with indexes of insulin resistance and WAT de novo lipogenesis gene expression, respectively. In obese individuals, chronic inhibition of lipolysis resulted in induction of WAT de novo lipogenesis gene expression. Thus, reduction in WAT lipolysis reshapes FA fluxes without increase of fat mass and improves glucose metabolism through cell-autonomous induction of fat cell de novo lipogenesis, which contributes to improved insulin sensitivity. PMID:23431266

  18. Partial inhibition of adipose tissue lipolysis improves glucose metabolism and insulin sensitivity without alteration of fat mass.

    PubMed

    Girousse, Amandine; Tavernier, Geneviève; Valle, Carine; Moro, Cedric; Mejhert, Niklas; Dinel, Anne-Laure; Houssier, Marianne; Roussel, Balbine; Besse-Patin, Aurèle; Combes, Marion; Mir, Lucile; Monbrun, Laurent; Bézaire, Véronic; Prunet-Marcassus, Bénédicte; Waget, Aurélie; Vila, Isabelle; Caspar-Bauguil, Sylvie; Louche, Katie; Marques, Marie-Adeline; Mairal, Aline; Renoud, Marie-Laure; Galitzky, Jean; Holm, Cecilia; Mouisel, Etienne; Thalamas, Claire; Viguerie, Nathalie; Sulpice, Thierry; Burcelin, Rémy; Arner, Peter; Langin, Dominique

    2013-01-01

    When energy is needed, white adipose tissue (WAT) provides fatty acids (FAs) for use in peripheral tissues via stimulation of fat cell lipolysis. FAs have been postulated to play a critical role in the development of obesity-induced insulin resistance, a major risk factor for diabetes and cardiovascular disease. However, whether and how chronic inhibition of fat mobilization from WAT modulates insulin sensitivity remains elusive. Hormone-sensitive lipase (HSL) participates in the breakdown of WAT triacylglycerol into FAs. HSL haploinsufficiency and treatment with a HSL inhibitor resulted in improvement of insulin tolerance without impact on body weight, fat mass, and WAT inflammation in high-fat-diet-fed mice. In vivo palmitate turnover analysis revealed that blunted lipolytic capacity is associated with diminution in FA uptake and storage in peripheral tissues of obese HSL haploinsufficient mice. The reduction in FA turnover was accompanied by an improvement of glucose metabolism with a shift in respiratory quotient, increase of glucose uptake in WAT and skeletal muscle, and enhancement of de novo lipogenesis and insulin signalling in liver. In human adipocytes, HSL gene silencing led to improved insulin-stimulated glucose uptake, resulting in increased de novo lipogenesis and activation of cognate gene expression. In clinical studies, WAT lipolytic rate was positively and negatively correlated with indexes of insulin resistance and WAT de novo lipogenesis gene expression, respectively. In obese individuals, chronic inhibition of lipolysis resulted in induction of WAT de novo lipogenesis gene expression. Thus, reduction in WAT lipolysis reshapes FA fluxes without increase of fat mass and improves glucose metabolism through cell-autonomous induction of fat cell de novo lipogenesis, which contributes to improved insulin sensitivity. PMID:23431266

  19. Sugars and light/dark exposure trigger differential regulation of ADP-glucose pyrophosphorylase genes in Arabidopsis thaliana (thale cress).

    PubMed

    Sokolov, L N; Déjardin, A; Kleczkowski, L A

    1998-12-15

    Expression of four Arabidopsis (thale cress) genes corresponding to the small (ApS) and large subunits (ApL1, ApL2, ApL3) of ADP-glucose pyrophosphorylase (AGPase), a key enzyme of starch biosynthesis, was found to be profoundly and differentially regulated by sugar and light/dark exposures. Transcript levels of both ApL2 and ApL3, and to a lesser extent ApS, increased severalfold upon feeding sucrose or glucose to the detached leaves in the dark, whereas the mRNA content for ApL1 decreased under the same conditions. Glucose was, in general, less effective than sucrose in inducing regulation of AGPase genes, possibly due to observed limitations in its uptake when compared with sucrose uptake by detached leaves. Osmotic agents [sorbitol, poly(ethylene glycol)] had no effect on ApS, ApL2 and ApL3 transcript level, but they did mimic the effect of sucrose on ApL1 gene, suggesting that the latter is regulated by osmotic pressure rather than any particular sugar. For all the genes the sugar effect was closely mimicked by an exposure of the dark-pre-adapted leaves to the light. Under both dark and light conditions, sucrose fed to the detached leaves was found to be rapidly metabolized to hexoses and, to some extent, starch. Starch production reflected most probably an increase in substrate availability for AGPase reaction rather than being due to changes in AGPase protein content, since both the sugar feeding and light exposure had little or no effect on the activity of AGPase or on the levels of its small and large subunit proteins in leaf extracts. The data suggest tight translational or post-translational control, but they may also reflect spatial control of AGPase gene expression within a leaf. The sugar/light-dependent regulation of AGPase gene expression may represent a part of a general cellular response to the availability/allocation of carbohydrates during photosynthesis. PMID:9841881

  20. Long-term exposure to abnormal glucose levels alters drug metabolism pathways and insulin sensitivity in primary human hepatocytes

    PubMed Central

    Davidson, Matthew D.; Ballinger, Kimberly R.; Khetani, Salman R.

    2016-01-01

    Hyperglycemia in type 2 diabetes mellitus has been linked to non-alcoholic fatty liver disease, which can progress to inflammation, fibrosis/cirrhosis, and hepatocellular carcinoma. Understanding how chronic hyperglycemia affects primary human hepatocytes (PHHs) can facilitate the development of therapeutics for these diseases. Conversely, elucidating the effects of hypoglycemia on PHHs may provide insights into how the liver adapts to fasting, adverse diabetes drug reactions, and cancer. In contrast to declining PHH monocultures, micropatterned co-cultures (MPCCs) of PHHs and 3T3-J2 murine embryonic fibroblasts maintain insulin-sensitive glucose metabolism for several weeks. Here, we exposed MPCCs to hypo-, normo- and hyperglycemic culture media for ~3 weeks. While albumin and urea secretion were not affected by glucose level, hypoglycemic MPCCs upregulated CYP3A4 enzyme activity as compared to other glycemic states. In contrast, hyperglycemic MPCCs displayed significant hepatic lipid accumulation in the presence of insulin, while also showing decreased sensitivity to insulin-mediated inhibition of glucose output relative to a normoglycemic control. In conclusion, we show for the first time that PHHs exposed to hypo- and hyperglycemia can remain highly functional, but display increased CYP3A4 activity and selective insulin resistance, respectively. In the future, MPCCs under glycemic states can aid in novel drug discovery and mechanistic investigations. PMID:27312339

  1. Transgenerational Glucose Intolerance of Tumor Necrosis Factor with Epigenetic Alteration in Rat Perirenal Adipose Tissue Induced by Intrauterine Hyperglycemia

    PubMed Central

    Su, Rina; Yan, Jie; Yang, Huixia

    2016-01-01

    Changes in DNA methylation may play a role in the genetic mechanism underlying glucose intolerance in the offspring of mothers with diabetes. Here, we established a rat model of moderate intrauterine hyperglycemia induced by streptozotocin to detect glucose and lipid metabolism of first-generation (F1) and second-generation (F2) offspring. Moderate intrauterine hyperglycemia induced high body weight in F1 and F2 offspring of diabetic mothers. F1 offspring had impaired glucose tolerance and abnormal insulin level. Additionally, F1 and F2 offspring that were exposed to intrauterine hyperglycemia had impaired insulin secretion from the islets. The tumor necrosis factor (Tnf) gene was upregulated in perirenal adipose tissue from F1 offspring and relatively increased in F2 offspring. Both F1 and F2 offspring showed similar hypomethylation level at the −1952 site of Tnf. We confirmed that DNA methylation occurs in offspring exposed to intrauterine hyperglycemia and that the DNA methylation is intergenerational and inherited. PMID:26881249

  2. Long-term exposure to abnormal glucose levels alters drug metabolism pathways and insulin sensitivity in primary human hepatocytes.

    PubMed

    Davidson, Matthew D; Ballinger, Kimberly R; Khetani, Salman R

    2016-01-01

    Hyperglycemia in type 2 diabetes mellitus has been linked to non-alcoholic fatty liver disease, which can progress to inflammation, fibrosis/cirrhosis, and hepatocellular carcinoma. Understanding how chronic hyperglycemia affects primary human hepatocytes (PHHs) can facilitate the development of therapeutics for these diseases. Conversely, elucidating the effects of hypoglycemia on PHHs may provide insights into how the liver adapts to fasting, adverse diabetes drug reactions, and cancer. In contrast to declining PHH monocultures, micropatterned co-cultures (MPCCs) of PHHs and 3T3-J2 murine embryonic fibroblasts maintain insulin-sensitive glucose metabolism for several weeks. Here, we exposed MPCCs to hypo-, normo- and hyperglycemic culture media for ~3 weeks. While albumin and urea secretion were not affected by glucose level, hypoglycemic MPCCs upregulated CYP3A4 enzyme activity as compared to other glycemic states. In contrast, hyperglycemic MPCCs displayed significant hepatic lipid accumulation in the presence of insulin, while also showing decreased sensitivity to insulin-mediated inhibition of glucose output relative to a normoglycemic control. In conclusion, we show for the first time that PHHs exposed to hypo- and hyperglycemia can remain highly functional, but display increased CYP3A4 activity and selective insulin resistance, respectively. In the future, MPCCs under glycemic states can aid in novel drug discovery and mechanistic investigations. PMID:27312339

  3. Naturally-occurring compensated insulin resistance selectively alters glucose transporters in visceral and subcutaneous adipose tissue without change in AS160 activation

    PubMed Central

    Waller, AP; Kohler, K; Burns, TA; Mudge, MC; Belknap, JK; Lacombe, VA

    2011-01-01

    Although the importance of adipose tissue (AT) glucose transport in regulating whole-body insulin sensitivity is becoming increasingly evident and insulin resistance (IR) has been widely recognized, the underlying mechanisms of IR are still not well understood. The purpose of the present study was to determine the early pathological changes in glucose transport by characterizing the alterations in glucose transporters (GLUT) in multiple visceral and subcutaneous adipose depots in a large animal model of naturally-occurring compensated IR. AT biopsies were collected from horses, which were classified as insulin-sensitive (IS) or compensated IR based on the results of an insulin-modified frequently-sampled intravenous glucose tolerance test. Protein expression of GLUT4 (major isoform) and GLUT12 (one of the most recently discovered isoforms) were measured by Western blotting in multiple AT depots, as well as AS160 (a potential key player in GLUT trafficking pathway). Using a biotinylated bis-mannose photolabeled technique, active cell surface GLUT content was quantified. Omental AT had the highest total GLUT content compared to other sites during the IS state. IR was associated with a significantly reduced total GLUT4 content in omental AT, without a change in content in other visceral or subcutaneous adipose sites. In addition, active cell surface GLUT-4, but not -12, was significantly lower in AT of IR compared to IS horses, without change in AS160 phosphorylation between groups. Our data suggest that GLUT4, but not GLUT12, is a pathogenic factor in AT during naturally-occurring compensated IR, despite normal AS160 activation. PMID:21352908

  4. Fuzzy cognitive map in differential diagnosis of alterations in urinary elimination: A nursing approach

    PubMed Central

    de Moraes Lopes, Maria Helena Baena; Ortega, Neli Regina Siqueira; Silveira, Paulo Sérgio Panse; Massad, Eduardo; Higa, Rosângela; de Fátima Marin, Heimar

    2013-01-01

    Purpose To develop a decision support system to discriminate the diagnoses of alterations in urinary elimination, according to the nursing terminology of NANDA International (NANDA-I). Methods A fuzzy cognitive map (FCM) was structured considering six possible diagnoses: stress urinary incontinence, reflex urinary incontinence, urge urinary incontinence, functional urinary incontinence, total urinary incontinence and urinary retention; and 39 signals associated with them. The model was implemented in Microsoft Visual C++® Edition 2005 and applied in 195 real cases. Its performance was evaluated through the agreement test, comparing its results with the diagnoses determined by three experts (nurses). The sensitivity and specificity of the model were calculated considering the expert’s opinion as a gold standard. In order to compute the Kappa’s values we considered two situations, since more than one diagnosis was possible: the overestimation of the accordance in which the case was considered as concordant when at least one diagnoses was equal; and the underestimation of the accordance, in which the case was considered as discordant when at least one diagnosis was different. Results The overestimation of the accordance showed an excellent agreement (kappa = 0.92, p < 0.0001); and the underestimation provided a moderate agreement (kappa = 0.42, p < 0.0001). In general the FCM model showed high sensitivity and specificity, of 0.95 and 0.92, respectively, but provided a low specificity value in determining the diagnosis of urge urinary incontinence (0.43) and a low sensitivity value to total urinary incontinence (0.42). Conclusions The decision support system developed presented a good performance compared to other types of expert systems for differential diagnosis of alterations in urinary elimination. Since there are few similar studies in the literature, we are convinced of the importance of investing in this kind of modeling, both from the theoretical and from

  5. α-Mangostin Improves Glucose Uptake and Inhibits Adipocytes Differentiation in 3T3-L1 Cells via PPARγ, GLUT4, and Leptin Expressions

    PubMed Central

    Taher, Muhammad; Mohamed Amiroudine, Mohamed Zaffar Ali; Tengku Zakaria, Tengku Muhamad Faris Syafiq; Ichwan, Solachuddin J. A.; Kaderi, Mohd Arifin; Ahmed, Qamar Uddin; Zakaria, Zainul Amiruddin

    2015-01-01

    Obesity has been often associated with the occurrence of cardiovascular diseases, type 2 diabetes, and cancer. The development of obesity is also accompanied by significant differentiation of preadipocytes into adipocytes. In this study, we investigated the activity of α-mangostin, a major xanthone component isolated from the stem bark of G. malaccensis, on glucose uptake and adipocyte differentiation of 3T3-L1 cells focusing on PPARγ, GLUT4, and leptin expressions. α-Mangostin was found to inhibit cytoplasmic lipid accumulation and adipogenic differentiation. Cells treated with 50 μM of α-mangostin reduced intracellular fat accumulation dose-dependently up to 44.4% relative to MDI-treated cells. Analyses of 2-deoxy-D-[3H] glucose uptake activity showed that α-mangostin significantly improved the glucose uptake (P < 0.05) with highest activity found at 25 μM. In addition, α-mangostin increased the amount of free fatty acids (FFA) released. The highest glycerol release level was observed at 50 μM of α-mangostin. qRT-PCR analysis showed reduced lipid accumulation via inhibition of PPARγ gene expression. Induction of glucose uptake and free fatty acid release by α-mangostin were accompanied by increasing mRNA expression of GLUT4 and leptin. These evidences propose that α-mangostin might be possible candidate for the effective management of obesity in future. PMID:25873982

  6. Sexual differentiation of the brain: a model for drug-induced alterations of the reproductive system

    SciTech Connect

    Gorski, R.A.

    1986-12-01

    The process of the sexual differentiation of the brain represents a valuable model system for the study of the chemical modification of the mammalian brain. Although there are numerous functional and structural sex differences in the adult brain, these are imposed on an essentially feminine or bipotential brain by testicular hormones during a critical phase of perinatal development in the rat. It is suggested that a relatively marked structural sex difference in the rat brain, the sexually dimorphic nucleus of the preoptic area (SDN-POA), is a morphological signature of the permanent or organizational action of estradiol derived from the aromatization of testicular testosterone. The SDN-POA of the male rat is severalfold larger in volume and is composed of more neurons than that of the female. The observation that the mitotic formation of the neurons of the SDN-POA is specifically prolonged has enabled us to identify the time course and pathway of neuronal migration into the nucleus. Study of the development of the SDN-POA suggests that estradiol in the male increases the number of neurons which survive a phase of neuronal death by exerting a neurite growth promoting action and/or a direct neuronotrophic action. Finally, although it is clear that gonadal hormones have dramatic permanent effects on the brain during perinatal development, even after puberty and in adulthood gonadal steroids can alter neuronal structure and, perhaps as a corollary to this, have permanent effects on reproductive function. Although the brain may be most sensitive to gonadal hormones or exogenous chemical factors during perinatal development, such as sensitivity does not appear limited to this period.

  7. Altered patterns of gene duplication and differential gene gain and loss in fungal pathogens

    PubMed Central

    Powell, Amy J; Conant, Gavin C; Brown, Douglas E; Carbone, Ignazio; Dean, Ralph A

    2008-01-01

    Background Duplication, followed by fixation or random loss of novel genes, contributes to genome evolution. Particular outcomes of duplication events are possibly associated with pathogenic life histories in fungi. To date, differential gene gain and loss have not been studied at genomic scales in fungal pathogens, despite this phenomenon's known importance in virulence in bacteria and viruses. Results To determine if patterns of gene duplication differed between pathogens and non-pathogens, we identified gene families across nine euascomycete and two basidiomycete species. Gene family size distributions were fit to power laws to compare gene duplication trends in pathogens versus non-pathogens. Fungal phytopathogens showed globally altered patterns of gene duplication, as indicated by differences in gene family size distribution. We also identified sixteen examples of gene family expansion and five instances of gene family contraction in pathogenic lineages. Expanded gene families included those predicted to be important in melanin biosynthesis, host cell wall degradation and transport functions. Contracted families included those encoding genes involved in toxin production, genes with oxidoreductase activity, as well as subunits of the vacuolar ATPase complex. Surveys of the functional distribution of gene duplicates indicated that pathogens show enrichment for gene duplicates associated with receptor and hydrolase activities, while euascomycete pathogens appeared to have not only these differences, but also significantly more duplicates associated with regulatory and carbohydrate binding functions. Conclusion Differences in the overall levels of gene duplication in phytopathogenic species versus non-pathogenic relatives implicate gene inventory flux as an important virulence-associated process in fungi. We hypothesize that the observed patterns of gene duplicate enrichment, gene family expansion and contraction reflect adaptation within pathogenic life

  8. Developmental Exposure to Estrogen Alters Differentiation and Epigenetic Programming in a Human Fetal Prostate Xenograft Model

    PubMed Central

    Saffarini, Camelia M.; McDonnell-Clark, Elizabeth V.; Amin, Ali; Huse, Susan M.; Boekelheide, Kim

    2015-01-01

    Prostate cancer is the most frequent non-cutaneous malignancy in men. There is strong evidence in rodents that neonatal estrogen exposure plays a role in the development of this disease. However, there is little information regarding the effects of estrogen in human fetal prostate tissue. This study explored early life estrogen exposure, with and without a secondary estrogen and testosterone treatment in a human fetal prostate xenograft model. Histopathological lesions, proliferation, and serum hormone levels were evaluated at 7, 30, 90, and 200-day time-points after xenografting. The expression of 40 key genes involved in prostatic glandular and stromal growth, cell-cycle progression, apoptosis, hormone receptors and tumor suppressors was evaluated using a custom PCR array. Epigenome-wide analysis of DNA methylation was performed on whole tissue, and laser capture-microdissection (LCM) isolated epithelial and stromal compartments of 200-day prostate xenografts. Combined initial plus secondary estrogenic exposures had the most severe tissue changes as revealed by the presence of hyperplastic glands at day 200. Gene expression changes corresponded with the cellular events in the KEGG prostate cancer pathway, indicating that initial plus secondary exposure to estrogen altered the PI3K-Akt signaling pathway, ultimately resulting in apoptosis inhibition and an increase in cell cycle progression. DNA methylation revealed that differentially methylated CpG sites significantly predominate in the stromal compartment as a result of estrogen-treatment, thereby providing new targets for future investigation. By using human fetal prostate tissue and eliminating the need for species extrapolation, this study provides novel insights into the gene expression and epigenetic effects related to prostate carcinogenesis following early life estrogen exposure. PMID:25799167

  9. Sex-specific alterations in glucose homeostasis and metabolic parameters during ageing of caspase-2-deficient mice.

    PubMed

    Wilson, C H; Nikolic, A; Kentish, S J; Shalini, S; Hatzinikolas, G; Page, A J; Dorstyn, L; Kumar, S

    2016-01-01

    Gender-specific differences are commonly found in metabolic pathways and in response to nutritional manipulation. Previously, we identified a role for caspase-2 in age-related glucose homeostasis and lipid metabolism using male caspase-2-deficient (Casp2 (-/-) ) mice. Here we show that the resistance to age-induced glucose tolerance does not occur in female Casp2 (-/-) mice and it appears to be independent of insulin sensitivity in males. Using fasting (18 h) as a means to further investigate the role of caspase-2 in energy and lipid metabolism, we identified sex-specific differences in the fasting response and lipid mobilization. In aged (18-22 months) male Casp2 (-/-) mice, a significant decrease in fasting liver mass, but not total body weight, was observed while in females, total body weight, but not liver mass, was reduced when compared with wild-type (WT) animals. Fasting-induced lipolysis of adipose tissue was enhanced in male Casp2 (-/-) mice as indicated by a significant reduction in white adipocyte cell size, and increased serum-free fatty acids. In females, white adipocyte cell size was significantly smaller in both fed and fasted Casp2 (-/-) mice. No difference in fasting-induced hepatosteatosis was observed in the absence of caspase-2. Further analysis of white adipose tissue (WAT) indicated that female Casp2 (-/-) mice may have enhanced fatty acid recycling and metabolism with expression of genes involved in glyceroneogenesis and fatty acid oxidation increased. Loss of Casp2 also increased fasting-induced autophagy in both male and female liver and in female skeletal muscle. Our observations suggest that caspase-2 can regulate glucose homeostasis and lipid metabolism in a tissue and sex-specific manner. PMID:27551503

  10. Sex-specific alterations in glucose homeostasis and metabolic parameters during ageing of caspase-2-deficient mice

    PubMed Central

    Wilson, C H; Nikolic, A; Kentish, S J; Shalini, S; Hatzinikolas, G; Page, A J; Dorstyn, L; Kumar, S

    2016-01-01

    Gender-specific differences are commonly found in metabolic pathways and in response to nutritional manipulation. Previously, we identified a role for caspase-2 in age-related glucose homeostasis and lipid metabolism using male caspase-2-deficient (Casp2−/−) mice. Here we show that the resistance to age-induced glucose tolerance does not occur in female Casp2−/− mice and it appears to be independent of insulin sensitivity in males. Using fasting (18 h) as a means to further investigate the role of caspase-2 in energy and lipid metabolism, we identified sex-specific differences in the fasting response and lipid mobilization. In aged (18–22 months) male Casp2−/− mice, a significant decrease in fasting liver mass, but not total body weight, was observed while in females, total body weight, but not liver mass, was reduced when compared with wild-type (WT) animals. Fasting-induced lipolysis of adipose tissue was enhanced in male Casp2−/− mice as indicated by a significant reduction in white adipocyte cell size, and increased serum-free fatty acids. In females, white adipocyte cell size was significantly smaller in both fed and fasted Casp2−/− mice. No difference in fasting-induced hepatosteatosis was observed in the absence of caspase-2. Further analysis of white adipose tissue (WAT) indicated that female Casp2−/− mice may have enhanced fatty acid recycling and metabolism with expression of genes involved in glyceroneogenesis and fatty acid oxidation increased. Loss of Casp2 also increased fasting-induced autophagy in both male and female liver and in female skeletal muscle. Our observations suggest that caspase-2 can regulate glucose homeostasis and lipid metabolism in a tissue and sex-specific manner. PMID:27551503

  11. Enhanced stability of maize endosperm ADP-glucose pyrophosphorylase is gained through mutants that alter subunit interactions.

    PubMed

    Greene, T W; Hannah, L C

    1998-10-27

    Temperature lability of ADP-glucose pyrophosphorylase (AGP; glucose-1-phosphate adenylyltransferase; ADP: alpha-D-glucose-1-phosphate adenylyltransferase, EC 2.7.7.27), a key starch biosynthetic enzyme, may play a significant role in the heat-induced loss in maize seed weight and yield. Here we report the isolation and characterization of heat-stable variants of maize endosperm AGP. Escherichia coli cells expressing wild type (WT) Shrunken2 (Sh2), and Brittle2 (Bt2) exhibit a reduced capacity to produce glycogen when grown at 42 degreesC. Mutagenesis of Sh2 and coexpression with WT Bt2 led to the isolation of multiple mutants capable of synthesizing copious amounts of glycogen at this temperature. An increase in AGP stability was found in each of four mutants examined. Initial characterization revealed that the BT2 protein was elevated in two of these mutants. Yeast two-hybrid studies were conducted to determine whether the mutant SH2 proteins more efficiently recruit the BT2 subunit into tetramer assembly. These experiments showed that replacement of WT SH2 with the heat-stable SH2HS33 enhanced interaction between the SH2 and BT2 subunits. In agreement, density gradient centrifugation of heated and nonheated extracts from WT and one of the mutants, Sh2hs33, identified a greater propensity for heterotetramer dissociation in WT AGP. Sequencing of Sh2hs33 and several other mutants identified a His-to-Tyr mutation at amino acid position 333. Hence, a single point mutation in Sh2 can increase the stability of maize endosperm AGP through enhanced subunit interactions. PMID:9789090

  12. PCP-induced alterations in cerebral glucose utilization in rat brain: blockade by metaphit, a PCP-receptor-acylating agent

    SciTech Connect

    Tamminga, C.A.; Tanimoto, K.; Kuo, S.; Chase, T.N.; Contreras, P.C.; Rice, K.C.; Jackson, A.E.; O'Donohue, T.L.

    1987-01-01

    The effects of phencyclidine (PCP) on regional cerebral glucose utilization was determined by using quantitative autoradiography with (/sup 14/C)-2-deoxyglucose. PCP increased brain metabolism in selected areas of cortex, particularly limbic, and in the basal ganglia and thalamus, whereas the drug decreased metabolism in areas related to audition. These results are consistent with the known physiology of central PCP neurons and may help to suggest brain areas involved in PCP-mediated actions. Moreover, based on the behavioral similarities between PCP psychosis and an acute schizophrenic episode, these data may be relevant to the understanding of schizophrenia. The PCP-receptor-acylating agent, metaphit, blocked most of these PCP actions. In addition, metaphit by itself was found to diminish glucose utilization rather uniformly throughout brain. These results indicate an antagonist effect of metaphit on the PCP system and suggest a widespread action of metaphit, putatively at a PCP-related site, possibly in connection with the N-methyl-D-aspartate (NMDA) receptor.

  13. Quercetin ameliorates glucose and lipid metabolism and improves antioxidant status in postnatally monosodium glutamate-induced metabolic alterations.

    PubMed

    Seiva, Fábio R F; Chuffa, Luiz Gustavo A; Braga, Camila Pereira; Amorim, João Paulo A; Fernandes, Ana Angélica H

    2012-10-01

    We reported the effects of quercetin on metabolic and hormonal profile as well as serum antioxidant activities in a model of MSG (monosodium glutamate)-induced obesity. Rats were divided into 4 groups: MSG group, submitted to neonatal treatment with high doses of MSG, administrated subcutaneously during 10 days, from 2 day-old; control groups, which received the same volume of saline. After completing 30 day-old, these groups were subdivided into 4 groups: control and MSG groups treated and non-treated with quercetin at doses of 75 mg/kg body weight (i.p.) over 42 days. BW gain and food consumption were higher in MSG treated rats and quercetin significantly reduced BW by 25%. While MSG increased triacylglycerol, total cholesterol and fractions, and reduced HDL concentrations, administration of quercetin normalized HDL-cholesterol and reduced others lipids. Insulin, leptin, glucose and creatinine levels were raised in MSG-treated rats and reduced after quercetin treatment. Alanine transaminase, aspartate transaminase, lactate dehydrogenase and alkaline phosphatase activities were lower after MSG-quercetin combination compared to rats given only MSG. MSG-quercetin combination augmented total protein and urea levels as well as glutathione peroxidase and superoxide dismutase activities in contrast to MSG-treated animals. Quercetin normalized serum lipid and glucose profile and minimized the MSG-related toxic effects, which was associated to its antioxidant properties. PMID:22809473

  14. Effects of altered glucose supply and adiposity on expression of hypothalamic energy balance regulatory genes in late gestation growth restricted ovine fetuses.

    PubMed

    Adam, C L; Bake, T; Findlay, P A; Milne, J S; Aitken, R P; Wallace, J M

    2011-11-01

    Intra-uterine growth restriction (IUGR) predisposes obesity in adulthood. This may be due to altered fetal nutrition causing sustained changes within the developing hypothalamic energy balance regulatory system. Using our established ovine model of IUGR, 130-day singleton fetuses (term=147 days) were obtained from growing adolescent mothers on control dietary intake (C), high intake (H) or H with growth hormone administration during either early (H+early GH) or late gestation (H+late GH) (n=6/group). GH increased maternal glycemia for the duration of treatment. H and H+early GH fetuses showed IUGR compared with C fetuses; body weight was partially restored in H+late GH fetuses, with 40% increased adiposity. In the fetal hypothalamic arcuate nucleus (ARC), cocaine- and amphetamine-regulated transcript mRNA (anorexigenic) was decreased in H fetuses and correlated across all groups with total fetal liver glycogen. Neuropeptide Y, agouti-related peptide (orexigenic) and proopiomelanocortin (anorexigenic) mRNAs were not different between groups. Insulin receptor mRNA in the ARC was increased in H, H+early GH and H+late GH fetuses and correlated negatively with fetal plasma insulin. Leptin receptor mRNA in the ARC correlated positively with fetal plasma leptin concentration and fetal fat content. Therefore, in IUGR fetuses, a key anorexigenic neuropeptide is sensitive to altered glucose supply and the hypothalamic leptin-signaling pathway is altered prenatally by increased adiposity and leptinemia. These changes could impact on postnatal energy balance regulation. PMID:21616134

  15. In vitro differentiation of unrestricted somatic stem cells into functional hepatic-like cells displaying a hepatocyte-like glucose metabolism.

    PubMed

    Waclawczyk, Simon; Buchheiser, Anja; Flögel, Ulrich; Radke, Teja F; Kögler, Gesine

    2010-11-01

    The hepatic-like phenotype resulting from in vitro differentiation of unrestricted somatic stem cells (USSC) derived from human umbilical cord blood (CB) was analyzed with regard to functional and metabolic aspects. USSC can be differentiated into cells of all three germ layers in vitro and in vivo and, although they share many features with mesenchymal stroma cells (MSC), can be distinguished from these by their expression of DLK1 as well as a restricted adipogenic differentiation potential. For the differentiation procedure described herein, a novel three-stage differentiation protocol resembling embryonic developmental processes of hepatic endoderm was applied. Hepatic pre-induction was performed by activinA and FGF4 resulting in enhanced SOX17 and FOXA2 expression. Further differentiation was achieved sequentially by retinoic acid, FGF4, HGF, EGF, and OSM resulting in a hepatic endodermal identity, characterized by the expression of AFP and HNF1alpha. Thereafter, expression of G6PC, ARG1, FBP1, and HNF4alpha was observed, thus indicating progressive differentiation. Functional studies concerning albumin secretion, urea formation, and cytochrome-p450-3A4 (CYP3A4) enzyme activity confirmed the hepatic-like phenotype. In order to characterize the differentiated cells at a metabolic level, USSC were incubated with [1-(13)C]glucose. By tracing the fate of the molecule's label via isotopomer analysis using (13)C NMR spectroscopy, formation of both glycogen and some gluconeogenetic activity could be observed providing evidence of a hepatocyte-like glucose metabolism in differentiated USSC. In conclusion, the results of the present study indicate that USSC represent a stem cell source with a substantial hepatic differentiation capacity which hold the potential for clinical applications. PMID:20458755

  16. High glucose blocks the effects of estradiol on human vascular cell growth: differential interaction with estradiol and raloxifene

    PubMed Central

    Somjen, Dalia; Paller, Channing J.; Gayer, Batya; Kohen, Fortune; Knoll, Esther; Stern, Naftali

    2013-01-01

    Because diabetic women appear not to be protected by estrogen in terms of propensity to cardiovascular disease, we tested the possibility that chronic hyperglycemia modulates the effects of E2 on vascular cell growth in vitro. Human endothelial cells (E304) and vascular smooth muscle cells (VSMC) were grown in normal glucose (5.5 mmol/l), high glucose (22 mmol/l) or high manitol (22 nmol/l; an osmotic control) for 7 days. In endothelial cells glucose per se stimulated DNA synthesis. However E2- (but not RAL-) stimulated [3H] thymidine incorporation was attenuated in the presence of high glucose. In parallel, E2-dependent MAP-kinase-kinase activity was blocked in the presence of high glucose. High glucose increased basal creatine kinase (CK) specific activity, but E2-stimulated CK was not significantly impaired in the presence of high glucose. In VSMC, high glucose prevented the inhibitory effect of high E2 (but not of high RAL) concentrations on DNA synthesis. High glucose also prevented E2-induced MAP-kinase-kinase activity. In contrast, while high glucose augmented basal CK, the relative E2-induced changes were roughly equal in normal and high high glucose media. Hence, high glucose blocks several effects of E2 on vascular cell growth, which are mediated, in part, via the MAP-kinase system and are likely contributors to E2’s anti-atherosclerotic properties. Since RAL’s estrogen-mimetic effects on human vascular cell growth were independent of MAP-kinase activation and were not affected by hyperglycemia, the potential use of RAL to circumvent the loss of estrogen function induced by hyperglycemia and diabetes in the human vasculature should be further explored. PMID:15026088

  17. Diet, age, and prior injury status differentially alter behavioral outcomes following concussion in rats.

    PubMed

    Mychasiuk, Richelle; Hehar, Harleen; van Waes, Linda; Esser, Michael J

    2015-01-01

    Mild traumatic brain injury (mTBI) or concussion affects a large portion of the population and although many of these individuals recover completely, a small subset of people experience lingering symptomology and poor outcomes. Little is known about the factors that affect individual susceptibility or resilience to poor outcomes after mTBI and there are currently no biomarkers to delineate mTBI diagnosis or prognosis. Based upon the growing literature associated with caloric intake and altered neurological aging and the ambiguous link between repetitive mTBI and progressive neurodegeneration, the current study was designed to examine the effect of a high fat diet (HFD), developmental age, and repetitive mTBI on behavioral outcomes following a mTBI. In addition, telomere length was examined before and after experimental mTBI. Sprague Dawley rats were maintained on a HFD or standard rat chow throughout life (including the prenatal period) and then experienced an mTBI/concussion at P30, P30 and P60, or only at P60. Behavioral outcomes were examined using a test battery that was administered between P61-P80 and included; beam-walking, open field, elevated plus maze, novel context mismatch, Morris water task, and forced swim task. Animals with a P30 mTBI often demonstrated lingering symptomology that was still present during testing at P80. Injuries at P30 and P60 rarely produced cumulative effects, and in some tests (i.e., beam walking), the first injury may have protected the brain from the second injury. Exposure to the high fat diet exacerbated many of the behavioral deficits associated with concussion. Finally, telomere length was shortened following mTBI and was influenced by the animal's dietary intake. Diet, age at the time of injury, and the number of prior concussion incidents differentially contribute to behavioral deficits and may help explain individual variations in susceptibility and resilience to poor outcomes following an mTBI. PMID:25270295

  18. Syndromic deafness mutations at Asn 14 differentially alter the open stability of Cx26 hemichannels.

    PubMed

    Sanchez, Helmuth A; Slavi, Nefeli; Srinivas, Miduturu; Verselis, Vytas K

    2016-07-01

    Connexin 26 (Cx26) is a transmembrane protein that forms hexameric hemichannels that can function when unopposed or dock to form intercellular gap junction channels. Aberrantly functioning unopposed hemichannels are a common feature of syndromic deafness associated with mutations in Cx26. In this study, we examine two different mutations at the same position in the N-terminal domain of Cx26, N14K and N14Y, which have been reported to produce different phenotypes in patients. We find that both N14K and N14Y, when expressed alone or together with wild-type (WT) Cx26, result in functional hemichannels with widely disparate functional properties. N14K currents are robust, whereas N14Y currents are small. The two mutants also exhibit opposite shifts in voltage-dependent loop gating, such that activation of N14K and N14Y is shifted in the hyperpolarizing and depolarizing directions, respectively. Deactivation kinetics suggests that N14K stabilizes and N14Y destabilizes the open state. Single N14K hemichannel recordings in low extracellular Ca(2+) show no evidence of stable closing transitions associated with loop gating, and N14K hemichannels are insensitive to pH. Together, these properties cause N14K hemichannels to be particularly refractory to closing. Although we find that the unitary conductance of N14K is indistinguishable from WT Cx26, mutagenesis and substituted cysteine accessibility studies suggest that the N14 residue is exposed to the pore and that the differential properties of N14K and N14Y hemichannels likely result from altered electrostatic interactions between the N terminus and the cytoplasmic extension of TM2 in the adjacent subunit. The combined effects that we observe on loop gating and pH regulation may explain the unusual buccal cutaneous manifestations in patients carrying the N14K mutation. Our work also provides new considerations regarding the underlying molecular mechanism of loop gating, which controls hemichannel opening in the plasma

  19. Transcription levels of CHS5 and CHS4 genes in Paracoccidioides brasiliensis mycelial phase, respond to alterations in external osmolarity, oxidative stress and glucose concentration.

    PubMed

    Niño-Vega, Gustavo A; Sorais, Françoise; San-Blas, Gioconda

    2009-10-01

    The complete sequence of Paracoccidioides brasiliensis CHS5 gene, encoding a putative chitin synthase revealed a 5583nt open reading frame, interrupted by three introns of 82, 87 and 97bp (GenBank Accession No EF654132). The deduced protein contains 1861 amino acids with a predicted molecular weight of 206.9kDa. Both its large size and the presence of a N-terminal region of approx. 800 residues with a characteristic putative myosin motor-like domain, allow us to include PbrChs5 into class V fungal chitin synthases. Sequence analysis of over 4kb from the 5' UTR region in CHS5, revealed the presence of a previously reported CHS4 gene in P. brasiliensis, arranged in a head-to-head configuration with CHS5. A motif search in this shared region showed the presence of stress response elements (STREs), three binding sites for the transcription activators Rlm1p (known to be stimulated by hypo-osmotic stress) and clusters of Adr1 (related to glucose repression). A quantitative RT-PCR analysis pointed to changes in transcription levels for both genes following oxidative stress, alteration of external osmolarity and under glucose-repressible conditions, suggesting a common regulatory mechanism of transcription. PMID:19616626

  20. Dietary Fatty Acids Differentially Associate with Fasting Versus 2-Hour Glucose Homeostasis: Implications for The Management of Subtypes of Prediabetes

    PubMed Central

    Guess, Nicola; Perreault, Leigh; Kerege, Anna; Strauss, Allison; Bergman, Bryan C.

    2016-01-01

    Over-nutrition has fuelled the global epidemic of type 2 diabetes, but the role of individual macronutrients to the diabetogenic process is not well delineated. We aimed to examine the impact of dietary fatty acid intake on fasting and 2-hour plasma glucose concentrations, as well as tissue-specific insulin action governing each. Normoglycemic controls (n = 15), athletes (n = 14), and obese (n = 23), as well as people with prediabetes (n = 10) and type 2 diabetes (n = 11), were queried about their habitual diet using a Food Frequency Questionnaire. All subjects were screened by an oral glucose tolerance test (OGTT) and studied using the hyperinsulinemic/euglycemic clamp with infusion of 6,62H2-glucose. Multiple regression was performed to examine relationships between dietary fat intake and 1) fasting plasma glucose, 2) % suppression of endogenous glucose production, 3) 2-hour post-OGTT plasma glucose, and 4) skeletal muscle insulin sensitivity (glucose rate of disappearance (Rd) and non-oxidative glucose disposal (NOGD)). The %kcal from saturated fat (SFA) was positively associated with fasting (β = 0.303, P = 0.018) and 2-hour plasma glucose (β = 0.415, P<0.001), and negatively related to % suppression of hepatic glucose production (β = -0.245, P = 0.049), clamp Rd (β = -0.256, P = 0.001) and NOGD (β = -0.257, P = 0.001). The %kcal from trans fat was also negatively related to clamp Rd (β = -0.209, P = 0.008) and NOGD (β = -0.210, P = 0.008). In contrast, the %kcal from polyunsaturated fat (PUFA) was negatively associated with 2-hour glucose levels (β = -0.383, P = 0.001), and positively related to Rd (β = 0.253, P = 0.007) and NOGD (β = 0.246, P = 0.008). Dietary advice to prevent diabetes should consider the underlying pathophysiology of the prediabetic state. PMID:26999667

  1. Dietary Fatty Acids Differentially Associate with Fasting Versus 2-Hour Glucose Homeostasis: Implications for The Management of Subtypes of Prediabetes.

    PubMed

    Guess, Nicola; Perreault, Leigh; Kerege, Anna; Strauss, Allison; Bergman, Bryan C

    2016-01-01

    Over-nutrition has fuelled the global epidemic of type 2 diabetes, but the role of individual macronutrients to the diabetogenic process is not well delineated. We aimed to examine the impact of dietary fatty acid intake on fasting and 2-hour plasma glucose concentrations, as well as tissue-specific insulin action governing each. Normoglycemic controls (n = 15), athletes (n = 14), and obese (n = 23), as well as people with prediabetes (n = 10) and type 2 diabetes (n = 11), were queried about their habitual diet using a Food Frequency Questionnaire. All subjects were screened by an oral glucose tolerance test (OGTT) and studied using the hyperinsulinemic/euglycemic clamp with infusion of 6,62H2-glucose. Multiple regression was performed to examine relationships between dietary fat intake and 1) fasting plasma glucose, 2) % suppression of endogenous glucose production, 3) 2-hour post-OGTT plasma glucose, and 4) skeletal muscle insulin sensitivity (glucose rate of disappearance (Rd) and non-oxidative glucose disposal (NOGD)). The %kcal from saturated fat (SFA) was positively associated with fasting (β = 0.303, P = 0.018) and 2-hour plasma glucose (β = 0.415, P<0.001), and negatively related to % suppression of hepatic glucose production (β = -0.245, P = 0.049), clamp Rd (β = -0.256, P = 0.001) and NOGD (β = -0.257, P = 0.001). The %kcal from trans fat was also negatively related to clamp Rd (β = -0.209, P = 0.008) and NOGD (β = -0.210, P = 0.008). In contrast, the %kcal from polyunsaturated fat (PUFA) was negatively associated with 2-hour glucose levels (β = -0.383, P = 0.001), and positively related to Rd (β = 0.253, P = 0.007) and NOGD (β = 0.246, P = 0.008). Dietary advice to prevent diabetes should consider the underlying pathophysiology of the prediabetic state. PMID:26999667

  2. "HepG2/erythroid/brain" type glucose transporter (GLUT1) is highly expressed in human epidermis: keratinocyte differentiation affects GLUT1 levels in reconstituted epidermis.

    PubMed

    Gherzi, R; Melioli, G; de Luca, M; D'Agostino, A; Distefano, G; Guastella, M; D'Anna, F; Franzi, A T; Cancedda, R

    1992-03-01

    In mature animals, the "HepG2/erythroid/brain" glucose transporter isoform (GLUT1) appears to be expressed at the highest levels at blood tissue barriers; however, these levels may still be lower than the levels of expression seen in fetal tissues. Also, glucose transporters might serve as water channels. Therefore, we decided to investigate GLUT1 expression in human epidermis, a very active tissue, in terms of metabolism, even if not directly vascularized. We found GLUT1 transcripts in human skin and demonstrated, by immunohistochemistry, that GLUT1 protein is highly expressed in the basal layer and, to a lower extent, in the immediately suprabasal layer of the epidermis. This distribution pattern suggested that GLUT1 expression is affected by keratinocyte differentiation. To investigate this possibility, we used human epidermis reconstituted in culture. Our culture system allows the reconstruction of a stratified squamous epithelium which has been successfully grafted onto patients presenting large skin defects. Human keratinocytes have been cultured under conditions which allow a modulation of cellular differentiation and stratification. We observed that (i) GLUT1 expression is 4-6-fold higher in "stem-like" basal cells than in large, differentiated keratinocytes; (ii) culture conditions causing cell differentiation reduce GLUT1 expression, while conditions which minimize either differentiation or stratification of keratinocytes enhance GLUT1 expression. Finally, we found that IGF-1 and insulin, probably acting through the IGF-1 receptor, increase GLUT1 expression and stimulate glucose transport activity in epidermis reconstituted in culture. In conclusion, our data demonstrate that GLUT1 is highly expressed in the basal layers of human epidermis and that its expression is modulated by keratinocyte differentiation. PMID:1537878

  3. Alternate Immersion in an External Glucose Solution Differentially Affects Blood Sugar Values in Older Versus Younger Zebrafish Adults.

    PubMed

    Connaughton, Victoria P; Baker, Cassandra; Fonde, Lauren; Gerardi, Emily; Slack, Carly

    2016-04-01

    Recently, zebrafish have been used to examine hyperglycemia-induced complications (retinopathy and neuropathy), as would occur in individuals with diabetes. Current models to induce hyperglycemia in zebrafish include glucose immersion and streptozotocin injections. Both are effective, although neither is reported to elevate blood sugar values for more than 1 month. In this article, we report differences in hyperglycemia induction and maintenance in young (4-11 months) versus old (1-3 years) zebrafish adults. In particular, older fish immersed in an alternating constant external glucose solution (2%) for 2 months displayed elevated blood glucose levels for the entire experimental duration. In contrast, younger adults displayed only transient hyperglycemia, suggesting the fish were acclimating to the glucose exposure protocol. However, modifying the immersion protocol to include a stepwise increasing glucose concentration (from 1% → 2%→3%) resulted in maintained hyperglycemia in younger zebrafish adults for up to 2 months. Glucose-exposed younger fish collected after 8 weeks of exposure also displayed a significant decrease in wet weight. Taken together, these data suggest different susceptibilities to hyperglycemia in older and younger fish and that stepwise increasing glucose concentrations of 1% are required for maintenance of hyperglycemia in younger adults, with higher concentrations of glucose resulting in greater increases in blood sugar values. PMID:26771444

  4. ENVIRONMENTAL ANTIANDROGENS: LOW DOSES OF VINCLOZOLIN ALTER SEXUAL DIFFERENTIATION OF THE MALE RAT

    EPA Science Inventory

    In humans and rodents, exposure to antiandrogenic chemicals during sexual differentiation can produce malformations of the reproductive tract. Perinatal administration of 100 or 200 mg vinclozolin (V) kg-1 day-1 during sexual differentiation in rats induces female-like anogenital...

  5. Msx2 alters the timing of retinal ganglion cells fate commitment and differentiation

    SciTech Connect

    Jiang, Shao-Yun; Wang, Jian-Tao; Dohney Eye Institute, Keck School of Medicine, University of Southern California, 1355 San Pablo Street, DOH 314, Los Angeles, CA 90033

    2010-05-14

    Timing of cell fate commitment determines distinct retinal cell types, which is believed to be controlled by a tightly coordinated regulatory program of proliferation, cell cycle exit and differentiation. Although homeobox protein Msx2 could induce apoptosis of optic vesicle, it is unclear whether Msx2 regulates differentiation and cell fate commitment of retinal progenitor cells (RPCs) to retinal ganglion cells (RGCs). In this study, we show that overexpression of Msx2 transiently suppressed the expression of Cyclin D1 and blocked cell proliferation. Meanwhile, overexpression of Msx2 delayed the expression of RGC-specific differentiation markers (Math5 and Brn3b), which showed that Msx2 could affect the timing of RGCs fate commitment and differentiation by delaying the timing of cell cycle exit of retinal progenitors. These results indicate Msx2 possesses dual regulatory functions in controlling cell cycle progression of retinal RPCs and timing of RGCs differentiation.

  6. Prenatal Exposure to Sodium Arsenite Alters Placental Glucose 1, 3, and 4 Transporters in Balb/c Mice

    PubMed Central

    Gutiérrez-Torres, Daniela Sarahí; González-Horta, Carmen; Del Razo, Luz María; Infante-Ramírez, Rocío; Ramos-Martínez, Ernesto; Levario-Carrillo, Margarita; Sánchez-Ramírez, Blanca

    2015-01-01

    Inorganic arsenic (iAs) exposure induces a decrease in glucose type 4 transporter (GLUT4) expression on the adipocyte membrane, which may be related to premature births and low birth weight infants in women exposed to iAs at reproductive age. The aim of this study was to analyze the effect of sodium arsenite (NaAsO2) exposure on GLUT1, GLUT3, and GLUT4 protein expression and on placental morphology. Female Balb/c mice (n = 15) were exposed to 0, 12, and 20 ppm of NaAsO2 in drinking water from 8th to 18th day of gestation. Morphological changes and GLUT1, GLUT3, and GLUT4 expression were evaluated in placentas by immunohistochemical and image analysis and correlated with iAs and arsenical species concentration, which were quantified by atomic absorption spectroscopy. NaAsO2 exposure induced a significant decrease in fetal and placental weight (P < 0.01) and increases in infarctions and vascular congestion. Whereas GLUT1 expression was unchanged in placentas from exposed group, GLUT3 expression was found increased. In contrast, GLUT4 expression was significantly lower (P < 0.05) in placentas from females exposed to 12 ppm. The decrease in placental GLUT4 expression might affect the provision of adequate fetal nutrition and explain the low fetal weight observed in the exposed groups. PMID:26339590

  7. PDX1 and ISL1 differentially coordinate with epigenetic modifications to regulate insulin gene expression in varied glucose concentrations.

    PubMed

    Wang, Weiping; Shi, Qiong; Guo, Ting; Yang, Zhe; Jia, Zhuqing; Chen, Ping; Zhou, Chunyan

    2016-06-15

    The mechanism of insulin gene transcription control in response to glucose concentration is poorly defined. The islet-restricted transcription factors PDX1 and ISL1 interact with BETA2, activating insulin gene expression. However, their contribution and hierarchical organization in insulin expression control based on glucose concentration remain unknown. We investigated PDX1 and ISL1 regulation of insulin gene expression in pancreatic β cells cultured in normal (5 mM/L) and high (25 mM/L) glucose conditions. ISL1 interacted with BETA2 to maintain basic insulin gene transcriptional activity under normal glucose. The ISL1-recruited cofactors SET9 and JMJD3 facilitated insulin gene histone modifications under normal glucose. In high-glucose concentrations, PDX1 formed a complex with BETA2 to enhance insulin gene expression. PDX1 also recruited SET9 and JMJD3 to promote the activation of histone modulation on the insulin promoter. This is the first evidence transcription factors orchestrate epigenetic modifications to control insulin gene expression based on glucose concentration. PMID:26994512

  8. Eucommia bark (Du-Zhong) improves diabetic nephropathy without altering blood glucose in type 1-like diabetic rats

    PubMed Central

    Niu, Ho-Shan; Liu, I-Min; Niu, Chiang-Shan; Ku, Po-Ming; Hsu, Chao-Tien; Cheng, Juei-Tang

    2016-01-01

    Background Eucommia bark, Eucommia ulmoides Oliver barks (Du-Zhong in Mandarin), is an herb used for renal dysfunction in Chinese traditional medicine. In an attempt to develop this herb as a treatment for diabetic nephropathy (DN), we investigated the effects of Du-Zhong on renal dysfunction in type 1-like diabetic rats. Methods Streptozotocin (STZ) was used to induce type 1-like diabetes in rats (STZ-diabetic rats). In addition to hyperglycemia, STZ-diabetic rats showed significant nephropathy, including higher plasma levels of blood urea nitrogen, creatinine, and renal fibrosis. Western blot analysis of renal cortical tissue was applied to characterize the changes in potential signals related to nephropathy. Results Oral administration of Du-Zhong (1 g/kg/day) to STZ-diabetic rats for 20 days not only decreased the plasma levels of blood urea nitrogen and creatinine but also improved renal fibrosis, whereas the plasma glucose level was not changed. The higher expressions of protein levels of transforming growth factor-beta (TGF-β) and connective tissue growth factor in diabetic rats were markedly attenuated by Du-Zhong. The increased phosphorylation of Smad2/3 in STZ-diabetic rats was also reduced by Du-Zhong. However, Du-Zhong cannot reverse the hyperglycemia-induced overproduction of signal transducers and activators of transcription 3 in the diabetic kidney. Conclusion Oral administration of Du-Zhong improves STZ-induced DN in rats by inhibiting TGF-β/Smad signaling and suppressing TGF-β/connective tissue growth factor expression. Therefore, active principle from Du-Zhong is suitable to develop as new agent for DN in the future. PMID:27041999

  9. Alterations in cellular differentiation, mitogenesis, cytoskeleton and growth characteristics during Syrian hamster embryo cell multistep in vitro transformation.

    PubMed

    Isfort, R J; Cody, D B; Doersen, C J; Kerckaert, G A; Leboeuf, R A

    1994-10-01

    In vitro Syrian hamster embryo (SHE) cell transformation is a neoplastic process that proceeds through several identifiable consecutive stages including in vitro morphological transformation (mt), acquisition of immortality (I+), acquisition of tumorigenicity (T+) and tumor-derived cells (I'TD). Eight transformed lineages consisting of cells at the mt, I+, T+ and I'TD stages were assayed for alterations in general markers of cell differentiation, mitogenic signaling pathways, cytoskeleton and cellular growth in 3D matrix. Alterations in cellular differentiation markers included a decrease in H19 gene expression and placental alkaline phosphatase enzymatic activity at the mt stage in all lineages examined with a complete absence of H19 gene expression and placental alkaline phosphatase enzymatic activity by the I'TD stage in a majority of transformed lineages. Changes in mitogenic signaling pathways included the production of autocrine growth factors and alterations in growth factor-induced immediate early gene expression by the I'TD stage of transformation in the majority of transformed lineages investigated. By the I'TD stage of transformation in most lineages, changes in both the cytoskeleton (including a decrease in tropomyosin-I gene expression) and the Matrigel growth characteristics of SHE cells were observed. PMID:7927892

  10. Identification of neural biomarkers of altered sexual differentiation following gestational exposure###

    EPA Science Inventory

    Sexual differentiation of the brain occurs during late gestation through the early postnatal period. The development of the phenotypical male brain is dependent on the aromatization of circulating testosterone to estradiol. Exposure to endocrine disrupting chemicals (EDCs) duri...

  11. IDENTIFICATION OF NEURAL BIOMARKERS OF ALTERED SEXUAL DIFFERENTIATION FOLLOWING GESTATIONAL EXPOSURE***

    EPA Science Inventory

    Sexual differentiation of the brain occurs during late gestation through the early postnatal period. The development of the phenotypical male brain is dependent on the aromatization of circulating testosterone to estradiol. Exposure to endocrine disrupting chemicals (EDCs) duri...

  12. Identification of neural biomarkers of altered sexual differentiation following gestational exposure

    EPA Science Inventory

    Sexual differentiation of the brain occurs during late gestation through the early postnatal period. The development of the phenotypical male brain is dependent on the aromatization of circulating testosterone to estradiol. Exposure to endocrine disrupting chemicals (EDCs) during...

  13. COMPOUND-INDUCED ALTERATIONS OF SEXUAL DIFFERENTIATION: A REVIEW OF EFFECTS IN HUMANS AND RODENTS

    EPA Science Inventory

    During sexual differentiation there are a number of critical periods when the reproductive system is uniquely susceptible to chemically-induced perturbations. At these times an inappropriate chemical signal can result in irreversible lesions that often result in infertility, wher...

  14. Ethanol alters the osteogenic differentiation of amniotic fluid-derived stem cells

    PubMed Central

    Hipp, Jennifer A; Hipp, Jason D; Atala, Anthony; Soker, Shay

    2010-01-01

    Background Fetal Alcohol Spectrum Disorder (FASD) is a set of developmental defects caused by prenatal alcohol exposure. Clinical manifestations of FASD are highly variable and include mental retardation and developmental defects of the heart, kidney, muscle, skeleton, and craniofacial structures. Specific effects of ethanol on fetal cells include induction of apoptosis as well as inhibition of proliferation, differentiation, and migration. This complex set of responses suggests that a bioinformatics approach could clarify some of the pathways involved in these responses. Methods In this study, the responses of fetal stem cells derived from the amniotic fluid (AFSCs) to treatment with ethanol have been examined. Large-scale transcriptome analysis of ethanol-treated AFSCs indicates that genes involved in skeletal development and ossification are up-regulated in these cells. Therefore, the effect of ethanol on osteogenic differentiation of AFSCs was studied. Results Exposure to ethanol during the first 48 hours of an osteogenic differentiation protocol increased in vitro calcium deposition by AFSCs and increased alkaline phosphatase activity. In contrast, ethanol treatment later in the differentiation protocol (day 8) had no significant effect on the activity of alkaline phosphatase. Conclusions These results suggest that transient exposure of AFSCs to ethanol during early differentiation enhances osteogenic differentiation of the cells. PMID:20608908

  15. Competitive (AP7) and non-competitive (MK-801) NMDA receptor antagonists differentially alter glucose utilization in rat cortex

    SciTech Connect

    Clow, D.W.; Lee, S.J.; Hammer, R.P. Jr. )

    1991-04-01

    The effects of D,L-2-amino-7-phosphonoheptanoic acid (AP7), a competitive N-methyl-D-aspartate (NMDA) receptor antagonist, and MK-801, a non-competitive NMDA receptor antagonist, on regional brain metabolism were studied in unanesthetized, freely moving rats by using the quantitative {sup 14}C2-deoxyglucose autoradiographic procedure. AP7 (338 or 901 mg/kg) produced a dose-dependent decrease of metabolic activity throughout most of the regions studied including sensory, motor, and limbic cortices. In contrast, MK-801 (0.1 or 1.0 mg/kg) resulted in a dose-dependent decrease of metabolic activity in sensory cortices, and an increase in limbic regions such as the hippocampal stratum lacunosum moleculare and entorhinal cortex. MK-801 also produced a biphasic response in agranular motor cortex, whereby the low dose increased while the high dose decreased labeling. In addition, MK-801 produced heterogeneous effects on regional cerebral metabolism in sensory cortices. Metabolic activity decreased in layer IV relative to layer Va following MK-801 treatment in primary somatosensory (SI) and visual (VI) cortices, suggesting a shift in activity from afferent fibers innervating layer IV to those innervating layer Va. MK-801 administration also decreased metabolic activity in granular SI relative to dysgranular SI, and in VI relative to secondary visual cortex (VII), thus providing a relative sparing of activity in dysgranular SI and VII. Thus, the non-competitive NMDA receptor antagonist suppressed activity from extrinsic neocortical sources, enhancing relative intracortical activity and stimulating limbic regions, while the competitive NMDA antagonist depressed metabolic activity in all cortical regions.

  16. Connecting differential responses of native and invasive riparian plants to climate change and environmental alteration.

    PubMed

    Flanagan, Neal E; Richardson, Curtis J; Ho, Mengchi

    2015-04-01

    Climate change is predicted to impact river systems in the southeastern United States through alterations of temperature, patterns of precipitation and hydrology. Future climate scenarios for the southeastern United States predict (1) surface water temperatures will warm in concert with air temperature, (2) storm flows will increase and base flows will decrease, and (3) the annual pattern of synchronization between hydroperiod and water temperature will be altered. These alterations are expected to disturb floodplain plant communities, making them more vulnerable to establishment of invasive species. The primary objective of this study is to evaluate whether native and invasive riparian plant assemblages respond differently to alterations of climate and land use. To study the response of riparian wetlands to watershed and climate alterations, we utilized an existing natural experiment imbedded in gradients of temperature and hydrology-found among dammed and undammed rivers. We evaluated a suite of environmental variables related to water temperature, hydrology, watershed disturbance, and edaphic conditions to identify the strongest predictors of native and invasive species abundances. We found that native species abundance is strongly influenced by climate-driven variables such as temperature and hydrology, while invasive species abundance is more strongly influenced by site-specific factors such as land use and soil nutrient availability. The patterns of synchronization between plant phenology, annual hydrographs, and annual water temperature cycles may be key factors sustaining the viability of native riparian plant communities. Our results demonstrate the need to understand the interactions between climate, land use, and nutrient management in maintaining the species diversity of riparian plant communities. Future climate change is likely to result in diminished competitiveness of native plant species, while the competitiveness of invasive species will increase

  17. Alterations in insulin binding accompanying differentiation of 3T3-L1 preadipocytes.

    PubMed Central

    Reed, B C; Kaufmann, S H; Mackall, J C; Student, A K; Lane, M D

    1977-01-01

    Expression of the adipocyte phenotype by differentiating 3T3-L1 preadipocytes occurs upon exposure of the cells to insulin. Differentiation-linked changes in 125I-labeled insulin binding to 3T3-L1 cells were monitored and compared with those in nondifferentiating 3T3-C2 controls treated similarly. Without chronic insulin treatment, 3T3-L1 cells failed to express the adipocyte phenotype but maintained a level of 25,000-35,000 insulin-binding sites per cell. Treatment of 3T3-L1 cells with insulin resulted in an initial suppression of insulin binding followed by a 12-fold increase that paralleled the appearance of differentiated cells. A maximum of 170,000 insulin-binding sites per cell was attained for a population in which greater than 75% of the cells had differentiated. The increase of insulin receptor level appears to be differentiation-dependent and is not a general response of cells to the culture conditions. 3T3-C2 cells maintained in the presence of insulin for 30 days exhibited the undifferentiated phenotype and suppressed levels of insulin binding (35,000 sites per cell). The binding capacity of 3T3-L1 cells for epidermal growth factor remained unchanged between 25,000 and 40;000 sites per cell and was independent of the state of differentiation. Thus, induction by insulin in receptor-specific changes. Insulin receptors increase in number but epidermal growth factor receptors remain constant. PMID:303773

  18. Androgens alter T-cell immunity by inhibiting T-helper 1 differentiation.

    PubMed

    Kissick, Haydn T; Sanda, Martin G; Dunn, Laura K; Pellegrini, Kathryn L; On, Seung T; Noel, Jonathan K; Arredouani, Mohamed S

    2014-07-01

    The hormonal milieu influences immune tolerance and the immune response against viruses and cancer, but the direct effect of androgens on cellular immunity remains largely uncharacterized. We therefore sought to evaluate the effect of androgens on murine and human T cells in vivo and in vitro. We found that murine androgen deprivation in vivo elicited RNA expression patterns conducive to IFN signaling and T-cell differentiation. Interrogation of mechanism showed that testosterone regulates T-helper 1 (Th1) differentiation by inhibiting IL-12-induced Stat4 phosphorylation: in murine models, we determined that androgen receptor binds a conserved region within the phosphatase, Ptpn1, and consequent up-regulation of Ptpn1 then inhibits IL-12 signaling in CD4 T cells. The clinical relevance of this mechanism, whereby the androgen milieu modulates CD4 T-cell differentiation, was ascertained as we found that androgen deprivation reduced expression of Ptpn1 in CD4 cells from patients undergoing androgen deprivation therapy for prostate cancer. Our findings, which demonstrate a clinically relevant mechanism by which androgens inhibit Th1 differentiation of CD4 T cells, provide rationale for targeting androgens to enhance CD4-mediated immune responses in cancer or, conversely, for modulating androgens to mitigate CD4 responses in disorders of autoimmunity. PMID:24958858

  19. Alterations in local cerebral metabolic rates for glucose (LCMRGlc) in childhood epilepsies as determined with FDG and PET

    SciTech Connect

    Phelps, M.E.; Chugani, H.T.; Mazziotta, J.C.; Engel, Jr.

    1985-05-01

    The authors investigated LCMRGlc in Lennox-Gastant Syndrome (LGS) (n=15), infantile spasm (IS) (n=14) and Sturge-Weber Syndrome (SWS) (n=5). In children with LGS, 3 distinct metabolic patterns are seen interically: 1) unilateral focal hypometabolism in frontal or temporal lobes, 2) unilateral diffuse hypometabolism, and 3) bilateral diffuse hypometabolism. Therapeutic implications of this classification are: surgical resection in focal (i.e., as for partial epilepsy), corpus callosotomy in diffuse unilateral, and elimination of surgery for those with bilateral diffuse hypometabolism. Babies with idiopathic IS showed symmetrical hypometabolism of lenticular nuclei and midbrain/brain stem compared to cortex and is characterized by slightly better prognosis. In contrast, babies with symtomatic IS had additional CMRGlc disturbances such as bilateral assymetric and multi focal hypometabolism in infant with neurofibromatosis; right parieto-occipital hypometabolims in infant with tuberous sclerosis; intense hypermetabolism of hypothalamus (34.5 vs 3.18 ..mu..moles/-min/100g in other regions) in another where x-ray CT showed only obstructive hydrocephalus. Findings support classical notion of subcortical involvement in this disorder. In SWS, PET showed marked hypometabolism in affected hemisphere in older children, while a 9 month old showed increased LCMRGlc unilaterally (40-50 vs 28-44 ..mu.. moles/min/100g contralateral) with cross cerebellar hypermetabolism (48-50 vs 27-31 ..mu.. moles/min/100g) with no behavioral or EEG evidence of seizure during study. PET studies of LCMRGlc appear sensitive and useful in classifying heterogeneous syndromes into subtypes regarding differential therapy and prognosis, and provide more comprehensive identification of sites of disturbance for investigating mechanisms of these disorders.

  20. Altered gastric chief cell lineage differentiation in histamine-deficient mice.

    PubMed

    Nozaki, Koji; Weis, Victoria; Wang, Timothy C; Falus, András; Goldenring, James R

    2009-06-01

    The orderly differentiation of cell lineages within gastric glands is regulated by a complicated interplay of local mucosal growth factors and hormones. Histamine secreted from enterochromaffin-like cells plays an important role in not only stimulated gastric acid secretion but also coordination of intramucosal growth and lineage differentiation. We have examined histidine-decarboxylase (HDC)-deficient mice, which lack endogenous histamine synthesis, to evaluate the influence of histamine on differentiation of fundic mucosal lineages and the development of metaplasia following induction of acute oxyntic atrophy. Stomachs from HDC-deficient mice and wild-type mice were evaluated at 8 wk and 12 mo of age. DMP-777 was administrated orally to 6-wk-old mice for 1 to 14 days. Sections of gastric mucosa were stained with antibodies against Mist1, intrinsic factor, H/K-ATPase, trefoil factor 2 (TFF2), chromogranin A, and Ext1 and for the cell cycle marker phospho-histone H3. HDC-deficient mice at 8 wk of age demonstrated a prominent increase in chief cells expressing Mist1 and intrinsic factor. Importantly Mist1-positive mature chief cells were present in the midgland region as well as at the bases of fundic glands, indicating a premature differentiation of chief cells. Mice dually deficient for both HDC and gastrin showed a normal distribution of chief cells in fundic glands. Treatment of HDC-deficient mice with DMP-777 led to loss of parietal cells and an accelerated and exaggerated emergence of mucous cell metaplasia with the presence of dual intrinsic factor and TFF2-expressing cells throughout the gland length, indicative of the emergence of spasmolytic polypeptide-expressing metaplasia (SPEM) from chief cells. These findings indicate that histamine, in concert with gastrin, regulates the appropriate differentiation of chief cells from mucous neck cells as they migrate toward the bases of fundic glands. Nevertheless, histamine is not required for emergence of SPEM

  1. Altered SDF-1-mediated differentiation of bone marrow-derived endothelial progenitor cells in diabetes mellitus

    PubMed Central

    De Falco, Elena; Avitabile, Daniele; Totta, Pierangela; Straino, Stefania; Spallotta, Francesco; Cencioni, Chiara; Torella, Anna Rita; Rizzi, Roberto; Porcelli, Daniele; Zacheo, Antonella; Vito, Luca Di; Pompilio, Giulio; Napolitano, Monica; Melillo, Guido; Capogrossi, Maurizio C; Pesce, Maurizio

    2009-01-01

    In diabetic patients and animal models of diabetes mellitus (DM), circulating endothelial progenitor cell (EPC) number is lower than in normoglycaemic conditions and EPC angiogenic properties are inhibited. Stromal cell derived factor-1 (SDF-1) plays a key role in bone marrow (BM) c-kit+ stem cell mobilization into peripheral blood (PB), recruitment from PB into ischemic tissues and differentiation into endothelial cells. The aim of the present study was to examine the effect of DM in vivo and in vitro, on murine BM-derived c-kit+ cells and on their response to SDF-1. Acute hindlimb ischemia was induced in streptozotocin-treated DM and control mice; circulating c-kit+ cells exhibited a rapid increase followed by a return to control levels which was significantly faster in DM than in control mice. CXCR4 expression by BM c-kit+ cells as well as SDF-1 protein levels in the plasma and in the skeletal muscle, both before and after the induction of ischemia, were similar between normoglycaemic and DM mice. However, BM-derived c-kit+ cells from DM mice exhibited an impaired differentiation towards the endothelial phenotype in response to SDF-1; this effect was associated with diminished protein kinase phosphorylation. Interestingly, SDF-1 ability to induce differentiation of c-kit+ cells from DM mice was restored when cells were cultured under normoglycaemic conditions whereas c-kit+ cells from normoglycaemic mice failed to differentiate in response to SDF-1 when they were cultured in hyperglycaemic conditions. These results show that DM diminishes circulating c-kit+ cell number following hindlimb ischemia and inhibits SDF-1-mediated AKT phosphorylation and differentiation towards the endothelial phenotype of BM-derived c-kit+ cells. PMID:20196780

  2. Low-dose dioxins alter gene expression related to cholesterol biosynthesis, lipogenesis, and glucose metabolism through the aryl hydrocarbon receptor-mediated pathway in mouse liver

    SciTech Connect

    Sato, Shoko; Shirakawa, Hitoshi Tomita, Shuhei; Ohsaki, Yusuke; Haketa, Keiichi; Tooi, Osamu; Santo, Noriaki; Tohkin, Masahiro; Furukawa, Yuji; Gonzalez, Frank J.; Komai, Michio

    2008-05-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental contaminant. TCDD binds and activates the transcription factor aryl hydrocarbon receptor (AHR), leading to adverse biological responses via the alteration of the expression of various AHR target genes. Although small amounts of TCDD are consumed via contaminated daily foodstuffs and environmental exposures, the effects of low-dose TCDD on gene expression in animal tissues have not been clarified, while a number of genes affected by high-dose TCDD were reported. In this study, we comprehensively analyzed gene expression profiles in livers of C57BL/6N mice that were orally administered relatively low doses of TCDD (5, 50, or 500 ng/kg body weight (bw) day{sup -1}) for 18 days. The hepatic TCDD concentrations, measured by gas chromatography-mass spectrometry, were 1.2, 17, and 1063 pg toxicity equivalent quantity (TEQ)/g, respectively. The mRNA level of the cytochrome P450 CYP1A1 was significantly increased by treatment with only TCDD 500 ng/kg bw day{sup -1}. DNA microarray and quantitative RT-PCR analyses revealed changes in the expression of genes involved in the circadian rhythm, cholesterol biosynthesis, fatty acid synthesis, and glucose metabolism in the liver with at all doses of TCDD employed. However, repression of expression of genes involved in energy metabolism was not observed in the livers of Ahr-null mice that were administered the same dose of TCDD. These results indicate that changes in gene expression by TCDD are mediated by AHR and that exposure to low-dose TCDD could affect energy metabolism via alterations of gene expression.

  3. Algal Toxin Azaspiracid-1 Induces Early Neuronal Differentiation and Alters Peripherin Isoform Stoichiometry

    PubMed Central

    Hjørnevik, Linda V.; Frøyset, Ann K.; Grønset, Toril A.; Rungruangsak-Torrissen, Krisna; Fladmark, Kari E.

    2015-01-01

    Azaspiracid-1 is an algal toxin that accumulates in edible mussels, and ingestion may result in human illness as manifested by vomiting and diarrhoea. When injected into mice, it causes neurotoxicological symptoms and death. Although it is well known that azaspiracid-1 is toxic to most cells and cell lines, little is known about its biological target(s). A rat PC12 cell line, commonly used as a model for the peripheral nervous system, was used to study the neurotoxicological effects of azaspiracid-1. Azaspiracid-1 induced differentiation-related morphological changes followed by a latter cell death. The differentiated phenotype showed peripherin-labelled neurite-like processes simultaneously as a specific isoform of peripherin was down-regulated. The precise mechanism behind this down-regulation remains uncertain. However, this study provides new insights into the neurological effects of azaspiracid-1 and into the biological significance of specific isoforms of peripherin. PMID:26694421

  4. Duration of maternal undernutrition differentially alters fetal growth and hormone concentrations.

    PubMed

    Field, M E; Anthony, R V; Engle, T E; Archibeque, S L; Keisler, D H; Han, H

    2015-04-01

    To investigate the impact of duration of maternal undernutrition in twin sheep pregnancies, ewes were either fed 100% (C) or 50% of their nutrient requirements from 28 to 78 d gestational age (dGA) and readjusted to 100% beginning at 79 dGA (LC) or continuously restricted from 28 to 135 dGA (LL). Weights of the fetus, empty carcass, brain, and liver were greater in the LC than LL fetuses at 135 dGA (P ≤ 0.05). Although umbilical vein (UmV) glucose concentrations did not differ, the UmV:umbilical artery (UmA) glucose gradient was smaller (0.26 ± 0.03 vs 0.38 ± 0.03 and 0.39 ± 0.04 mmol L(-1); P ≤ 0.05) in LL than C and LC fetuses, respectively. Umbilical vein concentrations of IGF-1 were less (46.7 ± 5.62 vs 74.3 ± 6.71 ng/mL; P ≤ 0.05) in LL than LC fetuses. Additionally, LL fetuses tended (P ≤ 0.10) to have lower UmA concentrations of insulin (0.24 ± 0.13 vs 0.70 ± 0.15 ng/mL) and IGF-1 (66.6 ± 7.51 vs 91.4 ± 8.97 ng/mL) than LC fetuses. Although most of the observed differences occurred between LC and LL pregnancies, LC fetuses tended (P ≤ 0.10) to have greater UmV and UmA pCO2 than C fetuses. Furthermore, the UmV:UmA O2 content gradient tended to be greater (5.02 ± 0.43 vs 3.41 ± 0.47; P ≤ 0.10) in C than LL fetuses. UmA placental lactogen also tended to be greater (46.6 ± 4.40 vs 31.1 ± 4.69 ng/mL; P ≤ 0.10) in LL than C fetuses. These data suggest that in twin pregnancies, maternal undernutrition followed by realimentation induces a different fetal outcome compared with continuous nutrient restriction, and both may differ physiologically from control fed pregnancies. PMID:25460066

  5. Physiological status alters immunological regulation of bovine follicle differentiation in dairy cattle.

    PubMed

    Walsh, S W; Fair, T; Browne, J A; Evans, A C O; McGettigan, P A

    2012-12-01

    Lactation in dairy cattle is associated with a multitude of endocrine, metabolic and immunological changes that not only influence animal health, but also affect fertility, and in particular ovarian function. We have previously generated a global transcriptomic profile of bovine follicular tissue using RNA sequencing. This study aimed to: identify key immune-related transcriptional changes that occur during follicle differentiation and luteinisation using ingenuity pathway analysis (IPA); and determine if a compromised model of stress (i.e. lactation) influences the temporal expression of these genes. Ovarian follicular tissue from Holstein-Friesian non-lactating heifers (n=17) and lactating cows (n=16) was compared at three stages of preovulatory follicle development: (A) the newly selected dominant follicle in the luteal phase (Selection); (B) the follicular phase before the LH surge (Differentiation), and (C) the preovulatory phase after the LH surge (Luteinisation). IPA revealed an over-representation of immune-related pathways in theca compared with granulosa cells during differentiation; these were related to leucocyte extravasation and chemotaxis. Conversely, luteinisation was characterised by over-representation of immune-related pathways in granulosa compared with theca cells; these were related to inflammation and innate immune response. Notably, comparison of follicles from heifers and lactating cows revealed a large number of differentially expressed genes associated with immune cell subpopulations and chemotaxis. In conclusion, identification of immune-related canonical pathways during follicle development supports the hypothesis that ovulation is an inflammatory event. This process is influenced by the physiological status of lactation and likely contributes to compromised peri-ovulatory follicle function by impairing the inflammatory process of ovulation. PMID:22980436

  6. Altered differentiation of CNS neural progenitor cells after transplantation into the injured adult rat spinal cord.

    PubMed

    Onifer, S M; Cannon, A B; Whittemore, S R

    1997-01-01

    Denervation of CNS neurons and peripheral organs is a consequence of traumatic SCI. Intraspinal transplantation of embryonic CNS neurons is a potential strategy for reinnervating these targets. Neural progenitor cell lines are being investigated as alternates to embryonic CNS neurons. RN33B is an immortalized neural progenitor cell line derived from embryonic rat raphe nuclei following infection with a retrovirus encoding the temperature-sensitive mutant of SV40 large T-antigen. Transplantation studies have shown that local epigenetic signals in intact or partially neuron-depleted adult rat hippocampal formation or striatum direct RN33B cell differentiation to complex multipolar morphologies resembling endogenous neurons. After transplantation into neuron-depleted regions of the hippocampal formation or striatum, RN33B cells were relatively undifferentiated or differentiated with bipolar morphologies. The present study examines RN33B cell differentiation after transplantation into normal spinal cord and under different lesion conditions. Adult rats underwent either unilateral lesion of lumbar spinal neurons by intraspinal injection of kainic acid or complete transection at the T10 spinal segment. Neonatal rats underwent either unilateral lesion of lumbar motoneurons by sciatic nerve crush or complete transection at the T10 segment. At 2 or 6-7 wk postinjury, lacZ-labeled RN33B cells were transplanted into the lumbar enlargement of injured and age-matched normal rats. At 2 wk posttransplantation, bipolar and some multipolar RN33B cells were found throughout normal rat gray matter. In contrast, only bipolar RN33B cells were seen in gray matter of kainic acid lesioned, sciatic nerve crush, or transection rats. These observations suggest that RN33B cell multipolar morphological differentiation in normal adult spinal cord is mediated by direct cell-cell interaction through surface molecules on endogenous neurons and may be suppressed by molecules released after SCI

  7. Multiple Antenatal Dexamethasone Treatment Alters Brain Vessel Differentiation in Newborn Mouse Pups.

    PubMed

    Neuhaus, Winfried; Schlundt, Marian; Fehrholz, Markus; Ehrke, Alexander; Kunzmann, Steffen; Liebner, Stefan; Speer, Christian P; Förster, Carola Y

    2015-01-01

    Antenatal steroid treatment decreases morbidity and mortality in premature infants through the maturation of lung tissue, which enables sufficient breathing performance. However, clinical and animal studies have shown that repeated doses of glucocorticoids such as dexamethasone and betamethasone lead to long-term adverse effects on brain development. Therefore, we established a mouse model for antenatal dexamethasone treatment to investigate the effects of dexamethasone on brain vessel differentiation towards the blood-brain barrier (BBB) phenotype, focusing on molecular marker analysis. The major findings were that in total brains on postnatal day (PN) 4 triple antenatal dexamethasone treatment significantly downregulated the tight junction protein claudin-5, the endothelial marker Pecam-1/CD31, the glucocorticoid receptor, the NR1 subunit of the N-methyl-D-aspartate receptor, and Abc transporters (Abcb1a, Abcg2 Abcc4). Less pronounced effects were found after single antenatal dexamethasone treatment and in PN10 samples. Comparisons of total brain samples with isolated brain endothelial cells together with the stainings for Pecam-1/CD31 and claudin-5 led to the assumption that the morphology of brain vessels is affected by antenatal dexamethasone treatment at PN4. On the mRNA level markers for angiogenesis, the sonic hedgehog and the Wnt pathway were downregulated in PN4 samples, suggesting fundamental changes in brain vascularization and/or differentiation. In conclusion, we provided a first comprehensive molecular basis for the adverse effects of multiple antenatal dexamethasone treatment on brain vessel differentiation. PMID:26274818

  8. Differential effects of fructose versus glucose on brain and appetitive responses to food cues and decisions for food rewards

    PubMed Central

    Luo, Shan; Monterosso, John R.; Sarpelleh, Kayan; Page, Kathleen A.

    2015-01-01

    Prior studies suggest that fructose compared with glucose may be a weaker suppressor of appetite, and neuroimaging research shows that food cues trigger greater brain reward responses in a fasted relative to a fed state. We sought to determine the effects of ingesting fructose versus glucose on brain, hormone, and appetitive responses to food cues and food-approach behavior. Twenty-four healthy volunteers underwent two functional magnetic resonance imaging (fMRI) sessions with ingestion of either fructose or glucose in a double-blinded, random-order cross-over design. fMRI was performed while participants viewed images of high-calorie foods and nonfood items using a block design. After each block, participants rated hunger and desire for food. Participants also performed a decision task in which they chose between immediate food rewards and delayed monetary bonuses. Hormones were measured at baseline and 30 and 60 min after drink ingestion. Ingestion of fructose relative to glucose resulted in smaller increases in plasma insulin levels and greater brain reactivity to food cues in the visual cortex (in whole-brain analysis) and left orbital frontal cortex (in region-of-interest analysis). Parallel to the neuroimaging findings, fructose versus glucose led to greater hunger and desire for food and a greater willingness to give up long-term monetary rewards to obtain immediate high-calorie foods. These findings suggest that ingestion of fructose relative to glucose results in greater activation of brain regions involved in attention and reward processing and may promote feeding behavior. PMID:25941364

  9. Hormone Autotrophic Growth and Differentiation Identifies Mutant Lines of Arabidopsis with Altered Cytokinin and Auxin Content or Signaling1

    PubMed Central

    Frank, Markus; Rupp, Hans-Michael; Prinsen, Els; Motyka, Václav; Van Onckelen, Harry; Schmülling, Thomas

    2000-01-01

    We describe mutant tissue lines of Arabidopsis that are able to grow in vitro as callus on hormone-free medium. The 14 lines presented here show different hormone autotrophic differentiation behaviors that can be classified into three categories: (a) forming roots (rooty callus), (b) forming shoots or shoot-like structures (shooty callus), or (c) growing without organ formation (callus). Three fast-growing lines showed altered steady-state mRNA levels of the Cdc2 and CycD3 cell cycle genes. Three of the six rooty callus lines contained about 20- to 30-fold higher levels of auxins than wild-type callus. These and two other lines with normal auxin content showed an increased steady-state level of IAA1 and IAA2 transcripts in the absence of exogenous auxin. Five of the six shooty callus lines had increased steady-state mRNA levels of the CKI1 gene and/or of the homeobox genes KNAT1 and STM, suggesting that the phenotype is linked to altered cytokinin signaling. Also, one cytokinin-overproducing line with only 5% of wild-type cytokinin oxidase activity was identified. These results indicate that screening for hormone-autonomous growth identifies mutants with altered hormone content or signaling. PMID:10712535

  10. Storage Temperature Alters the Expression of Differentiation-Related Genes in Cultured Oral Keratinocytes

    PubMed Central

    Utheim, Tor Paaske; Islam, Rakibul; Fostad, Ida G.; Eidet, Jon R.; Sehic, Amer; Olstad, Ole K.; Dartt, Darlene A.; Messelt, Edward B.; Griffith, May; Pasovic, Lara

    2016-01-01

    Purpose Storage of cultured human oral keratinocytes (HOK) allows for transportation of cultured transplants to eye clinics worldwide. In a previous study, one-week storage of cultured HOK was found to be superior with regard to viability and morphology at 12°C compared to 4°C and 37°C. To understand more of how storage temperature affects cell phenotype, gene expression of HOK before and after storage at 4°C, 12°C, and 37°C was assessed. Materials and Methods Cultured HOK were stored in HEPES- and sodium bicarbonate-buffered Minimum Essential Medium at 4°C, 12°C, and 37°C for one week. Total RNA was isolated and the gene expression profile was determined using DNA microarrays and analyzed with Partek Genomics Suite software and Ingenuity Pathway Analysis. Differentially expressed genes (fold change > 1.5 and P < 0.05) were identified by one-way ANOVA. Key genes were validated using qPCR. Results Gene expression of cultures stored at 4°C and 12°C clustered close to the unstored control cultures. Cultures stored at 37°C displayed substantial change in gene expression compared to the other groups. In comparison with 12°C, 2,981 genes were differentially expressed at 37°C. In contrast, only 67 genes were differentially expressed between the unstored control and the cells stored at 12°C. The 12°C and 37°C culture groups differed most significantly with regard to the expression of differentiation markers. The Hedgehog signaling pathway was significantly downregulated at 37°C compared to 12°C. Conclusion HOK cultures stored at 37°C showed considerably larger changes in gene expression compared to unstored cells than cultured HOK stored at 4°C and 12°C. The changes observed at 37°C consisted of differentiation of the cells towards a squamous epithelium-specific phenotype. Storing cultured ocular surface transplants at 37°C is therefore not recommended. This is particularly interesting as 37°C is the standard incubation temperature used for cell

  11. Differential Rearing Alters Forced Swim Test Behavior, Fluoxetine Efficacy, and Post-Test Weight Gain in Male Rats.

    PubMed

    Arndt, David L; Peterson, Christy J; Cain, Mary E

    2015-01-01

    Environmental factors play a key role in the etiology of depression. The rodent forced swim test (FST) is commonly used as a preclinical model of depression, with increases in escape-directed behavior reflecting antidepressant effects, and increases in immobility reflecting behavioral despair. Environmental enrichment leads to serotonergic alterations in rats, but it is unknown whether these alterations may influence the efficacy of common antidepressants. Male Sprague-Dawley rats were reared in enriched (EC), standard (SC), or isolated (IC) conditions. Following the rearing period, fluoxetine (10 or 20 mg/kg, i.p.) was administered 23.5 hrs, 5 hrs, and 1 hr before locomotor and FST measures. Following locomotor testing and FST exposure, rats were weighed to assess fluoxetine-, FST-, and environmental condition-induced moderations in weight gain. Results revealed an antidepressant effect of environmental enrichment and a depressant effect of isolation. Regardless of significant fluoxetine effects on locomotor activity, fluoxetine generally decreased swimming and increased immobility in all three environmental conditions, with IC-fluoxetine (10 mg/kg) rats and EC-fluoxetine (20 mg/kg) rats swimming less than vehicle counterparts. Subchronic 20 mg/kg fluoxetine also induced significant weight loss, and differential rearing appeared to moderate weight gain following FST stress. These results suggest that differential rearing has the ability to alter FST behaviors, fluoxetine efficacy, and post-stressor well-being. Moreover, 20 mg/kg fluoxetine, administered subchronically, may lead to atypical effects of those commonly observed in the FST, highlighting the importance and impact of both environmental condition and dosing regimen in common animal models of depression. PMID:26154768

  12. Differential display detects host nucleic acid motifs altered in scrapie-infected brain.

    PubMed

    Lathe, Richard; Harris, Alyson

    2009-09-25

    The transmissible spongiform encephalopathies (TSEs) including scrapie have been attributed to an infectious protein or prion. Infectivity is allied to conversion of the endogenous nucleic-acid-binding protein PrP to an infectious modified form known as PrP(sc). The protein-only theory does not easily explain the enigmatic properties of the agent including strain variation. It was previously suggested that a short nucleic acid, perhaps host-encoded, might contribute to the pathoetiology of the TSEs. No candidate host molecules that might explain transmission of strain differences have yet been put forward. Differential display is a robust technique for detecting nucleic acid differences between two populations. We applied this technique to total nucleic acid preparations from scrapie-infected and control brain. Independent RNA preparations from eight normal and eight scrapie-infected (strain 263K) hamster brains were randomly amplified and visualized in parallel. Though the nucleic acid patterns were generally identical in scrapie-infected versus control brain, some rare bands were differentially displayed. Molecular species consistently overrepresented (or underrepresented) in all eight infected brain samples versus all eight controls were excised from the display, sequenced, and assembled into contigs. Only seven ros contigs (RNAs over- or underrepresented in scrapie) emerged, representing <4 kb from the transcriptome. All contained highly stable regions of secondary structure. The most abundant scrapie-only ros sequence was homologous to a repetitive transposable element (LINE; long interspersed nuclear element). Other ros sequences identified cellular RNA 7SL, clathrin heavy chain, visinin-like protein-1, and three highly specific subregions of ribosomal RNA (ros1-3). The ribosomal ros sequences accurately corresponded to LINE; retrotransposon insertion sites in ribosomal DNA (p<0.01). These differential motifs implicate specific host RNAs in the pathoetiology

  13. Altered chromatin occupancy of master regulators underlies evolutionary divergence in the transcriptional landscape of erythroid differentiation.

    PubMed

    Ulirsch, Jacob C; Lacy, Jessica N; An, Xiuli; Mohandas, Narla; Mikkelsen, Tarjei S; Sankaran, Vijay G

    2014-12-01

    Erythropoiesis is one of the best understood examples of cellular differentiation. Morphologically, erythroid differentiation proceeds in a nearly identical fashion between humans and mice, but recent evidence has shown that networks of gene expression governing this process are divergent between species. We undertook a systematic comparative analysis of six histone modifications and four transcriptional master regulators in primary proerythroblasts and erythroid cell lines to better understand the underlying basis of these transcriptional differences. Our analyses suggest that while chromatin structure across orthologous promoters is strongly conserved, subtle differences are associated with transcriptional divergence between species. Many transcription factor (TF) occupancy sites were poorly conserved across species (∼25% for GATA1, TAL1, and NFE2) but were more conserved between proerythroblasts and cell lines derived from the same species. We found that certain cis-regulatory modules co-occupied by GATA1, TAL1, and KLF1 are under strict evolutionary constraint and localize to genes necessary for erythroid cell identity. More generally, we show that conserved TF occupancy sites are indicative of active regulatory regions and strong gene expression that is sustained during maturation. Our results suggest that evolutionary turnover of TF binding sites associates with changes in the underlying chromatin structure, driving transcriptional divergence. We provide examples of how this framework can be applied to understand epigenomic variation in specific regulatory regions, such as the β-globin gene locus. Our findings have important implications for understanding epigenomic changes that mediate variation in cellular differentiation across species, while also providing a valuable resource for studies of hematopoiesis. PMID:25521328

  14. Altered Chromatin Occupancy of Master Regulators Underlies Evolutionary Divergence in the Transcriptional Landscape of Erythroid Differentiation

    PubMed Central

    Ulirsch, Jacob C.; Lacy, Jessica N.; An, Xiuli; Mohandas, Narla; Mikkelsen, Tarjei S.; Sankaran, Vijay G.

    2014-01-01

    Erythropoiesis is one of the best understood examples of cellular differentiation. Morphologically, erythroid differentiation proceeds in a nearly identical fashion between humans and mice, but recent evidence has shown that networks of gene expression governing this process are divergent between species. We undertook a systematic comparative analysis of six histone modifications and four transcriptional master regulators in primary proerythroblasts and erythroid cell lines to better understand the underlying basis of these transcriptional differences. Our analyses suggest that while chromatin structure across orthologous promoters is strongly conserved, subtle differences are associated with transcriptional divergence between species. Many transcription factor (TF) occupancy sites were poorly conserved across species (∼25% for GATA1, TAL1, and NFE2) but were more conserved between proerythroblasts and cell lines derived from the same species. We found that certain cis-regulatory modules co-occupied by GATA1, TAL1, and KLF1 are under strict evolutionary constraint and localize to genes necessary for erythroid cell identity. More generally, we show that conserved TF occupancy sites are indicative of active regulatory regions and strong gene expression that is sustained during maturation. Our results suggest that evolutionary turnover of TF binding sites associates with changes in the underlying chromatin structure, driving transcriptional divergence. We provide examples of how this framework can be applied to understand epigenomic variation in specific regulatory regions, such as the β-globin gene locus. Our findings have important implications for understanding epigenomic changes that mediate variation in cellular differentiation across species, while also providing a valuable resource for studies of hematopoiesis. PMID:25521328

  15. Deregulated KLF4 Expression in Myeloid Leukemias Alters Cell Proliferation and Differentiation through MicroRNA and Gene Targets

    PubMed Central

    Morris, Valerie A.; Cummings, Carrie L.; Korb, Brendan; Boaglio, Sean

    2015-01-01

    Acute myeloid leukemia (AML) is characterized by increased proliferation and blocked differentiation of hematopoietic progenitors mediated, in part, by altered myeloid transcription factor expression. Decreased Krüppel-like factor 4 (KLF4) expression has been observed in AML, but how decreased KLF4 contributes to AML pathogenesis is largely unknown. We demonstrate decreased KLF4 expression in AML patient samples with various cytogenetic aberrations, confirm that KLF4 overexpression promotes myeloid differentiation and inhibits cell proliferation in AML cell lines, and identify new targets of KLF4. We have demonstrated that microRNA 150 (miR-150) expression is decreased in AML and that reintroducing miR-150 expression induces myeloid differentiation and inhibits proliferation of AML cells. We show that KLF family DNA binding sites are necessary for miR-150 promoter activity and that KLF2 or KLF4 overexpression induces miR-150 expression. miR-150 silencing, alone or in combination with silencing of CDKN1A, a well-described KLF4 target, did not fully reverse KLF4-mediated effects. Gene expression profiling and validation identified putative KLF4-regulated genes, including decreased MYC and downstream MYC-regulated gene expression in KLF4-overexpressing cells. Our findings indicate that decreased KLF4 expression mediates antileukemic effects through regulation of gene and microRNA networks, containing miR-150, CDKN1A, and MYC, and provide mechanistic support for therapeutic strategies increasing KLF4 expression. PMID:26644403

  16. Glucose and Palmitate Differentially Regulate PFKFB3/iPFK2 and Inflammatory Responses in Mouse Intestinal Epithelial Cells

    PubMed Central

    Botchlett, Rachel; Li, Honggui; Guo, Xin; Qi, Ting; Zhao, JiaJia; Zheng, Juan; Woo, Shih-Lung; Pei, Ya; Liu, Mengyang; Hu, Xiang; Chen, Guang; Guo, Ting; Yang, Sijun; Li, Qifu; Xiao, Xiaoqiu; Huo, Yuqing; Wu, Chaodong

    2016-01-01

    The gene PFKFB3 encodes for inducible 6-phosphofructo-2-kinase, a glycolysis-regulatory enzyme that protects against diet-induced intestine inflammation. However, it is unclear how nutrient overload regulates PFKFB3 expression and inflammatory responses in intestinal epithelial cells (IECs). In the present study, primary IECs were isolated from small intestine of C57BL/6J mice fed a low-fat diet (LFD) or high-fat diet (HFD) for 12 weeks. Additionally, CMT-93 cells, a cell line for IECs, were cultured in low glucose (LG, 5.5 mmol/L) or high glucose (HG, 27.5 mmol/L) medium and treated with palmitate (50 μmol/L) or bovine serum albumin (BSA) for 24 hr. These cells were analyzed for PFKFB3 and inflammatory markers. Compared with LFD, HFD feeding decreased IEC PFKFB3 expression and increased IEC proinflammatory responses. In CMT-93 cells, HG significantly increased PFKFB3 expression and proinflammatory responses compared with LG. Interestingly, palmitate decreased PFKFB3 expression and increased proinflammatory responses compared with BSA, regardless of glucose concentrations. Furthermore, HG significantly increased PFKFB3 promoter transcription activity compared with LG. Upon PFKFB3 overexpression, proinflammatory responses in CMT-93 cells were decreased. Taken together, these results indicate that in IECs glucose stimulates PFKFB3 expression and palmitate contributes to increased proinflammatory responses. Therefore, PFKFB3 regulates IEC inflammatory status in response to macronutrients. PMID:27387960

  17. The glucose sensor ChREBP links de-novo lipogenesis to PPARgamma activity and adipocyte differentiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reduced de-novo lipogenesis DNL)in adipose tissue, often observed in obese individuals, is thought to contribute to insulin resistance. Besides trapping excess glucose and providing for triglycerides and energy storage, endogenously synthesized lipids can function as potent signaling molecules. Inde...

  18. High-Affinity Glucose Transport in Aspergillus nidulans Is Mediated by the Products of Two Related but Differentially Expressed Genes

    PubMed Central

    Ventura, Luisa; González, Ramón; Ramón, Daniel; MacCabe, Andrew P.

    2014-01-01

    Independent systems of high and low affinity effect glucose uptake in the filamentous fungus Aspergillus nidulans. Low-affinity uptake is known to be mediated by the product of the mstE gene. In the current work two genes, mstA and mstC, have been identified that encode high-affinity glucose transporter proteins. These proteins' primary structures share over 90% similarity, indicating that the corresponding genes share a common origin. Whilst the function of the paralogous proteins is little changed, they differ notably in their patterns of expression. The mstC gene is expressed during the early phases of germination and is subject to CreA-mediated carbon catabolite repression whereas mstA is expressed as a culture tends toward carbon starvation. In addition, various pieces of genetic evidence strongly support allelism of mstC and the previously described locus sorA. Overall, our data define MstC/SorA as a high-affinity glucose transporter expressed in germinating conidia, and MstA as a high-affinity glucose transporter that operates in vegetative hyphae under conditions of carbon limitation. PMID:24751997

  19. Castration differentially alters basal and leucine-stimulated tissue protein synthesis in skeletal muscle and adipose tissue.

    PubMed

    Jiao, Qianning; Pruznak, Anne M; Huber, Danuta; Vary, Thomas C; Lang, Charles H

    2009-11-01

    Reduced testosterone as a result of catabolic illness or aging is associated with loss of muscle and increased adiposity. We hypothesized that these changes in body composition occur because of altered rates of protein synthesis under basal and nutrient-stimulated conditions that are tissue specific. The present study investigated such mechanisms in castrated male rats (75% reduction in testosterone) with demonstrated glucose intolerance. Over 9 wk, castration impaired body weight gain, which resulted from a reduced lean body mass and preferential sparing of adipose tissue. Castration decreased gastrocnemius weight, but this atrophy was not associated with reduced basal muscle protein synthesis or differences in plasma IGF-I, insulin, or individual amino acids. However, oral leucine failed to normally stimulate muscle protein synthesis in castrated rats. In addition, castration-induced atrophy was associated with increased 3-methylhistidine excretion and in vitro-determined ubiquitin proteasome activity in skeletal muscle, changes that were associated with decreased atrogin-1 or MuRF1 mRNA expression. Castration decreased heart and kidney weight without reducing protein synthesis and did not alter either cardiac output or glomerular filtration. In contradistinction, the weight of the retroperitoneal fat depot was increased in castrated rats. This increase was associated with an elevated rate of basal protein synthesis, which was unresponsive to leucine stimulation. Castration also decreased whole body fat oxidation. Castration increased TNFα, IL-1α, IL-6, and NOS2 mRNA in fat but not muscle. In summary, the castration-induced muscle wasting results from an increased muscle protein breakdown and the inability of leucine to stimulate protein synthesis, whereas the expansion of the retroperitoneal fat depot appears mediated in part by an increased basal rate of protein synthesis-associated increased inflammatory cytokine expression. PMID:19755668

  20. Differential elastic responses to barrier-altering agonists in two types of human lung endothelium.

    PubMed

    Viswanathan, P; Ephstein, Y; Garcia, J G N; Cho, M; Dudek, S M

    2016-09-16

    Vascular integrity is primarily determined by endothelial cell (EC) cytoskeletal structure that is differentially regulated by various stimuli. In this study, atomic force microscopy (AFM) was used to characterize structural and mechanical properties in the cytoskeleton of cultured human pulmonary artery EC (HPAEC) and human lung microvascular EC (HLMVEC) by determining elastic properties (Young's modulus) in response to endogenous barrier protective agents sphingosine 1-phosphate (S1P) and hepatocyte growth factor (HGF), or the barrier disruptive molecule thrombin. Initial studies in unstimulated cells indicate higher baseline peripheral elastic modulus values in HPAEC (mean 2.9 KPa) than in HLMVEC (1.8 KPa). After 30 min of stimulation, S1P induced the highest Young's modulus increase (6.1 KPa) compared to the other barrier enhancing stimuli, HGF (5.8 KPa) and the pharmaceutical agent and S1P analog FTY720 (4.1 KPa). In contrast, the barrier disruptive agent thrombin decreased values from 2.5 KPa to 0.7 KPa depending on the cell type and treatment time. AFM topographical imaging supports these quantitative biophysical data regarding differential peripheral elastic properties in EC. Overall, these AFM studies provide novel insights into the biomechanical properties of human lung EC that regulate vascular barrier function and have potential applicability to pathophysiologic vascular leak syndromes such as acute lung injury. PMID:27473658

  1. Altered Differential Control of Sympathetic Outflow Following Sedentary Conditions: Role of Subregional Neuroplasticity in the RVLM

    PubMed Central

    Subramanian, Madhan; Mueller, Patrick J.

    2016-01-01

    Despite the classically held belief of an “all-or-none” activation of the sympathetic nervous system, differential responses in sympathetic nerve activity (SNA) can occur acutely at varying magnitudes and in opposing directions. Sympathetic nerves also appear to contribute differentially to various disease states including hypertension and heart failure. Previously we have reported that sedentary conditions enhanced responses of splanchnic SNA (SSNA) but not lumbar SNA (LSNA) to activation of the rostral ventrolateral medulla (RVLM) in rats. Bulbospinal RVLM neurons from sedentary rats also exhibit increased dendritic branching in rostral regions of the RVLM. We hypothesized that regionally specific structural neuroplasticity would manifest as enhanced SSNA but not LSNA following activation of the rostral RVLM. To test this hypothesis, groups of physically active (10–12 weeks on running wheels) or sedentary, male Sprague-Dawley rats were instrumented to record mean arterial pressure, LSNA and SSNA under Inactin anesthesia and during microinjections of glutamate (30 nl, 10 mM) into multiple sites within the RVLM. Sedentary conditions enhanced SSNA but not LSNA responses and SSNA responses were enhanced at more central and rostral sites. Results suggest that enhanced SSNA responses in rostral RVLM coincide with enhanced dendritic branching in rostral RVLM observed previously. Identifying structural and functional neuroplasticity in specific populations of RVLM neurons may help identify new treatments for cardiovascular diseases, known to be more prevalent in sedentary individuals. PMID:27486405

  2. Perinatal exposure to diethylstilbestrol alters the functional differentiation of the adult rat uterus.

    PubMed

    Bosquiazzo, Verónica L; Vigezzi, Lucía; Muñoz-de-Toro, Mónica; Luque, Enrique H

    2013-11-01

    The exposure to endocrine disrupters and female reproductive tract disorders has not been totally clarified. The present study assessed the long-term effect of perinatal (gestation+lactation) exposure to diethylstilbestrol (DES) on the rat uterus and the effect of estrogen replacement therapy. DES (5μg/kg bw/day) was administered in the drinking water from gestational day 9 until weaning and we studied the uterus of young adult (PND90) and adult (PND360) females. To investigate whether perinatal exposure to DES modified the uterine response to a long-lasting estrogen treatment, 12-month-old rats exposed to DES were ovariectomized and treated with 17β-estradiol for 3 months (PND460). In young adult rats (PND90), the DES treatment decreased both the proliferation of glandular epithelial cells and the percentage of glandular perimeter occupied by α-smooth muscle actin-positive cells. The other tissue compartments remained unchanged. Cell apoptosis was not altered in DES-exposed females. In control adult rats (PND360), there were some morphologically abnormal uterine glands. In adult rats exposed to DES, the incidence of glands with cellular anomalies increased. In response to estrogens (PND460), the incidence of cystic glands increased in the DES group. We observed glands with daughter glands and conglomerates of glands only on PND460 and in response to estrogen replacement therapy, independently of DES exposure. The p63 isoforms were expressed without changes on PND460. Estrogen receptors α and β showed no changes, while the progesterone receptor decreased in the subepithelial stroma of DES-exposed animals with estrogen treatment. The long-lasting effects of perinatal exposure to DES included the induction of abnormalities in uterine tissues of aged female rats and an altered response of the adult uterus to estradiol. PMID:23454116

  3. TNFα Altered Inflammatory Responses, Impaired Health and Productivity, but Did Not Affect Glucose or Lipid Metabolism in Early-Lactation Dairy Cows

    PubMed Central

    Mamedova, Laman K.; Sordillo, Lorraine M.; Bradford, Barry J.

    2013-01-01

    Inflammation may be a major contributing factor to peripartum metabolic disorders in dairy cattle. We tested whether administering an inflammatory cytokine, recombinant bovine tumor necrosis factor-α (rbTNFα), affects milk production, metabolism, and health during this period. Thirty-three Holstein cows (9 primiparous and 24 multiparous) were randomly assigned to 1 of 3 treatments at parturition. Treatments were 0 (Control), 1.5, or 3.0 µg/kg body weight rbTNFα, which were administered once daily by subcutaneous injection for the first 7 days of lactation. Statistical contrasts were used to evaluate the treatment and dose effects of rbTNFα administration. Plasma TNFα concentrations at 16 h post-administration tended to be increased (P<0.10) by rbTNFα administration, but no dose effect (P>0.10) was detected; rbTNFα treatments increased (P<0.01) concentrations of plasma haptoglobin. Most plasma eicosanoids were not affected (P>0.10) by rbTNFα administration, but 6 out of 16 measured eicosanoids changed (P<0.05) over the first week of lactation, reflecting elevated inflammatory mediators in the days immediately following parturition. Dry matter and water intake, milk yield, and milk fat and protein yields were all decreased (P<0.05) by rbTNFα treatments by 15 to 18%. Concentrations of plasma glucose, insulin, β-hydroxybutyrate, non-esterified fatty acids, triglyceride, 3-methylhistidine, and liver triglyceride were unaffected (P>0.10) by rbTNFα treatment. Glucose turnover rate was unaffected (P = 0.18) by rbTNFα administration. The higher dose of rbTNFα tended to increase the risk of cows developing one or more health disorders (P = 0.08). Taken together, these results indicate that administration of rbTNFα daily for the first 7 days of lactation altered inflammatory responses, impaired milk production and health, but did not significantly affect liver triglyceride accumulation or nutrient metabolism in dairy cows. PMID:24260367

  4. Human colon epithelial cells productively infected with human immunodeficiency virus show impaired differentiation and altered secretion.

    PubMed Central

    Fantini, J; Yahi, N; Baghdiguian, S; Chermann, J C

    1992-01-01

    Selected strains of the human immunodeficiency virus (HIV) types 1 and 2 are able to infect human colon epithelial cells in vitro, suggesting a mechanism for the anal route of HIV transmission. In some cases, HIV is not produced by infected colon cells but can be rescued after coculture with T-lymphoid cells. One of the HIV strains (HIV1-NDK) replicated well in colonic cells. A transmission electron microscope study demonstrated two major structural perturbations in producer colon cells: an unusual number of secretion bodies and the appearance of intracellular lumina with disorganized microvilli, indicating a defect in brush border assembly and differentiation. Either abnormality could account for HIV-induced enteropathy consisting of chronic diarrhea and malabsorption in the absence of enteric pathogens. Moreover, HT29 cells infected with HIV provide a unique model for selection of enterotropic HIV strains. Images PMID:1727501

  5. Galpha-subunits differentially alter the conformation and agonist affinity of kappa-opioid receptors.

    PubMed

    Yan, Feng; Mosier, Philip D; Westkaemper, Richard B; Roth, Bryan L

    2008-02-12

    Although ligand-induced conformational changes in G protein-coupled receptors (GPCRs) are well-documented, there is little direct evidence for G protein-induced changes in GPCR conformation. To investigate this possibility, the effects of overexpressing Galpha-subunits (Galpha16 or Galphai2) with the kappa-opioid receptor (KOR) were examined. The changes in KOR conformation were subequently examined via the substituted cysteine accessibility method (SCAM) in transmembrane domains 6 (TM6) and 7 (TM7) and extracellular loop 2 (EL2). Significant conformational changes were observed on TM7, the extracellular portion of TM6, and EL2. Seven SCAM-sensitive residues (S3107.33, F3147.37, and I3167.39 to Y3207.43) on TM7 presented a cluster pattern when the KOR was exposed to baseline amounts of G protein, and additional residues became sensitive upon overexpression of various G proteins. In TM7, S3117.34 and N3267.49 were found to be sensitive in Galpha16-overexpressed cells and Y3137.36, N3227.45, S3237.46, and L3297.52 in Galphai2-overexpressed cells. In addition, the degree of sensitivity for various TM7 residues was augmented, especially in Galphai2-overexpressed cells. A similar phenomenon was also observed for residues in TM6 and EL2. In addition to an enhanced sensitivity of certain residues, our findings also indicated that a slight rotation was predicted to occur in the upper part of TM7 upon G protein overexpression. These relatively modest conformational changes engendered by G protein overexpression had both profound and differential effects on the abilities of agonists to bind to KOR. These data are significant because they demonstrate that Galpha-subunits differentially modulate the conformation and agonist affinity of a prototypical GPCR. PMID:18205395

  6. Developmental exposure to bisphenol A (BPA) alters sexual differentiation in painted turtles (Chrysemys picta)

    USGS Publications Warehouse

    Jandegian, Caitlin M.; Deem, Sharon L.; Bhandari, Ramji K.; Holliday, Casey M.; Nicks, Diane; Rosenfeld, Cheryl S.; Selcer, Kyle; Tillitt, Donald E.; vom Saal, Fredrick S.; Velez, Vanessa; Yang, Ying; Holliday, Dawn K.

    2015-01-01

    Environmental chemicals can disrupt endocrine signaling and adversely impact sexual differentiation in wildlife. Bisphenol A (BPA) is an estrogenic chemical commonly found in a variety of habitats. In this study, we used painted turtles (Chrysemys picta), which have temperature-dependent sex determination (TSD), as an animal model for ontogenetic endocrine disruption by BPA. We hypothesized that BPA would override TSD and disrupt sexual development. We incubated farm-raised turtle eggs at the male-producing temperature (26 °C), randomly assigned individuals to treatment groups: control, vehicle control, 17β-estradiol (E2, 20 ng/g-egg) or 0.01, 1.0, 100 μg BPA/g-egg and harvested tissues at hatch. Typical female gonads were present in 89% of the E2-treated “males”, but in none of the control males (n = 35). Gonads of BPA-exposed turtles had varying amounts of ovarian-like cortical (OLC) tissue and disorganized testicular tubules in the medulla. Although the percentage of males with OLCs increased with BPA dose (BPA-low = 30%, BPA-medium = 33%, BPA-high = 39%), this difference was not significant (p = 0.85). In all three BPA treatments, SOX9 patterns revealed disorganized medullary testicular tubules and β-catenin expression in a thickened cortex. Liver vitellogenin, a female-specific liver protein commonly used as an exposure biomarker, was not induced by any of the treatments. Notably, these results suggest that developmental exposure to BPA disrupts sexual differentiation in painted turtles. Further examination is necessary to determine the underlying mechanisms of sex reversal in reptiles and how these translate to EDC exposure in wild populations.

  7. High glucose and hyperglycemic sera from type 2 diabetic patients impair DC differentiation by inducing ROS and activating Wnt/β-catenin and p38 MAPK.

    PubMed

    Gilardini Montani, Maria Saveria; Granato, Marisa; Cuomo, Laura; Valia, Sandro; Di Renzo, Livia; D'Orazi, Gabriella; Faggioni, Alberto; Cirone, Mara

    2016-04-01

    Type 2 is the type of diabetes with higher prevalence in contemporary time, representing about 90% of the global cases of diabetes. In the course of diabetes, several complications can occur, mostly due to hyperglycemia and increased reactive oxygen species (ROS) production. One of them is represented by an increased susceptibility to microbial infections and by a reduced capacity to clear them. Therefore, knowing the impact of hyperglycemia on immune system functionality is of utmost importance for the management of the disease. In this study, we show that medium containing high glucose reduced the in-vitro differentiation of monocytes into functional DCs and their activation mediated by PAMPs or DAMPs. Most importantly, the same effects were mediated by the hyperglycemic sera derived by type 2 diabetic patients, mimicking a more physiologic condition. DC dysfunction caused by hyperglycemia may be involved in the inefficient control of infections observed in diabetic patients, given the pivotal role of these cells in both the innate and adaptive immune response. Searching for the molecular mechanisms underlying DC dysfunction, we found that canonical Wnt/β-catenin and p38 MAPK pathways were activated in the DCs differentiated either in the presence of high glucose or of hyper-glycemic sera. Interestingly, the activation of these pathways and the DC immune dysfunction were partially counteracted by the anti-oxidant quercetin, a flavonoid already known to exert several beneficial effects in diabetes. PMID:26769359

  8. The alteration of H4-K16ac and H3-K27met influences the differentiation of neural stem cells.

    PubMed

    An, Mingrui; Shen, Hongyan; Cao, Jun; Pei, Xiucong; Chang, Yanxu; Ma, Shuaipeng; Bao, Jintao; Zhang, Xuefei; Bai, Xue; Ma, Yuanhui

    2016-09-15

    The neural stem cell therapy provides a promising future for patients with central nerve system damage, thus an insight into its differentiation mechanism is urgently needed. Herein, we aimed to identify various histone modifications and reveal their impact on the differentiation of neural stem cells (NSCs) toward neurons. Firstly, we labeled primary NSCs using the stable isotope labeling with amino acids in cell culture (SILAC) technique. Then we induced these NSCs to differentiate by all-trans retinoic acid (atRA) or SB216763. Next, we identified the alteration of histone modifications in early-differentiated NSCs by mass spectrometry and verified them by Western blot. Interestingly, these modification alterations and phenotype changes were found similar in NSCs induced by the two different drugs. More interestingly, during the differentiation process H3-K27met was significantly up-regulated while H4-K16ac was not altered at the global level but down-regulated in some low-abundance combinatorial codes. We inhibited the methyltransferase of H3-K27 and deacetylase of H4-K16 simultaneously and found the differentiation procedure was obviously delayed. The function of H4-K16ac and H3-K27met in NSCs differentiation would be useful to reveal the differentiation mechanism and valuable for further neural stem cell therapy. PMID:27396496

  9. Cytolethal Distending Toxin Family Members Are Differentially Affected by Alterations in Host Glycans and Membrane Cholesterol*

    PubMed Central

    Eshraghi, Aria; Maldonado-Arocho, Francisco J.; Gargi, Amandeep; Cardwell, Marissa M.; Prouty, Michael G.; Blanke, Steven R.; Bradley, Kenneth A.

    2010-01-01

    Cytolethal distending toxins (CDTs) are tripartite protein exotoxins produced by a diverse group of pathogenic Gram-negative bacteria. Based on their ability to induce DNA damage, cell cycle arrest, and apoptosis of cultured cells, CDTs are proposed to enhance virulence by blocking cellular division and/or directly killing epithelial and immune cells. Despite the widespread distribution of CDTs among several important human pathogens, our understanding of how these toxins interact with host cells is limited. Here we demonstrate that CDTs from Haemophilus ducreyi, Aggregatibacter actinomycetemcomitans, Escherichia coli, and Campylobacter jejuni differ in their abilities to intoxicate host cells with defined defects in host factors previously implicated in CDT binding, including glycoproteins, and glycosphingolipids. The absence of cell surface sialic acid sensitized cells to intoxication by three of the four CDTs tested. Surprisingly, fucosylated N-linked glycans and glycolipids, previously implicated in CDT-host interactions, were not required for intoxication by any of the CDTs tested. Finally, altering host-cellular cholesterol, also previously implicated in CDT binding, affected intoxication by only a subset of CDTs tested. The findings presented here provide insight into the molecular and cellular basis of CDT-host interactions. PMID:20385557

  10. Structural Analysis of Alterations in Zebrafish Muscle Differentiation Induced by Simvastatin and Their Recovery with Cholesterol

    PubMed Central

    Campos, Laise M.; Rios, Eduardo A.; Midlej, Victor; Atella, Georgia C.; Herculano-Houzel, Suzana; Benchimol, Marlene; Mermelstein, Claudia; Costa, Manoel Luís

    2015-01-01

    In vitro studies show that cholesterol is essential to myogenesis. We have been using zebrafish to overcome the limitations of the in vitro approach and to study the sub-cellular structures and processes involved during myogenesis. We use simvastatin—a drug widely used to prevent high levels of cholesterol and cardiovascular disease—during zebrafish skeletal muscle formation. Simvastatin is an efficient inhibitor of cholesterol synthesis that has various myotoxic consequences. Here, we employed simvastatin concentrations that cause either mild or severe morphological disturbances to observe changes in the cytoskeleton (intermediate filaments and microfilaments), extracellular matrix and adhesion markers by confocal microscopy. With low-dose simvastatin treatment, laminin was almost normal, and alpha-actinin was reduced in the myofibrils. With high simvastatin doses, laminin and vinculin were reduced and appeared discontinuous along the septa, with almost no myofibrils, and small amounts of desmin accumulating close to the septa. We also analyzed sub-cellular alterations in the embryos by electron microscopy, and demonstrate changes in embryo and somite size, septa shape, and in myofibril structure. These effects could be reversed by the addition of exogenous cholesterol. These results contribute to the understanding of the mechanisms of action of simvastatin in muscle cells in particular, and in the study of myogenesis in general. PMID:25786435

  11. Foods that are perceived as healthy or unhealthy differentially alter young women's state body image.

    PubMed

    Hayes, Jacqueline F; D'Anci, Kristen E; Kanarek, Robin B

    2011-10-01

    Body image can be influenced by day-to-day events, including food intake. The present study investigated the effects of foods typically perceived as "healthy" or "unhealthy" on state body image and mood. College-aged women were told the experiment was designed to assess the effects of food on cognition. Using a between-subjects design, participants consumed isocaloric amounts of foods perceived to be healthy (banana) or unhealthy (donut) or ate nothing. Next, participants completed three cognitive tasks. Prior to eating and following the cognitive tests, participants completed the BISS, POMS, the Figure Rating Scale, and the Restraint Scale. Body satisfaction decreased following intake of a donut, but was not altered in the other conditions. Depression scores significantly decreased after intake of either a donut or banana, but did not decrease in the no-food condition. Tension scores decreased significantly after consumption of a banana and in the no-food condition, but did not decrease following consumption of a donut. These results indicate that intake of a food that is perceived as unhealthy negatively affects state body image. PMID:21669241

  12. Cortisol differentially alters claudin isoforms in cultured puffer fish gill epithelia.

    PubMed

    Bui, Phuong; Bagherie-Lachidan, Mazdak; Kelly, Scott P

    2010-04-12

    A primary cultured gill epithelium from the puffer fish Tetraodon nigroviridis was developed to examine the corticosteroid regulation of claudin isoform mRNA abundance in fish gills. Preparations were composed of polygonal epithelial cells exhibiting concentric apical microridges and zonula occludens-1 immunoreactivity along cell margins. No evidence was found to indicate the presence of Na(+)-K(+)-ATPase-immunoreactive or mitochondria-rich cells in cultured preparations. Therefore, epithelia appear to be composed of gill pavement cells (PVCs) only. An RT-PCR profile of 12 salinity responsive gill claudin tight junction (TJ) proteins (Tncldn3a, -3c, -6, -8d, -10d, -10e, -11a, -23b, -27a, -27c, -32a, and -33b) revealed the absence of Tncldn6, -10d and -10e in cultured epithelia, suggesting that these isoforms are not associated with gill PVCs. Cortisol treatment of cultured epithelia dose-dependently increased or decreased mRNA abundance of select claudin isoforms. Transcript abundance of several claudin isoforms was unaffected by cortisol treatment. These data provide evidence for the cell specific distribution of claudins in fish gills and suggest that heterogeneous alterations in the abundance of select claudin isoforms contribute to the corticosteroid regulation of gill permeability. PMID:19969041

  13. Thermal acclimation of interactions: differential responses to temperature change alter predator–prey relationship

    PubMed Central

    Grigaltchik, Veronica S.; Ward, Ashley J. W.; Seebacher, Frank

    2012-01-01

    Different species respond differently to environmental change so that species interactions cannot be predicted from single-species performance curves. We tested the hypothesis that interspecific difference in the capacity for thermal acclimation modulates predator–prey interactions. Acclimation of locomotor performance in a predator (Australian bass, Macquaria novemaculeata) was qualitatively different to that of its prey (eastern mosquitofish, Gambusia holbrooki). Warm (25°C) acclimated bass made more attacks than cold (15°C) acclimated fish regardless of acute test temperatures (10–30°C), and greater frequency of attacks was associated with increased prey capture success. However, the number of attacks declined at the highest test temperature (30°C). Interestingly, escape speeds of mosquitofish during predation trials were greater than burst speeds measured in a swimming arena, whereas attack speeds of bass were lower than burst speeds. As a result, escape speeds of mosquitofish were greater at warm temperatures (25°C and 30°C) than attack speeds of bass. The decline in the number of attacks and the increase in escape speed of prey means that predation pressure decreases at high temperatures. We show that differential thermal responses affect species interactions even at temperatures that are within thermal tolerance ranges. This thermal sensitivity of predator–prey interactions can be a mechanism by which global warming affects ecological communities. PMID:22859598

  14. Altered retinal cell differentiation in the AP-3 delta mutant (Mocha) mouse.

    PubMed

    Baguma-Nibasheka, Mark; Kablar, Boris

    2009-11-01

    Adaptor-related protein complex 3 delta 1 (Ap3d1) encodes the delta 1 subunit of an adaptor protein regulating intracellular vesicle-mediated transport, and the Ap3d-deletion mutant (Mocha) mouse undergoes rapid photoreceptor degeneration leading to blindness soon after birth. Previous microarray analysis revealed Ap3d down-regulation in the retina of mouse embryos specifically lacking cholinergic amacrine cells as a result of the absence of skeletal musculature. To investigate the role of Ap3d in the determination of retinal cell fate, the present study examined retinal morphology in newborn Ap3d-/- mice. The Ap3d-/- retina showed a complete absence of cholinergic amacrine cells and a decrease in parvalbumin-expressing amacrine cells and syntaxin- and VC1.1-expressing amacrine precursor cells, but had a normal number of cell layers and number of cells in each layer with no detectable difference in cell proliferation or apoptosis. These findings indicate that, despite having no apparent effect on the basic spatial organization of the retina at this stage of development, Ap3d could be involved in the regulation of progenitor cell competence and the eventual ratio of resulting differentiated cells. Finding the mouse mutant which phenocopies the eye defect seen in fetuses with no striated muscle was accomplished by the Systematic Subtractive Microarray Analysis Approach (SSMAA), explained in the discussion section. PMID:19631730

  15. Curcumin inhibits cellular condensation and alters microfilament organization during chondrogenic differentiation of limb bud mesenchymal cells.

    PubMed

    Kim, Dong Kyun; Kim, Song Ja; Kang, Shin Sung; Jin, Eun Jung

    2009-09-30

    Curcumin is a well known natural polyphenol product isolated from the rhizome of the plant Curcuma longa, anti-inflammatory agent for arthritis by inhibiting synthesis of inflammatory prostaglandins. However, the mechanisms by which curcumin regulates the functions of chondroprogenitor, such as proliferation, precartilage condensation, cytoskeletal organization or overall chondrogenic behavior, are largely unknown. In the present report, we investigated the effects and signaling mechanism of curcumin on the regulation of chondrogenesis. Treating chick limb bud mesenchymal cells with curcumin suppressed chondrogenesis by stimulating apoptotic cell death. It also inhibited reorganization of the actin cytoskeleton into a cortical pattern concomitant with rounding of chondrogenic competent cells and down-regulation of integrin beta1 and focal adhesion kinase (FAK) phosphorylation. Curcumin suppressed the phosphorylation of Akt leading to Akt inactivation. Activation of Akt by introducing a myristoylated, constitutively active form of Akt reversed the inhibitory actions of curcumin during chondrogenesis. In summary, for the first time, we describe biological properties of curcumin during chondrogenic differentiation of chick limb bud mesenchymal cells. Curcumin suppressed chondrogenesis by stimulating apoptotic cell death and down-regulating integrin-mediated reorganization of actin cytoskeleton via modulation of Akt signaling. PMID:19478554

  16. Altered feeding differentially regulates circadian rhythms and energy metabolism in liver and muscle of rats.

    PubMed

    Reznick, Jane; Preston, Elaine; Wilks, Donna L; Beale, Susan M; Turner, Nigel; Cooney, Gregory J

    2013-01-01

    Energy metabolism follows a diurnal pattern responding to the light/dark cycle and food availability. This study investigated the impact of restricting feeding to the daylight hours and feeding a high fat diet on circadian clock (bmal1, dbp, tef and e4bp4) and metabolic (pepck, fas, ucp3, pdk4) gene expression and markers of energy metabolism in muscle and liver of rats. The results show that in chow-fed rats switched to daylight feeding, the peak diurnal expression of genes in liver was shifted by 6-12h while expression of these genes in muscle remained in a similar phase to rats feeding ad libitum. High fat feeding during the daylight hours had limited effect on clock gene expression in liver or muscle but shifted the peak expression of metabolic genes (pepck, fas) in liver by 6-12h. The differential effects of daylight feeding on gene and protein expression in muscle and liver were accompanied by an 8% reduction in whole body energy expenditure, a 20-30% increased glycogen content during the light phase in muscle of day-fed rats and increased adipose tissue deposition per gram food consumed. These data demonstrate that a mismatch of feeding and light/dark cycle disrupts tissue metabolism in muscle with significant consequences for whole body energy homeostasis. PMID:22952003

  17. Exposure to zearalenone mycotoxin alters in vitro porcine intestinal epithelial cells by differential gene expression.

    PubMed

    Taranu, Ionelia; Braicu, Cornelia; Marin, Daniela Eliza; Pistol, Gina Cecilia; Motiu, Monica; Balacescu, Loredana; Beridan Neagoe, Ioana; Burlacu, Radu

    2015-01-01

    The gut represents the main route of intoxication with mycotoxins. To evaluate the effect and the underlying molecular changes that occurred when the intestine is exposed to zearalenone, a Fusarium sp mycotoxin, porcine epithelial cells (IPEC-1) were treated with 10μM of ZEA for 24h and analysed by microarray using Gene Spring GX v.11.5. Our results showed that 10μM of ZEA did not affect cell viability, but can increase the expression of toll like receptors (TLR1-10) and of certain cytokines involved in inflammation (TNF-α, IL-1β, IL-6, IL-8, MCP-1, IL-12p40, CCL20) or responsible for the recruitment of immune cells (IL-10, IL-18). Microarray results identified 190 genes significantly and differentially expressed, of which 70% were up-regulated. ZEA determined the over expression of ITGB5 gene, essential against the attachment and adhesion of ETEC to porcine jejunal cells and of TFF2 implicated in mucosal protection. An up-regulation of glutathione peroxidase enzymes (GPx6, GPx2, GPx1) was also observed. Upon ZEA challenge, genes like GTF3C4 responsible for the recruitment of polymerase III and initiation of tRNA transcription in eukaryotes and STAT5B were significantly higher induced. The up-regulation of CD97 gene and the down-regulation of tumour suppressor genes (DKK-1, PCDH11X and TC531386) demonstrates the carcinogenic potential of ZEA. PMID:25455459

  18. Low-dose photon irradiation alters cell differentiation via activation of hIK channels.

    PubMed

    Roth, Bastian; Gibhardt, Christine S; Becker, Patrick; Gebhardt, Manuela; Knoop, Jan; Fournier, Claudia; Moroni, Anna; Thiel, Gerhard

    2015-08-01

    To understand the impact of ionizing irradiation from diagnostics and radiotherapy on cells, we examined K(+) channel activity before and immediately after exposing cells to X-rays. Already, low dose in the cGy range caused in adenocarcinoma A549 cells within minutes a hyperpolarization following activation of the human intermediate-conductance Ca(2+)-activated K(+) channel (hIK). The response was specific for cells, which functionally expressed hIK channels and in which hIK activity was low before irradiation. HEK293 cells, which do not respond to X-ray irradiation, accordingly develop a sensitivity to this stress after heterologous expression of hIK channels. The data suggest that hIK activation involves a Ca(2+)-mediated signaling cascade because channel activation is suppressed by a strong cytosolic Ca(2+) buffer. The finding that an elevation of H2O2 causes an increase in the concentration of cytosolic Ca(2+) suggests that radicals, which emerge early in response to irradiation, trigger this Ca(2+) signaling cascade. Inhibition of hIK channels by specific blockers clotrimazole and TRAM-34 slowed cell proliferation and migration in "wound" scratch assays; ionizing irradiation, in turn, stimulated the latter process presumably via its activation of the hIK channels. These data stress an indirect radiosensitivity of hIK channels with an impact on cell differentiation. PMID:25277267

  19. Differential spectral power alteration following acupuncture at different designated places revealed by magnetoencephalography

    NASA Astrophysics Data System (ADS)

    You, Youbo; Bai, Lijun; Dai, Ruwei; Xue, Ting; Zhong, Chongguang; Liu, Zhenyu; Wang, Hu; Feng, Yuanyuan; Wei, Wenjuan; Tian, Jie

    2012-03-01

    As an ancient therapeutic technique in Traditional Chinese Medicine, acupuncture has been used increasingly in modern society to treat a range of clinical conditions as an alternative and complementary therapy. However, acupoint specificity, lying at the core of acupuncture, still faces many controversies. Considering previous neuroimaging studies on acupuncture have mainly employed functional magnetic resonance imaging, which only measures the secondary effect of neural activity on cerebral metabolism and hemodynamics, in the current study, we adopted an electrophysiological measurement technique named magnetoencephalography (MEG) to measure the direct neural activity. 28 healthy college students were recruited in this study. We filtered MEG data into 5 consecutive frequency bands (delta, theta, alpha, beta and gamma band) and grouped 140 sensors into 10 main brain regions (left/right frontal, central, temporal, parietal and occipital regions). Fast Fourier Transformation (FFT) based spectral analysis approach was further performed to explore the differential band-limited power change patterns of acupuncture at Stomach Meridian 36 (ST36) using a nearby nonacupoint (NAP) as control condition. Significantly increased delta power and decreased alpha as well as beta power in bilateral frontal ROIs were observed following stimulation at ST36. Compared with ST36, decreased alpha power in left and right central, right parietal as well as right temporal ROIs were detected in NAP group. Our research results may provide additional evidence for acupoint specificity.

  20. Neuronal Cell Death Induced by Mechanical Percussion Trauma in Cultured Neurons is not Preceded by Alterations in Glucose, Lactate and Glutamine Metabolism.

    PubMed

    Jayakumar, A R; Bak, L K; Rama Rao, K V; Waagepetersen, H S; Schousboe, A; Norenberg, M D

    2016-02-01

    Traumatic brain injury (TBI) is a devastating neurological disorder that usually presents in acute and chronic forms. Brain edema and associated increased intracranial pressure in the early phase following TBI are major consequences of acute trauma. On the other hand, neuronal injury, leading to neurobehavioral and cognitive impairments, that usually develop months to years after single or repetitive episodes of head trauma, are major consequences of chronic TBI. The molecular mechanisms responsible for TBI-induced injury, however, are unclear. Recent studies have suggested that early mitochondrial dysfunction and subsequent energy failure play a role in the pathogenesis of TBI. We therefore examined whether oxidative metabolism of (13)C-labeled glucose, lactate or glutamine is altered early following in vitro mechanical percussion-induced trauma (5 atm) to neurons (4-24 h), and whether such events contribute to the development of neuronal injury. Cell viability was assayed using the release of the cytoplasmic enzyme lactate dehydrogenase (LDH), together with fluorescence-based cell staining (calcein and ethidium homodimer-1 for live and dead cells, respectively). Trauma had no effect on the LDH release in neurons from 1 to 18 h. However, a significant increase in LDH release was detected at 24 h after trauma. Similar findings were identified when traumatized neurons were stained with fluorescent markers. Additionally (13)C-labeling of glutamate showed a small, but statistically significant decrease at 14 h after trauma. However, trauma had no effect on the cycling ratio of the TCA cycle at any time-period examined. These findings indicate that trauma does not cause a disturbance in oxidative metabolism of any of the substrates used for neurons. Accordingly, such metabolic disturbance does not appear to contribute to the neuronal death in the early stages following trauma. PMID:26729365

  1. Differential alterations of resting-state functional connectivity in generalized anxiety disorder and panic disorder.

    PubMed

    Cui, Huiru; Zhang, Jie; Liu, Yicen; Li, Qingwei; Li, Hui; Zhang, Lanlan; Hu, Qiang; Cheng, Wei; Luo, Qiang; Li, Jianqi; Li, Wei; Wang, Jijun; Feng, Jianfeng; Li, Chunbo; Northoff, Georg

    2016-04-01

    Generalized anxiety disorder (GAD) and panic disorder (PD) are most common anxiety disorders with high lifetime prevalence while the pathophysiology and disease-specific alterations still remain largely unclear. Few studies have taken a whole-brain perspective in the functional connectivity (FC) analysis of these two disorders in resting state. It limits the ability to identify regionally and psychopathologically specific network abnormalities with their subsequent use as diagnostic marker and novel treatment strategy. The whole brain FC using a novel FC metric was compared, that is, scaled correlation, which they demonstrated to be a reliable FC statistics, but have higher statistical power in two-sample t-test of whole brain FC analysis. About 21 GAD and 18 PD patients were compared with 22 matched control subjects during resting-state, respectively. It was found that GAD patients demonstrated increased FC between hippocampus/parahippocampus and fusiform gyrus among the most significantly changed FC, while PD was mainly associated with greater FC between somatosensory cortex and thalamus. Besides such regional specificity, it was observed that psychopathological specificity in that the disrupted FC pattern in PD and GAD correlated with their respective symptom severity. The findings suggested that the increased FC between hippocampus/parahippocampus and fusiform gyrus in GAD were mainly associated with a fear generalization related neural circuit, while the greater FC between somatosensory cortex and thalamus in PD were more likely linked to interoceptive processing. Due to the observed regional and psychopathological specificity, their findings bear important clinical implications for the potential treatment strategy. Hum Brain Mapp 37:1459-1473, 2016. © 2016 Wiley Periodicals, Inc. PMID:26800659

  2. Differential alterations of cortical glutamatergic binding sites in senile dementia of the Alzheimer type

    SciTech Connect

    Chalmers, D.T.; Dewar, D.; Graham, D.I.; Brooks, D.N.; McCulloch, J. )

    1990-02-01

    Involvement of cortical glutamatergic mechanisms in senile dementia of the Alzheimer type (SDAT) has been investigated with quantitative ligand-binding autoradiography. The distribution and density of Na(+)-dependent glutamate uptake sites and glutamate receptor subtypes--kainate, quisqualate, and N-methyl-D-aspartate--were measured in adjacent sections of frontal cortex obtained postmortem from six patients with SDAT and six age-matched controls. The number of senile plaques was determined in the same brain region. Binding of D-(3H)aspartate to Na(+)-dependent uptake sites was reduced by approximately 40% throughout SDAT frontal cortex relative to controls, indicating a general loss of glutamatergic presynaptic terminals. (3H)Kainate receptor binding was significantly increased by approximately 70% in deep layers of SDAT frontal cortex compared with controls, whereas this binding was unaltered in superficial laminae. There was a positive correlation (r = 0.914) between kainate binding and senile plaque number in deep cortical layers. Quisqualate receptors, as assessed by 2-amino-3-hydroxy-5-(3H)methylisoxazole-4-propionic acid binding, were unaltered in SDAT frontal cortex compared with controls. There was a small reduction (25%) in N-methyl-D-aspartate-sensitive (3H)glutamate binding only in superficial cortical layers of SDAT brains relative to control subjects. (3H)Glutamate binding in SDAT subjects was unrelated to senile plaque number in superficial cortical layers (r = 0.104). These results indicate that in the presence of cortical glutamatergic terminal loss in SDAT plastic alterations occur in some glutamate receptor subtypes but not in others.

  3. Anacardic Acid, Salicylic Acid, and Oleic Acid Differentially Alter Cellular Bioenergetic Function in Breast Cancer Cells.

    PubMed

    Radde, Brandie N; Alizadeh-Rad, Negin; Price, Stephanie M; Schultz, David J; Klinge, Carolyn M

    2016-11-01

    Anacardic acid is a dietary and medicinal phytochemical that inhibits breast cancer cell proliferation and uncouples oxidative phosphorylation (OXPHOS) in isolated rat liver mitochondria. Since mitochondrial-targeted anticancer therapy (mitocans) may be useful in breast cancer, we examined the effect of anacardic acid on cellular bioenergetics and OXPHOS pathway proteins in breast cancer cells modeling progression to endocrine-independence: MCF-7 estrogen receptor α (ERα)+ endocrine-sensitive; LCC9 and LY2 ERα+, endocrine-resistant, and MDA-MB-231 triple negative breast cancer (TNBC) cells. At concentrations similar to cell proliferation IC50 s, anacardic acid reduced ATP-linked oxygen consumption rate (OCR), mitochondrial reserve capacity, and coupling efficiency while increasing proton leak, reflecting mitochondrial toxicity which was greater in MCF-7 compared to endocrine-resistant and TNBC cells. These results suggest tolerance in endocrine-resistant and TNBC cells to mitochondrial stress induced by anacardic acid. Since anacardic acid is an alkylated 2-hydroxybenzoic acid, the effects of salicylic acid (SA, 2-hydroxybenzoic acid moiety) and oleic acid (OA, monounsaturated alkyl moiety) were tested. SA inhibited whereas OA stimulated cell viability. In contrast to stimulation of basal OCR by anacardic acid (uncoupling effect), neither SA nor OA altered basal OCR- except OA inhibited basal and ATP-linked OCR, and increased ECAR, in MDA-MB-231 cells. Changes in OXPHOS proteins correlated with changes in OCR. Overall, neither the 2-hydroxybenzoic acid moiety nor the monounsaturated alky moiety of anacardic acid is solely responsible for the observed mitochondria-targeted anticancer activity in breast cancer cells and hence both moieties are required in the same molecule for the observed effects. J. Cell. Biochem. 117: 2521-2532, 2016. © 2016 Wiley Periodicals, Inc. PMID:26990649

  4. Altered melanocyte differentiation and retinal pigmented epithelium transdifferentiation induced by Mash1 expression in pigment cell precursors.

    PubMed

    Lanning, Jessica L; Wallace, Jaclyn S; Zhang, Deming; Diwakar, Ganesh; Jiao, Zhongxian; Hornyak, Thomas J

    2005-10-01

    Transcription factor genes governing pigment cell development that are associated with spotting mutations in mice include members of several structural transcription factor classes but not members of the basic helix-loop-helix (bHLH) class, important for neurogenesis and myogenesis. To determine the effects of bHLH factor expression on pigment cell development, the neurogenic bHLH factor Mash1 was expressed early in pigment cell development in transgenic mice from the dopachrome tautomerase (Dct) promoter. Dct:Mash1 transgenic founders exhibit variable microphthalmia and patchy coat color hypopigmentation. Transgenic F1 mice exhibit microphthalmia with complete coat color dilution. Marker analysis demonstrates that Mash1 expression in the retinal pigmented epithelium (RPE) initiates neurogenesis in this cell layer, whereas expression in remaining neural crest-derived melanocytes alters their differentiation, in part by profoundly downregulating expression of the p (pink-eyed dilution) gene, while maintaining their cell fate. The effects of transcriptional perturbation of pigment cell precursors by Mash1 further highlight differences between pigment cells of distinct developmental origins, and suggest a mechanism for the alteration of melanogenesis to result in marked coat color dilution. PMID:16185282

  5. Pyrethroids Differentially Alter Voltage-Gated Sodium Channels from the Honeybee Central Olfactory Neurons

    PubMed Central

    Kadala, Aklesso; Charreton, Mercedes; Jakob, Ingrid; Cens, Thierry; Rousset, Matthieu; Chahine, Mohamed; Le Conte, Yves; Charnet, Pierre; Collet, Claude

    2014-01-01

    The sensitivity of neurons from the honey bee olfactory system to pyrethroid insecticides was studied using the patch-clamp technique on central ‘antennal lobe neurons’ (ALNs) in cell culture. In these neurons, the voltage-dependent sodium currents are characterized by negative potential for activation, fast kinetics of activation and inactivation, and the presence of cumulative inactivation during train of depolarizations. Perfusion of pyrethroids on these ALN neurons submitted to repetitive stimulations induced (1) an acceleration of cumulative inactivation, and (2) a marked slowing of the tail current recorded upon repolarization. Cypermethrin and permethrin accelerated cumulative inactivation of the sodium current peak in a similar manner and tetramethrin was even more effective. The slow-down of channel deactivation was markedly dependent on the type of pyrethroid. With cypermethrin, a progressive increase of the tail current amplitude along with successive stimulations reveals a traditionally described use-dependent recruitment of modified sodium channels. However, an unexpected decrease in this tail current was revealed with tetramethrin. If one considers the calculated percentage of modified channels as an index of pyrethroids effects, ALNs are significantly more susceptible to tetramethrin than to permethrin or cypermethrin for a single depolarization, but this difference attenuates with repetitive activity. Further comparison with peripheral neurons from antennae suggest that these modifications are neuron type specific. Modeling the sodium channel as a multi-state channel with fast and slow inactivation allows to underline the effects of pyrethroids on a set of rate constants connecting open and inactivated conformations, and give some insights to their specificity. Altogether, our results revealed a differential sensitivity of central olfactory neurons to pyrethroids that emphasize the ability for these compounds to impair detection and processing

  6. Truncated DNMT3B isoform DNMT3B7 suppresses growth, induces differentiation, and alters DNA methylation in human neuroblastoma

    PubMed Central

    Ostler, Kelly R.; Yang, Qiwei; Looney, Timothy J.; Zhang, Li; Vasanthakumar, Aparna; Tian, Yufeng; Kocherginsky, Masha; Raimondi, Stacey L.; DeMaio, Jessica G.; Salwen, Helen R.; Gu, Song; Chlenski, Alexandre; Naranjo, Arlene; Gill, Amy; Peddinti, Radhika; Lahn, Bruce T.; Cohn, Susan L.; Godley, Lucy A.

    2012-01-01

    Epigenetic changes in pediatric neuroblastoma may contribute to the aggressive pathophysiology of this disease, but little is known about the basis for such changes. In this study, we examined a role for the DNA methyltransferase DNMT3B, in particular, the truncated isoform DNMT3B7 which is generated frequently in cancer. To investigate if aberrant DNMT3B transcripts alter DNA methylation, gene expression, and phenotypic character in neuroblastoma, we measured DNMT3B expression in primary tumors. Higher levels of DNMT3B7 were detected in differentiated ganglioneuroblastomas compared to undifferentiated neuroblastomas, suggesting that expression of DNMT3B7 may induce a less aggressive clinical phenotype. To test this hypothesis, we investigated the effects of enforced DNMT3B7 expression in neuroblastoma cells, finding a significant inhibition of cell proliferation in vitro and angiogenesis and tumor growth in vivo. DNMT3B7-positive cells had higher levels of total genomic methylation and a dramatic decrease in expression of the FOS and JUN family members that comprise AP1 transcription factors. Consistent with an established antagonistic relationship between AP1 expression and retinoic acid receptor activity, increased differentiation was seen in the DNMT3B7-expressing neuroblastoma cells following treatment with all-trans retinoic acid (ATRA) compared to controls. Our results indicate that DNMT3B7 modifies the epigenome in neuroblastoma cells to induce changes in gene expression, inhibit tumor growth, and increase sensitivity to ATRA. PMID:22815530

  7. Retinoic Acid Induces Embryonic Stem Cell Differentiation by Altering Both Encoding RNA and microRNA Expression

    PubMed Central

    Yu, Mengying; Wu, Haibo; Ai, Zhiying; Wu, Yongyan; Liu, Hongliang; Du, Juan; Guo, Zekun; Zhang, Yong

    2015-01-01

    Retinoic acid (RA) is a vitamin A metabolite that is essential for early embryonic development and promotes stem cell neural lineage specification; however, little is known regarding the impact of RA on mRNA transcription and microRNA levels on embryonic stem cell differentiation. Here, we present mRNA microarray and microRNA high-output sequencing to clarify how RA regulates gene expression. Using mRNA microarray analysis, we showed that RA repressed pluripotency-associated genes while activating ectoderm markers in mouse embryonic stem cells (mESCs). Moreover, RA modulated the DNA methylation of mESCs by altering the expression of epigenetic-associated genes such as Dnmt3b and Dnmt3l. Furthermore, H3K4me2, a pluripotent histone modification, was repressed by RA stimulation. From microRNA sequence data, we identified two downregulated microRNAs, namely, miR-200b and miR-200c, which regulated the pluripotency of stem cells. We found that miR-200b or miR-200c deficiency suppressed the expression of pluripotent genes, including Oct4 and Nanog, and activated the expression of the ectodermal marker gene Nestin. These results demonstrate that retinoid induces mESCs to differentiate by regulating miR-200b/200c. Our findings provide the landscapes of mRNA and microRNA gene networks and indicate the crucial role of miR-200b/200c in the RA-induced differentiation of mESCs. PMID:26162091

  8. Intrafetal glucose infusion alters glucocorticoid signaling and reduces surfactant protein mRNA expression in the lung of the late-gestation sheep fetus.

    PubMed

    McGillick, Erin V; Morrison, Janna L; McMillen, I Caroline; Orgeig, Sandra

    2014-09-01

    Increased circulating fetal glucose and insulin concentrations are potential inhibitors of fetal lung maturation and may contribute to the pathogenesis of respiratory distress syndrome (RDS) in infants of diabetic mothers. In this study, we examined the effect of intrafetal glucose infusion on mRNA expression of glucose transporters, insulin-like growth factor signaling, glucocorticoid regulatory genes, and surfactant proteins in the lung of the late-gestation sheep fetus. The numerical density of the cells responsible for producing surfactant was determined using immunohistochemistry. Glucose infusion for 10 days did not affect mRNA expression of glucose transporters or IGFs but did decrease IGF-1R expression. There was reduced mRNA expression of the glucocorticoid-converting enzyme HSD11B-1 and the glucocorticoid receptor, potentially reducing glucocorticoid responsiveness in the fetal lung. Furthermore, surfactant protein (SFTP) mRNA expression was reduced in the lung following glucose infusion, while the number of SFTP-B-positive cells remained unchanged. These findings suggest the presence of a glucocorticoid-mediated mechanism regulating delayed maturation of the surfactant system in the sheep fetus following glucose infusion and provide evidence for the link between abnormal glycemic control during pregnancy and the increased risk of RDS in infants of uncontrolled diabetic mothers. PMID:24990855

  9. Necator americanus Infection: A Possible Cause of Altered Dendritic Cell Differentiation and Eosinophil Profile in Chronically Infected Individuals

    PubMed Central

    Fujiwara, Ricardo T.; Cançado, Guilherme G. L.; Freitas, Paula A.; Santiago, Helton C.; Massara, Cristiano Lara; dos Santos Carvalho, Omar; Corrêa-Oliveira, Rodrigo; Geiger, Stefan M.; Bethony, Jeffrey

    2009-01-01

    Background Hookworms survive for several years (5 to 7 years) in the host lumen, inducing a robust but largely ineffective immune response. Among the most striking aspects of the immune response to hookworm (as with many other helminths) is the ablation of parasite-specific T cell proliferative response (hyporesponsiveness). While the role of the adaptive immune response in human helminth infection has been well investigated, the role of the innate immune responses (e.g., dendritic cells and eosinophils) has received less attention and remains to be clearly elucidated. Methodology/Principal Findings We report on the differentiation/maturation of host dendritic cells in vitro and the eosinophil activation/function associated with human hookworm infection. Mature DCs (mDCs) from Necator americanus (Necator)–infected individuals showed an impaired differentiation process compared to the mDCs of non-infected individuals, as evidenced by the differential expression of CD11c and CD14. These same hookworm-infected individuals also presented significantly down-regulated expression of CD86, CD1a, HLA-ABC, and HLA-DR. The lower expression of co-stimulatory and antigen presentation molecules by hookworm-infected–derived mDCs was further evidenced by their reduced ability to induce cell proliferation. We also showed that this alternative DC differentiation is partially induced by excreted-secreted hookworm products. Conversely, eosinophils from the same individuals showed a highly activated status, with an upregulation of major cell surface markers. Antigen-pulsed eosinophils from N. americanus–infected individuals induced significant cell proliferation of autologous PBMCs, when compared to non-infected individuals. Conclusion Chronic N. americanus infection alters the host's innate immune response, resulting in a possible modulation of the maturation process of DCs, a functional change that may diminish their ability for antigen presentation and thus contribute to the

  10. A programmable synthetic lineage-control network that differentiates human IPSCs into glucose-sensitive insulin-secreting beta-like cells.

    PubMed

    Saxena, Pratik; Heng, Boon Chin; Bai, Peng; Folcher, Marc; Zulewski, Henryk; Fussenegger, Martin

    2016-01-01

    Synthetic biology has advanced the design of standardized transcription control devices that programme cellular behaviour. By coupling synthetic signalling cascade- and transcription factor-based gene switches with reverse and differential sensitivity to the licensed food additive vanillic acid, we designed a synthetic lineage-control network combining vanillic acid-triggered mutually exclusive expression switches for the transcription factors Ngn3 (neurogenin 3; OFF-ON-OFF) and Pdx1 (pancreatic and duodenal homeobox 1; ON-OFF-ON) with the concomitant induction of MafA (V-maf musculoaponeurotic fibrosarcoma oncogene homologue A; OFF-ON). This designer network consisting of different network topologies orchestrating the timely control of transgenic and genomic Ngn3, Pdx1 and MafA variants is able to programme human induced pluripotent stem cells (hIPSCs)-derived pancreatic progenitor cells into glucose-sensitive insulin-secreting beta-like cells, whose glucose-stimulated insulin-release dynamics are comparable to human pancreatic islets. Synthetic lineage-control networks may provide the missing link to genetically programme somatic cells into autologous cell phenotypes for regenerative medicine. PMID:27063289

  11. A programmable synthetic lineage-control network that differentiates human IPSCs into glucose-sensitive insulin-secreting beta-like cells

    PubMed Central

    Saxena, Pratik; Heng, Boon Chin; Bai, Peng; Folcher, Marc; Zulewski, Henryk; Fussenegger, Martin

    2016-01-01

    Synthetic biology has advanced the design of standardized transcription control devices that programme cellular behaviour. By coupling synthetic signalling cascade- and transcription factor-based gene switches with reverse and differential sensitivity to the licensed food additive vanillic acid, we designed a synthetic lineage-control network combining vanillic acid-triggered mutually exclusive expression switches for the transcription factors Ngn3 (neurogenin 3; OFF-ON-OFF) and Pdx1 (pancreatic and duodenal homeobox 1; ON-OFF-ON) with the concomitant induction of MafA (V-maf musculoaponeurotic fibrosarcoma oncogene homologue A; OFF-ON). This designer network consisting of different network topologies orchestrating the timely control of transgenic and genomic Ngn3, Pdx1 and MafA variants is able to programme human induced pluripotent stem cells (hIPSCs)-derived pancreatic progenitor cells into glucose-sensitive insulin-secreting beta-like cells, whose glucose-stimulated insulin-release dynamics are comparable to human pancreatic islets. Synthetic lineage-control networks may provide the missing link to genetically programme somatic cells into autologous cell phenotypes for regenerative medicine. PMID:27063289

  12. Differential effects of "Advanced glycation endproducts" and beta-amyloid peptide on glucose utilization and ATP levels in the neuronal cell line SH-SY5Y.

    PubMed

    Kuhla, B; Loske, C; Garcia De Arriba, S; Schinzel, R; Huber, J; Münch, G

    2004-03-01

    Beta-amyloid peptide (Abeta) and "Advanced glycation endproducts" (AGEs) are components of the senile plaques in Alzheimer's disease patients. It has been proposed that both AGEs and Abeta exert many of their effects, which include the upregulation of pro-inflammatory cytokines, through RAGE ("receptor for advanced glycation endproducts"). To investigate whether Abeta and AGEs cause similar or identical effects on cell survival and energy metabolism, we have compared the effects of a model-AGE and Abeta on cell viability, ATP level, glucose consumption and lactate production in the neuroblastoma cell line SH-SY5Y. The results show that AGEs and Abeta increase glucose consumption and decrease ATP levels in a dose dependent manner. Furthermore, both compounds decrease mitochondrial activity measured by the MTT assay. However, only AGEs decrease the number of cells and significantly increase lactate production. These data indicate that both AGEs and Abeta can cause differential disturbances in neuronal metabolism, which may contribute to the pathophysiological findings in Alzheimer's disease. However, their signalling pathways are apparently quite distinct, a fact which should stimulate a more detailed investigation in this field, e.g. for the purpose of a rational design of potential "neuroprotective" RAGE antagonists. PMID:14991463

  13. Loss of function of PTEN alters the relationship between glucose concentration and cell proliferation, increases glycolysis, and sensitizes cells to 2-deoxyglucose.

    PubMed

    Blouin, Marie-José; Zhao, Yunhua; Zakikhani, Mahvash; Algire, Carolyn; Piura, Esther; Pollak, Michael

    2010-03-28

    PTEN loss of function enhances proliferation, but effects on cellular energy metabolism are less well characterized. We used an inducible PTEN expression vector in a PTEN-null glioma cell line to examine this issue. While proliferation of PTEN-positive cells was insensitive to increases in glucose concentration beyond 2.5mM, PTEN-null cells significantly increased proliferation with increasing glucose concentration across the normal physiologic range to approximately 10mM, coinciding with a shift to glycolysis and "glucose addiction". This demonstrates that the impact of loss of function of PTEN is modified by glucose concentration, and may be relevant to epidemiologic results linking hyperglycemia to cancer risk and cancer mortality. PMID:19744772

  14. Three dissimilar high fat diets differentially regulate lipid and glucose metabolism in obesity-resistant Slc:Wistar/ST rats.

    PubMed

    Hashimoto, Yoko; Yamada, Kazuyo; Tsushima, Hiromi; Miyazawa, Daisuke; Mori, Mayumi; Nishio, Koji; Ohkubo, Takeshi; Hibino, Hidehiko; Ohara, Naoki; Okuyama, Harumi

    2013-08-01

    Epidemiologic and ecologic studies suggest that dietary fat plays an important role in the development of obesity. Certain Wistar rat strains do not become obese when fed high-fat diets unlike others. In a preliminary study, we confirmed that Slc:Wistar/ST rats did not become obese when fed high-fat diets. The mechanisms governing the response of hepatic lipid-metabolizing enzymes to large quantities of dietary lipids consumed by obesity-resistant animals are unknown. The aim of the present study is to examine how obesity-resistant animals metabolize various types of high-fat diets and why they do not become obese. For this purpose, male Slc:Wistar/ST rats were fed a control low-fat diet (LS) or a high-fat diet containing fish oil (HF), soybean oil (HS), or lard (HL) for 4 weeks. We observed their phenotypes and determined lipid profiles in plasma and liver as well as mRNA expression levels in liver of genes related to lipid and glucose metabolism using DNA microarray and quantitative reverse transcriptase polymerase chain analyses. The body weights of all dietary groups were similar due to isocaloric intakes, whereas the weight of white adipose tissues in the LS group was significantly lower. The HF diet lowered plasma lipid levels by accelerated lipolysis in the peroxisomes and suppressed levels of very-low-density lipoprotein (VLDL) secretion. The HS diet promoted hepatic lipid accumulation by suppressed lipolysis in the peroxisomes and normal levels of VLDL secretion. The lipid profiles of rats fed the LS or HL diet were similar. The HL diet accelerated lipid and glucose metabolism. PMID:23807365

  15. Expression of Human NSAID Activated Gene 1 in Mice Leads to Altered Mammary Gland Differentiation and Impaired Lactation

    PubMed Central

    Binder, April K.; Kosak, Justin P.; Janhardhan, Kyathanahalli S.; Moser, Glenda; Eling, Thomas E.; Korach, Kenneth S.

    2016-01-01

    Transgenic mice expressing human non-steroidal anti-inflammatory drug activated gene 1 (NAG-1) have less adipose tissue, improved insulin sensitivity, lower insulin levels and are resistant to dietary induced obesity. The hNAG-1 expressing mice are more metabolically active with a higher energy expenditure. This study investigates female reproduction in the hNAG-1 transgenic mice and finds the female mice are fertile but have reduced pup survival after birth. Examination of the mammary glands in these mice suggests that hNAG-1 expressing mice have altered mammary epithelial development during pregnancy, including reduced occupancy of the fat pad and increased apoptosis via TUNEL positive cells on lactation day 2. Pups nursing from hNAG-1 expressing dams have reduced milk spots compared to pups nursing from WT dams. When CD-1 pups were cross-fostered with hNAG-1 or WT dams; reduced milk volume was observed in pups nursing from hNAG-1 dams compared to pups nursing from WT dams in a lactation challenge study. Milk was isolated from WT and hNAG-1 dams, and the milk was found to have secreted NAG-1 protein (approximately 25 ng/mL) from hNAG-1 dams. The WT dams had no detectable hNAG-1 in the milk. A decrease in non-esterified free fatty acids in the milk of hNAG-1 dams was observed. Altered milk composition suggests that the pups were receiving inadequate nutrients during perinatal development. To examine this hypothesis serum was isolated from pups and clinical chemistry points were measured. Male and female pups nursing from hNAG-1 dams had reduced serum triglyceride concentrations. Microarray analysis revealed that genes involved in lipid metabolism are differentially expressed in hNAG-1 mammary glands. Furthermore, the expression of Cidea/CIDEA that has been shown to regulate milk lipid secretion in the mammary gland was reduced in hNAG-1 mammary glands. This study suggests that expression of hNAG-1 in mice leads to impaired lactation and reduces pup survival due to

  16. Alterations in Energy/Redox Metabolism Induced by Mitochondrial and Environmental Toxins: A Specific Role for Glucose-6-Phosphate-Dehydrogenase and the Pentose Phosphate Pathway in Paraquat Toxicity

    PubMed Central

    2015-01-01

    Parkinson’s disease (PD) is a multifactorial disorder with a complex etiology including genetic risk factors, environmental exposures, and aging. While energy failure and oxidative stress have largely been associated with the loss of dopaminergic cells in PD and the toxicity induced by mitochondrial/environmental toxins, very little is known regarding the alterations in energy metabolism associated with mitochondrial dysfunction and their causative role in cell death progression. In this study, we investigated the alterations in the energy/redox-metabolome in dopaminergic cells exposed to environmental/mitochondrial toxins (paraquat, rotenone, 1-methyl-4-phenylpyridinium [MPP+], and 6-hydroxydopamine [6-OHDA]) in order to identify common and/or different mechanisms of toxicity. A combined metabolomics approach using nuclear magnetic resonance (NMR) and direct-infusion electrospray ionization mass spectrometry (DI-ESI-MS) was used to identify unique metabolic profile changes in response to these neurotoxins. Paraquat exposure induced the most profound alterations in the pentose phosphate pathway (PPP) metabolome. 13C-glucose flux analysis corroborated that PPP metabolites such as glucose-6-phosphate, fructose-6-phosphate, glucono-1,5-lactone, and erythrose-4-phosphate were increased by paraquat treatment, which was paralleled by inhibition of glycolysis and the TCA cycle. Proteomic analysis also found an increase in the expression of glucose-6-phosphate dehydrogenase (G6PD), which supplies reducing equivalents by regenerating nicotinamide adenine dinucleotide phosphate (NADPH) levels. Overexpression of G6PD selectively increased paraquat toxicity, while its inhibition with 6-aminonicotinamide inhibited paraquat-induced oxidative stress and cell death. These results suggest that paraquat “hijacks” the PPP to increase NADPH reducing equivalents and stimulate paraquat redox cycling, oxidative stress, and cell death. Our study clearly demonstrates that alterations

  17. THE FUNGICIDE PROCYMIDONE ALTERS SEXUAL DIFFERENTIATION IN THE MALE RAT BY ACTING AS AN ANDROGEN-RECEPTOR ANTAGONIST IN VIVO AND IN VITRO

    EPA Science Inventory

    The fungicide procymidone alters sexual differentiation in the male rat by acting as an androgen-receptor antagonist in vivo and in vitro.

    Ostby J, Kelce WR, Lambright C, Wolf CJ, Mann P, Gray LE Jr.

    Endocrinology Branch, National Health and Environmental Effects Re...

  18. Gentamicin differentially alters cellular metabolism of cochlear hair cells as revealed by NAD(P)H fluorescence lifetime imaging

    PubMed Central

    Zholudeva, Lyandysha V.; Ward, Kristina G.; Nichols, Michael G.; Smith, Heather Jensen

    2015-01-01

    Abstract. Aminoglycoside antibiotics are implicated as culprits of hearing loss in more than 120,000 individuals annually. Research has shown that the sensory cells, but not supporting cells, of the cochlea are readily damaged and/or lost after use of such antibiotics. High-frequency outer hair cells (OHCs) show a greater sensitivity to antibiotics than high- and low-frequency inner hair cells (IHCs). We hypothesize that variations in mitochondrial metabolism account for differences in susceptibility. Fluorescence lifetime microscopy was used to quantify changes in NAD(P)H in sensory and supporting cells from explanted murine cochleae exposed to mitochondrial uncouplers, inhibitors, and an ototoxic antibiotic, gentamicin (GM). Changes in metabolic state resulted in a redistribution of NAD(P)H between subcellular fluorescence lifetime pools. Supporting cells had a significantly longer lifetime than sensory cells. Pretreatment with GM increased NAD(P)H intensity in high-frequency sensory cells, as well as the NAD(P)H lifetime within IHCs. GM specifically increased NAD(P)H concentration in high-frequency OHCs, but not in IHCs or pillar cells. Variations in NAD(P)H intensity in response to mitochondrial toxins and GM were greatest in high-frequency OHCs. These results demonstrate that GM rapidly alters mitochondrial metabolism, differentially modulates cell metabolism, and provides evidence that GM-induced changes in metabolism are significant and greatest in high-frequency OHCs. PMID:25688541

  19. Trpm4 differentially regulates Th1 and Th2 function by altering calcium signaling and NFAT localization

    PubMed Central

    Weber, K. Scott; Hildner, Kai; Murphy, Kenneth M.; Allen, Paul M.

    2010-01-01

    T helper cell subsets have unique calcium (Ca2+) signals when activated with identical stimuli. The regulation of these Ca2+ signals and their correlation to the biological function of each T cell subset remains unclear. Trpm4 is a Ca2+-activated cation channel that we found is expressed at higher levels in Th2 cells compared to Th1 cells. Inhibition of Trpm4 expression increased Ca2+ influx and oscillatory levels in Th2 cells and decreased influx and oscillations in Th1 cells. This inhibition of Trpm4 expression also significantly altered T cell cytokine production and motility. Our experiments revealed that decreasing Trpm4 levels divergently regulates nuclear localization of NFATc1. Consistent with this, gene profiling did not show Trpm4 dependent transcriptional regulation and T-bet and GATA-3 levels remain identical. Thus, Trpm4 is expressed at different levels on T helper cells and plays a distinctive role in T cell function by differentially regulating Ca2+ signaling and NFATc1 localization. PMID:20656926

  20. Genomic profiling of Sézary Syndrome identifies alterations of key T-cell signaling and differentiation genes

    PubMed Central

    Wang, Linghua; Ni, Xiao; Covington, Kyle R.; Yang, Betty Y.; Shiu, Jessica; Zhang, Xiang; Xi, Liu; Meng, Qingchang; Langridge, Timothy; Drummond, Jennifer; Donehower, Lawrence A.; Doddapaneni, Harshavardhan; Muzny, Donna M.; Gibbs, Richard A.; Wheeler, David A.; Duvic, Madeleine

    2016-01-01

    Sézary Syndrome is a rare leukemic form of cutaneous T-cell lymphoma defined as erythroderma, adenopathy, and circulating atypical T-lymphocytes. It is rarely curable with poor prognosis. Here we present a multi-platform genomic analysis of 37 Sézary Syndrome patients that implicates dysregulation of the cell cycle checkpoint and T-cell signaling. Frequent somatic alterations were identified in TP53, CARD11, CCR4, PLCG1, CDKN2A, ARID1A, RPS6KA1, and ZEB1. Activating CCR4 and CARD11 mutations were detected in nearly a third of patients. ZEB1, a transcription repressor essential for T-cell differentiation, was deleted in over half of patients. IL32 and IL2RG were over-expressed in nearly all cases. Analysis of T-cell receptor Vβ and Vα expression revealed ongoing rearrangement of the receptors after the expansion of a malignant clone in one third of subjects. Our results demonstrate profound disruption of key signaling pathways in Sézary Syndrome and suggest potential targets for novel therapies. PMID:26551670

  1. Gentamicin differentially alters cellular metabolism of cochlear hair cells as revealed by NAD(P)H fluorescence lifetime imaging

    NASA Astrophysics Data System (ADS)

    Zholudeva, Lyandysha V.; Ward, Kristina G.; Nichols, Michael G.; Smith, Heather Jensen

    2015-05-01

    Aminoglycoside antibiotics are implicated as culprits of hearing loss in more than 120,000 individuals annually. Research has shown that the sensory cells, but not supporting cells, of the cochlea are readily damaged and/or lost after use of such antibiotics. High-frequency outer hair cells (OHCs) show a greater sensitivity to antibiotics than high- and low-frequency inner hair cells (IHCs). We hypothesize that variations in mitochondrial metabolism account for differences in susceptibility. Fluorescence lifetime microscopy was used to quantify changes in NAD(P)H in sensory and supporting cells from explanted murine cochleae exposed to mitochondrial uncouplers, inhibitors, and an ototoxic antibiotic, gentamicin (GM). Changes in metabolic state resulted in a redistribution of NAD(P)H between subcellular fluorescence lifetime pools. Supporting cells had a significantly longer lifetime than sensory cells. Pretreatment with GM increased NAD(P)H intensity in high-frequency sensory cells, as well as the NAD(P)H lifetime within IHCs. GM specifically increased NAD(P)H concentration in high-frequency OHCs, but not in IHCs or pillar cells. Variations in NAD(P)H intensity in response to mitochondrial toxins and GM were greatest in high-frequency OHCs. These results demonstrate that GM rapidly alters mitochondrial metabolism, differentially modulates cell metabolism, and provides evidence that GM-induced changes in metabolism are significant and greatest in high-frequency OHCs.

  2. Xenobiotics that affect oxidative phosphorylation alter differentiation of human adipose-derived stem cells at concentrations that are found in human blood

    PubMed Central

    Llobet, Laura; Toivonen, Janne M.; Montoya, Julio; Ruiz-Pesini, Eduardo; López-Gallardo, Ester

    2015-01-01

    ABSTRACT Adipogenesis is accompanied by differentiation of adipose tissue-derived stem cells to adipocytes. As part of this differentiation, biogenesis of the oxidative phosphorylation system occurs. Many chemical compounds used in medicine, agriculture or other human activities affect oxidative phosphorylation function. Therefore, these xenobiotics could alter adipogenesis. We have analyzed the effects on adipocyte differentiation of some xenobiotics that act on the oxidative phosphorylation system. The tested concentrations have been previously reported in human blood. Our results show that pharmaceutical drugs that decrease mitochondrial DNA replication, such as nucleoside reverse transcriptase inhibitors, or inhibitors of mitochondrial protein synthesis, such as ribosomal antibiotics, diminish adipocyte differentiation and leptin secretion. By contrast, the environmental chemical pollutant tributyltin chloride, which inhibits the ATP synthase of the oxidative phosphorylation system, can promote adipocyte differentiation and leptin secretion, leading to obesity and metabolic syndrome as postulated by the obesogen hypothesis. PMID:26398948

  3. Altered glucose metabolism rather than naive type 2 diabetes mellitus (T2DM) is related to vitamin D status in severe obesity

    PubMed Central

    2014-01-01

    Context The last decades have provided insights into vitamin D physiology linked to glucose homeostasis. Uncertainties remain in obesity due to its intrinsic effects on vitamin D and glucose tolerance. Objectives To assess the relationship between vitamin D and glucose abnormalities in severely obese individuals previously unknown to suffer from abnormal glucose metabolism. Setting Tertiary care centre. Patients 524 obese patients (50.3 ± 14.9 yrs; BMI, 47.7 ± 7.3 kg/m2) screened by OGTT, HbA1c and the lipid profile. Vitamin D status was assessed by 25(OH)D3, PTH and electrolyte levels. 25(OH)D3 deficiency/insufficiency were set at 20 and 30 ng/ml, respectively. All comparative and regression analyses were controlled for age, BMI and gender. Results The prevalence of vitamin D deficiency/insufficiency and secondary hyperparathyroidism were 95% and 50.8%, respectively. Normal glucose tolerance (NGT), impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) were found in 37.8%, 40.5% and 21.7% of cases, respectively. Large variations in metabolic parameters were seen across categories of vitamin D status, but the only significant differences were found for C-peptide, tryglicerides, LDL- and HDL-cholesterol levels (p < 0.05 for all). The prevalence of vitamin D deficiency was documented to be slightly but significantly more frequent in glucose-intolerant patients (IFG + IGT + T2DM) compared to the -normotolerant counterpart (87% vs. 80%, p < 0.05). In partial correlation analyses, there was no association between vitamin D levels and glucose-related markers but for HbA1c (r = −0.091, p < 0.05), and both basal and OGTT-stimulated insulin levels (r = 0.097 and r = 0.099; p < 0.05 for all). Vitamin D levels were also correlated to HDL-cholesterol (r = 0.13, p = 0.002). Multivariate regression analysis inclusive of vitamin D, age, BMI, gender and fat mass as

  4. Altered expression of uncoupling protein 2 in GLP-1-producing cells after chronic high glucose exposure: implications for the pathogenesis of diabetes mellitus.

    PubMed

    Urbano, Francesca; Filippello, Agnese; Di Pino, Antonino; Barbagallo, Davide; Di Mauro, Stefania; Pappalardo, Alessandro; Rabuazzo, Agata Maria; Purrello, Michele; Purrello, Francesco; Piro, Salvatore

    2016-04-01

    Glucagon-like peptide-1 (GLP-1) is a gut L-cell hormone that enhances glucose-stimulated insulin secretion. Several approaches that prevent GLP-1 degradation or activate the GLP-1 receptor are being used to treat type 2 diabetes mellitus (T2DM) patients. In T2DM, GLP-1 secretion has been suggested to be impaired, and this defect appears to be a consequence rather than a cause of impaired glucose homeostasis. However, although defective GLP-1 secretion has been correlated with insulin resistance, little is known about the direct effects of chronic high glucose concentrations, which are typical in diabetes patients, on GLP-1-secreting cell function. In the present study, we demonstrate that glucotoxicity directly affects GLP-1 secretion in GLUTag cells chronically exposed to high glucose. Our results indicate that this abnormality is associated with a decrease in ATP production due to the elevated expression of mitochondrial uncoupling protein 2 (UCP2). Furthermore, UCP2 inhibition using small interfering RNA (siRNA) and the application of glibenclamide, an ATP-sensitive potassium (KATP(+)) channel blocker, reverse the GLP-1 secretion defect induced by chronic high-glucose treatment. These results show that glucotoxicity diminishes the secretory responsiveness of GLP-1-secreting cells to acute glucose stimulation. We conclude that the loss of the incretin effect, as observed in T2DM patients, could at least partially depend on hyperglycemia, which is typical in diabetes patients. Such an understanding may not only provide new insight into diabetes complications but also ultimately contribute to the identification of novel molecular targets within intestinal L-cells for controlling and improving endogenous GLP-1 secretion. PMID:26739488

  5. ATP-Binding Cassette Transport System Involved in Regulation of Morphological Differentiation in Response to Glucose in Streptomyces griseus

    PubMed Central

    Seo, Jeong-Woo; Ohnishi, Yasuo; Hirata, Aiko; Horinouchi, Sueharu

    2002-01-01

    Streptomyces griseus NP4, which was derived by UV mutagenesis from strain IFO13350, showed a bald and wrinkled colony morphology in response to glucose. Mutant NP4 formed ectopic septa at intervals along substrate hyphae, and each of the compartments developed into a spore which was indistinguishable from an aerial spore in size, shape, and thickness of the spore wall and in susceptibility to lysozyme and heat. The ectopic spores of NP4 formed in liquid medium differed from “submerged spores” in lysozyme sensitivity. Shotgun cloning experiments with a library of the chromosomal DNA of the parental strain and mutant NP4 as the host gave rise to DNA fragments giving two different phenotypes; one complementing the bald phenotype of the host, and the other causing much severe wrinkled morphology in the host. Subcloning identified a gene (dasR) encoding a transcriptional repressor belonging to the GntR family that was responsible for the reversal of the bald phenotype and a gene (dasA) encoding a lipoprotein probably serving as a substrate-binding protein in an ATP-binding cassette (ABC) transport system that was responsible for the severe wrinkled morphology. These genes were adjacent but divergently encoded. Two genes, named dasB and dasC, encoding a membrane-spanning protein were present downstream of dasA, which suggested that dasRABC comprises a gene cluster for an ABC transporter, probably for sugar import. dasR was transcribed actively during vegetative growth, and dasA was transcribed just after commencement of aerial hypha formation and during sporulation, indicating that both were developmentally regulated. Transcriptional analysis and direct sequencing of dasRA in mutant NP4 suggested a defect of this mutant in the regulatory system to control the expression of these genes. Introduction of multicopies of dasA into the wild-type strain caused ectopic septation in very young substrate hyphae after only 1 day of growth and subsequent sporulation in response

  6. Microglia and macrophages differentially modulate cell death after brain injury caused by oxygen-glucose deprivation in organotypic brain slices.

    PubMed

    Girard, Sylvie; Brough, David; Lopez-Castejon, Gloria; Giles, James; Rothwell, Nancy J; Allan, Stuart M

    2013-05-01

    Macrophage can adopt several phenotypes, process call polarization, which is crucial for shaping inflammatory responses to injury. It is not known if microglia, a resident brain macrophage population, polarizes in a similar way, and whether specific microglial phenotypes modulate cell death in response to brain injury. In this study, we show that both BV2-microglia and mouse bone marrow derived macrophages (BMDMs) were able to adopt different phenotypes after LPS (M1) or IL-4 (M2) treatment in vitro, but regulated cell death differently when added to mouse organotypic hippocampal brain slices. BMDMs induced cell death when added to control slices and exacerbated damage when combined with oxygen-glucose deprivation (OGD), independently of their phenotype. In contrast, vehicle- and M2-BV2-microglia were protective against OGD-induced death. Direct treatment of brain slices with IL-4 (without cell addition) was protective against OGD and induced an M2 phenotype in the slice. In vivo, intracerebral injection of LPS or IL-4 in mice induced microglial phenotypes similar to the phenotypes observed in brain slices and in cultured cells. After injury induced by middle cerebral artery occlusion, microglial cells did not adopt classical M1/M2 phenotypes, suggesting that another subtype of regulatory phenotype was induced. This study highlights functional differences between macrophages and microglia, in response to brain injury with fundamentally different outcomes, even if both populations were able to adopt M1 or M2 phenotypes. These data suggest that macrophages infiltrating the brain from the periphery after an injury may be cytotoxic, independently of their phenotype, while microglia may be protective. PMID:23404620

  7. Altered energy state reversibly controls smooth muscle contractile function in human saphenous vein during acute hypoxia-reoxygenation: Role of glycogen, AMP-activated protein kinase, and insulin-independent glucose uptake.

    PubMed

    Pyla, Rajkumar; Pichavaram, Prahalathan; Fairaq, Arwa; Park, Mary Anne; Kozak, Mark; Kamath, Vinayak; Patel, Vijay S; Segar, Lakshman

    2015-09-01

    Hypoxia is known to promote vasodilation of coronary vessels through several mediators including cardiac-derived adenosine and endothelium-derived prostanoids and nitric oxide. To date, the impact of endogenous glycogen depletion in vascular smooth muscle and the resultant alterations in cellular energy state (e.g., AMP-activated protein kinase, AMPK) on the contractile response to G protein-coupled receptor agonists (e.g., serotonin, 5-HT) has not yet been studied. In the present study, ex vivo exposure of endothelium-denuded human saphenous vein rings to hypoxic and glucose-deprived conditions during KCl-induced contractions for 30 min resulted in a marked depletion of endogenous glycogen by ∼80% (from ∼1.78 μmol/g under normoxia to ∼0.36 μmol/g under hypoxia). Importantly, glycogen-depleted HSV rings, which were maintained under hypoxia/reoxygenation and glucose-deprived conditions, exhibited significant increases in basal AMPK phosphorylation (∼6-fold ↑) and 5-HT-induced AMPK phosphorylation (∼19-fold ↑) with an accompanying suppression of 5-HT-induced maximal contractile response (∼68% ↓), compared with respective controls. Exposure of glycogen-depleted HSV rings to exogenous D-glucose, but not the inactive glucose analogs, prevented the exaggerated increase in 5-HT-induced AMPK phosphorylation and restored 5-HT-induced maximal contractile response. In addition, the ability of exogenous D-glucose to rescue cellular stress and impaired contractile function occurred through GLUT1-mediated but insulin/GLUT4-independent mechanisms. Together, the present findings from clinically-relevant human saphenous vein suggest that the loss of endogenous glycogen in vascular smooth muscle and the resultant accentuation of AMPK phosphorylation by GPCR agonists may constitute a yet another mechanism of metabolic vasodilation of coronary vessels in ischemic heart disease. PMID:26212549

  8. Estrogenic environmental contaminants alter the mRNA abundance profiles of genes involved in gonadal differentiation of the American bullfrog

    PubMed Central

    Wolff, Stephanie E.; Veldhoen, Nik; Helbing, Caren C.; Ramirez, Claire A.; Malpas, Janae M.; Propper, Catherine R.

    2015-01-01

    Wildlife and human populations are exposed to anthropogenic mixtures of chemicals in the environment that may adversely influence normal reproductive function and development. We determined the effects of exposure to estrogenic chemicals and wastewater effluent (WWE) on developing gonads of the American bullfrog, Rana (Lithobates) catesbeiana, a species whose widespread distribution make it an ideal model for environmental monitoring for endocrine effects of chemical contaminants. Premetamorphic bullfrog tadpoles were exposed to treatment vehicle, 17β-estradiol (E2; 10−9 M) or 4-tert-octylphenol (OP; 10−9 M, 10−8 M, and 10−7 M). Additionally, gonadal differentiation was evaluated in bullfrog tadpoles from a WWE-containing site versus those from a reference location receiving no WWE. In both studies, phenotypic sex, steroidogenic factor-1 (nr5a1), and aromatase (cyp19a1) mRNA levels using quantitative real-time PCR were determined. Exposure to E2 or OP did not alter sex ratios. In controls, both nr5a1 and cyp19a1 transcript levels exhibited sexual dimorphism, with males demonstrating higher levels of nr5a1 and females greater abundance of cyp19a1. However, E2 exposure increased cyp19a1 mRNA abundance in testes and decreased levels in ovaries, eliminating the sexual dimorphism observed in controls. E2-exposed males exhibited increased nr5a1 transcript levels in the testes compared to controls, while females demonstrated no E2 effect. OP treatment had no effect on female cyp19a1 mRNA abundance, but exposure to 10−7 M OP increased testicular transcript levels. Treatment with 10−9 and 10−8 M OP, but not 10−7 M, resulted in decreased abundance of nr5a1 transcript in both ovaries and testes. Animals from the field had sexually dimorphic gonadal levels of cyp19a1, but both sexes from the WWE site exhibited elevated cyp19a1 transcript abundance compared to the reference location. Individual chemical compounds and anthropogenic wastewater effluent dispersed

  9. Episodic intrusion, internal differentiation, and hydrothermal alteration of the miocene tatoosh intrusive suite south of Mount Rainier, Washington

    USGS Publications Warehouse

    du Bray, E.A.; Bacon, C.R.; John, D.A.; Wooden, J.L.; Mazdab, F.K.

    2011-01-01

    The Miocene Tatoosh intrusive suite south of Mount Rainier is composed of three broadly granodioritic plutons that are manifestations of ancestral Cascades arc magmatism. Tatoosh intrusive suite plutons have individually diagnostic characteristics, including texture, mineralogy, and geochemistry, and apparently lack internal contacts. New ion-microprobe U-Pb zircon ages indicate crystallization of the Stevens pluton ca. 19.2 Ma, Reflection-Pyramid pluton ca. 18.5 Ma, and Nisqually pluton ca. 17.5 Ma. The Stevens pluton includes rare, statistically distinct ca. 20.1 Ma zircon antecrysts. Wide-ranging zircon rare earth element (REE), Hf, U, and Th concentrations suggest late crystallization from variably evolved residual liquids. Zircon Eu/Eu*-Hf covariation is distinct for each of the Reflection-Pyramid, Nisqually, and Stevens plutons. Although most Tatoosh intrusive suite rocks have been affected by weak hydrothermal alteration, and sparse mineralized veins cut some of these rocks, significant base or precious metal mineralization is absent. At the time of shallow emplacement, each of these magma bodies was largely homogeneous in bulk composition and petrographic features, but, prior to final solidification, each of the Tatoosh intrusive suite plutons developed internal compositional variation. Geochemical and petrographic trends within each pluton are most consistent with differential loss of residual melt, possibly represented by late aplite dikes or erupted as rhyolite, from crystal-rich magma. Crystal-rich magma that formed each pluton evidently accumulated in reservoirs below the present level of exposure and then intruded to a shallow depth. Assembled by episodic intrusion, the Tatoosh intrusive suite may be representative of midsized composite plutonic complexes beneath arc volcanoes. ?? 2011 Geological Society of America.

  10. Adolescent methylphenidate treatment differentially alters adult impulsivity and hyperactivity in the Spontaneously Hypertensive Rat model of ADHD.

    PubMed

    Somkuwar, S S; Kantak, K M; Bardo, M T; Dwoskin, L P

    2016-02-01

    Impulsivity and hyperactivity are two facets of attention deficit/hyperactivity disorder (ADHD). Impulsivity is expressed as reduced response inhibition capacity, an executive control mechanism that prevents premature execution of an intermittently reinforced behavior. During methylphenidate treatment, impulsivity and hyperactivity are decreased in adolescents with ADHD, but there is little information concerning levels of impulsivity and hyperactivity in adulthood after adolescent methylphenidate treatment is discontinued. The current study evaluated impulsivity, hyperactivity as well as cocaine sensitization during adulthood after adolescent methylphenidate treatment was discontinued in the Spontaneously Hypertensive Rat (SHR) model of ADHD. Treatments consisted of oral methylphenidate (1.5mg/kg) or water vehicle provided Monday-Friday from postnatal days 28-55. During adulthood, impulsivity was measured in SHR and control strains (Wistar Kyoto and Wistar rats) using differential reinforcement of low rate (DRL) schedules. Locomotor activity and cocaine sensitization were measured using the open-field assay. Adult SHR exhibited decreased efficiency of reinforcement under the DRL30 schedule and greater levels of locomotor activity and cocaine sensitization compared to control strains. Compared to vehicle, methylphenidate treatment during adolescence reduced hyperactivity in adult SHR, maintained the lower efficiency of reinforcement, and increased burst responding under DRL30. Cocaine sensitization was not altered following adolescent methylphenidate in adult SHR. In conclusion, adolescent treatment with methylphenidate followed by discontinuation in adulthood had a positive benefit by reducing hyperactivity in adult SHR rats; however, increased burst responding under DRL compared to SHR given vehicle, i.e., elevated impulsivity, constituted an adverse consequence associated with increased risk for cocaine abuse liability. PMID:26657171

  11. The differential role of NOS inhibitors on stress-induced anxiety and neuroendocrine alterations in the rat.

    PubMed

    Joung, Hye-Young; Jung, Eun-Yee; Kim, Kyungsoo; Lee, Mi-Sook; Her, Song; Shim, Insop

    2012-12-01

    The inhibitors of nitric oxide synthase (NOS) have been shown to possess antidepressant- and anxiolytic-properties in animal model. In order to examine the involvement of nitric oxide (NO) on stress-induced neurobehavioral changes and the concomitant alterations of neuroendocrinological factors, we studied the effects of the nonselective NOS inhibitor, N(ω)-Nitro L-arginine methyl ester hydrochloride (L-NAME) and the specific neuronal NOS inhibitor, 7-nitroindazole (7-NI) on restraint stress-induced anxiety in the elevated plus maze (EPM) test and biochemical analysis. Restraint stress significantly reduced the latency time in open arm and the percentage of open arm entries of the plus maze. Pretreatment with L-NAME (10 mg/kg) or 7-NI (10 mg/kg) significantly attenuated stress-induced anxiety response. In addition, administration of L-NAME (10 mg/kg) reversed stress-induced increase in corticosterone and NO metabolites (NO(x)) in plasma. The administration of 7-NI, but not L-NAME, reversed stress-induced NO(x) in paraventricular nucleus of the hypothalamus (PVN) and locus coeruleus (LC), accompanying with decrease of NADPH-d reactivity in the PVN and lateral dorsal tegmental nucleus (LTDg). These results showed that L-NAME influences HPA axis activity such as corticosterone levels and NO(x) in plasma, whereas 7-NI produced anxiolytic-like effects through the direct reduction in NO(x) in the brain. The results of this study demonstrated that NOS inhibitors have differential effect on stress responses and inhibition of NO could be responsible for the beneficial effect on regulation of stress. PMID:22884925

  12. Short-term high-fat diet alters postprandial glucose metabolism and circulating vascular cell adhesion molecule-1 in healthy males.

    PubMed

    Numao, Shigeharu; Kawano, Hiroshi; Endo, Naoya; Yamada, Yuka; Takahashi, Masaki; Konishi, Masayuki; Sakamoto, Shizuo

    2016-08-01

    Short-term intake of a high-fat diet aggravates postprandial glucose metabolism; however, the dose-response relationship has not been investigated. We hypothesized that short-term intake of a eucaloric low-carbohydrate/high-fat diet (LCHF) would aggravate postprandial glucose metabolism and circulating adhesion molecules in healthy males. Seven healthy young males (mean ± SE; age: 26 ± 1 years) consumed either a eucaloric control diet (C, approximately 25% fats), a eucaloric intermediate-carbohydrate/intermediate-fat diet (ICIF, approximately 50% fats), or an LCHF (approximately 70% fats) for 3 days. An oral meal tolerance test (MTT) was performed after the 3-day dietary intervention. The concentrations of plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 (VCAM-1) were determined at rest and during MTT. The incremental area under the curve (iAUC) of plasma glucose concentration during MTT was significantly higher in LCHF than in C (P = 0.009). The first-phase insulin secretion indexes were significantly lower in LCHF than in C (P = 0.04). Moreover, the iAUC of GLP-1 and VCAM-1 concentrations was significantly higher in LCHF than in C (P = 0.014 and P = 0.04, respectively). The metabolites from ICIF and C were not significantly different. In conclusion, short-term intake of eucaloric diet containing a high percentage of fats in healthy males excessively increased postprandial glucose and VCAM-1 concentrations and attenuated first-phase insulin release. PMID:27454856

  13. Differential time course of liver and kidney glucose-6 phosphatase activity during long-term fasting in rat correlates with differential time course of messenger RNA level.

    PubMed

    Minassian, C; Zitoun, C; Mithieux, G

    1996-02-01

    We have studied the role of Glc6Pase mRNA abundance in the time course of Glc6Pase activity in liver and kidney during long-term fasting in rat. Refered to the mRNA level in the fed state, Glc6Pase mRNA abundance was increased by 3.5 +/- 0.5 and 3.7 +/- 0.5 times (mean +/- S.E.M., n = 5) in the 24 h and 48 h-fasted liver, respectively. Then, the liver Glc6Pase mRNA was decreased to the level of the fed liver after 72 and 96 h of fasting (1.0 +/- 0.3 and 1.4 +/- 0.3). In the kidney, Glc6Pase mRNA abundance was increased by 2.7 +/- 1.0 and 5 +/- 1.2 times at 24 and 48 h of fasting, respectively. Then, it plateaued at the level of the 48 h fasted kidney after 72 h and 96 h of fasting (4.5 +/- 1.0 and 4.3 +/- 1.0). After 24 and 48 h-refeeding, the abundance of Glc6Pase mRNA in 48 h-fasted rats was decreased to the level found in the liver and kidney of fed rats. The time course of the activity of Glc6Pase catalytic subunit during fasting and refeeding was strikingly parallel to the time course of Glc6Pase mRNA level in respective tissues. These data strongly suggest that the differential expression of Glc6Pase activity in liver and kidney in the course of fasting may be accounted for by the respective time course of mRNA abundance in both organs. PMID:8717437

  14. Effect of high glucose concentrations on human erythrocytes in vitro

    PubMed Central

    Viskupicova, Jana; Blaskovic, Dusan; Galiniak, Sabina; Soszyński, Mirosław; Bartosz, Grzegorz; Horakova, Lubica; Sadowska-Bartosz, Izabela

    2015-01-01

    Exposure to high glucose concentrations in vitro is often employed as a model for understanding erythrocyte modifications in diabetes. However, effects of such experiments may be affected by glucose consumption during prolonged incubation and changes of cellular parameters conditioned by impaired energy balance. The aim of this study was to compare alterations in various red cell parameters in this type of experiment to differentiate between those affected by glycoxidation and those affected by energy imbalance. Erythrocytes were incubated with 5, 45 or 100 mM glucose for up to 72 h. High glucose concentrations intensified lipid peroxidation and loss of activities of erythrocyte enzymes (glutathione S-transferase and glutathione reductase). On the other hand, hemolysis, eryptosis, calcium accumulation, loss of glutathione and increase in the GSSG/GSH ratio were attenuated by high glucose apparently due to maintenance of energy supply to the cells. Loss of plasma membrane Ca2+-ATPase activity and decrease in superoxide production were not affected by glucose concentration, being seemingly determined by processes independent of both glycoxidation and energy depletion. These results point to the necessity of careful interpretation of data obtained in experiments, in which erythrocytes are subject to treatment with high glucose concentrations in vitro. PMID:26141922

  15. Ablation of the Id2 Gene Results in Altered Circadian Feeding Behavior, and Sex-Specific Enhancement of Insulin Sensitivity and Elevated Glucose Uptake in Skeletal Muscle and Brown Adipose Tissue

    PubMed Central

    Mathew, Deepa; Zhou, Peng; Pywell, Cameron M.; van der Veen, Daan R.; Shao, Jinping; Xi, Yang; Bonar, Nicolle A.; Hummel, Alyssa D.; Chapman, Sarah; Leevy, W. Matthew; Duffield, Giles E.

    2013-01-01

    Inhibitor of DNA binding 2 (ID2) is a helix-loop-helix transcriptional repressor rhythmically expressed in many adult tissues. Our earlier studies have demonstrated a role for ID2 in the input pathway, core clock function and output pathways of the mouse circadian system. We have also reported that Id2 null (Id2−/−) mice are lean with low gonadal white adipose tissue deposits and lower lipid content in the liver. These results coincided with altered or disrupted circadian expression profiles of liver genes including those involved in lipid metabolism. In the present phenotypic study we intended to decipher, on a sex-specific basis, the role of ID2 in glucose metabolism and in the circadian regulation of activity, important components of energy balance. We find that Id2−/− mice exhibited altered daily and circadian rhythms of feeding and locomotor activity; activity profiles extended further into the late night/dark phase of the 24-hr cycle, despite mice showing reduced total locomotor activity. Also, male Id2−/− mice consumed a greater amount of food relative to body mass, and displayed less weight gain. Id2−/− females had smaller adipocytes, suggesting sexual-dimorphic programing of adipogenesis. We observed increased glucose tolerance and insulin sensitivity in male Id2−/− mice, which was exacerbated in older animals. FDG-PET analysis revealed increased glucose uptake by skeletal muscle and brown adipose tissue of male Id2−/− mice, suggesting increased glucose metabolism and thermogenesis in these tissues. Reductions in intramuscular triacylglycerol and diacylglycerol were detected in male Id2−/− mice, highlighting its possible mechanistic role in enhanced insulin sensitivity in these mice. Our findings indicate a role for ID2 as a regulator of glucose and lipid metabolism, and in the circadian control of feeding/locomotor behavior; and contribute to the understanding of the development of obesity and diabetes, particularly in shift

  16. Effects of uremic toxin p-cresol on proliferation, apoptosis, differentiation, and glucose uptake in 3T3-L1 cells.

    PubMed

    Tanaka, Sayuri; Yano, Shozo; Sheikh, Abdullah M; Nagai, Atsushi; Sugimoto, Toshitsugu

    2014-07-01

    Malnutrition is a common feature seen in chronic dialysis patients, and the survival rate of obese patients receiving such treatment is higher than that of lean patients. Irrespective of obesity or diabetes, dialysis patients commonly have insulin resistance, and the leading cause of death is cardiovascular (CV) disease. It has been reported that the concentration of p-cresol, a uremic toxin, is highly associated with CV events. As uremic toxin levels are high in dialysis patients, they may be involved in the pathogenesis of insulin resistance and CV disease in this population. However, little is known so far. Thus, we focused on this uremic toxin to examine its effects on adipocytes and their precursors. 3T3-L1 cells, a mouse preadipocyte cell line, were cultured until 90% confluency. The cells were then differentiated with 500 μM 3-isobutyl-methylxanthine, 250 nM dexamethasone, and 10 μg/mL insulin. Cell proliferation was evaluated by cell counting and bromodeoxyuridine (Brd-U) incorporation assay. Glucose uptake was estimated using radiolabeled 2-deoxyglucose. The range of concentrations of p-cresol used in the experiments was from 2 to 200 μM. The investigation of cell proliferation by cell counting revealed that, compared with control, 3T3-L1 cells treated with 100 and 200 μM p-cresol were significantly decreased in number at day 3 and day 7 of culture. The Brd-U incorporation assay also demonstrated similar inhibitory effects on cell proliferation, suggesting that p-cresol affected the normal cell cycle. Oil Red O staining at day 7 showed that the number of mature adipocytes was decreased by treatment with 200 μM p-cresol. Consistent with that finding, the number of apoptotic cells at day 7 was increased by treatment with 100 and 200 μM p-cresol. Peroxisome proliferator-activated receptor γ (PPARγ) mRNA expression increased time-dependently during the differentiation process of 3T3-L1 cells. p-Cresol dose-dependently decreased

  17. Hyperglycemic glucose concentrations up-regulate the expression of type VI collagen in vitro. Relevance to alterations of peripheral nerves in diabetes mellitus.

    PubMed Central

    Muona, P.; Jaakkola, S.; Zhang, R. Z.; Pan, T. C.; Pelliniemi, L.; Risteli, L.; Chu, M. L.; Uitto, J.; Peltonen, J.

    1993-01-01

    Electron microscopy of peripheral nerves obtained from two diabetic patients revealed large deposits of microfibrils and the presence of Luse bodies in the vicinity of perineurial cells. Microfibrils were found to accumulate also in the sciatic nerves of diabetic BB rats; these microfibrillar deposits were shown to contain type VI collagen by immunoelectron microscopy. Connective tissue cells cultured from rat sciatic nerves were exposed to high glucose concentrations. High glucose concentrations up-regulated the mRNA steady-state levels of alpha 1(VI), alpha 2(VI), and alpha 3(VI) chains of type VI collagen and caused accumulation of type VI collagen-containing fibrils in the cultures. Immunostaining and in situ hybridizations demonstrated that perineurial cells, Schwann cells, and fibroblasts expressed type VI collagen at the mRNA and protein levels. The results suggest that the turnover and supramolecular assembly of type VI collagen are perturbed in diabetic nerves and that glucose per se increases the expression of type VI collagen in vitro. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:8494053

  18. Medullary Endocannabinoids Contribute to the Differential Resting Baroreflex Sensitivity in Rats with Altered Brain Renin-Angiotensin System Expression.

    PubMed

    Schaich, Chris L; Grabenauer, Megan; Thomas, Brian F; Shaltout, Hossam A; Gallagher, Patricia E; Howlett, Allyn C; Diz, Debra I

    2016-01-01

    CB1 cannabinoid receptors are expressed on vagal afferent fibers and neurons within the solitary tract nucleus (NTS), providing anatomical evidence for their role in arterial baroreflex modulation. To better understand the relationship between the brain renin-angiotensin system (RAS) and endocannabinoid expression within the NTS, we measured dorsal medullary endocannabinoid tissue content and the effects of CB1 receptor blockade at this brain site on cardiac baroreflex sensitivity (BRS) in ASrAOGEN rats with low glial angiotensinogen, normal Sprague-Dawley rats and (mRen2)27 rats with upregulated brain RAS expression. Mass spectrometry revealed higher levels of the endocannabinoid 2-arachidonoylglycerol in (mRen2)27 compared to ASrAOGEN rats (2.70 ± 0.28 vs. 1.17 ± 0.09 ng/mg tissue; P < 0.01), while Sprague-Dawley rats had intermediate content (1.85 ± 0.27 ng/mg tissue). Microinjection of the CB1receptor antagonist SR141716A (36 pmol) into the NTS did not change cardiac BRS in anesthetized Sprague-Dawley rats (1.04 ± 0.05 ms/mmHg baseline vs. 1.17 ± 0.11 ms/mmHg after 10 min). However, SR141716A in (mRen2)27 rats dose-dependently improved BRS in this strain: 0.36 pmol of SR141716A increased BRS from 0.43 ± 0.03 to 0.71 ± 0.04 ms/mmHg (P < 0.001), and 36 pmol of SR141716A increased BRS from 0.47 ± 0.02 to 0.94 ± 0.10 ms/mmHg (P < 0.01). In contrast, 0.36 pmol (1.50 ± 0.12 vs. 0.86 ± 0.08 ms/mmHg; P < 0.05) and 36 pmol (1.38 ± 0.16 vs. 0.46 ± 0.003 ms/mmHg; P < 0.01) of SR141716A significantly reduced BRS in ASrAOGEN rats. These observations reveal differential dose-related effects of the brain endocannabinoid system that influence cardiovagal BRS in animals with genetic alterations in the brain RAS. PMID:27375489

  19. Medullary Endocannabinoids Contribute to the Differential Resting Baroreflex Sensitivity in Rats with Altered Brain Renin-Angiotensin System Expression

    PubMed Central

    Schaich, Chris L.; Grabenauer, Megan; Thomas, Brian F.; Shaltout, Hossam A.; Gallagher, Patricia E.; Howlett, Allyn C.; Diz, Debra I.

    2016-01-01

    CB1 cannabinoid receptors are expressed on vagal afferent fibers and neurons within the solitary tract nucleus (NTS), providing anatomical evidence for their role in arterial baroreflex modulation. To better understand the relationship between the brain renin-angiotensin system (RAS) and endocannabinoid expression within the NTS, we measured dorsal medullary endocannabinoid tissue content and the effects of CB1 receptor blockade at this brain site on cardiac baroreflex sensitivity (BRS) in ASrAOGEN rats with low glial angiotensinogen, normal Sprague-Dawley rats and (mRen2)27 rats with upregulated brain RAS expression. Mass spectrometry revealed higher levels of the endocannabinoid 2-arachidonoylglycerol in (mRen2)27 compared to ASrAOGEN rats (2.70 ± 0.28 vs. 1.17 ± 0.09 ng/mg tissue; P < 0.01), while Sprague-Dawley rats had intermediate content (1.85 ± 0.27 ng/mg tissue). Microinjection of the CB1receptor antagonist SR141716A (36 pmol) into the NTS did not change cardiac BRS in anesthetized Sprague-Dawley rats (1.04 ± 0.05 ms/mmHg baseline vs. 1.17 ± 0.11 ms/mmHg after 10 min). However, SR141716A in (mRen2)27 rats dose-dependently improved BRS in this strain: 0.36 pmol of SR141716A increased BRS from 0.43 ± 0.03 to 0.71 ± 0.04 ms/mmHg (P < 0.001), and 36 pmol of SR141716A increased BRS from 0.47 ± 0.02 to 0.94 ± 0.10 ms/mmHg (P < 0.01). In contrast, 0.36 pmol (1.50 ± 0.12 vs. 0.86 ± 0.08 ms/mmHg; P < 0.05) and 36 pmol (1.38 ± 0.16 vs. 0.46 ± 0.003 ms/mmHg; P < 0.01) of SR141716A significantly reduced BRS in ASrAOGEN rats. These observations reveal differential dose-related effects of the brain endocannabinoid system that influence cardiovagal BRS in animals with genetic alterations in the brain RAS. PMID:27375489

  20. Glucose oxidase facilitates osteogenic differentiation and mineralization of embryonic stem cells through the activation of Nrf2 and ERK signal transduction pathways.

    PubMed

    Sim, Hyun-Jaung; Kim, Jae-Hwan; Kook, Sung-Ho; Lee, Seung-Youp; Lee, Jeong-Chae

    2016-08-01

    Nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase-1 (HO-1) signal is known to play important roles in controlling bone homeostasis. This study examined how oxidative stress affects the mineralization of embryonic stem (ES) cells by exposing them to glucose oxidase (GO), which continuously generates H2O2 at low concentrations. The roles of Nrf2/HO-1 and mitogen-activated protein kinases on osteogenesis in GO-exposed ES cells were also investigated. GO treatment at relatively low concentrations did not change the viability of ES cells, whereas it enhanced osteogenic differentiation and mineralization in the cells. GO treatment (1 mU/ml) augmented the induction of runt-related transcription factor 2 (Runx2), Nrf2, and HO-1 in ES cells. GO-mediated acceleration of Runx2 expression and mineralization was inhibited either by Nrf2 knockdown or by treating with 5 μM PD98059, an inhibitor of phospho-extracellular signal-regulated kinase (p-ERK). The GO-stimulated mineralization was also suppressed by treating the cells with reduced glutathione or catalase, but not by superoxide dismutase or N-acetyl-cysteine. Collectively, our results demonstrate that a mild oxidative stress activates Nrf2/HO-1 signaling and an ERK-mediated pathway, and facilitates the mineralization of ES cells with a corresponding increase in Runx2. PMID:27431005

  1. Neuroprotective effects of nimodipine and nifedipine in the NGF-differentiated PC12 cells exposed to oxygen-glucose deprivation or trophic withdrawal.

    PubMed

    Lecht, Shimon; Rotfeld, Elena; Arien-Zakay, Hadar; Tabakman, Rinat; Matzner, Henry; Yaka, Rami; Lelkes, Peter I; Lazarovici, Philip

    2012-10-01

    The goal of this study was to compare the neuroprotective properties of the L-type Ca²⁺ channel blockers, nimodipine and nifedipine, using nerve growth factor (NGF)-differentiated PC12 neuronal cultures exposed to oxygen-glucose deprivation (OGD) and trophic withdrawal-induced cell death. Nimodipine (1-100 μM) conferred 65±13% neuroprotection upon exposure to OGD and 35±6% neuroprotection towards different trophic withdrawal-induced cell death measured by lactate dehydrogenase and caspase 3 activities. The time window of nimodipine conferred neuroprotection was detected during the first 5h but not at longer OGD exposures. Nifedipine (1-100 μM), to a lower potency than nimodipine, conferred 30-55±8% neuroprotection towards OGD in PC12 cells and 29±5% in rat hypocampal slices, and 10±3% neuroprotection at 100 μM towards trophic withdrawal-induced PC12 cell death. The ability to demonstrate that nimodipine conferred neuroprotection in a narrow therapeutic time-window indicates that the OGD PC12 model mimics the in vivo models and therefore suitable for neuroprotective drug discovery and development. PMID:22677442

  2. Altered insulin receptor messenger ribonucleic acid splicing in liver is associated with deterioration of glucose tolerance in the spontaneously obese and diabetic rhesus monkey: Analysis of controversy between monkey and human studies

    SciTech Connect

    Huang, Ze; Shuldiner, A.R.; Zenilman, M.E.

    1996-04-01

    There are two insulin receptor (IR) isoforms (designated type A and type B), derived from alternative splicing of exon 11 of the IR gene. Recently, we reported that an increase in the exon 11- (i.e. lacking exon 11) (type A) IR messenger RNA (mRNA) variant in muscle is associated with hyperinsulinemia, an early risk factor for noninsulin-dependent diabetes mellitus (NIDDM), in the spontaneously obese, diabetic rhesus monkey. To explore further the role of IR mRNA splicing in insulin resistance of NIDDM, we studied liver, another target organ that is resistant to insulin action in NIDDM. The relative amounts of the two IR mRNA-splicing variants in liver were quantitated by RT-PCR in normal, prediabetic, and diabetic (NIDDM) monkeys. The percentage of the exon 11- mRNA variant in liver (n = 24) was significantly correlated with fasting plasma glucose (r = 0.55, P < 0.01) and intravenous glucose disappearance rate (r = -0.45, P < 0.05). The exon 11- mRNA variant was increased significantly from 29.8 {+-} 1.6% in monkeys with normal fasting glucose to 39.2 {+-} 2.9% in monkeys with elevated fasting glucose (P < 0.01). These studies provide the first direct evidence in vivo that the relative expression of the two IR mRNA-splicing variants is altered in liver and suggest that increased expression of the exon 11- IR isoform may contribute to hepatic insulin resistance and NIDDM or may compensate for some yet unidentified defect. 33 refs., 3 figs., 1 tab.

  3. Altered sensitivity to ellagic acid in neuroblastoma cells undergoing differentiation with 12-O-tetradecanoylphorbol-13-acetate and all-trans retinoic acid.

    PubMed

    Alfredsson, Christina Fjæraa; Rendel, Filip; Liang, Qui-Li; Sundström, Birgitta E; Nånberg, Eewa

    2015-12-01

    Ellagic acid has previously been reported to induce reduced proliferation and activation of apoptosis in several tumor cell lines including our own previous data from non-differentiated human neuroblastoma SH-SY5Y cells. The aim of this study was now to investigate if in vitro differentiation with the phorbol ester 12-O- tetradecanoylphorbol-13-acetate or the vitamin A derivative all-trans retinoic acid altered the sensitivity to ellagic acid in SH-SY5Y cells. The methods used were cell counting and LDH-assay for evaluation of cell number and cell death, flow cytometric analysis of SubG1- and TUNEL-analysis for apoptosis and western blot for expression of apoptosis-associated proteins. In vitro differentiation was shown to reduce the sensitivity to ellagic acid with respect to cell detachment, loss of viability and activation of apoptosis. The protective effect was phenotype-specific and most prominent in all-trans retinoic acid-differentiated cultures. Differentiation-dependent up-regulation of Bcl-2 and integrin expression is introduced as possible protective mechanisms. The presented data also point to a positive correlation between proliferative activity and sensitivity to ellagic-acid-induced cell detachment. In conclusion, the presented data emphasize the need to consider degree of neuronal differentiation and phenotype of neuroblastoma cells when discussing a potential pharmaceutical application of ellagic acid in tumor treatment. PMID:26653548

  4. Sodium arsenite delays the differentiation of C2C12 mouse myoblast cells and alters methylation patterns on the transcription factor myogenin

    SciTech Connect

    Steffens, Amanda A.; Hong Giaming; Bain, Lisa J.

    2011-01-15

    Epidemiological studies have correlated arsenic exposure with cancer, skin diseases, and adverse developmental outcomes such as spontaneous abortions, neonatal mortality, low birth weight, and delays in the use of musculature. The current study used C2C12 mouse myoblast cells to examine whether low concentrations of arsenic could alter their differentiation into myotubes, indicating that arsenic can act as a developmental toxicant. Myoblast cells were exposed to 20 nM sodium arsenite, allowed to differentiate into myotubes, and expression of the muscle-specific transcription factor myogenin, along with the expression of tropomyosin, suppressor of cytokine signaling 3 (Socs3), prostaglandin I2 synthesis (Ptgis), and myocyte enhancer 2 (Mef2), was investigated using QPCR and immunofluorescence. Exposing C2C12 cells to 20 nM sodium arsenite delayed the differentiation process, as evidenced by a significant reduction in the number of multinucleated myotubes, a decrease in myogenin mRNA expression, and a decrease in the total number of nuclei expressing myogenin protein. The expression of mRNA involved in myotube formation, such as Ptgis and Mef2 mRNA, was also significantly reduced by 1.6-fold and 4-fold during differentiation. This was confirmed by immunofluorescence for Mef2, which showed a 2.6-fold reduction in nuclear translocation. Changes in methylation patterns in the promoter region of myogenin (-473 to + 90) were examined by methylation-specific PCR and bisulfite genomic sequencing. Hypermethylated CpGs were found at -236 and -126 bp, whereas hypomethylated CpGs were found at -207 bp in arsenic-exposed cells. This study indicates that 20 nM sodium arsenite can alter myoblast differentiation by reducing the expression of the transcription factors myogenin and Mef2c, which is likely due to changes in promoter methylation patterns. The delay in muscle differentiation may lead to developmental abnormalities.

  5. Stretch and/or oxygen glucose deprivation (OGD) in an in vitro traumatic brain injury (TBI) model induces calcium alteration and inflammatory cascade

    PubMed Central

    Salvador, Ellaine; Burek, Malgorzata; Förster, Carola Y.

    2015-01-01

    The blood-brain barrier (BBB), made up of endothelial cells of capillaries in the brain, maintains the microenvironment of the central nervous system. During ischemia and traumatic brain injury (TBI), cellular disruption leading to mechanical insult results to the BBB being compromised. Oxygen glucose deprivation (OGD) is the most commonly used in vitro model for ischemia. On the other hand, stretch injury is currently being used to model TBI in vitro. In this paper, the two methods are used alone or in combination, to assess their effects on cerebrovascular endothelial cells cEND in the presence or absence of astrocytic factors. Applying severe stretch and/or OGD to cEND cells in our experiments resulted to cell swelling and distortion. Damage to the cells induced release of lactate dehydrogenase enzyme (LDH) and nitric oxide (NO) into the cell culture medium. In addition, mRNA expression of inflammatory markers interleukin (I L)-6, IL-1α, chemokine (C-C motif) ligand 2 (CCL2) and tumor necrosis factor (TNF)-α also increased. These events could lead to the opening of calcium ion channels resulting to excitotoxicity. This could be demonstrated by increased calcium level in OGD-subjected cEND cells incubated with astrocyte-conditioned medium. Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression. In addition, permeability of the endothelial cell monolayer increased. Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD. Overall, the effects of OGD on cEND cells appear to be more prominent than that of stretch with regards to TJ proteins, NO, glut1 expression, and calcium level. Astrocytes potentiate these effects on calcium level in cEND cells. Combining both methods to model TBI in vitro shows a promising improvement to currently available models. PMID:26347611

  6. Exposure to Bisphenol-A during Pregnancy Partially Mimics the Effects of a High-Fat Diet Altering Glucose Homeostasis and Gene Expression in Adult Male Mice

    PubMed Central

    García-Arevalo, Marta; Alonso-Magdalena, Paloma; Rebelo Dos Santos, Junia; Quesada, Ivan; Carneiro, Everardo M.; Nadal, Angel

    2014-01-01

    Bisphenol-A (BPA) is one of the most widespread EDCs used as a base compound in the manufacture of polycarbonate plastics. The aim of our research has been to study how the exposure to BPA during pregnancy affects weight, glucose homeostasis, pancreatic β-cell function and gene expression in the major peripheral organs that control energy flux: white adipose tissue (WAT), the liver and skeletal muscle, in male offspring 17 and 28 weeks old. Pregnant mice were treated with a subcutaneous injection of 10 µg/kg/day of BPA or a vehicle from day 9 to 16 of pregnancy. One month old offspring were divided into four different groups: vehicle treated mice that ate a normal chow diet (Control group); BPA treated mice that also ate a normal chow diet (BPA); vehicle treated animals that had a high fat diet (HFD) and BPA treated animals that were fed HFD (HFD-BPA). The BPA group started to gain weight at 18 weeks old and caught up to the HFD group before week 28. The BPA group as well as the HFD and HFD-BPA ones presented fasting hyperglycemia, glucose intolerance and high levels of non-esterified fatty acids (NEFA) in plasma compared with the Control one. Glucose stimulated insulin release was disrupted, particularly in the HFD-BPA group. In WAT, the mRNA expression of the genes involved in fatty acid metabolism, Srebpc1, Pparα and Cpt1β was decreased by BPA to the same extent as with the HFD treatment. BPA treatment upregulated Pparγ and Prkaa1 genes in the liver; yet it diminished the expression of Cd36. Hepatic triglyceride levels were increased in all groups compared to control. In conclusion, male offspring from BPA-treated mothers presented symptoms of diabesity. This term refers to a form of diabetes which typically develops in later life and is associated with obesity. PMID:24959901

  7. The renin-angiotensin system: a target of and contributor to dyslipidemias, altered glucose homeostasis, and hypertension of the metabolic syndrome.

    PubMed

    Putnam, Kelly; Shoemaker, Robin; Yiannikouris, Frederique; Cassis, Lisa A

    2012-03-15

    The renin-angiotensin system (RAS) is an important therapeutic target in the treatment of hypertension. Obesity has emerged as a primary contributor to essential hypertension in the United States and clusters with other metabolic disorders (hyperglycemia, hypertension, high triglycerides, low HDL cholesterol) defined within the metabolic syndrome. In addition to hypertension, RAS blockade may also serve as an effective treatment strategy to control impaired glucose and insulin tolerance and dyslipidemias in patients with the metabolic syndrome. Hyperglycemia, insulin resistance, and/or specific cholesterol metabolites have been demonstrated to activate components required for the synthesis [angiotensinogen, renin, angiotensin-converting enzyme (ACE)], degradation (ACE2), or responsiveness (angiotensin II type 1 receptors, Mas receptors) to angiotensin peptides in cell types (e.g., pancreatic islet cells, adipocytes, macrophages) that mediate specific disorders of the metabolic syndrome. An activated local RAS in these cell types may contribute to dysregulated function by promoting oxidative stress, apoptosis, and inflammation. This review will discuss data demonstrating the regulation of components of the RAS by cholesterol and its metabolites, glucose, and/or insulin in cell types implicated in disorders of the metabolic syndrome. In addition, we discuss data supporting a role for an activated local RAS in dyslipidemias and glucose intolerance/insulin resistance and the development of hypertension in the metabolic syndrome. Identification of an activated RAS as a common thread contributing to several disorders of the metabolic syndrome makes the use of angiotensin receptor blockers and ACE inhibitors an intriguing and novel option for multisymptom treatment. PMID:22227126

  8. Melanogenesis stimulation in B16-F10 melanoma cells induces cell cycle alterations, increased ROS levels and a differential expression of proteins as revealed by proteomic analysis

    SciTech Connect

    Cunha, Elizabeth S.; Kawahara, Rebeca; Kadowaki, Marina K.; Amstalden, Hudson G.; Noleto, Guilhermina R.; Cadena, Silvia Maria S.C.; Winnischofer, Sheila M.B.; Martinez, Glaucia R.

    2012-09-10

    Considering that stimulation of melanogenesis may lead to alterations of cellular responses, besides melanin production, our main goal was to study the cellular effects of melanogenesis stimulation of B16-F10 melanoma cells. Our results show increased levels of the reactive oxygen species after 15 h of melanogenesis stimulation. Following 48 h of melanogenesis stimulation, proliferation was inhibited (by induction of cell cycle arrest in the G1 phase) and the expression levels of p21 mRNA were increased. In addition, melanogenesis stimulation did not induce cellular senescence. Proteomic analysis demonstrated the involvement of proteins from other pathways besides those related to the cell cycle, including protein disulfide isomerase A3, heat-shock protein 70, and fructose biphosphate aldolase A (all up-regulated), and lactate dehydrogenase (down-regulated). In RT-qPCR experiments, the levels of pyruvate kinase M2 mRNA dropped, whereas the levels of ATP synthase (beta-F1) mRNA increased. These data indicate that melanogenesis stimulation of B16-F10 cells leads to alterations in metabolism and cell cycle progression that may contribute to an induction of cell quiescence, which may provide a mechanism of resistance against cellular injury promoted by melanin synthesis. -- Highlights: Black-Right-Pointing-Pointer Melanogenesis stimulation by L-tyrosine+NH{sub 4}Cl in B16-F10 melanoma cells increases ROS levels. Black-Right-Pointing-Pointer Melanogenesis inhibits cell proliferation, and induced cell cycle arrest in the G1 phase. Black-Right-Pointing-Pointer Proteomic analysis showed alterations in proteins of the cell cycle and glucose metabolism. Black-Right-Pointing-Pointer RT-qPCR analysis confirmed alterations of metabolic targets after melanogenesis stimulation.

  9. Morc3 mutant mice exhibit reduced cortical area and thickness, accompanied by altered haematopoietic stem cells niche and bone cell differentiation

    PubMed Central

    Jadhav, Gaurav; Teguh, Dian; Kenny, Jacob; Tickner, Jennifer; Xu, Jiake

    2016-01-01

    Morc3, a member of a highly conserved nuclear matrix protein super-family plays an important part in chromatin remodeling, DNA repair, epigenetic regulation and cellular senescence. However, its role in bone homeostasis is not known. In the present study, a phenotype-driven ENU mouse mutagenesis screen revealed that Morc3mut +/− mice exhibit reduced cortical area and thickness with increased cortical porosity. Morc3mut +/− mice displayed reduced osteoclast numbers and surface per bone surface as well as osteocyte numbers, concomitant with altered gene expressions such as Rankl/Opg and Sost in ex vivo long bones. In vitro experiments revealed a significant increase in the number of Sca-1+/c-kit+ haematopoietic stem cells (HSCs), and a significant reduction in senescence associated β-galactosidase activity in bone marrow macrophages (BMMs). In addition, we observed a decrease in osteoclastogenesis and bone resorption accompanied by upregulation of STAT1 expression in osteoclast lineage cells. Strikingly, Morc3 protein localization within the nuclear membrane was shifted to the cytoplasm in Morc3mut +/− osteoclasts. Further, Morc3mut +/− mice displayed increased osteoblast differentiation and altered gene expression. Collectively, our data show that Morc3 is a previously unreported regulator of cortical bone homeostasis and haematopoietic stem cells niche, accompanied by altered bone cell differentiation. PMID:27188231

  10. NLRP7 affects trophoblast lineage differentiation, binds to overexpressed YY1 and alters CpG methylation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maternal-effect mutations in NLRP7 cause rare biparentally inherited hydatidiform moles (BiHMs), abnormal pregnancies containing hypertrophic vesicular trophoblast but no embryo. BiHM trophoblasts display abnormal DNA methylation patterns affecting maternally methylated germline differentially methy...

  11. Effect of pycnogenol on glucose transport in mature 3T3-L1 adipocytes.

    PubMed

    Lee, Hee-Hyun; Kim, Kui-Jin; Lee, Ok-Hwan; Lee, Boo-Yong

    2010-08-01

    Pycnogenol, a procyanidins-enriched extract of Pinus maritima bark, possesses antidiabetic properties, which improves the altered parameters of glucose metabolism that are associated with type 2 diabetes mellitus (T2DM). Since the insulin-stimulated antidiabetic activities of natural bioactive compounds are mediated by GLUT4 via the phosphatidylinositol-3-kinase (PI3K) and/or p38 mitogen activated protein kinase (p38-MAPK) pathway, the effects of pycnogenol were examined on the molecular mechanism of glucose uptake by the glucose transport system. 3T3-L1 adipocytes were treated with various concentrations of pycnogenol, and glucose uptake was examined using a non-radioisotope enzymatic assay and by molecular events associated with the glucose transport system using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The results show that pycnogenol increased glucose uptake in fully differentiated 3T3-L1 adipocytes and increased the relative abundance of both GLUT4 and Akt mRNAs through the PI3K pathway in a dose dependent manner. Furthermore, pycnogenol restored the PI3K antagonist-induced inhibition of glucose uptake in the presence of wartmannin, an inhibitor of the PI3K. Overall, these results indicate that pycnogenol may stimulate glucose uptake via the PI3K dependent tyrosine kinase pathways involving Akt. Further the results suggest that pycnogenol might be useful in maintaining blood glucose control. PMID:20658573

  12. Optical coherence tomography for blood glucose monitoring through signal attenuation

    NASA Astrophysics Data System (ADS)

    De Pretto, Lucas R.; Yoshimura, Tania M.; Ribeiro, Martha S.; de Freitas, Anderson Z.

    2016-03-01

    Development of non-invasive techniques for glucose monitoring is crucial to improve glucose control and treatment adherence in patients with diabetes. Hereafter, Optical Coherence Tomography (OCT) may offer a good alternative for portable glucometers, since it uses light to probe samples. Changes in the object of interest can alter the intensity of light returning from the sample and, through it, one can estimate the sample's attenuation coefficient (μt) of light. In this work, we aimed to explore the behavior of μt of mouse's blood under increasing glucose concentrations. Different samples were prepared in four glucose concentrations using a mixture of heparinized blood, phosphate buffer saline and glucose. Blood glucose concentrations were measured with a blood glucometer, for reference. We have also prepared other samples diluting the blood in isotonic saline solution to check the effect of a higher multiple-scattering component on the ability of the technique to differentiate glucose levels based on μt. The OCT system used was a commercial Spectral Radar OCT with 930 nm central wavelength and spectral bandwidth (FWHM) of 100 nm. The system proved to be sensitive for all blood glucose concentrations tested, with good correlations with the obtained attenuation coefficients. A linear tendency was observed, with an increase in attenuation with higher values of glucose. Statistical difference was observed between all groups (p<0.001). This work opens the possibility towards a non-invasive diagnostic modality using OCT for glycemic control, which eliminates the use of analytes and/or test strips, as in the case with commercially available glucometers.

  13. Immortalization and altered differentiation of human keratinocytes in vitro by the E6 and E7 open reading frames of human papillomavirus type 18.

    PubMed Central

    Hudson, J B; Bedell, M A; McCance, D J; Laiminis, L A

    1990-01-01

    The E6-E7 region of human papillomavirus types 16 and 18 is selectively retained and expressed in cervical carcinoma cells. In cultured human keratinocytes, expression of the E6 and E7 open reading frames of human papillomavirus type 18, under the control of its homologous promoter, resulted in high-frequency immortalization. Furthermore, by using a system that allows for stratification of keratinocytes in vitro (raft system), we observed that the morphological differentiation of these E6-E7 immortalized cells was altered such that parabasal cells extended throughout most of the epithelium, with abnormal nuclei present in the upper regions. Examination of E6-E7-expressing cell lines in the raft system at a later passage revealed that complete loss of morphological differentiation had occurred. E7 alone was a much less effective immortalizing agent than E6 and E7 together and acted only minimally to alter morphological differentiation in vitro. No such activities were found for E6 alone. High-frequency transformation of human epithelial cells thus appears to require expression of both E6 and E7 gene products. Images PMID:2153221

  14. Does apical membrane GLUT2 have a role in intestinal glucose uptake?

    PubMed Central

    Naftalin, Richard J

    2014-01-01

    It has been proposed that the non-saturable component of intestinal glucose absorption, apparent following prolonged exposure to high intraluminal glucose concentrations, is mediated via the low affinity glucose and fructose transporter, GLUT2, upregulated within the small intestinal apical border. The evidence that the non-saturable transport component is mediated via an apical membrane sugar transporter is that it is inhibited by phloretin, after exposure to phloridzin. Since the other apical membrane sugar transporter, GLUT5, is insensitive to inhibition by either cytochalasin B, or phloretin, GLUT2 was deduced to be the low affinity sugar transport route. As in its uninhibited state, polarized intestinal glucose absorption depends both on coupled entry of glucose and sodium across the brush border membrane and on the enterocyte cytosolic glucose concentration exceeding that in both luminal and submucosal interstitial fluids, upregulation of GLUT2 within the intestinal brush border will usually stimulate downhill glucose reflux to the intestinal lumen from the enterocytes; thereby reducing, rather than enhancing net glucose absorption across the luminal surface. These states are simulated with a computer model generating solutions to the differential equations for glucose, Na and water flows between luminal, cell, interstitial and capillary compartments. The model demonstrates that uphill glucose transport via SGLT1 into enterocytes, when short-circuited by any passive glucose carrier in the apical membrane, such as GLUT2, will reduce transcellular glucose absorption and thereby lead to increased paracellular flow. The model also illustrates that apical GLUT2 may usefully act as an osmoregulator to prevent excessive enterocyte volume change with altered luminal glucose concentrations. PMID:25671087

  15. Altered glucose 1,6-bisphosphate and fructose 2,6-biphosphate levels in low-frequency stimulated rabbit fast-twitch muscle.

    PubMed

    Green, H J; Cadefau, J; Pette, D

    1991-04-22

    Glucose 1,6-bisphosphate (Glc-1,6-P2) and fructose 2,6-bisphosphate (Fru-2,6-P2) concentrations display pronounced increases in rabbit fast-twitch muscle during chronic low-frequency stimulation. These increases are first seen after stimulation periods exceeding 3 h and reach maxima after 12-24 h of stimulation (approximately 3-fold for Glc-1,6-P2 and 5-fold for Fru-2,6-P2). Both metabolites regress to normal values after stimulation periods longer than 4 days. The fact that their increases coincide with the replenishment of glycogen after its initial depletion, could point to a role of Glc-1,6-P2 and Fru-2,6-P2 in glycogen metabolism. PMID:2026244

  16. A study of the FDG model in the presence of an altered blood brain barrier (BBB) and glucose metabolic/flow relationships in human brain tumors with PET

    SciTech Connect

    Hawkins, R.A.; Phelps, M.E.; Huang, S.C.; Wapenski, J.A.; Silberman, A.W.

    1985-05-01

    The authors performed 3 hour kinetic FDG studies (5 parameter model, 5th parameter represents cerebral blood volume (CBV) on 8 patients with primary or metastatic brain tumors. One subject also had a direct measurement of BBB permeability with Ga-68 EDTA and 5 subjects also had cerebral blood flow (CBF) determinations with bolus injections of 0-15 water. Estimates of hexose distribution volumes (HDV=k/sub 1/*/k/sub 2/*), FDG distribution volumes (DV=k/sub 1/*/(k/sub 2/*+k/sub 3/*), a ratio R=k/sub 3/*k/sub 2/* that is related to the stability of the lumped constant (LC) and glucose extraction ratios (GER) were calculated. GER averaged 8.8 (+- 4.6)% in tumors, 7.7 (+- 1.7)% in gray matter, 10.3 (+- 3.8)% in white matter and 8.4 (+- 2.1)% in hemispheric regions. R averaged 0.46 (+- 0.19) in tumors, 0.47 (+- 0.24) in gray matter, 0.45 (+- 0.18) in white matter and 0.57 (+- 0.25) in hemispheric regions. HDV estimates were 0.33 (+- 0.11) in tumors, 0.48 (+- 0.25) in gray matter, 0.34 (+- 0.14) in white matter and 0.38 (+- 0.25) in hemispheric regions. DV estimates were smaller than HDV but were not significantly different over the same groups. These results suggest that the compartmental configuration of the FDG model is still appropriate in this set of patients with increased BBB permeability and that LC is relatively stable. A lack of significant increase in the FDG rate constants k/sub 1/* and k/sub 2/* with increases BBB permeability suggests that facilitated diffusion remains the dominant mechanism of glucose transport even with BBB abnormalities.

  17. Does Ramadan fasting alter body weight and blood lipids and fasting blood glucose in a healthy population? A meta-analysis.

    PubMed

    Kul, Seval; Savaş, Esen; Öztürk, Zeynel Abidin; Karadağ, Gülendam

    2014-06-01

    In this study, we conducted a meta-analysis of self-controlled cohort studies comparing body weights, blood levels of lipids and fasting blood glucose levels before and after Ramadan taking into account gender differences. Several databases were searched up to June 2012 for studies showing an effect of Ramadan fasting in healthy subjects, yielding 30 articles. The primary finding of this meta-analysis was that after Ramadan fasting, low-density lipoprotein (SMD = -1.67, 95 % CI = -2.48 to -0.86) and fasting blood glucose levels (SMD = -1.10, 95 % CI = -1.62 to -0.58) were decreased in both sex groups and also in the entire group compared to levels prior to Ramadan. In addition, in the female subgroup, body weight (SMD = -0.04, 95 % CI = -0.20, 0.12), total cholesterol (SMD = 0.05, 95 % CI = -0.51 to 0.60), and triglyceride levels (SMD = 0.03, 95 % CI = -0.31, 0.36) remained unchanged, while HDL levels (SMD = 0.86, 95 % CI = 0.11 to 1.61, p = 0.03) were increased. In males, Ramadan fasting resulted in weight loss (SMD = -0.24, 95 % CI = -0.36, -0.12, p = 0.001). Also, a substantial reduction in total cholesterol (SMD = -0.44, 95 % CI = -0.77 to -0.11) and LDL levels (SMD = -2.22, 95 % CI = -3.47 to -0.96) and a small decrease in triglyceride levels (SMD = -0.35, 95 % CI = -0.67 to -0.02) were observed in males. In conclusion, by looking at this data, it is evident that Ramadan fasting can effectively change body weight and some biochemical parameters in healthy subjects especially in males compared to pre-Ramadan period. PMID:23423818

  18. Altered 13C glucose metabolism in the cortico–striato–thalamo–cortical loop in the MK-801 rat model of schizophrenia

    PubMed Central

    Eyjolfsson, Elvar M; Nilsen, Linn Hege; Kondziella, Daniel; Brenner, Eiliv; Håberg, Asta; Sonnewald, Ursula

    2011-01-01

    Using a modified MK-801 (dizocilpine) N-methyl--aspartic acid (NMDA) receptor hypofunction model for schizophrenia, we analyzed glycolysis, as well as glutamatergic, GABAergic, and monoaminergic neurotransmitter synthesis and degradation. Rats received an injection of MK-801 daily for 6 days and on day 6, they also received an injection of [1-13C]glucose. Extracts of frontal cortex (FCX), parietal and temporal cortex (PTCX), thalamus, striatum, nucleus accumbens (NAc), and hippocampus were analyzed using 13C nuclear magnetic resonance spectroscopy, high-performance liquid chromatography, and gas chromatography–mass spectrometry. A pronounced reduction in glycolysis was found only in PTCX, in which 13C labeling of glucose, lactate, and alanine was decreased. 13C enrichment in lactate, however, was reduced in all areas investigated. The largest reductions in glutamate labeling were detected in FCX and PTCX, whereas in hippocampus, striatum, and Nac, 13C labeling of glutamate was only slightly but significantly reduced. The thalamus was the only region with unaffected glutamate labeling. γ-Aminobutyric acid (GABA) labeling was reduced in all areas, but most significantly in FCX. Glutamine and aspartate labeling was unchanged. Mitochondrial metabolites were also affected. Fumarate labeling was reduced in FCX and thalamus, whereas malate labeling was reduced in FCX, PTCX, striatum, and NAc. Dopamine turnover was decreased in FCX and thalamus, whereas that of serotonin was unchanged in all regions. In conclusion, neurotransmitter metabolism in the cortico–striato–thalamo–cortical loop is severely impaired in the MK-801 (dizocilpine) NMDA receptor hypofunction animal model for schizophrenia. PMID:21081956

  19. Apolipoprotein A-I glycation by Glucose and Reactive Aldehydes Alters Phospholipid Affinity but Not Cholesterol Export from Lipid-Laden Macrophages

    PubMed Central

    Brown, Bronwyn E.; Nobecourt, Estelle; Zeng, Jingmin; Jenkins, Alicia J.; Rye, Kerry-Anne; Davies, Michael J.

    2013-01-01

    Increased protein glycation in people with diabetes may promote atherosclerosis. This study examined the effects of non-enzymatic glycation on the association of lipid-free apolipoproteinA-I (apoA-I) with phospholipid, and cholesterol efflux from lipid-loaded macrophages to lipid-free and lipid-associated apoA-I. Glycation of lipid-free apoA-I by methylglyoxal and glycolaldehyde resulted in Arg, Lys and Trp loss, advanced glycation end-product formation and protein cross-linking. The association of apoA-I glycated by glucose, methylglyoxal or glycolaldehyde with phospholipid multilamellar vesicles was impaired in a glycating agent dose-dependent manner, with exposure of apoA-I to both 30 mM glucose (42% decrease in kslow) and 3 mM glycolaldehyde (50% decrease in kfast, 60% decrease in kslow) resulting is significantly reduced affinity. Cholesterol efflux to control or glycated lipid-free apoA-I, or discoidal reconstituted HDL containing glycated apoA-I (drHDL), was examined using cholesterol-loaded murine (J774A.1) macrophages treated to increase expression of ATP binding cassette transporters A1 (ABCA1) or G1 (ABCG1). Cholesterol efflux from J774A.1 macrophages to glycated lipid-free apoA-I via ABCA1 or glycated drHDL via an ABCG1-dependent mechanism was unaltered, as was efflux to minimally modified apoA-I from people with Type 1 diabetes, or controls. Changes to protein structure and function were prevented by the reactive carbonyl scavenger aminoguanidine. Overall these studies demonstrate that glycation of lipid-free apoA-I, particularly late glycation, modifies its structure, its capacity to bind phospholipids and but not ABCA1- or ABCG1-dependent cholesterol efflux from macrophages. PMID:23741493

  20. Perfluorooctane sulfonate induces neuronal and oligodendrocytic differentiation in neural stem cells and alters the expression of PPARγ in vitro and in vivo

    SciTech Connect

    Wan Ibrahim, Wan Norhamidah; Tofighi, Roshan; Onishchenko, Natalia; Rebellato, Paola; Bose, Raj; Uhlén, Per; Ceccatelli, Sandra

    2013-05-15

    Perfluorinated compounds are ubiquitous chemicals of major concern for their potential adverse effects on the human population. We have used primary rat embryonic neural stem cells (NSCs) to study the effects of perfluorooctane sulfonate (PFOS) on the process of NSC spontaneous differentiation. Upon removal of basic fibroblast growth factor, NSCs were exposed to nanomolar concentrations of PFOS for 48 h, and then allowed to differentiate for additional 5 days. Exposure to 25 or 50 nM concentration resulted in a lower number of proliferating cells and a higher number of neurite-bearing TuJ1-positive cells, indicating an increase in neuronal differentiation. Exposure to 50 nM also significantly increased the number of CNPase-positive cells, pointing to facilitation of oligodendrocytic differentiation. PPAR genes have been shown to be involved in PFOS toxicity. By q-PCR we detected an upregulation of PPARγ with no changes in PPARα or PPARδ genes. One of the downstream targets of PPARs, the mitochondrial uncoupling protein 2 (UCP2) was also upregulated. The number of TuJ1- and CNPase-positive cells increased after exposure to PPARγ agonist rosiglitazone (RGZ, 3 μM) and decreased after pre-incubation with the PPARγ antagonist GW9662 (5 μM). RGZ also upregulated the expression of PPARγ and UCP2 genes. Meanwhile GW9662 abolished the UCP2 upregulation and decreased Ca{sup 2+} activity induced by PFOS. Interestingly, a significantly higher expression of PPARγ and UCP3 genes was also detected in mouse neonatal brain after prenatal exposure to PFOS. These data suggest that PPARγ plays a role in the alteration of spontaneous differentiation of NSCs induced by nanomolar concentrations of PFOS. - Highlights: • PFOS decreases proliferation of neural stem cells (NSCs). • PFOS induces neuronal and oligodendrocytic differentiation in NSCs. • PFOS alters expression of PPARγ and UCP2 in vitro. • PFOS alters expression of PPARγ and UCP3 in vivo. • Block of PPAR

  1. Altered MicroRNA Expression Profile in Exosomes during Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells

    PubMed Central

    Zhang, Shui-Jun; Zhao, Chen; Qiu, Bin-Song; Gu, Hai-Feng; Hong, Jian-Fei; Cao, Li; Chen, Yu; Xia, Bing; Bi, Qin; Wang, Ya-Ping

    2014-01-01

    The physiological role of microRNAs (miRNAs) in osteoblast differentiation remains elusive. Exosomal miRNAs isolated from human bone marrow-derived mesenchymal stem cells (BMSCs) culture were profiled using miRNA arrays containing probes for 894 human matured miRNAs. Seventy-nine miRNAs (∼8.84%) could be detected in exosomes isolated from BMSC culture supernatants when normalized to endogenous control genes RNU44. Among them, nine exosomal miRNAs were up regulated and 4 miRNAs were under regulated significantly (Relative fold>2, p<0.05) when compared with the values at 0 day with maximum changes at 1 to 7 days. Five miRNAs (miR-199b, miR-218, miR-148a, miR-135b, and miR-221) were further validated and differentially expressed in the individual exosomal samples from hBMSCs cultured at different time points. Bioinformatic analysis by DIANA-mirPath demonstrated that RNA degradation, mRNA surveillance pathway, Wnt signaling pathway, RNA transport were the most prominent pathways enriched in quantiles with differential exosomal miRNA patterns related to osteogenic differentiation. These data demonstrated exosomal miRNA is a regulator of osteoblast differentiation. PMID:25503309

  2. β-Adrenergic Receptor-Dependent Alterations in Murine Cardiac Transcript Expression Are Differentially Regulated by Gefitinib In Vivo

    PubMed Central

    Talarico, Jennifer A.; Carter, Rhonda L.; Grisanti, Laurel A.; Yu, Justine E.; Repas, Ashley A.; Tilley, Douglas G.

    2014-01-01

    β-adrenergic receptor (βAR)-mediated transactivation of epidermal growth factor receptor (EGFR) has been shown to promote cardioprotection in a mouse model of heart failure and we recently showed that this mechanism leads to enhanced cell survival in part via regulation of apoptotic transcript expression in isolated primary rat neonatal cardiomyocytes. Thus, we hypothesized that this process could regulate cardiac transcript expression in vivo. To comprehensively assess cardiac transcript alterations in response to acute βAR-dependent EGFR transactivation, we performed whole transcriptome analysis of hearts from C57BL/6 mice given i.p. injections of the βAR agonist isoproterenol in the presence or absence of the EGFR antagonist gefitinib for 1 hour. Total cardiac RNA from each treatment group underwent transcriptome analysis, revealing a substantial number of transcripts regulated by each treatment. Gefitinib alone significantly altered the expression of 405 transcripts, while isoproterenol either alone or in conjunction with gefitinib significantly altered 493 and 698 distinct transcripts, respectively. Further statistical analysis was performed, confirming 473 transcripts whose regulation by isoproterenol were significantly altered by gefitinib (isoproterenol-induced up/downregulation antagonized/promoted by gefinitib), including several known to be involved in the regulation of numerous processes including cell death and survival. Thus, βAR-dependent regulation of cardiac transcript expression in vivo can be modulated by the EGFR antagonist gefitinib. PMID:24901703

  3. Differential population responses of native and alien rodents to an invasive predator, habitat alteration and plant masting.

    PubMed

    Fukasawa, Keita; Miyashita, Tadashi; Hashimoto, Takuma; Tatara, Masaya; Abe, Shintaro

    2013-12-22

    Invasive species and anthropogenic habitat alteration are major drivers of biodiversity loss. When multiple invasive species occupy different trophic levels, removing an invasive predator might cause unexpected outcomes owing to complex interactions among native and non-native prey. Moreover, external factors such as habitat alteration and resource availability can affect such dynamics. We hypothesized that native and non-native prey respond differently to an invasive predator, habitat alteration and bottom-up effects. To test the hypothesis, we used Bayesian state-space modelling to analyse 8-year data on the spatio-temporal patterns of two endemic rat species and the non-native black rat in response to the continual removal of the invasive small Indian mongoose on Amami Island, Japan. Despite low reproductive potentials, the endemic rats recovered better after mongoose removal than did the black rat. The endemic species appeared to be vulnerable to predation by mongooses, whose eradication increased the abundances of the endemic rats, but not of the black rat. Habitat alteration increased the black rat's carrying capacity, but decreased those of the endemic species. We propose that spatio-temporal monitoring data from eradication programmes will clarify the underlying ecological impacts of land-use change and invasive species, and will be useful for future habitat management. PMID:24197409

  4. Phenolic composition of basil plants is differentially altered by plant nutrient status and inoculation with mycorrhizal fungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quality of basil plants (Ocimum basilicum) used in certain fresh and dry products is a function of its production of secondary metabolites, including phenolic compounds. Nutrient availability, particularly phosphorus (P), can alter plant production of secondary metabolites, and root infection by arb...

  5. Differential population responses of native and alien rodents to an invasive predator, habitat alteration and plant masting

    PubMed Central

    Fukasawa, Keita; Miyashita, Tadashi; Hashimoto, Takuma; Tatara, Masaya; Abe, Shintaro

    2013-01-01

    Invasive species and anthropogenic habitat alteration are major drivers of biodiversity loss. When multiple invasive species occupy different trophic levels, removing an invasive predator might cause unexpected outcomes owing to complex interactions among native and non-native prey. Moreover, external factors such as habitat alteration and resource availability can affect such dynamics. We hypothesized that native and non-native prey respond differently to an invasive predator, habitat alteration and bottom-up effects. To test the hypothesis, we used Bayesian state-space modelling to analyse 8-year data on the spatio-temporal patterns of two endemic rat species and the non-native black rat in response to the continual removal of the invasive small Indian mongoose on Amami Island, Japan. Despite low reproductive potentials, the endemic rats recovered better after mongoose removal than did the black rat. The endemic species appeared to be vulnerable to predation by mongooses, whose eradication increased the abundances of the endemic rats, but not of the black rat. Habitat alteration increased the black rat's carrying capacity, but decreased those of the endemic species. We propose that spatio-temporal monitoring data from eradication programmes will clarify the underlying ecological impacts of land-use change and invasive species, and will be useful for future habitat management. PMID:24197409

  6. Natural killer group 2D and CD28 receptors differentially activate mammalian/mechanistic target of rapamycin to alter murine effector CD8+ T-cell differentiation.

    PubMed

    McQueen, Bryan; Trace, Kelsey; Whitman, Emily; Bedsworth, Taylor; Barber, Amorette

    2016-03-01

    Memory CD8+ T cells are an essential component of anti-tumour and anti-viral immunity. Activation of the mammalian/mechanistic target of rapamycin (mTOR) pathway has been implicated in regulating the differentiation of effector and memory T cells. However, the mechanisms that control mTOR activity during immunity to tumours and infections are not well known. Activation of co-stimulatory receptors, including CD28 and natural killer group 2D (NKG2D), activate phosphatidylinositol-3 kinase and subsequently may activate the mTOR pathway in CD8+ T cells. This study compared the activation of the mTOR signalling pathway after co-stimulation through CD28 or NKG2D receptors in murine effector CD8+ T cells. Compared with CD28 co-stimulation, activation through CD3 and NKG2D receptors had weaker activation of mTORc1, as shown by decreased phosphorylation of mTORc1 targets S6K1, ribosomal protein S6 and eukaryotic initiation factor 4E binding protein 1. NKG2D co-stimulation also showed increased gene expression of tuberous sclerosis protein 2, a negative regulator of mTORc1, whereas CD28 co-stimulation increased gene expression of Ras homologue enriched in brain, an activator of mTORc1, and hypoxia-inducible factor-1α and vascular endothelial growth factor-α, pro-angiogenic factors downstream of mTORc1. Strong mTORc1 activation in CD28-co-stimulated cells also increased expression of transcription factors that support effector cell differentiation, namely T-bet, B lymphocyte-induced maturation protein (BLIMP-1), interferon regulatory factor 4, and inhibitor of DNA binding 2, whereas low levels of mTORc1 activation allowed for the expression of Eomes, B-cell lymphoma 6 (BCL6), and inhibitor of DNA binding 3 during NKG2D stimulation, and increased expression of memory markers CD62 ligand and CD127. These data show that compared with CD28, co-stimulation through the NKG2D receptor leads to the differential activation of the mTOR signalling pathway and potentially supports

  7. Structure Function Relationships of ADP-Glucose Pyrophosphorylase and Branching Enzyme: Manipulation of Their Genes for Alteration of Starch Quanlity and Quantity

    SciTech Connect

    Jack Preiss

    2006-02-16

    Conversion of the Potato tuber ADP-glucose Pyrophopshorylase Regulatory Subunit into a Catalytic Subunit. ADP-glucose synthesis, a rate-limiting reaction in starch synthesis, is catalyzed by ADP-glucose pyrophosphorylase (ADPGlc PPase). The enzyme in plants is allosterically activated by 3-phosphoglycerate (3PGA) and inhibited by inorganic phosphate (Pi) and is composed of two subunits as a heterotetramer, a2b2. Subunit a is the catalytic subunit and subunit b is designated as the regulatory subunit.The b subunit increases the affinty of the activator for the catalytic subunit. Recent results have shown that the subunits are derived from the same ancestor subunit as the regulatory subunit can be converted to a catalytically subunit via mutation of just two amino acids. Lys44 and Thr54 in the large subunit from potato tuber were converted to the homologous catalytic subunit residues, Arg33 and Lys43. The activity of the large subunit mutants cannot be readily tested with a co-expressed wild-type small (catalytic) subunit because of the intrinsic activity of the latter. We co-expressed the regulatory-subunit mutants with SmallD145N, an inactive S subunit in which the catalytic Asp145 was mutated. The activity of the small (catalytic) subunit was reduced more than three orders of magnitude. Coexpression of the L subunit double mutant LargeK44R/T54K with SmallD145N generated an enzyme with considerable activity, 10% and 18% of the wildtype enzyme, in the ADP-glucose synthetic and pyrophosphorolytic direction, respectively. Replacement of those two residues in the small subunit by the homologous amino acids in the L subunits (mutations R33K and K43T) decreased the activity one and two orders of magnitude. The wild-type enzyme and SmallD145NLargeK44R/T54K had very similar kinetic properties indicating that the substrate site has been conserved. The fact that only two mutations in the L subunit restored enzyme activity is very strong evidence that the large subunit is

  8. Forcing neural progenitor cells to cycle is insufficient to alter cell-fate decision and timing of neuronal differentiation in the spinal cord

    PubMed Central

    Lobjois, Valérie; Bel-Vialar, Sophie; Trousse, Françoise; Pituello, Fabienne

    2008-01-01

    cycle exit. Conclusion Our findings indicate that maintaining neural progenitor cells in proliferation is insufficient to prevent differentiation or alter cell-fate choice. Furthermore, our results indicate that the programs of neuronal specification and differentiation are controlled independently of cell cycle exit. PMID:18271960

  9. Prenatal Alcohol Exposure and Chronic Mild Stress Differentially Alter Depressive- and Anxiety-Like Behaviors in Male and Female Offspring

    PubMed Central

    Hellemans, Kim G. C.; Verma, Pamela; Yoon, Esther; Yu, Wayne K.; Young, Allan H.; Weinberg, Joanne

    2016-01-01

    Background Fetal Alcohol Spectrum Disorder (FASD) is associated with numerous neuro behavioral alterations, as well as disabilities in a number of domains, including a high incidence of depression and anxiety disorders. Prenatal alcohol exposure (PAE) also alters hypothalamic-pituitary-adrenal (HPA) function, resulting in increased responsiveness to stressors and HPA dysregulation in adulthood. Interestingly, data suggest that pre-existing HPA abnormalities may be a major contributory factor to some forms of depression, particularly when an individual is exposed to stressors later in life. We tested the hypothesis that exposure to stressors in adulthood may unmask an increased vulnerability to depressive- and anxiety-like behaviors in PAE animals. Methods Male and female offspring from prenatal alcohol (PAE), pair-fed (PF), and ad libitumfed control (C) treatment groups were tested in adulthood. Animals were exposed to 10 consecutive days of chronic mild stress (CMS), and assessed in a battery of well-validated tasks sensitive to differences in depressive- and / or anxiety-like behaviors. Results We report here that the combination of PAE and CMS in adulthood increases depressive- and anxiety-like behaviors in a sexually dimorphic manner. PAE males showed impaired hedonic responsivity (sucrose contrast test), locomotor hyperactivity (open field), and alterations in affiliative and nonaffiliative social behaviors (social interaction test) compared to control males. By contrast, PAE and, to a lesser extent, PF, females showed greater levels of “behavioral despair” in the forced swim test, and PAE females showed altered behavior in the final 5 minutes of the social interaction test compared to control females. Conclusions These data support the possibility that stress may be a mediating or contributing factor in the psychopathologies reported in FASD populations. PMID:20102562

  10. Loss of lysophosphatidic acid receptor LPA1 alters oligodendrocyte differentiation and myelination in the mouse cerebral cortex.

    PubMed

    García-Díaz, Beatriz; Riquelme, Raquel; Varela-Nieto, Isabel; Jiménez, Antonio Jesús; de Diego, Isabel; Gómez-Conde, Ana Isabel; Matas-Rico, Elisa; Aguirre, José Ángel; Chun, Jerold; Pedraza, Carmen; Santín, Luis Javier; Fernández, Oscar; Rodríguez de Fonseca, Fernando; Estivill-Torrús, Guillermo

    2015-11-01

    Lysophosphatidic acid (LPA) is an intercellular signaling lipid that regulates multiple cellular functions, acting through specific G-protein coupled receptors (LPA(1-6)). Our previous studies using viable Malaga variant maLPA1-null mice demonstrated the requirement of the LPA1 receptor for normal proliferation, differentiation, and survival of the neuronal precursors. In the cerebral cortex LPA1 is expressed extensively in differentiating oligodendrocytes, in parallel with myelination. Although exogenous LPA-induced effects have been investigated in myelinating cells, the in vivo contribution of LPA1 to normal myelination remains to be demonstrated. This study identified a relevant in vivo role for LPA1 as a regulator of cortical myelination. Immunochemical analysis in adult maLPA1-null mice demonstrated a reduction in the steady-state levels of the myelin proteins MBP, PLP/DM20, and CNPase in the cerebral cortex. The myelin defects were confirmed using magnetic resonance spectroscopy and electron microscopy. Stereological analysis limited the defects to adult differentiating oligodendrocytes, without variation in the NG2+ precursor cells. Finally, a possible mechanism involving oligodendrocyte survival was demonstrated by the impaired intracellular transport of the PLP/DM20 myelin protein which was accompanied by cellular loss, suggesting stress-induced apoptosis. These findings describe a previously uncharacterized in vivo functional role for LPA1 in the regulation of oligodendrocyte differentiation and myelination in the CNS, underlining the importance of the maLPA1-null mouse as a model for the study of demyelinating diseases. PMID:25226845

  11. Differentiation-specific alterations to glutathione synthesis in and hormonally stimulated release from human skeletal muscle cells.

    PubMed

    Cotgreave, Ian A; Goldschmidt, Lina; Tonkonogi, Michail; Svensson, Michael

    2002-03-01

    Muscle atrophy and cachexia are associated with many human diseases. These catabolic states are often associated with the loss of glutathione (GSH), which is thought to contribute to the induction of oxidative stress within the muscle. Glutathione synthesis and secretary characteristics were studied in human skeletal muscle myoblasts and myotube-like cells derived from the myoblasts by growth factor restriction. Differentiation was associated with a shift in the sulfur amino acid precursor specificity for synthesis of GSH from cystine to cysteine, as well as loss in ability to use extracellular glutathione and activation of methionine use. The thiol drug N-acetylcysteine was also shown to be an effective precursor irrespective of the state of differentiation. Additionally, myoblasts and myotube cultures were shown to secrete GSH continually, but only the differentiated cells responded to stress hormones such as glucagon, vasopressin, and phenylephrine, by increased secretion of the tripeptide. The data suggest that the skeletal muscle cells may provide an important hormonally regulated extra-hepatic source of systemic GSH and also shed light on the mechanisms of accelerated turnover of GSH operating during strenuous muscle activity and trauma. The data may also provide biochemical rationales for the nutritional and/or pharmacological manipulation of GSH with sulfur amino acid precursors during the treatment of muscle-specific oxidative stress and atrophy. PMID:11821257

  12. Differential Proteomic Analysis Using iTRAQ Reveals Alterations in Hull Development in Rice (Oryza sativa L.)

    PubMed Central

    Xiao, Wenfei; Yang, Changdeng; Xin, Ya; Qiu, Jieren; Hu, Weimin; Ying, Wu; Fu, Yaping; Tong, Jianxin; Hu, Guocheng; Chen, Zhongzhong; Fang, Xianping; Yu, Hong; Lai, Wenguo; Ruan, Songlin; Ma, Huasheng

    2015-01-01

    Rice hull, the outer cover of the rice grain, determines grain shape and size. Changes in the rice hull proteome in different growth stages may reflect the underlying mechanisms involved in grain development. To better understand these changes, isobaric tags for relative and absolute quantitative (iTRAQ) MS/MS was used to detect statistically significant changes in the rice hull proteome in the booting, flowering, and milk-ripe growth stages. Differentially expressed proteins were analyzed to predict their potential functions during development. Gene ontology (GO) terms and pathways were used to evaluate the biological mechanisms involved in rice hull at the three growth stages. In total, 5,268 proteins were detected and characterized, of which 563 were differentially expressed across the development stages. The results showed that the flowering and milk-ripe stage proteomes were more similar to each other (r=0.61) than either was to the booting stage proteome. A GO enrichment analysis of the differentially expressed proteins was used to predict their roles during rice hull development. The potential functions of 25 significantly differentially expressed proteins were used to evaluate their possible roles at various growth stages. Among these proteins, an unannotated protein (Q7X8A1) was found to be overexpressed especially in the flowering stage, while a putative uncharacterized protein (B8BF94) and an aldehyde dehydrogenase (Q9FPK6) were overexpressed only in the milk-ripe stage. Pathways regulated by differentially expressed proteins were also analyzed. Magnesium-protoporphyrin IX monomethyl ester [oxidative] cyclase (Q9SDJ2), and two magnesium-chelatase subunits, ChlD (Q6ATS0), and ChlI (Q53RM0), were associated with chlorophyll biosynthesis at different developmental stages. The expression of Q9SDJ2 in the flowering and milk-ripe stages was validated by qRT-PCR. The 25 candidate proteins may be pivotal markers for controlling rice hull development at various

  13. Differential Larval Toxicity and Oviposition Altering Activity of Some Indigenous Plant Extracts against Dengue and Chikungunya Vector Aedes albopictus

    PubMed Central

    Yadav, Ruchi; Tyagi, Varun; Tikar, Sachin N; Sharma, Ajay K; Mendki, Murlidhar J; Jain, Ashok K; Sukumaran, Devanathan

    2014-01-01

    Background: Mosquitoes are well known as vectors of several disease causing pathogens. The extensive use of synthetic insecticides in the mosquito control strategies resulted to the development of pesticide resistance and fostered environmental deterioration. Hence in recent years plants become alternative source of mosquito control agents. The present study assessed the larvicidal and oviposition altering activity of six different plants species-Alstonia scholaris, Callistemon viminalis, Hyptis suaveolens, Malvastrum coromandelianum, Prosopis juliflora, Vernonia cinerea against Aedes albopictus mosquito in laboratory. Methods: Leaf extracts of all the six plants species in five different solvents of various polarities were used in the range of 20–400ppm for larval bioassay and 50,100 and 200ppm for cage bioassay (for the study of oviposition behavior) against Ae. albopictus. The larval mortality data were recorded after 24 h and subjected to Probit analysis to determine the lethal concentrations (LC50), while OAI (Oviposition activity index) was calculated for oviposition altering activity of the plant extracts. Results: Vernonia cinerea extract in acetone and C. viminalis extract in isopropanol were highly effective against Aedes albopictus larvae with LC50 value 64.57, 71.34ppm respectively. Acetone extract of P. juliflora found to be strong oviposition-deterrent which inhibited >2 fold egg laying (OAI-0.466) at 100ppm. Conclusion: Vernonia cinerea and C. viminallis leaf extracts have the potential to be used as larvicide and P. juliflora as an oviposition-deterrent for the control of Ae. albopictus mosquito. PMID:26114131

  14. Landscape alterations influence differential habitat use of nesting buteos and ravens within sagebrush ecosystem: implications for transmission line development

    USGS Publications Warehouse

    Coates, Peter S.; Howe, Kristy B.; Casazza, Michael L.; Delehanty, David J.

    2014-01-01

    A goal in avian ecology is to understand factors that influence differences in nesting habitat and distribution among species, especially within changing landscapes. Over the past 2 decades, humans have altered sagebrush ecosystems as a result of expansion in energy production and transmission. Our primary study objective was to identify differences in the use of landscape characteristics and natural and anthropogenic features by nesting Common Ravens (Corvus corax) and 3 species of buteo (Swainson's Hawk [Buteo swainsoni], Red-tailed Hawk [B. jamaicensis], and Ferruginous Hawk [B. regalis]) within a sagebrush ecosystem in southeastern Idaho. During 2007–2009, we measured multiple environmental factors associated with 212 nest sites using data collected remotely and in the field. We then developed multinomial models to predict nesting probabilities by each species and predictive response curves based on model-averaged estimates. We found differences among species related to nesting substrate (natural vs. anthropogenic), agriculture, native grassland, and edge (interface of 2 cover types). Most important, ravens had a higher probability of nesting on anthropogenic features (0.80) than the other 3 species (Artemisia spp.), favoring increased numbers of nesting ravens and fewer nesting Ferruginous Hawks. Our results indicate that habitat alterations, fragmentation, and forthcoming disturbances anticipated with continued energy development in sagebrush steppe ecosystems can lead to predictable changes in raptor and raven communities.

  15. Sinorhizobium fredii HH103 bacteroids are not terminally differentiated and show altered O-antigen in nodules of the Inverted Repeat-Lacking Clade legume Glycyrrhiza uralensis.

    PubMed

    Crespo-Rivas, Juan C; Guefrachi, Ibtissem; Mok, Kenny C; Villaécija-Aguilar, José A; Acosta-Jurado, Sebastián; Pierre, Olivier; Ruiz-Sainz, José E; Taga, Michiko E; Mergaert, Peter; Vinardell, José M

    2016-09-01

    In rhizobial species that nodulate inverted repeat-lacking clade (IRLC) legumes, such as the interaction between Sinorhizobium meliloti and Medicago, bacteroid differentiation is driven by an endoreduplication event that is induced by host nodule-specific cysteine rich (NCR) antimicrobial peptides and requires the participation of the bacterial protein BacA. We have studied bacteroid differentiation of Sinorhizobium fredii HH103 in three host plants: Glycine max, Cajanus cajan and the IRLC legume Glycyrrhiza uralensis. Flow cytometry, microscopy analyses and viability studies of bacteroids as well as confocal microscopy studies carried out in nodules showed that S. fredii HH103 bacteroids, regardless of the host plant, had deoxyribonucleic acid (DNA) contents, cellular sizes and survival rates similar to those of free-living bacteria. Contrary to S. meliloti, S. fredii HH103 showed little or no sensitivity to Medicago NCR247 and NCR335 peptides. Inactivation of S. fredii HH103 bacA neither affected symbiosis with Glycyrrhiza nor increased bacterial sensitivity to Medicago NCRs. Finally, HH103 bacteroids isolated from Glycyrrhiza, but not those isolated from Cajanus or Glycine, showed an altered lipopolysaccharide. Our studies indicate that, in contrast to the S. meliloti-Medicago model symbiosis, bacteroids in the S. fredii HH103-Glycyrrhiza symbiosis do not undergo NCR-induced and bacA-dependent terminal differentiation. PMID:26521863

  16. Differential alterations in gene expression profiles contribute to time-dependent effects of nandrolone to prevent denervation atrophy

    PubMed Central

    2010-01-01

    Background Anabolic steroids, such as nandrolone, slow muscle atrophy, but the mechanisms responsible for this effect are largely unknown. Their effects on muscle size and gene expression depend upon time, and the cause of muscle atrophy. Administration of nandrolone for 7 days beginning either concomitantly with sciatic nerve transection (7 days) or 29 days later (35 days) attenuated denervation atrophy at 35 but not 7 days. We reasoned that this model could be used to identify genes that are regulated by nandrolone and slow denervation atrophy, as well as genes that might explain the time-dependence of nandrolone effects on such atrophy. Affymetrix microarrays were used to profile gene expression changes due to nandrolone at 7 and 35 days and to identify major gene expression changes in denervated muscle between 7 and 35 days. Results Nandrolone selectively altered expression of 124 genes at 7 days and 122 genes at 35 days, with only 20 genes being regulated at both time points. Marked differences in biological function of genes regulated by nandrolone at 7 and 35 days were observed. At 35, but not 7 days, nandrolone reduced mRNA and protein levels for FOXO1, the mTOR inhibitor REDD2, and the calcineurin inhibitor RCAN2 and increased those for ApoD. At 35 days, correlations between mRNA levels and the size of denervated muscle were negative for RCAN2, and positive for ApoD. Nandrolone also regulated genes for Wnt signaling molecules. Comparison of gene expression at 7 and 35 days after denervation revealed marked alterations in the expression of 9 transcriptional coregulators, including Ankrd1 and 2, and many transcription factors and kinases. Conclusions Genes regulated in denervated muscle after 7 days administration of nandrolone are almost entirely different at 7 versus 35 days. Alterations in levels of FOXO1, and of genes involved in signaling through calcineurin, mTOR and Wnt may be linked to the favorable action of nandrolone on denervated muscle. Marked

  17. A prospective evaluation of the influence of three bariatric procedures on insulin resistance improvement. Should the extent of undiluted bile transit be considered a key postoperative factor altering glucose metabolism?

    PubMed Central

    Proczko, Monika; Wiśniewski, Piotr; Stankiewicz, Marta; Gill, Derek; Śledziński, Zbigniew

    2015-01-01

    Introduction Insulin resistance (IR), the essential step in development of type 2 diabetes mellitus (T2DM), resolves quickly after bariatric surgery, but the effectiveness depends on the type of the procedure. Although the long-term influence on IR improvement is well documented, the mechanisms of the ultra-fast response after restrictive and bypass procedures require explanation. Aim To determine IR evolution from the initial preparative period to 6 months after the operation, exposing the rapid postoperative response while comparing the 3 bariatric methods, with the belief that the metabolic effect may be correlated with anatomical combinations. Material and methods From January to December, 2013, a cohort of severely obese, insulin resistant individuals recruited to the prospective study underwent laparoscopic sleeve gastrectomy (SG-30), Roux-en-Y gastric bypass (RYGB-30) and one-anastomosis gastric bypass (OAGB-30). Main laboratory parameters of glucose metabolism were evaluated in fasting patients preoperatively, 4 days and 1, 3 and 6 months after surgery. Results Within the whole observation period the most significant improvement in homeostasis model assessment for IR (HOMA-IR) was observed in the first 4 days after each operation. The decrease of HOMA-IR was higher (p < 0.0001) in gastric bypass groups than in patients after SG (–41%). The difference between bypass groups favors OAGB over RYGB (63 vs. –56%, p = 0.0489). Conclusions Among all bariatric management factors, operation type is the most important in IR improvement. The significant difference in response after SG vs. RYGB and OAGB supports the concept of metabolic competence of duodeno-jejunal exclusion. Altered bile flow after duodeno-jejunal exclusion may be responsible for enhanced glucose metabolism improvement. PMID:26240621

  18. Targeted Expression of GLI1 in the Salivary Glands Results in an Altered Differentiation Program and Hyperplasia

    PubMed Central

    Fiaschi, Marie; Kolterud, Åsa; Nilsson, Mats; Toftgård, Rune; Rozell, Björn

    2011-01-01

    Hedgehog (Hh) signaling is a regulator of salivary gland morphogenesis, but its role in postnatal glands has only recently begun to be addressed. To examine the effects of deregulated Hh signaling in the salivary gland, we expressed the Hh effector protein GLI1, in salivary epithelial cells using both cytokeratin 5 and mouse mammary tumor virus (MMTV) transgenic systems. Ectopic pathway activation resulted in restrained acinar differentiation, formation of cystic lesions, and prominent appearance of ductal structures. Moreover, induced expression of GLI1 aids the formation of hyperplastic lesions, which closely resemble GLI1-induced changes in murine skin and mammary glands, suggesting that GLI1 targets cells with similar characteristics in different tissues. Furthermore, GLI1-expressing salivary epithelial cells are actively dividing, and GLI1-induced lesions are proliferative, an incident accompanied by enhanced expression of the Hh target genes, cyclin D1, and Snail. GLI1-induced salivary lesions regress after transgene withdrawal and become histologically normalized. Taken together, our data reveal the ability of GLI1 to modulate salivary acinar differentiation and to promote proliferation of ductal epithelial cells. PMID:21933656

  19. Perfluorinated chemicals: Differential toxicity, inhibition of aromatase activity and alteration of cellular lipids in human placental cells

    SciTech Connect

    Gorrochategui, Eva; Pérez-Albaladejo, Elisabet; Casas, Josefina; Lacorte, Sílvia; Porte, Cinta

    2014-06-01

    The cytotoxicity of eight perfluorinated chemicals (PFCs), namely, perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorododecanoic acid (PFDoA), perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS) and perfluorooctanesulfonate (PFOS) was assessed in the human placental choriocarcinoma cell line JEG-3. Only the long chain PFCs – PFOS, PFDoA, PFNA, PFOA – showed significant cytotoxicity in JEG-3 cells with EC50 values in the range of 107 to 647 μM. The observed cytotoxicity was to some extent related to a higher uptake of the longer chain PFCs by cells (PFDoA > PFOS ≫ PFNA > PFOA > PFHxA). Moreover, this work evidences a high potential of PFOS, PFOA and PFBS to act as aromatase inhibitors in placental cells with IC50s in the range of 57–80 μM, the inhibitory effect of PFBS being particularly important despite the rather low uptake of the compound by cells. Finally, exposure of JEG-3 cells to a mixture of the eight PFCs (0.6 μM each) led to a relative increase (up to 3.4-fold) of several lipid classes, including phosphatidylcholines (PCs), plasmalogen PC and lyso plasmalogen PC, which suggests an interference of PFCs with membrane lipids. Overall, this work highlights the ability of the PFC mixture to alter cellular lipid pattern at concentrations well below those that generate toxicity, and the potential of the short chain PFBS, often considered a safe substitute of PFOS, to significantly inhibit aromatase activity in placental cells. - Highlights: • Eight perfluorinated chemicals of different chain lengths have been selected. • Long chain ones – PFOS, PFDoA, PFNA, PFOA – were cytotoxic in placenta cells. • The uptake of long chain perfluorinated chemicals by cells was comparatively higher. • PFOS, PFOA and the short chain PFBS significantly inhibited aromatase activity. • A mixture of perfluorinated chemicals significantly altered placenta cell

  20. Increased temperature and altered summer precipitation have differential effects on biological soil crusts in a dryland ecosystem

    USGS Publications Warehouse

    Johnson, Shannon L.; Kuske, Cheryl R.; Carney, Travis D.; Housman, David C.; Gallegos-Graves, La Verne; Belnap, Jayne

    2012-01-01

    Biological soil crusts (biocrusts) are common and ecologically important members of dryland ecosystems worldwide, where they stabilize soil surfaces and contribute newly fixed C and N to soils. To test the impacts of predicted climate change scenarios on biocrusts in a dryland ecosystem, the effects of a 2–3 °C increase in soil temperature and an increased frequency of smaller summer precipitation events were examined in a large, replicated field study conducted in the cold desert of the Colorado Plateau, USA. Surface soil biomass (DNA concentration), photosynthetically active cyanobacterial biomass (chlorophyll a concentration), cyanobacterial abundance (quantitative PCR assay), and bacterial community composition (16S rRNA gene sequencing) were monitored seasonally over 2 years. Soil microbial biomass and bacterial community composition were highly stratified between the 0–2 cm depth biocrusts and 5–10 cm depth soil beneath the biocrusts. The increase in temperature did not have a detectable effect on any of the measured parameters over 2 years. However, after the second summer of altered summer precipitation pattern, significant declines occurred in the surface soil biomass (avg. DNA concentration declined 38%), photosynthetic cyanobacterial biomass (avg. chlorophyll a concentration declined 78%), cyanobacterial abundance (avg. gene copies g−1 soil declined 95%), and proportion of Cyanobacteria in the biocrust bacterial community (avg. representation in sequence libraries declined 85%). Biocrusts are important contributors to soil stability, soil C and N stores, and plant performance, and the loss or reduction of biocrusts under an altered precipitation pattern associated with climate change could contribute significantly to lower soil fertility and increased erosion and dust production in dryland ecosystems at a regional scale.

  1. Glucose Controls Morphodynamics of LPS-Stimulated Macrophages

    PubMed Central

    Venter, Gerda; Oerlemans, Frank T. J. J.; Wijers, Mietske; Willemse, Marieke; Fransen, Jack A. M.; Wieringa, Bé

    2014-01-01

    Macrophages constantly undergo morphological changes when quiescently surveying the tissue milieu for signs of microbial infection or damage, or after activation when they are phagocytosing cellular debris or foreign material. These morphofunctional alterations require active actin cytoskeleton remodeling and metabolic adaptation. Here we analyzed RAW 264.7 and Maf-DKO macrophages as models to study whether there is a specific association between aspects of carbohydrate metabolism and actin-based processes in LPS-stimulated macrophages. We demonstrate that the capacity to undergo LPS-induced cell shape changes and to phagocytose complement-opsonized zymosan (COZ) particles does not depend on oxidative phosphorylation activity but is fueled by glycolysis. Different macrophage activities like spreading, formation of cell protrusions, as well as phagocytosis of COZ, were thereby strongly reliant on the presence of low levels of extracellular glucose. Since global ATP production was not affected by rewiring of glucose catabolism and inhibition of glycolysis by 2-deoxy-D-glucose and glucose deprivation had differential effects, our observations suggest a non-metabolic role for glucose in actin cytoskeletal remodeling in macrophages, e.g. via posttranslational modification of receptors or signaling molecules, or other effects on the machinery that drives actin cytoskeletal changes. Our findings impute a decisive role for the nutrient state of the tissue microenvironment in macrophage morphodynamics. PMID:24796786

  2. Differential partition of virulent Aeromonas salmonicida and attenuated derivatives possessing specific cell surface alterations in polymer aqueous-phase systems

    NASA Technical Reports Server (NTRS)

    Van Alstine, J. M.; Trust, T. J.; Brooks, D. E.

    1986-01-01

    Two-polymer aqueous-phase systems in which partitioning of biological matter between the phases occurs according to surface properties such as hydrophobicity, charge, and lipid composition are used to compare the surface properties of strains of the fish pathogen Aeromonas salmonicida. The differential ability of strains to produce a surface protein array crucial to their virulence, the A layer, and to produce smooth lipopolysaccharide is found to be important in the partitioning behavior of Aeromonas salmonicida. The presence of the A layer is shown to decrease the surface hydrophilicity of the pathogen, and to increase specifically its surface affinity for fatty acid esters of polyethylene glycol. The method has application to the analysis of surface properties crucial to bacterial virulence, and to the selection of strains and mutants with specific surface characteristics.

  3. Exosomes derived from mineralizing osteoblasts promote ST2 cell osteogenic differentiation by alteration of microRNA expression.

    PubMed

    Cui, Yazhou; Luan, Jing; Li, Haiying; Zhou, Xiaoyan; Han, Jinxiang

    2016-01-01

    Mineralizing osteoblasts (MOBs) can release exosomes, although the functional significance remains unclear. In the present study, we demonstrate that exosomes derived from mineralizing pre-osteoblast MC3T3-E1 cells can promote bone marrow stromal cell (ST2) differentiation to osteoblasts. We reveal that MOB-derived exosomes significantly influence miRNA profiles in recipient ST2 cells, and these changes tend to activate the Wnt signaling pathway by inhibiting Axin1 expression and increasing β-catenin expression. We also suggest that MOB derived-exosomes partly induce the variation in miRNA expression in recipient ST2 cells by exosomal miRNA transfer. These findings suggest an exosome-mediated mode of cell-to-cell communication in the osteogenic microenvironment, and also indicate the potential of MOB exosomes in bone tissue engineering. PMID:26763102

  4. Disruption of Aryl Hydrocarbon Receptor Homeostatic Levels during Embryonic Stem Cell Differentiation Alters Expression of Homeobox Transcription Factors that Control Cardiomyogenesis

    PubMed Central

    Wang, Qin; Chen, Jing; Ko, Chia-I; Fan, Yunxia; Carreira, Vinicius; Chen, Yinglei; Xia, Ying; Medvedovic, Mario

    2013-01-01

    , Ko CI, Fan Y, Carreira V, Chen Y, Xia Y, Medvedovic M, Puga A. 2013. Disruption of aryl hydrocarbon receptor homeostatic levels during embryonic stem cell differentiation alters expression of homeobox transcription factors that control cardiomyogenesis. Environ Health Perspect 121:1334–1343; http://dx.doi.org/10.1289/ehp.1307297 PMID:24058054

  5. Pyruvate kinase isoenzyme M2 is a glycolytic sensor differentially regulating cell proliferation, cell size and apoptotic cell death dependent on glucose supply

    SciTech Connect

    Spoden, Gilles A.; Tumorvirology Research Group, Tyrolean Cancer Research Institute, Medical University Innsbruck, Innrain 66, 6020 Innsbruck ; Rostek, Ursula; Lechner, Stefan; Mitterberger, Maria; Mazurek, Sybille; ScheBo Biotech AG, Netanyastrasse 3, 35394 Giessen ; Zwerschke, Werner; Tumorvirology Research Group, Tyrolean Cancer Research Institute, Medical University Innsbruck, Innrain 66, 6020 Innsbruck

    2009-10-01

    The glycolytic key regulator pyruvate kinase M2 (M2-PK or PKM2) can switch between a highly active tetrameric and an inactive dimeric form. The transition between the two conformations regulates the glycolytic flux in tumor cells. We developed specific M2-PK-binding peptide aptamers which inhibit M2-PK, but not the 96% homologous M1-PK isoenzyme. In this study we demonstrate that, at normal blood glucose concentrations, peptide aptamer-mediated inhibition of M2-PK induces a significant decrease of the population doubling (PDL rate) and cell proliferation rate as well as an increase in cell size, whereas under glucose restriction an increase in PDL and cell proliferation rates but a decrease in cell size was observed. Moreover, M2-PK inhibition rescues cells from glucose starvation-induced apoptotic cell death by increasing the metabolic activity. These findings suggest that M2-PK is a metabolic sensor which regulates cell proliferation, cell growth and apoptotic cell death in a glucose supply-dependent manner.

  6. Differential Effects of Sucrose, Fructose, Glucose, and Lactose on Crying in 1- to 3-Day-Old Human Infants: Qualitative and Quantitative Considerations.

    ERIC Educational Resources Information Center

    Blass, Elliott M.; Smith, Barbara A.

    1992-01-01

    The potency of different sugars as calming agents in human infants was investigated in 2 experiments with 40 infants. Sucrose and fructose were equally effective calming agents, whereas glucose was less effective. Results indicate that the calming effects of milk lie in components other than its sugar. (LB)

  7. Differential effects of glucagon-like peptide-1 on microvascular recruitment and glucose metabolism in short- and long-term insulin resistance

    PubMed Central

    Sjøberg, Kim A; Rattigan, Stephen; Jeppesen, Jacob F; Lundsgaard, Anne-Marie; Holst, Jens J; Kiens, Bente

    2015-01-01

    Abstract Acute infusion of glucagon-like peptide-1 (GLP-1) has potent effects on blood flow distribution through the microcirculation in healthy humans and rats. A high fat diet induces impairments in insulin-mediated microvascular recruitment (MVR) and muscle glucose uptake, and here we examined whether this could be reversed by GLP-1. Using contrast-enhanced ultrasound, microvascular recruitment was assessed by continuous real-time imaging of gas-filled microbubbles in the microcirculation after acute (5 days) and prolonged (8 weeks) high fat diet (HF)-induced insulin resistance in rats. A euglycaemic hyperinsulinaemic clamp (3 mU min−1 kg−1), with or without a co-infusion of GLP-1 (100 pmol l−1), was performed in anaesthetized rats. Consumption of HF attenuated the insulin-mediated MVR in both 5 day and 8 week HF interventions which was associated with a 50% reduction in insulin-mediated glucose uptake compared to controls. Acute administration of GLP-1 restored the normal microvascular response by increasing the MVR after both 5 days and 8 weeks of HF intervention (P < 0.05). This effect of GLP-1 was associated with a restoration of both whole body insulin sensitivity and increased insulin-mediated glucose uptake in skeletal muscle by 90% (P < 0.05) after 5 days of HF but not after 8 weeks of HF. The present study demonstrates that GLP-1 increases MVR in rat skeletal muscle and can reverse early stages of high fat diet-induced insulin resistance in vivo. Key points Acute glucagon-like peptide-1 (GLP-1) infusion reversed the high fat diet-induced microvascular insulin resistance that occurred after both 5 days and 8 weeks of a high fat diet intervention. When GLP-1 was co-infused with insulin it had overt effects on whole body insulin sensitivity as well as insulin-mediated skeletal muscle glucose uptake after 5 days of a high fat diet, but not after 8 weeks of high fat diet intervention. Acute GLP-1 infusion did not have an additive

  8. Differential Progression of Structural and Functional Alterations in Distinct Retinal Ganglion Cell Types in a Mouse Model of Glaucoma

    PubMed Central

    Della Santina, Luca; Inman, Denise M.; Lupien, Caroline B.; Horner, Philip J.

    2013-01-01

    Intraocular pressure (IOP) elevation is a principal risk factor for glaucoma. Using a microbead injection technique to chronically raise IOP for 15 or 30 d in mice, we identified the early changes in visual response properties of different types of retinal ganglion cells (RGCs) and correlated these changes with neuronal morphology before cell death. Microbead-injected eyes showed reduced optokinetic tracking as well as cell death. In such eyes, multielectrode array recordings revealed that four RGC types show diverse alterations in their light responses upon IOP elevation. OFF-transient RGCs exhibited a more rapid decline in both structural and functional organizations compared with other RGCs. In contrast, although the light-evoked responses of OFF-sustained RGCs were perturbed, the dendritic arbor of this cell type remained intact. ON-transient and ON-sustained RGCs had normal functional receptive field sizes but their spontaneous and light-evoked firing rates were reduced. ON- and OFF-sustained RGCs lost excitatory synapses across an otherwise structurally normal dendritic arbor. Together, our observations indicate that there are changes in spontaneous activity and light-evoked responses in RGCs before detectable dendritic loss. However, when dendrites retract, we found corresponding changes in receptive field center size. Importantly, the effects of IOP elevation are not uniformly manifested in the structure and function of diverse RGC populations, nor are distinct RGC types perturbed within the same time-frame by such a challenge. PMID:24174678

  9. Prenatal exposure to di-n-butyl phthalate (DBP) differentially alters androgen cascade in undeformed versus hypospadiac male rat offspring.

    PubMed

    Jiang, Jun-Tao; Zhong, Chen; Zhu, Yi-Ping; Xu, Dong-Liang; Wood, Kristofer; Sun, Wen-Lan; Li, En-Hui; Liu, Zhi-Hong; Zhao, Wei; Ruan, Yuan; Xia, Shu-Jie

    2016-06-01

    This study was to compare the alterations of androgen cascades in di-n-butyl phthalate (DBP)-exposed male offspring without hypospadias (undeformed) versus those with hypospadias. To induce hypospadias in male offspring, pregnant rats received DBP via oral gavage at a dose of 750mg/kg BW/day during gestational days 14-18. The mRNA expression levels of genes downstream of the androgen signaling pathway, such as androgen receptor (AR) and Srd5a2, in testes of undeformed rat pups were similar to those in controls; in hypospadiac rat pups these levels were significantly lower than those of control pups. In contrast, both undeformed and hypospadiac rats had decreased serum testosterone levels, reduced mRNA expression of key enzymes in the androgen synthetic pathway in the testes, and ablated genes of developmental pathways, such as Shh, Bmp4, Fgf8, Fgf10 and Fgfr2, in the genital tubercle (GT) as compared to those in DBP-unexposed controls, albeit hypospadiac rats had a more severe decrement than those of undeformed rats. Although other possibilities cannot be excluded, our findings suggest that the relatively normal levels of testosterone-AR-Srd5a2 may contribute to the resistance to DBP toxicity in undeformed rats. In conclusion, our results showed a potential correlation between decreased testosterone levels, reduced mRNA expression of AR and Srd5a2 and the occurrence of hypospadias in male rat offspring prenatally exposed to DBP. PMID:26948521

  10. Differential effects of conifer and broadleaf litter inputs on soil organic carbon chemical composition through altered soil microbial community composition.

    PubMed

    Wang, Hui; Liu, Shi-Rong; Wang, Jing-Xin; Shi, Zuo-Min; Xu, Jia; Hong, Pi-Zheng; Ming, An-Gang; Yu, Hao-Long; Chen, Lin; Lu, Li-Hua; Cai, Dao-Xiong

    2016-01-01

    A strategic selection of tree species will shift the type and quality of litter input, and subsequently magnitude and composition of the soil organic carbon (SOC) through soil microbial community. We conducted a manipulative experiment in randomized block design with leaf litter inputs of four native subtropical tree species in a Pinus massoniana plantation in southern China and found that the chemical composition of SOC did not differ significantly among treatments until after 28 months of the experiment. Contrasting leaf litter inputs had significant impacts on the amounts of total microbial, Gram-positive bacterial, and actinomycic PLFAs, but not on the amounts of total bacterial, Gram-negative bacterial, and fungal PLFAs. There were significant differences in alkyl/O-alkyl C in soils among the leaf litter input treatments, but no apparent differences in the proportions of chemical compositions (alkyl, O-alkyl, aromatic, and carbonyl C) in SOC. Soil alkyl/O-alkyl C was significantly related to the amounts of total microbial, and Gram-positive bacterial PLFAs, but not to the chemical compositions of leaf litter. Our findings suggest that changes in forest leaf litter inputs could result in changes in chemical stability of SOC through the altered microbial community composition. PMID:27256545

  11. Differential progression of structural and functional alterations in distinct retinal ganglion cell types in a mouse model of glaucoma.

    PubMed

    Della Santina, Luca; Inman, Denise M; Lupien, Caroline B; Horner, Philip J; Wong, Rachel O L

    2013-10-30

    Intraocular pressure (IOP) elevation is a principal risk factor for glaucoma. Using a microbead injection technique to chronically raise IOP for 15 or 30 d in mice, we identified the early changes in visual response properties of different types of retinal ganglion cells (RGCs) and correlated these changes with neuronal morphology before cell death. Microbead-injected eyes showed reduced optokinetic tracking as well as cell death. In such eyes, multielectrode array recordings revealed that four RGC types show diverse alterations in their light responses upon IOP elevation. OFF-transient RGCs exhibited a more rapid decline in both structural and functional organizations compared with other RGCs. In contrast, although the light-evoked responses of OFF-sustained RGCs were perturbed, the dendritic arbor of this cell type remained intact. ON-transient and ON-sustained RGCs had normal functional receptive field sizes but their spontaneous and light-evoked firing rates were reduced. ON- and OFF-sustained RGCs lost excitatory synapses across an otherwise structurally normal dendritic arbor. Together, our observations indicate that there are changes in spontaneous activity and light-evoked responses in RGCs before detectable dendritic loss. However, when dendrites retract, we found corresponding changes in receptive field center size. Importantly, the effects of IOP elevation are not uniformly manifested in the structure and function of diverse RGC populations, nor are distinct RGC types perturbed within the same time-frame by such a challenge. PMID:24174678

  12. Differential effects of conifer and broadleaf litter inputs on soil organic carbon chemical composition through altered soil microbial community composition

    PubMed Central

    Wang, Hui; Liu, Shi-Rong; Wang, Jing-Xin; Shi, Zuo-Min; Xu, Jia; Hong, Pi-Zheng; Ming, An-Gang; Yu, Hao-Long; Chen, Lin; Lu, Li-Hua; Cai, Dao-Xiong

    2016-01-01

    A strategic selection of tree species will shift the type and quality of litter input, and subsequently magnitude and composition of the soil organic carbon (SOC) through soil microbial community. We conducted a manipulative experiment in randomized block design with leaf litter inputs of four native subtropical tree species in a Pinus massoniana plantation in southern China and found that the chemical composition of SOC did not differ significantly among treatments until after 28 months of the experiment. Contrasting leaf litter inputs had significant impacts on the amounts of total microbial, Gram-positive bacterial, and actinomycic PLFAs, but not on the amounts of total bacterial, Gram-negative bacterial, and fungal PLFAs. There were significant differences in alkyl/O-alkyl C in soils among the leaf litter input treatments, but no apparent differences in the proportions of chemical compositions (alkyl, O-alkyl, aromatic, and carbonyl C) in SOC. Soil alkyl/O-alkyl C was significantly related to the amounts of total microbial, and Gram-positive bacterial PLFAs, but not to the chemical compositions of leaf litter. Our findings suggest that changes in forest leaf litter inputs could result in changes in chemical stability of SOC through the altered microbial community composition. PMID:27256545

  13. Combinational losses of synucleins reveal their differential requirements for compensating age-dependent alterations in motor behavior and dopamine metabolism.

    PubMed

    Connor-Robson, Natalie; Peters, Owen M; Millership, Steven; Ninkina, Natalia; Buchman, Vladimir L

    2016-10-01

    Synucleins are involved in multiple steps of the neurotransmitter turnover, but the largely normal synaptic function in young adult animals completely lacking synucleins suggests their roles are dispensable for execution of these processes. Instead, they may be utilized for boosting the efficiency of certain molecular mechanisms in presynaptic terminals, with a deficiency of synuclein proteins sensitizing to or exacerbating synaptic malfunction caused by accumulation of mild alterations, which are commonly associated with aging. Although functional redundancy within the family has been reported, it is unclear whether the remaining synucleins can fully compensate for the deficiency of a lost family member or whether some functions are specific for a particular member. We assessed several structural and functional characteristics of the nigrostriatal system of mice lacking members of the synuclein family in every possible combination and demonstrated that stabilization of the striatal dopamine level depends on the presence of α-synuclein and cannot be compensated by other family members, whereas β-synuclein is required for efficient maintenance of animal's balance and coordination in old age. PMID:27614017

  14. Chronic food restriction and streptozotocin-induced diabetes differentially alter prodynorphin mRNA levels in rat brain regions.

    PubMed

    Berman, Y; Devi, L; Spangler, R; Kreek, M J; Carr, K D

    1997-06-01

    It was previously reported that chronic food restriction and streptozotocin-induced diabetes lead to brain region-specific changes in levels of Prodyn-derived peptides. These changes parallel behavioral adaptations that are reversed by opioid antagonists. In the present study, effects of food restriction and diabetes on Prodyn gene expression were measured in rat brain regions using a quantitative solution hybridization mRNA assay. Picogram amounts of Prodyn mRNA were determined in extracts of five brain regions. The highest density of Prodyn mRNA was observed in extracts of nucleus accumbens (4.68 pg/microg total RNA), bed nucleus of the stria terminalis (4.18 pg/microg), and in caudate nucleus (3.51 pg/microg). Lower levels were observed in the lateral hypothalamus (1.87 pg/microg) and central nucleus of the amygdala (1.22 pg/microg). Food restriction and diabetes both markedly increased the levels of Prodyn mRNA in the central amygdala (163% and 93%, respectively). Levels in the lateral hypothalamus were also increased (35% and 29%, respectively), though only the food-restriction effect was statistically significant. Neither treatment altered prodynorphin mRNA levels in the caudate nucleus, nucleus accumbens or bed nucleus of the stria terminalis. These results suggest that dynorphin neurons in central amygdala and lateral hypothalamus may be involved in behavioral or physiological adaptations to sustained metabolic need. PMID:9191075

  15. Subdiaphragmatic vagus nerve activity and hepatic venous glucose are differentially regulated by the central actions of insulin in Wistar and SHR

    PubMed Central

    Ribeiro, Izabela Martina R; Ferreira-Neto, Hildebrando C; Antunes, Vagner R

    2015-01-01

    Glucose is the most important energy substrate for the maintenance of tissues function. The liver plays an essential role in the control of glucose production, since it is able to synthesize, store, and release glucose into the circulation under different situations. Hormones like insulin and catecholamines influence hepatic glucose production (HGP), but little is known about the role of the central actions of physiological doses of insulin in modulating HGP via the autonomic nervous system in nonanesthetized rats especially in SHR where we see a high degree of insulin resistance and metabolic dysfunction. Wistar and SHR received ICV injection of insulin (100 nU/μL) and hepatic venous glucose concentration (HVGC) was monitored for 30 min, as an indirect measure of HGP. At 10 min after insulin injection, HVGC decreased by 27% in Wistar rats, with a negligible change (3%) in SHR. Pretreatment with atropine totally blocked the reduction in HVGC, while pretreatment with propranolol and phentolamine induced a decrease of 8% in HVGC after ICV insulin injection in Wistar. Intracarotid infusion of insulin caused a significant increase in subdiaphragmatic vagus nerve (SVN) activity in Wistar (12 ± 2%), with negligible effects on the lumbar splanchnic sympathetic nerve (LSSN) activity (−6 ± 3%). No change was observed in SVN (−2 ± 2%) and LSSN activities (2 ± 3%) in SHR after ICA insulin infusion. Taken together, these results show, in nonanesthetized animals, the importance of the parasympathetic nervous system in controlling HVGC, and subdiaphragmatic nerve activity following central administration of insulin; a mechanism that is impaired in the SHR. PMID:25948821

  16. Glucocorticoids alter neuronal differentiation of human neuroepithelial-like cells by inducing long-lasting changes in the reactive oxygen species balance.

    PubMed

    Raciti, Marilena; Ong, Jennie; Weis, Laura; Edoff, Karin; Battagli, Cristina; Falk, Anna; Ceccatelli, Sandra

    2016-08-01

    Prenatal exposure to excess glucocorticoid has been shown to have adverse effects on the developing nervous system that may lead to alterations of fetal and adult neurogenesis, resulting in behavioral changes. In addition, an imbalance of the redox state, with an increased susceptibility to oxidative stress, has been observed in rodent neural stem cells exposed to the synthetic glucocorticoid analog dexamethasone (Dex). In the present study, we used the induced pluripotent stem cells (IPSC)-derived lt-NES AF22 cell line, representative of the neuroepithelial stage in central nervous system development, to investigate the heritable effects of Dex on reactive oxygen species (ROS) balance and its impact on neuronal differentiation. By analysing gene expression in daughter cells that were never directly exposed to Dex, we could observe a downregulation of four key antioxidant enzymes, namely Catalase, superoxide dismutase 1, superoxide dismutase 2 and glutathione peroxidase7, along with an increased intracellular ROS concentration. The imbalance in the intracellular REDOX state was associated to a significant downregulation of major neuronal markers and a concomitant increase of glial cells. Interestingly, upon treatment with the antioxidant N-acetyl-cysteine (NAC), the misexpression of both neuronal and glial markers analyzed was recovered. These novel findings point to the increased ROS concentration playing a direct role in the heritable alterations of the differentiation potential induced by Dex exposure. Moreover, the data support the hypothesis that early insults may have detrimental long-lasting consequences on neurogenesis. Based on the positive effects exerted by NAC, it is conceivable that therapeutic strategies including antioxidants may be effective in the treatment of neuropsychiatric disorders that have been associated to increased ROS and impaired neurogenesis. PMID:26992751

  17. Altered differential hemocyte count in 3rd instar larvae of Drosophila melanogaster as a response to chronic exposure of Acephate

    PubMed Central

    Rajak, Prem; Dutta, Moumita

    2015-01-01

    Acephate, an organophosphate (OP) pesticide, was used to investigate the effects of its chronic exposure on hemocyte abundance in a non-target dipteran insect Drosophila melanogaster. For this purpose, six graded concentrations ranging from 1 to 6 μg/ml were selected, which are below the reported residual values (up to 14 μg/ml) of the chemical. 1st instar larvae were fed with these concentrations up to the 3rd instar stage and accordingly hemolymph smears from these larvae were prepared for differential hemocyte count. Three types of cells are found in Drosophila hemolymph, namely, plasmatocytes, lamellocytes and crystal cells. Plasmatocyte count was found to decrease with successive increase in treatment concentrations. Crystal cells showed an increasing trend in their number. Though the number of lamellocytes was very low, a bimodal response was noticed. Lamellocyte number was found to increase with the initial three concentrations, followed by a dose dependent reduction in their number. As hemocytes are directly linked to the immune system of fruit flies, fluctuations in normal titer of these cells may affect insect immunity. Hemocytes share homologies in their origin and mode of action with the immune cells of higher organisms including man. Thus the present findings suggest that immune cells of humans and other organisms may be affected adversely under chronic exposure to Acephate. PMID:27486365

  18. Altered neuronal gene expression in brain regions differentially affected by Alzheimer’s disease: a reference data set

    PubMed Central

    Liang, Winnie S.; Dunckley, Travis; Beach, Thomas G.; Grover, Andrew; Mastroeni, Diego; Ramsey, Keri; Caselli, Richard J.; Kukull, Walter A.; McKeel, Daniel; Morris, John C.; Hulette, Christine M.; Schmechel, Donald; Reiman, Eric M.; Rogers, Joseph; Stephan, Dietrich A.

    2009-01-01

    Alzheimer’s Disease (AD) is the most widespread form of dementia during the later stages of life. If improved therapeutics are not developed, the prevalence of AD will drastically increase in the coming years as the world’s population ages. By identifying differences in neuronal gene expression profiles between healthy elderly persons and individuals diagnosed with AD, we may be able to better understand the molecular mechanisms that drive AD pathogenesis, including the formation of amyloid plaques and neurofibrillary tangles. In this study, we expression profiled histopathologically normal cortical neurons collected with laser capture microdissection (LCM) from six anatomically and functionally discrete postmortem brain regions in 34 AD-afflicted individuals, using Affymetrix Human Genome U133 Plus 2.0 microarrays. These regions include the entorhinal cortex, hippocampus, middle temporal gyrus, posterior cingulate cortex, superior frontal gyrus, and primary visual cortex. This study is predicated on previous parallel research on the postmortem brains of the same six regions in 14 healthy elderly individuals, for which LCM neurons were similarly processed for expression analysis. We identified significant regional differential expression in AD brains compared with control brains including expression changes of genes previously implicated in AD pathogenesis, particularly with regards to tangle and plaque formation. Pinpointing the expression of factors that may play a role in AD pathogenesis provides a foundation for future identification of new targets for improved AD therapeutics. We provide this carefully phenotyped, laser capture microdissected intraindividual brain region expression data set to the community as a public resource. PMID:18270320

  19. Quantum Dots Do Not Alter the Differentiation Potential of Pancreatic Stem Cells and Are Distributed Randomly among Daughter Cells.

    PubMed

    Danner, S; Benzin, H; Vollbrandt, T; Oder, J; Richter, A; Kruse, C

    2013-01-01

    With the increasing relevance of cell-based therapies, there is a demand for cell-labeling techniques for in vitro and in vivo studies. For the reasonable tracking of transplanted stem cells in animal models, the usage of quantum dots (QDs) for sensitive cellular imaging has major advances. QDs could be delivered to the cytoplasm of the cells providing intense and stable fluorescence. Although QDs are emerging as favourable nanoparticles for bioimaging, substantial investigations are still required to consider their application for adult stem cells. Therefore, rat pancreatic stem cells (PSCs) were labeled with different concentrations of CdSe quantum dots (Qtracker 605 nanocrystals). The QD labeled PSCs showed normal proliferation and their usual spontaneous differentiation potential in vitro. The labeling of the cell population was concentration dependent, with increasing cell load from 5 nM QDs to 20 nM QDs. With time-lapse microscopy, we observed that the transmission of the QD particles during cell divisions was random, appearing as equal or unequal transmission to daughter cells. We report here that QDs offered an efficient and nontoxic way to label pancreatic stem cells without genetic modifications. In summary, QD nanocrystals are a promising tool for stem cell labeling and facilitate tracking of transplanted cells in animal models. PMID:23997768

  20. Quantum Dots Do Not Alter the Differentiation Potential of Pancreatic Stem Cells and Are Distributed Randomly among Daughter Cells

    PubMed Central

    Danner, S.; Benzin, H.; Vollbrandt, T.; Oder, J.; Richter, A.; Kruse, C.

    2013-01-01

    With the increasing relevance of cell-based therapies, there is a demand for cell-labeling techniques for in vitro and in vivo studies. For the reasonable tracking of transplanted stem cells in animal models, the usage of quantum dots (QDs) for sensitive cellular imaging has major advances. QDs could be delivered to the cytoplasm of the cells providing intense and stable fluorescence. Although QDs are emerging as favourable nanoparticles for bioimaging, substantial investigations are still required to consider their application for adult stem cells. Therefore, rat pancreatic stem cells (PSCs) were labeled with different concentrations of CdSe quantum dots (Qtracker 605 nanocrystals). The QD labeled PSCs showed normal proliferation and their usual spontaneous differentiation potential in vitro. The labeling of the cell population was concentration dependent, with increasing cell load from 5 nM QDs to 20 nM QDs. With time-lapse microscopy, we observed that the transmission of the QD particles during cell divisions was random, appearing as equal or unequal transmission to daughter cells. We report here that QDs offered an efficient and nontoxic way to label pancreatic stem cells without genetic modifications. In summary, QD nanocrystals are a promising tool for stem cell labeling and facilitate tracking of transplanted cells in animal models. PMID:23997768

  1. Differential alterations in the expression of neurotransmitter receptors in inner retina following loss of photoreceptors in rd1 mouse.

    PubMed

    Srivastava, Prerna; Sinha-Mahapatra, Sumit K; Ghosh, Abhinaba; Srivastava, Ipsit; Dhingra, Narender K

    2015-01-01

    Loss of photoreceptors leads to significant remodeling in inner retina of rd1 mouse, a widely used model of retinal degeneration. Several morphological and physiological alterations occur in the second- and third-order retinal neurons. Synaptic activity in the excitatory bipolar cells and the predominantly inhibitory amacrine cells is enhanced. Retinal ganglion cells (RGCs) exhibit hyperactivity and aberrant spiking pattern, which adversely affects the quality of signals they can carry to the brain. To further understand the pathophysiology of retinal degeneration, and how it may lead to aberrant spiking in RGCs, we asked how loss of photoreceptors affects some of the neurotransmitter receptors in rd1 mouse. Using Western blotting, we measured the levels of several neurotransmitter receptors in adult rd1 mouse retina. We found significantly higher levels of AMPA, glycine and GABAa receptors, but lower levels of GABAc receptors in rd1 mouse than in wild-type. Since GABAa receptor is expressed in several retinal layers, we employed quantitative immunohistochemistry to measure GABAa receptor levels in specific retinal layers. We found that the levels of GABAa receptors in inner plexiform layer of wild-type and rd1 mice were similar, whereas those in outer plexiform layer and inner nuclear layer combined were higher in rd1 mouse. Specifically, we found that the number of GABAa-immunoreactive somas in the inner nuclear layer of rd1 mouse retina was significantly higher than in wild-type. These findings provide further insights into neurochemical remodeling in the inner retina of rd1 mouse, and how it might lead to oscillatory activity in RGCs. PMID:25835503

  2. Maternal choline supplementation differentially alters the basal forebrain cholinergic system of young-adult Ts65Dn and disomic mice

    PubMed Central

    Kelley, Christy M.; Powers, Brian E.; Velazquez, Ramon; Ash, Jessica A.; Ginsberg, Stephen D.; Strupp, Barbara J.; Mufson, Elliott J.

    2014-01-01

    Down syndrome (DS), trisomy 21, is a multifaceted condition marked by intellectual disability and early presentation of Alzheimer’s disease (AD) neuropathological lesions including degeneration of the basal forebrain cholinergic neuron (BFCN) system. While DS is diagnosable during gestation, there is no treatment option for expectant mothers or DS individuals. Using the Ts65Dn mouse model of DS that displays age-related degeneration of the BFCN system, we investigated the effects of maternal choline supplementation on the BFCN system in adult Ts65Dn mice and disomic (2N) littermates at 4.3–7.5 mos of age. Ts65Dn dams were maintained on a choline supplemented diet (5.1 g/kg choline chloride) or a control, unsupplemented diet with adequate amounts of choline (1 g/kg choline chloride) from conception until weaning of offspring; postweaning, offspring were fed the control diet. Mice were transcardially perfused with paraformaldehyde, brains were sectioned, and immunolabeled for choline acetyltransferase (ChAT) or p75-neurotrophin receptor (p75NTR). BFCN number and size, the area of the regions, and the intensity of hippocampal labeling were determined. Ts65Dn unsupplemented mice displayed region- and immunolabel-dependent increased BFCN number, larger areas, smaller BFCNs, and overall increased hippocampal ChAT intensity compared with 2N unsupplemented mice. These effects were partially normalized by maternal choline supplementation. Taken together, the results suggest a developmental imbalance in the Ts65Dn BFCN system. Early maternal-diet choline supplementation attenuates some of the genotype-dependent alterations in the BFCN system, suggesting this naturally occurring nutrient as a treatment option for pregnant mothers with knowledge that their offspring is trisomy 21. PMID:24178831

  3. Chemotherapy Agents Alter Plasma Lipids in Breast Cancer Patients and Show Differential Effects on Lipid Metabolism Genes in Liver Cells.

    PubMed

    Sharma, Monika; Tuaine, Jo; McLaren, Blair; Waters, Debra L; Black, Katherine; Jones, Lynnette M; McCormick, Sally P A

    2016-01-01

    Cardiovascular complications have emerged as a major concern for cancer patients. Many chemotherapy agents are cardiotoxic and some appear to also alter lipid profiles, although the mechanism for this is unknown. We studied plasma lipid levels in 12 breast cancer patients throughout their chemotherapy. Patients received either four cycles of doxorubicin and cyclophosphamide followed by weekly paclitaxel or three cycles of epirubicin, cyclophosphamide and 5'-fluorouracil followed by three cycles of docetaxel. Patients demonstrated a significant reduction (0.32 mmol/L) in high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA1) levels (0.18 g/L) and an elevation in apolipoprotein B (apoB) levels (0.15 g/L) after treatment. Investigation of the individual chemotherapy agents for their effect on genes involved in lipoprotein metabolism in liver cells showed that doxorubicin decreased ATP binding cassette transporter A1 (ABCA1) via a downregulation of the peroxisomal proliferator activated receptor γ (PPARγ) and liver X receptor α (LXRα) transcription factors. In contrast, ABCA1 levels were not affected by cyclophosphamide or paclitaxel. Likewise, apoA1 levels were reduced by doxorubicin and remained unaffected by cyclophosphamide and paclitaxel. Doxorubicin and paclitaxel both increased apoB protein levels and paclitaxel also decreased low density lipoprotein receptor (LDLR) protein levels. These findings correlate with the observed reduction in HDL-C and apoA1 and increase in apoB levels seen in these patients. The unfavourable lipid profiles produced by some chemotherapy agents may be detrimental in the longer term to cancer patients, especially those already at risk of cardiovascular disease (CVD). This knowledge may be useful in tailoring effective follow-up care plans for cancer survivors. PMID:26807857

  4. Chemotherapy Agents Alter Plasma Lipids in Breast Cancer Patients and Show Differential Effects on Lipid Metabolism Genes in Liver Cells

    PubMed Central

    Sharma, Monika; Tuaine, Jo; McLaren, Blair; Waters, Debra L.; Black, Katherine

    2016-01-01

    Cardiovascular complications have emerged as a major concern for cancer patients. Many chemotherapy agents are cardiotoxic and some appear to also alter lipid profiles, although the mechanism for this is unknown. We studied plasma lipid levels in 12 breast cancer patients throughout their chemotherapy. Patients received either four cycles of doxorubicin and cyclophosphamide followed by weekly paclitaxel or three cycles of epirubicin, cyclophosphamide and 5’-fluorouracil followed by three cycles of docetaxel. Patients demonstrated a significant reduction (0.32 mmol/L) in high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1 (apoA1) levels (0.18 g/L) and an elevation in apolipoprotein B (apoB) levels (0.15 g/L) after treatment. Investigation of the individual chemotherapy agents for their effect on genes involved in lipoprotein metabolism in liver cells showed that doxorubicin decreased ATP binding cassette transporter A1 (ABCA1) via a downregulation of the peroxisomal proliferator activated receptor γ (PPARγ) and liver X receptor α (LXRα) transcription factors. In contrast, ABCA1 levels were not affected by cyclophosphamide or paclitaxel. Likewise, apoA1 levels were reduced by doxorubicin and remained unaffected by cyclophosphamide and paclitaxel. Doxorubicin and paclitaxel both increased apoB protein levels and paclitaxel also decreased low density lipoprotein receptor (LDLR) protein levels. These findings correlate with the observed reduction in HDL-C and apoA1 and increase in apoB levels seen in these patients. The unfavourable lipid profiles produced by some chemotherapy agents may be detrimental in the longer term to cancer patients, especially those already at risk of cardiovascular disease (CVD). This knowledge may be useful in tailoring effective follow-up care plans for cancer survivors. PMID:26807857

  5. Human ApoE Isoforms Differentially Modulate Glucose and Amyloid Metabolic Pathways in Female Brain: Evidence of the Mechanism of Neuroprotection by ApoE2 and Implications for Alzheimer's Disease Prevention and Early Intervention.

    PubMed

    Keeney, Jeriel Thomas-Richard; Ibrahimi, Shaher; Zhao, Liqin

    2015-01-01

    Three major genetic isoforms of apolipoprotein E (ApoE), ApoE2, ApoE3, and ApoE4, exist in humans and lead to differences in susceptibility to Alzheimer's disease (AD). This study investigated the impact of human ApoE isoforms on brain metabolic pathways involved in glucose utilization and amyloid-β (Aβ) degradation, two major areas that are significantly perturbed in preclinical AD. Hippocampal RNA samples from middle-aged female mice with targeted human ApoE2, ApoE3, and ApoE4 gene replacement were comparatively analyzed with a qRT-PCR custom array for the expression of 85 genes involved in insulin/insulin-like growth factor (Igf) signaling. Consistent with its protective role against AD, ApoE2 brain exhibited the most metabolically robust profile among the three ApoE genotypes. When compared to ApoE2 brain, both ApoE3 and ApoE4 brains exhibited markedly reduced levels of Igf1, insulin receptor substrates (Irs), and facilitated glucose transporter 4 (Glut4), indicating reduced glucose uptake. Additionally, ApoE4 brain exhibited significantly decreased Pparg and insulin-degrading enzyme (Ide), indicating further compromised glucose metabolism and Aβ dysregulation associated with ApoE4. Protein analysis showed significantly decreased Igf1, Irs, and Glut4 in ApoE3 brain, and Igf1, Irs, Glut4, Pparg, and Ide in ApoE4 brain compared to ApoE2 brain. These data provide the first documented evidence that human ApoE isoforms differentially affect brain insulin/Igf signaling and downstream glucose and amyloid metabolic pathways, illustrating a potential mechanism for their differential risk in AD. A therapeutic strategy that enhances brain insulin/Igf1 signaling activity to a more robust ApoE2-like phenotype favoring both energy production and amyloid homeostasis holds promise for AD prevention and early intervention. PMID:26402005

  6. Exposure to bloom-like concentrations of two marine Synechococcus cyanobacteria (strains CC9311 and CC9902) differentially alters fish behaviour

    PubMed Central

    Hamilton, T. J.; Paz-Yepes, J.; Morrison, R. A.; Palenik, B.; Tresguerres, M.

    2014-01-01

    Coastal California experiences large-scale blooms of Synechococcus cyanobacteria, which are predicted to become more prevalent by the end of the 21st century as a result of global climate change. This study investigated whether exposure to bloom-like concentrations of two Synechococcus strains, CC9311 and CC9902, alters fish behaviour. Black perch (Embiotoca jacksoni) were exposed to Synechococcus strain CC9311 or CC9902 (1.5 × 106 cells ml−1) or to control seawater in experimental aquaria for 3 days. Fish movement inside a testing arena was then recorded and analysed using video camera-based motion-tracking software. Compared with control fish, fish exposed to CC9311 demonstrated a significant preference for the dark zone of the tank in the light–dark test, which is an indication of increased anxiety. Furthermore, fish exposed to CC9311 also had a statistically significant decrease in velocity and increase in immobility and they meandered more in comparison to control fish. There was a similar trend in velocity, immobility and meandering in fish exposed to CC9902, but there were no significant differences in behaviour or locomotion between this group and control fish. Identical results were obtained with a second batch of fish. Additionally, in this second trial we also investigated whether fish would recover after a 3 day period in seawater without cyanobacteria. Indeed, there were no longer any significant differences in behaviour among treatments, demonstrating that the sp. CC9311-induced alteration of behaviour is reversible. These results demonstrate that blooms of specific marine Synechococcus strains can induce differential sublethal effects in fish, namely alterations light–dark preference behaviour and motility. PMID:27293641

  7. Chronic treatment with the gamma-secretase inhibitor LY-411,575 inhibits beta-amyloid peptide production and alters lymphopoiesis and intestinal cell differentiation.

    PubMed

    Wong, Gwendolyn T; Manfra, Denise; Poulet, Frederique M; Zhang, Qi; Josien, Hubert; Bara, Thomas; Engstrom, Laura; Pinzon-Ortiz, Maria; Fine, Jay S; Lee, Hu-Jung J; Zhang, Lili; Higgins, Guy A; Parker, Eric M

    2004-03-26

    Inhibition of gamma-secretase, one of the enzymes responsible for the cleavage of the amyloid precursor protein (APP) to produce the pathogenic beta-amyloid (Abeta) peptides, is an attractive approach to the treatment of Alzheimer disease. In addition to APP, however, several other gamma-secretase substrates have been identified (e.g. Notch), and altered processing of these substrates by gamma-secretase inhibitors could lead to unintended biological consequences. To study the in vivo consequences of gamma-secretase inhibition, the gamma-secretase inhibitor LY-411,575 was administered to C57BL/6 and TgCRND8 APP transgenic mice for 15 days. Although most tissues were unaffected, doses of LY-411,575 that inhibited Abeta production had marked effects on lymphocyte development and on the intestine. LY-411,575 decreased overall thymic cellularity and impaired intrathymic differentiation at the CD4(-)CD8(-)CD44(+)CD25(+) precursor stage. No effects on peripheral T cell populations were noted following LY-411,575 treatment, but evidence for the altered maturation of peripheral B cells was observed. In the intestine, LY-411,575 treatment increased goblet cell number and drastically altered tissue morphology. These effects of LY-411,575 were not seen in mice that were administered LY-D, a diastereoisomer of LY-411,575, which is a very weak gamma-secretase inhibitor. These studies show that inhibition of gamma-secretase has the expected benefit of reducing Abeta in a murine model of Alzheimer disease but has potentially undesirable biological effects as well, most likely because of the inhibition of Notch processing. PMID:14709552

  8. Rapid throughput analysis demonstrates that chemicals with distinct seizurogenic mechanisms differentially alter Ca2+ dynamics in networks formed by hippocampal neurons in culture.

    PubMed

    Cao, Zhengyu; Zou, Xiaohan; Cui, Yanjun; Hulsizer, Susan; Lein, Pamela J; Wulff, Heike; Pessah, Isaac N

    2015-04-01

    Primary cultured hippocampal neurons (HN) form functional networks displaying synchronous Ca(2+) oscillations (SCOs) whose patterns influence plasticity. Whether chemicals with distinct seizurogenic mechanisms differentially alter SCO patterns was investigated using mouse HN loaded with the Ca(2+) indicator fluo-4-AM. Intracellular Ca(2+) dynamics were recorded from 96 wells simultaneously in real-time using fluorescent imaging plate reader. Although quiescent at 4 days in vitro (DIV), HN acquired distinctive SCO patterns as they matured to form extensive dendritic networks by 16 DIV. Challenge with kainate, a kainate receptor (KAR) agonist, 4-aminopyridine (4-AP), a K(+) channel blocker, or pilocarpine, a muscarinic acetylcholine receptor agonist, caused distinct changes in SCO dynamics. Kainate at <1 µM produced a rapid rise in baseline Ca(2+) (Phase I response) associated with high-frequency and low-amplitude SCOs (Phase II response), whereas SCOs were completely repressed with >1 µM kainate. KAR competitive antagonist CNQX [6-cyano-7-nitroquinoxaline-2,3-dione] (1-10 µM) normalized Ca(2+) dynamics to the prekainate pattern. Pilocarpine lacked Phase I activity but caused a sevenfold prolongation of Phase II SCOs without altering either their frequency or amplitude, an effect normalized by atropine (0.3-1 µM). 4-AP (1-30 µM) elicited a delayed Phase I response associated with persistent high-frequency, low-amplitude SCOs, and these disturbances were mitigated by pretreatment with the KCa activator SKA-31 [naphtho[1,2-d]thiazol-2-ylamine]. Consistent with its antiepileptic and neuroprotective activities, nonselective voltage-gated Na(+) and Ca(2+) channel blocker lamotrigine partially resolved kainate- and pilocarpine-induced Ca(2+) dysregulation. This rapid throughput approach can discriminate among distinct seizurogenic mechanisms that alter Ca(2+) dynamics in neuronal networks and may be useful in screening antiepileptic drug candidates. PMID:25583085

  9. Correlation between the rate of proteolysis of mitochondrial translation products and fluidity of the mitochondrial inner membrane in Saccharomyces cerevisiae yeast. Alteration of the rate of proteolysis under glucose repression.

    PubMed Central

    Luzikov, V N; Novikova, L A; Tikhonov, A N; Zubatov, A S

    1983-01-01

    Our previous results [Kalnov, Novikova, Zubatov & Luzikov (1979) FEBS Lett. 101, 355-358; Biochem. J. 182, 195-202] suggested that in yeast the mitochondrial translation products localized in the mitochondrial inner membrane are rapidly broken down by a proteolytic system inherent in the membrane. In the present work, it is demonstrated that, on glucose repression in undividing cells of Saccharomyces cerevisiae, there is no proteolysis of the mitochondrial translation products. This effect is not likely to be associated with lower activity of the proteolytic system of the mitochondrial inner membrane. Nor is the cessation of proteolysis due to qualitative changes in the composition of mitochondrial translation products. What repression does cause is a considerable alteration in the physical state (i.e. structure of the lipid bilayer) of the mitochondrial inner membrane; this was established by experiments involving lipid-soluble spin probes. The conclusion is reached that the rate of proteolysis of mitochondrial translation products in the mitochondrial inner membrane depends on the physical state of the membrane, which in its turn is controlled by the relative content of unsaturated fatty acid chains in the mitochondrial phospholipids. PMID:6354177

  10. Mutant Kras Promotes Hyperplasia and Alters Differentiation in the Colon Epithelium But Does Not Expand the Presumptive Stem Cell Pool

    PubMed Central

    Feng, Ying; Bommer, Guido T.; Zhao, Jenny; Green, Maranne; Sands, Evan; Zhai, Yali; Brown, Kelly; Burberry, Aaron; Cho, Kathleen R.; Fearon, Eric R.

    2011-01-01

    BACKGROUND & AIMS Adenomatous polyps are precursors to colorectal cancer (CRC), whereas hyperplastic polyps (HPPs) have a small risk of progression to CRC. Mutations in KRAS are found in ~40% of CRCs and large adenomas and a subset of HPPs. We investigated the reasons that HPPs with KRAS mutations lack malignant potential; we compared the effects of Kras/KRAS activation to those of Adenomatous polyposis coli (Apc)/APC inactivation, which promotes adenoma formation. METHODS We activated a KrasG12D mutant allele or inactivated Apc alleles in mouse colon epithelium and analyzed phenotypes and expression of selected genes and proteins. The mouse data were validated using samples of human HPPs and adenomas. Signaling pathways and factors that contribute to Kras/KRAS-induced phenotypes were studied in intestinal epithelial cells. RESULTS Activation of Kras led to hyperplasia and serrated crypt architecture akin to that observed in human HPPs. We also observed loss of Paneth cells and increases in goblet cell numbers. Abnormalities in Kras-mediated differentiation and proliferation required mitogen-activated protein kinase (MAPK) signaling and were linked to activation of the Hes1 transcription factor. Human HPPs also had activation of HES1. In contrast to Apc/APC inactivation, Kras/KRAS activation did not increase expression of crypt stem cell markers in colon epithelium or colony formation in vitro. Kras/KRAS activation was not associated with substantial induction of p16INK4a protein expression in mouse colon epithelium or human HPPs. CONCLUSIONS Although Kras/KRAS mutation promotes serrated and hyperplastic morphological features in colon epithelium, it is not able to initiate adenoma development, perhaps in part because activated Kras/KRAS signaling does not increase the number of presumptive stem cells in affected crypts. PMID:21699772

  11. Differential courtship activity and alterations of reproductive success of competing gupply males as an indicator for low concentrations of aquatic pollutants

    SciTech Connect

    Schroeder, J.H.; Peters, K.

    1988-09-01

    Differential courtship activity of guppy males competing for the same females was used as a bioindicator for low concentrations of water-borne pollutants in a previous study. Patterns of male sexual activity were chosen because they determine reproductive success. The mean difference between courtship activities of two male competitors determines the relative fitness of the male in question. Accordingly, the decrease in mean differential courtship after exposure to aquatic contaminants was predicted to cause a corresponding change in the relative reproductive success. The present study completed the previous one by repeating the experiment with a 10% addition of wastewater drawn from the last clearing basin of a Munich purification plant this time using virgin (non-inseminated) females which were receptive to male courtship. The females subsequently were allowed to produce as many offspring as possible. The number of young guppies sired by individual male competitors could easily be traced by the use of sex-linked phenotypic color patterns as markers. The purpose of these two studies was to show that the quantification of sexual activities of male guppies is useful for monitoring environmental alterations which affect fitness characters.

  12. Differential Reovirus-Specific and Herpesvirus-Specific Activator Protein 1 Activation of Secretogranin II Leads to Altered Virus Secretion

    PubMed Central

    Berard, Alicia R.; Severini, Alberto

    2015-01-01

    families interact with the host. Here we show that secretogranin II (SCG2), a protein not previously studied in the context of virus infections, alters virus output in a virus-specific manner and that the quantity of SCG2 is inversely related to amounts of infectious-virus secretion. Herpesviruses may target this protein to facilitate enhanced virus release from the host. PMID:26378181

  13. Glucose control.

    PubMed

    Preiser, Jean-Charles

    2013-01-01

    Stress-related hyperglycemia is a common finding in acutely ill patients, and is related to the severity and outcome of the critical illness. The pathophysiology of stress hyperglycemia includes hormonal and neural signals, leading to increased production of glucose by the liver and peripheral insulin resistance mediated by the translocation of transmembrane glucose transporters. In one pioneering study, tight glycemic control by intensive insulin therapy in critically ill patients was associated with improved survival. However, this major finding was not confirmed in several other prospective randomized controlled trials. The reasons underlying the discrepancy between the first and the subsequent studies could include nutritional strategy (amount of calories provided, use of parenteral nutrition), case-mix, potential differences in the optimal blood glucose level (BG) in different types of patients, hypoglycemia and its correction, and the magnitude of glucose variability. Therefore, an improved understanding of the physiology and pathophysiology of glycemic regulation during acute illness is needed. Safe and effective glucose control will need improvement in the definition of optimal BG and in the measurement techniques, perhaps including continuous monitoring of insulin algorithms and closed-loop systems. PMID:23075589

  14. Differential Kinetics in Alteration and Recovery of Cognitive Processes from a Chronic Sleep Restriction in Young Healthy Men.

    PubMed

    Rabat, Arnaud; Gomez-Merino, Danielle; Roca-Paixao, Laura; Bougard, Clément; Van Beers, Pascal; Dispersyn, Garance; Guillard, Mathias; Bourrilhon, Cyprien; Drogou, Catherine; Arnal, Pierrick J; Sauvet, Fabien; Leger, Damien; Chennaoui, Mounir

    2016-01-01

    Chronic sleep restriction (CSR) induces neurobehavioral deficits in young and healthy people with a morning failure of sustained attention process. Testing both the kinetic of failure and recovery of different cognitive processes (i.e., attention, executive) under CSR and their potential links with subject's capacities (stay awake, baseline performance, age) and with some biological markers of stress and anabolism would be useful in order to understand the role of sleep debt on human behavior. Twelve healthy subjects spent 14 days in laboratory with 2 baseline days (B1 and B2, 8 h TIB) followed by 7 days of sleep restriction (SR1-SR7, 4 h TIB), 3 sleep recovery days (R1-R3, 8 h TIB) and two more ones 8 days later (R12-R13). Subjective sleepiness (KSS), maintenance of wakefulness latencies (MWT) were evaluated four times a day (10:00, 12:00 a.m. and 2:00, 4:00 p.m.) and cognitive tests were realized at morning (8:30 a.m.) and evening (6:30 p.m.) sessions during B2, SR1, SR4, SR7, R2, R3 and R13. Saliva (B2, SR7, R2, R13) and blood (B1, SR6, R1, R12) samples were collected in the morning. Cognitive processes were differently impaired and recovered with a more rapid kinetic for sustained attention process. Besides, a significant time of day effect was only evidenced for sustained attention failures that seemed to be related to subject's age and their morning capacity to stay awake. Executive processes were equally disturbed/recovered during the day and this failure/recovery process seemed to be mainly related to baseline subject's performance and to their capacity to stay awake. Morning concentrations of testosterone, cortisol and α-amylase were significantly decreased at SR6-SR7, but were either and respectively early (R1), tardily (after R2) and not at all (R13) recovered. All these results suggest a differential deleterious and restorative effect of CSR on cognition through biological changes of the stress pathway and subject's capacity (ClinicalTrials-NCT01989741

  15. Differential Kinetics in Alteration and Recovery of Cognitive Processes from a Chronic Sleep Restriction in Young Healthy Men

    PubMed Central

    Rabat, Arnaud; Gomez-Merino, Danielle; Roca-Paixao, Laura; Bougard, Clément; Van Beers, Pascal; Dispersyn, Garance; Guillard, Mathias; Bourrilhon, Cyprien; Drogou, Catherine; Arnal, Pierrick J.; Sauvet, Fabien; Leger, Damien; Chennaoui, Mounir

    2016-01-01

    Chronic sleep restriction (CSR) induces neurobehavioral deficits in young and healthy people with a morning failure of sustained attention process. Testing both the kinetic of failure and recovery of different cognitive processes (i.e., attention, executive) under CSR and their potential links with subject’s capacities (stay awake, baseline performance, age) and with some biological markers of stress and anabolism would be useful in order to understand the role of sleep debt on human behavior. Twelve healthy subjects spent 14 days in laboratory with 2 baseline days (B1 and B2, 8 h TIB) followed by 7 days of sleep restriction (SR1-SR7, 4 h TIB), 3 sleep recovery days (R1–R3, 8 h TIB) and two more ones 8 days later (R12–R13). Subjective sleepiness (KSS), maintenance of wakefulness latencies (MWT) were evaluated four times a day (10:00, 12:00 a.m. and 2:00, 4:00 p.m.) and cognitive tests were realized at morning (8:30 a.m.) and evening (6:30 p.m.) sessions during B2, SR1, SR4, SR7, R2, R3 and R13. Saliva (B2, SR7, R2, R13) and blood (B1, SR6, R1, R12) samples were collected in the morning. Cognitive processes were differently impaired and recovered with a more rapid kinetic for sustained attention process. Besides, a significant time of day effect was only evidenced for sustained attention failures that seemed to be related to subject’s age and their morning capacity to stay awake. Executive processes were equally disturbed/recovered during the day and this failure/recovery process seemed to be mainly related to baseline subject’s performance and to their capacity to stay awake. Morning concentrations of testosterone, cortisol and α-amylase were significantly decreased at SR6-SR7, but were either and respectively early (R1), tardily (after R2) and not at all (R13) recovered. All these results suggest a differential deleterious and restorative effect of CSR on cognition through biological changes of the stress pathway and subject’s capacity (Clinical

  16. Hepatic and Extrahepatic Insulin Clearance Are Differentially Regulated: Results From a Novel Model-Based Analysis of Intravenous Glucose Tolerance Data.

    PubMed

    Polidori, David C; Bergman, Richard N; Chung, Stephanie T; Sumner, Anne E

    2016-06-01

    Insulin clearance is a highly variable and important factor that affects circulating insulin concentrations. We developed a novel model-based method to estimate both hepatic and extrahepatic insulin clearance using plasma insulin and C-peptide profiles obtained from the insulin-modified frequently sampled intravenous glucose tolerance test. Data from 100 African immigrants without diabetes (mean age 38 years, body weight 81.7 kg, fasting plasma glucose concentration 83 mg/dL, and fasting insulin concentration 37 pmol/L) were used. Endogenous insulin secretion (calculated by C-peptide deconvolution) and insulin infusion rates were used as inputs to a new two-compartment model of insulin kinetics and hepatic and extrahepatic clearance parameters were estimated. Good agreement between modeled and measured plasma insulin profiles was observed (mean normalized root mean square error 6.8%), and considerable intersubject variability in parameters of insulin clearance among individuals was identified (the mean [interquartile range] for hepatic extraction was 25.8% [32.7%], and for extrahepatic insulin clearance was 20.7 mL/kg/min [11.7 mL/kg/min]). Parameters of insulin clearance were correlated with measures of insulin sensitivity and acute insulin response to glucose. The method described appears promising for future research aimed at characterizing variability in insulin clearance and the mechanisms involved in the regulation of insulin clearance. PMID:26993071

  17. Glucose Variability

    PubMed Central

    2013-01-01

    The proposed contribution of glucose variability to the development of the complications of diabetes beyond that of glycemic exposure is supported by reports that oxidative stress, the putative mediator of such complications, is greater for intermittent as opposed to sustained hyperglycemia. Variability of glycemia in ambulatory conditions defined as the deviation from steady state is a phenomenon of normal physiology. Comprehensive recording of glycemia is required for the generation of any measurement of glucose variability. To avoid distortion of variability to that of glycemic exposure, its calculation should be devoid of a time component. PMID:23613565

  18. Antihypertensive drugs and glucose metabolism

    PubMed Central

    Rizos, Christos V; Elisaf, Moses S

    2014-01-01

    Hypertension plays a major role in the development and progression of micro- and macrovascular disease. Moreover, increased blood pressure often coexists with additional cardiovascular risk factors such as insulin resistance. As a result the need for a comprehensive management of hypertensive patients is critical. However, the various antihypertensive drug categories have different effects on glucose metabolism. Indeed, angiotensin receptor blockers as well as angiotensin converting enzyme inhibitors have been associated with beneficial effects on glucose homeostasis. Calcium channel blockers (CCBs) have an overall neutral effect on glucose metabolism. However, some members of the CCBs class such as azelnidipine and manidipine have been shown to have advantageous effects on glucose homeostasis. On the other hand, diuretics and β-blockers have an overall disadvantageous effect on glucose metabolism. Of note, carvedilol as well as nebivolol seem to differentiate themselves from the rest of the β-blockers class, being more attractive options regarding their effect on glucose homeostasis. The adverse effects of some blood pressure lowering drugs on glucose metabolism may, to an extent, compromise their cardiovascular protective role. As a result the effects on glucose homeostasis of the various blood pressure lowering drugs should be taken into account when selecting an antihypertensive treatment, especially in patients which are at high risk for developing diabetes. PMID:25068013

  19. Development and use of a new perfusion technique to study glucose metabolism of the aortic wall in normal and alloxan-diabetic rabbits

    SciTech Connect

    Brown, B.J.M.

    1985-01-01

    This study investigated (1) possible alterations in glucose uptake and utilization in the perfused, normal, and diabetic vascular wall of rabbits and (2) the effects thereon of insulin and exogenous glucose concentration. Part I involved development and characterization of an in vitro perfusion technique that closely reproduced predetermined in vivo conditions of aortic blood flow, arterial blood pressure, heart rate and pulse pressure. The responsiveness of the preparation to vasoactive agents was assessed with concentrations of norepinephrine (NE) from 10/sup -9/ to 10/sup -4/ M. In Part II, the effects of NE-induced tension development on glucose metabolism were determined by perfusion with oxygenated physiological salt solution (PSS) containing 7 mM glucose and tracer amounts of uniformly labeled /sup 14/C-glucose. Aortas from 8 week-diabetic rabbits were perfused under similar conditions employing a NE infusion in the presence or absence of insulin (150 uU/ml) and variable levels of glucose. Effects of NE-induced tension development include an apparent increase (39%) in glucose uptake and a twofold increase in /sup 14/CO/sub 2/ and lactate production. Aortas from diabetic rabbits perfused with PSS containing 7 mM glucose demonstrated marked decreases in glucose uptake (74%), /sup 14/CO/sub 2/ (68%), lactate (30%), total tissue glycogen (75%) and labeled tissue phospholipids (70%). Insulin or elevation of exogenous glucose to 25 mM (diabetic levels) normalized glucose uptake, but had differential effects on the pattern of substrate utilization. The marked alterations of glucose metabolism in the diabetic state may contribute to the functional changes observed in diabetic blood vessels.

  20. Differential gene expression pattern in hypothalamus of chickens during fasting-induced metabolic reprogramming: functions of glucose and lipid metabolism in the feed intake of chickens.

    PubMed

    Fang, Xin-Ling; Zhu, Xiao-Tong; Chen, Sheng-Feng; Zhang, Zhi-Qi; Zeng, Qing-Jie; Deng, Lin; Peng, Jian-Long; Yu, Jian-Jian; Wang, Li-Na; Wang, Song-Bo; Gao, Ping; Jiang, Qing-Yan; Shu, Gang

    2014-11-01

    Fasting-induced hypothalamic metabolic reprogramming is involved in regulating energy homeostasis and appetite in mammals, but this phenomenon remains unclear in poultry. In this study, the expression patterns of a panel of genes related to neuropeptides, glucose, and lipid metabolism enzymes in the hypothalamus of chickens during fasting and refeeding were characterized by microarray analysis and quantitative PCR. Results showed that 48 h of fasting upregulated (P < 0.05) the mRNA expressions of orexigenic neuropeptide Y and agouti-related protein but downregulated (P < 0.05) that of anorexigenic neuropeptide pro-opiomelanocortin; growth hormone-releasing hormone; islet amyloid polypeptide; thyroid-stimulating hormone, β; and glycoprotein hormones, α polypeptide. After 48 h of fasting, the mRNA expression of fatty acid β-oxidation [peroxisome proliferator-activated receptor α (PPARα), carnitine palmitoyltransferase 1A, and forkhead box O1], energy sensor protein [sirtuin 1 (SIRT1) and forkhead box O1], and glycolysis inhibitor (pyruvate dehydrogenase kinase, isozyme 4) were enhanced, but that of fatty acid synthesis and transport associated genes (acetyl-CoA carboxylase α, fatty acid synthase, apolipoprotein A-I, endothelial lipase, and fatty acid binding protein 7) were suppressed. Liver and muscle also demonstrated similar expression patterns of genes related to glucose and lipid metabolism with hypothalamus, except for that of acetyl-CoA carboxylase α, acyl-CoA synthetase long-chain family member 4, and apolipoprotein A-I. The results of intracerebroventricular (ICV) injection experiments confirmed that α-lipoic acid (ALA, pyruvate dehydrogenase kinase, isozyme 4 inhibitor, 0.10 μmol) and NADH (SIRT1 inhibitor, 0.80 μmol) significantly suppressed the appetite of chickens, whereas 2-deoxy-d-glucose (glycolytic inhibitor, 0.12 to 1.20 μmol) and NAD(+) (SIRT1 activator, 0.08 to 0.80 μmol) increased feed intake in chickens. The orexigenic effect of NAD

  1. Differential half-maximal effects of human insulin and its analogs for in situ glucose transport and protein synthesis in rat soleus muscle

    NASA Technical Reports Server (NTRS)

    Weinstein, Randi B.; Eleid, Noura; LeCesne, Catherine; Durando, Bianca; Crawford, Julie T.; Heffner, Michelle; Layton, Christle; O'Keefe, Matthew; Robinson, Jennifer; Rudinsky, Suzy; Henriksen, Erik J.; Tischler, Marc E.

    2002-01-01

    Analogs of human insulin have been used to discriminate between responses of metabolic and mitogenic (growth-related) pathways. This study compared the stimulatory effects of human insulin (HI) and 2 analogs (X2, B-Asp(9), B-Glu(27) and H2, A-His(8),B-His(4),B-Glu(10), B-His(27)) on glucose uptake and protein synthesis in rat soleus muscle in situ. Glucose uptake, estimated by intramuscular (IM) injection of 2-deoxy[1,2-3H]glucose with or without insulin, was maximally increased at 10(-6) mol/L for HI and X2 and 10(-7) mol/L for H2. HI had a larger effect (318%) than either X2 (156%) or H2 (124%). The half-maximal effect (ED(50)) values for HI, X2, and H2 were 3.3 x10(-8) mol/L, 1.7 x 10(-7) mol/L, and 1.6 x 10(-9) mol/L, respectively. Protein synthesis, estimated by protein incorporation of [(3)H]phenylalanine injected into muscles with or without insulin, was maximally increased at 10(-5) mol/L for HI and 10(-6) for X2 and H2. HI had a larger effect in stimulating protein synthesis (34%) than either X2 (25%) or H2 (19.8%). The ED(50) values for HI, X2, and H2 were 3.0 x 10(-7) mol/L, 3.2 x 10(-7) mol/L, and 1.0 x 10(-9) mol/L, respectively. The biological potency of each analog (ED(50)insulin/ED(50)analog) showed X2 to be less potent than HI for both glucose uptake (0.2) and protein synthesis (0.9), whereas H2 is more potent than HI with ratios of 20 and 300, respectively. These data suggest that this approach for studying insulin responsiveness in a single muscle in situ may be a useful tool for investigating insulin signaling in muscle in vivo. Copyright 2002, Elsevier Science (USA). All rights reserved.

  2. Basal regulation of HPA and dopamine systems is altered differentially in males and females by prenatal alcohol exposure and chronic variable stress

    PubMed Central

    Uban, Kristina A.; Comeau, Wendy; Ellis, Linda A.; Galea, Liisa A. M.; Weinberg, Joanne

    2013-01-01

    Effects of prenatal alcohol exposure (PAE) on central nervous system function include an increased prevalence of mental health problems, including substance use disorders (SUD). The hypothalamic-pituitary-adrenal (HPA) and dopamine systems have overlapping neurocircuitries and are both implicated in SUD. PAE alters both HPA and dopaminergic activity and regulation, resulting in increased HPA tone and an overall reduction in tonic dopamine activity. However, effects of PAE on the interaction between HPA and dopamine (DA) systems have not been investigated. The present study examined PAE effects on basal regulation of central stress and dopamine systems in key brain regions where these systems intersect. Adult Sprague-Dawley male and female offspring from prenatal alcohol-exposed (PAE), pairfed (PF), and ad libitum-fed control (C) groups were subjected to chronic variable stress (CVS) or remained as a no stress (non-CVS) control group. Corticotropin releasing hormone (CRH) mRNA, as well as glucocorticoid and DA receptor (DA-R) expression were measured under basal conditions 24 hours following the end of CVS. We show, for the first time, that regulation of basal HPA and DA systems, and likely, HPA-DA interactions, are altered differentially in males and females by PAE and CVS. PAE augmented the typical attenuation in weight gain during CVS in males and caused increased weight loss in females. Increased basal corticosterone levels in control, but not PAE, females suggest that PAE alters the profile of basal hormone secretion throughout CVS. CVS downregulated basal CRH mRNA in the prefrontal cortex and throughout the bed nucleus of the stria terminalis (BNST) in PAE females but only in the posterior BNST of control females. PAE males and females exposed to CVS exhibited more widespread upregulation of basal mineralocorticoid receptor (MR) mRNA throughout the hippocampus, and an attenuated decrease in DA-R expression throughout the nucleus accumbens and striatum compared

  3. Tumorigenicity by human papillomavirus type 16 E6 and E7 in transgenic mice correlates with alterations in epithelial cell growth and differentiation.

    PubMed Central

    Griep, A E; Herber, R; Jeon, S; Lohse, J K; Dubielzig, R R; Lambert, P F

    1993-01-01

    The human papillomavirus type 16 (HPV-16) E6 and E7 oncogenes are thought to play a role in the development of most human cervical cancers. These E6 and E7 oncoproteins affect cell growth control at least in part through their association with and inactivation of the cellular tumor suppressor gene products, p53 and Rb. To study the biological activities of the HPV-16 E6 and E7 genes in epithelial cells in vivo, transgenic mice were generated in which expression of E6 and E7 was targeted to the ocular lens. Expression of the transgenes correlated with bilateral microphthalmia and cataracts (100% penetrance) resulting from an efficient impairment of lens fiber cell differentiation and coincident induction of cell proliferation. Lens tumors formed in 40% of adult mice from the mouse lineage with the highest level of E6 and E7 expression. Additionally, when lens cells from neonatal transgenic animals were placed in tissue culture, immortalized cell populations grew out and acquired a tumorigenic phenotype with continuous passage. These observations indicate that genetic changes in addition to the transgenes are likely necessary for tumor formation. These transgenic mice and cell lines provide the basis for further studies into the mechanism of action of E6 and E7 in eliciting the observed pathology and into the genetic alterations required for HPV-16-associated tumor progression. Images PMID:8382301

  4. Genome polymorphisms and gene differential expression in a 'back-and-forth' ploidy-altered series of weeping lovegrass (Eragrostis curvula).

    PubMed

    Mecchia, Martín A; Ochogavía, Ana; Pablo Selva, Juan; Laspina, Natalia; Felitti, Silvina; Martelotto, Luciano G; Spangenberg, Germán; Echenique, Viviana; Pessino, Silvina C

    2007-08-01

    Molecular markers were used to analyze the genomic structure of an euploid series of Eragrostis curvula, obtained after a tetraploid dihaploidization procedure followed by chromosome re-doubling with colchicine. Considerable levels of genome polymorphisms were detected between lines. Curiously, a significant number of molecular markers showed a revertant behavior following the successive changes of ploidy, suggesting that genome alterations were specific and conferred genetic structures characteristic of a given ploidy level. Genuine reversion was confirmed by sequencing. Cluster analysis demonstrated grouping of tetraploids while the diploid was more distantly related with respect to the rest of the plants. Polymorphic revertant sequences involved mostly non-coding regions, although some of them displayed sequence homology to known genes. A revertant sequence corresponding to a P-type adenosine triphosphatase was found to be differentially represented in cDNA libraries obtained from the diploid and a colchiploid, but was not found expressed in the original tetraploid. Transcriptome profiling of inflorescence followed by real-time polymerase chain reaction validation showed 0.34% polymorphic bands between apomictic tetraploid and sexual diploid plants. Several of the polymorphic sequences corresponded to known genes. Possible correlation between the results observed here and a recently reported genome-wide non-Mendelian inheritance mechanism in Arabidopsis thaliana are discussed. PMID:16919366

  5. Differentially regulated protein kinase A (PKA) activity in adipose tissue and liver is associated with resistance to diet-induced obesity and glucose intolerance in mice that lack PKA regulatory subunit type IIα.

    PubMed

    London, Edra; Nesterova, Maria; Sinaii, Ninet; Szarek, Eva; Chanturiya, Tatyana; Mastroyannis, Spyridon A; Gavrilova, Oksana; Stratakis, Constantine A

    2014-09-01

    The cAMP-dependent protein kinase A (PKA) signaling system is widely expressed and has a central role in regulating cellular metabolism in all organ systems affected by obesity. PKA has four regulatory (RIα, RIIα, RIβ, RIIβ) and four catalytic (Cα, Cβ, Cγ, Prkx) subunit isoforms that have tissue-specific expression profiles. In mice, knockout (KO) of RIIβ, the primary PKA regulatory subunit in adipose tissue or knockout of the catalytic subunit Cβ resulted in a lean phenotype that resists diet-induced obesity and associated metabolic complications. Here we report that the disruption of the ubiquitously expressed PKA RIIα subunit in mice (RIIαKO) confers resistance to diet-induced obesity, glucose intolerance, and hepatic steatosis. After 2-week high-fat diet exposure, RIIαKO mice weighed less than wild-type littermates. Over time this effect was more pronounced in female mice that were also leaner than their wild-type counterparts, regardless of the diet. Decreased intake of a high-fat diet contributed to the attenuated weight gain in RIIαKO mice. Additionally, RIIα deficiency caused differential regulation of PKA in key metabolic organs: cAMP-stimulated PKA activity was decreased in liver and increased in gonadal adipose tissue. We conclude that RIIα represents a potential target for therapeutic interventions in obesity, glucose intolerance, and nonalcoholic fatty liver disease. PMID:24914943

  6. Basal expression of nucleoside transporter mRNA differs among small intestinal epithelia of beef steers and is differentially altered by ruminal or abomasal infusion of starch hydrolysate.

    PubMed

    Liao, S F; Alman, M J; Vanzant, E S; Miles, E D; Harmon, D L; McLeod, K R; Boling, J A; Matthews, J C

    2008-04-01

    In ruminants, microbial-derived nucleic acids are a major source of N and are absorbed as nucleosides by small intestinal epithelia. Although the biochemical activities of 2 nucleoside transport systems have been described for cattle, little is known regarding the regulation of their gene expression. This study was conducted to test 2 hypotheses: (1) the small intestinal epithelia of beef cattle differentially express mRNA for 3 concentrative (CNT1, 2, 3) and 2 equilibrative (ENT1, 2) nucleoside transporters (NT), and (2) expression of these NT is responsive to small intestine luminal supply of rumen-derived microbes (hence, nucleosides), energy (cornstarch hydrolysate, SH), or both. Eighteen ruminally and abomasally catheterized Angus steers (260 +/- 17 kg of BW) were fed an alfalfa cube-based diet at 1.33x NE(m) requirement. Six steers in each of 3 periods were blocked by BW (heavy vs. light). Within each block, 3 steers were randomly assigned to 3 treatments (n = 6): ruminal and abomasal water infusion (control), ruminal SH infusion/abomasal water infusion, or ruminal water infusion/abomasal SH infusion. The dosage of SH infusion amounted to 20% of ME intake. After a 14-or 16-d infusion period, steers were slaughtered, and duodenal, jejunal, and ileal epithelia were harvested for total RNA extraction and the relative amounts of mRNA expressed were determined using real-time RT-PCR quantification methodologies. All 5 NT mRNA were found expressed by each epithelium, but their abundance differed among epithelia. Specifically, jejunal expression of all 5 NT mRNA was higher than that by the ileum, whereas jejunal expression of CNT1, CNT3, and ENT1 mRNA was higher, or tended to be higher, than duodenal expression. Duodenal expression of CNT2, CNT3, and ENT2 mRNA was higher than ileal expression. With regard to SH infusion treatments, ruminal infusion increased duodenal expression of CNT3 (67%), ENT1 (51%), and ENT2 (39%) mRNA and ileal expression of CNT3 (210%) and

  7. Advanced glycation end products (AGEs), but not high glucose, inhibit the osteoblastic differentiation of mouse stromal ST2 cells through the suppression of osterix expression, and inhibit cell growth and increasing cell apoptosis.

    PubMed

    Okazaki, Kyoko; Yamaguchi, Toru; Tanaka, Ken-Ichiro; Notsu, Masakazu; Ogawa, Noriko; Yano, Shozo; Sugimoto, Toshitsugu

    2012-10-01

    Diabetes mellitus is known to be associated with osteoporotic fractures through a decrease in osteoblastic bone formation rather than an increase in osteoclastic bone resorption. However, its precise mechanism is unknown, and we examined whether or not high glucose or advanced glycation end products (AGEs), which play key roles in the pathogenesis and complications of diabetes, would affect the osteoblastic differentiation, growth, and apoptosis of mouse stromal ST2 cells. Ten to 200 μg/mL AGE2 or AGE3 alone dose-dependently inhibited the mineralization. AGE2 or AGE3 alone (200 μg/mL) significantly inhibited alkaline phosphatase (ALP) activities as well as the mineralization of the cells (p < 0.01). In contrast, 22 mM glucose alone or in combination with 200 μg/mL AGE2 or AGE3 did not affect these cellular phenotypes. Real-time PCR showed that AGE2 or AGE3 alone (200 μg/mL) significantly decreased mRNA expressions of osteocalcin as well as osterix on day 14 (p < 0.01). Western blot analysis showed that AGE2 or AGE3 alone (200 μg/mL) also decreased the levels of Runx2 and osterix protein expressions on days 7 and 14. AGE2 or AGE3 significantly suppressed cell growth and increased apoptotic cell death in time- and dose-dependent manners (p < 0.01). Moreover, AGE3 alone (200 μg/mL) significantly increased mRNA expression of the receptor for AGEs (RAGE) on days 2 and 3 (p < 0.01). These results suggest that AGE2 and AGE3, but not high glucose, may inhibit the osteoblastic differentiation of stromal cells by decreasing osterix expression and partly by increasing RAGE expression, as well as inhibiting cell growth and increasing cell apoptosis. PMID:22903508

  8. Differential effect of polyphenol-rich dark chocolate on biomarkers of glucose metabolism and cardiovascular risk factors in healthy, overweight and obese subjects: a randomized clinical trial.

    PubMed

    Almoosawi, S; Tsang, C; Ostertag, L M; Fyfe, L; Al-Dujaili, E A S

    2012-10-01

    The association between excess cortisol and various parameters of metabolic syndrome including hypertension, insulin resistance and dyslipidaemia is increasingly recognised. The present single-blind randomised placebo-controlled cross-over study compared the effect of polyphenol-rich dark chocolate (DC) on biomarkers of glucose metabolism, lipid profile, and blood pressure (BP) in females with BMI ≥ 25 kg m(-2) (n = 21) and females with BMI < 25 kg m(-2) (n = 21). Volunteers consumed 20 g of DC containing 500 mg polyphenols or a placebo DC with negligible polyphenol-content daily for 4 weeks, separated by a 2-week washout period. Systolic BP and diastolic BP decreased after 4 weeks of polyphenol-rich DC. Placebo raised fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and salivary cortisol, an effect that was significantly different from polyphenol-rich DC which had a negligible effect on fasting insulin, HOMA-IR and salivary cortisol. Females with BMI ≥ 25 kg m(-2) responded less favourably to placebo than lean females and consequently had higher fasting insulin and HOMA-IR, in addition to a lower quantitative sensitivity check index (QUICKI) after ingestion of placebo compared to polyphenol-rich DC. No significant changes in lipid profile were observed. This study provides evidence for the metabolic benefits of consuming polyphenol-rich dark chocolate while demonstrating the possibility of adverse effects occurring with polyphenol-poor chocolate placebo. PMID:22796902

  9. DFP initiated early alterations of PKA/p-CREB pathway and differential persistence of {beta}-tubulin subtypes in the CNS of hens contributes to OPIDN

    SciTech Connect

    Damodaran, Tirupapuliyur V.; Gupta, Ram P.; Attia, Moustafa K.; Abou-Donia, Mohamed B.

    2009-10-15

    Organophosphorus ester-induced delayed neurotoxicity (OPIDN) is a neurodegenerative disorder characterized by ataxia progressing to paralysis with a concomitant central and peripheral distal axonapathy. Diisopropylphosphorofluoridate (DFP) produces OPIDN in the chicken, which results in mild ataxia in 7-14 days and severe paralysis as the disease progresses with a single dose. White leghorn layer hens were treated with DFP (1.7 mg/kg, sc) after prophylactic treatment with atropine (1 mg/kg, sc) in normal saline and eserine (1 mg/kg, sc) in dimethyl sulfoxide. Control groups were treated with vehicle propylene glycol (0.1 mL/kg, sc), atropine in normal saline and eserine in dimethyl sulfoxide. The hens were sacrificed at different time points such as 2, 4, and 8 h, as well as 1, 2, 5, 10 and 20 days, and the tissues from cerebrum, midbrain, cerebellum brainstem and spinal cord were quickly dissected and frozen for protein (western) and mRNA (northern) studies. Subcellular fractionation, SDS-PAGE and immunoblotting of the nuclear and supernatant fractions using standard protocols from spinal cord and cerebrum showed differential expression of protein levels of PKA, CREB and phosphorylated CREB (p-CREB). There was an increase in PKA level in spinal cord nuclear fraction after 4 h (130 {+-} 5%) and 8 h (133 {+-} 6 %), while cerebrum nuclear fraction showed decrease (77 {+-} 5%) at 4 h and remained at the same level at 8 h. No change was seen in either spinal cord or cerebrum soluble fraction at any time points. There was an increase in CREB level in the spinal cord supernatant (133 {+-} 3%) after 5 days, while nuclear and supernatant fraction of the cerebrum did not show any alterations at any time point. p-CREB was induced in the spinal cord nuclear fraction at 1 day (150 {+-} 3%) and 5 days (173{+-}{+-}7%) of treatment, in contrast to the decreased levels p-CREB (72 {+-} 4%) at 10 days in cerebrum nuclear fraction. Supernatant fraction of spinal cord and cerebrum did

  10. [Regulation of bone homeostasis by glucose].

    PubMed

    Fukasawa, Kazuya; Hinoi, Eiichi

    2016-08-01

    Synthesis of type Ⅰ collagen, a major component of the bone matrix, precedes the expression of Runt-related transcription factor 2(Runx2), a master regulator in osteoblast differentiation. Thus, a direct link between osteoblast differentiation and bone formation is seemingly absent, and how these are maintained in a coordinated matter remains unclear. It was recently demonstrated that osteoblasts depend on glucose, which glucose transporter type 1(GLUT1)takes up as an energy source, and it was found that glucose uptake promotes osteoblast differentiation and bone formation via AMP-activated protein kinase. It was also shown that Runx2 upregulates GLUT1 expression, and this Runx2-GLUT1 feedforward regulation integrates and coordinates osteoblast differentiation and bone formation throughout life. These previous findings revealed that the energy metabolism balance in osteoblasts integrates the differentiation and function of osteoblasts, and re-emphasized the importance of crosstalk between bone and sugar metabolism. PMID:27461500

  11. Glucose test (image)

    MedlinePlus

    ... person with diabetes constantly manages their blood's sugar (glucose) levels. After a blood sample is taken and tested, it is determined whether the glucose levels are low or high. If glucose levels ...

  12. Low Blood Glucose (Hypoglycemia)

    MedlinePlus

    ... Other Dental Problems Diabetic Eye Disease Low Blood Glucose (Hypoglycemia) What is hypoglycemia? Hypoglycemia, also called low ... actions can also help prevent hypoglycemia: Check blood glucose levels Knowing your blood glucose level can help ...

  13. Cardiac Energy Dependence on Glucose Increases Metabolites Related to Glutathione and Activates Metabolic Genes Controlled by Mechanistic Target of Rapamycin

    PubMed Central

    Schisler, Jonathan C.; Grevengoed, Trisha J.; Pascual, Florencia; Cooper, Daniel E.; Ellis, Jessica M.; Paul, David S.; Willis, Monte S.; Patterson, Cam; Jia, Wei; Coleman, Rosalind A.

    2015-01-01

    Background Long chain acyl‐CoA synthetases (ACSL) catalyze long‐chain fatty acids (FA) conversion to acyl‐CoAs. Temporal ACSL1 inactivation in mouse hearts (Acsl1H−/−) impaired FA oxidation and dramatically increased glucose uptake, glucose oxidation, and mTOR activation, resulting in cardiac hypertrophy. We used unbiased metabolomics and gene expression analyses to elucidate the cardiac cellular response to increased glucose use in a genetic model of inactivated FA oxidation. Methods and Results Metabolomics analysis identified 60 metabolites altered in Acsl1H−/− hearts, including 6 related to glucose metabolism and 11 to cysteine and glutathione pathways. Concurrently, global cardiac transcriptional analysis revealed differential expression of 568 genes in Acsl1H−/− hearts, a subset of which we hypothesized were targets of mTOR; subsequently, we measured the transcriptional response of several genes after chronic mTOR inhibition via rapamycin treatment during the period in which cardiac hypertrophy develops. Hearts from Acsl1H−/− mice increased expression of several Hif1α‐responsive glycolytic genes regulated by mTOR; additionally, expression of Scl7a5, Gsta1/2, Gdf15, and amino acid‐responsive genes, Fgf21, Asns, Trib3, Mthfd2, were strikingly increased by mTOR activation. Conclusions The switch from FA to glucose use causes mTOR‐dependent alterations in cardiac metabolism. We identified cardiac mTOR‐regulated genes not previously identified in other cellular models, suggesting heart‐specific mTOR signaling. Increased glucose use also changed glutathione‐related pathways and compensation by mTOR. The hypertrophy, oxidative stress, and metabolic changes that occur within the heart when glucose supplants FA as a major energy source suggest that substrate switching to glucose is not entirely benign. PMID:25713290

  14. 2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced change in intestinal function and pathology: evidence for the involvement of arylhydrocarbon receptor-mediated alteration of glucose transportation

    SciTech Connect

    Ishida, Takumi; Kan-o, Shoko; Mutoh, Junpei; Takeda, Shuso; Ishii, Yuji; Hashiguchi, Isamu; Akamine, Akifumi; Yamada, Hideyuki . E-mail: yamada@xenoba.phar.kyushu-u.ac.jp

    2005-05-15

    Although numerous studies have been performed to clarify the mechanism(s) underlying the toxicological responses induced by dioxins, their effect on the intestine is less well understood. To address this issue, we examined the effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the pathology and function of the intestine in arylhydrocarbon receptor (AhR)-sensitive (C57BL/6J) and -less-sensitive (DBA/2J) mice. A single oral administration of TCDD (100 {mu}g/kg) to C57BL/6J mice produced changes in villous structure and nuclear/cytoplasm ratio in the epithelial cells of the intestine. Furthermore, in an oral glucose tolerance test, the serum glucose level was significantly increased in the C57BL/6J mouse but not in the DBA/2J mouse by TCDD treatment. In agreement with this, the expression of intestinal mRNAs coding sodium-glucose co-transporter 1 (SGLT1) and glucose transporter type 2 were increa