Stimulation Of Glycogen Synthesis Research Articles

Transformation of sulfur and nitrogen compounds by sulfidogenic and phototrophic bacteria under the influence of sodium fluoride and potassium bromide

Anthropogenically altered media are characterized by complex pollution, which contains a wide range of organic and inorganic pollutants, including halogen compounds. The influence of halides on transformed ecosystems, in particular, on their sulfidogenic and photosynthetic microbiota and its properties, remains insufficiently studied. The influence of sodium fluoride and potassium bromide at concentrations that are equal and 0.5–4.0 times differed from the maximum permissible concentrations (MPC) (MPC of fluorides and bromides are 0.0789 and 0.0025 mM, respectively) on the reduction of sulfate ions or sulfur (3.47 mM) by sulfidogenic bacteria of Desulfovibrio and Desulfuromonas genera, as well as on the use of thiosulfate or nitrite ions (4.167 mM) as electron donors of anoxygenic photosynthesis by phototrophic purple and green sulfur bacteria of Thiocapsa, Lamprocystis and Chlorobium genera, isolated from the Yavorivske Lake, was investigated. The biomass of bacteria was determined by the turbidimetric method, the content of H2S, SO42-, NО2ˉ and NО3ˉ in the cultural liquid – by the spectrophotometric method, the concentration of S2O32- – by the titrometric method. The intracellular glucose and glycogen content was determined enzymatically in cell-free extracts, using the analytical kit “Diagluc-2”. It was found that sodium fluoride and potassium bromide at concentrations 3.0–4.0 times higher than the MPC repress the biomass accumulation by bacteria Desulfovibrio sp. in the medium with sulfates 2.7−5.8 and 2.1−4.2 times, respectively, and inhibit the hydrogen sulfide production by them 1.8−3.4 and 2.0−3.2 times, respectively. NaF and KBr at concentrations that are equal and 2.0–4.0 times higher than the MPC repress the biomass accumulation by bacteria Desulfuromonas sp. in the medium with sulfur 2.2–6.9 and 2.1–5.6 times, respectively, and at concentrations 3.0–4.0 times higher than the MPC inhibit the hydrogen sulfide production by bacteria 1.9−3.7 and 2.0−2.7 times, respectively. Sodium fluoride and potassium bromide at concentration that 4.0 times exceeded the MPC inhibit the biomass accumulation by bacteria of Thiocapsa, Lamprocystis and Chlorobium genera in the medium with thiosulfates 2.0–2.3 and 1.7–2.0 times, respectively, reduce thiosulfate ions oxidation by them by 31.9–38.5 and 27.1–33.7%, respectively, compared to the control, but stimulate glycogen synthesis by cells of green sulfur bacteria by 106.7 and 64.0%, respectively. NaF and KBr at concentration 4.0 times higher than the MPC inhibit the biomass accumulation by phototrophic bacteria in the medium with nitrites 2.1−2.4 and 1.8−1.9 times, respectively, slow down nitrite ions oxidation by bacteria by 23.5–26.1 and 17.1–20.1%, respectively, compared to the control, but stimulate glycogen synthesis by cells of green sulfur bacteria by 134.7 and 115.0%, respectively. Glycogen content in Chlorobium limicola IMV K-8 cells grown in the media with Na2S2O3 or NaNO2 and NaF at concentration that 4.0 times exceeded the MPC was 81.33 and 84.13 mg/g of dry weight of cells, respectively. Fluoride ions showed a greater toxic effect on bacteria than bromide ions. The resistance of all tested bacteria strains to inorganic pollutants at high concentrations indicates their high biotechnological potential.

Active Glycogen Synthase in the Liver Prevents High-Fat Diet-Induced Glucose Intolerance, Decreases Food Intake, and Lowers Body Weight.

Many lines of evidence demonstrate a correlation between liver glycogen content and food intake. We previously demonstrated that mice overexpressing protein targeting to glycogen (PTG) specifically in the liver-which have increased glycogen content in this organ-are protected from high-fat diet (HFD)-induced obesity by reduced food intake. However, the use of PTG to increase liver glycogen implies certain limitations. PTG stimulates glycogen synthesis but also inhibits the enzyme responsible for glycogen degradation. Furthermore, as PTG is a regulatory subunit of protein phosphatase 1 (PP1), which regulates many cellular functions, its overexpression could have side effects beyond the regulation of glycogen metabolism. Therefore, it is necessary to determine whether the direct activation of glycogen synthesis, without affecting its degradation or other cellular functions, has the same effects. To this end, we generated mice overexpressing a non-inactivatable form of glycogen synthase (GS) specifically in the liver (9A-MGSAlb mice). Control and 9a-MGSAlb mice were fed a standard diet (SD) or HFD for 16 weeks. Glucose tolerance and feeding behavior were analyzed. 9A-MGSAlb mice showed an increase in hepatic glycogen in fed and fasting conditions. When fed an HFD, these animals preserved their hepatic energy state, had a reduced food intake, and presented a lower body weight and fat mass than control animals, without changes in energy expenditure. Furthermore, 9A-MGSAlb animals showed improved glucose tolerance when fed an SD or HFD. Moreover, liver triacylglycerol levels that were increased after HFD feeding were lower in these mice. These results confirm that increased liver glycogen stores contribute to decreased appetite and improve glucose tolerance in mice fed an HFD. On the basis of our findings, strategies to preserve hepatic glycogen stores emerge as potential treatments for obesity and hyperglycemia.

HM-chromanone reverses the blockade of insulin signaling induced by high glucose levels in human HepG2 cells

This study investigated whether (E)-5-hydroxy-7-methoxy-3-(2′-hydroxybenzyl)-4-chromanone (HM-chromanone) could counteract the high glucose level-induced blockade of insulin signaling in human HepG2 cells. Cells were pre-incubated with glucose (5.5 or 33 mM) and then incubated with a medium containing various concentrations of HM-chromanone. Assays for glucose uptake, glycogen synthesis, and glucose production were performed. Western blotting helped elucidate the underlying molecular mechanisms. High glucose concentration (33 mM) significantly increased p-IRS-1ser307 levels and decreased p-Akt levels. However, HM-chromanone significantly decreased p-IRS-1ser307 levels while increasing p-IRS-1tyr612 and Akt levels, which restored insulin signaling disturbed by high glucose concentration. HM-chromanone significantly increased p-AMPK levels, which were reduced by high glucose in HepG2 cells. Knockdown of AMPK using siRNA increased p-IRS-1ser307 and decreased p-Akt levels, even after treatment with HM-chromanone in high glucose concentration-treated cells. HM-chromanone stimulated glycogen synthesis by increasing p-GSK3βser9 and decreasing p-GSser641 levels in HepG2 cells under high glucose concentration; this effect was blocked by AMPK siRNA. HM-chromanone significantly decreased PEPCK, G6Pase, and hepatic glucose production, which were also blocked by AMPK siRNA. These results suggest that HM-chromanone could reverse insulin signaling blockade (induced by high glucose levels) through the activation of AMPK and stimulation of glucose uptake and glycogen synthesis in HepG2 cells.

Coronarin A modulated hepatic glycogen synthesis and gluconeogenesis via inhibiting mTORC1/S6K1 signaling and ameliorated glucose homeostasis of diabetic mice.

Promotion of hepatic glycogen synthesis and inhibition of hepatic glucose production are effective strategies for controlling hyperglycemia in type 2 diabetes mellitus (T2DM), but agents with both properties were limited. Herein we report coronarin A, a natural compound isolated from rhizomes of Hedychium gardnerianum, which simultaneously stimulates glycogen synthesis and suppresses gluconeogenesis in rat primary hepatocytes. We showed that coronarin A (3, 10 μM) dose-dependently stimulated glycogen synthesis accompanied by increased Akt and GSK3β phosphorylation in rat primary hepatocytes. Pretreatment with Akt inhibitor MK-2206 (2 μM) or PI3K inhibitor LY294002 (10 μM) blocked coronarin A-induced glycogen synthesis. Meanwhile, coronarin A (10 μM) significantly suppressed gluconeogenesis accompanied by increased phosphorylation of MEK, ERK1/2, β-catenin and increased the gene expression of TCF7L2 in rat primary hepatocytes. Pretreatment with β-catenin inhibitor IWR-1-endo (10 μM) or ERK inhibitor SCH772984 (1 μM) abolished the coronarin A-suppressed gluconeogenesis. More importantly, we revealed that coronarin A activated PI3K/Akt/GSK3β and ERK/Wnt/β-catenin signaling via regulation of a key upstream molecule IRS1. Coronarin A (10, 30 μM) decreased the phosphorylation of mTOR and S6K1, the downstream target of mTORC1, which further inhibited the serine phosphorylation of IRS1, and subsequently increased the tyrosine phosphorylation of IRS1. In type 2 diabetic ob/ob mice, chronic administration of coronarin A significantly reduced the non-fasting and fasting blood glucose levels and improved glucose tolerance, accompanied by the inhibited hepatic mTOR/S6K1 signaling and activated IRS1 along with enhanced PI3K/Akt/GSK3β and ERK/Wnt/β-catenin pathways. These results demonstrate the anti-hyperglycemic effect of coronarin A with a novel mechanism by inhibiting mTORC1/S6K1 to increase IRS1 activity, and highlighted coronarin A as a valuable lead compound for the treatment of T2DM.

Effect of estradiol and IGF1 on glycogen synthesis in bovine uterine epithelial cells.

Glucose is an important nutrient for the endometrium and embryo during pregnancy. This study shows that estradiol (E2)/IGF1 signaling stimulates glycogen synthesis in the uterine epithelium of cows, which could provide glucose when needed. Glycogen storage in the uterine epithelium peaks near estrus and is a potential source of glucose for the endometrium and embryos. However, the hormonal regulation of glycogen synthesis in the uterine epithelium is poorly understood. Our objective was to evaluate the effect of E2 and insulin-like growth factor 1 (IGF1) on glycogenesis in immortalized bovine uterine epithelial (BUTE) cells. Treatment of BUTE cells with E2 (0.1-10 nM) did not increase glycogen levels. However, treatment of BUTE cells with IGF1 (50 or 100 ng/mL) resulted in a >2-fold increase in glycogen. To determine if the uterine stroma produced IGF1 in response to E2, bovine uterine fibroblasts were treated with E2, which increased IGF1 levels. Immunohistochemistry showed higher levels of IGF1 in the stroma on day 1 than on day 11, which coincides with higher glycogen levels in the uterine epithelium. Western blots revealed that IGF1 treatment increased the levels of phospho-AKT, phospho-GSKβ, hexokinase 1, and glycogen synthase in BUTE cells. Metabolomic (GC-MS) analysis showed that IGF1 increased 3-phosphoglycerate and lactate, potentially indicative of increased flux through glycolysis. We also found higher levels of N-acetyl-glucosamine and protein glycosylation after IGF1 treatment, indicating increased hexosamine biosynthetic pathway activity. In conclusion, IGF1 is produced by uterine fibroblasts due to E2, and IGF1 increases glucose metabolism and glycogenesis in uterine epithelial cells. Glycogen stored in the uterine epithelium due to E2/IGF1 signaling at estrus could provide glucose to the endometrium or be secreted into the uterine lumen as a component of histotroph.

Camel whey protein (CWP) ameliorates liver injury in type 2 diabetes mellitus rats and insulin resistance (IR) in HepG2 cells via activation of the PI3K/Akt signaling pathway.

This research investigated the effects of camel whey protein (CWP) treatment on type 2 diabetes mellitus (T2DM) rats and insulin resistance (IR) HepG2 cell models. Body weight and fasting blood glucose were observed in type 2 diabetes mellitus (T2DM) rats every week, and biochemical parameters in serum samples were evaluated after 6 weeks. Antioxidant activity in the liver was estimated, and histological examination of the liver tissues was conducted. After CWP treatment, the glucose uptake and lipid accumulation were examined in insulin-resistant HepG2 cells. Our results indicated that CWP mitigated the body weight loss, reversed dyslipidemia, and inhibited the inflammatory response, in T2DM rats. Meanwhile, it protected the liver from being injured by reducing the level of oxidative stress. In the CWP group, the pathological changes were significantly reduced, while the liver lobule structure, liver cell arrangement, as well as congestion, edema, and vacuolization were improved. Our results from quantitative real-time PCR and western blot analyses showed that CWP could up-regulate the expression levels of insulin receptor substrate-2 (IRS-2), phosphoinositide3-kinase (PI3K), protein kinase B (AKT), and glycogen synthase (GS). An active protein component CWP8 was isolated and identified, which was shown to be able to stimulate glycogen synthesis and ameliorate lipid accumulation in IR HepG2 cells. These data indicate that CWP and CWP8 might act as potential natural products regulating glucose and lipid metabolism in T2DM.

Nitrite oxidation by phototrophic bacteria of Chlorobium, Thiocapsa and Lamprocystis genera under the influence of inorganic pollutants

Pollutants of inorganic nature (acids, alkalis, mineral salts of different composition, metals) change the course of biological processes of environmental purification, but their influence on the physiological properties of phototrophic sulfur bacteria has not been studied enough. The usage of nitrite ions as an electron donor of anoxygenic photosynthesis by cells of phototrophic green and purple sulfur bacteria Chlorobium limicola IMV K-8, Thiocapsa sp. Ya-2003 and Lamprocystis sp. Ya-2003, isolated from Yavorivske Lake, under the influence of the most widespread inorganic pollutants – hydro- and dihydrophosphates, sulfates, chlorides and chlorates, has been studied. It is shown that KH2PO4, K2HPO4, Na2SO4, NaCl and KClO3, present in the van Niel medium with 4.2 mM NaNO2 at concentrations that are 0.5, 1.0, 2.0, 3.0, 4.0 times different from the maximum permissible concentrations (MPC), influenced the biomass accumulation and nitrite ions oxidation by phototrophic green and purple sulfur bacteria. In media with hydro- and dihydrophosphate ions at concentrations 4.0 times higher than the MPC, inhibition of bacterial growth was up to 1.7 times lower than in the control. The biomass accumulation by bacteria in media with chloride and chlorate ions at concentrations 3.0–4.0 times higher than MPC was 2.0–2.8 times lower compared to the control. In the medium with Na2SO4 at concentrations 2.0–4.0 times higher than MPC, the biomass was 2.0–4.0 times lower than in the control. Nitrites’ oxidation by all strains in the media with the studied pollutants was slowed down. The residual content of nitrite ions in media with hydro- and dihydrophosphate, chloride and chlorate ions at their concentrations 4.0 times higher than MPC, exceeded the NO2– content in the control variants up to 1.7 times. If in the medium without pollutants the cells of C. limicola IMV K-8, Thiocapsa sp. Ya-2003 and Lamprocystis sp. Ya-2003 strains oxidized 72.7%, 72.2% and 71.4%, respectively, of nitrite ions present in the medium, then in the medium with sulfate ions at concentration 4.0 times higher than the MPC, bacteria oxidized nitrite ions only at 39.6%, 34.4% and 27.0%, respectively. Oxidation of a lower quantity of nitrites by phototrophic bacteria in the media with inorganic pollutants led to the production by them of a lower quantity of nitrates. The content of NO3– in the media with hydro-, dihydrophosphate and chlorate ions at all concentrations was up to 1.9 times lower than in the control. In media with sulfate ions at concentrations 2.0–4.0 times higher than MPC and chloride at concentration 4.0 times higher than MPC, the content of nitrate ions was 2.1–4.3 and 2.0 times, respectively, lower than in the control variants. Inorganic pollutants stimulated the synthesis of intracellular carbohydrates in C. limicola IMV K-8. If the content of intracellular glucose in cells grown in the medium without pollutants was 10.3 mg/g dry cell weight, then in cells grown in media with K2HPO4, KH2PO4, Na2SO4, NaCl and KClO3 at concentrations 4.0 times higher than MPC, its content increased by 12.2%, 10.7%, 51.6%, 17.1% and 35.9%, respectively. The glycogen content in the cells grown in the medium without pollutants was 45.1 mg/g dry cell weight. Hydro- and dihydrophosphate, chloride and chlorate ions at concentrations 4.0 times higher than MPC stimulated glycogen synthesis in cells by 47.5%, 57.6%, 67.4% and 74.6%, respectively. The glycogen content in cells grown in the medium with Na2SO4 at concentrations 3.0 and 4.0 times higher than MPC increased by 102.9% and 107.5%, respectively. Therefore, it is established that pollutants of inorganic nature affect the physiological properties of photosynthetic sulfur bacteria and thus change the course of biological processes of environment purification, in particular, from nitrite ions.

Relevance of Mango Use in Patients with 2 Type Diabetes mellitus

Mango fruits and mango leaf extracts (Mangifera indica) are a medicinal plant used to treat diabetes and its complications. The tender leaves of the mango tree contain tannins called anthocyanidins, which help treat early diabetes. The leaves contain the compound 3 betataraxerol and ethyl acetate extract, which interacts with insulin, activating GLUT4 and stimulating glycogen synthesis. Mango leaves have powerful antioxidant properties because they contain a large amount of flavonoids, phenols, zeaxanthin and beta-carotene. Animal studies have shown that mangiferin can counteract the free radical associated with cancer, diabetes, and other diseases.

236-OR: Molecular and Biological Properties of Insulin Icodec, a New Insulin Analog Designed to Give a Long Half-Life Suitable for Once-Weekly Dosing

Insulin icodec is a novel insulin analog with a terminal elimination half-life of ∼196 hours currently in clinical development, designed to be able to cover a full week’s basal insulin requirements with a single subcutaneous injection. To attain such a long half-life, the insulin molecule was modified to achieve an albumin-bound circulating depot of icodec which acts just as human insulin (HI) but is more slowly cleared.Addition of a C20 fatty diacid containing side chain at B29K via a hydrophilic linker imparts strong but reversible albumin binding (10x that of insulin detemir). Three amino acid substitutions (A14E, B16H and B25H) ensure reduced enzymatic degradation of icodec and contribute to attenuating insulin receptor (IR) binding and clearance, further prolonging the half-life. In vitro studies demonstrated that icodec is a specific and full agonist of the human IR, and that it displays the same dose-dependent mode of action as HI, exemplified by its ability to phosphorylate the IR and stimulate intracellular signaling pathways (phospho-AKT and -ERK). Functional assays have demonstrated that icodec elicits the same pattern of metabolic effects as HI, including glucose uptake and lipogenesis in fat cells, and stimulation of glycogen synthesis in liver cells. The affinity of icodec for the IGF-1 receptor was found to be proportionately lower than its binding to the IR. The in vitro mitogenic effect of icodec in primary human mammary cells (HMEC), as well as in mammary and colon carcinoma cells (MCF-7 and COLO 205) was found to be low relative to that of HI. In conclusion, icodec is a new insulin analog designed to achieve a slowly cleared, albumin-bound circulating depot which results in a long half-life suited for once weekly injections, covering the basal insulin requirements for a full week. *Insulin icodec (proposed INN). Disclosure E. Nishimura: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. Stock/Shareholder; Spouse/Partner; Novo Nordisk A/S. T. Kjeldsen: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. Stock/Shareholder; Spouse/Partner; Novo Nordisk A/S. F. Hubalek: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. T. Glendorf: Employee; Spouse/Partner; Novo Nordisk A/S. Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Spouse/Partner; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. C.E. Stidsen: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. B.F. Hansen: Stock/Shareholder; Self; Novo Nordisk A/S. T.A. Pedersen: Employee; Self; Novo Nordisk A/S. A. Luetzen: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. L. Pridal: None. P. Madsen: Employee; Self; Novo Nordisk A/S.

1734-P: High Dietary Fat Intake Exacerbates Insulin Resistance in a Type 2 Diabetes Genetic Mouse Model

GLUT4, an insulin-sensitive glucose transporter, plays a major role of postprandial glucose disposal. We previously reported that human GLUT4 promoter-driven insulin receptor knockout (GIRKO) mice have reduced insulin signaling in central and peripheral tissues and develop hyperglycemia, albeit at a lower rate in an age-dependent manner on normal chow diet. Long-term high fat diet (HFD) feeding is well established for causing adiposity gain, increased inflammation, and insulin resistance. We hypothesized that HFD feeding will exacerbate the insulin resistance and result in rapid progression to overt diabetes in GIRKO mice. To test this, we examined the physiological response of euglycemic GIRKO mice to HFD in a time course study. We used indirect calorimetry analysis and found that GIRKO mice showed differences in energy partitioning shortly after HFD feeding started. The majority of GIRKO mice cohorts had 5-fold higher circulating insulin and 1.5-fold elevated blood glucose after 1 month of HFD feeding. In addition to the hyperglycemia and hyperinsulinemia, GIRKO mice also exhibited impaired glucose tolerance and islet hyperplasia, suggesting extreme insulin resistance exceeded the compensatory increase of insulin production. After 3 months on HFD, GIRKO mice had increased relative liver size, elevated hepatic triglycerides, and reduced hepatic glycogen, demonstrating impaired hepatic insulin signaling to stimulate glycogen synthesis and inhibit gluconeogenesis. We also confirmed the increase of key hepatic gluconeogenic gene expression, which likely contributed to hyperglycemia. The rapid progression of metabolic defects of GIRKO mice on HFD is not due to excessive weight or adiposity gain. In conclusion, our studies of HFD-fed GIRKO mouse will offer insights in the role of the dietary contribution to diabetes disease progression without the confounding factor of increased adiposity. Disclosure A. Reilly: None. S. Yan: None. A.J. Loncharich: None. H. Ren: None. Funding Indiana University Diabetes and Obesity Research Training Program (T32DK064466); National Institute of Diabetes and Digestive and Kidney Diseases (R01DK120772, R00DK098294); Indiana Diabetes Center (P30DK097512); Indiana Clinical and Translational Sciences Institute (UL1TR002529)

Multi-omics insights into functional alterations of the liver in insulin-deficient diabetes mellitus

ObjectiveThe liver regulates the availability of insulin to other tissues and is the first line insulin response organ physiologically exposed to higher insulin concentrations than the periphery. Basal insulin during fasting inhibits hepatic gluconeogenesis and glycogenolysis, whereas postprandial insulin peaks stimulate glycogen synthesis. The molecular consequences of chronic insulin deficiency for the liver have not been studied systematically. MethodsWe analyzed liver samples of a genetically diabetic pig model (MIDY) and of wild-type (WT) littermate controls by RNA sequencing, proteomics, and targeted metabolomics/lipidomics. ResultsCross-omics analyses revealed increased activities in amino acid metabolism, oxidation of fatty acids, ketogenesis, and gluconeogenesis in the MIDY samples. In particular, the concentrations of the ketogenic enzyme 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2) and of retinol dehydrogenase 16 (RDH16), which catalyzes the first step in retinoic acid biogenesis, were highly increased. Accordingly, elevated levels of retinoic acid, which stimulates the expression of the gluconeogenic enzyme phosphoenolpyruvate carboxykinase (PCK1), were measured in the MIDY samples. In contrast, pathways related to extracellular matrix and inflammation/pathogen defense response were less active than in the WT samples. ConclusionsThe first multi-omics study of a clinically relevant diabetic large animal model revealed molecular signatures and key drivers of functional alterations of the liver in insulin-deficient diabetes mellitus. The multi-omics data set provides a valuable resource for comparative analyses with other experimental or clinical data sets.

SAT-180 MicroRNA Library Screening Identifies a Subset of Cooperative MicroRNAs That Affects Differentiation and Glucose Metabolism of Human Skeletal Muscle Cells

Skeletal muscle is a key target tissue for regulating whole body metabolism. Decreased muscle mass during the ageing process contributes to deteriorated metabolism and, next to obesity, is a major driver for the increasing prevalence of type 2 diabetes. Strategies to improve regeneration and glucose metabolism in skeletal muscle are therefore urgently needed. microRNAs (miRNAs) are important contributors to muscle formation and potential therapeutic targets, but the relevant miRNAs to improve muscle formation and insulin action are still poorly defined. Here, we aimed to develop strategies to identify miRNA networks during muscle regeneration irrespective of aberrant expression patterns in affected muscle tissues. Using miRNA library screening we determined that miRNA cooperativity controls differentiation in muscle cells that lack endogenous miRNAs after deletion of the RNA-binding protein DiGeorge syndrome critical region gene 8 (DGCR8). A group of only six miRNAs rescued morphological and gene expression changes in these knockout cells. Conversely, combinatorial inhibition of five of the six miRNAs (let7-5p, miR-29a-3p, miR-125b-5p, miR-199a-5p, and miR-221-3p) markedly enhanced differentiation in wildtype muscle cells from mice and humans. Improved muscle differentiation translated into improved insulin stimulated glycogen synthesis (+30%, p<0.05, Ant-5x versus control myotubes). Mechanistically, miRNA add-back and loss-of-function most significantly affected genes involved in focal adhesion signalling and antagonizing the subset of miRNAs in human skeletal muscle cells enhanced phosphorylation of p38 mitogen-activated protein kinase and AKT highlighting the importance of cues from the extracellular matrix for muscle formation and the regulation of glucose metabolism.

Efektivitas antara Brisk Walk Exercise dan Relaksasi Otot Progresif terhadap Penurunan Kadar Gula Darah pada Diabetes Mellitus tipe 2

Kadar gula darah pada pasien diabetes mellitus tipe 2 dapat diturunkan dengan terapi brisk walk exercise dan relaksasi otot progresif. Hal ini dikarenakan bila latihan jalan kaki dilakukan secara teratur dapat merangsang sintesis glikogen melalui peningkatan aksi insulin dan merangsang transportasi glukosa oleh tranporter glukosa GLUT4. Sedangkan ketika relaksasi otot progresif dilakukan secara teratur mampu menghambat jalur stressor sehingga memperkuat sikap positif terhadap rangsangan stress dan mengakibatkan hipotalamus berkurang. Penelitian ini bertujuan untuk mengetahui efektivitas antara Brisk Walk Exercise dan Relaksasi Otot Progresif terhadap penurunan kadar gua darah pada Diabetes Mellitus Tipe 2. Desain penelitian ini menggunakan Quasy Eksperimental dengan jenis rancangan Pre-test and Post-test Group Design dengan teknik pengambilan sample consecutive sampling. Besar Sample adalah 30 responden, dibagi menjadi 2 kelompok yaitu kelompok Brisk Walk Exercise dan kelompok RelaksasiEfektivitas Antara Brisk Walk Exercise Dan Relaksasi Otot...60 pISSN 2301-4024 eISSN 2442-6873Otot Progresif. Hasil uji Paired T-test kelompok Brisk Walk Exercise didapatkan nilai Pvalue =0,000&lt;α=0.05 hal ini berarti ada perbedaan yang signifikan. Sedangkan pada kelompok Relaksasi Otot Progresif nilai Pvalue=0,000&lt;α=0.05 berarti ada perbedaan yang signifikan. Pada uji Paired T-test didapatkan nilai Pvalue =0,000&lt;α=0.05 artinya ada perbedaan bermakna antara Brisk Walk Exercise dan Relaksasi Otot Progresif. Sebagai perawat diharapkan dapat menerapkan terapi non farmakologis seperti Brisk Walk Exercise dan Relaksasi Otot Progresif sebagai terapi alternatif pilihan pasien yang mudah untuk dilakukan untuk menurunkan kadar gula darah.

Possible Antidiabetic Mechanism of Action of Ex-maradi Okra Fruit Variety (&lt;i&gt;Abelmoscus esculentus&lt;/i&gt;) on Alloxan Induced Diabetic Rats

Increasing evidences suggest that postprandial hyperglycemia plays an important role in the development of diabetes complications. Therefore, therapeutic approaches that act via lowering of postprandial glucose leading to reduce insulin requirement are currently very attractive. The present study investigated some possible mechanisms of hypoglycemic action of different parts (Whole Okra ‘WO’; Okra Peel ‘OP’ and Okra Seed ‘OS’) of Ex-maradi Okra fruit variety in the management of diabetes mellitus in alloxan induced diabetic rats. Standard analytical procedures were employed in the study. The results indicated that various parts of Okra fruit have ability to stimulate glycogen synthesis in the liver and delay intestinal absorption of glucose with very significant glucose dialysis retardation index (GDRI) and high glucose adsorption capacity (GAC). Histological examination of the pancreatic tissue after administration of Okra fruit revealed evidence of pancreatic islets cells regeneration. These results suggest that the possible mechanisms of antidiabetic effect of Okra fruit is multidimensional and might involve increase glycogenesis, delay glucose absorption and pancreatic islets regeneration leading to increase insulin secretion. These might help control postprandial hyperglycemia in diabetes mellitus.

Deoxysphingolipids—Novel Skeletal Muscle Lipids Related to Insulin Resistance in Humans That Decrease Insulin Sensitivity In Vitro

Accumulation of sphingolipids are thought to promote skeletal muscle insulin resistance. Deoxysphingolipids (dSL) are a novel type of sphingolipid made by condensing palmitate with alanine (deoxydihydroceramide - dDHCer) or glycine (deoxymethylceramide - dMeCer) instead of serine. In plasma, dSL are increased in individuals with type 2 diabetes and cause beta cell dysfunction in vitro. However, their role in skeletal muscle is unknown. We evaluated skeletal muscle dSL content in endurance trained athletes (n=13), lean (n=14), obese (n=12), and type 2 diabetic (n=10) men and women. Muscle dSL content was measured from biopsies using LC/MS/MS, and insulin sensitivity using a hyperinsulinemic-euglycemic clamp. After adjusting for repeated measures, total and C18:0 muscle dDHCer were inversely related to insulin sensitivity (p=0.0008, and p=0.0003, respectively), while dMeCer were below the limit of detection. Total and C18:0 dDHCer were significantly greater in obese and T2D compared to athletes and lean (p&amp;lt;0.004). In primary myotubes, dSL content was increased to determine effects on insulin sensitivity by altering media amino acid content with 5x alanine/glycine (no serine) or 1x alanine/glycine/serine as a control, and replaced every 24 hours for 2 days. Alanine and glycine supplementation increased myotube dDHCer content by 3.6 fold, dMeCer content by 21 fold, and decreased ceramide content by 30% relative to control. Fluorescence lifetime imaging revealed decreased oxidative flux in enhanced dSL conditions. Insulin sensitivity, measured using the percent increase in insulin stimulated glycogen synthesis, decreased from 55±9.1% in control to 4±9% in enhanced dSL conditions. Combined, these data reveal that dSL accumulate in insulin resistant human muscle, and appear to cause insulin resistance in vitro. These data suggest decreasing skeletal muscle deoxysphingolipid content may prevent or treat skeletal muscle insulin resistance. Disclosure S. Zarini: None. L. Perreault: Advisory Panel; Self; Novo Nordisk A/S. Speaker's Bureau; Self; Novo Nordisk A/S. Advisory Panel; Self; Merck &amp; Co., Inc.. Speaker's Bureau; Self; Merck &amp; Co., Inc., AstraZeneca, Janssen Pharmaceuticals, Inc., Boehringer Ingelheim Pharmaceuticals, Inc.. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Advisory Panel; Self; Sanofi. Speaker's Bureau; Self; Sanofi. S.A. Newsom: None. D.E. Kahn: None. A. Kerege: None. K.A. Harrison: None. B. Bergman: Research Support; Self; Eli Lilly and Company. Advisory Panel; Spouse/Partner; Novo Nordisk Inc., Merck &amp; Co., Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company.

Activation of the IGF1 receptor stimulates glycogen synthesis by mink uterine epithelial cells.

Glycogen synthesis by mink uterine epithelial cells is stimulated by estradiol (E2 ) during estrus, although the mechanism/s through which the steroid promotes glycogen accumulation are unknown. Our aim was to determine if insulin is required for E2 induced glycogen synthesis by an immortalized mink uterine epithelial cell line (GMMe). We show that the cells expressed the genes for glycogen metabolizing enzymes (hexokinase 1, glucose-6-phosphatase 3, glycogen synthase 1, and glycogen phosphorylase-muscle), receptors for insulin, insulin-like growth factor 1 and E2 (Esr1). Interestingly, treatment of cells with E2 alone failed to stimulate glycogen production, whereas supraphysiological concentrations of insulin (50 μg/ml) only, significantly increased glycogen content. Moreover, insulin + E2 increased glycogen content when compared to insulin alone (p < 0.05), an affect that was blocked when cells were treated with the pure E2 receptor antagonist ICI 182,780. Glycogen synthesis in response to insulin was significantly inhibited when cells were pre-treated with picropodophyllotoxin, an IGF1R antagonist. Treatment of cells with LY294002, a phosphatidylinositol 3-kinase (PI3K) antagonist, blocked insulin's effects on glycogen production whereas treatment with U0126, an inhibitor of mitogen activated kinase-kinase (MEK1/2) was without effect. These findings suggest to us that the affects of E2 on glycogen synthesis by GMMe cells is mediated through Esr1 and increased responsiveness of the cells to insulin. Because picropodophylotoxin blocked the effects of insulin on glycogen production, and both insulin and IGF1 act through PI3K, it is possible that IGF1 plays a role in glycogen production by these cells.

Multi-Omics Insights into Functional Alterations of the Liver in Insulin-Deficient Diabetes Mellitus

The liver regulates the availability of insulin to other tissues and is the first line insulin response organ being physiologically exposed to higher insulin concentrations than the periphery. Basal insulin during fasting inhibits hepatic gluconeogenesis and glycogenolysis, whereas postprandial insulin peaks stimulate glycogen synthesis. The molecular consequences of chronic insulin deficiency for the liver have not been studied systematically. We analyzed liver samples of a genetically diabetic pig model (MIDY) and of wild-type (WT) littermate controls by RNA sequencing, proteomics and targeted metabolomics/lipidomics. Cross-omics analyses revealed increased activity in gluconeogenesis, ketogenesis, amino acid metabolism and oxidation of fatty acids in the MIDY samples, whereas pathways related to extracellular matrix and inflammation/pathogen defense response were less active than in the WT samples. Our study identified key drivers of these alterations, such as RDH16 and HMGCS2 for stimulated gluconeogenesis and ketogenesis, in a clinically relevant large animal model for insulin-deficient diabetes mellitus.

Cichoric acid regulates the hepatic glucose homeostasis via AMPK pathway and activates the antioxidant response in high glucose-induced hepatocyte injury

CA regulates hepatic glucose homeostasisviathe AMPK pathway and improves hepatocyte injuryviaantioxidant responsein vitroandin vivo.

High-molecular-weight cocoa procyanidins possess enhanced insulin-enhancing and insulin mimetic activities in human primary skeletal muscle cells compared to smaller procyanidins

Dysregulation of glucose metabolism is a primary hallmark of metabolic disease (i.e., diabetes, obesity, etc.). Complementary nonpharmaceutical strategies are needed to prevent and/or ameliorate dysregulation of glucose metabolism and prevent progression from normoglycemia to prediabetes and type 2 diabetes across the lifespan. Cocoa compounds, particularly the procyanidins, have shown promise for improving insulin sensitivity and blood glucose homeostasis. However, the molecular mechanisms by which cocoa procyanidins exert these functions remain poorly understood. Furthermore, cocoa procyanidins exhibit size diversity, and evidence suggests that procyanidin bioactivity and size may be related. Here, we show that a procyanidin-rich cocoa extract elicits an antidiabetic effect by stimulating glycogen synthesis and glucose uptake, independent of insulin. Cocoa procyanidins did not appear to act via stimulation of AMPK or CaMKII activities. Additionally, in the presence of insulin, glycogen synthesis and AKT phosphorylation were affected. These mechanisms of action are most pronounced in response to oligomeric and polymeric procyanidins. These results demonstrate (1) specific mechanisms by which cocoa procyanidins improve glucose utilization in skeletal muscle and (2) that larger procyanidins appear to possess enhanced activities. These mechanistic insights suggest specific strategies and biological contexts that may be exploited to maximize the antidiabetic benefits of cocoa procyanidins.

Insulin-mimicking bioactivities of acylated inositol glycans in several mouse models of diabetes with or without obesity.

Insulin-mimetic species of low molecular weight are speculated to mediate some intracellular insulin actions. These inositol glycans, which are generated upon insulin stimulation from glycosylphosphatidylinositols, might control the activity of a multitude of insulin effector enzymes. Acylated inositol glycans (AIGs) are generated by cleavage of protein-free GPI precursors through the action of GPI-specific phospholipase C (GPI-PLC) and D (GPI-PLD). We synthesized AIGs (IG-1, IG-2, IG-13, IG-14, and IG-15) and then evaluated their insulin-mimicking bioactivities. IG-1 significantly stimulated glycogen synthesis and lipogenesis in 3T3-L1 adipocytes and rat isolated adipocytes dose-dependently. IG-2 significantly stimulated lipogenesis in rat isolated adipocytes dose-dependently. IG-15 also enhanced glycogen synthesis and lipogenesis in 3T3-L1 adipocytes. The administration of IG-1 decreased plasma glucose, increased glycogen content in liver and skeletal muscles and improved glucose tolerance in C57B6N mice with normal diets. The administration of IG-1 decreased plasma glucose in STZ-diabetic C57B6N mice. The treatment of IG-1 decreased plasma glucose, increased glycogen content in liver and skeletal muscles and improved glucose tolerance in C57B6N mice with high fat-diets and db/db mice. The long-term treatment of IG-1 decreased plasma glucose and reduced food intake and body weight in C57B6N mice with high fat-diets and ob/ob mice. Thus, IG-1 has insulin-mimicking bioactivities and improves glucose tolerance in mice models of diabetes with or without obesity.