scholarly journals Scavenging ROS Decreases Amyloid-beta Levels via Activation of PI3K/Akt/GLUT1 pathway in N2a/APP695swe Cells

2021 ◽  
Author(s):  
Yan Peng ◽  
Li Zhang ◽  
Fanlin Zhou ◽  
Yangyang Wang ◽  
Shijie Li ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Akt Pathway ◽  
Glucose Transporter 1 ◽  
Abnormal Glucose Metabolism ◽  
Glut1 Expression ◽  
Ros Scavenger ◽  
Underlying Mechanisms ◽  
The Brain

Abstract Dysregulated glucose metabolism in the brain is considered to be the underlying cause of Alzheimer's disease (AD). Abnormal glucose metabolism in AD is associated with decreased glucose transporter 1 (GLUT1) and GLUT3 in the brain, but the underlying mechanisms remains unclear. Here, we reported that GLUT1 expression was decreased in N2a/APP695swe cells and GLUT3 expression was not significantly changed. Flow Cytometry analysis showed a significant increase of intracellular ROS content in N2a/APP695swe cells and GLUT1 expression was upregulated after treatment with the ROS scavenger N-acetyl-L-Cysteine (NAC). Cellular glucose uptake and ATP levels were reduced following decreased GLUT1 expression and increased after upregulating GLUT1. Western blot analyses showed that phosphorylation of PI3K/Akt pathway decreased in N2a/APP695swe cells. Aβ levels decreased after upregulation of GLUT1 expression and increased after downregulation of GLUT1. After NAC treatment, PI3K/Akt pathway phosphorylation levels and GLUT1 expression were upregulated, glucose uptake and ATP contents were increased, and Aβ levels were decreased. After adding PI3K/Akt pathway inhibitor LY29004, GLUT1 expression was reduced and Aβ levels were increased. Besides, the increased glucose uptake and ATP contents by the Akt activator SC79 were hindered with the GLUT1 inhibitor WZB117. Aβ levels decreased after SC79 treatment and increased after WZB117 treatment. Overall, our data suggest that ROS reduced GLUT1 expression by inhibiting PI3K/Akt pathway activity resulting in impaired glucose metabolism and scavenging ROS prevents Aβ via activation of PI3K/Akt/GLUT1 pathway in N2a/APP695swe cells.

scholarly journals Aspirin, a potential GLUT1 inhibitor in a vascular endothelial cell line

Open Medicine ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 552-560 ◽  
Author(s):  
Yabo Hu ◽  
Xiaohan Lou ◽  
Ruirui Wang ◽  
Chanjun Sun ◽  
Xiaomeng Liu ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial Cell ◽  
Vascular Endothelial ◽  
Glucose Transporter 1 ◽  
Glut1 Expression ◽  
Inhibition Of Angiogenesis ◽  
Underlying Mechanisms

AbstractRecent epidemiological and preclinical studies have revealed that aspirin possesses antitumor properties; one of the mechanisms results from inhibition of angiogenesis. However, the underlying mechanisms of such action remain to be elucidated, in particular, the effect of aspirin on glucose metabolism of vascular endothelial cells (ECs) has not yet been reported. Herein, we demonstrate that glucose transporter 1 (GLUT1), a main glucose transporter in ECs, can be down-regulated by aspirin. Exposure to 4-mM aspirin significantly decreased GLUT1 at the mRNA and protein level, resulting in impaired glucose uptake capacity in vascular ECs. In addition, we also showed that exposure to 4-mM aspirin led to an inhibition of intracellular ATP and lactate synthesis in vascular ECs, and a down-regulation of the phosphorylation level of NF-κB p65 was observed. Taken together, these findings indicate 4-mM aspirin inhibits glucose uptake and glucose metabolism of vascular ECs through down-regulating GLUT1 expression and suggest that GLUT1 has potential to be a target for aspirin in vascular ECs.

scholarly journals LncRNA HOTAIR regulates glucose transporter Glut1 expression and glucose uptake in macrophages during inflammation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monira Obaid ◽  
S. M. Nashir Udden ◽  
Prasanna Alluri ◽  
Subhrangsu S. Mandal
Keyword(s):  
Immune Response ◽  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Immune Cells ◽  
Glucose Transporter ◽  
Energy Needs ◽  
Glut1 Expression ◽  
Lncrna Hotair ◽  
Upstream Regulators ◽  
Glucose Transporter Glut1

AbstractInflammation plays central roles in the immune response. Inflammatory response normally requires higher energy and therefore is associated with glucose metabolism. Our recent study demonstrates that lncRNA HOTAIR plays key roles in NF-kB activation, cytokine expression, and inflammation. Here, we investigated if HOTAIR plays any role in the regulation of glucose metabolism in immune cells during inflammation. Our results demonstrate that LPS-induced inflammation induces the expression of glucose transporter isoform 1 (Glut1) which controls the glucose uptake in macrophages. LPS-induced Glut1 expression is regulated via NF-kB activation. Importantly, siRNA-mediated knockdown of HOTAIR suppressed the LPS-induced expression of Glut1 suggesting key roles of HOTAIR in LPS-induced Glut1 expression in macrophage. HOTAIR induces NF-kB activation, which in turn increases Glut1 expression in response to LPS. We also found that HOTAIR regulates glucose uptake in macrophages during LPS-induced inflammation and its knockdown decreases LPS-induced increased glucose uptake. HOTAIR also regulates other upstream regulators of glucose metabolism such as PTEN and HIF1α, suggesting its multimodal functions in glucose metabolism. Overall, our study demonstrated that lncRNA HOTAIR plays key roles in LPS-induced Glut1 expression and glucose uptake by activating NF-kB and hence HOTAIR regulates metabolic programming in immune cells potentially to meet the energy needs during the immune response.

Differential glycolytic and glycogenogenic transduction pathways in male and female bovine embryos produced in vitro

2012 ◽  
Vol 24 (2) ◽  
pp. 344 ◽  
Author(s):  
M. Garcia-Herreros ◽  
I. M. Aparicio ◽  
D. Rath ◽  
T. Fair ◽  
P. Lonergan
Keyword(s):  
Glucose Metabolism ◽  
Protein Expression ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Glycogen Synthase ◽  
Bovine Embryos ◽  
High Concentration ◽  
Glucose Transporter 1 ◽  
Male And Female ◽  
Glut 1

Previous studies have shown that developmental kinetic rates following IVF are lower in female than in male blastocysts and that this may be related to differences in glucose metabolism. In addition, an inhibition of phosphatidylinositol 3-kinase (PI3-K) inhibits glucose uptake in murine blastocysts. Therefore, the aim of this study was to identify and compare the expression of proteins involved in glucose metabolism (hexokinase-I, HK-I; phosphofructokinase-1, PFK-1; pyruvate kinase1/2, PK1/2; glyceraldehyde-3-phosphate dehydrogenase, GAPDH; glucose transporter-1, GLUT-1; and glycogen synthase kinase-3, GSK-3) in male and female bovine blastocysts to determine whether PI3-K has a role in the regulation of the expression of these proteins. Hexokinase-I, PFK-1, PK1/2, GAPDH and GLUT-1 were present in bovine embryos. Protein expression of these proteins and GSK-3 was significantly higher in male compared with female blastocysts. Inhibition of PI3-K with LY294002 significantly decreased the expression of HK-I, PFK-1, GAPDH, GSK-3 A/B and GLUT-1. Results showed that the expression of glycolytic proteins HK-I, PFK-1, GAPDH and PK1/2, and the transporters GLUT-1 and GSK-3 is regulated by PI3-K in bovine blastocysts. Moreover, the differential protein expression observed between male and female blastocysts might explain the faster developmental kinetics seen in males, as the expression of main proteins involved in glycolysis and glycogenogenesis was significantly higher in male than female bovine embryos and also could explain the sensitivity of male embryos to a high concentration of glucose, as a positive correlation between GLUT-1 expression and glucose uptake in embryos has been demonstrated.

scholarly journals Glucose uptake inhibition decreases expressions of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteocalcin in osteocytic MLO-Y4-A2 cells

2018 ◽  
Vol 314 (2) ◽  
pp. E115-E123 ◽  
Author(s):  
Ayumu Takeno ◽  
Ippei Kanazawa ◽  
Masakazu Notsu ◽  
Ken-ichiro Tanaka ◽  
Toshitsugu Sugimoto
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
P38 Mapk ◽  
Glucose Transporter ◽  
Mek Inhibitor ◽  
Long Bone ◽  
Uptake Inhibition ◽  
Glucose Transporter 1 ◽  
P38 Inhibitor ◽  
Glucose Levels

Bone and glucose metabolism are closely associated with each other. Both osteoblast and osteoclast functions are important for the action of osteocalcin, which plays pivotal roles as an endocrine hormone regulating glucose metabolism. However, it is unknown whether osteocytes are involved in the interaction between bone and glucose metabolism. We used MLO-Y4-A2, a murine long bone-derived osteocytic cell line, to investigate effects of glucose uptake inhibition on expressions of osteocalcin and bone-remodeling modulators in osteocytes. We found that glucose transporter 1 (GLUT1) is expressed in MLO-Y4-A2 cells and that treatment with phloretin, a GLUT inhibitor, significantly inhibited glucose uptake. Real-time PCR and Western blot showed that phloretin significantly and dose-dependently decreased the expressions of RANKL and osteocalcin, whereas osteoprotegerin or sclerostin was not affected. Moreover, phloretin activated AMP-activated protein kinase (AMPK), an intracellular energy sensor. Coincubation of ara-A, an AMPK inhibitor, with phloretin canceled the phloretin-induced decrease in osteocalcin expression, but not RANKL. In contrast, phloretin suppressed phosphorylation of ERK1/2, JNK, and p38 MAPK, and treatments with the p38 inhibitor SB203580 and the MEK inhibitor PD98059, but not the JNK inhibitor SP600125, significantly decreased expressions of RANKL and osteocalcin. These results indicate that glucose uptake by GLUT1 is required for RANKL and osteocalcin expressions in osteocytes, and that inhibition of glucose uptake decreases their expressions through AMPK, ERK1/2, and p38 MAPK pathways. These findings suggest that lowering glucose uptake into osteocytes may contribute to maintain blood glucose levels by decreasing osteocalcin expression and RANKL-induced bone resorption.

Effect of oocyte vitrification on glucose transport in mouse metaphase II oocytes

Reproduction ◽  
2021 ◽  
Vol 161 (5) ◽  
pp. 549-559
Author(s):  
Yufei Wang ◽  
Haoya Chang ◽  
Qifu He ◽  
Yaxing Xue ◽  
Kang Zhang ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Energy Levels ◽  
Oocyte Vitrification ◽  
Abnormal Glucose Metabolism ◽  
Cell Embryo ◽  
Irreversible Effect ◽  
Metaphase Ii Oocytes

Oocyte vitrification has significantly improved the survival rate and become the mainstream method for cryopreserving oocytes. Previous studies have demonstrated that the ultrastructure, mitochondrial function, DNA methylation, and histone modification exhibit an irreversible effect after oocyte vitrification. However, little is known about the effects of oocyte vitrification on glucose transport and metabolism. This study aims to determine whether mouse oocyte vitrification causes abnormal glucose metabolism and identify a strategy to correct abnormal glucose metabolism. Furthermore, this study further investigates the effects of oocyte vitrification on glucose uptake, and glucose metabolism, and energy levels. The results indicated that vitrification significantly reduced the glucose transport activity, NADPH, glutathione, and ATP levels, and increased reactive oxygen species levels in oocytes (P  < 0.01). Vitrification also reduced the expression of glucose transporter isoform 1 (GLUT1) (P  < 0.01). Adding a GLUT1 inhibitor reduced the glucose uptake capacity of oocytes. Furthermore, the inclusion of vitamin C into thawing and culture solutions restored abnormal glucose transportation and metabolism and improved the survival, two-cell embryo, and blastocyst rates of the vitrified groups via parthenogenesis (P  < 0.05). Overall, this method may improve the quality and efficiency of oocyte vitrification.

Hormonal regulation of glucose and system A amino acid transport in first trimester placental villous fragments

2005 ◽  
Vol 288 (3) ◽  
pp. R656-R662 ◽  
Author(s):  
Anette Ericsson ◽  
Bengt Hamark ◽  
Nina Jansson ◽  
Bengt R. Johansson ◽  
Theresa L. Powell ◽  
...  
Keyword(s):  
Amino Acid ◽  
Glucose Uptake ◽  
Fetal Growth ◽  
Hormonal Regulation ◽  
Glucose Transporter ◽  
First Trimester ◽  
Glucose Transporter 1 ◽  
System A ◽  
Underlying Mechanisms ◽  
Growth Abnormalities

Alterations in placental nutrient transfer have been implicated in fetal growth abnormalities. In pregnancies complicated by diabetes and accelerated fetal growth, upregulations of glucose transporter 1 (GLUT1) and amino acid transporter system A have been shown in the syncytiotrophoblast of term placenta. In contrast, intrauterine growth restriction is associated with a downregulation of placental system A transporters. However, underlying mechanisms of transporter regulation are poorly understood, particularly in early pregnancy. In this study, hormonal regulation of placental glucose and system A transporters was investigated. The uptake of 3-O-[methyl-14C]-d-glucose was studied in villous fragments isolated from first trimester (6–13 wk of gestation) and term human placenta. Villous fragments were incubated in buffer containing insulin, leptin, cortisol, growth hormone (GH), prolactin, IGF-I, or under hypo/hyperglycemic conditions for 1 h. Subsequently, 3-O-[methyl-14C]-d-glucose uptake was measured with and without phloretin for 70 s in first trimester tissue and 20 s in term tissue. Methylaminoisobutyric uptake was measured with and without Na+ for 20 min. Glucose uptake was unaltered by hormones or hypo/hyperglycemia. GH decreased system A activity by 31% in first trimester ( P < 0.05). The uptake of glucose was 50% higher in term compared with first trimester fragments and increased markedly between 6 and 13 wk of gestation ( P < 0.05). We conclude that placental glucose transporter activity is not regulated by short exposures to the hormones or glucose concentrations tested. In contrast to term placental villous fragments, system A activity was not regulated by insulin or leptin in first trimester but was downregulated by GH.

scholarly journals Metformin protects against insulin resistance induced by high uric acid in cardiomyocytes via AMPK signaling pathways in vitro and in vivo

2021 ◽  
Author(s):  
Zhenyu Jiao ◽  
Yingqun Chen ◽  
Yang Xie ◽  
Yanbing Li ◽  
Zhi Li
Keyword(s):  
Insulin Resistance ◽  
Uric Acid ◽  
Glucose Metabolism ◽  
Glucose Tolerance ◽  
Mouse Model ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Abnormal Glucose Metabolism ◽  
Insulin Tolerance

Abstract BackgroundHigh uric acid (HUA) is associated with insulin resistance and abnormal glucose metabolism in cardiomyocytes. Metformin is a recognized agonist of AMP-activated protein kinase (AMPK) and an antidiabetic drug widely used for type 2 diabetes. It can play a cardioprotective role in many pathways. We investigated whether metformin protects against HUA-induced insulin resistance and abnormal glucose metabolism in cardiomyocytes.MethodsWe exposed primary cardiomyocytes to HUA, and cellular glucose uptake was quantified by measuring the uptake of 2-NBDG, a fluorescent glucose analog, after insulin excitation.ResultsTreatment with metformin (10 µmol/L) protected against HUA-inhibited glucose uptake induced by insulin in primary cardiomyocytes, as shown by fluorescence microscopy and flow cytometry analysis. HUA directly inhibited the phosphorylation of Akt and the translocation of glucose transporter type 4 (GLUT4) induced by insulin, which was blocked by metformin. Metformin promoted phosphorylation of AMPK, renewed HUA-inhibited glucose uptake induced by insulin and protected against insulin resistance in cardiomyocytes. As a result of these effects, in a mouse model of acute hyperuricemia, metformin improved insulin tolerance and glucose tolerance, accompanied by increased AMPK phosphorylation, Akt phosphorylation and translocation of GLUT4 in myocardial tissues. As expected, AICAR, another AMPK activator, had equivalent effects to metformin, demonstrating the important role of AMPK activation in protecting against insulin resistance induced by HUA in cardiomyocytes. Metformin protects against insulin resistance induced by HUA in cardiomyocytes and improves insulin tolerance and glucose tolerance in an acute hyperuricemic mouse model, along with the activation of AMPK.ConclusionsConsequently, metformin may be an important potential new treatment strategy for hyperuricemia-related cardiovascular disease.

scholarly journals GnRH increases glucose transporter-1 expression and stimulates glucose uptake in the gonadotroph

2011 ◽  
Vol 212 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Valerie M Harris ◽  
Sachin V Bendre ◽  
Francina Gonzalez De Los Santos ◽  
Alemu Fite ◽  
Ahmad El-Yaman El-Dandachli ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Mrna Expression ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Subcellular Location ◽  
Pcr Analysis ◽  
Glucose Transporter 1 ◽  
Glut1 Protein ◽  
Main Regulator ◽  
Exogenous Treatment

GnRH is the main regulator of the hypothalamic–pituitary–gonadal (H–P–G) axis. GnRH stimulates the pituitary gonadotroph to synthesize and secrete gonadotrophins (LH and FSH), and this effect of GnRH is dependent on the availability of glucose and other nutrients. Little is known about whether GnRH regulates glucose metabolism in the gonadotroph. This study examined the regulation of glucose transporters (Gluts) by GnRH in the LβT2 gonadotroph cell line. Using real-time PCR analysis, the expression ofGlut1, -2, -4, and -8 was detected, butGlut1mRNA expression level was more abundant than the mRNA expression levels ofGlut2, -4, and -8. After the treatment of LβT2 cells with GnRH,Glut1mRNA expression was markedly induced, but there was no GnRH-induction ofGlut2, -4, or -8 mRNA expression in LβT2 cells. The effect of GnRH onGlut1mRNA expression is partly mediated by ERK activation. GnRH increased GLUT1 protein and stimulated GLUT1 translocation to the cell surface of LβT2 cells. Glucose uptake assays were performed in LβT2 cells and showed that GnRH stimulates glucose uptake in the gonadotroph. Finally, exogenous treatment of mice with GnRH increased the expression ofGlut1but not the expression ofGlut2, -4, or -8 in the pituitary. Therefore, regulation of glucose metabolism by GnRH via changes inGlutsexpression and subcellular location in the pituitary gonadotroph reveals a novel response of the gonadotroph to GnRH.

scholarly journals Metformin protects against insulin resistance induced by high uric acid in cardiomyocytes via AMPK signaling pathways in vitro and in vivo

2021 ◽  
Author(s):  
Zhenyu Jiao ◽  
Yingqun Chen ◽  
Yang Xie ◽  
Yanbing Li ◽  
Zhi Li
Keyword(s):  
Insulin Resistance ◽  
Uric Acid ◽  
Glucose Metabolism ◽  
Glucose Tolerance ◽  
Mouse Model ◽  
Glucose Uptake ◽  
Glucose Transporter ◽  
Abnormal Glucose Metabolism ◽  
Insulin Tolerance ◽  
High Uric Acid

AbstractHigh uric acid (HUA) is associated with insulin resistance and abnormal glucose metabolism in cardiomyocytes. Metformin is a recognized agonist of AMP-activated protein kinase (AMPK) and an antidiabetic drug widely used for type 2 diabetes. It can play a cardioprotective role in many pathways. We investigated whether metformin protects against HUA-induced insulin resistance and abnormal glucose metabolism in cardiomyocytes. We exposed primary cardiomyocytes to HUA, and cellular glucose uptake was quantified by measuring the uptake of 2-NBDG, a fluorescent glucose analog, after insulin excitation. Treatment with metformin (10 μmol/L) protected against HUA-inhibited glucose uptake induced by insulin in primary cardiomyocytes, as shown by fluorescence microscopy and flow cytometry analysis. HUA directly inhibited the phosphorylation of Akt and the translocation of glucose transporter type 4 (GLUT4) induced by insulin, which was blocked by metformin. Metformin promoted phosphorylation of AMPK, renewed HUA-inhibited glucose uptake induced by insulin and protected against insulin resistance in cardiomyocytes. As a result of these effects, in a mouse model of acute hyperuricemia, metformin improved insulin tolerance and glucose tolerance, accompanied by increased AMPK phosphorylation, Akt phosphorylation and translocation of GLUT4 in myocardial tissues. As expected, AICAR, another AMPK activator, had equivalent effects to metformin, demonstrating the important role of AMPK activation in protecting against insulin resistance induced by HUA in cardiomyocytes. Metformin protects against insulin resistance induced by HUA in cardiomyocytes and improves insulin tolerance and glucose tolerance in an acute hyperuricemic mouse model, along with the activation of AMPK. Consequently, metformin may be an important potential new treatment strategy for hyperuricemia-related cardiovascular disease.

8-bromo-cyclicAMP stimulates glucose transporter-1 expression in a human choriocarcinoma cell line

2000 ◽  
Vol 164 (2) ◽  
pp. 171-178 ◽  
Author(s):  
K Ogura ◽  
M Sakata ◽  
Y Okamoto ◽  
Y Yasui ◽  
C Tadokoro ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Cell Line ◽  
Glucose Transporter ◽  
Morphological Differentiation ◽  
First Trimester ◽  
Bewo Cell ◽  
Glucose Transporter 1 ◽  
Bewo Cells ◽  
Glut1 Expression ◽  
Hcg Secretion

Facilitative glucose transporter-1 (GLUT1) is abundant in trophoblast cells and is responsible for glucose transport in the placenta. However, the change in GLUT expression in human placenta upon trophoblast differentiation remains to be clarified. Therefore, we first examined the localization of GLUT1 and GLUT3 using human first-trimester chorionic villi. We found that GLUT1 and GLUT3 were mainly localized to syncytiotrophoblast and cytotrophoblast cells respectively. We analyzed whether placental GLUT1 and GLUT3 expression changes during differentiation using a human choriocarcinoma (BeWo) cell line which is known to show functional and morphological differentiation in response to cAMP in culture. Treatment of BeWo cells with 8-bromo-cyclicAMP (8-bromo-cAMP) increased the level of hCG secretion and induced cell fusion leading to the formation of large syncytia. Treatment of BeWo cells with 8-bromo-cAMP also resulted in a significant increase in glucose uptake on days 2-3 of culture. The stimulating effect of 8-bromo-cAMP on glucose uptake was concentration dependent. Northern and immunoblot analyses revealed that the levels of mRNA and protein of GLUT1, but not of GLUT3, were significantly increased by 8-bromo-cAMP. These findings suggest that 8-bromo-cAMP stimulates GLUT1 expression with differentiation in BeWo cells.

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