Epigenetic upregulation by valproic acid of transferrin receptor 1, and not glucose transporter 1 or CD98hc, at the blood-brain barrier

Abstract BackgroundThe objectives of the present study were to investigate whether the expression of transferrin receptor 1 (TfR1), glucose transporter 1 (Glut1), or Cluster of Differentiation 98 Heavy Chain (CD98hc) is epigenetically regulated in brain capillary endothelial cells (BCECs) denoting the blood-brain barrier (BBB).MethodsThe expression of these targets was investigated both in vitro and in vivo following treatment with the histone deacetylase inhibitor (HDACi) valproic acid (VPA). Mice were injected intraperitoneally with VPA followed by analysis of isolated brain capillaries, and the capillary depleted brain samples. Brain tissue, isolated brain capillaries, and cultured primary endothelial cells were analyzed by RT-qPCR, immunolabeling and ELISA for expression of TfR1, Glut1 and CD98hc. We also studied the vascular targeting in VPA-treated mice injected with monoclonal anti-transferrin receptor (Ri7) conjugated with 1.4 nm gold nanoparticles. ResultsValidating the effects of VPA on gene transcription in BCECs, transcriptomic analysis identified 24,371 expressed genes, of which 305 were differentially expressed with 192 upregulated and 113 downregulated genes. In vitro using BCECs co-cultured with glial cells, the mRNA expression of Tfrc was significantly higher after VPA treatment for 6 h with its expression returning to baseline after 24 h. Conversely, the mRNA expression of Glut1 and Cd98hc was unaffected by VPA treatment. In vivo, the TfR1 protein expression in brain capillaries increased significantly after treatment with both 100 mg/kg and 400 mg/kg VPA. Conversely, VPA treatment did not increase GLUT1 or CD98hc. Using ICP-MS-based quantification, the brain uptake of nanogold conjugated anti-TfR1 antibodies was non-significant in spite of increased expression of TfR1. ConclusionsWe report that VPA treatment upregulates TfR1 at the BBB both in vivo and in vitro in isolated primary endothelial cells. In contrast, VPA treatment does not influence the expression of GLUT1 and CD98hc. The increase in the overall TfR1 protein expression however does not increase transport of TfR-targeted monoclonal antibody and indicates that targeted delivery using the transferrin receptor should aim for increased mobilization of already available transferrin receptor molecules to improve trafficking through the BBB.

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Extracts and flavonoids from onion inhibit the intestinal sodium-coupled glucose transporter 1 (SGLT1) in vitro but show no anti-hyperglycaemic effects in vivo in normoglycaemic mice and human volunteers

Journal of Functional Foods ◽

10.1016/j.jff.2015.06.037 ◽

2015 ◽

Vol 18 ◽

pp. 117-128 ◽

Cited By ~ 9

Author(s):

Christine Schulze ◽

Adina Bangert ◽

Bettina Schwanck ◽

Henning Vollert ◽

Wolfgang Blaschek ◽

...

Keyword(s):

Glucose Transporter ◽

Glucose Transporter 1 ◽

Human Volunteers

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Ecklonia cavaInhibits Glucose Absorption and Stimulates Insulin Secretion in Streptozotocin-Induced Diabetic Mice

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2012/439294 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Hye Kyung Kim

Keyword(s):

Insulin Secretion ◽

Protein Expression ◽

Glucose Uptake ◽

Glucose Transporter ◽

Islet Cells ◽

Glucose Absorption ◽

Oral Glucose ◽

Diabetic Mice ◽

Glucose Transporter 1

Aims of study. Present study investigated the effect ofEcklonia cava(EC) on intestinal glucose uptake and insulin secretion.Materials and methods. Intestinal Na+-dependent glucose uptake (SGU) and Na+-dependent glucose transporter 1 (SGLT1) protein expression was determined using brush border membrane vesicles (BBMVs). Glucose-induced insulin secretion was examined in pancreatic β-islet cells. The antihyperglycemic effects of EC, SGU, and SGLT1 expression were determined in streptozotocin (STZ)-induced diabetic mice.Results. Methanol extract of EC markedly inhibited intestinal SGU of BBMV with the IC50value of 345 μg/mL. SGLT1 protein expression was dose dependently down regulated with EC treatment. Furthermore, insulinotrophic effect of EC extract was observed at high glucose media in isolated pancreatic β-islet cellsin vitro. We next conducted the antihyperglycemic effect of EC in STZ-diabetic mice. EC supplementation markedly suppressed SGU and SGLT1 abundance in BBMV from STZ mice. Furthermore, plasma insulin level was increased by EC treatment in diabetic mice. As a result, EC supplementation improved postprandial glucose regulation, assessed by oral glucose tolerance test, in diabetic mice.Conclusion. These results suggest that EC play a role in controlling dietary glucose absorption at the intestine and insulinotrophic action at the pancreas contributing blood glucose homeostasis in diabetic condition.

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Combined temozolomide and ionizing radiation induces galectin-1 and galectin-3 expression in a model of human glioma

Tumor Microenvironment and Therapy ◽

10.1515/tumor-2015-0002 ◽

2015 ◽

Vol 2 (1) ◽

Cited By ~ 3

Author(s):

Lauren A. Bailey ◽

Azemat Jamshidi-Parsian ◽

Tulsi Patel ◽

Nathan A. Koonce ◽

Alan B. Diekman ◽

...

Keyword(s):

Endothelial Cells ◽

Ionizing Radiation ◽

Protein Expression ◽

Glioma Cell ◽

Glioma Cells ◽

Human Glioma ◽

Glioma Recurrence ◽

Galectin 3

AbstractBackground Despite aggressive treatment for glioblastoma multiforme (GBM), including surgical resection, radiotherapy and temozolomide (TMZ) chemotherapy, over 90% of patients experience tumor recurrence. Galectins are carbohydrate-binding proteins that are overexpressed in the stroma of GBM tumors, and are potent modulators of GBM cell migration and angiogenesis. The objective of this study was to analyze glioma and endothelial cell galectin expression in response to combined chemoradiation. Methodology The effects of TMZ, ionizing radiation, or combined chemoradiation on galectin protein secretion and expression were assessed in U87 orthotopically grown GBM tumors in mice, as well as in vitro in U87 human glioma cells and human umbilical vein endothelial cells (HUVECs). Results We found that combination chemoradiation increased galectin-1 and galectin-3 protein expression in U87 glioma cells. In response to radiation alone, U87 cells secreted significant levels of galectin-1 and galectin-3 into the microenvironment. HUVEC co-culture increased U87 galectin-1 and galectin-3 protein expression 14 - 20% following chemoradiation, and conferred a radioprotective benefit to U87 glioma cells. In vivo, radiation alone and combination chemoradiation significantly increased tumor galectin-1 expression in an orthotopic murine model of GBM. Conclusions Glioma cell galectin expression increased following combined chemoradiation, both in vitro and in vivo. The presence of endothelial cells further increased glioma cell galectin expression and survival, suggesting that crosstalk between tumor and endothelial cells in response to standard chemoradiation may be an important factor in mediating glioma recurrence, potentially via galectin upregulation.

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Comparative study of expression and activity of glucose transporters between stem cell-derived brain microvascular endothelial cells and hCMEC/D3 cells

AJP Cell Physiology ◽

10.1152/ajpcell.00116.2017 ◽

2017 ◽

Vol 313 (4) ◽

pp. C421-C429 ◽

Cited By ~ 14

Author(s):

Abraham J. Al-Ahmad

Keyword(s):

Stem Cells ◽

Endothelial Cells ◽

Glucose Uptake ◽

Glucose Transporter ◽

Glucose Transporters ◽

Microvascular Endothelial Cells ◽

Brain Microvascular Endothelial Cells ◽

Glucose Transporter 1 ◽

Microvascular Endothelial

Glucose constitutes a major source of energy of mammalian brains. Glucose uptake at the blood-brain barrier (BBB) occurs through a facilitated glucose transport, through glucose transporter 1 (GLUT1), although other isoforms have been described at the BBB. Mutations in GLUT1 are associated with the GLUT1 deficiency syndrome, yet none of the current in vitro models of the human BBB maybe suited for modeling such a disorder. In this study, we investigated the expression of glucose transporters and glucose diffusion across brain microvascular endothelial cells (BMECs) derived from healthy patient-derived induced pluripotent stem cells (iPSCs). We investigated the expression of different glucose transporters at the BBB using immunocytochemistry and flow cytometry and measured glucose uptake and diffusion across BMEC monolayers obtained from two iPSC lines and from hCMEC/D3 cells. BMEC monolayers showed expression of several glucose transporters, in particular GLUT1, GLUT3, and GLUT4. Diffusion of glucose across the monolayers was mediated via a saturable transcellular mechanism and partially inhibited by pharmacological inhibitors. Taken together, our study suggests the presence of several glucose transporters isoforms at the human BBB and demonstrates the feasibility of modeling glucose across the BBB using patient-derived stem cells.

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Glucosamine Interferes With Myelopoiesis and Enhances the Immunosuppressive Activity of Myeloid-Derived Suppressor Cells

Frontiers in Nutrition ◽

10.3389/fnut.2021.762363 ◽

2021 ◽

Vol 8 ◽

Author(s):

Eric Chang-Yi Lin ◽

Shuoh-Wen Chen ◽

Luen-Kui Chen ◽

Ting-An Lin ◽

Yu-Xuan Wu ◽

...

Keyword(s):

Glucose Transporter ◽

Immune Cell ◽

Suppressor Cells ◽

Therapeutic Benefit ◽

Myeloid Derived Suppressor Cells ◽

Hematopoietic Stem ◽

Glucose Transporter 1 ◽

Arginase 1

Glucosamine (GlcN) is the most widely consumed dietary supplement and exhibits anti-inflammatory effects. However, the influence of GlcN on immune cell generation and function is largely unclear. In this study, GlcN was delivered into mice to examine its biological function in hematopoiesis. We found that GlcN promoted the production of immature myeloid cells, known as myeloid-derived suppressor cells (MDSCs), both in vivo and in vitro. Additionally, GlcN upregulated the expression of glucose transporter 1 in hematopoietic stem and progenitor cells (HSPCs), influenced HSPC functions, and downregulated key genes involved in myelopoiesis. Furthermore, GlcN increased the expression of arginase 1 and inducible nitric oxide synthase to produce high levels of reactive oxygen species, which was regulated by the STAT3 and ERK1/2 pathways, to increase the immunosuppressive ability of MDSCs. We revealed a novel role for GlcN in myelopoiesis and MDSC activity involving a potential link between GlcN and immune system, as well as the new therapeutic benefit.

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Myeloperoxidase and Septic Conditions Disrupt Sphingolipid Homeostasis in Murine Brain Capillaries In Vivo and Immortalized Human Brain Endothelial Cells In Vitro

International Journal of Molecular Sciences ◽

10.3390/ijms21031143 ◽

2020 ◽

Vol 21 (3) ◽

pp. 1143 ◽

Cited By ~ 1

Author(s):

Madeleine Goeritzer ◽

Eva Bernhart ◽

Ioanna Plastira ◽

Helga Reicher ◽

Christina Leopold ◽

...

Keyword(s):

Endothelial Cells ◽

Sickness Behavior ◽

Brain Endothelial Cells ◽

Brain Capillaries ◽

Barrier Dysfunction ◽

Pharmacological Inhibition ◽

Regulated Gene Expression ◽

The Impact

During inflammation, activated leukocytes release cytotoxic mediators that compromise blood–brain barrier (BBB) function. Under inflammatory conditions, myeloperoxidase (MPO) is critically involved in inflicting BBB damage. We used genetic and pharmacological approaches to investigate whether MPO induces aberrant lipid homeostasis at the BBB in a murine endotoxemia model. To corroborate findings in a human system we studied the impact of sera from sepsis and non-sepsis patients on brain endothelial cells (hCMEC/D3). In response to endotoxin, the fatty acid, ceramide, and sphingomyelin content of isolated mouse brain capillaries dropped and barrier dysfunction occurred. In mice, genetic deficiency or pharmacological inhibition of MPO abolished these alterations. Studies in metabolic cages revealed increased physical activity and less pronounced sickness behavior of MPO−/− compared to wild-type mice in response to sepsis. In hCMEC/D3 cells, exogenous tumor necrosis factor α (TNFα) potently regulated gene expression of pro-inflammatory cytokines and a set of genes involved in sphingolipid (SL) homeostasis. Notably, treatment of hCMEC/D3 cells with sera from septic patients reduced cellular ceramide concentrations and induced barrier and mitochondrial dysfunction. In summary, our in vivo and in vitro data revealed that inflammatory mediators including MPO, TNFα induce dysfunctional SL homeostasis in brain endothelial cells. Genetic and pharmacological inhibition of MPO attenuated endotoxin-induced alterations in SL homeostasis in vivo, highlighting the potential role of MPO as drug target to treat inflammation-induced brain dysfunction.

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High concentration of glucose decreases glucose transporter-1 expression in mouse placenta in vitro and in vivo

Journal of Endocrinology ◽

10.1677/joe.0.1600443 ◽

1999 ◽

Vol 160 (3) ◽

pp. 443-452 ◽

Cited By ~ 27

Author(s):

K Ogura ◽

M Sakata ◽

M Yamaguchi ◽

H Kurachi ◽

Y Murata

Keyword(s):

Glucose Concentration ◽

Glucose Transporter ◽

Cytochalasin B ◽

High Concentration ◽

Glucose Transporter 1 ◽

Protein Levels ◽

Placental Cells ◽

Glut1 Mrna

Facilitative glucose transporter-1 (GLUT1) is expressed abundantly and has an important role in glucose transfer in placentas. However, little is known about the regulation of GLUT1 expression in placental cells. We studied the changes in placental GLUT1 levels in relation to changes in glucose concentration in vitro and in vivo. In in vitro experiments, dispersed mouse placental cells were incubated under control (5.5 mM) and moderately high (22 mM) glucose concentrations, and 2-deoxyglucose uptake into cells was studied on days 1-5 of culture. After 4 days of incubation under both conditions, GLUT1 mRNA and proten levels were examined by Northern and immunoblot analyses. Treatment of cells with 22 mM glucose resulted in a significant decrease in 2-deoxyglucose uptake compared with control, from day 2 to day 5 of culture. Moreover, GLUT1 mRNA and protein levels on day 4 of culture were significantly reduced in cells incubated with 22 mM glucose compared with control. Next, we rendered mice diabetic by administering 200 micrograms/g body weight streptozotocin (STZ) on day 8 of pregnancy. Animals were killed on day 12 of pregnancy and placental tissues were obtained. [3H]Cytochalasin B binding study was carried out to assess total GLUTs, and GLUT1 mRNA and protein were measured as above. [3H]Cytochalasin B binding sites in placentas from STZ-treated mice were significantly less than those in control mice. Northern and immunoblot analyses revealed a significant decrease in GLUT1 mRNA and protein levels in diabetic mice compared with the controls. These findings suggest that the glucose concentration may regulate the expression of placental GLUT1.

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