Orthosteric–allosteric dual inhibitors of PfHT1 as selective antimalarial agents

AbstractArtemisinin-resistant malaria parasites have emerged and been spreading, posing a significant public health challenge. Anti-malarial drugs with novel mechanisms of action are therefore urgently needed. In this report, we exploit a “selective starvation” strategy by selectively inhibiting Plasmodium falciparum hexose transporter 1 (PfHT1), the sole hexose transporter in Plasmodium falciparum, over human glucose transporter 1 (hGLUT1), providing an alternative approach to fight against multidrug-resistant malaria parasites. Comparison of the crystal structures of human GLUT3 and PfHT1 bound to C3361, a PfHT1-specific moderate inhibitor, revealed an inhibitor binding-induced pocket that presented a promising druggable site. We thereby designed small-molecules to simultaneously block the orthosteric and allosteric pockets of PfHT1. Through extensive structure-activity relationship (SAR) studies, the TH-PF series was identified to selectively inhibit PfHT1 over GLUT1 and potent against multiple strains of the blood-stage P. falciparum. Our findings shed light on the next-generation chemotherapeutics with a paradigm-shifting structure-based design strategy to simultaneously targeting the orthosteric and allosteric sites of a transporter.Significance statementBlocking sugar uptake in P. falciparum by selectively inhibiting the hexose transporter PfHT1 kills the blood-stage parasites without affecting the host cells, indicating PfHT1 as a promising therapeutic target. Here, we report the development of novel small-molecule inhibitors that are selectively potent to the malaria parasites over human cell lines by simultaneously targeting the orthosteric and the allosteric binding sites of PfHT1. Our findings established the basis for the rational design of next-generation anti-malarial drugs.

Download Full-text

A possible role for a mammalian facilitative hexose transporter in the development of resistance to drugs.

Molecular and Cellular Biology ◽

10.1128/mcb.11.7.3407 ◽

1991 ◽

Vol 11 (7) ◽

pp. 3407-3418 ◽

Cited By ~ 14

Author(s):

J C Vera ◽

G R Castillo ◽

O M Rosen

Keyword(s):

Xenopus Oocytes ◽

Glucose Transporter ◽

Cytochalasin B ◽

Chinese Hamster ◽

Multidrug Resistant ◽

Xenopus Laevis Oocytes ◽

Hexose Transporter ◽

P Glycoprotein ◽

Glut1 Protein ◽

Facilitative Glucose Transporter

We show that D- but not L-hexoses modulate the accumulation of radioactive vinblastine in injected Xenopus laevis oocytes expressing the murine Mdr1b P-glycoprotein. We also show that X. laevis oocytes injected with RNA encoding the rat erythroid/brain glucose transport protein (GLUT1) and expressing the corresponding functional transporter exhibit a lower accumulation of [3H]vinblastine and show a greater capacity to extrude the drug than do control oocytes not expressing the rat GLUT1 protein. Cytochalasin B and phloretin, two inhibitors of the mammalian facilitative glucose transporters, can overcome the reduced drug accumulation conferred by expression of the rat GLUT1 protein in Xenopus oocytes but have no significant effect on the accumulation of drug by Xenopus oocytes expressing the mouse Mdr1b P-glycoprotein. These drugs also increase the accumulation of [3H]vinblastine in multidrug-resistant Chinese hamster ovary cells. Cytochalasin E, an analog of cytochalasin B that does not affect the activity of the facilitative glucose transporter, has no effect on the accumulation of vinblastine by multidrug-resistant Chinese hamster cells or by oocytes expressing either the mouse Mdr1b P-glycoprotein or the GLUT1 protein. In all three cases, the drug verapamil produces a profound effect on the cellular accumulation of vinblastine. Interestingly, although immunological analysis indicated the presence of massive amounts of P-glycoprotein in the multidrug-resistant cells, immunological and functional studies revealed only a minor increase in the expression of a hexose transporter-like protein in resistant versus drug-sensitive cells. Taken together, these results suggest the participation of the mammalian facilitative glucose transporter in the development of drug resistance.

Download Full-text

Transient Silencing of a Type IV P-Type ATPase,Atp10c, Results in Decreased Glucose Uptake in C2C12 Myotubes

Journal of Nutrition and Metabolism ◽

10.1155/2012/152902 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

S. E. Hurst ◽

S. C. Minkin ◽

J. Biggerstaff ◽

M. S. Dhar

Keyword(s):

Type 2 Diabetes ◽

Glucose Uptake ◽

Glucose Transporter ◽

Mapk Pathway ◽

Specific Inhibitor ◽

C2c12 Myotubes ◽

Glucose Transporter 1 ◽

Transfected Cells

Atp10cis a strong candidate gene for diet-induced obesity and type 2 diabetes. To identify molecular and cellular targets of ATP10C,Atp10cexpression was alteredin vitroin C2C12 skeletal muscle myotubes by transient transfection with anAtp10c-specific siRNA. Glucose uptake assays revealed that insulin stimulation caused a significant 2.54-fold decrease in 2-deoxyglucose uptake in transfected cells coupled with a significant upregulation of native mitogen-activated protein kinases (MAPKs), p38, and p44/42. Additionally, glucose transporter-1 (GLUT1) was significantly upregulated; no changes in glucose transporter-4 (GLUT4) expression were observed. The involvement of MAPKs was confirmed using the specific inhibitor SB203580, which downregulated the expression of native and phosphorylated MAPK proteins in transfected cells without any changes in insulin-stimulated glucose uptake. Results indicate thatAtp10cregulates glucose metabolism, at least in part via the MAPK pathway, and, thus, plays a significant role in the development of insulin resistance and type 2 diabetes.

Download Full-text

Identification of Hexose Transporter-Like Sensor HXS1 and Functional Hexose Transporter HXT1 in the Methylotrophic Yeast Hansenula polymorpha

Eukaryotic Cell ◽

10.1128/ec.00028-08 ◽

2008 ◽

Vol 7 (4) ◽

pp. 735-746 ◽

Cited By ~ 27

Author(s):

Olena G. Stasyk ◽

Mykola M. Maidan ◽

Oleh V. Stasyk ◽

Patrick Van Dijck ◽

Johan M. Thevelein ◽

...

Keyword(s):

Transcriptional Repression ◽

Glucose Transporter ◽

Glucose Repression ◽

Sequence Similarity ◽

Hansenula Polymorpha ◽

Methylotrophic Yeast ◽

Hexose Transporter ◽

Autophagic Degradation ◽

Hexose Carrier ◽

Hexose Uptake

ABSTRACT We identified in the methylotrophic yeast Hansenula polymorpha (syn. Pichia angusta) a novel hexose transporter homologue gene, HXS1 (hexose sensor), involved in transcriptional regulation in response to hexoses, and a regular hexose carrier gene, HXT1 (hexose transporter). The Hxs1 protein exhibits the highest degree of primary sequence similarity to the Saccharomyces cerevisiae transporter-like glucose sensors, Snf3 and Rgt2. When heterologously overexpressed in an S. cerevisiae hexose transporter-less mutant, Hxt1, but not Hxs1, restores growth on glucose or fructose, suggesting that Hxs1 is nonfunctional as a carrier. In its native host, HXS1 is expressed at moderately low level and is required for glucose induction of the H. polymorpha functional low-affinity glucose transporter Hxt1. Similarly to other yeast sensors, one conserved amino acid substitution in the Hxs1 sequence (R203K) converts the protein into a constitutively signaling form and the C-terminal region of Hxs1 is essential for its function in hexose sensing. Hxs1 is not required for glucose repression or catabolite inactivation that involves autophagic degradation of peroxisomes. However, HXS1 deficiency leads to significantly impaired transient transcriptional repression in response to fructose, probably due to the stronger defect in transport of this hexose in the hxs1Δ deletion strain. Our combined results suggest that in the Crabtree-negative yeast H. polymorpha, the single transporter-like sensor Hxs1 mediates signaling in the hexose induction pathway, whereas the rate of hexose uptake affects the strength of catabolite repression.

Download Full-text

A possible role for a mammalian facilitative hexose transporter in the development of resistance to drugs

Molecular and Cellular Biology ◽

10.1128/mcb.11.7.3407-3418.1991 ◽

1991 ◽

Vol 11 (7) ◽

pp. 3407-3418

Author(s):

J C Vera ◽

G R Castillo ◽

O M Rosen

Keyword(s):

Xenopus Oocytes ◽

Glucose Transporter ◽

Cytochalasin B ◽

Chinese Hamster ◽

Multidrug Resistant ◽

Xenopus Laevis Oocytes ◽

Hexose Transporter ◽

P Glycoprotein ◽

Glut1 Protein ◽

Facilitative Glucose Transporter

We show that D- but not L-hexoses modulate the accumulation of radioactive vinblastine in injected Xenopus laevis oocytes expressing the murine Mdr1b P-glycoprotein. We also show that X. laevis oocytes injected with RNA encoding the rat erythroid/brain glucose transport protein (GLUT1) and expressing the corresponding functional transporter exhibit a lower accumulation of [3H]vinblastine and show a greater capacity to extrude the drug than do control oocytes not expressing the rat GLUT1 protein. Cytochalasin B and phloretin, two inhibitors of the mammalian facilitative glucose transporters, can overcome the reduced drug accumulation conferred by expression of the rat GLUT1 protein in Xenopus oocytes but have no significant effect on the accumulation of drug by Xenopus oocytes expressing the mouse Mdr1b P-glycoprotein. These drugs also increase the accumulation of [3H]vinblastine in multidrug-resistant Chinese hamster ovary cells. Cytochalasin E, an analog of cytochalasin B that does not affect the activity of the facilitative glucose transporter, has no effect on the accumulation of vinblastine by multidrug-resistant Chinese hamster cells or by oocytes expressing either the mouse Mdr1b P-glycoprotein or the GLUT1 protein. In all three cases, the drug verapamil produces a profound effect on the cellular accumulation of vinblastine. Interestingly, although immunological analysis indicated the presence of massive amounts of P-glycoprotein in the multidrug-resistant cells, immunological and functional studies revealed only a minor increase in the expression of a hexose transporter-like protein in resistant versus drug-sensitive cells. Taken together, these results suggest the participation of the mammalian facilitative glucose transporter in the development of drug resistance.

Download Full-text

Design, synthesis, and evaluation of positron emission tomography/fluorescence dual imaging probes for targeting facilitated glucose transporter 1 (GLUT1)

Organic & Biomolecular Chemistry ◽

10.1039/d1ob00199j ◽

2021 ◽

Vol 19 (14) ◽

pp. 3241-3254

Author(s):

Richard Yuen ◽

Michael Wagner ◽

Susan Richter ◽

Jennifer Dufour ◽

Melinda Wuest ◽

...

Keyword(s):

Breast Cancer Cells ◽

Glucose Transporter ◽

Fluorescent Imaging ◽

Hexose Transporter ◽

Design Synthesis ◽

Glucose Transporter 1 ◽

Positron Emission ◽

Imaging Probes ◽

Dual Imaging ◽

Transporter Glut1

We describe the synthesis and analysis of novel different glucose-based dual probes for tandem PET and fluorescent imaging of facilitated hexose transporter GLUT1 in breast cancer cells.

Download Full-text

Targeting Glycolysis in Macrophages Confers Protection Against Pancreatic Ductal Adenocarcinoma

International Journal of Molecular Sciences ◽

10.3390/ijms22126350 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6350

Author(s):

Hweixian Leong Penny ◽

Je Lin Sieow ◽

Sin Yee Gun ◽

Mai Chan Lau ◽

Bernett Lee ◽

...

Keyword(s):

Pancreatic Ductal Adenocarcinoma ◽

Glucose Transporter ◽

Cell Activity ◽

Specific Inhibitor ◽

Standard Of Care ◽

Tumor Burden ◽

Ductal Adenocarcinoma ◽

Current Standard ◽

Orthotopic Mouse Model ◽

Glucose Transporter 1

Inflammation in the tumor microenvironment has been shown to promote disease progression in pancreatic ductal adenocarcinoma (PDAC); however, the role of macrophage metabolism in promoting inflammation is unclear. Using an orthotopic mouse model of PDAC, we demonstrate that macrophages from tumor-bearing mice exhibit elevated glycolysis. Macrophage-specific deletion of Glucose Transporter 1 (GLUT1) significantly reduced tumor burden, which was accompanied by increased Natural Killer and CD8+ T cell activity and suppression of the NLRP3-IL1β inflammasome axis. Administration of mice with a GLUT1-specific inhibitor reduced tumor burden, comparable with gemcitabine, the current standard-of-care. In addition, we observe that intra-tumoral macrophages from human PDAC patients exhibit a pronounced glycolytic signature, which reliably predicts poor survival. Our data support a key role for macrophage metabolism in tumor immunity, which could be exploited to improve patient outcomes.

Download Full-text

HIF1-α-Mediated Gene Expression Induced by Vitamin B1 Deficiency

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000159 ◽

2013 ◽

Vol 83 (3) ◽

pp. 188-197 ◽

Cited By ~ 21

Author(s):

Rebecca L. Sweet ◽

Jason A. Zastre

Keyword(s):

Gene Expression ◽

Thiamine Deficiency ◽

Glucose Transporter ◽

Neuroblastoma Cell ◽

Hypoxia Inducible Factor ◽

Clinical Manifestations ◽

Vitamin B1 ◽

Low Oxygen ◽

Glucose Transporter 1 ◽

Metabolic Intermediates

It is well established that thiamine deficiency results in an excess of metabolic intermediates such as lactate and pyruvate, which is likely due to insufficient levels of cofactor for the function of thiamine-dependent enzymes. When in excess, both pyruvate and lactate can increase the stabilization of the hypoxia-inducible factor 1-alpha (HIF-1α) transcription factor, resulting in the trans-activation of HIF-1α regulated genes independent of low oxygen, termed pseudo-hypoxia. Therefore, the resulting dysfunction in cellular metabolism and accumulation of pyruvate and lactate during thiamine deficiency may facilitate a pseudo-hypoxic state. In order to investigate the possibility of a transcriptional relationship between hypoxia and thiamine deficiency, we measured alterations in metabolic intermediates, HIF-1α stabilization, and gene expression. We found an increase in intracellular pyruvate and extracellular lactate levels after thiamine deficiency exposure to the neuroblastoma cell line SK-N-BE. Similar to cells exposed to hypoxia, there was a corresponding increase in HIF-1α stabilization and activation of target gene expression during thiamine deficiency, including glucose transporter-1 (GLUT1), vascular endothelial growth factor (VEGF), and aldolase A. Both hypoxia and thiamine deficiency exposure resulted in an increase in the expression of the thiamine transporter SLC19A3. These results indicate thiamine deficiency induces HIF-1α-mediated gene expression similar to that observed in hypoxic stress, and may provide evidence for a central transcriptional response associated with the clinical manifestations of thiamine deficiency.

Download Full-text