Oncogenic activation of the PI3K/Akt pathway promotes cellular glucose uptake by downregulating the expression of thioredoxin-interacting protein

2016 ◽  
Vol 28 (5) ◽  
pp. 377-383 ◽  
Author(s):  
Shin Yee Hong ◽  
Fa-Xing Yu ◽  
Yan Luo ◽  
Thilo Hagen
2014 ◽  
Vol 35 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Mohan R. Kaadige ◽  
Jingye Yang ◽  
Blake R. Wilde ◽  
Donald E. Ayer

Mammalian target of rapamycin (mTOR) integrates multiple signals, including nutrient status, growth factor availability, and stress, to regulate cellular and organismal growth. How mTOR regulates transcriptional programs in response to these diverse stimuli is poorly understood. MondoA and its obligate transcription partner Mlx are basic helix-loop-helix leucine zipper (bHLHZip) transcription factors that sense and execute a glucose-responsive transcriptional program. MondoA-Mlx complexes activate expression of thioredoxin-interacting protein (TXNIP), which is a potent inhibitor of cellular glucose uptake and aerobic glycolysis. Both mTOR and MondoA are central regulators of glucose metabolism, yet whether they interact physically or functionally is unknown. We show that inhibition of mTOR induces MondoA-dependent expression of TXNIP, coinciding with reduced glucose uptake. Mechanistically, mTOR binds to MondoA in the cytoplasm and prevents MondoA-Mlx complex formation, restricting MondoA's nuclear entry and reducing TXNIP expression. Further, we show that mTOR inhibitors and reactive oxygen species (ROS) regulate interaction between MondoA and mTOR in an opposing manner. Like mTOR's suppression of the MondoA-TXNIP axis, MondoA can also suppress mTOR complex 1 (mTORC1) activity via its direct transcriptional regulation of TXNIP. Collectively, these studies reveal a regulatory relationship between mTOR and the MondoA-TXNIP axis that we propose contributes to glucose homeostasis.


2018 ◽  
Vol 125 (2) ◽  
pp. 596-604 ◽  
Author(s):  
Emi Kawamoto ◽  
Keigo Tamakoshi ◽  
Song-Gyu Ra ◽  
Hiroyuki Masuda ◽  
Kentaro Kawanaka

Acute short duration of disuse induces the development of insulin resistance for glucose uptake in rodent skeletal muscle. Because thioredoxin-interacting protein (TXNIP) has been implicated in the downregulation of insulin signaling and glucose uptake, we examined the possibility that muscle disuse rapidly induces insulin resistance via increased TXNIP mRNA and protein expression. Male Wistar rats were subjected to unilateral 6-h hindlimb immobilization by plaster cast. At the end of this period, the soleus muscles from both immobilized and contralateral nonimmobilized hindlimbs were excised and examined. The 6-h immobilization resulted in an increase in TXNIP mRNA and protein expressions together with a decrease in insulin-stimulated 2-deoxyglucose uptake in the rat soleus muscle. Additionally, in the rats euthanized 6 h after the plaster cast removal, TXNIP protein expression and insulin-stimulated glucose uptake in the immobilized muscle had both been restored to a normal level. Various interventions (pretreatment with transcription inhibitor actinomycin D or AMP-dependent protein kinase activator 5-aminoimidazole-4-carboxamide ribonucleotide) also suppressed the increase in TXNIP protein expression in 6-h-immobilized muscle together with partial prevention of insulin resistance for glucose uptake. These results suggested the possibility that increased TXNIP protein expression in immobilized rat soleus muscles was associated with the rapid induction of insulin resistance for glucose uptake in that tissue. NEW & NOTEWORTHY The cellular mechanism by which disuse rapidly induces muscle insulin resistance for glucose uptake remains to be identified. Using a rat hindlimb immobilization model, our findings suggest the possibility that transcriptional upregulation of thioredoxin-interacting protein is associated with the immobilization-induced rapid development of insulin resistance in skeletal muscle.


2016 ◽  
Vol 479 (4) ◽  
pp. 933-939 ◽  
Author(s):  
Ashok Mandala ◽  
Nabanita Das ◽  
Sudarshan Bhattacharjee ◽  
Bidisha Mukherjee ◽  
Satinath Mukhopadhyay ◽  
...  

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Bing F Wang ◽  
Ronald B Myers ◽  
Gregory M Fomovsky ◽  
Samuel Lee ◽  
Parth Patwari ◽  
...  

A change in basal glucose transport into skeletal muscle, heart, and adipose is a critical feature of insulin resistance and diabetes. Glucose transport is tightly regulated by a protein family of glucose transporters (GLUTs). Thus, defining how cardiomyocytes adapt to changes in extracellular and intracellular glucose concentrations by recruiting GLUTs is crucial to understanding cardiac metabolism under both normal and diabetic conditions. Thioredoxin-Interacting Protein (Txnip), originally characterized as a binding partner of antioxidant thioredoxin, is now known to be a member of the arrestin protein superfamily. We have previously shown that glucose uptake is robustly enhanced in Txnip-knockout hearts; however, the precise mechanism for this effect remains elusive. Here, we present a novel feedback mechanism by which Txnip controls glucose metabolism. High glucose levels induced Txnip expression in rat cardiomyocytes in vitro and in the myocardium of streptozotocin (STZ)-induced diabetic mice in vivo. Our proteomic and functional analyses found that Txnip directly interacts with GLUT1 and GLUT4 and strikingly inhibits cellular glucose uptake through direct interactions with GLUTs. Using inducible cardiac-specific deletion of Txnip (Txnip-CKO), we further demonstrated that Txnip plays a functional role in STZ-induced diabetic cardiomyopathy. While β-adrenergic challenge revealed a blunted myocardial inotropic response in wild type diabetic animals, Txnip-CKO diabetic mice retained a greater cardiac response to β-adrenergic stimulation. An ex vivo analysis of perfused hearts further demonstrated that the enhanced functional reserve afforded by deletion of Txnip was associated with myocardial glucose utilization during β-adrenergic stimulation. Thus, a high extracellular glucose concentration represses glucose uptake into the cytoplasm via Txnip-mediated inhibition of GLUTs. The metabolic alterations affected by Txnip deletion promote myocardial glucose uptake, directing cardiomyocyte towards enhanced functional reserve under diabetic conditions. These results provide a novel link between GLUTs and Txnip and highlight a fundamental regulatory mechanism of glucose homeostasis in the heart.


2020 ◽  
Vol 318 (3) ◽  
pp. E405-E416
Author(s):  
XiaoLong Jiang ◽  
YunWei Pang ◽  
ShanJiang Zhao ◽  
HaiSheng Hao ◽  
XueMing Zhao ◽  
...  

The extent of glucose metabolism during oocyte maturation is closely related to oocyte developmental potential. Thioredoxin-interacting protein (TXNIP) is an α-arrestin family protein that negatively regulates glucose uptake into cells. However, little information is available regarding the function of TXNIP in bovine oocytes. Accordingly, the present study was performed to investigate the influence of TXNIP on glucose metabolism in bovine oocytes during in vitro maturation. Pharmacological inhibition of TXNIP by azaserine enhanced glucose uptake and imparted a specific metabolic effect on glycolysis and pentose phosphate pathway (PPP). RNA interference (RNAi) was adopted to further determine the biological significance of TXNIP in regulating glucose metabolism. The maturation rate and the developmental competence of TXNIP siRNA-treated oocytes were significantly improved. Knockdown of TXNIP in bovine oocytes significantly increased glycolysis by increasing the activities of phosphofructokinase (PFK), pyruvate kinase, and lactate dehydrogenase; pyruvate and lactate production; and intracellular ATP level, as well as mitochondrial activity. Furthermore, glucose metabolism through PPP was also enhanced by TXNIP depletion, as TXNIP siRNA treatment promoted glucose-6-phosphate dehydrogenase (G6PDH) activity and NADPH content, and helped maintain a high level of glutathione and a low level of reactive oxygen species within the oocytes. Further studies revealed that inhibition of TXNIP resulted increases in glucose transporter 1 (GLUT1) expression, as well as PFK1 platelet isoform ( PFKP) and G6PDH mRNA levels. These results reveal that TXNIP depletion promotes oocyte maturation by enhancing both glycolysis and the PPP. During in vitro maturation of bovine oocytes, TXNIP serves as a key regulator of glucose uptake by controlling GLUT1 expression.


2021 ◽  
pp. 1-12
Author(s):  
Pengli Wang ◽  
Dan Zheng ◽  
Hongyang Qi ◽  
Qi Gao

BACKGROUND: MicroRNAs (miRNAs) play potential role in the development of various types of cancer conditions including pancreatic cancer (PC) targeting several cellular processes. Present study was aimed to evaluate function of miR-125b and the mechanism involved in PC. METHODS: Cell migration, MTT and BrdU study was done to establish the migration capability, cell viability and cell proliferation respectively. Binding sites for miR-125b were recognized by luciferase assay, expression of protein by western blot and immunofluorescence assay. In vivo study was done by BALB/c nude xenograft mice for evaluating the function of miR-125b. RESULTS: The study showed that expression of miR-125b was elevated in PC cells and tissues, and was correlated to proliferation and migration of cells. Also, over-expression of miR-125b encouraged migration, metastasis and proliferation of BxPC-3 cells, the suppression reversed it. We also noticed that thioredoxin-interacting protein (TXNIP) was the potential target of miR-125b. The outcomes also suggested that miR-125b governed the expression of TXNIP inversely via directly attaching to the 3′-UTR activating hypoxia-inducible factor 1α (HIF1α). Looking into the relation between HIF1α and TXNIP, we discovered that TXNIP caused the degradation and export of HIF1α by making a complex with it. CONCLUSION: The miR-125b-TXNIP-HIF1α pathway may serve useful strategy for diagnosing and treating PC.


2021 ◽  
Vol 224 (2) ◽  
pp. S243-S244
Author(s):  
Sivan Farladansky-Gershnabel ◽  
Ishai Heusler ◽  
Tal Biron-Shental ◽  
Keren Cohen-Hagai ◽  
Sydney Benchetrit ◽  
...  

2021 ◽  
pp. 105399
Author(s):  
Saifudeen Ismael ◽  
Sanaz Nasoohi ◽  
Lexiao Li ◽  
Khurram Aslam ◽  
Mohammad Moshahid Khan ◽  
...  

2021 ◽  
Vol 22 (5) ◽  
pp. 2754
Author(s):  
Naila Qayyum ◽  
Muhammad Haseeb ◽  
Moon Suk Kim ◽  
Sangdun Choi

Thioredoxin-interacting protein (TXNIP), widely known as thioredoxin-binding protein 2 (TBP2), is a major binding mediator in the thioredoxin (TXN) antioxidant system, which involves a reduction-oxidation (redox) signaling complex and is pivotal for the pathophysiology of some diseases. TXNIP increases reactive oxygen species production and oxidative stress and thereby contributes to apoptosis. Recent studies indicate an evolving role of TXNIP in the pathogenesis of complex diseases such as metabolic disorders, neurological disorders, and inflammatory illnesses. In addition, TXNIP has gained significant attention due to its wide range of functions in energy metabolism, insulin sensitivity, improved insulin secretion, and also in the regulation of glucose and tumor suppressor activities in various cancers. This review aims to highlight the roles of TXNIP in the field of diabetology, neurodegenerative diseases, and inflammation. TXNIP is found to be a promising novel therapeutic target in the current review, not only in the aforementioned diseases but also in prolonged microvascular and macrovascular diseases. Therefore, TXNIP inhibitors hold promise for preventing the growing incidence of complications in relevant diseases.


Author(s):  
Yanbing Li ◽  
Yu Geng ◽  
Boda Zhou ◽  
Xuejiao Wu ◽  
Ou Zhang ◽  
...  

AbstractIt is formerly conducted that long non-coding RNA growth arrest-specific 5 (GAS5) is involved in the process of coronary atherosclerosis (AS). The regulatory effects of GAS5 on the microRNA (miR)-194-3p/thioredoxin-interacting protein (TXNIP) axis in AS have been insufficiently explored yet. Thereafter, this work is started from GAS5/miR-194-3p/TXNIP axis in AS. AS rats were modeled to obtain their coronary vascular tissues and endothelial cells (ECs), in which GAS5, miR-194-3p, and TXNIP expression were tested. ECs were identified by immunohistochemistry. The mechanism among GAS5, miR-194-3p, and TXNIP was determined. ECs were transfected with inhibited GAS5 or overexpressed miR-194-3p to decipher their functions in proliferation and apoptosis of ECs in AS. Raised GAS5 and TXNIP and degraded miR-194-3p expression levels exhibited in AS. GAS5 bound to miR-194-3p while miR-194-3p targeted TXNIP. Depleting GAS5 or restoring miR-194-3p enhanced proliferation and depressed apoptosis of ECs in AS. This work clearly manifests that inhibited GAS5 facilitates the growth of ECs through miR-194-3p-targeted TXNIP in AS, consolidating the basal reference to the curing for AS.


Sign in / Sign up

Export Citation Format

Share Document