The Warburg effect promoted the activation of the NLRP3 inflammasome induced by Ni-refining fumes in BEAS-2B cells

2020 ◽  
Vol 36 (8) ◽  
pp. 580-590
Author(s):  
Rui Wang ◽  
Sheng-Yuan Wang ◽  
Yue Wang ◽  
Rui Xin ◽  
Bing Xia ◽  
...  

Nickel (Ni) is a known human carcinogen that has an adverse effect on various human organs in occupational workers during Ni refinement and smelting. In the present study, we used real-time polymerase chain reactions, Western blot analysis, and a lactate production assay to investigate whether an increase in the NLRP3 inflammasome induced by Ni-refining fumes was associated with the Warburg effect in BEAS-2B cells, a nonmalignant pulmonary epithelial line. Exposure to Ni-refining fumes suppressed cell proliferation and increased lactate production compared with those in an untreated control group in a dose- and time-dependent manner. Ni-refining fumes induced the Warburg effect, which was observed based on increases in the levels of hypoxia-inducible factor-1α, hexokinase 2, pyruvate kinase isozyme type M2, and lactate dehydrogenase A. In addition, Ni-refining fumes promoted increased expression of NLRP3 at both the gene and protein levels. Furthermore, inhibition of the Warburg effect by 2-Deoxy-d-glucose reversed the increased expression of NLRP3 induced by Ni-refining fumes. Collectively, our data demonstrated that the Warburg effect can promote the expression of the NLRP3 inflammasome induced by the Ni-refining fumes in BEAS-2B cells. This indicates a new phenomenon in which alterations in energy production in human cells induced by Ni-refining fumes regulate the inflammatory response.

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1652
Author(s):  
Chinmaya Panda ◽  
Clara Voelz ◽  
Pardes Habib ◽  
Christian Mevissen ◽  
Thomas Pufe ◽  
...  

Intra-neuronal misfolding of monomeric tau protein to toxic β-sheet rich neurofibrillary tangles is a hallmark of Alzheimer’s disease (AD). Tau pathology correlates not only with progressive dementia but also with microglia-mediated inflammation in AD. Amyloid-beta (Aβ), another pathogenic peptide involved in AD, has been shown to activate NLRP3 inflammasome (NOD-like receptor family, pyrin domain containing 3), triggering the secretion of proinflammatory interleukin-1β (IL1β) and interleukin-18 (IL18). However, the effect of tau protein on microglia concerning inflammasome activation, microglial polarization, and autophagy is poorly understood. In this study, human microglial cells (HMC3) were stimulated with the unaggregated and aggregated forms of the tau-derived PHF6 peptide (VQIVYK). Modulation of NLRP3 inflammasome was examined by qRT-PCR, immunocytochemistry, and Western blot. We demonstrate that fibrillar aggregates of VQIVYK upregulated the NLRP3 expression at both mRNA and protein levels in a dose- and time-dependent manner, leading to increased expression of IL1β and IL18 in HMC3 cells. Aggregated PHF6-peptide also activated other related inflammation and microglial polarization markers. Furthermore, we also report a time-dependent effect of the aggregated PHF6 on BECN1 (Beclin-1) expression and autophagy. Overall, the PHF6 model system-based study may help to better understand the complex interconnections between Alzheimer’s PHF6 peptide aggregation and microglial inflammation, polarization, and autophagy.


Cancers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 5557
Author(s):  
Alexandre Vallée ◽  
Yves Lecarpentier ◽  
Jean-Noël Vallée

The canonical WNT/β-catenin pathway is upregulated in cancers and plays a major role in proliferation, invasion, apoptosis and angiogenesis. Nuclear β-catenin accumulation is associated with cancer. Hypoxic mechanisms lead to the activation of the hypoxia-inducible factor (HIF)-1α, promoting glycolytic and energetic metabolism and angiogenesis. However, HIF-1α is degraded by the HIF prolyl hydroxylase under normoxia, conditions under which the WNT/β-catenin pathway can activate HIF-1α. This review is therefore focused on the interaction between the upregulated WNT/β-catenin pathway and the metabolic processes underlying cancer mechanisms under normoxic conditions. The WNT pathway stimulates the PI3K/Akt pathway, the STAT3 pathway and the transduction of WNT/β-catenin target genes (such as c-Myc) to activate HIF-1α activity in a hypoxia-independent manner. In cancers, stimulation of the WNT/β-catenin pathway induces many glycolytic enzymes, which in turn induce metabolic reprogramming, known as the Warburg effect or aerobic glycolysis, leading to lactate overproduction. The activation of the Wnt/β-catenin pathway induces gene transactivation via WNT target genes, c-Myc and cyclin D1, or via HIF-1α. This in turn encodes aerobic glycolysis enzymes, including glucose transporter, hexokinase 2, pyruvate kinase M2, pyruvate dehydrogenase kinase 1 and lactate dehydrogenase-A, leading to lactate production. The increase in lactate production is associated with modifications to the tumor microenvironment and tumor growth under normoxic conditions. Moreover, increased lactate production is associated with overexpression of VEGF, a key inducer of angiogenesis. Thus, under normoxic conditions, overstimulation of the WNT/β-catenin pathway leads to modifications of the tumor microenvironment and activation of the Warburg effect, autophagy and glutaminolysis, which in turn participate in tumor growth.


2021 ◽  
Author(s):  
Shonagh Russell ◽  
Liping Xu ◽  
Yoonseok Kam ◽  
Dominique Abrahams ◽  
Bryce Ordway ◽  
...  

Aggressive cancers commonly ferment glucose to lactic acid at high rates, even in the presence of oxygen. This is known as aerobic glycolysis, or the “Warburg Effect”. It is widely assumed that this is a consequence of the upregulation of glycolytic enzymes. Oncogenic drivers can increase the expression of most proteins in the glycolytic pathway, including the terminal step of exporting H+ equivalents from the cytoplasm. Proton exporters maintain an alkaline cytoplasmic pH, which can enhance all glycolytic enzyme activities, even in the absence of oncogene-related expression changes. Based on this observation, we hypothesized that increased uptake and fermentative metabolism of glucose could be driven by the expulsion of H+ equivalents from the cell. To test this hypothesis, we stably transfected lowly-glycolytic MCF-7, U2-OS, and glycolytic HEK293 cells to express proton exporting systems: either PMA1 (yeast H+-ATPase) or CAIX (carbonic anhydrase 9). The expression of either exporter in vitro enhanced aerobic glycolysis as measured by glucose consumption, lactate production, and extracellular acidification rate. This resulted in an increased intracellular pH, and metabolomic analyses indicated that this was associated with an increased flux of all glycolytic enzymes upstream of pyruvate kinase. These cells also demonstrated increased migratory and invasive phenotypes in vitro, and these were recapitulated in vivo by more aggressive behavior, whereby the acid-producing cells formed higher grade tumors with higher rates of metastases. Neutralizing tumor acidity with oral buffers reduced the metastatic burden. Therefore, cancer cells with increased H+ export increase intracellular alkalization, even without oncogenic driver mutations, and this is sufficient to alter cancer metabolism towards a Warburg phenotype.


Author(s):  
Svetlana Čapenko ◽  
Marija Mihailova ◽  
Santa Rasa ◽  
Angelika Krūmiņa ◽  
Zane Zazerska ◽  
...  

Abstract Fibromyalgia (FM) is a chronic widespread pain disorder that impacts 0.5%-7% of the general population worldwide. The aetiology and pathogenesis of the disease are still unknown. Human herpesvirus-6 and -7 belong to the family Herpesviridae, subfamily Betaherpesvirinae, and genus Roseolovirus and are immunomodulating viruses potentially pathogenic to the nervous system. Presence of anti-HHV-6 and -HHV-7 antibodies and viral genomic sequences, viral loads, HHV-6 variant-specificity, and TNF-α level were studied in 41 FM patients and 50 healthy individuals using polymerase chain reactions, restriction endonuclease analysis and ELISA. There was no difference in the presence of anti-HHV-6 and anti-HHV-7 IgG class antibodies between FM patients and control group individuals. Viral sequences were found in 80.5% of FM patients and in 62.0% of controls. Significantly higher rate of concurrent HHV-6 and HHV-7 infection and higher viral loads in peripheral blood were detected in FM patients compared to the control group individuals. Plasma viremia was detected only in FM patients. Significantly higher TNF-α levels were detected in virus positive FM patients. From all positive cases only in two FM patients HHV-6A was revealed. Significantly higher detection frequency of concurrent HHV-6 and HHV-7 infection, simultaneous HHV-6 and HHV-7 activation, higher viral loads and TNF-α expression levels in primary FM patients than in control group individuals indicate the potential involvement of Roseoloviruses in development of this disorder.


2020 ◽  
Vol 21 (5) ◽  
pp. 1661
Author(s):  
Anamarija Mojzeš ◽  
Marko Tomljanović ◽  
Lidija Milković ◽  
Renata Novak Kujundžić ◽  
Ana Čipak Gašparović ◽  
...  

In order to support uncontrolled proliferation, cancer cells need to adapt to increased energetic and biosynthetic requirements. One such adjustment is aerobic glycolysis or the Warburg effect. It is characterized by increased glucose uptake and lactate production. Curcumin, a natural compound, has been shown to interact with multiple molecules and signaling pathways in cancer cells, including those relevant for cell metabolism. The effect of curcumin and its solvent, ethanol, was explored on four different cancer cell lines, in which the Warburg effect varied. Vital cellular parameters (proliferation, viability) were measured along with the glucose consumption and lactate production. The transcripts of pyruvate kinase 1 and 2 (PKM1, PKM2), serine hydroxymethyltransferase 2 (SHMT2) and phosphoglycerate dehydrogenase (PHGDH) were quantified with RT-qPCR. The amount and intracellular localization of PKM1, PKM2 and signal transducer and activator of transcription 3 (STAT3) proteins were analyzed by Western blot. The response to ethanol and curcumin seemed to be cell-type specific, with respect to all parameters analyzed. High sensitivity to curcumin was present in the cell lines originating from head and neck squamous cell carcinomas: FaDu, Detroit 562 and, especially, Cal27. Very low sensitivity was observed in the colon adenocarcinoma-originating HT-29 cell line, which retained, after exposure to curcumin, a higher levels of lactate production despite decreased glucose consumption. The effects of ethanol were significant.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1177
Author(s):  
Johannes H.G.M. van Beek

Background: Tumor cells show the Warburg effect: high glucose uptake and lactate production despite sufficient oxygen supply. Otto Warburg found this effect in tissue slices and in suspensions of Ehrlich ascites tumor cells. Remarkably, these ascites tumor cells can transiently take up glucose an order of magnitude faster than the steady high rate measured by Warburg for hours. Methods: The purpose of the transiently very high glucose uptake is investigated here with a computational model of glycolysis, oxidative phosphorylation and ATP consumption which reproduces short kinetic experiments on the ascites tumor cells as well as the long-lasting Warburg, Crabtree and Pasteur effects. The model, extended with equations for glucose and O2 transport in tissue, is subsequently used to predict metabolism in tumor cells during fluctuations of tissue blood flow resulting in cycling hypoxia. Results: The model analysis suggests that the head section of the glycolytic chain in the tumor cells is partially inhibited in about a minute when substantial amounts of glucose have been taken up intracellularly; this head section of the glycolytic chain is subsequently disinhibited slowly when concentrations of glycolytic intermediates are low. Based on these dynamic characteristics, simulations of tissue with fluctuating O2 and glucose supply predict that tumor cells greedily take up glucose when this periodically becomes available, leaving very little for other cells. The glucose is stored as fructose 1,6-bisphosphate and other glycolytic intermediates, which are used for ATP production during   O2 and glucose shortages. Conclusions: The head section of glycolysis which phosphorylates glucose may be dynamically regulated and takes up glucose at rates exceeding the Warburg effect if glucose levels have been low for some time. The hypothesis is put forward here that dynamic regulation of the powerful glycolytic enzyme system in tumors is used to buffer oxygen and nutrient fluctuations in tissue.


2008 ◽  
Vol 136 (3-4) ◽  
pp. 126-130
Author(s):  
Momcilo Ristanovic ◽  
Vera Bunjevacki ◽  
Cane Tulic ◽  
Ivana Novakovic ◽  
Tatjana Ille ◽  
...  

Introduction Y chromosome microdeletions are the second most frequent genetic cause of male infertility after Klinefelter's syndrome. Objective The aim of the study was to determine the frequency of Y chromosome microdeletions in a group of infertile men with an idiophatic cause of infertility, candidates for microfertilization (Intra-cytoplasmic Sperm Injection - ICSI) in Serbia and to correlate genotype-phenotype in patients with Y chromosome microdeletions. METHOD One hundred and sixty patients with low sperm count (less than 5x106 spermatozoa/ml) were enrolled in the study. Forty patients were excluded from the study: ten because they were diagnosed with cytogenetic abnormality and thirty patients were diagnosed with other known causes of infertility. The control group consisted of 150 men who fathered at least one child in the last two years. Genomic DNA was extracted from peripheral blood samples and two multiplex polymerase chain reactions (PCR) analyses were performed using specific primers to confirm the presence or absence of Y chromosome microdeletions. Results Microdeletions were detected in 12 of 120 (10%) cases, while no deletions were detected in the control group. Of total number of 12 deletions, nine were detected in AZFc region (75%), one in AZFa (8%), and two in AZFbc (17%). Conclusion Testing for Y chromosome microdeletions should be considered as an important element in diagnosis and genetic counselling of infertile couples in Serbia. Decisions regarding the assisted reproduction should be made based on the detailed clinical, endocrinological and cytogenetic examinations, spermogram, presence or absence and type of AZF microdeletions and CFTR gene mutations. .


2021 ◽  
Vol 22 (16) ◽  
pp. 8610
Author(s):  
Nives Škorja Milić ◽  
Klemen Dolinar ◽  
Katarina Miš ◽  
Urška Matkovič ◽  
Maruša Bizjak ◽  
...  

Inhibition of pyruvate dehydrogenase kinase (PDK) emerged as a potential strategy for treatment of cancer and metabolic disorders. Dichloroacetate (DCA), a prototypical PDK inhibitor, reduces the abundance of some PDK isoenzymes. However, the underlying mechanisms are not fully characterized and may differ across cell types. We determined that DCA reduced the abundance of PDK1 in breast (MDA-MB-231) and prostate (PC-3) cancer cells, while it suppressed both PDK1 and PDK2 in skeletal muscle cells (L6 myotubes). The DCA-induced PDK1 suppression was partially dependent on hypoxia-inducible factor-1α (HIF-1α), a transcriptional regulator of PDK1, in cancer cells but not in L6 myotubes. However, the DCA-induced alterations in the mRNA and the protein levels of PDK1 and/or PDK2 did not always occur in parallel, implicating a role for post-transcriptional mechanisms. DCA did not inhibit the mTOR signaling, while inhibitors of the proteasome or gene silencing of mitochondrial proteases CLPP and AFG3L2 did not prevent the DCA-induced reduction of the PDK1 protein levels. Collectively, our results suggest that DCA reduces the abundance of PDK in an isoform-dependent manner via transcriptional and post-transcriptional mechanisms. Differential response of PDK isoenzymes to DCA might be important for its pharmacological effects in different types of cells.


2017 ◽  
Vol 114 (52) ◽  
pp. 13732-13737 ◽  
Author(s):  
Yang Wang ◽  
Jia Liu ◽  
Xin Jin ◽  
Dapeng Zhang ◽  
Dongxue Li ◽  
...  

The Warburg effect, characterized by increased glucose uptake and lactate production, is a well-known universal across cancer cells and other proliferating cells. PKM2, a splice isoform of the pyruvate kinase (PK) specifically expressed in these cells, serves as a major regulator of this metabolic reprogramming with an adjustable activity subjected to numerous allosteric effectors and posttranslational modifications. Here, we have identified a posttranslational modification on PKM2, O-GlcNAcylation, which specifically targets Thr405 and Ser406, residues of the region encoded by the alternatively spliced exon 10 in cancer cells. We show that PKM2 O-GlcNAcylation is up-regulated in various types of human tumor cells and patient tumor tissues. The modification destabilized the active tetrameric PKM2, reduced PK activity, and led to nuclear translocation of PKM2. We also observed that the modification was associated with an increased glucose consumption and lactate production and enhanced level of lipid and DNA synthesis, indicating that O-GlcNAcylation promotes the Warburg effect. In vivo experiments showed that blocking PKM2 O-GlcNAcylation attenuated tumor growth. Thus, we demonstrate that O-GlcNAcylation is a regulatory mechanism for PKM2 in cancer cells and serves as a bridge between PKM2 and metabolic reprogramming typical of the Warburg effect.


2018 ◽  
Vol 45 (6) ◽  
pp. 2548-2559 ◽  
Author(s):  
Yuanyuan Zhou ◽  
Xia Zheng ◽  
Jiaojiao Lu ◽  
Wei Chen ◽  
Xu Li ◽  
...  

Background/Aims: The Warburg effect is one of the main energy metabolism features supporting cancer cell growth. 20(S)-Rg3 exerts anti-tumor effect on ovarian cancer partly by inhibiting the Warburg effect. microRNAs are important regulators of the Warburg effect. However, the microRNA regulatory network mediating the anti-Warburg effect of 20(S)-Rg3 was largely unknown. Methods: microRNA deep sequencing was performed to identify the 20(S)-Rg3-influenced microRNAs in SKOV3 ovarian cancer cells. miR-532-3p was overexpressed by mimic532-3p transfection in SKOV3 and A2780 cells or inhibited by inhibitor532-3p transfection in 20(S)-Rg3-treated cells to examine the changes in HK2 and PKM2 expression, glucose consumption, lactate production and cell growth. Dual-luciferase reporter assay was conducted to verify the direct binding of miR-532-3p to HK2. The methylation status in the promoter region of pre-miR-532-3p gene was examined by methylation-specific PCR. Expression changes of key molecules controlling DNA methylation including DNMT1, DNMT3A, DNMT3B, and TET1-3 were examined in 20(S)-Rg3-treated cells. DNMT3A was overexpressed in 20(S)-Rg3-treated cells to examine its influence on miR-532-3p level, HK2 and PKM2 expression, glucose consumption and lactate production. Results: Deep sequencing results showed that 11 microRNAs were increased and 9 microRNAs were decreased by 20(S)-Rg3 in SKOV3 cells, which were verified by qPCR. More than 2-fold increase of miR-532-3p was found in 20(S)-Rg3-treated SKOV3 cells. Forced expression of miR-532-3p reduced HK2 and PKM2 expression, glucose consumption and lactate production in SKOV3 and A2780 ovarian cancer cells. Inhibition of miR-532-3p antagonized the suppressive effect of 20(S)-Rg3 on HK2 and PKM2 expression, glucose consumption and lactate production in ovarian cancer cells. Dual-luciferase reporter assay showed that miR-532-3p directly suppressed HK2 rather than PKM2. miR-532-3p level was controlled by the methylation in the promoter region of its host gene. 20(S)-Rg3 inhibited DNMT3A expression while exerted insignificant effect on DNMT1, DNMT3B and TET1-3. 20(S)-Rg3 reversed DNMT3A-mediated methylation in the promoter of the host gene of miR-532-3p, and thus elevated miR-532-3p level followed by suppression of HK2 and PKM2 expression, glucose consumption and lactate production. Conclusions: 20(S)-Rg3 modulated microRNAs to exert the anti-tumor effect in ovarian cancer. 20(S)-Rg3 lessened the DNMT3A-mediated methylation and promoted the suppression of miR-532-3p on HK2 to antagonize the Warburg effect of ovarian cancer cells.


Sign in / Sign up

Export Citation Format

Share Document