scholarly journals A natural variant of the sole pyruvate kinase of fission yeast lowers glycolytic flux triggering increased respiration and oxidative-stress resistance but decreased growth

2019 ◽  
Author(s):  
Stephan Kamrad ◽  
Jan Grossbach ◽  
Maria Rodríguez-López ◽  
StJohn Townsend ◽  
Michael Mülleder ◽  
...  

AbstractCells balance glycolysis with respiration to support their energetic and biosynthetic needs in different environmental or physiological contexts. With abundant glucose, many cells prefer to grow by aerobic glycolysis, or fermentation in yeast. Using 161 natural isolates of fission yeast, we investigated the genetic basis and phenotypic effects of the fermentation-respiration balance. The laboratory and a few other strains were more dependent on respiration. This trait was associated with a missense variant in a highly conserved region of Pyk1. Pyk1 is the single pyruvate kinase in fission yeast, while most organisms possess isoforms with different activity. This variant reduced Pyk1 activity and glycolytic flux. Replacing the ‘low-activity’ pyk1 allele in the laboratory strain with the common ‘high-activity’ allele was sufficient to increase fermentation and decrease respiration. This metabolic reprogramming triggered systems-level adaptations in the transcriptome and proteome, and in cellular phenotypes, including increased growth and chronological lifespan, but decreased resistance to oxidative stress. Thus, low Pyk1 activity provided no growth advantage but stress tolerance, despite increased respiration. The genetic tuning of glycolytic flux by a single-nucleotide change might reflect an adaptive trade-off in a species lacking pyruvate-kinase isoforms.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Feng Gao ◽  
Xiaojun Zhang ◽  
Shuyue Wang ◽  
Lihua Zheng ◽  
Ying Sun ◽  
...  

AbstractMetabolic reprogramming is a hallmark of malignancy. Testes-specific protease 50 (TSP50), a newly identified oncogene, has been shown to play an important role in tumorigenesis. However, its role in tumor cell metabolism remains unclear. To investigate this issue, LC–MS/MS was employed to identify TSP50-binding proteins and pyruvate kinase M2 isoform (PKM2), a known key enzyme of aerobic glycolysis, was identified as a novel binding partner of TSP50. Further studies suggested that TSP50 promoted aerobic glycolysis in HCC cells by maintaining low pyruvate kinase activity of the PKM2. Mechanistically, TSP50 promoted the Warburg effect by increasing PKM2 K433 acetylation level and PKM2 acetylation site (K433R) mutation remarkably abrogated the TSP50-induced aerobic glycolysis, cell proliferation in vitro and tumor formation in vivo. Our findings indicate that TSP50-mediated low PKM2 pyruvate kinase activity is an important determinant for Warburg effect in HCC cells and provide a mechanistic link between TSP50 and tumor metabolism.



2019 ◽  
Vol 19 (17) ◽  
pp. 1521-1534 ◽  
Author(s):  
Anatoly Sorokin ◽  
Vsevolod Shurkhay ◽  
Stanislav Pekov ◽  
Evgeny Zhvansky ◽  
Daniil Ivanov ◽  
...  

Cells metabolism alteration is the new hallmark of cancer, as well as an important method for carcinogenesis investigation. It is well known that the malignant cells switch to aerobic glycolysis pathway occurring also in healthy proliferating cells. Recently, it was shown that in malignant cells de novo synthesis of the intracellular fatty acid replaces dietary fatty acids which change the lipid composition of cancer cells noticeably. These alterations in energy metabolism and structural lipid production explain the high proliferation rate of malignant tissues. However, metabolic reprogramming affects not only lipid metabolism but many of the metabolic pathways in the cell. 2-hydroxyglutarate was considered as cancer cell biomarker and its presence is associated with oxidative stress influencing the mitochondria functions. Among the variety of metabolite detection methods, mass spectrometry stands out as the most effective method for simultaneous identification and quantification of the metabolites. As the metabolic reprogramming is tightly connected with epigenetics and signaling modifications, the evaluation of metabolite alterations in cells is a promising approach to investigate the carcinogenesis which is necessary for improving current diagnostic capabilities and therapeutic capabilities. In this paper, we overview recent studies on metabolic alteration and oncometabolites, especially concerning brain cancer and mass spectrometry approaches which are now in use for the investigation of the metabolic pathway.





Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3018
Author(s):  
Marek Samec ◽  
Alena Liskova ◽  
Lenka Koklesova ◽  
Kevin Zhai ◽  
Elizabeth Varghese ◽  
...  

Metabolic reprogramming characterized by alterations in nutrient uptake and critical molecular pathways associated with cancer cell metabolism represents a fundamental process of malignant transformation. Melatonin (N-acetyl-5-methoxytryptamine) is a hormone secreted by the pineal gland. Melatonin primarily regulates circadian rhythms but also exerts anti-inflammatory, anti-depressant, antioxidant and anti-tumor activities. Concerning cancer metabolism, melatonin displays significant anticancer effects via the regulation of key components of aerobic glycolysis, gluconeogenesis, the pentose phosphate pathway (PPP) and lipid metabolism. Melatonin treatment affects glucose transporter (GLUT) expression, glucose-6-phosphate dehydrogenase (G6PDH) activity, lactate production and other metabolic contributors. Moreover, melatonin modulates critical players in cancer development, such as HIF-1 and p53. Taken together, melatonin has notable anti-cancer effects at malignancy initiation, progression and metastasing. Further investigations of melatonin impacts relevant for cancer metabolism are expected to create innovative approaches supportive for the effective prevention and targeted therapy of cancers.



2021 ◽  
Vol 11 (3) ◽  
pp. 1259
Author(s):  
Qiong Wu ◽  
Bo Zhao ◽  
Guangchao Sui ◽  
Jinming Shi

Aberrant metabolism is one of the hallmarks of cancers. The contributions of dysregulated metabolism to cancer development, such as tumor cell survival, metastasis and drug resistance, have been extensively characterized. “Reprogrammed” metabolic pathways in cancer cells are mainly represented by excessive glucose consumption and hyperactive de novo lipogenesis. Natural compounds with anticancer activities are constantly being demonstrated to target metabolic processes, such as glucose transport, aerobic glycolysis, fatty acid synthesis and desaturation. However, their molecular targets and underlying anticancer mechanisms remain largely unclear or controversial. Mounting evidence indicated that these natural compounds could modulate the expression of key regulatory enzymes in various metabolic pathways at transcriptional and translational levels. Meanwhile, natural compounds could also inhibit the activities of these enzymes by acting as substrate analogs or altering their protein conformations. The actions of natural compounds in the crosstalk between metabolism modulation and cancer cell destiny have become increasingly attractive. In this review, we summarize the activities of natural small molecules in inhibiting key enzymes of metabolic pathways. We illustrate the structural characteristics of these compounds at the molecular level as either inhibitor of various enzymes or regulators of metabolic pathways in cancer cells. Our ultimate goal is to both facilitate the clinical application of natural compounds in cancer therapies and promote the development of novel anticancer therapeutics.



2021 ◽  
Vol 22 (3) ◽  
pp. 1171
Author(s):  
Dexter L. Puckett ◽  
Mohammed Alquraishi ◽  
Winyoo Chowanadisai ◽  
Ahmed Bettaieb

Pyruvate kinase is a key regulator in glycolysis through the conversion of phosphoenolpyruvate (PEP) into pyruvate. Pyruvate kinase exists in various isoforms that can exhibit diverse biological functions and outcomes. The pyruvate kinase isoenzyme type M2 (PKM2) controls cell progression and survival through the regulation of key signaling pathways. In cancer cells, the dimer form of PKM2 predominates and plays an integral role in cancer metabolism. This predominance of the inactive dimeric form promotes the accumulation of phosphometabolites, allowing cancer cells to engage in high levels of synthetic processing to enhance their proliferative capacity. PKM2 has been recognized for its role in regulating gene expression and transcription factors critical for health and disease. This role enables PKM2 to exert profound regulatory effects that promote cancer cell metabolism, proliferation, and migration. In addition to its role in cancer, PKM2 regulates aspects essential to cellular homeostasis in non-cancer tissues and, in some cases, promotes tissue-specific pathways in health and diseases. In pursuit of understanding the diverse tissue-specific roles of PKM2, investigations targeting tissues such as the kidney, liver, adipose, and pancreas have been conducted. Findings from these studies enhance our understanding of PKM2 functions in various diseases beyond cancer. Therefore, there is substantial interest in PKM2 modulation as a potential therapeutic target for the treatment of multiple conditions. Indeed, a vast plethora of research has focused on identifying therapeutic strategies for targeting PKM2. Recently, targeting PKM2 through its regulatory microRNAs, long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) has gathered increasing interest. Thus, the goal of this review is to highlight recent advancements in PKM2 research, with a focus on PKM2 regulatory microRNAs and lncRNAs and their subsequent physiological significance.



2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Xiaoqing Luo ◽  
Enze Zheng ◽  
Li Wei ◽  
Han Zeng ◽  
Hong Qin ◽  
...  

AbstractMetabolic reprogramming is a new hallmark of cancer but it remains poorly defined in hepatocellular carcinogenesis (HCC). The fatty acid receptor CD36 is associated with both lipid and glucose metabolism in the liver. However, the role of CD36 in metabolic reprogramming in the progression of HCC still remains to be elucidated. In the present study, we found that CD36 is highly expressed in human HCC as compared with non-tumor hepatic tissue. CD36 overexpression promoted the proliferation, migration, invasion, and in vivo tumor growth of HCC cells, whereas silencing CD36 had the opposite effects. By analysis of cell metabolic phenotype, CD36 expression showed a positive association with extracellular acidification rate, a measure of glycolysis, instead of oxygen consumption rate. Further experiments verified that overexpression of CD36 resulted in increased glycolysis flux and lactic acid production. Mechanistically, CD36 induced mTOR-mediated oncogenic glycolysis via activation of Src/PI3K/AKT signaling axis. Pretreatment of HCC cells with PI3K/AKT/mTOR inhibitors largely blocked the tumor-promoting effect of CD36. Our findings suggest that CD36 exerts a stimulatory effect on HCC growth and metastasis, through mediating aerobic glycolysis by the Src/PI3K/AKT/mTOR signaling pathway.



Metabolites ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 346
Author(s):  
Adrian Benito ◽  
Nabil Hajji ◽  
Kevin O’Neill ◽  
Hector C. Keun ◽  
Nelofer Syed

Metabolic regulation of immune cells has arisen as a critical set of processes required for appropriate response to immunological signals. While our knowledge in this area has rapidly expanded in leukocytes, much less is known about the metabolic regulation of brain-resident microglia. In particular, the role of alternative nutrients to glucose remains poorly understood. Here, we use stable-isotope (13C) tracing strategies and metabolomics to characterize the oxidative metabolism of β-hydroxybutyrate (BHB) in human (HMC3) and murine (BV2) microglia cells and the interplay with glucose in resting and LPS-activated BV2 cells. We found that BHB is imported and oxidised in the TCA cycle in both cell lines with a subsequent increase in the cytosolic NADH:NAD+ ratio. In BV2 cells, stimulation with LPS upregulated the glycolytic flux, increased the cytosolic NADH:NAD+ ratio and promoted the accumulation of the glycolytic intermediate dihydroxyacetone phosphate (DHAP). The addition of BHB enhanced LPS-induced accumulation of DHAP and promoted glucose-derived lactate export. BHB also synergistically increased LPS-induced accumulation of succinate and other key immunometabolites, such as α-ketoglutarate and fumarate generated by the TCA cycle. Finally, BHB upregulated the expression of a key pro-inflammatory (M1 polarisation) marker gene, NOS2, in BV2 cells activated with LPS. In conclusion, we identify BHB as a potentially immunomodulatory metabolic substrate for microglia that promotes metabolic reprogramming during pro-inflammatory response.



2011 ◽  
Vol 435 (2) ◽  
pp. 519-528 ◽  
Author(s):  
Brian E. Sansbury ◽  
Daniel W. Riggs ◽  
Robert E. Brainard ◽  
Joshua K. Salabei ◽  
Steven P. Jones ◽  
...  

During cardiac remodelling, the heart generates higher levels of reactive species; yet an intermediate ‘compensatory’ stage of hypertrophy is associated with a greater ability to withstand oxidative stress. The mechanisms underlying this protected myocardial phenotype are poorly understood. We examined how a cellular model of hypertrophy deals with electrophilic insults, such as would occur upon ischaemia or in the failing heart. For this, we measured energetics in control and PE (phenylephrine)-treated NRCMs (neonatal rat cardiomyocytes) under basal conditions and when stressed with HNE (4-hydroxynonenal). PE treatment caused hypertrophy as indicated by augmented atrial natriuretic peptide and increased cellular protein content. Hypertrophied myocytes demonstrated a 2.5-fold increase in ATP-linked oxygen consumption and a robust augmentation of oligomycin-stimulated glycolytic flux and lactate production. Hypertrophied myocytes displayed a protected phenotype that was resistant to HNE-induced cell death and a unique bioenergetic response characterized by a delayed and abrogated rate of oxygen consumption and a 2-fold increase in glycolysis upon HNE exposure. This augmentation of glycolytic flux was not due to increased glucose uptake, suggesting that electrophile stress results in utilization of intracellular glycogen stores to support the increased energy demand. Hypertrophied myocytes also had an increased propensity to oxidize HNE to 4-hydroxynonenoic acid and sustained less protein damage due to acute HNE insults. Inhibition of aldehyde dehydrogenase resulted in bioenergetic collapse when myocytes were challenged with HNE. The integration of electrophile metabolism with glycolytic and mitochondrial energy production appears to be important for maintaining myocyte homoeostasis under conditions of increased oxidative stress.



Sign in / Sign up

Export Citation Format

Share Document