Dual Inhibition of Pyruvate Dehydrogenase Complex and Respiratory Chain Complex Induces Apoptosis by a Mitochondria‐Targeted Fluorescent Organic Arsenical in vitro and in vivo

ChemMedChem ◽  
2020 ◽  
Vol 15 (6) ◽  
pp. 552-558
Author(s):  
Yu‐Jiao Liu ◽  
Xiao‐Yang Fan ◽  
Dong‐Dong Zhang ◽  
Yin‐Zheng Xia ◽  
Yan‐Jun Hu ◽  
...  
2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Liang Zhang ◽  
Jianong Zhang ◽  
Yan Liu ◽  
Pingzhao Zhang ◽  
Ji Nie ◽  
...  

AbstractSignal transducer and activator 5a (STAT5A) is a classical transcription factor that plays pivotal roles in various biological processes, including tumor initiation and progression. A fraction of STAT5A is localized in the mitochondria, but the biological functions of mitochondrial STAT5A remain obscure. Here, we show that STAT5A interacts with pyruvate dehydrogenase complex (PDC), a mitochondrial gatekeeper enzyme connecting two key metabolic pathways, glycolysis and the tricarboxylic acid cycle. Mitochondrial STAT5A disrupts PDC integrity, thereby inhibiting PDC activity and remodeling cellular glycolysis and oxidative phosphorylation. Mitochondrial translocation of STAT5A is increased under hypoxic conditions. This strengthens the Warburg effect in cancer cells and promotes in vitro cell growth under hypoxia and in vivo tumor growth. Our findings indicate distinct pro-oncogenic roles of STAT5A in energy metabolism, which is different from its classical function as a transcription factor.


1988 ◽  
Vol 253 (3) ◽  
pp. 819-825 ◽  
Author(s):  
T Pawelczyk ◽  
R A Easom ◽  
M S Olson

The activity of pyruvate dehydrogenase complex (PDC) purified from pig kidney cortex was found to be affected by various uni- and bi-valent ions. At a constant strength of 0.13 M at pH 7.8, K+, Na+, Cl-, HCO3- and HPO4(2-) had significant effects on the activity of PDC: Na+, K+ and HPO4(2-) stimulated, but HCO3- and Cl- inhibited. The stimulatory effect of Na+ was mediated by a change in the Vmax. of PDC only, whereas K+ produced an increase in Vmax. and a change in the Hill coefficient (h). The extent of stimulation produced by HPO4(2-)4 on the activity of PDC was dependent on the concentrations of K+ and Na+. Both cations at concentrations higher than 40 mM partially prevented the effect of HPO4(2-)4. Cl- and HCO3- anions decreased the Vmax. of the enzyme and increased the S0.5 for pyruvate. The effects of Na+, K+, Cl-, HPO4(2-) and HCO3- on the activity of PDC were additive. In the presence of 80 mM-K+, 20 mM-Na+, 10 mM-HPO4(2-), 20 mM-Cl- and 20 mM-HCO3- the activity of PDC was increased by 30%, the S0.5 for pyruvate was increased from 75 to 158 microM and h was decreased from 1.3 to 1.1. Under these conditions and at 1.0 mM-pyruvate, the activity of PDC was 80% of the maximal activity achieved in the presence of these ions and 4.5 mM-pyruvate. The present study suggests that PDC may operate under non-saturating concentrations for substrate in vivo.


1985 ◽  
Vol 40 (11-12) ◽  
pp. 917-918 ◽  
Author(s):  
Uwe Homeyer ◽  
D. Schulze-Siebert ◽  
G. Schultz

Abstract In vitro incubation of intact spinach chloroplasts with 1 mᴍ Pyruvate was used to study the specificity of action of the herbicide Chlorsulfuron on the synthesis of valine, alanine and fatty acids. As a result, increasing concentrations of the herbicide strongly inhibited valine synthesis while fatty acid synthesis via pyruvate dehydrogenase complex (PDC) and alanine formation by transamination reaction was promoted.


1992 ◽  
Vol 151 (3) ◽  
pp. 192-195 ◽  
Author(s):  
W. Sperl ◽  
W. Ruitenbeek ◽  
R. C. A. Sengers ◽  
J. M. F. Trijbels ◽  
H. Bentlage ◽  
...  

1993 ◽  
Vol 289 (1) ◽  
pp. 81-85 ◽  
Author(s):  
J Quinn ◽  
A G Diamond ◽  
A K Masters ◽  
D E Brookfield ◽  
N G Wallis ◽  
...  

The dihydrolipoamide acetyltransferase subunit (E2p) of mammalian pyruvate dehydrogenase complex has two highly conserved lipoyl domains each modified with a lipoyl cofactor bound in amide linkage to a specific lysine residue. A sub-gene encoding the inner lipoyl domain of human E2p has been over-expressed in Escherichia coli. Two forms of the domain have been purified, corresponding to lipoylated and non-lipoylated species. The apo-domain can be lipoylated in vitro with partially purified E. coli lipoate protein ligase, and the lipoylated domain can be reductively acetylated by human E1p (pyruvate dehydrogenase). Availability of the two forms will now allow detailed biochemical and structural studies of the human lipoyl domains.


1987 ◽  
Vol 248 (2) ◽  
pp. 351-358 ◽  
Author(s):  
B Laber ◽  
N Amrhein

The alanine analogue 1-aminoethylphosphinate [H3C-CH(NH2)-PO2H2] effectively inhibited anthocyanin synthesis in buckwheat hypocotyls and caused an increase in the concentrations of alanine and alanine-derived metabolites. Aminotransferase inhibitors partially alleviated the effects of the analogue. 1-Aminoethylphosphinate did not affect the growth of Klebsiella pneumoniae under anaerobic conditions, but under aerobic conditions it inhibited growth and caused the massive excretion of pyruvate. The analogue inhibited the pyruvate dehydrogenase complex in vitro in the presence of an aminotransferase activity. The transamination product of 1-aminoethylphosphinate, acetylphosphinate (H3C-CO-PO2H2), was found to inhibit the pyruvate dehydrogenase complex in a time-dependent reaction that followed first-order and saturation kinetics and required the presence of thiamin pyrophosphate.


2021 ◽  
Author(s):  
Ionica Masgras ◽  
Giuseppe Cannino ◽  
Francesco Ciscato ◽  
Carlos Sanchez-Martin ◽  
Marco Pizzi ◽  
...  

Neurofibromin loss drives neoplastic growth and a rewiring of mitochondrial metabolism. Here, we report that neurofibromin ablation dampens expression and activity of NADH dehydrogenase, the respiratory chain complex I, in an ERK-dependent fashion. This provides cells with resistance to pro-oxidants targeting complex I and decreases both respiration and intracellular NAD+. Expression of the alternative NADH dehydrogenase NDI1 raises NAD+/NADH ratio, enhances the activity of the mitochondrial NAD+-dependent deacetylase SIRT3 and interferes with tumorigenicity in neurofibromin-deficient cells. This anti-neoplastic effect is mimicked both in vitro and in vivo by administration of NAD+ precursors or by rising expression of the NAD+ deacetylase SIRT3, and is synergistic with ablation of the mitochondrial chaperone TRAP1, which augments succinate dehydrogenase activity further contributing to block pro-neoplastic metabolic changes of these cells. These findings shed light on chemotherapeutic resistance and on bioenergetic adaptations of tumors lacking neurofibromin, linking complex I inhibition to mitochondrial NAD+/NADH unbalance and SIRT3 inhibition, as well as to down-regulation of succinate dehydrogenase. This metabolic rewiring could unveil attractive therapeutic targets for neoplasms related to neurofibromin loss.


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