Glutamate dehydrogenase enables Salmonella to survive under oxidative stress and escape from clearance in macrophages

FEBS Letters ◽  
2021 ◽  
Author(s):  
Xi Huang ◽  
Wenji Lao ◽  
Youci Zhou ◽  
Yunwei Sun ◽  
Qijun Wang
2009 ◽  
Vol 191 (12) ◽  
pp. 3804-3810 ◽  
Author(s):  
Ryan J. Mailloux ◽  
Ranji Singh ◽  
Guy Brewer ◽  
Christopher Auger ◽  
Joseph Lemire ◽  
...  

ABSTRACT α-Ketoglutarate (KG) is a crucial metabolite in all living organisms, as it participates in a variety of biochemical processes. We have previously shown that this keto acid is an antioxidant and plays a key role in the detoxification of reactive oxygen species (ROS). In an effort to further confirm this intriguing phenomenon, Pseudomonas fluorescens was exposed to menadione-containing media, with various amino acids as the sources of nitrogen. Here, we demonstrate that KG dehydrogenase (KGDH) and NAD-dependent glutamate dehydrogenase (GDH) work in tandem to modulate KG homeostasis. While KGDH was sharply decreased in cells challenged with menadione, GDH was markedly increased in cultures containing arginine (Arg), glutamate (Glu), and proline (Pro). When ammonium (NH4) was utilized as the nitrogen source, both KGDH and GDH levels were diminished. These enzymatic profiles were reversed when control cells were incubated in menadione media. 13C nuclear magnetic resonance and high-performance liquid chromatography studies revealed how KG was utilized to eliminate ROS with the concomitant formation of succinate. The accumulation of KG in the menadione-treated cells was dependent on the redox status of the lipoic acid residue in KGDH. Indeed, the treatment of cellular extracts from the menadione-exposed cells with dithiothreitol, a reducing agent, partially restored the activity of KGDH. Taken together, these data reveal that KG is pivotal to the antioxidative defense strategy of P. fluorescens and also point to the ROS-sensing role for KGDH.


Author(s):  
Sahabettin Selek ◽  
Ayse Zehra Gul ◽  
Nil Atakul ◽  
Sedat Meydan ◽  
Alime Sarıkaya ◽  
...  

Introduction: Preeclampsia, a high cause of fetomaternal morbidity-mortality, remains a significant burden affecting 8% of all pregnancies. Environmental conditions induce disease development leading to endothelial dysfunction in genetically predisposed women. Our aim is to discuss oxidative stress as a well-established contributing factor to disease progression with being the first study to show new evidence about serum dehydrogenase enzyme levels (isocitrate, malate, glutamate dehydrogenase) with oxidative markers (myeloperoxidase, total antioxidant-oxidant status, oxidative stress index). Methods: Serum parameters were analyzed with photometric method (Abbott ARCHITECT c8000). Results: Results showed that the enzyme levels and oxidative markers were significantly higher in patients, supporting the redox imbalance in preeclampsia. According to ROC analysis, malate dehydrogenase showed an outstanding diagnostic ability with the highest AUC value of 0.9 and the cut-off value of 51.2 IU/L. Discriminant analysis including malate, isocitrate and glutamate dehydrogenase had predicted preeclampsia with an overall %87.9 accuracy. Discussion: Considering the above results, we propose that the enzyme levels increase with oxidative stress functioning as antioxidant defense factors. The unique finding of the study is that the serum levels of malate, isocitrate and glutamate dehydrogenase can be used both separately and combined in the early prediction of preeclampsia. As a novel approach, we also offer combining serum isocitrate and glutamate dehydrogenase levels with ALT, AST tests to state liver functions more reliably in patients. Still, larger sample-sized studies investigating enzyme expression levels are required to confirm the recent findings and to reveal underlying mechanisms.


2020 ◽  
Vol 11 (10) ◽  
pp. 8547-8559
Author(s):  
Hongjing Zhao ◽  
Yu Wang ◽  
Mengyao Mu ◽  
Menghao Guo ◽  
Hongxian Yu ◽  
...  

Antibiotics are used worldwide to treat diseases in humans and other animals; most of them and their secondary metabolites are discharged into the aquatic environment, posing a serious threat to human health.


2019 ◽  
Vol 476 (24) ◽  
pp. 3705-3719 ◽  
Author(s):  
Avani Vyas ◽  
Umamaheswar Duvvuri ◽  
Kirill Kiselyov

Platinum-containing drugs such as cisplatin and carboplatin are routinely used for the treatment of many solid tumors including squamous cell carcinoma of the head and neck (SCCHN). However, SCCHN resistance to platinum compounds is well documented. The resistance to platinum has been linked to the activity of divalent transporter ATP7B, which pumps platinum from the cytoplasm into lysosomes, decreasing its concentration in the cytoplasm. Several cancer models show increased expression of ATP7B; however, the reason for such an increase is not known. Here we show a strong positive correlation between mRNA levels of TMEM16A and ATP7B in human SCCHN tumors. TMEM16A overexpression and depletion in SCCHN cell lines caused parallel changes in the ATP7B mRNA levels. The ATP7B increase in TMEM16A-overexpressing cells was reversed by suppression of NADPH oxidase 2 (NOX2), by the antioxidant N-Acetyl-Cysteine (NAC) and by copper chelation using cuprizone and bathocuproine sulphonate (BCS). Pretreatment with either chelator significantly increased cisplatin's sensitivity, particularly in the context of TMEM16A overexpression. We propose that increased oxidative stress in TMEM16A-overexpressing cells liberates the chelated copper in the cytoplasm, leading to the transcriptional activation of ATP7B expression. This, in turn, decreases the efficacy of platinum compounds by promoting their vesicular sequestration. We think that such a new explanation of the mechanism of SCCHN tumors’ platinum resistance identifies novel approach to treating these tumors.


2004 ◽  
Vol 71 ◽  
pp. 121-133 ◽  
Author(s):  
Ascan Warnholtz ◽  
Maria Wendt ◽  
Michael August ◽  
Thomas Münzel

Endothelial dysfunction in the setting of cardiovascular risk factors, such as hypercholesterolaemia, hypertension, diabetes mellitus and chronic smoking, as well as in the setting of heart failure, has been shown to be at least partly dependent on the production of reactive oxygen species in endothelial and/or smooth muscle cells and the adventitia, and the subsequent decrease in vascular bioavailability of NO. Superoxide-producing enzymes involved in increased oxidative stress within vascular tissue include NAD(P)H-oxidase, xanthine oxidase and endothelial nitric oxide synthase in an uncoupled state. Recent studies indicate that endothelial dysfunction of peripheral and coronary resistance and conductance vessels represents a strong and independent risk factor for future cardiovascular events. Ways to reduce endothelial dysfunction include risk-factor modification and treatment with substances that have been shown to reduce oxidative stress and, simultaneously, to stimulate endothelial NO production, such as inhibitors of angiotensin-converting enzyme or the statins. In contrast, in conditions where increased production of reactive oxygen species, such as superoxide, in vascular tissue is established, treatment with NO, e.g. via administration of nitroglycerin, results in a rapid development of endothelial dysfunction, which may worsen the prognosis in patients with established coronary artery disease.


2001 ◽  
Vol 120 (5) ◽  
pp. A217-A217
Author(s):  
C SPADA ◽  
S SANTINI ◽  
F FOSCHIA ◽  
M PANDOLFI ◽  
V PERRI ◽  
...  

2001 ◽  
Vol 120 (5) ◽  
pp. A116-A116
Author(s):  
S ALEYNIK ◽  
M ALEYNIK ◽  
C LIEBER
Keyword(s):  

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