scholarly journals Increasing NADPH impairs fungal H2O2 resistance by perturbing transcriptional regulation of peroxiredoxin

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Jingyi Li ◽  
Yanwei Sun ◽  
Feiyun Liu ◽  
Yao Zhou ◽  
Yunfeng Yan ◽  
...  

AbstractNADPH provides the reducing power for decomposition of reactive oxygen species (ROS), making it an indispensable part during ROS defense. It remains uncertain, however, if living cells respond to the ROS challenge with an elevated intracellular NADPH level or a more complex NADPH-mediated manner. Herein, we employed a model fungus Aspergillus nidulans to probe this issue. A conditional expression of glucose-6-phosphate dehydrogenase (G6PD)-strain was constructed to manipulate intracellular NADPH levels. As expected, turning down the cellular NADPH concentration drastically lowered the ROS response of the strain; it was interesting to note that increasing NADPH levels also impaired fungal H2O2 resistance. Further analysis showed that excess NADPH promoted the assembly of the CCAAT-binding factor AnCF, which in turn suppressed NapA, a transcriptional activator of PrxA (the key NADPH-dependent ROS scavenger), leading to low antioxidant ability. In natural cell response to oxidative stress, we noticed that the intracellular NADPH level fluctuated “down then up” in the presence of H2O2. This might be the result of a co-action of the PrxA-dependent NADPH consumption and NADPH-dependent feedback of G6PD. The fluctuation of NADPH is well correlated to the formation of AnCF assembly and expression of NapA, thus modulating the ROS defense. Our research elucidated how A. nidulans precisely controls NADPH levels for ROS defense. Graphical Abstract

Author(s):  
Qian Wu ◽  
Youmei Li ◽  
Ying Li ◽  
Dong Wang ◽  
Ben Zhong Tang

Hydrogen peroxide (H2O2), as one kind of key reactive oxygen species (ROS), is mainly produced endogenously primarily in the mitochondria. The selective monitoring of H2O2 in living cells is of...


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Huey-Chun Huang ◽  
Hsiao-Fen Wang ◽  
Kuang-Hway Yih ◽  
Long-Zen Chang ◽  
Tsong-Min Chang

The antimelanogenic and antioxidant activities of the essential oil extracted from the leaves ofAcorus macrospadiceus(Yamamoto) F. N. Wei et Y. K. Li have never been explored. The essential oil effectively inhibited mushroom tyrosinase activity (EC50= 1.57 mg/mL) and B16F10 tyrosinase activity (IC50= 1.01 mg/mL), decreased the melanin content (EC50= 1.04 mg/mL), and depleted the cellular level of the reactive oxygen species (ROS) (EC50= 1.87 mg/mL). The essential oil effectively scavenged 2,2-diphenyl-1-picryl-hydrazyl (DPPH) (EC50= 0.121 mg/mL) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) ABTS+radicals (EC50= 0.122 mg/mL). It also exhibited an apparent reducing power (EC50= 0.021 mg/mL) and metal-ion chelating activity (EC50= 0.029 mg/mL). The chemical constituents of the essential oil are ethers (55.73%), ketones (19.57%), monoterpenes (7.82%), alcohols (3.85%), esters (3.77%), sesquiterpenes (3.72%), and aromatic compounds (2.85%). The results confirm thatA. macrospadiceusessential oil is a natural antioxidant and inhibitor of melanogenesis.


2013 ◽  
Vol 295-298 ◽  
pp. 475-478 ◽  
Author(s):  
Zhi Xiang Han ◽  
Ming Hui Du ◽  
Guo Xi Liang ◽  
Xiang Yang Wu

Rhodamine B thiohydrazide (RBS) was firstly employed as turn-on fluorescent probe for hypochlorite in aqueous solution and living cells. It exhibits a stable response to hypochlorite from 1.0×10-6to 1.0×10-5M with a detection limit of 3.3×10-7M. The response of this probe to hypochlorite is fast and highly selective compared with other reactive oxygen species (such as.OH,1O2, H2O2) and other common anions (such as X-, ClO2-, ClO4-, NO3-, NO2-, OH-, Ac-, CO32-, SO42-).


2021 ◽  
Author(s):  
Jee Hyung Sohn ◽  
Yul Ji ◽  
Chang-Yun Cho ◽  
Hahn Nahmgoong ◽  
Sangsoo Lim ◽  
...  

Reactive oxygen species (ROS) are associated with various roles of brown adipocytes. Glucose-6-phosphate dehydrogenase (G6PD) controls cellular redox potentials by producing NADPH. Although G6PD upregulates cellular ROS levels in white adipocytes, the roles of G6PD in brown adipocytes remain elusive. Here, we found that G6PD defect in brown adipocytes impaired thermogenic function through excessive cytosolic ROS accumulation. Upon cold exposure, G6PD-deficient mutant (G6PD<sup>mut</sup>) mice exhibited cold intolerance and downregulated thermogenic gene expression in brown adipose tissue (BAT). In addition, G6PD-deficient brown adipocytes had increased cytosolic ROS levels, leading to ERK activation. In BAT of G6PD<sup>mut</sup> mice, administration of antioxidant restored the thermogenic activity by potentiating thermogenic gene expression and relieving ERK activation. Consistently, body temperature and thermogenic execution were rescued by ERK inhibition in cold-exposed G6PD<sup>mut</sup> mice. Taken together, these data suggest that G6PD in brown adipocytes would protect against cytosolic oxidative stress, leading to cold-induced thermogenesis.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1800
Author(s):  
Ruijun Feng ◽  
Xiaomin Wang ◽  
Li He ◽  
Shengwang Wang ◽  
Junjie Li ◽  
...  

G6PDH provides intermediate metabolites and reducing power (nicotinamide adenine dinucleotide phosphate, NADPH) for plant metabolism, and plays a pivotal role in the cellular redox homeostasis. In this study, we cloned five G6PDH genes (HvG6PDH1 to HvG6PDH5) from highland barley and characterized their encoded proteins. Functional analysis of HvG6PDHs in E. coli showed that HvG6PDH1 to HvG6PDH5 encode the functional G6PDH proteins. Subcellular localization and phylogenetic analysis indicated that HvG6PDH2 and HvG6PDH5 are localized in the cytoplasm, while HvG6PDH1, HvG6PDH3, and HvG6PDH4 are plastidic isoforms. Analysis of enzymatic activities and gene expression showed that HvG6PDH1 to HvG6PDH4 are involved in responses to salt and drought stresses. The cytosolic HvG6PDH2 is the major isoform against oxidative stress. HvG6PDH5 may be a house-keeping gene. In addition, HvG6PDH1 to HvG6PDH4 and their encoded enzymes responded to jasmonic acid (JA) and abscisic acid (ABA) treatments, implying that JA and ABA are probably critical regulators of HvG6PDHs (except for HvG6PDH5). Reactive oxygen species analysis showed that inhibition of cytosolic and plastidic G6PDH activities leads to increased H2O2 and O2− contents in highland barley under salt and drought stresses. These results suggest that G6PDH can maintain cellular redox homeostasis and that cytosolic HvG6PDH2 is an irreplaceable isoform against oxidative stress in highland barley.


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