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Preservative Resistance
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Enterobacter gergoviae is known to cause microbial contamination of cosmetic and personal care product formulations (30,31). In addition to esterase hydrolysis, E. gergoviae parabens resistance has also been attributed to overexpression of a 25-kDa peroxiredoxin enzyme that is involved in oxidative detoxification (32). Peroxiredoxins are cysteine-based peroxidases that can act as redox sensors and biomarkers of oxidative stress. Cysteine is oxidized to reduce peroxides by forming an intermolecular disulphide bond with peroxiredoxin. The disulphide-bonded peroxiredoxins are subsequently reduced and reactivated by thiol-containing reductants such as alkyl hydroperoxidase subunit F (AhpF) and thioredoxin (TrxA). It should be noted that the isothiazolinone preservatives are able to inhibit microbial growth and metabolism and to cause the loss of viability due to its interactivity with cysteine (33–36). Excess cysteine is also able to neutralize the antimicrobial activity of (MCIT) (33). Because peroxiredoxins are cysteine-based peroxidases, it is possible that the cysteine component of this enzyme is able to neutralize the antimicrobial activity of MCIT.
Micronutrients in the Management of Prion Disease
Published in Kedar N. Prasad, Micronutrients in Health and Disease, 2019
Members of the peroxiredoxin class of enzymes are all antioxidants and peroxiredoxin 6 (Prdx6) protects human neuroblastoma cells (SK-N-SH) against oxidative stress caused by H2O2, hydroperoxides, or peroxynitrite.82 In mice infected with prion disease, the overexpression of Prdx6 protects against oxidative damage, reduces severity of behavioral deficits, and diminishes progression of neuropathology. This increases the survival time in comparison to parallel treatment of mice with knockout of Prdx6.82
Basal Redox Status Influences the Adaptive Redox Response to Regular Exercise
Published in James N. Cobley, Gareth W. Davison, Oxidative Eustress in Exercise Physiology, 2022
Ethan L. Ostrom, Tinna Traustadóttir
Hydrogen peroxide (H2O2) has been viewed as the main signaling molecule in redox signal transduction, where it was assumed that H2O2 reacts directly with protein thiols to initiate a signaling cascade. However, there are several problems with this assumption. Peroxiredoxins (Prxs) are some of the most abundantly and ubiquitously expressed antioxidant proteins in mammalian cells (Stocker et al., 2018), and they react with H2O2 on orders of magnitude faster than even the most reactive solvent-exposed protein thiols. Therefore, it would appear that Prxs are able to quench the oxidative stress signal from endogenous and exogenous signals before it can initiate a signal transduction cascade through other protein thiols (Stocker et al., 2018). Thus, Prxs likely outcompete most if not all protein thiols in the cell that utilize redox signaling mechanisms. The floodgate hypothesis proposes that H2O2 signaling persists by first causing hyperoxidation-induced inhibition of Prx enzymes, which then allows H2O2 to accumulate and diffuse throughout the cell to react with other protein thiols to initiate a redox signaling cascade. This model, if true, would circumvent the problems with kinetic efficiencies between H2O2 and Prxs versus H2O2 and protein thiols (Wood et al., 2003). While this may occur as there is some experimental evidence to support it (Hanzen et al., 2016), the floodgate hypothesis still does not explain redox signaling specificity. How does H2O2 react with some protein thiols and not others? More recently, it has been shown that Prxs may act as redox signaling intermediates rather than just peroxide quenchers, overcoming the kinetic and reaction specificity problems of the floodgate model.
PRDX6 alleviates lipopolysaccharide-induced inflammation and ferroptosis in periodontitis
Published in Acta Odontologica Scandinavica, 2022
Wen-Ying Yang, Xiang Meng, Yue-Rong Wang, Qing-Qing Wang, Xin He, Xiao-Yu Sun, Nan Cheng, Lei Zhang
PRDX6 contains single cysteine and mainly acts PL hydroperoxide GPx (PHGPx) activity, unlike other peroxiredoxins. It also has two additional catalytic sites, phospholipase A2 activity (PLA2) activity and LPC acyl transferase (LPCAT) activity [21,22]. Therefore, PRDX6 plays a paradoxical role in inflammatory and immune responses [23–25]. Furthermore, PRDX6 is regulated by the nuclear factor erythropoietin 2-related factor 2 (NRF2) transcription factor, a vital regulator of cellular oxidative stress [26,27]. The activated NRF2 can be transported to the nucleus and subsequently bind to antioxidant response element to improve the transcription of antioxidant genes [28,29]. The microarray results showed that PRDX6 was upregulated in periodontitis [30]. However, the detailed function of PRDX6 and NRF2 in LPS-induced periodontitis has not been explored intensively.
Confirmation of Xp22.11 Duplication as a Germline Susceptibility Alteration in a Wilms Tumor Arising in Horseshoe Kidney
Published in Fetal and Pediatric Pathology, 2022
Hui-fang Zhou, Ina E. Amarillo, Stacy Snyder, Jorge L. Granadillo, Christopher J. O’Conor, Patrick Dillon, David Wilson, Frederick S. Huang, Louis P. Dehner, Mai He
PRDX4, also known as PRX-4, encodes peroxiredoxin 4, an endoplasmic reticulum-resident antioxidant [8]. Peroxiredoxin 4 scavenges excess hydrogen peroxide to provide a favorable microenvironment for cell proliferation. If redox balance is disrupted, a cell might undergo an uncontrollable proliferation and eventually oncogenesis. PRDX4 has been implicated in oncogenesis in a wide variety of malignancies, including breast cancer, prostate cancer, ovarian cancer, colorectal cancer, lung cancer, glioma, hematologic malignancy, and oral cavity squamous cell carcinoma [8]. The peroxiredoxin 4 protein is present in many tissues including kidney but is enriched in liver and pancreas [9]. Overexpression of PRDX4 has been shown in oral cavity squamous cell carcinoma and it has been suggested that this overexpression can be used as both prognostic and therapeutic marker [10]. Although the mechanism is largely unknown, it has been proposed that the accumulation of PRDX4 protects tumor cells from the toxic damage of reactive oxygen species and affects drug metabolism [11].
Proteomic profiling of carbonic anhydrase CA3 in skeletal muscle
Published in Expert Review of Proteomics, 2021
Paul Dowling, Stephen Gargan, Margit Zweyer, Hemmen Sabir, Dieter Swandulla, Kay Ohlendieck
The expression of cytosolic CA3 increases especially in adult soleus muscle and its activity is crucial for maintaining the intracellular pH in skeletal muscle fibers and protect the voluntary contractile system from oxidative stress [4]. As reviewed by Monti et al. [81], muscle CA3 can act as an oxy-radical scavenger enzyme to prevent damage due to the high levels of oxidative burden in contractile fibers. Thus, cytosolic CAs, peroxiredoxins, and related proteins play important cytoprotective roles in the reduction of oxidative damage. The importance of the CA3 enzyme in slow contractile tissues was demonstrated by the fact that the lack of this enzyme in slow-twitching muscle tissue of CA3 knockout mice is linked to abnormal mitochondrial ATP synthesis [82]. In contrast, transgenic expression of CA3 in cardiomyocytes (that otherwise lack this isoform) were shown to better tolerate acidotic stress and exhibit an improved maintenance of intracellular pH homeostasis [83].