Small Stress Proteins: Modulation of Intracellular Redox State and Protection Against Oxidative Stress

Numerous strategies allowing bacteria to detect and respond to oxidative conditions depend on the cell redox state. Here we examined the ability of Lactococcus lactis to survive aerobically in the presence of the reducing agent dithiothreitol (DTT), which would be expected to modify the cell redox state and disable the oxidative stress response. DTT inhibited L. lactis growth at 37 °C in aerobic conditions, but not in anaerobiosis. Mutants selected as DTT resistant all mapped to the pstFEDCBA locus, encoding a high-affinity phosphate transporter. Transcription of pstFEDCBA and a downstream putative regulator of stress response, phoU, was deregulated in a pstA strain, but amounts of major oxidative stress proteins were unchanged. As metals participate in oxygen radical formation, we compared metal sensitivity of wild-type and pstA strains. The pstA mutant showed approximately 100-fold increased resistance to copper and zinc. Furthermore, copper or zinc addition exacerbated the sensitivity of a wild-type L. lactis strain to DTT. Inactivation of pstA conferred a more general resistance to oxidative stress, alleviating the oxygen- and thermo-sensitivity of a clpP mutant. This study establishes a role for the pst locus in metal homeostasis, suggesting that pst inactivation lowers intracellular reactivity of copper and zinc, which would limit bacterial sensitivity to oxygen.

Download Full-text

Faculty Opinions recommendation of Bacterial community morphogenesis is intimately linked to the intracellular redox state.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718352816.793493886 ◽

2014 ◽

Author(s):

Matthew Parsek

Keyword(s):

Bacterial Community ◽

Redox State ◽

Intracellular Redox

Download Full-text

Imaging NAD(H) Redox Alterations in Cryopreserved Alveolar Macrophages from Ozone-Exposed Mice and the Impact of Nutrient Starvation during Long Lag Times

Antioxidants ◽

10.3390/antiox10050767 ◽

2021 ◽

Vol 10 (5) ◽

pp. 767

Author(s):

He N. Xu ◽

Joanna Floros ◽

Lin Z. Li ◽

Shaili Amatya

Keyword(s):

Oxidative Stress ◽

Alveolar Macrophages ◽

Redox State ◽

Redox Status ◽

Nutrient Starvation ◽

Ozone Exposure ◽

Reduced Form ◽

Time Period ◽

Lag Times ◽

The Impact

Employing the optical redox imaging technique, we previously identified a significant redox shift of nicotinamide adenine dinucleotide (NAD and the reduced form NADH) in freshly isolated alveolar macrophages (AM) from ozone-exposed mice. The goal here was twofold: (a) to determine the NAD(H) redox shift in cryopreserved AM isolated from ozone-exposed mice and (b) to investigate whether there is a difference in the redox status between cryopreserved and freshly isolated AM. We found: (i) AM from ozone-exposed mice were in a more oxidized redox state compared to that from filtered air (FA)-exposed mice, consistent with the results obtained from freshly isolated mouse AM; (ii) under FA exposure, there was no significant NAD(H) redox difference between fresh AM that had been placed on ice for 2.5 h and cryopreserved AM; however, under ozone exposure, fresh AM were more oxidized than cryopreserved AM; (iii) via the use of nutrient starvation and replenishment and H2O2-induced oxidative stress of an AM cell line, we showed that this redox difference between cryopreserved and freshly isolated AM is likely the result of the double “hit”, i.e., the ozone-induced oxidative stress plus nutrient starvation that prevented freshly isolated AM from a full recovery after being on ice for a prolonged time period. The cryopreservation technique we developed eliminates/minimizes the effects of oxidative stress and nutrient starvation on cells. This method can be adopted to preserve lung macrophages from animal models or clinical patients for further investigations.

Download Full-text

Serum Albumin Redox States: More than Oxidative Stress Biomarker

Antioxidants ◽

10.3390/antiox10040503 ◽

2021 ◽

Vol 10 (4) ◽

pp. 503

Author(s):

Fuka Tabata ◽

Yasuaki Wada ◽

Satomi Kawakami ◽

Kazuhiro Miyaji

Keyword(s):

Oxidative Stress ◽

Serum Albumin ◽

Animal Studies ◽

Redox State ◽

Ex Vivo ◽

Pathological Condition ◽

Analytical Techniques ◽

Cysteine Residue ◽

Research Field ◽

Systemic Oxidative Stress

Serum albumin is the most abundant circulating protein in mammals including humans. It has three isoforms according to the redox state of the free cysteine residue at position 34, named as mercaptalbumin (reduced albumin), non-mercaptalbumin-1 and -2 (oxidized albumin), respectively. The serum albumin redox state has long been viewed as a biomarker of systemic oxidative stress, as the redox state shifts to a more oxidized state in response to the severity of the pathological condition in various diseases such as liver diseases and renal failures. However, recent ex vivo studies revealed oxidized albumin per se could aggravate the pathological conditions. Furthermore, the possibility of the serum albumin redox state as a sensitive protein nutrition biomarker has also been demonstrated in a series of animal studies. A paradigm shift is thus ongoing in the research field of the serum albumin. This article provides an updated overview of analytical techniques for serum albumin redox state and its association with human health, focusing on recent findings.

Download Full-text

A manganese oxide nanozyme prevents the oxidative damage of biomolecules without affecting the endogenous antioxidant system

Nanoscale ◽

10.1039/c8nr09397k ◽

2019 ◽

Vol 11 (9) ◽

pp. 3855-3863 ◽

Cited By ~ 22

Author(s):

Namrata Singh ◽

Mohammed Azharuddin Savanur ◽

Shubhi Srivastava ◽

Patrick D'Silva ◽

Govindasamy Mugesh

Keyword(s):

Oxidative Stress ◽

Oxidative Damage ◽

Manganese Oxide ◽

Antioxidant System ◽

Mammalian Cells ◽

Redox State ◽

Stress Conditions ◽

System P ◽

Endogenous Antioxidant ◽

Antioxidant Machinery

Multi-enzyme mimetic Mn3O4 nanoflowers (Mp) modulate the redox state of mammalian cells without altering the cellular antioxidant machinery under oxidative stress conditions.

Download Full-text

MP66-05 OXIDATIVE STRESS PROTEINS IDENTIFIED IN HUMAN SPERMATOZOA BY PROTEOMIC AND BIOINFORMATIC ANALYSIS

The Journal of Urology ◽

10.1016/j.juro.2014.02.2052 ◽

2014 ◽

Vol 191 (4S) ◽

Author(s):

Rakesh Sharma ◽

Ashok Agarwal ◽

Damayanthi Durairajanayagam ◽

Zhihong Cui ◽

Ahmet Ayaz ◽

...

Keyword(s):

Oxidative Stress ◽

Stress Proteins ◽

Bioinformatic Analysis ◽

Human Spermatozoa

Download Full-text

Reactive Oxygen Species-Mediated Control of Mitochondrial Biogenesis

International Journal of Cell Biology ◽

10.1155/2012/403870 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 36

Author(s):

Edgar D. Yoboue ◽

Anne Devin

Keyword(s):

Oxidative Stress ◽

Mitochondrial Biogenesis ◽

Redox State ◽

Mitochondrial Genomes ◽

Oxygen Species ◽

Mitochondrial Content ◽

Cellular Redox ◽

High Importance ◽

Complex Process ◽

Long Time

Mitochondrial biogenesis is a complex process. It necessitates the contribution of both the nuclear and the mitochondrial genomes and therefore crosstalk between the nucleus and mitochondria. It is now well established that cellular mitochondrial content can vary according to a number of stimuli and physiological states in eukaryotes. The knowledge of the actors and signals regulating the mitochondrial biogenesis is thus of high importance. The cellular redox state has been considered for a long time as a key element in the regulation of various processes. In this paper, we report the involvement of the oxidative stress in the regulation of some actors of mitochondrial biogenesis.

Download Full-text