scholarly journals Aerobiosis is not associated with GC content and G to T mutations are not the signature of oxidative stress in prokaryotic evolution

2017 ◽  
Author(s):  
Sidra Aslam ◽  
Xin-Ran Lan ◽  
Bo-Wen Zhang ◽  
Zheng-Lin Chen ◽  
Deng-Ke Niu

AbstractBackground: Among the four bases, guanine is the most susceptible to damage from oxidative stress. Replication of DNA containing damaged guanines result in G to T mutations. Therefore, the mutations resulting from oxidative DNA damage are generally expected to predominantly consist of G to T (and C to A when the damaged guanine is not in the reference strand) and result in decreased GC content. However, the opposite pattern was reported 16 years ago in a study of prokaryotic genomes. Although that result has been widely cited and confirmed by nine later studies with similar methods, the omission of the effect of shared ancestry requires a re-examination of the reliability of the results.Results: We retrieved 70 aerobe-anaerobe pairs of prokaryotes, and members of each pair were adjacent on the phylogenetic tree. Pairwise comparisons of either whole-genome GC content or the GC content at 4-fold degenerate sites of orthologous genes among these 70 pairs did not show significant differences between aerobes and anaerobes. The signature of guanine oxidation on GC content evolution has not been detected even after extensive controlling of other influencing factors. Furthermore, the anaerobes were not different from the aerobes in the rate of either G to T, C to A, or other directions of substitutions. The presence of the enzymes responsible for guanine oxidation in anaerobic prokaryotes provided additional evidence that guanine oxidation might be prevalent in anaerobic prokaryotes. In either aerobes or anaerobes, the rates of G:C to T:A mutations were not significantly higher than the reverse mutations.Conclusions: The previous counterintuitive results on the relationship between oxygen requirement and GC content should be attributed to the methodological artefact resulting from phylogenetically non-independence among the analysed samples. Our results showed that aerobiosis does not increase or decrease GC content in evolution. Furthermore, our study challenged the widespread belief that abundant G:C to T:A transversions are the signature of oxidative stress in prokaryotic evolution.

Author(s):  
Su ◽  
Pan ◽  
Hsu ◽  
Lai

Oxidative stress plays a crucial role in the development of diseases induced by welding fumes. To our knowledge, little information is available on the relationship between multiple heavy metal exposure and oxidative stress in welders. We assessed the relationship between multiple heavy metal exposure and oxidative damage by analyzing 174 nonsmoking male welders in a shipyard. Urinary metals were used as the internal dose of exposure to metals in welding fumes, and urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG) was used as an oxidative DNA damage marker. The relationship between workers’ metal levels and 8-OHdG was estimated using a multiple linear regression model. The geometric mean levels of urinary chromium (Cr), nickel (Ni), cadmium (Cd), and lead (Pb) were considerably higher in welders than in controls. Urinary Cr and Ni were determined as effective predictors of urinary 8-OHdG levels after adjusting for covariates. Oxidative DNA damage was associated with both Cr and Ni of welding fume exposure in shipyard welders (Ln Cr: β = 0.33, 95%C.I. = 0.16–0.49; Ln Ni: β = 0.27, 95%C.I. = 0.12–0.43). In this study, we investigated the significantly positive relationship between urinary metals (especially Cr and Ni) and 8-OHdG in nonsmoking shipyard welders. Moreover, the use of particulate respirators did not reduce metal exposure and oxidative damage. Therefore, we infer that hazard identification for welders should be conducted.


2005 ◽  
Vol 25 (12) ◽  
pp. 5196-5204 ◽  
Author(s):  
Nicole A. Doudican ◽  
Binwei Song ◽  
Gerald S. Shadel ◽  
Paul W. Doetsch

ABSTRACT Mitochondria contain their own genome, the integrity of which is required for normal cellular energy metabolism. Reactive oxygen species (ROS) produced by normal mitochondrial respiration can damage cellular macromolecules, including mitochondrial DNA (mtDNA), and have been implicated in degenerative diseases, cancer, and aging. We developed strategies to elevate mitochondrial oxidative stress by exposure to antimycin and H2O2 or utilizing mutants lacking mitochondrial superoxide dismutase (sod2Δ). Experiments were conducted with strains compromised in mitochondrial base excision repair (ntg1Δ) and oxidative damage resistance (pif1Δ) in order to delineate the relationship between these pathways. We observed enhanced ROS production, resulting in a direct increase in oxidative mtDNA damage and mutagenesis. Repair-deficient mutants exposed to oxidative stress conditions exhibited profound genomic instability. Elimination of Ntg1p and Pif1p resulted in a synergistic corruption of respiratory competency upon exposure to antimycin and H2O2. Mitochondrial genomic integrity was substantially compromised in ntg1Δ pif1Δ sod2Δ strains, since these cells exhibit a total loss of mtDNA. A stable respiration-defective strain, possessing a normal complement of mtDNA damage resistance pathways, exhibited a complete loss of mtDNA upon exposure to antimycin and H2O2. This loss was preventable by Sod2p overexpression. These results provide direct evidence that oxidative mtDNA damage can be a major contributor to mitochondrial genomic instability and demonstrate cooperation of Ntg1p and Pif1p to resist the introduction of lesions into the mitochondrial genome.


2016 ◽  
pp. 45-49
Author(s):  
P.N. Veropotvelyan ◽  
◽  
I.S. Tsehmistrenko ◽  
N.P. Veropotvelyan ◽  
N.S. Rusak ◽  
...  

Was to conduct a systematic review of data on the relationship between polymorphisms genes of detoxification system and development of preeclampsia (РЕ). Рresents the main genes of detoxification system (GSTPI, GSTМI, GSTТI, GРХI, ЕРНХI, SOD-2, SOD-3, CYPIAL, MTHЕR, MTR) and their functions. Of interest is the possibility of calculating the individual risk of PE based on the results about the presence of a combination of different polymorphisms in the genotype of the female. Question about early diagnosis of РЕ remains controversial and not fully understood. It is necessary to conduct further in-depth, extended study of this problem. Key words: preeclampsia, oxidative stress, genes of the detoxification system.


Author(s):  
I. A. Umnyagina ◽  
L. A. Strakhova ◽  
T. V. Blinova

In the blood serum of 70% individuals exposed to harmful factors of the working environment, a high level of oxidative stress and the DNA damage marker 8-Hydroxy-2’-Deoxyguanosine (8-OHdG) were detected.


2019 ◽  
Vol 70 (8) ◽  
pp. 2822-2825 ◽  
Author(s):  
Cornel Moisa ◽  
Mihnea Alexandru Gaman ◽  
Camelia Cristina Diaconu ◽  
Amelia Maria Gaman

Essential thrombocythemia (ET) is a BCR-ABL1-negative myeloproliferative neoplasm associated with thrombotic and haemorrhagic complications. Reactive oxygen species (ROS) overexpression induces a growth advantage to JAK2V617F-positive clones and, in association with a higher number of immature platelets, leukocytosis, and additional cardiovascular risk factors, leads to an increased risk for thrombotic events. We evaluated oxidative stress by measuring ROS levels and the total antioxidant capacity (TAC) in 62 ET patients and investigated the relationship between oxidative stress, JAK2V617F mutational status and the development of thrombotic events. We found higher oxidative stress levels in JAK2V617F-positive vs. JAK2V617F-negative ET cases with no significant differences between homozygous and heterozygous genotypes. Increased ROS levels and thrombotic events were more frequent in ET patients with old age at diagnosis, higher haematocrit levels or leukocytosis.


2015 ◽  
Vol 23 (4) ◽  
pp. 397-406 ◽  
Author(s):  
Adriana Iliesiu ◽  
Alexandru Campeanu ◽  
Daciana Marta ◽  
Irina Parvu ◽  
Gabriela Gheorghe

Abstract Background. Oxidative stress (OS) and inflammation are major mechanisms involved in the progression of chronic heart failure (CHF). Serum uric acid (sUA) is related to CHF severity and could represent a marker of xanthine-oxidase activation. The relationship between sUA, oxidative stress (OS) and inflammation markers was assessed in patients with moderate-severe CHF and reduced left ventricular (LV) ejection fraction (EF). Methods. In 57 patients with stable CHF, functional NYHA class III, with EF<40%, the LV function was assessed by N-terminal of the prohormone brain natriuretic peptide (NT-proBNP) levels and echocardiographically through the EF and E/e’ ratio, a marker of LV filling pressures. The relationship between LV function, sUA, malondialdehyde (MDA), myeloperoxidase (MPO), paraoxonase 1 (PON-1) as OS markers and high sensitivity C-reactive protein (hsCRP) and interleukin 6 (IL-6) as markers of systemic inflammation was evaluated. Results. The mean sUA level was 7.9 ± 2.2 mg/dl, and 61% of the CHF patients had hyperuricemia. CHF patients with elevated LV filling pressures (E/e’ ≥ 13) had higher sUA (8.6 ± 2.3 vs. 7.3 ± 1.4, p=0.08) and NT-proBNP levels (643±430 vs. 2531±709, p=0.003) and lower EF (29.8 ± 3.9 % vs. 36.3 ± 4.4 %, p=0.001). There was a significant correlation between sUA and IL-6 (r = 0.56, p<0.001), MDA (r= 0.49, p= 0.001), MPO (r=0.34, p=0.001) and PON-1 levels (r= −0.39, p= 0.003). Conclusion. In CHF, hyperuricemia is associated with disease severity. High sUA levels in CHF with normal renal function may reflect increased xanthine-oxidase activity linked with chronic inflammatory response.


2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Simón Quetzalcoatl Rodríguez-Lara ◽  
Ernesto German Cardona-Muñoz ◽  
Ernesto Javier Ramírez-Lizardo ◽  
Sylvia Elena Totsuka-Sutto ◽  
Araceli Castillo-Romero ◽  
...  

Ischemia/reperfusion (I/R) lesions are a phenomenon that occurs in multiple pathological states and results in a series of events that end in irreparable damage that severely affects the recovery and health of patients. The principal therapeutic approaches include preconditioning, postconditioning, and remote ischemic preconditioning, which when used separately do not have a great impact on patient mortality or prognosis. Oxidative stress is known to contribute to the damage caused by I/R; however, there are no pharmacological approaches to limit or prevent this. Here, we explain the relationship between I/R and the oxidative stress process and describe some pharmacological options that may target oxidative stress-states.


2013 ◽  
Vol 47 (9) ◽  
pp. 1056-1060 ◽  
Author(s):  
V. V. Suslov ◽  
D. A. Afonnikov ◽  
N. L. Podkolodny ◽  
Yu. L. Orlov

2021 ◽  
pp. 12-17
Author(s):  
A. A. Hotko ◽  
N. S. Rudneva

The article is of an overview nature and contains up-to-date information on comorbid cardiovascular pathology in psoriasis. Various studies have shown that psoriasis is associated with a higher prevalence of CVD risk factors, including hypertension, diabetes mellitus, dyslipidemia, obesity, and metabolic syndrome. The relationship between the severity of psoriasis and the risk of cardiovascular disease, as well as the prognostic risks with mortality rates, are discussed. Proposed common pathogenetic mechanisms include genetic factors, inflammatory pathways, adipokine secretion, insulin resistance, lipoprotein composition and function, angiogenesis, oxidative stress, and hypercoagulability.


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