scholarly journals Critical Role of Zinc as Either an Antioxidant or a Prooxidant in Cellular Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Sung Ryul Lee

Zinc is recognized as an essential trace metal required for human health; its deficiency is strongly associated with neuronal and immune system defects. Although zinc is a redox-inert metal, it functions as an antioxidant through the catalytic action of copper/zinc-superoxide dismutase, stabilization of membrane structure, protection of the protein sulfhydryl groups, and upregulation of the expression of metallothionein, which possesses a metal-binding capacity and also exhibits antioxidant functions. In addition, zinc suppresses anti-inflammatory responses that would otherwise augment oxidative stress. The actions of zinc are not straightforward owing to its numerous roles in biological systems. It has been shown that zinc deficiency and zinc excess cause cellular oxidative stress. To gain insights into the dual action of zinc, as either an antioxidant or a prooxidant, and the conditions under which each role is performed, the oxidative stresses that occur in zinc deficiency and zinc overload in conjunction with the intracellular regulation of free zinc are summarized. Additionally, the regulatory role of zinc in mitochondrial homeostasis and its impact on oxidative stress are briefly addressed.

2021 ◽  
Vol 12 ◽  
Author(s):  
Amy V. Thees ◽  
Kathryn M. Pietrosimone ◽  
Clare K. Melchiorre ◽  
Jeremiah N. Marden ◽  
Joerg Graf ◽  
...  

The opportunistic pathogen Pseudomonas aeruginosa expresses a small molecular weight, cysteine-rich protein (PmtA), identified as a metallothionein (MT) protein family member. The MT family proteins have been well-characterized in eukaryotes as essential for zinc and copper homeostasis, protection against oxidative stress, and the ability to modify a variety of immune activities. Bacterial MTs share sequence homology, antioxidant chemistry, and heavy metal-binding capacity with eukaryotic MTs, however, the impact of bacterial MTs on virulence and infection have not been well-studied. In the present study, we investigated the role of PmtA in P. aeruginosa PAO1 using a PmtA-deficient strain (ΔpmtA). Here we demonstrated the virulence factor, pyocyanin, relies on the expression of PmtA. We showed that PmtA may be protective against oxidative stress, as an alternative antioxidant, glutathione, can rescue pyocyanin expression. Furthermore, the expression of phzM, which encodes a pyocyanin precursor enzyme, was decreased in the ΔpmtA mutant during early stationary phase. Upregulated pmtA expression was previously detected in confluent biofilms, which are essential for chronic infection, and we observed that the ΔpmtA mutant was disrupted for biofilm formation. As biofilms also modulate antibiotic susceptibility, we examined the ΔpmtA mutant susceptibility to antibiotics and found that the ΔpmtA mutant is more susceptible to cefepime and ciprofloxacin than the wild-type strain. Finally, we observed that the deletion of pmtA results in decreased virulence in a waxworm model. Taken together, our results support the conclusion that PmtA is necessary for the full virulence of P. aeruginosa and may represent a potential target for therapeutic intervention.


2019 ◽  
Vol 24 (6) ◽  
pp. 509-520 ◽  
Author(s):  
Eduardo Fuentes ◽  
Rodrigo Moore-Carrasco ◽  
Antonio Marcus de Andrade Paes ◽  
Andres Trostchansky

Myocardial infarction, commonly known as heart attack, evolves from the rupture of unstable atherosclerotic plaques to coronary thrombosis and myocardial ischemia–reperfusion injury. A body of evidence supports a close relationship between the alterations following an ischemia–reperfusion injury-induced oxidative stress and platelet activity. Through their critical role in thrombogenesis and inflammatory responses, platelets are fully (totally) implicated from atherothrombotic plaque formation to myocardial infarction onset and expansion. However, mere platelet aggregation prevention does not offer full protection, suggesting that other antiplatelet therapy mechanisms may also be involved. Thus, the present review discusses the integrative role of platelets, oxidative stress, and antiplatelet therapy in triggering myocardial infarction pathophysiology.


2020 ◽  
Vol 17 (4) ◽  
pp. 394-401
Author(s):  
Yuanhua Wu ◽  
Yuan Huang ◽  
Jing Cai ◽  
Donglan Zhang ◽  
Shixi Liu ◽  
...  

Background: Ischemia/reperfusion (I/R) injury involves complex biological processes and molecular mechanisms such as autophagy. Oxidative stress plays a critical role in the pathogenesis of I/R injury. LncRNAs are the regulatory factor of cerebral I/R injury. Methods: This study constructs cerebral I/R model to investigate role of autophagy and oxidative stress in cerebral I/R injury and the underline regulatory mechanism of SIRT1/ FOXO3a pathway. In this study, lncRNA SNHG12 and FOXO3a expression was up-regulated and SIRT1 expression was down-regulated in HT22 cells of I/R model. Results: Overexpression of lncRNA SNHG12 significantly increased the cell viability and inhibited cerebral ischemicreperfusion injury induced by I/Rthrough inhibition of autophagy. In addition, the transfected p-SIRT1 significantly suppressed the release of LDH and SOD compared with cells co-transfected with SIRT1 and FOXO3a group and cells induced by I/R and transfected with p-SNHG12 group and overexpression of cells co-transfected with SIRT1 and FOXO3 further decreased the I/R induced release of ROS and MDA. Conclusion: In conclusion, lncRNA SNHG12 increased cell activity and inhibited oxidative stress through inhibition of SIRT1/FOXO3a signaling-mediated autophagy in HT22 cells of I/R model. This study might provide new potential therapeutic targets for further investigating the mechanisms in cerebral I/R injury and provide.


Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 45
Author(s):  
Helena Beatriz Ferreira ◽  
Tânia Melo ◽  
Artur Paiva ◽  
Maria do Rosário Domingues

Rheumatoid arthritis (RA) is a highly debilitating chronic inflammatory autoimmune disease most prevalent in women. The true etiology of this disease is complex, multifactorial, and is yet to be completely elucidated. However, oxidative stress and lipid peroxidation are associated with the development and pathogenesis of RA. In this case, oxidative damage biomarkers have been found to be significantly higher in RA patients, associated with the oxidation of biomolecules and the stimulation of inflammatory responses. Lipid peroxidation is one of the major consequences of oxidative stress, with the formation of deleterious lipid hydroperoxides and electrophilic reactive lipid species. Additionally, changes in the lipoprotein profile seem to be common in RA, contributing to cardiovascular diseases and a chronic inflammatory environment. Nevertheless, changes in the lipid profile at a molecular level in RA are still poorly understood. Therefore, the goal of this review was to gather all the information regarding lipid alterations in RA analyzed by mass spectrometry. Studies on the variation of lipid profile in RA using lipidomics showed that fatty acid and phospholipid metabolisms, especially in phosphatidylcholine and phosphatidylethanolamine, are affected in this disease. These promising results could lead to the discovery of new diagnostic lipid biomarkers for early diagnosis of RA and targets for personalized medicine.


2021 ◽  
Vol 22 (9) ◽  
pp. 4370
Author(s):  
Cássia de Fáveri ◽  
Paula M. Poeta Fermino ◽  
Anna P. Piovezan ◽  
Lia K. Volpato

The pathogenesis of endometriosis is still controversial, although it is known that the inflammatory immune response plays a critical role in this process. The resolution of inflammation is an active process where the activation of endogenous factors allows the host tissue to maintain homeostasis. The mechanisms by which pro-resolving mediators (PRM) act in endometriosis are still little explored. Thus, this integrative review aims to synthesize the available content regarding the role of PRM in endometriosis. Experimental and in vitro studies with Lipoxin A4 demonstrate a potential inhibitory effect on endometrial lesions’ progression, attenuating pro-inflammatory and angiogenic signals, inhibiting proliferative and invasive action suppressing intracellular signaling induced by cytokines and estradiol, mainly through the FPR2/ALX. Investigations with Resolvin D1 demonstrated the inhibition of endometrial lesions and decreased pro-inflammatory factors. Annexin A1 is expressed in the endometrium and is specifically present in women with endometriosis, although the available studies are still inconsistent. Thus, we believe there is a gap in knowledge regarding the PRM pathways in patients with endometriosis. It is important to note that these substances’ therapeutic potential is evident since the immune and abnormal inflammatory responses play an essential role in endometriosis development and progression.


2020 ◽  
Vol 66 (1) ◽  
pp. 47-55
Author(s):  
Era B. Popyhova ◽  
Tatiana V. Stepanova ◽  
Dar’ya D. Lagutina ◽  
Tatiana S. Kiriiazi ◽  
Alexey N. Ivanov

The vascular endothelium performs many functions. It is a key regulator of vascular homeostasis, maintains a balance between vasodilation and vasoconstriction, inhibition and stimulation of smooth muscle cell migration and proliferation, fibrinolysis and thrombosis, and is involved to regulation of platelet adhesion and aggregation. Endothelial dysfunction (ED) plays the critical role in pathogenesis of diabetes mellitus (DM) vascular complications. The purpose of this review was to consider the mechanisms leading to the occurrence of ED in DM. The paper discusses current literature data concerning the role of hyperglycemia, oxidative stress, advanced glycation end products in endothelial alteration. A separate section is devoted to the particularities of the functioning of the antioxidant system and their significance in the development of ED in DM. The analysis of the literature allows to conclude that pathological activation of glucose utilization pathways causes damage of endothelial cells, which is accompanied by disorders of all their basic functions. Metabolic disorders in DM cause a pronounced imbalance of free radical processes and antioxidant defense, accompanied by oxidative stress of endotheliocytes, which contributes to the progression of ED and the development of vascular complications. Many aspects of multicomponent regulatory reactions in the pathogenesis of the development of ED in DM have not been sufficiently studied.


2020 ◽  
Vol 11 (1) ◽  
pp. e9-e9
Author(s):  
Zahra Lotfi ◽  
Abbas Ali Zeraati ◽  
Elaheh Dashti ◽  
Tina Zeraati ◽  
Maryam Arghiany ◽  
...  

Introduction: Systemic bacterial infections are a common cause of mortality and morbidity in hemodialysis patients. Zinc has a critical role in several immune system functions. Patients who have enough amounts of zinc are able to better face infections caused by various pathogens in comparison to those with zinc insufficiency Objective We sought to assess the role of zinc deficiency in dialysis-associated bacterial infections. Patients and Methods: Eighty-Three adult patients with end-stage renal disease (ESRD) on hemodialysis including 43 patients with bacterial infectious complications and 40 non-infected patients as well as 41 healthy individuals were enrolled. Clinical data, laboratory values including serum zinc level and imaging findings were collected. SPSS was utilized to analyze the data with a significance cutoff set at P < 0.05. Results: Out of 124 participants, 80 (64.51%) were males and 44 (35.49%) were females. The mean age of infected hemodialysis group, non-infected hemodialysis group, and healthy controls were 50.8 ± 16.25, 49.1 ± 18.1, and 56.3 ± 18.2 years, respectively. Catheter site infection (37.3%) and urinary tract infection (30.2%) were the most common infections. The mean serum zinc concentration was significantly lower in the infected patients, compared to non-infected patients and healthy individuals (P < 0.001). Conclusion: The ESRD patients on hemodialysis have lower serum zinc levels which are associated with increased risk of bacterial infection. The role of screening for zinc deficiency and use of supplemental zinc in these patients need to be studied.


2020 ◽  
Vol 21 (7) ◽  
pp. 2440 ◽  
Author(s):  
Alexandre Vallée ◽  
Yves Lecarpentier

Endometriosis is one of the main common gynecological disorders, which is characterized by the presence of glands and stroma outside the uterine cavity. Some findings have highlighted the main role of inflammation in endometriosis by acting on proliferation, apoptosis and angiogenesis. Oxidative stress, an imbalance between reactive oxygen species and antioxidants, could have a key role in the initiation and progression of endometriosis by resulting in inflammatory responses in the peritoneal cavity. Nevertheless, the mechanisms underlying this disease are still unclear and therapies are not currently efficient. Curcumin is a major anti-inflammatory agent. Several findings have highlighted the anti-oxidant, anti-inflammatory and anti-angiogenic properties of curcumin. The purpose of this review is to summarize the potential action of curcumin in endometriosis by acting on inflammation, oxidative stress, invasion and adhesion, apoptosis and angiogenesis.


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