scholarly journals The Acclimation Mechanisms of Chlamydomonas reinhardtii against Nitrosative Stress: A Role of NADPH Oxidase (RBOL2) in the Regulation of Nitric Oxide-Mediated ER Stress and Glutathione Redox State

2020 ◽  
Author(s):  
Tse-Min Lee ◽  
Eva YuHua Kuo ◽  
Wen-Chyi Dai ◽  
Mu-Ting Lee ◽  
Zheng Yu Yun
2021 ◽  
Vol 22 (12) ◽  
pp. 6183
Author(s):  
Delia Acevedo-León ◽  
Lidia Monzó-Beltrán ◽  
Segundo Ángel Gómez-Abril ◽  
Nuria Estañ-Capell ◽  
Natalia Camarasa-Lillo ◽  
...  

The role of oxidative stress (OS) in cancer is a matter of great interest due to the implication of reactive oxygen species (ROS) and their oxidation products in the initiation of tumorigenesis, its progression, and metastatic dissemination. Great efforts have been made to identify the mechanisms of ROS-induced carcinogenesis; however, the validation of OS byproducts as potential tumor markers (TMs) remains to be established. This interventional study included a total of 80 colorectal cancer (CRC) patients and 60 controls. By measuring reduced glutathione (GSH), its oxidized form (GSSG), and the glutathione redox state in terms of the GSSG/GSH ratio in the serum of CRC patients, we identified significant changes as compared to healthy subjects. These findings are compatible with the effectiveness of glutathione as a TM. The thiol redox state showed a significant increase towards oxidation in the CRC group and correlated significantly with both the tumor state and the clinical evolution. The sensitivity and specificity of serum glutathione levels are far above those of the classical TMs CEA and CA19.9. We conclude that the GSSG/GSH ratio is a simple assay which could be validated as a novel clinical TM for the diagnosis and monitoring of CRC.


2003 ◽  
Vol 285 (6) ◽  
pp. H2364-H2372 ◽  
Author(s):  
Valentina Grishko ◽  
Viktor Pastukh ◽  
Viktoriya Solodushko ◽  
Mark Gillespie ◽  
Junichi Azuma ◽  
...  

Angiotensin II contributes to ventricular remodeling by promoting both cardiac hypertrophy and apoptosis; however, the mechanism underlying the latter phenomenon is poorly understood. One possibility that has been advanced is that angiotensin II activates NADPH oxidase, generating free radicals that trigger apoptosis. In apparent support of this notion, it was found that angiotensin II-mediated apoptosis in the cardiomyocyte is blocked by the NADPH oxidase inhibitor diphenylene iodonium. However, three lines of evidence suggest that peroxynitrite, rather than superoxide, is responsible for angiotensin II-mediated DNA damage and apoptosis. First, the inducible nitric oxide inhibitor aminoguanidine prevents angiotensin II-induced DNA damage and apoptosis. Second, based on ligation-mediated PCR, the pattern of angiotensin II-induced DNA damage resembles peroxynitritemediated damage rather than damage caused by either superoxide or nitric oxide. Third, angiotensin II activates p53 through the phosphorylation of Ser15 and Ser20, residues that are commonly phosphorylated in response to DNA damage. It is proposed that angiotensin II promotes the oxidation of DNA, which in turn activates p53 to mediate apoptosis.


2012 ◽  
Vol 302 (6) ◽  
pp. R674-R681 ◽  
Author(s):  
An Huang ◽  
Yang-Ming Yang ◽  
Attila Feher ◽  
Zsolt Bagi ◽  
Gabor Kaley ◽  
...  

To test the deterioration of endothelial function during the progression of diabetes, shear stress-induced dilation (SSID; 10, 20, and 40 dyn/cm2) was determined in isolated mesenteric arteries (80–120 μm in diameter) of 6-wk (6W), 3-mo (3M), and 9-mo (9M)-old male db/db mice and their wild-type (WT) controls. Nitric oxide (NO)-mediated SSID was comparable in 6W WT and db/db mice, but the dilation was significantly reduced in 3M db/db mice and declined further in 9M db/db mice. Vascular superoxide production was progressively increased in 3M and 9M db/db mice, associated with an increased expression of NADPH oxidase. Inhibition of NADPH oxidase significantly improved NO-mediated SSID in arteries of 3M, but not in 9M, db/db mice. Although endothelial nitric oxide synthase (eNOS) expression was comparable in all groups, a progressive reduction in shear stress-induced eNOS phosphorylation existed in vessels of 3M and 9M db/db mice. Moreover, inducible NOS (iNOS) that was not detected in WT, nor in 6W and 3M db/db mice, was expressed in vessels of 9M db/db mice. A significantly increased expression of nitrotyrosine in total protein and immunoprecipitated eNOS was also found in vessels of 9M db/db mice. Thus, impaired NO bioavailability plays an essential role in the endothelial dysfunction of diabetic mice, which becomes aggravated when endothelial nitrosative stress is further activated via perhaps, an additional iNOS-mediated pathway during the progression of diabetes.


Author(s):  
Constancio Gonzalez ◽  
Gloria Sanz-Alfayate ◽  
Ana Obeso ◽  
Maria Teresa Agapito

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Rhanany Alan Calloi Palozi ◽  
Maysa Isernhagen Schaedler ◽  
Cleide Adriane Signor Tirloni ◽  
Aniely Oliveira Silva ◽  
Francislaine Aparecida dos Reis Lívero ◽  
...  

Although Acanthospermum hispidum is used in Brazilian folk medicine as an antihypertensive, no study evaluated its effects on a renovascular hypertension and ovariectomy model. So, this study investigated the mechanisms involved in the antihypertensive effects of an ethanol-soluble fraction obtained from A. hispidum (ESAH) using two-kidney-one-clip hypertension in ovariectomized rats (2K1C plus OVT). ESAH was orally administered at doses of 30, 100, and 300 mg/kg, daily, for 28 days, after 5 weeks of surgery. Enalapril (15 mg/kg) and hydrochlorothiazide (25 mg/kg) were used as standard drugs. Diuretic activity was evaluated on days 1, 7, 14, 21, and 28. Systolic, diastolic, and mean blood pressure and heart rate were recorded. Serum creatinine, urea, thiobarbituric acid reactive substances, nitrosamine, nitrite, aldosterone, vasopressin levels, and ACE activity were measured. The vascular reactivity and the role of nitric oxide (NO) and prostaglandins (PG) in the vasodilator response of ESAH on the mesenteric vascular bed (MVB) were also investigated. ESAH treatment induced an important saluretic and antihypertensive response, therefore recovering vascular reactivity in 2K1C plus OVT-rats. This effect was associated with a reduction of oxidative and nitrosative stress with a possible increase in the NO bioavailability. Additionally, a NO and PG-dependent vasodilator effect was observed on the MEV.


2019 ◽  
Vol 77 (15) ◽  
pp. 3059-3075 ◽  
Author(s):  
Aneta Manda-Handzlik ◽  
Weronika Bystrzycka ◽  
Adrianna Cieloch ◽  
Eliza Glodkowska-Mrowka ◽  
Ewa Jankowska-Steifer ◽  
...  

Abstract Despite great interest, the mechanism of neutrophil extracellular traps (NETs) release is not fully understood and some aspects of this process, e.g. the role of reactive nitrogen species (RNS), still remain unclear. Therefore, our aim was to investigate the mechanisms underlying RNS-induced formation of NETs and contribution of RNS to NETs release triggered by various physiological and synthetic stimuli. The involvement of RNS in NETs formation was studied in primary human neutrophils and differentiated human promyelocytic leukemia cells (HL-60 cells). RNS (peroxynitrite and nitric oxide) efficiently induced NETs release and potentiated NETs-inducing properties of platelet activating factor and lipopolysaccharide. RNS-induced NETs formation was independent of autophagy and histone citrullination, but dependent on the activity of phosphoinositide 3-kinases (PI3K) and myeloperoxidase, as well as selective degradation of histones H2A and H2B by neutrophil elastase. Additionally, NADPH oxidase activity was required to release NETs upon stimulation with NO, as shown in NADPH-deficient neutrophils isolated from patients with chronic granulomatous disease. The role of RNS was further supported by increased RNS synthesis upon stimulation of NETs release with phorbol 12-myristate 13-acetate and calcium ionophore A23187. Scavenging or inhibition of RNS formation diminished NETs release triggered by these stimuli while scavenging of peroxynitrite inhibited NO-induced NETs formation. Our data suggest that RNS may act as mediators and inducers of NETs release. These processes are PI3K-dependent and ROS-dependent. Since inflammatory reactions are often accompanied by nitrosative stress and NETs formation, our studies shed a new light on possible mechanisms engaged in various immune-mediated conditions.


2021 ◽  
Vol 6 (3) ◽  
pp. 322-326
Author(s):  
Dipak Kumar Dhar

Dementia broadly refers to a global decline in cognitive and higher functions of the brain. With the gradually increasing number of aging population, the incidence of dementia has been steadily rising and expected to increase further in the coming years. The causes and forms of dementia are wide-ranging and diverse, with Alzheimer’s disease being its best studied form. With increasing knowledge about various effects and mechanisms of nitric oxide, this chemical neurotransmitter appears to be the connecting link in the cellular pathogenesis of dementia. An exhaustive search of research articles, commentaries and books published from 1990s onwards was performed with various words and combinations linked to dementia and nitric oxide. The existing medical literature shows both neuroprotective and neurotoxic effects of nitric oxide. The present article intends to delve into this topic and provide a lucid understanding of the role of nitric oxide in dementia. Keywords: Dementia, Nitric Oxide, Alzheimer’s disease, excitotoxicity, nitrosative stress.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1231 ◽  
Author(s):  
Kinga Rusinek ◽  
Przemysław Sołek ◽  
Anna Tabęcka-Łonczyńska ◽  
Marek Koziorowski ◽  
Jennifer Mytych

Neuroinflammation is defined as the activation of the brain’s innate immune system in response to an inflammatory challenge and is considered to be a prominent feature of neurodegenerative diseases. The contribution of overactivated neuroglial cells to neuroinflammation and neurodegenerative disorders is well documented, however, the role of hippocampal neurons in the neuroinflammatory process remains fragmentary. In this study, we show for the first time, that klotho acts as a signal transducer between pro-survival and pro-apoptotic crosstalk mediated by ER stress in HT-22 hippocampal neuronal cells during LPS challenge. In control HT-22 cells, LPS treatment results in activation of the IRE1α-p38 MAPK pathway leading to increased secretion of anti-inflammatory IL-10, and thus, providing adaptation mechanism. On the other hand, in klotho-deficient HT-22 cells, LPS induces oxi-nitrosative stress and genomic instability associated with telomere dysfunctions leading to p53/p21-mediated cell cycle arrest and, in consequence, to ER stress, inflammation as well as of apoptotic cell death. Therefore, these results indicate that klotho serves as a part of the cellular defense mechanism engaged in the protection of neuronal cells against LPS-mediated neuroinflammation, emerging issues linked with neurodegenerative disorders.


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