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Reactive Oxygen Species

Posted: Wed Sep 11, 2019 10:55 am
by Petr75
2019 Jun 30
Department of Pathology, University of Veterinary Medicine Hannover, Germany
Reactive Oxygen Species Are Key Mediators of Demyelination in Canine Distemper Leukoencephalitis but not in Theiler's Murine Encephalomyelitis.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6651464/

Abstract
Background: Canine distemper virus (CDV)-induced demyelinating leukoencephalitis (CDV-DL) in dogs and Theiler's murine encephalomyelitis (TME) virus (TMEV)-induced demyelinating leukomyelitis (TMEV-DL) are virus-induced demyelinating conditions mimicking Multiple Sclerosis (MS). Reactive oxygen species (ROS) can induce the degradation of lipids and nucleic acids to characteristic metabolites such as oxidized lipids, malondialdehyde, and 8-hydroxyguanosine. The hypothesis of this study is that ROS are key effector molecules in the pathogenesis of myelin membrane breakdown in CDV-DL and TMEV-DL. (2) Methods: ROS metabolites and antioxidative enzymes were assessed using immunofluorescence in cerebellar lesions of naturally CDV-infected dogs and spinal cord tissue of TMEV-infected mice. The transcription of selected genes involved in ROS generation and detoxification was analyzed using gene-expression microarrays in CDV-DL and TMEV-DL. (3) Results: Immunofluorescence revealed increased amounts of oxidized lipids, malondialdehyde, and 8-hydroxyguanosine in CDV-DL while TMEV-infected mice did not reveal marked changes. In contrast, microarray-analysis showed an upregulated gene expression associated with ROS generation in both diseases. (4) Conclusion: In summary, the present study demonstrates a similar upregulation of gene-expression of ROS generation in CDV-DL and TMEV-DL. However, immunofluorescence revealed increased accumulation of ROS metabolites exclusively in CDV-DL. These results suggest differences in the pathogenesis of demyelination in these two animal models.

Re: Reactive Oxygen Species

Posted: Sun Feb 09, 2020 2:50 am
by Petr75
2020 Feb 7
University of Hong Kong, Oral and Maxilofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, University of Hong Kong, China
Reactive Oxygen Species (ROS) and Their Impact in Neurodegenerative Diseases: Literature Landscape Analysis
https://pubmed.ncbi.nlm.nih.gov/3203099 ... -analysis/


Abstract

Significance: Excessive production of reactive oxygen species (ROS) has been linked to neurodegenerative diseases (NDs), and therefore, many scientific works were published on the impact of ROS on the development of prevalent NDs, such as Alzheimer's (AD) and Parkinson's disease (PD). Since quantitative and qualitative bibliometric analyses on this research area has not been done yet, the aim of the current work is to explore the scientific literature implying ROS in NDs and to identify the major contributors, mainstream research themes, and topics on the rise. Recent Advances: Overall, 22,885 publications were identified and analysed within the Web of Science (WoS) Core Collection electronic database. Most of the manuscripts were published in the 21st century. The publications were mainly related to the WoS categories Neurosciences and Biochemistry molecular biology. The United States is the major contributor, harbouring the most productive authors and institutions. China, South Korea, and India have emerged as upcoming major contributors in the 2010s.
Critical issues: AD, PD, and amyotrophic lateral sclerosis (ALS) were much more investigated than multiple sclerosis (MS) and Huntington's disease (HD). Vitamin E and curcumin were frequently mentioned as potential antioxidant therapeutics, but their efficacy in treating NDs requires more clinical studies, since the existing evidences were mainly from in vitro experiments and in vivo animal studies.
Future directions: Mitochondrial dysfunction, autophagy, and nuclear factor erythroid 2-related factor 2 were among the author keywords with rising prevalence. Further research in these directions should advance our understanding of the mechanism and treatment of NDs.

Re: Reactive Oxygen Species

Posted: Wed Jul 29, 2020 11:27 am
by Petr75
2020 Jul 3
School of Life Sciences, BK21 plus KNU Creative BioResearch Group, Kyungpook National University, Korea
Control of Reactive Oxygen Species for the Prevention of Parkinson's Disease: The Possible Application of Flavonoids
https://pubmed.ncbi.nlm.nih.gov/32635299/

Abstract

Oxidative stress reflects an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense systems, and it can be associated with the pathogenesis and progression of neurodegenerative diseases such as multiple sclerosis, stroke, and Parkinson's disease (PD). The application of antioxidants, which can defend against oxidative stress, is able to detoxify the reactive intermediates and prevent neurodegeneration resulting from excessive ROS production. There are many reports showing that numerous flavonoids, a large group of natural phenolic compounds, can act as antioxidants and the application of flavonoids has beneficial effects in the adult brain. For instance, it is well known that the long-term consumption of the green tea-derived flavonoids catechin and epigallocatechin gallate (EGCG) can attenuate the onset of PD. Also, flavonoids such as ampelopsin and pinocembrin can inhibit mitochondrial dysfunction and neuronal death through the regulation of gene expression of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Additionally, it is well established that many flavonoids exhibit anti-apoptosis and anti-inflammatory effects through cellular signaling pathways, such as those involving (ERK), glycogen synthase kinase-3β (GSK-3β), and (Akt), resulting in neuroprotection. In this review article, we have described the oxidative stress involved in PD and explained the therapeutic potential of flavonoids to protect the nigrostriatal DA system, which may be useful to prevent PD.

Re: Reactive Oxygen Species

Posted: Sun Sep 06, 2020 10:47 am
by Petr75
2020 Jun 25
Immunology Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
The Influence of Reactive Oxygen Species in the Immune System and Pathogenesis of Multiple Sclerosis
https://pubmed.ncbi.nlm.nih.gov/32789026/


Abstract

Multiple roles have been indicated for reactive oxygen species (ROS) in the immune system in recent years. ROS have been extensively studied due to their ability to damage DNA and other subcellular structures. Noticeably, they have been identified as a pivotal second messenger for T-cell receptor signaling and T-cell activation and participate in antigen cross-presentation and chemotaxis. As an agent with direct toxic effects on cells, ROS lead to the initiation of the autoimmune response. Moreover, ROS levels are regulated by antioxidant systems, which include enzymatic and nonenzymatic antioxidants. Enzymatic antioxidants include superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Nonenzymatic antioxidants contain vitamins C, A, and E, glutathione, and thioredoxin. Particularly, cellular antioxidant systems have important functions in maintaining the redox system homeostasis. This review will discuss the significant roles of ROS generation and antioxidant systems under normal conditions, in the immune system, and pathogenesis of multiple sclerosis.

Re: Reactive Oxygen Species

Posted: Sun Sep 06, 2020 9:02 pm
by NHE
Petr75 wrote:
Sun Sep 06, 2020 10:47 am
2020 Jun 25
Immunology Department, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
The Influence of Reactive Oxygen Species in the Immune System and Pathogenesis of Multiple Sclerosis
https://pubmed.ncbi.nlm.nih.gov/32789026/
https://www.ncbi.nlm.nih.gov/pmc/articl ... 793817.pdf


Image

Figure 3: Summary of ROS function in the pathogenesis MS. CNS, central nervous system; VCAM, vascular cell adhesion molecule.