scholarly journals Mechanisms of TLR4-Mediated Autophagy and Nitroxidative Stress

2021 ◽  
Vol 11 ◽  
Author(s):  
Kunli Zhang ◽  
Qiuyan Huang ◽  
Shoulong Deng ◽  
Yecheng Yang ◽  
Jianhao Li ◽  
...  
Keyword(s):  
Public Health ◽  
Immune Cells ◽  
Reactive Nitrogen Species ◽  
Oxygen Species ◽  
Nitrogen Species ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Nitroxidative Stress ◽  
Recognition Receptor

Pathogenic infections have badly affected public health and the development of the breeding industry. Billions of dollars are spent every year fighting against these pathogens. The immune cells of a host produce reactive oxygen species and reactive nitrogen species which promote the clearance of these microbes. In addition, autophagy, which is considered an effective method to promote the destruction of pathogens, is involved in pathological processes. As research continues, the interplay between autophagy and nitroxidative stress has become apparent. Autophagy is always intertwined with nitroxidative stress. Autophagy regulates nitroxidative stress to maintain homeostasis within an appropriate range. Intracellular oxidation, in turn, is a strong inducer of autophagy. Toll-like receptor 4 (TLR4) is a pattern recognition receptor mainly involved in the regulation of inflammation during infectious diseases. Several studies have suggested that TLR4 is also a key regulator of autophagy and nitroxidative stress. In this review, we describe the role of TLR4 in autophagy and oxidation, and focus on its function in influencing autophagy-nitroxidative stress interactions.

scholarly journals Role of ROS/RNS in Preeclampsia: Are Connexins the Missing Piece?

2020 ◽  
Vol 21 (13) ◽  
pp. 4698 ◽  
Author(s):  
María F. Rozas-Villanueva ◽  
Paola Casanello ◽  
Mauricio A. Retamal
Keyword(s):  
Reactive Nitrogen Species ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Transmembrane Proteins ◽  
Pregnancy Complication ◽  
Oxygen Species ◽  
Nitrogen Species ◽  
Gap Junction Channels ◽  
Contraction And Relaxation

Preeclampsia is a pregnancy complication that appears after 20 weeks of gestation and is characterized by hypertension and proteinuria, affecting both mother and offspring. The cellular and molecular mechanisms that cause the development of preeclampsia are poorly understood. An important feature of preeclampsia is an increase in oxygen and nitrogen derived free radicals (reactive oxygen species/reactive nitrogen species (ROS/RNS), which seem to be central players setting the development and progression of preeclampsia. Cell-to-cell communication may be disrupted as well. Connexins (Cxs), a family of transmembrane proteins that form hemichannels and gap junction channels (GJCs), are essential in paracrine and autocrine cell communication, allowing the movement of signaling molecules between cells as well as between the cytoplasm and the extracellular media. GJCs and hemichannels are fundamental for communication between endothelial and smooth muscle cells and, therefore, in the control of vascular contraction and relaxation. In systemic vasculature, the activity of GJCs and hemichannels is modulated by ROS and RNS. Cxs participate in the development of the placenta and are expressed in placental vasculature. However, it is unknown whether Cxs are modulated by ROS/RNS in the placenta, or whether this potential modulation contributes to the pathogenesis of preeclampsia. Our review addresses the possible role of Cxs in preeclampsia, and the plausible modulation of Cxs-formed channels by ROS and RNS. We suggest these factors may contribute to the development of preeclampsia.

scholarly journals The Role of Vitamin E in Immunity

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1614 ◽  
Author(s):  
Ga Lee ◽  
Sung Han
Keyword(s):  
Vitamin E ◽  
Immune Cells ◽  
Reactive Nitrogen Species ◽  
Oxygen Species ◽  
Immunomodulatory Effects ◽  
Specific Effects ◽  
Immunological Diseases ◽  
Modulate Signal ◽  
Immunological Changes

Vitamin E is a fat-soluble antioxidant that can protect the polyunsaturated fatty acids (PUFAs) in the membrane from oxidation, regulate the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), and modulate signal transduction. Immunomodulatory effects of vitamin E have been observed in animal and human models under normal and disease conditions. With advances in understating of the development, function, and regulation of dendritic cells (DCs), macrophages, natural killer (NK) cells, T cells, and B cells, recent studies have focused on vitamin E’s effects on specific immune cells. This review will summarize the immunological changes observed with vitamin E intervention in animals and humans, and then describe the cell-specific effects of vitamin E in order to understand the mechanisms of immunomodulation and implications of vitamin E for immunological diseases.

Essential role of toll-like receptor 4 in Acinetobacter baumannii-induced immune responses in immune cells

2013 ◽  
Vol 54 ◽  
pp. 20-25 ◽  
Author(s):  
Chang-Hwan Kim ◽  
Yu-Jin Jeong ◽  
Junglim Lee ◽  
Soo-Jin Jeon ◽  
Se-Ra Park ◽  
...  
Keyword(s):  
Immune Responses ◽  
Acinetobacter Baumannii ◽  
Immune Cells ◽  
Essential Role ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4

Interactive role of the toll-like receptor 4 and reactive oxygen species in LPS-induced microglia activation

Glia ◽  
2005 ◽  
Vol 52 (1) ◽  
pp. 78-84 ◽  
Author(s):  
Liya Qin ◽  
Guorong Li ◽  
Xun Qian ◽  
Yuxin Liu ◽  
Xuefei Wu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Microglia Activation ◽  
Oxygen Species ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4

scholarly journals Obese Adipose Tissue Secretion Induces Inflammation in Preadipocytes: Role of Toll-Like Receptor-4

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2828 ◽  
Author(s):  
Mariana Renovato-Martins ◽  
Catharina Moreira-Nunes ◽  
Georgia C. Atella ◽  
Christina Barja-Fidalgo ◽  
João Alfredo de Moraes
Keyword(s):  
Adipose Tissue ◽  
Nuclear Translocation ◽  
Low Grade ◽  
Dependent Manner ◽  
Oxygen Species ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Proinflammatory Mediators ◽  
Low Grade Inflammation

In obesity, the dysfunctional adipose tissue (AT) releases increased levels of proinflammatory adipokines such as TNFα, IL-6, and IL-1β and free fatty acids (FFAs), characterizing a chronic, low-grade inflammation. Whilst FFAs and proinflammatory adipokines are known to elicit an inflammatory response within AT, their relative influence upon preadipocytes, the precursors of mature adipocytes, is yet to be determined. Our results demonstrated that the conditioned medium (CM) derived from obese AT was rich in FFAs, which guided us to evaluate the role of TLR4 in the induction of inflammation in preadipocytes. We observed that CM derived from obese AT increased reactive oxygen species (ROS) levels and NF-ĸB nuclear translocation together with IL-6, TNFα, and IL-1β in 3T3-L1 cells in a TLR4-dependent manner. Furthermore, TLR4 signaling was involved in the increased expression of C/EBPα together with the release of leptin, adiponectin, and proinflammatory mediators, in response to the CM derived from obese AT. Our results suggest that obese AT milieu secretes lipokines, which act in a combined paracrine/autocrine manner, inducing inflammation in preadipocytes via TLR4 and ROS, thus creating a paracrine loop that facilitates the differentiation of adipocytes with a proinflammatory profile.

Redox signaling: thiol chemistry defines which reactive oxygen and nitrogen species can act as second messengers

2004 ◽  
Vol 287 (2) ◽  
pp. C246-C256 ◽  
Author(s):  
Henry Jay Forman ◽  
Jon M. Fukuto ◽  
Martine Torres
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Nitrogen Species ◽  
Second Messengers ◽  
Large Body ◽  
Reactive Oxygen ◽  
Protein Tyrosine Phosphatases ◽  
Oxygen Species ◽  
Nitrogen Species ◽  
Signaling Components

Except for the role of NO in the activation of guanylate cyclase, which is well established, the involvement of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in signal transduction remains controversial, despite a large body of evidence suggestive of their participation in a variety of signaling pathways. Several problems have limited their acceptance as signaling molecules, with the major one being the difficulty in identifying the specific targets for each pathway and the chemical reactions supporting reversible oxidation of these signaling components, consistent with a second messenger role for ROS and RNS. Nevertheless, it has become clear that cysteine residues in the thiolate (i.e., ionized) form that are found in some proteins can be specific targets for reaction with H2O2 and RNS. This review focuses on the chemistry of the reversible oxidation of those thiolates, with a particular emphasis on the critical thiolate found in protein tyrosine phosphatases as an example.

scholarly journals Oxidative Stress as an Important Contributor to the Pathogenesis of Psoriasis

2020 ◽  
Vol 21 (17) ◽  
pp. 6206 ◽  
Author(s):  
Joanna Pleńkowska ◽  
Magdalena Gabig-Cimińska ◽  
Paweł Mozolewski
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Reactive Nitrogen Species ◽  
Oxygen Species ◽  
Nitrogen Species ◽  
Induced Stress ◽  
Full Picture ◽  
Cellular Dysfunction

This review discusses how oxidative stress (OS), an imbalance between oxidants and antioxidants in favor of the oxidants, increased production of reactive oxygen species (ROS)/reactive nitrogen species (RNS), and decreased concentration/activity of antioxidants affect the pathogenesis or cause the enhancement of psoriasis (Ps). Here, we also consider how ROS/RNS-induced stress modulates the activity of transcriptional factors and regulates numerous protein kinase cascades that participate in the regulation of crosstalk between autophagy, apoptosis, and regeneration. Answers to these questions will likely uncover novel strategies for the treatment of Ps. Action in the field will avoid destructive effects of ROS/RNS-mediated OS resulting in cellular dysfunction and cell death. The combination of the fragmentary information on the role of OS can provide evidence to extend the full picture of Ps.

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