NADPH oxidase-dependent free radical generation and protein adduct formation in neutrophils.

Neutrophils mediate the early innate immune response through extracellular traps comprising intracellular protein and DNA. These traps play a pivotal role in both immunity against invading pathogens and the development of immunopathological reactions through the production of reactive oxygen species (ROS). Proteins serve as the main target for ROS, resulting in the formation of protein adducts.

NOX2 and NOX4 expression in monocytes and macrophages-extracellular vesicles in signalling and therapeutics.

Extracellular vesicles (EVs) are a type of cytoplasmic vesicles secreted by a variety of cells. EVs originating from cells have been known to participate in cell communication, antigen presentation, immune cell activation, tolerance induction, etc. These EVs can also carry the active form of Nicotinamide Adenine Dinucleotide Phosphate Oxidase Hydrogen (NADPH) oxidase, which is very essential for the production of reactive oxygen species (ROS) and that can then modulate processes such as cell regeneration.

ROS signaling in innate immunity via oxidative protein modifications.

The innate immune response represents the first-line of defense against invading pathogens. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) have been implicated in various aspects of innate immune function, which involves respiratory bursts and inflammasome activation. These reactive species widely distributed within the cellular environment are short-lived intermediates that play a vital role in cellular signaling and proliferation and are likely to depend on their subcellular site of formation.

Differential effects of ascorbic acid on monocytic cell morphology and protein modification: Shifting from pro-oxidative to antioxidant properties.

In this study, we investigated the properties of ascorbic acid (vitamin C), which is a naturally occurring water-soluble vitamin. Our goal is to evaluate its pro-oxidative and/or antioxidant capabilities. To do this, we initially used a confocal laser scanning microscope (CLSM) to visualize the differentiation pattern in U-937 cells under the treatment of variable concentrations of ascorbic acid.

Formation of free acetaldehydes derived from lipid peroxidation in U937 monocyte-like cells.

Acetaldehyde can be found in human cells as a byproduct of various metabolic pathways, including oxidative processes such as lipid peroxidation. This secondary product of lipid peroxidation plays a role in various pathological processes, leading to various types of civilization diseases. In this study, the formation of free acetaldehyde induced by oxygen-centred radicals was studied in monocyte-like cell line U937.

Imaging and Characterization of Oxidative Protein Modifications in Skin.

Skin plays an important role in protection, metabolism, thermoregulation, sensation, and excretion whilst being consistently exposed to environmental aggression, including biotic and abiotic stresses. During the generation of oxidative stress in the skin, the epidermal and dermal cells are generally regarded as the most affected regions. The participation of reactive oxygen species (ROS) as a result of environmental fluctuations has been experimentally proven by several researchers and is well known to contribute to ultra-weak photon emission via the oxidation of biomolecules (lipids, proteins, and nucleic acids).

Detection and characterization of free oxygen radicals induced protein adduct formation in differentiating macrophages.

Reactive oxygen species play a key role in cellular homeostasis and redox signaling at physiological levels, where excessive production affects the function and integrity of macromolecules, specifically proteins. Therefore, it is important to define radical-mediated proteotoxic stress in macrophages and identify target protein to prevent tissue dysfunction. A well employed, THP-1 cell line was utilized as in vitro model to study immune response and herein we employ immuno-spin trapping technique to investigate radical-mediated protein oxidation in macrophages.

Bioactive Compounds and Their Impact on Protein Modification in Human Cells.

Reactive oxygen species (ROS) represent a group of molecules with a signaling role that are involved in regulating human cell proliferation and differentiation. Increased ROS concentrations are often associated with the local nonspecific oxidation of biological macromolecules, especially proteins and lipids. Free radicals, in general, may randomly damage protein molecules through the formation of protein-centered radicals as intermediates that, in turn, decay into several end oxidation products.

Free Radical-Mediated Protein Radical Formation in Differentiating Monocytes.

Free radical-mediated activation of inflammatory macrophages remains ambiguous with its limitation to study within biological systems. U-937 and HL-60 cell lines serve as a well-defined model system known to differentiate into either macrophages or dendritic cells in response to various chemical stimuli linked with reactive oxygen species (ROS) production. Our present work utilizes phorbol 12-myristate-13-acetate (PMA) as a stimulant, and factors such as concentration and incubation time were considered to achieve optimized differentiation conditions.

Molecular Mechanism of T-2 Toxin-Induced Cerebral Edema by Aquaporin-4 Blocking and Permeation.

The present study aimed to reveal the molecular mechanism of T-2 toxin-induced cerebral edema by aquaporin-4 (AQP4) blocking and permeation. AQP4 is a class of aquaporin channels that is mainly expressed in the brain, and its structural changes lead to life-threatening complications such as cardio-respiratory arrest, nephritis, and irreversible brain damage. We employed molecular dynamics simulation, text mining, and in vitro and in vivo analysis to study the structural and functional changes induced by the T-2 toxin on AQP4.

Combined Inhibitory Effects of Citrinin, Ochratoxin-A, and T-2 Toxin on Aquaporin-2.

Aquaporins form a large family of transmembrane protein channel that facilitates selective and fast water transport across the cell membrane. The inhibition of aquaporin channels leads to many water-related diseases such as nephrogenic diabetes insipidus, edema, cardiac arrest, and stroke. Herein, we report the molecular mechanism of mycotoxins (citrinin, ochratoxin-A, and T-2 mycotoxin) inhibition of aquaporin-2 (AQP2) and arginine vasopressin receptor 2.