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Topic Review
Cross-Talk of Gasotransmitters and Sphingolipid Signalling
Redox-active mediators are now appreciated as powerful molecules to regulate cellular dynamics such as viability, proliferation, migration, cell contraction, and relaxation, as well as gene expression under physiological and pathophysiological conditions. These molecules include the various reactive oxygen species (ROS), and the gasotransmitters nitric oxide (NO∙), carbon monoxide (CO), and hydrogen sulfide (H2S). For each of these molecules, direct targets have been identified which transmit the signal from the cellular redox state to a cellular response. There is a cross-regulation existing between the redox mediators and sphingolipid molecules that have a fundamental impact on a cell’s fate and organ function. 
  • 1.3K
  • 03 Apr 2023
Topic Review
The Clinical Significance of Cyclic Glycine-Proline
Cyclic Glycine-Proline and insulin-like growth factor binding protein (IGFBP)-3 collectively regulate the bioavailability of IGF-1. The molar ratio of cGP/IGF-1 represents the amount of bioavailable and functional IGF-1 in circulation. The cGP/IGF-1 molar ratio is low in patients with age-related conditions, including hypertension, stroke, and neurological disorders with cognitive impairment. Stroke patients with a higher cGP/IGF-1 molar ratio have more favorable clinical outcomes. The elderly with more cGP have better memory retention. An increase in the cGP/IGF-1 molar ratio with age is associated with normal cognition, whereas a decrease in this ratio with age is associated with dementia in Parkinson disease. In addition, cGP administration reduces systolic blood pressure, improves memory, and aids in stroke recovery. These clinical and experimental observations demonstrate the role of cGP in regulating IGF-1 function and its potential clinical applications in age-related brain diseases as a plasma biomarker for—and an intervention to improve—IGF-1 function.
  • 1.2K
  • 07 Feb 2023
Topic Review
Mechanisms Underlying SCFAs Protective Effect on Blood–Brain Barrier
Impairment of the blood–brain barrier (BBB) integrity is implicated in the numerous neurological disorders associated with neuroinflammation, neurodegeneration and aging. Short-chain fatty acids (SCFAs), mainly acetate, butyrate and propionate, produced by anaerobic bacterial fermentation of the dietary fiber in the intestine, have a key role in the communication between the gastrointestinal tract and nervous system and are critically important for the preservation of the BBB integrity under different pathological conditions.
  • 1.2K
  • 25 Jun 2023
Topic Review
Carotenoids in Human Skin
Carotenoids having ≥10 π-π-conjugated C=C double bonds serve as an objective marker of the antioxidant status of human stratum corneum (SC) in vivo according to the principle: the higher the concentration of carotenoids the higher the antioxidant status of the entire SC. The exposure to doses of radiation in the visible (>50 J/cm2) and near-infrared (>120 J/cm2) spectral ranges cause the formation of free radicals in human skin, which can be determined in vivo by a decrease in the concentration of carotenoids in the SC. The topical application of sunscreen containing antioxidants has a protective effect on the skin. A diet containing antioxidants, in particular fruit and vegetables or food supplements, leads to an increase in the carotenoid concentration and the antioxidant status of the SC. The concentration of carotenoids in the SC can reflect the individual lifestyle habits and health status. Resonance Raman spectroscopy and diffuse reflectance spectroscopy are optical methods that provide a rapid and non-invasive screening of the kinetics of carotenoids and changes in the antioxidant status of the human SC, which can be useful in in vivo skin research.
  • 1.2K
  • 08 Aug 2022
Topic Review
Diets and Exercise-Induced Oxidative Stress
Exhaustive exercise can induce excessive generation of reactive oxygen species (ROS), which may enhance oxidative stress levels. Besides single dosages of antioxidants, whole diets rich in antioxidants are gaining more attention due to their practicality and multicomponent ingredients. 
  • 1.2K
  • 29 Apr 2021
Topic Review
O-GlcNAcylation Regulate Skeletal Muscle
O-GlcNAcylation is a highly dynamic, reversible and atypical glycosylation that regulates the activity, biological function, stability, sublocation and interaction of target proteins. O-GlcNAcylation receives and coordinates different signal inputs as an intracellular integrator similar to the nutrient sensor and stress receptor, which target multiple substrates with spatio-temporal analysis specifically to maintain cellular homeostasis and normal physiological functions.
  • 1.2K
  • 13 Jun 2022
Topic Review
ZIKA Virus and Male Infertility
Zika virus (ZIKV) has been reported by several groups as an important virus causing pathological damage in the male reproductive tract. ZIKV can infect and persist in testicular somatic and germ cells, as well as spermatozoa, leading to cell death and testicular atrophy. ZIKV has also been detected in semen samples from ZIKV-infected patients. This has huge implications for human reproduction. Global scientific efforts are being applied to understand the mechanisms related to arboviruses persistency, pathogenesis, and host cellular response to suggest a potential target to develop robust antiviral therapeutics and vaccines. Here, we discuss the cellular modulation of the immunologic and physiologic properties of the male reproductive tract environment caused by arboviruses infection, focusing on ZIKV. We also present an overview of the current vaccine effects and therapeutic targets against ZIKV infection that may impact the testis and male fertility.
  • 1.2K
  • 01 Nov 2020
Topic Review
Nitrosative Stress in Retinal Pathologies
Nitric oxide (NO) is a gas molecule with diverse physiological and cellular functions. In the eye, NO is used to maintain normal visual function as it is involved in photoreceptor light transduction. In addition, NO acts as a rapid vascular endothelial relaxant, is involved in the control of retinal blood flow under basal conditions and mediates the vasodilator responses of different substances such as acetylcholine, bradykinin, histamine, substance P or insulin. However, the retina is rich in polyunsaturated lipid membranes and is sensitive to the action of reactive oxygen and nitrogen species. Products generated from NO (i.e., dinitrogen trioxide (N2O3) and peroxynitrite) have great oxidative damaging effects. Oxygen and nitrogen species can react with biomolecules (lipids, proteins and DNA), potentially leading to cell death, and this is particularly important in the retina.
  • 1.2K
  • 22 Sep 2021
Topic Review
Rhythm Generation
Rhythms are essential to living beings. They allow fluxes to coordinate with one another. Rhythms, thereby, constitute an information system for body functions. Biosphere rhythmicity largely relates to geophysical oscillations. To ignore the latter also affects human health and performance.
  • 1.2K
  • 01 Nov 2020
Topic Review
Roles of Nox3 in Diseases
Reactive oxygen species (ROS) were formerly known as mere byproducts of metabolism with damaging effects on cellular structures. The discovery and description of NADPH oxidases (Nox) as a whole enzyme family that only produce this harmful group of molecules was surprising. Among the Nox isoforms, the NADPH oxidase 3 is the perhaps most underrated Nox enzyme, since it was firstly discovered in the inner ear. Despite the fact that Nox3 is expressed not only in the inner ear but also in various cell types and organs, the “inner ear stigma” remains until today. However ,the involvment of Nox3 is not just limited to the inner ear but extends to various organs and the related diseases.
  • 1.2K
  • 20 Feb 2024
Topic Review
Oxidative Stress in Cardiovascular Diseases
       This entry aims to introduce the physiological roles and pathological implications of oxidative stress in cardiovascular tissues
  • 1.2K
  • 28 Sep 2021
Topic Review
Transient Receptor Potential Ankyrin 1
The transient receptor potential ankyrin 1 (TRPA1), a member of the TRP superfamily of channels, is primarily localized in a subpopulation of primary sensory neurons of the trigeminal, vagal, and dorsal root ganglia, where its activation mediates neurogenic inflammatory responses. TRPA1 expression in resident tissue cells, inflammatory, and immune cells, through the indirect modulation of a large series of intracellular pathways, orchestrates a range of cellular processes, such as cytokine production, cell differentiation, and cytotoxicity. 
  • 1.2K
  • 05 May 2022
Topic Review
Calcium’s Role and Signaling in Muscle Aging
Calcium signaling involves the movement of calcium ions within or between cells, which can affect the electrochemical gradients between intra- and extracellular membranes, ligand binding, enzyme activity, and other mechanisms that determine cell fate. Calcium signaling in muscle, as elucidated by the sliding filament model, plays a significant role in muscle contraction. However, as organisms age, alterations occur within muscle tissue. These changes include sarcopenia, loss of neuromuscular junctions, and changes in mineral concentration, all of which have implications for calcium’s role. Additionally, a field of study that has gained recent attention, cellular senescence, is associated with aging and disturbed calcium homeostasis, and is thought to affect sarcopenia progression. 
  • 1.2K
  • 06 Dec 2023
Topic Review
Episodic Memory Performance
The aim of this entry was to investigate whether oxygen is a rate limiting factor for any of the main cognitive domains in healthy young individuals. Subjects were randomly assigned to either increased oxygen supply using hyperbaric oxygen (two atmospheres of 100% oxygen) or to a “sham” treatment (simulation of increased pressure in the chamber breathing normal air). While in the chamber, participants went through a battery of tests evaluating the major cognitive domains including information processing speed, episodic memory, working memory, cognitive flexibility, and attention. The results demonstrated that from all evaluated cognitive domains, a statistically significant improvement was found in the episodic memory of the hyper-oxygenized group. The hyper-oxygenized group demonstrated a better learning curve and a higher resilience to interference. The results of this study indicate that memory function is a continuum that does not reach its maximal ceiling effect at the normal sea level environment even in healthy young individuals. Understanding the biological limitation of our cognitive functions is important for future development of interventional tools that can be used in the daily clinical practice.
  • 1.2K
  • 30 Sep 2021
Topic Review
Mental States and Molecular Biology
Today, it is possible to investigate the biological paths and mechanisms that link mental life to biological life. Emotions, feelings, desires, and cognitions influence biological systems. In recent decades, psychoneuroendocrinoimmunology research has highlighted the routes linking the psyche–brain–immune systems. Recently, epigenetics research has shown the molecular mechanisms by which stress and mental states modulate the information contained in the genome.
  • 1.2K
  • 09 May 2022
Topic Review
Mitochondrial Ca2+ Signaling and Bioenergetics in Alzheimer’s Disease
Alzheimer’s disease (AD) is a hereditary and sporadic neurodegenerative illness defined by the gradual and cumulative loss of neurons in specific brain areas. The processes that cause AD are still under investigation and there are no available therapies to halt it. Progress puts at the forefront the “calcium (Ca2+) hypothesis” as a key AD pathogenic pathway, impacting neuronal, astrocyte and microglial function. An increasing body of evidence points out the early and crucial role of cellular Ca2+ handling dysregulation in AD pathogenesis. Interestingly, Ca2+ is a key regulator of several mitochondrial functions, such as ATP production, and brain cells rely mostly on OXPHOS to match their energy demands.
  • 1.2K
  • 09 Dec 2022
Topic Review
Autophagy Modulated in Cancer Cachexia
Cancer cachexia is a syndrome experienced by many patients with cancer. Exercise can act as an autophagy modulator, and thus holds the potential to be used to treat cancer cachexia. Autophagy imbalance plays an important role in cancer cachexia, and is correlated to skeletal and cardiac muscle atrophy and energy-wasting in the liver. The molecular mechanism of autophagy modulation in different types of exercise has not yet been clearly defined. This review aims to elaborate on the role of exercise in modulating autophagy in cancer cachexia.
  • 1.2K
  • 18 Aug 2021
Topic Review
Fibrinogen, Fibrinogen Chains, Its Derivatives, and Fibrinogen-Like Proteins
Fibrinogen (Fg), its derivatives and Fg-like other proteins play a considerable role in many diseases. For example, increased levels of Fg have been found in many inflammatory diseases, such as Alzheimer’s disease, multiple sclerosis, traumatic brain injury, rheumatoid arthritis, systemic lupus erythematosus, and cancer. Associations of Fg, Fg chains, its derivatives and Fg-like proteins with various diseases have been established and their specific effects and the mechanisms of actions gradually become more evident. 
  • 1.2K
  • 27 Jul 2022
Topic Review
Biomolecular Paradigm of Active Resolution Mechanisms in Heart
Inflammation is a complex program of active processes characterized by the well-orchestrated succession of an initiation and a resolution phase aiming to promote homeostasis. When the resolution of inflammation fails, the tissue undergoes an unresolved inflammatory status which, if it remains uncontrolled, can lead to chronic inflammatory disorders due to aggravation of structural damages, development of a fibrous area, and loss of function. Various human conditions show a typical unresolved inflammatory profile. Inflammatory diseases include cancer, neurodegenerative disease, asthma, right heart disease, atherosclerosis, myocardial infarction, or atrial fibrillation. New evidence has started to emerge on the role, including pro-resolution involvement of chemical mediators in the acute phase of inflammation. Although flourishing knowledge is available about the role of specialized pro-resolving mediators in neurodegenerative diseases, atherosclerosis, obesity, or hepatic fibrosis, little is known about their efficacy to combat inflammation-associated arrhythmogenic cardiac disorders. It has been shown that resolvins, including RvD1, RvE1, or Mar1, are bioactive mediators of resolution. Resolvins can stop neutrophil activation and infiltration, stimulate monocytes polarization into anti-inflammatory-M2-macrophages, and activate macrophage phagocytosis of inflammation-debris and neutrophils to promote efferocytosis and clearance.
  • 1.2K
  • 27 May 2022
Topic Review
Reactive Oxygen Species in the Brain
Reactive oxygen and nitrogen species are crucial contributors to the age-dependent decline in all tissues. Neural tissue, one of the main oxygen consumers in the mammalian body, is especially prone to reactive species-mediated damage. Brain cells, including neurons, astrocytes, and microglia, produce reactive oxygen species (ROS) by specific enzymatic systems, including complexes of the mitochondrial respiratory chain, multienzyme flavin-containing complexes, monoamine and xanthine oxidases, microglial and endothelial NADPH oxidases and cyclooxygenases in addition to non-enzymatic and potentially uncontrolled mechanisms of ROS production, such as autooxidation of quinones or other aromatic compounds. Nitric oxide produced by nitric oxide synthases powers the conversion of ROS into reactive nitrogen species (RNS). Both ROS and RNS play important signaling roles and are also capable of modifying other molecules such as proteins, nucleic and fatty acids, lipids and carbohydrates. The antioxidant system, comprising low molecular mass antioxidants (e.g., tocopherol, ascorbic acid and glutathione) and high molecular mass antioxidants such as enzymes (e.g., catalases, peroxidases, superoxide dismutases) and others, protects cells from potential damage caused by ROS or RNS. Powering antioxidant systems by NADPH provides neural tissue with defense against ROS but may also trigger ROS production by NADPH oxidases and cyclooxygenases. In turn, mitochondria start using ketone bodies as an energy source under certain conditions. Increased steady-state levels of ROS and RNS, along with the aforementioned ROS-modified molecules, activate the organisms’ immune system including brain’s microglia.
  • 1.2K
  • 09 Nov 2021
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