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Topic Review
Adaptive Response to Environmental Stress
Exposure of living organisms to environmental stress triggers defensive responses resulting in the activation of protective processes. Whenever exposure occurs at low doses, defensive effects overwhelm the adverse effects of the exposures; this adapative situation is referred as ‘hormesis’. Environmental, physical and nutritional hormetins lead to the stimulation and strengthening of the maintenance and repair systems in cells and tissues. Exercise, heat and irradiation are examples of physical hormetins, which activate heat shock-, DNA repair- and anti-oxidative-stress responses. The health promoting effect of many bio-actives in fruits and vegetables can be seen as the effect of mildly toxic compounds triggering this adaptive stimulus. Numerous studies indicate that living organisms possess the ability to adapt to adverse environmental conditions studies as examplified by the fact that DNA damage and gene expression profiling in populations living in the environment with high levels of air pollution do not correspond to the concentrations of pollutants. The molecular mechanisms of the hormetic response include modulation of (a) transcription factor Nrf2 activating the synthesis of glutathione and the subsequent protection of the cell; (b) DNA methylation; and (c) microRNA. These findings provide evidence that hormesis is a toxicological event, occurring at low exposures doses to environmental stressors, having benefit for the maintenance of healthy status.
  • 2.6K
  • 26 Oct 2020
Topic Review
Lonone
The term ionone is derived from “iona” (Greek for violet) which refers to the violet scent and “ketone” due to its structure. Ionones can either be chemically synthesized or endogenously produced via asymmetric cleavage of β-carotene by β-carotene oxygenase 2 (BCO2). 
  • 2.6K
  • 05 Jan 2021
Topic Review
L-Carnitine in Autism Spectrum Disorder
L-carnitine plays an important role in the functioning of the central nervous system, and especially in the mitochondrial metabolism of fatty acids. Altered carnitine metabolism, abnormal fatty acid metabolism in patients with autism spectrum disorder (ASD) has been documented. ASD is a complex heterogeneous neurodevelopmental condition that is usually diagnosed in early childhood. Patients with ASD require careful classification as this heterogeneous clinical category may include patients with an intellectual disability or high functioning, epilepsy, language impairments, or associated Mendelian genetic conditions. L-carnitine participates in the long-chain oxidation of fatty acids in the brain, stimulates acetylcholine synthesis (donor of the acyl groups), stimulates expression of growth-associated protein-43, prevents cell apoptosis and neuron damage and stimulates neurotransmission.
  • 2.6K
  • 16 May 2022
Topic Review
Hydrogen Bond
The hydrogen bond may be treated as a local stabilizing interaction that acts between the proton or the electron charge deficient region of hydrogen centre and the electron rich region that is related to one or more centres. This may be named as the two-sites hydrogen bond definition. However in numerous studies the A-H proton donating bond with the positively charged H-atom and the proton acceptor, say B, being the electron rich centre are taken into account. Thus so-called A-H∙∙∙B hydrogen bridges are often considered. In such a way the three-sites hydrogen bond definition may be proposed that the hydrogen bond is the A-H∙∙∙B local stabilizing system with the proton situated between two A and B electron rich sites, most often closer to one of them, forming the A-H covalent bond; both A and B may correspond to one or more atomic centres.
  • 2.6K
  • 07 Sep 2021
Topic Review
Bilirubin
Bilirubin is a yellow endogenous derivate of the heme catabolism. Since the 1980s, it has been recognized as one of the most potent antioxidants in nature, able to counteract 10,000× higher intracellular concentrations of H2O2. In the recent years, not only bilirubin, but also its precursor biliverdin, and the enzymes involved in their productions (namely heme oxygenase and biliverdin reductase; altogether the "yellow players"-YPs) have been recognized playing a protective role in diseases characterized by a chronic prooxidant status. 
  • 2.6K
  • 28 Sep 2021
Topic Review
Nucleoside Analogs
As the non-naturally occurring biomolecules, modified DNA/RNA nucleoside and oligonucleotide analogues composed of L-(deoxy)riboses, have been designed and applied as innovative therapeutics with superior plasma stability, weakened cytotoxicity, and inexistent immunogenicity.
  • 2.6K
  • 29 Dec 2021
Topic Review
Hsp70 and Hsp90
Hsp70, Hsp90, and their co-chaperones are crucial members of the proteostasis network that are able to recognize misfolded proteins, aberrant condensates and protein aggregates, triaging proteins for refolding or degradation. These members of the chaperome are considered major sentinels impeding the molecular processes that lead to cell damage in the course of degenerative proteinopathies. Indeed, Hsp70, Hsp90 and their co-chaperones are increasingly recognized as therapeutic targets for the development of treatments against prevalent protein misfolding diseases.
  • 2.6K
  • 23 Dec 2020
Topic Review
B-cell non-Hodgkin lymphoma
The term B-cell non-Hodgkin lymphoma (B-NHL) encompasses different neoplasms characterized by an abnormal proliferation of lymphoid B cells.
  • 2.6K
  • 13 Jan 2022
Topic Review
Sex-Reversed Females of Salmonid Fish
Sex-reversed females (SRFs; masculinised females, neomales) are genetically females; however, owing to masculinisation, they are capable of producing spermatozoa.
  • 2.6K
  • 12 May 2021
Topic Review
Nature and Cultural Aspects of Astaxanthin
Astaxanthin (AX), a lipid-soluble pigment belonging to the xanthophyll carotenoids family, has recently garnered significant attention due to its unique physical properties, biochemical attributes, and physiological effects.
  • 2.6K
  • 13 Oct 2023
Topic Review
BCR-ABL1 Tyrosine Kinase Complex Signaling Transduction
The constitutively active BCR-ABL1 tyrosine kinase, found in t(9;22)(q34;q11) chromosomal translocation-derived leukemia, initiates an extremely complex signaling transduction cascade that induces a strong state of resistance to chemotherapy. Targeted therapies based on tyrosine kinase inhibitors (TKIs), such as imatinib, dasatinib, nilotinib, bosutinib, and ponatinib, have revolutionized the treatment of BCR-ABL1-driven leukemia, particularly chronic myeloid leukemia (CML). However, TKIs do not cure CML patients, as some develop TKI resistance and the majority relapse upon withdrawal from treatment. Importantly, although BCR-ABL1 tyrosine kinase is necessary to initiate and establish the malignant phenotype of Ph-related leukemia, in the later advanced phase of the disease, BCR-ABL1-independent mechanisms are also in place. 
  • 2.6K
  • 09 Feb 2022
Topic Review
Role of MPO in Human Diseases and Inflammation
Myeloperoxidase (MPO), also called hydrogen peroxide oxidoreductase with a particular (EC 1.11.1.7), is an enzyme found in the primary granules of granulocytic cells (neutrophils, eosinophils, and, to a lesser extent, monocytes). Lymphocytes lack MPO enzyme activity. However, the most common sources are neutrophils, where the enzyme is located at the lysosomal level in the azurophil granules.
  • 2.6K
  • 27 Sep 2022
Topic Review
Fe Uptake and Transport
The mode of iron (Fe) uptake and transport in cereal species is distinguished from that in other plant species by the synthesis and utilization of phytosiderophores, which are a group of Fe chelators involved in Fe mobilization from the environment as well as within the plant body. In this entry, the overview of the molecular mechanisms behind the Fe uptake and transport is presented, highlighting the commonality and diversity among cereal species.
  • 2.6K
  • 29 Oct 2020
Topic Review
Molecular Structure and Biochemistry of Post-Proline Cleaving Enzymes
Post-proline cleaving enzymes (PPCEs) are involved in various biological functions in diverse taxa of organisms including microbes, fungi, animals, and plants.
  • 2.5K
  • 24 May 2022
Topic Review
Electrodiffusion in Neuroscience and NPP-Equations
There are two main processes governing the ionic transport, i.e., diffusion—the particle motion caused by a gradient of concentration, and migration—motion of ions caused by a gradient of electrical potential. These two processes are referred to as electrodiffusion. Electrodiffusion of electrolytes serves as a mean for communication in the nervous system. It can directly affect the excitatory transmission in the synaptic cleft. Electrodiffusion maintains the local ions concentration in brain extracellular spaces at heathy levels but may be also involved in the propagation of epileptic seizures during pathological conditions. The accurate interpretation of physiological observations requires better understanding of the underlying electrodiffusion phenomena.The description of electrodiffusion is very often performed using the Nernst–Planck–Poisson (NPP) model. It has been acknowledged that the spatiotemporal dynamics of the ion concentrations in thin dendrites and dendritic spines of nerve cells follow the Nernst–Planck equation, and sub-membrane currents in neuronal membrane have already been successfully described using the NPP model.
  • 2.5K
  • 29 Apr 2021
Topic Review
Bone ECM Signaling
Bone mineral density, a bone matrix parameter frequently used to predict fracture risk, is not the only one to affect bone fragility. Other factors, including the extracellular matrix (ECM) composition and microarchitecture, are of paramount relevance in this process. The bone ECM is a noncellular three-dimensional structure secreted by cells into the extracellular space, which comprises inorganic and organic compounds. The main inorganic components of the ECM are calcium-deficient apatite and trace elements, while the organic ECM consists of collagen type I and noncollagenous proteins. Bone ECM dynamically interacts with osteoblasts and osteoclasts to regulate the formation of new bone during regeneration. Thus, the composition and structure of inorganic and organic bone matrix may directly affect bone quality. Moreover, proteins that compose ECM, beyond their structural role have other crucial biological functions, thanks to their ability to bind multiple interacting partners like other ECM proteins, growth factors, signal receptors and adhesion molecules. Thus, ECM proteins provide a complex network of biochemical and physiological signals.
  • 2.5K
  • 17 Dec 2020
Topic Review
Zeaxanthin and Lutein in Humans
Many factors in the environment (including radiation, pathogens, and various stresses) prompt internal formation of oxidants that orchestrate beneficial adjustments in human metabolism and but can also lead to damage and disease. To prevent adverse effects of these oxidants, humans require antioxidants and anti-inflammatories, many of which are vitamins and other essential micronutrients that must be consumed with the diet. The xanthophylls zeaxanthin and lutein are unique human micronutrients that protect the integrity and function of biological membranes – especially in the human eye and brain.
  • 2.5K
  • 16 Feb 2021
Topic Review
Artemisia Genus as Biopesticides
The Artemisia L. genus includes over 500 species with worldwide distribution and diverse chemical composition. Many secondary metabolites of this genus are known for their antimicrobial, insecticidal, parasiticidal, and phytotoxic properties, which recommend them as possible biological control agents against plant pests. Given the negative impact of synthetic pesticides on human health and on the environment, Artemisia‐derived biopesticides and their nanoformulations emerge as promising ecofriendly alternatives to pest management.
  • 2.5K
  • 02 Jul 2021
Topic Review
Neurodegeneration in Multiple Sclerosis
Neurodegeneration in multiple sclerosis is believed to underlie disease progression and permanent disability. Many mechanisms of neurodegeneration in MS have been proposed, such as mitochondrial dysfunction, oxidative stress, neuroinflammation, and most recently RNA-binding protein dysfunction. Studying RNA-binding protein dysfunction addresses a gap in our understanding of the pathogenesis of MS, which may allow for novel therapies to be generated to attenuate neurodegeneration before irreversible central nervous system damage occurs.
  • 2.5K
  • 29 Jun 2021
Topic Review
Chemical Enzymology of Monoamine Oxidase
Monoamine oxidase (E.C. 1.4.3.4) enzymes MAO A and MAO B are FAD-containing proteins located on the outer face of the mitochondrial inner membrane, retained there by hydrophobic interactions and a transmembrane helix. The redox co-factor (FAD) is covalently attached to a cysteine and buried deep inside the protein behind an aromatic cage that aligns substrates towards the flavin. MAO metabolizes neurotransmitters such as dopamine and serotonin in the nervous system so is a target for drugs to modify amine levels. MAO also metabolizes a wide range of biogenic amines in all tissues. Current accumulated evidence, particularly from theoretical modelling, supports hydride transfer as the chemical mechanism. The long active site cavity accommodates a wide chemical variety of small molecules designed as inhibitors, including coumarins, chromones, triazoles, and more. Inactivators that bind covalently to MAO include hydrazines, cyclopropylamines and propargylamines. This entry is an extract adapted from a review outlining the remaining uncertainties in the understanding of this key drug target.
  • 2.5K
  • 19 Oct 2021
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