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Topic Review
Bioactive Compounds from Marine Sponges
Marine sponges are sessile invertebrates that can be found in temperate, polar and tropical regions. They are known to be major contributors of bioactive compounds, which are discovered in and extracted from the marine environment. The compounds extracted from these sponges are known to exhibit various bioactivities, such as antimicrobial, antitumor and general cytotoxicity.
  • 1.9K
  • 25 May 2021
Topic Review
Glucosinolates
Glucosinolates (GSLs) are secondary plant metabolites abundantly found in plant order Brassicales. GSLs are constituted by an S-β-d-glucopyrano unit anomerically connected to O-sulfated (Z)-thiohydroximate moiety. The side-chain of the O-sulfate thiohydroximate moiety, which is derived from a different amino acid, contributes to the diversity of natural GSL, with more than 130 structures identified and validated to this day. Both the structural diversity of GSL and their biological implication in plants have been biochemically studied. While intact GSLs are biologically inactive, various products, including isothiocyanates, nitriles, epithionitriles, and cyanides obtained through enzyme-catalyzed hydrolysis of GSLs, exhibit many different biological activities, among which several therapeutic benefits have been suggested. 
  • 1.9K
  • 12 Oct 2020
Topic Review
Vertebrate Cutaneous Sensory Corpuscles
Vertebrate cutaneous sensory corpuscles are specialized sensory nerve formations located in the skin of all vertebrates and responsible for tactile sensation. Functionally, they are mechanoreceptors transducing external mechanical stimuli into electrical signals which will be later led to the Central Nervous System. The afferent innervation of vertebrate skin is supplied by nerve fibers (Aβ, Aδ, C) which are originated from peripheral neurons localized in the dorsal root ganglia (DRG). Aβ nerve fibers end at the dermis level forming several morphotypes of sensory corpuscles with capacity of detecting different stimuli: Merkel cell–neurite complexes, Ruffini corpuscles, Meissner’s corpuscles and Pacinian corpuscles are present in the glabrous skin; while pilo-neural complexes are found in hairy skin. The structure of sensory corpuscles is formed by an axon, non-myelinating Schwann-like cells, a capsule of endoneurial and/or perineurial origin and extracelullar matrix molecules.  The vertebrate skin contains sensory corpuscles that are receptors for different qualities of mechanosensitivity like light brush, touch, pressure, stretch or vibration. These specialized sensory organs are linked anatomically and functionally to mechanosensory neurons, which function as low-threshold mechanoreceptors connected to peripheral skin through Aβ nerve fibers. Furthermore, low-threshold mechanoreceptors associated with Aδ and C nerve fibers have been identified in hairy skin. The process of mechanotransduction requires the conversion of a mechanical stimulus into electrical signals (action potentials) through the activation of mechanosensible ion channels present both in the axon and the periaxonal cells of sensory corpuscles (i.e., Schwann-, endoneurial- and perineurial-related cells). Most of those putative ion channels belong to the degenerin/epithelial sodium channel (especially the family of acid-sensing ion channels), the transient receptor potential channel superfamilies, and the Piezo family.
  • 1.9K
  • 07 Sep 2020
Topic Review
Adenosine A1 Receptor and Epilepsy
Adenosine acts as an endogenous anticonvulsant and seizure terminator in the brain. Many of its anticonvulsive effects are mediated through activation of the adenosine A1 receptor, a G protein-coupled receptor with a wide array of targets. Various signaling pathways are involved in the neuronal inhibition caused by adenosine A1 receptor activation. These include direct interactions of G protein subunits, the adenyl cyclase pathway and the phospholipase C pathway, which all mediate neuronal hyperpolarization and suppression of synaptic transmission.
  • 1.9K
  • 19 Jan 2021
Topic Review
PCR and NGS in Acute Myeloid Leukemia
Acute myeloid leukemia (AML) is a clonal disorder that affects myeloid progenitor cells residing in the bone marrow (BM). This implies altered differentiation with subsequent abnormal proliferation and accumulation of inadequately matured myeloid cells. The detection of leukemic cells moved in the last two decades from immune-phenotyping to polymerase chain reaction (PCR) and real-time quantitative PCR (RT-qPCR). This technique was shown to be reproducible, accurate and highly sensitive for MRD monitoring, with a significant capacity in predicting prognosis, treatment effectiveness and relapse risk. NGS or massively parallel sequencing is a revolutionary method of DNA and RNA sequencing. It is called parallel because it sequences millions of DNA fragments simultaneously. In the early years of its appearance, Next Generation Sequencing (NGS) platforms were used primarily for cancer research purposes. Recently, they are increasingly emerging as irreplaceable diagnostic tools in clinical settings.
  • 1.9K
  • 10 Feb 2022
Topic Review
Cholesterol
Cholesterol, the most important sterol in mammals, helps maintain plasma membrane fluidity and is a precursor of bile acids, oxysterols, and steroid hormones. Cholesterol in the body is obtained from the diet or can be de novo synthetized. Cholesterol homeostasis is mainly regulated by the liver, where cholesterol is packed in lipoproteins for transport through a tightly regulated process. Changes in circulating lipoprotein cholesterol levels lead to atherosclerosis development, which is initiated by an accumulation of modified lipoproteins in the subendothelial space; this induces significant changes in immune cell differentiation and function. In this entry, we describe the main regulatory pathways and mechanisms of cholesterol metabolism.
  • 1.9K
  • 17 Jan 2022
Topic Review
β-Endorphin
β-Endorphins are peptides that exert a wide variety of effects throughout the body. Produced through the cleavage pro-opiomelanocortin (POMC), β-endorphins are the primarily agonist of mu opioid receptors, which can be found throughout the body, brain, and cells of the immune system that regulate a diverse set of systems. As an agonist of the body’s opioid receptors, β-endorphins are most noted for their potent analgesic effects, but they also have their involvement in reward-centric and homeostasis-restoring behaviors, among other effects. These effects have implicated the peptide in psychiatric and neurodegenerative disorders, making it a research target of interest.
  • 1.9K
  • 16 Apr 2021
Topic Review
Aminoacyl-tRNA Synthetases
Aminoacyl-tRNA synthetases (aaRSs) are a family of essential and universal ‘house-keeping’ enzymes responsible for catalyzing the esterification of amino acids to their cognate tRNAs.
  • 1.9K
  • 09 Mar 2021
Topic Review
RNA-Targeting CRISPR–Cas Systems
Many CRISPR–Cas systems have been used as a backbone for the development of potent research tools, with Cas9 being the most widespread. While most of the utilized systems are DNA-targeting, recently more and more attention is being gained by those that target RNA. Their ability to specifically recognize a given RNA sequence in an easily programmable way makes them ideal candidates for developing new research tools. 
  • 1.8K
  • 23 Dec 2020
Topic Review
3′UTR Length Dynamics: Releasing mRNAs from Stability Control
The 3′Untranslated regions (3′UTRs) of mRNAs, are non-coding regulatory platforms that control stability, fate and the correct spatiotemporal translation of mRNAs. Although initially considered as stabilizing features of the ORF, further work identified a number of new 3’UTR functions that controlled where, when and how mRNAs were translated. Furthermore, recent research has enriched the view of 3’UTRs from static regulators of mRNA translation to highly dynamic and modular regulatory platforms that respond to different stimuli by changing their structure. By using alternative polyadenylation and cleavage sites, alternative exons or by including exonized Alu cassettes, 3’UTRs modify their length, change their sequence and consequently their inventory of associated regulatory sites to establish different co-regulatory events.
  • 1.8K
  • 13 Sep 2022
Topic Review
Natural Cyclopeptides
Cyclopeptides, also known as cyclic peptides, are polypeptides formed from amino acids arranged in a cyclic ring structure.
  • 1.8K
  • 07 May 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. 
  • 1.8K
  • 28 Sep 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.
  • 1.8K
  • 16 May 2022
Topic Review
3D Genome
The genome is the most functional part of a cell, and genomic contents are organized in a compact three-dimensional (3D) structure. The genome contains millions of nucleotide bases organized in its proper frame. Rapid development in genome sequencing and advanced microscopy techniques have enabled us to understand the 3D spatial organization of the genome. Chromosome capture methods using a ligation approach and the visualization tool of a 3D genome browser have facilitated detailed exploration of the genome. 
  • 1.8K
  • 04 Nov 2021
Topic Review
Thioxanthenes
Thioxanthenes are one of the three major groups of antipsychotics (the others being phenothiazines and butyrophenones).  Thioxanthene is a chemical compound having a central triple ring structure closely related to one of the other group of antipsychotics (phenothiazines, which also has the triple ring). The major structural difference between the two classes is that the carbon in position 10 in thioxanthenes is replaced by a nitrogen atom in phenothiazines. In thioxanthenes, this C10  shares a double bond with the side chain. Thioxanthenes are represented in two geometric stereoisomers: Z- and E-compounds.
  • 1.8K
  • 24 Jan 2022
Topic Review
Pectolinarin and Pectolinarigenin
Flavonoids are metabolites widely distributed in plants and commonly present in foods, such as fruits and vegetables. Pectolinarin, which belongs to the flavone subclass, has attracted considerable attention due to its presence in many medicinal plants. It has turned out to be a good biological agent especially due to its antioxidant, anti-inflammatory, antidiabetic, and antitumor activities, evaluated both in vitro and in vivo. Its aglycone, the metabolite pectolinarigenin, is also known for a series of biological properties including anti-inflammatory and antidiabetic effects. In the first overview on the two metabolites here presented, their collection, isolation and the results of their biological evaluation are reported
  • 1.8K
  • 28 Dec 2020
Topic Review
Melanogenesis in Immune Systems
Melanocytes and melanin play a wide range of roles such as adsorption of metals, thermoregulation, and protection from foreign enemies by camouflage.
  • 1.8K
  • 14 Jan 2021
Topic Review
Molecularly Imprinted Polymers-Based Biosensors
The MIP (molecularly imprinted polymer)-based biosensor can be considered an artificial antibody-integrated polymeric active layer that readily sustains stability in challenging testing chemical environments, such as high-temperature limits up to ~300 °C. Since general proteins are usually denatured in irreversible forms higher than ~80 °C, MIP-based biosensors are more stable in storage and even suitable for applications requiring a high-temperature range.
  • 1.8K
  • 08 Mar 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.
  • 1.8K
  • 29 Oct 2020
Topic Review
Bacterial Resistance to Antimicrobial Agents
Bacterial pathogens as causative agents of infection constitute an alarming concern in the public health sector. In particular, bacteria with resistance to multiple antimicrobial agents can confound chemotherapeutic efficacy towards infectious diseases. Multidrug-resistant bacteria harbor various molecular and cellular mechanisms for antimicrobial resistance. These antimicrobial resistance mechanisms include active antimicrobial efflux, reduced drug entry into cells of pathogens, enzymatic metabolism of antimicrobial agents to inactive products, biofilm formation, altered drug targets, and protection of antimicrobial targets. These microbial systems represent suitable focuses for investigation to establish the means for their circumvention and to reestablish therapeutic effectiveness.
  • 1.8K
  • 01 Aug 2022
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