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Topic Review
Cells Fusion
The biological phenomenon of cell fusion remains a mystery. Even though it is mandatory for several physiological and pathopyhsiological processes considerably less is still known how the merging of two (and more) cells is regulated. Cells are not fusogenic per se. They first have to be converted into a pro-fusogenic state and have to re-enter to a non-fusogenic state after hybridisation. Likewise, different cell fusion mechanisms have been developed during evolution depending on different proteins and different membrane merging strategies. This entry gives a brief overview about those molecules and conditions that direct cell fusion.
  • 1.9K
  • 27 Oct 2020
Topic Review
Haemophilus influenzae HP1 Bacteriophage
Haemophilus influenzae is an obligate commensal of the upper respiratory tract in humans and may be responsible for upper respiratory tract infections and even meningitis. Seven biologically active H. influenzae dsDNA phages have been currently described: HP1, HP2, HP3, S2A, S2B, S2C, N3 and Mu-like phage φflu. The most studied is the group of HP1/S2 phages. The temperate H. influenzae phage HP1 belongs to the Myoviridae family of phages and infects Rd strains of H. influenzae. HP1 has a head-tail structure. Its genome is about 32 kb long and encodes 41 potential proteins. Early promoters, which control the lysis-versus-lysogeny decision seem to be located toward the 5’ end of the genome. The late promoter is located between orf16 and orf17, and regulates the expression of late genes, including the lys and hol genes, encoding a SAR-endolysin and a pinholin. Endolysin alone is responsible for cell lysis. The control of endolysin activity seems to be related to conformational changes in holin structure. HP1 phages encodes Dam methyltransferase, which role in HP1 life cycle remains unknown.
  • 1.9K
  • 06 Nov 2020
Topic Review
Adenosine-to-Inosine RNA Editing
Adenosine-to-inosine RNA editing is a system of post-transcriptional modification widely distributed in metazoans which is catalyzed by ADAR enzymes and occurs mostly in double-stranded RNA (dsRNA) before splicing. This type of RNA editing changes the genetic code, as inosine generally pairs with cytosine in contrast to adenosine, and this expectably modulates RNA splicing.
  • 1.9K
  • 20 May 2022
Topic Review
Coenzyme Q10 Metabolism
The variable success in the outcome of randomised controlled trials supplementing coenzyme Q10 (CoQ10) may in turn be associated with a number of currently unresolved issues relating to CoQ10 metabolism.
  • 1.9K
  • 27 Feb 2023
Topic Review
Seminal Plasma
For a long time, the substantial significance of seminal plasma factors’ functions has been underestimated, which is restricted to spermatozoa transport and protection. Notably, significant advancements have been made in dissecting seminal plasma components, revealing new insights into multiple aspects of sperm function, as well as fertilization and pregnancy outcomes in recent years. In this review, we summarize the state-of-art discoveries regarding SP compositions and their implications in male fertility, particularly describing the novel understanding of seminal plasma components and related modifications using “omics” approaches and mainly focusing on proteome and RNA-seq data in the latest decade. Meanwhile, we highlighted the proposed mechanism of the regulation of SP molecules on immunomodulation in the female reproductive tract. Moreover, we also discussed the proteins investigated as non-invasive diagnosis biomarkers for male infertility in the clinic.
  • 1.9K
  • 17 Nov 2020
Topic Review
Histone Deacetylase Inhibitors
Histone deacetylases (HDACs) are key components of the epigenetic machinery controlling gene expression. They are involved in chromatin remodeling events via post-translational histone modifications but may also act on nonhistone proteins, influencing many fundamental cellular processes. Due to the key involvement of HDACs in serious human pathologies, including cancer, HDAC inhibitors (HDACis) have received increased attention in recent years. It is known that marine invertebrates produce significant amounts of secondary metabolites showing active pharmacological properties and an extensive spectrum of biomedical applications. Some of these compounds possess HDACi properties.
  • 1.9K
  • 11 Dec 2020
Topic Review
Software for Mass Spectrometry-based Lipidomics
Mass spectrometry (MS) is a state-of-the-art analytical technology, which enables the rapid and consistent identification and quantification of lipids in lipidomics, metabolites in metabolomics and proteins in proteomics for biomedical and biochemical research purposes.
  • 1.9K
  • 01 Jul 2022
Topic Review
Prebiotic Synthesis of Ribose
Prebiotic reactions describe how biomolecules such as ribose, was synthesized and protected from degradation, nucleobases generated from HCN oligomers and other derivatives including prebiotic RNA (preRNA) were formed at the given circumstances. Prebiotic conditions remained a subject of debate, but a reasonable aspect to consider is that tetrahedral structure shaping biomolecules consisted almost exclusively of elements belonging to the CHNOPS group in the periodic table, where capital letters correspond to the elements of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Intermediary steps in the formose reaction network contain aldol condensation, aldose-ketose isomerizations, producing C3 - C6 carbohydrates including pentoses. The generation of genetic material could have developed from the formose reaction to ribose and further to non-genetic prebiotic  RNA (preRNA) [1-9]. Consecutive reactions of this pathway are not known. Those known abiotic chemical reactions were selected that could have resulted in preRNA and genetic RNA (genRNA).  Processes generating primitive life on Earth consisted of three successive stages: i) abiotic reactions generating organic molecules, ii) formation of molecular aggregates showing primitive metabolism, iii) development of primitive cells and organisms resembling those that exist today. Only cellular life is known that adapted in every aspect to conditions that exist only on Earth. Here only the 1st stage, the abiotic phase is dealt with. Prebiotic conditions remained subjects of debate ranging from a strong reductive to a strong oxidative climate. Our theory is based on a mildly reductive atmosphere that could have existed at the beginning of life some 4.3 -4.5 billion years ago, much before the Great Oxidation Event that took place much later 2.3 - 2.5 billion years ago. During the abiotic synthesis of organic molecules, ribose was selected as the precursor to life. .
  • 1.9K
  • 15 Jun 2021
Topic Review
Mast Cells
Mast Cells (MCs), from the German mast meaning well-fed, were first described by Paul Ehrlich in 1878 based on the unique color-changing granules within these cells. In fact, MCs are easily recognizable with characteristic toluidine blue-positive granules in the cytoplasm. Their granules contain several elements, such as histamine, serotonin, heparin, proteases (chymase, tryptase, carboxypeptidase), cytokines and other growth factors (vascular endothelial growth factor, VEGF; fibroblast growth factor-2, FGF-2). Tryptases and chymases are considered MC-specific proteases, but the granules also contain some non-specific enzymes, such as metalloproteinase-9.
  • 1.9K
  • 28 Sep 2021
Topic Review
Cytoplasmic Actin Mutations
Cytoplasmic actins are abundant molecules in non-muscle cells, including white blood cells. Two forms exist which are referred to as beta- or gamma-cytoplasmic actin encoded by ACTB and ACTG1, respectively. They form the building blocks of the dynamic actin polymers of the cytoskeleton that are involved in migration and motility processes of cells. Whereas mutations in cytoplasmic actins have been discovered in congenital diseases, their prevalence in cancer types has not been studied in detail. We show that within hematological cancer cytoplasmic actin mutations occur with higher frequency in two specific subtypes. Beta-actin mutations occur mainly in the subtype diffuse large B-cell lymphoma or DLBCL whereas gamma-actin mutations occur mainly in multiple myeloma. Mapping these mutations on the three dimensional structure reveals they map to regions of actin that are important in actin polymer formation and, for gamma-actin also for myosin interaction. Given their occurrence in these functionally important regions, their role as potential driver mutations or in disease progression merits further investigation.
  • 1.9K
  • 28 Oct 2020
Topic Review
Fluorescence Microscopy to Aanalyze Lignin
Lignin is one of the most studied and analyzed materials due to its importance in cell structure and in lignocellulosic biomass. Because lignin exhibits autofluorescence, fluorescence microscopy methods have been developed that allow it to be analyzed and characterized directly in plant tissue and in samples of lignocellulose fibers. Compared to destructive and costly analytical techniques, fluorescence microscopy presents suitable alternatives for the analysis of lignin autofluorescence. The existing qualitative methods are Epifluorescence and Confocal Laser Scanning Microscopy; however, other semi-qualitative methods have been developed that allow fluorescence measurements and to quantify the differences in the structural composition of lignin. The methods are fluorescence lifetime spectroscopy, two-photon microscopy, Föster resonance energy transfer, fluorescence recovery after photobleaching, total internal reflection fluorescence, and stimulated emission depletion. With these methods, it is possible to analyze the transport and polymerization of lignin monomers, distribution of lignin of the syringyl or guaiacyl type in the tissues of various plant species, and changes in the degradation of wood by pulping and biopulping treatments as well as identify the purity of cellulose nanofibers through lignocellulosic biomass.
  • 1.9K
  • 21 Mar 2022
Topic Review
Oxidative Stress in NAFLD
Oxidative stress is defined as an imbalance between the cellular levels of antioxidants and that of pro-oxidants, including ROS and reactive nitrogen species, which causes cellular damage and, in most cases, cell death. Non-alcoholic fatty liver disease (NAFLD) is often the hepatic expression of metabolic syndrome and its comorbidities that comprise, among others, obesity and insulin-resistance. At the molecular level, several models have been proposed for the pathogenesis of NAFLD. Most importantly, oxidative stress and mitochondrialdamage have been reported to be causative in NAFLD initiation and progression.
  • 1.9K
  • 02 Aug 2021
Topic Review
DPSCs in Regenerative Therapy
Recently, dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHEDs) have attracted substantial attention as promising cell sources for tissue regeneration. Here, we summarized the features of DPSCs and SHEDs such as high growth capacity, multipotency, expression of cell markers, immunomodulatory effects, and their potential to regenerate various somatic tissues.  Mesenchymal stem cells (MSCs) have the capacity for self-renewal and multilineage differentiation potential, and are considered a promising cell population for cell-based therapy and tissue regeneration. MSCs are isolated from various organs including dental pulp, which originates from cranial neural crest-derived ectomesenchyme. Recently, dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHEDs) have been isolated from dental pulp tissue of adult permanent teeth and deciduous teeth, respectively. Because of their MSC-like characteristics such as high growth capacity, multipotency, expression of MSC-related markers, and immunomodulatory effects, they are suggested to be an important cell source for tissue regeneration.
  • 1.9K
  • 09 Nov 2020
Topic Review
Cobra Venom
Cobras (genus Naja) are widely distributed over Asia and Africa, and cobra envenomation is responsible for a large number of mortality and morbidity on these continents. Like other elapid venoms, cobra venoms are neurotoxic in nature; however, they also exhibit local cytotoxic effects at the envenomed site, and the extent of cytotoxicity may vary from species to species. Cobra venoms are predominated by the non-enzymatic three-finger toxin family which constitutes about 60-75% of the total venom. Cytotoxins (CTXs), an essential class of the non-enzymatic three-finger toxin family, are ubiquitously present in cobra venoms. These low-molecular-mass toxins, contributing to about 40 to 60% of the cobra venom proteome, play a significant role in cobra venom-induced toxicity, more prominently in dermonecrosis (local effects).
  • 1.9K
  • 12 Dec 2022
Topic Review
HIV Infection within the CNS
HIV can traverse the BBB using a Trojan horse-like mechanism. Hidden within infected immune cells, HIV can infiltrate the highly safeguarded CNS and propagate disease. Once integrated within the host genome, HIV becomes a stable provirus, which can remain dormant, evade detection by the immune system or antiretroviral therapy (ART), and result in rebound viraemia. As ART targets actively replicating HIV, has low BBB penetrance, and exposes patients to long-term toxicity, further investigation into novel therapeutic approaches is required.
  • 1.9K
  • 13 Jul 2022
Topic Review
Regulation of Membrane Fluidity in Cold Environments
Temperature changes and periods of detrimental cold occur frequently for many organisms in their natural habitats. Homeothermic animals have evolved metabolic adaptation strategies to increase mitochondrial-based energy expenditure and heat production, largely relying on fat as a fuel source. Alternatively, certain species are able to repress their metabolism during cold periods and enter a state of decreased physiological activity known as torpor. By contrast, poikilotherms, which are unable to maintain their internal temperature, predominantly increase membrane fluidity to diminish cold-related damage from low-temperature stress.
  • 1.9K
  • 05 Jun 2023
Topic Review
Biological Actions of Curcumin
Curcumin (CCM) is one of the most frequently explored plant compounds with various biological actions such as antibacterial, antiviral, antifungal, antineoplastic, and antioxidant/anti-inflammatory properties. The laboratory data and clinical trials have demonstrated that the bioavailability and bioactivity of curcumin are influenced by the feature of the curcumin molecular complex types. Curcumin has a high capacity to form molecular complexes with proteins (such as whey proteins, bovine serum albumin, β-lactoglobulin), carbohydrates, lipids, and natural compounds (e.g., resveratrol, piperine, quercetin).
  • 1.9K
  • 02 Feb 2023
Topic Review
Zika Virus
Zika virus (ZIKV) is an emergent arthropod-borne virus whose outbreak in Brazil has brought major public health problems. Infected individuals have different symptoms, including rash and pruritus, which can be relieved by the administration of antiallergics. In the case of pregnant women, ZIKV can cross the placenta and infect the fetus leading to congenital defects. We have identified that mast cells in the placentae of patients who had Zika during pregnancy can be infected. This led to our investigation on the possible role of mast cells during a ZIKV infection, using the HMC-1 cell line. We analyzed their permissiveness to infection, release of mediators and ultrastructural changes. Flow cytometry detection of ZIKV-NS1 expression 24h post infection in 45.3% of cells showed that HMC-1 cells are permissive to ZIKV infection. Following infection, β-hexosaminidase was measured in the supernatant of the cells with a notable release at 30 min. In addition, an increase in TNF-α, IL-6, IL-10 and VEGF levels were measured at 6h and 24h post infection. Lastly, different intracellular changes were observed in an ultrastructural analysis of infected cells. Our findings suggest that mast cells may represent an important source of mediators that can activate other immune cell types during a ZIKV infection, which has the potential to being a major contributor in the spread of the virus in cases of vertical transmission.
  • 1.9K
  • 30 Oct 2020
Topic Review
Bioactive Antimicrobial Peptides
Among the biomolecules of emerging scientific interest are antimicrobial peptides (AMPs), potent biomolecules that can potentially act as important weapons against infectious diseases. Moreover, synthetic AMPs are easily tailored (bioinformatically) to target specific features of the pathogens to hijack, inducing no or very low resistance. 
  • 1.9K
  • 17 Aug 2022
Topic Review
Pistachio as a Regular Food
The pistachio is regarded as a relevant source of biologically active components that, compared to other nuts, possess a healthier nutritional profile with low-fat content composed mainly of monounsaturated fatty acids, a high source of vegetable protein and dietary fibre, remarkable content of minerals, especially potassium, and an excellent source of vitamins, such as vitamins C and E. A rich composition in terms of phytochemicals, such as tocopherols, carotenoids, and, importantly, phenolic compounds, makes pistachio a powerful food to explore its involvement in the prevention of prevalent pathologies. 
  • 1.9K
  • 29 Sep 2022
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