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Topic Review
Peroxidase Mimetic Nanozymes in Cancer
Peroxidase (POD) mimetic nanozymes converts endogenous H2O2 to water (H2O) and reactive oxygen species (ROS) in a hypoxic tumor microenvironment is a fascinating approach.
  • 1.2K
  • 31 Aug 2021
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
Topic Review
MiRNA–RBP Binding Functions
MicroRNAs (miRNAs), short-chain RNAs of 18–22 nt chain length, are expressed in all vertebrates and control tissue development, differentiation, cell growth, and apoptosis in non-cancer and cancer cells. Additionally, miRNAs target mRNAs on the basis of their sequence and decrease protein production by inhibiting mRNA translation or destroying the mRNAs, thereby controlling cellular homeostasis. miRNA expression is controlled through DNA modification, such as by methylation and transcriptional factors through the signal-transduction pathway. miRNAs are transcribed as pri-mature from DNA and are then processed by the Drosha complex, thus generating pre-miRNAs. These pre-miRNAs are transported by exportin 5 from the nucleus to the cytoplasm and further processed by Dicer to form the double-stranded miRNA RNA-induced silencing complex (RISC). RISCs involving single-strand miRNAs, comprising Ago, Dicer, and trans-activation-responsive RNA-binding protein (TRBP) 2, are directed to the mRNA targets, thus regulating protein expressions. To date, the bioinformatics databases TargetScan (http://www.targetscan.org/vert_72/, 26 September 2021) and miRTarBase (http://mirtarbase.cuhk.edu.cn/php/index.php, 26 September 2021) have been used to predict the interaction between miRNAs and target mRNAs.
  • 1.2K
  • 01 Dec 2021
Topic Review
Pulmonary Stem Cell Senescence and Differentiation Disorders
Pulmonary senescence is accelerated by unresolved DNA damage response, underpinning susceptibility to pulmonary fibrosis. Recently it was reported that the SARS-Cov-2 viral infection induces acute pulmonary epithelial senescence followed by fibrosis. Notably, the TGF-β signalling pathway mediates alveolar epithelial stem cell senescence by mechanisms involving suppression of the telomerase reverse transcriptase gene in pulmonary fibrosis. Alternatively, telomere uncapping caused by stress-induced telomeric shelterin protein TPP1 degradation mediates DNA damage response, pulmonary senescence and fibrosis. However, targeted intervention of cellular senescence disrupts pulmonary remodelling and fibrosis by clearing senescent cells using senolytics or preventing senescence using telomere dysfunction inhibitor (TELODIN). Studies indicate that the development of senescence-associated differentiation disorders is reprogrammable and reversible by inhibiting stem cell replicative senescence in pulmonary fibrosis, providing a framework for targeted intervention of the molecular mechanisms of alveolar stem cell senescence and pulmonary fibrosis.
  • 1.2K
  • 18 Mar 2022
Topic Review
Toxic Effects of Highly Active Antiretroviral Therapy
Highly active antiretroviral therapy (HAART) comprises a combination of two or three antiretroviral (ARV) drugs that are administered together in a single tablet. These drugs target different steps within the human immunodeficiency virus (HIV) life cycle, providing either a synergistic or additive antiviral effect; this enhances the efficiency in which viral replication is suppressed. HIV cannot be completely eliminated, making HAART a lifetime treatment. With long-term HAART usage, an increasing number of patients experience a broadening array of complications, and this significantly affects their quality of life, despite cautious use. 
  • 1.2K
  • 08 Oct 2022
Topic Review
Cellular Prion Protein in Cancer Biology
Prion-like proteins and prions (PrPC), the prion protein cellular form, shares 90% of its amino acid sequence with other mammalian proteins. PrPCs are expressed almost in all tissues of an organism, but a higher amount of PrPCs has been found in the central nervous system (CNS), particularly the synaptic membranes and PrPC are linked. Scrapie PrP (PrPSc), a mutant cellular prion protein with an altered structure, is assumed to be the key etiological cause of prion diseases. Cancers are worldwide health concerns, whether they are sporadic or hereditary. The fundamental mechanism that causes somatic or oncogenic mutations and ultimately aids cancer development is still unknown. However, mammalian cells with protein-only somatic inheritance may also contribute to cancerous malignancies. Emerging data from a recent study show that prion-like proteins and prions (PrPC) are crucial entities that have a functional role in developing neurological disorders and cancer. Furthermore, excessive PrPC expression profiling has also been detected in non-neuronal tissues, such as the lymphoid cells, kidney, GIT, lung, muscle, and mammary glands. PrPC expression is strongly linked with the proliferation and metastasis of pancreatic, prostate, colorectal, and breast malignancies. Experimental investigation presented that the PrPC expression, including the prion protein-coding gene (PRNP) and p53 ag are directly associated with tumorigenicity and metastasis (tumor suppressor gene). The ERK2 (extracellular signal-regulated kinase) pathway also confers a robust metastatic capability for PrPC-induced epithelial to mesenchymal transition. Additionally, prions could alter the epigenetic regulation of genes and overactive the mitogen-activated protein kinase (MAPK) signaling pathway, which promotes the development of cancer in humans. 
  • 1.2K
  • 17 Jul 2025
Topic Review
Glycosaminoglycans in Cancer Therapy
The tumor microenvironment (TME) is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded by the components of the extracellular matrix (ECM). Glycosaminoglycans (GAGs), natural biomacromolecules, essential ECM, and cell membrane components are extensively altered in cancer tissues. During disease progression, the GAG fine structure changes in a manner associated with disease evolution. Thus, changes in the GAG sulfation pattern are immediately correlated to malignant transformation. Their molecular weight, distribution, composition, and fine modifications, including sulfation, exhibit distinct alterations during cancer development. GAGs and GAG-based molecules, due to their unique properties, are suggested as promising effectors for anticancer therapy. Considering their participation in tumorigenesis, their utilization in drug development has been the focus of both industry and academic research efforts. These efforts have been developing in two main directions; (i) utilizing GAGs as targets of therapeutic strategies and (ii) employing GAGs specificity and excellent physicochemical properties for targeted delivery of cancer therapeutics.
  • 1.2K
  • 24 Mar 2021
Topic Review
Biological Activities of Some Species of Genus Eryngium
There are approximately 250 species of Eryngium L. distributed throughout the world, with North America and South America being centers of diversity on this continent. In the central-western region of Mexico there may be around 28 species of this genus. Some Eryngium species are cultivated as leafy vegetables, ornamental, and medicinal plants. In traditional medicine they are used to treat respiratory and gastrointestinal conditions, diabetes, and dyslipidemia, among others. 
  • 1.2K
  • 30 May 2023
Topic Review
Extracellular Vesicles Cargo and Roles
Extracellular vesicles (EVs) are membranous structures produced in the endosomal system or generated by plasma membrane shedding, which have been identified as an important hallmark for intercellular communication. Among them, a particular category of EVs are the exosomes, which are nanovesicles of approximately 30-150 nm, produced in the endosomal pathway. 
  • 1.2K
  • 27 Nov 2020
Topic Review
Gestational Factors Throughout Fetal Neurodevelopment
Serotonin (5-HT) is a critical player in brain development and neuropsychiatric disorders. Fetal 5-HT levels can be influenced by several gestational factors, such as maternal genotype, diet, stress, medication, and immune activation. In this review, addressing both human and animal studies, we discuss how these gestational factors affect placental and fetal brain 5-HT levels, leading to changes in brain structure and function and behavior. We conclude that gestational factors are able to interact and thereby amplify or counteract each other’s impact on the fetal 5-HT-ergic system. We, therefore, argue that beyond the understanding of how single gestational factors affect 5-HT-ergic brain development and behavior in offspring, it is critical to elucidate the consequences of interacting factors. Moreover, we describe how each gestational factor is able to alter the 5-HT-ergic influence on the thalamocortical- and prefrontal-limbic circuitry and the hypothalamo-pituitary-adrenocortical-axis. These alterations have been associated with risks to develop attention deficit hyperactivity disorder, autism spectrum disorders, depression, and/or anxiety. Consequently, the manipulation of gestational factors may be used to combat pregnancy-related risks for neuropsychiatric disorders.
  • 1.2K
  • 27 Oct 2020
Topic Review
The anticancer properties of Oligonucleotides
       Telomerase provides cancer cells with replicative immortality, and its overexpression serves as a near-universal marker of cancer. Oligonucleotide-based therapies that inhibit telomerase through direct or indirect modulation of its subunits, human telomerase reverse transcriptase (hTERT) and human telomerase RNA gene (hTERC), are a unique and diverse subclass of telomerase inhibitors which hold clinical promise. 
  • 1.2K
  • 25 Aug 2020
Topic Review
Amsacrine
Amsacrine, an anticancer drug first synthesised in 1970 by Professor Cain and colleagues, showed excellent preclinical activity and underwent clinical trial in 1978 under the auspices of the US National Cancer Institute, showing activity against acute lymphoblastic leukaemia.
  • 1.2K
  • 25 Feb 2021
Topic Review
MEIS1 in Hematopoiesis and Cancer
MEIS1 is highly expressed in the bone marrow, and its predominant and better-known role is in embryonic and adult hematopoiesis. Along withPBX1 and HOXA9, MEIS1 is expressed in hematopoietic stem cells (HSCs) but downregulated during their differentiation.
  • 1.2K
  • 27 Oct 2021
Topic Review
Ursolic Acid in Cancer and Diabetic Neuropathy Diseases
Ursolic acid (UA) is a promising triterpenoid compound present in several plants’ leaves, flowers, and fruits. It shows a broad range of pharmaceutical properties and therapeutic effects. UA has been utilized as a herbal medicine with excellent pharmacological activities.
  • 1.2K
  • 19 Nov 2021
Topic Review
Evaluation of Biological Activity of Natural Compounds
Natural compounds have diverse structures and are present in different forms of life. Metabolites such as tannins, anthocyanins, and alkaloids, among others, serve as a defense mechanism in live organisms and are undoubtedly compounds of interest for the food, cosmetic, and pharmaceutical industries.
  • 1.2K
  • 01 Aug 2022
Topic Review
RNA Structure and RNA–RNA Interactions
Complex RNA–RNA interactions are increasingly known to play key roles in numerous biological processes from gene expression control to ribonucleoprotein granule formation. By contrast, the nature of these interactions and characteristics of their interfaces, especially those that involve partially or wholly structured RNAs, remain elusive. This entry describes different modalities of RNA–RNA interactions with an emphasis on those that depend on secondary, tertiary, or quaternary structure, and highlight a two-way relationship between RNA structure and interactions.
  • 1.2K
  • 12 Jan 2022
Topic Review
α-Helices in the T3SEs
Type III Secretion Systems (T3SSs) are multicomponent nanomachines located at the cell envelope of Gram-negative bacteria. Their main function is to transport bacterial proteins either extracellularly or directly into the eukaryotic host cell cytoplasm. Type III Secretion effectors (T3SEs), latest to be secreted T3S substrates, are destined to act at the eukaryotic host cell cytoplasm and occasionally at the nucleus, hijacking cellular processes through mimicking eukaryotic proteins. T3SE families adopt novel folds to target eukaryotic functions. These folds comprise a high helical content, which possibly reflects the specific requirements from T3SS effectors. In particular, effectors must (i) be able to be easily unfolded, (ii) cross the narrow T3S channel, (iii) be highly folded as soon as they will be found inside the host cell, in order to evade the host defense mechanisms, and (iv) display functional competence and structural plasticity in their final destination. α-helices can optimally fulfil these requirements.
  • 1.2K
  • 06 Jun 2021
Topic Review
ADAM Proteases
Limited proteolysis reactions by a disintegrin and metalloproteases (ADAMs) are key events in several paracrine signalling pathways. Therefore, ADAM proteases might also represent master-switches during hepatic fibrosis and other pathophysiologic events. Known and potential fibrosis-associated pathways regulated by ADAM proteases are discussed and the current knowledge on ADAM protease implication in several disease states is reviewed.
  • 1.2K
  • 13 Jul 2023
Topic Review
Polymorphism in α-Synuclein
The synucleinopathies exhibit differences in their clinical and pathological representations, reminiscent of prion disorders. Emerging evidence suggests that α-Syn self-assembles and polymerizes into conformationally diverse polymorphs in vitro and in vivo, similar to prions. These α-Syn polymorphs arising from the same precursor protein may exhibit strain-specific biochemical properties and the ability to induce distinct pathological phenotypes upon their inoculation in animal models.
  • 1.2K
  • 20 Oct 2021
Topic Review
Potential Chemicals from Plastic Wastes
Plastic is referred to as a “material of every application”. From the packaging and automotive industries to the medical apparatus and computer electronics sectors, plastic materials are fulfilling demands efficiently. These plastics usually end up in landfills and incinerators, creating plastic waste pollution. According to the Environmental Protection Agency (EPA), in 2015, 9.1% of the plastic materials generated in the U.S. municipal solid waste stream was recycled, 15.5% was combusted for energy, and 75.4% was sent to landfills. 
  • 1.2K
  • 10 Jun 2021
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