ResearchPad - pharmacology-toxicology https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Cytotoxicity of snake venom enzymatic toxins: phospholipase A<sub>2</sub> and <span style="font-variant: all-small-caps">l</span>-amino acid oxidase]]> https://www.researchpad.co/article/elastic_article_9179 The phospholipase A2 (PLA2) and l-amino acid oxidase (LAAO) are two major enzymes found in the venoms from most snake species. These enzymes have been structurally and functionally characterised for their pharmacological activities. Both PLA2 and LAAO from different venoms demonstrate considerable cytotoxic effects on cancer cells via induction of apoptosis, cell cycle arrest and suppression of proliferation. These enzymes produce more pronounced cytotoxic effects in cancer cells than normal cells, thus they can be potential sources as chemotherapeutic agents. It is proposed that PLA2 and LAAO contribute to an elevated oxidative stress due to their catalytic actions, for instance, the ability of PLA2 to produce reactive oxygen species during lipolysis and formation of H2O2 from LAAO catalytic activity which consequently lead to cell death. Nonetheless, the cell-death signalling pathways associated with exposure to these enzymatic toxins are not fully elucidated yet. Here in this review, we will discuss the cytotoxic effects of PLA2 and LAAO in relationship to their catalytic mechanisms and the underlying mechanisms of cytotoxic actions.

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<![CDATA[Small molecules that target the ubiquitin system]]> https://www.researchpad.co/article/elastic_article_9166 Eukaryotic life depends upon the interplay between vast networks of signaling pathways composed of upwards of 109–1010 proteins per cell. The integrity and normal operation of the cell requires that these proteins act in a precise spatial and temporal manner. The ubiquitin system is absolutely central to this process and perturbation of its function contributes directly to the onset and progression of a wide variety of diseases, including cancer, metabolic syndromes, neurodegenerative diseases, autoimmunity, inflammatory disorders, infectious diseases, and muscle dystrophies. Whilst the individual components and the overall architecture of the ubiquitin system have been delineated in some detail, how ubiquitination might be successfully targeted, or harnessed, to develop novel therapeutic approaches to the treatment of disease, currently remains relatively poorly understood. In this review, we will provide an overview of the current status of selected small molecule ubiquitin system inhibitors. We will further discuss the unique challenges of targeting this ubiquitous and highly complex machinery, and explore and highlight potential ways in which these challenges might be met.

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<![CDATA[Avidin-biotin technology to synthesize multi-arm nano-construct for drug delivery]]> https://www.researchpad.co/article/elastic_article_5891 Image, graphical abstract

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<![CDATA[Pipeline for the removal of hardware related artifacts and background noise for Raman spectroscopy]]> https://www.researchpad.co/article/N62784fe2-635a-4b82-912b-cad3436d7cd3 Image, graphical abstract

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<![CDATA[Effect of X-rays on transcript expression of rat brain microvascular endothelial cells: role of calcium signaling in X-ray-induced endothelium damage]]> https://www.researchpad.co/article/N72b39923-c2d8-4ebf-a27e-945e6e2318e0 Radiation-induced brain edema is a serious adverse effect of radiotherapy. Although there are many causes of radiation-induced brain edema, the pathogenesis is not clear and clinical treatment is not ideal. Therefore, knowing the differential expression of the brain microvascular endothelial cell (BMEC) transcriptome after brain radiotherapy may shed light on the pathogenesis of radiation-induced brain edema. The present study used RNA-Seq technique to identify 383 BMEC transcripts differentially expressed (many 2-fold or higher; P < 0.05) between control and X-ray–treated primary cultured rat BMECs. Compared with controls, X-ray–treated BMECs had 183 significantly up-regulated transcripts and 200 significantly down-regulated transcripts. The differentially expressed genes were associated with the biological processes of the cell cycle, apoptosis, vascular permeability, and extracellular junctions. The functional changes identified in the X-ray–treated BMECs included Ca2+ signaling, phosphoinositide 3-kinase–Akt signaling, and methionine degradation. These results indicated that transcript expression was substantially affected by radiation exposure and the proteins encoded by these differentially expressed genes may play a significant role in radiotherapy-induced brain edema. Our findings provide additional insight into the molecular mechanisms of radiation-induced brain edema and may be helpful in the development of clinical treatment of this adverse reaction to radiotherapy.

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<![CDATA[A novel method for the collection of highly developmental murine immature oocytes]]> https://www.researchpad.co/article/N2cfb2892-63b5-43ce-982e-b341a580758c Image, graphical abstract

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<![CDATA[Data on metabolic stability, aqueous solubility and CYP inhibition of novel triazole-based nicotinamide phosphoribosyltransferase (NAMPT) inhibitors]]> https://www.researchpad.co/article/N60ba1e8b-af71-45b3-ab92-d5cb2dc5e5e0

In the related research article, entitled “Identification of novel triazole-based nicotinamide phosphoribosyltransferase (NAMPT) inhibitors endowed with antiproliferative and antiinflammatory activity” [1], we reported the in vitro hepatic metabolism data for compounds 30c, 48b, and 31b (here named as E5, A6, and T1), in comparison with the reference compounds GPP78 and FK866 [1–3]. In this article, we retrieved the available data about the hepatic microsomal stability and metabolites structural characterization of the entire library of triazole-based NAMPT inhibitors, also implementing the given information with data regarding aqueous solubility and CYP inhibition. Compounds are divided in subclasses based on the hydrolytic resistant groups replacing the amide function of GPP78 [1, 2].

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<![CDATA[Data of ureagenesis from ammonia, glutamine and alanine, and mitochondrial aquaporin-8 expression in thioacetamide-treated hepatocytes]]> https://www.researchpad.co/article/N31bbd1ba-207b-4380-9fa0-013b26ff2dd3

We present data about the synthesis of urea from different substrates, i.e., free ammonia, glutamine and alanine in primary cultured rat hepatocytes treated or untreated with the model hepatotoxic agent thioacetamide (TAA). We also provide data about the expression of mitochondrial aquaporin-8 (mtAQP8), a hepatocyte channel protein which facilitates ammonia diffusion into mitochondria to supply the urea cycle. Ammonia-derived ureagenesis was significantly inhibited by about 30% while that from the both amino acids resulted unaffected in TAA-treated hepatocytes. Protein expression of mtAQP8 was decreased by about 80% after TAA treatment. These data can be useful for the understanding of the mechanisms of drug-induced hepatic dysfunction.

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<![CDATA[Data on the stability of darunavir/cobicistat suspension after tablet manipulation]]> https://www.researchpad.co/article/Nb07c557b-e791-4fd2-8ef9-697b722fc19b

The COVID-19 outbreak is now one of the most critical crises to manage for most of the national healthcare systems in the world. In the absence of authorised pharmacological treatments, many antiretrovirals, including darunavir/cobicistat fixed combination, are used off-label in the hospital wards as life-treating medicines for COVID-19 patients. Unfortunately, for most of them, the drug products available on the market are not designed to be administered by a nasogastric tube to inpatients of intensive care units. Therefore, their manipulation, even if it can strongly affect the product quality, is necessary for the preparation of suspension to meet patients’ need. In this situation, it is urgent to provide data and guidance to support hospital pharmacists and clinicians in their activity. The data in this article indicate that darunavir/cobicistat suspensions compounded by pharmacists using as active ingredient a commercially available tablet can be stable at least for one week.

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<![CDATA[Secondary prevention of acute coronary syndrome with antiplatelet agents in real life: A high-dimensional propensity score matched cohort study in the French National claims database]]> https://www.researchpad.co/article/N40eff8b8-f258-43ec-82a3-f4c81c576861

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<![CDATA[Extracellular DNA in blood products and its potential effects on transfusion]]> https://www.researchpad.co/article/N2c43a6d9-b325-4827-8d79-69a6ffb5c163

Abstract

Blood transfusions are sometimes necessary after a high loss of blood due to injury or surgery. Some people need regular transfusions due to medical conditions such as haemophilia or cancer. Studies have suggested that extracellular DNA including mitochondrial DNA present in the extracellular milieu of transfused blood products has biological actions that are capable of activating the innate immune systems and potentially contribute to some adverse reactions in transfusion. From the present work, it becomes increasingly clear that extracellular DNA encompassed mitochondrial DNA is far from being biologically inert in blood products. It has been demonstrated to be present in eligible blood products and thus can be transfused to blood recipients. Although the presence of extracellular DNA in human plasma was initially detected in 1948, some aspects have not been fully elucidated. In this review, we summarize the potential origins, clearance mechanisms, relevant structures, and potential role of extracellular DNA in the innate immune responses and its relationship with individual adverse reactions in transfusion.

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<![CDATA[The method simulating spontaneous pain in patients with nociplastic pain using rats with fibromyalgia-like condition]]> https://www.researchpad.co/article/N7b23d9d7-4da4-4ec5-a86b-1cd7d92bc21e

The method shown in this article simulates spontaneous pain in patients with nociplastic pain using rats; the measurement with this method could be related to better translation of analgesic efficacies of therapeutic compounds between rats and humans. Nociplastic pain occurs in various disorders including fibromyalgia. Because the pain in patients occurs without an external stimulus, we assessed spontaneous pain in rats. The grimace scale, a methodology for rating facial expression, has been used for measuring spontaneous pain in animals. However, the responses in animals have been rather short-lived, and the scale has never been applied to animals exhibiting nociplastic pain. Here, we apply the rat grimace scale (RGS) to the reserpine-induced fibromyalgia-like rat, which induces nociplastic pain. The ratings of the orbital tightening, nose/cheek flattening, and changes in characteristics of ears and whiskers by three raters, who were blinded to the treatment allocated to rats, demonstrated substantial, long-lasting change in facial expression of rats. In this article, reference images for raters, and sample images used for rater training are provided. All raters independently indicated that the RGS score is significantly elevated with this methodology in reserpine-induced fibromyalgia-like rats.

  • The grimace scale, a method for rating facial expression, is applied to the reserpine-induced fibromyalgia-like rat, which manifests nociplastic pain.

  • Facial expression change in the reserpine-induced fibromyalgia-like rat is substantial and long-lasting.

  • Elevation of the RGS score in the reserpine-induced fibromyalgia-like rat may simulate spontaneous pain in patients with nociplastic pain.

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<![CDATA[Data on GC-MS analysis, in vitro anti-oxidant and anti-microbial activity of the Catharanthus roseus and Moringa oleifera leaf extracts]]> https://www.researchpad.co/article/N6a38c90d-0037-4102-b25f-966a2cdd83eb

The article reports data on chemical profiling by gas chromatography-mass spectrometry (GC-MS) of aqueous and methanolic leaf extracts of Madagascar periwinkle (Catharanthus roseus) and drumstick tree (Moringa oleifera) and on their antioxidant and antibacterial effects against three clinical human pathogens. In total 105 compounds were tentatively identified; in which 65 in Catharanthus roseus and 40 in Moringa oleifera compounds. A large number of peaks with good area percentage was found in methanolic extract of Catharanthus roseus with core chemical constituents such as trans-squalene, n-hexadecanoic acid, Eicosyl acetate, stearin, 1H-Benz(G)indole-3-carboxylic acid. The corresponding constituents from Moringa oleifera include 9-Octadecenoic acid (z)-, Heptadecanoic acid and phytol acetate. The highest scavenging activity (87.7% at 200 μg/mL) was shown by DPPH aqueous leaf extract of C. roseus. Moreover, the methanolic scavenging of both plant extracts was in the order of FRAP>DPPH>NO> H2O2 with lowest antioxidant activity (51.4% at 200 μg/mL) exposed by Catharanthus roseus in comparison of all cases. Good antibacterial action was examined against three different organisms (E.coli, B. subtilis and S. aureus) of aqueous infusion of Catharanthus roseus.

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<![CDATA[A method to dissolve 3-MCPD mono- and di-esters in aqueous cell culture media]]> https://www.researchpad.co/article/N845aa6e8-ad45-4619-a30e-ca25563e4888

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<![CDATA[Effects of emodin on inflammatory bowel disease-related osteoporosis]]> https://www.researchpad.co/article/Ndf5dd2c6-1bd2-42f9-92d8-2a5c6fe403f5

Abstract

Inflammatory bowel diseases (IBD) are related to bone loss. Emodin can influence the activity and differentiation of osteoblasts and osteoclasts. However, few studies have shown the effects of emodin on IBD-induced bone damage. The aim of the present study was to investigate the role of emodin in IBD-induced osteoporosis in an animal model. An IBD model in Sprague Dawley male rats was established by administering 2.5% dextran sulfate sodium (DSS) in the drinking water. Emodin was administered orally (30 mg/kg body weight) every other day starting in the third week for 9 weeks. Blood, colon and bone samples were obtained for biomarker assays and histological analysis. Bone biomechanical properties, microCT, metabolic biomarkers and bone histological changes were analyzed. The bone mass was significantly decreased, and the bone biomechanical properties and bone microstructure parameters of IBD rats were significantly worse than those of control rats (P<0.05). Tartrate resistant acid phosphatase staining also showed that the number of osteoclasts in bone in IBD rats were larger than that in bone in control rats. Emodin intervention abolished the changes in bone microstructure and biomechanical properties (P<0.05) induced by IBD. Osteoclast formation and serum C-terminal cross-linked peptide (CTX) and tumor necrosis factor α (TNF-α) were also inhibited by emodin (P<0.05). Emodin significantly abolished IBD-enhanced Traf6, NFATC1 and c-fos expression. Our data demonstrated that emodin suppresses IBD-induced osteoporosis by inhibiting osteoclast formation.

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<![CDATA[Immobilized DNA aptamers used as potent attractors for vascular endothelial cell: in vitro study of female rat]]> https://www.researchpad.co/article/N22bf139b-96b7-4760-8738-29be5d4e06b2

Abstract

Vascular endothelial cells are essential to vascular function and maintenance. Dysfunction of these cells can lead to the development of cardiovascular disease or contribute to tumorigenesis. As such, the therapeutic modulation and monitoring of vascular endothelial cells are of significant clinical interest, and several endothelial-specific ligands have been developed for drug delivery and the monitoring of endothelial function. However, the application of these ligands has been limited by their high cost and tendency to induce immune responses, highlighting a need for alternate methods of targeting vascular endothelial cells. In the present study, we explore the therapeutic potential of DNA aptamers. Using cell-SELEX technology, we identified two aptamers with specific binding affinity for vascular endothelial cells and propose that these molecules show potential for use as new ligands for drug and biomarker research concerning vascular endothelial cells.

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<![CDATA[Proteostasis regulators modulate proteasomal activity and gene expression to attenuate multiple phenotypes in Fabry disease]]> https://www.researchpad.co/article/Ncb67bb93-58cf-4196-99ee-9f62076d3ef2

The lysosomal storage disorder Fabry disease is characterized by a deficiency of the lysosomal enzyme α-Galactosidase A. The observation that missense variants in the encoding GLA gene often lead to structural destabilization, endoplasmic reticulum retention and proteasomal degradation of the misfolded, but otherwise catalytically functional enzyme has resulted in the exploration of alternative therapeutic approaches. In this context, we have investigated proteostasis regulators (PRs) for their potential to increase cellular enzyme activity, and to reduce the disease-specific accumulation of the biomarker globotriaosylsphingosine in patient-derived cell culture. The PRs also acted synergistically with the clinically approved 1-deoxygalactonojirimycine, demonstrating the potential of combination treatment in a therapeutic application. Extensive characterization of the effective PRs revealed inhibition of the proteasome and elevation of GLA gene expression as paramount effects. Further analysis of transcriptional patterns of the PRs exposed a variety of genes involved in proteostasis as potential modulators. We propose that addressing proteostasis is an effective approach to discover new therapeutic targets for diseases involving folding and trafficking-deficient protein mutants.

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<![CDATA[Protocol for evaluating the abilities of diverse nitroaromatic prodrug metabolites to exit a model Gram negative bacterial vector]]> https://www.researchpad.co/article/N3dad3f2d-00d1-4f45-af16-275f5285761b

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<![CDATA[2-Methylquinazoline derivative 23BB as a highly selective histone deacetylase 6 inhibitor alleviated cisplatin-induced acute kidney injury]]> https://www.researchpad.co/article/N3754d22e-423e-4038-bba7-89aa96f82518

Abstract

Histone deacetylases 6 (HDAC6) has been reported to be involved in the pathogenesis of cisplatin-induced acute kidney injury (AKI). Selective inhibition of HDAC6 might be a potential treatment for AKI. In our previous study, a highly selective HDAC6 inhibitor (HDAC6i) 23BB effectively protected against rhabdomyolysis-induced AKI with good safety. However, whether 23BB possessed favorable renoprotection against cisplatin-induced AKI and the involved mechanisms remained unknown. In the study, cisplatin-injected mice developed severe AKI symptom as indicated by acute kidney dysfunction and pathological changes, companied by the overexpression of HDAC6 in tubular epithelial cells. Pharmacological inhibition of HDAC6 by the treatment of 23BB significantly attenuated sCr, BUN and renal tubular damage. Mechanistically, 23BB enhanced the acetylation of histone H3 to reduce the HDAC6 activity. Cisplatin-induced AKI triggered multiple signal mediators of endoplasmic reticulum (ER) stress including PERK, ATF6 and IRE1 pathway, as well as CHOP, GRP78, p-JNK and caspase 12 proteins. Oral administration of our HDAC6i 23BB at a dose of 40 mg/kg/d for 3 days notably improved above-mentioned responses in the injured kidney tissues. HDAC6 inhibition also reduced the number of TUNEL-positive tubular cells and regulated apoptosis-related protein expression. Overall, these data highlighted that HDAC6 inhibitor 23BB modulated apoptosis via the inhibition of ER stress in the tubular epithelial cells of cisplatin-induced AKI.

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<![CDATA[Cooperation of SRPK2, Numb and p53 in the malignant biology and chemosensitivity of colorectal cancer]]> https://www.researchpad.co/article/Nbb56808c-ef28-40d3-9370-b8c07b1ec26c

Abstract

Serine-arginine protein kinase 2 (SRPK2) is aberrantly expressed in human malignancies including colorectal cancer (CRC). However, little is known about the molecular mechanisms, and the role of SRPK2 in chemosensitivity remains unexplored in CRC. We recently showed that SRPK2 promotes pancreatic cancer progression by down-regulating Numb and p53. Therefore, we investigated the cooperation between SRPK2, Numb and p53 in the cell migration, invasion and chemosensitivity of CRC in vitro. Here, we showed that SRPK2 expression was higher in CRC tumors than in nontumor tissues. SRPK2 expression was positively associated with clinicopathological characteristics of CRC patients, including tumor differentiation, T stage, N stage and UICC stage. Additionally, SRPK2 had no association with mutant p53 (mtp53) in SW480 and SW620 cells, but negatively regulated Numb and wild-type p53 (wtp53) in response to 5-fluorouracil or cisplatin treatment in HCT116 cells. Moreover, SRPK2, Numb and p53 coimmunoprecipitated into a triple complex with or without the treatment of 5-fluorouracil in HCT116 cells, and p53 knockdown reversed the up-regulation of wtp53 induced by SRPK2 silencing with chemical agent treatment. Furthermore, overexpression of SRPK2 increased cell migration and invasion and decreased chemosensitivity to 5-fluorouracil or cisplatin in HCT116 cells. Conversely, SRPK2 silencing decreased cell migration and invasion and increased chemosensitivity to 5-fluorouracil or cisplatin, yet these effects could be reversed by p53 knockdown under chemical agent treatment. These results thus reveal a novel role of SRPK2-Numb-p53 signaling in the progression of CRC and demonstrate that SRPK2 is a potential therapeutic target for CRC clinical therapy.

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