Search results for "toxicity"
showing 10 items of 2261 documents
Oligodendrocytes Provide Antioxidant Defense Function for Neurons by Secreting Ferritin Heavy Chain.
2020
An evolutionarily conserved function of glia is to provide metabolic and structural support for neurons. To identify molecules generated by glia and with vital functions for neurons, we used Drosophila melanogaster as a screening tool, and subsequently translated the findings to mice. We found that a cargo receptor operating in the secretory pathway of glia was essential to maintain axonal integrity by regulating iron buffering. Ferritin heavy chain was identified as the critical secretory cargo, required for the protection against iron-mediated ferroptotic axonal damage. In mice, ferritin heavy chain is highly expressed by oligodendrocytes and secreted by employing an unconventional secret…
Could formaldehyde induce mutagenic and cytotoxic effects in buccal epithelial cells during anatomy classes?
2017
Background Due to increased formaldehyde exposure, carcinogenic to humans, several researches have been studying the potential toxicity and the safe levels for human beings. The aim of this study was to investigate mutagenicity and cytotoxicity in buccal epithelial exfoliated cells (BEC) of students subjected to formaldehyde (FA) during anatomy classes. Material and Methods BEC were collected periodically from 17 volunteers of undergraduate programs, who had participated in practical anatomy classes, before and after FA exposure. Cells were stained according to Feulgen method and then micronucleus test was applied. A total of 1,500 cells were assessed per individual in this study for the mi…
Inter-individual differences in the susceptibility of primary human hepatocytes towards drug-induced cholestasis are compound and time dependent.
2018
Abstract Cholestasis represents a major subtype of drug-induced liver injury and novel preclinical models for its prediction are needed. Here we used primary human hepatocytes (PHH) from different donors in 2D-sandwich (2D-sw) and/or 3D-spheroid cultures to study inter-individual differences in the response towards cholestatic hepatotoxins after short-term (48–72 hours) and long-term repeated exposures (14 days). The cholestatic liabilities of drugs were determined by comparing cell viability upon exposure to the highest non-cytotoxic drug concentration in the presence and absence of a non-cytotoxic concentrated bile acid mixture. In 2D-sw culture, cyclosporine A and amiodarone presented cl…
VEGF-B gene therapy inhibits doxorubicin-induced cardiotoxicity by endothelial protection
2016
Congestive heart failure is one of the leading causes of disability in long-term survivors of cancer. The anthracycline antibiotic doxorubicin (DOX) is used to treat a variety of cancers, but its utility is limited by its cumulative cardiotoxicity. As advances in cancer treatment have decreased cancer mortality, DOX-induced cardiomyopathy has become an increasing problem. However, the current means to alleviate the cardiotoxicity of DOX are limited. We considered that vascular endothelial growth factor-B (VEGF-B), which promotes coronary arteriogenesis, physiological cardiac hypertrophy, and ischemia resistance, could be an interesting candidate for prevention of DOX-induced cardiotoxicity …
Silver nanoparticle based coatings enhance adipogenesis compared to osteogenesis in human mesenchymal stem cells through oxidative stress.
2020
Silver nanoparticle (AgNP) based antibacterial surfaces were fabricated using plasma polymerization technology and their effects on differentiation of human bone-marrow derived mesenchymal stem cells (hMSCs) were investigated in this study. The results showed that AgNP coated surfaces do not affect the initial adhesion, spreading and proliferation of hMSCs. Furthermore, the silver coated surface promoted adipogenic differentiation of hMSCs as demonstrated by more accumulation of lipid droplets and upregulation of adipogenesis-related genes such as peroxisome proliferator activated receptor gamma (PPAR gamma), adipocyte determination and differentiation factor (ADD1) and CCAAT/enhancer bindi…
Drosophila melanogaster Models of Metal-Related Human Diseases and Metal Toxicity
2017
Iron, copper and zinc are transition metals essential for life because they are required in a multitude of biological processes. Organisms have evolved to acquire metals from nutrition and to maintain adequate levels of each metal to avoid damaging effects associated with its deficiency, excess or misplacement. Interestingly, the main components of metal homeostatic pathways are conserved, with many orthologues of the human metal-related genes having been identified and characterized in Drosophila melanogaster. Drosophila has gained appreciation as a useful model for studying human diseases, including those caused by mutations in pathways controlling cellular metal homeostasis. Flies have m…
Sex-dependent metabolism of nevirapine in rats: impact on plasma levels, pharmacokinetics and interaction with nortriptyline.
2017
Abstract Nevirapine (NVP) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) widely used in the treatment of human immunodeficiency virus type 1 (HIV-1) and is the first-choice NNRTI during pregnancy. NVP shows a sex dimorphic profile in humans with sex differences in bioavailability, biotransformation and toxicity. In this study, sex differences in NVP metabolism and inhibition of NVP metabolism by the antidepressant nortriptyline (NT) were evaluated using rats as experimental animals. NVP was administered orally to male and female rats and sex differences in plasma levels and pharmacokinetic parameters were analysed. NVP plasma levels were higher in female compared with male rats…
The purine analogues abacavir and didanosine increase acetaminophen-induced hepatotoxicity by enhancing mitochondrial dysfunction
2016
Background NRTIs are essential components of HIV therapy with well-documented, long-term mitochondrial toxicity in hepatic cells, but whose acute effects on mitochondria are unclear. As acetaminophen-induced hepatotoxicity also involves mitochondrial interference, we hypothesized that it would be exacerbated in the context of ART. Methods We evaluated the acute effects of clinically relevant concentrations of the most widely used NRTIs, alone or combined with acetaminophen, on mitochondrial function and cellular viability. Results The purine analogues abacavir and didanosine produced an immediate and concentration-dependent inhibition of oxygen consumption and complex I and III activity. Th…
New Synthetic Nitro-Pyrrolomycins as Promising Antibacterial and Anticancer Agents
2020
: Pyrrolomycins (PMs) are polyhalogenated antibiotics known as powerful biologically active compounds, yet featuring high cytotoxicity. The present study reports the antibacterial and antitumoral properties of new chemically synthesized PMs, where the three positions of the pyrrolic nucleus were replaced by nitro groups, aiming to reduce their cytotoxicity while maintaining or even enhancing the biological activity. Indeed, the presence of the nitro substituent in diverse positions of the pyrrole determined an improvement of the minimal bactericidal concentration (MBC) against Gram-positive (i.e., Staphylococcus aureus) or -negative (i.e., Pseudomonas aeruginosa) pathogen strains as compare…
Evaluation of cytocompatibility of calcium silicate-based endodontic sealers and their effects on the biological responses of mesenchymal dental stem…
2015
Aim To investigate in vitro the cytocompatibility of the calcium silicate-containing endodontic sealers MTA Fillapex and TotalFill BC Sealer on human periodontal ligament stem cells (hPDLSCs) by assaying their biological responses and compare them with that observed when using an epoxy resin-based sealer (AH Plus). Methodology Specimens from the three different endodontic sealers were eluated with culture medium for 24 h. The cytotoxicity of these eluates was evaluated using the MTT assay. In addition, an in vitro scratch wound healing model was used to determine their effects on cell migration. Cell adhesion to collagen type I after treatment with the different sealer eluates was also meas…