J Toxicol Sci [JOURNAL]
Sun
200 papers
Discovery and development of COVID-19 vaccines and therapeutics: nonclinical perspectives.
Khan N, Sathish J, Rohde CM
J Toxicol Sci · 2024 · PMID 38432955 · Publisher ↗
The development and regulatory review of BNT162b2, a COVID-19 vaccine, and Paxlovid (nirmatrelvir tablets/ritonavir tablets), a COVID-19 therapeutic, are benchmarks for accelerated innovation during a global pandemic. Ra...
The development and regulatory review of BNT162b2, a COVID-19 vaccine, and Paxlovid (nirmatrelvir tablets/ritonavir tablets), a COVID-19 therapeutic, are benchmarks for accelerated innovation during a global pandemic. Rapid choice of the SARS-CoV-2 spike protein and main protease (Mpro) as targets for the vaccine and therapeutic, respectively, leveraged the available knowledge of the biology of SARS-CoV-2 and related viruses. The nonclinical immunogenicity and safety of BNT162b2 was rigorously assessed. Likewise, a comprehensive nonclinical safety assessment was conducted for the therapeutic candidates, lufotrelvir (PF-07304814) and nirmatrelvir (PF-07321332). The development and regulatory review of BNT162b2 and Paxlovid was enabled through close collaboration of the pharmaceutical industry with regulatory agencies and public health organizations. This experience highlights approaches that could be adopted for pandemic preparedness including risk-based investment strategies, conduct of activities in parallel that normally are conducted sequentially, quick kill decisions, simultaneous evaluation of multiple candidates, and use of flexible, established vaccine platforms.
Developing a GNN-based AI model to predict mitochondrial toxicity using the bagging method.
Igarashi Y, Kojima R, Matsumoto S … +3 more , Iwata H, Okuno Y, Yamada H
J Toxicol Sci · 2024 · PMID 38432954 · Publisher ↗
Mitochondrial toxicity has been implicated in the development of various toxicities, including hepatotoxicity. Therefore, mitochondrial toxicity has become a major screening factor in the early discovery phase of drug de...
Mitochondrial toxicity has been implicated in the development of various toxicities, including hepatotoxicity. Therefore, mitochondrial toxicity has become a major screening factor in the early discovery phase of drug development. Several models have been developed to predict mitochondrial toxicity based on chemical structures. However, they only provide a binary classification of positive or negative results and do not provide the substructures that contribute to a positive decision. Therefore, we developed an artificial intelligence (AI) model to predict mitochondrial toxicity and visualize structural alerts. To construct the model, we used the open-source software library kMoL, which employs a graph neural network approach that allows learning from chemical structure data. We also utilized the integrated gradient method, which enables the visualization of substructures that contribute to positive results. The dataset used to construct the AI model exhibited a significant imbalance, with significantly more negative than positive data. To address this, we employed the bagging method, which resulted in a model with high predictive performance, as evidenced by an F1 score of 0.839. This model can also be used to visualize substructures that contribute to mitochondrial toxicity using the integrated gradient method. Our AI model predicts mitochondrial toxicity based on chemical structures and may contribute to screening mitochondrial toxicity in the early stages of drug discovery.
DTox: A deep neural network-based in visio lens for large scale toxicogenomics data.
Hase T, Ghosh S, Aisaki KI … +4 more , Kitajima S, Kanno J, Kitano H, Yachie A
J Toxicol Sci · 2024 · PMID 38432953 · Publisher ↗
With the advancement of large-scale omics technologies, particularly transcriptomics data sets on drug and treatment response repositories available in public domain, toxicogenomics has emerged as a key field in safety p...
With the advancement of large-scale omics technologies, particularly transcriptomics data sets on drug and treatment response repositories available in public domain, toxicogenomics has emerged as a key field in safety pharmacology and chemical risk assessment. Traditional statistics-based bioinformatics analysis poses challenges in its application across multidimensional toxicogenomic data, including administration time, dosage, and gene expression levels. Motivated by the visual inspection workflow of field experts to augment their efficiency of screening significant genes to derive meaningful insights, together with the ability of deep neural architectures to learn the image signals, we developed DTox, a deep neural network-based in visio approach. Using the Percellome toxicogenomics database, instead of utilizing the numerical gene expression values of the transcripts (gene probes of the microarray) for dose-time combinations, DTox learned the image representation of 3D surface plots of distinct time and dosage data points to train the classifier on the experts' labels of gene probe significance. DTox outperformed statistical threshold-based bioinformatics and machine learning approaches based on numerical expression values. This result shows the ability of image-driven neural networks to overcome the limitations of classical numeric value-based approaches. Further, by augmenting the model with explainability modules, our study showed the potential to reveal the visual analysis process of human experts in toxicogenomics through the model weights. While the current work demonstrates the application of the DTox model in toxicogenomic studies, it can be further generalized as an in visio approach for multi-dimensional numeric data with applications in various fields in medical data sciences.
Valproic acid elevates HIF-1α-mediated CGB expression and suppresses glucose uptake in BeWo cells.
Kitahara G, Higashisaka K, Nakamoto Y … +7 more , Yamamoto R, Okuno W, Serizawa M, Sakahashi Y, Tsujino H, Haga Y, Tsutsumi Y
J Toxicol Sci · 2024 · PMID 38296531 · Publisher ↗
Placental dysfunction can disrupt pregnancy. However, few studies have assessed the effects of chemical-induced toxicity on placental function. Here, we examined the effects of valproic acid (VPA) as a model chemical on...
Placental dysfunction can disrupt pregnancy. However, few studies have assessed the effects of chemical-induced toxicity on placental function. Here, we examined the effects of valproic acid (VPA) as a model chemical on production of hormones and on glucose uptake in human choriocarcinoma cell line BeWo. Cells were treated with forskolin to differentiate into syncytiotrophoblasts, which were then treated with VPA for 72 hr. Real-time RT-PCR analysis showed that VPA significantly increased the mRNA expression of chorionic gonadotropin β (CGB), a hormone that is produced by the placenta in the first trimester of pregnancy, relative to that in the forskolin-only group. It also suppressed the increase in intracellular glucose uptake and GLUT1 level observed in the forskolin-only group. RNA-seq analysis and pathway database analysis revealed that VPA consistently decreased the level of HIF-1α protein and expression of its downstream target genes HK2 and ADM in the hypoxia pathway. Cobalt chloride, a HIF-1α inducer, inhibited CGB upregulation in VPA-treated cells and rescued VPA-induced suppression of glucose uptake and GLUT1 level. Thus, HIF-1α-mediated elevation of CGB expression and suppression of glucose uptake by VPA is a novel mechanism of placental dysfunction.
A simple air-liquid interface exposure system for exposing cultured human 3D epidermis and cornea to PM2.5 collected through cyclonic separation.
Kono M, Takaishi M, Okuda T … +3 more , Fujihara M, Noguchi S, Ishihara Y
J Toxicol Sci · 2024 · PMID 38296530 · Publisher ↗
Particulate matter (PM) is among the major air pollutants suspended in the atmosphere. PM2.5 has a particle size of 2.5 µm; it is known to cause inflammation, especially in the respiratory tract and skin. Since the skin...
Particulate matter (PM) is among the major air pollutants suspended in the atmosphere. PM2.5 has a particle size of 2.5 µm; it is known to cause inflammation, especially in the respiratory tract and skin. Since the skin acts a primary barrier against harmful environmental substances that may enter the body, it is highly exposed to PM2.5 present in the environment. However, the adverse health effects of PM2.5 exposure on human skin have not been accurately examined due to the lack of a system that exposes human epidermal tissue to the actual environmental concentration of PM2.5. In this study, we developed an air-liquid interface exposure system for exposing cultured human 3D epidermis and cornea to PM2.5 collected through cyclonic separation. PM2.5 suspension was nebulized in an acrylic chamber, and the resulting mist was pumped through a diffusion dryer into a glass exposure chamber. A particle counter was connected to the exposure chamber to continuously measure the spatial mass concentration of PM. Human 3D epidermis was cultured in the exposure chamber. Exposure of the human 3D epidermis to PM aerosol increased interleukin-8 release into the media around 50 µg/m. Mass concentrations above 100 µg/m caused cell death. Furthermore, a human corneal model showed similar responses against PM2.5 exposure as 3D epidermis. The air-liquid interface exposure system developed in this study is considered useful for evaluating the health effects induced by environmental PM2.5 and can be used as an alternative to experiments involving actual human or animals.
Methylmercury-induced brain neuronal death in CHOP-knockout mice.
Iijima Y, Miki R, Fujimura M … +2 more , Oyadomari S, Uehara T
J Toxicol Sci · 2024 · PMID 38296529 · Publisher ↗
Apoptosis is one of the hallmarks of MeHg-induced neuronal cell death; however, its molecular mechanism remains unclear. We previously reported that MeHg exposure induces neuron-specific ER stress in the mouse brain. Exc...
Apoptosis is one of the hallmarks of MeHg-induced neuronal cell death; however, its molecular mechanism remains unclear. We previously reported that MeHg exposure induces neuron-specific ER stress in the mouse brain. Excessive ER stress contributes to apoptosis, and CHOP induction is considered to be one of the major mechanisms. CHOP is also increased by MeHg exposure in the mouse brain, suggesting that it correlates with increased apoptosis. In this study, to clarify whether CHOP mediates MeHg-induced apoptosis, we examined the effect of CHOP deletion on MeHg exposure in CHOP-knockout mice. Our data showed that CHOP deletion had no effect on MeHg exposure-induced weight loss or hindlimb impairment in mice, nor did it increase apoptosis or inhibit neuronal cell loss. Hence, CHOP plays little role in MeHg toxicity, and other apoptotic pathways coupled with ER stress may be involved in MeHg-induced cell death.
Drosophila melanogaster as potential alternative animal model for evaluating acute inhalation toxicity.
Cho Y, Park CM, Heo YJ … +2 more , Park HB, Kim MS
J Toxicol Sci · 2024 · PMID 38296528 · Publisher ↗
Drosophila melanogaster (D. melanogaster) is a promising model biological system. It has a short life cycle and can provide a substantial number of specimens suitable for comprehensive genetic and molecular analyses in a...
Drosophila melanogaster (D. melanogaster) is a promising model biological system. It has a short life cycle and can provide a substantial number of specimens suitable for comprehensive genetic and molecular analyses in a short time. In this study, we investigated the acute inhalation toxicity of methylisothiazolinone (MIT) and chloromethylisothiazolinone (CMIT) in a D. melanogaster model. During exposure, environmental conditions, mass median aerodynamic and geometric standard diameters were measured. After inhalation exposure, the survival rate, climbing ability, and bang sensitivity were measured on days 1, 2, and 7. Notably, the survival rate of flies decreased in an exposure concentration-dependent manner. Climbing ability and bang sensitivity were also altered in the MIT/CMIT group, compared with the negative control group. Overall, these results provide a reliable D. melanogaster model system for inhalation toxicity study.
Development of a risk assessment method for the detailed consideration of the effects of liquid toxic substance leakage incidents on the human body: ethanol as a model substance.
Horiguchi A, Numazawa S
J Toxicol Sci · 2023 · PMID 38191200 · Publisher ↗
To ensure safety in chemical plants handling a wide variety of liquid and gaseous hazardous substances, it is necessary to carry out highly accurate risk assessments and take appropriate measures. In this study, a risk a...
To ensure safety in chemical plants handling a wide variety of liquid and gaseous hazardous substances, it is necessary to carry out highly accurate risk assessments and take appropriate measures. In this study, a risk assessment method was developed for the problem of the leakage of liquid hazardous substances. The risk assessment of toxic liquid leaks must consider the exposure of workers to the liquid and toxic gases produced by vaporization. The absorption and subsequent metabolism of hazardous substances in the body via multiple pathways after exposure to liquids and gases was calculated using a pharmacokinetic model. Estimation of exposure concentrations of toxic gases volatilized from leaked liquids was reproduced by computational fluid dynamics simulation. In this study, ethanol was selected as the hazardous substance and the risk of hazardous liquid leakage was assessed. The results of the analysis, which considered liquid and gas exposure under the conditions of the assumed scenario, showed that the maximum blood concentration of ethanol was 1640 µmol/L, which is sufficiently low compared to the concentration of 10,900 µmol/L at which acute toxic effects become apparent. These results suggest that work can be carried out safely under the conditions of the assumed scenario. The risk assessment methodology for liquid spills in this study confirms that risk assessment is possible under multiple scenarios, including individual differences, activity conditions, and the use of protective equipment.
Paternal methamphetamine exposure differentially affects first and second generations in mice.
Munetomo-Aoki S, Kaizaki-Mitsumoto A, Nakano R … +1 more , Numazawa S
J Toxicol Sci · 2024 · PMID 38191192 · Publisher ↗
Amphetamine-type stimulants are abused worldwide, and methamphetamine (METH) accounts for a large majority of seized abused drug cases. Recently, the paternal origin of health and disease theory has been proposed as a co...
Amphetamine-type stimulants are abused worldwide, and methamphetamine (METH) accounts for a large majority of seized abused drug cases. Recently, the paternal origin of health and disease theory has been proposed as a concept wherein paternal factors influence descendants. Although METH abuse is more common among males, its effects on their descendants were not examined. Therefore, we investigated the effects of paternal METH exposure on F1 and F2 levels in a mouse model. Sires were administered METH for 21 days and mated with female mice to obtain F1 mice. Growth evaluations (number of births, survival rate, body weight, righting reflex, cliff avoidance tests, and wire-hanging maneuver) were performed on F1 mice. Upon reaching six weeks of age, the mice were subjected to spontaneous locomotion, elevated plus-maze, acute METH treatment, and passive avoidance tests. Additionally, RNA-seq was performed on the striatum of male mice. Male F1 mice were mated with female mice to obtain F2 mice. They were subjected to the same tests as the F1 mice. Paternal METH exposure resulted in delayed growth and decreased memory function in F1 mice, overweight in F2 mice, decreased METH sensitivity, and reduced anxiety-related behaviors in female F2 mice. Enrichment analysis revealed significant enrichment of terms related to behavior in F1 and protein folding in F2. These results indicated that the effects of paternal METH exposure vary across generations. The effects of paternal factors need to be examined not only in F1, but also in F2 and beyond.
Industrially produced trans-fatty acids are potent promoters of DNA damage-induced apoptosis.
Hirata Y, Kojima R, Ashida R … +5 more , Nada Y, Kimura S, Sato E, Noguchi T, Matsuzawa A
J Toxicol Sci · 2024 · PMID 38191191 · Publisher ↗
trans-Fatty acids (TFAs) are unsaturated fatty acids harboring at least one carbon-carbon double bond in trans configuration, which are categorized into two groups according to their origin: industrial and ruminant TFAs,...
trans-Fatty acids (TFAs) are unsaturated fatty acids harboring at least one carbon-carbon double bond in trans configuration, which are categorized into two groups according to their origin: industrial and ruminant TFAs, hereafter called iTFAs and rTFAs, respectively. Numerous epidemiological studies have shown a specific link of iTFAs to various diseases, such as cardiovascular and neurodegenerative diseases. However, there is little evidence for underlying mechanisms that can explain the specific toxicity of iTFAs, and how to mitigate their toxicity. Herein, we show that iTFAs, including elaidic acid (EA) and linoelaidic acid, but not rTFAs, facilitate apoptosis induced by doxorubicin (Dox), triggering DNA double-strand breaks. We previously established that EA promotes Dox-induced apoptosis by accelerating c-Jun N-terminal kinase (JNK) activation through mitochondrial reactive oxygen species (ROS) overproduction. Consistently, iTFAs specifically enhanced Dox-induced JNK activation. Furthermore, Dox-induced pro-apoptotic signaling by iTFAs was blocked in the presence of oleic acid (OA), the geometrical cis isomer of EA. These results demonstrate that iTFAs specifically exert their toxicity during DNA damage-induced apoptosis, which could be effectively suppressed by OA. Our study provides evidence for understanding the difference in toxic actions between TFA species, and for new strategies to prevent and combat TFA-related diseases.
Involvement of microRNA-4680-3p against phenytoin-induced cell proliferation inhibition in human palate cells.
Tsukiboshi Y, Horita H, Mikami Y … +4 more , Noguchi A, Yokota S, Ogata K, Yoshioka H
J Toxicol Sci · 2024 · PMID 38191190 · Publisher ↗
Cleft palate (CP) is one of the most common birth defects and is caused by a combination of genetic and/or environmental factors. Environmental factors such as pharmaceutical exposure in pregnant women are known to induc...
Cleft palate (CP) is one of the most common birth defects and is caused by a combination of genetic and/or environmental factors. Environmental factors such as pharmaceutical exposure in pregnant women are known to induce CP. Recently, microRNA (miRNA) was found to be affected by environmental factors. The aim of the present study was to investigate the involvement of miRNA against phenytoin (PHE)-induced inhibition of proliferation in human embryonic palatal mesenchymal (HEPM) cells. We demonstrated that PHE inhibited HEPM cell proliferation in a dose-dependent manner. We found that treatment with PHE downregulated cyclin-D1 and cyclin-E expressions in HEPM cells. Furthermore, PHE increased miR-4680-3p expression and decreased two downstream genes (ERBB2 and JADE1). Importantly, an miR-4680-3p-specific inhibitor restored HEPM cell proliferation and altered expression of ERBB2 and JADE1 in cells treated with PHE. These results suggest that PHE suppresses cell proliferation via modulation of miR-4680-3p expression.
Lead suppresses perlecan expression via EGFR-ERK1/2-COX-2-PGI pathway in cultured bovine vascular endothelial cells.
Hara T, Kumagai R, Tanaka T … +5 more , Nakano T, Fujie T, Fujiwara Y, Yamamoto C, Kaji T
J Toxicol Sci · 2023 · PMID 38044127 · Publisher ↗
Vascular endothelial cell growth is essential for the repair of intimal injury. Perlecan, a large heparan sulfate proteoglycan, intensifies fibroblast growth factor-2 (FGF-2) signaling as a co-receptor for FGF-2 and its...
Vascular endothelial cell growth is essential for the repair of intimal injury. Perlecan, a large heparan sulfate proteoglycan, intensifies fibroblast growth factor-2 (FGF-2) signaling as a co-receptor for FGF-2 and its receptor, and promotes the proliferation of vascular endothelial cells. Previously, we reported that 2 µM of lead, a toxic heavy metal, downregulated perlecan core protein expression and then suppressed the growth of vascular endothelial cells. However, since the mechanisms involved in the repression of perlecan by lead remains unclear, we analyzed its detailed signaling pathway using cultured bovine aortic endothelial cells. Our findings indicate that 2 µM of lead inhibited protein tyrosine phosphatase (PTP) activity and induced cyclooxygenase-2 (COX-2) via phosphorylation of the epidermal growth factor receptor (EGFR) and its downstream extracellular signal-regulated kinases (ERK1/2). In addition, among the prostanoids regulated by COX-2, prostaglandin I (PGI) specifically contributes to the downregulation of perlecan expression by lead. This study revealed an intracellular pathway-the EGFR-ERK1/2-COX-2-PGI pathway activated by inhibition of PTP by lead-as a pathway that downregulates endothelial perlecan synthesis. The pathway is suggested to serve as a mechanism for the repression of perlecan expression, which leads to a delay in cell proliferation by lead.
Cardiovascular safety pharmacology of ivermectin assessed using the isoflurane-anesthetized beagle dogs: ICH S7B follow-up study.
Suzuki N, Kambayashi R, Goto A … +4 more , Izumi-Nakaseko H, Takei Y, Naito AT, Sugiyama A
J Toxicol Sci · 2023 · PMID 38044126 · Publisher ↗
Antiparasitic ivermectin has been reported to induce cardiovascular adverse events, including orthostatic hypotension, tachycardia and cardiopulmonary arrest, of which the underlying pathophysiology remains unknown. Sinc...
Antiparasitic ivermectin has been reported to induce cardiovascular adverse events, including orthostatic hypotension, tachycardia and cardiopulmonary arrest, of which the underlying pathophysiology remains unknown. Since its drug repurposing as an antiviral agent is underway at higher doses than those for antiparasitic, we evaluated the cardiovascular safety pharmacology of ivermectin using isoflurane-anesthetized beagle dogs (n=4). Ivermectin in doses of 0.1 followed by 1 mg/kg was intravenously infused over 10 min with an interval of 20 min, attaining peak plasma concentrations of 0.94 ± 0.04 and 8.82 ± 1.25 μg/mL, which were 29-31 and 276-288 times higher than those observed after its antiparasitic oral dose of 12 mg/body, respectively. The latter peak concentration was > 2 times greater than those inhibiting proliferation of dengue virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and hepatitis B virus in vitro. Ivermectin decreased heart rate without altering mean blood pressure, suggesting that ivermectin does not cause hypotension or tachycardia directly. Ivermectin hardly altered atrioventricular nodal or intraventricular conduction, indicating a lack of inhibitory action on Ca or Na channel in vivo. Ivermectin prolonged QT interval/QTcV in a dose-related manner and tended to slow the repolarization speed in a reverse frequency-dependent manner, supporting previously described its I inhibition, which would explain T-T prolongation and heart-rate reduction in this study. Meanwhile, ivermectin did not significantly prolong J-Tc or terminal repolarization period, indicating torsadogenic potential of ivermectin leading to the onset of cardiopulmonary arrest would be small. Thus, ivermectin has a broad range of cardiovascular safety profiles, which will help facilitate its drug repurposing.
A case of pulmonary edema due to guanfacine intoxication with measurement of serum guanfacine concentrations.
Ayata R, Fujita M, Harada K … +7 more , Esaki Y, Koga Y, Hisamoto Y, Asami-Noyama M, Takeda S, Harada K, Tsuruta R
J Toxicol Sci · 2023 · PMID 38044125 · Publisher ↗
Guanfacine hydrochloride extended-release (GXR) is used to treat attention deficit hyperactivity disorder. It is a selective α2A-adrenorecepor agonist that was reported to cause QT prolongation and hypotension in the eve...
Guanfacine hydrochloride extended-release (GXR) is used to treat attention deficit hyperactivity disorder. It is a selective α2A-adrenorecepor agonist that was reported to cause QT prolongation and hypotension in the event of overdosing. We report the case of a 17-year-old man who took 226 tablets of GXR 3 mg for attempted suicide. He was found complaining of dyspnea, and emergency medical services were called. When the patient was transferred to our hospital, his Glasgow coma scale was 12 (E4V3M5). He was agitated and hypoxemic. He was intubated for invasive mechanical ventilation under sedation. His chest X-ray and computed tomography scan showed pulmonary edema. Transthoracic echocardiography showed markedly reduced cardiac function. His serum guanfacine concentration peaked on day 3 after admission. His pulmonary edema improved quickly after a decrease in serum guanfacine concentration, but cardiac decompensation persisted for about 1 month. This case reveals that the decline in cardiac function after guanfacine intoxication is prolonged even after its serum concentration has decreased.
Continuous infiltration of small peritoneal macrophages in the mouse peritoneum through CCR2-dependent and -independent routes during fibrosis and mesothelioma development induced by a multiwalled carbon nanotube, MWNT-7.
Shimizu M, Hojo M, Ikushima K … +10 more , Yamamoto Y, Maeno A, Sakamoto Y, Ishimaru N, Taquahashi Y, Kanno J, Hirose A, Suzuki J, Inomata A, Nakae D
J Toxicol Sci · 2023 · PMID 38044124 · Publisher ↗
Although toxicities of multiwalled carbon nanotube (MWCNT) have been found to be related with activities of macrophages phagocytosing the fibers, the exact relationship between macrophage population and pathogenesis of f...
Although toxicities of multiwalled carbon nanotube (MWCNT) have been found to be related with activities of macrophages phagocytosing the fibers, the exact relationship between macrophage population and pathogenesis of fibrosis and mesotheliomas induced by MWCNTs is largely unknown. CCL2-CCR2 axis, a major monocyte/macrophage infiltration route, is thought to be involved in not only acute inflammation but also the formation of tumor microenvironment. We therefore described a time-course of alteration of macrophage population in an attempt to clarify the contribution of the Ccr2 gene to mesotheliomagenesis. Wild-type (WT) C57BL/6 mice and Ccr2-knockout (KO) mice were intraperitoneally administered with MWNT-7 and were sequentially necropsied at 1, 7, 28, 90, and 245 day(s) after the injection. Peritoneal fibrosis was prominent in all MWCNT-treated mice, with a lower severity in the KO mice. No differences were observed in the incidences of neoplastic lesions of mesothelia between WT and KO mice. A flow cytometric analysis revealed that after gross disappearance of macrophages after MWCNT exposure, small peritoneal macrophages (SPMs) were exclusively refurbished by the CCR2-dependent route at day 1 (as Ly-6CMHC class II cells), followed by additional CCR2-independent routes (as Ly-6CMHC class II cells); i.e., the only route in KO mice; with a delay of 1-7 days. The SPMs derived from both routes appeared to differentiate into maturated cells as Ly-6CMHC class II, whose ratio increased in a time-dependent manner among the total SPM population. Additionally, most macrophages expressed M1-like features, but a small fraction of macrophages exhibited an M1/M2 mixed status in MWCNT-treated animals. Our findings demonstrate a long-persistent activation of the CCL2-CCR2 axis after MWCNT exposure and enable a better understanding of the participation and potential roles of SPMs in fibrous material-induced chronic toxicities.
Effects of microsampling on toxicity evaluation of 1-naphthylisothiocyanate (ANIT), a hepatotoxic substance, in a mouse toxicity study.
Takahashi K, Kawaguchi S, Ikeda T … +9 more , Tomonari Y, Funakoshi T, Nakai K, Fujimoto T, Yamamoto D, Okamura T, Uchida H, Saito Y, Otake S
J Toxicol Sci · 2023 · PMID 37914288 · Publisher ↗
ICH S3A Q&A focused on microsampling (MS) was published to help accelerate the use of MS and states that MS is useful because toxicokinetic (TK) evaluation with conventional blood sampling volume requires many animals fo...
ICH S3A Q&A focused on microsampling (MS) was published to help accelerate the use of MS and states that MS is useful because toxicokinetic (TK) evaluation with conventional blood sampling volume requires many animals for TK satellite groups; however, there are few reports of MS application in mice. We investigated the influence of MS on toxicity evaluation in mice by comparing the toxicity parameters with and without MS after a single oral administration of 1-naphthylisothiocyanate (ANIT), a hepatotoxic substance. Blood samples (50 µL/point) were collected from the tail vein of 3 mice per group at 2 or 3 time points during a 24-hr period, and toxicity was evaluated 2 days after administration. ANIT-related changes suggesting liver or gallbladder injury were noted in blood chemistry and histopathology. Some of these changes such as increases in focal hepatocyte necrosis and inflammatory cell infiltration in the liver as well as mucosal epithelium necrosis in the gallbladder were apparently influenced by MS. A tendency to anemia was noted in animals with MS but not without MS, which was also noted in the vehicle-treated controls, suggesting influence of blood loss. The current results indicate that ANIT hepatotoxicity could be evaluated in mice in which blood samples were collected by MS for most parameters; however, parameters in anemia and pathology in the liver and gallbladder were influenced by MS in this study condition with ANIT. Therefore, MS application in mice should be carefully considered.
Effects of salt supplementation in uninephrectomized KK-Ay mice: Examining the potential of a diabetic kidney disease model.
Sano R, Ryu K, Sasase T … +7 more , Shinozaki Y, Teoh SH, Yamaguchi A, Uno K, Maekawa T, Ohta T, Miyajima K
J Toxicol Sci · 2023 · PMID 37914287 · Publisher ↗
Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD). Although current therapeutic strategies for DKD, including sodium-glucose cotransporter-2 inhibitors and mineralocorticoid receptor an...
Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD). Although current therapeutic strategies for DKD, including sodium-glucose cotransporter-2 inhibitors and mineralocorticoid receptor antagonists, have shown some degree of efficacy, they have failed to completely halt the progression of DKD to ESRD owing to the complexity of DKD pathogenesis. Elucidating the pathophysiological mechanism of DKD is essential for the development of novel therapeutic strategies. In this study, we investigated the pathophysiological characteristics of uninephrectomized (UNx) KK-Ay mice and examined the effects of salt supplementation on the acceleration of renal injury in these mice. UNx KK-Ay mice exhibited pathophysiological renal abnormalities with glomerular and tubulointerstitial fibrosis. Additionally, salt supplementation exacerbated renal injury, particularly tubular injury. These results suggest that UNx KK-Ay mice are useful models for advanced DKD and that salt exacerbates tubular damage in DKD.
Lidocaine induces neurotoxicity in spinal cord neurons in Goto-Kakizaki rats via AMPK-mediated mitophagy.
Chen L, Fan C, Zhang X … +3 more , Chen S, Ye L, Zheng X
J Toxicol Sci · 2023 · PMID 37914286 · Publisher ↗
OBJECTIVE: Lidocaine has been reported to induce neurotoxicity, which is further enhanced by high glucose levels. This study is aimed to explore the underlying mechanisms of lidocaine neurotoxicity in spinal cord neurons...
OBJECTIVE: Lidocaine has been reported to induce neurotoxicity, which is further enhanced by high glucose levels. This study is aimed to explore the underlying mechanisms of lidocaine neurotoxicity in spinal cord neurons of diabetes. METHODS: Take thirty specific pathogen-free (SPF) healthy Sprague-Dawley (SD) rats and thirty Goto-Kakizaki (GK) rats, aged 12 weeks, weighing 180-200 g. The spinal cord neurons of rats were isolated and cultured in vitro. Cell Counting Kit-8 was used to detect cell proliferation to determine the appropriate concentration and duration of lidocaine. Mitochondrial function was assessed using ATP content, cellular oxygen consumption rate, mitochondrial membrane potential, ROS production, and mitochondrial ultrastructure. Western blot was applied to detect the expression of autophagy- and mitophagy-related molecules PINK1, p-AMPK, LC-3II/LC3-I ratio and mTORC1. Immunofluorescent staining was used to detect the expression of PINK1 and LC3. RESULTS: Lidocaine decreased cell viability of spinal cord neurons in concentration- and time-dependent manners. And lidocaine treatment aggravated mitochondrial dysfunction in GK rats. Furthermore, mitophagy was activated in diabetes, and lidocaine exposure up-regulated mitophagy. AMPK activator MK8722 aggravated mitochondrial damage, increased the expression of PINK1, p-AMPK, LC-3II/LC3-I ratio, and decreased the expression of mTORC1, while AMPK inhibitor Compound C and autophagy inhibitor Bafilomycin A1 reduced mitochondrial damage and decreased the expression of PINK1, p-AMPK, LC-3II/LC3-I ratio, and increased the expression of mTORC1. CONCLUSIONS: Lidocaine induced neurotoxicity of spinal cord neurons in GK rats via AMPK-mediated mitophagy.
Epigenetic mutagen-like environmental chemicals alter neural differentiation of human induced pluripotent stem cells.
Arai Y, Nishino K
J Toxicol Sci · 2023 · PMID 37914285 · Publisher ↗
Various chemicals, including pesticides, heavy metals, and metabolites of tobacco, have been detected in fetal environment. Fetuses are exposed to these chemicals at relatively low concentrations; however, their risk of...
Various chemicals, including pesticides, heavy metals, and metabolites of tobacco, have been detected in fetal environment. Fetuses are exposed to these chemicals at relatively low concentrations; however, their risk of developing neurological and behavioral disorders increases after birth. We aimed to evaluate the effects of five chemicals (diethylphosphate, cotinine, octachlorodipropyl ether, mercury, and selenium) detected in the serum of pregnant mothers on neural development using human neurospheres (NSphs) differentiated from induced pluripotent stem cells. Exposure to each chemical at serum concentrations revealed no effects on NSph development. However, combined exposure to the five chemicals caused a significant decrease in NSph size and altered gene expression and neural differentiation. Thus, we next focused on DNA methylation to investigate changes in NSph properties caused by chemical exposure. Combined exposure to chemicals had extremely small effects on the DNA methylation status of NSphs at individual gene loci. However, stochastic changes in methylation status caused by chemical exposure were significantly accumulated throughout the entire genome. These results suggest that the five chemicals acted as epimutagens that alter the epigenetic status during human neural development at the biological level. Taken together, we showed for the first time, the epimutagen-induced alterations in neural differentiation at serum concentrations using an in vitro human neuronal model.
N-acetyl cysteine inhibits IL-1α release from murine keratinocytes induced by 2-hydroxyethyl methacrylate.
Kaji T, Kuroishi T, Bando K … +2 more , Takahashi M, Sugawara S
J Toxicol Sci · 2023 · PMID 37778984 · Publisher ↗
The hydrophilic compound 2-hydroxyethyl methacrylate (HEMA) is a major component of dental bonding materials, and it enhances the binding of resin-composites to biomolecules. However, HEMA is a well-known contact sensiti...
The hydrophilic compound 2-hydroxyethyl methacrylate (HEMA) is a major component of dental bonding materials, and it enhances the binding of resin-composites to biomolecules. However, HEMA is a well-known contact sensitizer. We reported previously that intradermal injection of HEMA induces the production of IL-1 locally in the skin. Keratinocytes are the first barrier against chemical insults and constitutively express IL-1α. In this study, we analyzed whether HEMA induces the production of inflammatory cytokines from murine keratinocyte cell line Pam212 cells. We demonstrated that HEMA induced the release of 17-kDa mature IL-1α and caused cytotoxicity. The activity of calpain, an IL-1α processing enzyme, was significantly higher in HEMA-treated cells. The thiol-containing antioxidant N-acetyl cysteine (NAC) inhibited HEMA-induced IL-1α release but not cytotoxicity. NAC inhibited intracellular calpain activity and reactive oxygen species (ROS) production induced by HEMA. NAC post-treatment also inhibited IL-1α release and intracellular ROS production induced by HEMA. Furthermore, HEMA-induced in vivo inflammation also inhibited by NAC. NAC inhibited polymerization of HEMA through adduct formation via sulfide bonds between the thiol group of NAC and the reactive double bond of HEMA. HEMA-induced IL-1α release and cytotoxicity were also inhibited if HEMA and NAC were pre-incubated before adding to the cells. These results suggested that NAC inhibited IL-1α release through decreases in intracellular ROS and the adduct formation with HEMA. We concluded that HEMA induces IL-1α release from skin keratinocytes, and NAC may be a promising candidate as a therapeutic agent against inflammation induced by HEMA.
About
- Frequency
- Sun
- Papers found
- 200
- RSS feed
- Subscribe