Cell toxicity mechanism and biomarker

Therapeutic Promises of Ferulic Acid and its Derivatives on Hepatic damage Related with Oxidative Stress and Inflammation: A Review with Mechanisms

Ferulic acid (FA) is a naturally occurring phenolic compound commonly found in the plant Ferula communis. This study aims to investigate the hepatoprotective effect of FA and its derivatives (methyl ferulic acid and trans-ferulic acid) against oxidative stress and inflammation-related hepatotoxicity due to toxicants based on the results of different non-clinical and preclinical tests. For this, data was collected from different reliable electronic databases such as PubMed, Google Scholar, and ScienceDirect, etc. The results of this investigation demonstrated that FA and its derivatives have potent hepatoprotective effects against oxidative stress and inflammation-related damage. The findings also revealed that these protective effects are due to the antioxidant and anti-inflammatory effects of the chemical compound. FA and its analogues significantly inhibit free radical generation and hinder the effects of proinflammatory markers and inflammatory enzymes, resulting in diminished cytotoxic and apoptotic hepatocyte death. The compounds also prevent intracellular lipid accumulation and provide protective effects.

Alternariol Monomethyl-Ether Induces Toxicity via Cell Death and Oxidative Stress in Swine Intestinal Epithelial Cells

Alternariol monomethyl-ether (AME), together with altenuene and alternariol, belongs to the Alternaria mycotoxins group, which can contaminate different substrates, including cereals. The aim of the present study was to obtain a deeper understanding concerning the effects of AME on pig intestinal health using epithelial intestinal cell lines as the data concerning the possible effects of Alternaria toxins on swine are scarce and insufficient for assessing the risk represented by Alternaria toxins for animal health. Our results have shown a dose-related effect on IPEC-1 cell viability, with an IC50 value of 10.5 μM. Exposure to the toxin induced an increase in total apoptotic cells, suggesting that AME induces programmed cell death through apoptosis based on caspase-3/7 activation in IPEC-1 cells. DNA and protein oxidative damage triggered by AME were associated with an alteration of the antioxidant response, as shown by a decrease in the enzymatic activity of catalase and superoxide dismutase. These effects on the oxidative response can be related to an inhibition of the Akt/Nrf2/HO-1 signaling pathway; however, further studies are needed in order to validate these in vitro data using in vivo trials in swine.

Combined use of multiparametric high-content-screening and in vitro circadian reporter assays in neurotoxicity evaluation

Accumulating evidence indicates that chronic circadian rhythm disruption is associated with the development of neurodegenerative diseases induced by exposure to neurotoxic chemicals. Herein, we examined the relationship between cellular circadian rhythm disruption and cytotoxicity in neural cells. Moreover, we evaluated the potential application of an in vitro cellular circadian rhythm assay in determining circadian rhythm disruption as a sensitive and early marker of neurotoxicant-induced adverse effects. To explore these objectives, we established an in vitro cellular circadian rhythm assay using human glioblastoma (U87 MG) cells stably transfected with a circadian reporter vector (PER2-dLuc) and determined the lowest-observed-adverse-effect levels (LOAELs) of several common neurotoxicants. Additionally, we determined the LOAEL of each compound on multiple cytotoxicity endpoints (nuclear size [NC], mitochondrial membrane potential [MMP], calcium ions, or lipid peroxidation) using a multiparametric high-content screening (HCS) assay using transfected U87 MG cells treated with the same neurotoxicants for 24 and 72 h. Based on our findings, the LOAEL for cellular circadian rhythm disruption for most chemicals was slightly higher than that for most cytotoxicity indicators detected using HCS, and the LOAEL for MMP in the first 24 h was the closest to that for cellular circadian rhythm disruption. Dietary antioxidants (methylselenocysteine and N-acetyl-l-cysteine) prevented or restored neurotoxicant-induced cellular circadian rhythm disruption. Our results suggest that cellular circadian rhythm disruption is as sensitive as cytotoxicity indicators and occurs early as much as cytotoxic events during disease development. Moreover, the in vitro cellular circadian rhythm assay warrants further evaluation as an early screening tool for neurotoxicants.

Aqueous distillate of mature leaves of Vernonia zeylanica (L.) Less. and Mallotus repandus (Rottler) Müll. Arg. cued from traditional medicine exhibits rapid wound healing properties

ETHNOPHARMACOLOGICAL RELEVANCE

Sri Lankan traditional medicine uses Vernonia zeylanica and Mallotus repandus broadly for the treatment of a multitude of disease conditions, including wound healing.

AIM OF THE STUDY

We aimed to scientifically validate the safety and efficacy of wound healing of an aqueous distillate of Vernonia zeylanica and Mallotus repandus (ADVM) mature leaves, tested on primary human dermal fibroblasts.

MATERIALS AND METHODS

Human dermal fibroblasts isolated from clinical waste from circumcision surgery were characterized by flowcytometry and trilineage differentiation. The MTT dye reduction assay, and the ex vivo wound healing scratch assay established wound healing properties of ADVM using the primary human dermal fibroblast cell line. Upregulation of genes associated with wound healing (MMP3, COL3A1, TGFB1, FGF2) were confirmed by RT qPCR. GC-MS chromatography evaluated the phytochemical composition of ADVM.

RESULTS

Compared to the synthetic stimulant, β fibroblast growth factor, ADVM at 0.25% concentration on the primary dermal fibroblast cell line exhibited significant ex vivo, (i) 1.7-fold % cell viability (178.7% vs 304.3 %, p < 0.001), (ii) twofold greater % wound closure (%WC) potential (47.74% vs 80.11%, p < 0.001), and (iii) higher rate of % WC (3.251 vs 3.456 % WC/h, p < 0.05), sans cyto-genotoxicity. Up regulated expression of FGF2, TGFB1, COL3A1 and MMP3, genes associated with wound healing, confirmed effective stimulation of pathways of the three overlapping phases of wound healing (P < 0.05). GC-MS profile of ADVM characterized four methyl esters, which may be posited as wound healing phytochemicals.

CONCLUSIONS

Exceeding traditional medicine claims, the exvivo demonstration of rapid skin regeneration, reiterated by upregulated expression of genes related to wound healing pathways, sans cytotoxicity, propounds ADVM, cued from traditional medicine, as a potential safe and effective natural stimulant for rapid wound-healing. Additionally, it may serve as an effective proliferative stimulant of dermal fibroblasts for cell therapy, with potential in reparative and regenerative therapy of skin disorders.

Classification of substances by health hazard using deep neural networks and molecular electron densities

In this paper we present a method that allows leveraging 3D electron density information to train a deep neural network pipeline to segment regions of high, medium and low electronegativity and classify substances as health hazardous or non-hazardous. We show that this can be used for use-cases such as cosmetics and food products. For this purpose, we first generate 3D electron density cubes using semiempirical molecular calculations for a custom European Chemicals Agency (ECHA) subset consisting of substances labelled as hazardous and non-hazardous for cosmetic usage. Together with their 3-class electronegativity maps we train a modified 3D-UNet with electron density cubes to segment reactive sites in molecules and classify substances with an accuracy of 78.1%. We perform the same process on a custom food dataset (CompFood) consisting of hazardous and non-hazardous substances compiled from European Food Safety Authority (EFSA) OpenFoodTox, Food and Drug Administration (FDA) Generally Recognized as Safe (GRAS) and FooDB datasets to achieve a classification accuracy of 64.1%. Our results show that 3D electron densities and particularly masked electron densities, calculated by taking a product of original electron densities and regions of high and low electronegativity can be used to classify molecules for different use-cases and thus serve not only to guide safe-by-design product development but also aid in regulatory decisions. SCIENTIFIC CONTRIBUTION: We aim to contribute to the diverse 3D molecular representations used for training machine learning algorithms by showing that a deep learning network can be trained on 3D electron density representation of molecules. This approach has previously not been used to train machine learning models and it allows utilization of the true spatial domain of the molecule for prediction of properties such as their suitability for usage in cosmetics and food products and in future, to other molecular properties. The data and code used for training is accessible at https://github.com/s-singh-ivv/eDen-Substances .

Potential of oligonucleotide- and protein/peptide-based therapeutics in the management of toxicant/stressor-induced diseases

Exposure to toxicants/stressors has been linked to the development of many human diseases. They could affect various cellular components, such as DNA, proteins, lipids, and non-coding RNAs (ncRNA), thereby triggering various cellular pathways, particularly oxidative stress, inflammatory responses, and apoptosis, which can contribute to pathophysiological states. Accordingly, modulation of these pathways has been the focus of numerous investigations for managing related diseases. The involvement of various ncRNAs, such as small interfering RNA (siRNA), microRNAs (miRNA), and long non-coding RNAs (lncRNA), as well as various proteins and peptides in mediating these pathways, provides many target sites for pharmaceutical intervention. In this regard, various oligonucleotide- and protein/peptide-based therapies have been developed to treat toxicity-induced diseases, which have shown promising results in vitro and in vivo. This comprehensive review provides information about various aspects of toxicity-related diseases including their causing factors, main underlying mechanisms and intermediates, and their roles in pathophysiological states. Particularly, it highlights the principles and mechanisms of oligonucleotide- and protein/peptide-based therapies in the treatment of toxicity-related diseases. Furthermore, various issues of oligonucleotides and proteins/peptides for clinical usage and potential solutions are discussed.

Vancomycin-loaded hydrogels with thermal-responsive, self-peeling, and sustainable antibacterial properties for wound dressing

Wound dressings play an important role in wound healing. However, many wound dressings lack antibacterial properties and are difficult to remove from newly grown tissues, causing secondary wound injuries and repeated medical treatment. This study reports a new type of thermal-responsive hydrogel dressing consisting of vancomycin-loaded gelatin nanospheres (GNs) and poly((N-isopropylacrylamide)-co-N-(methylol acrylamide)) functional components that could impart self-peeling and sustainable antibacterial properties. SEM images showed that the prepared hydrogel possessed a porous microstructure and the homogeneous distribution of GNs in its network. Excellent swelling ratios and thermal-induced self-peeling characteristics were confirmed by qualitative analysis. The GNs not only enhanced the strain at break of the hydrogel, but also acted as drug carriers to slow down the drug release from the hydrogel, achieving sustainable antibacterial properties and balanced biocompatibility. Therefore, this vancomycin-loaded hydrogel with self-peeling characteristics provides an effective way of preventing wound infection and can be used as a novel platform for wide-ranging applications of wound dressings.

Comparative analysis of energy transfer mechanisms for neural implants

As neural implant technologies advance rapidly, a nuanced understanding of their powering mechanisms becomes indispensable, especially given the long-term biocompatibility risks like oxidative stress and inflammation, which can be aggravated by recurrent surgeries, including battery replacements. This review delves into a comprehensive analysis, starting with biocompatibility considerations for both energy storage units and transfer methods. The review focuses on four main mechanisms for powering neural implants: Electromagnetic, Acoustic, Optical, and Direct Connection to the Body. Among these, Electromagnetic Methods include techniques such as Near-Field Communication (RF). Acoustic methods using high-frequency ultrasound offer advantages in power transmission efficiency and multi-node interrogation capabilities. Optical methods, although still in early development, show promising energy transmission efficiencies using Near-Infrared (NIR) light while avoiding electromagnetic interference. Direct connections, while efficient, pose substantial safety risks, including infection and micromotion disturbances within neural tissue. The review employs key metrics such as specific absorption rate (SAR) and energy transfer efficiency for a nuanced evaluation of these methods. It also discusses recent innovations like the Sectored-Multi Ring Ultrasonic Transducer (S-MRUT), Stentrode, and Neural Dust. Ultimately, this review aims to help researchers, clinicians, and engineers better understand the challenges of and potentially create new solutions for powering neural implants.

Rational understanding of chiral fungicide penthiopyrad stereoselectivity: Bioactivity, aquatic toxicity and cytotoxicity

Penthiopyrad is a novel chiral succinate dehydrogenase inhibitor (SDHI) fungicide with two enantiomers. However, enantioselective information on the biological activity, nontarget organisms and human health risk of penthiopyrad is not comprehensive, which may cause inaccurate risk assessment. In this study, the enantioselective bioactivity to three kinds of phytopathogens (Rhizoctonia solani, Botrytis cinerea and Sclerotinia sclerotiorum) was first disclosed, and the antifungal activity of S-(+)-penthiopyrad was higher than that of R-(-)-penthiopyrad by 12-37 times. Moreover, its enantioselective toxicity to Raphidocelis subcapitata and Daphnia magna was also clarified, and the order of toxicity was S-(+)-penthiopyrad > rac-penthiopyrad >R-(-)-penthiopyrad, with 1.8- and 5.3-fold differences between the two enantiomers. Furthermore, the enantioselectivity of penthiopyrad on HepG2 cytotoxicity was studied. The data showed that the cytotoxicity of S-(+)-penthiopyrad was 1.8 times higher than that of R-(-)-penthiopyrad, and S-(+)-penthiopyrad had a stronger impact on cell proliferation, oxidative stress and lipid peroxidation. In summary, due to the enantioselectivity of the activity and toxicity of the chiral pesticide, the efficacy and risk evaluation of penthiopyrad should be considered at the enantiomer level.

Recent advances in metal-organic frameworks: Synthesis, application and toxicity

Metal-organic frameworks (MOFs) are a new class of crystalline porous hybrid materials with high porosity, large specific surface area and adjustable channel structure and biocompatibility, which are being investigated with increasing interest for energy storage and conversion, gas adsorption/separation, catalysis, sensing and biomedicine. However, the practical applications of MOFs make them release into the environment inevitable, posing a threat to humans and organisms. In this article, we cover advances in the currently available MOFs synthesis methods and the emerging applications of MOFs, especially in the biomedical field (therapeutic agents and bioimaging). Additionally, after evaluating the current status of main exposure routes and affecting factors in the field of MOFs-toxicity, the molecular mechanism is also clarified and identified. Knowledge gaps are identified from such a summarization and frontier development are explored for MOFs. Afterwards, we also present the limitations, challenges, and future perspectives in the study of the entire life cycle of MOFs. This review emphasizes the need for a more targeted discussion of the latest, widely used and effective versatile material class in order to exploit the full potential of high-performance and non-toxicity MOFs in the future.

Current Aspects on the Plastic Nano- and Microparticles Toxicity in Zebrafish-Focus on the Correlation between Oxidative Stress Responses and Neurodevelopment

Recent reports focusing on the extent of plastic pollution have shown that many types of fibers and polymers can now be found in most marine species. The severe contamination of plastic nano-/microparticles (NPs/MPs) mainly results in immediate negative outcomes, such as organic impairments and tissue damage, as well as long-termed negative effects, such as developmental retardation and defects, chronic inflammation, oxidative stress (OS), metabolic imbalance, mutagenesis, and teratogenesis. Oxidative responses are currently considered the first line molecular signal to potential toxic stimuli exposure, as the oxidative balance in electron exchange and reactive oxygen species signaling provides efficient harmful stimuli processing. Abnormal signaling or dysregulated ROS metabolism-OS-could be an important source of cellular toxicity, the source of a vicious cycle of environmental and oxidative signaling-derived toxicity. As chemical environmental pollutants, plastic NPs/MPs can also be a cause of such toxicity. Thus, we aimed to correlate the possible toxic effects of plastic NPs/MPs in zebrafish models, by focusing on OS and developmental processes. We found that plastic NPs/MPs toxic effects could be observed during the entire developmental span of zebrafish in close correlation with OS-related changes. Excessive ROS production and decreased antioxidant enzymatic defense due to plastic NPs/MPs exposure and accumulation were frequently associated with acetylcholinesterase activity inhibition, suggesting important neurodevelopmental negative outcomes (cognitive abnormalities, neurodevelopmental retardation, behavioral impairments) and extraneuronal effects, such as impaired digestive physiology.

Particulate toxicity of metal-organic framework UiO-66 to white rot fungus Phanerochaete chrysosporium

Metal-organic frameworks (MOF) are emerging materials with fantastic properties and wide applications. The release of metal ions from MOF materials is usually regarded as the origin of soluble MOF toxicity. However, whether the stable MOF particulates would induce environmental hazards is not clear. Herein, we aimed to reveal the particulate toxicity of MOF materials using the insoluble UiO-66 as the representative MOF and Phanerochaete chrysosporium as the model microorganism. UiO-66 nanoparticles (NPs) were synthesized by solvothermal method and their diameter was 68.4 ± 8.5 nm. UiO-66 NPs were stable in the culture system and the dissolution rate of 500 mg/L group was 0.26% after 14 d incubation. UiO-66 NPs did not affect the fungus growth according to the fresh weight increases and unchanged dry weights. Fungus mycelia kept even at concentrations up to 500 mg/L. Ultrastructural observation showed that UiO-66 NPs did not enter the fungal cells, but slightly destroyed the cell wall. UiO-66 NPs inhibited the laccase activity and promoted the activity of manganese peroxidase. The overall impact on the decomposition activity of P. chrysosporium was low in dye coloration test and sawdust degradation assay. Meaningful oxidative stress was aroused by UiO-66 NPs, as indicated by the decreases of catalase, glutathione, and total superoxide dismutase, and the increases of H₂O₂. Our results collectively suggested that the MOF particulates could induce mild mechanical damage to fungi and the toxicity was low comparing to other instable MOF materials.

Toxic Effects of Cadmium on Fish

Large amounts of enriched cadmium (Cd) in the environment seriously threatens the healthy and sustainable development of the aquaculture industry and greatly restricts the development of the food processing industry. Studying the distribution and toxic effects of Cd in fish, as well as the possible toxic effects of Cd on the human body, is very significant. A large number of studies have shown that the accumulation and distribution of Cd in fish are biologically specific, cause tissue differences, and seriously damage the integrity of tissue structure and function, the antioxidant defense system, the reproductive regulation system, and the immune system. The physiological, biochemical, enzyme, molecular, and gene expression levels change with different concentrations and times of Cd exposure, and these changes are closely related to the target sites of Cd action and tissues in fish. Therefore, the toxic effects of Cd on fish occur with multiple tissues, systems, and levels.

Brain Protection by Methylene Blue and Its Derivative, Azur B, via Activation of the Nrf2/ARE Pathway in Cisplatin-Induced Cognitive Impairment

Cisplatin is a cytotoxic chemotherapeutic drug that leads to DNA damage and is used in the treatment of various types of tumors. However, cisplatin has several serious adverse effects, such as deterioration in cognitive ability. The aim of our work was to study neuroprotectors capable of preventing cisplatin-induced neurotoxicity. Methylene blue (MB) and AzurB (AzB) are able to neutralize the neurotoxicity caused by cisplatin by protecting nerve cells as a result of the activation of the Ntf2 signaling pathway. We have shown that cisplatin impairs learning in the Morris water maze. This is due to an increase in the amount of mtDNA damage, a decrease in the expression of most antioxidant genes, the main determinant of the induction of which is the Nrf2/ARE signaling pathway, and genes involved in mitophagy regulation in the cortex. The expression of genes involved in long-term potentiation was suppressed in the hippocampus of cisplatin-injected mice. MB in most cases prevented cisplatin-induced impairment of learning and decrease of gene expression in the cortex. AzB prevented the cisplatin-induced decrease of genes in the hippocampus. Also, cisplatin induced disbalance in the gut microbiome, decreased levels of Actinotalea and Prevotella, and increased levels of Streptococcus and Veillonella. MB and AzB also prevented cisplatin-induced changes in the bacterial composition of the gut microbiome.

Cell-penetrating peptide-mediated delivery of therapeutic peptides/proteins to manage the diseases involving oxidative stress, inflammatory response and apoptosis

OBJECTIVES

Peptides and proteins represent great potential for modulating various cellular processes including oxidative stress, inflammatory response, apoptosis and consequently the treatment of related diseases. However, their therapeutic effects are limited by their inability to cross cellular barriers. Cell-penetrating peptides (CPPs), which can transport cargoes into the cell, could resolve this issue, as would be discussed in this review.

KEY FINDINGS

CPPs have been successfully exploited in vitro and in vivo for peptide/protein delivery to treat a wide range of diseases involving oxidative stress, inflammatory processes and apoptosis. Their in vivo applications are still limited due to some fundamental issues of CPPs, including nonspecificity, proteolytic instability, potential toxicity and immunogenicity.

SUMMARY

Totally, CPPs could potentially help to manage the diseases involving oxidative stress, inflammatory response and apoptosis by delivering peptides/proteins that could selectively reach proper intracellular targets. More studies to overcome related CPP limitations and confirm the efficacy and safety of this strategy are needed before their clinical usage.

Investigation of toxicity effect of TiCN coated on 304 SS and 410 SS substrates in rat fibroblasts and B-lymphocytes

In the present study, TiCN thin films were coated on AISI 304 and AISI 410 stainless steel (SS) substrates by Cathodic Arc Physical Vapor Deposition method. TiCN-coated substrates were confirmed by the XRD analysis results. Dense morphology and fine-grained surface of TiCN film were established by SEM images. Cellular toxicity of the coated 304 SS and 410 SS substrates was investigated in the fibroblasts and B-lymphocyte. In respect to that, we have shown coated substrates cytotoxicity, oxidative stress as well as cell viability, reactive oxygen species (ROS), lipid peroxidation (MDA), protein carbonyl, glutathione oxidase (GSSG), and glutathione reductase (GSH) assessment, releasing cytochrome c (Cytc), lysosomal membrane destabilization (AO) may lead to cell death signaling. Our results showed that the coated 304 SS and 410 SS substrates induced cells dysfunction via a significant increase in ROS production, MDA (P < 0.01 and P < 0.001), protein carbonyl (P < 0.05), and GSSG (P < 0.05 and P < 0.01) that correlated to cytochrome c release (P < 0.01). In addition, increased disturbance in oxidative phosphorylation was also shown by the decrease in cell viability (P < 0.001) and GSH (P < 0.01 and P < 0.001) in the coated 304 SS and 410 SS substrates-treated fibroblast and B-lymphocytes. The coated 304 SS and 410 SS substrates contacted cells and trafficked to the lysosomes and this is followed by lysosomal damage, leading to apoptosis/Necrosis. Our results indicated that these materials cause cellular dysfunction and subsequent oxidative stress leading to cognitive impairment in the rat fibroblasts and B-lymphocytes cells.

Toxicity of metal-organic framework nanoparticles: from essential analyses to potential applications

In the last two decades, the field of metal-organic frameworks (MOFs) has exploded, and MOF nanoparticles in particular are being investigated with increasing interest for various applications, including gas storage and separation, water harvesting, catalysis, energy conversion and storage, sensing, diagnosis, therapy, and theranostics. To further pave their way into real-world applications, and to push the synthesis of MOF nanoparticles that are 'safe-and-sustainable-by-design', this tutorial review aims to shed light on the importance of a systematic toxicity assessment. After clarifying and working out the most important terms and aspects from the field of nanotoxicity, the current state-of-the-art of in vitro and in vivo toxicity studies of MOF nanoparticles is evaluated. Moreover, the key aspects affecting the toxicity of MOF nanoparticles such as their chemical composition, their physico-chemical properties, including their colloidal and chemical stability, are discussed. We highlight the need of more targeted synthesis of MOF nanoparticles that are 'safe-and-sustainable-by-design', and their tailored hazard assessment in the context of their potential applications in order to tap the full potential of this versatile material class in the future.

Genistein-based reactive oxygen species-responsive nanomaterial site-specifically relieves the intestinal toxicity of endocrine-disrupting chemicals

Endocrine-disrupting chemicals (EDCs) can disrupt the gastrointestinal endocrine system and induce oxidative stress, which eventually leads to intestinal toxicity. Genistein (Gen) has a beneficial effect on the physiological functions of the gastrointestinal tract and can alleviate EDCs damage. As an estrogen-like substance, Gen may also synergize the deleterious influence of EDCs. Therefore, the targeting and concentration of Gen must be controlled during its application. In this study, a novel reactive oxygen species (ROS)-responsive nanomaterial (Gen-NM-2) containing Tempol conjugated β-cyclodextrin and Gen was prepared. The nano-polymer exhibits a uniform rod-like morphology with an average diameter of 833±12 nm and a negative zeta-potential of -20.3±3.7 mV. Gen-NM-2 protected Gen from rapid metabolism in gastrointestinal tract and displayed a strong ROS scavenging ability. In response to high ROS levels, this material can effectively locate the target site and release Gen, which then exerted its effect by reducing the ROS content and regulating the ERβ signaling pathway. Owing to its high bioavailability, Gen-NM-2 at relatively low doses can reduce the intestinal cytotoxicity of EDCs, thus providing a basis for the development of EDCs detoxification therapy.

In vitro toxicological evaluation of mesoporous silica microparticles functionalised with carvacrol and thymol

The cytotoxicity of carvacrol- and thymol-functionalised mesoporous silica microparticles (MCM-41) was assessed in the human hepatocarcinoma cell line (HepG2). Cell viability, lactate dehydrogenase (LDH) activity, reactive oxygen species (ROS) production, mitochondrial membrane potential (ΔΨm), lipid peroxidation (LPO) and apoptosis/necrosis analyses were used as endpoints. The results showed that both materials induced cytotoxicity in a time- and concentration-dependent manner, and were more cytotoxic than free essential oil components and bare MCM-41. This effect was caused by cell-particle interactions and not by degradation products released to the culture media, as demonstrated in the extract dilution assays. LDH release was a less sensitive endpoint than the MTT (thiazolyl blue tetrazolium bromide) assay, which suggests the impairment of the mitochondrial function as the primary cytotoxic mechanism. In vitro tests on specialised cell functions showed that exposure to sublethal concentrations of these materials did not induce ROS formation during 2 h of exposure, but produced LPO and ΔΨm alterations in a concentration-dependent manner when cells were exposed for 24 h. The obtained results generally support the hypothesis that the carvacrol- and thymol-functionalised MCM-41 microparticles induced toxicity in HepG2 cells by an oxidative stress-related mechanism that resulted in apoptosis through the mitochondrial pathway.

New focuses on roles of communications between endoplasmic reticulum and mitochondria in identification of biomarkers and targets

The communication between endoplasmic reticulum (ER) and mitochondria (Mt) plays important roles in maintenance of intra- and extra-cellular microenvironment, metabolisms, signaling activities and cell-cell communication. The present review aims to overview the advanced understanding about roles of ER-Mt structural contacts, molecular interactions and chemical exchanges, signal transmissions and inter-organelle regulations in ER-Mt communication. We address how the ER-Mt communication contributes to the regulation of lipid, amino acid and glucose metabolisms by enzymes, transporters and regulators in the process of biosynthesis. We specially emphasize the importance of deep understanding about molecular mechanisms of ER-Mt communication for identification and development of biology-specific, disease-specific and metabolism-specific biomarkers and therapeutic targets for human diseases. The inhibitors and modulators of the ER-Mt communication are categorized according to therapeutic targets. Rapid development of biotechnologies will provide new insights for spatiotemporally understanding the molecular mechanisms of ER-Mt communication.

Mitotic Index Determination on Live Cells From Label-Free Acquired Quantitative Phase Images Using a Supervised Autoencoder

This interdisciplinary work focuses on the interest of a new auto-encoder for supervised classification of live cell populations growing in a thermostated imaging station and acquired by a Quantitative Phase Imaging (QPI) camera. This type of camera produces interferograms that have to be processed to extract features derived from quantitative linear retardance and birefringence measurements. QPI is performed on living populations without any manipulation or treatment of the cells. We use the efficient new autoencoder classification method instead of the classical Douglas-Rachford method. Using this new supervised autoencoder, we show that the accuracy of the classification of the cells present in the mitotic phase of the cell cycle is very high using QPI features. This is a very important finding since we demonstrate that it is now possible to very precisely follow cell growth in a non-invasive manner, without any bias. No dye or any kind of markers are necessary for this live monitoring. Any studies requiring analysis of cell growth or cellular response to any treatment could benefit from this new approach by simply monitoring the proportion of cells entering mitosis in the studied cell population.

Functional state of the myometrium of rats under chronic in vivo effect of nanostructured ZnO and ТіО2 materials

The specificities of the structure and blood supply of the uterus facilitate a considerable accumulation of nanosized xenobiotics, including nanoparticles of metal oxides, in its tissues. Numerous in vitro and in vivo experiments demonstrated that nanoparticles of metal oxides (ZnO and TiO2) have significant cytotoxic activity, caused by oxidative stress induction. However, there is no information about the impact of these nanomaterials on the functional state of the myometrium under chronic exposure on the organism. Tenzometric methods and mechanokinetic analysis were used in our work to investigate the contractile activity of the myometrium of non-pregnant rats. The contractile activity was either spontaneous or induced by oxytocin (the uterotonic hormone) and acetylcholine (the agonist of muscarinic choline receptors) under chronic peroral intake of the ZnO and TiO2 aqueous nanocolloids into the organism. It was found that after burdening of rats with ZnO and ТіО2 aqueous nanocolloids there were no changes in the pacemaker-dependent mechanisms forming the frequency of spontaneous contractions in the myometrium, but there was a considerably induced increase in the AU index of contractions. It was shown that during the oxytocin-induced excitation of the myometrium under both chronic and short-term burdening of the rats with ZnO and TiO2 aqueous nanocolloids, the mechanisms that regulate the intracellular concentration of Ca2+ ions are the target for the nanomaterials. When the rats were burdened with ZnO aqueous nanocolloids for 6 months, during cholinergic excitation there was hyperstimulation of both M3-receptor-dependent mechanisms of Са2+ ions intake via the potential-governed Са2+-channels of L-type into the smooth muscles of the myometrium, and M2-receptor-dependent mechanisms, controlling the intracellular concentration of these cations. Thus, the regularities and mechanisms of the change in the functioning of uterine smooth muscles under chronic intake of the ZnO and TiO2 aqueous nanocolloids were determined in this study.

Investigating the Molecular Processes behind the Cell-Specific Toxicity Response to Titanium Dioxide Nanobelts

Some engineered nanomaterials incite toxicological effects, but the underlying molecular processes are understudied. The varied physicochemical properties cause different initial molecular interactions, complicating toxicological predictions. Gene expression data allow us to study the responses of genes and biological processes. Overrepresentation analysis identifies enriched biological processes using the experimental data but prompts broad results instead of detailed toxicological processes. We demonstrate a targeted filtering approach to compare public gene expression data for low and high exposure on three cell lines to titanium dioxide nanobelts. Our workflow finds cell and concentration-specific changes in affected pathways linked to four Gene Ontology terms (apoptosis, inflammation, DNA damage, and oxidative stress) to select pathways with a clear toxicity focus. We saw more differentially expressed genes at higher exposure, but our analysis identifies clear differences between the cell lines in affected processes. Colorectal adenocarcinoma cells showed resilience to both concentrations. Small airway epithelial cells displayed a cytotoxic response to the high concentration, but not as strongly as monocytic-like cells. The pathway-gene networks highlighted the gene overlap between altered toxicity-related pathways. The automated workflow is flexible and can focus on other biological processes by selecting other GO terms.

Regulatory roles of osteopontin in human lung cancer cell epithelial-to-mesenchymal transitions and responses

BACKGROUND

Lung cancer is still the main cause of death in patients with cancer, due to poor understanding of intracellular regulations. Of those, osteopontin (OPN) may induce the epithelial-to-mesenchymal transition (EMT) to promote tumor cell metastasis. The present study aims to evaluate the regulatory mechanism of internal and external OPN in the development of lung cancer.

METHODS

We evaluated genetic variations and different bioinformatics of genes in chromosome 4 among subtypes of lung cancer using global databases. We validated the expression of OPN and EMT-related proteins (e.g., E-cadherin, vimentin) in 208 non-small-cell lung cancer (NSCLC) tumors and the adjacent nontumorous tissues, further to explore the function of OPN in the progression of lung cancer, with a focus on a potential communication between OPN and EMT in the lung cancer.

RESULTS

We found that OPN might act as a target molecule in lung cancer, which is associated with lymph node metastasis, postresection recurrence/metastasis, and prognosis of patients with lung cancer. Biological behaviors and pathological responses of OPN varied among diseases, challenges, and severities. Overexpression of OPN was correlated with the existence of EMT in lung cancer tissues. Internal and external OPN plays the decisive roles in lung cancer cell movement, proliferation, and EMT formation, through the upregulation of OPN-PI3K and OPN-MEK pathways. PI3K and MEK inhibitors downregulated the process of EMT and biological behaviors of lung cancer cells, probably through altering vimentin-associated cytoskeletons.

CONCLUSION

OPN can be a metastasis-associated or specific biomarker for lung cancer and a potential target for antimetastatic treatment.

A novel anti-angiogenic radio/photo sensitizer for prostate cancer imaging and therapy: 89Zr-Pt@TiO2-SPHINX, synthesis and in vitro evaluation

Prostate cancer is the most common malignancy and leading cause of cancer deaths in men. Thus, the development of novel strategies for performing combined prostate cancer imaging and therapy methods is crucial and could have a significant impact on patient care. This current study aimed to design a multimodality nanoconjugate to be used for both PET and optical imaging and as a therapeutic radio/photo sensitizer and anti-angiogenesis agent. Initial characterization of this novel nanoconjugate was performed via HPLC, FTIR, TEM and DLS analyses. Pt@TiO2-SPHINX was further evaluated using fluorometric and radiochromatographic methods. Cytotoxicity, cell uptake and internalization were also investigated as well as therapy with photodynamic/radio therapy combinations. Both nanoparticles and nanoconjugates were robustly synthesized according to literature methods. Radiochemistry and cell culture assays showed high 89Zr radiolabeling efficiency with sufficient stability for studies at later time points. Pt@TiO2-SPHINX was shown to target prostate cancer cells (PC3 and LNCaP), and was non-toxic to normal prostate cells (RWPE-1). This finding was supported by the WST-8 assay and AFM images. The uptake of the compound in prostate cancer cells is significantly higher than prostate normal cells and according to ELISA results, Pt@TiO2-SPHINX can increase anti-angiogenic VEGFA165b. Additionally, Pt@TiO2-SPHINX dramatically decreased the cell viability of prostate cancer cells when photodynamic and radio therapy were performed at the same time. In vitro results are promising for future studies of Pt@TiO2-SPHINX as a PET imaging agent and anti-angiogenic radio sensitizer.

Growth differentiation factor 11 mitigates cardiac radiotoxicity via activating AMPKα

Cardiac radiotoxicity largely impedes the therapeutic benefits of radiotherapy to malignancies. Growth differentiation factor 11 (GDF11) is implicated in the pathogenesis of cardiac diseases under different pathological conditions. This study aims to investigate the role and underlying mechanisms of GDF11 on cardiac radiotoxicity. Mice were injected with cardiotropic adeno-associated virus 9 carrying the full-length mouse GDF11 gene or negative control under a cTnT promoter from the tail vein, and then received a single dose of 20 Gray (Gy) whole-heart irradiation (WHI) for 16 weeks to imitate cardiac radiotoxicity. Compound C (CC, 20 mg/kg) was intraperitoneally injected every two days at 1 week before WHI stimulation to inhibit 5' AMP-activated protein kinase α (AMPKα). Cardiac GDF11 expression was significantly suppressed at both the protein and mRNA levels. GDF11 overexpression decreased oxidative stress, apoptosis, and fibrosis in radiated hearts, thereby mitigating cardiac radiotoxicity, and dysfunction. Further detection revealed that GDF11 activated AMPKα to reduce radiation-induced oxidative damage and that AMPKα inhibition by CC offset the cardioprotective effects by GDF11. GDF11 mitigates cardiac radiotoxicity via activating AMPKα and it is a promising candidate to treat cardiac radiotoxicity.

Implant-derived CoCrMo alloy nanoparticle disrupts DNA replication dynamics in neuronal cells

The complexity of cobalt-chromium-molybdenum (CoCrMo) nanoparticles generated from the hip modular taper interfaces resulted in inconclusive outcomes on the level of toxicity in orthopedic patients. We used a hip simulator to generate physiologically relevant CoCrMo degradation products (DPs) to demonstrate the variation in the level of toxicity in neurons in comparison to processed degradation products (PDPs). The study outcomes indicate that DP induces a higher level of DNA damage in the form of double- and single-stranded DNA breaks and alkaline labile DNA adducts versus PDPs. The scientific advancements of this study are the following: (i) how DPs mimic more closely to the implant debris from hip implants in terms of bioactivity, (ii) how hip implant debris causes local and systemic issues, and (iii) methods to augment the biologic impact of implant debris. We discovered that DP is bioactive compared with PDP, and this should be considered in the toxicity evaluation related to implants. • The physicochemical characteristics of the CoCrMo is a major factor to consider for implant-related cytotoxicity or genotoxicity experimental design. • Elevated levels of intracellular ROS induced by the physiologically relevant wear particle are detrimental to the neuronal cells. • The DP can induce variation in DNA replication dynamics compared to PDP.

Development of an Oil-in-Water Self-Emulsifying Microemulsion for Cutaneous Delivery of Rose Bengal: Investigation of Anti-Melanoma Properties

The topical delivery route is proposed as an alternative or adjunctive approach to melanoma treatment, since the target site for melanoma treatment-the epidermal basal layer-is potentially accessible by this route. Microemulsion systems are effective delivery vehicles for enhanced, targeted skin delivery. This work investigated the effect of Rose Bengal (RB) and RB-loaded self-emulsifying microemulsions (SEMEs) on growth inhibition of human melanoma and normal skin cell monolayers, the safety of the excipients incorporated in SEMEs on human cell lines, and the in-vitro human skin penetration of RB delivered in SEMEs and control solution. Cellular toxicity was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the growth inhibitory mechanism of RB was investigated by flow cytometry using PI staining. Unloaded SEMEs caused reduced cellular toxicity compared to the surfactant excipient, Labrasol^®. RB-loaded SEMEs increased cell growth inhibition compared to the RB aqueous solution. Flow cytometry revealed apoptotic cells after treatment with RB-loaded SEMEs, indicating that apoptosis may be one of the mechanisms of cell death. Preliminary results of multiphoton microscopy with fluorescence lifetime imaging (MPM-FLIM) analysis showed deeper penetration with greater skin concentrations of RB delivered from SEMEs compared to the RB aqueous solution. This study highlights the enhanced skin penetration and antimelanoma effects of RB loaded in a SEME system.

Research Advances on DNA Methylation in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic complex lung disease with no specific treatment and poor prognosis, characterized by the pulmonary progressive fibrosis and dysfunctions that lead to respiratory failure. Several factors may impact the progress of IPF, including age, cigarette smoking, and dusts, of which genetic and epigenetic factors mainly contribute to lung tissue fibrosis. DNA methylation is one of epigenetic processes that occur in many diseases and regulate chromosomal and extrachromosomal DNA functions in response to environmental exposures. The methylation plays pivotal roles in regulation of gene expression to facilitate the formation of fibroblastic foci and lung fibrosis. This chapter will describe alterations and effects of the DNA methylation on gene expression, the potential application of DNA methylation as a biomarker, and significance as therapeutic targets. Those understanding will provide us new insight into the treatment and prognosis of IPF.

Nanovolcano microelectrode arrays: toward long-term on-demand registration of transmembrane action potentials by controlled electroporation

Volcano-shaped microelectrodes (nanovolcanoes) functionalized with nanopatterned self-assembled monolayers have recently been demonstrated to report cardiomyocyte action potentials after gaining spontaneous intracellular access. These nanovolcanoes exhibit recording characteristics similar to those of state-of-the-art micro-nanoelectrode arrays that use electroporation as an insertion mechanism. In this study, we investigated whether the use of electroporation improves the performance of nanovolcano arrays in terms of action potential amplitudes, recording durations, and yield. Experiments with neonatal rat cardiomyocyte monolayers grown on nanovolcano arrays demonstrated that electroporation pulses with characteristics derived from analytical models increased the efficiency of nanovolcano recordings, as they enabled multiple on-demand registration of intracellular action potentials with amplitudes as high as 62 mV and parallel recordings in up to ~76% of the available channels. The performance of nanovolcanoes showed no dependence on the presence of functionalized nanopatterns, indicating that the tip geometry itself is instrumental for establishing a tight seal at the cell-electrode interface, which ultimately determines the quality of recordings. Importantly, the use of electroporation permitted the recording of attenuated cardiomyocyte action potentials during consecutive days at identical sites, indicating that nanovolcano recordings are nondestructive and permit long-term on-demand recordings from excitable cardiac tissues. Apart from demonstrating that less complex manufacturing processes can be used for next-generation nanovolcano arrays, the finding that the devices are suitable for performing on-demand recordings of electrical activity from multiple sites of excitable cardiac tissues over extended periods of time opens the possibility of using the devices not only in basic research but also in the context of comprehensive drug testing.

Malignancy and tumorigenicity of melanoma B16 cells are not affected by silver and gold nanoparticles

Gold (AuNP) and silver (AgNP) nanoparticles have been incorporated into many therapeutic and diagnostic applications. However, previous studies revealed toxic properties as well as the hormesis phenomenon of many nanoparticles in different biological models. To evaluate the effects of low concentrations of AuNP and AgNP on murine melanoma cells B16F1 and B16F10 and relate them with phenotype changes, cells were exposed for 24 and 48 h. No cytotoxicity was observed for B16 cells through neutral red, MTT, trypan blue, and crystal violet assays at concentrations from 0.01 to 10 ng mL^-1. Likewise, the nanoparticles did not interfere with drug-efflux activity, cell migration, cell cycle, and colony formation. Slight toxicity was observed for B16F10 exposed to 100 ng mL^-1, with a decreased number of viable and attached cells, indicating differential sensitivity of B16F1 and B16F10 cells to the nanoparticles. Furthermore, colony size dispersion decreased for both B16 cell sub-lines. Therefore, there is no evidence that the tested concentrations of AuNP and AgNP can render B16 cells more aggressive and malignant, which is important since both nanoparticles are already largely used in nanotechnological products. Considering studies that have showed the hormesis effect of nanoparticles at low concentrations, which could protect cancer cells against chemotherapy, further investigation is advised.

Adverse outcome pathways as a tool for the design of testing strategies to support the safety assessment of emerging advanced materials at the nanoscale

Toxicity testing and regulation of advanced materials at the nanoscale, i.e. nanosafety, is challenged by the growing number of nanomaterials and their property variants requiring assessment for potential human health impacts. The existing animal-reliant toxicity testing tools are onerous in terms of time and resources and are less and less in line with the international effort to reduce animal experiments. Thus, there is a need for faster, cheaper, sensitive and effective animal alternatives that are supported by mechanistic evidence. More importantly, there is an urgency for developing alternative testing strategies that help justify the strategic prioritization of testing or targeting the most apparent adverse outcomes, selection of specific endpoints and assays and identifying nanomaterials of high concern. The Adverse Outcome Pathway (AOP) framework is a systematic process that uses the available mechanistic information concerning a toxicological response and describes causal or mechanistic linkages between a molecular initiating event, a series of intermediate key events and the adverse outcome. The AOP framework provides pragmatic insights to promote the development of alternative testing strategies. This review will detail a brief overview of the AOP framework and its application to nanotoxicology, tools for developing AOPs and the role of toxicogenomics, and summarize various AOPs of relevance to inhalation toxicity of nanomaterials that are currently under various stages of development. The review also presents a network of AOPs derived from connecting all AOPs, which shows that several adverse outcomes induced by nanomaterials originate from a molecular initiating event that describes the interaction of nanomaterials with lung cells and involve similar intermediate key events. Finally, using the example of an established AOP for lung fibrosis, the review will discuss various in vitro tests available for assessing lung fibrosis and how the information can be used to support a tiered testing strategy for lung fibrosis. The AOPs and AOP network enable deeper understanding of mechanisms involved in inhalation toxicity of nanomaterials and provide a strategy for the development of alternative test methods for hazard and risk assessment of nanomaterials.

Anti-Aging Effects of GDF11 on Skin

Human skin is composed of three layers: the epidermis, the dermis, and the hypodermis. The epidermis has four major cell layers made up of keratinocytes in varying stages of progressive differentiation. Skin aging is a multi-factorial process that affects every phase of its biology and function. The expression profiles of inflammation-related genes analyzed in resident immune cells demonstrated that these cells have a strong ability to regenerate adult skin stem cells and to produce endogenous substances such as growth differentiation factor 11 (GDF11). GDF11 appears to be the key to progenitor proliferation and/or differentiation. The preservation of youthful phenotypes has been tied to the presence of GDF11 in different human tissues, and, in the skin, this factor inhibits inflammatory responses. The protective role of GDF11 depends on a multi-factorial process implicating various types of skin cells such as keratinocytes, fibroblasts and inflammatory cells. GDF11 should be further studied for the purpose of developing novel therapies for the treatment of skin diseases.

An Integrated In Vitro-In Silico Approach for Silver Nanoparticle Dosimetry in Cell Cultures

Potential human and environmental hazards resulting from the exposure of living organisms to silver nanoparticles (Ag NPs) have been the subject of intensive discussion in the last decade. Despite the growing use of Ag NPs in biomedical applications, a quantification of the toxic effects as a function of the total silver mass reaching cells (namely, target cell dose) is still needed. To provide a more accurate dose-response analysis, we propose a novel integrated approach combining well-established computational and experimental methodologies. We first used a particokinetic model (ISD3) for providing experimental validation of computed Ag NP sedimentation in static-cuvette experiments. After validation, ISD3 was employed to predict the total mass of silver reaching human endothelial cells and hepatocytes cultured in 96 well plates. Cell viability measured after 24 h of culture was then related to this target cell dose. Our results show that the dose perceived by the cell monolayer after 24 h of exposure is around 85% lower than the administered nominal media concentration. Therefore, accurate dosimetry considering particle characteristics and experimental conditions (e.g., time, size and shape of wells) should be employed for better interpreting effects induced by the amount of silver reaching cells.

Roles of transforming growth factor-β and phosphatidylinositol 3-kinase isoforms in integrin β1-mediated bio-behaviors of mouse lung telocytes

Background

Telocytes (TCs) have the capacity of cell–cell communication with adjacent cells within the tissue, contributing to tissue repair and recovery from injury. The present study aims at investigating the molecular mechanisms by which the TGFβ1-ITGB1-PI3K signal pathways regulate TC cycle and proliferation.

Methods

Gene expression of integrin (ITG) family were measured in mouse primary TCs to compare with other cells. TC proliferation, movement, cell cycle, and PI3K isoform protein genes were assayed in ITGB1-negative or positive mouse lung TCs treated with the inhibition of PI3Kp110α, PI3Kα/δ, PKCβ, or GSK3, followed by TGFβ1 treatment.

Results

We found the characters and interactions of ITG or PKC family member networks in primary mouse lung TCs, different from other cells in the lung tissue. The deletion of ITGB1 changed TCs sensitivity to treatment with multifunctional cytokines or signal pathway inhibitors. The compensatory mechanisms occur among TGFβ1-induced PI3Kp110α, PI3Kα/δ, PKCβ, or GSK3 when ITGB1 gene was deleted, leading to alterations of TC cell cycle and proliferation. Of those PI3K isoform protein genes, mRNA expression of PIK3CG altered with ITGB1-negative TC cycle and proliferation.

Conclusion

TCs have strong capacity of proliferation through the compensatory signaling mechanisms and contribute to the development of drug resistance due to alterations of TC sensitivity.

Ouabain induces apoptotic cell death in human prostate DU 145 cancer cells through DNA damage and TRAIL pathways

Ouabain, a cardiotonic steroid and specific Na⁺ /K⁺ -ATPase inhibitor, has a potential to induce cancer cell apoptosis but the mechanisms of apoptosis induced by ouabain are not fully understand. The aim of this study was to investigate the cytotoxic effects of ouabain on human prostate cancer DU 145 cells in vitro. Cell morphological changes were examined by phase contrast microscopy. Cell viability, cell cycle distribution, cell apoptosis, DNA damage, the production of ROS and Ca²⁺ , and mitochondrial membrane potential (ΔΨ_m ) were measured by flow cytometry assay. Results indicated that ouabain induced cell morphological changes, decreased total cell viability, induced G0/G1 phase arrest, DNA damage, and cell apoptosis, increased ROS and Ca²⁺ production, but decreased the levels of ΔΨ_m in DU 145 cells. Ouabain also increased the activities of caspase-3, -8, and -9. Western blotting was used for measuring the alterations of apoptosis-associated protein expressions in DU 145 cells and results indicated that ouabain increased the expression of DNA damage associated proteins (pATM^Ser1981 , p-H2A.X^Ser139 , and p-p53^Ser15 ) and ER-stress-associated proteins (Grp78, ATF6β, p-PERK^Thr981 , PERK, eIF2A, GADD153, CaMKIIβ, and caspase-4) in time-dependently. Furthermore, ouabain increased apoptosis-associated proteins (DR4, DR5, Fas, Fas Ligand, and FADD), TRAIL pathway, which related to extrinsic pathway, promoted the pro-apoptotic protein Bax, increased apoptotic-associated proteins, such as cytochrome c, AIF, Endo G, caspase-3, -8, and -9, but reduced anti-apoptotic protein Bcl-2 and Bcl-x in DU 145 cells. In conclusion, we may suggest that ouabain decreased cell viability and induced apoptotic cell death may via caspase-dependent and mitochondria-dependent pathways in human prostate cancer DU 145 cells.

High-content analysis boosts identification of the initial cause of triptolide-induced hepatotoxicity

Triptolide (TP) has been widely used in China for more than 40 years as an immunosuppressive agent. Recently, serious concerns have been raised over TP-induced liver injury, though the real hepatotoxic mechanism is still unclear, particularly in terms of the initial cause. To our knowledge, this study is the first to screen systematically the mechanism of TP-induced toxicity through a global cytotoxicity profile high-content analysis using three independent cytotoxic assay panels with multiple endpoints of cytotoxicity, including cell loss, mitochondrial membrane potential, nuclear membrane permeability, manganese superoxide dismutase, phosphorylated gamma-H2AX, light chain 3B, lysosome, reactive oxygen species and glutathione. We assessed nine parameters and four stress response pathway models by labeling nuclear factor erythroid 2-related factor 2, activating transcription factor 6, hypoxia inducible factor 1α and nuclear factor κB and found that all testing parameters except glutathione and manganese superoxide dismutase showed concentration- and time-dependent changes, as well as increased cell loss after TP treatment. Considering that RNA polymerase II is the molecular target of TP, we quantified transcription from inducible genes, bromodeoxyuridine incorporation, and expression from transiently transfected green fluorescence protein plasmids in HepG2 cells. The results show that inhibition of global transcription by TP took place at earlier times and at lower concentrations than those observed for cell death. Therefore, global transcriptional suppression and the cell dysfunction it drives play a central role in TP-induced hepatotoxicity. This provides valuable information for the safe use of TP in the clinic.