Animal tests like the guinea pig maximization test (GPMT) and murine local lymph node assay (LLNA) were historically used to assess skin sensitization in cosmetics. The EU banned animal testing for cosmetics in 2013, prompting the development of alternative in vitro methods and new approach methodologies (NAMs) based on adverse outcome pathways (AOPs). These NAMs are integrated into Defined Approaches (DAs) to evaluate skin sensitization hazards and potency, which challenge is incorporating them into next-generation risk assessment (NGRA) frameworks. To address this challenge, we aim to achieve quantitative risk assessment in humans. The NGRA framework proposed by Cosmetics Europe emphasizes read-across methods, which predict toxicity using data from similar substances. This approach, which utilizes data from analogues, is described as an effective way to reduce uncertainty in risk assessment. This paper proposes a transparent read-across method using the OECD QSAR Toolbox, ranked by reliability based on structural similarity, protein binding, sensitization alerts, and percutaneous absorption. The sensitization data of the extracted analogues prioritize the LLNA EC3 values, followed by predicted EC3 values from Derek nexus or GPMT data. A case study using p-isobutyl-α-methyl hydrocinnamaldehyde confirmed the target's classification as a moderate sensitizer. The proposed method ensures transparency by relying on publicly available tools, reducing uncertainty in NGRA.
Acute kidney injuries and renal dysfunction caused by ethylene glycol poisoning are often associated with nephrolithiasis. Calcium oxalate (CaOx) crystal formation is considered one of the most common events at the early stage of nephrolithiasis. The aim of this study is to investigate molecular mechanisms underlying CaOx crystal formation on renal tubular epithelial cells in vitro. We applied oxalate or potassium oxalate (final concentrations, 200-1200 µM) in the medium culturing NRK-52E rat proximal tubular epithelial cells. Cell death was observed with levels of oxalate or potassium oxalate above 800 µM 48 hr after addition. Crystals, mainly consisting of CaOx as confirmed by polarized light microscopy, were detected on cells treated with 800 µM oxalate or potassium oxalate. Transcriptome analysis showed that a gene (S100A11-like) belonging to the S100 family, which consists of homologous Ca-binding proteins, many of which can form complexes with annexin family proteins, was the gene most upregulated by 800 µM oxalate. Immunoblot as well as immunocytochemical analysis indicated not only upregulation but also alteration of intracellular localization of S100A11. The same altered pattern of localization was also observed for annexin A2, which has been shown to be involved in the formation of CaOx crystals. This study presents the possibility that, in addition to annexin family proteins, S100 family proteins might be involved in the regulation of CaOx crystal formation and/or other events associated with crystal formation.
Perinatal exposure to chemicals such as valproic acid (VPA) increases the risk of neurodevelopmental disorders, including autism spectrum disorder (ASD). Because maternal drug metabolism complicates the assessment of fetal impacts in mammalian models, Xenopus laevis tadpoles have emerged as an effective alternative for neurotoxicology. Tadpoles exhibit "schooling," a polarized social aggregation behavior. Previous studies, which exposed tadpoles to VPA continuously from stage NF42 to NF49, suggested that VPA-induced social behavior abnormalities are triggered during this period. In this study, we re-evaluated the ontogeny of schooling behavior and its vulnerability to VPA by administering short-term exposures at specific developmental stages. Using computational modeling and statistical analyses, we compared the spatial distribution of live tadpoles with computer-simulated random models. Untreated tadpoles exhibited significant, non-random social aggregation as early as stage NF42, indicating that the sensorimotor circuitry for schooling is established earlier than previously assumed. Furthermore, tadpoles exposed to VPA for 4 days starting at stages NF42 and NF48 maintained schooling behavior, whereas VPA exposure starting at stage NF52 significantly disrupted spatial cohesion. These findings indicate that while social behavior is acquired prior to NF42, NF52 represents a critical window of heightened pharmacological vulnerability to teratogens, providing new insights into the etiology of environmentally induced neurodevelopmental disorders.
Methylisothiazolinone (MIT) is a widely used biocidal preservative in industrial and cosmetic products. However, evidence of its neurotoxic effects is limited, and the mechanistic pathways are poorly defined. This study investigated the neurotoxic potential of MIT and the molecular mechanisms underlying its cellular toxicity in SH-SY5Y cells. After exposing SH-SY5Y cells to MIT various concentrations (30 to 120 μM) for 24 hr, apoptosis and inflammatory responses were quantified alongside the determination of apoptotic-, oxidative stress-, cell survival-, and angiogenic-related biomarkers. To reinforce the experimental findings, a set of in silico chemoinformatics studies, including network toxicology and molecular docking were conducted to pinpoint and evaluate the potential molecular targets of MIT. The IC50 value of MIT was found 115 µM. Total apoptotic cells increasing to 56.5% at 120 µM. ELISA results indicated activation of the intrinsic apoptotic pathway, evidenced by significant upregulation of p53 (9.54-fold), BAX (4.52-fold), and APAF-1 (8.85-fold), along with a disruption in the BAX/BCL-2 (4.52/4.37-fold) balance. Furthermore, an elevation in the COX/COX-2 (8.04/6.93-fold), SRC (7.08-fold), and VEGFR2 (20.96-fold) levels which indicated the concurrent oxidative stress and stress-induced pro-survival signaling at 120 µM. MIT selectively amplified some inflammatory mediators, suggesting inflammasome-driven neuroinflammation. In silico analysis further support MIT as a polypharmacological toxicant with the potential to modulate key molecular targets, including PARP-1, GSK-3β, and iNOS. MIT induced multifaceted neurotoxicity in SH-SY5Y cells through the simultaneous activation of intrinsic apoptotic signaling, oxidative stress, and selective neuroinflammatory pathways. The findings emphasize the potential neurotoxic risks associated with MIT exposure and underscore the necessity for strengthened regulatory evaluation and in vivo validation.
Reliable early prognostic tools for acute poisoning remain limited. This study examined whether four first-measured routine biomarkers - glucose, lactate, bicarbonate, and white blood cell count (WBC) - carry prognostic signal for 30-day mortality in emergency department (ED) patients with acute poisoning, using a pre-processed, de-identified electronic health records dataset derived from MIMIC-IV (Medical Information Mart for Intensive Care, version 3.1; a publicly available critical care database from Beth Israel Deaconess Medical Center, Boston, USA, hosted on PhysioNet; n=12,039 ED visits; 59 deaths; 30-day mortality 0.49%). Due to extreme non-random missingness across all four biomarkers (lactate 95.2%; bicarbonate/glucose/WBC 88-89%), multivariable modelling was restricted to a complete-case subgroup (n=503; deaths=19). This subgroup was markedly non-representative: intensive care unit (ICU) admission rate 66.4% versus 2.1% in excluded visits (standardised mean difference [SMD]=1.844), reflecting selective laboratory ordering in clinically severe patients. In univariable analyses across available cases, all four biomarkers were significantly associated with 30-day mortality. Within the complete-case subgroup, glucose alone demonstrated good discrimination (area under the receiver operating characteristic curve [AUROC]=0.812; 95% confidence interval [CI] 0.721-0.885), and glucose and WBC were independently associated with mortality in multivariable analysis (adjusted odds ratios [aOR] 1.05 and 1.13, respectively). The calibration slope of 0.646 for the primary four-biomarker model indicated systematic overestimation of absolute risk. These findings are strictly exploratory. Critical limitations - extreme non-random missingness, ICU-enriched complete-case subgroup, absent age and vital signs, low event count (n=19), and absence of external validation - preclude clinical application. This work defines data and design requirements for a future adequately powered prospective prognostic study in acute poisoning.
