Toxicology Research最新文献

Targeted therapy is one crucial therapeutic approach frequently employed in cancer treatment. In almost 30% of human breast cancers, a transmembrane tyrosine kinase receptor named the HER2 (human epidermal growth factor receptor 2) is overexpressed, establishing HER-2 as a promising target for cancer treatment. The goal of the current work is to computationally design and analyze a new chimeric protein that could selectively target HER2-positive breast cancer cells based on a single polypeptide chain variable fragment and leptulipin (an anticancer peptide) fusion. After the computational joining of the secondary structure, 3D modeling, quality validation, physicochemical properties, docking, interaction analysis, MD simulation, and energy calculations were performed using various computational tools and online servers. The most precise predicted chimeric protein model was docked to the HER-2 receptor using ClusPro 2.0, which revealed a significant number of hydrogen bonds and salt bridges reflecting the fusion protein's quality, validity, interaction, and stability. These results were further supported by MD simulation on the Desmond Schrodinger module, which predicted a stable docked complex. This was also evident by principal component analysis and the negative energy value of MM/PBSA. These comprehensive in silico analyses, coupled with a high predicted expression value of 0.94 in E. coli by the SOLUPROT, collectively highlight the potential of fusion protein as a potent therapeutic agent against breast cancer and open a potential avenue for targeted cancer therapy and provide a groundwork for in vitro and in vivo validation that might lead to clinical implication.

Silicosis is an incurable chronic fibrotic lung disease caused by long-term exposure to respirable silica particles. It is characterized by persistent inflammation and progressive fibrosis of lung tissues, which eventually leads to respiratory failure and seriously affects human health. The high incidence and mortality associated with silicosis have made the disease a widespread public health concern. However, its pathogenesis has not been fully elucidated. Mitochondrial biogenesis plays a crucial role under various fibrotic conditions. However, the mechanism of this process in silicosis is still unclear. Therefore, this study aimed to explore the influence of the PGC-1α gene on mitochondrial biogenesis in the development of silicosis. We established in vivo and in vitro silicosis models by exposing rats and rat type-2 alveolar epithelial cells (RLE-6TN) to silica. Our findings revealed alterations in the mitochondrial structure and function, decreased mitochondrial biogenesis, and reduced expression of mtDNA (Mitochondrial DNA) content. By upregulating the PGC-1α gene in RLE-6TN cells, we activated the PGC-1α- NRF1-TFAM signaling pathway, enhancing mitochondrial biogenesis, increasing citrate synthase and mtDNA content, improving mitochondrial function, and mitigating fibrosis. Our results indicate that the regulation of mitochondrial biogenesis can affect silicosis-induced fibrosis, highlighting the significance of reduced mitochondrial biogenesis in the progression of silicosis-induced fibrosis.

Recent advances have established lipid droplets as dynamic innate immune hubs coordinating cellular metabolism and defense mechanisms. While previous studies primarily focused on nanomaterials (NMs) altering lipid metabolism to influence lipid droplet dynamics, this study pioneers the investigation of NM-induced immune modulation via Toll-like receptor (TLR) pathways as a novel regulatory axis for lipid droplets. Building on our prior findings that graphene oxide (GO) impaired TLR3-mediated lipid signaling, we systematically explored the role of GO's diameter in modulating this process. Mice were subjected to daily intratracheal instillation of three GO variants (50-200 nm, <500 nm or > 500 nm) at 1 mg/kg for 7 days. Although no significant change in body weight or organ coefficient was observed, all GO exposure suppressed lipid staining in mouse lungs and livers, correlating with altered co-localization of TLR3 and perilipin 2 (PLIN2), critical regulators of lipid droplet biogenesis. Down-regulation of TLR3 signaling components, namely interferon induced protein with tetratricopeptide repeats 1 (IFIT1), radical S-adenosyl methionine domain containing 2 (RSAD2), and PLIN2, occurred in a diameter-dependent manner, with GO 50-200 nm showing the most pronounced effects, likely attributable to the smallest hydrodynamic size and polydispersity index in suspension. This work provides evidence that NM geometry governs TLR-mediated lipid droplet regulation, bridging the knowledge gap between nanotoxicology and immunometabolic cross-talking, a paradigm distinct from conventional lipid metabolism-focused nanotoxicological studies.

Peptic ulcer is a chronic inflammatory disorder affecting large portion of population with difficulty in treatment. Treatment options include inhibition of gastric acid secretion, histamine inhibitors, eradication of Helicobacter pylori infection and tissue lining protection. These therapeutic options have several side effects, low bioavailability and bio-distribution. To further increase bioavailability, control release, stability, site specific delivery and minimize organoleptic side effects of phytochemical, nano-encapsulation is a suitable strategy. Chitosan is a suitable nano-carrier for drug delivery applications in treating peptic ulcer as it is biodegradable, biocompatible, safe and cost-effective. Therefore, Ficus religiosa (FR) leaf extract was loaded into chitosan NPs by ion gelation method for in vivo anti-ulcerative activity in indomethacin-induced peptic ulcer rats. Results showed that FR extract was successfully loaded into CNPs with 84% encapsulation efficiency while the size of empty CNPs was reported to be 620.3 nm as compared to FR-loaded CNPs 811.5 nm. FR-loaded CNPs showed homogeneous size distribution as well greater physical stability. Furthermore, in vivo studies revealed gastro-protective activity of FR-loaded CNPs in reducing the ulcer index (UI) to 0.51 (71.30% inhibition) while indomethacin only untreated rats showed UI 2.99 and insignificant ulcer inhibition 11.02%. Furthermore, FR-loaded CNPs restored gastric pH, healed rat stomach completely without ulcers or hemorrhagic spot and improved antioxidants and blood profiles compared to plant extract or CNPs. These findings confirmed the effective application of FR extract loaded CNPs as anti-ulcer agents and reinforces the importance of nano-encapsulation in improving drug efficacy.

The perioperative respiratory adverse events (PRAE) are ineluctable during pediatric anesthesia. Accurate assessment of preoperative anesthesia is significant to reduce surgical risks in general anesthesia. This study focused on the expression level and predictive performance of lncRNA MALAT1 in PRAE for general anesthesia children. 236 medical records from children patients were included and they were divided into the No-PRAE group (n = 129) and the PRAE group (n = 107). Blood samples obtained before general anesthesia were used to evaluate the relative levels of MALAT1 by qRT-PCR. The multivariate logistic regression analysis was carried out to identify underlying risk factors. The receiver operator characteristic (ROC) curve was plotted to estimate the diagnostic performance of MALAT1 in the occurrence of PRAE. The serum MALAT1 in the PRAE group was identified to be higher than that in the No-PRAE group. The regression analysis indicated that patients with preoperative airway disease (OR: 2.813; 95%CI: 1.327-5.961) or longer anesthesia duration (OR: 2.131; 95%CI: 1.111-4.088) or higher levels of MALAT1 (OR: 13.019; 95%CI: 6.769-25.039) faced a higher risk of PRAE. The area under the ROC curve was 0.885 while the sensitivity and specificity were 79.44% and 82.17%, respectively, identifying the referrible value of MALAT1 as a risk factor for predicting PRAE in general anesthesia children. In conclusion, the increased MALAT1 was a potential indicator of predicting PRAE in general anesthesia children.

Alantolactone, a bioactive sesquiterpene lactone derived from the roots of Inula helenium (elecampane), has garnered attention in biomedical and pharmacological research for its diverse therapeutic properties, including anticancer, anti-inflammatory, antimicrobial, and antioxidant activities. Despite its well-documented bioactivity, the effects of alantolactone on calcium ion (Ca²⁺) signaling and the underlying mechanisms in human breast cancer cells remain poorly understood. This study explored how alantolactone influences intracellular Ca²⁺ levels ([Ca²⁺]_i), cell viability, and the role of Ca²⁺-dependent pathways in T-47D human breast cancer cells. Specifically, it examined the relationship between Ca²⁺ signaling and cytotoxicity in cells exposed to alantolactone, with or without the Ca²⁺ chelator BAPTA-AM. The findings reveal that alantolactone (25-75 μM) increases [Ca²⁺]_i in a concentration-dependent manner, while concentrations of 25-100 μM induce cytotoxicity, an effect that can be reversed by BAPTA-AM pre-treatment. Removing extracellular Ca²⁺ significantly inhibits Ca²⁺ influx, and both SKF96365 and 2-APB, modulators of store-operated Ca²⁺ channels, block the alantolactone-induced Ca²⁺ entry. Additionally, in a Ca²⁺-free environment, thapsigargin, an inhibitor of the endoplasmic reticulum Ca²⁺ pump, suppresses the alantolactone-induced rise in [Ca²⁺]_i, while alantolactone reduces the [Ca²⁺]_i increase triggered by thapsigargin. Moreover, inhibiting phospholipase C (PLC) with U73122 abolishes the alantolactone-induced [Ca²⁺]_i elevation. These results suggest that alantolactone-induced cell death in T-47D cells is Ca²⁺-dependent, involving Ca²⁺ entry via store-operated channels and Ca²⁺ release from the endoplasmic reticulum, with PLC playing a pivotal role. Importantly, the ability of BAPTA-AM to reverse alantolactone's cytotoxic effects highlights its potential therapeutic significance in breast cancer research.

Marine endophytic fungi serve as a valuable source of bioactive molecules, with growing applications in enzyme production. This study investigates the therapeutic potential of glutaminase- and urease-free Type II L-asparaginase derived from the mangrove endophyte Penicillium citrinum MEF 455 against neoplastic cells. Extracellular L-asparaginase production was done using Czapek Dox broth amended with L-asparagine and a 66 kDa molecular mass asparaginase could be observed. The specific activity of 41.6 U/mg with 5.8-fold purification was attained using DEAE cellulose and Sephacryl S-200 column. The kinetic study showed that the Km, Vmax_, and Kcat were 1.370 mM, 161.29 U/mL/min, and 1240.69/min, respectively. Purified L-asparaginase displayed optimal activity at 40 °C and pH 8, with a substrate concentration of 2.5 mM L-asparagine. Metallic ions like Na⁺, K⁺, Mg²⁺, Co²⁺, and Li⁺, improved asparaginase activity. The enzyme displayed strong anticancer potential with considerable reduction in the growth of HL-60, and NCI-H 460 cells with IC₅₀ values of 0.37 ± 0.225 U/mL and 0.39 ± 0.176 U/mL, respectively. Major cancer-controlling genes i.e. p53, caspase-3, caspase-9, NF-kB, Bax, and Rb1 were up-regulated. In contrast, anti-apoptotic i.e. Cox-2 and Bcl-2 were down-regulated on asparaginase treatment in Human cancer cell lines HL-60 and NCI-H 460. The experimental study demonstrates that Type II L-asparaginase produced from an endophytic fungal source, P. citrinum MEF 455, was free from glutaminase and urease activity, thereby minimizing associated immunogenic complications. In general, understanding the physicochemical properties and functionality of the enzyme highlights its potential as a promising antitumor candidate for therapeutic development and clinical applications.

Both epidemiological and laboratory evidence indicate a significant relationship between formaldehyde (FA) exposure and allergic asthma. However, the mechanisms underlying the relationship remain unclear. Research has demonstrated that endoplasmic reticulum (ER) stress is closely associated with the onset of allergic asthma. Nonetheless, it has yet to be established whether FA exposure exacerbates allergic asthma by activating ER stress. To systematically investigate the exacerbation of allergic asthma-like symptoms due to FA exposure (0.5 mg/m³) in Balb/c mice, we assessed lung function and histopathology, serum immunoglobulin levels, neuropeptide substance P (SP) and calcitonin gene-related peptide (CGRP) levels, Th2 (IL-4, IL-5, IL-13) and Th17 (IL-22, IL-17A) cytokine levels and biomarkers of the ER stress pathway (IRE1α, PERK, and ATF-6). Additionally, we employed the ER stress antagonist phenylbutyric acid (4-PBA) to confirm the mediating role of ER stress in FA-aggravated allergic asthma. Our findings suggest that prolonged exposure to FA increases levels of ER stress markers, SP, CGRP, Th2 and Th17 cytokines, and immunoglobulin, leading to increased airway mucus hyperplasia and airway remodeling. Furthermore, we demonstrated that blocking ER stress with 4-PBA effectively alleviated associated allergic asthma-like symptoms. In conclusion, we provide evidence that the ER stress signaling pathway plays a significant role in the exacerbation of allergic asthma due to FA exposure.

Epidemiological evidence links osteoarthritis to fetal origins. Our study shows prenatal caffeine exposure (PCE) in rats predisposes adult offspring to osteoarthritis, associated with elevated intrauterine glucocorticoid levels. Previous research indicates that chenodeoxycholic acid (CDCA), a bile acid, can slow osteoarthritis progression when administered intra-articularly. This study explored if disrupted bile acid metabolism in cartilage affects osteoarthritis risk in adult offspring with PCE. Our findings indicate that the expression of MMP3/MMP13 was upregulated, while endogenous CDCA levels were reduced in the cartilage of PCE-exposed offspring. Furthermore, we observed a persistent reduction in H3K27ac levels at the CYP7B1 promoter and its expression in the cartilage of PCE offspring from fetus to adulthood. Moreover, a sub-physiological level of CDCA promoted NF-κB phosphorylation and the expression of MMP3/MMP13 in chondrocytes in vitro. High levels of glucocorticoids reduced H3K27ac levels and CYP7B1 expression in the promoter region of CYP7B1 through the glucocorticoid receptor and histone deacetylase 4, consequently leading to decreased CDCA levels. In summary, our findings suggest that intrauterine low-expression programming of CYP7B1, induced by elevated glucocorticoid levels, reduces local CDCA levels in the cartilage of PCE offspring, ultimately leading to increased matrix degradation and susceptibility to osteoarthritis.

Cigarette butts (CBs) have emerged as one of the most significant pollutants affecting the environment, particularly aquatic ecosystems. With trillions of cigarettes being manufactured worldwide each year, the disposal of discarded cigarette butts has become a major environmental issue. These butts contain various toxic substances such as nicotine, heavy metals, and other chemicals that can leach into water bodies, posing serious risks to aquatic organisms and disrupting the delicate balance of aquatic life. In this context, freshwater snails, specifically Pila virens, were selected as a model organism to evaluate the impact of CBs on aquatic health. The study exposed P. virens to varying concentrations of CBs-10, 25, and 50%-for different exposure durations (24 h and 48 h). The investigation revealed significant changes in key biomarkers related to oxidative stress and neurotoxicity, including a reduction in glutathione sulfotransferase (GST), protein carbonyl (PC), reduced glutathione (GSH), lipid peroxidation (LPO), glutathione peroxidase (GPx) and Acetylcholine esterase (AChE), respectively. These alterations suggest that CBs induce oxidative stress and neurotoxicity in P. virens, impairing their cellular defense mechanisms. The findings highlight the harmful ecological effects of CBs pollution, emphasizing the urgent need to address this growing environmental concern and its potential consequences on freshwater life. The study contributes valuable insights into the ecotoxicology of CBs contamination in aquatic environments.