The regulatory roles of DDIT4 in TDCIPP-induced autophagy and apoptosis in PC12 cells

Neurotoxicity induced by difenoconazole in zebrafish larvae via activating oxidative stress and the protective role of resveratrol

Difenoconazole (DIF) is a typical triazole fungicide detected in the aquatic ecosystem and organisms. However, the neurotoxic effects of DIF remain largely unknown. This study aimed to investigate the neurotoxicity of DIF in zebrafish and the underlying neuroprotective properties of resveratrol (RES, an antioxidant polyphenol). Zebrafish embryos/larvae were treated with 0.6 and 1.2 mg/L DIF from 4 to 96 h post fertilization (hpf) and neurodevelopment was systematically assessed. DIF induced developmental toxicity and aberrant neurobehaviors, including decreased movement time, swimming distance and clockwise rotation times. DIF suppressed the neurogenesis of the central nervous system (CNS) in HuC:egfp transgenic zebrafish and the length of motor neuron axon in hb9:egfp transgenic zebrafish. DIF inhibited cholinesterase activities and downregulated neurodevelopment related genes. DIF also increased oxidative stress via excessive production of reactive oxygen species and decreased activities of antioxidant enzymes, subsequently triggering neuronal apoptosis in the brain. RES partially reinstated DIF-induced neurotoxicity and developmental toxicity by inhibiting excessive oxidative stress and apoptosis, suggesting the involvement of oxidative stress in DIF-induced neurotoxicity. Overall, this study identified the potential mechanisms underlying DIF-induced neurotoxicity and suggested RES as a promising therapeutic strategy.

Molecular Mechanism of Indoor Exposure to Airborne Halogenated Flame Retardants TCIPP (Tris(1,3-Dichloro-2-Propyl) Phosphate) and TCEP Tris(2-chloroethyl) Phosphate and Their Hazardous Effects on Biological Systems

TCIPP (tris(1,3-dichloro-2-propyl) phosphate) and TCEP (tris(2-chloroethyl) phosphate) are organophosphate ester flame retardants found in various consumer products, posing significant health and environmental risks through inhalation, ingestion, and dermal exposure. Research reveals these compounds cause oxidative stress, inflammation, endocrine disruption, genotoxicity, neurotoxicity, and potentially hepatotoxicity, nephrotoxicity, cardiotoxicity, developmental, reproductive, and immunotoxicity. This review summarizes the current knowledge on the toxicological mechanisms of TCIPP and TCEP and presents the latest data on their toxicological effects obtained in vitro and in vivo, using omic systems, and on the basis of computational modelling. It also elaborates on the scope of further toxicities and highlights the necessity of ongoing mechanistic research, integration of new technologies, and successful transfer of the acquired knowledge into risk evaluation, policies and regulations, and the creation of safer products. Since flame retardants are already present in homes, schools, offices, and daycare centres, efforts to scale back the exposure to these chemicals, most especially the hazardous ones, must be made to protect human health and the environment. Therefore, effective and timely prevention, based upon a deep knowledge of the entire toxicological profile of these substances, is the only way to face this difficult toxicological issue and provide for a healthy and safe future.

DDIT4/mTOR signaling pathway mediates cantharidin-induced hepatotoxicity and cellular damage

Background

Cantharidin (CTD) extracted from the traditional Chinese medicine Mylabris has significant therapeutic effects on various tumors. However, the high toxicity of CTD can cause serious liver damage, although the related molecular mechanisms remain unclear.

Methods

In this study, we established models of CTD-induced liver and L-O2 cell damage in mice in vivo and in vitro. Subsequently, liver function indicators were detected in mouse serum, while liver tissues were subjected to pathological and transmission electron microscopy observations. L-O2 cell activity was investigated using the CCK-8 assay, and the mRNA and protein expression of DNA damage-induced transcription factor 4 (DDIT4) in liver tissue and L-O2 cells was detected using qPCR, immunohistochemistry, and western blotting. Western blotting was also used to detect the expression levels of autophagy- and apoptosis-related proteins in liver tissue and L-O2 cells. After RNAi interference with DDIT4, Rap, and 3-MA treatment, autophagy and apoptosis of L-O2 cells were detected using western blotting, flow cytometry, transmission electron microscopy, and confocal microscopy.

Results

Following CTD exposure, the mouse liver showed significant pathological damage and an increase in autophagic lysosomes, while the vitality of L-O2 cells showed a significant decrease. CTD led to a significant increase in the mRNA and protein levels of DDIT4 in both liver tissue and L-O2 cells, as well as a significant increase in LC3-II, Beclin1, and Bax, whereas p-mTOR and Bcl-2 were significantly decreased. Following DDIT4 interference and 3-MA treatment, the levels of autophagy and apoptosis induced by CTD in L-O2 cells were reduced. After Rap treatment, both autophagy and apoptosis of CTD-induced L-O2 cells were significantly enhanced.

Conclusion

The molecular mechanism of CTD-induced toxicity in mouse liver and L-O2 cells is mainly through DDIT4/mTOR signaling pathway activation, leading to an increase in autophagy and apoptosis levels.

Chronic Expression of Interleukin-10 Transgene Modulates Cardiac Sympathetic Ganglion Resulting in Reduced Ventricular Arrhythmia

The cardiac autonomic nervous system (CANS) is intimately connected to the regulation of electrophysiology and arrhythmogenesis in cardiac systems. This work aimed at investigating whether interleukin-10 (IL-10) could effectively modulate CANS and suppress ischemia-induced ventricular arrhythmia (VA) through chronically acting on the cardiac sympathetic ganglion (CSG). Using an adeno-associated virus (AAV), we achieved local chronic overproduction of IL-10 in the CSG, left stellate ganglion (LSG). As a result, in the IL-10 group, we observed a decreased number of tyrosine hydroxylase-positive (TH+) cells in the LSG. IL-10 markedly downregulated the nerve growth factor, synaptophysin, as well as growth-associated protein 43 expression. In vivo, results from ambulatory electrocardiography showed that IL-10 overexpression significantly inhibited the cardiac sympathetic nervous system activity and improved heart rate variability. Meanwhile, we observed decreased LSG function as well as prolonged ventricular effective refractory period and suppressed VA after myocardial infarction (MI) in the IL-10 group. In addition, IL-10 overexpression attenuated inflammation and decreased norepinephrine levels in the myocardium after acute MI. In conclusion, our data suggest that chronic IL-10 overexpression modulates cardiac sympathetic nerve remodeling and suppresses VA induced by MI. Neuromodulation through AAV-mediated IL-10 overexpression may have the characteristics of and advantages as a potential neuroimmunotherapy for preventing MI-induced VAs.

Sevoflurane upregulates neuron death process-related Ddit4 expression by NMDAR in the hippocampus

Postoperative cognitive dysfunction (POCD) is a serious and common complication induced by anesthesia and surgery. Neuronal apoptosis induced by general anesthetic neurotoxicity is a high-risk factor. However, a comprehensive analysis of general anesthesia-regulated gene expression patterns and further research on molecular mechanisms are lacking. Here, we performed bioinformatics analysis of gene expression in the hippocampus of aged rats that received sevoflurane anesthesia in GSE139220 from the GEO database, found a total of 226 differentially expressed genes (DEGs) and investigated hub genes according to the number of biological processes in which the genes were enriched and performed screening by 12 algorithms with cytoHubba in Cytoscape. Among the screened hub genes, Agt, Cdkn1a, Ddit4, and Rhob are related to the neuronal death process. We further confirmed that these genes, especially Ddit4, were upregulated in the hippocampus of aged mice that received sevoflurane anesthesia. NMDAR, the core target receptor of sevoflurane, rather than GABAAR, mediates the sevoflurane regulation of DDIT4 expression. Our study screened sevoflurane-regulated DEGs and focused on the neuronal death process to reveal DDIT4 as a potential target mediated by NMDAR, which may provide a new target for the treatment of sevoflurane neurotoxicity.