In silico identification of molecular mechanisms for stroke risk caused by heavy metals and their mixtures: sponges and drugs involved

Mechanistic Analysis of Decabromodiphenyl Ether-Induced Neurotoxicity in Humans Using Network Toxicology and Molecular Docking

Commercial decabromodiphenyl ether (c-decaBDE) is a widely used additive flame retardant in textiles and plastics. This formulation predominantly consists of the congener BDE-209, with trace amounts of other brominated diphenyl ether congeners, such as nonabromodiphenyl ether and octabromodiphenyl ether. Recognized as a persistent organic pollutant due to its potential for long-range environmental transport, c-decaBDE poses significant environmental threats and serious human health risks, including endocrine, reproductive, developmental, and neurotoxic effects. The mechanisms underlying its neurotoxicity remain largely undefined. This study investigates the neurotoxic effects of BDE-209 in humans through network toxicology, multi-level bioinformatics approaches, and molecular docking analyses. Prediction results indicate that BDE-209 can cross the blood-brain barrier, entering the central nervous system and inducing neurotoxic effects. A comprehensive analysis has identified 294 potential targets linked to the neurotoxicity induced by BDE-209. Gene-gene interaction and pathway enrichment analyses revealed significant associations related to cellular responses to chemical stress and synaptic transmission. Further investigation of protein-protein interactions, combined with centrality analysis, identified 14 hub targets, including CaMK-II alpha, PSD-95, GluR-1, and GluN2B, as key proteins in this process. Molecular docking results indicate that BDE-209 exhibits a stronger binding affinity to GluN2B, a subunit of the N-methyl-D-aspartate (NMDA) receptors, compared to other key targets. These findings suggest that BDE-209 may disrupt the function of GluN2B-containing NMDA receptors, potentially leading to their inhibition. Such inhibition could result in reduced excitatory neurotransmission, impairing synaptic potentiation and plasticity, and ultimately contributing to neurotoxicity.

Cerebrovascular accidents association between serum trace elements and toxic metals level, a case-control study

BACKGROUND

Cerebrovascular accidents (CVAs) are among the most common complications of patients today. As the prevalence of ischemic CVAs rises, detecting related risk factors is crucial. Metal concentration has previously been considered a major risk factor in several neural complications, and in this study, we will investigate this.

METHODS

In this case-control study, 70 CVA (clinically approved ischemic stroke cases by imaging and NIH Stroke Scale (NIHSS)) and 70 individuals with no history of CVA controls were enrolled as the control group. The serum level of several metals, including Fe (Iron), Co (Cobalt), Ni (Nickel), Cu (copper), Zn (Zinc), Mn (Manganese), Pb (lead), Hg (Mercury), has been assessed using Inductively coupled plasma mass spectrometry (ICP-MS) method. Logistic regression (LR) has also been used to determine the association between metals' levels and CVA occurrence.

RESULTS

As the mean age of the CVA group was 48.68  ±  15.25 years and for the non-CVA group was 47.89 ± 9.65 years, the result indicated that the serum level of Cu and Pb has been statically higher in the CVA group (respectively; P  <  0.001 and P  =  0.002) and Ni level was significantly lower (P  =  0.003). Other measured metals' levels (Fe, Co, Ni, Mn, Hg) were not significantly different between CVA and non-CVA groups. In the LR model, all Cu, Pb, and Zn metals had a P value of 0.03 and an odd ratio (OR) and confidence interval (CI) of 1.34 (1.02-1.75), 1.19 (1.01-1.39) and 1.01 (1.001-1.02) respectively.

CONCLUSION

Given that some metals are associated with a higher risk of CVA, researchers and physicians must better understand the risk factors and causes of the burden of CVA. However, further studies with a larger population and investigation of the exact pathogenesis of these metals are needed.

The molecular mechanisms of steroid hormone effects on cognitive function

OBJECTIVE

There is a lack of information on the molecular mechanisms by which steroid hormones (testosterone, estrogen, and progesterone) regulate cognitive impairment. Thus, we aimed to identify the protective effects of steroid hormones on cognitive function.

METHODS

We analyzed the literature on the molecular mechanisms, biological activities, physicochemical properties, and pharmacokinetics of steroid hormones.

RESULTS

Steroid hormones can protect against cognitive impairment by regulating key genes (INS, TNF, STAT3, ESR1). Specific microRNAs, namely hsa-miR-335-5p, hsa-miR-16-5p, and hsa-miR-26b-5p, along with transcription factors NFKB1, PPARG, NR3C1, GATA2, EGR1, ATF3, and CEBPA, play a significant role in this protective mechanism. The involvement in cognitive processes, regulation of phosphorylation, neuronal apoptosis, and signaling pathways related to Alzheimer's disease significantly influence the protein-protein interaction network underlying these effects. Additionally, steroid hormones exhibit anti-hypercholesterolemic properties, anti-inflammatory activity, antitoxic properties, and function as inhibitors of acetylcholine neuromuscular transmission. They also hold promise as therapeutic agents for the treatment of dementia. Promising therapeutic interventions for cognitive impairment include the use of miRNA sponges targeting hsa-miR-16-5p, along with the administration of capsaicin, minocycline, dopamine, sertraline, and minaprine. The gut microbiota species Lactobacillus amylovorus, Paraprevotella clara, Libanicoccus massiliensis, Prevotella oris, Turicibacter sanguinis, and Dubosiella newyorkensis were identified as significant contributors to cognitive impairment and altered levels of steroid hormones.

CONCLUSION

Steroid hormones are promising compounds for improving cognitive function. Further research is needed to validate these findings through focused investigations into apoptosis, regulation of neuronal cell death, miRNA sponges, interactions with gut microbiota, and the potential efficacy of pharmaceutical agents.

Molecular mechanisms of sulforaphane in Alzheimer's disease: insights from an in-silico study

This study was to identify the molecular pathways that may explain sulforaphane's Alzheimer's disease (AD) benefits using multiple advanced in silico approaches. We found that sulforaphane regulates 45 targets, including TNF, INS, and BCL2. Therefore, it may help treat AD by reducing neuroinflammation, insulin resistance, and apoptosis. The important relationships were co-expression and pathways. 45 targets were linked to the midbrain, metabolite interconversion enzymes, 14q23.3 and 1q31.1 chromosomes, and modified residues. "Amyloid precursor protein catabolic process", "regulation of apoptotic signaling pathway", and "positive regulation of nitric oxide biosynthetic process" were the main pathways, while NFKB1, SP1, RELA, hsa-miR-17-5p, hsa-miR-16-5p, and hsa-miR-26b-5p were transcription factors and miRNAs implicated in sulforaphane In AD treatment, miRNA sponges, dexibuprofen, and sulforaphane may be effective. Furthermore, its unique physicochemical, pharmacokinetic, and biological qualities make sulforaphane an effective AD treatment, including efficient gastrointestinal absorption, drug-like properties, absence of CYP450 enzyme inhibition, not being a substrate for P-glycoprotein, ability to cross the blood-brain barrier, glutathione S-transferase substrate, immunostimulant effects, and antagonistic neurotransmitter effects. Sulforaphane is a promising compound for AD management. Further work is needed to elucidate its therapeutic effects based on our findings, including genes, miRNAs, molecular pathways, and transcription factors.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-024-00267-4.

Predicting the Metal Mixture Toxicity with a Toxicokinetic-Toxicodynamic Model Considering the Time-Dependent Adverse Outcome Pathways

Chemicals mainly exist in ecosystems as mixtures, and understanding and predicting their effects are major challenges in ecotoxicology. While the adverse outcome pathway (AOP) and toxicokinetic-toxicodynamic (TK-TD) models show promise as mechanistic approaches in chemical risk assessment, there is still a lack of methodology to incorporate the AOP into a TK-TD model. Here, we describe a novel approach that integrates the AOP and TK-TD models to predict mixture toxicity using metal mixtures (specifically Cd-Cu) as a case study. We preliminarily constructed an AOP of the metal mixture through temporal transcriptome analysis together with confirmatory bioassays. The AOP revealed that prolonged exposure time activated more key events and adverse outcomes, indicating different modes of action over time. We selected a potential key event as a proxy for damage and used it as a measurable parameter to replace the theoretical parameter (scaled damage) in the TK-TD model. This refined model, which connects molecular responses to organism outcomes, effectively predicts Cd-Cu mixture toxicity over time and can be extended to other metal mixtures and even multicomponent mixtures. Overall, our results contribute to a better understanding of metal mixture toxicity and provide insights for integrating the AOP and TK-TD models to improve risk assessment for chemical mixtures.

Effects of mixed heavy metals on obstructive lung function: findings from epidemiological and toxicogenomic data

The molecular mechanisms and associations of mixed heavy metals (lead, mercury, and cadmium) on obstructive lung function (OLF) in males and females remain unknown. Here, we evaluated the interaction between the forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio and three common heavy metals in males and females (n = 6221). Molecular processes involved in OLF development caused by mixed heavy metals were also identified to corroborate the earlier findings. In both males and females, as well as across the entire population, we found that serum cadmium levels were inversely related to the FEV1/FVC ratio. Interactions between serum cadmium and lead, as well as cadmium and mercury, were observed in relation to the FEV1/FVC ratio. Additionally, we observed negative correlations between the FEV1/FVC ratio and mixed serum cadmium, lead, and mercury in both men and women as well as in the overall population. Seven genes were identified as contributing to the etiology of OLF and targeted by combined heavy metals in silico analysis (CYP1A1, CRP, CXCL8, HMOX1, IL6, NOS2, and TNF). The primary relationships between these genes were co-expression interactions. The significant transcription factors and miRNAs associated with OLF and a combination of the examined heavy metals were identified as NFKB2, hsa-miR-155-5p, and hsa-miR-203a-3p. The main biological processes involved in the emergence of OLF induced by mixed heavy metals were listed as inflammatory and oxidative stress pathways, lung fibrosis, chronic obstructive pulmonary disease, as well as cytokine activity, monooxygenase activity, oxidoreductase activity, and interleukin-8 production. Threshold estimations and miRNA sponge patterns for heavy metal exposure levels associated with OLF were evaluated for both males and females. This study found that cadmium plays the most important role in the mixture of cadmium, lead, and mercury in the pathogenesis of OLF. Future studies are required to verify our findings and uncover the molecular mechanisms of long-term exposure to a variety of heavy metals, especially cadmium, in other populations, including children, adolescents, and the elderly.