The role of NF-κB and AhR transcription factors in lead-induced lung toxicity in human lung cancer A549 cells

Molecular Mechanism of Action of Endocrine-Disrupting Chemicals on the Respiratory System

Endocrine-disrupting chemicals (EDCs) are a growing health hazard for humankind and respiratory health in particular. Such chemical compounds are present in the environment and food and may interfere with physiological processes through interference with functions of the endocrine system, making humans more susceptible to various types of diseases. This review aims to discuss the effects of EDCs on the respiratory system. Exposure to EDCs during fetal development and adulthood increases susceptibility to respiratory diseases such as asthma, COPD, and pulmonary fibrosis. EDCs are both multiple and complex in the ways they can act. Indeed, these chemicals may induce oxidative stress, modify cell proliferation and differentiation, interfere with tissue repair, and modulate the inflammatory response. Moreover, EDCs may also break the integrity of the blood-air barrier, allowing noxious substances to penetrate into the lung and thus enhancing the opportunity for infection. In conclusion, the scientific evidence available tends to indicate that EDCs exposure is strongly linked to the initiation of respiratory disease. Further research will be important in discovering the underlying molecular mechanisms and devising preventive and therapeutic measures.

Soybean Extract Ameliorates Lung Injury induced by Uranium Inhalation: An integrated strategy of network pharmacology, metabolomics, and transcriptomics

AIM

This study aimed to evaluate the protective effect of soybean extract (SE) against uranium-induced lung injury in rats.

MATERIALS AND METHODS

A rat lung injury model was established through nebulized inhalation of uranyl nitrate. Pretreatment with SE or sterile water (control group) by gavage for seven days before uranium exposure and until the experiment endpoints. The levels of uranium in lung tissues were detected by ICP-MS. Paraffin embedding-based hematoxylin & eosin staining and Masson's staining for the lung tissue were performed to observe the histopathological imaging features. A public database was utilized to analyze the network pharmacological association between SE and lung injury. The expression levels of proteins indicating fibrosis were measured by enzyme-linked immunosorbent assay. RNA-seq transcriptomic and LC-MS/MS targeted metabolomics were conducted in lung tissues.

RESULTS

Uranium levels in the lung tissues were lower in SE-pretreated rats than in the uranium-treated group. Inflammatory cell infiltration and the deposition of extracellular matrix were attenuated, and the levels of alpha-smooth muscle actin, transforming growth factor beta1, and hydroxyproline decreased in SE-pretreated rats compared to the uranium-treated group. Active ingredients of SE were related to inflammation, oxidative stress, and drug metabolism. A total of 67 differentially expressed genes and 39 differential metabolites were identified in the SE-pretreated group compared to the uranium-treated group, focusing on the drug metabolism-cytochrome P450, glutathione metabolism, IL-17 signaling pathway, complement, and coagulation cascades.

CONCLUSIONS

These findings suggest that SE may ameliorate uranium-induced pulmonary inflammation and fibrosis by regulating glutathione metabolism, chronic inflammation, and immune regulation.

Genetic polymorphism in untranslated regions of PRKCZ influences mRNA structure, stability and binding sites

BACKGROUND

Variations in untranslated regions (UTR) alter regulatory pathways impacting phenotype, disease onset, and course of disease. Protein kinase C Zeta (PRKCZ), a serine-threonine kinase, is implicated in cardiovascular, neurological and oncological disorders. Due to limited research on PRKCZ, this study aimed to investigate the impact of UTR genetic variants' on binding sites for transcription factors and miRNA. RNA secondary structure, eQTLs, and variation tolerance analysis were also part of the study.

METHODS

The data related to PRKCZ gene variants was downloaded from the Ensembl genome browser, COSMIC and gnomAD. The RegulomeDB database was used to assess the functional impact of 5' UTR and 3'UTR variants. The analysis of the transcription binding sites (TFBS) was done through the Alibaba tool, and the Kyoto Encyclopaedia of Genes and Genomes (KEGG) was employed to identify pathways associated with PRKCZ. To predict the effect of variants on microRNA binding sites, PolymiRTS was utilized for 3' UTR variants, and the SNPinfo tool was used for 5' UTR variants.

RESULTS

The results obtained indicated that a total of 24 variants present in the 3' UTR and 25 variants present in the 5' UTR were most detrimental. TFBS analysis revealed that 5' UTR variants added YY1, repressor, and Oct1, whereas 3' UTR variants added AP-2alpha, AhR, Da, GR, and USF binding sites. The study predicted TFs that influenced PRKCZ expression. RNA secondary structure analysis showed that eight 5' UTR and six 3' UTR altered the RNA structure by either removal or addition of the stem-loop. The microRNA binding site analysis highlighted that seven 3' UTR and one 5' UTR variant altered the conserved site and also created new binding sites. eQTLs analysis showed that one variant was associated with PRKCZ expression in the lung and thyroid. The variation tolerance analysis revealed that PRKCZ was an intolerant gene.

CONCLUSION

This study laid the groundwork for future studies aimed at targeting PRKCZ as a therapeutic target.

Selected Functions and Disorders of Mitochondrial Metabolism under Lead Exposure

Mitochondria play a fundamental role in the energy metabolism of eukaryotic cells. Numerous studies indicate lead (Pb) as a widely occurring environmental factor capable of disrupting oxidative metabolism by modulating the mitochondrial processes. The multitude of known molecular targets of Pb and its strong affinity for biochemical pathways involving divalent metals suggest that it may pose a health threat at any given dose. Changes in the bioenergetics of cells exposed to Pb have been repeatedly demonstrated in research, primarily showing a reduced ability to synthesize ATP. In addition, lead interferes with mitochondrial-mediated processes essential for maintaining homeostasis, such as apoptosis, mitophagy, mitochondrial dynamics, and the inflammatory response. This article describes selected aspects of mitochondrial metabolism in relation to potential mechanisms of energy metabolism disorders induced by Pb.

Sinapic acid protects against lead acetate-induced lung toxicity by reducing oxidative stress, apoptosis, inflammation, and endoplasmic reticulum stress damage

Lead acetate (PbAc) is a compound that produces toxicity in many tissues after exposure. Sinapic acid (SNP) possesses many biological and pharmacological properties. This study aimed to investigate the efficacy of SNP on the toxicity of PbAc in lung tissue. PbAc was administered orally at 30 mg/kg and SNP at 5 or 10 mg/kg for 7 days. Biochemical, genetic, and histological methods were used to investigate inflammatory, apoptotic, endoplasmic reticulum stress, and oxidative stress damage levels in lung tissue. SNP administration induced PbAc-reduced antioxidant (GSH, SOD, CAT, and GPx) and expression of HO-1 in lung tissue. It also reduced MDA, induced by PbAc, and thus alleviated oxidative stress. SNP decreased the inflammatory markers NF-κB, TNF-α and IL-1β levels induced by PbAc in lung tissue and exhibited anti-inflammatory effect. PbAc increased apoptotic Bax, Apaf-1, and Caspase-3 mRNA transcription levels and decreased anti-apoptotic Bcl-2 in lung tissues. SNP decreased apoptotic damage by reversing this situation. On the other hand, SNP regulated these markers and brought them closer to the levels of the control group. PbAc caused prolonged ER stress by increasing the levels of ATF6, PERK, IRE1α, GRP78 and this activity was stopped and tended to retreat with SNP. After evaluating all the data, While PbAc caused toxic damage in lung tissue, SNP showed a protective effect by reducing this damage.

New insights into resveratrol attenuates hepatotoxicity in emamectin benzoate-exposed grass carp (Ctenopharyngodon idella) via NO system/NF-κB signaling pathway

Emamectin benzoate (EMB) is extensively used as a crop protection agent. Overuse of EMB poses a serious threat to the quality of water and non-target organisms in the environment. Resveratrol (RES) is a natural phytoalexin with the function of anti-oxidation and anti-inflammation. Nonetheless, it is unclear whether EMB affects the expression of cytokines and induces autophagy, apoptosis, and necroptosis of hepatocytes (L8824 cell) in grass carp (Ctenopharyngodon idella), and whether RES has an attenuate function in this process. Therefore, we established the L8824 cells model of EMB exposure and treated it with RES. The results showed that compared with the control (CON) group, EMB exposure significantly increased the nitric oxide (NO) content, inducible nitric oxide synthase (iNOS) activity, and the expression of iNOS and phosphorylated nuclear factor kappa B (p-NF-κB) (P < 0.05). In addition, compared with the CON group, the results of flow cytometry and dansylcadaverine (MDC) staining showed a significant increase in apoptosis and autophagy in the EMB-exposed group (P < 0.05) with the activation of the B-cell lymphoma-2 (Bcl-2)/Bcl-2 associated X (Bax)/cysteine-aspartic acid protease 3 (Caspase-3)/cysteine-aspartic acid protease 9 (Caspase-9) pathway and microtubule-associated protein light chain 3 (LC3)/sequestosome 1 (p62)/Beclin1 pathway. EMB exposure significantly increased the mRNA and protein expression of receptor-interacting protein 1 (RIPK1)/receptor-interacting protein 3 (RIPK3)/mixed the lineage kinase domain-like (MLKL) pathway (P < 0.05). Moreover, EMB exposure significantly increased the expression of genes related to immunity (immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin D (IgD), and antimicrobial peptide-related genes expression including β-defensin and hepcidin) (P < 0.05). The addition of RES significantly diminished autophagy, apoptosis, necroptosis, and immunity-related gene expression by inhibiting iNOS activity, NO content, and the protein expression of iNOS and p-NF-κB. In conclusion, RES attenuated autophagy, apoptosis, and necroptosis in EMB-exposed L8824 cells via suppression of the NO system/NF-κB signaling pathway.

Insights into the mechanism of transcription factors in Pb2+-induced apoptosis

The health risks associated with exposure to heavy metals, such as Pb2+, are increasingly concerning the public. Pb2+ can cause significant harm to the human body through oxidative stress, autophagy, inflammation, and DNA damage, disrupting cellular homeostasis and ultimately leading to cell death. Among these mechanisms, apoptosis is considered crucial. It has been confirmed that transcription factors play a central role as mediators during the apoptosis process. Interestingly, these transcription factors have different effects on apoptosis depending on the concentration and duration of Pb2+ exposure. In this article, we systematically summarize the significant roles of several transcription factors in Pb2+-induced apoptosis. This information provides insights into therapeutic strategies and prognostic biomarkers for diseases related to Pb2+ exposure.

Syk/BLNK/NF-κB signaling promotes pancreatic injury induced by tacrolimus and potential protective effect from rapamycin

BACKGROUND

The treatment of tacrolimus-induced post-transplantation diabetes mellitus (PTDM) has become a hot topic to improve the long-term survival of organ transplant patients, however whose pathogenesis has not been fully elucidated. In pancreas, the up-regulation of NF-κB has been reported to stimulate cytokine IL-1β/TNF-α secretion, inducing pancreatic injury, meanwhile other studies have reported the inhibitory effect of rapamycin on NF-κB.

PURPOSE

The aim of this study was to clarify the mechanism of tacrolimus-induced pancreatic injury and to explore the potential effect from small dose of sirolimus.

METHODS

Wistar rats were randomly divided normal control (NC) group, PTDM group, sirolimus intervention (SIR) group. Transcriptomic analysis was used to screen potential mechanism of PTDM. Biochemical index detections were used to test the indicators of pancreatic injury. Pathological staining, immumohistochemical staining, immunofluorescent staining, western blot were used to verify the underlying mechanism.

RESULTS

Compared with NC group, the level of insulin was significant reduction (P < 0.01), inversely the level of glucagon was significantly increase (P < 0.01) in PTDM group. Transcriptomic analysis indicated Syk/BLNK/NF-κB signaling was significantly up-regulated in PTDM group. Pathological staining, immumohistochemical staining, immunofluorescent staining, western blot verified Syk/BLNK/NF-κB and TNF-α/IL-1β were all significantly increased (P < 0.05 or P < 0.01), demonstrating the mechanism of tacrolimus-induced pancreatic injury via Syk/BLNK/NF-κB signaling. In addition, compared with PTDM group, the levels of weight, FPG, AMY, and GSP in SIR group were significant ameliorative (P < 0.05 or P < 0.01), and the expressions of p-NF-κB, TNF-α/IL-1β in SIR group were significantly reduction (P < 0.05 or P < 0.01), showing Syk/BLNK/NF-κB signaling promoted pancreatic injury induced by tacrolimus and potential protective effect from rapamycin reducing NF-κB.

CONCLUSION

Syk/BLNK/NF-κB signaling promotes pancreatic injury induced by tacrolimus and rapamycin has a potentially protective effect by down-regulating NF-κB. Further validation and clinical studies are needed in the future.

Particulate matter composition drives differential molecular and morphological responses in lung epithelial cells

Particulate matter (PM) is a ubiquitous component of air pollution that is epidemiologically linked to human pulmonary diseases. PM chemical composition varies widely, and the development of high-throughput experimental techniques enables direct profiling of cellular effects using compositionally unique PM mixtures. Here, we show that in a human bronchial epithelial cell model, exposure to three chemically distinct PM mixtures drive unique cell viability patterns, transcriptional remodeling, and the emergence of distinct morphological subtypes. Specifically, PM mixtures modulate cell viability, DNA damage responses, and induce the remodeling of gene expression associated with cell morphology, extracellular matrix organization, and cellular motility. Profiling cellular responses showed that cell morphologies change in a PM composition-dependent manner. Finally, we observed that PM mixtures with higher cadmium content induced increased DNA damage and drove redistribution among morphological subtypes. Our results demonstrate that quantitative measurement of individual cellular morphologies provides a robust, high-throughput approach to gauge the effects of environmental stressors on biological systems and score cellular susceptibilities to pollution.

Heavy metals, oxidative stress, and the role of AhR signaling

The Aryl Hydrocarbon Receptor (AhR) is a ligand-activated transcriptional factor pivotal in responding to environmental stress and maintaining cellular homeostasis. Exposure to specific xenobiotics or industrial compounds in the environment activates AhR and its subsequent signaling, inducing oxidative stress and related toxicity. Past research has also identified and characterized several classes of endogenous ligands, particularly some tryptophan (Trp) metabolic/catabolic products, that act as AhR agonists, influencing a variety of physiological and pathological states, including the modulation of immune responses and cell death. Heavy metals, being non-essential elements in the human body, are generally perceived as toxic and hazardous, originating either naturally or from industrial activities. Emerging evidence indicates that heavy metals significantly influence AhR activation and its downstream signaling. This review consolidates current knowledge on the modulation of the AhR signaling pathway by heavy metals, explores the consequences of co-exposure to AhR ligands and heavy metals, and investigates the interplay between oxidative stress and AhR activation, focusing on the regulation of immune responses and ferroptosis.

Particulate matter composition drives differential molecular and morphological responses in lung epithelial cells

Particulate matter (PM) is a ubiquitous component of indoor and outdoor air pollution that is epidemiologically linked to many human pulmonary diseases. PM has many emission sources, making it challenging to understand the biological effects of exposure due to the high variance in chemical composition. However, the effects of compositionally unique particulate matter mixtures on cells have not been analyzed using both biophysical and biomolecular approaches. Here, we show that in a human bronchial epithelial cell model (BEAS-2B), exposure to three chemically distinct PM mixtures drives unique cell viability patterns, transcriptional remodeling, and the emergence of distinct morphological subtypes. Specifically, PM mixtures modulate cell viability and DNA damage responses and induce the remodeling of gene expression associated with cell morphology, extracellular matrix organization and structure, and cellular motility. Profiling cellular responses showed that cell morphologies change in a PM composition-dependent manner. Lastly, we observed that particulate matter mixtures with high contents of heavy metals, such as cadmium and lead, induced larger drops in viability, increased DNA damage, and drove a redistribution among morphological subtypes. Our results demonstrate that quantitative measurement of cellular morphology provides a robust approach to gauge the effects of environmental stressors on biological systems and determine cellular susceptibilities to pollution.

Environmental impact of metal halide perovskite solar cells and potential mitigation strategies: A critical review

Metal halide perovskite solar cells (PSCs) have gained extensive attention in the field of solar photovoltaic technology over the past few years. Despite being a remarkable alternative to fossil fuels, solar cells may have detrimental effects on the environment and human health owing to the use of toxic materials during manufacturing. Although modern metal-halide-based PSCs are stable and have encapsulation to prevent the release of potentially toxic materials into the environment, their destruction due to strong winds, hail, snow, landslides, fires, or waste disposal can result in the exposure of these materials to the environment. This may lead to the contamination of soil and groundwater, and uptake of potentially toxic elements by plants, subsequently affecting humans and other living organisms via food chain contamination. Despite worldwide concern, the environmental and ecotoxicological impacts of metal-halide-based PSCs have not been comprehensively surveyed. This review summarizes and critically evaluates the current status of metal-halide-based PSC production and its impact on environmental sustainability, food security, and human health. Furthermore, safe handling and disposal methods for the waste generated from metal-halide-based PSCs are proposed, with a focus on recycling and reuse. Although some studies have suggested that the amount of lead released from metal halide PSCs is far below the maximum permissible levels in most soils, a clear conclusion cannot be reached until real contamination scenarios are assessed under field conditions. Precautions must be taken to minimize environmental contamination throughout the lifecycle of PSCs until nontoxic and similarly performing alternative solar photovoltaic products are developed.

Clarifying winter clean heating importance: Insight chemical compositions and cytotoxicity exposure to primary and aged pollution emissions in China rural areas

Residential solid fuel combustion (RSFC) is an important source of PM_2.5. Here we investigate the cytotoxicity of primarily emitted and photochemically aged PM_2.5 to A549 cells. Owing to the formation of water-soluble ions and organics (e.g., oPAHs and nPAHs), emission factors of PM_2.5 were increased by 44.4% on average after 7-day equivalent photochemical aging, which greatly altered chemical profiles of freshly emitted PM_2.5. Consequently, the cytotoxicity varied with aging duration that 2-day and 7-day aged PM_2.5 induced 22.5% and 35.1%, respectively, higher levels of reactive oxygen species than primary emissions. Similar increases were also observed for multi-cytotoxicity. Correlation analysis and western blot results collectively confirmed HO-1/Nrf-2 signaling pathway dominated the cytotoxicity of aged PM_2.5 from RSFC, which was regulated by the enhanced o-PAHs and n-PAHs during photochemical aging. Thus, aged and secondary aerosol exposure needs to be paid more attention due to the enhanced cytotoxicity and the vast crowd involved.

Effects of Para-Toluenesulfonamide on Canine Melanoma Xenotransplants in a BALB/c Nude Mouse Model

The pharmacological pathway of para-toluenesulfonamide (PTS) restricts the kinase activity of the mammalian target of rapamycin, potentially leading to reductions in cell division, cell growth, cell proliferation, and inflammation. These pathways have a critical effect on tumorigenesis. We aimed to examine the antitumor effect of PTS or PTS combined with cisplatin on canine melanoma implanted in BALB/c nude mice by estimating tumor growth, apoptosis expression, inflammation, and metastasis. The mice were randomly divided into four groups: control, cisplatin, PTS, and PTS combined with cisplatin. Mice treated with PTS or PTS combined with cisplatin had retarded tumor growth and increased tumor apoptosis through the enhanced expression of cleaved caspase 3 and extracellular signal-regulated kinase phosphorylation, decreased inflammatory cytokine levels, reduced inflammation-related factors, enhanced anti-inflammation-related factors, and inhibition of metastasis-related factors. Mice treated with PTS combined with cisplatin exhibited significantly retarded tumor growth, reduced tumor size, and increased tumor inhibition compared with those treated with cisplatin or PTS alone. PTS or PTS combined with cisplatin could retard canine melanoma growth and inhibit tumorigenesis. PTS and cisplatin were found to have an obvious synergistic tumor-inhibiting effect on canine melanoma. PTS alone and PTS combined with cisplatin may be antitumor agents for canine melanoma treatment.

The anticancer effects of cyanidin 3-O-glucoside combined with 5-fluorouracil on lung large-cell carcinoma in nude mice

The haskap (Lonicera caerulea L., Caprifoliaceae) berry has been widely used in traditional medicine in Kuril Islands, Russia, Japan, and China. Cyanidin-3-O-glucoside (C3G) is the most abundant anthocyanin in haskap berries, and C3G induces antiproliferative pharmacological activity in various cancer cells. However, no study has investigated its anti-lung large-cell carcinoma (LCC) pharmacological role. Therefore, this study determined whether C3G alone or C3G combined with 5-fluorouracil (5-FU) inhibits human lung LCC. We determined the tumor growth, apoptosis, inflammation, and metastasis in the H661 lung LCC lines xenografted into BALB/c nude mice. The mice were administered saline (control), 5-FU, C3G, or both C3G and 5-FU. Relative to the control mice, those treated with C3G alone or both C3G and 5-FU exhibited impaired tumor growth; increased tumor apoptosis; decreased inflammatory cytokine levels (e.g., IL-1β, TNF-α, C-reactive protein, and IL-6); decreased inflammation-related factors, including cyclooxygenase-2 protein and nuclear factor-κB (NF-κB) mRNA; increased inhibition of NF-κB kinase α mRNA; and downregulated metastasis-related factors, such as transforming growth factor-β, CD44, epidermal growth factor receptor, and vascular endothelial growth factor. In addition, C3G alone or combined with 5-FU affected the expression of the tumor microenvironment-related factors Ki67, CD45, PDL1, and CD73. Compared with the mice treated with 5-FU or C3G alone, those treated with both C3G and 5-FU exhibited significantly impaired tumor growth, decreased tumor sizes, and increased tumor inhibition. This in vivo study demonstrated that C3G alone or combined with 5-FU may impair the growth of lung LCC and inhibit tumorigenesis. The findings indicate that C3G alone or C3G combined with 5-FU may be beneficial for treating human lung LCC.

Aryl Hydrocarbon Receptor: From Homeostasis to Tumor Progression

Transcription factor aryl hydrocarbon receptor (AHR) has emerged as one of the main regulators involved both in different homeostatic cell functions and tumor progression. Being a member of the family of basic-helix-loop-helix (bHLH) transcriptional regulators, this intracellular receptor has become a key member in differentiation, pluripotency, chromatin dynamics and cell reprogramming processes, with plenty of new targets identified in the last decade. Besides this role in tissue homeostasis, one enthralling feature of AHR is its capacity of acting as an oncogene or tumor suppressor depending on the specific organ, tissue and cell type. Together with its well-known modulation of cell adhesion and migration in a cell-type specific manner in epithelial-mesenchymal transition (EMT), this duality has also contributed to the arise of its clinical interest, highlighting a new potential as therapeutic tool, diagnosis and prognosis marker. Therefore, a deregulation of AHR-controlled pathways may have a causal role in contributing to physiological and homeostatic failures, tumor progression and dissemination. With that firmly in mind, this review will address the remarkable capability of AHR to exert a different function influenced by the phenotype of the target cell and its potential consequences.

The antagonistic effect of selenium on lead-induced apoptosis and necroptosis via P38/JNK/ERK pathway in chicken kidney

Lead (Pb), as a toxic heavy metal pollutant, has been paid much attention. Pb is often discharged into the environment through the soot, wastewater and waste residue in industrial production, which poses a great threat to animal health. Selenium (Se) is a trace element known to antagonize the toxicity caused by heavy metals. However, the interaction between Se and Pb in chicken kidney and its specific biological mechanism are still unclear. So, we constructed chicken models of Pb exposure and Pb, Se co-exposure. Therefore, we used western blot and qRT-PCR to detect the expression of related genes. The results showed that Pb activated the MAPK signaling pathway by up-regulating the expression of MARK pathway genes to induce the expression of pro-apoptotic genes and necroptosis-related genes. Se can regulate the MARK signaling pathway and attenuated the expression of MAPK pathway genes altered by Pb to reduce apoptosis and necroptosis of chicken kidney cells. Our study gives new ideas for the specific mechanism of Pb nephrotoxicity and provides a reference for comparative medicine and clinical medication.

Epstein-Barr Virus Infection in Lung Cancer: Insights and Perspectives

Lung cancer (LC) is the leading cause of cancer death worldwide. Tobacco smoke is the most frequent risk factor etiologically associated with LC, although exposures to other environmental factors such as arsenic, radon or asbestos are also involved. Additionally, the involvement of some viral infections such as high-risk human papillomaviruses (HR-HPVs), Merkel cell polyomavirus (MCPyV), Jaagsiekte Sheep Retrovirus (JSRV), John Cunningham Virus (JCV), and Epstein-Barr virus (EBV) has been suggested in LC, though an etiological relationship has not yet been established. EBV is a ubiquitous gamma herpesvirus causing persistent infections and some lymphoid and epithelial tumors. Since EBV is heterogeneously detected in LCs from different parts of the world, in this review we address the epidemiological and experimental evidence of a potential role of EBV. Considering this evidence, we propose mechanisms potentially involved in EBV-associated lung carcinogenesis. Additional studies are warranted to dissect the role of EBV in this very frequent malignancy.

Anti-Cancer Effects of Zotarolimus Combined with 5-Fluorouracil Treatment in HCT-116 Colorectal Cancer-Bearing BALB/c Nude Mice

Zotarolimus is a semi-synthetic derivative of rapamycin and an inhibitor of mammalian target of rapamycin (mTOR) signaling. Currently, zotarolimus is used to prolong the survival time of organ grafts, but it is also a novel immunosuppressive agent with potent anti-proliferative activity. Here, we examine the anti-tumor effect of zotarolimus, alone and in combination with 5-fluorouracil, on HCT-116 colorectal adenocarcinoma cells implanted in BALB/c nude mice. Compared with the control mice, mice treated with zotarolimus or zotarolimus combined with 5-FU showed retarded tumor growth; increased tumor apoptosis through the enhanced expression of cleaved caspase 3 and extracellular signal-regulated kinase (ERK) phosphorylation; reduced inflammation-related factors such as IL-1β, TNF-α, and cyclooxygenase-2 (COX-2) protein; and inhibited metastasis-related factors such as CD44, epidermal growth factor receptor (EGFR), transforming growth factor β (TGF-β), and vascular endothelial growth factor (VEGF). Notably, mice treated with a combination of zotarolimus and 5-FU showed significantly retarded tumor growth, reduced tumor size, and increased tumor inhibition compared with mice treated with 5-FU or zotarolimus alone, indicating a strong synergistic effect. This in vivo study confirms that zotarolimus or zotarolimus combined with 5-FU can be used to retard colorectal adenocarcinoma growth and inhibit tumorigenesis. Our results suggest that zotarolimus may increase the chemo-sensitization of tumor cells. Therefore, zotarolimus alone and zotarolimus combined with 5-FU may be potential anti-tumor agents in the treatment of human colon adenocarcinoma. Future research on zotarolimus may lead to the development of new therapeutic strategies.

A toxicity pathway-based approach for modeling the mode of action framework of lead-induced neurotoxicity

BACKGROUND

The underlying mechanisms of lead (Pb) toxicity are not fully understood, which makes challenges to the traditional risk assessment. There is growing use of the mode of action (MOA) for risk assessment by integration of experimental data and system biology. The current study aims to develop a new pathway-based MOA for assessing Pb-induced neurotoxicity.

METHODS

The available Comparative Toxicogenomic Database (CTD) was used to search genes associated with Pb-induced neurotoxicity followed by developing toxicity pathways using Ingenuity Pathway Analysis (IPA). The spatiotemporal sequence of disturbing toxicity pathways and key events (KEs) were identified by upstream regulator analysis. The MOA framework was constructed by KEs in biological and chronological order.

RESULTS

There were a total of 71 references showing the relationship between lead exposure and neurotoxicity, which contained 2331 genes. IPA analysis showed that the neuroinflammation signaling pathway was the core toxicity pathway in the enriched pathways relevant to Pb-induced neurotoxicity. The upstream regulator analysis demonstrated that the aryl hydrocarbon receptor (AHR) signaling pathway was the upstream regulator of the neuroinflammation signaling pathway (11.76% overlap with upstream regulators, |Z-score|=1.451). Therefore, AHR activation was recognized as the first key event (KE1) in the MOA framework. The following downstream molecular and cellular key events were also identified. The pathway-based MOA framework of Pb-induced neurotoxicity was built starting with AHR activation, followed by an inflammatory response and neuron apoptosis.

CONCLUSION

Our toxicity pathway-based approach not only advances the development of risk assessment for Pb-induced neurotoxicity but also brings new insights into constructing MOA frameworks of risk assessment for new chemicals.

Clozapine Worsens Glucose Intolerance, Nonalcoholic Fatty Liver Disease, Kidney Damage, and Retinal Injury and Increases Renal Reactive Oxygen Species Production and Chromium Loss in Obese Mice

Clozapine is widely employed in the treatment of schizophrenia. Compared with that of atypical first-generation antipsychotics, atypical second-generation antipsychotics such as clozapine have less severe side effects and may positively affect obesity and blood glucose level. However, no systematic study of clozapine’s adverse metabolic effects—such as changes in kidney and liver function, body weight, glucose and triglyceride levels, and retinopathy—was conducted. This research investigated how clozapine affects weight, the bodily distribution of chromium, liver damage, fatty liver scores, glucose homeostasis, renal impairment, and retinopathy in mice fed a high fat diet (HFD). We discovered that obese mice treated with clozapine gained more weight and had greater kidney, liver, and retroperitoneal and epididymal fat pad masses; higher daily food efficiency; higher serum or hepatic triglyceride, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, and creatinine levels; and higher hepatic lipid regulation marker expression than did the HFD-fed control mice. Furthermore, the clozapine group mice exhibited insulin resistance, poorer insulin sensitivity, greater glucose intolerance, and less Akt phosphorylation; their GLUT4 expression was lower, they had renal damage, more reactive oxygen species, and IL-1 expression, and, finally, their levels of antioxidative enzymes (superoxide dismutase, glutathione peroxidase, and catalase) were lower. Moreover, clozapine reduced the thickness of retinal cell layers and increased iNOS and NF-κB expression; a net negative chromium balance occurred because more chromium was excreted through urine, and this influenced chromium mobilization, which did not help overcome the hyperglycemia. Our clozapine group had considerably higher fatty liver scores, which was supported by the findings of lowered adiponectin protein levels and increased FASN protein, PNPLA3 protein, FABP4 mRNA, and SREBP1 mRNA levels. We conclude that clozapine can worsen nonalcoholic fatty liver disease, diabetes, and kidney and retinal injury. Therefore, long-term administration of clozapine warrants higher attention.

The Anti-Cancer Effects of a Zotarolimus and 5-Fluorouracil Combination Treatment on A549 Cell-Derived Tumors in BALB/c Nude Mice

Zotarolimus is a semi-synthetic derivative of rapamycin and a novel immunosuppressive agent used to prevent graft rejection. The pharmacological pathway of zotarolimus restricts the kinase activity of the mammalian target of rapamycin (mTOR), which potentially leads to reductions in cell division, cell growth, cell proliferation, and inflammation. These pathways have a critical influence on tumorigenesis. This study aims to examine the anti-tumor effect of zotarolimus or zotarolimus combined with 5-fluorouracil (5-FU) on A549 human lung adenocarcinoma cell line implanted in BALB/c nude mice by estimating tumor growth, apoptosis expression, inflammation, and metastasis. We established A549 xenografts in nude mice, following which we randomly divided the mice into four groups: control, 5-FU (100 mg/kg/week), zotarolimus (2 mg/kg/day), and zotarolimus combined with 5-FU. Compared the results with those for control mice, we found that mice treated with zotarolimus or zotarolimus combined with 5-FU retarded tumor growth; increased tumor apoptosis through the enhanced expression of cleaved caspase 3 and extracellular signal-regulated kinase (ERK) phosphorylation; decreased inflammation cytokines levels (e.g., IL-1β, TNF-α, and IL-6); reduced inflammation-related factors such as cyclooxygenase-2 (COX-2) protein and nuclear factor-κB (NF-κB) mRNA; enhanced anti-inflammation-related factors including IL-10 and inhibitor of NF-κB kinase α (IκBα) mRNA; and inhibited metastasis-related factors such as transforming growth factor β (TGF-β), CD44, epidermal growth factor receptor (EGFR), and vascular endothelial growth factor (VEGF). Notably, mice treated with zotarolimus combined with 5-FU had significantly retarded tumor growth, reduced tumor size, and increased tumor inhibition compared with the groups of mice treated with 5-FU or zotarolimus alone. The in vivo study confirmed that zotarolimus or zotarolimus combined with 5-FU could retard lung adenocarcinoma growth and inhibit tumorigenesis. Zotarolimus and 5-FU were found to have an obvious synergistic tumor-inhibiting effect on lung adenocarcinoma. Therefore, both zotarolimus alone and zotarolimus combined with 5-FU may be potential anti-tumor agents for treatment of human lung adenocarcinoma.

Small in Size, but Large in Action: microRNAs as Potential Modulators of PTEN in Breast and Lung Cancers

MicroRNAs (miRNAs) are well-known regulators of biological mechanisms with a small size of 19–24 nucleotides and a single-stranded structure. miRNA dysregulation occurs in cancer progression. miRNAs can function as tumor-suppressing or tumor-promoting factors in cancer via regulating molecular pathways. Breast and lung cancers are two malignant thoracic tumors in which the abnormal expression of miRNAs plays a significant role in their development. Phosphatase and tensin homolog (PTEN) is a tumor-suppressor factor that is capable of suppressing the growth, viability, and metastasis of cancer cells via downregulating phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling. PTEN downregulation occurs in lung and breast cancers to promote PI3K/Akt expression, leading to uncontrolled proliferation, metastasis, and their resistance to chemotherapy and radiotherapy. miRNAs as upstream mediators of PTEN can dually induce/inhibit PTEN signaling in affecting the malignant behavior of lung and breast cancer cells. Furthermore, long non-coding RNAs and circular RNAs can regulate the miRNA/PTEN axis in lung and breast cancer cells. It seems that anti-tumor compounds such as baicalein, propofol, and curcumin can induce PTEN upregulation by affecting miRNAs in suppressing breast and lung cancer progression. These topics are discussed in the current review with a focus on molecular pathways.

Cadmium exposure induces mitochondrial pathway apoptosis in swine myocardium through xenobiotic receptors-mediated CYP450s activation

Cadmium (Cd) pollution has become an important public and environmental health issue. Xenobiotic receptors (XRs, aryl hydrocarbon receptor, AHR; constitutive androstane receptor, CAR; pregnane X receptor, PXR) modulate downstream cytochrome P450 enzymes (CYP450s) expression to metabolize xenobiotics and environmental contaminants. However, the underlying mechanisms of cardiotoxicity induced by Cd(II) in swine and the roles of XRs and CYP450s remain poorly understood. In this study, the cardiotoxicity of Cd(II) was investigated by establishing a Cd(II)-exposed swine model (CdCl₂, 20 mg Cd/Kg diet). Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) assay and transmission electron microscope were used to observe the apoptosis. Antioxidant capacity was evaluated by free radicals contents and antioxidant enzymes activities. RT-PCR and western blot were used to measure the expression of XRs, CYP450s and apoptosis-related genes. Our results revealed that Cd(II) exposure activated the XRs and increased the CYP450s expression, contributing to the production of reactive oxygen species (ROS). Cd(II) exposure restrained the antioxidant capacity, causing oxidative stress. Moreover, mitogen-activated protein kinase (MAPK) pathway including c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and P38 mitogen-activated protein kinase (P38) was activated, triggering the mitochondrial apoptotic pathway. In brief, we concluded that Cd(II) caused mitochondrial pathway apoptosis in swine myocardium via the oxidative stress-MAPK pathway, and XRs-mediated CYP450s expression might participate in this process through promoting the ROS.

Dysregulation of ferroptosis may involve in the development of non-small-cell lung cancer in Xuanwei area

The Xuanwei area of Yunnan Province, China, is one of the regions suffering from the highest occurrence and mortality rate of lung cancer in the world. Local residents tend to use bituminous coal as domestic fuel, which causes serious indoor air pollution and is established as the main carcinogen. After the local government carried out furnace and stove reform work, lung cancer rate including incidence and mortality among residents remains high. We herein wonder if there are specific mechanisms at protein level for the development of non-small-cell lung cancer (NSCLC) in this area. We investigated the changes of protein profiling in tumour of the patients from Xuanwei area. Tandem mass tag (TMT) was employed to screen the differential proteins between carcinoma and para-carcinoma tissues. We identified a total of 422 differentially expressed proteins, among which 162 proteins were significantly up-regulated and 260 were downregulated compared to para-carcinoma tissues. Many of the differentially expressed proteins were related to extracellular matrix (ECM)-receptor interaction, focal adhesion, PI3K/AKT pathway and ferroptosis. Further experiments on the two differential proteins, thioredoxin 2 (TXN2) and haptoglobin (HP), showed that the change of their expressions could make the lung cancer cell lines more resistant to erastin or RSL-induced ferroptosis in vitro, and promote the growth of tumour in nude mice. In conclusion, this study revealed that aberrant regulation of ferroptosis may involve in the development of lung cancer in Xuanwei area.

AhR and Cancer: From Gene Profiling to Targeted Therapy

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that has been shown to be an essential regulator of a broad spectrum of biological activities required for maintaining the body’s vital functions. AhR also plays a critical role in tumorigenesis. Its role in cancer is complex, encompassing both pro- and anti-tumorigenic activities. Its level of expression and activity are specific to each tumor and patient, increasing the difficulty of understanding the activating or inhibiting roles of AhR ligands. We explored the role of AhR in tumor cell lines and patients using genomic data sets and discuss the extent to which AhR can be considered as a therapeutic target.

Toxic metal exposure as a possible risk factor for COVID-19 and other respiratory infectious diseases

Multiple medical, lifestyle, and environmental conditions, including smoking and particulate pollution, have been considered as risk factors for COronaVIrus Disease 2019 (COVID-19) susceptibility and severity. Taking into account the high level of toxic metals in both particulate matter (PM2.5) and tobacco smoke, the objective of this review is to discuss recent data on the role of heavy metal exposure in development of respiratory dysfunction, immunotoxicity, and severity of viral diseases in epidemiological and experimental studies, as to demonstrate the potential crossroads between heavy metal exposure and COVID-19 severity risk. The existing data demonstrate that As, Cd, Hg, and Pb exposure is associated with respiratory dysfunction and respiratory diseases (COPD, bronchitis). These observations corroborate laboratory findings on the role of heavy metal exposure in impaired mucociliary clearance, reduced barrier function, airway inflammation, oxidative stress, and apoptosis. The association between heavy metal exposure and severity of viral diseases, including influenza and respiratory syncytial virus has been also demonstrated. The latter may be considered a consequence of adverse effects of metal exposure on adaptive immunity. Therefore, reduction of toxic metal exposure may be considered as a potential tool for reducing susceptibility and severity of viral diseases affecting the respiratory system, including COVID-19.