Alteration of miRNA expression in early endothelial cells after exposure with sub-lethal sulfur mustard concentrations

Identification and characterization of lncRNA-miRNA-mRNA tripartite network of sulfur mustard exposed patients

BACKGROUND

Alkylating cellular DNA, sulfur mustard (SM) is a chemical warfare agent that causes severe damage to the skin, eyes, and respiratory tract. Exposure can result in painful burns, chronic lung disease, immune system suppression, and an increased chance of developing cancer. The symptoms of itching, redness, and blistering are frequently followed by long-term genetic and psychological damage. By exploring the interaction between microRNA (miRNA), mRNA, and long non-coding RNA (lncRNA) in these patients, it is possible to identify gene expression patterns that could reduce cancer risk or improve treatment outcomes.

METHODS

The purpose of this study is to examine transcriptome data from PBMC samples obtained from sulfur mustard exposed patients (Mild, Moderate, Severe) and healthy Control, separated into six groups (SC, SMo, SMi, MoMi, MoC, and MiC). miRNA, lncRNA, and mRNA interactions were explored using miRNA, lncRNA, and mRNA tools and databases, such as miRTarBase, miRDB, miRNET, miRcode, and DIANA. A tripartite mRNA-miRNA-lncRNA network was modeled with the aid of Cytoscape software, and functional analyses were performed to gain an understanding of molecular pathways using GO and KEGG functional analyses.

RESULTS

By extracting miRNAs shared between lncRNAs and mRNAs, six groups were identified and Cytoscape software was used to visualize the lncRNA-miRNA-mRNA network. Betweenness, closeness, and degree filters identified key genes, with INO80D and lncRNAs MINCR, LINC00662, NEAT1, and DHRS4-AS1, along with miRNAs hsa-miR-1-3p, hsa-miR-124-3p, and hsa-let-7b-5p as the main players in all groups.

CONCLUSION

The interaction between key genes involved in chemical injuries and their association with genes implicated in lung cancer is highlighted in this study. By targeting these genes and their proteins, we can improve treatment strategies for sulfur mustard exposed patients and potentially reduce lung cancer risk.

Toxicology of Blister Agents: Is Melatonin a Potential Therapeutic Option?

Blister or vesicant chemical warfare agents (CWAs) have been widely used in different military conflicts, including World War I and the Iran-Iraq War. However, their mechanism of action is not fully understood. Sulfur and nitrogen mustard exert toxic effects not only through the alkylation of thiol-bearing macromolecules, such as DNA and proteins, but also produce free radicals that can develop direct toxic effects in target organs such as the eyes, skin, and respiratory system. The lack of effective treatments against vesicant CWAs-induced injury makes us consider, in this complex scenario, the use and development of melatonin-based therapeutic strategies. This multifunctional indoleamine could facilitate neutralization of the oxidative stress, modulate the inflammatory response, and prevent the DNA damage, as well as the long-term health consequences mediated by vesicant CWAs-induced epigenetic mechanisms. In this context, it would be essential to develop new galenic formulations for the use of orally and/or topically applied melatonin for the prophylaxis against vesicant CWAs, as well as the development of post-exposure treatments in the near future.

Ocular toxicity of mustard gas: A concise review

Sulfur mustard (SM) is a chemical warfare agent that has been used throughout recent history and remains a threat today. Exposed soldiers and civilians experience a variety of symptoms primarily in the respiratory system, skin, and eyes. The ocular tissues are highly sensitive to damage by SM and undergo unique manifestations of acute, chronic, and delayed complications that can persist for months and years after exposure. The mechanisms of this unique mustard gas keratopathy are still not fully understood and animal models for the study of this disease are discussed. Recent advances in mechanisms of injury are included in this review. Ophthalmic manifestations of SM injury including persistent epithelial defects, limbal stem cell deficiency, corneal neovascularization, dry eye, and corneal opacification have been reported. A wide variety of medical and surgical therapies have been studied and are reviewed here along with potential future therapies.

Deciphering the role of microRNAs in mustard gas-induced toxicity

Mustard gas (sulfur mustard, SM), a highly vesicating chemical warfare agent, was first deployed in warfare in 1917 and recently during the Iraq-Iran war (1980s) and Syrian conflicts (2000s); however, the threat of exposure from stockpiles and old artillery shells still looms large. Whereas research has been long ongoing on SM-induced toxicity, delineating the precise molecular pathways is still an ongoing area of investigation; thus, it is important to attempt novel approaches to decipher these mechanisms and develop a detailed network of pathways associated with SM-induced toxicity. One such avenue is exploring the role of microRNAs (miRNAs) in SM-induced toxicity. Recent research on the regulatory role of miRNAs provides important results to fill in the gaps in SM toxicity-associated mechanisms. In addition, differentially expressed miRNAs can also be used as diagnostic markers to determine the extent of toxicity in exposed individuals. Thus, in our review, we have summarized the studies conducted so far in cellular and animal models, including human subjects, on the expression profiles and roles of miRNAs in SM- and/or SM analog-induced toxicity. Further detailed research in this area will guide us in devising preventive strategies, diagnostic tools, and therapeutic interventions against SM-induced toxicity.

Extracellular vesicles of U937 macrophage cell line infected with DENV-2 induce activation in endothelial cells EA.hy926

Endothelial activation and alteration during dengue virus (DENV) infection are multifactorial events; however, the role of extracellular vesicles (EVs) in these phenomena is not known. In the present study, we characterized the EVs released by DENV-2 infected U937 macrophage cell line and evaluated the changes in the physiology and integrity of the EA.hy926 endothelial cells exposed to them. U937 macrophages were infected, supernatants were collected, and EVs were purified and characterized. Then, polarized endothelial EA.hy926 cells were exposed to the EVs for 24 h, and the transendothelial electrical resistance (TEER), monolayer permeability, and the expression of tight junction and adhesion proteins and cytokines were evaluated. The isolated EVs from infected macrophages corresponded to exosomes and apoptotic bodies, which contained the viral NS3 protein and different miRs, among other products. Exposure of EA.hy926 cells to EVs induced an increase in TEER, as well as changes in the expression of VE-cadherin and ICAM in addition leads to an increase in TNF-α, IP-10, IL-10, RANTES, and MCP-1 secretion. These results suggest that the EVs of infected macrophages transport proteins and miR that induce early changes in the physiology of the endothelium, leading to its activation and eliciting a defense program against damage during first stages of the disease, even in the absence of the virus.

Overview of biological mechanisms of human carcinogens

This review summarizes the carcinogenic mechanisms for 109 Group 1 human carcinogens identified as causes of human cancer through Volume 106 of the IARC Monographs. The International Agency for Research on Cancer (IARC) evaluates human, experimental and mechanistic evidence on agents suspected of inducing cancer in humans, using a well-established weight of evidence approach. The monographs provide detailed mechanistic information about all carcinogens. Carcinogens with closely similar mechanisms of action (e.g. agents emitting alpha particles) were combined into groups for the review. A narrative synopsis of the mechanistic profiles for the 86 carcinogens or carcinogen groups is presented, based primarily on information in the IARC monographs, supplemented with a non-systematic review. Most carcinogens included a genotoxic mechanism.

MicroRNA-150-5p and SRC kinase signaling inhibitor 1 involvement in the pathological development of gastric cancer

The current study aimed to assess the regulatory mechanism of microRNA-150-5p (miR-150-5p) in the pathogenesis of gastric cancer. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to verify the expression of miR-150-5p in gastric cancer tissues and cell lines, which was revealed to be highly expressed in each. In addition, the expression of miR-150-5p was associated with advanced gastric cancer and lymph node metastasis. The current study then hypothesized that SRC kinase signaling inhibitor 1 (SRCIN1) was the target gene of miR-150-5p, a theory that was confirmed via a dual luciferase reporter gene assay. RT-qPCR and western blotting were then performed to verify the expression of SRCIN1 in gastric cancer tissues and cell lines. The results demonstrated that SRCIN1 was lowly expressed in gastric cancer tissues and cells. To assess the effect of miR-150-5p on gastric cancer cells, experiments were conducted with BGC-823 cells transfected with a miR-150-5p inhibitor or a miR-150-5p inhibitor+SRCIN1-small interfering (si)RNA respectively. A cell counting kit-8 assay and flow cytometry were also used to assess cell viability and apoptosis, respectively. Western blotting and RT-qPCR were further used to measure the expression of specific markers of epithelial mesenchymal transition (EMT), including epithelial cell markers (E-cadherin and zona occluding-1) and interstitial cell markers (vimentin, N-cadherin and β-catenin). The results revealed that the miR-150-5p inhibitor attenuated cell viability, induced apoptosis, decreased the expression of interstitial cell markers and increased epithelial cell marker expression. However, all effects of the miR-150-5p inhibitor were reversed following SRCIN1-siRNA treatment. In summary, the current study indicated that the miR-150-5p inhibitor attenuated cell viability, induced apoptosis and inhibited gastric cancer cell EMT by targeting SRCIN1.

Alteration of miRNA expression in a sulfur mustard resistant cell line

BACKGROUND

MicroRNAs (miRNAs) are responsible for post-transcriptional control of protein expression. Numerous miRNAs have been identified to be responsible for the resistance of tumor cells to cytostatic drugs. Possibly, the same miRNAs also play a role in the sulfur mustard (SM)-resistance of the keratinocyte cell line HaCaT/SM as alkylating cytostatics exhibit similar cytotoxic effects as SM.

METHODS

Basal expression levels of 1920 miRNAs in total were analyzed in HaCaT/SM compared to the origin human keratinocyte cell line HaCaT. The effect for selected miRNAs on cell survival was analyzed using antagomirs for ectopic miRNA level decrease or miRNA mimics for increase. Cell survival was calculated as SM dose-dependent-curves.

RESULTS

Out of 1920 miRNAs analyzed, 49 were significantly up- and 29 were significantly downregulated in HaCaT/SM when compared to HaCaT controls. Out of these, 36 could be grouped in miRNA families. Most of the 15 miRNA family members showed either a common increase or decrease. Only the members of miR-10, miR-154, miR-430 and miR-548 family showed an inconsistent picture. The ectopic increase of miR-181 in HaCaT/SM had a positive effect on cell survival in the presence of SM.

CONCLUSION

In summary, the extensive differences in miRNA expression pattern between these cell lines indicate that specific miRNAs may play a role in the resistance mechanism against sulfur mustard. The miR-125b-2 and miR-181b alone are not responsible for the resistance development against SM, but an ectopic increase of miR-181 even enhances the SM resistance of HaCaT/SM. Improving the resistance in normal keratinocytes by treatment with either both miRNAs together or a different combination might be used as an initial step in development of an innovative new drug or prophylactic agent against SM.

Epigenetic alterations induced by genotoxic occupational and environmental human chemical carcinogens: A systematic literature review

Accumulating evidence suggests that epigenetic alterations play an important role in chemically-induced carcinogenesis. Although the epigenome and genome may be equally important in carcinogenicity, the genotoxicity of chemical agents and exposure-related transcriptomic responses have been more thoroughly studied and characterized. To better understand the evidence for epigenetic alterations of human carcinogens, and the potential association with genotoxic endpoints, we conducted a systematic review of published studies of genotoxic carcinogens that reported epigenetic endpoints. Specifically, we searched for publications reporting epigenetic effects for the 28 agents and occupations included in Monograph Volume 100F of the International Agency for the Research on Cancer (IARC) that were classified as "carcinogenic to humans" (Group 1) with strong evidence of genotoxic mechanisms of carcinogenesis. We identified a total of 158 studies that evaluated epigenetic alterations for 12 of these 28 carcinogenic agents and occupations (1,3-butadiene, 4-aminobiphenyl, aflatoxins, benzene, benzidine, benzo[a]pyrene, coke production, formaldehyde, occupational exposure as a painter, sulfur mustard, and vinyl chloride). Aberrant DNA methylation was most commonly studied, followed by altered expression of non-coding RNAs and histone changes (totaling 85, 59 and 25 studies, respectively). For 3 carcinogens (aflatoxins, benzene and benzo[a]pyrene), 10 or more studies reported epigenetic effects. However, epigenetic studies were sparse for the remaining 9 carcinogens; for 4 agents, only 1 or 2 published reports were identified. While further research is needed to better identify carcinogenesis-associated epigenetic perturbations for many potential carcinogens, published reports on specific epigenetic endpoints can be systematically identified and increasingly incorporated in cancer hazard assessments.