The denitrosylase S-nitrosoglutathione reductase (GSNOR) is a central regulator of nitric oxide (NO) signaling, by controlling protein S-nitrosylation. GSNOR is downregulated in several human cancers, with breast cancer representing one of the major hits. However, the mechanisms driving its suppression and its precise role in tumor progression remain elusive. Here, we identify microRNAs as key post-transcriptional regulators of GSNOR in breast cancer, specifically miR-455-3p and miR-519a-5p. Restoring GSNOR levels, either directly or by inhibiting these onco-miRs, reduced global protein S-nitrosylation, including that of glycogen synthase kinase 3β (GSK3β). This event was associated with decreased GSK3β inhibitory phosphorylation and consequent subsequent suppression of oncogenic signaling pathways. Functionally, GSNOR restoration inhibited epithelial-mesenchymal transition by increasing E-cadherin and reducing nuclear SNAI1 levels, attenuated β-catenin signaling, and impaired cell invasion, motility, and mammospheres viability. Altogether, our findings unveil a novel regulatory axis in which specific microRNAs control protein S-nitrosylation by targeting GSNOR, thereby driving breast cancer progression, and establish GSNOR as a crucial tumor suppressor.
The activity of S-nitrosoglutathione reductase (ADH5/GSNOR) has been proposed being essential to limit oxidative stress and preserve mitochondrial quality control. Here we identify a redox-dependent ATM-CHK2-SOD1 signaling axis that drives ADH5/GSNOR transcription in SH-SY5Y cells expressing the ALS-associated SOD1G93A mutant. ATM-CHK2 activation promotes the interaction of SOD1 with CHK2, leading to SOD1 nuclear translocation and binding to the ADH5 promoter. Pharmacological inhibition of ATM or CHK2 abolishes these effects. ADH5/GSNOR overexpression protects cells from SOD1G93A-induced toxicity suggesting that the modulation of GSNOR activity may represent a potential strategy to restore redox homeostasis in ALS.
The effect of a mucilage extracted from Opuntia ficus-indica (L.) Mill (OFI) cladodes was tested in lipopolysaccharide (LPS)-challenged HepG2 hepatocarcinoma cells, through a combined in vitro-in silico approach. The OFI mucilage was characterized by gas chromatography-mass spectrometry and liquid chromatography-high resolution mass spectrometry. In cells treated with OFI (5-10 µg/mL) prior to LPS (1 µg/mL, 24 h), the gene expression profile of pro-inflammatory mediators, namely tumor necrosis factor alpha, interleukin-1 beta, interleukin-8, and cyclo-oxygenase-2, was significantly (p < 0.01) reduced if compared to single LPS-challenged cells. The OFI-mediated cytokines reduction was also validated in polystyrene scaffold-grown 3D HepG2 cultures, undergoing treatment with the OFI mucilage (50 µg/mL, 24 h) and LPS stimulation (50 µg/mL, 24 h). We further demonstrated that OFI suppresses the LPS-triggered inflammatory response via impairment of the Toll-like receptor 4 (TLR4)/Myeloid differentiation protein-88/Nuclear factor-kappa B (NF-kB) pathway, by interfering with NF-kB phosphorylation at Serine 536. By molecular docking approach, we provided in silico demonstration of the direct molecular interaction between the mucilage monosaccharides and the TLR4 that interferes with the LPS receptor binding and down-stream inflammatory cascade activation. We also demonstrated that OFI cladodes mucilage downregulates the TLR4 pathway, showing an anti-inflammatory potential in HepG2 cells.
Saffron (Crocus sativus L.) contains bioactive compounds with potential health benefits, including modulation of protein function and gene expression. However, their ability to tune the epigenetic machine remains poorly understood. This study employs molecular docking (AutoDock Vina 1.4), dynamics simulations, and MM/PBSA calculations to investigate the interactions between four saffron-derived molecules—crocetin, beta-D-glucosyl trans-crocetin, picrocrocin and safranal—and four epigenetic enzymes—DNMT1, DNMT3a, HDAC2, and SIRT1. Our in silico screening identifies beta-D-glucosyl trans-crocetin, one of the saffron’s crocins, as a potential DNMT1 inhibitor. Along with crocetin, it also shows the ability to inhibit HDAC2 and activate SIRT1. Picrocrocin displays a resveratrol-like ability to activate SIRT1. None of the saffron-derived compounds effectively bind or inhibit DNMT3a. Among the tested molecules, safranal shows no interaction with the selected epigenetic targets. These findings highlight saffron’s nutriepigenomic potential and emphasize the need for functional validation within relevant in vitro and in vivo experimental methodologies.
Ionizing radiation is widely used in medicine but can cause genotoxic and cytotoxic effects in healthy tissues. Natural radioprotectors represent a promising strategy to mitigate the radiation-induced damage. This study investigates the radioprotective efficacy of a mucilage extract from Opuntia ficus-indica (OFI) cladodes in human peripheral blood lymphocytes (PBLs). PBLs were treated with two concentrations of OFI extract (0.01 and 0.05 µg/mL) and assessed for cytotoxicity, viability and chromosomal integrity. Cytokinesis block micronucleus (CBMN) assay and cytokinesis block proliferation index (CBPI) were used to evaluate genotoxicity and cytotoxicity, respectively. For radioprotection assays, PBLs were pretreated with OFI extract prior to exposure to 60 Co γ -rays (0.5 and 1 Gy) and the frequency of micronuclei was determined. OFI extract per se did not induce cytotoxic or genotoxic effects. Exposure to gamma radiation significantly increased micronuclei frequency in a dose-dependent manner. Pretreatment with OFI extract resulted in a significant reduction in radiation-induced micronuclei formation at 1 Gy total absorbed dose, indicating a protective effect against chromosome damage. In conclusion, OFI mucilage extract is non-toxic to human lymphocytes and exhibits radioprotective potential, likely due to its bioactive phytocompounds. These preliminary findings support further investigation of OFI as a natural radioprotective agent in clinical or environmental settings. Graphical abstract
Heterozygous mutations or genetic variants in the GBA1 gene, which encodes for the β-glucocerebrosidase (GCase), a lysosomal hydrolase enzyme, may increase the risk of Parkinson’s disease (PD) onset. The heterozygous E326K form is one of the most common genetic risk factors for PD worldwide, but, to date, the underlying molecular mechanisms remain unclear. Here, we investigate the effect of the E326K on the structure, stability, dimerization process, and interaction mode with some proteins of the interactome of GCase using multiple molecular dynamics (MD) simulations at pH 5.5 and pH 7.0 to mimic the lysosomal and endoplasmic reticulum environments, respectively. The analysis of the MD trajectories highlights that the E326K mutation did not significantly alter the structural conformation of the catalytic dyad but significantly makes the structure of the dimeric complexes unstable, especially at lysosomal pH, potentially impacting the organization of the quaternary structure. Furthermore, the E326K mutation significantly impacts protein interactions by altering the binding mode with the activator Saposin C (SapC), reducing the binding affinity with the inhibitor α-Synuclein (α-Syn), and increasing the affinity for the Lysosomal integral membrane protein-2 (LIMP-2) transporter.
Associations between indoor air pollution from fine particulate matter (PM with aerodynamic diameter dp < 2.5 μm) and human health are poorly understood. Here, we analyse the concentration-response curves for fine and ultrafine PM, the gene expression, and the methylation patterns in human bronchial epithelial cells (BEAS-2B) exposed at the air-liquid interface (ALI) within a classroom in downtown Rome.Our results document the upregulation of aryl hydrocarbon receptor (AhR) and genes associated with xenobiotic metabolism (CYP1A1 and CYP1B1) in response to single exposure of cells to fresh urban aerosols at low fine PM mass concentrations within the classroom. This is evidenced by concentrations of ultrafine particles (UFPs, dp < 0.1 μm), polycyclic aromatic hydrocarbons (PAH), and ratios of black carbon (BC) to organic aerosol (OA). Additionally, an interleukin 18 (IL-18) down-regulation was found during periods of high human occupancy.Despite the observed gene expression dysregulation, no changes were detected in the methylation levels of the promoter regions of these genes, indicating that the altered gene expression is not linked to changes in DNA methylation and suggesting the involvement of another epigenetic mechanism in the gene regulation.Gene expression changes at low exposure doses have been previously reported. Here, we add the possibility that lung epithelial cells, when singly exposed to real environmental concentrations of fine PM that translate into ultra-low doses of treatment, may undergo epigenetic alteration in the expression of genes related to xenobiotic metabolism.Our findings provide a perspective for future indoor air quality regulations. We underscore the potential role of indoor UFPs as carriers of toxic molecules with low-pressure weather conditions, when rainfall and strong winds may favour low levels of fine PM.
BACKGROUND:The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency electromagnetic field (RF-EMF) exposure and adverse health effects. Reproductive health outcomes have been identified among the priority topics to be addressed. OBJECTIVES:To evaluate the effect of RF-EMF exposure on male fertility of experimental mammals and on human sperm exposed in vitro. METHODS:Three electronic databases (PubMed, Scopus and EMF Portal) were last searched on September 17, 2022. Two independent reviewers screened the studies, which were considered eligible if met the following criteria: 1) Peer-reviewed publications of sham controlled experimental studies, 2) Non-human male mammals exposed at any stage of development or human sperm exposed in vitro, 3) RF-EMF exposure within the frequency range of 100 kHz-300 GHz, including electromagnetic pulses (EMP), 4) one of the following indicators of reproductive system impairment:Two reviewers extracted study characteristics and outcome data. We assessed risk of bias (RoB) using the Office of Health Assessment and Translation (OHAT) guidelines. We categorized studies into 3 levels of overall RoB: low, some or high concern. We pooled study results in a random effects meta-analysis comparing average exposure to no-exposure and in a dose-response meta-analysis using all exposure doses. For experimental animal studies, we conducted subgroup analyses for species, Specific Absorption Rate (SAR) and temperature increase. We grouped studies on human sperm exposed in vitro by the fertility status of sample donors and SAR. We assessed the certainty of the evidence using the GRADE approach after excluding studies that were rated as "high concern" for RoB. RESULTS:One-hundred and seventeen papers on animal studies and 10 papers on human sperm exposed in vitro were included in this review. Only few studies were rated as "low concern" because most studies were at RoB for exposure and/or outcome assessment. Subgrouping the experimental animal studies by species, SAR, and temperature increase partly accounted for the heterogeneity of individual studies in about one third of the meta-analyses. In no case was it possible to conduct a subgroup analysis of the few human sperm in vitro studies because there were always 1 or more groups including less than 3 studies. Among all the considered endpoints, the meta-analyses of animal studies provided evidence of adverse effects of RF-EMF exposure in all cases but the rate of infertile males and the size of the sired litters. The assessment of certainty according to the GRADE methodology assigned a moderate certainty to the reduction of pregnancy rate and to the evidence of no-effect on litter size, a low certainty to the reduction of sperm count, and a very low certainty to all the other meta-analysis results. Studies on human sperm exposed in vitro indicated a small detrimental effect of RF-EMF exposure on vitality and no-effect on DNA/chromatin alterations. According to GRADE, a very low certainty was attributed to these results. The few studies that used EMP exposure did not show effects on the outcomes. A low to very low certainty was attributed to these results. DISCUSSION:Many of the studies examined suffered of severe limitations that led to the attribution of uncertainty to the results of the meta-analyses and did not allow to draw firm conclusions on most of the endpoints. Nevertheless, the associations between RF-EMF exposure and decrease of pregnancy rate and sperm count, to which moderate and low certainty were attributed, are not negligible, also in view of the indications that in Western countries human male fertility potential seems to be progressively declining. It was beyond the scope of our systematic review to determine the shape of the dose-response relationship or to identify a minimum effective exposure level. The subgroup and the dose-response fitting analyses did not show a consistent relationship between the exposure levels and the observed effects. Notably, most studies evaluated RF-EMF exposure levels that were higher than the levels to which human populations are typically exposed, and the limits set in international guidelines. For these reasons we cannot provide suggestions to confirm or reconsider current human exposure limits. Considering the outcomes of this systematic review and taking into account the limitations found in several of the studies, we suggest that further investigations with better characterization of exposure and dosimetry including several exposure levels and blinded outcome assessment were conducted. PROTOCOL REGISTRATION:Protocols for the systematic reviews of animal studies and of human sperm in vitro studies were published in Pacchierotti et al., 2021. The former was also registered in PROSPERO (CRD42021227729 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID = 227729) and the latter in Open Science Framework (OSF Registration DOI https://doi.org/10.17605/OSF.IO/7MUS3).
Pomegranate is an important source of bioactive molecules with proven beneficial effects on human health. The aim of this study was to investigate the potential anti-inflammatory effect of a pomegranate extract (PE), obtained from the whole fruit and previously characterized by Reversed Phase-Ultra High-Pressure Liquid Chromatography-High Resolution Mass Spectrometry (RP-UHPLC-HRMS), on HepG2 human hepatocellular carcinoma cells challenged with the lipopolysaccharide (LPS). In LPS-treated cells (1 µg/ml, 24h), the PE treatment (administered at the non-cytotoxic dose of 1 µg/ml, 24h) induced a significant reduction of three key pro-inflammatory cytokines, i.e. interleukin-8 (IL-8), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α), at both gene expression (as assayed by real-time PCR) and secretion levels (by Enzyme-linked Immunosorbent Assay, ELISA). Although further in vivo studies are needed to prove its efficacy, this preliminary in vitro study suggests that the PE might be useful for ameliorating liver inflammation.
The exposure to man-made extremely low electromagnetic fields (ELF-MFs < 300 Hz) and radiofrequency (RF-EMFs 10 MHz–300 GHz) has grown as the demand for electronic wireless devices increases. This has raised several doubts and concerns about their effect on biological systems, mainly related to the alteration of the redox balance. The higher sensitivity of the nervous system to this kind of radiation has made it the most studied tissue. In this chapter, a complete and in-depth analysis of epidemiological, in vivo, and in vitro studies about this topic is performed. Results highlight an incomplete understanding of the effects of EMFs on biological systems due to the intrinsic difficulty in tracing the actual exposure to which humans are subjected daily in terms of time, intensity, distance from the source, and in the lack of a fully knowledge of the molecular and cellular pathways affected by EMFs.
An ethanolic extract of Corylus avellana L. hazelnut was characterised by liquid chromatography coupled to high resolution mass spectrometry. We here evaluated the in vitro cytotoxic response to such extract in HepG2 cells and tried to depict the underlying mechanism(s) in terms of microRNA-34b/c involvement. Following long-term exposure (144h) of HepG2 cells with 0.04-0.4 mg/ml of hazelnut extract, we demonstrated that miR-34 precursor RNA and both mature miR-34b and miR-34c molecules underwent a significant stimulation (>2-fold change, p < 0.05) in cells treated with the highest concentration. The epigenetic modulation was accompanied by the inhibition of cell proliferation, the decrease of viability and activation of apoptosis at 144h of treatment with 0.4 mg/ml of hazelnut.These in vitro findings demonstrate the cytotoxic effect of the C. avellana extract in HepG2 cells and open the way to in vivo validation of possible application of hazelnut-based extracts, and/or its metabolites, as promising epigenetics drugs.
The occurrence of long-lasting adverse effects of the environmental contaminants on human health is a current emerging issue. In particular, phthalates, poly- and perfluoroalkyl substances are proposed to trigger toxic effects as well as persistent changes on human development and metabolism by different mechanisms, including epigenetic modifications, although the specific underlying pathways are still unknown. This study contributes to identify the potential molecular initiating events of epigenetic-mediated adverse effects by an in silico approach, which combines molecular docking and molecular dynamics simulation. The approach probes the potential molecular interaction between several different phthalates and persistent organic pollutants and a specific class of epigenetic modulators, namely the DNA methyltransferases (DNMTs). The dynamics of interaction and the binding free energies of the ligand-DNMTs complexes demonstrated that pollutants can be classified into two main groups, according to the ligand-target complex stability: (1) a larger class of phthalates (DBP, DEHP, MBP and MEHP) acting as inhibitors of the enzymatic activity of the epigenetic targets and (2) a smaller class of phthalates (DMP and MMP) and perfluoroalkyl substances (PFOA and PFOS) which do not interact stably with the human DNMTs. These findings provide the first valuable in silico insights on the ability of these specific environmental pollutants to directly bind and inhibit a key class of epigenetic regulators. Communicated by Ramaswamy H. Sarma.
BACKGROUND:The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency electromagnetic field (RF-EMF) exposure and adverse health effects. Within the project, 6 topics have been prioritized by an expert group, which include reproductive health outcomes. OBJECTIVES:According to the protocol published in 2021, a systematic review and meta-analyses on the adverse effects of RF-EMF exposure during pregnancy in offspring of experimental animals were conducted. METHODS:Three electronic databases (PubMed, Scopus and EMF Portal) were last searched on September 8 or 17, 2022. Based on predefined selection criteria, the obtained references were screened by two independent reviewers. Studies were included if they met the following criteria: 1) original, sham controlled experimental study on non-human mammals exposed in utero, published in peer-reviewed journals, 2) the experimental RF-EMF exposure was within the frequency range 100 kHz-300 GHz, 3) the effects of RF-EMF exposure on fecundity (litter size, embryonic/fetal losses), on the offspring health at birth (decrease of weight or length, congenital malformations, changes of sex ratio) or on delayed effects (neurocognitive alterations, female infertility or early-onset cancer) were studied. Study characteristics and outcome data were extracted by two reviewers. Risk of bias (RoB) was assessed using the Office of Health Assessment and Translation (OHAT) guidelines. Study results were pooled in a random effects meta-analysis comparing average exposure to no-exposure and in a dose-response meta-analysis using all exposure doses, after exclusion of studies that were rated at "high concern" for RoB. Subgroup analyses were conducted for species, Specific Absorption Rate (SAR) and temperature increase. The certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. RESULTS:Eighty-eight papers could be included in this review. Effects on fecundity. The meta-analysis of studies on litter size, conducted at a whole-body average SAR of 4.92 W/kg, did not show an effect of RF-EMF exposure (MD 0.05; 95% CI -0.21 to 0.30). The meta-analysis of studies on resorbed and dead fetuses, conducted at a whole-body average SAR of 20.26 W/kg, showed a significant increase of the incidence in RF-EMF exposed animals (OR 1.84; 95% CI 1.27 to 2.66). The results were similar in the dose-response analysis. Effects on the offspring health at birth. The meta-analysis of studies on fetal weight, conducted at a whole-body average SAR of 9.83 W/kg, showed a small decrease in RF-EMF exposed animals (SMD 0.31; 95% CI 0.15 to 0.48). The meta-analysis of studies on fetal length, conducted at a whole-body average SAR of 4.55 W/kg, showed a moderate decrease in length at birth (SMD 0.45; 95% CI 0.07 to 0.83). The meta-analysis of studies on the percentage of fetuses with malformations, conducted at a whole-body average SAR of 6.75 W/kg, showed a moderate increase in RF-EMF exposed animals (SMD -0.45; 95% CI -0.68 to -0.23). The meta-analysis of studies on the incidence of litters with malformed fetuses, conducted at a whole-body average SAR of 16.63 W/kg, showed a statistically significant detrimental RF-EMF effect (OR 3.22; 95% CI 1.9 to 5.46). The results were similar in the dose-response analyses. Delayed effects on the offspring health. RF-EMF exposure was not associated with detrimental effects on brain weight (SMD 0.10; 95% CI -0.09 to 0.29) and on learning and memory functions (SMD -0.54; 95% CI -1.24 to 0.17). RF-EMF exposure was associated with a large detrimental effect on motor activity functions (SMD 0.79; 95% CI 0.21 to 1.38) and a moderate detrimental effect on motor and sensory functions (SMD -0.66; 95% CI -1.18 to -0.14). RF-EMF exposure was not associated with a decrease of the size of litters conceived by F2 female offspring (SMD 0.08; 95% CI -0.39 to 0.55). Notably, meta-analyses of neurobehavioural effects were based on few studies, which suffered of lack of independent replication deriving from only few laboratories. DISCUSSION:There was high certainty in the evidence for a lack of association of RF-EMF exposure with litter size. We attributed a moderate certainty to the evidence of a small detrimental effect on fetal weight. We also attributed a moderate certainty to the evidence of a lack of delayed effects on the offspring brain weight. For most of the other endpoints assessed by the meta-analyses, detrimental RF-EMF effects were shown, however the evidence was attributed a low or very low certainty. The body of evidence had limitations that did not allow an assessment of whether RF-EMF may affect pregnancy outcomes at exposure levels below those eliciting a well-known adverse heating impact. In conclusion, in utero RF-EMF exposure does not have a detrimental effect on fecundity and likely affects offspring health at birth, based on the meta-analysis of studies in experimental mammals on litter size and fetal weight, respectively. Regarding possible delayed effects of in utero exposure, RF-EMF probably does not affect offspring brain weight and may not decrease female offspring fertility; on the other hand, RF-EMF may have a detrimental impact on neurobehavioural functions, varying in magnitude for different endpoints, but these last findings are very uncertain. Further research is needed on the effects at birth and delayed effects with sample sizes adequate for detecting a small effect. Future studies should use standardized endpoints for testing prenatal developmental toxicity and developmental neurotoxicity (OECD TG 414 and 426), improve the description of the exposure system design and exposure conditions, conduct appropriate dosimetry characterization, blind endpoint analysis and include several exposure levels to better enable the assessment of a dose-response relationship. PROTOCOL REGISTRATION AND PUBLICATION:The protocol was published in Pacchierotti et al., 2021 and registered in PROSPERO CRD42021227746 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=227746).
Supplementary Table 1 from The Isopeptidase USP2a Protects Human Prostate Cancer from Apoptosis
Supplementary Table 2 from The Isopeptidase USP2a Protects Human Prostate Cancer from Apoptosis
In this work, an improved simulation model was proposed to assess the transmembrane potential (TMP) evolution on the cellular membrane exposed to time-varying magnetic fields (TMFs). Comparatively, we extended the research on TMP induced by TMF to the electroporation phenomenon by introducing the Smoluchowski function, thereby predicting the occurrence of electroporation. The simulation results based on our numerical model showed that with exposure to the sub-microsecond trapezoidal pulsed magnetic field (PMF), the pore density did not reach the conventional electroporation criterion (1014 m−2) even if the TMP exceeded the electroporation threshold (1 V); however, with the same energy import, it was easier for the nanosecond pulse to electroporate the membrane evidenced by higher pore density. Further, the capability of predicting the occurrence of electroporation was verified by extending our simulation model to compare experimental results. The comparative analysis showed that our simulation model has predictive and guiding significance for experimental studies and practical applications.
With the aim of characterising the hypo-lipidemic function of the Brumex (TM) ingredient obtained from the whole fruit of Citrus bergamia, a combined pre-clinical and clinical study was conducted. In the HepG2 experimental model, we first demonstrated that Brumex (TM) does not trigger any significant alteration in cell viability over the tested concentration range of 1-2000 mu g/mL (4 and 24 h). By stimulating the phosphorylation of AMP-activated protein kinase (AMPK) at threonine 172, Brumex (TM) significantly reduces both cholesterol and triglyceride (TG) intracellular content of HepG2 cells and impairs the expression levels of lipid synthesis-related genes (namely, SREBF1c, SREBF2, ACACA, SCD1, HMGCR and FASN). In vitro data have been validated in a dedicated double-blind, placebo-controlled, randomised clinical trial performed in 50 healthy moderately hyper-cholesterolemic subjects, undergoing supplementation with either Brumex (TM) (400 mg) or placebo for 12 weeks. Clinical and blood laboratory data were evaluated at the baseline and at the end of the trial. Brumex (TM) positively impacted on both plasma lipid pattern and liver enzymes compared with the placebo, mainly in terms of significant reduction of total cholesterol (TC), TG, low-density lipoprotein-cholesterol (LDL-C), non-high-density lipoprotein-cholesterol (non-HDL-C), apolipoprotein B100 (ApoB), fasting plasma glucose (FPG), glutamic-oxaloacetic transaminase (GOT), glutamate pyruvate transaminase (GPT) and gamma-glutamyl-transferase (gGT).