Previous results indicated that LPS treatment of human macrophages is associated with the induction of glutamate-ammonia-ligase (GLUL)GLUL, the enzyme that synthesizes glutamine, although the effects on cell Gln level were not assessed by those studies. Here, we show that M1 polarization of human THP-1 macrophage-like cells with LPS and IFNγ induces not only GLUL but also the exchange Gln transporter ASCT2 and the bidirectional carrier SNAT5. Consequently, Gln influx markedly increases, with ASCT2 and SNAT5 inhibitors suppressing the effect. Notwithstanding these changes, cell Gln is comparable in human M0 and M1 macrophages. However, under Gln-free conditions, Gln efflux is three-fold faster in M1 macrophages. With the same approach, we have demonstrated that cell glutamate mostly derives from extracellular Gln. Furthermore, Glu efflux is markedly higher in M1 macrophages, consistent with the induction of the Glu-cystine exchanger xCT. Induction of GLUL, SNAT5 and xCT, along with SNAT5-dependent stimulation of Gln transport, are clearly detectable also in primary human macrophages, derived from monocytes of peripheral blood and M1-polarized with LPS/IFNγ. These data indicate that, through a stimulation of Gln and Glu efflux, M1-polarized human macrophages can increase the concentration of both amino acids in the extracellular microenvironment.

Background Tobacco smoking is a leading cause of morbidity and mortality worldwide, responsible for about 61,300 deaths annually in Italy. In addition to tobacco cigarettes, the use of electronic cigarettes (e-cigs) and heated tobacco products (HTPs) has increased among young people, raising public health concerns. This study aimed to investigate smoking habits, exposure to passive smoke, and awareness of health risks among Italian university students. Methods A multicentre observational survey was carried out by 8 Italian Universities to promote smoke-free lifestyles among students. All students were sent an anonymous online questionnaire via email regarding their smoking habits, their exposure to second-hand smoke, and their knowledge of, and opinions on, smoking. Descriptive statistics and multinomial logistic regression models were applied to assess associations between tobacco and nicotine use with sex and areas of study. Results A total of 20,644 students from different study areas were included in the study: 62.3% did not smoke, 9.9% were former smokers, 14.4% were smokers of tobacco cigarettes exclusively, 6.5% of e-cigs or HTPs, and 6.9% were dual smokers (total smokers 27.8%). Smoking prevalence was highest among Law (35.9%) and Economics (33.7%) students, and lowest among Medicine and Sciences and Technology students (22%). Males were more likely to smoke tobacco or to be dual users, while females reported higher e-cig use; most smokers consumed fewer than 10 cigarettes/day with mild nicotine dependence. Among e-cig/HTP users, over 60% started as an alternative to cigarettes, but 22% started or resumed tobacco smoking after using them and 22% had never smoked tobacco cigarettes before. Passive smoke exposure was common: 26.5% lived with smokers and 58.9% reported peer exposure. While nearly all students recognized the harms of both active and passive tobacco smoking, only 60% considered passive exposure to e-cigs/HTPs as dangerous. About 70% were favourable to stricter enforcement of university smoking bans. Conclusions: Traditional cigarettes remain the most used product among Italian university students, but e-cigs and HTPs are increasingly widespread and socially accepted, even among never smokers. Awareness of the risks of alternative products is limited, and passive exposure remains underestimated. These findings underline the importance of targeted educational campaigns and stronger enforcement of smoke-free policies in academic settings.

Multiple myeloma (MM) is a glutamine (Gln)-auxotroph and Gln-addicted cancer, with Gln synthetase (GS)-deficient MM cells avidly taking up extracellular Gln to sustain their metabolism. Thus, MM cells create a peculiar metabolic niche in the patients' bone marrow (BM), where low levels of Gln contribute to the osteolytic bone lesions by inhibiting the osteoblastic differentiation of mesenchymal stromal cells (MSCs). The effects of the altered MM metabolic niche on other BM cell populations remain to be clarified. We demonstrate here that MM cells secrete high amounts of glutamate through the exchange transporter SLC7A11/xCT. In turn, BM MSCs, but neither MM cells nor osteoblasts (OBs), actively take up extracellular glutamate through the transporter EAAT3 (SLC1A1), whose expression decreases during osteogenesis. GS-positive MSCs secrete Gln, a process boosted by extracellular glutamate in undifferentiated MSCs, but not in differentiated OBs. Coculture of MSCs with MM cells promotes the expression of the bidirectional transporter SNAT5 (SLC38A5), suggesting its involvement in Gln efflux. Consistently, MSCs, derived from either patients with MM or healthy donors, sustain MM growth in a low-Gln environment, an effect suppressed by the inhibition or silencing of glutamate uptake or Gln synthesis. In conclusion, a metabolic cycle occurs in MM BM microenvironment, where Gln-auxotroph MM cells extrude glutamate that is converted into Gln by MSC, sustaining in turn MM anabolism through Gln secretion. The inhibition of this metabolic trade-off impairs MM cell growth, thus highlighting novel potential, niche-oriented therapeutic targets.

Due to their environmental persistence, widespread application, and toxicity to living organisms, contamination by PFAS has become a significant global concern. The ability of industrial hemp (Cannabis sativa L.) to accumulate PFAS in its aerial tissues makes it a candidate for PFAS phytoremediation, as well as a suitable biological model for assessing the toxicological effects of PFAS in higher eukaryotes. After in vitro culturing of industrial hemp for 14 days in the presence of 1mgL-1 PFOA or 1mgL-1 PFOS, no visible damage or macroscopic morphological alterations were evident, and a significant increase in shoot biomass and chlorophyll content following PFOA exposure was observed. Despite the higher accumulation of PFOS compared to PFOA both inhibited antioxidant enzymes activity, specifically catalase and ascorbate peroxidase, respectively. Alkaline Comet Assay showed nuclear damage in hemp leaves following both PFOA and PFOS accumulation, with the former significantly increasing 8-oxo-deoxyguanosine formation. Comparative proteomics analyses showed that PFOA and PFOS disrupt specific biological processes, with the former promoting the synthesis of proteins involved in the chlorophyll biosynthetic pathway. Both PFOA and PFOS altered the abundance of chloroplastic proteins, suggesting that this cellular compartment could be involved in the phytotoxicity mechanisms triggered by PFAAs.

Multiple Myeloma (MM) is a glutamine (Gln)-addicted cancer. Consequently, the MM bone microenvironment (BM) is characterized by lower Gln and higher glutamate (Glu) levels than those in pre-malignant monoclonal gammopathies. Such MM-dependent metabolic perturbation impairs osteoblast differentiation in the bone microenvironment, but its effect on osteoclast (OCL) bone resorption is still unknown. We first show that bone marrow mononuclear cells from MM patients release higher levels of Glu compared to those from patients with monoclonal gammopathy of undetermined significance (MGUS) or smoldering multiple myeloma (SMM). This increased Glu production correlates with elevated bone resorption activity. We then demonstrate that Glu stimulates OCL differentiation via the activation of NF-κB-NFATc1 pathway in low-Glu BM samples from pre-malignant patients but not in high-Glu samples of MM patients. Secondly, the early phase of OCL formation was associated with high Glu intracellular content and induction of the Glu transporter EAAT1. Consistently, the pharmacological inhibition of EAAT1 hinders OCL differentiation by blocking the RANKL-dependent signaling pathway and actin cytoskeleton reorganization. Overall, our data indicate that high Glu levels in MM bone marrow are involved in OCL formation, suggesting that targeting Glu transport may represent a novel approach for the prevention of osteolytic lesions in MM patients.

The use of PGPR is widely accepted as a promising tool for a more sustainable agricultural production and improved plant abiotic stress resistance. This study tested the ability of PVr_9, a novel bacterial strain, homologous to Beijerinckia fluminensis, to increase salt stress tolerance in A. thaliana. In vitro plantlets inoculated with PVr_9 and treated with 150 mM NaCl showed a reduction in primary root growth inhibition compared to uninoculated ones, and a leaf area significantly less affected by salt. Furthermore, salt-stressed PVr_9-inoculated plants had low ROS and 8-oxo-dG, osmolytes, and ABA content along with a modulation in antioxidant enzymatic activities. A significant decrease in Na+ in the leaves and a corresponding increase in the roots were also observed in salt-stressed inoculated plants. SOS1, NHX1 genes involved in plant salt tolerance, were up-regulated in PVr_9-inoculated plants, while different MYB genes involved in salt stress signal response were down regulated in both roots and shoots. Thus, PVr_9 was able to increase salt tolerance in A. thaliana, thereby suggesting a role in ion homeostasis by reducing salt stress rather than inhibiting total Na+ uptake. These results showed a possible molecular mechanism of crosstalk between PVr_9 and plant roots to enhance salt tolerance, and highlighted this bacterium as a promising PGPR for field applications on agronomical crops.

Abstract Introduction Standardized exposure monitoring procedures and suitable biomarkers and biological matrices are needed to evaluate the potential health risk of occupational exposure to graphene-based nanomaterials. Methods We enrolled 5 workers of a graphene start up (mean age 39±13) and 5 controls (mean age 38±12). Harmonized OECD methodology was used to measure workplace and personal worker exposure. We used Buccal Micronucleus Cytome (BMCyt) assay (buccal cells) for local cyto-genotoxic effects and fpg-comet test (lymphocytes) and oxidized DNA bases 8-oxoGua, 8-oxoGuo and 8-oxodGuo measurements (urine) for systemic genotoxic/oxidative effects. Results Particle number concentration during the graphene-based powders handling differs significantly from the background (Wilcoxon test p<0.05). Furthermore morphological analyses on airborne sampled materials showed rare particles attributable in size and shape to the produced graphene-based nanomaterials. BMCyt assay showed in exposed workers nuclear buds (indicative of genic amplification) and slight MN frequency induction and a subject MN positive (exceeding a fixed cut-off value for MN frequency 1.5‰). Fpg-comet assay showed induction of direct and oxidative DNA damage in exposed vs controls. A slight increase of urinary oxidized DNA bases in exposed workers was also found. Discussion The study confirms BMCyt and fpg-comet assays as the most sensitive biomarkers of early, still reparable, genotoxic and oxidative effects that, related to exposure measurements, represent useful non-invasive tools for the biomonitoring of workers involved in graphene production. Conclusions The integrated approach including workplace exposure characterization and biomonitoring of early health effects is useful for risk assessment and could be also used for long-term studies of workers exposed to nanomaterials.

B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) blasts strictly depend on the transport of extra-cellular asparagine (Asn), yielding a rationale for L-asparaginase (ASNase) therapy. However, the carriers used by ALL blasts for Asn transport have not been identified yet. Exploiting RS4;11 cells as BCP-ALL model, we have found that cell Asn is lowered by either silencing or inhibition of the transporters ASCT2 or SNAT5. The inhibitors V-9302 (for ASCT2) and GluγHA (for SNAT5) markedly lower cell proliferation and, when used together, suppress mTOR activity, induce autophagy and cause a severe nutritional stress, leading to a proliferative arrest and a massive cell death in both the ASNase-sensitive RS4;11 cells and the relatively ASNase-insensitive NALM-6 cells. The cytotoxic effect is not prevented by coculturing leukaemic cells with primary mesenchymal stromal cells. Leukaemic blasts of paediatric ALL patients express ASCT2 and SNAT5 at diagnosis and undergo marked cytotoxicity when exposed to the inhibitors. ASCT2 expression is positively correlated with the minimal residual disease at the end of the induction therapy. In conclusion, ASCT2 and SNAT5 are the carriers exploited by ALL cells to transport Asn, and ASCT2 expression is associated with a lower therapeutic response. ASCT2 may thus represent a novel therapeutic target in BCP-ALL.

Household smoking is one of the main sources of environmental tobacco smoke (ETS) exposure for children, a population considered to be at high risk for associated negative health outcomes. Several studies evidenced the occurrence of early effects related to ETS exposure, including the development of the oxidative stress process. The aim of this study was to evaluate the correlation between urinary levels of 8-oxo-7,8-dihydro-2-deoxyguanosine (8oxodGuo), a nucleic acid oxidation biomarker, and socio-demographic features and lifestyle factors in school children (aged 5–11 years). A cross-sectional study was conducted among 154 healthy children, residing in rural zones of central Italy. For each participant, one urine sample was analyzed by the HPLC-MS/MS technique to simultaneously quantify 8oxodGuo and cotinine (a biomarker of ETS exposure), while information on the children was collected using a questionnaire filled out by the parents. Urinary levels of 8oxodGuo was found to be significantly higher in children exposed to ETS compared to those not exposed (5.53 vs. 4.78 μg/L; p = 0.019). This result was confirmed by the significant association observed between urinary levels of cotinine and 8oxodGuo (r = 0.364, p < 0.0001). Additionally, children exposed to ETS with no smoking ban at home showed a further increased difference than those not exposed (6.35 μg/L vs. 4.78 μg/L; p = 0.008). Considering the great number of adverse effects on human health due to exposure to passive smoking, especially if this exposure begins early in life, it is essential to implement health promotion interventions in this area.

Obstructive sleep apnea (OSA) can have long-term cardiovascular and metabolic effects. The identification of OSA-related impairments would provide diagnostic and prognostic value. Heart rate variability (HRV) as a measure of cardiac autonomic regulation is a promising candidate marker of OSA and OSA-related conditions. We took advantage of the Physionet Apnea-ECG database for two purposes. First, we performed time- and frequency-domain analysis of nocturnal HRV on each recording of this database to evaluate the cardiac autonomic regulation in patients with nighttime sleep breathing disorders. Second, we conducted a logistic regression analysis (backward stepwise) to identify the HRV indices able to predict the apnea-hypopnea index (AHI) categories (i.e., "Severe OSA", AHI ≥ 30; "Moderate-Mild OSA", 5 ≥ AHI < 30; and "Normal", AHI < 5). Compared to the "Normal", the "Severe OSA" group showed lower high-frequency power in normalized units (HFnu) and higher low-frequency power in normalized units (LFnu). The standard deviation of normal R-R intervals (SDNN) and the root mean square of successive R-R interval differences (RMSSD) were independently associated with sleep-disordered breathing. Our findings suggest altered cardiac autonomic regulation with a reduced parasympathetic component in OSA patients and suggest a role of nighttime HRV in the characterization and identification of sleep breathing disorders.

Metabolic alterations in cancer are not only functional to ensure malignant cell growth but also shape a pro-tumor behavior of normal cell populations in the tumor microenvironment. Multiple myeloma (MM) is the only human cancer that is both glutamine-addicted and glutamine-auxotroph, a feature that renders MM growth completely dependent upon extracellular glutamine availability. Indeed, plasma cells from most MM patients do not express Glutamine Synthetase (GS), the only enzyme able to synthetize glutamine from glutamate and ammonium, while express high levels of Glutaminase (GLS), which catalyze the first step of glutaminolysis by deamidating glutamine into glutamate and ammonium. As a consequence, the bone marrow (BM) plasma of MM patients has low-glutamine/high glutamate levels compared to patients with smoldering MM (SMM) and Monoclonal Gammopathy of Uncertain Significance (MGUS), as firstly demonstrated by our group. This particular metabolic microenvironment induces GS expression in mesenchymal stromal cells (MSCs) impairing osteoblast (OB) differentiation of MSCs, thus favoring MM bone lesions typical of active MM. The impact of these metabolic alterations on other BM cell populations is much less defined and it has been investigated in this study. For instance, although MM BM displays an oversized adipocyte population, which sustain MM growth by providing free fatty acids, the effects of MM metabolism on MSCs and their adipocyte differentiation remain to be characterized. First we show that 13C 5-Gln isotopomer distribution revealed that almost 50% of total glutamate in human myeloma cell lines (HMLCs) directly derives from glutamine deamidation by GLS. Furthermore, in standard culture conditions, HMLCs secreted glutamate likely through the SLC7A11 transporter, whose activity was higher in HMLCs than in MSCs. On the other hand, HMCLs were not able to take up glutamate from the extracellular space, while human primary MSCs isolated from healthy donors displayed high activity of the sodium-dependent glutamate transporters of the EAAT family. Moreover, glutamate uptake was higher in undifferentiated MSCs than in MSC incubated for 14 days in osteogenic medium (10 -8 M dexamethasone and 50 µg/ml ascorbic acid). Consistently, a public transcriptional profile of MSCs and OBs obtained from bone biopsies of healthy donors (n=7) or MM patients (n=16) revealed that the expression of the inward Glu transporter EAAT3 is higher in MSCs compared to OBs. In glutamine-free conditions, MSCs produced and secreted glutamine, a process boosted by extracellular glutamate in a dose-dependent manner. Glutamine secretion was hindered by either l-methionine sulfoximine (MSO), an irreversible inhibitor of GS, or D-aspartate (D-Asp), a high-affinity inhibitor of EAAT3 that hinders glutamate uptake. In a co-culture system, HMCLs induced the expression of SNAT5 glutamine efflux transporter in MSCs. Consistently, upon glutamine withdrawal, primary undifferentiated MSCs from healthy donors sustained HMCLs growth, while this nutritional support was markedly impaired by either inhibition or silencing of GS and EAAT3, with a substantial decrease in MM cell viability. Lastly, primary human MSCs were incubated under adipogenic conditions (0.5 mM 3-Isobutyl-1-methylxanthine, 5 µM indomethacin, 50 µM dexamethasone and 10 mg/ml human insulin) in the presence or in the absence of glutamine to mimic, respectively, normal or MM BM microenvironment. Glutamine deprivation increased lipogenesis, assessed with Oil Red O staining, as well as the expression of the adipocyte markers PPARG, LEP, and ADIPOQ. These data point to a MM-driven metabolic pro-tumor BM niche in which MSCs feed glutamine-addicted MM cells, and MSC differentiation is skewed from osteogenesis to adipogenesis. Several steps of these deranged pathways are amenable to pharmacological inhibition, pointing to possible novel therapeutic approaches to counteract MM growth and its effects on the BM niche.

Abstract Background Acute coronary syndrome (ACS) is the main cause of mortality worldwide and despite the adherence to guidelines it is still burdened by an unacceptable risk for cardiovascular (CV) events recurrence, highlighting the need to identify other than traditional cardiovascular risk factors (CVrF) implicated in atherosclerotic plaque instability. In this regard, psychosocial stress appears to be a crucial player in the development of CV disease. Nevertheless, stress is not easy to standardize and the mechanisms by which it promotes coronary artery disease (CAD) are poorly understood. Materials and Methods We therefore prospectively enrolled patients with ACS, stable coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI) and subjects presenting traditional CVrF but without established CV disease. Multimodality cortisol assessment, expression of acute and chronic stress, through blood, urine and hair samples collection was ascertained at baseline. A regression analysis was performed to assess the relationships between significant variables at univariate analysis. Results Fifty patients were enrolled in the present study. Cortisol levels in blood and urine were numerically higher in patients with ACS compared to CAD patients and subjects with traditional CVrF only. Hair cortisol levels did not differ between the three groups. The regression analysis showed an inverse correlation (R= -,532, p<0.001 and R=-,615, p<0.001 respectively) between urinary cortisol (UC) and UC/creatinine ratio and left ventricular ejection fraction (LVEF). Conclusion The preliminary results of our study showed that patients with ACS did not have significantly higher levels of hair cortisol compared to stable patients. The finding of an inverse relationship between higher UC, UC/C ratio levels and lower LVEF values support a link between a hyperactivity of the hypothalamic-pituitary-adrenal axis and a worse ACS presentation. These preliminary data will be implemented with serial multimodality assessment of cortisol that allow potential implications in diagnosis and outcome.

During nanomaterial (NM) production, workers could be exposed, particularly by inhalation, to NMs and other chemicals used in the synthesis process, so it is important to have suitable biomarkers to monitor potential toxic effects. Aim of this study was to evaluate the effectiveness of the introduction of exposure mitigation measures on workers unintentionally exposed to graphene co-pollutants during production process monitoring the presumable reduction of workplace NM contamination and of early genotoxic and oxidative effects previously found on these workers. We used Buccal Micronucleus Cytome (BMCyt) assay and Fpg-comet test, resulted the most sensitive biomarkers on our first biomonitoring work, to measure the genotoxic effects. We also detected urinary oxidized nucleic acid bases 8-oxoGua, 8-oxoGuo and 8-oxodGuo to evaluate oxidative damage. The genotoxic and oxidative effects were assessed on the same graphene workers (N = 6) previously studied, comparing the results with those found in the first biomonitoring and with the control group (N = 11). This was achieved 6 months after the installation of a special filter hood (where to perform the phases at higher risk of NM emission) and the improvement of environmental and personal protective equipment. Particle number concentration decreased after the mitigation measures. We observed reduction of Micronucleus (MN) frequency and oxidative DNA damage and increase of 8-oxodGuo excretion compared to the first biomonitoring. These results, although limited by the small subject number, showed the efficacy of adopted exposure mitigation measures and the suitability of used sensitive and noninvasive biomarkers to bio-monitor over time workers involved in graphene production process.

Mechanisms underlying the resistance of acute lymphoblastic leukemia (ALL) blasts to L-asparaginase are still incompletely known. Here we demonstrate that human primary bone marrow mesenchymal stromal cells (MSCs) successfully adapt to L-asparaginase and markedly protect leukemic blasts from the enzyme-dependent cytotoxicity through an amino acid tradeoff. ALL blasts synthesize and secrete glutamine, thus increasing extracellular glutamine availability for stromal cells. In turn, MSCs use glutamine, either synthesized through glutamine synthetase (GS) or imported, to produce asparagine, which is then extruded to sustain asparagine-auxotroph leukemic cells. GS inhibition prevents mesenchymal cells adaptation to t-asparaginase, lowers glutamine secretion by ALL blasts, and markedly hinders the protection exerted by MSCs on leukemic cells. The pro-survival amino acid exchange is hindered by the inhibition or silencing of the asparagine efflux transporter SNAT5, which is induced in mesenchymal cells by ALL blasts. Consistently, primary MSCs from ALL patients express higher levels of SNAT5 (P < .05), secrete more asparagine (P < .05), and protect leukemic blasts (P < .05) better than MSCs isolated from healthy donors. In conclusion, ALL blasts arrange a pro-leukemic amino acid trade-off with bone marrow mesenchymal cells, which depends on GS and SNAT5 and promotes leukemic cell survival during L-asparaginase treatment.

The data that support the findings of this study are available from the corresponding author [S.R.] upon reasonable request.

Background: In recent decades, there has been an increase in male infertility, and in many cases, the etiology remains unclear. Several studies relate male hypo-fertility to xenobiotic exposure, even if no data exist about multiple exposure at the environmental level. Methods: The study involved 86 males with diagnosis of idiopathic male infertility (IMI), and 46 controls with no alteration in sperm characteristics. Seminal plasma (SP) and urine samples were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) to quantify biomarkers of exposure (the main metabolites of benzene, toluene, 1,3-butadiene, 3-monochloropropanediol, styrene, and naphthol) and effect (oxidized products of nucleic acids).Results: Biomarker concentrations were similar in subjects with IMI and controls even if a stronger correlation between biomarkers of exposure and effects were observed in SP. Data show that, both in SP and urine, most metabolites were inter-correlated, indicating a simultaneous co-exposure to the selected substances at the environmental level. Principal component analysis showed in SP the clustering of mercapturic acids indicating a preferential metabolic pathway with Glutathione (GSH) depletion and, consequently, an increase of oxidative stress. This result was also confirmed by multivariable analysis through the development of explanatory models for oxidized products of nucleic acids. Conclusions: This study highlights how oxidative stress on the male reproductive tract can be associated with a different representation of metabolic pathways making the reproductive tract itself a target organ for different environmental pollutants. Our results demonstrate that SP is a suitable matrix to assess the exposure and evaluate the effects of reproductive toxicants in environmental/occupational medicine. The statistical approach proposed in this work represents a model appropriate to study the relationship between multiple exposure and effect, applicable even to a wider variety of chemicals.

New psychoactive substances (NPS) represent an important focus nowadays and are continually produced with minimal structural modifications in order to circumvent the law and increase the difficulty of identifying them. Moreover, since there are a high number of different compounds, it is arduous to develop analytical screening and/or confirmation methods that allow the identification and quantification of these compounds. The aim of this work is to develop and validate a bioanalytical method for detecting new synthetic drugs in biological samples, specifically oral fluid, using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) with minimal sample pretreatment. Oral fluid samples were simply centrifuged and denaturized with different rapid procedures before injection into the LC-MS/MS system. Calibration curves covered a linear concentration range from LOQ to 100 ng/mL. Validation parameters such as linearity, precision, accuracy, selectivity, matrix effect and thermal stability were evaluated and showed satisfactory results, in accordance with US Food & Drug Administration guidelines. The inter-day analytical bias and imprecision at two levels of quality control (QC) were within ±15% for most compounds. This method was able to identify and calculate the concentration of 10 NPS validated in this biological sample, even in the presence of matrix effect.

The study aims to investigate the influence of exposure to low concentrations of benzene on urinary biomarkers of nucleic acid oxidative damage and methylation. Benzene exposure was characterized for 93 coke production workers by measuring both airborne benzene and S-phenylmercapturic acid (SPMA) and unmodified benzene (U-B) in urine samples, collected at the end of the shift (ES) and at the next morning before shift (next BS). In the same urinary samples, biomarkers of nucleic acid oxidative damage and methylation were determined. Urinary concentrations of cotinine and creatinine were also determined to evaluate the smoking effect and to normalize urinary concentrations of analytes, respectively. The biomarkers of benzene internal dose, of oxidative damage (8-hydroxyy-7,8-dihydroguanine, 8-hydroxy-7,8-dihydroguanosine and 8-hydroxy-7,8-2'deoxyguanosine) and some of the biomarkers of nucleic acid methylation (5-Methyl-Cytosine, 1-Methyl-Guanine and 7-Methyl-Guanine) were higher in the ES than the next BS samples. Positive associations between ES 5-Methyl-Cytosine and both SPMA and U-B were found. In conclusion, occupational exposure to low levels of benzene seems to be related to urinary ES 5-Methyl-Cytosine that could be a possible biomarker to evaluate the changes of the nucleic acid methylation status.

Multiple myeloma (MM) cells consume huge amounts of glutamine and, as a consequence, the amino acid concentration is lower-than-normal in the bone marrow (BM) of MM patients. Here we show that MM-dependent glutamine depletion induces glutamine synthetase in stromal cells, as demonstrated in BM biopsies of MM patients, and reproduced in vitro by co-culturing human mesenchymal stromal cells (MSCs) with MM cells. Moreover, glutamine depletion hinders osteoblast differentiation of MSCs, which is also severely blunted by the spent, low-glutamine medium of MM cells, and rescued by glutamine restitution. Glutaminase and the concentrative glutamine transporter SNAT2 are induced during osteoblastogenesis in vivo and in vitro, and both needed for MSCs differentiation, pointing to enhanced the requirement for the amino acid. Osteoblastogenesis also triggers the induction of glutamine-dependent asparagine synthetase (ASNS), and, among non-essential amino acids, asparagine rescues differentiation of glutamine-starved MSCs, by restoring the transcriptional profiles of differentiating MSCs altered by glutamine starvation. Thus, reduced asparagine availability provides a mechanistic link between MM-dependent Gln depletion in BM and impairment of osteoblast differentiation. Inhibition of Gln metabolism in MM cells and supplementation of asparagine to stromal cells may, therefore, constitute novel approaches to prevent osteolytic lesions in MM.