Is chemical exposure present in informal work associated with Sars-CoV-2 infection?

OBJECTIVE

To compare the incidence of covid-19 symptoms between informal home-based workers and a control group and to assess the association of these cases with blood elements concentrations and other relevant risk factors for Sars-Cov-2 infection.

METHODS

Welders chemically exposed to potentially toxic elements (PTEs) (n = 26) and control participants (n = 25) answered questionnaires on adherence to social distancing and signs and symptoms of the disease for five months during the covid-19 pandemic. After follow-up, covid-19 serology tests were performed on a subsample of 12 chemically exposed workers and 20 control participants. Before the pandemic, PTE concentrations in blood (As, Mn, Ni, Cd, Hg, Sb, Sn, Cu, Zn, and Pb) were measured by ICP-MS.

RESULTS

The chemically exposed group had higher lead and cadmium levels in blood (p < 0.01). The control group presented lower adherence to social distancing (p = 0.016). Although not significant, welders had a 74% greater chance of having at least one covid-19 symptom compared with control participants, but their adherence to social distancing decreased this chance by 20%. The use of taxis for transportation was a risk factor significantly associated with covid-19 symptoms.

CONCLUSION

The lower adherence to social distancing among the control group greatly influences the development of covid-19. The literature lacks data linking exposure to PTEs and Sars-Cov-2 infection and/or severity. In this study, despite chemical exposure, working from home may have protected welders against covid-19, considering that they maintained greater social distancing than control participants.

Dysregulation of glycerophospholipid metabolism during Behçet's disease contributes to a pro-inflammatory phenotype of circulating monocytes

Behçet's disease (BD) is a relapsing, multisystem and inflammatory condition characterized by systemic vasculitis of small and large vessels. Although the etiopathogenesis of BD remains unknown, immune-mediated mechanisms play a major role in the development of the disease. BD patients present leukocyte infiltration in the mucocutaneous lesions as well as neutrophil hyperactivation. In contrast to neutrophils, whose involvement in the pathogenesis of BD has been extensively studied, the biology of monocytes during BD is less well known. In this study, we analyzed the phenotype and function of circulating monocytes of 38 BD patients from Hospital of Braga. In addition, we evaluated the impact of inflammatory and metabolomic plasma environment on monocyte biology. We observed a worsening of mitochondrial function, with lower mitochondrial mass and increased ROS production, on circulating monocytes of BD patients. Incubation of monocytes from healthy donors with the plasma of BD patients mimicked the observed phenotype, strongly suggesting the involvement of serum mediators. BD patients, regardless of their symptoms, had higher serum pro-inflammatory TNF-α and IP-10 levels and IL-1β/IL-1RA ratio. Untargeted metabolomic analysis identified a dysregulation of glycerophospholipid metabolism on BD patients, where a significant reduction of phospholipids was observed concomitantly with an increase of lysophospholipids and fatty acids. These observations converged to an enhanced phospholipase A2 (PLA2) activation. Indeed, inhibition of PLA2 with dexamethasone or the downstream cyclooxygenase (COX) enzyme with ibuprofen was able to significantly revert the mitochondrial dysfunction observed on monocytes of BD patients. Our results show that the plasma inflammatory environment coupled with a dysregulation of glycerophospholipid metabolism in BD patients contribute to a dysfunction of circulating monocytes.

Targeted analysis reveals alteration in pathway in 5p minus individuals

Cri du Chat or 5p minus (5p-) syndrome is characterized by a deletion located on the chromosome 5 short (-p) arm and has an incidence rate of 1 in 50,000 individuals worldwide. This disease manifests in disturbances across a range of systems biochemicals. Therefore, a targeted metabolomics analysis was evaluated in patients with 5p- syndrome to help unravel the biochemical changes that occur in this disease. Urine samples were collected from people of both sexes aged 1-38 years old and analyzed by ultra-performance liquid chromatography coupled to mass spectrometry. Student' statistical test, metabolomic pathway analysis and metabolite set enrichment analysis were applied to the data. Alterations of some amino acids and amine biogenics levels were found in Cri du Chat Syndrome individuals. The alteration of most of these metabolites is associated with energy recuperation and glycolysis. In general, we found the catabolism of some metabolic pathways to be affected in 5p- patients.

High blood lead levels are associated with lead concentrations in households and day care centers attended by Brazilian preschool children

BACKGROUND

A previous study observed high blood lead levels (BLL) in preschool children attending 50 day care centers (DCC) in São Paulo, Brazil.

OBJECTIVE

To identify whether lead levels found in both homes and DCC environments are associated with high blood lead levels.

METHODS

Children attending 4 DCCs, quoted here as NR, VA, PS and PF, were divided into two groups according to BLL: high exposure (HE: ≥13.9 μg/dL; 97.5 percentile of the 2013 year sample) and low exposure (LE: <5 μg/dL). For in situ lead measurements (lead paint mode: mg/cm² and ROHS mode: μg/g) in the children's households and in the DCC environments, a field portable X-ray-fluorescence analyzer was used. Multiple logistic regressions were performed to control for confounding factors. Odds ratios were adjusted for age, sex, day care center's measured lead, and tobacco.

RESULTS

In an NR DCC building, 33.8% of the measurements had lead levels >600 μg/g, whereas such levels were observed in 77.1% of NR playground measurements. In VA DCC, 22% and 23% of the measurements in the building and in the playgrounds had levels higher than 600 μg/g, respectively. The percentage of high lead levels in the children's houses of the LE group was 5.9% (95% CI: 4.3-7.6%) and 13.2 (95% CI: 8.3-18.0%) in the HE group. Moreover, a significant association was found between high BLLs and lead levels found both in households and DCCs (p < 0.001). Most of the high lead measurements were found in tiles and playground equipment.

CONCLUSIONS

Lead exposure estimated from the DCCs, where children spend about 10 h/day, can be as relevant as their household exposure. Therefore, public authorities should render efforts to provide a rigorous surveillance for lead-free painting supplies and for all objects offered to children.

Effects of Diacetyl Flavoring Exposure in Mice Metabolism

Diacetyl is a flavoring that imparts a buttery flavor to foods, but the use or exposure to diacetyl has been related to some diseases. We investigated the effect of oral intake of diacetyl in male and female C57/Bl mice. We performed a target metabolomics assay using ultraperformance liquid chromatography paired with triple quadrupole mass spectrometry (UPLC-MS/MS) for the determination and quantification of plasmatic metabolites. We observed alterations in metabolites present in the urea and tricarboxylic acid (TCA) cycles. Peroxynitrite plasmatic levels were evaluated by a colorimetric method, final activity of superoxide dismutase (SOD) was evaluated by an enzymatic method, and mouse behavior was evaluated. Majority of the assay showed differences between control and treatment groups, as well as between genders. This may indicate the involvement of sex hormones in the regulation of a normal metabolic profile, and the implication of sex differences in metabolite disease response.

Quantification, 2DE analysis and identification of enriched glycosylated proteins from mouse muscles: Difficulties and alternatives

One of the problems with 2DE is that proteins present in low amounts in a sample are usually not detected, since their signals are masked by the predominant proteins. The elimination of these abundant proteins is not a guaranteed solution to achieve the desired results. The main objective of this study was the comparison of common and simple methodologies employed for 2DE analysis followed by MS identification, focusing on a pre-purified sample using a wheat germ agglutinin (WGA) column. Adult male C57Black/Crj6 (C57BL/6) mice were chosen as the model animal in this study; the gastrocnemius muscles were collected and processed for the experiments. The initial fractionation with succinylated WGA was successful for the elimination of the most abundant proteins. Two quantification methods were employed for the purified samples, and bicinchoninic acid (BCA) was proven to be most reliable for the quantification of glycoproteins. The gel staining method, however, was found to be decisive for the detection of specific proteins, since their structures affect the interaction of the dye with the peptide backbone. The Coomassie Blue R-250 dye very weakly stained the gel with the WGA purified sample. When the same gel was stained with silver nitrate, however, MS could positively assign 12 new spots. The structure of the referred proteins was not found to be prone to interaction with Coomassie blue.

L-Arginine Transport and Nitric Oxide Production in Kinin Receptor B1-/- Endothelial Cells

Kinins are important vasoactive peptides, but the role of the B1 receptor subtype in the vascular control is poorly understood. This study analyzed the nitric oxide (NO) release, L-arginine (L-Arg) uptake and the expression of the cationic amino acid transporter (CAT) -1 in endothelial cells obtained from B1 receptor knockout (B1-/-) and wild type (WT) mice. NO production was assessed through a fluorescent dye in living cells stimulated with acetylcholine. L-Arg uptake was determined indirectly in the culture medium by HPLC, in the presence or absence of the CAT-1 blocker N-ethylmaleimide (NEM). CAT-1 mRNA levels and protein expression were determined by qPCR and western blot, respectively. NO release was significantly reduced in B1-/- when compared to WT cells. This result was accompanied by a decreased rate in the L-Arg uptake by B1-/- cells. Incubation with NEM impaired the L-Arg uptake in WT, but had no effect in B1-/- cells. Protein expression and mRNA levels for CAT-1 were reduced in B1-/- in comparison to WT cells. These findings suggest an important role of the endothelial B1 receptor in the vascular control by interfering with CAT-1 expression, L-Arg uptake and NO release.

Abstract 588: Search for potential penile cancer biomarkers using frozen tissue proteome profiling by mass spectrometry

Penile squamous cell carcinoma (SCC) corresponds to 2.1% of Brazilian men's malignant tumors. In the present study, it was our objective to provide information regarding the differential protein pattern in penile SCC and look for potential prognostic markers. Twenty-four frozen samples, fourteen of penile SCC and ten of normal penile epithelium (NPE) were compared, using two-dimensional gel electrophoresis. A total of 268 spots were identified, 23 were identified only in penile SCC, 207 only in normal tissue and 38 proteins were found differentially expressed between the two groups (p&lt;0.05). Additionally, ongoing experiments for protein identification by Matrix-Assisted Laser Desorption/Ionization - Time of Flight - Mass Spectrometry (MALDI-TOF) have already detected two key proteins with critical role in all aspects of RNA metabolism. The heterogeneous nuclear ribonucleoprotein C (C1/C2) (HNRNPC) were found expressed only in penile SCC and the RNA helicase DEAD (Asp-Glu-Ala-Asp) box polypeptide 59 (DDX59) were upregulated on tumor samples, which both are associated to tumor aggressiveness. Our data provide a novel proteomic approach to investigate the protein profile of penile SCC and might represent the basis for further studies on the characterization of these proteins, some of which may be of potential clinical value.

Note: This abstract was not presented at the meeting.

Citation Format: Adriana Bulgarelli, Elisângela de Jesus Silva, Nilson Antonio Assunção, Isabela Werneck Cunha, Stenio de Cássi Zequi, Gustavo Cardoso Guimarães, Fernando Augusto Soares, José Vassallo. Search for potential penile cancer biomarkers using frozen tissue proteome profiling by mass spectrometry. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 588. doi:10.1158/1538-7445.AM2015-588