Evaluation of the proteomic profile in saliva of brazilian home-based and informal workers

Abstract

BACKGROUND AND AIM: The Brazilian city of Limeira consolidates a pole of jewelry production with homemade and informal processes of assembly, welding, and electroplating, constituting a scenario of outsourced services. These processes can expose workers to potentially toxic elements (PTE: Hg, Pb, Ni, Cd, Zn, As, Cu, Cr, and Sn), and the productive chain encompasses the related families. This study aimed to evaluate the effects of PTE exposure on protein expression performing a proteomic approach. METHODS: Saliva samples were collected from 26 individuals, Welders Group (n=13) and Control Group (n=13). Blood PTE levels were determined by ICP-MS and saliva samples’ proteins by UPLC coupled to a mass spectrometry (Q-TOF), shotgun runs. Bioinformatics analysis was performed using PEAKS Studio 8.5. RESULTS:Significant differences were found for Sn (p0.000004) and Cu (p0.0005) concentrations between the groups. In total, 979 proteins were identified in both groups and, removed the proteins with fifty percent of missing values, and substituted by mean values, 411 proteins. The data was autoscaled, then performed the multivariate analyses using MetaboAnalyst 4.0. Principal components analyses and partial least square discriminate analysis showed a group separation. By t-student test performed, we found 40 significant proteins (p0.05). Gene ontology analysis showed biological processes more represented for viral transcription, maintenance of cell polarity, nuclear-transcribed mRNA catabolic process, and nonsense-mediated decay. Pearson correlation showed 28 significant proteins correlated with metals (p0.05). ARP2 and 1433G proteins were correlated with Pb and Sn. IF4A1, ARF6, RS10, PLBL1 and RS9 correlated with Sb. The proteins MNDA, CRBG1, RAB5B, SAP, LV39, NUCB1, CAPZB, HV64D, IMB1, ARP3, LV743, SPR1A, HV459, HV461, HVD82, HVD34, DDX3X, CDC42, PDIA6, CAN1, TM11D, ARG1, FLNB correlated with Sn. We found 16 of these proteins with greater expression in the Welders group. CONCLUSIONS:The informal, home and outsourced work performed by welders is influencing their internal exposome. KEYWORDS: Proteomics, toxic elements, informal work.