title: Influence of exposure to pesticides on telomere length in tobacco farmers: A biology system approach.
abstract: Various pesticides in the form of mixtures must be used to keep tobacco crops pest-free. Recent studies have shown a link between occupational exposure to pesticides in tobacco crops and increased damage to the DNA, mononuclei, nuclear buds and binucleated cells in buccal cells as well as micronuclei in lymphocytes. Furthermore, pesticides used specifically for tobacco crops shorten telomere length (TL) significantly. However, the molecular mechanism of pesticide action on telomere length is not fully understood. Our study evaluated the interaction between a complex mixture of chemical compounds (tobacco cultivation pesticides plus nicotine) and proteins associated with maintaining TL, as well as the biological processes involved in this exposure by System Biology tools to provide insight regarding the influence of pesticide exposure on TL maintenance in tobacco farmers. Our analysis showed that one cluster was associated with TL proteins that act in bioprocesses such as (i) telomere maintenance via telomere lengthening; (ii) senescence; (iii) age-dependent telomere shortening; (iv) DNA repair (v) cellular response to stress and (vi) regulation of proteasome ubiquitin-dependent protein catabolic process. We also describe how pesticides and nicotine regulate telomere length. In addition, pesticides inhibit the ubiquitin proteasome system (UPS) and consequently increase proteins of the shelterin complex, avoiding the access of telomerase in telomere and, nicotine activates UPS mechanisms and promotes the degradation of human telomerase reverse transcriptase (hTERT), decreasing telomerase activity.
authors: Laboratory of Genetic Toxicology, PPGBioSaúde and PPGGTA, Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil.
authors: Vivian Francília Silva
authors: VFS
authors: Kahl
authors: Laboratory of Genetic Toxicology, PPGBioSaúde and PPGGTA, Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil. Electronic address: juliana.silva@ulbra.br.
authors: Juliana
authors: J
authors: da Silva
authors: Master's Degree in Environmental Impact Evaluation, Centro Universitário La Salle, Canoas, RS, Brazil. Electronic address: fernanda.silva@unilasalle.edu.br.
authors: Fernanda Rabaioli
authors: FR
authors: da Silva
mesh_terms: D001938:Brazil; D004268:DNA-Binding Proteins / Q000378:metabolism*; D000067565:Farmers; D006801:Humans; D009538:Nicotine / Q000633:toxicity*; D016273:Occupational Exposure / Q000009:adverse effects*; D010575:Pesticides / Q000633:toxicity*; D060066:Protein Interaction Maps; D049490:Systems Biology; D016615:Telomere / Q000187:drug effects / Q000378:metabolism; D059506:Telomere Shortening / Q000187:drug effects*; D014026:Nicotiana / Q000009:adverse effects / Q000737:chemistry / Q000254:growth & development
chemical_list: D004268:DNA-Binding Proteins; D010575:Pesticides; D009538:Nicotine
keywords: Nicotine; Pesticide; System biology; Telomere length; Tobacco farmers exposure