Network prediction of the potential molecular mechanisms in birds of prey exposed to organochlorine pesticides / Red de predicción de potenciales mecanismos moleculares en aves de presa expuestas a pesticidas organoclorados

Abstract In the 1960s, organochlorine compounds were responsible for the decline of birds of prey populations such as Haliaee- tus leucocephalus and Falco peregrinus. Pesticides similar to DDT cause bioaccumulation in birds, affecting their eggshell com- position and compromising their development. Using system biology tools, the goal of this study was to better comprehend how organochlorines act on birds. We performed a literature review, using the STITCH 5.0 platform, searching for the terms DDT and TCDD. The sub-networks were amplified in 100 interactions in STRING 10.5 and joined by the Cytoscape 3.4.0 Merge software, using the experimental animal model Gallus gallus. Clusterization, gene ontology, and centrality were the parameters evaluated in the resulting network. The resulting network had 1,417 interactions and 137 nodes. The clusterization indicated four clusters and the gene ontology pointed to biological processes related to cell signaling and morphological development. The centrality analysis indicated ESR1 and HSP90AB1 as hub/bottleneck proteins involved in the estrogen pathway and calcium transport. Therefore, it is possible that HSP90 proteins have increased expression in birds contaminated with organochlorine pesticides, favoring ESRI-organochlorines interaction and disturbing the calcium availability related to the eggshell formation. The presence or absence of heat shock proteins, such as HSP90, influences several aspects of reproduction in many species. Therefore, the relationship between the HSP90 protein expression and thin-shell syndrome was identified for the first time in this in silico study.

Resumen En los años 60, los organoclorados fueron responsables del declive de aves de rapiña como Haliaeetus leucocephalus y Falco peregrinus. Pesticidas como el DDT, causan biomagnificación en las aves, afectando las cáscaras de los huevos y dañando su desarrollo. El objetivo de este trabajo fue, a través de herramientas de biología de sistemas, comprender cómo los organoclorados actúan en el organismo de las aves. A través de una revisión bibliográfica se incluyeron dos compuestos, DDT y TCDD. Estos fue ron prospectos en la plataforma STITCH 5.0. Las subredes encontradas fueron aumentadas en 100 interacciones en la plataforma STRING 10.5 y unidas por la herramienta Merge del programa Cytoscape 3.4.0, usando el modelo experimental Gallus gallus. En la red resultante se analizaron la clusterización, la ontología génica y la centralidad. La red resultante presentó 137 nudos y 1.417 interacciones. El análisis de clusterización indicó 4 clusters, siendo que el análisis y ontología génica apuntó procesos biológicos ligados a la señalización y al desarrollo morfológico. El estudio de centralidad apuntó a ESR1 y HSP90AB1 como los hubs-bottle- neck proteínas que estaban involucradas en la vía de recepción de estrógeno y en el transporte de calcio. De acuerdo con los resultados podemos inferir que las proteínas HSP90 tienen su expresión aumentada, en aves contaminadas con pesticidas organoclo rados, favoreciendo la interacción entre ESRI y DDT / TCDD. Con ello, la interacción ESRI y la hormona estrógeno se compromete perjudicando el transporte de calcio y consecuentemente la formación de la cáscara del huevo en aves expuestas. La expresión de proteínas de choque térmico ha sido asociada a varios aspectos de la reproducción en muchas especies, sin embargo, una asociación entre HSP90 y el síndrome de la cáscara fina del huevo fue identificada por primera vez en este experimento in silico.

Amido Black 10B a widely used azo dye causes DNA damage in pro- and eukaryotic indicator cells.

Acid Black 10B (AB10B) is widely used for the production of textiles, leather and prints. It is a representative of azo dyes and it is well documented that some of these compounds are mutagenic per se, and that cleavage products (in particular aromatic amines) may cause damage of the genetic material and cancer. Since no toxicological data on AB10B have been published, we evaluated its mutagenic activity in Salmonella/microsome assays and studied its acute toxic and genotoxic properties in a human derived liver cell line (HepG2) which retained the activities of drug metabolizing enzymes. The compound did not cause cytotoxicity (MTT assay), but clear genotoxic effects were detected in pro- and eukaryotic indicator cells. Dose dependent induction of his+ revertants was seen in strain TA98 which detects frameshift mutations without metabolic activation; a more pronounced effect was seen in its derivative YG1024 which overexpresses N-acetyltransferase. Induction of single/double strand breaks by Comet assay was detected with concentrations > 0.125 mg/mL in liver derived cells; as well as increased rates for micronucleus (reflecting structural and numeric chromosomal aberrations) and nuclear buds which are a consequence of gene amplifications were seen with a higher dose (2.0 mg/mL) (p < 0.05; Tukey's test). The mutational pattern which was observed in the bacterial tests indicates that the cleavage product p-nitroaniline may cause the genotoxic effects of the dye. Our findings indicate that exposure of humans and the release of the compound into the environment may lead to adverse effects due to its DNA damaging activity.