INVESTIGADORES
LASCANO Cecilia Ines
congresos y reuniones científicas
Título:
DIFFERENTIAL ORGANOPHOSPHATE-DERIVED GENE REGULATION ON POLYAMINE AND OXIDATIVE STRESS PATHWAYS AT TRANSCRIPTOME LEVEL
Autor/es:
PIRES, NATALIA SUSANA; CESCHIN, DANILO GUILLERMO; VENTURINO, ANDRÉS; LASCANO, CECILIA INÉS
Lugar:
Buenos Aires
Reunión:
Congreso; Reunión Conjunta SAIB/SAMIGE 2020; 2020
Resumen:
The pesticides azinphos-methyl (AZM) and chlorpyrifos (CPF) have been massively used over the last decade in the fruit-producing region of Alto Valle of Rio Negro and Neuquén. Their residues have been detected in both soil and water of this region. Previous studies performed have demonstrated the impact of organophosphorus pesticides on development, target enzymes, antioxidant defense system, oxidative stress and polyamine metabolism in the native organism, the common toad, Rhinella arenarum. The main objective of this work was to analyze the expression of genes involved in the aforementioned processes as well as their regulation by transcription factors, using data mining on our transcriptome database (http://rhinella.uncoma.edu.ar) obtained from RNA-Seq gene expression analysis from 10-d tadpoles exposed up to 24h to 0.1 mg L-1 CPF and 0.5 mg L-1 AZM. We first determined adequate housekeeping genes from possible candidates, establishing that Tubulin A1, B1, B2 and B4B; actin B; glyceraldehyde-3P-dehydrogenase; Ribosomal protein-L8; Elongation factors 1-alfa and its somatic version, 1-beta, 1-gamma A and 1-delta to be used for gene expression normalization. Transcripts of the target enzyme acetylcholinesterase and c-FOS as its upregulating transcription factor were increased in exposed larvae to both pesticides, but carboxylesterase 5A transcript was early decreased at 6h. Antioxidant response transcripts were also decreased for superoxide dismutases C (Cu-Zn, 24h) and E (extracellular, 6h), while were induced for glutathione peroxidases 1 (at 6h by CPF) and 3 (24h for both pesticides); transcription factor Nrf2 transcript was decreased by CPF (6h) and AZM (24h), affecting the antioxidant response. Proenzyme for polyamine key regulator S-adenosylmethionine decarboxylase, AMD1, increased up to 3X in larvae exposed to both insecticides, which could be attributed to the need of increasing higher polyamines levels to activate apoptosis and eliminate ROS-damaged cells. Polyamine oxidative metabolism was differentially regulated by pesticides, both decreasing spermidine/spermine N1-acetyltransferases 1 and 2 (SSAT), while AZM increased acetylpolyamine oxidase (PAOX) and slightly spermine oxidase (SMOX) expression. Taken together, the increase in AMD1 and decrease in SSAT tend to increase higher polyamines, counteracted by higher levels of the oxidases in AZM-exposed larvae which is in line with previously reported spermine and spermidine decreases, but not in CPF exposed-larvae. In turn, diamine oxidase shows downregulation in transcript levels by both pesticides, that added to the aforementioned effects for AZM lead to the reported increase in putrescine.