CONICET | Buscador de Institutos y Recursos Humanos

Treacher Collins Syndrome (TCS) is a hereditary mandibulofacial dysostosis with variable expressivity caused primarily by mutations in the TCOF1 gene. Previously, we have described increased reactive oxygen species (ROS) levels together with an association between the expression of CNBP, a central protein of cranial development sensitive to ROS, and the severity of the TCS in a zebrafish model of the disease. CNBP phosphorylation by AMP-activated protein kinase (AMPK) prevents its proteasomemediated degradation. Metformin, an anti-diabetic biguanide, is an activator of AMPK and a modulator of ROS. Our working hypothesis is that Metformin prevents TCS severe manifestations due to its effects on cell metabolism. Here our aim was to evaluate the effects of Metformin on embryonic cranial development in the zebrafish TCS model and explore its mechanism of action. TCS model was generated by specific Morpholino injection of zebrafish embryos. Negative controls were injected with the standard universal Morpholino. Incubations with varying concentrations of Metformin diluted in embryo medium were carried out from 6 to 24 hours post-fertilization. Embryo craniofacial cartilage morphology was analyzed by Alcian Blue staining of larvae. 1 mM Metformin induced statistically significant morphological improvements of the craniofacial cartilages of TCS-like larvae. Analysis of embryo ROS levels (using DCFH-DA) and neuro-epithelial cell death (by Acridine Orange staining) showed normalization in TCS-like embryos treated with 1 mM Metformin. Expression of redox-response genes (sod2, cat, nfe2l2α) analyzed by qPCR agreed with these results. Also, CNBP protein levels responded to Metformin treatment. These results suggest that Metformin was able to prevent TCS manifestations in the zebrafish model.