TREACLE DEPLETION IN Danio rerio INDUCES OXIDATIVE STRESS AND APOPTOSIS

MOUGUELAR, VALERIA S.; PORCEL DE PERALTA, MAURO S.; COUX, GABRIELA; CALCATERRA, NORA B

ROSARIO

Congreso; 50th Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2014

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular

Treacher-Collins Syndrome (TCS) is a disorder of craniofacial development due to mutations in TCOF1, whichencodes the protein Treacle. TCS patients show variable expressivity in phenotype. Treacle deficit seems to increasecranial neural crest cells apoptosis. Recently, it has been informed that Treacle has antioxidant activity inpneumocytes. We developed a TCS-like model injecting in zebrafish embryos morpholinos against the tcof1 ortholog(TcofMO). The aims here were to assess in TCS-like zebrafish embryos: I) the apoptosis occurrence (pattern andgene markers) and, II) the oxidative stress induction. We studied noxa, cyclinG1, trp53inp, and hsp70 expression byRT-qPCR; the levels of reactive oxygen species (ROS) by incubation with DA-DCFH; and apoptosis events byAcridine Orange stain. The expression of apoptotic marker genes was induced in TCS-like embryos (noxa 3.0±0.4,cyclinG1: 3.5±1.0 and, trp53inp1: 1.4±0.1 times vs. control morpholinos (MisMO) embryos). Besides, TCS-likeembryos showed increased hsp70 expression (2.0±0.6 times) and ROS levels (MisMO=46.6±1.2 andTcofMO=69.8±2.5 UA, p<0.001). We also observed a rise on apoptotic cell number, mainly located on cephalic structures. The results show that zebrafish TCS-like embryos have enhanced apoptosis and increased ROSproduction suggesting oxidative stress as a factor involved in TCS variable expressivity.