PROTEASOME INHIBITORS IMPROVE TREACHER COLLINS SYNDROME (TCS) IN A ZEBRAFISH ( Danio re- rio ) MODEL.

COUX, GABRIELA; LORENZATTI, AGUSTIN; GIL ROSAS, MAUCO S; CALCATERRA, NORA B

Buenos Aires

Congreso; REUNIÓN CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

Sociedades Biociencias

TCS is a congenital disease characterized by defects in the craniofacialskeleton and absence of mental alterations. We modeled TCS in D. rerio embryos through themicroinjection of Morpholino oligonucleotides blocking the translation of theortholog of the causative gene (TCOF1).Cnbp, a protein required for proper craniofacial development, was detected inlower levels (without changes in its mRNA expression) in TCS-like embryos. As Cnbpdegradation is carried out through the proteasomal pathway, we tested if proteasomeinhibitors (MG132 and Bortezomib) were able to ameliorate cranial skeletonmalformations in TCS. Two-cell embryos were injected with control Morpholino (C) or tcof1 translation blocking Morpholino(TC). At 6 hours post fertilization (hpf) embryos were exposed to MG132 (5 µM),Bortezomib (0.5 µM) or vehicle for 18 hours. Cnbp protein level was measured bywestern-blot in total extracts from 24 hpf specimens. Cranial cartilages measurementswere performed in 4 days post-fertilization larvae stained with Alcian Blue by usingthe ImageJ software. Embryo viability was not affected by any treatment. Controlinjected embryos did not show any effect on cranial cartilages induced by MG132,Bortezomib or vehicle and were pooled together as control group (C). Inarbitrary units, Meckel length: C:100.0 ±0.7, TC: 89.3±3.1*, TC+Bort:98.7266±2.0, TC+MG132: 91.5795±2.8, Ceratohyal angle: C: 99.4±1.3, TC:157.3±14.9*, TC+Bort: 103.0±4.6, TC+MG132: 124.3±10.7, p<0.05 vs. C, ANOVA. Allthe craniofacial parameters measured behaved similarly. The results suggestthat both drugs (especially Bortezomib) partially rescued the phenotype. Cnbpprotein recovered under both treatments although not to control levels.  Data suggest that proteasome inhibitors improve TCS in the zebrafishmodel, likely by preventing Cnbp protein proteasome degradation. This findingmay have potential therapeutic implications for TCS management.