Banca de QUALIFICAÇÃO: GABRIELI BOVI DOS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : GABRIELI BOVI DOS SANTOS
DATE: 12/12/2023
TIME: 13:00
LOCAL: São Bernardo do Campo
TITLE:

ESTABLISHMENT OF A 3D IN VITRO MODEL OF RETINITIS PIGMENTOSA

PAGES: 53
BIG AREA: Ciências Biológicas
AREA: Morfologia
SUBÁREA: Citologia e Biologia Celular
SUMMARY:

The retina can be affected by different types of diseases, with or without origin in genetic changes, which can compromise its morphological structure and the survival of specific cells. Among these diseases, retinitis pigmentosa (RP) is a hereditary disease related to around 100 mutations, especially in genes that encode proteins necessary for phototransduction in rod photoreceptors. RP with mutations in the phosphodiesterase 6 β (PDE6β) gene causes the loss of rods due to the high toxic level of cyclic guanosine monophosphate (cGMP). Mutation in PDE6β alters cellular activity that results in apoptosis, but a new cell death pathway has recently been related to RP, necroptosis. Necroptosis can be considered as a 'programmed necrosis' and, in addition, can influence the transcription of inflammatory genes, with literature on necroptosis in RP being scarce. This work aims to establish a three-dimensional (3D) model of RP in vitro, which can recapitulate the loss of photoreceptors that occurs during the progression of RP. Obtaining this model will help test new molecules and gene manipulations to establish therapeutic strategies for treating RP. As a starting point, we standardized the formation of neurospheres, 3D arrangements composed of retinal progenitor cells. In a second step, we tested protocols for differentiation into rods, an arrangement called photosphere. In parallel, we performed 2D mixed retinal cultures of WT (C57 mouse and LE rat) and PDE6β knockout (RD1 mouse) to standardize experiments with light stimulation. We used LEDs in the cell incubator to stimulate mixed retinal cultures exposed to 200 lux and 12,000 lux for 2 and 5 hours. Cell cultures performed from WT and RD1 animals had no change in cell viability by MTT and PrestoBlue at 200 lux. In cell cultures stimulated with 12,000 lux, we observed a significant decrease in cell viability with PrestoBlue and increased TUNEL labeling. Double-labeling experiments revealed that the TUNEL-positive cells were, in the vast majority, rods. Given that 12,000 lux induced rod cell death in the RD1 model and not in the WT, we will use this light intensity to evaluate the effects on the photosphere. Continuing this work, we will analyze cell death pathways to study and test new therapeutic alternatives for RP.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1227329 - CESAR AUGUSTO JOAO RIBEIRO
Membro Titular - Examinador(a) Interno ao Programa - 1887027 - FERNANDO AUGUSTO DE OLIVEIRA RIBEIRO
Membro Titular - Examinador(a) Externo à Instituição - GUILHERME SHIGUETO VILAR HIGA - USP
Membro Suplente - Examinador(a) Externo à Instituição - JULIANE MIDORI IKEBARA