Banca de QUALIFICAÇÃO: ERIVALDO DAVI DOS SANTOS JUNIOR

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ERIVALDO DAVI DOS SANTOS JUNIOR
DATE: 27/09/2021
TIME: 09:00
LOCAL: Sala virtual do Google Meet
TITLE:

Layered double hydroxide-based nanosystem for inhibition of microRNAs:
characterization of toxicity and inhibition efficiency.

KEY WORDS:

Keywords: Layered Double Hydroxide; microRNAs; Functional Assay;
Epilepsy.

PAGES: 50
BIG AREA: Ciências Biológicas
AREA: Genética
SUBÁREA: Genética Animal
SUMMARY:

Temporal Lobe Epilepsy (TLE) is the most common epilepsy and 30% of patients do
not present complete remission of seizures, even with the use of antiepileptic drugs
(AEDs). Thus, there is a need to seek new therapeutic approaches, such as
functional modulation of microRNAs (miRs) by pharmacological approach (MIMIC /
miRs inhibitors). Layered Double Hydroxide (LDH) based nanoparticles have been
used as siRNA carriers, however, the application of LDH for the delivery of miRs
inhibitors still requires investigation. In this work, we produced and tested a
nanocarrier based on Mg-Al-LDH complexed with miRs inhibitor against miR-196b-
5p. LDHs were synthesized by coprecipitation method and subjected to
physicochemical characterization regarding hydrodynamic size, surface charge,
crystallinity and the chemical groups present. Regarding the biological effects,
thymus endothelial cells (tEnd.1) were transfected with LDH/inhibitor and were
evaluated for: i. cell viability by MTT, trypan blue and propidium iodide assays; ii.
transfection efficiency by flow cytometry and iii. depletion of miR-196b-5p by RT-
qPCR. In addition, Drosophila melanogaster larvae were fed LDH and were
evaluated for: i. impairment of larval motility; ii. pupation rate; iii. delay to
pupation; iv. lethality, and V. number of adult hatches. Finally, LNA inhibitors were
used for miR-196b-5p inhibition assay in an experimental TLE model, where the
relative expression of miR-196b-5p and its predicted target SLC9A6 was evaluated
by RT-qPCR. We observed that LDH-type nanoparticles are stable in aqueous
solutions and exhibit a regular hexagonal shape. The LDH/inhibitor complex showed
a transfection efficiency of 93% and led to significant depletion of miR-196b-5p 48h
after transfection. We observed no cytotoxic effects in tEnd.1 cells at
concentrations up to 50 μg/ml, as well as in Drosophilas exposed up to 500 μg of
LDH. In vivo functional assay in rats induced Status Epilepticus revealed a significant
depletion of hippocampal levels of miR196b-5p as well as a significant increase in
the relative expression of the target gene SLC9A6. In conclusion, our data suggest
that LDH presents itself as a biocompatible and efficient carrier for miRNA inhibitors
and can be used as a viable and effective tool in functional miRNA inhibition assays.

BANKING MEMBERS:
Presidente - 2579081 - DANIEL LEITE GOES GITAI
Interna - 2022362 - ANA CATARINA REZENDE LEITE
Externa ao Programa - 2024367 - MELISSA FONTES LANDELL