Banca de DEFESA: INGRID SANTANA DE SOUZA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : INGRID SANTANA DE SOUZA
DATE: 31/10/2022
TIME: 13:00
LOCAL: Auditório Aluízio Prata
TITLE:

Characterization of intracellular traffic in induced pluripotent stem cells derived of autistic syndrome disorder patient and missense mutation in VPS13B gene.

KEY WORDS:

Neurodevelopment, hiPSC, ASD, intracellular traffic, vesicles, endosomes, autophagy, recycling, Rab, Golgi complex, VPS13B

PAGES: 66
BIG AREA: Ciências Biológicas
AREA: Morfologia
SUMMARY:

INTRODUCTION: Autism spectrum disorder (ASD) is related to behavioral patterns, stereotypes, cognitive and social deficits. Endosomal and autophagic traffic ensure the dynamic flow of cytoplasmic loads and both pathways act in a complementary way, but through different mechanisms, preventing accumulation of damaged proteins and organelles. The Golgi complex is an intersection between several converging intracellular pathways where Rab proteins identify and direct the compartments along intracellular traffic. The VPS13B protein is associated with the membrane of the Golgi Complex in an interdependent manner in terms of functions and structure. The VPS13B protein transports phospholipids directly between endosomes, favoring the interaction between endosomal compartments and the Golgi apparatus in retrograde flow. The mutation in VPS13B brings connections between neurodevelopmental disorders such as Cohen Syndrome and ASD with comorbidities such as microcephaly and intellectual disability. Therefore, induced pluripotent stem cells (hiPSC) from a donor patient can provide functional interpretations of the VPS13B gene and its relationship with ASD, favoring the development of alternatives that provide quality of life for affected individuals without specific therapeutic perspectives. GOALS: To investigate the intracellular traffic of vesicles in hiPSCs derived from an autistic patient with a missense mutation in the VPS13B gene. MATERIAL AND METHODS: hiPSCs were obtained from a healthy neurotypical donor (EA1) and from an ASD patient (IM5). Two missense variants of the VPS13B gene were identified in the whole exome of the donor patient with ASD, N2968S being confirmed by Sanger sequencing. To analyze the compartments, immunofluorescence, lentiviral transfection, plasmid nucleofection and transmission electron microscopy (TEM) techniques were used. RESULTS: IM5 hiPSCs showed endocytic alterations, such as increased endosomal (RAB5 and RAB7), lysosomal degradative (LAMP1) and autophagic (LC3) activity with a reduction in the recycling system (RAB11B). The IM5 lineage also showed ultrastructural alterations, revealing loss of the normal morphology of the Golgi Complex and an increase in the presence of autophagic vacuoles. CONCLUSIONS: Our results suggest that the VPS13B gene is relevant for intracellular transport in hiPSCs so that the partial loss damaged the structure of the Golgi complex, reduced the Rab11b-mediated recycling system, stimulating lysosomal degradation and autophagic activity.

COMMITTEE MEMBERS:
Presidente - ***.601.955-** - BRUNO SOLANO DE FREITAS SOUZA - UFBA
Interna - ***.762.515-** - JULIANA PERRONE BEZERRA DE MENEZES FULLAM - UFBA
Interna - ***.269.055-** - PATRICIA SAMPAIO TAVARES VERAS - Fiocruz - RJ