Banca de QUALIFICAÇÃO: BEATRIZ CINTRA MORENA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : BEATRIZ CINTRA MORENA
DATA : 18/03/2020
HORA: 14:00
LOCAL: sala S24, Térreo, Bloco Delta, Campus SBC da Fundação Universidade Federal do ABC, localizada na Alameda da Universidade, s/n, Bairro Anchieta - São Bernardo do Campo, SP.
TÍTULO:

THE FUNCTIONAL ROLE OF MyD88 ON NEUROINFLAMMATION PROCESS AND LOCOMOTOR RECOVERY AFTER SPINAL CORD INJURY

 

PÁGINAS: 64
GRANDE ÁREA: Ciências Biológicas
ÁREA: Fisiologia
RESUMO:

Spinal cord injury (SCI) is a clinical condition of high importance that can be triggered by a traumatic (mechanical) or non-traumatic insult, leading to the disruption of the communication between the central nervous system and muscles and organs located below the injury site. Traumatic SCI can be divided into two phases: i) the immediate consequences of mechanical trauma and ii) the activation of inflammatory response. Neuroinflammation after SCI is usually mediated by the activation of the Toll-like receptor (TLR) family, which is located mostly in microglia. TLRs are activated by specific pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs), directly triggering MyD88 intracellular signaling pathway. MyD88 is a cytosolic adaptor protein that mediates signal transduction initiated by most TLRs, and culminates on the expression of nuclear factor (NF)-κB, leading to the production of inflammatory mediators that impair tissue regeneration. However, the role of MyD88 pathway on spinal cord recovery after injury is still poorly understood. Considering this, we aim to disclose the functional role of MyD88 on neuroinflammation, tissue regeneration, microglial phenotype and recovery of the motor function after SCI. To this end, we combined immunofluorescence (IF) analyses, western blotting (WB) and cell death assays. Results were compared by two-way repeated measures ANOVA followed by appropriate posthoc test. All procedures were conducted in accordance with CEUA (2169280119). MyD88 protein levels do not change 24h after SCI (sham: 17,860.96 ± 2,013.71; SCI: 16,636.25 ± 3,011.98). IBA1 IF assay showed that MyD88 KO mice have less microglial cells than wild-type (WT) 24h after SCI (WT: 26.43 ± 1.85; MyD88 KO: 15.33 ± 0.77; P<0.001).  In turn, skeleton analysis revealed that MyD88 mice have increased branch length (WT: 2.36 ± 0.49; MyD88 KO: 5.84 ± 0,63; P<0.001) and more end points (WT: 21.89 ± 3.23; MyD88 KO: 44.25 ± 3.10; P<0.01) than WT 24h after SCI, presenting a ramified morphology. Furthermore, IF assay showed that MyD88 KO mice have less CD86 positive cells on white matter than WT mice 24h after SCI (WT: 23.77 ± 3.70; MyD88 KO:14.16 ± 2.20; P<0.05). We were also able to verify that the difference of TUNEL positive cells on wild-type and MyD88 KO 24h after SCI is not statistically significant (WT: 111.03 ± 2.67; MyD88 KO: 89.91 ± 3.86), although a tendency to decrease is present. Finally, we observed that MyD88 KO mice have less GS positive cells (WT: 51.83 ± 7.62; MyD88 KO: 9.25 ± 2.64; P< 0.001) when compared to wild-type mice 24h after SCI, as evidenced by IF assay. All these data suggest that MyD88 can modulate microglia activation and proliferation, as well as the cross talking between microglia and astrocytes, and in the immunological innate response, controlling CD86 expression. Consequently, it is possible that the modulation of the cytotoxic environment will be able to improve motor recovery and tissue regeneration after SCI.

 

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 2353139 - ELOAH RABELLO SUAREZ
Membro Titular - Examinador(a) Externo ao Programa - 1872537 - MARCELA BERMUDEZ ECHEVERRY
Membro Titular - Examinador(a) Externo ao Programa - 3066269 - VINICIUS DE ANDRADE OLIVEIRA
Membro Suplente - Examinador(a) Externo ao Programa - 1994696 - SILVIA HONDA TAKADA