Banca de DEFESA: NATALIA KRYZIA DOS SANTOS LIMA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : NATALIA KRYZIA DOS SANTOS LIMA
DATE: 11/09/2023
TIME: 13:00
LOCAL: Sala 3, Departamento de Fisiologia e Farmacologia, Centro de Biociências, UFPE
TITLE:
KEY WORDS:

Acute kidney injury; Ischemia-reperfusion; Lysophosphatidic acid; Oxidative stress; NADPH oxidase.

PAGES: 78
BIG AREA: Ciências Biológicas
AREA: Fisiologia
SUMMARY:

Acute kidney injury (AKI) is a multifactorial syndrome that presents underlying factors that are still not fully understood, such as the role of lysophosphatidic acid (LPA). The renal proximal tubule is very sensitive to AKI, mainly because this environmente is sensitive to oxidative stress. In this study, we investigated the effect of lysophosphatidic acid (LPA) on renal redox status and sodium reabsorption under normal conditions and in the presence of injury, using in vitro and in vivo experimental models. LLC-PK1 cells, a lineage of proximal tubule epithelial cells, was exposed to different doses of LPA, at different times, in addition to previous exposure to the LPA receptor 1/3 inhibitor (LPAR1/3) Ki16425, to the NADPH oxidase inhibitor apocynin and the superoxide dismutase (SOD) mimetic tempol. Another part of the study was performed using 120-day-old male Wistar rats that were submitted to AKI induction through bilateral ischemia-reperfusion (IR) (n=12), followed by reperfusion for 24 hours. Part of these animals (n=6) received a single dose of LPA 1 hour before the IR procedure (5 mg/kg of body weight, intraperitoneally). Another group was submitted to a Sham surgery (n=6). In LLC-PK1 cells, LPA showed a concentration-dependent and time-dependent effect in decreasing cell viability under basal conditions and in the presence of injury induced by hypoxia-reoxygenation. LPA also induced, in a concentration-dependent manner, an increase in the production of reactive oxygen species (ROS). The effects of LPA on LLC-PK1 cells were inhibited by the LPAR1/3 inhibitor, the NADPH oxidase inhibitor and the SOD mimetic. In rats, the presence of LPA intensified the IR-induced kidney injury, as observed by the amplification of: i) the twice increase in serum levels of creatinine and urea (P<0.001); ii) inhibition of (Na++K+)ATPase (P<0.05); iii) NADPH oxidase activation (P<0.05); and iv) catalase inhibition (P<0.05). These data indicate that LPA represents a cellular signaling pathway associated with renal dysfunction, and therefore is a potential therapeutic target in acute kidney injury.

COMMITTEE MEMBERS:
Presidente - 2069591 - LEUCIO DUARTE VIEIRA FILHO
Interna - 1132498 - BELMIRA LARA DA SILVEIRA ANDRADE DA COSTA
Interna - 3245891 - NATALIA TABOSA MACHADO CALZERRA
Externa ao Programa - 1899454 - DAYANE APARECIDA GOMES - UFPEExterna ao Programa - 1912221 - FERNANDA DAS CHAGAS ANGELO MENDES TENORIO - UFPE