Analysis of XBP1 contribution to hyperosmolarity-induced lipid synthesis.

CASALI, CECILIA I.; PARRA, LEANDRO; ERJAVEC, LUCIANA C.; FERNÁNDEZ TOME, MARIA DEL CARMEN

Springer Protocols - The unfolded Protein Response: Methods and Protocols

Humana

Lugar: Nueva York; Año: 2022; p. 169 - 187

The unfolded protein response (UPR) is a complex network of intracellular pathways that transmits signals from ER lumen and/or ER bilayer to the nuclear compartment in order to activate gene transcription. UPR is activated by the loss of ER capacities, known as ER stress, and occurs to restore ER properties. In this regard, glycerolipid (GL) synthesis activation contributes to ER membrane homeostasis and IRE1𝛂-XBP1, one UPR pathway, has a main role in lipogenic genes transcription. Herein we describe the strategy and methodology used to evaluate whether IRE1𝛂-XBP1 pathway regulates lipid metabolism in renal epithelial cells subjected to hyperosmolar environment. XBP1s activity was hindered by blocking IRE1𝛂 RNAse activity and by impeding its expression; under these conditions, we determined GL synthesis and lipogenic enzymes expression.