Hexosamine pathway regulates StarD7 expression in JEG-3 cells

FLORES-MARTÍN, JÉSICA; REYNA, LUCIANA; CRUZ DEL PUERTO, MARIANO; ROJAS, MARÍA L.; PANZETTA-DUTARI, GRACIELA M.; GENTI-RAIMONDI, SUSANA

MOLECULAR BIOLOGY REPORTS

SPRINGER

Año: 2018 vol. 45 p. 2593 - 2593

0301-4851

tarD7 is a lipid binding protein involved in the delivery of phosphatidylcholine to the mitochondria whose promoter is activated by Wnt/β-catenin signaling. Although the majority of glucose enters glycolysis, ~ 2?5% of it can be metabolized via the hexosamine biosynthetic pathway (HBP). Considering that HBP has been implicated in the regulation of β-catenin we explored if changes in glucose levels modulate StarD7 expression by the HBP in trophoblast cells. We found an increase in StarD7 as well as in β-catenin expression following high-glucose (25 mM) treatment in JEG-3 cells; these effects were abolished in the presence of HBP inhibitors. Moreover, since HBP is able to promote unfolded protein response (UPR) the protein levels of GRP78, Ire1α, calnexin, p-eIF2α and total eIF2α as well as XBP1 mRNA was measured. Our results indicate that a diminution in glucose concentration leads to a decrease in StarD7 expression and an increase in the UPR markers: GRP7