Castro K, et al. - The purpose of this study is to research endoplasmic reticulum (ER) stress markers expression in chorionic villi from normotensive control (NTC) pregnant women, stimulated with NTC and pre-eclampsia (PE) pregnant women serum. The increase in the expression of GRP78 in NTC placentas stimulated with PE serum recommends that PE environment conditions are able to activate UPR pathway. This gene expression results demonstrated an increase in GADD34 marker at this time-point. GADD34 is a marker for PERK branch of UPR, and it is responsible for dephosphorylating p-eif2a allowing the restoration of the cellular homeostasis (a late response of UPR).

Methods

• In this study, chorionic villi from NTC were dissected and cultured (n=4) with serum from pregnant patients with PE and NTC for 24h.
• Gene expression of CHOP, GADD34, SDF2 and sXBP1 were investigated utilizing qRT-PCR.
• YWHAZ gene was utilized as endogenous control and chorionic villi cultured with fetal bovine serum was used for normalization.
• GRP78, SDF2 and eIF2a protein expression were analyzed by western blotting and B-actin was utilized as the loading control.
• Bands were densitometricaly quantified by Image J software and cell viability detected by MTT assay.

Results

• They observed expression of GRP78 protein is increased in placentas with PE compared to NTC groups (p=0.008).
• Furthermore, GRP78 protein expression also increased in placentas from NTC group stimulated with PE serum compared with NTC placentas stimulated with NTC serum (p=0.01).
• No major change was observed in eIF2a and SDF2 protein expression.
• Levels of GADD34 mRNA were significantly higher in the NTC placentas stimulated with PE serum (p=0.04).
• No differences was seen in CHOP, sXBP1 and SDF2 mRNA. Cell viability did not change with the serum treatments.