# G protein-coupled receptor 1 participating in the mechanism of mediating gestational diabetes mellitus by phosphorylating the AKT pathway

## TL;DR

This study explores how GPR1 affects gestational diabetes by influencing the AKT pathway in pregnant rats, suggesting GPR1 could be a new treatment target.

## Contribution

The study identifies GPR1 as a potential novel therapeutic target for gestational diabetes mellitus through its role in AKT pathway phosphorylation.

## Key findings

- GPR1, AKT, and ERK expression and phosphorylation were significantly lower in GDM group placental tissue compared to controls.
- GPR1 antagonist treatment increased blood glucose and insulin resistance but improved offspring outcomes in GDM rats.
- Enhanced GPR1 expression may activate AKT phosphorylation, offering a new approach for managing gestational diabetes.

## Abstract

Gestational diabetes mellitus (GDM) is a metabolic disease that occurs during pregnancy. Herein, we investigate G protein-coupled receptor 1 (GPR1) in mediating GDM through the phosphorylation of serine/threonine kinase (AKT) pathway. Thirty pregnant SD rats were grouped into: normal pregnancy control group (NC), GDM model group, and GDM model + high-dose GPR1 antagonist treatment (GDM + Ari) group. GDM model was established, and the GDM + Ari group adopted GPR1 antagonist aripiprazole. The blood glucose level, insulin level, and insulin resistance (IR) were detected. The expression and phosphorylation of GPR1, AKT, and extracellular signal-regulated kinase (ERK) in placental tissue were detected using reverse transcription-polymerase chain reaction (RT-PCR) and western blotting (WB). The serum insulin concentration, glucose concentration, and glycated hemoglobin concentration during pregnancy in GDM group SD rats were significantly higher than those in the NC group (P < 0.05). The expression and phosphorylation levels of GPR1, AKT, and ERK in the placental tissue of SD pregnant rats in the GDM group were significantly lower than those in the NC group. Furthermore, compared with the GDM group, the expression of GPR1, AKT, and ERK in placental tissue was significantly reduced in the GDM + Ari group, while simultaneously enhancing the blood glucose level and IR level. In addition, the survival number, body weight, and malformation rate of the offspring of the GDM + Ari group were significantly improved, and there was no significant effect on the number of offspring. The expressions of GPR1, AKT, and ERK in placental tissue exhibited a significant decrease, while the glucose level and IR were observed to increase in the GDM + Ari group. Enhancing the expression of GPR1 may activate AKT phosphorylation to alleviate GDM. GPR1 could potentially serve as a novel target for diabetes treatment, offering new insights into managing GDM.