Endocrine Abstracts

Introduction: Ghrelin is an orexigenic hormone with two isoforms: Acyl Ghrelin (AG) and Desacyl Ghrelin (DAG). AG binds to its specific receptor GHS-R1 and stimulates growth hormone secretion. DAG also binds to GHS-R1 receptor, but with 1000 times less affinity than AG. Effect of DAG on cell proliferation and inhibition of apoptosis has been reported. However, there are no studies of DAG function in human placenta. For first time, this work analyzed the effect of DAG on viability, proliferation and protein expression of GHS-R1 of human placenta cells.

Objective: To evaluate the effect of DAG on viability, proliferation and protein expression of GHS-R1 receptor in human placental cells line BeWo.

Materials and methods: BeWo cells were cultured in F-12K medium and incubated for 72 h at 37 °C and 5% CO2. First, BeWo cells were incubated for 24 h. Then, cells were treated with 3nM DAG for 12, 24, 48 and 72 h for viability assay and 24 h in the case of cell proliferation assay. To evaluate protein expression of GHS-R1 receptor, cellular homogenates were analyzed by Western Blot using anti-GHS-R1 (1:1000) as first antibody by 20 h and anti-mouse (1:22500) as secondary antibody by 2 h. Results were analyzed by ANOVA; p ≤0.05 was considered as significant.

Results: Cells treated with DAG did not show differences in cellular viability (P>0.05) compared against control cells at all times examined. Similarly, proliferation of cells treated with DAG was not different (P>0.05) from control cells at 24 h. GHS-R1 protein expression of cells treated with DAG increased 42% at 12 h (P=0.029) and 36% at 24 h (P=0.025). However, GHS-R1 protein expression decreased 35% at 48 h (P=0.005) compared with control cells.

Conclusions: DAG has no effect on viability and proliferation of human placental cytotrophoblast cells. However, DAG induces changes in protein expression of GHS-R1 receptor, suggesting that could induce signals downstream of this receptor, on sensors or nutrient transporters.