Endocrine Abstracts

Introduction: Asprosin, a novel adipokine, is a circulating hormone mainly secreted by white adipose tissue. Asprosin is encoded by the penultimate 2 exons of the fibrillin 1 (FBN1) gene. Protein product of FBN1 is profibrillin-1, which undergoes a proteolytic cleavage by furin enzyme to produce mature fibrillin-1 and asprosin. Literature data indicated that asprosin is involved in the development of diabetes, obesity, cardiomyopathy, cancer, and polycystic ovarian syndrome. Moreover, asprosin is able to affect various cellular and physiological processes like appetite stimulation, insulin secretion, glucose release, apoptosis and inflammation through activation of Olfr734, an olfactory G-protein-coupled receptor. However, whether it can regulate the hypothalamic cells function has not been yet investigated. This study intended to examine i) the mRNA and protein levels of asprosin/Olfr734/furin in mouse hypothalamus and GT1-7 cells and ii) in vitro effect of asprosin on GT1-7 cells proliferation and GnRH secretion.

Materials and Methods: To measure the mRNA (real time PCR) and protein (Western blot) expression of asprosin/Olfr734/furin we used hypothalamus collected from C57BL/6J female mice at diestrous (n=3) as well as mouse hypothalamic GT1-7 cells. Moreover, immunolocalization of asprosin/Olfr734/furin were analyzed in GT1-7 cells. To study effect of asprosin on cells proliferation (AlamarBlue test) and GnRH secretion (ELISA), GT1-7 cells were cultured with recombinant mouse asprosin at doses 1, 10, 100 ng/ml. Statistical analysis was performed in Graph Pad Prism 7 software, using one-way ANOVA and Tukey’s test (n = 5, P< 0.05).

Results: We demonstrated mRNA and protein expression of asprosin/Olfr734/furin both in mouse hypothalamic and GT1-7 cells. Moreover, we detected asprosin/Olfr734/furin signals in GT1-7 cells. We noted a modulating effect of asprosin on GT1-7 cells proliferation and GnRH secretion.

Conclusion: Our preliminary findings suggest that the novel adipokine asprosin may play a regulatory role in the mouse hypothalamus.

Funding: National Science Centre, Poland (project no. 2021/42/E/NZ4/00088).