New aspects on the regulation of inhibin production int he male gonad: role of FSH oligosaccharide structure at different stages of Sertoli cell maturation

ANDREONE L; AMBAO V; PELLIZZARI E; LORETI N; CIGORRAGA S; CAMPO S

Modena

Conferencia; IV International Conference on Gonadotropins and Receptors; 2017

FSH is synthesized and secreted as a family of glycosylation variants,which differ from each other in the oligosaccharide composition and in theability to induce biological responses. During the last years, inhibin B (InhB) has been considered a reliable marker of Sertoli cell function; its productionis stimulated by FSH and factors produced in the seminiferous tubules. The aimof the present study was to investigate the role of FSH oligosaccharidestructure in the regulation of monomeric (Pro-αC) and dimeric inhibin (Inh B) production at two maturation stages of the Sertolicell. The effect of native recombinant human FSH (rhFSH) and its glycosylationvariants was evaluated in vitro on immature Sertoli cells isolated from 8-day-old rats and cellsin the process of terminal maturation isolated from 20-day-old rats. rhFSHcharge analogues were isolated by preparative Isoelectric Focusing (IEF) andConcanavalin A (Con-A) was used to isolate rhFSH glycoforms on the basis oftheir oligosaccharide complexity. Native rhFSH stimulated Pro-αC in a dose-dependent manner but did not induce changes in basal Inh B productionin immature Sertoli cells. The less acidic/sialylated rhFSH charge analogues(BA) resulted in a more potent stimulus than the more acidic/sialylated ones(AC) for Pro-αC production (p<0.05); theywere also able to stimulate Inh B (p<0.01). Native rhFSH stimulated both Pro-αC and Inh B production in a dose-dependent manner in Sertoli cells at moreadvanced stages of maturation. All rhFSH glycosylation variants increased Inh Band Pro-αC (p<0.05), with a moremarked effect on the monomeric inhibin production. The BA charge analogues preparationexerted a more marked stimulatory effect on Inh B and Pro-αC production (p<0.05) than the AC preparation. Glycoforms bearing highmannose and hybrid-type oligosaccharides (HY) stimulated Inh B and Pro-αC production more effectively than those bearing complex oligosaccharides(CO) (p<0.05). The results obtained herein demonstrated that the sialylationdegree as well as the complexity of oligosaccharides present in the FSHmolecule should be considered as additional factors in the modulation ofinhibin production in the Sertoli cell at different stages of maturation.