Differential effects of follicle-stimulating hormone glycoforms on the transcriptome profile of cultured rat granulosa cells as disclosed by RNA-seq.
Authors: Zariñán Teresa, Espinal-Enriquez Jesús, De Anda-Jáuregui Guillermo, Lira-Albarrán Saúl, Hernández-Montes Georgina, Gutiérrez-Sagal Rubén, Rebollar-Vega Rosa G, Bousfield George R, Butnev Viktor Y, Hernández-Lemus Enrique, Ulloa-Aguirre Alfredo
Journal: PloS one
Summary
# Editorial Summary Follicle-stimulating hormone (FSH) exists in multiple glycosylated forms with varying carbohydrate structures, yet whether these structural differences translate to functionally distinct cellular responses has remained unclear. Researchers exposed cultured rat granulosa cells to four highly purified FSH variants—two hypo-glycosylated forms (human pituitary FSH18/21 and equine FSH) and two fully glycosylated forms (human pituitary FSH24 and recombinant FSH)—for 6 and 12 hours, then performed RNA sequencing to map comprehensive transcriptomic changes across approximately 10-15 million reads per sample. Each FSH glycoform produced a distinct molecular signature: at 6 hours, fewer than 1% of the top 200 differentially expressed genes overlapped across all four glycoforms, though this convergence increased to 40% by 12 hours, indicating glycoform-specific early responses that gradually harmonised. The glycoforms differentially activated key signalling pathways (cAMP-PKA, MAPK, and PI3/AKT), with recombinant FSH demonstrating notably stronger and more sustained pathway activation at 12 hours compared to native pituitary forms. For equine practitioners and reproductive specialists, these findings underscore that FSH glycosylation patterns meaningfully alter granulosa cell behaviour and signal transduction, suggesting that the glycoform composition of FSH supplements or endogenous FSH profiles during reproductive cycles may influence follicle development outcomes and warrant consideration in assisted reproductive protocols and performance mare management.
Read the full abstract on PubMed
Practical Takeaways
- •This basic science research demonstrates that FSH glycosylation structure directly affects how granulosa cells respond at the molecular level; practitioners involved in equine reproduction should recognize that equine FSH has unique biochemical properties compared to human-derived formulations.
- •The findings suggest that when using FSH products (whether endogenous equine FSH or exogenous human preparations) in reproductive management, the specific glycoform composition may influence ovarian cell behavior and treatment outcomes—consideration for standardization and consistency in breeding programs.
- •Understanding that different FSH sources activate distinct intracellular signaling pathways provides mechanistic insight into why equine FSH products may produce different superovulation responses compared to recombinant human FSH in clinical applications.
Key Findings
- •Four FSH glycoforms with different glycosylation patterns produced distinct transcriptome profiles in cultured rat granulosa cells, with only 0.6% of top 200 differentially expressed genes shared at 6 hours but 40% shared at 12 hours.
- •Each FSH glycoform exhibited unique patterns of biological process activation, with recFSH showing the strongest and most glycoform-specific responses at 12 hours.
- •FSH glycoforms differentially activated cAMP-PKA, MAPK, and PI3/AKT signaling pathways, with each glycoform displaying a distinct molecular signature.
- •Equine FSH demonstrated different temporal patterns of gene regulation compared to human pituitary and recombinant FSH forms, suggesting species-specific glycosylation effects on cellular responses.