Evidence and manipulation of O-GlcNAcylation in granulosa cells of bovine antral follicles.

Evidence and manipulation of O-GlcNAcylation in granulosa cells of bovine antral follicles. Biol Reprod. 2021 Feb 08;: Authors: Maucieri AM, Townson DH Abstract Glucose is a preferred energy substrate for metabolism by bovine granulosa cells (GCs). O-linked N-acetylglucosaminylation (O-GlcNAcylation), is a product of glucose metabolism that occurs as the hexosamine biosynthesis pathway (HBP) shunts O-GlcNAc sugars to serine and threonine residues of proteins. O-GlcNAcylation through the HBP is considered a nutrient sensing mechanism that regulates many cellular processes. Yet little is known of its importance in GCs. Here, O-GlcNAcylation in GCs and its effects on GC proliferation were determined. Bovine ovaries from an abattoir, staged to the mid-to-late estrous period were used. Follicular fluid and GCs were aspirated from small (3-5 mm) and large (>10 mm) antral follicles. Freshly isolated GCs of small follicles exhibited greater expression of O-GlcNAcylation and O-GlcNAc transferase (OGT) than large follicles. Less glucose and more lactate was detectable in the follicular fluid of small versus large follicles. Culture of GCs revealed that inhibition of the HBP via the glutamine fructose-6-phosphate aminotransferase inhibitor, DON (50 μM), impaired O-GlcNAcylation and GC proliferation, regardless of follicle size. Direct inhibition of O-GlcNAcylation via the OGT inhibitor, OSMI-1 (50 μM), also prevented proliferation, but...
Source: Biology of Reproduction - Category: Reproduction Medicine Authors: Tags: Biol Reprod Source Type: research