235. Abberant murine embryonic development following glucosamine exposure during IVM or embryo culture

Abstract

The hexosamine biosynthesis pathway is an alternate fate for glucose metabolism providing glycosylation moieties and is significantly upregulated by addition of glucosamine, a common dietary supplement. Here we determined the impact of glucosamine addition to cumulus oocyte complex (COC) maturation or during embryo culture on subsequent embryonic development. COCs were collected from 23-day-old mice 46 h post-eCG, and matured under several conditions prior to being fertilized and cultured: (1) 10 mL/COC a MEM (5.56 mM glucose) + 0, 1.25 or 5 mM glucosamine; (2) 10 mL/COC a MEM (20 mM glucose) + 0, 1.25 or 5 mM glucosamine; (3) 100 mL/COC G2.3 (5 mM glucose) + 0, 1.25 or 2.5 mM glucosamine. One-cell embryos were also flushed from age-matched donors 24 h after mating and cultured in 0, 1.25 or 2.5 mM glucosamine in G 1.3/2.3 sequential media. No differences in rates of embryonic development were detected between COCs matured in 10 mL of media with 5.56 mM glucose with glucosamine. However, blastocyst formation was significantly impaired (P < 0.001) when COC maturation occurred in equivalent volumes of media that contained 20 mM glucose + 1.25 mM (49.98%) or 5 mM glucosamine (44.7%) v. control (86.55%). Intriguingly, embryonic viability was significantly (P < 0.001) reduced in COCs matured in 100 mL G2.3 containing 5 mM glucose + 1.25 mM (44.6%) or 2.5 mM glucosamine (40.1%) v. control (79.81%), suggesting a volume × glucose concentration interaction. In contrast, embryonic development was significantly reduced (34%, P < 0.002) and completely ablated when 1-cell embryos were cultured in media containing 1.25 mM and 2.5 mM glucosamine, respectively (control = 88.57%). These results suggest that glucosamine up-regulated hexosamine pathway activity in both COCs and early embryos impairs subsequent embryonic development by as yet undescribed mechanisms.

Funded by NIH and NHMRC