GLP2 and EGF Stimulated EC Proliferation of TPN Derived Enteroids

Abstract

Background Glucogan like peptide 2 (GLP2) and epidermal growth factor (EGF) are critical for epithelial cell (EC) growth and survival.Both growth factors were decreased in total parenteral nutrition (TPN) mouse model with mucosal atrophy. Methods: Jejunal crypts from sham and TPN mice(N=5/group) were isolated and 100 crypts were seeded and planted. Enteroids were cultured with basal medium, additional EGF, GLP2 or both were added. Enteroid growth was observed,the enteroids were passaged at 7 day post-culture and observed for a total of 14 days. Enteroid number and size were measured, and enteroid mRNA extracted and examined for stem cell marker Lgr5 and OLMF4, cell proliferation marker PCNA,and EGF/EGFR with real-time PCR. Results:Decreased EGF/EGFR and GLP2/GLP2R expression in TPN mice small intestine ,how these 2 factors work on the enteroids growth were analysised. In Sham mice 90% of crypts formed enteroids versus 50% in TPN mice at 7 days after culture. Additional EGF or GLP2 increased enteroids formation rate to 60-70% in TPN group, but had no additive effect with both growth factors combination(70%). Enteroid size was smaller in TPN mice ((50% of sham),additional EGF or GLP2 led to preservation of enteroids size. PCNA and EGF expression in TPN enteroids were decreased versus shams, and both growth factors partially protected their expression.The decline of EGFR expression were prevented with addition of either EGF or EGF+GLP2, GLP2 alone failed to protect. Both Lgr5 and OLMF4 expression decreased in TPN enteroids. EGF preserved OLMF4 expression but GLP2, neither EGF nor GLP2 affected Lgr5 expression.Conclusion: TPN-associated decline of EC proliferation were related the decreased of EGF and GLP2. Both growth factors could stimulated enteroids growth from TPN mice.