Prostaglandin F2α regulation of the mRNA for AP-1 transcriptional factors in porcine corpora lutea: Lack of induction of JUN and JUND in CL without luteolytic capacity

摘要

Porcine CL develop sensitivity to regression by PGF2α, termed luteolytic capacity, about 13 d after estrus. We postulated that PGF2α regulation of AP-1 transcriptional factor expression underlies acquisition of luteolytic capacity. Gilts on Day 9 (estrous cycle) or Day 17 (pseudopregnancy) had CL collected before or after PGF2α treatment with mRNA measured for FOS, FOSB, FOSL1, FOSL2, JUN, JUNB, and JUND and AP-1 target genes CCL2 and SERPINE1. At 0.5h after PGF2α, both Day 9 and Day 17 CL had increased (P < 0.01) mRNA for FOS (2,225% and 1,817%), JUNB (237% and 358%), and FOSB (1,060% and 925%). Intriguingly, at 0.5 h after PGF2α there were increased (P < 0.01) mRNA encoding JUN (1099%) and JUND (300%) in Day 17 but not Day 9 CL. At 10 h after PGF2α there was elevated FOSB mRNA in Day 17 (771%) but not Day 9 CL and no PGF2α-induced change in FOS, JUN, JUND, and JUNB mRNA in Day 9 or Day 17 CL. Treatment with PGF2α increased mRNA for AP-1-responsive genes, CCL2, at 0.5 h (202%) and CCL2 and SERPINE1 at 10 h (719% and 1515%) only in Day 17 CL. Thus, many of the fos family of transcription factors are dramatically induced by PGF2α in CL with or without luteolytic capacity. However, PGF only induced JUN and JUND expression in CL with luteolytic capacity, a finding that may be key for understanding acquisition of luteolytic capacity given that JUN is the only AP-1 family member with strong N-terminal trans-activation activity.