Endometrial expression of the insulin-like growth factor system during uterine involution in the postpartum dairy cow.
Rapid uterine involution in the postpartum period of dairy cows is important to achieve a short interval to conception. Expression patterns for members of the insulin-like growth factor (IGF) family were determined by in situ hybridisation at day 14+/-0.4 postpartum (n=12 cows) to investigate a potential role for IGFs in modulating uterine involution. Expression in each uterine tissue region was measured as optical density units and data were analysed according to region and horn. IGF-I mRNA was localized to the sub-epithelial stroma (SES) of inter-caruncular and caruncular endometrium. Both IGF-II and IGF-1R expression was detected in the deep endometrial stroma (DES), the caruncular stroma and myometrium. IGFBP-2, IGFBP-4 and IGFBP-6 mRNAs were all localised to the SES of inter-caruncular and caruncular uterine tissue, and in the DES and caruncular stroma, with IGFBP-4 mRNA additionally expressed in myometrium. IGFBP-3 mRNA was only detectable in luminal epithelium. IGFBP-5 mRNA was found in myometrium, inter-caruncular and caruncular SES and caruncular stroma. These data support a role for IGF-I and IGF-II in the extensive tissue remodelling and repair which the postpartum uterus undergoes to return to its non-pregnant state. The differential expression of binding proteins between tissues (IGFBP-3 in epithelium, IGFBP-2, -4, -5 and -6 in stroma and IGFBP-4 and -5 in myometrium) suggest tight control of IGF activity within each compartment. Differential expression of many members of the IGF family between the significantly larger previously gravid horn and the previously non-gravid horn may relate to differences in their rate of tissue remodelling.
Llewellyn
S
S
Reproduction, Genes and Development Group, Department of Veterinary Basic Sciences, Royal Veterinary College, Hawkshead Lane, Hatfield, Herts, London AL9 7TA, UK.
Fitzpatrick
R
R
Kenny
D A
DA
Patton
J
J
Wathes
D C
DC
D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D003612:Dairying; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D018969:Insulin-Like Growth Factor Binding Proteins / Q000235:genetics / Q000378:metabolism; D009929:Organ Size / Q000235:genetics; D049590:Postpartum Period / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D013002:Somatomedins / Q000235:genetics* / Q000378:metabolism; D014599:Uterus / Q000378:metabolism / Q000502:physiology*
D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger; D013002:Somatomedins; D017526:Receptor, IGF Type 1