Publications [#174184] of G. Allan Johnson

Papers Published

1. J Kim, G Song, H Gao, JL Farmer, MC Satterfield, RC Burghardt, G Wu, GA Johnson, TE Spencer, FW Bazer, Insulin-like growth factor II activates phosphatidylinositol 3-kinase-protooncogenic protein kinase 1 and mitogen-activated protein kinase cell Signaling pathways, and stimulates migration of ovine trophectoderm cells., Endocrinology, vol. 149 no. 6 (June, 2008), pp. 3085-94, ISSN 0013-7227 [doi]
   (last updated on 2010/04/30)

   Abstract:
   IGF-II, a potent stimulator of cellular proliferation, differentiation, and development, regulates uterine function and conceptus growth in several species. In situ hybridization analyses found that IGF-II mRNA was most abundant in the caruncular endometrial stroma of both cyclical and pregnant ewes. In the intercaruncular endometrium, IGF-II mRNA transitioned from stroma to luminal epithelium between d 14 and 20 of pregnancy. IGF-II mRNA was present in all cells of the conceptus but was particularly abundant in the yolk sac. Immunohistochemical analyses revealed that phosphorylated (p)-protooncogenic protein kinase 1, p-ribosomal protein S6 kinase, p-ERK1/2, and p-P38 MAPK proteins were present at low levels in a majority of endometrial cells but were most abundant in the nuclei of endometrial luminal epithelium and conceptus trophectoderm of pregnant ewes. In mononuclear trophectoderm cells isolated from d-15 conceptuses, IGF-II increased the abundance of p-pyruvate dehydrogenase kinase 1, p-protooncogenic protein kinase 1, p-glycogen synthase kinase 3B, p-FK506 binding protein 12-rapamycin associated protein 1, and p-ribosomal protein S6 kinase protein within 15 min, and the increase was maintained for 90 min. IGF-II also elicited a rapid increase in p-ERK1/2 and p-P38 MAPK proteins that was maximal at 15 or 30 min posttreatment. Moreover, IGF-II increased migration of trophectoderm cells. Collectively, these results support the hypothesis that IGF-II coordinately activates multiple cell signaling pathways critical to survival, growth, and differentiation of the ovine conceptus during early pregnancy.

   Keywords:
   Animals • Cell Differentiation • Cell Division • Cloning, Molecular • Female • Insulin-Like Growth Factor II • MAP Kinase Signaling System • Male • Pregnancy • Proto-Oncogene Proteins c-akt • RNA, Messenger • Ribosomal Protein S6 Kinases, 90-kDa • Sheep • Uterus • Vasectomy • genetics • metabolism • p38 Mitogen-Activated Protein Kinases • physiology • physiology*