Expression of Functional Prolactin Receptors in Nonpregnant Human Endometrium: Janus Kinase-2, Signal Transducer and Activator of Transcription-1 (STAT1), and STAT5 Proteins Are Phosphorylated after Stimulation with Prolactin

H. N. Jabbour, H. O. D. Critchley, S. C. Boddy
1998 Journal of Clinical Endocrinology and Metabolism  
PRL is synthesized by decidualized endometrial stromal cells from the midsecretory phase in a nonconception cycle and throughout pregnancy. The exact role of PRL in the human endometrium remains to be elucidated; however, the pattern of expression supports a role for PRL during implantation and placentation. This study investigated the site and pattern of expression of PRL receptors in the nonpregnant human endometrium. In situ hybridization and immunohistochemistry localized expression of the
more » ... expression of the receptor in the glandular epithelium and a subset of stromal cells of the endometrium. As judged by the intensity of staining, expression of the receptor was dramatically up-regulated during the secretory phase. Expression of the PRL receptor gene in the endometrium from the secretory phase of the menstrual cycle was confirmed by ribonuclease protection assay using 50 g total ribonucleic acid. Phosphorylation of Janus kinase-2 (JAK2), STAT1 (signal transducer and activator of transcription-1), and STAT5 proteins in response to PRL was investigated to establish the signaling pathway of PRL in the human endometrium. Endome-
doi:10.1210/jcem.83.7.4989 pmid:9661641 fatcat:jof5sfwxqnehdgqi6pukqo5r2m