Coexpression of pinopodes and leukemia inhibitory factor, as well as its receptor, in human endometrium.
OBJECTIVE
To determine cell-type-specific expression of leukemia inhibitory factor (LIF) and LIF receptor (LIFR) proteins relative to formation of pinopodes in human endometrial samples.


METHODS
Prospective clinical study.


METHODS
Hospital-based unit for reproductive health and university-affiliated reproductive research laboratories.


METHODS
Twenty-six healthy fertile women with normal menstrual cycles.


METHODS
Routine blood and urine samples were obtained, and vaginal ultrasonography and endometrial biopsy were performed. Pinopode formation and expression of LIF and LIFR were examined in endometrial samples.


RESULTS
Samples obtained during LH days 6 through 9 had pinopodes at different developmental stages. Both surface and glandular epithelial cells expressed maximal levels of LIF and LIFR protein, in biopsy samples showed fully developed pinopodes. Immunostaining of LIF was more intense in the glandular epithelium, whereas immunostaining of LIFR was most intense in the surface epithelium. Before and after the appearance of pinopodes, LIF and LIFR immunostaining was less intense or faint. Stromal endometrial cells showed faint LIF accumulation.


CONCLUSIONS
The simultaneous positive spatial and temporal expression of pinopodes and LIF and LIFR proteins in endometrial samples from healthy women suggests that both molecular and structural cell changes are important in the initiation of human blastocyst implantation.
Aghajanova
Lusine
L
Department of Clinical Science, Division of Obstetrics and Gynecology, Karolinska Institutet, Huddinge University Hospital, Stockholm, Sweden. lusine.aghajanova@klinvet.ki.se
Stavreus-Evers
Anneli
A
Nikas
Yorgos
Y
Hovatta
Outi
O
Landgren
Britt-Marie
BM
D000328:Adult; D001706:Biopsy; D004717:Endometrium / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D006131:Growth Inhibitors / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008183:Luteal Phase / Q000378:metabolism; D007986:Luteinizing Hormone / Q000652:urine; D008222:Lymphokines / Q000096:biosynthesis*; D008855:Microscopy, Electron, Scanning; D011446:Prospective Studies; D018121:Receptors, Cytokine / Q000096:biosynthesis*; D053606:Receptors, OSM-LIF
D006131:Growth Inhibitors; D015850:Interleukin-6; C507837:LIF protein, human; C507840:LIFR protein, human; D053605:Leukemia Inhibitory Factor; D053680:Leukemia Inhibitory Factor Receptor alpha Subunit; D008222:Lymphokines; D018121:Receptors, Cytokine; D053606:Receptors, OSM-LIF; D007986:Luteinizing Hormone