Identification of genes with differential regulation in primate endometrium during the proliferative and secretory phases of the cycle

To study gene expression in the endometrium at different stages of the menstrual cycle, differential mRNA display and reverse Northern analysis were performed on uterine tissues from cynomolgus monkeys. Eutopic endometrial RNA was prepared from uteri of animals that were either ovariectomized and supplemented with hormones, or were not ovariectomized but were subjected to surgically induced endometriosis. A number of genes were identified whose levels fluctuated between the proliferative and secretory phases of the cycle. Expression of four genes thus identified was further examined by in situ hybridization to normal human endometrial biopsies. Iodothyronine deiodinase was uniformly expressed at all stages of the human cycle that were studied: proliferative, secretory, and menstrual. Fibulin 1, osteopontin, and cathepsin H exhibited complex temporal and spatial regulation. Fibulin 1 was expressed in glandular epithelia during the menstrual phase, but expression switched to the stroma during the secretory phase. During the menstrual phase, osteopontin was expressed at high levels in glandular epithelia and in isolated stromal cells that may be of immune origin. Secretory phase expression of osteopontin was confined to a sub-population of epithelial cells. Cathepsin H was expressed in proliferative and menstrual phase endometrium, but expression disappeared in the secretory phase. Messenger RNA for fibulin 1, osteopontin, and iodothyronine deiodinase was detected in an endometriosis sample. Our data support functional roles for fibulin 1, osteopontin, cathepsin H and thyroid hormone in endometrium.