Identification by Hybridization Histochemistry of Human Endometrial Cells Expressing mRNAs Encoding a Uterine β-Lactoglobulin Homologue and Insulin-Like Growth Factor-Binding Protein-1

Abstract

A beta-lactoglobulin homologue (beta LG/PP14) and insulin-like growth factor-binding protein-1 (IGFBP-1) are two major secretory proteins of the human endometrium. In the present study, we have shown that beta LG/PP14 mRNA is expressed in the endometrium in a cyclic manner, being hardly detectable in midcycle and most abundant during the late secretory phase. IGFBP-1 mRNA is also expressed in endometrium, but in amounts smaller than those encoding beta LG/PP14 and with maximal accumulation earlier in the secretory phase. The expression of these two mRNAs occurs in different cell types of the endometrium, as revealed by in situ hybridization techniques using single-stranded RNA probes. The glandular epithelial cells accumulate beta LG/PP14 mRNA during the late secretory phase of the cycle, whereas only the stromal cells of the late secretory endometrium express IGFBP-1 mRNA. In contrast to the endometrium, the two mRNAs are present at very low abundance in the fallopian tubes where they are expressed in the epithelial cells of the mucosa.

IGFs and IGF-binding proteins in the regulation of human ovarian and endometrial function

“…IGFBP-4 and IGFBP-5 mRNAs remain unchanged during the menstrual cycle (Rutanen et al 1993). IGFBP-1 mRNA is not detected in proliferative endometrium but is present in the stromal cells of the secretory endometrium ( Julkunen et al 1990, Zhou et al 1994.…”

“…After ovulation, progesterone is prominent and stimulates the endometrial stromal cells to secrete IGFBP-1, which in turn modulates the bioactivity of IGF-I (Rutanen & Pekonen 1991). In addition, IGFBP-1 mRNA is localized to predecidualized stromal cells in late secretory endometrium and to decidual cells in pregnancy endometrium ( Julkunen et al 1990. The timing and cellular localization of IGFBP-1 in human endometrium suggest that this protein is associated with decidual differentiation of the stromal cells.…”

Implications of Insulin Resistance / Hyperinsulinemia on Reproductive Function in Infertile Women with Polycystic Ovary Syndrome

“…Glycodelin is a protein synthesized by secretary / decidualized endometrial glands. Circulating glycodelin may reflect endometrial function such as endometrial maturation and inhibition of endometrial immune response to the embryo (M. Seppala, et al 1988;M. Julkunen, et al 1990; AE.…”

The Pathophysiology of Miscarriage in Women with Polycystic Ovary Syndrome. Review and Proposed Hypothesis of Mechanisms Involved

“…A retrospective study 15 divided 712 women who became pregnant after receiving donat-inhibiting the immune response of the endometrium to the embryo [25][26][27][28][29] . More specifically, it has been shown to primarily inhibit mixed lymphocyte reaction and natural killer cell activity 27,29 .…”

“…Glycodelin (previously known as PP14) and IGF binding protein-1 (IGFBP-1) are two proteins secreted by the endometrium that appear to play important roles in endometrial receptivity during implantation and early pregnancy 24,25 . Glycodelin is a glycoprotein produced by secretory and decidualized endometrial glands during the luteal phase that facilitates implantation by…”