Cellular localization of human relaxin-like factor in the cyclic endometrium and placenta

Abstract

We have studied the cellular localization of the relaxin-like factor (RLF) in the histologically normal cyclic endometrium collected from days 3--26 of the menstrual cycle. RLF transcripts and protein were detected in the luminal and glandular epithelium and in stromal cells at all stages of the cyclic endometrium. Increased expression of RLF was observed in endometrial tissues in the proliferative as compared to the secretory phase, suggesting that oestrogens affect RLF gene activity in the human endometrium. The cellular localization of RLF transcripts and protein was also determined in first trimester placental tissues obtained from normal and ectopic tubal implantation sites and in third trimester placentae of normal and pre-eclamptic pregnancies. In first trimester placenta, weaker expression of RLF was observed in the syncytiotrophoblast as compared to the underlying cytotrophoblast. Extravillous trophoblast cells constitutively expressed RLF. Trophoblast cells were the main source of RLF in the human placenta and trophoblastic RLF gene activity was unaffected by either the site of implantation or the invasive properties of the cytotrophoblast as demonstrated by samples from patients with tubal implantation and pre-eclampsia respectively. Decidual cells weakly expressed RLF. The presence of unprocessed and cleaved immunoreactive RLF in term placenta was determined by Western analysis. The above results suggest a functional role for both RLF isoforms within normal placental tissue.

Human testicular insulin-like factor 3: in relation to development, reproductive hormones and andrological disorders

“…, 2008). Notably, both INSL3 and RXFP2 have been reported to be present in human placenta (Hombach‐Klonisch et al. , 2001).…”

International Union of Pharmacology LVII: Recommendations for the Nomenclature of Receptors for Relaxin Family Peptides

“…Although both INSL3 and RLF are used in the literature, for the purposes of this review the hormone will be designated insulin-like peptide 3 (INSL3). INSL3 expression is not confined to the male; it is also expressed in the ovary within both the follicular theca interna cells and the corpora lutea (Bathgate et al, 1996;Roche et al, 1996;Kawamura et al, 2004), as well as in the placenta (Hombach- Klonisch et al, 2001), breast (Hombach- Klonisch et al, 2000), and thyroid gland (Hombach- Klonisch et al, 2003).…”

Expression of leucine-rich repeat-containing G-protein-coupled receptors in the human cyclic endometrium

“…Five micrograms of total RNA were used, and priming was performed with 1.6g oligo(dT) 15 primers according to kit instructions. Equal RNA input in the cDNA synthesis was controlled by loading 4 L of the cDNA synthesis reaction on an agarose gel and by measurement of the optical density (OD) of 18S and 28S rRNA bands with the Kodak Image Station 440 (PerkinElmer Life Sciences, Boston, MA).…”

“…We used the oligo-(dT) 15 primer, and the obtained cDNA was diluted 1:1 with sterile water. Real time PCR was performed with the LightCycler (Roche).…”