transport. Endocannabinoid and the uterus In the uterus, the endometrium represents a significant source of endogenous cannabinoids, and AEA levels are higher than in other reproductive tissues ( Das et al . 1995 , Schmid et al . 1997 ). The expression of
Anna Maria Di Blasio, Michele Vignali and Davide Gentilini
W M Liu, Y J Cao, Y J Yang, J Li, Z Hu and E-K Duan
identified as a surface antigen on a pre-B cell line ( Kersey et al. 1981 ), CD9 is also expressed on blastocysts in mice and endometrium epithelial cells in human and cattle ( Le Naour et al. 2000 , Park et al. 2000 , Xiang & MacLaren 2002 ). Given
Qi Zhang and Wen Xuan Wu
termination. In many experimental animal models, including pregnant sheep, the uterus and the cervix undergo considerable growth and ripening throughout gestation, and the intrauterine prostaglandin system develops throughout the course of pregnancy when
Fabien Duval, Esther Dos Santos, Benoît Maury, Valérie Serazin, Khadija Fathallah, François Vialard and Marie-Noëlle Dieudonné
.e.m. of ten separate experiments. * P < 0.05. Wilcoxon test. A full colour version of this figure is available at https://doi.org/10.1530/JME-18-0013 . Discussion For many years, the endometrium (like the uterus in general) was
C. Azuma, F. Saji, T. Kimura, Y. Tokugawa, M. Takemura, Y. Samejima and O. Tanizawa
We investigated the biological effects of sex-steroid hormones, secreted from the corpus luteum and placenta, on the induction of mRNAs encoding macrophage colony-stimulating factor (MCSF) and c-fms proto-oncogene (MCSF receptor) in human endometrium. RNA was extracted from the placenta and endometrium of both pregnant and non-pregnant women, and Northern blot analysis was performed on poly(A)+ RNA using MCSF or c-fms proto-oncogene cDNA as the probe. Results showed: (1) that MCSF mRNA was expressed in the placenta and endometrium of the pregnant uterus, (2) that c-fms proto-oncogene mRNA was also expressed in the placenta and endometrium of the pregnant uterus, and (3) that exogenous sex-steroid hormones could induce the expression of MCSF and c-fms proto-oncogene mRNAs in the endometrium of non-pregnant women. These results indicate that sex-steroid hormones secreted by the corpus luteum and/or placenta influence endometrial and placental growth and differentiation via a mechanism of action involving local production of MCSF and its receptor.
C Keil, B Husen, J Giebel, G Rune and R Walther
In the present study we demonstrate for the first time the expression of glycodelin mRNA in the female and male genital tracts of rats using non-radioactive in situ hybridisation. Glycodelin fragment 1 (+41 to +141) shares 100% homology with the human gene sequence. In the ovary, glycodelin mRNA was restricted to granulosa cells. In the uterus, glycodelin mRNA was expressed in all epithelial cells of the endometrium. In the male reproductive tract, glycodelin mRNA was distributed in all epithelial cells of the epididymis, the prostate and the seminal vesicle. However, in the testis, glycodelin mRNA was predominantly found in spermatogonia and in spermatocytes of the seminiferous epithelium. The expression in several reproductive organs of rats offers an excellent tool to study further the physiological role of glycodelin, which is so far thought to act as an immunosuppressive factor.
K R Stevenson, P R Riley, H J Stewart, A P F Flint and D C Wathes
A synthetic 45-mer oligonucleotide corresponding to part of the ovine endometrial oxytocin receptor cDNA was hybridized to sections of ovine uterus collected from 40 ewes at different stages during the oestrous cycle, the first 3 weeks of pregnancy and seasonal anoestrus. The quantity of oxytocin receptor mRNA was measured as the optical density (OD) value on autoradiographs using image analysis. Message first appeared in the luminal epithelium on days 14–15 of the cycle, increasing to a peak OD of 0·48 at oestrus and decreasing again between days 2 and 5. Oxytocin receptor mRNA in the superficial glands, deep glands and caruncular stroma increased between day 15 and oestrus to peak OD values of 0·17, 0·11 and 0·11 respectively, declining again by day 2 and reaching basal values (OD<0·015) by day 5. Hybridization to the myometrium tended to rise from a mean OD value of 0·01 on days 2–15 to a peak of 0·03±0·01 (mean±s.e.m.) on days 0–1, but the change was not significant. In pregnant ewes there was no detectable oxytocin receptor mRNA on days 14–15 in any region, but hybridization to the luminal epithelium was present in two of three ewes on day 21. In anoestrous ewes oxytocin receptor mRNA concentrations in all areas of the endometrium were approximately half those measured at oestrus.
Optical density readings for oxytocin receptor mRNA in the various uterine compartments were compared with measurements of oxytocin receptors in the same regions as assessed by binding studies using the 125I-labelled oxytocin antagonist d(CH2)5[Tyr(Me)2,Thr4,Tyr-NH29]-vasotocin (125I-labelled OTA). In the endometrium, receptor mRNA and 125I-labelled OTA binding patterns changed in parallel, and both sets of measurements were significantly correlated (P<0·01). In the myometrium, a significant increase in 125I-labelled OTA binding occurred at oestrus; this was not accompanied by a similar increase in oxytocin receptor mRNA hybridization.
This study helps to confirm that the previously identified cDNA clone is derived from the ovine oxytocin receptor, as patterns of oxytocin receptor mRNA expression in the endometrium closely resembled those of oxytocin binding. Maximum expression and binding both occurred at oestrus, suggesting that regulation of the oxytocin receptor gene in the uterus occurs principally at the transcriptional, rather than at the translational, level. Failure to detect a significant increase in myometrial mRNA expression at oestrus may indicate that the endometrial and myometrial oxytocin receptors are of different isoforms.
JC Whitley, C Moore, AS Giraud and A Shulkes
The bombesin receptor subtype 3 (BRS-3) is considered an orphan receptor as it has a low affinity for bombesin-like peptides and no identified natural ligand. We have reported a novel form of gastrin-releasing peptide (GRP) present in high abundance in the pregnant uterus of women and sheep. As BRS-3 was originally cloned from guinea pig uterus, we postulated that the uterine GRP-like peptide may be its natural ligand. We have therefore cloned the gene for the sheep homologue of BRS-3 and determined its distribution. The sheep BRS-3 gene spans 4 kbp and comprises three exons with intron-exon borders at positions similar to those observed for the human and mouse BRS-3 genes. The predicted amino acid sequence of ovine BRS-3 has approximately 85% identity with the human, mouse and guinea pig receptors. Highly conserved amino acids important in mediating receptor G-protein coupling to second messengers and important in ligand binding were found to be conserved in ovine BRS-3. One potentially important deviation was noted: ovine BRS-3 possesses an arginine residue at position 294 instead of a histidine residue as found in all other BRS-3. His(294) was previously identified as important in ligand-receptor interactions while Arg(294) was implicated in high ligand affinity. Thus ovine BRS-3 may have binding characteristics different from those of the human, mouse and guinea pig BRS-3 receptors. In the ewe, BRS-3 mRNA expression was detected in pituitary and hypothalamus but not in tissues of the pregnant uterus (endometrium, myometrium, chorioallantois or amnion). Nor was BRS-3 expression detected in the non-pregnant uterus or in testis. This pattern of BRS-3 expression is similar to that observed in the mouse but different from that observed in the human, rat and guinea pig. We conclude that there is no local interaction between uterine GRP-like peptide and BRS-3. However, the high expression of BRS-3 in the pituitary coupled with elevated circulating levels of this GRP-like peptide during pregnancy suggests an alternate pathway. Cloning of the ovine BRS-3 gene will permit a detailed functional analysis of this receptor in the sheep and its role in the mediation of action of uterine GRP.
AR Green, RE Edwards, P Greaves and IN White
Oral dosing of CD-1 mice on days 2-5 after birth with tamoxifen but not raloxifene disrupts the development of the myometrium, resulting in adult uterine adenomyosis. Using laser capture microdissection and RT-PCR we have investigated nerve growth factor (NGF) and cognate receptor expression in uterine cells of 6-day-old pups that may be important in early developmental changes that give rise to adenomyosis. NGF down-regulation is known to occur during terminal myogenic differentiation. NGF was found exclusively in endometrial luminal epithelium of controls. It was up-regulated 18-fold in the luminal epithelium following dosing with tamoxifen but not raloxifene. Western blotting for NGF protein in the whole uterus showed a 25-fold increase after tamoxifen treatment. Expression of the low affinity p75 neutrophin receptor (p75(NTR)) was twofold higher in the myometrium compared with luminal epithelium or stroma. This was not altered following tamoxifen treatment. There was no detectable expression of high affinity tyrosine kinase receptor (trkA(NGFR)). This study shows luminal epithelial cells of the endometrium primarily form NGF. This suggests that NGF normally regulates the differentiation of the mesenchyme into uterine myocytes through paracrine mechanisms and that an early disturbance of this process plays a key role in the subsequent development of adenomyosis.
Yawen Xu, Jinhua Lu, Jinxiang Wu, Ruiwei Jiang, Chuanhui Guo, Yedong Tang, Haibin Wang, Shuangbo Kong and Suqing Wang
Decidualization is a critical process for embryo implantation and pregnancy maintenance in humans. The homeobox gene HOXA10 has been widely studied in endometrial receptivity establishment and decidualization. MEIS1, a three-amino-acid loop extension (TALE) family homeobox gene, has been proven to be a co-factor for HOXA10 in mouse uterus. However, the interaction between MEIS1 and HOXA10 in the human decidual cells remains to be elucidated. siRNA and CRISPR-Cas9 were employed to knockdown and knockout MEIS1 in the cultured human endometrial stromal cells, and it was found that MEIS1 deficiency leads to impaired decidualization. The physical interaction between the MEIS1 and HOXA10 in human endometrium stromal cell was confirmed by immunoprecipitation. Moreover, KAT2B and ETA were proved to be downregulated in the absence of MEIS1, and Luciferase reporter and ChIP assays demonstrated that MEIS1-HOXA10 complex binds to the promoters of KAT2B and ETA and regulates their activity. Overexpression of KAT2B and ETA can partially rescue the decidualization defects in MEIS1 knockout HESCs. Taken together, these data suggest that MEIS1 plays an indispensable role in decidualization in human endometrial stromal cells, and MEIS1 interacts with HOXA10 to regulate the downstream genes, such as KAT2B and ETA. These findings will contribute to our understanding about the regulatory network in the process of decidualization in humans.