Vascular endothelial growth factor induces growth of uterine cervix and immune cell recruitment in mice

Transcriptomic profile of VEGF-regulated genes in human cervical epithelia

Cervical epithelial cells play a central role in cervical remodeling (CR) during pregnancy and cervical events during menstrual cycle, including mounting physical and immunological barriers, proliferation and differentiation, maintenance of fluid balance, and likely in withstanding the mechanical force exerted by the growing fetus prior to term. In the present study, we attempt to decipher the specific roles of VEGF in fetal human cervical epithelial cells by delineating VEGF signature genes using RNA sequencing in order to characterize the specific biological effects of VEGF in these cells.Out of a total of 25,000 genes screened, 162 genes were found to be differentially expressed in human cervical epithelial cells, of which 12 genes were found to be statistically significantly differentially expressed. The differentially expressed genes (162) were categorized by biological function, which included (1) proliferation, (2) immune response, (3) structure/matrix, (4) mitochondrial function, and (5) cell adhesion/communication and others (pseudogenes, non-coding RNA, miscellaneous genes, and uncharacterized genes). We conclude that VEGF plays a key role in CR by altering the expression of genes that regulate proliferation, immune response, energy metabolism and cell structure, and biological processes that are essential to development and likely CR.

CCR3 antagonist impairs estradiol-induced eosinophil migration to the uterus in ovariectomized mice

Eosinophils are abundant in the reproductive tract, contributing to the remodeling and successful implantation of the embryo. However, the mechanisms by which eosinophils migrate into the uterus and their relationship to edema are still not entirely clear, since there are a variety of chemotactic factors that can cause migration of these cells. Therefore, to evaluate the role of CCR3 in eosinophil migration, ovariectomized C57BL/6 mice were treated with CCR3 antagonist SB 328437 and 17β-estradiol. The hypothesis that the CCR3 receptor plays an important role in eosinophil migration to the mouse uterus was confirmed, because we observed reduction in eosinophil peroxidase activity in these antagonist-treated uteruses. The antagonist also influenced uterine hypertrophy, inhibiting edema formation. Finally, histological analysis of the orcein-stained uteruses showed that the antagonist reduced eosinophil migration together with edema. These data showed that the CCR3 receptor is an important target for studies that seek to clarify the functions of these cells in uterine physiology.

Immunity in the Cervix: Interphase between Immune and Cervical Epithelial Cells

The cervix is divided into two morphologically and immunologically distinct regions, namely, (1) the microbe-laden ectocervix, which is proximal to the vagina, and (2) the "sterile" endocervix, which is distal to the uterus. The two cervical regions are bordered by the cervical transformation zone (CTZ), an area of changing cells, and are predominantly composed of cervical epithelial cells. Epithelial cells are known to play a crucial role in the initiation, maintenance, and regulation of innate and adaptive response in collaboration with immune cells in several tissue types, including the cervix, and their dysfunction can lead to a spectrum of clinical syndromes. For instance, epithelial cells block progression and neutralize or kill microorganisms through multiple ways. These (ways) include mounting physical (intercellular junctions, secretion of mucus) and immune barriers (pathogen-recognition receptor-mediated pathways), which collectively and ultimately lead to the release of specific chemokines and or cytokines. The cytokines subsequently recruit subsets of immune cells appropriate to a particular immune context and response, such as dendritic cells (DCs), T, B, and natural killer (NK) cells. The immune response, as most biological processes in the female reproductive tract (FRT), is mainly regulated by estrogen and progesterone and their (immune cells) responses vary during different physiological phases of reproduction, such as menstrual cycle, pregnancy, and post menopause. The purpose of the present review is to compare the immunological profile of the mucosae and immune cells in the ecto- and endocervix and their interphase during the different phases of female reproduction.

Mechanobiology of mice cervix: expression profile of mechano-related molecules during pregnancy

There is a known reciprocation between the chronic exertion of force on tissue and both increased tissue density (e.g., bone) and hypertrophy (e.g., heart). This can also be seen in cervical tissue where the excessive gravitational forces associated with multiple fetal pregnancies promote preterm births. While there is a well-known regulation of cervical remodeling (CR) by sex steroid hormones and growth factors, the role of mechanical force is less appreciated. Using proteome-wide technology, we previously provided evidence for the presence of and alteration in mechano-related signaling molecules in the mouse cervix during pregnancy. Here, we profile the expression of select cytoskeletal factors (filamin-A, gelsolin, vimentin, actinin-1, caveolin-1, transgelin, keratin-8, profilin-1) and their associated signaling molecules [focal adhesion kinase (FAK) and the Rho GTPases CDC42, RHOA, and RHOB] in cervices of pregnant mice by real-time PCR and confocal immunofluorescence microscopy. Messenger RNA and protein levels increased for each of these 12 factors, except for 3 (keratin-8, profilin-1, RHOA) that decreased during the course of pregnancy and this corresponded with an increase in gravitational force exerted by the fetus on the cervix. We therefore conclude that size or weight of the growing fetus likely plays a key role in CR through mechanotransduction processes.

Neonatal Estrogen Receptor β Is Important in the Permanent Inhibition of Epithelial Cell Proliferation in the Mouse Uterus

Estrogen receptor α (ERα) plays a pivotal role in the mouse uterine and vaginal epithelial cell proliferation stimulated by estrogen, whereas ERβ inhibits cell proliferation. ERβ mRNA is expressed in neonatal uteri and vaginae; however, its functions in neonatal tissues have not been ascertained. In this study, we investigated the ontogenic mRNA expression and localization of ERβ, and its roles in cell proliferation in neonatal uteri and vaginae of ERβ knockout (βERKO) mice. ERβ mRNA and protein were abundant in the uterine and vaginal epithelia of 2-day-old mice and decreased with age. In uterine and vaginal epithelia of 2-day-old βERKO mice, cell proliferation was greater than that in wild-type animals and in uterine epithelia of 90- and 365-day-old βERKO mice. In addition, p27 protein, known as a cyclin-dependent kinase inhibitor, was decreased in the uteri of 90- and 365-day-old βERKO mice. Inhibition of neonatal ERs by ICI 182780 (an ER antagonist) treatment stimulated cell proliferation and decreased p27 protein in the uterine luminal epithelium of 90-day-old mice but not in the vaginal epithelium. These results suggest that neonatal ERβ is important in the persistent inhibition of epithelial cell proliferation with accumulation of p27 protein in the mouse uterus. Thus, suppression of ERβ function in the uterine epithelium during the neonatal period may be responsible for a risk for proliferative disease in adults.

Postpartum cervical repair in mice: a morphological characterization and potential role for angiogenic factors

The cervix undergoes marked mechanical trauma during delivery of the baby at birth. As such, a timely and complete tissue repair postpartum is necessary to prevent obstetrical complications, such as cervicitis, ectropion, hemorrhage, repeated miscarriages or abortions and possibly preterm labor and malignancies. However, our knowledge of normal cervical repair is currently incomplete and factors that influence repair are unclear. Here, we characterize the morphological and angiogenic profile of postpartum repair in mice cervix during the first 48 h of postpartum. The key findings presented here are: (1) cervical epithelial folds and size are diminished during the first 48 h of postpartum repair, (2) hypoxic inducible factor 1a, vascular endothelial growth factor (VEGF), and VEGF receptor 1 expression are pronounced early in postpartum cervical repair, and (3) VEGF receptor 2 gene and protein expressions are variable. We conclude that postpartum cervical repair involves gross and microscopic changes and is linked to expression of angiogenic factors. Future studies will assess the suitability of these factors, identified in the present study, as potential markers for determining the phase of postpartum cervical repair in obstetrical complications, such as cervical lacerations.

Assessment of cervicovaginal vascular endothelial growth factor in predicting preterm delivery

AIM

The aim of this study is to estimate the effectiveness of cervicovaginal vascular endothelial growth factor (VEGF) in predicting preterm delivery.

METHODS

Cervicovaginal VEGF was measured in 30 women who presented symptoms or signs of threatened preterm labor and the control group of 30 healthy pregnant patients by enzyme-linked immunoassay.

RESULTS

There was no statistically significant difference in cervicovaginal VEGF values between the threatened preterm labor group and the control group (P > 0.05). Similarly, no statistically significant difference was observed in terms of cervical length and cervicovaginal VEGF values between preterm and term-delivered groups (P > 0.05). Additionally, there was no correlation between cervicovaginal VEGF values and cervical length (P > 0.05) between the threatened preterm labor and the control groups.

CONCLUSION

No correlation was found between cervicovaginal VEGF values and the preterm delivery. However, we believe that the role of VEGF in preterm delivery needs to be investigated further in well-designed studies with larger samples.