A proteomic profile of postpartum cervical repair in mice

Macrophage polarisation in caesarean scar diverticulum

AIMS

To determine immunohistochemical features and correlations between M1/M2 polarisation status with disease severity of post-caesarean scar diverticulum (CSD).

METHODS

Histological and immunohistological stainings were performed and inflammatory (CD16, CD163 and tumour necrosis factor-α (TNF-α)), fibrosis (α-smooth muscle actin (α-SMA)) and angiogenic (CD31) markers were examined in uterine tissues collected from patients with uterine scar diverticula (CSD) (n=37) and caesarean section (CS) (n=3).

RESULTS

CSD tissues have higher expression of α-SMA, TNF-α, CD16 and CD31 and lower expression of CD163 than CS tissue (p<0.05). Compared with adjacent tissues, thick-walled blood vessels, glands and fibrotic sites have higher expression of α-SMA, TNF-α and CD16. Statistical correlation was observed between the expression of CD16 and TNF-α (R=0.693, p<0.001), α-SMA (R=0.404, p<0.05) and CD31 (R=0.253, p<0.05) in CSD tissues, especially with the ratio of CD16/CD163 (R=0.590, p<0.01). A more significant difference was observed between the expression of CD16/CD163 and α-SMA (R=0.556, p<0.001), TNF-α (R=0.633, p<0.0001) and CD31 (R=0.336, p<0.05).

CONCLUSIONS

In this study, TNF-α, α-SMA, CD16 and CD31 proteins were overexpressed in all CSD cases, and CD16/CD163 was positively correlated with tissue inflammation, fibrosis and neovascularisation. Abnormal mononuclear macrophage infiltration may be involved in the origin and progression of CSD.

Estrogen Receptor Modulators in Viral Infections Such as SARS-CoV-2: Therapeutic Consequences

COVID-19 is a pandemic respiratory disease caused by the SARS-CoV-2 coronavirus. The worldwide epidemiologic data showed higher mortality in males compared to females, suggesting a hypothesis about the protective effect of estrogens against severe disease progression with the ultimate end being patient's death. This article summarizes the current knowledge regarding the potential effect of estrogens and other modulators of estrogen receptors on COVID-19. While estrogen receptor activation shows complex effects on the patient's organism, such as an influence on the cardiovascular/pulmonary/immune system which includes lower production of cytokines responsible for the cytokine storm, the receptor-independent effects directly inhibits viral replication. Furthermore, it inhibits the interaction of IL-6 with its receptor complex. Interestingly, in addition to natural hormones, phytestrogens and even synthetic molecules are able to interact with the estrogen receptor and exhibit some anti-COVID-19 activity. From this point of view, estrogen receptor modulators have the potential to be included in the anti-COVID-19 therapeutic arsenal.

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.

Extracellular Matrix Rigidity Modulates Human Cervical Smooth Muscle Contractility-New Insights into Premature Cervical Failure and Spontaneous Preterm Birth

Spontaneous preterm birth (sPTB), a major cause of infant morbidity and mortality, must involve premature cervical softening/dilation for a preterm vaginal delivery to occur. Yet, the mechanism behind premature cervical softening/dilation in humans remains unclear. We previously reported the non-pregnant human cervix contains considerably more cervical smooth muscle cells (CSMC) than historically appreciated and the CSMC organization resembles a sphincter. We hypothesize that premature cervical dilation leading to sPTB may be due to (1) an inherent CSMC contractility defect resulting in sphincter failure and/or (2) altered cervical extracellular matrix (ECM) rigidity which influences CSMC contractility. To test these hypotheses, we utilized immunohistochemistry to confirm this CSMC phenotype persists in the human pregnant cervix and then assessed in vitro arrays of contractility (F:G actin ratios, PDMS pillar arrays) using primary CSMC from pregnant women with and without premature cervical failure (PCF). We show that CSMC from pregnant women with PCF do not have an inherent CSMC contractility defect but that CSMC exhibit decreased contractility when exposed to soft ECM. Given this finding, we used UPLC-ESI-MS/MS to evaluate collagen cross-link profiles in the cervical tissue from non-pregnant women with and without PCF and found that women with PCF have decreased collagen cross-link maturity ratios, which correlates to softer cervical tissue. These findings suggest having soft cervical ECM may lead to decreased CSMC contractile tone and a predisposition to sphincter laxity that contributes to sPTB. Further studies are needed to explore the interaction between cervical ECM properties and CSMC cellular behavior when investigating the pathophysiology of sPTB.

Evidence of macrophage modulation in the mouse pubic symphysis remodeling during the end of first pregnancy and postpartum

In mouse pregnancy, pubic symphysis (PS) remodels into an elastic interpubic ligament (IpL) in a temporally regulated process to provide safe delivery. It restores at postpartum to assure reproductive tract homeostasis. Recently, macrophage localization in the IpL and dynamic changes in the expression of inflammatory mediators observed from the end of pregnancy (D18, D19) to early days postpartum (1dpp, 3dpp) highlighted the necessity of the identification of the key molecules involved in innate immune processes in PS remodeling. Therefore, this study uses morphological and high-sensitivity molecular techniques to identify both macrophage association with extracellular matrix (ECM) remodeling and the immunological processes involved in PS changes from D18 to 3dpp. Results showed macrophage association with active gelatinases and ECM components and 25 differentially expressed genes (DEGs) related to macrophage activities in interpubic tissues from D18 to 3dpp. Additionally, microarray and proteomic analysis showed a significant association of interpubic tissue DEGs with complement system activation and differentially expressed proteins (DEPs) with phagocytosis, highlighting the involvement of macrophage-related activities in mouse PS remodeling. Therefore, the findings suggest that PS ECM remodeling is associated with evidence of macrophage modulation that ensures both IpL relaxation and fast PS recovery postpartum for first labor.

Immunobiology of Cervix Ripening

The cervix is the essential gatekeeper for birth. Incomplete cervix remodeling contributes to problems with delivery at or post-term while preterm birth is a major factor in perinatal morbidity and mortality in newborns. Lack of cervix biopsies from women during the period preceding term or preterm birth have led to use of rodent models to advanced understanding of the mechanism for prepartum cervix remodeling. The critical transition from a soft cervix to a compliant prepartum lower uterine segment has only recently been recognized to occur in various mammalian species when progesterone in circulation is at or near the peak of pregnancy in preparation for birth. In rodents, characterization of ripening resembles an inflammatory process with a temporal coincidence of decreased density of cell nuclei, decline in cross-linked extracellular collagen, and increased presence of macrophages in the cervix. Although a role for inflammation in parturition and cervix remodeling is not a new concept, a comprehensive examination of literature in this review reveals that many conclusions are drawn from comparisons before and after ripening has occurred, not during the process. The present review focuses on essential phenotypes and functions of resident myeloid and possibly other immune cells to bridge the gap with evidence that specific biomarkers may assess the progress of ripening both at term and with preterm birth. Moreover, use of endpoints to determine the effectiveness of various therapeutic approaches to forestall remodeling and reduce risks for preterm birth, or facilitate ripening to promote parturition will improve the postpartum well-being of mothers and newborns.

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.