Transforming Growth Factor (TGF) β and Endometrial Vascular Maturation

EV-microRNA signatures in pregnant women with idiopathic recurrent pregnancy loss: deciphering microRNAome pathway networks at feto-maternal interface

Background

Despite extensive research in the past decade, the exact pathogenesis of recurrent pregnancy loss (RPL) remains unknown. At the time of pregnancy, human placenta releases microRNAs (miRNAs) enclosed in extracellular vesicles (EVs), which enter into maternal circulation and play an important role at feto-maternal interface to sustain a successful pregnancy. Aberrant expression of these miRNAs often results in adverse pregnancy complications. Therefore, studying the expression of these EV-miRNAs in maternal circulation could provide insights into the pathogenesis of RPL.

Methods

The present study included idiopathic currently pregnant (<22 weeks of gestation) RPL women (n=10) and gestational-age-matched healthy pregnant women as control (n=5). EVs were isolated from plasma samples and characterized for their morphology and cell-surface marker. Total RNA was isolated and subjected to miRNA sequencing on Illumina NovaSeq 6000 platform. Differentially expressed (DE) miRNAs were identified using DESeq package. Target prediction and pathway analysis were done using TargetScan, miRDB, miRTarBase, and DIANA-miRPath v3.0 online tool. Protein-protein interaction was done using STRING, and hub genes were identified using Cytoscape software.

Results

miRNA sequencing revealed 66 (44 known and 22 novel) significantly DE miRNAs between RPL and healthy pregnant women. Among these, 37 were downregulated and 29 were upregulated, log2|FC| ≥ 1. Network-based analysis showed highest degree for nine miRNAs (hsa-miR-155-5p, hsa-miR-26a-5p, hsa-miR-204-5p, hsa-miR-140-5p, hsa-miR-139-5p, hsa-let-7e-5p, hsa-miR-149-5p, hsa-miR-374a-5p, and hsa-miR-190a-5p). Gene Ontology (GO) and KEGG pathway analysis of target genes showed significant involvement of Hippo, FoxO, TGF-β, and p53 signaling pathways, which play a crucial role in RPL. Top 10 identified hub genes (NFKB1, IL6, JUN, FOS, CXCL8, PTGS2, TGFB1, MMP9, STAT1, and CD4) were significantly enriched in immunological pathways-Th1/Th2/Th17 differentiation, NF-κB pathway, TNF-α signaling, IL-17 signaling pathway, and vascular endothelial growth factor (VEGF) pathway.

Conclusion

These results suggest that circulating EV-miRNAs in maternal blood could provide clinical insights into the pathogenesis of RPL and dysregulated immunological and molecular pathways at feto-maternal interface.

Angiopoietin-2 regulates the phenotypic switch of vascular smooth muscle cells

During uterine spiral artery remodeling, vascular smooth muscle cells (VSMCs) become disorganized and undergo phenotypic switching from a contractile to a more synthetic phenotype. We have previously reported that uterine natural killer cells induce this VSMC phenotypic switching by secreting angiopoietin-2 (Ang-2). Here, we identified the specific mechanisms by which Ang-2 plays a role in this phenomenon. VSMCs isolated from human umbilical arteries were used as an in vitro model to investigate the role of Ang-2 in phenotypic switching. Human decidua tissue from preeclamptic and control pregnancies was collected to compare the expression levels of related proteins. Ang-2 induced a more synthetic phenotype in VSMCs as evidenced by decreased contractile marker expression, increased proliferation and migration, and an altered cytoskeleton. VSMC expressed integrin β6 interacted directly with Ang-2 and induced phosphorylation of FAK (S910 and Y397), AKT (S473), and mTOR (S2448). Knockdown of FAK recovered the calponin loss induced by Ang-2 and resulted in lower EZH2 abundance. Inhibition of FAK and EZH2 both attenuated Ang-2-induced inhibition of the LC3 II/LC3 I ratio and ATG7 expression, and proliferation. Lipid peroxidation inhibition by ferrostatin-1 or the IL-8 receptor antagonist navarixin inhibited the Ang-2-induced migration. IL-8 secretion was significantly lower with lipid peroxidation inhibition. In preeclamptic decidua, there were more unremodeled spiral arteries, and the abundance of Ang-2 was dysregulated. Ang-2 dysregulation may disrupt spiral artery remodeling and contribute to preeclampsia. Ang-2 may be a novel therapeutic target for the treatment of pregnancy complications affected by incomplete spiral artery remodeling.

Integral Roles of the TGFβ Signaling Pathway in Uterine Function and Disease

The uterus is a complex organ that requires precise signaling networks to mediate functions necessary for homeostasis and reproductive processes. The transforming growth factor β (TGFβ) superfamily regulates integral signaling pathways throughout many physiological processes, including cell proliferation, differentiation, and development. In this review, we summarize the current understanding of how the TGFβ signaling family controls key uterine functions, with a specific focus on the endometrium. These uterine functions include endometrial receptivity, implantation, decidualization, placentation, remodeling, and regeneration. Improving our understanding of the signaling networks that regulate these processes is integral to identifying, diagnosing, and treating uterine and reproductive diseases such as endometriosis, adenomyosis, recurrent pregnancy loss, and recurrent implantation failure.

Factors Influencing Collateral Circulation Formation After Indirect Revascularization for Moyamoya Disease: a Narrative Review

Indirect revascularization is one of the main techniques for the treatment of Moyamoya disease. The formation of good collateral circulation is a key measure to improve cerebral blood perfusion and reduce the risk of secondary stroke, and is the main method for evaluating the effect of indirect revascularization. Therefore, how to predict and promote the formation of collateral circulation before and after surgery is important for improving the success rate of indirect revascularization in Moyamoya disease. Previous studies have shown that vascular endothelial growth factor, endothelial progenitor cells, Caveolin-1, and other factors observed in patients with Moyamoya disease may play a key role in the generation of collateral vessels after indirect revascularization through endothelial hyperplasia and smooth muscle migration. In addition, mutations in the genetic factor RNF213 have also been associated with this process. This study summarizes the factors and mechanisms influencing collateral circulation formation after indirect revascularization in Moyamoya disease.

Angiogenesis in abnormal uterine bleeding: a narrative review

BACKGROUND

Abnormal uterine bleeding (AUB) has a significant socioeconomic impact since it considerably impacts quality of life. Therapeutic options are frequently based on trial and error and do not target disease aetiology. Pathophysiological insight in this disease is required for the development of novel treatment options. If no underlying cause is found for the AUB (e.g. fibroids, adenomyosis, polyps), endometrial-AUB (AUB-E) is usually caused by a primary endometrium disorder. When AUB is induced by prescribed (exogenous) hormones, it is classified as iatrogenic-AUB (AUB-I). Considering vascular modulation and function, AUB-E and AUB-I both could potentially result from abnormal vascularization in the endometrium due to alterations in the process of angiogenesis and vascular maturation.

OBJECTIVE AND RATIONALE

We aim to investigate the fundamental role of angiogenesis and vascular maturation in patients with AUB and hypothesize that aberrant endometrial angiogenesis has an important role in the aetiology of both AUB-E and AUB-I, possibly through different mechanisms.

SEARCH METHODS

A systematic literature search was performed until September 2021 in the Cochrane Library Databases, Embase, PubMed, and Web of Science, with search terms such as angiogenesis and abnormal uterine bleeding. Included studies reported on angiogenesis in the endometrium of premenopausal women with AUB-E or AUB-I. Case reports, letters, reviews, editorial articles, and studies on AUB with causes classified by the International Federation of Gynecology and Obstetrics as myometrial, oncological, or infectious, were excluded. Study quality was assessed by risk of bias, using the Cochrane tool and the Newcastle-Ottawa Scale.

OUTCOMES

Thirty-five out of 2158 articles were included. In patients with AUB-E, vascular endothelial growth factor A and its receptors (1 and 2), as well as the angiopoietin-1:angiopoietin-2 ratio and Tie-1, were significantly increased. Several studies reported on the differential expression of other pro- and antiangiogenic factors in patients with AUB-E, suggesting aberrant vascular maturation and impaired vessel integrity. Overall, endometrial microvessel density (MVD) was comparable in patients with AUB-E and controls. Interestingly, patients with AUB-I showed a higher MVD and higher expression of proangiogenic factors when compared to controls, in particular after short-term hormone exposure. This effect was gradually lost after longer-term exposure, while alterations in vessel maturation were observed after both short- and long-term exposures.

WIDER IMPLICATIONS

AUB-E and AUB-I are most likely associated with aberrant endometrial angiogenesis and impaired vessel maturation. This review supports existing evidence that increased proangiogenic and decreased antiangiogenic factors cause impaired vessel maturation, resulting in more fragile and permeable vessels. This matches our hypothesis and these mechanisms appear to play an important role in the pathophysiology of AUB-E and AUB-I. Exploring the alterations in angiogenesis in these patients could provide treatment targets for AUB.

Cyclic processes in the uterine tubes, endometrium, myometrium, and cervix: pathways and perturbations

This review leads the 2023 Call for Papers in MHR: 'Cyclical function of the female reproductive tract' and will outline the complex and fascinating changes that take place in the reproductive tract during the menstrual cycle. We will also explore associated reproductive tract abnormalities that impact or are impacted by the menstrual cycle. Between menarche and menopause, women and people who menstruate living in high-income countries can expect to experience ∼450 menstrual cycles. The primary function of the menstrual cycle is to prepare the reproductive system for pregnancy in the event of fertilization. In the absence of pregnancy, ovarian hormone levels fall, triggering the end of the menstrual cycle and onset of menstruation. We have chosen to exclude the ovaries and focus on the other structures that make up the reproductive tract: uterine tubes, endometrium, myometrium, and cervix, which also functionally change in response to fluctuations in ovarian hormone production across the menstrual cycle. This inaugural paper for the 2023 MHR special collection will discuss our current understanding of the normal physiological processes involved in uterine cyclicity (limited specifically to the uterine tubes, endometrium, myometrium, and cervix) in humans, and other mammals where relevant. We will emphasize where knowledge gaps exist and highlight the impact that reproductive tract and uterine cycle perturbations have on health and fertility.

A cross-sectional study comparing the inflammatory profile of menstrual effluent vs. peripheral blood

Background and Aims

Cytokine profiles of peripheral blood and other bodily fluids provide diagnostic indicators for assessing inflammatory processes. Menstrual effluent may provide a noninvasive source of biological material for monitoring cytokine levels in blood and in endometrial tissues. This pilot study investigated the potential of measuring cytokines in menstrual effluent, and compared the cytokine profiles of menstrual versus peripheral blood.

Methods

Seven healthy donors (aged ≥18 and ≤45 years) collected menstrual effluent on day 2 of menses. Matched peripheral blood samples were collected by venous blood draw on the same day. Levels of 62 cytokines were measured in all samples by 62-plex Luminex assay.

Results

Peripheral blood and menstrual effluent cytokine profiles were tenuously correlated (r 2 = 0.26, p < 0.0001), with higher levels detected in menstrual effluent for 48/62 cytokines. Thirty five cytokines were significantly elevated in menstrual effluent compared to peripheral blood samples (IL-8, CCL2, CCL4, LIF, IL-1RA, IL-6, IL-1β, HGF, CCL3, FGF-2, TNF-α, VEGF-A, IL-1α, CXCL1, IL-9, IL-10, EGF, CXCL5, CSF3, EOTAXIN, TGF-α, TRAIL, CXCL10, VEGF-D, IL-12P40, CXCL9, IL-18 RESISTIN, IL-22, IL-21, CSF1, IFN-γ, IL-17A, CXCL12, IL-12p70). Two cytokines (LEPTIN, CSF2) were expressed at significantly lower levels in menstrual effluent compared to peripheral blood. Linear regression of individual cytokines found low predictive power (linear regression p > 0.05) for 53/62 cytokines in menstrual effluent versus peripheral blood. Levels of TGF-β (r 2 = 0.87, p = 0.002) and CCL7 (r 2 = 0.63, p = 0.033) were significantly positively correlated between matched menstrual and peripheral blood samples.

Conclusion

In this group of study participants, the cytokine profile of menstrual effluent was quantitatively distinct from peripheral blood, and also characterized by higher levels of inflammatory signaling. This pattern of comparative menstrual blood cytokine profiles points to a need for further studies to evaluate the relationship between peripheral and menstrual blood cytokines in broader populations including both healthy and diseased states.

Expression deregulation of matrix metalloproteinases and vasoconstriction related genes in Pakistani females with abnormal uterine bleeding

BACKGROUND

Abnormal uterine bleeding (AUB) is irregular menstrual bleeding which has great impact on female health and life style. Various genetic factors are involved in etiology and pathology of AUB. Present study was designed to explore the association of PTGFR, MMP9, MMP2, TGFB3 and VEGFB with AUB.

METHODS

Blood samples of 212 females with AUB were collected along with age-matched healthy control. Expression variation of targeted genes was evaluated using qPCR. Present study cohort was divided into different groups based on demographic parameters and all targeted genes were correlated with study demographics.

RESULTS

Expression of targeted genes was significantly (P < 0.001) downregulated in females with AUB compared to control. Reduced (P < 0.01) expression of targeted genes was observed in all age groups (21-30, 31-40, 41-50 year) of AUB patients compared to respective control. Expression of VEGFB increased (P < 0.05) in AUB females with > 9 days bleeding compared to AUB patient had < 9 days bleeding. AUB women with miscarriage history showed upregulation in MMP2, TGFB3 (P < 0.05), and downregulation in MMP9 and VEGFB (P < 0.05) expression compared to AUB group with no miscarriage history. Expression of MMP2 increased (P < 0.05) in AUB females with > 60 kg body weigh compared to AUB patient with < 60 kg weight.

CONCLUSION

Present study open a new window for diagnosis of AUB at early stages and suggested a possible involvement of PTGFR, MMP9, MMP2, TGFB3 and VEGFB as candidate biomarkers in AUB.

TGFβ1 as a Predictive Biomarker for Collateral Formation Within Ischemic Moyamoya Disease

Objective

Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease characterized by progressive steno-occlusion within the terminal segment of the internal carotid artery. However, good collaterals from an external carotid artery are essential to compensate for the ischemia in moyamoya disease. This study aimed to investigate the transforming growth factor-beta 1 (TGFβ1) in plasma as a potential biomarker for predicting collateral formation in ischemic MMD.

Methods

The transcriptome profile downloaded from Gene Expression Omnibus (GEO) was used to analyze the differential expression of genes between the ischemic MMD and the control groups. We prospectively recruited 23 consecutive patients with ischemic MMD that was diagnosed via digital subtraction angiography (DSA). Nine patients with intracranial aneurysms and four healthy people served as controls. The collaterals from the external carotid artery were examined using DSA. We evaluated whether the collateral formation was associated with TGFβ1 in patients with ischemic MMD. Western blot, RT-qPCR, ELISA, and tube formation assay were used to explore the relationship between TGFβ1 and angiogenesis, as well as the potential mechanisms.

Results

The mRNA levels of TGFβ1 were upregulated in the patients with ischemic MMD. The plasma TGFβ1 levels were higher in the patients with ischemic MMD than in the aneurysm and healthy patients (p < 0.05). The collateral formation group has higher levels of serum TGFβ1 than the non-collateral formation group (p < 0.05). The levels of vascular endothelial growth factor (VEGF) are positively correlated with TGFβ1 levels in the plasma (R² = 0.6115; p < 0.0001). TGFβ1 regulates VEGF expression via the activation of the TGFβ pathway within HUVEC cells, as well as TGFβ1 stimulating HUVEC cells to secrete VEGF into the cell culture media. An in vitro assay revealed that TGFβ1 promotes angiogenesis within the endothelial cells.

Conclusion

Our findings suggest that TGFβ1 plays a vital role in promoting collateral formation by upregulating VEGF expression in ischemic MMD.

Uterine bleeding: how understanding endometrial physiology underpins menstrual health

Menstruation is a physiological process that is typically uncomplicated. However, up to one third of women globally will be affected by abnormal uterine bleeding (AUB) at some point in their reproductive years. Menstruation (that is, endometrial shedding) is a fine balance between proliferation, decidualization, inflammation, hypoxia, apoptosis, haemostasis, vasoconstriction and, finally, repair and regeneration. An imbalance in any one of these processes can lead to the abnormal endometrial phenotype of AUB. Poor menstrual health has a negative impact on a person's physical, mental, social, emotional and financial well-being. On a global scale, iron deficiency and iron deficiency anaemia are closely linked with AUB, and are often under-reported and under-recognized. The International Federation of Gynecology and Obstetrics have produced standardized terminology and a classification system for the causes of AUB. This standardization will facilitate future research endeavours, diagnosis and clinical management. In a field where no new medications have been developed for over 20 years, emerging technologies are paving the way for a deeper understanding of the biology of the endometrium in health and disease, as well as opening up novel diagnostic and management avenues.

The Menstrual Endometrium: From Physiology to Future Treatments

Abnormal uterine bleeding (AUB) is experienced by up to a third of women of reproductive age. It can cause anaemia and often results in decreased quality of life. A range of medical and surgical treatments are available but are associated with side effects and variable effectiveness. To improve the lives of those suffering from menstrual disorders, delineation of endometrial physiology is required. This allows an increased understanding of how this physiology may be disturbed, leading to uterine pathologies. In this way, more specific preventative and therapeutic strategies may be developed to personalise management of this common symptom. In this review, the impact of AUB globally is outlined, alongside the urgent clinical need for improved medical treatments. Current knowledge of endometrial physiology at menstruation is discussed, focusing on endocrine regulation of menstruation and local endometrial inflammation, tissue breakdown, hypoxia and endometrial repair. The contribution of the specialised endometrial vasculature and coagulation system during menstruation is highlighted. What is known regarding aberrations in endometrial physiology that result in AUB is discussed, with a focus on endometrial disorders (AUB-E) and adenomyosis (AUB-A). Gaps in existing knowledge and areas for future research are signposted throughout, with a focus on potential translational benefits for those experiencing abnormal uterine bleeding. Personalisation of treatment strategies for menstrual disorders is then examined, considering genetic, environmental and demographic characteristics of individuals to optimise their clinical management. Finally, an ideal model of future management of AUB is proposed. This would involve targeted diagnosis of specific endometrial aberrations in individuals, in the context of holistic medicine and with due consideration of personal circumstances and preferences.

Main actors behind the endometrial receptivity and successful implantation

Embryo implantation occurs during a short period of time, the implantation window, in the mid-secretory phase of the menstrual cycle. The cross-talk between the endometrium and the embryo, at the stage of blastocyst, is a necessary condition for successful implantation. Till now, no single molecule or receptor has been identified to play an essential role on embryo implantation but a huge number of mediators, including cytokines, lipids, adhesion molecules, growth factors, and others, are reported to support the establishment of pregnancy. Therefore, the aim of this review is not only to describe the different actors involved in the implantation process, but also to try to characterize the relationships between these factors as well as their time-regulated activation. Moreover, the availability of in vitro culture systems to study the interactions between embryo and endometrium as well as the paracrine communication regulated by exosomal vesicles will be investigated, as an innovative approach for a more precise characterization of the interactions between the different molecules involved in this process. The in-depth knowledge of all these complex mechanisms will allow to address the reasons of implantation failure and infertility, thus providing new avenues for promoting the successful establishment of a pregnancy.