Association between tissue stress reaction and ACE2/TMPRSS2 expression in endometria of reproductive aged women before and during Covid-19 pandemic.

BACKGROUND: A potential concern has been raised regarding fertility and reproductive outcome during the Covid-19 pandemic with growing stress and anxiety. However, information on the association between tissue stress reaction and expression profiles of SARS-CoV-2 viral entry proteins, ACE2 and TMPRSS2, in endometria collected from women before (pre-pandemic) and during the Covid-19 pandemic (in-pandemic) is unknown. We aim to investigate the relationship between the expression of stress-reactive proteins and of ACE2 and TMPRSS2 in endometria collected from women during these two different time frames. METHODS: We retrospectively retrieved tissue blocks of endometrial samples from 25 women in 2019 (pre-pandemic) and 25 women in 2020 (in-pandemic) who underwent hysterectomy for different gynecological indications. Immunohistochemical analysis was performed with endometrial tissue samples that were collected before and during the pandemic, using respective antibodies targeting ACE2/TMPRSS2, ADRB2 and NK1R (stress and anxiety receptor markers, respectively). The quantification of immunoreactive cells for each marker was calculated by the immunoreactive score (IRS) analysis. This retrospective cohort study was limited to small sample size. RESULTS: No significant differences in the IRS of ACE2 and TMPRSS2 were found between the endometria that were collected before and during the pandemic with a lack of correlation between ACE2 and TMPRSS2 expression in respective endometria (r = 0.11, pre-pandemic; r = 0.04, in-pandemic). The immunostaining levels of stress marker, ADRB2 were significantly higher in the endometria of in-pandemic group (p = 0.015) comparing to that of pre-pandemic group. Pearson's correlation coefficient analysis showed a significant correlation in the expression between ADRB2 and TMPRSS2 (r = 0.41, p = 0.042) in the endometria of in-pandemic group but not in the pre-pandemic group. CONCLUSION: The rise in stress and anxiety among women during current pandemic may elicit substantial amount of tissue stress reaction with consequent increase in the expression of SARS-CoV-2 viral entry proteins in their endometria. A lack of correlation between ACE2 and TMPRSS2 expression in endometria may reassure women in their reproductive age that they are not more susceptible to infection by SARS-CoV-2 and suggest that stressful women during this pandemic can safely decide to conceive naturally or by artificial reproductive technology.

Inhibition of Myeloperoxidase Pro-Fibrotic Effect by Noscapine in Equine Endometrium.

Myeloperoxidase is an enzyme released by neutrophils when neutrophil extracellular traps (NETs) are formed. Besides myeloperoxidase activity against pathogens, it was also linked to many diseases, including inflammatory and fibrotic ones. Endometrosis is a fibrotic disease of the mare endometrium, with a large impact on their fertility, where myeloperoxidase was shown to induce fibrosis. Noscapine is an alkaloid with a low toxicity, that has been studied as an anti-cancer drug, and more recently as an anti-fibrotic molecule. This work aims to evaluate noscapine inhibition of collagen type 1 (COL1) induced by myeloperoxidase in equine endometrial explants from follicular and mid-luteal phases, at 24 and 48 h of treatment. The transcription of collagen type 1 alpha 2 chain (COL1A2), and COL1 protein relative abundance were evaluated by qPCR and Western blot, respectively. The treatment with myeloperoxidase increased COL1A2 mRNA transcription and COL1 protein, whereas noscapine was able to reduce this effect with respect to COL1A2 mRNA transcription, in a time/estrous cycle phase-dependent manner (in explants from the follicular phase, at 24 h of treatment). Our study indicates that noscapine is a promising drug to be considered as an anti-fibrotic molecule to prevent endometrosis development, making noscapine a strong candidate to be applied in future endometrosis therapies.

Predicted COVID-19 molecular effects on endometrium reveal key dysregulated genes and functions.

COVID-19 exerts systemic effects that can compromise various organs and systems. Although retrospective and in silico studies and prospective preliminary analysis have assessed the possibility of direct infection of the endometrium, there is a lack of in-depth and prospective studies on the impact of systemic disease on key endometrial genes and functions across the menstrual cycle and window of implantation. Gene expression data have been obtained from (i) healthy secretory endometrium collected from 42 women without endometrial pathologies and (ii) nasopharyngeal swabs from 231 women with COVID-19 and 30 negative controls. To predict how COVID-19-related gene expression changes impact key endometrial genes and functions, an in silico model was developed by integrating the endometrial and COVID-19 datasets in an affected mid-secretory endometrium gene co-expression network. An endometrial validation set comprising 16 women (8 confirmed to have COVID-19 and 8 negative test controls) was prospectively collected to validate the expression of key genes. We predicted that five genes important for embryo implantation were affected by COVID-19 (downregulation of COBL, GPX3 and SOCS3, and upregulation of DOCK2 and SLC2A3). We experimentally validated these genes in COVID-19 patients using endometrial biopsies during the secretory phase of the menstrual cycle. The results generally support the in silico model predictions, suggesting that the transcriptomic landscape changes mediated by COVID-19 affect endometrial receptivity genes and key processes necessary for fertility, such as immune system function, protection against oxidative damage and development vital for embryo implantation and early development.

SARS-CoV-2 infection risk assessment in the endometrium: viral infection-related gene expression across the menstrual cycle.

OBJECTIVE: To determine the susceptibility of the endometrium to infection by-and thereby potential damage from-SARS-CoV-2. DESIGN: Analysis of SARS-Cov-2 infection-related gene expression from endometrial transcriptomic data sets. SETTING: Infertility research department affiliated with a public hospital. PATIENT(S): Gene expression data from five studies in 112 patients with normal endometrium collected throughout the menstrual cycle. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Gene expression and correlation between viral infectivity genes and age throughout the menstrual cycle. RESULT(S): Gene expression was high for TMPRSS4, CTSL, CTSB, FURIN, MX1, and BSG; medium for TMPRSS2; and low for ACE2. ACE2, TMPRSS4, CTSB, CTSL, and MX1 expression increased toward the window of implantation. TMPRSS4 expression was positively correlated with ACE2, CTSB, CTSL, MX1, and FURIN during several cycle phases; TMPRSS2 was not statistically significantly altered across the cycle. ACE2, TMPRSS4, CTSB, CTSL, BSG, and MX1 expression increased with age, especially in early phases of the cycle. CONCLUSION(S): Endometrial tissue is likely safe from SARS-CoV-2 cell entry based on ACE2 and TMPRSS2 expression, but susceptibility increases with age. Further, TMPRSS4, along with BSG-mediated viral entry into cells, could imply a susceptible environment for SARS-CoV-2 entry via different mechanisms. Additional studies are warranted to determine the true risk of endometrial infection by SARS-CoV-2 and implications for fertility treatments.

Clinical molecular genetics evaluation in women with reproductive failures.

Molecular diagnostics is a rapidly growing branch of the clinical laboratory and has accelerated the advance of personalized medicine in the fields of pharmacogenomics, pharmacogenetics, and nutrigenomics. The versatility of molecular biology allows it to be effective in several medical fields that include reproduction, immunogenetics, and virology. Implementation of molecular and sequencing technology in reproductive medicine can add another layer of understanding to better define the causes behind infertility and recurrent reproductive loss. In the following, we examine current molecular methods for probing factors behind reproductive pregnancy loss including reverse transcription polymerase chain reaction and next generation sequencing (NGS). We review several current and potential genetic (DNA) and transcriptional (RNA)-based parameters in women with infertility that can be significant in diagnosis and treatment. These molecular factors can be inferred either from genomic DNA or RNA locally within the endometrium. Furthermore, we consider infection-based abnormalities such as human herpesvirus-6 and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Finally, we present future directions as well as data demonstrating the potential role of human endogenous retroviruses in pregnancy loss. We hope these discussions will assist the clinician in delineating some of the intricate molecular factors that can contribute to infertility and recurrent reproductive failures.