Metformin ameliorates endometrial thickness in a rat model of thin endometrium.

Metformin, a well-established anti-diabetic drug, is also used in managing various other metabolic disorders including polycystic ovarian syndrome (PCOS). There are evidences to show that metformin improves endometrial functions in PCOS women. However, fewer studies have explored the direct effects of metformin on endometrium. Previous in vitro studies have shown that therapeutic serum concentrations of metformin enhance endometrial epithelial cell proliferation. The present study was undertaken to investigate in vivo effects of metformin on endometrial proliferation in a rat model of thin endometrium. Toward this, a rat model of thin endometrium was developed. Metformin (0.1% or 1% w/v) was administrated orally for 15 days in rats with thin endometrium. Oral metformin administration for three consecutive estrous cycles (15 days) in the thin endometrium rat model led to an increase in endometrial thickness compared to sham endometrium. Histological analysis showed a significant increase in the number of endometrial glands (P < 0.05), stromal cells (P < 0.01) and blood vessels (P < 0.01) in metformin-treated (n = 10 in each group) uterine horns compared to sham (saline-treated) uterine horns in rats. The expression of proliferating cell nuclear antigen and vascular epithelial growth factor was found to be upregulated on treatment with 1% metformin-treated group (n = 7). However, pregnancy outcomes in the rats treated with metformin remained unaltered despite the restoration of endometrial thickness. In conclusion, the study demonstrated that metformin ameliorates endometrial thickness in a rat model of thin endometrium by increasing endometrial proliferation and angiogenesis, without restoration of embryo implantation.

The dynamics of SARS-CoV-2 infection in unvaccinated and vaccinated populations in Mumbai, India, between 28 December 2020 and 30 August 2021.

The emergence and evolution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants that could compromise vaccine efficacy (VE) with re-infections in immunized individuals have necessitated continuous surveillance of VE. Here, the occurrence and dynamics of SARS-CoV-2 infections in the context of vaccination during the second wave of infection in Mumbai were evaluated. RT-PCR cycle threshold (Ct) values of the open reading frame (ORF)/envelope (E)/nucleocapsid (N) genes obtained from a total of 42415 samples, comprising unvaccinated (96.88%) and vaccinated cases (3.12%) were analyzed between December 28, 2020, and August 30, 2021. A lower incidence of SARS-CoV-2 infection in fully vaccinated cases (5.07%) compared to partially vaccinated cases (6.5%) and unvaccinated cases (13.453%) was recorded. VE was significant after the first dose of vaccination (ORF gene p-value = 0.003429, and E/N gene p-value = 0.000866). Furthermore, VE was observed to be significant when the post-immunization (first dose) period was stratified to within 30 days (ORF gene p-value = 0.0094 and E/N gene p-value = 0.0023) and to 60 days following the second dose of vaccination (ORF gene p-value = 0.0238). Also, significantly higher efficacy was observed within individuals receiving two doses compared to a single dose (ORF gene p-value = 0.0132 and E/N gene p-value = 0.0387). The emergence of breakthrough infections was also evident (odds ratio= 0.34; 95% confidence interval= 0.27-0.43). Interestingly, viral loads trended towards being higher in some groups of partially vaccinated individuals compared to completely vaccinated and unvaccinated populations. Finally, our results delineated a significantly higher incidence of SARS-CoV-2 acquisition in males, asymptomatic individuals, individuals with comorbidities, and those who were unvaccinated.

Pregnancy outcomes among Indian women: increased prevalence of miscarriage and stillbirth during 2015-2021.

BACKGROUND: Pregnancy outcome is an important health indicator of the quality of maternal health. Adverse pregnancy outcomes is a major public health problem, which can lead to poor maternal and neonatal outcomes. This study investigates the trends in pregnancy outcomes prevalent during 2015-2021 in Indian women. METHODS: The study analysed the data presented in the fourth (2015-16) and fifth (2019-21) rounds of National Family Health Survey (NFHS). The absolute and relative changes in the birth outcomes of last pregnancy during the five years preceding the surveys were estimated using data collected from 195,470 women in NFHS-4 and from 255,549 women in NFHS-5. RESULTS: Livebirth decreased by 1.3 points (90.2% vs. 88.9%), and nearly half of the Indian states/UTs (n = 17/36) had lower than the national average of livebirth (88.9%) reported during 2019-21. A higher proportion of pregnancy loss was noted, particularly miscarriages increased in both urban (6.4% vs. 8.5%) and rural areas (5.3% vs. 6.9%), and stillbirth increased by 28.6% (0.7% vs. 0.9%). The number of abortions decreased (3.4% vs. 2.9%) among Indian women. Nearly half of the abortions were due to unplanned pregnancies (47.6%) and more than one-fourth (26.9%) of abortions were performed by self. Abortions among adolescent women in Telangana was eleven times higher during 2019-21 as compared to 2015-16 (8.0% vs. 0.7%). CONCLUSION: Our study presents evidence of a decrease in the livebirth and an increase in the frequency of miscarriage and stillbirth among Indian women during 2015-2021. This study emphasises that there is a need of regional-specific, comprehensive and quality maternal healthcare programs for improving livebirth among Indian women.

Therapeutic metformin concentrations positively regulate proliferation in endometrial epithelial cells via mTOR activation and augmented mitochondrial strength.

Metformin, an antidiabetic drug, has recently been repositioned in the treatment of several nondiabetic disorders, including reproductive disorders such as polycystic ovarian syndrome, where it improves endometrial functions. In vitro studies employing supratherapeutic concentrations (5-20 mmol/L) of metformin have reported antiproliferative effects on endometrial epithelial and stromal cells. However, animal and human studies have revealed that therapeutic serum concentrations of metformin range between 20 and 70 µmol/L. In the present study, the effect of therapeutic concentrations of metformin was studied on endometrial epithelial cells (EECs). Therapeutic concentrations of metformin induced proliferation in Ishikawa and HEC-1A cells. The proliferation of EECs was found to be mammalian target of rapamycin (mTOR) dependent. Interestingly, therapeutic metformin concentrations were not able to activate the classical AMP-activated protein kinase (AMPK) signaling. On the contrary, supratherapeutic metformin concentration (10 mmol/L) inhibited mTOR and activated AMPK signaling. Microarray analysis of metformin-treated HEC-1A cells revealed dose-dependent differential effects on biological pathways associated with translation, ribosomal RNA processing, mitochondrial translation, and cell proliferation. Therapeutic concentrations of metformin upregulated mitochondrial number as demonstrated by increased MitoTracker™ Red staining and enhanced succinate dehydrogenase expression; however, higher concentration (10 mmol/L) abrogated the same. Our results suggest that therapeutic concentrations of metformin augment mitochondrial strength and induce mTOR-dependent endometrial cell proliferation.

Dysregulation of X-ray repair cross-complementing 4 expression in the eutopic endometrium of women with endometriosis.

Recent data suggest that the DNA damage response (DDR) is altered in the eutopic endometrium (EE) of women with endometriosis and this probably ensues in response to higher DNA damage encountered by the EE in endometriosis. DDR operates in a tissue-specific manner and involves different pathways depending on the type of DNA lesions. Among these pathways, the non-homologous end joining (NHEJ) pathway plays a critical role in the repair of dsDNA breaks. The present study was undertaken to explore whether NHEJ is affected in the EE of women with endometriosis. Toward this, we focused on the X-ray repair cross-complementing 4 (XRCC4) protein, one of the core components of the NHEJ pathway. Endometrial XRCC4 protein levels in the mid-proliferative phase were found significantly (P < 0.05) downregulated in women with endometriosis, compared to control women. Investigation of a microarray-based largest dataset in the Gene Expression Omnibus database (GSE51981) revealed a similar trend at the transcript level in the EE of women with endometriosis, compared to control women. Further in vitro studies were undertaken to explore the effects of H2O2-induced oxidative stress on DNA damage, as assessed by γ-H2AX and 8-hydroxy-2'-deoxyguanosine (8-OHdG) immunolocalization, and XRCC4 protein levels in endometrial stromal (hTERT immortalized human endometrial stromal cell line (ThESCs)) and epithelial (Ishikawa) cells. A significant decrease in XRCC4 protein levels and significantly higher localization of γ-H2AX and 8-OHdG were evident in ThESCs and Ishikawa cells experiencing oxidative stress. Overall, the study demonstrates that the endometrial XRCC4 expression is dysregulated in women with endometriosis and this could be due to higher oxidative stress in endometriosis.

Endometrial DNA damage response is modulated in endometriosis.

STUDY QUESTION: Is the DNA damage response (DDR) dysregulated in the eutopic endometrium of women with endometriosis? SUMMARY ANSWER: Endometrial expression of genes involved in DDR is modulated in women with endometriosis, compared to those without the disease. WHAT IS KNOWN ALREADY: Ectopic endometriotic lesions are reported to harbour somatic mutations, thereby hinting at dysregulation of DDR and DNA repair pathways. However, it remains inconclusive whether the eutopic endometrium also manifests dysregulated DDR in endometriosis. STUDY DESIGN, SIZE, DURATION: For this case-control study conducted between 2015 and 2019, eutopic endometrial (E) samples (EE- from women with endometriosis, CE- from women without endometriosis) were collected in either mid-proliferative (EE-MP, n = 23; CE-MP, n = 17) or mid-secretory (EE-MS, n = 17; CE-MS, n = 9) phases of the menstrual cycle. This study compares: (i) DNA damage marker localization, (ii) expression of DDR genes and (iii) expression of DNA repair genes in eutopic endometrial samples from women with and without endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study included (i) 40 women (aged 31.9 ± 0.81 years) with endometriosis and (ii) 26 control women (aged 31.4 ± 1.02 years) without endometriosis. Eutopic endometrial samples from the two groups were divided into different parts for histological analysis, immunohistochemistry, RNA extraction, protein extraction and comet assays. Eighty-four genes of relevance in the DNA damage signalling pathway were evaluated for their expression in eutopic endometrial samples, using RT2 Profiler PCR arrays. Validations of the expression of two GADD (Growth Arrest DNA Damage Inducible) proteins - GADD45A and GADD45G were carried out by immunoblotting. DNA damage was assessed by immunohistochemical localization of γ-H2AFX (a phosphorylated variant of histone H2AX) and 8-OHdG (8-hydroxy-2'-deoxyguanosine). RNA sequencing data from mid-proliferative (EE-MP, n = 4; CE-MP, n = 3) and mid-secretory phase (EE-MS and CE-MS, n = 4 each) endometrial samples were scanned to compare the expression status of all the genes implicated in human DNA repair. PCNA (Proliferating Cell Nuclear Antigen) expression was determined to assess endometrial proliferation. Residual DNA damage in primary endometrial cells was checked by comet assays. Public datasets were also scanned for the expression of DDR and DNA repair genes as our RNASeq data were limited by small sample size. All the comparisons were made between phase-matched endometrial samples from women with and without endometriosis. MAIN RESULTS AND THE ROLE OF CHANCE: Endometrial expression of DDR genes and intensity of immunolocalized γ-H2AFX were significantly (P < 0.05) higher in EE, compared to CE samples. DDR proteins, especially those belonging to the GADD family, were found to be differentially abundant in EE, as compared to CE. These patterns were evident in both mid-proliferative and mid-secretory phases. Intriguingly, higher DDR was associated with increased cell proliferation in EE-MP, compared to CE-MP. Furthermore, among the differentially expressed transcripts (DETs) encoded by DNA repair genes, the majority showed up-regulation in EE-MP, compared to CE-MP. Interestingly, CE-MP and EE-MP had a comparable percentage (P > 0.05) of cells with residual DNA damage. However, unlike the mid-proliferative phase data, many DETs encoded by DNA repair genes were down-regulated in EE-MS, compared to CE-MS. An analysis of the phase-matched control and endometriosis samples included in the GSE51981 dataset available in the Gene Expression Omnibus database also revealed significant (P < 0.05) alterations in the expression of DDR and DNA repair genes in EE, compared to CE. LARGE-SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The study was conducted on a limited number of endometrial samples. Also, the study does not reveal the causes underlying dysregulated DDR in the eutopic endometrium of women with endometriosis. WIDER IMPLICATIONS OF THE FINDINGS: Alterations in the expression of DDR and DNA repair genes indirectly suggest that eutopic endometrium, as compared to its healthy counterpart, encounters DNA damage-inducing stimuli, either of higher strength or for longer duration in endometriosis. It will be worthwhile to identify the nature of such stimuli and also explore the role of higher genomic insults and dysregulated DDR/DNA repair in the origin and/or progression of endometriosis. STUDY FUNDING/COMPETING INTEREST(S): The study was supported by the Department of Biotechnology and Indian Council of Medical Research, Government of India. No conflict of interest is declared.

An overview of preclinical animal models for SARS-CoV-2 pathogenicity.

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 has caused millions of fatalities globally since its origin in November 2019. The SARS-CoV-2 shares 79 and 50 per cent genome similarity with its predecessors, severe SARS-CoV and Middle East respiratory syndrome (MERS) coronavirus, all belonging to the same genus, Betacoronavirus. This relatively new virus has stymied the effective control of COVID-19 pandemic and caused huge social and economic impact worldwide. The FDA-approved drugs were re-purposed to reduce the number of fatalities caused by SARS-CoV-2. However, controversy surrounds about the efficacy of these re-purposed antiviral drugs against SARS-CoV-2.This necessitates the identification of new drug targets for SARS-CoV-2. Hence, the development of pre-clinical animal model is warranted. Such animal models may help us gain better understanding of the pathophysiology of SARS-CoV-2 infection and will be effective tools for the evaluation and licensure of therapeutic strategies against SARS-CoV-2. This review provides a summary of the attempts made till to develop a suitable animal model to understand pathophysiology and effectiveness of therapeutic agents against SARS-CoV-2.

Plasma membrane proteome of adhesion-competent endometrial epithelial cells and its modulation by Rab11a.

Human endometrial epithelium (EE) is composed of a multitude of proteins, amongst which those localized on the plasma membrane [plasma membrane proteins (PMPs)] are of critical relevance in the early stages of implantation. Evidence supports the key role of few PMPs in implantation. However, many remain unidentified, as efforts have not been made till date to generate the plasma membrane proteome of human EE cells, using a gel-free approach. This study presents a protein catalog of the PMP enriched fraction of Ishikawa cell line; often used as an in vitro model for embryo-adhesive EE. Liquid chromatography with tandem mass spectrometry identified 3,598 proteins. Of these, 1,963 proteins were annotated for their membrane localization. Of 1,963 proteins, 1,321 were found to have a transmembrane domain and 43 proteins had glycophosphatidylinositol (GPI) anchor. Extensive data mining revealed endometrial expression of 943 proteins reported in humans and/or rodents. Further, quantitative alterations were observed in the plasma membrane proteome on the perturbation of intracellular trafficking. Silencing of Rab11a (known for its role in plasma membrane organization) expression caused alteration in the abundance of 74 proteins. Caveolin-1 and EpCAM levels were reduced whereas Rab4a abundance increased in the PMP extracts of Rab11a deficient cells, compared with control cells. Briefly, the study reports the identity of several novel plasma membrane-localized proteins. A major spin-off of the study is the identification of novel proteins trafficked by Rab11a to the plasma membrane. Targeted analysis of novel PMPs may reveal their specific roles in endometrial receptivity and implantation.

Membrane-initiated estrogen signaling in prostate cancer: A route to epithelial-to-mesenchymal transition.

The plasma membrane (PM) is considered as a major druggable site. More than 50% of the existing drugs target PM proteins. In the wake of emerging data indicating a key role of estrogens in prostate cancer (PCa) pathogenesis, the study was undertaken to explore whether the estrogen binding sites exist on the PM and if such sites are functionally relevant in PCa. Estradiol (E2) binding to the PM was detected in androgen-dependent (LNCaP), androgen-independent (PC3, DU145) PCa cell lines, nontumorigenic (RWPE1) prostate epithelial cell line, and rat prostate cells. Conventional estrogen receptors (nuclear estrogen receptors), known for their nuclear localization, were detected in the PM enriched extracts. This was indirectly confirmed by reduced localization of ERs on the PM of cells, silenced for the expression of their cognate genes. Further, unlike cell-permeable E2, stimulation with cell-impermeable estradiol (E2-BSA) did not induce proliferation in LNCaP cells. However, stimulation with E2-BSA led to alterations in the phosphorylation status of several kinases including GSK3 and AKT, along with the hyperphosphorylation of cytoskeletal proteins such as ß-actin and cytokeratin 8 in LNCaP. This was accompanied by epithelial-to-mesenchymal (EMT) features such as increased migration and invasion; higher vimentin expression, and a concomitant decrease in the E-cadherin expression. These effects were not observed in RWPE1 cells. Interestingly, cell-permeable E2 failed to induce EMT in PCa cells. This in vitro study is the first to suggest that the PM-initiated estrogen signaling contributes to higher invasiveness in PCa cells. Plasma membrane ERs may act as novel targets for PCa therapeutics.

Rab11a drives adhesion molecules to the surface of endometrial epithelial cells.

STUDY QUESTION: Is Rab11a GTPase, a regulator of intracellular trafficking, of significance in endometrial functions? SUMMARY ANSWER: Rab11a is an important component of the cascades involved in equipping the endometrial epithelium (EE) with 'adhesiveness' and 'cohesiveness'. WHAT IS KNOWN ALREADY: Cell adhesion molecules (CAMs) have been investigated extensively for modulation in their endometrial expression during the peri-implantation phase. However, the mechanisms by which CAMs are transported to the EE surface have not received the same attention. Rab11a facilitates transport of specific proteins to the plasma membrane in endothelial cells, fibroblasts, embryonic ectodermal cells, etc. However, its role in the transport of CAMs in EE remains unexplored. STUDY DESIGN, SIZE, DURATION: In-vitro investigations were directed towards deciphering the role of Rab11a in trafficking of CAMs (integrins and E-cadherin) to the cell surface of Ishikawa, an EE cell line. Towards this, Rab11a stable knockdown (Rab-kd) and control clones of Ishikawa were generated. JAr (human trophoblastic cell line) cells were used to form multicellular spheroids. Pre-receptive (n = 6) and receptive (n = 6) phase endometrial tissues from women with proven fertility and receptive phase (n = 6) endometrial tissues from women with unexplained infertility were used. PARTICIPANTS/MATERIALS, SETTING, METHODS: Rab-kd and control clones were used for in-vitro assays. Live cells were used for biotinylation, JAr spheroid assays, flow cytometry, trans-epithelial electrical resistance assays and wound-healing assays. Lysosome and Golgi membranes were isolated by ultracentrifugation. Confocal microscopy, immunoblotting, qRT-PCR and immunohistochemistry were employed for assessing the expression of Rab11a, integrins and E-cadherin. MAIN RESULTS AND THE ROLE OF CHANCE: shRNA-mediated attenuation of Rab11a expression led to a significant (P < 0.01) decline in the surface localization of αVß3 integrin. Cell surface protein extracts of Rab-kd clones showed a significant (P < 0.05) reduction in the levels of αV integrin. Further, a significant (P < 0.01) decrease was observed in the percent JAr spheroids attached to Rab-kd clones, compared to control clones. Rab-kd clones also showed a significant (P < 0.001) decline in the total levels of E-cadherin. This was caused neither by reduced transcription nor by increased lysosomal degradation. The role of Rab11a in maintaining the epithelial nature of the cells was evident by a significant increase in the migratory potential, presence of stress-fibres and a decrease in the trans-epithelial resistance in Rab-kd monolayers. Further, the levels of endometrial Rab11a and E-cadherin in the receptive phase were found to be significantly (P < 0.05) lower in women with unexplained infertility compared to that in fertile women. Taken together, these observations hint at a key role of Rab11a in the trafficking of αVß3 integrin and maintenance of E-cadherin levels at the surface of EE cells. LARGE-SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The in-vitro setting of the study is a limitation. Further immunohistochemical localizations of Rab11a and CAMs were conducted on a limited number of human endometrial samples. WIDER IMPLICATIONS OF THE FINDINGS: Rab11a-mediated trafficking of endometrial CAMs in EE cells can be explored further for its potential as a target for fertility regulation or infertility management. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Indian Council of Medical Research (ICMR), the Department of Science and Technology (DST), the Council of Scientific and Industrial Research (CSIR), Government of India. No competing interests are declared.

Estradiol: A Steroid with Multiple Facets.

Seventy-five glorious years have passed since estradiol was discovered by Edward Doisy. From discovery in the ovaries to delineation of diverse physiological effects, research on estrogens has covered a lot of ground. Estrogen receptors that mediate estrogenic effects, have been detected not only in reproductive organs, but also in other body organs. Estrogen receptors function either as conventional transcription factors or as rapid signal transducers. These different modes of action are opted by estrogens to elicit an array of reproductive and non-reproductive functions. It is well established that estrogens promote cell proliferation in various tissues and hence are also linked to carcinogenesis. Anti-estrogens are being used as adjunct therapies for cancers since several years. On the other hand, estrogen-based strategies are used to alleviate adverse effects of menopause. Apart from estrogens synthesized in various organs, exposure to environmental estrogens can also impact physiology. Thus, too much or too less of estrogens can tip the balance and lead to unfavorable consequences. Multiple estrogen receptors with their tissue- or cell type-specific expression eliciting dose-dependent effects make it perplexing to 'unify' estrogenic actions in diverse tissues/organs. This warrants more research on estrogen-mediated effects and their regulation in somatic and reproductive tissues. This review presents physiological and pathological aspects of estrogens thus highlighting the good, bad, and ugly facets of estrogens.

Proliferation and decidualization of endometrial stromal cells during embryo-attachment stage in bonnet monkeys (Macaca radiata).

We report embryo-induced alterations occurring in endometrial stromal cells (ESCs) during the embryo-attachment stage in bonnet monkeys (Macaca radiata). Laser micro-dissected ESCs obtained from pregnant and non-pregnant animals were compared for levels of selected proliferation and decidualization-associated factors by analysis with quantitative real-time polymerase chain reaction or immunohistochemistry. Stromal cells exhibited extensive cellular proliferation, as indicated by cellular compaction and significantly higher (P < 0.05) levels of proliferating cell nuclear antigen and of estrogen receptor 1, c-Myc, and Cyclin D1 transcripts in pregnant animals as compared with non-pregnant animals. A significant decrease (P < 0.05) was observed in the transcript levels of stromal interleukin-6 (IL-6) in pregnant animals. Cell proliferation was accompanied by a significant increase (P < 0.001) in the levels of decidualization-associated molecules such as IL-1ß in the luminal and glandular epithelium and of stromal insulin-like growth-factor-binding protein-1 (IGFBP-1) and prostaglandin-endoperoxide synthase-2 (PTGS-2) proteins. In pregnant animals, proliferation was evident throughout the gestational stroma, whereas decidualization was more pronounced in the embryo-attachment zone than in the non-attachment zone. To our knowledge, this is the first report of alterations in the endometrial stroma during the embryo-attachment stage in a non-human primate model.

Proteomics in reproductive biology: beacon for unraveling the molecular complexities.

Proteomics, an interface of rapidly evolving advances in physics and biology, is rapidly developing and expanding its potential applications to molecular and cellular biology. Application of proteomics tools has contributed towards identification of relevant protein biomarkers that can potentially change the strategies for early diagnosis and treatment of several diseases. The emergence of powerful mass spectrometry-based proteomics technique has added a new dimension to the field of medical research in liver, heart diseases and certain forms of cancer. Most proteomics tools are also being used to study physiological and pathological events related to reproductive biology. There have been attempts to generate the proteomes of testes, sperm, seminal fluid, epididymis, oocyte, and endometrium from reproductive disease patients. Here, we have reviewed proteomics based investigations in humans over the last decade, which focus on delineating the mechanism underlying various reproductive events such as spermatogenesis, oogenesis, endometriosis, polycystic ovary syndrome, embryo development. The challenge is to harness new technologies like 2-DE, DIGE, MALDI-MS, SELDI-MS, MUDPIT, LC-MS etc., to a greater extent to develop widely applicable clinical tools in understanding molecular aspects of reproduction both in health and disease.

High mobility group box 1 (HMGB1) protein in human uterine fluid and its relevance in implantation.

STUDY QUESTION: Does a differential abundance of high mobility group box 1 (HMGB1) protein in uterine fluid (UF) have a functional significance? SUMMARY ANSWER: In rats, an excess of HMGB1 in UF during the receptive phase is detrimental to pregnancy. WHAT IS KNOWN ALREADY: The identification of constituents of the human uterine secretome has been a subject of renewed interest, due to the advent of high throughput proteomic technologies. Proteomic-based investigations of human UF have revealed the presence of several proteins such as mucins, host defense proteins S100, heat shock protein 27 and haptoglobin, etc. The present study reports on the presence of HMGB1, a nuclear protein, in human UF. Activated macrophages/monocytes, natural killer cells, mature dendritic cells, pituicytes and erythroleukemic cells are also known to secrete HMGB1. Existing data suggest that extracellular HMGB1 plays a role in inflammation. STUDY DESIGN, SIZE, DURATION: The human part of this study was cross-sectional in design. UF and endometrial tissues were collected from regularly cycling women in the early secretory (i.e. pre-receptive phase, Day 2 post-ovulation, n = 7) or secretory phase (i.e. receptive phase, Day 6 post-ovulation, n = 7) of their menstrual cycles. Samples were also collected from cycling rats in the proestrous (n = 8) or metestrous (n = 8) phase of their estrous cycles. Uteri were also collected from HMGB1-treated pregnant (n = 7) and untreated pseudo-pregnant (n = 7) rats and from pregnant rats at Day 3-5 post-coitum (p.c.) (n = 18, 3 each for six-time points). PARTICIPANTS/MATERIALS, SETTING, METHODS: In each group of human samples, four samples were used for isobaric tag for relative and absolute quantification (iTRAQ) analysis and three samples were used for immunoblotting experiments to determine the abundance of HMGB1 in pre-receptive and receptive phase UF samples. HMGB1 levels in rat UF and endometrial tissue samples were estimated by ELISA and immunohistochemical studies, respectively. The expression of inflammation-associated molecules, such as nuclear factor kappa B (NFκB), receptor for advanced glycation end products (RAGEs), tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), was analyzed by immunohistochemistry in HMGB1-treated and pseudo-pregnant rats. MAIN RESULTS AND THE ROLE OF CHANCE: HMGB1 was identified as one of the differentially abundant proteins in the list generated by 8-plex iTRAQ analysis of receptive and pre-receptive phase UF samples. In both humans and rats, secreted and cellular levels of HMGB1 showed a similar pattern, i.e. significantly (P < 0.05) lower abundance in the receptive phase compared with that in the pre-receptive phase. A significant (P < 0.05) decline was also observed in the endometrial expression of HMGB1 on the day of implantation in pregnant rats. Exogenous administration of recombinant HMGB1, on Day 3 p.c., led to pregnancy failure, whereas administration of recombinant leukemia inhibitory factor or saline had no effect on pregnant rats. Further investigations revealed morphological changes in the endometrium, an increase in the expression of luminal epithelial NFκB and significantly (P < 0.05) higher expression levels of endometrial RAGE, TNF-α and IL-6 in HMGB1-treated rats, compared with untreated pseudo-pregnant rats. LIMITATIONS, REASONS FOR CAUTION: The mechanisms, contributing to a decline in the cellular and extracellular levels of HMGB1 during the receptive phase, remain to be ascertained. WIDER IMPLICATIONS OF THE FINDINGS: An excess of HMGB1 in the UF may be associated with infertility in women.

Cell surfactomes of two endometrial epithelial cell lines that differ in their adhesiveness to embryonic cells.

Adhesiveness of the endometrial epithelium to an embryo plays a critical role in the initiation of pregnancy. Loss or gain of adhesiveness also dictates the potential of endometrial epithelial cells to metastasize, an event that can result from certain genetic insults. A proteomics-based exploration of the "adhesiveness" these epithelial cells was employed that could identify targets that could disrupt embryo-endometrium interactions and/or metastasis of endometrial cancer cells. The present study defined the surfactomes of two human endometrial epithelial cell lines known for their differential adhesiveness to embryonic cells. Comparative, two-dimensional electrophoretic analysis of the surfactomes of RL95-2 (exhibiting higher adhesiveness to the embryonic cell line JAr) and HEC-1A (exhibiting reduced adhesiveness to JAr cells) revealed 55 differentially enriched proteins. Of these, 10 proteins were identified by MALDI-TOF/TOF or LC-MS/MS. TUBB2C, ADAMTS3, and elongation factor beta were more abundant on the HEC-1A cell surface whereas HSP27, HSPA9, GP96, CRT, Tapasin-ERP57, PDI, and ß-actin were more abundant on the RL95-2 cell surface. Nano LC-MS/MS was also employed to generate a more comprehensive surfactomes of RL95-2 and HEC-1A. The study also demonstrated a pro-adhesive role of CRT and HSPA9 and an anti-adhesive role of TUBB2C populations found on the cell surface. In brief, this study identifies the cell-surface protein complements of two human endometrial epithelial cell lines, and reveals the role of three proteins in heterotypic cell adhesion.

Secretomes from Conventional Insemination and Intra-Cytoplasmic Sperm Injection Derived Embryos Differentially Modulate Endometrial Cells In Vitro.

Conventional Insemination (CI) and Intra-Cytoplasmic Sperm Injection (ICSI) are routinely used insemination methods in clinical Assisted Reproductive Technologies (ART) settings. However, the existing data on the developmental competence and implantation potential of CI and ICSI derived embryos are not unequivocal. This prospective study on 23 patients undergoing ART treatment explored whether the secretomes of CI- and ICSI-derived embryo differentially alter the expression of integrins (αv and ß3 integrin) and MUCIN-1 (MUC-1) in a human endometrial epithelial cell line (Ishikawa). Immunocytochemical data demonstrated that the secretome of CI-derived top quality (GI) embryos induced higher (p < 0.05) expression of ɑv ß3 compared to sibling ICSI derived G1 embryos in Ishikawa cells. Though, relative levels of the transcript for MUC-1, anti-adhesion molecule did not show a significant difference between the study groups, immunocytochemical analysis demonstrated significantly (p < 0.0001) higher expression of MUC-1 in cells treated with ICSI-derived embryo secretome, compared to that treated with CI -derived embryo secretome. These results suggest that secretomes from CI and ICSI embryos differentially modulate the endometrial cells in vitro. This hints at differences in the ability of CI- and ICSI- derived embryos to alter endometrial profile.

Uterine secretome and its modulation in rat (Rattus norvegicus).

The present study identifies uterine fluid (UF) proteins that display differential abundance during the embryo-permissive phase in nonconception and conception cycles in rats. UF samples were collected from nonpregnant rats in the proestrous (n=17) and metestrous (n=18) phases and also from pregnant (n=17) and pseudopregnant (n=17) rats on day 4 post coitus. UF protein profile in the metestrous phase was compared with that in the proestrous phase. Similarly, UF protein profile of the pregnant rats was compared with that of the pseudopregnant rats. Two-dimensional PAGE, followed by densitometric analysis of the paired protein spots, revealed differential abundance of 44 proteins in the metestrous phase, compared with that in the proestrous phase. Of these, 29 proteins were identified by matrix-assisted laser desorption/ionization time-of-flight or liquid chromatography-tandem mass spectrometry. Functional groups such as proteases, protease inhibitors, and oxidoreductases were enriched in differentially abundant proteins. Total protease activity in UF was found to be significantly (P<0.05; t-test) higher in the proestrous phase, compared with that in the metestrous phase. Furthermore, 41 UF proteins were found to be differentially abundant in pregnant rats, compared with pseudopregnant rats. Of these, 11 proteins could be identified. Immunoblotting analysis confirmed significantly higher (P<0.05; t-test) abundance of ß-actin, Rho-specific guanine nucleotide dissociation inhibitor alpha (Rho-GDIα), and peroxiredoxin-2 and -6 in the metestrous phase, compared with that in the proestrous phase. Compared with pseudopregnant rats, pregnant rats had significantly higher (P<0.05; t-test) levels of UF ß-actin and Rho-GDIα. Furthermore, these proteins could be detected in the culture supernatants of endometrial epithelial cell lines, thereby providing an evidence of their secretion from endometrial epithelial cells. Data obtained from the study expand our knowledge on the uterine milieu that favours embryo implantation.

Cytomegalovirus reactivation in a SARS-CoV-2 infected woman experiencing fetal demise in the first trimester with fetal trisomy 21: A case report.

Cytomegalovirus (CMV) is the most common cause of congenital viral infections. Women seropositive for CMV prior to pregnancy can develop a non-primary CMV infection. Here, we present a case of first trimester pregnancy loss during active SARS-CoV-2 infection. There was no evidence of SARS-CoV-2 RNA in placenta and fetal tissue, but there was presence of congenital cytomegalovirus infection by nested PCR. To the best of our knowledge, this is the first report demonstrating association of early congenital CMV infection due to reactivation and fetal demise in a SARS-CoV-2 positive woman with fetal trisomy 21.

Endometrial epithelial cell modifications in response to embryonic signals in bonnet monkeys (Macaca radiata).

The present investigation reports embryo-induced modifications in the epithelial cells of the endometrium in a primate species. In vivo, epithelial cell response to the embryonic signals was assessed at the embryo attachment stage in the gestational uterus of bonnet monkeys (Macaca radiata) and in vitro response was investigated by treating human endometrial epithelial cell line (Ishikawa) with human embryo conditioned media (CM). Endometrial epithelial (EE) cells at the embryo attachment stage in bonnet monkeys revealed higher proliferation accompanied by significant up regulation (p < 0.05) in the expression of estrogen receptor (ER)α and down regulation (p < 0.05) in ERß expression. Further gestational EE cells showed higher (p < 0.001) expression of mucin-1, except in the embryo attachment site. Also, observed were significantly higher expression (p < 0.05) and altered cytoplasmic distribution of α(v) and ß(3) integrins, when compared to non-pregnant animals. In pregnant animals, the embryo attachment zone showed differential expression of immunoreactive integrins as compared to the non-attachment zone. This suggested the role of embryo secreted factors in modulation of the epithelial cell profile. In vitro studies partially supported this assumption. Significantly higher proliferation (p < 0.05), as well as increased expression of ERα, integrin ß(3) and mucin-1 (p < 0.05) were observed in Ishikawa cells, on stimulation with CM. Taken together, these results indicated the proliferation and modulation in the expression of estrogen receptors and cell adhesion molecules in the EE cells; at the embryo attachment stage in bonnet monkeys. Further it is likely that embryo secreted factors contribute to some of these modifications in EE cells. This report is the first account of discrete cellular events, which occur in the uterine epithelium, at the embryo attachment stage in a primate species.

Clinical presentation, pregnancy complications, and outcomes of pregnant women with COVID-19 during the Omicron-dominant third wave in Mumbai, India.

OBJECTIVE: To study clinical presentation, disease severity, pregnancy complications, and maternal outcomes in women affected with coronavirus disease 2019 (COVID-19) during the third wave compared with the first and second waves of COVID-19. METHODS: A retrospective, observational cohort study was conducted among 2058 pregnant and postpartum women with COVID-19 admitted during three wave periods at a tertiary care COVID-19-dedicated hospital. RESULTS: The number of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) -infected pregnant and postpartum women with symptoms of COVID-19 was four times higher during the third wave compared with the first (odds ratio [OR] 4.6, 95% confidence interval [CI] 3.5-6.0, P < 0.001). There was a significantly lower proportion of pregnant and postpartum women with moderate to severe COVID-19 during the third wave (0.6%, 2/318) compared with those during the first wave (2.4%, 27/1143, P < 0.001) and second wave (14.4%, 86/597, P < 0.001). The intensive care/high dependency unit admissions during the third wave were significantly lower (2.5%, 8/318) than during the second wave (14.7%, 88/597; OR 0.2, 95% CI 0.1-0.3, P < 0.001) but similar to the first wave (2.4%, 27/1143). CONCLUSIONS: Decreased severity of COVID-19, reduced maternal mortality, and morbidity were reported in the third wave compared with the first wave and second wave of COVID-19 in the Mumbai Metropolitan Region, India. TRIAL REGISTRATION: The study is registered with the Clinical Trial Registry of India (Registration no: CTRI/2020/05/025423).