LHX2 in germ cells control tubular organization in the developing mouse testis.

In the gonads of mammalian XY embryos, the organization of cords is the hallmark of testis development. This organization is thought to be controlled by interactions of the Sertoli cells, endothelial and interstitial cells with little or no role of germ cells. Challenging this notion, herein we show that the germ cells play an active role in the organization of the testicular tubules. We observed that the LIM-homeobox gene, Lhx2 is expressed in the germ cells of the developing testis between E12.5-E15.5. In Lhx2 knockout-fetal testis there was altered expression of several genes not just in germ cells but also in the supporting (Sertoli) cells, endothelial cells, and interstitial cells. Further, loss of Lhx2 led to disrupted endothelial cell migration and expansion of interstitial cells in the XY gonads. The cords in the developing testis of Lhx2 knockout embryos are disorganized with a disrupted basement membrane. Together, our results show an important role of Lhx2 in testicular development and imply the involvement of germ cells in the tubular organization of the differentiating testis. The preprint version of this manuscript is available at https://doi.org/10.1101/2022.12.29.522214.

Lhx2 in germ cells suppresses endothelial cell migration in the developing ovary.

LIM-homeobox genes play multiple roles in developmental processes, but their roles in gonad development are not completely understood. Herein, we report that Lhx2, Ils2, Lmx1a, and Lmx1b are expressed in a sexually dimorphic manner in mouse, rat, and human gonads during sex determination. Amongst these, Lhx2 has female biased expression in the developing gonads of species with environmental and genetic modes of sex determination. Single-cell RNAseq analysis revealed that Lhx2 is exclusively expressed in the germ cells of the developing mouse ovaries. To elucidate the roles of Lhx2 in the germ cells, we analyzed the phenotypes of Lhx2 knockout XX gonads. While the gonads developed appropriately in Lhx2 knockout mice and the somatic cells were correctly specified in the developing ovaries, transcriptome analysis revealed enrichment of genes in the angiogenesis pathway. There was an elevated expression of several pro-angiogenic factors in the Lhx2 knockout ovaries. The elevated expression of pro-angiogenic factors was associated with an increase in numbers of endothelial cells in the Lhx2-/- ovaries at E13.5. Gonad recombination assays revealed that the increased numbers of endothelial cells in the XX gonads in absence of Lhx2 was due to ectopic migration of endothelial cells in a cell non-autonomous manner. We also found that, there was increased expression of several endothelial cell-enriched male-biased genes in Lhx2 knockout ovaries. Also, in absence of Lhx2, the migrated endothelial cells formed an angiogenic network similar to that of the wild type testis, although the coelomic blood vessel did not form. Together, our results suggest that Lhx2 in the germ cells is required to suppress vascularization in the developing ovary. These results suggest a need to explore the roles of germ cells in the control of vascularization in developing gonads. Preprint version of the article is available on BioRxiv at https://doi.org/10.1101/2022.03.07.483280.

Endometrial and placental stem cells in successful and pathological pregnancies.

The endometrium is a dynamic tissue that undergoes extensive remodeling during the menstrual cycle and further gets modified during pregnancy. Different kinds of stem cells are reported in the endometrium. These include epithelial stem cells, endometrial mesenchymal stem cells, side population stem cells, and very small embryonic-like stem cells. Stem cells are also reported in the placenta which includes trophoblast stem cells, side population trophoblast stem cells, and placental mesenchymal stem cells. The endometrial and placental stem cells play a pivotal role in endometrial remodeling and placental vasculogenesis during pregnancy. The dysregulation of stem cell function is reported in various pregnancy complications like preeclampsia, fetal growth restriction, and preterm birth. However, the mechanisms by which it does so are yet elusive. Herein, we review the current knowledge of the different type of stem cells involved in pregnancy initiation and also highlight how their improper functionality leads to pathological pregnancy.

Outcomes in neonates born to mothers with COVID-19 during the second wave in India.

COVID-19 pandemic has affected all age groups globally including pregnant women and their neonates. The aim of the study was to understand outcomes in neonates of mothers with COVID-19 during the first and second waves of COVID-19 pandemic. A retrospective analysis of 2524 neonates born to SARS-CoV-2-infected mothers was conducted during the first wave (n = 1782) and second wave (n = 742) of the COVID-19 pandemic at five study sites of the PregCovid registry in Maharashtra, India. A significant difference was noted in preterm birth, which was higher in the second wave (15.0%, 111/742) compared to the first wave (7.8%, 139/1782) (P < 0.001). The proportion of neonates requiring NICU admission was significantly higher in the second wave (19.0%, 141/742) as compared to that in the first wave (14.8%, 264/1782) (P < 0.05). On comparing regional differences, significantly higher neonatal complications were reported from Mumbai metropolitan region (P < 0.05). During the second wave of COVID-19, birth asphyxia and prematurity were 3.8- and 2.1-fold higher respectively (P < 0.001). Neonatal resuscitation at birth was significantly higher in second wave (3.4%, 25/742 vs 1.8%, 32/1782) (P < 0.05). The prevalence of SARS-CoV-2 infection in neonates was comparable (4.2% vs 4.6%) with no significant difference between the two waves. CONCLUSION: Higher incidence of adverse outcomes in neonates born to SARS-CoV-2-infected mothers in the second wave of COVID-19 as compared to the first wave. TRIAL REGISTRATION: PregCovid study is registered with the Clinical Trial Registry of India (CTRI/2020/05/025423, Registered on 28/05/2020). WHAT IS KNOWN: • The second wave of COVID-19 was more lethal to pregnant women than the first wave. Newborns are at risk of developing complications. WHAT IS NEW: • Birth asphyxia, prematurity, and neonatal resuscitation at birth were significantly higher in the second wave as compared to those in the first wave of the COVID-19 pandemic in India.

Association of AMH and AMHR2 gene polymorphisms with ovarian response and pregnancy outcomes in Indian women.

PURPOSE: To evaluate the association of single-nucleotide polymorphisms (SNPs) in the anti-Müllerian hormone (AMH) and AMH type II receptor (AMHR2) genes with ovarian response and clinical pregnancy outcomes in women undergoing controlled ovarian hyperstimulation. METHODS: In this prospective study, we genotyped AMH polymorphisms (c. -649 T > C, c. 146 T > G, c. 252 G > A, and c. 303 G > A) in 365 women and AMHR2 polymorphisms (c. -482 A > G, c. 622-6 C > T, c. 4952 G > A, c. 10 A > G) in 80 women undergoing controlled ovarian hyperstimulation for IVF. RESULTS: Higher doses of exogenous FSH and lower numbers of preovulatory follicles were noted in women having AMH c. -649 T > C and AMH c. -146 T > G polymorphisms, respectively. Overall, we found that the presence of a polymorphic genotype (homozygous or heterozygous) at positions c. -649 T > C, c. 146 T > G, c. 252 G > A, and c. 303 G > A in the AMH gene was associated with higher doses of FSH for ovulation induction (p < 0.001). Interestingly, a higher live birth rate was noted in women with a homozygous polymorphic genotype for all four AMH SNPs investigated while none of the women showing a homozygous polymorphic genotype at all AMHR2 SNPs investigated in this study had a live birth. CONCLUSION: Our results show that presence of AMHR2 SNPs (c. 482 A > G, c. 622-6 C > T, c. 4952 G > A, and c. 10 A > G) negatively correlate with live birth rate. However, these findings need to be validated by using larger sample size.

Persistence of SARS-CoV-2 in the first trimester placenta leading to transplacental transmission and fetal demise from an asymptomatic mother.

Coronavirus disease 2019 (COVID-19) is caused by infection of the respiratory tract by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which survives in the tissues during the clinical course of infection but there is limited evidence on placental infection and vertical transmission of SARS-CoV-2. The impact of COVID-19 in first trimester pregnancy remains poorly understood. Moreover, how long SARS-CoV-2 can survive in placenta is unknown. Herein, we report a case of a pregnant woman in the first trimester who tested positive for SARS-CoV-2 at 8 weeks of gestation, although her clinical course was asymptomatic. At 13 weeks of gestation, her throat swab tested negative for SARS-CoV-2 but viral RNA was detected in the placenta, and the Spike (S) proteins (S1 and S2) were immunolocalized in cytotrophoblast and syncytiotrophoblast cells of the placental villi. Histologically, the villi were generally avascular with peri-villus fibrin deposition and in some areas the syncytiotrophoblast layer appeared lysed. The decidua also had fibrin deposition with extensive leukocyte infiltration suggestive of inflammation. The SARS-CoV-2 crossed the placental barrier, as the viral RNA was detected in the amniotic fluid and the S proteins were detected in the fetal membrane. Ultrasonography revealed extensively subcutaneous edema with pleural effusion suggestive of hydrops fetalis and the absence of cardiac activity indicated fetal demise. This is the first study to provide concrete evidence of persistent placental infection of SARS-CoV-2 and its congenital transmission is associated with hydrops fetalis and intrauterine fetal demise in early pregnancy.

Commentary on two recently published formal guidelines on management of "mosaic" embryos after preimplantation genetic testing for aneuploidy (PGT-A).

Two professional societies recently published opinions on the clinical management of "mosaic" results from preimplantation genetic testing for aneuploidy (PGT-A) in human blastocyst-stage embryos in associations with in vitro fertilization (IVF). We here point out three principal shortcomings: (i) Though a most recent societal opinion states that it should not be understood as an endorsement of the use of PGT-A, any discussion of how PGT-A should be clinically interpreted for all practical purposes does offer such an endorsement. (ii) The same guideline derived much of its opinion from a preceding guidance in favor of utilization of PGT-A that did not follow even minimal professional requirements for establishment of practice guidelines. (iii) Published guidelines on so-called "mosaic" embryos from both societies contradict basic biological characteristics of human preimplantation-stage embryos. They, furthermore, are clinically unvalidated and interpret results of a test, increasingly seen as harmful to IVF outcomes for many infertile women. Qualified professional organizations, therefore, should finally offer transparent guidelines about the utilization of PGT-A in association with IVF in general.

Central residues of FSHß (89-97) peptide are not critical for FSHR binding: Implications for peptidomimetic design.

In our previous study, we had identified a 9-mer peptide (FSHß (89-97)) derived from seat belt loop of human FSHß and demonstrated its ability to function as FSHR antagonist in vivo. Structure analysis revealed that the four central residues 91STDC94 within this peptide may not be critical for receptor binding. In the present study, 91STDC94 residues were substituted with alanine to generate ΔFSHß 89-97(91STDC94/AAAA) peptide. Analogous to the parent peptide, ΔFSHß 89-97(91STDC94/AAAA) peptide inhibited binding of iodinated FSH to rat FSHR and reduced FSH-induced cAMP production. The peptide could impede granulosa cell proliferation leading to reduction in FSH-mediated ovarian weight gain in immature female rats. In these rats, peptide administration further downregulated androgen receptor and estrogen receptor-alpha expression and upregulated estrogen receptor-beta expression. The results indicate that substitution of 91STDC94 with alanine did not significantly alter FSHR antagonist activity of FSHß (89-97) peptide implying that these residues are not critical for FSH-FSHR interaction and can be replaced with non-peptidic moieties for development of more potent peptidomimetics.

Clinical characteristics, outcomes, & mortality in pregnant women with COVID-19 in Maharashtra, India: Results from PregCovid registry.

Background & objectives: The PregCovid registry was established to document the clinical presentations, pregnancy outcomes and mortality of pregnant and post-partum women with COVID-19. Methods: The PregCovid registry prospectively collects information in near-real time on pregnant and post-partum women with a laboratory-confirmed diagnosis of SARS-CoV-2 from 19 medical colleges across the State of Maharashtra, India. Data of 4203 pregnant women collected during the first wave of the COVID-19 pandemic (March 2020-January 2021) was analyzed. Results: There were 3213 live births, 77 miscarriages and 834 undelivered pregnancies. The proportion of pregnancy/foetal loss including stillbirths was six per cent. Five hundred and thirty-four women (13%) were symptomatic, of which 382 (72%) had mild, 112 (21%) had moderate, and 40 (7.5%) had severe disease. The most common complication was preterm delivery (528, 16.3%) and hypertensive disorders in pregnancy (328, 10.1%). A total of 158 (3.8%) pregnant and post-partum women required intensive care, of which 152 (96%) were due to COVID-19 related complications. The overall case fatality rate (CFR) in pregnant and post-partum women with COVID-19 was 0.8 per cent (34/4203). Higher CFR was observed in Pune (9/853, 1.1%), Marathwada (4/351, 1.1%) regions as compared to Vidarbha (9/1155, 0.8%), Mumbai Metropolitan (11/1684, 0.7%), and Khandesh (1/160, 0.6%) regions. Comorbidities of anaemia, tuberculosis and diabetes mellitus were associated with maternal deaths. Interpretation & conclusions: The study demonstrates the adverse outcomes including severe COVID-19 disease, pregnancy loss and maternal death in women with COVID-19 in Maharashtra, India.

Clinical Characteristics, Management, and Short-Term Outcome of Neonates Born to Mothers with COVID-19 in a Tertiary Care Hospital in India.

INTRODUCTION: We describe the clinical characteristics, management, and short-term outcomes of SARS-CoV-2 neonates born to mothers with COVID-19 in a tertiary care hospital in Mumbai, India. METHODS: The study is a retrospective analysis of 524 neonates born to mothers with COVID-19 admitted from 14th April 2020 to 31st July 2020. RESULTS: SARS-CoV-2 infection was detected in 6.3% of the newborns of the mothers with COVID-19. No significant differences were observed between maturity at gestation, birth weight and sex of SARS-CoV-2 infected and noninfected newborns. The risk of sepsis was 4.09 [95% confidence interval (95% CI) 1.28-13.00] fold higher in the neonates with SARS-CoV-2 as compared to the noninfected group (p = 0.031). Poor feeding was significantly more common among SARS-CoV-2 infected neonates (12.1%) as compared to the noninfected neonates (2.7%) (p = 0.017). There was a total of 13 neonatal deaths, of which 3 deaths occurred in SARS-CoV-2 infected neonates (9%) while 10 (2.04%) in the SAR-CoV-2 negative group. The risk of neonatal death was higher in SARS-CoV-2 infected newborns [odds ratio (OR) 4.8; 95% CI 1.25-18.36]. CONCLUSION: Neonatal SARS-CoV-2 infection is observed in almost 6% of neonates born to mothers with perinatal COVID-19. There is a higher risk of adverse outcomes such as neonatal sepsis and death in the SARS-CoV-2 infected as compared to the noninfected neonates.

The current pandemic of COVID-19 has affected all the countries globally. However, the adverse impact of the pandemic is more seen in the low-income and middle-income countries (LMICs). Although there is evidence on the adverse impact of the SARS-CoV-2 on the health of mothers and neonates, the evidence is mainly from high-income countries. For reducing the mortality and morbidity due to COVID-19 in LMICs, there is a need to generate evidence from the LMICs. The present study is a part of the National Registry of pregnant women with COVID-19 in India (PregCovid registry). Our study demonstrates a higher risk of adverse outcomes such as neonatal sepsis and death in the SARS-CoV-2 infected as compared to the noninfected neonates. The study also showed the risk of SARS-CoV-2 infection in 6.3% of neonates born to mothers with COVID-19.

Clinical Presentation of Cases with SARS-CoV-2 Reinfection/ Reactivation.

BACKGROUND: Reinfection/reactivation of SARS-CoV-2 has been a matter of great interest from the immunological and vaccine perspective. However, little is known about the clinical presentation of such reinfection/reactivation. We report a case series of 9 COVID-19 patients having experienced two clinically- and/or virologically-confirmed episodes of COVID-19. METHODS: Epidemiological and clinical characteristics of 9 healthcare workers (HCWs) with two episodes of SARS-CoV-2 are described. RESULTS: The incidence of reinfection/reactivation amongst the HCWs was 2% (9 out of 491) with an average remission period of 66 days (range 43-78 days). Amongst the cases of reinfection 4/9 were asymptomatic in first episode were symptomatic in second episode. There is negative correlation between numbers of days the patients took to become SARS-CoV-2 negative by RT-CPR and/or clinically recover in the first episode and the second episode irrespective for the time spent in remission. CONCLUSION: Shorter durations of SARS-COV-2 infection in the first episode are associated with longer time to recovery in the second episode in patients with re-infection/reactivation.

Crusted scabies in a pediatric renal transplant recipient on immunosuppressants.

BACKGROUND: Crusted scabies (CS) is a rare, severe and highly contagious form of scabies, which has been reported in immunosuppressed patients. A high index of suspicion and awareness of CS is essential to treat this infestation. CASE: A 13-year-old boy presented with pruritic hyperkeratotic squamous plaques located on both inner wrists, the web spaces of both his hands and his feet, and the genital area of 12 months duration. He was diagnosed with focal segmental glomerulosclerosis at the age of 5 and received a kidney transplant at the age of 9. He has been on a maintenance dose of prednisone (5 mg/d) and mycophenolate mofetil (250 mg/d) for the past 2 years. He had a contact history with a school friend with similar lesions. A skin punch biopsy demonstrated the presence of multiple mites in the stratum corneum confirming the diagnosis of CS. Ivermectin, the recommended drug of choice for crusted scabies, is not available in South Africa. The patient was commenced on topical benzoyl benzoate lotion but discontinued its use because of intolerable irritation. We subsequently prescribed the daily application of topical 5% sulfur in petrolatum to which his pruritus subsided significantly after 2 weeks with resolution of all skin lesions at the end of 8 weeks. CONCLUSION: This case is the first documented report of CS in a pediatric renal transplant patient. Our management highlights that classic formularies of magistral drugs are still effective treatment options and can be used especially when standard therapies cannot be tolerated or when optimum treatments are not available.

Spatial and temporal changes in the expression of steroid hormone receptors in mouse model of endometriosis.

PURPOSE: Endometriosis is recognized as a steroid hormone-dependent disorder. However, controversies exist regarding the status of the steroid hormone receptor expression in endometriotic tissues. The purpose of this study was to determine the ontogeny of cellular changes in the expression of estrogen receptors (ERα, ERß), G protein-coupled estrogen receptor 1 (GPER1), and progesterone receptors (PRs) in endometriosis using a mouse model. METHODS: We used the autologous uterine tissue transfer mouse model and studied the mRNA and protein expression of ERα, ERß, GPER1, and PR in ectopic lesions at 2, 4, and 8 weeks of induction of endometriosis. RESULT: As compared to endometrium of controls, in the ectopic endometrium, ERα is reduced while ERß was elevated in stromal cells; however, Gper1 and PR levels are reduced in both stromal and epithelial cells in a time-specific manner. There is a high inter-animal variation in the levels of these receptors in ectopic endometrium as compared to controls; the levels also varied by almost 100-fold within the same lesion resulting in "micro-heterogeneity." The expression of all these receptors also deferred between two lesions from the same animal. CONCLUSION: In the endometriotic tissue, there is extensive inter-animal and intra-lesion heterogeneity in the expression of ERα, ERß, GPER1, and PR. These changes are not due to the influence of the peritoneal environment but appear to be tissue intrinsic. We propose that the variable outcomes in hormonal therapy for endometriosis could be possibly due to heterogeneity in the expression of steroid hormone receptors in the ectopic endometrium.

Extracellular vesicle mediated embryo-endometrial cross talk during implantation and in pregnancy.

Extracellular vesicles are lipoproteinaceous membrane-enclosed nanometer-sized structures produced by cells and are thought to mediate cellular communications. Loaded with a specific set of miRNA and protein depending on their tissue of origin, these extracellular vesicles modulate diverse set of biological processes in their target tissues. In recent years, data has gathered on the roles of extracellular vesicles in embryo implantation and pregnancy. Embryo, oviduct, endometrial epithelium and stroma/decidua derived vesicles interact with trophoblast cells and promote their growth and differentiation to aid in embryo implantation. The placental vesicles are detected in maternal circulation that aids in feto-maternal immune tolerance, their levels vary in women with pregnancy-related complications like preeclampsia. Beyond the host, the microbes in the genital tract are also reported to produce extracellular vesicles which are thought to be responsible for inflammation and preterm births. This review focuses on the extracellular vesicular trafficking involved in success of pregnancy.

Consequences of Y chromosome microdeletions beyond male infertility.

PURPOSE: The human Y chromosome plays a central role in sex determination and spermatogenesis. The azoospermia factor (AZF) loci on the Y chromosome contain genes that were thought to be testis specific with their deletions leading to spermatogenic failure. However, beyond the testis, the AZF genes (mainly those in AZFa and AZFb loci) are widely expressed in multiple tissues. Further, these genes are predicted to play roles in processes such as gene regulation and protein synthesis. These observations suggest that the AZF genes may have functions beyond regulation of fertility. RESULTS: Three major areas have emerged where alternations in AZF genes have effects beyond infertility. (1) Poor-quality embryos are generated in assisted reproduction when sperm from men harboring Y chromosome microdeletions are used, (2) a higher preponderance of neuropsychiatry disorders is observed in men with deletions in AZF genes, and (3) copy number variations and altered expression of AZF genes are found in several cancers. CONCLUSION: While our data is preliminary and observational in nature, systematic studies are required to address how genetic alterations in the Y chromosome can affect the health of men beyond infertility. This information will provide a different perspective in the area of androgenetics and have implications in devising strategies for maintaining the overall well-being of infertile males.

Correction to: Progesterone requires heat shock protein 90 (HSP90) in human sperm to regulate motility and acrosome reaction.

In the original Fig 1, we had inadvertently placed the DAPI channel image of the HSP90α as negative control.

Membrane Vesicles of Group B Streptococcus Disrupt Feto-Maternal Barrier Leading to Preterm Birth.

Infection of the genitourinary tract with Group B Streptococcus (GBS), an opportunistic gram positive pathogen, is associated with premature rupture of amniotic membrane and preterm birth. In this work, we demonstrate that GBS produces membrane vesicles (MVs) in a serotype independent manner. These MVs are loaded with virulence factors including extracellular matrix degrading proteases and pore forming toxins. Mice chorio-decidual membranes challenged with MVs ex vivo resulted in extensive collagen degradation leading to loss of stiffness and mechanical weakening. MVs when instilled vaginally are capable of anterograde transport in mouse reproductive tract. Intra-amniotic injections of GBS MVs in mice led to upregulation of pro-inflammatory cytokines and inflammation mimicking features of chorio-amnionitis; it also led to apoptosis in the chorio-decidual tissue. Instillation of MVs in the amniotic sac also resulted in intrauterine fetal death and preterm delivery. Our findings suggest that GBS MVs can independently orchestrate events at the feto-maternal interface causing chorio-amnionitis and membrane damage leading to preterm birth or fetal death.

Genetics of the human Y chromosome and its association with male infertility.

The human Y chromosome harbors genes that are responsible for testis development and also for initiation and maintenance of spermatogenesis in adulthood. The long arm of the Y chromosome (Yq) contains many ampliconic and palindromic sequences making it predisposed to self-recombination during spermatogenesis and hence susceptible to intra-chromosomal deletions. Such deletions lead to copy number variation in genes of the Y chromosome resulting in male infertility. Three common Yq deletions that recur in infertile males are termed as AZF (Azoospermia Factor) microdeletions viz. AZFa, AZFb and AZFc. As estimated from data of nearly 40,000 Y chromosomes, the global prevalence of Yq microdeletions is 7.5% in infertile males; however the European infertile men are less susceptible to Yq microdeletions, the highest prevalence is in Americans and East Asian infertile men. In addition, partial deletions of the AZFc locus have been associated with infertility but the effect seems to be ethnicity dependent. Analysis of > 17,000 Y chromosomes from fertile and infertile men has revealed an association of gr/gr deletion with male infertility in Caucasians and Mongolian men, while the b2/b3 deletion is associated with male infertility in African and Dravidian men. Clinically, the screening for Yq microdeletions would aid the clinician in determining the cause of male infertility and decide a rational management strategy for the patient. As these deletions are transmitted to 100% of male offspring born through assisted reproduction, testing of Yq deletions will allow the couples to make an informed choice regarding the perpetuation of male infertility in future generations. With the emerging data on association of Yq deletions with testicular cancers and neuropsychiatric conditions long term follow-up data is urgently needed for infertile men harboring Yq deletions. If found so, the information will change the current the perspective of androgenetics from infertility and might have broad implication in men health.

Oviductal glycoprotein 1 (OVGP1) is expressed by endometrial epithelium that regulates receptivity and trophoblast adhesion.

PURPOSE: To study the regulation and functions of oviductal glycoprotein 1 (OVGP1) in endometrial epithelial cells. METHODS: Expression of OVGP1 in mouse endometrium during pregnancy and in the endometrial epithelial cell line (Ishikawa) was studied by immunofluorescence, Western blotting, and RT-PCR. Regulation of OVGP1 in response to ovarian steroids and human chorionic gonadotropin (hCG) was studied by real-time RT-PCR. OVGP1 expression was knockdown in Ishikawa cells by shRNA, and expression of receptivity associated genes was studied by real-time RT-PCR. Adhesion of trophoblast cell line (JAr) was studied by in vitro adhesion assays. RESULTS: OVGP1 was localized exclusively in the luminal epithelial cells of mouse endometrium at the time of embryo implantation. Along with estrogen and progesterone, hCG induced the expression of OVGP1 in Ishikawa cells. Knockdown of OVGP1 in Ishikawa cells reduced mRNA expression of ITGAV, ITGB3, ITGA5, HOXA10, LIF, and IL15; it increased the expression of HOXA11, MMP9, TIMP1, and TIMP3. Supernatants derived from OVGP1 knockdown Ishikawa cells reduced the adhesiveness of JAr cells in vitro. Expression of OVGP1 mRNA was found to be significantly lowered in the endometrium of women with recurrent implantation failure. CONCLUSION: OVGP1 is specifically induced in the luminal epithelium at the time of embryo implantation where it regulates receptivity-related genes and aids in trophoblast adhesion.