Syncytiotrophoblast Markers Are Downregulated in Placentas from Idiopathic Stillbirths

The trophoblast cells are responsible for the transfer of nutrients between the mother and the foetus and play a major role in placental endocrine function by producing and releasing large amounts of hormones and growth factors. Syncytiotrophoblast cells (STB), formed by the fusion of mononuclear cytotrophoblasts (CTB), constitute the interface between the foetus and the mother and are essential for all of these functions. We performed transcriptome analysis of human placental samples from two control groups-live births (LB), and stillbirths (SB) with a clinically recognised cause-and from our study group, idiopathic stillbirths (iSB). We identified 1172 DEGs in iSB, when comparing with the LB group; however, when we compared iSB with the SB group, only 15 and 12 genes were down- and upregulated in iSB, respectively. An assessment of these DEGs identified 15 commonly downregulated genes in iSB. Among these, several syncytiotrophoblast markers, like genes from the PSG and CSH families, as well as ALPP, KISS1, and CRH, were significantly downregulated in placental samples from iSB. The transcriptome analysis revealed underlying differences at a molecular level involving the syncytiotrophoblast. This suggests that defects in the syncytial layer may underlie unexplained stillbirths, therefore offering insights to improve clinical obstetrics practice.

Characterization of the human fetal gonad and reproductive tract by single-cell transcriptomics

During human fetal development, sex differentiation occurs not only in the gonads but also in the adjacent developing reproductive tract. However, while the cellular composition of male and female human fetal gonads is well described, that of the adjacent developing reproductive tract remains poorly characterized. Here, we performed single-cell transcriptomics on male and female human fetal gonads together with the adjacent developing reproductive tract from first and second trimesters, highlighting the morphological and molecular changes during sex differentiation. We validated different cell populations of the developing reproductive tract and gonads and compared the molecular signatures between the first and second trimesters, as well as between sexes, to identify conserved and sex-specific features. Together, our study provides insights into human fetal sex-specific gonadogenesis and development of the reproductive tract beyond the gonads.

Efficient and scalable generation of primordial germ cells in 2D culture using basement membrane extract overlay

Current methods to generate human primordial germ cell-like cells (hPGCLCs) from human pluripotent stem cells (hPSCs) can be inefficient, and it is challenging to generate sufficient hPGCLCs to optimize in vitro gametogenesis. We present a differentiation method that uses diluted basement membrane extract (BMEx) and low BMP4 concentration to efficiently induce hPGCLC differentiation in scalable 2D cell culture. We show that BMEx overlay potentiated BMP/SMAD signaling, induced lumenogenesis, and increased expression of key hPGCLC-progenitor markers such as TFAP2A and EOMES. hPGCLCs that were generated using the BMEx overlay method were able to upregulate more mature germ cell markers, such as DAZL and DDX4, in human fetal ovary reconstitution culture. These findings highlight the importance of BMEx during hPGCLC differentiation and demonstrate the potential of the BMEx overlay method to interrogate the formation of PGCs and amnion in humans, as well as to investigate the next steps to achieve in vitro gametogenesis.

AAV-mediated gene augmentation therapy of CRB1 patient-derived retinal organoids restores the histological and transcriptional retinal phenotype

Retinitis pigmentosa and Leber congenital amaurosis are inherited retinal dystrophies that can be caused by mutations in the Crumbs homolog 1 (CRB1) gene. CRB1 is required for organizing apical-basal polarity and adhesion between photoreceptors and Müller glial cells. CRB1 patient-derived induced pluripotent stem cells were differentiated into CRB1 retinal organoids that showed diminished expression of variant CRB1 protein observed by immunohistochemical analysis. Single-cell RNA sequencing revealed impact on, among others, the endosomal pathway and cell adhesion and migration in CRB1 patient-derived retinal organoids compared with isogenic controls. Adeno-associated viral (AAV) vector-mediated hCRB2 or hCRB1 gene augmentation in Müller glial and photoreceptor cells partially restored the histological phenotype and transcriptomic profile of CRB1 patient-derived retinal organoids. Altogether, we show proof-of-concept that AAV.hCRB1 or AAV.hCRB2 treatment improved the phenotype of CRB1 patient-derived retinal organoids, providing essential information for future gene therapy approaches for patients with mutations in the CRB1 gene.

Successful Pregnancy and Persistent Polyclonal B Cell Lymphocytosis (PPBL): A Case Study of a Rare Co-Existence

Patient: Female, 35-year-old

Final Diagnosis: Succesful pregnancy

Symptoms: Pain • pregnancy

Medication: —

Clinical Procedure: —

Specialty: Hematology • Obstetrics and Gynecology

Transcriptional progression during meiotic prophase I reveals sex-specific features and X chromosome dynamics in human fetal female germline

During gametogenesis in mammals, meiosis ensures the production of haploid gametes. The timing and length of meiosis to produce female and male gametes differ considerably. In contrast to males, meiotic prophase I in females initiates during development. Hence, the knowledge regarding progression through meiotic prophase I is mainly focused on human male spermatogenesis and female oocyte maturation during adulthood. Therefore, it remains unclear how the different stages of meiotic prophase I between human oogenesis and spermatogenesis compare. Analysis of single-cell transcriptomics data from human fetal germ cells (FGC) allowed us to identify the molecular signatures of female meiotic prophase I stages leptotene, zygotene, pachytene and diplotene. We have compared those between male and female germ cells in similar stages of meiotic prophase I and revealed conserved and specific features between sexes. We identified not only key players involved in the process of meiosis, but also highlighted the molecular components that could be responsible for changes in cellular morphology that occur during this developmental period, when the female FGC acquire their typical (sex-specific) oocyte shape as well as sex-differences in the regulation of DNA methylation. Analysis of X-linked expression between sexes during meiotic prophase I suggested a transient X-linked enrichment during female pachytene, that contrasts with the meiotic sex chromosome inactivation in males. Our study of the events that take place during meiotic prophase I provide a better understanding not only of female meiosis during development, but also highlights biomarkers that can be used to study infertility and offers insights in germline sex dimorphism in humans.

Hippocampal glucocorticoid target genes associated with enhancement of memory consolidation

Glucocorticoids enhance memory consolidation of emotionally arousing events via largely unknown molecular mechanisms. This glucocorticoid effect on the consolidation process also requires central noradrenergic neurotransmission. The intracellular pathways of these two stress mediators converge on two transcription factors: the glucocorticoid receptor (GR) and phosphorylated cAMP response element‐binding protein (pCREB). We therefore investigated, in male rats, whether glucocorticoid effects on memory are associated with genomic interactions between the GR and pCREB in the hippocampus. In a two‐by‐two design, object exploration training or no training was combined with post‐training administration of a memory‐enhancing dose of corticosterone or vehicle. Genomic effects were studied by chromatin immunoprecipitation followed by sequencing (ChIP‐seq) of GR and pCREB 45 min after training and transcriptome analysis after 3 hr. Corticosterone administration induced differential GR DNA‐binding and regulation of target genes within the hippocampus, largely independent of training. Training alone did not result in long‐term memory nor did it affect GR or pCREB DNA‐binding and gene expression. No strong evidence was found for an interaction between GR and pCREB. Combination of the GR DNA‐binding and transcriptome data identified a set of novel, likely direct, GR target genes that are candidate mediators of corticosterone effects on memory consolidation. Cell‐specific expression of the identified target genes using single‐cell expression data suggests that the effects of corticosterone reflect in part non‐neuronal cells. Together, our data identified new GR targets associated with memory consolidation that reflect effects in both neuronal and non‐neuronal cells.

Emerging patterns of resistance in a cohort of Greek patients with recurrent UTIs: a pilot study

Bacterial urogenital infections caused by multi-drug resistant organisms (MDROs), are increasingly becoming a severe public health issue. The purpose of the present study was to examine the epidemiology of recurrent UTIs along with antimicrobial resistance patterns in a cohort of patients followed as outpatients at an Infectious Disease clinic of a tertiary care center in Greece. One hundred, sequential patients suffering from recurrent UTIs and coming for clinical evaluation, follow-up and treatment were examined; microbiological urine culture results were analyzed. Patients were separated into Group A: patients with ≥3 urogenital infections during the last study year, and Group B: patients with ≤2 urogenital infections. Furthermore, antimicrobial resistance patterns and presence of MDROs in relation to the number of urogenital infections during a three years period was evaluated. Group A had a mean of 4.3 ± 1.7 urogenital infections during the last year of the study, while patients in Group B 1.9 ± 0.3 infections over a three years period. An age cut-off of 30 years was critical for higher UTI rates. Escherichia Coli was the predominant isolated pathogen in 96.2% of the patients. Patients with diabetes mellitus had a 3 fold-higher risk for ≥3 UTIs. Resistance to colistin and imipenem was associated with a history of more than 2 episodes of UTIs but observed in a small number of patients with comorbidities. In this pilot study MDRO detection in patients suffering from recurrent UTIs emphasizes the need for continuous epidemiological surveillance in order to improve our understanding of the evolution of resistance in a common community infection as well as to implement successful prevention strategies.

Single-cell reconstruction of follicular remodeling in the human adult ovary

The ovary is perhaps the most dynamic organ in the human body, only rivaled by the uterus. The molecular mechanisms that regulate follicular growth and regression, ensuring ovarian tissue homeostasis, remain elusive. We have performed single-cell RNA-sequencing using human adult ovaries to provide a map of the molecular signature of growing and regressing follicular populations. We have identified different types of granulosa and theca cells and detected local production of components of the complement system by (atretic) theca cells and stromal cells. We also have detected a mixture of adaptive and innate immune cells, as well as several types of endothelial and smooth muscle cells to aid the remodeling process. Our results highlight the relevance of mapping whole adult organs at the single-cell level and reflect ongoing efforts to map the human body. The association between complement system and follicular remodeling may provide key insights in reproductive biology and (in)fertility.

Variation in DNA methylation in the KvDMR1 (ICR2) region in first-trimester human pregnancies

OBJECTIVE

To investigate the levels of DNA methylation in the KvDMR1 (KvLQT1 differentially methylated region 1) in embryonic and extra-embryonic tissues.

DESIGN

Cross-sectional study.

SETTING

University medical center and clinical hospital.

PATIENT(S)

Embryonic and/or extraembryonic tissues (umbilical cord, chorionic villus, chorion, decidua, and/or amnion) collected from 27 first-trimester pregnancies (up to 12 weeks of gestation, single embryos) from elective abortions, extravillous trophoblasts (EVTs) from the top of individual chorionic villi, and chorionic villi from 10 normal full-term placentas collected after birth.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

DNA methylation of the KvDMR1 region evaluated using quantitative analysis of DNA methylation followed by real-time polymerase chain reaction (qAMP) and bisulfite sequencing (bis-seq) analysis.

RESULT(S)

The results showed variability in KvDMR1 DNA methylation in different tissues from the same pregnancy. The average of DNA methylation was not different between the embryo, umbilical cord, amnion, and chorionic villi, despite the relatively low level of methylation observed in the amnion (33.50% ± 14.48%). Chorionic villi from term placentas showed a normal methylation pattern at KvDMR1 (42.60% ± 6.08%). The normal methylation pattern at KvDMR1 in chorionic villi (as well as in EVTs) from first-trimester placentas was confirmed by bis-seq.

CONCLUSION(S)

Our results highlight an existing heterogeneity in DNA methylation of the KvDMR1 region during first trimester and a consistent hypomethylation in the amnion in this period of gestation.

Communication between a nongrafted left internal mammary artery and left anterior descending coronary artery following saphenous vein bypass grafting

A case is described in which a pericardial branch of a nongrafted left internal mammary artery communicated directly with the distal left anterior descending artery, following saphenous vein bypass grafting. This type of collateralization following coronary artery bypass surgery seems to be very rare, and perhaps could protect the myocardium from severe ischemia.