Valosin-containing protein is associated with maintenance of meiotic arrest in mouse oocytes†

Knockdown of Csnk1a1 results in preimplantation developmental arrest in mice

Casein kinase 1, alpha 1 (CSNK1A1), is a member of the highly conserved serine/threonine protein kinase family. This study was established to analyze the expression and localization of CSNK1A1 and its function in early embryonic development in mice. Csnk1a1 mRNA and protein are expressed in multiple mouse tissues including the ovary. After ovulation and fertilization, Csnk1a1 mRNA and protein were detected in preimplantation embryos and their expression was highest in two-cell-stage embryos. CSNK1A1 protein was also mainly localized in the cytoplasm of preimplantation embryos. Moreover, knockdown of Csnk1a1 in zygotes led to a significant decrease in the rate of blastocyst formation. Furthermore, treatment of zygotes with the CSNK1A1-specific inhibitor D4476 also resulted in embryonic developmental arrest. These results provide the first evidence for a novel function of CSNK1A1 in early embryonic development in mice.

The immunoexpression of valosin-containing protein and small VCP-interacting protein in rat ovaries

Numerous cellular processes are controlled by the ubiquitin-proteasome-mediated degradation pathway, involve the 97-kDa valosin-containing protein (p97/VCP). Small p97/VCP-interacting protein (SVIP) was first discovered as one of the novel androgen-responsive genes as well as one of the many cofactors controlling p97/VCP. The aim of the study was to investigate localization and immunoexpression of p97/VCP and SVIP in rat ovarian tissue. The histomorphological examination of rat ovarian tissue was performed by using haematoxylin-eosin (HE) staining. Using the immunohistochemical technique, cellular location and expression of p97/VCP and SVIP in rat ovarian tissue were examined. The nuclear and cytoplasmic immunoexpression of p97/VCP and SVIP was observed in the different stages of ovarian follicles and corpus luteum in the rat ovaries. The immunolocalization of SVIP and VCP in the rat ovaries suggest that they may be involved in the oogenesis. Further studies should be performed about the function of the VCP and SVIP in the female reproductive tract.

Causal and Candidate Gene Variants in a Large Cohort of Women With Primary Ovarian Insufficiency

CONTEXT

A genetic etiology likely accounts for the majority of unexplained primary ovarian insufficiency (POI).

OBJECTIVE

We hypothesized that heterozygous rare variants and variants in enhanced categories are associated with POI.

DESIGN

The study was an observational study.

SETTING

Subjects were recruited at academic institutions.

PATIENTS

Subjects from Boston (n = 98), the National Institutes of Health and Washington University (n = 98), Pittsburgh (n = 20), Italy (n = 43), and France (n = 32) were diagnosed with POI (amenorrhea with an elevated follicle-stimulating hormone level). Controls were recruited for health in old age or were from the 1000 Genomes Project (total n = 233).

INTERVENTION

We performed whole exome sequencing (WES), and data were analyzed using a rare variant scoring method and a Bayes factor-based framework for identifying genes harboring pathogenic variants. We performed functional studies on identified genes that were not previously implicated in POI in a D. melanogaster model.

MAIN OUTCOME

Genes with rare pathogenic variants and gene sets with increased burden of deleterious variants were identified.

RESULTS

Candidate heterozygous variants were identified in known genes and genes with functional evidence. Gene sets with increased burden of deleterious alleles included the categories transcription and translation, DNA damage and repair, meiosis and cell division. Variants were found in novel genes from the enhanced categories. Functional evidence supported 7 new risk genes for POI (USP36, VCP, WDR33, PIWIL3, NPM2, LLGL1, and BOD1L1).

CONCLUSIONS

Candidate causative variants were identified through WES in women with POI. Aggregating clinical data and genetic risk with a categorical approach may expand the genetic architecture of heterozygous rare gene variants causing risk for POI.

Isolation and Characterization of Equine Uterine Extracellular Vesicles: A Comparative Methodological Study

Extracellular vesicles (EVs) have been identified in the uterine fluid in different species and have been pointed as key players in the embryo-maternal dialogue, maternal recognition of pregnancy and establishment of pregnancy. However, little is known about the uterine EVs in the mare. Therefore, the present study aimed at characterizing EVs from uterine lavage of cyclic mares by comparing five EVs isolation methods and the combination of them: (1) ultracentrifugation (UC); (2) concentration of lavage volume by Centricon ultrafiltration (CE); (3) the use of CE with different washing steps (phosphate-buffered saline with or without trehalose); (4) size-exclusion chromatography with iZON-qEV columns, and (5) a combination of the methods with best results based on EVs yield, purity, and protein cargo profiles. Transmission electron microscopy and Western blotting confirmed the isolation of EVs by all methods but with quantitative and qualitative differences. Mass spectrometry provided differences in protein profiles between methods, number of identified proteins, and protein classes. Our results indicate that the combination of CE/trehalose/iZON/UC is an optimal method to isolate equine uterine EVs with good yield and purity that can be applied in future studies to determine the role of equine uterine EVs in embryo-maternal interactions.