No abstract

PRL was originally identified as a neuroendocrine hormone of pituitary origin; however, its synthesis is not limited to the hypophysis since numerous extrapituitary tissues also express this protein, including the placenta, ovary, testis, mammary gland, skin, adipose tissue, endothelial cells, and immune cells [1]. This wide-spread PRL expression might explain its involvement in very different processes such as reproduction, metabolism, immunology, and behavior.PRL expression and secretion are regulated by different stimuli provided by the environment and the internal milieu. Although pituitary PRL secretion is under a tonic and Prolactin 54Prolactin in the Immune System 55 regulated at the level of transcription. The regulation of PRL gene expression is quite complex, due to the presence of several enhancer and silencer domains as well as the formation of chromatin loops with consequences for transcription dynamics. Two independent promoters with differential responses to regulatory mediators direct PRL transcription in a cell-type specific manner [4].The human PRL locus consists of a single gene containing 5 coding exons transcribed directly from a pituitary-specific promoter (proximal promoter) and a non-coding exon (1a) transcribed from an alternative promoter (also known as the decidual or superdistal promoter) with a transcriptional start site located 5.8 kb upstream of exon 1b (Figure 1). This alternative promoter drives expression in extrapituitary tissues [4,5] and seems to have evolved from a long terminal repeat transposable element, previously described as primate specific [6]. The differential promoter usage produces different sized gene products, which may vary in a cell-specific manner depending on the functional elements used within the particular promoter. In general, extrapituitary PRL mRNA is 150 bp longer than pituitary PRL mRNA; however, mRNA identical to that in the pituitary gland has been found in normal and tumoral breast tissues, breast cell lines, and prostate [7,8]. Therefore, the dichotomy of promoter usage in pituitary versus extrapituitary sites is not absolute [9].As a consequence of the distal transcription start site, the alternative promoter does not respond to the same regulators of gene expression that operate with the proximal promoter, such as the pituitary transcriptional factor-1 (Pit-1), which is paramount for the activation of pituitary PRL transcription. An exception to this generalization is the hormonal form of vitamin D, calcitriol, which stimulates PRL expression in pituitary cells as well as in decidua and resting lymphocytes. Other cell-specific cases will be further discussed below. Regulation of PRL in the immune systemIn the immune system, PRL is thought to act as a locally produced cytokine with relevance for immune regulation and modulation of T-and B-cell function. Nevertheless, the molecular mechanisms regulating PRL expression in the immune system and the factors implicated are still not fully understood. Within the immune system, PRL is produced by Tand ...

The preimplantation stage of development is exquisitely sensitive to environmental stresses, and changes occurring during this developmental phase may have long-term health effects. Animal studies indicate that IVF offspring display metabolic alterations, including hypertension, glucose intolerance and cardiac hypertrophy, often in a sexual dimorphic fashion. The detailed nature of epigenetic changes following in-vitro culture is however unknown. This study was performed to evaluate the epigenetic (using WGBS and ATAC-seq) and transcriptomic changes (using RNA-seq) occurring in the inner cell mass (ICM) of male or female mouse embryos generated in vivo or by IVF. We found that the ICM of IVF embryos, compared to the in-vivo ICM, differed in 3% of differentially methylated regions (DMR), of which 0.1% were located on CpG islands. ATAC-seq revealed that 293 regions were more accessible and 101 were less accessible in IVF embryos, while RNA-seq revealed that 21 genes were differentially regulated in IVF embryos. Functional enrichment analysis revealed that stress signaling (STAT and NF-kB signaling), developmental processes and cardiac hypertrophy signaling showed consistent changes in WGBS and ATAC-seq platforms. In contrast, male and female embryos showed minimal changes. Male ICM had an increased number of significantly hypermethylated DMRs, while only 27 regions showed different chromatin accessibility and only one gene was differentially expressed. In summary, this study provides the first comprehensive analysis of DNA methylation, chromatin accessibility and RNA expression changes induced by IVF in male and female ICMs. This dataset can be of value to all researchers interested in the developmental origin of health and disease (DOHaD) hypothesis and might lead to a better understanding of how early embryonic manipulation may affect adult health.

No abstract

Dogs (Canis lupus familiaris) have unique and peculiar reproductive characteristics. While the interplay between in vitro oviductal cell-derived extracellular vesicles (OC-EVs) and cumulus-oocyte complexes in dogs has begun to be elucidated, no study has yet provided extensive information on the biological content and physiological function of OC-EVs and their role in canine oocyte development. Here, we aimed to provide the first comprehensive proteomic analysis of OC-EVs. We identified 398 proteins as present in all OC-EVs samples. The functional enrichment analysis using Gene Ontology terms and an Ingenuity Pathway Analysis revealed that the identified proteins were involved in several cellular metabolic processes, including translation, synthesis, expression, and protein metabolism. Notably, the proteins were also involved in critical canonical pathways with essential functions in oocyte and embryo development, such as ERK/MAPK, EIF2, PI3K/AKT, and mTOR signaling. These data would be an important resource for studying canine reproductive physiology and establishing a successful in vitro embryo production system in dogs.