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Receptive endometrium is a prerequisite for successful embryo implantation, and it follows that poor endometrial receptivity is a leading cause of implantation failure. miRNAs play important roles as epigenetic regulators of endometrial receptivity and embryo implantation through post-transcriptional modifications. However, the mechanisms of action of many miRNAs are poorly understood. In this study, we investigated the role of the miR-183 family, comprising three miRNAs (miR-183-5p, miR-182-5p, and miR-96-5p) in endometrial receptivity and embryo implantation. The miR-183 family shows estrogen-dependent upregulation in endometrial Ishikawa (IK) cells. The miR-183 family also has a positive role in migration and proliferation of IK cells. Furthermore, JAr spheroid attachment experiments show that attachment rates were significantly decreased after treatment of IK cells with inhibitors for miR-183-5p and miR-182-5p and increased after treatment with miR-183-5p-mimic and miR-96-5p-mimic, respectively. The downstream analysis shows that catenin alpha 2 (CTNNA2) is a potential target gene for miR-183-5p, and this was confirmed in luciferase reporter assays. An in vivo mouse pregnancy model shows that inhibition of miR-183-5p significantly decreases embryo implantation rates and increases CTNNA2 expression. Downregulation of CTNNA2 in endometrial cells by miR-183-5p may be significant in mediating estrogenic effects on endometrial receptivity. In conclusion, miR-183-5p and the CTNNA2 gene may be potential biomarkers for endometrial receptivity and may be useful diagnostic and therapeutic targets for successful embryo implantation.

An ectopic ureter is a ureter that does not correctly connect to the trigone of the bladder and drains outside of the bladder. Here, we presented five cases of ectopic ureter opening into the vagina, whose clinical symptoms and malformations were rarely described in previous case reports. All five patients were hospitalized with complaints of gynecologic disease. Three of the five cases did not present the typical symptoms of urinary incontinence. Three of these cases showed congenital malformations of the female genital tract. Four cases were diagnosed in adulthood. All patients were analyzed using various imaging examinations. This study suggests that the ectopic ureter should be considered in the differential diagnosis of a pelvic mass in a patient with urinary and reproductive system abnormalities. It is essential to comprehensively evaluate complex malformations of the genitourinary system with multiple imaging tests.

Gestational and postpartum high‐fat diets (HFDs) have been implicated as causes of obesity in offspring in later life. The present study aimed to investigate the effects of gestational and/or postpartum HFD on obesity in offspring. We established a mouse model of HFD exposure that included gestation, lactation and post‐weaning periods. We found that gestation was the most sensitive period, as the administration of a HFD impaired lipid metabolism, especially fatty acid oxidation in both foetal and adult mice, and caused obesity in offspring. Mechanistically, the DNA hypermethylation level of the nuclear receptor, peroxisome proliferator‐activated receptor‐α (Pparα), and the decreased mRNA levels of ten‐eleven translocation 1 (Tet1) and/or ten‐eleven translocation 2 (Tet2) were detected in the livers of foetal and adult offspring from mothers given a HFD during gestation, which was also associated with low Pparα expression in hepatic cells. We speculated that the hypermethylation of Pparα resulted from the decreased Tet1/2 expression in mothers given a HFD during gestation, thereby causing lipid metabolism disorders and obesity. In conclusion, this study demonstrates that a HFD during gestation exerts long‐term effects on the health of offspring via the DNA demethylation of Pparα, thereby highlighting the importance of the gestational period in regulating epigenetic mechanisms involved in metabolism.

Background The existing reports about intergenerational or transgenerational effects of intrauterine hyperglycemia have included both intrauterine and postnatal metabolic exposure factors, while the impact of intrauterine hyperglycemia per se has not been assessed alone. A number of studies suggest DNA methylation reprogramming of gametes plays a crucial role in the metabolic inheritance, but it is unclear when and how DNA methylation patterns are altered when exposed to intrauterine hyperglycemia. In this study, we selected nondiabetic F1- and F2-gestational diabetes mellitus (GDM) male mice as founders to examine metabolic changes in the next generation and performed methylome sequencing of day 13.5 primordial germ cells (PGCs) from F1-GDM to explore the underlying epigenetic mechanism. Results We found that intrauterine hyperglycemia exposure resulted in obesity, insulin resistance, and/or glucose intolerance in F2 male mice, but no metabolic changes in F3 male mice at 8 weeks. Using reduced representation bisulfite sequencing, we found DNA methylome of day 13.5 PGCs from F1-GDM fetuses revealed differently methylated genes enriched in obesity and diabetes. Methylation validation of the insulin resistance and fat accumulation gene Fyn showed a consistent hypomethylation status in F1 PGCs, F1 fetal testes, sperm from F1/C-GDM mice, and somatic cells from F2-GDM male mice. In contrast, no methylation alteration was observed in F2-GDM male germ cells and F3-GDM somatic cells. Conclusion We provide evidence that intrauterine hyperglycemia exposure per se contributes to intergenerational metabolic changes in the F2 but not F3 generation. And the aberrant DNA methylation reprogramming occurs as early as day 13.5 in PGCs of the F1 generation. Our findings suggest that intrauterine exposure alone is sufficient to cause the epigenetic inheritance in F2 offspring, and the epigenetic memory carried by DNA methylation pattern could be erased by the second wave of methylation reprogramming in F2 PGCs during fetal development. Electronic supplementary material The online version of this article (10.1186/s13072-018-0192-2) contains supplementary material, which is available to authorized users.

Additional file 3. Distribution of differentially methylated loci in gene elements, and hierarchical clustering presentation of RRBS sequencing.

Probiotics are viable microorganisms with the capacity to alter the gastrointestinal microbiota of the host. The recent scientific advancements and development of probiotic formulations have rekindled the importance of these clinical interpretations, underlining the starring role of the gut flora in host metabolism, defense and immune regulation. Despite encouraging preliminary results from randomized clinical trials of probiotics for various clinical conditions including irritable bowel syndrome, necrotizing enterocolitis, gastroenteritis, antibiotic-associated diarrhea, infantile colic, and improvement of digestion and immune function, further evidence is needed to determine the reproducibility of the findings and elucidate the underlying mechanisms. In this review, we have considered the postnatal development of gut flora and appraised the role of probiotics in health and disease condition among infants.

Additional file 2. Metabolic phenotypes and bio-parameters of F2/C-GDM male mice at 8Â weeks.

Additional file 6. DNA methylation validation in control and STZ-treated nondiabetic mice.

Additional file 2. Metabolic phenotypes and bio-parameters of F2/C-GDM male mice at 8Â weeks.

Additional file 6. DNA methylation validation in control and STZ-treated nondiabetic mice.