Effects of paternal exposure to cigarette smoke on sperm DNA methylation and long-term metabolic syndrome in offspring.

BACKGROUND: Although paternal exposure to cigarette smoke may contribute to obesity and metabolic syndrome in offspring, the underlying mechanisms remain uncertain. METHODS: In the present study, we analyzed the sperm DNA-methylation profiles in tobacco-smoking normozoospermic (SN) men, non-tobacco-smoking normozoospermic (N) men, and non-smoking oligoasthenozoospermic (OA) men. Using a mouse model, we also analyzed global methylation and differentially methylated regions (DMRs) of the DLK1 gene in paternal spermatozoa and the livers of progeny. In addition, we quantified DLK1 expression, executed an intra-peritoneal glucose tolerance test (IPGTT), measured serum metabolites, and analyzed liver lipid accumulation in the F1 offspring. RESULTS: Global sperm DNA-methylation levels were significantly elevated (p < 0.05) in the SN group, and the methylation patterns were different among N, SN, and OA groups. Importantly, the methylation level of the DLK1 locus (cg11193865) was significantly elevated in the SN group compared to both N and OA groups (p < 0.001). In the mouse model, the group exposed to cigarette smoke extract (CSE) exhibited a significantly higher global methylation DNA level in spermatozoa (p < 0.001) and on the DMR sites of Dlk1 in 10-week-old male offspring (p < 0.05), with a significant increase in Dlk1 expression in their livers (p < 0.001). In addition, IPGTT and LDL levels were significantly altered (p < 0.001), with elevated liver fat accumulation (p < 0.05) in F1 offspring. CONCLUSION: Paternal exposure to cigarette smoke led to increased global methylation of sperm DNA and alterations to the DMR of the DLK1 gene in the F1 generation, which may be inherited parentally and may perturb long-term metabolic function.

Uterine damage induces placenta accreta and immune imbalance at the maternal-fetal interface in the mouse.

INTRODUCTION: Placenta accreta spectrum (PAS) disorder is one of the major complications resulting in maternal death and serious adverse pregnancy outcomes. Uterine damage - principally that associated with cesarean section - is the leading risk factor for the development of PAS. However, the underlying pathogenesis of PAS related to uterine damage remains unclear. METHODS: For this study, we constructed a mouse PAS model using hysterotomy to simulate a cesarean section in humans. Pregnant mice were sacrificed on embryonic days 12.5 (E12.5) and E17.5. Trophoblast invasion and placental vascularization were analyzed using Hematoxylin-Eosin (H&E) staining and immunohistochemistry (IHC), and the proportions of immune cells at the maternal-fetal interface were analyzed using flow cytometry. We analyzed the expressions of genes in the decidua and placenta using RNA sequencing and subsequent validation by QPCR, and measured serum angiogenic factors by ELISA. RESULTS: Uterine damage led to increased trophoblast invasion and placental vascularization, with extensive changes to the immune-cell profiles at the maternal-fetal interface. The proportions of T and NK cells in the deciduas diminished significantly, with the decidual NK cells and M - 2 macrophages showing the greatest decline. The expression of TNF-α and IL4 was upregulated in the deciduas, while that of IFN-γ and IL10 was downregulated significantly. The expression of Mmp2, Mmp9, Mmp3, and Dock4 was significantly elevated in the placenta, and the serum levels of anti-angiogenic factors were significantly attenuated. DISCUSSION: Uterine damage can cause immune imbalance at the maternal-fetal interface, which may contribute to abnormal trophoblast invasion and enhanced vascularization of the mouse placenta.

Serum miRNA biomarker discovery for placenta accreta spectrum.

Placenta accreta spectrum (PAS) disorder is a major cause of maternal and fetal morbidity, and in vitro biomarkers are highly desired in clinic. This study enrolled three phases of 186 pregnant women, including controls, PAS patients, placenta previa (PP) patients, and pre-eclamptic (PE) patients. Initial miRNA array screened 42 out of 768 serum miRNAs in the screening phase, and then validated four miRNAs by quantitative RT-PCR in the training phase and validation phase. Their performance for PAS prenatal screening was analyzed by the receiver operating characteristic (ROC) curve, sensitivity, and specificity. Data validated that four miRNAs (miR-139-3p, miR-196a-5p, miR-518a-3p, and miR-671-3p) were down-regulated in PAS group comparing with controls in three phases of subjects. Except for miR-518a-3p, the expression levels of these miRNAs also were significantly different between the PAS and the group including PP and PE. In addition, these biomarkers demonstrated modest screening efficiency, as the AUC ranged from 0.59 to 0.74, sensitivity 0.54 to 0.80, and specificity 0.62 to 0.76. However, the AUC and specificity can improve greatly (AUC 0.91, specificity 0.92) using a 'diagnostic signature' that combined the four miRNAs and four clinical parameters into one panel. GO and KEGG signaling pathway analysis indicated their target genes were involved in angiogenesis, embryonic development, cell migration and adhesion, and tumor-related pathways. In conclusion, the four miRNAs discovered in this study not only can be used for future non-invasive prenatal PAS screening, but also provide a new experimental basis for future research on PAS etiology.