The composition of human vaginal microbiota transferred at birth affects offspring health in a mouse model

Newborns are colonized by maternal microbiota that is essential for offspring health and development. The composition of these pioneer communities exhibits individual differences, but the importance of this early-life heterogeneity to health outcomes is not understood. Here we validate a human microbiota-associated model in which fetal mice are cesarean delivered and gavaged with defined human vaginal microbial communities. This model replicates the inoculation that occurs during vaginal birth and reveals lasting effects on offspring metabolism, immunity, and the brain in a community-specific manner. This microbial effect is amplified by prior gestation in a maternal obesogenic or vaginal dysbiotic environment where placental and fetal ileum development are altered, and an augmented immune response increases rates of offspring mortality. Collectively, we describe a translationally relevant model to examine the defined role of specific human microbial communities on offspring health outcomes, and demonstrate that the prenatal environment dramatically shapes the postnatal response to inoculation.

Recent African strains of Zika virus display higher transmissibility and fetal pathogenicity than Asian strains

The global emergence of Zika virus (ZIKV) revealed the unprecedented ability for a mosquito-borne virus to cause congenital birth defects. A puzzling aspect of ZIKV emergence is that all human outbreaks and birth defects to date have been exclusively associated with the Asian ZIKV lineage, despite a growing body of laboratory evidence pointing towards higher transmissibility and pathogenicity of the African ZIKV lineage. Whether this apparent paradox reflects the use of relatively old African ZIKV strains in most laboratory studies is unclear. Here, we experimentally compare seven low-passage ZIKV strains representing the recently circulating viral genetic diversity. We find that recent African ZIKV strains display higher transmissibility in mosquitoes and higher lethality in both adult and fetal mice than their Asian counterparts. We emphasize the high epidemic potential of African ZIKV strains and suggest that they could more easily go unnoticed by public health surveillance systems than Asian strains due to their propensity to cause fetal loss rather than birth defects.

The Metabolic Reprogramming of Frem2 Mutant Mice Embryos in Cryptophthalmos Development

BackgroundCryptophthalmos is characterized by congenital ocular dysplasia with eyelid malformation. The pathogenicity of mutations in genes encoding components of the FRAS1/FREM protein complex is well established, but the underlying pathomechanisms of this disease are still unclear. In the previous study, we generated mice carrying Frem2R725X/R2156W compound heterozygous mutations using CRISPR/Cas9 and showed that these mice recapitulated the human cryptophthalmos phenotype.MethodsIn this study, we tracked changes in the metabolic profile of embryos and expression of metabolism-related genes in Frem2 mutant mice on E13.5 compared with wild-type mice. RNA sequencing (RNA-seq) was utilized to decipher the differentiated expression of genes associated with metabolism. Untargeted metabolomics and targeted metabolomics analyses were performed to detect and verify the shifts in the composition of the embryonic metabolome.ResultsDifferentially expressed genes participating in amino acid metabolism and energy metabolism were observed by RNA-seq. Transcriptomic analysis suggests that 821 (39.89%) up-regulated genes and 320 (32.99%) down-regulated genes were involved in the metabolic process in the enriched GO terms. A total of 92 significantly different metabolites were identified including creatine, guanosine 5′-monophosphate, cytosine, cytidine 5′-monophosphate, adenine, and L-serine. Interestingly, major shifts related to ATP binding cassette transporters (ABC transporters) and the biosynthesis of amino acids in the composition of the embryonic metabolome were observed by KEGG metabolic analysis, indicating that these pathways could also be involved in the pathogenesis of cryptophthalmos.ConclusionWe demonstrate that Frem2 mutant fetal mice have increased susceptibility to the disruption of eye morphogenesis in association with distinct transcriptomic and metabolomic signatures. Our findings suggest that the metabolomic signature established before birth may play a role in mediating cryptophthalmos in Frem2 mutant mice, which may have important implications for the pathogenesis of cryptophthalmos.

Teratogenic Toxicity Evaluation of Bladder Cancer Specific Oncolytic Adenovirus on Mice

Background: In our previous studies, we had demonstrated the efficiency and specificity of constructed bladder tissue specific adenovirus Ad-PSCAE-UPII-E1A-AR (APU-EIA-AR) on bladder cancer, we also investigated the virus biodistribution and body toxicity in nude mice. However, the safety of the bladder cancer specific oncolytic adenovirus on fetal mice and F1 mice should be under intense investigation. Objectives: In order to evaluate the teratogenic toxicity of bladder cancer specific oncolytic adenovirus APU-EIA-AR on mice, in this study, we investigated the fetal mice weight, fetal body length and tail length, fetal skeleton development, as well as the F1 mice weight, growth curve, and major organ pathology. These teratogenic toxicity data of bladder tissue specific adenovirus AdPSCAE-UPII-E1A-AR (AD) would provide safe information prior to embarking on clinical trials. Methods: At sixth day of being fertilized, the pregnant mice began to be intramuscular administrated with AD (1×107VP, 1×108VP, 1×109VP) every other day for ten days. Then ,the pregnants were devided into two groups. One group was euthanized at seventeenth day, took out the fetal mice ,observing the bone structure of the infants. The oth er group was observed until natural childbirth. The Filial Generation (F1) are feeded and growth for 30 days, the variation in the growth progress and developmen t were assessed. Then the mice were euthenazied, the organ tissue were performed pathological section and HE staining, observing the changes under microscope. Results: In the process of teratogenic toxicity test , comparing with control group ,the Placenta weight ,fetal mice weight , body len gth and tail length of mice fetal in adenovirus treated group did not reveal any alteration. Comparing with PBS group, there is no obvious change in skeleton of fetal mice treated with adenovirus. During the development process of F1 mice treated with adenovirus, the changes of mice weight show statistical significance. Howerer, in the progress of growth curve, this difference is not very obvious. Furthermore, the pathological section showed no obvious alteration in major organs. Conclusion: Our study demonstrated that bladder cancer specific adenovirus Ad-PSCAE-UPII-E1A-AR appear safe in the pregnant mice without any discernable effects on fetal mice and F1 development. Hence, It is a relatively safe for tumor gene therapy.

AT1-receptor autoantibody exposure in utero contributes to cardiac dysfunction and increased glycolysis in fetal mice

Exposure to adverse factors in utero may lead to adaptive changes in cardiac structure and metabolism, which increases the risk of chronic cardiovascular disease later in life. Studies showed that the angiotensin II type 1 receptor autoantibodies (AT1-AAs) are able to cross the placenta into the circulation of pregnant rodents’ embryo, which adversely affects embryogenesis. However, the effects of AT1-AA exposure on the fetal heart in utero are still unknown. In this study, we investigated whether intrauterine AT1-AA exposure has adverse effects on fetal heart structure, function and metabolism. AT1-AA-positive pregnant mouse models were successfully established by passive immunity, evidenced by increased AT1-AA content. Morphological and ultrasonic results showed that the fetal mice on embryonic day 18 (E18) of AT1-AA group have loose and disordered myocardial structure, and decreased left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), compared with control groups. The myocardium of AT1-AA group fetal mice on E18 exhibited increased expression of the key molecules in the glycolytic pathway, pyruvate and lactic acid content and ATP production, suggesting that the glycolysis rate was enhanced. Furthermore, the enhanced effect of glycolysis caused by AT1-AA is mainly through the PPARβ/δ pathway. These data confirmed that fetus exposure to AT1-AA in utero developed left ventricular dysfunction, myocardial structural arrangement disorders, and enhanced glycolysis on E18. Our results support AT1-AA being a potentially harmful factor for cardiovascular disease in fetal mice.

miR-184 mediates hyperoxia-induced injury by targeting cell death and angiogenesis signalling pathways in the developing lung

MicroRNAs (miRs) have been shown to disrupt normal lung development and function by interrupting alveolarization and vascularisation leading to development of bronchopulmonary dysplasia (BPD). Here we report that miR-184 has a critical role in the induction of BPD phenotype characterised by abnormal alveolarization and pulmonary angiogenesis in the developing lung. We observed an increased expression of miR-184 in BPD clinical specimens: tracheal aspirates (TA), human neonatal lungs with BPD and in fetal human lung Type II alveolar epithelial cells (TIIAECs) exposed to hyperoxia. Consistent with this, we also detected an upregulated miR-184-3p expression in whole lungs, in freshly isolated TIIAECs from lungs of hyperoxia-induced experimental BPD mice and in fetal mice lung TIIAECs exposed to hyperoxia. We demonstrate that overexpression of miR-184-3p exacerbates the BPD pulmonary phenotype, while downregulation of miR-184-3p expression ameliorated the BPD phenotype and also improved respiratory function. We identified miR-184 specific targets: platelet-derived growth factor-beta (Pdgf-β) and friend of Gata 2 (Fog2), also known as zinc finger protein family member (Zfpm2), and show that they are critically involved in pulmonary alveolarization and angiogenesis. Using cell-based luciferase analysis, downregulation of miR-184-3p expression and gene knockdown of miR-184-3p targets Pdgf-β and Fog2 in lung TIIAECs and endothelial cells, we mechanistically show that inhibition of miR-184-3p expression improves pulmonary alveolarization by regulating PDGF-β/AKT/Foxo3/Bax, Bcl2 signalling and enhances angiogenesis by Fog2/VEGF-A/Angiopoietin-1/2 pathway. Collectively, these data suggest that the use of miR-184-3p specific inhibitors may act as novel therapeutic interventions to control the adverse effects of hyperoxia on lung development and function.