Preeclampsia is a relatively common pregnancy-related disorder. Both maternal and fetal lives will be endangered if it proceeds unabated. Recently, the placenta-derived anti-angiogenic factors, such as soluble fms-like tyrosine kinase-1 (sFLT1) and soluble endoglin (sENG), have attracted attention in the progression of preeclampsia. Here, we established a unique experimental model to test the role of sFLT1 in preeclampsia using a lentiviral vector-mediated placenta-specific expression system. The model mice showed hypertension and proteinuria during pregnancy, and the symptoms regressed after parturition. Intrauterine growth restriction was also observed. We further showed that pravastatin induced the VEGF-like angiogenic factor placental growth factor (PGF) and ameliorated the symptoms. We conclude that our experimental preeclamptic murine model phenocopies the human case, and the model identifies low-dose statins and PGF as candidates for preeclampsia treatment.3-hydroxy-3-methyl-glutaryl-CoA | hemolytic anemia, elevated liver enzymes, and low platelet count | trophoblast P reeclampsia originates from placental insufficiency and is observed in ≈5% of pregnant females (1). Although preeclampsia is a major cause of maternal and infantile morbidity and mortality worldwide, the fundamental therapy available is to terminate the pregnancy. Therefore understanding the pathogenesis of preeclampsia is highly important and the generation of an appropriate animal model would be helpful to develop therapeutic drugs. In preeclamptic women, Maynard et al. found that increased soluble fms-like tyrosine kinase-1 (sFLT1) associated with decreased circulating levels of free VEGF and placental growth factor (PGF) (2). Because sFLT1 is a truncated form of VEGF receptor 1 and antagonizes VEGF and PGF function, impaired angiogenic signaling most likely results in endothelial dysfunction and preeclampsia (3).To establish an animal model of preeclampsia, placenta-specific gene manipulation is preferable because preeclampsia originates from a failure in placentation, and factors up-/ or down-regulated in the impaired placenta accentuate the symptoms. However, the lack of a facile and efficient method for placenta-specific gene manipulation has hampered the investigation of preeclampsia. The systemic administration of adenoviral vector (AdV-) expressing sFLT1 into pregnant rats resulted in classic signs of preeclampsia such as hypertension, proteinuria, and glomerular endotheliosis. However, unlike in patients, the sFLT1 expression in the rat model was transient and was mainly produced in the maternal liver, not in the placenta (2, 4). Previously, we and other groups have reported the placenta-specific transgenesis and expression by transducing blastocysts-stage embryos with HIV-I-based self-inactivating lentiviral vectors (5-7). The lentiviral vectors transduced the outermost layer of the blastocyst, the trophectoderm, that provides most of the main and functional components of the future placenta. By contrast, the vectors were not ab...

Placental dysfunction underlies many complications during pregnancy, and better understanding of gene function during placentation could have considerable clinical relevance. However, the lack of a facile method for placenta-specific gene manipulation has hampered investigation of placental organogenesis and the treatment of placental dysfunction. We showed previously that transduction of fertilized mouse eggs with lentiviral vectors leads to transgene expression in both the fetus and the placenta. Here we report placenta-specific gene incorporation by lentiviral transduction of mouse blastocysts after removal of the zona pellucida. All of the placentas analyzed, but none of the fetuses, were transgenic. Application of this method substantially rescued mice deficient in Ets2, Mapk14 (also known as p38alpha) and Mapk1 (also known as Erk2) from embryonic lethality caused by placental defects. Ectopic expression of Mapk11 also complemented Mapk14 deficiency during placentation.

Obesity is a major global public health problem, and understanding its pathogenesis is critical for identifying a cure. In this study, a gene knockout strategy was used in post-neonatal mice to delete synoviolin (Syvn)1/Hrd1/Der3, an ER-resident E3 ubiquitin ligase with known roles in homeostasis maintenance. Syvn1 deficiency resulted in weight loss and lower accumulation of white adipose tissue in otherwise wild-type animals as well as in genetically obese (ob/ob and db/db) and adipose tissue-specific knockout mice as compared to control animals. SYVN1 interacted with and ubiquitinated the thermogenic coactivator peroxisome proliferatoractivated receptor coactivator (PGC)-1b, and Syvn1 mutants showed upregulation of PGC-1b target genes and increase in mitochondrion number, respiration, and basal energy expenditure in adipose tissue relative to control animals. Moreover, the selective SYVN1 inhibitor LS-102 abolished the negative regulation of PGC-1b by SYVN1 and prevented weight gain in mice. Thus, SYVN1 is a novel post-translational regulator of PGC-1b and a potential therapeutic target in obesity treatment.

There are currently more than 15 million preterm births each year. We propose that gene-environment interaction is a major contributor to preterm birth. To address this experimentally, we generated a mouse model with uterine deletion of Trp53, which exhibits approximately 50% incidence of spontaneous preterm birth due to premature decidual senescence with increased mTORC1 activity and COX2 signaling. Here we provide evidence that this predisposition provoked preterm birth in 100% of females exposed to a mild inflammatory insult with LPS, revealing the high significance of gene-environment interactions in preterm birth. More intriguingly, preterm birth was rescued in LPS-treated Trp53-deficient mice when they were treated with a combination of rapamycin (mTORC1 inhibitor) and progesterone (P 4 ), without adverse effects on maternal or fetal health. These results provide evidence for the cooperative contributions of two sites of action (decidua and ovary) toward preterm birth. Moreover, a similar signature of decidual senescence with increased mTORC1 and COX2 signaling was observed in women undergoing preterm birth. Collectively, our findings show that superimposition of inflammation on genetic predisposition results in high incidence of preterm birth and suggest that combined treatment with low doses of rapamycin and P 4 may help reduce the incidence of preterm birth in high-risk women.

Although it has been reported that hypoxia inducible factor 2 α (Hif2a), a major transcriptional factor inducible by low oxygen tension, is expressed in the mouse uterus during embryo implantation, its role in pregnancy outcomes remains unclear. This study aimed to clarify functions of uterine HIF using transgenic mouse models. Mice with deletion of Hif2a in the whole uterus (Hif2a-uKO mice) showed infertility due to implantation failure. Supplementation with progesterone (P4) and leukemia inhibitory factor (LIF) restored decidual growth arrest and aberrant position of implantation sites in Hif2a-uKO mice, respectively, but did not rescue pregnancy failure. Histological analyses in Hif2a-uKO mice revealed persistence of the intact luminal epithelium, which blocked direct contact between stroma and embryo, inactivation of PI3K-AKT pathway (embryonic survival signal), and failed embryo invasion. Mice with stromal deletion of Hif2a (Hif2a-sKO mice) showed infertility with impaired embryo invasion and those with epithelial deletion of Hif2a (Hif2a-eKO mice) showed normal fertility, suggesting the importance of stromal HIF2α in embryo invasion. This was reflected in reduced expression of membrane type 2 metalloproteinase (MT2-MMP), lysyl oxidase (LOX), VEGF, and adrenomedullin (ADM) in Hif2a-uKO stroma at the attachment site, suggesting that stromal HIF2α regulates these mediators to support blastocyst invasion. These findings provide new insight that stromal HIF2α allows trophoblast invasion through detachment of the luminal epithelium and activation of an embryonic survival signal.