Transcription profiling of mouse embryos 1.5, 3 and 6 hr after maternal treatment with the teratogen sodium valproate
ABSTRACT: The antiepileptic drug valproic acid (vpa) is known teratogen giving neural tube defects (ntd:s). Administration of vpa to female NMRI on gestation day 8 induces a high incidence of ntd. In this study we investigate the time dependent gene expression changes induced in the embryo 1.5, 3 respectively 6 hr after maternal sodium valproate treatment.
Project description:In the process of evaluating teratogenic properties of xenobiotica, the consumption of laboratory animals is high and costly which makes the development of alternative methods desirable. The pluripotent embryocarcinoma cell line P19, which closely resembles the early stage of an embryo, may be relevant as an in vitro model of teratogenicity. The antiepileptic drug Valproic acid (VPA) is a potent inducer of neural tube defects (ntd:s) in both human and mouse, but its mechanism of teratogenicity is not know. P19 cells were here treated with sodium valproate in a both time and dose dependent matter to profile the gene expression response with Codelink UniSet Mouse 20K I Bioarrays. This profile may reveal biomarkers of ntd:s as well as give mechanistic input of the teratogenicity of VPA.
Project description:Valproic acid (VPA) is a potent inducer of neural tube defects (ntd:s) in both human and mouse, but its mechanism of teratogenicity is not know. The mouse embryonic stem cell line R1, may be relevant as an in vitro model of teratogenicity and was evaluated with exposures to VPA,and the two VPA anlogs (S)-2-pentyl-4-pentynoic acid, and 2-ethyl-4-methyl-pentanoic acid to profile the gene expression response. Those profiles may reveal biomarkers of teratogenic exposures in an in vitro system as well as give mechanistic input of the teratogenicity of VPA.
Project description:This series represents murine dorsal neural tube bisected along the midline with one half from each embryo used for control and the other half treated with 10-6M RA dissolved in ethanol for 6, 12, 24 or 48 h. For 6 h exposures, the explants were cultured overnight on fibronectin coated 35mm dishes (Biocoat, Becton Dickinson Labware, Bedford, MA) in DMEM with 10% horse serum in order to allow for sufficient outgrowth of neural crest cells. The RA was added the following morning; RMA Express 0.2 used to initially normalize data; GeneSpring (Silicon Genetics, Inc.) used for subsequent analysis; Samples were analyzed at 6, 12, 24, and 48 hours.
Project description:This SuperSeries is composed of the following subset Series:; GSE6881: Embryonic Testis Developmental Time Course; GSE6882: Embryonic Ovary Developmental Time Course Experiment Overall Design: Refer to individual Series
Project description:Neural tube defects (NTDs) are serious birth defects with an estimated worldwide incidence of 1 per 1,000 live births. The multifactorial nature of NTDs in humans has made it difficult to elucidate pathogenesis mechanisms. However, a strong relationship has been established between folate-homocysteine metabolism and NTD risk. Prevention of a substantial proportion of fetal NTDs can be achieved through maternal folic acid (FA) supplementation. However the mechanism by which FA exerts its beneficial effect remains unclear. METHODS: To improve our understanding of the underlying mechanisms of NTD pathogenesis and the ways in which folate exerts its beneficial effect, we analyzed mRNA profiles as well as folate and vitamin B12 levels in five NTD mouse mutants whose response to dietary FA was previously established. RESULTS: Differentially expressed genes representing the effect of each NTD-causing mutation were identified and associated with biologic pathways. Interestingly, the panel of NTD mutants collectively revealed pathways related to two nuclear receptors, retinoid X receptor (RXR) and pregnane X receptor (PXR), suggesting that these pathways may be related to a shared mechanism of NTD development. Moreover, the NTD-causing mutations that were associated with FA responsiveness had expression profiles that were related to folate-homocysteine metabolic pathways. These pathways were not strongly associated with mutants that do not respond to FA supplementation, implying that FA may be beneficial when the NTD mutation affects pathways related to folate-homocysteine metabolism. 5 groups of NTD mutants were studied. From each mutant group Heterozygous (test) and wild-type (control) female pups were used for this study at 6-8 weeks of age. 4 biological replicates were used for each of the test and control groups of each mutant. All mice used for the experiments were fasted 4-5 hours before dissection. A total of 36 samples were analyzed.
Project description:Here, we performed the first iTRAQ-based proteomic analysis of early embryonic longissimus dorsi muscle from Landrance (LR) and miniature pig (Wuzhishan WZS) ranging from 21 to 42 days post coitus (dpc). 4431 proteins were identified. In both WZS and LR, the largest amount of differentially expressed proteins (DEPs) were found between 28 and 35 dpc. 252 breed-DEPs were selected by GO analysis, including 8 myofibrillar proteins. Only MYHCⅠ/IIA mRNA were detected due to early embryonic stages, and significantly higher expression of them were found in WZS during these 4 stages. MYHCⅠ was first found in WZS at 28 dpc and expressed in both breeds at later stages, while MYHCII protein was not detected until 35 dpc in both breeds. Thus, 33 myogenic breed-DEPs selected from last two stages were analyzed by STRING, which showed that some myofibrillar proteins (MYH1, TPM4, MYH10, et.al) and functional proteins (CSRP2, CASQ2, OTC, et.al), together with candidate myogenic proteins (H3F3A, HDGFRP2, et.al), probably participate in the regulatory network of myofiber formation. Thus, our study provides new data on myofiber type development during early embryo stages, which contributes to the improved understanding in the regulation mechanism of early myogenesis in agricultural animals.
Project description:Rett syndrome (RTT) is a devastating neurodevelopmental disorder that occurs once in every 10,000-15,000 live female births. Despite intensive research, no effective cure is yet available. Valproic acid (VPA) has been used widely to treat mood disorder, epilepsy, and a growing number of other disorders. In limited clinical studies, VPA has also been used to control seizure in RTT patients with promising albeit somewhat unclear efficacy. In this study we tested the effect of VPA on the neurological symptoms of RTT and discovered that short-term VPA treatment during the symptomatic period could reduce neurological symptoms in RTT mice. We found that VPA restores the expression of a subset of genes in RTT mouse brains, and these genes clustered in neurological disease and developmental disorder networks. Our data suggest that VPA could be used as a drug to alleviate RTT symptoms. Wild type or MeCP2KO mice received daily injections of VPA (300 mg/kg) for 2 weeks. Each experimental condition: WT control, KO treated with VPA (KO+VPA), and KO treated with saline (KO+saline). Half brain samples were retrieved.
Project description:Valproic acid (VPA) is a potent inducer of neural tube defects (NTDs), but its mechanism of teratogenicity is not known. To study the transcriptional response of VPA during the susceptible period, i.e. when VPA is likely to exert most of its teratogenic effect, RNA was extracted from 8.25-dpc embryos (6 h post treatment) from control and VPA-treated dams, and subjected to microarray analysis (four arrays). To be more useful for risk assessment, in vitro models, using cells, may bridge biomarkers discovered by gene expression profiling in an animal in vivo model. Since pluripotent embryocarcinoma (EC) cell lines may be relevant models for early embryonic cells, P19 mouse EC cells were treated with or without 1 mM sodium valproate for 24 h and alos subjected to microarray analysis (four arrays).
Project description:Purpose: Valproic acid(VPA) has anti-cancer activity attributed to histone deacetylase inhibition(HDACi). We published the Genomically–Derived Sensitivity Signature for VPA(GDSS-VPA), a gene expression biomarker predicting breast cancer sensitivity to VPA in vitro and in vivo. We conducted a window-of-opportunity study examining the tolerability of VPA and the ability of the GDSS-VPA to predict biologic changes in breast tumors from VPA. Methods: Eligible women had untreated breast cancer with breast tumors over 1.5 cm. After a biopsy, women took VPA for 7-12 days, increasing from 30mg/kg/day PO divided BID to a maximum of 50mg/kg/day. After VPA treatment, serum VPA level was measured followed by breast surgery or a biopsy. Tumor proliferation was assessed by Ki-67 immunohistochemistry. Peripheral blood mononuclear cells(PBMCs) histone acetylation was assessed by Western blot. Results: Thirty women were evaluable. The median age was 54(range 31-73). 52% of women tolerated 50mg/kg/day, but 10% missed more than two doses due to adverse events(AEs). Grade 3 AEs included one patient with vomiting and diarrhea and one with fatigue. The end serum VPA level correlated with change in PBMC histone acetylation(rho=0.451, p=0.024). 50% of women with triple-negative breast cancer(TNBC) had a Ki-67 reduction of at least 10%, compared with 17% of other women. GDSS-VPA correlated with a Ki-67 decrease of at least 10%(AUC 0.66). Conclusions: Most women tolerate VPA. VPA treatment caused a decrease in proliferation of breast tumors. The genomic biomarker correlated with decreased proliferation. HDACi is a valid strategy for drug development in TNBC using gene expression biomarkers. Overall design: RNA was extracted from breast tumors before and after treatment for 7-12 days with valproic acid