ABSTRACT
Birth defects result from interactions between genetic and environmental factors, but the mechanisms remain poorly understood. We find that mutations and teratogens interact in predictable ways to cause birth defects by changing target cell sensitivity to Hedgehog (Hh) ligands. These interactions converge on a membrane protein complex, the MMM complex, that promotes degradation of the Hh transducer Smoothened (SMO). Deficiency of the MMM component MOSMO results in elevated SMO and increased Hh signaling, causing multiple birth defects. In utero exposure to a teratogen that directly inhibits SMO reduces the penetrance and expressivity of birth defects in Mosmo-/- embryos. Additionally, tissues that develop normally in Mosmo-/- embryos are refractory to the teratogen. Thus, changes in the abundance of the protein target of a teratogen can change birth defect outcomes by quantitative shifts in Hh signaling. Consequently, small molecules that re-calibrate signaling strength could be harnessed to rescue structural birth defects.
Subject(s)
Abnormalities, Drug-Induced/genetics , Gene-Environment Interaction , Hedgehog Proteins/metabolism , Penetrance , Animals , Cells, Cultured , HEK293 Cells , Humans , Mice , Mice, Inbred C57BL , NIH 3T3 Cells , Signal Transduction , Smoothened Receptor/genetics , Smoothened Receptor/metabolismABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: Clerodendrum cyrtophyllum Turcz has been used in traditional medicine for the treatment of various diseases. In spite of its therapeutic applications, research on its toxicity and teratogenicity is still limited. AIM OF THE STUDY: The study aimed to investigate the developmental toxicity of the ethanol extract of C. cyrtophyllum (EE) in zebrafish embryo model. MATERIAL AND METHODS: Major compounds from crude ethanol extract of Clerodendron cyrtophyllum Turcz leaves were determined using HPLC-DAD-Orbitrap-MS analysis. The developmental toxicity of EE were investigated using zebrafish embryo model. Zebrafish embryos at 6 h post-fertilization (hpf) were treated with EE at different concentrations. Egg coagulation, mortality, hatching, yolk sac edema, pericardial edema and teratogenicity were recorded each day for during a 5-day exposure. At time point 120 hpf, body length, pericardial area, heartbeat and yolk sac area were assessed. In order to elucidate molecular mechanisms for the developmental toxicity of EE, we further evaluated the effects of the EE on the expression of genes involved on signaling pathways affecting fish embryo's development such as heart development (gata5, myl7, myh6, has2, hand2, nkx 2.5), oxidative stress (cat, sod1, gpx4, gstp2), wnt pathway (ß-catenin, wnt3a, wnt5, wnt8a, wnt11), or cell apoptosis (p53, bax, bcl2, casp3, casp8, casp9, apaf-1, gadd45bb) using qRT-PCR analysis. RESULTS: Our results demonstrated that three major components including acteoside, cirsilineol and cirsilineol-4'-O-ß-D-glucopyranoside were identified from EE. EE exposure during 6-96 h post-fertilization (hpf) at doses ranging from 80 to 200 µg/mL increased embryo mortality and reduced hatching rate. EE exposure at 20 and 40 µg/mL until 72-120 hpf induced a series of malformations, including yolk sac edema, pericardial edema, spine deformation, shorter body length. Based on two prediction models using a teratogenic index (TI), a 25% lethality concentration (LD25) and the no observed-adverse-effect level (NOAEL), EE is considered as teratogenic for zebrafish embryos with TI (LC50/EC50) and LD25/NOAEC values at 96 hpf reaching 3.87 and 15.73 respectively. The mRNA expression levels of p53, casp8, bax/bcl2, gstp2, nkx2.5, wnt3a, wnt11, gadd45bb and gata5 were significantly upregulated by EE exposure at 20 and 40 µg/mL while the expression of wnt5, hand2 and bcl2 were downregulated. CONCLUSIONS: These results provide evidence for toxicity effects of EE to embryo stages and provide an insight into the potential toxicity mechanisms on embryonic development.
Subject(s)
Abnormalities, Drug-Induced/etiology , Clerodendrum/toxicity , Embryo, Nonmammalian/drug effects , Plant Extracts/toxicity , Zebrafish/embryology , Abnormalities, Drug-Induced/genetics , Abnormalities, Drug-Induced/metabolism , Abnormalities, Drug-Induced/pathology , Animals , Apoptosis/drug effects , Clerodendrum/chemistry , Dose-Response Relationship, Drug , Embryo, Nonmammalian/metabolism , Embryo, Nonmammalian/pathology , Ethanol/chemistry , Gene Expression Regulation, Developmental , No-Observed-Adverse-Effect Level , Oxidative Stress/drug effects , Plant Extracts/isolation & purification , Solvents/chemistry , Wnt Signaling Pathway/drug effects , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolismABSTRACT
Failure to predict drug-induced toxicity reactions is a major problem contributing to a high attrition rate and tremendous cost in drug development. Drug screening in X. laevis embryos is high-throughput relative to screening in rodents, potentially making them ideal for this use. Xenopus embryos have been used as a toxicity model in the frog embryo teratogenesis assay on Xenopus (FETAX) for the early stages of drug safety evaluation. We previously developed compound-screening methods using Xenopus embryos and believe they could be used for in vitro drug-induced toxicity safety assessment before expensive preclinical trials in mammals. Specifically, Xenopus embryos could help predict drug-induced hepatotoxicity and consequently aid lead candidate prioritization. Here we present methods, which we have modified for use on Xenopus embryos, to help measure the potential for a drug to induce liver toxicity. One such method examines the release of the liver-specific microRNA (miRNA) miR-122 from the liver into the vasculature as a result of hepatocellular damage, which could be due to drug-induced acute liver injury. Paracetamol, a known hepatotoxin at high doses, can be used as a positive control. We previously showed that some of the phenotypes of mammalian paracetamol overdose are reflected in Xenopus embryos. Consequently, we have also included here a method that measures the concentration of free glutathione (GSH), which is an indicator of paracetamol-induced liver injury. These methods can be used as part of a panel of protocols to help predict the hepatoxicity of a drug at an early stage in drug development.
Subject(s)
Abnormalities, Drug-Induced/diagnosis , Biological Assay/methods , Chemical and Drug Induced Liver Injury/diagnosis , Embryo, Nonmammalian/drug effects , Xenopus laevis/embryology , Abnormalities, Drug-Induced/genetics , Abnormalities, Drug-Induced/metabolism , Animals , Chemical and Drug Induced Liver Injury/genetics , Chemical and Drug Induced Liver Injury/metabolism , Drug Evaluation, Preclinical/methods , Embryo, Nonmammalian/metabolism , Liver/drug effects , Liver/embryology , Liver/metabolism , MicroRNAs/genetics , Reproducibility of Results , Sensitivity and Specificity , Toxicity Tests/methods , Xenopus laevis/genetics , Xenopus laevis/metabolismABSTRACT
Valproic acid (VPA), an antiepileptic and mood-stabilizing drug, is prescribed to women of reproductive age. VPA is associated with a 1-2% increase in neural tube defects in offspring following gestational exposure and results in epigenetic modifications induced by perturbations in transcription cofactors. Cbp and p300, two transcription cofactors, play key roles in embryonic neural development. p300 is a downstream target of Akt, a protein kinase B associated with cell survival and anti-apoptotic mechanisms, as part of the Akt-p300 axis. We examined the effects of in utero VPA exposure on Cbp, p300, and Akt in gestational day (GD)9, GD10 and GD13 CD-1 mouse embryos following a teratogenic maternal dose of 400 mg/kg. Embryos were collected at 0, 1, 3 and 6 h post-dosing on GD9, 24 h post-dosing on GD10 and on GD13. GD10 embryos were grouped according to the status of neural tube closure in control, closed and open groups. GD13 heads were grouped as control, exposed but non-exencephalic and exencephalic. Our data indicate that Cbp, p300 and Akt mRNA levels were downregulated at 1 and 3 h post-exposure in GD9 embryos while Cbp and p300 protein levels remained stable. Akt protein levels were significantly increased 1 h post-exposure. No significant changes were observed in either mRNA or protein expression in embryos with closed or open neural tubes compared to the control group at GD10. Downregulated expression of Cbp, p300, and Akt may play a key role in VPA-induced neural tube defects considering their vitally important role in embryonic development.
Subject(s)
Abnormalities, Drug-Induced/metabolism , CREB-Binding Protein , E1A-Associated p300 Protein , Neural Tube Defects/metabolism , Proto-Oncogene Proteins c-akt , Valproic Acid , Abnormalities, Drug-Induced/genetics , Animals , CREB-Binding Protein/genetics , CREB-Binding Protein/metabolism , Down-Regulation , E1A-Associated p300 Protein/genetics , E1A-Associated p300 Protein/metabolism , Embryo, Mammalian/drug effects , Embryo, Mammalian/metabolism , Mice , Neural Tube Defects/chemically induced , Neural Tube Defects/genetics , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolismABSTRACT
OBJECTIVE: The mechanisms by which antiepileptic drugs (AEDs) cause birth defects (BDs) are unknown. Data suggest that AED-induced BDs may result from a genome-wide increase of de novo variants in the embryo, a mechanism that we investigated. METHODS: Whole exome sequencing data from child-parent trios were interrogated for de novo single-nucleotide variants/indels (dnSNVs/indels) and de novo copy number variants (dnCNVs). Generalized linear models were applied to assess de novo variant burdens in children exposed prenatally to AEDs (AED-exposed children) versus children without BDs not exposed prenatally to AEDs (AED-unexposed unaffected children), and AED-exposed children with BDs versus those without BDs, adjusting for confounders. Fisher exact test was used to compare categorical data. RESULTS: Sixty-seven child-parent trios were included: 10 with AED-exposed children with BDs, 46 with AED-exposed unaffected children, and 11 with AED-unexposed unaffected children. The dnSNV/indel burden did not differ between AED-exposed children and AED-unexposed unaffected children (median dnSNV/indel number/child [range] = 3 [0-7] vs 3 [1-5], p = 0.50). Among AED-exposed children, there were no significant differences between those with BDs and those unaffected. Likely deleterious dnSNVs/indels were detected in 9 of 67 (13%) children, none of whom had BDs. The proportion of cases harboring likely deleterious dnSNVs/indels did not differ significantly between AED-unexposed and AED-exposed children. The dnCNV burden was not associated with AED exposure or birth outcome. INTERPRETATION: Our study indicates that prenatal AED exposure does not increase the burden of de novo variants, and that this mechanism is not a major contributor to AED-induced BDs. These results can be incorporated in routine patient counseling. ANN NEUROL 2020;87:897-906.
Subject(s)
Abnormalities, Drug-Induced/genetics , Anticonvulsants/adverse effects , Genetic Load , Genetic Variation/genetics , Teratogens , Abnormalities, Drug-Induced/epidemiology , Adult , DNA/genetics , DNA Copy Number Variations/genetics , Exome/genetics , Female , Humans , Infant, Newborn , Male , Paternal Age , Polymorphism, Single Nucleotide/genetics , PregnancyABSTRACT
Completion of the Human Genome Project has led to the identification of a large number of transcription start sites that are not paired with protein-coding genes, supporting the growing recognition of the abundance of encoded nonprotein-coding RNAs (ncRNAs) and their importance for speciation and species-specific development. Present in both plants and animals, ncRNAs vary in size, function, primary sequence, and secondary structure. While microRNAs (miRNAs) are the best known, there are a number of other ncRNAs (long[er] nonprotein-coding RNA, pseudogenes, circular RNAs, and so on) that have been shown to play an important role in the development either directly or via networks of proteins and other ncRNAs, including modulating the impact of miRNAs. Furthermore, these ncRNAs and their developmental regulatory networks are sensitive to teratogens such as ethanol, cannabis, cocaine, and nicotine. A better understanding of the developmental role of ncRNAs and their capacity to mediate teratogenesis is a necessary step in efforts to minimize the long-term consequences of developmental exposures to drugs-of-abuse. Moreover, with increasing awareness of the prevalence of polydrug use, experimental models will need to incorporate more complex drug exposure paradigms into meaningful assessments of developmental ncRNA function.
Subject(s)
Abnormalities, Drug-Induced/genetics , Congenital Abnormalities/genetics , Gene Regulatory Networks/drug effects , RNA, Untranslated/genetics , Animals , Cannabis/adverse effects , Cocaine/adverse effects , Ethanol/adverse effects , Humans , Nicotine/adverse effects , Teratology/methodsABSTRACT
Warfarin is the most worldwide used anticoagulant drug and rodenticide. Since it crosses placental barrier it can induce warfarin embryopathy (WE), a fetal mortality in neonates characterized by skeletal deformities in addition to brain hemorrhages. Although the effects of warfarin exposure in aquatic off target species were already described, the particular molecular toxicological mechanisms during early development are still unclear. Here, we used zebrafish (Danio rerio) to describe and compare the developmental effects of warfarin exposure (0, 15.13, 75.68 and 378.43â¯mM) on two distinct early developmental phases (embryos and eleuthero-embryos). Although exposure to both developmental phases induced fish mortality, only embryos exposed to the highest warfarin level exhibited features mimicking mammalian WE, e.g. high mortality, higher incidence of hemorrhages and altered skeletal development, among other effects. To gain insights into the toxic mechanisms underlying warfarin exposure, the transcriptome of embryos exposed to warfarin was explored through RNA-Seq and compared to that of control embryos. 766 differentially expressed (564 up- and 202 down-regulated) genes were identified. Gene Ontology analysis revealed particular cellular components (cytoplasm, extracellular matrix, lysosome and vacuole), biological processes (mainly amino acid and lipid metabolism and response to stimulus) and pathways (oxidative stress response and apoptosis signaling pathways) being significantly overrepresented in zebrafish embryos upon warfarin exposure. Protein-protein interaction further evidenced an altered redox system, blood coagulation and vasculogenesis, visual phototransduction and collagen formation upon warfarin exposure. The present study not only describes for the first time the WE in zebrafish, it provides new insights for a better risk assessment, and highlights the need for programming the rat eradication actions outside the fish spawning season to avoid an impact on off target fish community. The urge for the development of more species-specific anticoagulants for rodent pest control is also highlighted.
Subject(s)
Abnormalities, Drug-Induced/metabolism , Anticoagulants/toxicity , Nasal Bone/abnormalities , Rodenticides/toxicity , Warfarin/adverse effects , Warfarin/toxicity , Water Pollutants, Chemical/toxicity , Abnormalities, Drug-Induced/genetics , Animals , Disease Models, Animal , Embryo, Nonmammalian/drug effects , Embryo, Nonmammalian/metabolism , Humans , Nasal Bone/metabolism , Oxidative Stress/drug effects , Transcriptome , Warfarin/metabolism , Zebrafish/embryology , Zebrafish/genetics , Zebrafish/metabolismABSTRACT
Teratology is the study of anatomical and physiological abnormalities, commonly known as birth defects. If an embryo is exposed to a harmful substance, or teratogen, during the critical period of development, an ensuing malformation may occur. These malformations and their associated mechanisms are studied and analyzed in laboratory animals in order to prevent them from occurring in humans. Rodents such as rats and mice have commonly been used in such studies because of their similarity to humans. In 1959, James G. Wilson designed, developed, and tested a protocol on how to observe and analyze structural malformations in rodent fetuses, which included: external examination, skeletal evaluation, soft tissue analysis, and data collection/analysis. For standardization purposes, i.e., to normalize findings from one lab to another, it is important that this protocol be followed with precision. Although many years have passed since Wilson initially created this protocol, it is still widely used to this day, and only minor changes have been made to his instructions such as the chemical reagents used in the experiments and methods of analysis of the experimental data. Such testing has resulted in major advances in the dissemination of teratology information, including the identification of an increasing number of teratogens and the understanding of the pathogenesis of birth defects. While mechanistically birth defect prevention will include the understanding of individual genomes and pharmacogenomics, overall, morphological assessment will still be required as an integral part of birth defects research. As the interaction between teratogenic and genetic factors is better understood, it is anticipated that the incidence of most types of defects will substantially be reduced.
Subject(s)
Abnormalities, Drug-Induced/diagnosis , Congenital Abnormalities/diagnosis , Teratogens/toxicity , Abnormalities, Drug-Induced/genetics , Animals , Bone and Bones/abnormalities , Bone and Bones/drug effects , Bone and Bones/embryology , Congenital Abnormalities/genetics , Female , Fetus/abnormalities , Fetus/drug effects , Humans , Mice , Pregnancy , RatsABSTRACT
OBJECTIVE: To investigate whether exposure to metformin during the first trimester of pregnancy, for diabetes or other indications, increases the risk of all or specific congenital anomalies. DESIGN: Population based exploratory case-control study using malformed controls. Cases of 29 specific subgroups of non-genetic anomalies, and all non-genetic anomalies combined, were compared with controls (all other non-genetic anomalies or genetic syndromes). SETTING: 11 EUROmediCAT European congenital anomaly registries surveying 1 892 482 births in Europe between 2006 and 2013. PARTICIPANTS: 50 167 babies affected by congenital anomaly (41 242 non-genetic and 8925 genetic) including live births, fetal deaths from 20 weeks' gestation, and terminations of pregnancy for fetal anomaly. MAIN OUTCOME MEASURE: Odds ratios adjusted for maternal age, registry, multiple birth, and maternal diabetes status. RESULTS: 168 babies affected by congenital anomaly (141 non-genetic and 27 genetic) were exposed to metformin, 3.3 per 1000 births. No evidence was found for a higher proportion of exposure to metformin during the first trimester among babies with all non-genetic anomalies combined compared with genetic controls (adjusted odds ratio 0.84, 95% confidence interval 0.55 to 1.30). The only significant result was for pulmonary valve atresia (adjusted odds ratio 3.54, 1.05 to 12.00, compared with non-genetic controls; 2.86, 0.79 to 10.30, compared with genetic controls). CONCLUSIONS: No evidence was found for an increased risk of all non-genetic congenital anomalies combined following exposure to metformin during the first trimester, and the one significant association was no more than would be expected by chance. Further surveillance is needed to increase sample size and follow up the cardiac signal, but these findings are reassuring given the increasing use of metformin in pregnancy.
Subject(s)
Abnormalities, Drug-Induced/etiology , Hypoglycemic Agents/adverse effects , Metformin/adverse effects , Abnormalities, Drug-Induced/genetics , Adult , Case-Control Studies , Female , Humans , Maternal Age , Odds Ratio , Pregnancy , Pregnancy Trimester, First/drug effects , Pregnancy in Diabetics/drug therapy , Registries , Risk Factors , Young AdultABSTRACT
Hydroxyurea, a ribonucleotide reductase inhibitor, is a potent teratogen in mice, causing severe limb and skeletal defects. The exposure of gestation day nine murine embryos to hydroxyurea elicits an early embryonic stress response that involves activation of the P53 transcription factor. The impact of this P53 activation on the embryotoxicity of hydroxyurea- is not known. The goal of this study was to test the hypothesis that P53 acts to suppress hydroxyurea embryotoxicity. Trp53+/- timed pregnant mice were treated with saline or hydroxyurea (200 or 400â¯mg/kg) on gestation day nine; fetuses were examined for viability and external and skeletal malformations on gestation day eighteen. Neither the deletion of Trp53 nor hydroxyurea treatment significantly affected fetal growth although a trend towards a decrease in fetal weights was observed in Trp53-/- fetuses. However, hydroxyurea induced a significantly higher incidence of malformations and resorptions in Trp53-/- fetuses compared to their wildtype littermates. Thus, fetal P53 genotype is an important determinant of the effects of hydroxyurea on organogenesis-stage embryos.
Subject(s)
Abnormalities, Drug-Induced/genetics , Abnormalities, Multiple/genetics , Antineoplastic Agents/toxicity , Embryo, Mammalian/drug effects , Hydroxyurea/toxicity , Teratogens/toxicity , Tumor Suppressor Protein p53/genetics , Abnormalities, Multiple/chemically induced , Animals , Embryonic Development/drug effects , Female , Genotype , Maternal-Fetal Exchange , Mice, Transgenic , Organogenesis/drug effects , PregnancyABSTRACT
Selenium (Se) is an essential element and its biological activity is related to its speciation. It is also well-known that in excess it can cause teratogenesis in fish and birds. In this study we compared dietary toxicity of elemental selenium nanoparticles (SeNPs) with selenite and selenomethionine (Se-Met). Japanese medaka (Oryzias latipes) was used as a laboratory model to determine Se effects on adults and their offspring. Adult females were individually exposed using a dry diet fortified with 0, 10 or 20⯵g/g of the three Se species for 7 days and then allowed to breed for 3 days. Fertilization rate and the proportion of malformed offspring were examined. The three Se diets led to significant increase in maternal tissue Se concentration in the order of Se-Met >>selenite > SeNP. However, in terms of proportion of malformed offspring, the effect of Se-Met = selenite > SeNP. The malformations included pericardial edema and craniofacial changes, which were typical for Se toxicity. The mismatch of maternal ovary Se concentration and proportion of malformed offspring suggested total Se concentration is a poor predictor of toxicity and teratogenesis. Comparing expression of four genes related to oxidative stress in maternal tissue also showed that there were significant differences in expression patterns between three Se diets in the order of selenite = SeNP > Se-Met. Our results showed that SeNPs cause similar toxicity as other Se species but require further study to elucidate the underlying mechanism.
Subject(s)
Abnormalities, Drug-Induced , Dietary Exposure , Maternal Exposure , Nanoparticles , Selenium/toxicity , Abnormalities, Drug-Induced/genetics , Abnormalities, Drug-Induced/metabolism , Animals , Female , Oryzias/genetics , Oryzias/metabolism , Oxidative Stress , Selenious Acid/toxicity , Selenomethionine/toxicityABSTRACT
Thalidomide is a drug used worldwide for several indications, but the molecular mechanisms of its teratogenic property are not fully understood. Studies in animal models suggest the oxidative stress, the inhibition of angiogenesis, and the binding to E3-ubiquitin ligase complex as mechanisms by which thalidomide can change the expression of genes important to embryonic development. In this study, seven polymorphisms in genes related to development (FGF8, FGF10, BMP4, SHH, TP53, TP63, and TP73) were analyzed in people with thalidomide embryopathy (TE) and compared to people without malformations. The sample consisted of 36 people with TE and 135 unrelated and nonsyndromic people who had their DNA genotyped by PCR real-time. Although no allelic or genotypic differences were observed between the groups, we hypothesized that other regions in these genes and related genes may play an important role in thalidomide teratogenesis, which is known to have a genetic contribution. Identifying such molecular mechanisms is essential for the development of a molecule that will be analogue to thalidomide but safe enough to avoid the emergence of new cases of TE.
Subject(s)
Abnormalities, Drug-Induced/genetics , Genetic Predisposition to Disease , Genotype , Polymorphism, Genetic , Thalidomide/adverse effects , Female , Humans , Infant, Newborn , Male , Real-Time Polymerase Chain Reaction , Thalidomide/administration & dosageABSTRACT
The impact of in-utero isotretinoin exposure has been widely reported, with many affected pregnancies failing to reach term.1 2 Due to the low numbers of in-utero isotretinoin exposed pregnancies, the interactions between this drug and rare genetic defects such as microduplication 1q21.1 are unclear, particularly how they might manifest phenotypically. We present this case of in-utero isotretinoin exposure occurring in a child with microduplication 1q21.1. The child was born with congenital abnormalities which did not fit into a single syndrome. Regrettably in-utero exposure to isotretinoin continues to occur. We hope this case will trigger further discussion on the dangers of dispensing Isotretinoin without ensuring stringent pregnancy testing and its potential interaction with genetic abnormalities, in particular with microduplication 1q21.1.
Subject(s)
Abnormalities, Drug-Induced/genetics , Cleft Lip/diagnosis , Cleft Palate/diagnosis , Isotretinoin/toxicity , Syndactyly/diagnosis , Teratogens/toxicity , Abnormalities, Drug-Induced/diagnosis , Abnormalities, Drug-Induced/diagnostic imaging , Cleft Lip/chemically induced , Cleft Lip/diagnostic imaging , Cleft Palate/chemically induced , Cleft Palate/diagnostic imaging , Diagnosis, Differential , Female , Fingers/abnormalities , Humans , Infant , Magnetic Resonance Imaging , Pregnancy , Prenatal Exposure Delayed Effects , Syndactyly/chemically induced , Syndactyly/diagnostic imaging , Toes/abnormalitiesSubject(s)
Abnormalities, Drug-Induced/genetics , Congenital Abnormalities/genetics , Teratogenesis/drug effects , Teratogens/toxicity , Teratology/education , Abnormalities, Drug-Induced/pathology , Abnormalities, Drug-Induced/physiopathology , Animals , Animals, Genetically Modified , Congenital Abnormalities/pathology , Congenital Abnormalities/physiopathology , Female , History, 21st Century , Humans , Placenta/abnormalities , Placenta/anatomy & histology , Placenta/drug effects , Placenta/metabolism , Pregnancy , Species Specificity , Spermatogenesis/genetics , Teratogenesis/genetics , Teratology/history , WorkforceABSTRACT
BACKGROUND: We previously reported that Wnt5a/CaMKIIδ (calcium/calmodulin-dependent protein kinase II delta) pathway was involved in the embryonic tongue deformity induced by excess retinoic acid (RA). Our latest study found that the expression of miR-31-5p, which was predicted to target the 3'UTR of CamkIIδ, was raised in the RA-treated embryonic tongue. Thus, we hypothesized that the excess RA regulated Wnt5a/CaMKIIδ pathway through miR-31-5p in embryonic tongue. METHODS: C2C12 myoblast line was employed as an in vitro model to examine the suppression of miR-31-5p on CamkIIδ expression, through which RA impaired the myoblast proliferation and differentiation in embryonic tongue. RESULTS: RA stimulated the expression of miR-31-5p in both embryonic tongue and C2C12 myoblasts. Luciferase reporter assay confirmed that the 3'UTR of CamkIIδ was a target of miR-31-5p. MiR-31-5p mimics disrupted CamkIIδ expression, C2C12 proliferation and differentiation as excess RA did, while miR-31-5p inhibitor partially rescued these defects in the presence of RA. CONCLUSIONS: Excess RA can stimulate miR-31-5p expression to suppress CamkIIδ, which represses the proliferation and differentiation of tongue myoblasts.
Subject(s)
Abnormalities, Drug-Induced/metabolism , Calcium-Calmodulin-Dependent Protein Kinase Type 2/genetics , MicroRNAs/genetics , Muscle Development , Tongue/abnormalities , Tretinoin/pharmacology , 3' Untranslated Regions , Abnormalities, Drug-Induced/genetics , Animals , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Cell Differentiation , Cell Proliferation , HEK293 Cells , Humans , Mice , MicroRNAs/metabolism , Myoblasts/drug effects , Myoblasts/metabolism , Myoblasts/physiology , Tongue/embryology , Tretinoin/toxicityABSTRACT
Objective To evaluate whether the association between maternal periconceptional use of selective serotonin reuptake inhibitors (SSRIs) and increased risk of congenital heart defects in offspring is modified by maternal or infant genetic variants in folate, homocysteine, or transsulfuration pathways.Design Population based study. DNA from mothers, fathers, and infants was genotyped with an Illumina GoldenGate custom single nucleotide polymorphism panel. A hybrid design based on a log linear model was used to calculate relative risks and Bayesian false discovery probabilities (BFDP) to identify polymorphisms associated with congenital heart defects modified by SSRI use.Data sources Data from the US National Birth Defects Prevention Study on 1180 liveborn infants with congenital heart defects and 1644 controls, born 1997-2008.Main outcome measures Cases included infants with selected congenital heart defects and control infants had no major defects. SSRI use was obtained from telephone interviews with mothers.Results For women who reported taking SSRIs periconceptionally, maternal SHMT1 (rs9909104) GG and AGgenotypes were associated with a 5.9 and 2.4 increased risk of select congenital heart defects in offspring, respectively, versus the AA genotype (BFDP=0.69). Compared with the AA genotype, BHMT (rs492842 and rs542852) GG and AG genotypes were associated with twice the riskof congenital heart defects (BFDP=0.74 and 0.79, respectively). MGST1 (rs2075237) CC and ACgenotypes were associated with an increased risk compared with the GG genotype (8.0 and 2.8, respectively; BFDP=0.79). Single nucleotide polymorphism in infant genes in the folate (MTHFS rs12438477), homocysteine (TRDMT1 rs6602178 and GNMT rs11752813) and transsulfuration (GSTP1 rs7941395 and MGST1 rs7294985) pathways were also associated with an increased risk of congenital heart defects.Conclusions Common maternal or infant genetic variants in folate, homocysteine, or transsulfuration pathways are associated with an increased risk of certain congenital heart defects among children of women taking SSRIs during cardiogenesis.
Subject(s)
Abnormalities, Drug-Induced/epidemiology , Abnormalities, Drug-Induced/genetics , Genetic Predisposition to Disease , Heart Defects, Congenital/epidemiology , Heart Defects, Congenital/genetics , Selective Serotonin Reuptake Inhibitors/therapeutic use , Abnormalities, Drug-Induced/prevention & control , Adult , Case-Control Studies , Female , Genotyping Techniques , Heart Defects, Congenital/prevention & control , Humans , Infant, Newborn , Interviews as Topic , Polymorphism, Single Nucleotide , Selective Serotonin Reuptake Inhibitors/adverse effects , United States/epidemiologyABSTRACT
Certain metals have been known for their toxic effects on embryos and fetal development. The vasculature in early pregnancy is extremely dynamic and plays an important role in organogenesis. Nascent blood vessels in early embryonic life are considered to be a primary and delicate target for many teratogens since the nascent blood islands follow a tightly controlled program to form vascular plexus around and inside the embryo for resourcing optimal ingredients for its development. The state of the distribution of toxic metals, their transport mechanisms and the molecular events by which they notch extra-embryonic and embryonic vasculatures are illustrated. In addition, pharmacological aspects of toxic metal induced teratogenicity have also been portrayed. The work reviewed state of the current knowledge of specific role of microRNAs (miRNAs) that are differentially expressed in response to toxic metals, and how they interfere with the vasculogenesis that manifests into embryonic anomalies.
Subject(s)
Abnormalities, Drug-Induced/genetics , Cardiovascular Abnormalities/chemically induced , Metals/toxicity , MicroRNAs , Neovascularization, Physiologic/genetics , Teratogens/toxicity , Animals , Cardiovascular Abnormalities/genetics , Humans , Organogenesis/drug effects , Organogenesis/geneticsABSTRACT
Thalidomide causes Thalidomide Embryopathy (TE), but is largely used to treat several conditions. Investigations with Cereblon, a thalidomide target protein encoded by CRBN gene, have helped to understand thalidomide therapeutic and teratogenic properties. We sequenced CRBN-thalidomide binding region in 38 TE individuals and 136 Brazilians without congenital anomalies, and performed in silico analyses. Eight variants were identified, seven intronic and one in 3'UTR. TE individuals had rare variants in higher frequency than the non-affected group (p=0.04). The genotype rs1620675 CC was related to neurological anomalies in TE individuals (p=0.004). Bioinformatics analysis suggested this genotype leads to potential alterations in splicing sites and binding to transcription factors. Comparison of the Cereblon-thalidomide binding domains in mammals demonstrated that CRBN is highly conserved across species. All the variants require evaluation in functional assays in order to understand their role in Cereblon-thalidomide binding and complex interactions that lead to TE.
Subject(s)
Abnormalities, Drug-Induced/genetics , Abnormalities, Multiple/genetics , Fetal Diseases/genetics , Peptide Hydrolases/genetics , Teratogens/toxicity , Thalidomide/toxicity , Abnormalities, Drug-Induced/etiology , Abnormalities, Multiple/chemically induced , Adaptor Proteins, Signal Transducing , Binding Sites , Brazil , Computer Simulation , Fetal Diseases/chemically induced , Genomics , Humans , Ubiquitin-Protein LigasesABSTRACT
BACKGROUND: Orofacial clefts (OFCs) are common birth defects, which include a range of disorders with a complex etiology affecting formation of craniofacial structures. Some forms of syndromic OFCs are produced by defects in the cholesterol pathway. The principal enzyme of the cholesterol pathway is the 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCR). Our aim is to study whether defects of HMGCR function would produce orofacial malformation similar to those found in disorders of cholesterol synthesis. METHODS: We used zebrafish hmgcrb mutants and HMGCR inhibition assay using atorvastatin during early and late stages of orofacial morphogenesis in zebrafish. To describe craniofacial phenotypes, we stained cartilage and bone and performed in situ hybridization using known craniofacial markers. Also, we visualized neural crest cell migration in a transgenic fish. RESULTS: Our results showed that mutants displayed loss of cartilage and diminished orofacial outgrowth, and in some cases palatal cleft. Late treatments with statin show a similar phenotype. Affected-siblings displayed a moderate phenotype, whereas early-treated embryos had a minor cleft. We found reduced expression of the downstream component of Sonic Hedgehog-signaling gli1 in ventral brain, oral ectoderm, and pharyngeal endoderm in mutants and in late atorvastatin-treated embryos. CONCLUSION: Our results suggest that HMGCR loss-of-function primarily affects postmigratory cranial neural crest cells through abnormal Sonic Hedgehog signaling, probably induced by reduction in metabolites of the cholesterol pathway. Malformation severity correlates with the grade of HMGCR inhibition, developmental stage of its disruption, and probably with availability of maternal lipids. Together, our results might help to understand the spectrum of orofacial phenotypes found in cholesterol synthesis disorders. Birth Defects Research (Part A) 106:814-830, 2016. © 2016 Wiley Periodicals, Inc.
Subject(s)
Abnormalities, Drug-Induced , Atorvastatin/adverse effects , Cleft Lip , Cleft Palate , Hydroxymethylglutaryl CoA Reductases , Mutation , Zebrafish Proteins , Zebrafish , Abnormalities, Drug-Induced/enzymology , Abnormalities, Drug-Induced/genetics , Animals , Atorvastatin/pharmacology , Cleft Lip/chemically induced , Cleft Lip/enzymology , Cleft Lip/genetics , Cleft Lip/pathology , Cleft Palate/chemically induced , Cleft Palate/enzymology , Cleft Palate/genetics , Cleft Palate/pathology , Hydroxymethylglutaryl CoA Reductases/genetics , Hydroxymethylglutaryl CoA Reductases/metabolism , Zebrafish/genetics , Zebrafish/metabolism , Zebrafish Proteins/antagonists & inhibitors , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolismABSTRACT
Mendelian diseases contain important biological information regarding developmental effects of gene mutations that can guide drug discovery and toxicity efforts. In this review, we focus on Smith-Lemli-Opitz syndrome (SLOS), a rare Mendelian disease characterized by compound heterozygous mutations in 7-dehydrocholesterol reductase (DHCR7) resulting in severe fetal deformities. We present a compilation of SLOS-inducing DHCR7 mutations and the geographic distribution of those mutations in healthy and diseased populations. We observed that several mutations thought to be disease causing occur in healthy populations, indicating an incomplete understanding of the condition and highlighting new research opportunities. We describe the functional environment around DHCR7, including pharmacological DHCR7 inhibitors and cholesterol and vitamin D synthesis. Using PubMed, we investigated the fetal outcomes following prenatal exposure to DHCR7 modulators. First-trimester exposure to DHCR7 inhibitors resulted in outcomes similar to those of known teratogens (50 vs 48% born-healthy). DHCR7 activity should be considered during drug development and prenatal toxicity assessment.