Premature Neural Progenitor Cell Differentiation Into Astrocytes in Retinoic Acid-Induced Spina Bifida Rat Model.
Ontology highlight
ABSTRACT:
SUBMITTER: Oria M
PROVIDER: S-EPMC9249056 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Background The vitamin A derivative, retinoic acid (RA), is a potent teratogenic agent that induces a variety of congenital abnormalities including neural tube defects. The embryopathology of RA has been extensively investigated and retinol receptors play important roles during organogenesis, development and neural tube closure. Still, the mechanisms by which RA influences these processes are not completely understood. Methods We used a custom-made mouse genome 32K oligonucleotide microarray to determine the gene expression profiles of mouse embryo spinal cord samples that had been exposed to vehicle or RA. Then, we performed a GSEA (gene set enrichment analysis) on the gene expression data by searching MSigDB (v2.5) c2 gene sets (canonical pathways) and c5 gene sets (curated GO terms), with set size restraints on the range to avoid over-narrow or over-broad categories. Results Using microarray technology, the present study identifies 85 genes in the spinal cord that exhibit at least a 1.5-fold change between control samples and samples with spina bifida aperta. A gene set enrichment analysis showed that maternal exposure to RA induced spinal bifida that were associated with altered expression of genes involved in pro- or anti-apoptosis, cell proliferation, migration, cytoskeleton components, and cell or focal adhesion, indicating that defective functions of these cell components and biological processes preceded the abnormal development of neural tube. Conclusions Maternal exposure to RA induced spinal bifida that were associated with altered expression of genes involved in pro- or anti-apoptosis, cell proliferation, migration, cytoskeleton components, and cell or focal adhesion. As shown in previous reports, defective functions of these cell components and biological processes preceded the abnormal development of the neural tube. Our study will help the understanding of the etiology and pathology of spinal bifida. However, it should be noted that the changes in gene expression induced by RA exposure may not be an effect on events other than neural tube closure; further study is required to fully understand the molecular mechanisms and consequence of neural tube defects in embryos exposed to RA. Our study provides a global analysis of gene expression patterns in spina bifida and will help the understanding of the etiology and pathology of neural tube defects.
2011-05-10 | GSE28834 | GEO
Project description:Spina bifida is a birth defect in which the vertebral column is open, often with spinal cord involvement. The most clinically significant subtype is myelomeningocele (open spina bifida), which is a condition characterized by failure of the lumbosacral spinal neural tube to close during embryonic development. The exposed neural tissue degenerates in utero, resulting in neurological deficit that varies with the level of the lesion. Occurring in approximately 1 per 1,000 births worldwide, myelomeningocele is one of the most common congenital malformations, but its cause is largely unknown. The genetic component is estimated at 60-70%, but few causative genes have been identified to date, despite much information from mouse models. Non-genetic maternal risk factors include reduced folate intake, anticonvulsant therapy, diabetes mellitus and obesity. Primary prevention by periconceptional supplementation with folic acid has been demonstrated in clinical trials, leading to food fortification programmes in many countries. Prenatal diagnosis is achieved by ultrasonography, enabling women to seek termination of pregnancy. Individuals who survive to birth have their lesions closed surgically, with subsequent management of associated defects, including the Chiari II brain malformation, hydrocephalus, and urological and orthopaedic sequelae. Fetal surgical repair of myelomeningocele has been associated with improved early neurological outcome compared with postnatal operation. Myelomeningocele affects quality of life during childhood, adolescence and adulthood, posing a challenge for individuals, families and society as a whole. For an illustrated summary of this Primer, visit: http://go.nature.com/fK9XNa.
| S-EPMC4898641 | biostudies-other
Project description:Spina bifida aperta is a congenital malformation characterized by the failure of neural tube closure resulting in an unprotected fetal spinal cord. The spinal cord then undergoes progressive damage, likely due to chemical and mechanical factors related to exposure to the intrauterine environment. Astrogliosis in exposed spinal cords has been described in animal models of spina bifida during embryonic life but its relationship with neuroinflammatory processes are completely unknown. Using a retinoic acid-induced rat model of spina bifida we demonstrated that, when exposed to amniotic fluid, fetal spinal cords showed progressive astrogliosis with neuronal loss at mid-gestation (E15) compared to unexposed spinal cords. The number of microglial cells with a reactive phenotype and activation marker expression increased during gestation and exhibited progressive disruption in the inhibitory immune ligand-receptor system. Specifically we demonstrate down-regulation of CD200 expression and up-regulation of CD200R. Exposed spinal cords demonstrated neuroinflammation with increased tissue water content and cytokine production by the end of gestation (E20), which correlated with active Caspase3 expression in the exposed layers. Our findings provide new evidence that microglia activation, including the disruption of the endogenous inhibitory system (CD200-CD200R), may participate in the pathogenesis of spina bifida through late gestation.
| S-EPMC6045622 | biostudies-literature
Project description:Background The vitamin A derivative, retinoic acid (RA), is a potent teratogenic agent that induces a variety of congenital abnormalities including neural tube defects. The embryopathology of RA has been extensively investigated and retinol receptors play important roles during organogenesis, development and neural tube closure. Still, the mechanisms by which RA influences these processes are not completely understood. Methods We used a custom-made mouse genome 32K oligonucleotide microarray to determine the gene expression profiles of mouse embryo spinal cord samples that had been exposed to vehicle or RA. Then, we performed a GSEA (gene set enrichment analysis) on the gene expression data by searching MSigDB (v2.5) c2 gene sets (canonical pathways) and c5 gene sets (curated GO terms), with set size restraints on the range to avoid over-narrow or over-broad categories. Results Using microarray technology, the present study identifies 85 genes in the spinal cord that exhibit at least a 1.5-fold change between control samples and samples with spina bifida aperta. A gene set enrichment analysis showed that maternal exposure to RA induced spinal bifida that were associated with altered expression of genes involved in pro- or anti-apoptosis, cell proliferation, migration, cytoskeleton components, and cell or focal adhesion, indicating that defective functions of these cell components and biological processes preceded the abnormal development of neural tube. Conclusions Maternal exposure to RA induced spinal bifida that were associated with altered expression of genes involved in pro- or anti-apoptosis, cell proliferation, migration, cytoskeleton components, and cell or focal adhesion. As shown in previous reports, defective functions of these cell components and biological processes preceded the abnormal development of the neural tube. Our study will help the understanding of the etiology and pathology of spinal bifida. However, it should be noted that the changes in gene expression induced by RA exposure may not be an effect on events other than neural tube closure; further study is required to fully understand the molecular mechanisms and consequence of neural tube defects in embryos exposed to RA. Our study provides a global analysis of gene expression patterns in spina bifida and will help the understanding of the etiology and pathology of neural tube defects. We assessed the changes in gene expression that coincide with spina bifida in RA-treated mouse fetuses. After generating an independent list of regulated genes, we analyzed samples by gene set enrichment analysis to expand our results. A pool of spinal cord tissue from spina bifida fetuses whose mothers were exposed to RA was compared to a pool of spinal cord tissue from fetuses whose mothers were exposed to olive oil vehicle. Three replicates each.
2011-05-10 | E-GEOD-28834 | biostudies-arrayexpress
Project description:Genome wide DNA methylation profiling of 10 patients with myelomeningocele (MMC) and 6 healthy controls
2016-10-03 | GSE81846 | GEO
Project description:Retinoic acid (RA) has several established functions during cardiac development, including actions in the fetal epicardium required for myocardial growth. An open question is if retinoid effects are limited to growth factor stimulation pathway(s) or if additional actions on uncommitted progenitor/stem populations might drive cardiac differentiation. Here we report the dual effects of RA deficiency on cardiac growth factor signaling and progenitor/stem biology using the mouse retinaldehyde dehydrogenase 2 (Raldh2) knockout model. Although early heart defects in Raldh2(-/-) embryos result from second-heart-field abnormalities, it is unclear whether this role is transient or whether RA has sustained effects on cardiac progenitors. To address this, we used transient maternal RA supplementation to overcome early Raldh2(-/-) lethality. By embryonic day 11.5-14.5, Raldh2(-/-) hearts exhibited reduced venticular compact layer outgrowth and altered coronary vessel development. Although reductions in Fgf2 and target pERK levels occurred, no alterations in Wnt/beta-catenin expression were observed. Cell proliferation is increased in compact zone myocardium, whereas cardiomyocyte differentiation is reduced, alterations that suggest progenitor defects. We report that the fetal heart contains a reservoir of stem/progenitor cells, which can be isolated by their ability to efflux a fluorescent dye and that retinoid signaling acts on this fetal cardiac side population (SP). Raldh2(-/-) hearts display increased SP cell numbers, with selective increases in expression of cardiac progenitor cell markers and reduced differentiation marker levels. Hence, although lack of RA signaling increases cardiac SP numbers, simultaneous reductions in Fgf signaling reduce cardiomyocyte differentiation, possibly accounting for long-term defects in myocardial growth.
| S-EPMC2889106 | biostudies-literature
Project description:Neural tube defects (NTDs) are the most severe congenital malformations that result from failure of neural tube closure during early embryonic development, and the underlying molecular mechanisms remain elusive. Mitophagy is the best-known way of mitochondrial quality control. However, the role and regulation of mitophagy in NTDs have not yet been elucidated. In this study, we used an all-trans retinoic acid (ATRA)-induced rat model to investigate mitophagy and its underlying mechanism in spina bifida aperta (SBA). The results of western blot, immunofluorescence and RT-qPCR analyses indicated that mitophagy was impaired and Sirt1 was downregulated in SBA. Administration of resveratrol-a strong specific Sirt1 activator-activated Sirt1, thus attenuating autophagy suppression and ameliorating SBA. RNA-sequencing and bioinformatics analysis results indicated that transcriptional regulation played an important role in NTDs. A luciferase reporter assay was performed to demonstrate that the transcription factor Bhlhe40 directly bound to and negatively regulated Sirt1 expression. Further, we discovered that the Bhlhe40/Sirt1 axis regulated mitophagy in neural stem cells. Collectively, our results for the first time demonstrate that Bhlhe40/Sirt1 axis regulated mitophagy is implicated in ATRA-induced SBA. Our findings provide new insights into pathogenesis of NTDs and a basis for potential therapeutic targets for NTDs.
| S-EPMC8111003 | biostudies-literature
Project description:O6-methylguanine DNA methyltransferase (MGMT), a DNA repair enzyme, has been reported in some congenital malformations, but it is less frequently reported in neural tube defects. This study investigated MGMT mRNA expression and methylation levels in the early embryo and in different embryonic stages, as well as the relationship between MGMT and neural tube defects. Spina bifida aperta was induced in rats by a single intragastric administration of all-trans retinoic acid on embryonic day (E) 10, whereas normal control rats received the same amount of olive oil on the same embryonic day. DNA damage was assessed by detecting γ-H2A.X in spina bifida aperta rats. Real time-polymerase chain reaction was used to examine mRNA expression of MGMT in normal control and spina bifida aperta rats. In normal controls, the MGMT mRNA expression decreased with increasing embryonic days, and was remarkably reduced from E11 to E14, reaching a minimum at E18. In the spina bifida aperta model, γ-H2A.X protein expression was increased, and mRNA expression of MGMT was markedly decreased on E14, E16, and E18. Bisulfite sequencing polymerase chain reaction for MGMT promoter methylation demonstrated that almost all CpG sites in the MGMT promoter remained unmethylated in both spina bifida aperta rats and normal controls, and there was no significant difference in methylation level between the two groups on either E14 or E18. Our results show that DNA damage occurs in spina bifida aperta rats. The mRNA expression of MGMT is downregulated, and this downregulation is independent of promoter DNA methylation.
| S-EPMC6301176 | biostudies-literature
Project description:BackgroundIn order to fulfill their chemosensory function, olfactory neurons are in direct contact with the external environment and are therefore exposed to environmental aggressive factors. Olfaction is maintained through life because, unlike for other sensory neuroepithelia, olfactory neurons have a unique capacity to regenerate after trauma. The mechanisms that control the ontogenesis and regenerative ability of these neurons are not fully understood. Here, we used various experimental approaches in two model systems (chick and mouse) to assess the contribution of retinoic acid signaling in the induction of the olfactory epithelium, the generation and maintenance of progenitor populations, and the ontogenesis and differentiation of olfactory neurons.ResultsWe show that retinoic acid signaling, although dispensable for initial induction of the olfactory placode, plays a key role in neurogenesis within this neuroepithelium. Retinoic acid depletion in the olfactory epithelium, both in chick and mouse models, results in a failure of progenitor cell maintenance and, consequently, differentiation of olfactory neurons is not sustained. Using an explant system, we further show that renewal of olfactory neurons is hindered if the olfactory epithelium is unable to synthesize retinoic acid.ConclusionsOur data show that retinoic acid is not a simple placodal inductive signal, but rather controls olfactory neuronal production by regulating the fate of olfactory progenitor cells. Retinaldehyde dehydrogenase 3 (RALDH3) is the key enzyme required to generate retinoic acid within the olfactory epithelium.
| S-EPMC3717070 | biostudies-literature
Project description:The worldwide incidence of neural tube defects (NTDs) ranges from 1.0 to 10.0 per 1,000 births with almost equal frequencies between two major categories: anencephaly and spina bifida (SB). Epidemiological studies have provided valuable insight for (a) researchers to identify nongenetic and genetic factors contributing to etiology, (b) public health officials to design and implement policies to prevent NTD pregnancies, and (c) individuals to take precautions to reduce the chance of having an NTD-affected pregnancy. Despite extensive research, our knowledge of the genetic etiology of human NTDs is limited. Although more than 200 small animal models with NTDs exist, most of these models do not replicate the human disease phenotype. Over a hundred candidate genes have been examined for risk association to human SB. The candidate genes studied include those important in folic acid metabolism, glucose metabolism, retinoid metabolism, and apoptosis. Many genes that regulate transcription in early embryogenesis and maintain planar cell polarity have also been tested as candidates. Additionally, genes identified through mouse models of NTDs have been explored as candidates. We do not know how many genes in the human genome may confer risk for NTDs in human. Less than 20% of the studied candidate genes have been determined to confer even a minor effect on risk association. Many studies have provided conflicting conclusions due to limitations in study design that potentially affect the power of statistical analysis. Future directions such as genomewide association studies (GWAS) and whole exome or even whole genome sequencing are discussed as possible avenues to identify genes that affect risk for human NTDs.
| S-EPMC3053142 | biostudies-literature