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The implementation of Zinc oxide nanoparticles (ZnO NPs) raises concerns regarding their potential toxic effects on human health. Although more and more researches have confirmed the toxic effects of ZnO NPs, limited attention has been given to their impact on the early embryonic nervous system. This study aimed to explore the impact of exposure to ZnO NPs on early neurogenesis and explore its underlying mechanisms. We conducted experiments here to confirm the hypothesis that exposure to ZnO NPs causes neural tube defects in early embryonic development. We first used mouse and chicken embryos to confirm that ZnO NPs and the Zn2+ they release are able to penetrate the placental barrier, influence fetal growth and result in incomplete neural tube closure. Using SH-SY5Y cells, we determined that ZnO NPs-induced incomplete neural tube closure was caused by activation of various cell death modes, including ferroptosis, apoptosis and autophagy. Moreover, dissolved Zn2+ played a role in triggering widespread cell death. ZnO NPs were accumulated within mitochondria after entering cells, damaging mitochondrial function and resulting in the over production of reactive oxygen species, ultimately inducing cellular oxidative stress. The N-acetylcysteine (NAC) exhibits significant efficacy in mitigating cellular oxidative stress, thereby alleviating the cytotoxicity and neurotoxicity brought about by ZnO NPs. These findings indicated that the exposure of ZnO NPs in early embryonic development can induce cell death through oxidative stress, resulting in a reduced number of cells involved in early neural tube closure and ultimately resulting in incomplete neural tube closure during embryo development. The findings of this study could raise public awareness regarding the potential risks associated with the exposure and use of ZnO NPs in early pregnancy.
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Desarrollo Embrionario , Defectos del Tubo Neural , Tubo Neural , Estrés Oxidativo , Especies Reactivas de Oxígeno , Óxido de Zinc , Óxido de Zinc/toxicidad , Animales , Estrés Oxidativo/efectos de los fármacos , Embrión de Pollo , Desarrollo Embrionario/efectos de los fármacos , Ratones , Tubo Neural/efectos de los fármacos , Tubo Neural/embriología , Tubo Neural/metabolismo , Humanos , Defectos del Tubo Neural/inducido químicamente , Defectos del Tubo Neural/metabolismo , Defectos del Tubo Neural/embriología , Defectos del Tubo Neural/patología , Especies Reactivas de Oxígeno/metabolismo , Apoptosis/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Femenino , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Nanopartículas del Metal/toxicidad , Autofagia/efectos de los fármacos , Línea Celular Tumoral , Nanopartículas/toxicidadRESUMEN
Two 1-day-old full-term female calves from different farms located in the Brazilian state of Rio Grande do Sul were unable to stand due to paresis of the pelvic limbs. Both calves had spina bifida on the spinal lumbar segment and were submitted to euthanasia due to poor prognosis. Postmortem examination revealed cerebellar herniation, caudal displacement of the brainstem, rostral deviation of the cranial nerves, caudal extension of occipital lobes, absence of dorsal lamina of lumbar vertebrae with exposed spinal cord, myelodysplasia, kyphosis, segmental spinal agenesis, renal fusion, muscular atrophy, and arthrogryposis. Histology highlighted myelodysplasia (syringomyelia and diplomyelia) and muscular atrophy. The reverse transcription-polymerase chain reactions for ruminant pestivirus were negative. Based on these lesions, the diagnosis of complex neural tube and skeletal malformations was made. A review of previous publications on calves diagnosed with these malformations, originally called Chiari or Arnold-Chiari malformations, revealed a wide range of nervous system and skeletal lesions. These variations amplified the uncertainty regarding whether all cases represent the same disorder and reinforced the importance of reconfiguring the terminology.
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Malformación de Arnold-Chiari , Enfermedades de los Bovinos , Animales , Bovinos , Femenino , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/patología , Enfermedades de los Bovinos/congénito , Malformación de Arnold-Chiari/veterinaria , Defectos del Tubo Neural/veterinaria , Defectos del Tubo Neural/diagnóstico , Defectos del Tubo Neural/patología , Animales Recién Nacidos , BrasilRESUMEN
Heparan sulfate proteoglycan 2 (HSPG2) gene encodes the matrix protein Perlecan, and genetic inactivation of this gene creates mice that are embryonic lethal with severe neural tube defects (NTDs). We discovered rare genetic variants of HSPG2 in 10% cases compared to only 4% in controls among a cohort of 369 NTDs. Endorepellin, a peptide cleaved from the domain V of Perlecan, is known to promote angiogenesis and autophagy in endothelial cells. The roles of enderepellin in neurodevelopment remain unclear so far. Our study revealed that endorepellin can migrate to the neuroepithelial cells and then be recognized and bind with the neuroepithelia receptor neurexin in vivo. Through the endocytic pathway, the interaction of endorepellin and neurexin physiologically triggers autophagy and appropriately modulates the differentiation of neural stem cells into neurons as a blocker, which is necessary for normal neural tube closure. We created knock-in (KI) mouse models with human-derived HSPG2 variants, using sperm-like stem cells that had been genetically edited by CRISPR/Cas9. We realized that any HSPG2 variants that affected the function of endorepellin were considered pathogenic causal variants for human NTDs given that the severe NTD phenotypes exhibited by these KI embryos occurred in a significantly higher response frequency compared to wildtype embryos. Our study provides a paradigm for effectively confirming pathogenic mutations in other genetic diseases. Furthermore, we demonstrated that using autophagy inhibitors at a cellular level can repress neuronal differentiation. Therefore, autophagy agonists may prevent NTDs resulting from failed autophagy maintenance and neuronal over-differentiation caused by deleterious endorepellin variants.
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Autofagia , Proteoglicanos de Heparán Sulfato , Defectos del Tubo Neural , Animales , Ratones , Proteoglicanos de Heparán Sulfato/metabolismo , Proteoglicanos de Heparán Sulfato/genética , Humanos , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/metabolismo , Defectos del Tubo Neural/patología , Tubo Neural/metabolismo , Tubo Neural/embriología , Tubo Neural/patología , Células-Madre Neurales/metabolismo , Células Neuroepiteliales/metabolismo , Femenino , Masculino , Modelos Animales de EnfermedadRESUMEN
Neurulation is a highly synchronized biomechanical process leading to the formation of the brain and spinal cord, and its failure leads to neural tube defects (NTDs). Although we are rapidly learning the genetic mechanisms underlying NTDs, the biomechanical aspects are largely unknown. To understand the correlation between NTDs and tissue stiffness during neural tube closure (NTC), we imaged an NTD murine model using optical coherence tomography (OCT), Brillouin microscopy and confocal fluorescence microscopy. Here, we associate structural information from OCT with local stiffness from the Brillouin signal of embryos undergoing neurulation. The stiffness of neuroepithelial tissues in Mthfd1l null embryos was significantly lower than that of wild-type embryos. Additionally, exogenous formate supplementation improved tissue stiffness and gross embryonic morphology in nullizygous and heterozygous embryos. Our results demonstrate the significance of proper tissue stiffness in normal NTC and pave the way for future studies on the mechanobiology of normal and abnormal embryonic development.
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Tubo Neural , Neurulación , Tomografía de Coherencia Óptica , Animales , Femenino , Ratones , Fenómenos Biomecánicos , Embrión de Mamíferos/metabolismo , Formiato-Tetrahidrofolato Ligasa/genética , Formiato-Tetrahidrofolato Ligasa/metabolismo , Formiatos/metabolismo , Metilenotetrahidrofolato Deshidrogenasa (NADP)/genética , Metilenotetrahidrofolato Deshidrogenasa (NADP)/metabolismo , Ratones Noqueados , Microscopía Confocal , Mutación/genética , Tubo Neural/metabolismo , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/metabolismo , Defectos del Tubo Neural/patología , Neurulación/genética , Tomografía de Coherencia Óptica/métodosRESUMEN
PURPOSE: To analyze the relationship between spinal cord and vertebral abnormalities from the point of view of embryology. METHODS: We analyzed the clinical and radiological data of 260 children with different types of spinal cord malformations in combination with vertebral abnormalities. RESULTS: Among 260 individuals, approximately 109 presented with open neural tube defects (ONTDs), 83 with split cord malformations (SCMs), and 83 with different types of spinal lipomas. Pathological spina bifida emerged as the most frequent vertebral anomaly, affecting 232 patients, with a higher prevalence in ONTD. Vertebral segmentation disorders, including unsegmented bars, butterfly vertebrae, and hemivertebrae, were present in 124 cases, with a higher prevalence in SCM. The third most common spinal anomaly group consisted of various forms of sacral agenesis (58 cases), notably associated with blunt conus medullaris, spinal lipomas, and sacral myelomeningocele. Segmental aplasia of the spinal cord had a typical association with segmental spinal absence (N = 17). CONCLUSION: The association between SCM and neuroenteric cyst/canal and vertebral segmentation disorders is strong. High ONTDs often coincide with pathological spina bifida posterior. Type 1 spinal lipomas and focal spinal nondisjunction also correlate with pathologic spina bifida. Segmental spinal absence or dysgenesis involves localized spinal and spinal cord aplasia, sometimes with secondary filar lipoma.
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Anomalías Múltiples , Hernia Diafragmática , Lipoma , Meningocele , Defectos del Tubo Neural , Disrafia Espinal , Niño , Humanos , Columna Vertebral/anomalías , Médula Espinal/patología , Meningocele/patología , Defectos del Tubo Neural/patología , Imagen por Resonancia MagnéticaRESUMEN
BACKGROUND: Tight filum terminale is a rare and challenging condition to diagnose because it presents with nonspecific symptoms and unclear imaging findings. This report documents an atypical case of tight filum terminale. CASE PRESENTATION: The patient was a previously healthy Asian 18-year-old male presenting with recurrent upper extremity and back pain, initially treated as nonspecific musculoskeletal pain. Notably, the patient's symptoms were inconsistent with the dermatome, showing no correlation with his skin's sensory innervation areas. In contrast to typical tight filum terminale presentations focused on lower extremity and lumbar region disturbances, this patient experienced pain and weakness predominantly in the upper extremities and back, hypothesized to result from traction myelopathy exacerbated by thoracic disc herniation. Investigations including blood and nerve function tests were inconclusive. However, a magnetic resonance imaging scan revealed a combination of tight filum terminale and tiny thoracic disc herniation. A diagnosis of tethered spinal cord syndrome was confirmed following further tests and imaging. The filum terminale was surgically removed, resolving the symptoms at a 7-month follow-up. CONCLUSIONS: This case underlines the importance of including tight filum terminale as a differential diagnosis in cases of unexplained upper or lower extremity pain. Primary care practitioners, particularly those managing undefined symptoms, should consider tight filum terminale in their diagnostic approach.
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Cauda Equina , Desplazamiento del Disco Intervertebral , Defectos del Tubo Neural , Masculino , Humanos , Adolescente , Cauda Equina/patología , Desplazamiento del Disco Intervertebral/diagnóstico , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Defectos del Tubo Neural/diagnóstico , Defectos del Tubo Neural/patología , Defectos del Tubo Neural/cirugía , Procedimientos Neuroquirúrgicos/métodos , Imagen por Resonancia Magnética , DolorRESUMEN
Adolescent idiopathic scoliosis is a commonly encountered condition often diagnosed on screening examination. Underlying, asymptomatic neural axis abnormalities may be present at the time of diagnosis. At certain institutions, total spine MRI is obtained preoperatively to identify these abnormalities. We provide a framework for the radiologist to follow while interpreting these studies. In part 1, we discuss Arnold Chiari malformations, syringomyelia, and the tethered cord. In part 2, we focus on spinal cord tumors, dysraphisms, to include diastematomyelia, and vertebral anomalies.
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Malformación de Arnold-Chiari , Defectos del Tubo Neural , Escoliosis , Neoplasias de la Médula Espinal , Humanos , Adolescente , Escoliosis/diagnóstico por imagen , Escoliosis/cirugía , Defectos del Tubo Neural/diagnóstico por imagen , Defectos del Tubo Neural/patología , Malformación de Arnold-Chiari/diagnóstico por imagen , Malformación de Arnold-Chiari/patología , Imagen por Resonancia Magnética , Neoplasias de la Médula Espinal/patología , Médula Espinal/diagnóstico por imagen , Columna Vertebral/patologíaRESUMEN
Sugammadex is a new generation drug that has led to significant changes in the practice of anesthesia. However, its effects on fetal development are not yet fully known. The aim of this study is to investigate the teratogenic effects of sugammadex on neural tube and embryonic development in early chick embryos. In this study, 50 0-day fertile specific non-pathogenic (SPF) eggs were used. Fifty eggs were divided into 5 different groups, each consisting of 10 pieces. While no substance was given to the control group at the 28th hour of the study, 4 different doses of sugammadex were administered to the experimental groups, respectively 2, 4, 8, 16 mg/kg. Cranio-caudal lengths of embryos, somite numbers, average number of argyrophilic nucleolar regulatory regions (AgNOR) per nucleus, total AgNOR area/total nuclear area (TAA/NA) ratios, Caspase-3 H-Score results, and presence of neural tube defect were compared among the groups. While the mean cranio-caudal lengths, somite counts, TAA/NA ratios and AgNOR counts of the embryos were found to be statistically significantly lower than the control group, Caspase-3 H-Score mean results were found to be significantly higher (p < .05). In addition, it was observed that there was an increase in neural tube patency and developmental delay. As a result, sugammadex crossing the placenta was revealed to increase the release of proapopitotic molecules and disrupt the developmental stages of embryos. Thus, it was determined that sugammadex in increased developmental delay and incidence of neural tube defects in early chick embryos with increased dose dependent. Despite these results, the effects of sugammadex on fetal development in in vivo and in vitro environments should be studied with further studies. RESEARCH HIGHLIGHTS: Sugammadex is a new generation drug that has led to significant changes in the practice of anesthesia. However, its effects on fetal development are not yet fully known. It has been observed that different doses of sugammadex increase the risk of neural tube defect development on chick embryos and slow the embryo development in a dose-dependent manner.
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Defectos del Tubo Neural , Tubo Neural , Animales , Embrión de Pollo , Tubo Neural/patología , Caspasa 3 , Sugammadex/farmacología , Defectos del Tubo Neural/inducido químicamente , Defectos del Tubo Neural/patología , Desarrollo EmbrionarioRESUMEN
BACKGROUND: Hyperglycemia from pregestational diabetes mellitus induces neural tube defects in the developing fetus. Folate supplementation is the only effective way to prevent neural tube defects; however, some cases of neural tube defects are resistant to folate. Excess folate has been linked to higher maternal cancer risk and infant allergy. Therefore, additional interventions are needed. Understanding the mechanisms underlying maternal diabetes mellitus-induced neural tube defects can identify potential targets for preventing such defects. Despite not yet being in clinical use, growing evidence suggests that microRNAs are important intermediates in embryonic development and can serve as both biomarkers and drug targets for disease intervention. Our previous studies showed that maternal diabetes mellitus in vivo activates the inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) in the developing embryo and that a high glucose condition in vitro reduces microRNA-322 (miR-322) levels. IRE1α is an RNA endonuclease; however, it is unknown whether IRE1α targets and degrades miR-322 specifically or whether miR-322 degradation leads to neural tube defects via apoptosis. We hypothesize that IRE1α can inhibit miR-322 in maternal diabetes mellitus-induced neural tube defects and that restoring miR-322 expression in developing neuroepithelium ameliorates neural tube defects. OBJECTIVE: This study aimed to identify potential targets for preventing maternal diabetes mellitus-induced neural tube defects and to investigate the roles and relationship of a microRNA and an RNA endonuclease in mouse embryos exposed to maternal diabetes mellitus. STUDY DESIGN: To determine whether miR-322 reduction is necessary for neural tube defect formation in pregnancies complicated by diabetes mellitus, male mice carrying a transgene expressing miR-322 were mated with nondiabetic or diabetic wide-type female mice to generate embryos with or without miR-322 overexpression. At embryonic day 8.5 when the neural tube is not yet closed, embryos were harvested for the assessment of 3 miR-322 transcripts (primary, precursor, and mature miR-322), tumor necrosis factor receptor-associated factor 3 (TRAF3), and neuroepithelium cell survival. Neural tube defect incidences were determined in embryonic day 10.5 embryos when the neural tube should be closed if there is no neural tube defect formation. To identify which miR-322 transcript is affected by maternal diabetes mellitus and high glucose conditions, 3 miR-322 transcripts were assessed in embryos from dams with or without diabetes mellitus and in C17.2 mouse neural stem cells treated with different concentrations of glucose and at different time points. To determine whether the endonuclease IRE1α targets miR-322, small interfering RNA knockdown of IRE1α or overexpression of inositol-requiring transmembrane kinase/endoribonuclease 1α by DNA plasmid transfection was used to determine the effect of IRE1α deficiency or overexpression on miR-322 expression. RNA immunoprecipitation was performed to reveal the direct targets of inositol-requiring transmembrane kinase/endoribonuclease 1α. RESULTS: Maternal diabetes mellitus suppressed miR-322 expression in the developing neuroepithelium. Restoring miR-322 expression in the neuroepithelium blocked maternal diabetes mellitus-induced caspase-3 and caspase-8 cleavage and cell apoptosis, leading to a neural tube defect reduction. Reversal of maternal diabetes mellitus-inhibited miR-322 via transgenic overexpression prevented TRAF3 up-regulation in embryos exposed to maternal diabetes mellitus. Activated IRE1α acted as an endonuclease and degraded precursor miR-322, resulting in mature miR-322 reduction. CONCLUSION: This study supports the crucial role of the IRE1α-microRNA-TRAF3 circuit in the induction of neuroepithelial cell apoptosis and neural tube defect formation in pregnancies complicated by diabetes mellitus and identifies IRE1α and miR-322 as potential targets for preventing maternal diabetes mellitus-induced neural tube defects.
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Diabetes Mellitus Experimental , Diabetes Gestacional , MicroARNs , Defectos del Tubo Neural , Embarazo en Diabéticas , Humanos , Embarazo , Masculino , Femenino , Ratones , Animales , MicroARNs/genética , MicroARNs/metabolismo , Factor 3 Asociado a Receptor de TNF/metabolismo , Endorribonucleasas/genética , Endorribonucleasas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/patología , Embarazo en Diabéticas/genética , Embarazo en Diabéticas/metabolismo , Diabetes Gestacional/genética , Glucosa , Ácido Fólico , InositolRESUMEN
Closed spinal dysraphisms are poorly understood malformations classified as neural tube (NT) defects. Several, including terminal myelocystocele, affect the distal spine. We have previously identified a NT closure-initiating point, Closure 5, in the distal spine of mice. Here, we document equivalent morphology of the caudal-most closing posterior neuropore (PNP) in mice and humans. Closure 5 forms in a region of active FGF signalling, and pharmacological FGF receptor blockade impairs its formation in cultured mouse embryos. Conditional genetic deletion of Fgfr1 in caudal embryonic tissues with Cdx2Cre diminishes neuroepithelial proliferation, impairs Closure 5 formation and delays PNP closure. After closure, the distal NT of Fgfr1-disrupted embryos dilates to form a fluid-filled sac overlying ventrally flattened spinal cord. This phenotype resembles terminal myelocystocele. Histological analysis reveals regional and progressive loss of SHH- and FOXA2-positive ventral NT domains, resulting in OLIG2 labelling of the ventral-most NT. The OLIG2 domain is also subsequently lost, eventually producing a NT that is entirely positive for the dorsal marker PAX3. Thus, a terminal myelocystocele-like phenotype can arise after completion of NT closure with localised spinal mis-patterning caused by disruption of FGFR1 signalling.
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Defectos del Tubo Neural , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos , Disrafia Espinal , Animales , Humanos , Ratones , Defectos del Tubo Neural/patología , Fenotipo , Médula Espinal/patología , Columna Vertebral/patología , Receptor Tipo 1 de Factor de Crecimiento de Fibroblastos/genéticaRESUMEN
PURPOSE: To evaluate whether deep prenatal phenotyping of fetal brain abnormalities (FBAs) increases diagnostic yield of trio-exome sequencing (ES) compared with standard phenotyping. METHODS: Retrospective exploratory analysis of a multicenter prenatal ES study. Participants were eligible if an FBA was diagnosed and subsequently found to have a normal microarray. Deep phenotyping was defined as phenotype based on targeted ultrasound plus prenatal/postnatal magnetic resonance imaging, autopsy, and/or known phenotypes of other affected family members. Standard phenotyping was based on targeted ultrasound alone. FBAs were categorized by major brain findings on prenatal ultrasound. Cases with positive ES results were compared with those that have negative results by available phenotyping, as well as diagnosed FBAs. RESULTS: A total of 76 trios with FBAs were identified, of which 25 (33%) cases had positive ES results and 51 (67%) had negative results. Individual modalities of deep phenotyping were not associated with diagnostic ES results. The most common FBAs identified were posterior fossa anomalies and midline defects. Neural tube defects were significantly associated with receipt of a negative ES result (0% vs 22%, P = .01). CONCLUSION: Deep phenotyping was not associated with increased diagnostic yield of ES for FBA in this small cohort. Neural tube defects were associated with negative ES results.
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Encefalopatías , Defectos del Tubo Neural , Embarazo , Femenino , Humanos , Diagnóstico Prenatal/métodos , Estudios Retrospectivos , Secuenciación del Exoma , Feto/anomalías , Encefalopatías/diagnóstico por imagen , Encefalopatías/genética , Encéfalo/diagnóstico por imagen , Defectos del Tubo Neural/patología , Ultrasonografía PrenatalRESUMEN
AIM: To investigate the effect of zinc oxide nanoparticles (ZnO-NPs) on neural tube development in early chicken embryos. MATERIAL AND METHODS: Fifty pathogen-free fertilized eggs were initially incubated for thirty hours. The eggs were divided into 5 groups. In the control group (C) the egg?s apex was opened and closed without any administration. In the distilled water group (DW), 10 microliters of distilled water were injected into the sub-blastodermic area. ZnO-NP suspensions were prepared in distilled water and injected sub-blastodermically into the low, medium and high dose ZnO-NP groups (10 mg/kg, 30 mg/kg, and 50 mg/kg, respectively). Incubation was completed in 72 hours, and embryological and neural tube development was evaluated histologically with a light microscope. RESULTS: Embryos in all groups were evaluated according to the Hamburger-Hamilton (HH) staging. It was observed that the staging progressed by the developmental process between 68-72 hours, which is equivalent to the 19-20th stage of HH. Differentiated otic vesicle, optic cup, lens vesicle, pharynx, and Rathke?s pouch were all observed in embryo sections. Both forebrain and hindbrain vesicles were easily distinguished in the sections by cranial flexion. Neural tube closure defect was not detected in any of the groups. CONCLUSION: In our observations, ZnO-NPs did not affect neural tube development at the applied dose ranges. We believe that additional studies with higher doses using a higher number of subjects will help clarify the conflicting data in the literature.
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Defectos del Tubo Neural , Óxido de Zinc , Animales , Embrión de Pollo , Humanos , Pollos , Óxido de Zinc/toxicidad , Tubo Neural , Defectos del Tubo Neural/inducido químicamente , Defectos del Tubo Neural/patología , Agua/farmacologíaRESUMEN
Neural tube (NT) defects arise from abnormal neurulation and result in the most common birth defects worldwide. Yet, mechanisms of primate neurulation remain largely unknown due to prohibitions on human embryo research and limitations of available model systems. Here, we establish a three-dimensional (3D) prolonged in vitro culture (pIVC) system supporting cynomolgus monkey embryo development from 7 to 25 days post-fertilization. Through single-cell multi-omics analyses, we demonstrate that pIVC embryos form three germ layers, including primordial germ cells, and establish proper DNA methylation and chromatin accessibility through advanced gastrulation stages. In addition, pIVC embryo immunofluorescence confirms neural crest formation, NT closure, and neural progenitor regionalization. Finally, we demonstrate that the transcriptional profiles and morphogenetics of pIVC embryos resemble key features of similarly staged in vivo cynomolgus and human embryos. This work therefore describes a system to study non-human primate embryogenesis through advanced gastrulation and early neurulation.
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Defectos del Tubo Neural , Neurulación , Técnicas de Cultivo de Tejidos , Animales , Humanos , Blastocisto , Embrión de Mamíferos , Desarrollo Embrionario , Macaca fascicularis , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/patología , Técnicas de Cultivo de Tejidos/métodosRESUMEN
INTRODUCTION: Myelomeningocele (MMC) is a malformation resulting from the neural tube's failure to close during embryonic development, and the majority of the cases of neural tube defects (NTDs) were prevalent as single location lesions along the spine; however, multiple NTDs (MNTDs) are a very rare condition. Only a few cases of MNTDs were found in the literature. CASE PRESENTATION: We report the case of a 2-month-old male infant prenatally diagnosed with MMC, presented with two unconnected lumbar and lumbosacral epidermal, soft, dome-shaped swellings located on both sides of the midline (paravertebral) covered by intact skin. MRI revealed double MMC at the level of L4-L5, with spinal nerve roots. The patient underwent surgical repair of the defects by replacing the spinal cord and its nerve roots inside the thecal sac and recreating a covering layer around the neural structures to resemble thecal sac. The outcome was favorable, and postoperative head CT scan did not show any complication. CONCLUSION: Our case report is considered the first from Algeria to report the condition and the first to report the occurrence of double lesions in the same spine region. MMC can be associated with neurological deficits or other congenital anomalies, thus it is necessary to thoroughly examine such patients. However, there was no antenatal folic acid deficiency in our case. We recommend antenatal care with adequate folic acid supplementation given that its deficiency during pregnancy is considered a ubiquitous risk factor for the condition. The optimal timing for surgery of MMC cases is 8 ± 5 days. Prenatal intrauterine repair of the condition provides favorable outcomes but carries high fetal and maternal risks. Surgical repair should include the sac removal, the reconstruction of the placode, and the closure of the overlying meninges. With early diagnosis and proper repair of such cases, MMC has good prognosis and favorable outcomes.
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Meningomielocele , Defectos del Tubo Neural , Lactante , Embarazo , Femenino , Humanos , Masculino , Meningomielocele/diagnóstico por imagen , Meningomielocele/cirugía , Meningomielocele/patología , Defectos del Tubo Neural/patología , Columna Vertebral/patología , Médula Espinal , FetoRESUMEN
BACKGROUND: Tramadol hydrochloride or tramadol is an opioid analgesic that acts on the central nervous system. The pregnancy category of tramadol is determined as "C" according to the Food and Drug Administration. There are no adequate and well-controlled studies in pregnant women. In this study, we aimed to reveal the effects of tramadol on neural tube (midline) closure by analyzing morphologically, histologically and genetically in chick embryos. METHODS: Ninety White Leghorn species, fertile and 0-day-old specific pathogen-free eggs (60 ± 5 g) were used in the study. Eggs were divided into a total of six groups (control, sham, and drug groups). Four different doses of tramadol (1, 2.5, 5, and 7.5 mg/egg) were administered subblastodermically at the 28th hour of the incubation. All eggs were opened at the 48th hour of incubation and evaluated. RESULTS: Embryos in the control group according to Hamburger-Hamilton classification were compatible with stages 13 and 14. In the groups treated with tramadol, it was determined that the embryos had neural tube closure defects (such as neck, tail regions) and some embryos showed developmental retardation due to the increase in the drug dose. In the statistical analysis performed, a significant difference was found between the control group and the group receiving the highest dose of tramadol in terms of crown-rump length and number of somites (p < .05). The brain and reproductive expression gene expression was upregulated in embryos at each of tramadol doses compared to control group. CONCLUSIONS: It was determined that tramadol causes neural tube closure defects in embryos depending on the dose.
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Defectos del Tubo Neural , Tramadol , Embarazo , Estados Unidos , Embrión de Pollo , Animales , Femenino , Humanos , Tubo Neural , Pollos , Tramadol/farmacología , Defectos del Tubo Neural/patología , Desarrollo EmbrionarioRESUMEN
Closure of the neural tube represents a highly complex and coordinated process, the failure of which constitutes common birth defects. The serine/threonine kinase p21-activated kinase 2 (PAK2) is a critical regulator of cytoskeleton dynamics; however, its role in the neurulation and pathogenesis of neural tube defects (NTDs) remains unclear. Here, the results show that Pak2-/- mouse embryos fail to develop dorsolateral hinge points (DLHPs) and exhibit craniorachischisis, a severe phenotype of NTDs. Pak2 knockout activates BMP signaling that involves in vertebrate bone formation. Single-cell transcriptomes reveal abnormal differentiation trajectories and transcriptional events in Pak2-/- mouse embryos during neural tube development. Two nonsynonymous and one recurrent splice-site mutations in the PAK2 gene are identified in five human NTD fetuses, which exhibit attenuated PAK2 expression and upregulated BMP signaling in the brain. Mechanistically, PAK2 regulates Smad9 phosphorylation to inhibit BMP signaling and ultimately induce DLHP formation. Depletion of pak2a in zebrafish induces defects in the neural tube, which are partially rescued by the overexpression of wild-type, but not mutant PAK2. The findings demonstrate the conserved role of PAK2 in neurulation in multiple vertebrate species, highlighting the molecular pathogenesis of PAK2 mutations in NTDs.
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Defectos del Tubo Neural , Tubo Neural , Animales , Ratones , Humanos , Tubo Neural/metabolismo , Tubo Neural/patología , Quinasas p21 Activadas/genética , Quinasas p21 Activadas/metabolismo , Pez Cebra/metabolismo , Transducción de Señal/genética , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/metabolismo , Defectos del Tubo Neural/patologíaRESUMEN
Split cord malformation co-existing with either congenital dermoid or myeloschisis has been previously reported. Theories exist which explain the underlying embryopathy behind the occurrence of each of these anomalies in conjunction with split cord malformation. However, the occurrence of all three anomalies in the same patient, to the best of our knowledge, has not yet been reported in the literature. We report two cases on the co-existence of congenital dermoid cyst with both myeloschisis and split cord malformation and review the literature on previous postulations of mechanisms that could possibly explain the simultaneous occurrence of all three distinct anomalies. They involve all three primary germ layers and therefore share a common embryonic origin from the epiblast. We try to explain their co-existence based on the theory of notochordal splitting and endomesechymal tract formation consequent on endodermal-ectodermal adhesion as postulated by Beardmore and Wigglesworth and discuss on implications in terms of treatment paradigms. The unusual combination of all three anomalies in both patients probably highlights a need for further research on their pathogenesis despite these previous theories. These cases demonstrate the fact that currently accepted embryological explanations of most pathologies especially outliers still fall short with much remaining to be understood.
Asunto(s)
Quiste Dermoide , Meningomielocele , Defectos del Tubo Neural , Humanos , Quiste Dermoide/complicaciones , Quiste Dermoide/diagnóstico por imagen , Quiste Dermoide/cirugía , Meningomielocele/complicaciones , Defectos del Tubo Neural/complicaciones , Defectos del Tubo Neural/cirugía , Defectos del Tubo Neural/patologíaRESUMEN
Neurenteric cyst (NC) shows benign histopathology and rarely demonstrate malignant transformation. We herein describe a case of NC that exhibited malignant transformation. A 65-year-old female presented with gait disturbance due to compression by a cystic mass on the dorsal surface of the medulla oblongata. Partial resection was performed twice, leading to improvement of her symptoms. Two years after the second surgery, gadolinium-perfused T1-weighted magnetic resonance imaging revealed an invasive lesion with contrast enhancement at the trigone of the left lateral ventricle for which partial resection followed by radiotherapy was performed. However, mass regrowth was observed, with the patient eventually succumbing to her disease 11 months after her third surgery. Histopathological analyses of the first and second surgical specimens identified pseudostratified cuboidal epithelial cells, with no nuclear or cellular atypia resembling gastrointestinal mucosa, lining the inner surface of the cystic wall. Based on these findings the lesion was diagnosed as NC. The third surgical specimen exhibited apparent malignant features of the epithelial cells with elongated and hyperchromatic nuclei, several mitotic figures, small necrotic foci, and a patternless or sheet-like arrangement. Based on these findings, the lesion was diagnosed as NC with malignant transformation. Next-generation sequencing revealed KRAS p.G12D mutation in all specimens. Additionally, the third surgical specimen harbored the following 12 de novo gene alterations: ARID1A loss, BAP1 p.F170L, CDKN1B loss, CDKN2A loss, CDKN2B loss, FLCN loss, PTCH1 loss, PTEN loss, PTPRD loss, SUFU loss, TP53 loss, and TSC1 loss. The aforementioned results suggest that KRAS mutation is associated with the development of the NC, and that the additional gene alterations contribute to malignant transformation of the NC.
Asunto(s)
Defectos del Tubo Neural , Humanos , Femenino , Anciano , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/patología , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Mutación , Proteínas Proto-Oncogénicas p21(ras)/genéticaRESUMEN
Recently, advanced knowledge on secondary neurulation and its application to the clinical experience have led to the deeper insight into the pathoembryogenesis of secondary neurulation with new classifications of the caudal spinal dysraphic entities. Here, we summarize the dynamic changes in the concepts of disordered secondary neurulation over the last two decades. In addition, we suggest our new pathoembryogenetic explanations for a few entities based on the literature and the data from our previous animal research. Disordered secondary neurulation at each phase may cause various corresponding lesions, such as (1) failed junction with the primary neural tube (junctional neural tube defect and segmental spinal dysgenesis), (2) dysgenesis or duplication of the caudal cell mass associated with disturbed activity of caudal mesenchymal tissue (caudal agenesis and caudal duplication syndrome), (3) abnormal continuity of medullary cord to the surrounding layers, namely, failed ingression of the primitive streak to the caudal cell mass (myelomeningocele), focal limited dorsal neurocutaneous nondisjunction (limited dorsal myeloschisis and congenital dermal sinus), and neuro-mesenchymal adhesion (lumbosacral lipomatous malformation), and (4) regression failure spectrum of the medullary cord (thickened filum and filar cyst, retained medullary cord and low-lying conus, terminal myelocele, and terminal myelocystocele). It seems that almost every anomalous entity of the primary neural tube may occur in the area of secondary neurulation. Furthermore, the close association of the caudal cell mass with the activity of caudal mesenchymal tissue involves a wider range of surrounding structures in secondary neurulation than in primary neurulation. Although the majority of the data are from animals and many theories are still conjectural, these changing concepts of normal and disordered secondary neurulation will provoke further advancements in our management strategies as well as in the pathoembryogenetic understanding of anomalous lesions in this area.
Asunto(s)
Meningomielocele , Defectos del Tubo Neural , Disrafia Espinal , Neoplasias de la Columna Vertebral , Animales , Imagen por Resonancia Magnética , Meningomielocele/patología , Defectos del Tubo Neural/patología , NeurulaciónRESUMEN
Neural tube defects (NTDs) are a heterogeneous set of malformations attributed to disruption in normal neural tube closure during early embryogenesis. An in-depth understanding of NTD etiology and mechanisms remains elusive, however. Among the proposed mechanisms, epigenetic changes are thought to play an important role in the formation of NTDs. Epigenomics covers a wide spectrum of genomic DNA sequence modifications that can be investigated via high-throughput techniques. Recent advances in epigenomic technologies have enabled epigenetic studies of congenital malformations and facilitated the integration of big data into the understanding of NTDs. Herein, we review clinical epigenomic data that focuses on DNA methylation, histone modification, and miRNA alterations in human neural tissues, placental tissues, and leukocytes to explore potential mechanisms by which candidate genes affect human NTD pathogenesis. We discuss the links between epigenomics and gene regulatory mechanisms, and the effects of epigenetic alterations in human tissues on neural tube closure.