scholarly journals Valproic Acid–Induced Deregulation In Vitro of Genes Associated In Vivo with Neural Tube Defects

2009 ◽  
Vol 108 (1) ◽  
pp. 132-148 ◽  
Author(s):  
Måns Jergil ◽  
Kim Kultima ◽  
Anne-Lee Gustafson ◽  
Lennart Dencker ◽  
Michael Stigson
Development ◽  
1982 ◽  
Vol 69 (1) ◽  
pp. 151-167
Author(s):  
A. J. Copp ◽  
M. J. Seller ◽  
P. E. Polani

A dye-injection technique has been used to determine the developmental stage at which posterior neuropore (PNP) closure occurs in normal and mutant curly tail mouse embryos. In vivo, the majority of non-mutant embryos undergo PNP closure between 30 and 34 somites whereas approximately 50% of all mutant embryos show delayed closure, and around 20% maintain an open PNP even at advanced stages of development. A similar result has been found for embryos developing in vitro from the headfold stage. Later in development, 50–60% of mutant embryos in vivo develop tail flexion defects, and 15–20% lumbosacral myeloschisis. This supports the view that delayed PNP closure is the main developmental lesion leading to the appearance of caudal neural tube defects in curly tail mice. The neural tube is closed in the region of tail flexion defects, but it is locally overexpanded and abnormal in position. The significance of these observations is discussed in relation to possible mechanisms of development of lumbosacral and caudal neural tube defects. This paper constitutes the first demonstration of the development of a genetically induced malformation in vitro.


2016 ◽  
Vol 130 (24) ◽  
pp. 2329-2340 ◽  
Author(s):  
Xiaojin Qiao ◽  
Yahui Liu ◽  
Peiqiang Li ◽  
Zhongzhong Chen ◽  
Huili Li ◽  
...  

The planar cell polarity (PCP) pathway is critical for proper embryonic development of the neural tube and heart. Mutations in these genes have previously been implicated in the pathogenesis of neural tube defects (NTDs), but not in congenital heart defects (CHDs) in humans. We systematically identified the mutation patterns of CELSR1–3, one family of the core PCP genes, in human cohorts composed of 352 individuals with NTDs, 412 with CHDs and matched controls. A total of 72 disease-specific, rare, novel, coding mutations were identified, of which 37 were identified in patients with CHDs and 36 in patients with NTDs. Most of these mutations differed between the two cohorts, because only one novel missense mutation in CELSR1 (c.2609G>A p.P870L) was identified in both NTD and CHD patients. Both in vivo and in vitro assays revealed that CELSR1 P870L is a gain-of-function mutation. It up-regulates not only the PCP pathway, but also canonical WNT signalling in cells, and also induces both NTDs and CHDs in zebrafish embryos. As almost equal numbers of mutations were identified in each cohort, our results provided the first evidence that mutations in CELSR genes are as likely to be associated with CHDs as with NTDs, although the specific mutations differ between the two cohorts. Such differences in mutation panels suggested that CELSRs [cadherin, EGF (epidermal growth factor), LAG (laminin A G-type repeat), seven-pass receptors)] might be regulated differently during the development of these two organ systems.


Development ◽  
1988 ◽  
Vol 104 (2) ◽  
pp. 297-303 ◽  
Author(s):  
A.J. Copp ◽  
J.A. Crolla ◽  
F.A. Brook

Homozygous mutant curly tail mouse embryos developing spinal neural tube defects (NTD) exhibit a cell-type-specific abnormality of cell proliferation that affects the gut endoderm and notochord but not the neuroepithelium. We suggested that spinal NTD in these embryos may result from the imbalance of cell proliferation rates between affected and unaffected cell types. In order to test this hypothesis, curly tail embryos were subjected to influences that retard growth in vivo and in vitro. The expectation was that growth of unaffected rapidly growing cell types would be reduced to a greater extent than affected slowly growing cell types, thus counteracting the genetically determined imbalance of cell proliferation rates and leading to normalization of spinal neurulation. Food deprivation of pregnant females for 48 h prior to the stage of posterior neuropore closure reduced the overall incidence of spinal NTD and almost completely prevented open spina bifida, the most severe form of spinal NTD in curly tail mice. Analysis of embryos earlier in gestation showed that growth retardation acts by reducing the incidence of delayed neuropore closure. Culture of embryos at 40.5 degrees C for 15–23 h from day 10 of gestation, like food deprivation in vivo, also produced growth retardation and led to normalization of posterior neuropore closure. Labelling of embryos in vitro with [3H]thymidine for 1 h at the end of the culture period showed that the labelling index is reduced to a greater extent in the neuroepithelium than in other cell types in growth-retarded embryos compared with controls cultured at 38 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)


2017 ◽  
Vol 114 (17) ◽  
pp. 4489-4494 ◽  
Author(s):  
Zhiyong Zhao ◽  
Lixue Cao ◽  
E. Albert Reece

Diabetes mellitus in early pregnancy increases the risk in infants of birth defects, such as neural tube defects (NTDs), known as diabetic embryopathy. NTDs are associated with hyperglycemia-induced protein misfolding and Caspase-8–induced programmed cell death. The present study shows that misfolded proteins are ubiquitinylated, suggesting that ubiquitin-proteasomal degradation is impaired. Misfolded proteins form aggregates containing ubiquitin-binding protein p62, suggesting that autophagic-lysosomal clearance is insufficient. Additionally, these aggregates contain the neurodegenerative disease-associated proteins α-Synuclein, Parkin, and Huntingtin (Htt). Aggregation of Htt may lead to formation of a death-inducing signaling complex of Hip1, Hippi, and Caspase-8. Treatment with chemical chaperones, such as sodium 4-phenylbutyrate (PBA), reduces protein aggregation in neural stem cells in vitro and in embryos in vivo. Furthermore, treatment with PBA in vivo decreases NTD rate in the embryos of diabetic mice, as well as Caspase-8 activation and cell death. Enhancing protein folding could be a potential interventional approach to preventing embryonic malformations in diabetic pregnancies.


2006 ◽  
Vol 175 (4S) ◽  
pp. 257-257
Author(s):  
Jennifer Sung ◽  
Qinghua Xia ◽  
Wasim Chowdhury ◽  
Shabana Shabbeer ◽  
Michael Carducci ◽  
...  

Development ◽  
1991 ◽  
Vol 113 (Supplement_2) ◽  
pp. 105-122 ◽  
Author(s):  
Marysia Placzek ◽  
Toshiya Yamada ◽  
Marc Tessier-Lavigne ◽  
Thomas Jessell ◽  
Jane Dodd

Distinct classes of neural cells differentiate at specific locations within the embryonic vertebrate nervous system. To define the cellular mechanisms that control the identity and pattern of neural cells we have used a combination of functional assays and antigenic markers to examine the differentiation of cells in the developing spinal cord and hindbrain in vivo and in vitro. Our results suggest that a critical step in the dorsoventral patterning of the embryonic CNS is the differentiation of a specialized group of midline neural cells, termed the floor plate, in response to local inductive signals from the underlying notochord. The floor plate and notochord appear to control the pattern of cell types that appear along the dorsoventral axis of the neural tube. The fate of neuroepithelial cells in the ventral neural tube may be defined by cell position with respect to the ventral midline and controlled by polarizing signals that originate from the floor plate and notochord.


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