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Developmental Diseases of the Nervous System
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
James H. Tonsgard, Nikolas Mata-Machado
Anomalies of gastrulation/disorders of notochord development: Neurenteric cysts.Split spinal cord malformations (SSCM; diastematomyelia).Dermal sinus.
The embryonic period
Published in Frank J. Dye, Human Life Before Birth, 2019
Gastrulation, which occurs very early in the developmental process, is critical for human development. If something goes wrong during this process, development will be significantly abnormal. Gastrulation is most dramatic during the third week of development and consists of profound morphogenetic movements.
Islet Transplantation in Type 1 Diabetes: Stem Cell Research and Therapy
Published in Debarshi Kar Mahapatra, Sanjay Kumar Bharti, Medicinal Chemistry with Pharmaceutical Product Development, 2019
DE then forms a primitive gut tube (GT) along which various endoderm organ domains are specified and directed [32]. Pancreas develops from the posterior foregut, emerging as buds from dorsal and ventral sides of the gut tube. At this early stage pancreatic development depends on retinoid signaling and inhibition of hedgehog signaling [33, 34]. The developing pancreas at this stage consists of epithelial progenitors that express Pdx1 (IPF1) and give rise to endocrine, exocrine and ductal cells of the pancreas. Moreover, this epithelium also expresses transcription factor genes such as Hlxb9, Hnf6, Ptf1a, and Nkx6-1. These transcription factors together with Pdx1 encode proteins that contribute to pancreatic development [35]. After initial bud formation, the epithelium grows, proliferates and differentiates in response to signals emanating from adjacent mesenchyme such as mesenchymal Fgf10 [36]. In addition to transcription factors, several growth factors regulate the process of gastrulation. For example, in mice Nodal, a member of transforming growth factor (TGF)-β super family, which, in turn, regulates the Wnt, fibroblast growth factor (FGF) and bone morphogenetic protein-4 (BMP-4) pathways that is important for development of anterior and posterior axes during gastrulation [31, 37].
Stiffness estimation of transversely anisotropic materials using a novel indentation tester with a rectangular hole
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Atsutaka Tamura, Mika Saiki, Jun-ichi Hongu, Takeo Matsumoto
Gastrulation is an essential step in the development of most animals. This process is fundamental to vertebrate animals, and it is the early developmental stage in which a single layer of cells gives rise to multiple germ layers, enabling the differentiation of the internal tissues of the body (Gilbert 2014; Urry et al. 2016); in other words, the body plan of the animal embryo is shaped through the process of gastrulation. In mammals, a cascade of morphogenesis-related molecular events, e.g. polarization, intercalation, and intercellular adhesion, occurs in specific embryonic territories although knowledge about how the territories grow physically and remodel has remained elusive. Thus, characterization of the early developmental process during gastrulation is important to accurately describe the precise timing of cell-type specification.
Connexins in the development and physiology of stem cells
Published in Tissue Barriers, 2021
Anaclet Ngezahayo, Frederike A. Ruhe
As shown in the abstract Figure, in developing embryos, Cxs are expressed as early as the 4–8 cell stage when the cells are totipotent. They continue to be expressed in pluripotent cells and multipotent cells in tissue. In organisms, it seems that Cxs and GJIC play minor roles in embryonic cells. Knock out of Cxs does not hinder gastrulation. The imperative role of Cxs manifests when tissues start to differentiate during gastrulation. In culture, Cxs are necessary for the stemness and differentiation of PSCs, iPSCs and adult stem cells. Pharmacological inhibition of GJIC or knockdown of Cx convincingly reveals that Cxs participate in the physiology and differentiation of different types of stem cells. The role of Cxs in stem cells involves their capacity to form GJ channels and hemichannels as well as their function as regulators of cell adhesion, cell migration and gene expression. As channels, it is still not clear which signals and metabolites are exchanged with respect to the different stem cell types. Likewise, many studies have been performed on Cx43. More studies involving the other expressed isoforms, mainly Cx26, Cx32, or Cx45, are needed to completely clarify the significance of Cxs in the physiology and development of stem cells.
Polystyrene nanoplastics exposure caused defective neural tube morphogenesis through caveolae-mediated endocytosis and faulty apoptosis
Published in Nanotoxicology, 2021
Jia-hui Nie, Yao Shen, Mohamed Roshdy, Xin Cheng, Guang Wang, Xuesong Yang
The nervous system originates from embryonic neurulation via the formation of neural primordia (Karfunkel 1974), which is a complex multistep event that is implicated in the accurately spatiotemporal regulation of gene expression (Smith and Schoenwolf 1997; Tanabe and Jessell 1996). In this study, we discovered that early chick embryos exposed to PS-NPs exhibited a high frequency of neural tube failure at both the cranial and trunk levels in addition to other developmental abnormalities (Figure 4). This finding implies that PS-NP-induced neural developmental abnormalities occur during gastrulation. Of course, one of the important reasons is that neurulation initiates at a very early stage; thus, neural precursors in the developing neural tube are also exposed to PS-NPs for a long period of time. Additionally, the neural tube undergoes dramatic morphological changes that are also extremely vulnerable to external environmental factors. Cecconi et al. reported that the etiology of neural tube defects was stalwartly multifactorial with both environmental and genetic factors and involved in numerous pathological mechanisms, including faulty cell death during neurulation (Cecconi, Piacentini, and Fimia 2008).