Proliferation Of Neural Crest Stem Cells Research Articles

Toxicity of o-phenylphenol on craniofacial cartilage development through ROS-induced oxidative stress in zebrafish embryos

O-phenylphenol (OPP), a commonly used antiseptic and bactericide, has some threat to human health and the environment. Environmental exposure to OPP may cause potential health hazards in animals and humans, and the developmental toxicity of OPP needs to be assessed. Therefore, the zebrafish model was used to evaluate the ecological impact of OPP, and the zebrafish craniofacial skeleton is mainly derived from the cranial neural crest stem cells (NCCs). In this study, zebrafish were exposed to 1,2,4 mg/L OPP from10 to 80 h post-fertilization (hpf). Our study observed that OPP could cause the early disorder of craniofacial pharyngeal arch development and lead to behavioural abnormalities. In addition, qPCR and enzyme activity revealed that OPP exposure would induce the production of reactive oxygen species (ROS) and oxidative stress. And proliferation cell nuclear antigen (PCNA) indicated that the proliferation of NCCs was reduced. The mRNA expression of genes related to migration, proliferation, and differentiation of NCCs has changed significantly under OPP exposure. Astaxanthin (AST), a widely used antioxidant, could partially rescue the craniofacial cartilage development exposed to OPP. The results showed improvements in oxidative stress, gene transcription, NCCs proliferation, and protein expression in zebrafish, suggesting that OPP may reduce antioxidant capacity and subsequently inhibit migration, proliferation, and differentiation of the NCCs. In conclusion, our study found that OPP may produce reactive oxygen species, leading to developmental toxicity in zebrafish craniofacial cartilage.

Transitions in development – an interview with Rosa Uribe

Rosa Uribe is an Assistant Professor of BioSciences at Rice University. Having established her lab in 2017, her research focusses on identifying the genetic, cellular and signalling-level mechanisms of neural crest stem cell proliferation, migration and differentiation during embryogenesis. We caught up with Rosa to find out more about her career, her opinions about mentorship and a series of virtual seminars that she co-organises.

Involvement of the lncRNA AFAP1-AS1/microRNA-195/E2F3 axis in proliferation and migration of enteric neural crest stem cells of Hirschsprung's disease.

What is the central question of this study? Long non-coding RNAs (lncRNAs) are widely involved in the progression of Hirschsprung's disease (HSCR), but the role of actin filament associated protein1 antisense RNA1 (AFAP1-AS1), an lncRNA, in HSCR has not been explored before. What is the main finding and its importance? Downregulation of AFAP1-AS1 blocks enteric neural crest stem cell proliferation, differentiation, migration and invasion and promotes the occurrence of HSCR via the miR-195/E2F3 axis, indicating thatAFAP1-AS might be a potential biomarker for HSCR patients. Long non-coding RNAs (lncRNAs) are involved in several human disorders. Nevertheless, it remains unclear whether they are implicated in the phenotypes of enteric neural crest stem cells (ENCSCs) in Hirschsprung's disease (HSCR). Therefore, we designed this study to explore the pathogenicity of AFAP1-AS1 for HSCR. Microarray analysis and bioinformatic tools were used to screen out the differentially lncRNAs and microRNAs (miRNAs) in patients with HSCR. Small interference RNA transfection was applied to carry out functional experiments in ENCSCs. Cellular activities were detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine, Transwell assays and flow cytometry. Finally, rescue experiments were performed to examine the cofunction of AFAP1-AS1 and miR-195 and of miR-195 and E2F transcription factor 3 (E2F3). AFAP1-AS1 was reduced in HSCR patients. Meanwhile, knockdown of AFAP1-AS1 reduced the cell migratory and proliferative capacities and facilitated cell apoptosis along with G0/G1 phase arrest. E2F3 was diminished when miR-195 was upregulated, and AFAP1-AS1 inhibition reduced its ability to bind to miR-195. Altogether, AFAP1-AS1 silencing acts as an endogenous RNA by interacting with miR-195 to alter E2F3 expression, thus conferring repressive effects on ENCSC activity and promoting HSCR progression.

Alternative NHEJ pathway proteins as components of MYCN oncogenic activity in human neural crest stem cell differentiation: implications for neuroblastoma initiation

Neuroblastoma is a cancer of neural crest stem cell (NCSC) lineage. Signaling pathways that regulate NCSC differentiation have been implicated in neuroblastoma tumorigenesis. This is exemplified by MYCN oncogene targets that balance proliferation, differentiation, and cell death similarly in normal NCSC and in high-risk neuroblastoma. Our previous work discovered a survival mechanism by which MYCN-amplified neuroblastoma circumvents cell death by upregulating components of the error-prone non-canonical alternative nonhomologous end-joining (alt-NHEJ) DNA repair pathway. Similar to proliferating stem cells, high-risk neuroblastoma cells have enhanced DNA repair capacity, overcoming DNA damage with higher repair efficiency than somatic cells. Adequate DNA maintenance is required for lineage protection as stem cells proliferate and during tumor progression to overcome oncogene-induced replication stress. On this basis, we hypothesized that alt-NHEJ overexpression in neuroblastoma is a cancer cell survival mechanism that originates from DNA repair systems of NCSC, the presumed progenitor cell of origin. A human NCSC model was generated in which inducible MYCN triggered an immortalized phenotype capable of forming metastatic neuroectodermal tumors in mice, resembling human neuroblastoma. Critical alt-NHEJ components (DNA Ligase III, DNA Ligase I, and Poly [ADP-ribose polymerase 1]) were highly expressed in normal early NCSC, and decreased as cells became terminally differentiated. Constitutive MYCN expression maintained high alt-NHEJ protein expression, preserving the expression pattern of the immature neural phenotype. siRNA knockdown of alt-NHEJ components reversed MYCN effects on NCSC proliferation, invasion, and migration. DNA Ligase III, Ligase I, and PARP1 silencing significantly decreased neuroblastoma markers expression (TH, Phox2b, and TRKB). These results utilized the first human NCSC model of neuroblastoma to uncover an important link between MYCN and alt-NHEJ expression in developmental tumor initiation, setting precedence to investigate alt-NHEJ repair mechanics in neuroblastoma DNA maintenance.

Stage-Specific Control of Neural Crest Stem Cell Proliferation by the Small Rho GTPases Cdc42 and Rac1

The neural crest (NC) generates a variety of neural and non-neural tissues during vertebrate development. Both migratory NC cells and their target structures contain cells with stem cell features. Here we show that these populations of neural crest-derived stem cells (NCSCs) are differentially regulated by small Rho GTPases. Deletion of either Cdc42 or Rac1 in the NC results in size reduction of multiple NC target structures because of increased cell-cycle exit, while NC cells emigrating from the neural tube are not affected. Consistently, Cdc42 or Rac1 inactivation reduces self-renewal and proliferation of later stage, but not early migratory NCSCs. This stage-specific requirement for small Rho GTPases is due to changes in NCSCs that, during development, acquire responsiveness to mitogenic EGF acting upstream of both Cdc42 and Rac1. Thus, our data reveal distinct mechanisms for growth control of NCSCs from different developmental stages.

GABA Stems Proliferation

Cell proliferation and differentiation, processes that are inversely correlated, are typically regulated during the G1 phase of the cell cycle. Self-renewing stem cells need to proliferate and remain multipotent; indeed, embryonic stem (ES) cells may lack the G1 pathways through which proliferation is regulated. Andäng et al . identified γ-aminobutyric acid type A receptor (GABA A R) subunits and GABA synthetic enzymes in mouse ES cells and peripheral neural crest stem (NCS) cells and combined electrophysiological analysis with use of a voltage-sensitive dye to confirm that the cells contained functional GABA A Rs. The GABA A R agonist muscimol inhibited proliferation of cultured stem cells, whereas the antagonist bicuculline promoted it, as did knockdown of the GABA A R β3 subunit (GABA A R β3) with RNA interference. Cell cycle distribution analysis indicated that receptor activation promoted the accumulation of ES cells in S phase. Moreover, muscimol stimulated the phosphorylation of histone H2AX (which is involved in the S/G2 DNA damage checkpoint response) by means of the checkpoint kinases ataxia telangiectasia mutated (ATM) and ataxia telangiectasia, Rad3-related (ATR), even though no overt DNA damage was evident. Furthermore, GABA-dependent inhibition of proliferation depended on H2AX. Muscimol decreased the incorporation of bromodeoxyuridine into blastocysts in vivo, and injection of siRNA directed against GABA A R β3 into zygotes led to the faster development of blastocyst-stage embryos. GABA also regulated proliferation of NCS cells. Thus the proliferation of ES and NCS cells appears to be regulated through autocrine- or paracrine-derived GABA through a pathway that uses components of the DNA damage checkpoint response. M. Andäng, J. Hjerling-Leffler, A. Moliner, T. K. Lundgren, G. Castelo-Branco, E. Nanou, E. Pozas, V. Bryja, S. Halliez, H. Nishimaru, J. Wilbertz, E. Arenas, M. Koltzenburg, P. Charnay, A. El Manira, C. F. Ibañez, P. Ernfors, Histone H2AX-dependent GABA A receptor regulation of stem cell proliferation. Nature 451 , 460-464 (2008). [PubMed]