Neural rosette formation is a critical morphogenetic process during neural development, whereby neural stem cells are enclosed in rosette niches to equipoise proliferation and differentiation. How neural rosettes form and provide a regulatory micro-environment remains to be elucidated. We employed the human embryonic stem cell-based neural rosette system to investigate the structural development and function of neural rosettes. Our study shows that neural rosette formation consists of five types of morphological change: intercalation, constriction, polarization, elongation and lumen formation. Ca2+ signaling plays a pivotal role in the five steps by regulating the actions of the cytoskeletal complexes, actin, myosin II and tubulin during intercalation, constriction and elongation. These, in turn, control the polarizing elements, ZO-1, PARD3 and β-catenin during polarization and lumen production for neural rosette formation. We further demonstrate that the dismantlement of neural rosettes, mediated by the destruction of cytoskeletal elements, promotes neurogenesis and astrogenesis prematurely, indicating that an intact rosette structure is essential for orderly neural development.

• MeSH
• aktiny metabolismus   MeSH
• apoptóza účinky léků   MeSH
• buněčný rodokmen účinky léků   MeSH
• cytoskelet účinky léků   metabolismus   MeSH
• lidé MeSH
• lidské embryonální kmenové buňky cytologie   účinky léků   metabolismus   MeSH
• myosin typu II metabolismus   MeSH
• nervové kmenové buňky cytologie   účinky léků   metabolismus   MeSH
• neurogeneze účinky léků   MeSH
• neurony cytologie   účinky léků   metabolismus   ultrastruktura   MeSH
• polarita buněk účinky léků   MeSH
• protein zonula occludens 1 metabolismus   MeSH
• tvar buňky * účinky léků   MeSH
• tvorba rozet * MeSH
• vápník farmakologie   MeSH
• vápníková signalizace * účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Development of neural tube has been extensively modeled in vitro using human pluripotent stem cells (hPSCs) that are able to form radially organized cellular structures called neural rosettes. While a great amount of research has been done using neural rosettes, studies have only inadequately addressed how rosettes are formed and what the molecular mechanisms and pathways involved in their formation are. Here we address this question by detailed analysis of the expression of pluripotency and differentiation-associated proteins during the early onset of differentiation of hPSCs towards neural rosettes. Additionally, we show that the BMP signaling is likely contributing to the formation of the complex cluster of neural rosettes and its inhibition leads to the altered expression of PAX6, SOX2 and SOX1 proteins and the rosette morphology. Finally, we provide evidence that the mechanism of neural rosettes formation in vitro is reminiscent of the process of secondary neurulation rather than that of primary neurulation in vivo. Since secondary neurulation is a largely unexplored process, its understanding will ultimately assist the development of methods to prevent caudal neural tube defects in humans.

• MeSH
• buněčná diferenciace * MeSH
• COUP transkripční faktor II genetika   metabolismus   MeSH
• faktory domény POU genetika   metabolismus   MeSH
• homeodoménové proteiny genetika   metabolismus   MeSH
• kultivované buňky MeSH
• lidé MeSH
• nervové kmenové buňky cytologie   metabolismus   MeSH
• neurální trubice cytologie   embryologie   metabolismus   MeSH
• neurulace * MeSH
• pluripotentní kmenové buňky cytologie   metabolismus   MeSH
• transkripční faktor PAX6 genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Primary cilia are key regulators of embryo development and tissue homeostasis. However, their mechanisms and functions, particularly in the context of human cells, are still unclear. Here, we analyzed the consequences of primary cilia modulation for human pluripotent stem cells (hPSCs) proliferation and differentiation. We report that neither activation of the cilia-associated Hedgehog signaling pathway nor ablation of primary cilia by CRISPR gene editing to knockout Tau Tubulin Kinase 2 (TTBK2), a crucial ciliogenesis regulator, affects the self-renewal of hPSCs. Further, we show that TTBK1, a related kinase without previous links to ciliogenesis, is upregulated during hPSCs-derived neural rosette differentiation. Importantly, we demonstrate that while TTBK1 fails to localize to the mother centriole, it regulates primary cilia formation in the differentiated, but not the undifferentiated hPSCs. Finally, we show that TTBK1/2 and primary cilia are implicated in the regulation of the size of hPSCs-derived neural rosettes.

• MeSH
• centrioly metabolismus   MeSH
• cilie metabolismus   MeSH
• lidé MeSH
• pluripotentní kmenové buňky * metabolismus   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny hedgehog * genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

This study elucidated the stage-specific roles of FGF2 signaling during neural development using in-vitro human embryonic stem cell-based developmental modeling. We found that the dysregulation of FGF2 signaling prior to the onset of neural induction resulted in the malformation of neural rosettes (a neural tube-like structure), despite cells having undergone neural induction. The aberrant neural rosette formation may be attributed to the misplacement of ZO-1, which is a polarized tight junction protein and shown co-localized with FGF2/FGFR1 in the apical region of neural rosettes, subsequently led to abnormal neurogenesis. Moreover, the FGF2 signaling inhibition at the stage of neural rosettes caused a reduction in cell proliferation, an increase in numbers of cells with cell-cycle exit, and premature neurogenesis. These effects may be mediated by NUMB, to which expression was observed enriched in the apical region of neural rosettes after FGF2 signaling inhibition coinciding with the disappearance of PAX6+/Ki67+ neural stem cells and the emergence of MAP2+ neurons. Moreover, our results suggested that the hESC-based developmental system reserved a similar neural stem cell niche in vivo.

• MeSH
• buněčná diferenciace účinky léků   MeSH
• buněčné linie MeSH
• časosběrné zobrazování MeSH
• chromony farmakologie   MeSH
• fibroblastový růstový faktor 2 farmakologie   MeSH
• imunohistochemie MeSH
• lidé MeSH
• lidské embryonální kmenové buňky cytologie   metabolismus   MeSH
• malá interferující RNA metabolismus   MeSH
• membránové proteiny metabolismus   MeSH
• morfoliny farmakologie   MeSH
• nervové kmenové buňky cytologie   metabolismus   MeSH
• neurogeneze účinky léků   MeSH
• neurony cytologie   metabolismus   MeSH
• protein zonula occludens 1 antagonisté a inhibitory   genetika   metabolismus   MeSH
• proteiny asociované s mikrotubuly metabolismus   MeSH
• proteiny nervové tkáně metabolismus   MeSH
• pyrimidiny farmakologie   MeSH
• receptor fibroblastových růstových faktorů, typ 1 metabolismus   MeSH
• RNA interference MeSH
• signální transdukce účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Neural differentiation of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) can produce a valuable and robust source of human neural cell subtypes, holding great promise for the study of neurogenesis and development, and for treating neurological diseases. However, current hESCs and hiPSCs neural differentiation protocols require either animal factors or embryoid body formation, which decreases efficiency and yield, and strongly limits medical applications. Here we develop a simple, animal-free protocol for neural conversion of both hESCs and hiPSCs in adherent culture conditions. A simple medium formula including insulin induces the direct conversion of >98% of hESCs and hiPSCs into expandable, transplantable, and functional neural progenitors with neural rosette characteristics. Further differentiation of neural progenitors into dopaminergic and spinal motoneurons as well as astrocytes and oligodendrocytes indicates that these neural progenitors retain responsiveness to instructive cues revealing the robust applicability of the protocol in the treatment of different neurodegenerative diseases. The fact that this protocol includes animal-free medium and human extracellular matrix components avoiding embryoid bodies makes this protocol suitable for the use in clinic. Stem Cells Translational Medicine 2017;6:1217-1226.

• MeSH
• buněčná a tkáňová terapie MeSH
• buněčná diferenciace fyziologie   MeSH
• embryonální kmenové buňky fyziologie   MeSH
• indukované pluripotentní kmenové buňky cytologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• pluripotentní kmenové buňky cytologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The 'gold standard' treatment of severe neonatal jaundice is phototherapy with blue-green light, which produces more polar photo-oxidation products that are easily excreted via the bile or urine. The aim of this study was to compare the effects of bilirubin (BR) and its major photo-oxidation product lumirubin (LR) on the proliferation, differentiation, morphology, and specific gene and protein expressions of self-renewing human pluripotent stem cell-derived neural stem cells (NSC). Neither BR nor LR in biologically relevant concentrations (12.5 and 25 µmol/L) affected cell proliferation or the cell cycle phases of NSC. Although none of these pigments affected terminal differentiation to neurons and astrocytes, when compared to LR, BR exerted a dose-dependent cytotoxicity on self-renewing NSC. In contrast, LR had a substantial effect on the morphology of the NSC, inducing them to form highly polar rosette-like structures associated with the redistribution of specific cellular proteins (β-catenin/N-cadherin) responsible for membrane polarity. This observation was accompanied by lower expressions of NSC-specific proteins (such as SOX1, NR2F2, or PAX6) together with the upregulation of phospho-ERK. Collectively, the data indicated that both BR and LR affect early human neurodevelopment in vitro, which may have clinical relevance in phototherapy-treated hyperbilirubinemic neonates.

• Publikační typ
• časopisecké články MeSH

The critical requirements in developing clinical-grade human-induced pluripotent stem cells-derived neural precursors (hiPSCs-NPCs) are defined by expandability, genetic stability, predictable in vivo post-grafting differentiation, and acceptable safety profile. Here, we report on the use of manual-selection protocol for generating expandable and stable human NPCs from induced pluripotent stem cells. The hiPSCs were generated by the reprogramming of peripheral blood mononuclear cells with Sendai-virus (SeV) vector encoding Yamanaka factors. After induction of neural rosettes, morphologically defined NPC colonies were manually harvested, re-plated, and expanded for up to 20 passages. Established NPCs showed normal karyotype, expression of typical NPCs markers at the proliferative stage, and ability to generate functional, calcium oscillating GABAergic or glutamatergic neurons after in vitro differentiation. Grafted NPCs into the striatum or spinal cord of immunodeficient rats showed progressive maturation and expression of early and late human-specific neuronal and glial markers at 2 or 6 months post-grafting. No tumor formation was seen in NPCs-grafted brain or spinal cord samples. These data demonstrate the effective use of in vitro manual-selection protocol to generate safe and expandable NPCs from hiPSCs cells. This protocol has the potential to be used to generate GMP (Good Manufacturing Practice)-grade NPCs from hiPSCs for future clinical use.

• MeSH
• buněčná diferenciace MeSH
• indukované pluripotentní kmenové buňky * MeSH
• krysa rodu rattus MeSH
• leukocyty mononukleární MeSH
• lidé MeSH
• nervové kmenové buňky * MeSH
• neurony metabolismus   MeSH
• virus Sendai genetika   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

In 1918, Stout defined the lesion in which small round cells originating from the ulnar nerve formed a rosette as neuroepithelioma. It was claimed that this tumor originated from neuroectodermis and was different from the classical neuroblastoma (1, 2). The term primitive neuroectodermal tumor (PNET) involves a group of tumors of the soft tissue originating from neural crest and resulting from the brain, spinal cord and branches of the sympathetic nervous system. Extracranial primitive neuroectodermal tumors originate from neural crest cells outside the sympathetic and central nervous system. PNET also has some distinctive histological, immunohistochemical and ultrastructural features. It is usually encountered in children and young adults; most frequently located in thoracopulmonary region (Askin’s tumor). The second most commonly involved body part is the extremities. It is very rarely located on the face (3-8). PNET is an aggressive tumor. In fact, the disease has a rapid progression, causes local or distant metastases and 50% of the patients die within two years of the presentation (7). It is treated with aggressive surgery as well as chemotherapy and radiotherapy. In this report, we presented a case of PNET located on the right cheek with multiple distant metastases. Clinicians should be on alert when treating facial tumors, not to skip PNET, which is a very aggressive one.

• MeSH
• lidé MeSH
• primitivní neuroektodermové nádory diagnóza   patologie   MeSH
• tvář patologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH