16 research outputs found

    Vascularisation is not necessary for gut colonisation by enteric neural crest cells

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    The vasculature and nervous system share striking similarities in their networked, tree-like architecture and in the way they are super-imposed in mature organs. It has previously been suggested that the intestinal microvasculature network directs the migration of enteric neural crest cells (ENCC) along the gut to promote the formation of the enteric nervous system (ENS). To investigate the inter-relationship of migrating ENCC, ENS formation and gut vascular development we combined fate-mapping of ENCC with immunolabelling and intravascular dye injection to visualise nascent blood vessel networks. We found that the enteric and vascular networks initially had very distinct patterns of development. In the foregut, ENCC migrated through areas devoid of established vascular networks. In vessel-rich areas, such as the midgut and hindgut, the distribution of migrating ENCC did not support the idea that these cells followed a pre-established vascular network. Moreover, when gut vascular development was impaired, either genetically in Vegfa120/120 or Tie2-Cre;Nrp1fl/- mice or using an in vitro Wnt1-Cre;Rosa26Yfp/+ mouse model of ENS development, ENCC still colonised the entire length of the gut, including the terminal hindgut. These results demonstrate that blood vessel networks are not necessary to guide migrating ENCC during ENS development. Conversely, in miRet51 mice, which lack ENS in the hindgut, the vascular network in this region appeared to be normal suggesting that in early development both networks form independently of each other

    In vivo transplantation of enteric neural crest cells into mouse gut; Engraftment, functional integration and long-term safety

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    Objectives: Enteric neuropathies are severe gastrointestinal disorders with unsatisfactory outcomes. We aimed to investigate the potential of enteric neural stem cell therapy approaches for such disorders by transplanting mouse enteric neural crest cells (ENCCs) into ganglionic and aganglionic mouse gut in vivo and analysing functional integration and long-term safety. Design: Neurospheres gene

    TALPID3/KIAA0586 Regulates Multiple Aspects of Neuromuscular Patterning During Gastrointestinal Development in Animal Models and Human

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    TALPID3/KIAA0586 is an evolutionary conserved protein, which plays an essential role in protein trafficking. Its role during gastrointestinal (GI) and enteric nervous system (ENS) development has not been studied previously. Here, we analyzed chicken, mouse and human embryonic GI tissues with TALPID3 mutations. The GI tract of TALPID3 chicken embryos was shortened and malformed. Histologically, the gut smooth muscle was mispatterned and enteric neural crest cells were scattered throughout the gut wall. Analysis of the Hedgehog pathway and gut extracellular matrix provided causative reasons for these defects. Interestingly, chicken intra-species grafting experiments and a conditional knockout mouse model showed that ENS formation did not require TALPID3, but was dependent on correct environmental cues. Surprisingly, the lack of TALPID3 in enteric neural crest cells (ENCC) affected smooth muscle and epithelial development in a non-cell-autonomous manner. Analysis of human gut fetal tissues with a KIAA0586 mutation showed strikingly similar findings compared to the animal models demonstrating conservation of TALPID3 and its necessary role in human GI tract development and patterning

    The Necrotic Signal Induced by Mycophenolic Acid Overcomes Apoptosis-Resistance in Tumor Cells

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    The amount of inosine monophosphate dehydrogenase (IMPDH), a pivotal enzyme for the biosynthesis of the guanosine tri-phosphate (GTP), is frequently increased in tumor cells. The anti-viral agent ribavirin and the immunosuppressant mycophenolic acid (MPA) are potent inhibitors of IMPDH. We recently showed that IMPDH inhibition led to a necrotic signal requiring the activation of Cdc42.Herein, we strengthened the essential role played by this small GTPase in the necrotic signal by silencing Cdc42 and by the ectopic expression of a constitutive active mutant of Cdc42. Since resistance to apoptosis is an essential step for the tumorigenesis process, we next examined the effect of the MPA–mediated necrotic signal on different tumor cells demonstrating various mechanisms of resistance to apoptosis (Bcl2-, HSP70-, Lyn-, BCR-ABL–overexpressing cells). All tested cells remained sensitive to MPA–mediated necrotic signal. Furthermore, inhibition of IMPDH activity in Chronic Lymphocytic Leukemia cells was significantly more efficient at eliminating malignant cells than apoptotic inducers.These findings indicate that necrosis and apoptosis are split signals that share few if any common hub of signaling. In addition, the necrotic signaling pathway induced by depletion of the cellular amount of GTP/GDP would be of great interest to eliminate apoptotic-resistant tumor cells

    Kasvattajien kokemuksia vanhempien kanssa tehtävästä yhteistyöstä varhaiskasvatuksessa : "Kunniatyö mulle, se, että ne on ottanu mukaan heidän lapsensa kasvatukseen"

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    Opinnäytetyön tavoitteena oli selvittää varhaiskasvattajien kokemuksia yhteistyöstä vanhempien kanssa. Lisäksi selvitettiin, millaiset toimintamallit ja käytänteet koetaan edistävinä, sekä mitkä tekijät ovat esteenä yhteistyön sujumiselle. Opinnäytetyö oli laadullinen. Tutkimusaineisto kerättiin kahdella eri ryhmäkeskustelukerralla, joihin osallistui yhteensä 10 kasvattajaa. Aineisto analysointiin soveltaen sisällönanalyysia. Varhaiskasvattajat kokivat yhteistyön luontevaksi osaksi varhaiskasvatustyötä. Vanhemmuuden ja lapsen kehityksen tukeminen nousivat vahvasti esille varhaiskasvattajien puheessa. Luottamus, avoimuus ja kunnioitus sekä niiden merkitys korostuivat avainsanoina tuloksissa. Haasteiksi varhaiskasvattajat nimesivät sekä vanhempien että varhaiskasvattajien kiireen, henkilökuntaresurssit, rauhallisen tilan löytämisen, työskentelytavat ja lasten osa-aikaisen hoidon. Kulttuurilliset ja kielelliset erot koetaan tulevaisuuden haasteiksi. Opinnäytetyötä voidaan käyttää osana varhaiskasvatuksen kehittämistä. Opinnäytetyön tuloksia voidaan käyttää myös työyhteisön kehittämisessä. Jatkotutkimuksena voisi kartoittaa vanhempien kokemuksia osallisuudesta ja yhteistyöstä varhaiskasvatuksessa.The purpose of this thesis was to study how day care educators experience the coopera-tion with parents. In addition, procedures that are considered either to promote or hinder the collaboration were examined. The thesis is a qualitative research. The data were collected during two group discussions in which altogether 10 day-care educators participated. The data were analysed using con-tent data analysis. Day-care educators considered the cooperation to be a natural part of early education. Supporting both parenthood and a child's development was highlighted in the educators' narrative. Trust, openness and respect appeared to be essential in this research whereas staff resources, ways of working, part-time day care, finding a calm space and educators' and parents' constant hurry were regarded as challenging by day care educators. Future challenges may include cultural and language-related differences. The results of this research can be utilised in developing early education. In addition, the results can be applied to developing work communities in early education. Further studies could be conducted on parents' experiences of cooperation and participation in day care

    KBP interacts with SCG10, linking Goldberg-Shprintzen syndrome to microtubule dynamics and neuronal differentiation

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    Goldberg-Shprintzen syndrome (GOSHS) is a rare clinical disorder characterized by central and enteric nervous system defects. This syndrome is caused by inactivating mutations in the Kinesin Binding Protein (KBP) gene, which encodes a protein of which the precise function is largely unclear. We show that KBP expression is upregulated during neuronal development in mouse cortical neurons. Moreover, KBP-depleted PC12 cells were defective in nerve growth factor-induced differentiation and neurite outgrowth, suggesting that KBP is required for cell differentiation and neurite development. To identify KBP interacting proteins, we performed a yeast twohybrid screen and found that KBP binds almost exclusively to microtubule associated or related proteins, specifically SCG10 and several kinesins. We confirmed these results by validating KBP interaction with one of these proteins: SCG10, a microtubule destabilizing protein. Zebrafish studies further demonstrated an epistatic interaction between KBP and SCG10 in vivo. To investigate the possibility of direct interaction between KBP and microtubules, we undertook co-localization and in vitro binding assays, but found no evidence of direct binding. Thus, our data indicate that KBP is involved in neuronal differentiation and that the central and enteric nervous system defects seen in GOSHS are likely caused by microtubule-related defects

    TALPID3/KIAA0586 Regulates Multiple Aspects of Neuromuscular Patterning During Gastrointestinal Development in Animal Models and Human

    No full text
    TALPID3/KIAA0586 is an evolutionary conserved protein, which plays an essential role in protein trafficking. Its role during gastrointestinal (GI) and enteric nervous system (ENS) development has not been studied previously. Here, we analyzed chicken, mouse and human embryonic GI tissues with TALPID3 mutations. The GI tract of TALPID3 chicken embryos was shortened and malformed. Histologically, the gut smooth muscle was mispatterned and enteric neural crest cells were scattered throughout the gut wall. Analysis of the Hedgehog pathway and gut extracellular matrix provided causative reasons for these defects. Interestingly, chicken intra-species grafting experiments and a conditional knockout mouse model showed that ENS formation did not require TALPID3, but was dependent on correct environmental cues. Surprisingly, the lack of TALPID3 in enteric neural crest cells (ENCC) affected smooth muscle and epithelial development in a non-cell-autonomous manner. Analysis of human gut fetal tissues with a KIAA0586 mutation showed strikingly similar findings compared to the animal models demonstrating conservation of TALPID3 and its necessary role in human GI tract development and patterning
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