Active Wnt/beta-catenin signaling is required for embryonic thymic epithelial development and functionality ex vivo.
The Wnt/beta-catenin signaling pathway plays an important role in the commitment and development of thymic epithelial precursors. Here we document similarities of thymic epithelial development during embryogenesis in human and mouse. We stained for thymic epithelial surface markers (EpCAM1, Ly51, K8) and ligand/receptor pair (Wnt4, Fz4). Our results confirm the relevance of using murine test systems to model human embryonic thymic epithelial cell development. We have efficiently transduced murine embryonic epithelial cells using mock (GFP) and Wnt/beta-catenin-inhibiting (ICAT-encoding) recombinant adenoviral vectors. The effect of Wnt4 was assayed in the form of Wnt4-containing supernatant. Gene expressional changes were assessed by Q-PCR and also morphology using conventional and confocal fluorescent microscopy. Functional aberration caused by ICAT was assessed through evaluation of thymocyte maturation. Our results demonstrate that ICAT and Wnt4 have reciprocal effects during embryonic thymic epithelial cell development. While Wnt4 is capable of increasing the expression level of characteristic intracellular (FoxN1), surface (MHCII) and secreted (IL7) molecules, Wnt/beta-catenin inhibition through ICAT can moderately decrease their expression. Morphological changes induced by ICAT resulted in the development of hollow, inflated thymic lobes with reduced epithelial cell numbers. The ICAT-treated thymic lobes also showed significant impairment in supporting thymocyte development and maturation.
Department of Pharmacological Biotechnology, University of Pecs, Hungary. Electronic address: kvell.krisztian@pte.hu.
Krisztian
K
Kvell
Department of Pharmacological Biotechnology, University of Pecs, Hungary.
Aniko V
AV
Fejes
Department of Anatomy, Division of Immunity and Infection, Institute for Biomedical Research, University of Birmingham, UK.
Sonia M
SM
Parnell
Department of Pharmacological Biotechnology, University of Pecs, Hungary; Department of Anatomy, Division of Immunity and Infection, Institute for Biomedical Research, University of Birmingham, UK.
Judit E
JE
Pongracz
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics; D002478:Cells, Cultured; D046149:Embryo Culture Techniques; D004848:Epithelium / Q000276:immunology / Q000473:pathology*; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D015851:Interleukin-7 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D060168:Thymocytes / Q000502:physiology*; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology*; D019076:Transgenes / Q000235:genetics; D060449:Wnt Signaling Pathway / Q000235:genetics; D060528:Wnt4 Protein / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; C498785:Ctnnbip1 protein, mouse; D051858:Forkhead Transcription Factors; D015851:Interleukin-7; D012097:Repressor Proteins; C090140:Whn protein; D060528:Wnt4 Protein; D051176:beta Catenin
Embryonic development; FoxN1; ICAT; Thymic epithelium; Wnt