Characterization of tissue specific expression of Notch-1 in human tissues.
Signaling through the Notch cell surface receptors is a highly conserved mechanism of cell fate specification. Notch signaling regulates proliferation, differentiation and cell death. In vertebrates, putative gene duplication has originated four Notch genes, Notch-1, -2, -3 and -4. They have been implicated in neurogenesis, hematopoiesis, T-cell development, vasculogenesis and brain cortical growth. We have investigated Notch-1 distribution in normal human tissues by immunohistochemistry and immunoblot. We detected widespread expression of Notch-1 cytoplasmatic staining, with different tissue distributions in the different organs examined. In particular, high expression of Notch-1 was detected in the intermediate suprabasal layers, but not in the dead cells at the extreme periphery of stratified epithelia. Moreover, a low/intermediate level of Notch-1 was observed in lymphocytes in several peripheral lymphoid tissues; in particular the germinal centers of lymph nodes showed the most abundant number of positive cells, which appeared to be centroblasts/immunoblasts based on nuclear morphology. Notch-1 participates in keratinocytes differentiation. We showed by Western blot analysis that Notch-1 level was clearly increased in HaCaT cells after Ca(++) addition and remained substantially elevated until late differentiation stages. These results suggest that Notch-1 may function in numerous cell types in processes beyond cell fate determination, such as neuronal plasticity, muscle hypertrophy, liver regeneration, and germinal center lymphopoiesis during the immune response.
Baldi
Alfonso
A
Department of Biochemistry and Biophysics F. Cedrangolo, Section of Pathologic Anatomy, Second University of Naples, Italy.
De Falco
Maria
M
De Luca
Luca
L
Cottone
Giuliano
G
Paggi
Marco G
MG
Nickoloff
Brian J
BJ
Miele
Lucio
L
De Luca
Antonio
A
D015153:Blotting, Western; D002454:Cell Differentiation; D002461:Cell Line, Transformed; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000378:metabolism*; D008221:Lymphoid Tissue / Q000166:cytology / Q000378:metabolism; D008297:Male; D009928:Organ Specificity; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015398:Signal Transduction; D012867:Skin / Q000166:cytology / Q000378:metabolism; D014018:Tissue Distribution; D014157:Transcription Factors / Q000378:metabolism*
C497761:NOTCH1 protein, human; D051881:Receptor, Notch1; D011956:Receptors, Cell Surface; D014157:Transcription Factors