Syk expression in endothelial cells and their morphologic defects in embryonic Syk-deficient mice.
Mice deficient in the Syk tyrosine kinase showed severe petechiae in utero and died shortly after birth. The mechanism of this bleeding, however, remains unknown. Here it is shown that this bleeding is caused by morphologic defects of Syk-deficient endothelial cells during embryogenesis. Immunoblot and reverse transcriptase-polymerase chain reaction Northern blot analysis indicated that Syk is expressed in several endothelial cell lines. Immunocytochemical analysis also confirmed that Syk is expressed in the normal embryonic endothelial cells and is absent in Syk-deficient mice. Furthermore, electron microscopic analysis of Syk-deficient mice revealed an abnormal morphogenesis and a decreased number of endothelial cells. The results indicate a critical role for Syk in endothelial cell function and in maintaining vascular integrity in vivo.
Yanagi
S
S
Department of Biochemistry, Kobe University School of Medicine, Chuo-ku, Japan.
Inatome
R
R
Ding
J
J
Kitaguchi
H
H
Tybulewicz
V L
VL
Yamamura
H
H
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000201:enzymology; D002417:Cattle; D004622:Embryo, Mammalian / Q000098:blood supply / Q000201:enzymology / Q000473:pathology; D004730:Endothelium, Vascular / Q000196:embryology / Q000201:enzymology* / Q000473:pathology; D004792:Enzyme Precursors / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008817:Mice, Mutant Strains / Q000196:embryology; D008854:Microscopy, Electron; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000378:metabolism*; D011693:Purpura / Q000196:embryology / Q000201:enzymology / Q000209:etiology; D000072377:Syk Kinase; D014471:Umbilical Veins / Q000166:cytology / Q000201:enzymology
D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D011505:Protein-Tyrosine Kinases; C000606896:SYK protein, human; D000072377:Syk Kinase; C000606897:Syk protein, mouse