Thrombin induces the release of angiopoietin-1 from platelets.
Blood platelets contain angiopoietin-1, a growth factor essential for blood vessel development via stabilization of proliferating endothelial cells. It has recently been reported that angiopoietin-1 can act as a vascular stability factor (Nature Medicine 6:460, 2000). In investigating the normal tissue distribution of angiopoietin-1 from surgically-removed frozen specimens by RT-PCR, we found it consistently present in platelets and megakaryocytes, usually absent in relatively non-vascular tissue: breast, colon, lung, skin, kidney, thyroid, testicle, cervix and occasionally present in tissue enriched with vasculature: prostate, endometrium, ovary, under conditions in which mRNA stability was verified by the positive detection of internal control, actin mRNA. The consistent distribution in platelets and relatively absent distribution in non-vascular normal tissue suggested that the well-known role of platelets in maintaining vascular stability, may in part be due to platelet release of angiopoietin-1 following platelet activation. In this communication we report the incidence of Ang-1 in various normal tissues and demonstrate that thrombin-treated human platelets release angiopoietin-1 in vitro.
Li
J J
JJ
Department of Medicine, New York University Medical School, NY 10016, USA.
Huang
Y Q
YQ
Basch
R
R
Karpatkin
S
S
D042683:Angiopoietin-1; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D002460:Cell Line; D005312:Fetal Blood / Q000166:cytology; D005333:Fetus / Q000378:metabolism; D005629:Frozen Sections; D006801:Humans; D008533:Megakaryocytes / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism; D013917:Thrombin / Q000494:pharmacology*; D014018:Tissue Distribution
C467630:ANGPT1 protein, human; D042683:Angiopoietin-1; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D013917:Thrombin