Fibronectin isoforms in megakaryocytes.
Our studies have shown that megakaryocytes (MK) can synthesize fibronectin (FN) and alternatively spliced fibronectin, FN EIIIB. FN EIIIB is primarily present in embryonic, proliferating and migrating cells, and thought to be important for cell maturation. MK, but not nonmegakaryocytic bone marrow cells, contain FN EIIIB and thus, MK and platelets are among a small number of adult cells and tissues that synthesize and contain FN EIIIB. Thrombin can induce the secretion of general FN, but does not cause the secretion of FN EIIIB into the medium. Analysis of immunostained cells by confocal microscopy revealed that both general FN and FN EIIIB accumulated on the MK surface following thrombin treatment. Thus, FN EIIIB can be released only to be bound to the MK surface. The expression of FN EIIIB on the MK surface may have a unique role in MK migration and maturation.
Schick
P K
PK
Cardeza Foundation for Hematologic Research and the Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107-5099, USA.
Wojensk
C M
CM
Bennett
V
V
Denisova
L
L
D000818:Animals; D001792:Blood Platelets / Q000378:metabolism; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000378:metabolism; D002455:Cell Division; D002465:Cell Movement; D004591:Electrophoresis, Polyacrylamide Gel; D005353:Fibronectins / Q000096:biosynthesis / Q000737:chemistry*; D006168:Guinea Pigs; D006801:Humans; D008533:Megakaryocytes / Q000737:chemistry* / Q000378:metabolism; D018613:Microscopy, Confocal; D020033:Protein Isoforms; D013917:Thrombin / Q000494:pharmacology
D005353:Fibronectins; D020033:Protein Isoforms; D013917:Thrombin