Detection of plasminogen activator inhibitor-1 (PAI-1) mRNA in human megakaryocytes by in situ hybridization.
Platelets have been described to contain a large proportion of the circulating plasminogen activator inhibitor type 1 (PAI-1) which is released on platelet activation. This protein could be taken up by platelets from the plasma or synthesized by megakaryocytes (MKs). Recently, PAI-1 mRNA has been detected in a human megakaryoblastic leukemia cell line (MEG-01) by the polymerase chain reaction (PCR). However, a direct-demonstration of its presence in normal human MKs is lacking. In order to prove directly the megakaryocytic origin of platelet PAI-1, the MEG-01 cell line, human bone marrow enriched in MKs, and bone marrow smears from allogeneic bone marrow transplantation donors were investigated for the presence of PAI-1 mRNA using in situ hybridization (ISH). Specimens of bone marrow were first stained with May-Grünwald Giemsa (MGG) for cell identification according to their morphology. Subsequently, the same slides were used for ISH. PAI-1 mRNA was clearly demonstrated in the MEG-01 cell line and in MKs, and its presence correlated with the detection of PAI-1 antigen by immunocytochemistry. PAI-1 mRNA was also detected in morphologically characterized mature granulocytes of marrow samples.
Alessi
M C
MC
Laboratory of Hematology, CHU Timone, Marseille, France.
Chomiki
N
N
Berthier
R
R
Schweitzer
A
A
Fossat
C
C
Juhan-Vague
I
I
D001853:Bone Marrow / Q000737:chemistry; D001854:Bone Marrow Cells; D016026:Bone Marrow Transplantation / Q000502:physiology; D002452:Cell Count; D002460:Cell Line; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008533:Megakaryocytes / Q000737:chemistry*; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*; D014184:Transplantation, Homologous
D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger