Plasminogen activators and their inhibitors in human saliva and salivary gland tissue.
The purpose of this study was to identify plasminogen activators (PA) and their specific inhibitors in human cell-free saliva and to investigate their expression in salivary gland tissue. Saliva samples were obtained from 34 patients visiting a neurological out-patient department. The activities of tissue and urokinase plasminogen activators (tPA and uPA, respectively), the relative inhibition of tPA, and the amounts of plasminogen activator inhibitors 1 and 2 (PAI-1 and PAI-2, respectively) in cell-free saliva were studied. The activities of tPA and uPA, and tPA inhibition, were measured using in-house microtiter plate assays, and PAI-1 and PAI-2 levels were measured using commercial enzyme-linked immunosorbent assay (ELISA) kits. Immunohistochemistry was used to evaluate the expression of PAs and PAIs in the salivary gland. Tissue plasminogen activator activity was found in most samples, with a mean activity of 0.63 IU ml(-1). uPA was observed in only a few samples. PAI-1 was not detected, but PAI-2 was present in all samples (with a mean value of 11.1 ng ml(-1)). The mean PAI-2 level in women was 12.4 and in men was 7.6 ng ml(-1). The activity of tPA and the relative inhibition of tPA seemed to be inversely associated. Tissue plasminogen activator, PAI-1, and PAI-2 were evident in salivary gland tissue, whereas the expression of uPA was low. The tPA activity in saliva suggests an active proteolysis. Plasminogen activator inhibitor 2 was found to be the main inhibitor of PAs in saliva.
Virtanen
Oskari J
OJ
Department of Virology, Haartman Institute, University of Helsinki, Finland. oskari.virtanen@helsinki.fi
Sirén
Vappu
V
Multanen
Juha
J
Färkkilä
Markus
M
Leivo
Ilmo
I
Vaheri
Antti
A
Koskiniemi
Marjaleena
M
D000328:Adult; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D010960:Plasminogen Activators / Q000032:analysis*; D015849:Plasminogen Inactivators / Q000032:analysis*; D012463:Saliva / Q000737:chemistry*; D012469:Salivary Glands / Q000737:chemistry*
D015849:Plasminogen Inactivators; D010960:Plasminogen Activators