OBJECTIVES

To investigate whether tissue expression of plasminogen activator inhibitor type 1 (PAI-1) is increased in the fibrotic plaque of human Peyronie's disease (PD). Increased tissue levels of PAI-1, an inhibitor of both fibrinolysis and collagenolysis, have been found in a variety of fibrotic conditions. Recently, it was reported that PAI-1 expression was also increased in the fibrotic plaque of an animal model of PD induced by the injection of fibrin into the tunica albuginea (TA) of the penis.

METHODS

Tissue (n = 10/group) and cells (n = 4/group) obtained from the penile TA plaque of patients with PD or from normal TA were subjected to RNA extraction and real-time reverse transcriptase-polymerase chain reaction. Tissues were also analyzed by immunohistochemistry (n = 8/group) for the detection of PAI-1 expression at the transcription and protein levels.

RESULTS

A significant 3.5-fold to 16-fold increase was found in both PAI-1 mRNA and protein levels in the human PD plaque and the respective fibroblast cultures compared with the normal non-PD TA.

CONCLUSIONS

The observed increase in PAI-1 in the human PD plaque agrees with what has been observed in the rat and suggests that PAI-1 may be a key pro-fibrotic factor in the development of human PD.