Lower levels of PAI-2 may contribute to impaired healing in venous ulcers — a preliminary study

Plasminogen activators may potentially influence the wound healing processes of cell migration, matrix degradation and cellular adhesion in venous ulcers by their regulation of protease activity. The aim of this study was to assess the levels of plasminogen activators in venous ulcers and to gain preliminary data from healing wounds. The concentrations of u-PA, t-PA, PAI-1 and PAI-2 antigen as well as functional u-PA were assessed in tissue homogenates from 20 chronic venous ulcers, six actively healing venous ulcers and five traumatic wounds. The concentrations of functional u-PA, u-PA antigen and PAI-1 were significantly greater and PAI-2 was significantly lower in the edge and base of chronic venous ulcers compared to adjacent intact skin (P<0.01). Healing wounds had significantly higher functional u-PA at the ulcer edge and higher u-PA antigen concentration in intact skin (P<0.05). PAI-2 levels were significantly higher in the ulcer edge and base in the healing wounds than in chronic venous ulcers (P<0.05). These findings suggest that regulation of protease activity by u-PA and PAI-2 may play a role in the impaired healing of chronic venous ulcers.