cathepsin-g and Leg-Ulcer

Human neutrophil elastase (HNE) and cathepsin G (CatG) are involved in the pathogenesis of a number of inflammatory disorders. These serine proteinases are released by neutrophils and monocytes in case of infection. Wound infection is a severe complication regarding wound healing causing diagnostic and therapeutic problems. In this study we have shown the potential of HNE and CatG to be used as markers for early detection of infection. Significant differences in HNE and CatG levels in infected and non-infected wound fluids were observed. Peptide substrates for these two enzymes were successfully immobilised on different surfaces, including collagen, modified collagen, polyamide polyesters and silica gel. HNE and CatG activities were monitored directly in wound fluid via hydrolysis of the chromogenic substrates. Infected wound fluids led to significant higher substrate hydrolysis compared with non-infected ones. These different approaches could be used for the development of devices which are able to detect elevated enzyme activities before manifestation of infection directly on bandages. This would allow a timely intervention by medical doctors thus preventing severe infections.

Topics: Bandages; Biomarkers; Cathepsin G; Chromogenic Compounds; Exudates and Transudates; Humans; Leg Ulcer; Leukocyte Elastase; Pressure Ulcer; Surgical Wound Infection; Wound Healing; Wound Infection; Wounds and Injuries

Although extracellular proteolysis is a prerequisite for normal wound healing, uncontrolled proteolytic tissue destruction appears to be a pathogenic factor in non-healing wounds. The aim of our study was to compare the activities of the serine proteinases of polymorphonuclear origin, elastase and cathepsin G, and the metalloproteinases, gelatinase and collagenase, in chronic leg ulcer exudate (10 patients) and acute wound fluid (6 patients). Serine proteinase activities were low in leg ulcer exudates but very high in some but not all acute wound fluids. Total collagenase activity, measured as activity against type I collagen monitored by SDS-PAGE and densitometry, was higher in chronic leg ulcer exudate than in acute wound fluid and its degree of autoactivation was relatively high. Doxycycline inhibition studies suggested that the collagenase activity in chronic leg ulcer exudate was MMP-1 ("fibroblast-type") and not MMP-8 ("neutrophil-type"). Zymographic analysis of the gelatinolytic enzymes in acute wound fluid showed a progressive increase from the day of operation to postoperative day 5, but the degree of activity was lower than in chronic leg ulcer exudate and the low molecular mass activation products were faint. The leg ulcer gelatinase profiles were characterized by high expression of 92/82- and 72/62-kDa duplex bands and by the presence of low molecular mass activation products. Leg ulcer collagenase seems to be derived from mononuclear rather than polymorphonuclear cells, which are known to be involved in acute wound healing. In conclusion, the present study shows that gelatinase and collagenase, but not elastase and cathepsin G are found in chronic leg ulcer exudate.

Topics: Aged; Cathepsin G; Cathepsins; Chronic Disease; Collagenases; Doxycycline; Female; Gelatinases; Humans; Leg Ulcer; Male; Middle Aged; Pancreatic Elastase; Serine Endopeptidases