Proteolytic activity in wound fluids and tissues derived from chronic venous leg ulcers
ABSTRACT Venous leg ulcers affect approximately 1% of the general population and 3.6% of those over the age of 65. The goal of the research described herein is to shorten the time to healing by developing wound care alternatives that are based on a comprehensive understanding of the venous ulcer wound environment. The proteolytic and inflammatory components in wound fluids and tissue biopsy samples were characterized in subjects with documented long-standing venous ulcers that had showed resistance to standard therapy. All wounds showed polymicrobial colonization with greater than 10(6) CFU/g. Myeloperoxidase, a measure of leukocyte infiltration, was also markedly elevated in these wounds. Zymography revealed the presence of both pro-matrix metalloproteinase (MMP)-2 and pro-MMP-9 in wound fluids and to a lesser extent in tissue biopsies. Using an immunocapture activity assay we reveal a sevenfold excess of MMP-9 in wound fluid as compared to tissue, with 73% in the activated form. In contrast, MMP-8 total protein levels were nearly equal in wound fluids and biopsies. Fibronectin, a critical component of the extracellular matrix, was shown to be degraded in both wound fluids and biopsy samples. Finally, the potential of a novel wound dressing to neutralize several constituents of this hostile wound environment is shown.
- SourceAvailable from: Martin Von Bergen[Show abstract] [Hide abstract]
ABSTRACT: Wound healing of soft tissue and bone defects is a complex process in which cellular differentiation and adaption are regulated by internal and external factors, among them are many different proteins. In contrast to insights into the significance of various single proteins based on model systems, the knowledge about the processes at the actual site of wound healing is still limited. This is caused by a general lack of methods that allow sampling of extracellular factors, metabolites, and proteins in situ. Sampling of wound fluids in combination with proteomics and metabolomics is one of the promising approaches to gain comprehensive and time resolved data on effector molecules. Here, we describe an approach to sample metabolites by microdialysis and to extract proteins simultaneously by adsorption. With this approach it is possible (i) to collect, enrich, and purify proteins for a comprehensive proteome analysis; (ii) to detect more than 600 proteins in different defects including more than 100 secreted proteins, of which many proteins have previously been demonstrated to have diagnostic or predictive power for the wound healing state; and (iii) to combine continuous sampling of cytokines and metabolites and discontinuous sampling of larger proteins to gain complementary information of the same defect.BioMed Research International 01/2014; 2014:934848. DOI:10.1155/2014/934848 · 2.71 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Matrix metalloproteinases (MMPs) were originally identified as matrixin proteases that act in the extracellular matrix. Recent works have uncovered nontraditional roles for MMPs in the extracellular space as well as in the cytosol and nucleus. There is strong evidence that subspecialized and compartmentalized matrixins participate in many physiological and pathological cellular processes, in which they can act as both degradative and regulatory proteases. In this review, we discuss the transcriptional and translational control of matrixin expression, their regulation of intracellular sorting, and the structural basis of activation and inhibition. In particular, we highlight the emerging roles of various matrixin forms in diseases. The activity of matrix metalloproteinases is regulated at several levels, including enzyme activation, inhibition, complex formation and compartmentalization. Most MMPs are secreted and have their function in the extracellular environment. MMPs are also found inside cells, both in the nucleus, cytosol and organelles. The role of intracellular located MMPs is still poorly understood, although recent studies have unraveled some of their functions. The localization, activation and activity of MMPs are regulated by their interactions with other proteins, proteoglycan core proteins and / or their glycosaminoglycan chains, as well as other molecules. Complexes formed between MMPs and various molecules may also include interactions with noncatalytic sites. Such exosites are regions involved in substrate processing, localized outside the active site, and are potential binding sites of specific MMP inhibitors. Knowledge about regulation of MMP activity is essential for understanding various physiological processes and pathogenesis of diseases, as well as for the development of new MMP targeting drugs.Progress in Histochemistry and Cytochemistry 03/2012; 47(1):27-58. DOI:10.1016/j.proghi.2011.12.002 · 5.91 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: Following injury, vascular damage results in the loss of perfusion and consequent low oxygen tension (hypoxia) which may be exacerbated by a rapid influx of inflammatory and mesenchymal cells with high metabolic demands for oxygen. Changes in systemic and cellular oxygen concentrations induce tightly regulated response pathways that attempt to restore oxygen supply to cells and modulate cell function in hypoxic conditions. Most of these responses occur through the induction of the transcription factor hypoxia-inducible factor-1 (HIF-1) which regulates many processes needed for tissue repair during ischemia in the damaged tissue. HIF-1 transcriptionally upregulates expression of metabolic proteins (GLUT-1), adhesion proteins (integrins), soluble growth factors (TGF-β and VEGF), and extracellular matrix components (type I collagen and fibronectin), which enhance the repair process. For these reasons, HIF-1 is viewed as a positive regulator of wound healing and a potential regulator of organ repair and tissue fibrosis. Understanding the complex role of hypoxia in the loss of function in scarring tissues and biology of chronic wound, and organ repair will aid in the development of pharmaceutical agents that can redress the detrimental outcomes often seen in repair and scarring.International review of cell and molecular biology 01/2012; 296:139-85. DOI:10.1016/B978-0-12-394307-1.00003-5 · 4.52 Impact Factor