Proteolysis is an intrinsic component of cutaneous wound repair and several matrix metalloproteinases have been shown to participate in various stages of this process. Therefore, we investigated the expression of a novel metalloproteinase, collagenase-3 (MMP-13), in normally healing cutaneous wounds and chronic venous ulcers. MMP-13 was expressed abundantly by fibroblasts deep in the chronic ulcer bed but was not detected in epidermis and all the acute wounds. The spatial expression of MMP-13 differed from that of collagenase-1 (MMP-1), which was prominently expressed by migrating keratinocytes and dermal cells located just beneath the wound surface. Northern blot hybridization did not reveal expression of MMP-13 by fibroblasts cultured on tissue culture plastic. In accordance with our in vivo findings, however, fibroblasts grown in a collagen gel produced MMP-13 mRNA abundantly. Our results suggest that MMP-13 can be induced in skin during wound repair after altered cell-matrix interactions. Although both MMP-1 and MMP-13 have the unique ability to degrade fibrillar collagens, their regulation and role during wound repair seem different. Collagenase-1 is critical for re-epithelialization, and MMP-13 most likely plays a role in the remodeling of collagenous matrix in chronic wounds.

Excessive accumulation of fibrillar collagens is a hallmark of the cutaneous fibrosis in both systemic and localized scleroderma. Turnover of the collagenous extracellular matrix is dependent on the balance between collagenolytic matrix metalloproteinases and their specific inhibitors. We have examined the expression of the novel, matrix associated tissue inhibitor of metalloproteinases-3 (TIMP-3) in normal and scleroderma skin fibroblasts in culture and in vivo. The levels of TIMP-3 mRNA were elevated up to 2.5-fold in five of seven systemic sclerosis fibroblast strains, whereas TIMP-1 mRNA expression was elevated up to 1.8-fold in two and TIMP-2 mRNA expression up to 1.8-fold in two systemic sclerosis strains. Using in situ hybridization, TIMP-3 mRNA was detected in seven of 12 localized scleroderma skin samples, specifically in fibroblasts within fibrotic collagen fibers or in the vicinity of inflammatory cells. TIMP-1 mRNA was detected in three of eight scleroderma skin samples in fibroblasts adjacent to inflammatory cells. The expression of TIMP-3 mRNA by systemic sclerosis and normal skin fibroblasts was enhanced to a similar extent (by 8.6- and 8.1-fold, respectively) by transforming growth factor-beta, and suppressed down to 34 and 54%, respectively, by tumor necrosis factor-alpha. Specific activation of TIMP-3 gene expression in scleroderma skin fibroblasts in culture and in vivo suggests a role for TIMP-3 in the pathogenesis of dermal fibrosis via inhibition of turnover of fibrotic dermal extracellular matrix, possibly due to upregulation of TIMP-3 expression by transforming growth factor-beta.

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BackgroundDuring a field course on spider taxonomy and ecology at the University of Helsinki, the authors had the opportunity to sample four plots with a dual objective of both teaching on field methods, spider identification and behaviour and uncovering the spider diversity patterns found in the southern coastal forests of Hankoniemi, Finland. As an ultimate goal, this field course intended to contribute to a global project that intends to uncover spider diversity patterns worldwide. With that purpose, a set of standardised methods and procedures was followed that allow the comparability of obtained data with numerous other projects being conducted across all continents.New informationA total of 104 species and 1997 adults was collected. Of these, 41 species (39%) were Linyphiidae and 13 (12%) Theridiidae. All other families had 6 or less species represented. Linyphiidae were also dominant in terms of adult individuals captured, with 1015 (51%), followed by 428 (21%) Lycosidae, 158 (8%) Tetragnathidae and 145 (7%) Theridiidae. All other families had less than 100 individuals. The most abundant species were Neriene peltata, Alopecosa taeniata, Piratula hygrophila and Dismodicus elevatus, all with more than 100 individuals. All sites had between 56 and 62 species and between 445 and 569 individuals.