Fibroblast extracellular matrix gene expression in response to keratinocyte‐releasable stratifin

Abstract

Termination of wound-healing process requires a fine balance between connective tissue deposition and its hydrolysis. Previously, we have demonstrated that keratinocyte-releasable stratifin, also known as 14-3-3 sigma protein, stimulates collagenase (MMP-1) expression in dermal fibroblasts. However, role of extracellular stratifin in regulation of extracellular matrix (ECM) factors and other matrix metalloproteinases (MMPs) in dermal fibroblast remains unexplored. To address this question, large-scale ECM gene expression profile were analyzed in human dermal fibroblasts co-cultured with keratinocytes or treated with recombinant stratifin. Superarray pathway-specific microarrays were utilized to identify upregulation or downregulation of 96 human ECM and adhesion molecule genes. RT-PCR and Western blot were used to validate microarray expression profiles of selected genes. Comparison of gene profiles with the appropriate controls showed a significant (more than twofold) increase in expression of collagenase-1, stromelysin-1 and -2, neutrophil collagenase, and membrane type 5 MMP in dermal fibroblasts treated with stratifin or co-cultured with keratinocytes. Expression of type I collagen and fibronectin genes decreased in the same fibroblasts. The results of a dose-response experiment showed that stratifin stimulates the expression of stromelysin-1 (MMP-3) mRNA by dermal fibroblasts in a concentration-dependent fashion. Furthermore, Western blot analysis of fibroblast-conditioned medium showed a peak in MMP-3 protein levels 48 h following treatment with recombinant stratifin. In a lasting-effect study, MMP-3 protein was detected in fibroblast-condition medium for up to 72 h post removal of stratifin. In conclusion, our results suggest that keratinocyte-releasable stratifin plays a major role in induction of ECM degradation by dermal fibroblasts through stimulation of key MMPs, such as MMP-1 and MMP-3. Therefore, stratifin protein may prove to be a useful target for clinical intervention in controlling excessive wound healing in fibrotic conditions.

Up-regulation of transforming growth factor-β3 and extracellular matrix proteins in acquired reactive perforating collagenosis

“…Thus, the balance between MMP and TIMP levels governs connective tissue homeostasis. 22,23 This was a systematic study on immunohistochemistry in ARPC indicating that TGF-ß signaling and MMPs and their inhibitors play a role in the pathogenesis of the disease. Limitations of the present study include the absence of polymerase chain reaction studies investigating the messenger RNA expression of TGF-ß.…”

Microarray‐based identification of aminopeptidase N target genes in keratinocyte conditioned medium‐stimulated dermal fibroblasts

“…Previously, we have shown that co-culture of dermal fibroblasts with keratinocytes and addition of stratifin to dermal fibroblasts both led to changes in the expression of MMP-1, MMP-3, and FN [Ghaffari et al, 2006]. In this study, the regulation of these genes as well as of MMP-12 and TN-C by APN was further investigated.…”

“…In the skin, the composition of the matrix is dynamically modulated by dermal fibroblasts, which continuously synthesize and degrade extracellular molecules and their receptors in response to signaling molecules released by keratinocytes and neighboring cells. Apart from the wellcharacterized signaling molecules at the epidermal-dermal junction, our group has successfully isolated stratifin (also known as 14-3-3 sigma) which functions as a keratinocyte-releasable stimulating factor of matrix metalloproteinases [Ghahary et al, 2004;Ghaffari et al, 2006]. Stratifin belongs to the 14-3-3 family of phospho-serine/threonine-binding proteins which normally function as intracellular chaperones in signal transduction, cell cycle regulation, molecular transport, and apoptosis [Baldin, 2000;Fu et al, 2000;van Hemert et al, 2001].…”

“…Stratifin belongs to the 14-3-3 family of phospho-serine/threonine-binding proteins which normally function as intracellular chaperones in signal transduction, cell cycle regulation, molecular transport, and apoptosis [Baldin, 2000;Fu et al, 2000;van Hemert et al, 2001]. Upon release by keratinocytes, stratifin stimulates the expression of matrix metalloproteinase (MMP)-1, -3, -8, and -24 in fibroblasts via the p38 MAPK signaling pathway [Ghahary et al, 2004;Lam et al, 2005;Ghaffari et al, 2006]. In vivo stratifin treatment in a fibrotic rabbit ear model showed improvement of hypertrophic scar in reducing scar thickness and cellularity [Rahmani-Neishaboor et al, 2010].…”

OMICS Integration Studies for New Insights on Atopic Dermatitis

“…The real-time PCR analyses showed that the transcriptional level of SFN is conspicuously upregulated 4.5-fold in ADI patient-derived keratinocytes. In the epidermis, SFN is known to stimulate the syntheses of ECM factors (collagen, proteoglycans, and fibronectin) and the matrix metalloproteinases [21][22][23]. SFN is also known to be involved in the response to DNA damage, and this protein is involved in the cell cycle (G2 arrest).…”