Elevated expression of extracellular matrix metalloproteinase inducer (CD147) and membrane-type matrix metalloproteinases in venous leg ulcers

BACKGROUND: Matrix metalloproteinases (MMPs) contribute to matrix remodelling in venous leg ulcers. Extracellular MMP inducer (EMMPRIN; CD147) has been reported to increase MMP expression, and membrane type 1 MMP (MT1-MMP) has been implicated in the activation of MMPs. OBJECTIVES: To examine whether and to what degree EMMPRIN, MMP-2, MT1-MMP and membrane type 2 MMP (MT2-MMP) are expressed in venous leg ulcers as well as the association with MMP activity. METHODS: EMMPRIN, MMP-2, MT1-MMP and MT2-MMP were analysed by zymography and immunohistochemistry in biopsies from healthy skin and lesional tissue from venous leg ulcers. RESULTS: Zymography provided direct evidence of increased proteolytic activity of MMP-2 in lesional skin in comparison with healthy controls. Immunostaining showed intense expression of EMMPRIN, MMP-2, MT1-MMP and MT2-MMP in dermal structures of venous leg ulcers, whereas only EMMPRIN and MMP-2 showed elevated expression in perivascular regions. Our findings indicate that venous leg ulcers are characterized by elevated expression of EMMPRIN, MMP-2, MT1-MMP and MT2-MMP. The immunohistological findings of skin alterations reflect the dynamic process of activation of soluble and membrane-bound MMPs, which may be highly induced by EMMPRIN. CONCLUSIONS: These data suggest for the first time that membrane-bound MMPs may favour enhanced turnover of the extracellular matrix and support unrestrained MMP activity in venous leg ulcers.     

Expression of matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and MT1-MMP in skin tumors of human papillomavirus type 8 transgenic mice

Human papillomaviruses (HPV) are small DNA viruses that induce a wide variety of hyperproliferative lesions in cutaneous and mucosal epithelia. It is proposed that HPV is involved in non-melanoma skin cancer development. We have previously shown that HPV8 transgenic mice spontaneously develop papillomatous skin tumors. Histology revealed epidermal hyperplasia, acanthosis and hypergranulosis and in some cases squamous cell carcinomas (SCC). Zymographic and immunoblot analysis of normal skin extracts identified increased amounts of matrix metalloproteinase (MMP)-9, MMP-13 and MT1-MMP in HPV8-positive mice compared with HPV8-negative animals. In situ gelatin zymography of tumor specimens displayed a strong proteolytic activity in papillomas, and SCC putatively attributed to the increased amounts of activated MMP-9 found in tissue extracts. In addition, immunoblot analysis revealed increased amounts of active MMP-13 and MT1-MMP in tumor extracts as compared with control extracts. Immunohistochemical stainings of SCC specimens depicted MMP-13 to be specifically expressed in stromal fibroblasts neighboring the tumor islands, whereas MT1-MMP was detected both in tumor cells and in stromal cells. Taken together, these results implicate a role for MMPs in the development of HPV8-induced cutaneous tumors.     

Tissue inhibitors of matrix metalloproteinase-1 levels are increased in serum of patients with allergic contact dermatitis

Allergic contact dermatitis (ACD) is an antigen-specific, T-cell-mediated skin inflammatory disease. Matrix metalloproteinases (MMPs) and their tissue inhibitors of matrix metalloproteinases (TIMPs) play a role in degradation of extracellular matrix and subsequent tissue remodelling during inflammatory process. The objective of this study was to examine a possible role of TIMP-1 and MMP-9 in the pathogenesis of ACD. The serum levels of MMP-9 and TIMP-1 have been measured using enzyme-linked immunosorbent assay in patients with disseminated ACD during exacerbation of skin lesions and the remission stage (n= 20) and were compared with healthy subjects (n= 20). The mean serum levels of TIMP-1 were significantly higher in patients with ACD than in control group (42.8 +/- 4.9 ng/ml). This difference was more prominent in patients with ACD during remission (69.01 +/- 6.99 ng/ml, P < 0.0001) than in patients with exacerbation of disease (46.8 +/- 3.6 ng/ml, P= 0.0054). Mean values of serum MMP-9 did not differ significantly between patients with ACD, both in the acute and in the remission stage, compared with healthy persons (P= 0.76 and P= 0.29, respectively). TIMP-1 might be involved in pathogenesis of ACD. It seems that moderately increased levels of TIMP-1 could reflect degree of activity of skin inflammation, whereas markedly increased levels could contribute to the maintenance of the remission of disease.     

Basement membrane alterations in psoriasis are accompanied by epidermal overexpression of MMP-2 and its inhibitor TIMP-2

Psoriasis is most probably an inherited disease characterized by cell proliferation, angiogenesis, and an inflammatory process. The pathophysiology remains unknown, although an alteration in cell-cell and cell-matrix adhesion versus an autoimmune process has been proposed as the primary defect. Here, we show evidence of a new mechanism involving basement membrane alterations accompanied by keratinocyte overexpression of matrix metalloproteinase (MMP) 2 and tissue inhibitor of MMP-2 (TIMP-2) in both uninvolved and involved psoriatic skin. Immunocytochemistry with antibodies against collagen IV (alpha1, alpha2 chains) and laminins (alpha2, alpha5, beta1, gamma1 chains) revealed gaps, folding, and reduplication of the epidermo-dermal basement membrane. There was overexpression of MMP-2 in the cytoplasm of suprabasal keratinocytes. Gelatin zymography revealed pro-MMP-2 and its activated form, a-MMP-2, in both uninvolved and involved psoriatic skin, whereas pro-MMP-9 was only present in involved skin. TIMP-2 was expressed at the cell surface of psoriatic involved suprabasal keratinocytes whereas it was restricted to basal keratinocytes in uninvolved areas. Western blots showed a marked increase in a-MMP-2 and TIMP-2 in uninvolved and involved psoriatic skin although it was more pronounced in the latter. MT1-MP, known to activate pro-MMP-2, was increased in involved areas. In situ hybridization revealed strong signals of MMP-2 mRNA in both uninvolved and involved psoriatic epidermis. The overexpression of MMP-2 in uninvolved and involved psoriatic epidermis supports the concept that the primary alteration may reside in the keratinocyte. In addition, the presence of the activated form of MMP-2 could be responsible for cell-cell and cell-matrix changes noted in psoriatic epidermis.     

Molecular balance of capillary tube formation versus regression in wound repair: role of matrix metalloproteinases and their inhibitors

In this review, we discuss the identification of distinct matrix metalloproteinases (MMPs) and their inhibitors that differentially control the processes of capillary tube formation (morphogenesis) versus capillary tube regression in three-dimensional (3D) collagen matrices. This work directly relates to both granulation tissue formation and regression during wound repair. The membrane metalloproteinase, MT1-MMP (MMP-14), is required for endothelial cell (EC) tube formation using in vitro assays that mimic vasculogenesis or angiogenic sprouting in 3D collagen matrices. These events are markedly blocked by small interfering RNA (siRNA) suppression of MT1-MMP in ECs or by addition of tissue inhibitor of metalloproteinases (TIMPs)-2,-3, and -4 but not TIMP-1. In contrast, MMP-1 and MMP-10 are strongly induced during EC tube formation to regulate the process of tube regression (following activation by serine proteases) rather than formation. TIMP-1, which selectively inhibits soluble MMPs, blocks tube regression by inhibiting MMP-1 and MMP-10 while having no influence on EC tube formation. siRNA suppression of MMP-1 and MMP-10 markedly blocks tube regression without affecting tube formation. Furthermore, we discuss that pericyte-induced stabilization of EC tube networks in our model system appears to occur through EC-derived TIMP-2 and pericyte-derived TIMP-3 to block both the capillary tube formation and regression pathways.     

Alteration of extracellular matrix modulators after nonablative laser therapy in skin rejuvenation

BACKGROUND: Nonablative laser therapy is widely practised for skin rejuvenation, which stimulates collagen production and dermal matrix remodelling. Matrix remodelling is primarily modulated by a coordinated action of matrix metalloproteinases (MMPs) and their inhibitors, but the effects of nonablative lasers on these matrix modulators are not fully investigated. OBJECTIVES: To evaluate the changes in matrix modulators, such as MMP-1, MMP-2, MMP-3, MMP-9 and MT1-MMP, and their inhibitors (TIMP-1, TIMP-2 and RECK in particular), after nonablative laser treatments of human facial skin. METHODS: Twenty-four adult volunteers received a series of four nonablative laser treatments separated by 3-week intervals on facial skin. Two-millimetre skin punch biopsies were obtained at baseline and 3 weeks after the last treatment. RESULTS: Nonablative laser treatments led to a robust increase in two major dermal matrix components, type I collagen and tropoelastin. Among MMPs tested, levels of MMP-2 mRNA were statistically significantly increased, but the amount of active MMP-2 was rather reduced. More importantly, the expression level of RECK was significantly enhanced by laser treatments. CONCLUSIONS: Clinical outcomes following nonablative laser treatments may result not only from increased biosynthesis but also from decreased degradation, via an induction of RECK expression, of matrix proteins.     

Human Scalp Dermal Papilla and Fibrous Sheath Cells have a different expression profile of Matrix Metalloproteinases <Emphasis Type="Italic">in vitro</Emphasis> when compared to Scalp Dermal Fibroblasts

The dermal papilla is a cluster of specialised mesenchymal cells at the bottom of the mammalian hair follicle, embedded in a loose extracellular matrix. These cells have the capability to induce and support hair growth via close epithelial–mesenchymal interactions with the keratinocytes surrounding the hair matrix. The extracellular matrix of the dermal papilla differs markedly from the interfollicular matrix and plays a key role in the maintenance of hair growth. In this study we investigated the expression pattern and activity of matrix metalloproteinases (MMP) and their tissue inhibitor in in vitro cultures of cells derived from scalp dermal papilla and fibrous sheath. Expression and activity of MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, TIMP-2 and MT1-MMP were analysed in those cells cultured in contact with one of the relevant protein component of the dermal matrix, collagen type I as well as in monolayer. Zymographic analysis showed activation of MMP-2 in all cells grown in three-dimensional collagen lattices whereas MMP-9 was activated only in three-dimensional collagen cultures of dermal fibroblasts and weakly in follicular cells. Expression of MMP-1, TIMP-1, TIMP-2 and MT1-MMP was similar in all cells, in both culture conditions, whereas expression of MMP-3 was absent in dermal papilla cells. In addition to a series of reported morphological and functional differences between dermal fibroblasts and the dermal mesenchyme-derived cells of the hair follicle, we reported differences in MMP expression in dermal papilla and fibrous sheath cells within the mesenchymal population of the hair follicle.     

MMP-2, TIMP-2 and MT1-MMP are differentially expressed in lesional skin of melanocytic nevi and their expression is modulated by UVB-light

BACKGROUND: In malignant melanoma, recent studies have demonstrated an important role of matrix-metalloproteinase 2 (MMP-2), its co-activating enzyme membrane-type matrix-metalloproteinase 1 (MT1-MMP), and the endogenous inhibitor of MMP-2, tissue-inhibitor of matrix metalloproteinase 2 (TIMP-2). Melanocytic nevi are benign neoplasms of the melanocytic lineage, but may exhibit dysplastic features that can be difficult to distinguish from early stage melanoma. As shown in earlier studies, nevi show important morphological and phenotypical changes in response to ultraviolet light (UVB) irradiation. OBJECTIVE: To clarify the role of MMP-2, TIMP-2 and MT1-MMP in UVB-irradiated vs. non-irradiated melanocytic nevi. METHODS: Immunohistochemical comparison of the MMP-2, TIMP-2 and MT1-MMP expression pattern. RESULTS: MMP-2 is expressed by lesional keratinocytes and its expression is up-regulated by UVB-irradiation. MMP-2 expression was not observed in melanocytic cells. TIMP-2, by contrast, is predominantly expressed by melanocytic nevus cells, and its expression is in part down-regulated by UVB-irradiation. MT1-MMP is expressed by basal keratinocytes and to a weaker extent by melanocytic nevus cells. CONCLUSIONS: MMP-2 expression by keratinocytes in nevi probably represents the result of activation of keratinocyte turnover in lesional epidermis. MMP-2 could play a role in the downward movement of junctional nevus cells into the dermis. The reduction of TIMP-2 expression in melanocytic cells by UV-light together with the enhanced expression of MMP-2 in the adjacent epidermis may promote basement membrane degradation. The expression pattern of MT1-MMP in close proximity to epithelial-mesenchymal interfaces underlines the synergistic role of MT1-MMP in this process.     

Epidermal-dermal interactions regulate gelatinase activity in Apligraf, a tissue-engineered human skin equivalent

BACKGROUND: Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) have important functions during skin development, repair and maintenance. MMP-2 and MMP-9 (gelatinase A and gelatinase B) are involved in regulating keratinocyte migration. OBJECTIVES: To analyse whether Apligraf, a bilayered tissue-engineered human skin equivalent (HSE), produces gelatinases and TIMPs and whether or not epidermal-dermal interactions regulate MMP activity. METHODS: The tissue distribution of MMP-2, MMP-9, TIMP-1, TIMP-2 and fibronectin was analysed by immunohistochemistry. Secreted MMP activity was quantified by a fluorimetric assay and gelatin zymography was used to monitor gelatinases in tissue culture supernatants. RESULTS: Apligraf expressed MMP-2 and MMP-9 and contained immunohistochemically detectable amounts of TIMP-1 and TIMP-2. The gelatinases were predominantly produced in the epidermis, whereas immunostaining of TIMP-1 and TIMP-2 was largely confined to the dermal component of the HSE. Fibronectin was expressed only in the dermis. Gelatin zymography demonstrated that intact Apligraf produced both MMP-2 and MMP-9, the latter predominantly in its latent form. Separation of the dermis from the epidermis resulted in an enhanced production and activation of MMP-9 by the epidermal layer, and secretion of latent and active MMP-2 by the dermal layer. Moreover, the incubation media of the separated epidermis demonstrated significantly stronger MMP activity than did intact Apligraf or its dermal component. CONCLUSIONS: These observations provide evidence that epidermal-dermal interactions suppress epidermal gelatinase activity. In addition, coexpression of TIMPs and fibronectin in the Apligraf dermis suggests that the product has the potential to counteract the imbalance between matrix production and degradation in chronic wounds and thus may support wound re-epithelialization.     

Modulation of skin collagen metabolism by irradiation: collagen synthesis is increased in irradiated human skin

Radiation-induced fibrosis is a common side-effect of cancer treatment. The pathophysiological events leading to fibrosis are not known in detail. We analysed the effect of therapeutic irradiation on human skin collagen synthesis, skin thickness, gelatinases and their inhibitors. Twenty randomly chosen women who had been treated for breast cancer with surgery and radiation therapy participated in the study. In each patient, the irradiated skin area was compared with a corresponding non-treated skin area. Suction blister fluid (SBF) and serum samples were analysed for the aminoterminal propeptides of type I and type III procollagens (PINP and PIIINP), tissue inhibitors of matrix metalloproteinases (MMPs) 1 and 2 (TIMP-1 and TIMP-2) and MMP-9 and MMP-2/TIMP-2 complex. Skin biopsies were analysed for PINP and immunohistochemical staining was used for PIIINP. In irradiated skin, PINP, PIIINP, TIMP-1 and MMP-2/TIMP-2 complex levels in SBF and the number of PINP-positive fibroblasts in tissue sections were significantly higher in comparison with non-treated skin. The levels of TIMP-2 in irradiated and non-irradiated skin were similar. MMP-9 could not be detected in SBF with the assay used. The serum levels of MMP-9 were higher in the treated subjects than the reference values. The serum values of PINP, PIIINP, TIMP-1, TIMP-2 and MMP-2/TIMP-2 complex were not significantly affected. These results indicate increased local collagen synthesis and accumulation of connective tissue in irradiated skin. The marked upregulation of collagen synthesis as a result of irradiation offers a possibility to treat this complication with compounds such as topical steroids which downregulate collagen synthesis.     

Cutis laxa: analysis of metalloproteinases and extracellular matrix expression by immunohistochemistry and histochemistry

Upregulation of matrix metalloproteinases (MMPs) and downregulation of tissue inhibitors of metalloproteinases (TIMP) have been reported in cultured fibroblasts from patients with congenital cutis laxa (CL) or anetoderma. We determined the protein expressions of MMP-1, MMP-2, MMP-3, MMP-9, MMP-12, TIMP-1 and collagen I, collagen III in vivo, to confirm their roles in the pathogenesis of cutis laxa. The protein expression of the MMPs and collagens from skin lesions of CL were detected by immunohistochemistry and analyzed by image analysis software. Markedly increased MMP-1, MMP-2, MMP-3, MMP-9, MMP-12, TIMP-1 associated with alteration of elastic and collagen fibers were found in two cases of CL, whereas increased MMP-3, MMP-9, MMP-12 accompanying a degradation of elastic fibers were detected in the third case. These results suggest an elevated expression of MMPs may play a role in the evolution or genesis of CL.     

Differential expression of matrix metalloproteinases and proteoglycans in Juvenile Hyaline Fibromatosis

Background

Juvenile Hyaline Fibromatosis (JHF) is a rare autosomal recessive disorder, histologically characterized by the production and deposition of an unidentified hyaline material in the skin and other organs. Extracellular matrix molecules are implicated in the development of skin lesion which is debilitating and recurrent and, so far, no treatment is satisfactory.

Objective

To investigate the expression of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs) and proteoglycans in lesional as compared to site-matched lesion-free skin tissue specimens of a JHF patient, aiming to elucidate the aetiopathological mechanisms involved in the development of JHF skin lesions.

Methods

Gelatinase activity of MMP-2 and MMP-9 was investigated by gelatine zymography. Protein levels of MMP-2, MMP-9, TIMP-1 and TIMP-2 in skin tissue extracts were measured by ELISA. Gene expression of MMPs, TIMPs and proteoglycans was examined by quantitative RT-PCR.

Results

JHF lesions exhibited significantly higher activity as well as elevated protein and gene expression of MMP-2 and MMP-9, as compared to lesion-free skin tissue specimens. Decorin was downregulated and aggrecan was upregulated in lesional skin, as compared to normal skin.

Conclusion

The results presented in this study indicate that MMPs and proteoglycans may be involved in the pathogenesis of JHF and therefore these molecules may offer alternative targets for pharmacological intervention to achieve more radical and effective treatment.     

Coordinate expression of membrane type-matrix metalloproteinases-2 and 3 (MT2-MMP and MT3-MMP) and matrix metalloproteinase-2 (MMP-2) in primary and metastatic melanoma cells

Expression of MMP-2 in melanoma cells has been demonstrated to be involved in the degradation of extracellular matrix during melanoma growth and to correlate with later melanoma metastasis. MMP-2 is considered to be activated by membrane-associated matrix metalloproteinases (MT-MMPs). To know whether MT-MMPs are involved in the activation of MMP-2 in melanoma cells, immunohistochemical studies were performed in primary and metastatic melanoma by use of the antibodies for MT1-MMP, MT2-MMP and MT3-MMP. Expression of MT1-MMP, MT2-MMP, MT3-MMP and MMP-2 in nevocellular nevus (n = 5), dysplastic nevus (n = 2) and juvenile melanoma (n = 3) was undetectable or detected in only a few cells. Superficial spreading melanoma (SSM) (n = 3) and acral lentiginous melanoma (ALM) (n = 3) showed a moderate expression of MT1 approximately 3-MMP. In nodular melanoma (NM) (n = 2) and metastatic melanoma (n = 3), MT1 approximately 3-MMP was more intensely expressed. Double immunofluorescence demonstrated a consistent colocalization of MT2-MMP/MMP-2 and MT3-MMP/MMP-2 in the NM and metastatic melanoma cells. The colocalization of MT2,3-MMP and MMP-2 in nodular and metastatic melanoma cells suggests that MT-MMPs and MMP-2 co-operate in the invasive and metastatic process of melanoma cells.     

Matrix metalloproteinases in human melanoma

Cutaneous melanoma is a highly invasive and metastatic tumor. Degradation of basement membranes and extracellular matrix is an essential step in melanoma cell migration, invasion, and metastasis formation. Matrix metalloproteinases and their tissue inhibitors play a crucial role in these complex multistep processes. Melanoma cells may express a number of matrix metalloproteinase family members (MMP-1, MMP-2, MMP-9, MMP-13, and MT1-MMP) as well as their tissue inhibitors (TIMP-1, TIMP-2, and TIMP-3). Numerous studies have examined matrix metalloproteinases, their tissue inhibitors, and the molecules that regulate their expression and/or activation in melanoma cell lines in vitro and in vivo, and in human melanocytic lesions. Recent results have indicated that adhesion molecules such as CD44 and integrin alphavbeta3 are involved in positioning activated matrix metalloproteinase molecules on the cell surface of invasive tumor cells. In this review we evaluate these novel aspects of the role of matrix metalloproteinases and their tissue inhibitors in melanoma progression. We conclude that the balance between levels of activated matrix metalloproteinases and expression levels of their tissue inhibitors, and the coexpression of activated matrix metalloproteinases and adhesion molecules are important factors in determining melanoma cell invasion, tumor growth, and metastasis formation.     

Anetoderma: an altered balance between metalloproteinases and tissue inhibitors of metalloproteinases

The amount of elastic fibers from lesional and healthy skin areas of five patients with anetoderma was determined by automated image analysis. Dermal elastic fibers were almost completely absent in anetodermic skin and preelastic fibers were undetectable or extremely rare. Organ cultures were performed using explants from affected and unaffected skin areas of the same patient. We identified and quantified proteases in the culture media of explants: MMP-1 (collagenase 1), MMP-2 and MMP-9 (gelatinases A and B), MMP-3 (stromelysin 1), MMP-7 (matrilysin 1), and tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-2. The data were compared with those of two healthy donors. For the five samples of anetodermic skin, MMP-1 levels were significantly higher compared with the uninvolved cultures and the two healthy samples. A significant increase of TIMP-1 expression was also observed in the affected cultures. We demonstrated a significant increase in the production of gelatinase A in lesional skin when compared with nonlesional skin and healthy donor samples. We found no significant production of TIMP-2 in the five samples of anetodermic skin compared with the samples from the two healthy donors. There was a significant decrease in TIMP-2 expression in the five nonlesional samples compared with the control samples. These data are in favor of an altered balance in anetodermic patients between MMP-2 and TIMP-2. Levels of MMP-9, MMP-3, and MMP-7 were significantly higher in the culture-conditioned media of the anetodermic skin samples than the nonlesional skin cultures. Because MMP-3, MMP-7, MMP-9 are known to degrade elastin, and MMP-3 can activate the latent forms of MMP-7 and MMP-9, we propose that these metalloproteinases also participate in the degradation of elastic fibers in anetodermic skin.     

Immunohistochemical study of membrane type-matrix metalloproteinases (MT-MMPs) and matrix metalloproteinase-2 (MMP-2) in dermatofibroma and malignant fibrous histiocytoma

Matrix metalloproteinases (MMPs) play an important role in tumor invasion and metastasis. Enhanced expression of matrix metalloproteinase-2 (MMP-2) has been demonstrated in dermatofibroma (DF) and malignant fibrous histiocytoma (MFH). MMP-2 has been shown to be activated by membrane-type MMPs (MT-MMPs). To study the role of MT-MMP in the activation of MMP-2, skin specimens of DF (five cases) and MFH (three cases) were immunohistochemically studied using in situ zymography and the antibodies against matrix metalloproteinase-2 (MMP-2) and membrane type 1-3-MMPs (MT1-3-MMPs). Both MMP-2 activity and its expression were significantly activated in the tumor cells in DF and MFH. Anti-MT2-MMP strongly reacted with tumor cells of all cases of DF and MFH, whereas anti-MT1 or 3-MMP antibody showed a weak reaction in some cases of DF and MFH. Double immunofluorescence labeling demonstrated that the immunoreactive cells with anti-MMP-2 antibody in DF and MFH consistently reacted with anti-MT2-MMP antibody. The results suggest that the activation of MMP-2 in the benign and malignant fibrous tumors is related to the activation of MT-MMPs.     

Stromal cells as the major source for matrix metalloproteinase-2 in cutaneous melanoma

Matrix metalloproteinases (MMPs) are essential for tumor progression, invasion and metastases formation. Expression of these proteinases is not only restricted to the tumor cells themselves, but also is found in normal stromal cells. Moreover, immunohistochemistry suggests stromal cells as the major source. To scrutinize this hypothesis we established a slowly growing, syngeneic tumor model using the B16-melanoma cell line B78D14. In vitro analysis demonstrated that B78D14 cells secreted MMP-2, MT1-MMP, and to a lesser degree MMP-9; in addition they expressed both MT1-MMP and EMMPRIN on their surface. In subcutaneous (s.c.) tumors of these cells MMP-2 expression was predominantly present at the tumor-stroma border indicating stromal cells as primary source for this protease in vivo. Indeed, double staining experiments and in situ zymography confirmed that tumor adjacent stromal cells at the invasive front expressed MMP-2 and only at this site activated MMP-2 was detectable. Notably, in an experimental pulmonary metastases model neither tumor nor stromal cells expressed MMP-2, suggesting that the capacity of stromal cells is largely dependent on the surrounding microenvironment.     

Decreased MMP-9 activity in the serum of patients with diffuse cutaneous systemic sclerosis

Matrix metalloproteinase-9 (MMP-9) and its inhibitor, tissue inhibitors of metalloproteinases-1 (TIMP-1) are involved in tissue inflammation and fibrotic processes. We previously reported an elevated serum TIMP-1 level in patients with systemic sclerosis (SSc). We measured serum TIMP-1 and active MMP-9 levels in 62 patients with SSc, 10 patients with rheumatoid arthritis (RA) and 15 normal controls using a modified enzyme-linked immunosorbent assay. The active MMP-9 level in the serum of the patients with RA or SSc was not significantly different from that of controls. Serum MMP-9 activity in patients with diffuse cutaneous SSc was significantly decreased compared with that of limited cutaneous SSc or normal controls. The MMP-9 activity and modified-Rodnan total skin thickness score in patients with SSc were negatively correlated. Serum MMP-9 activity and TIMP-1 level in patients with SSc were not correlated. Serum MMP-9 activity might be a useful indicator of disease activity, especially skin severity, in SSc patients.     

皮肤鳞状细胞癌和基底细胞上皮瘤膜型基质金属蛋白酶-1、基质金属蛋白酶-2表达

目的 探讨皮肤鳞状细胞癌(简称鳞癌)和基底细胞上皮瘤(简称BCE)膜型基质金属蛋白酶-1(MT1-MMP)、基质金属蛋白酶-2(MMP-2)表达及其与临床病理特征的关系。方法 应用原位杂交和ABC免疫组化技术检测48例皮肤鳞癌和41例BCE手术切除标本中MT1-MMP、MMP-2表达。结果 鳞癌中MT1-MMP、MMP-2表达明显高于BCE(P<0.05),且二者的表达呈显著正相关(r=0.370,P<0.05)。MT1-MMP表达在高分化或伴有淋巴结转移的鳞癌中明显上调(P<0.05),而MMP-2表达增加仅见于伴有淋巴结转移的鳞癌(P<0.05)。鳞癌和BCE中MT1-MMP、MMP-2表达与患者性别、年龄、病程、发病部位、原发/转移病灶及BCE侵袭性无关(P>0.05)。结论 MT1-MMP、MMP-2表达上调与皮肤鳞癌的淋巴结转移有关。MT1-MMP、MMP-2表达水平不能区别BCE是否具有侵袭性。     

Matrix metalloproteinases and their inhibitors in oral lichen planus

BACKGROUND: Oral lichen planus (OLP) is characterized by a sub-epithelial lymphocytic infiltrate, basement membrane (BM) disruption, intra-epithelial T-cell migration and apoptosis of basal keratinocytes. BM damage and T-cell migration in OLP may be mediated by matrix metalloproteinases (MMPs). METHODS: We examined the distribution, activation and cellular sources of MMPs and their inhibitors (TIMPs) in OLP using immunohistochemistry, ELISA, RT-PCR and zymography. RESULTS: MMP-2 and -3 were present in the epithelium while MMP-9 was associated with the inflammatory infiltrate. MMP-9 and TIMP-1 secretion by OLP lesional T cells was greater than OLP patient (p < 0.01) and healthy control subject (p < 0.001) peripheral blood T cells. MMP-9 and TIMP-1 mRNA levels were greater in OLP lesional T cells compared with healthy control subject peripheral blood T cells p < 0.01). Tumor necrosis factor (TNF)-alpha upregulated OLP lesional T-cell MMP-9 (not TIMP-1) mRNA and secretion (p < 0.05). The in vitro activation rate of MMP-9 from OLP lesional T cells was greater than that from OLP peripheral blood T cells (p < 0.05). CONCLUSION: T-cell-derived MMP-9 may be involved in the pathogenesis of OLP. Relative over-expression of MMP-9 (compared with TIMP-1) may cause BM disruption and facilitate intra-epithelial T-cell migration in OLP.