Endostatin inhibits migration and invasion of head and neck squamous cell carcinoma cells

Head and neck cancers are significant due to their high morbidity and associated complications. We report, for the first time, that endostatin directly affects epithelial lineage human cells derived from tumors of patients with head and neck squamous cell carcinoma (HNSCC). This study investigated endostatin's effects on several HNSCC cellular functions that are essential for tumor progression. We determined that exposure of HNSCC cells to endostatin activated the transcription-activating factors, NF-xB and AP-1 in a cell-line-dependent fashion. Endostatin also down-regulated the gene expression of several pro-migratory molecules. Migration and invasion assays showed that endostatin significantly inhibited these functions that are essential for tumor progression. Fluorescent labeling studies showed endostatin co-localized to tropomysin-binding HNSCC the microfilaments, suggesting endostatin's suppression of HNSCC cell migration and invasion may reflect perturbation of the microfilament function. Our data imply that endostatin's clinical efficacy extends beyond angiostatic properties to encompass a direct anti-tumorigenic effect against HNSCC cells.

The effects of progesterone on matrix metalloproteinases in cultured human gingival fibroblasts

BACKGROUND

Although pregnancy gingivitis is widely believed to result from elevated hormone concentrations, the mechanism(s) involved in the etiology of this condition remain unknown. Paradoxically, despite the apparent inflammation for a prolonged period, pregnancy gingivitis rarely progresses to periodontitis and usually resolves postpartum. We used several methods to test in vitro the hypothesis that the elevated progesterone levels of pregnancy might inhibit the production of some of the matrix metalloproteinases (MMPs) that are responsible for periodontal destruction.

METHODS

Cultured human gingival fibroblasts (GF) were tested in phenol red-free, serum-free medium with or without the progestogen, medroxyprogesterone acetate (MPA; 10(-6) M), using interleukin-1beta (IL-1beta) to initiate immune responses and MMP production. These MMP responses were examined by macroarrays, reverse transcription-polymerase chain reaction (RT-PCR), zymograms, and enzyme-linked immunosorbent assay (ELISA).

RESULTS

Array analysis showed that pretreatment of GF with MPA reduced mRNA induction for MMPs-1, -3, and -10 in response to 6 to 8 hours incubation with IL-1beta. RT-PCR confirmed, that after 24 hours with IL-1beta , GF pretreated with MPA had undetectable levels of mRNA for MMPs-1, -2, -3, -7, -10, and -13. Zymograms of culture media from this 24-hour period showed reduction in several proteolytic activities. Examination of such 24-hour media using ELISA for MMP-3 and pro-MMP-13 confirmed that secretion of these enzymes was upregulated by IL-1beta and modulated downward by pretreatment with MPA.

CONCLUSIONS

Production by GF of numerous MMPs in response to IL-1beta was significantly reduced by progesterone. This steroidal modulation of proteolytic enzymes could help to explain why pregnancy gingivitis typically is not characterized by progression to periodontitis.

Matrix-metalloproteinases in Hodgkin lymphoma

BACKGROUND

Classical Hodgkin lymphomas are characterized by relatively few tumour cells and prominent proliferation of plasma cells, histiocytes, lymphocytes and eosinophils. In addition there is a varying degree of sclerosis, which is especially prominent in nodular sclerosis. These morphological peculiarities led to the idea that the interaction between tumour cells and bystander cells as well as the extracellular matrix may be important in Hodgkin lymphomas.

MATERIALS AND METHODS

Thirty-four classical Hodgkin lymphomas (CHL) were analysed regarding the expression of EMMPRIN, MMP-2, -7, -9, -10 and-11 using immunohistochemistry.

RESULTS

The tumour cells were positive for EMMPRIN in 100% of the cases. In 82% of CHL the Hodgkin and Reed-Sternberg cells (HRS) were negative for MMP-2. In contrast the surrounding non-neoplastic cells were MMP-2-positive in 71% of the cases. The HRS cells stained positive for MMP-7 in 68% of CHL, whereas only a few surrounding cells were positive for this marker. In all but one case (97%) the HRS cells were negative for MMP-9. However, the surrounding cells stained positive in 32%, thus resembling the staining pattern for MMP-2. Only scattered cells of both populations, HRS cells as well as bystander cells, stained for MMP-10 and -11, and no specific staining pattern was observed.

CONCLUSION

Our data indicate a complex interaction between tumour cells and bystander cells with regard to metalloproteinases. The expression of EMMPRIN in the tumour cells may induce the expression of MMP-2 in the surrounding non-neoplastic cells. MMP-2 can be activated by MMP-7, which is expressed in the tumour cells. It is tempting to speculate that an interruption of this cycle could be of therapeutic benefit.

Unique expression patterns of matrix metalloproteinases in regenerating newt limbs

The process of regeneration of urodele limbs includes a drastic remodeling of extracellular matrices (ECMs) that is induced by matrix metalloproteinases (MMPs) and is thought to be one of the triggers of the regeneration. We studied this remodeling in limbs of Japanese newt, Cynops pyrrhogaster, by using five genes of newt MMPs (nMMPs) as probes: nMMP9, nMMP3/10-a, nMMP3/10-b, and nMMP13 that had been characterized previously, and nMMPe that was newly cloned in the present study. nMMPe was 502 amino acid residues long and showed a low homology to other known vertebrate MMPs. Reverse transcriptase-polymerase chain reactions analysis localized the transcript of nMMPe in the apical epidermal cap (AEC) and the non-blastemal wound epidermis but not in the blastemal mesenchyme or the normal epidermis. Northern blot analysis localized the transcripts of nMMP9, nMMP3/10-a, and nMMP13 in the bone of regenerating limbs, whereas those of nMMP3/10-b in AEC. mRNA in situ hybridization experiments identified the nMMP-expressing cells. nMMP9 gene was strongly expressed in chondrocytes of the cartilage of epiphysis. Of interest, basal cells of AEC, but not those of the normal skin, expressed nMMP3/10-b intensely. Immunohistochemical analysis showed that the nMMP9 proteins synthesized by chondrocytes were secreted and distributed widely in the basement membrane of bone and ECMs of the amputation plane. These nMMPs characterized in the present study might cooperatively work to remodel ECMs of regenerating limbs.

Identification of genes differentially expressed in cultured human osteoblasts versus human fibroblasts by DNA microarray analysis

Little is known about patterns of gene expression from cells populating the connective tissues. This study investigated the possible variance of gene expression profile between human osteoblasts (HO) and human fibroblasts (HF) in vitro, using DNA microarray technology. Clustering identification was used to compare expression patterns between HO and HF for biological significance. Our results showed that genes encoding the extracellular matrix or apoptosis-related proteins tended to be expressed in greater abundance in HO, while more proteolysis-related proteins were expressed in higher level in HF. Significant differences in expression were also noted with genes related to signaling pathways. To confirm the array results, three genes (periostin, MFG-E8, MMP-10) were selected and analyzed independently by RT-PCR and northern blot. The results were found consistent with the array data in HO and HF. The present findings suggest that HO and HF differ not only phenotypically but in the expression level of tissue specific genes to assure the turnover and homeostasis of their respective tissues.

Upregulation of matrix metalloproteinases in a model of T cell mediated tissue injury in the gut: analysis by gene array and in situ hybridisation

BACKGROUND AND AIM

Matrix metalloproteinases (MMPs) have been implicated in tissue remodelling and ulceration in inflammatory bowel disease and coeliac disease. Studies to date have concluded that stromelysin 1 is functionally involved in mucosal degradation. However, there are many other MMPs whose function in the gut is currently unknown. This work had two aims: firstly, to use gene array technology to measure changes in MMP and tissue inhibitor of metalloproteinase (TIMP) expression in a model of T cell mediated injury in the gut, and secondly, to correlate data from gene arrays with that generated by in situ hybridisation.

METHODS

T cells in explants of human fetal gut were activated with pokeweed mitogen or anti-CD3 plus interleukin 12. Gene array analysis and in situ hybridisation were performed to investigate changes in MMP gene expression.

RESULTS

Both gene array analysis and in situ hybridisation indicated marked upregulation of stromelysin 2 and macrophage metalloelastase expression in the explants associated with mucosal destruction. The arrays also confirmed our previous observation that interstitial collagenase (MMP-1), stromelysin 1 (MMP-3), and gelatinase B (MMP-9) are upregulated but there was no change in MMP-2, -7, -8, -9, -11, -13, -14-17, or -19. Following T cell activation, transcripts for TIMPs were reduced.

CONCLUSIONS

These results show that there is differential upregulation of MMPs during T cell responses in the gut and suggest that further studies on the role of stromelysin 2 and macrophage metalloelastase may show that they have a functional role. In addition, the increase in MMPs and reduction in TIMPs suggest that the protease/antiprotease balance in the mucosa may determine the extent of mucosal degradation.

Stromelysin-2 overexpression in human esophageal squamous cell carcinoma: potential clinical implications

The degradation of the extracellular matrix (ECM) is a major step in the process of tumor invasion and metastasis, mediated by matrix metalloproteinases (MMPs). Knowledge of alterations in the expression of stromelysin-2 (ST-2) or MMP-10 in human esophageal squamous cell carcinoma (ESCC) is meager. Immunohistochemical analysis of ST-2 expression was carried out in surgically resected ESCCs (50 cases) and paired distal histologically normal esophageal tissues (50 cases), correlated with clinicopathological parameters. Overexpression of ST-2 protein, in tumor cell cytoplasm and stromal elements, was observed in 37 of the 50 (74%) ESCCs localized in tumor cell cytoplasm and stromal elements. Low levels of ST-2 were observed in 8 of the 50 (16%) matched histologically normal esophageal tissues. Significant associations were observed between ST-2 overexpression and tumor size (r = 0.02, P = 0.04), local invasiveness of the tumor (r = -0.30, P = 0.002) and distant organ metastasis (r = -0.227, P = 0.02), suggestive of its involvement in development and progression of ESCCs. The data underscore the significance of ST-2 expression in context to the aggressive tumor characteristics observed in ESCCs in the Indian population, wherein extremely poor prognosis has been ascribed to extensive local invasion and metastasis.

Characterization of the living skin equivalent as a model of cutaneous re-epithelialization

The living skin equivalent, a three-dimensional organotypic model, has been widely used to investigate many aspects of cutaneous biology. However, there are relatively few studies assessing how faithfully the skin equivalent reproduces normal skin biology. The skin equivalent was fabricated by seeding human epidermal keratinocytes onto the upper surface of a hydrated collagen lattice populated with human dermal fibroblasts and subsequently raised to the air-liquid interface where keratinocyte stratification and differentiation led to the formation of a tissue which showed many common morphological features to that of normal skin. Histology and immunohistochemical detection of keratinocyte integrins and matrix metalloproteinases (MMPs) were used as cytological markers to assess the accuracy of the model during cutaneous re-epithelialization. Analysis of expression of keratinocyte integrins revealed that whilst there were a number of similarities to normal skin, skin equivalent keratinocytes appeared to be 'activated' and hyper-proliferating. Wounding of the skin equivalent, by complete bisection, induced re-epithelialization from both wound edges within 8-12 h, which completely restored the epidermis within 4 days. This migration, like that in vivo, was associated with nascent expression of MMPs and upregulation of certain integrins. However, whilst integrin expression, was similar to in vivo re-epithelialization, there were subtle differences in the level of expression and distribution of certain integrins.

Disruption of the tissue inhibitor of metalloproteinase-1 gene in reproductive-age female mice is associated with estrous cycle stage-specific increases in stromelysin messenger RNA expression and activity

Tissue inhibitors of metalloproteinases (TIMPs) are expressed in the uteri of virtually all species, yet the precise role of these factors in uterine physiology is uncertain. It has been previously demonstrated that disruption of the TIMP-1 gene product in vivo results in altered reproductive cycles and an aberrant uterine phenotype. Because this phenotype may be due to an elevation in uterine matrix metalloproteinase (MMP) activity, the purpose of the following experiments was to identify which uterine MMPs may have their expression altered in response to disruption of the TIMP-1 gene. Mature female TIMP-1 wild-type and null mice were killed during each stage of the estrous cycle, and uterine MMP activity and transcript expression were assessed. Disruption of the TIMP-1 gene product was associated with an increase in total uterine protease activity. Gel zymography further revealed that uterine stromelysin (stromelysin-1, -2, and -3) activity was significantly increased in the TIMP-1 null mice, whereas Northern blot analysis indicated that an up-regulation of stromelysin-1 and -3 mRNA expression may contribute to this increase in activity. It is concluded from this study that TIMP-1 plays a pivotal role in regulating uterine stromelysins both at the level of protease activity and the level of transcript expression.

Interleukin-6 treatment augments cutaneous wound healing in immunosuppressed mice

It has been postulated that the inflammatory response that occurs after cutaneous wounding is a prerequisite for healing and that inflammatory cytokines, such as interleukin-6 (IL-6) are involved in this process. We showed previously that IL-6-deficient mice display delayed wound healing, which could be reversed by administration of a murine IL-6 expression plasmid or recombinant murine IL-6 (rMuIL-6). In the present study, we observed that delayed cutaneous wound healing, which occurs as a result of glucocorticoid-induced immunosuppression, can also be reversed by rMuIL-6, as evidenced by epithelialization, granulation tissue formation, and wound closure. In vehicle control mice, rMuIL-6 did not augment healing but rather delayed the process. Immunochemical studies indicated that the expression of matrix metalloproteinase-10 (MMP-10) was increased in dexamethasone-treated mice and that rMuIL-6 treatment reduced its expression, indicating that IL-6 may influence dermal matrix formation and, specifically, collagen synthesis. These results demonstrate that IL-6 can restore abnormal wound repair that occurs in immunodeficiency and suggest its use as a potential therapy.

Matrix metalloproteinases in neoplasm-induced extracellular matrix remodeling in breast carcinomas

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during normal and pathologic tissue remodeling and neoplastic cell invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been identified to be critical modulators of ECM composition and are thus, crucial in neoplastic cell progression, invasion and metastasis. Expression of MMP-2, -3, -9, -10, and -13 was investigated in human breast carcinomas (BCs) employing an indirect, biotin-streptavidin based, alkaline phosphatase conjugated immunocytochemical technique. Evaluation of the results was based on (a) the percent of neoplastically transformed cells/surrounding stroma that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D (negative)]. The two forms of stromelysin, MMP-3 and -10, share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in BCs, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells (++++), and the staining intensity was also the strongest possible (A). High intensity immunoreactivity (A,B) but focal was detected employing a MoAB targeted against the MMP-9 enzyme. No presence of MMP-2 or -13 could be established in the BC cases observed by us. Based on these results we propose that MMP-3 and -10 are implicated in the pathogenesis of BC, while MMP-9 is possibly involved in neo-angiogenic events also closely associated with growth and expansion of the neoplastically transformed cell mass, as well as metastasis of individual, extremely aggressive, expressing dedifferentiated cellular immunophenotype (IP) cell clones selected during the microevolution of the BC.

Induction of putative tumor-suppressing genes in Rat-1 fibroblasts by oncogenic Raf-1 as evidenced by robot-assisted complex hybridization

The growth factor receptor-dependent protein kinase Raf-1 is activated by GTP-bound Ras, thereby activating the mitogen-activated protein kinase pathway. To study the role of Raf in transformation we transduced Rat-1 cells with a tetracycline-regulatable retroviral vector encoding the constitutively active oncogenic C-terminal fragment of the human Raf-1 protein. Using subtractive hybridization of mRNAs from induced and noninduced cells and robot-assisted screening by complex hybridization, Raf-induced genes with various different characteristics of induction were investigated. Among the strongly induced genes were those involved in carcinogenesis such as metalloproteinases 3, 10 and 13, cathepsin L, ornithine decarboxylase, and putative tumor-suppressing genes such as monocyte chemoattracting protein 1, interferon-induced protein 10, a recently identified 2'-5' oligoadenylate synthetase-like protein, and plasminogen activator inhibitor type 2. Other components of the plasminogen activator system were not induced. Plasminogen activator inhibitor type 2 is a down-regulator of the proteolytic cascade consisting of various metalloproteinases, some of which are induced by a carboxy-terminal Raf mutant (RafCT). In conclusion, RafCT induces factors which act in a conflicting manner in respect of carcinogenesis, especially within the proteolytic system of the extracellular matrix.

Differential patterns of stromelysin-2 (MMP-10) and MT1-MMP (MMP-14) expression in epithelial skin cancers

Co-expression of several members of the matrix metalloproteinase (MMP) family is characteristic of human malignant tumours. To investigate the role of stromelysin-2 (MMP-10) in growth and invasion of skin tumours, we studied cutaneous carcinomas with high metastatic capacity (squamous cell carcinomas, SCCs), only locally destructive tumours (basal cell carcinomas, BCCs) and pre-malignant lesions (Bowen's disease and actinic keratosis) using in situ hybridization. Expression of MMP-10 was compared with that of stromelysin-1 (MMP-3) and of MT1-MMP, the expression of which has been shown to correlate with tumour invasiveness. MMP-10 was expressed in 13/21 SSCs and 11/19 BCCs only in epithelial laminin-5 positive cancer cells, while premalignant lesions were entirely negative. MT1-MMP mRNA was detected in 19/21 SCCs both in epithelial cancer cells and stromal fibroblasts and in 14/18 BCCs only in fibroblasts. The level of MMP-10 was upregulated in a cutaneous SCC cell line (UT-SCC-7) by transforming growth factor-alpha and keratinocyte growth factor, and by interferon-gamma in combination with transforming growth factor-beta1 and tumour necrosis factor-alpha both in UT-SCC-7 and HaCaT cells. Our results show that MMP-10 expression does not correlate with the invasive behaviour of tumours as assessed by their histology and MT1-MMP expression, but may be induced by the wound healing and inflammatory matrix remodelling events associated with skin tumours.

Expression and activity of matrix metalloproteases in human malignant mesothelioma cell lines

The extracellular matrix metalloproteases (MMPs) secreted by various human tumor cells play a crucial role in tumor cell invasion and metastasis, but their expression in malignant mesothelioma (MM) cells has not been examined. In this study, we have investigated the spectrum of MMPs and tissue inhibitors of metalloproteases (TIMPs) produced by 8 MM cell lines. Using RT-PCR, we found that all investigated MM cell lines expressed genes encoding mRNA for MMP-1 (interstitial collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin-1), MMP-9 (gelatinase B) and TIMPs 1, 2 and 3. We also found that 6/8 MM cell lines expressed MMP-7 (matrilysin) and 3/8 MM cell lines expressed MMP-10 (stromelysin-2). MMP-11 (stromelysin-3) was not detected in any of the MM cell lines. Production of MMP-2 and MMP-9 was confirmed using gelatin zymography. In addition, all MM cell lines secreted a 66 kDa metalloprotease, while 3/8 MM cell lines secreted 46, 48, 51 and 63 kDa metalloproteases which specifically degraded the extracellular matrix components fibronectin, vitronectin and laminin. The 66 kDa protease was identified as MMP-3 by Western blot. Our results reveal a broad spectrum of MMPs and TIMPs produced by MM cells and indicate that different substrate specificities of MMPs may play a role in MM cell invasion.

Invasion and metastasis: the expression and significance of matrix metalloproteinases in carcinomas of the lung

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during tissue remodeling and tumor invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been shown to be critical modulators of ECM composition and are thus, crucial in neoplastic cell invasion and metastasis. Expression of MMP-2, -3, -9, -10, and -13 was investigated in human lung adenocarcinomas employing an indirect alkaline phosphatase conjugated immunocytochemical technique. Evaluation of the results was based on (a) the percent of neoplastically transformed cells/surrounding stroma that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D]. The two forms of stromelysin, MMP-3 and -10, share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in lung adenocarcinomas, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells (++++), and the staining intensity was also the strongest possible (A,B). Focal (+), high intensity (A,B) staining could be detected for MMP-2, -9, and -13. Thus, it seems that the stromelysins are involved in the generalized growth and expansion of the neoplastic cell mass, while MMP-2, -9 and -13 are involved in the neoangiogenic and focal clonal selection and expansion phenomena associated with in situ tumor progression, invasion of the microvasculature, and metastasis.

Immunocytochemical detection of matrix metalloproteinase expression in prostate cancer

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during tissue remodeling and tumor invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been shown to be critical modulators of ECM composition and are, thus, crucial in neoplastic cell invasion and metastasis. Expression of MMP-2, -3, -9, -10, and -13 was investigated in human prostatic carcinomas employing an indirect alkaline phosphatase conjugated immunocytochemical technique. Evaluation of the results was based on (a) the percent of neoplastically transformed cells/surrounding stroma that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D]. The two forms of stromelysin, MMP-3 and -10, share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in lung adenocarcinomas, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells (++++), and the staining intensity was also the strongest possible (A,B). Focal (+), low to high intensity (C to A) staining could be detected for MMP-2, while no immunoreactivity was observed employing MoABs directed against MMP-9 and -13. Thus, it seems that the stromelysins are involved in the generalized growth and expansion of the neoplastic cell mass, while MMP-2 is involved in the neoangiogenic and focal clonal selection and expansion phenomena associated with in situ tumor progression, invasion of the microvasculature, and metastasis.

Matrix metalloproteinase expression in malignant melanomas: tumor-extracellular matrix interactions in invasion and metastasis

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during tissue remodeling and tumor invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been shown to be critical modulators of ECM composition and are, thus, crucial in neoplastic cell invasion and metastasis. Expression of MMP-2, -3, -9, -10, and -13 was investigated in human malignant melanomas (MMs) employing an indirect alkaline phosphatase conjugated immunocytochemical technique. Evaluation of the results was based on (a) the percent of neoplastically transformed cells/surrounding stroma that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D]. The two forms of stromelysin, MMP-3 and -10, share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in MMs, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells (++++), and the staining intensity was also the strongest possible (A,B). Focal (+), high intensity (A,B) staining could be detected for MMP-2, -9, and -13. Thus, it seems that the stromelysins are involved in the generalized growth and expansion of the neoplastic cell mass, while MMP-2, -9 and -13 are involved in the neoangiogenic and focal clonal selection and expansion phenomena associated with in situ tumor progression, invasion of the microvasculature, and metastasis.

Immunocytochemical detection of the expression of members of the matrix metalloproteinase family in adenocarcinomas of the pancreas

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during tissue remodeling and tumor invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been shown to be critical modulators of ECM composition and are, thus, crucial in neoplastic cell invasion and metastasis. Expression of MMP-2, -3, -9, -10, and -13 was investigated in human pancreatic adenocarcinomas employing an indirect alkaline phosphatase conjugated immunocytochemical technique. Evaluation of the results was based on (a) the percent of neoplastically transformed cells/surrounding stroma that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D]. The two forms of stromelysin, MMP-3 and -10, share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in lung adenocarcinomas, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells (++++), and the staining intensity was also the strongest possible (A,B). Focal (+), high intensity (A,B) staining could be detected for MMP-2 and -13, while no immunoreactivity was observed employing the anti-MMP-9 MoAB. Thus, it seems that the stromelysins are involved in the generalized growth and expansion of the neoplastic cell mass, while MMP-2 and -13 are involved in the neoangiogenic and focal clonal selection and expansion phenomena associated with in situ tumor progression, invasion of the microvasculature, and metastasis.

MMP and TIMP gene expression in head and neck squamous cell carcinomas and adjacent tissues

OBJECTIVE

To compare the frequency of gene expression of matrix metalloproteinases (MMP) stromelysins -1, -2 and -3 (MMP-3, -10, and -11), matrilysin (MMP-7), MTI-MMP (MMP-14), and of TIMPs (Tissue Inhibitors of MMPs) -1, -2, -3 and -4 in head and neck squamous cell carcinomas with those of matched adjacent normal tissues.

MATERIALS AND METHODS

The present study included 20 surgically removed head and neck squamous cell carcinomas, seven of which were accompanied by matched adjacent oral mucosa excised from the border of the specimens outside the tumor area. RNA isolated from tumors and control samples was subjected to RT-PCR using primers specific for MMP-3, -7, -10, -11 and -14 and for TIMPs -1, -2, -3, and -4.

RESULTS

Our findings demonstrate that each of the five MMP genes studied were expressed in essentially all the tumors, while the adjacent marginal tissue samples showed a more varied picture: while stromelysin-3 was located to a majority of the marginal samples, matrilysin was expressed in four of seven adjacent samples, stromelysin-1 and MTI-MMP genes were each expressed in three of these samples, and stromelysin-2 transcript was only expressed in two marginal tissue samples. Whereas TIMP-1 and TIMP-2 transcripts were identified in all tumor and adjacent tissue samples studied, TIMP-3 was expressed, albeit often at low levels, in 17 of 20 tumor samples but only in three of seven adjacent tissues. The novel TIMP-4 gene was not expressed at all.

CONCLUSIONS

Specific MMP (MMP-3, -7, -10, -14) and TIMP-3 transcripts observed in head and neck squamous cell carcinomas compared to their frequency in specimens of matching tissues provide important information about expression of extracellular matrix degrading enzymes and their tissue inhibitors in head and neck carcinomas.

Stromelysin-2 is upregulated during normal wound repair and is induced by cytokines

Stromelysin-2 is a matrix metalloproteinase that degrades in vitro several protein components relevant to wound repair such as collagens III and IV, gelatin, nidogen, laminin-1, proteoglycans, and elastin. Furthermore, it can activate other matrix metalloproteinases, such as collagenase-1 (matrix metalloproteinase-1) and collagenase-2 (matrix metalloproteinase-8), as well as 92 kDa gelatinase. The aim of this study was to determine in a large variety of wounds (normally healing dermal and mucosal wounds, suction blisters, ex vivo cultures, diabetic, decubitus, rheumatic, and venous ulcers) and keratinocyte cultures, which factors contribute to stromelysin-2 expression and how it is induced in relation to other matrix metalloproteinases. Our results show that stromelysin-2 mRNA and protein are upregulated later (at 3 d) than matrix metalloproteinase-1 in normally healing wounds and ex vivo explants, in which stromelysin-2 is invariably expressed by keratinocytes migrating over dermal matrix. The number of keratinocytes expressing stromelysin-2 was greatest in chronic inflamed diabetic and venous ulcers compared with rheumatoid and decubitus ulcers, six of which had no signal. In keratinocyte cultures, tumor necrosis factor-alpha, epidermal growth factor, and transforming growth factor-beta1 induced stromelysin-2 expression as measured by quantitative reverse transcriptase-polymerase chain reaction, whereas different matrices did not upregulate the mRNA. Immunostaining demonstrated stromal transforming growth factor-beta1 in contact with the stromelysin-2-positive keratinocytes. Our results suggest that stromelysin-2 expression is important for the normal repair process and is upregulated by cytokines rather than cell-matrix interactions. Stromelysin-2 is most likely to participate in the remodeling of the newly formed basement membrane, and is not overexpressed in retarded wound healing.

Immunocytochemical detection of MMP-3 and -10 expression in hepatocellular carcinomas

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during tissue remodeling and tumor invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been shown to be critical modulators of ECM composition and are thus crucial in neoplastic cell invasion and metastasis. Expression of MMP-2, -3, -9, -10, and -13 was investigated in human hepatocellular carcinomas (HCCs) employing an indirect alkaline phosphatase conjugated immunocytochemical technique. Evaluation of the results was based on (a) the persent of neoplastically transformed cells/surrounding stroma that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D]. The two forms of stromelysin, MMP-3 and -10, share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in HCCs, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells (++++), and the staining intensity was also the strongest possible (A,B). No immunoreactivity was detected using antibodies directed against MMP-2, -9, and -13.

Matrix metalloproteinase expression in childhood astrocytomas

Structural changes in the extracellular matrix (ECM) are necessary for cell migration during tissue remodeling and local neoplastic cell invasion. The matrix metalloproteinases (MMPs) and their inhibitors have been shown to be critical modulators of ECM composition and are thus, crucial in tumor cell invasion and metastasis. The immunocytochemical profile of MMP-2, -3, -9, -10, and -13 expression was observed in 24 primary human childhood astrocytomas (ASTRs) employing an indirect alkaline phosphatase conjugated antigen detection technique. Evaluation of the results was based on (a) the percent of neoplastically transformed cells that reacted positively and (b) a measure of staining intensity [graded from A (highest) to D (negative)]. The two forms of stromelysin, MMP-3 and -10, share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. Strong overall expression of MMP-3 and -10 was found in ASTRs, especially in the ECM adjacent to blood vessels. Positive immunoreactivity could be seen for these two MMPs in the ECM surrounding over 90% of the neoplastically transformed cells (+4) and the staining intensity was also the strongest possible (A,B). No immunoreactivity was detected using antibodies directed against MMP-2, -9, and -13. Based on these results, MMP-3 and -10 are implicated in the pathogenesis of pediatric ASTRs. Further characterization of the expression and utilization of MMPs and their inhibitors in the progression of ASTRs may establish differential regulation and utilization of the various MMPs during the progression of glial tumors, from low-grade pilocytic ASTR to high-grade glioblastoma multiforme.

Expression of matrix metalloproteinases and their inhibitors during hepatic tissue repair in the rat

Matrix metalloproteinases (MMPs) and their specific inhibitors (TIMPs) are thought to play an essential role in liver injury associated with tissue remodeling. However, their distinct expression profile in different liver repair models still remains to be established. Hepatic expression of collagenase (MMP-13), gelatinases A and B (MMP-2, -9), stromelysin-1 and -2 (MMP-3, -10), membrane-type MMP-1 (MMP-14), and TIMP-1 and -2 was studied following single and repeated CCl4-mediated injury and after partial hepatectomy. Expression was analyzed by reverse transcription-PCR (RT-PCR), northern blot analysis, zymography, and immunohistochemistry. Following a single toxic liver injury, MMPs and TIMPs were induced in a distinct time frame in that expression of most MMPs was induced during the early phase of liver injury, was maximal during the inflammatory reaction, and was diminished in the recovery phase. In contrast, TIMP and MMP-2 steady state mRNA levels remained constant in the early phase, were strongly induced during tissue inflammation, and remained increased until the recovery phase. Interestingly, hepatic TNF-alpha expression paralleled the MMP induction profile, while the increase of TGF-beta1 expression mapped to the increase of TIMPs. Chronic liver injury was accompanied by an increase in the steady state mRNA levels of MMP-2 and TIMPs, while other MMPs remained more or less unchanged or were diminished. Partial hepatectomy was followed by a dramatic increase of MMP-14 and to a lesser extent also of TIMP-1 expression; other MMPs and TIMPs were not significantly induced. Liver injury is accompanied by profound changes in hepatic MMP/TIMP expression, the latter being critically dependent on the type of injury. Single toxic injury resulting in complete restoration was characterized by a sequential induction of MMPs and TIMPs suggesting initial matrix breakdown and matrix restoration thereafter. Chronic liver injury leading to fibrosis displays overall diminished matrix degradation mainly through TIMP induction, while liver regeneration induced by partial hepatectomy caused an induction of MMP-14 and TIMP-1 only, which might be unrelated to matrix turnover but connected to pericellular fibrinolysis or fibrolysis required for hepatocellular replication.

Stromelysins in placental membranes and amniotic fluid with premature rupture of membranes

OBJECTIVE

To determine the expression and site of production of stromelysins in fetal membranes and to measure stromelysin 1 levels in amniotic fluid and amniochorion culture media.

METHODS

Amniochorionic membranes were cultured from organ explant. Membranes were stimulated with lipopolysaccharide for 24 hours after a 48-hour preincubation period. Membranes were also collected from women after vaginal deliveries. RNA samples from those tissues were subjected to reverse transcriptase-polymerase chain reaction using primers specific for stromelysin 1, stromelysin 2, stromelysin 3, and matrilysin. In situ hybridization and immunohistochemistry were used to localize stromelysin mRNA and peptide. Levels of stromelysin 1 in culture media and amniotic fluid collected from women with preterm premature rupture of membranes (PROM) and at term with intact membranes were compared using enzyme-linked immunosorbant assay.

RESULTS

Amniochorion in culture and from laboring and nonlaboring women expressed all three stromelysins. In situ hybridization showed stromelysin mRNA in amnion, chorion, and extracellular matrix. Immunohistochemical analysis localized stromelysin 1 protein to those same regions. Amniotic fluid levels of stromelysin 1 were higher in preterm PROM amniotic fluids (median 3.2 ng/mL) compared with term deliveries with intact membranes (median 1.3 ng/mL) (P = .02). Lipopolysaccharide stimulation in culture increased the release of stromelysin 1 from fetal membranes compared with control (median 70.35 versus 15.8 ng/mL, respectively, P = .05).

CONCLUSION

Human fetal membranes are a source of stromelysins 1, 2, and 3. Increased stromelysin 1 during preterm PROM and in vitro after lipopolysaccharide stimulation suggests a possible effect of that matrix metalloproteinase in PROM.

Purification of active matrix metalloproteinase catalytic domains and its use for screening of specific stromelysin-3 inhibitors

The matrix metalloproteinase (MMP) stromelysin-3 (ST3) has been shown to be involved in malignant tumor progression and therefore represents an attractive therapeutical target. In order to screen for ST3 synthetic inhibitors, we have produced and purified the catalytic domain of ST3, matrilysin, stromelysin-2, and membrane type-1 MMP from inclusion bodies in a bacterial system. Our strategy allowed the purification of MMPs directly in the active form, thereby avoiding in vitro activation. A total of 140,000 synthetic compounds from the Bristol-Myers Pharmaceutical Research Institute chemical deck were tested, using a substrate-based colorimetric enzymatic assay, in which ST3 activity was evaluated through its ability to cleave and inactivate alpha-1 proteinase inhibitor. One ST3 inhibitor belonging to the cephalosporin family of antibiotics was thereby identified.

Stromelysin-1 (MMP-3) and stromelysin-2 (MMP-10) expression in developing human bone: potential roles in skeletal development

Stromelysin, a member of the matrix metalloproteinase family, demonstrates wide substrate specificity with the ability to degrade proteoglycan, fibronectin, laminin, casein, and the nonhelical region of collagen. The two forms of stromelysin (SL), types 1 (MMP-3) and 2 (MMP-10), share 82% sequence homology, but exhibit differences in cellular synthesis and inducibility by cytokines and growth factors in vitro. However, the distribution of the two isoforms in bone has not been reported. We investigated the presence of SL-1 and SL-2 in human osteophytic and neonatal rib bone using immunohistochemistry and, combined with a new method of in situ zymography, determined the activity of the immunolocalized stromelysins. Latent SL-1 was strongly expressed in the extracellular matrix in fibrous tissue surrounding areas of endochondral ossification in osteophytes, and adjacent to the periosteum of fetal rib bone. Active SL-1 expression was detected in osteocytes and the matrix surrounding osteocytic lacunae. SL-2 showed intense cell-associated staining at sites of resorption in areas of endochondral ossification and in resorptive cells at the chondro-osseous junction, which correlated with enzyme activity detected by zymography. Within the rib, active SL-2 expression was localized in chondrocytes of the growth plate, whereas only occasional SL-1 signal was evident. Vascular areas showed strong SL-2 staining with some proteolytic activity. SL-2, but not SL-1, was strongly expressed in osteoclasts and most mononuclear cells within the marrow. At sites of bone formation both isoforms were expressed by osteoblasts with SL-1 also present in osteoid. These results demonstrate, for the first time, the differential expression of SL-1 and SL-2 in developing human bone, indicating specific roles for the two isoforms. In situ zymography demonstrates that SL-2 is produced in an active form with associated degradation, whereas SL-1, in a matrix-bound proenzyme form, may act as a reservoir for later activation.

Differential expression of matrix metalloproteinases and their physiological inhibitors in acute murine skin wounds

Metalloproteinase-mediated proteolysis plays an important role during all stages of wound repair. In acute murine wounds, murine collagenase, matrix metalloproteinase (MMP)-9, stromelysin-1, stromelysin-2 and tissue inhibitor of metalloproteinase (TIMP)-1 are strongly induced within 24 h after wounding. At the time of reepithelialization the expression of these gene transcripts has declined more or less completely. Each gene shows a unique spatial and temporal transcription pattern.

Role of the matrix metalloproteinase and tissue inhibitors of metalloproteinase families in noninvasive and invasive tumors transplanted in mice with severe combined immunodeficiency

OBJECTIVES

To elucidate the role of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human urothelial cancers, we studied gene expressions of MMPs, TIMPs, and membrane-type 1 matrix metalloproteinase (MT1-MMP) in noninvasive or invasive tumor lines transplanted in mice with severe combined immunodeficiency (SCID).

METHODS

The UCT-1 tumor line, derived from bladder cancer, is a noninvasive transplantable tumor with no evidence of metastasis. The UCT-2 tumor line, derived from a renal pelvic tumor, extensively invades without metastasis. We examined gene expressions of MMPs-1, 2, 3, 7, 8, 9, 10, and 11, TIMPs-1, 2, and 3, and MT1-MMP in UCT-1 and 2 by semiquantitative polymerase chain reaction analysis.

RESULTS

Significantly higher gene expression of MMP-2 was detected in the invasive UCT-2 tumor line than in the noninvasive UCT-1 tumor line. Although both tumor lines expressed TIMP-1 and MT1-MMP, stronger gene expression of MT1-MMP was observed in the UCT-2 tumor line than in the UCT-1 tumor line. The other MMPs or TIMPs were not detected in either of the lines.

CONCLUSIONS

MMP-2 and MT1-MMP may have an important role in the invasion mechanism of urothelial cancers.

[Matrix metalloproteinases and their biological functions]

Matrix metalloproteases (MMPs) play a key role in the metabolism of connective tissue proteins in the norm and in pathology. Major MMP subfamilies (collagenases, gelatinases, and stromelysins) and matrixins, which have not been attributed to any subfamily, are reviewed. The main characteristics of these enzymes; their structural properties; their specificity; the regulation of their activity; and their role in the normal development of the matrix, the oncogenic transformation of the cell, and angiogenesis are discussed.

Distinct expression profiles of stromelysin-2 (MMP-10), collagenase-3 (MMP-13), macrophage metalloelastase (MMP-12), and tissue inhibitor of metalloproteinases-3 (TIMP-3) in intestinal ulcerations

Programmed expression of matrix metalloproteinases is involved in wound healing in various organs. We have previously demonstrated enhanced expression of collagenase-1, stromelysin-1, matrilysin, and tissue inhibitor of metalloproteinases (TIMP-1) in gastrointestinal ulcerations. To further define the role of matrix-degrading enzymes and their inhibitors in intestinal inflammation and ulcerations, the expression of stromelysin-2 (MMP-10), collagenase-3 (MMP-13), macrophage metalloelastase (HME, MMP-12), and TIMP-3 mRNAs was studied using in situ hybridization and immunohistochemistry in 38 samples representing ulcerative colitis, Crohn's disease, ischemic colitis, and normal intestine. As controls for normally healing intestinal wounds, 12 postoperative samples of rat experimental jejunal anastomoses were also examined. The colitis types studied did not essentially differ in their MMP expression. We found stromelysin-2 mRNA in laminin-5-positive and Ki-67-negative enterocytes bordering the ulcerations. HME was abundantly expressed by macrophages in the vicinity of shedding mucosal epithelium and beneath the necrotic surface of the ulcers. Collagenase-3 and TIMP-3 were expressed by fibroblast-like cells deeper in the remodeling intestinal wall. Expression for stromelysin-2 and collagenase-3 was observed in granulation tissue, but not the epithelium, of the rat anastomoses. Our results suggest a role for stromelysin-2 in epithelial migration and for metalloelastase in macrophage movement and epithelial cell shedding.

Activation of the precursor of human stromelysin 2 and its interactions with other matrix metalloproteinases

Matrix metalloproteinases (MMP) are synthesized as inactive zymogens (proMMP) and subsequently activated by many factors to degrade the extracellular matrix (ECM). In the present study, we have examined the intermolecular activation mechanisms of proMMP by MMP-10 (stromelysin 2). ProMMP-10 was purified from the culture media of OSC-20 human oral squamous carcinoma cells stimulated with 12-O-tetradecanoylphorbol 13-acetate. The final products are partially activated (approximately 38% of the full activity) during the purification steps and contain proMMP-10 of Mr 56,000 with minor protein bands of Mr 47,000, 24,000 and 22,000. The zymogen is activated by 4-aminophenylmercuric acetate and processed to the active forms of Mr 47,000 and 24,000. The NH2-terminal sequence of the 47,000- and 24,000-Mr species is Phe82-Ser-Ser-Phe-Pro-Gly, which is identical to that of stromelysin 2. ProMMP-9 (progelatinase B) is activated by MMP-10 to its full activity and processed to the low-Mr species of Mr 81,000, 65,000, 57,000 and 55,000, the former two of which show proteolytic activity on a gelatin zymography. The NH2-terminal sequence analysis indicates that the 81,000-, 65,000- and 57,000-M, species have the identical sequence of Phe88-Gln-Thr-Phe-Glu-Gly, suggesting the cleavage of the Arg87-Phe88 peptide bond for activation and both NH2-terminal and COOH-terminal truncation in the 65,000- and 57,000-Mr forms. MMP-10 also activates proMMP-7 (promatrilysin) up to about 60% of the full activity and generates the same active species of Mr 19,000 as that obtained by activation with 4-aminophenylmercuric acetate. Incubation of proMMP-2 (progelatinase A) or proMMP-3 with MMP-10 does not result in activation of these proMMP. These results indicate that in addition to the previously reported activation of proMMP-1 (tissue procollagenase) and proMMP-8 (neutrophil procollagenase), MMP-10 can also activate proMMP-9 and proMMP-7, and suggest the possibility that MMP-10 may replace a role of MMP-3 in the ECM degradation in concert with other MMP under various pathological conditions.

Overview of matrix metalloproteinase expression in cultured human cells

The matrix metalloproteinases (MMP) have been implicated in tumor invasion and metastasis both by immunohistochemical studies and from the observation that specific metalloproteinase inhibitors block tumor invasion and metastasis. Oligonucleotide primers for thirteen MMPs (MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-10, MMP-11, MMP-12, MMP-13, MMP-14, MMP-15, MMP-16) were optimized for use in RT-PCR. A semi-quantitative RT-PCR assay was used to determine the pattern of MMP mRNA expression in 84 normal and transformed or carcinogen transformed human cell lines and strains derived from different tissues. The results demonstrate one or more cell lines which express thirteen members of the MMP family. In addition, various oncogene transfected human fibroblast cell strains were analyzed for MMP expression. We confirm that over-expression of the H-ras oncoprotein correlates with up-regulation of MMP-9 and demonstrate that over-expression of v-sis also up-regulates MMP-9. A cell line immortalized following myc expression was found to up-regulate MMP-7, MMP-11 and MMP-13. Inappropriate expression of several MMP mRNAs was detected in breast, prostate, bone, colon and oral tumor derived cell lines. Identification of at least one cell line expressing each of thirteen MMPs and the observation of oncogene induced expression of several MMPs should facilitate analysis of the transcriptional mechanisms controlling each MMP.

cDNA cloning and expression of the gene encoding murine stromelysin-2 (MMP-10)

Recently, we demonstrated a biphasic induction of the epithelial broad-spectrum matrix metalloproteinase (MMP) stromelysin-2 during cutaneous wound healing. Now we have generated a murine wound cDNA libary and have used it to isolate the putative cDNA of this murine matrix metalloproteinase. The predicted sequence of the protein shows 76 and 89% identity with its human and rat analogues, respectively. Stromelysin-2 and stromelysin-1 transcripts were both detected at very low levels in the lung and the heart of adult Balb/c mice, whereas stromelysin-2 mRNA expression alone was found at comparatively high levels in the small intestine, a tissue characterized by continuous epithelial renewal. Recombinant forms of murine stromelysin-1 and -2 produced in transfected COS cells were secreted and could be induced to undergo autocatalytic processing by addition of the organomercurial salt 4-aminophenylmercuric acetate (APMA).

Regulation of the expression of stromelysin-2 by growth factors in keratinocytes: implications for normal and impaired wound healing

Keratinocyte growth factor (KGF) has been implicated in wound re-epithelialization and branching morphogenesis of several organs. To determine whether KGF induces these effects via induction of matrix metalloproteinase expression we have analysed the effect of KGF on the expression of stromelysin-2 in cultured HaCaT keratinocytes. Here we show a strong induction of stromelysin-2 mRNA within 5-8 h of stimulation of these cells with KGF. The degree of induction was similar to that achieved by treatment with epidermal growth factor or tumour necrosis factor alpha, whereas the stimulatory effect of transforming growth factor beta 1 was even stronger. To determine whether the induction of stromelysin-2 expression by growth factors and cytokines might be important for wound healing, we analysed the expression of this gene during the healing process of full-thickness excisional wounds in mice. Whereas stromelysin-2 mRNA could hardly be detected in unwounded skin, a biphasic induction was seen after injury and highest levels were found at days 1 and 5 after wounding. Hybridization in situ revealed the presence of stromelysin-2 mRNA in basal keratinocytes at the wound edge but not in the underlying mesenchymal tissue. During impaired wound healing as seen in glucocorticoid-treated mice, stromelysin-2 expression was significantly increased compared with untreated control mice. Taken together, these results suggest that correct regulation of this broad-spectrum metalloproteinase might be important for normal repair.

Non-human primate models; artificial menstrual cycles, endometrial matrix metalloproteinases and s.c. endometrial grafts

Rhesus monkeys are useful models in which to examine the hormonal regulation of endometrial matrix metalloproteinases (MMP) and to evaluate the role of MMP in uterine bleeding. Artificial 28 day menstrual cycles can be induced in ovariectomized monkeys by inserting an oestradiol implant for 2 weeks, then inserting a progesterone implant for 2 weeks, and then, with the oestradiol implant remaining in place, removing and reinserting the progesterone implant at 2 week intervals. To examine MMP during menses, we established such cycles and removed uteri by hysterectomy at closely spaced intervals before, during and after menses, as well as at later time points. Some samples were also obtained during menses induced by the withdrawal of both progesterone and oestradiol. We examined mRNA of the following MMP by Northern blotting: matrilysin, stromelysin-1, stromelysin-2, stromelysin-3 and the tissue inhibitor of MMP TIMP-1. The expression of these MMP mRNA increased substantially by 2-3 days after progesterone withdrawal, whether or not oestradiol was maintained. The expression of some of the MMP (stromelysins-1 and -2) returned very rapidly to baseline levels by 5 days after progesterone withdrawal, while the expression of others (matrilysin, stromelysin-3 and TIMP-1) declined more slowly, reaching a baseline level by 10 days after progesterone withdrawal, with little or no further decline after progesterone concentrations rose during the induced luteal phase. Immunocytochemical studies showed that matrilysin was expressed primarily in the glands of the upper functionalis. In other work with the rhesus monkey model, we used a s.c. endometrial autograft technique in which pieces of endometrium were autotransplanted to the abdominal skin. During menses in the grafts, matrilysin was expressed in the glands of the grafts similar to the glands in the eutopic endometrium. Endometrial autografts can serve as a useful model for the study of MMP in uterine bleeding.

Activation of human neutrophil procollagenase by stromelysin 2

Neutrophil procollagenase (MMP-8) was efficiently activated by incubation with active stromelysin 2 (MMP-10). A single-step activation mechanism involving the cleavage of the Gly78-Phe79 peptide bond at the end of the propeptide domain was observed. Determination of the collagenolytic activity revealed the generation of active neutrophil collagenase displaying high specific activity. When compared with the specific activity following mercurial activation, which generates active collagenase by autoproteolytic cleavage of either Phe79-Met8O or Met8O-Leu81 peptide bonds [Bläser, J., Knäuper, V., Osthues, A., Reinke, H. & Tschesche, H. (1991) Eur J. Biochem. 202, 1223-1230], the specific activity of the stromelysin-2-activated enzyme was considerably higher. Thus, human neutrophil procollagenase was 'superactivated' by stromelysin 2, as was recently shown for the stromelysin-1-activated enzyme [Knäuper, V., Wilhelm, S. M., Seperack, P. K., De Clerck, Y. A., Langley, K. E., Osthues, A. & Tschesche, H. 1993 a) Biochem. J. 295, 581-586].

Expression of interstitial collagenase during skeletal development of the mouse is restricted to osteoblast-like cells and hypertrophic chondrocytes

We determined the expression pattern of the matrix metalloproteinase interstitial collagenase (MMP-1) during mouse embryo development using in situ hybridization and immunohistochemistry. Localized MMP-1 mRNA was first detected at 14.5 days postconceptus. The spatial and temporal expression was restricted to areas of endochondral and intramembranous bone formation, such as in the mandibula, maxilla, clavicle, scapula, in the vertebrae, and in the dorsal, but not the ventral part of the ribs. The highest levels of MMP-1 transcripts and MMP-1 protein were found in the metaphyses and diaphyses of the long bones. MMP-1 was expressed by hypertrophic chondrocytes and by osteoblastic cells localized along the newly formed bone trabeculae. No expression was detected in osteoclasts. Two other related members of the MMP family, stromelysin-1 (MMP-3) and stromelysin-2 (MMP-10), were not expressed during days 7.5 and 16.5 of mouse embryogenesis. The tissue-specific expression of MMP-1 and the exclusive ability of interstitial collagenase to digest native collagen of types I, II, III, and X, the major components of bone, cartilage, and tendon, strongly suggests an important and specific function of this enzyme in bone development and remodeling.

The human collagenase-3 (CLG3) gene is located on chromosome 11q22.3 clustered to other members of the matrix metalloproteinase gene family

The gene coding for human collagenase-3 (CLG3), a recently described matrix metalloproteinase produced by breast carcinomas, has been localized by fluorescence in situ hybridization on chromosome 11q22.3. Physical mapping of an isolated YAC clone containing CLG3 has revealed that this gene is tightly linked to those encoding other matrix metalloproteinases, including fibroblast collagenase (CLG1), stromelysin-1 (STMY1), and stromelysin-2 (STMY2). Further mapping of this region using pulsed-field gel electrophoresis has shown that the CLG3 gene is localized to the telomeric side of the matrix metalloproteinase cluster, the relative order of the loci being centromere-STMY2-CLG1-STMY1-CLG3-telomere.

Thyroid hormone regulates stromelysin expression, protease secretion and the morphogenetic potential of normal polarized mammary epithelial cells

Stromelysins are a group of proteases which degrade the extracellular matrix and activate other secreted proteases. Stromelysin (ST)-1 and ST-2 genes are induced by tumor promoters, oncogenes and growth factors, and have been involved in acquisition of the malignant phenotype. We show here that the thyroid hormone (T3) increases ST-1 and ST-2 expression in a non-transformed mouse mammary epithelial cell line (EpH4) in a way that is dependent on the level of thyroid receptor/c-erbA (TR alpha-1) expression. In agreement with this, T3 increases the secreted stromelysin activity and enhances the gelatinolytic activity of type IV collagenase. We have also demonstrated that T3 affects the epithelial polarity of EpH4 cells, diminishing the transepithelial electrical resistance of monolayers cultured on permeable filters, causing an abnormal distribution of polarization markers and the disruption of the organized 3-D structures formed by these cells in type I collagen gels. These results indicate that the ligand-activated TR alpha-1 plays an important role in regulating the morphogenetic and invasive capacities of mammary epithelial cells. Because the c-erbA locus is altered in several types of carcinoma, an altered or deregulated TR alpha-1 expression may also be important for breast cancer development and metastasis.

Immunolocalisation studies on six matrix metalloproteinases and their inhibitors, TIMP-1 and TIMP-2, in synovia from patients with osteo- and rheumatoid arthritis

OBJECTIVE

To assess the likely importance of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in the arthritic process.

METHODS

Synovial samples from seven joints with rheumatoid arthritis and three osteoarthritic joints were analysed by indirect immunofluorescence microscopy. Using specific human antisera, we documented the frequencies and distributions of collagenase, stromelysins 1 and 2, matrilysin, gelatinases A and B, TIMP-1, and TIMP-2.

RESULTS

Stromelysin 1 was found in all synovia, bound to extracellular matrix, within cells, or both, indicating stromelysin synthesis. Matrilysin was present in only one active inflammatory synovium, and focal synthesis of collagenase and gelatinase A was seen in four synovia. Stromelysin 2 and TIMP-2 were not observed, but TIMP-1 synthesis was seen in five synovia, and in two active synovia the distribution of TIMP-1 positive cells was more widespread than that of MMPs.

CONCLUSIONS

The presence of stromelysin 1 in all synovia clearly implicates this enzyme in joint damage. Collagenase, gelatinase A and matrilysin may also have a role in rheumatoid arthritis, but are not significant in osteoarthritis. However, marked regional variations were found in the synthesis of these MMPs, indicating not only that these diseases are episodic but that control of enzyme synthesis is focal. Only TIMP-1 may be considered an inhibitory factor.

Patterns of matrix metalloproteinase expression in cycling endometrium imply differential functions and regulation by steroid hormones

Matrix metalloproteinases are a highly regulated family of enzymes, that together can degrade most components of the extracellular matrix. These proteins are active in normal and pathological processes involving tissue remodeling; however, their sites of synthesis and specific roles are poorly understood. Using in situ hybridization, we determined cellular distributions of matrix metalloproteinases and tissue inhibitor of metalloproteinase-1, an inhibitor of matrix metalloproteinases, in endometrium during the reproductive cycle. The mRNAs for all the metalloproteinases were detected in menstrual endometrium, but with different tissue distributions. The mRNA for matrilysin was localized to epithelium, while the others were detected in stromal cells. Only the transcripts for the 72-kD gelatinase and tissue inhibitor of metalloproteinases-1 were detected throughout the cycle. Transcripts for stromelysin-2 and the 92-kD gelatinase were only detected in late secretory and menstrual endometrium, while those for matrilysin, the 72-kD gelatinase, and stromelysin-3 were also consistently detected in proliferative endometrium. These data indicate that matrix metalloproteinases are expressed in cell-type, tissue, and reproductive cycle-specific patterns, consistent with regulation by steroid hormones, and with specific roles in the complex tissue growth and remodeling processes occurring in the endometrium during the reproductive cycle.

Distinct populations of basal keratinocytes express stromelysin-1 and stromelysin-2 in chronic wounds

Wound repair involves cell migration and tissue remodeling, and these ordered and regulated processes are facilitated by matrix-degrading proteases. We reported that interstitial collagenase is invariantly expressed by basal keratinocytes at the migrating front of healing epidermis (Saarialho-Kere, U. K., E. S. Chang, H. G. Welgus, and W. C. Parks, 1992. J. Clin. Invest. 90:1952-1957). Because of the limited substrate specificity of collagenase, principally for interstitial fibrillar collagens, other enzymes must also be produced in the wound environment to effectively restructure tissues with a complex matrix composition. Stromelysins-1 and -2 are closely related, yet distinct metalloproteinases, and both can degrade many noncollagenous connective tissue macromolecules. Using in situ hybridization and immunohistochemistry, we found that both stromelysins are produced by distinct populations of keratinocytes in a variety of chronic ulcers. Stromelysin-1 mRNA and protein were detected in basal keratinocytes adjacent to but distal from the wound edge in what probably represents the sites of proliferating epidermis. In contrast, stromelysin-2 mRNA was seen only in basal keratinocytes at the migrating front, in the same epidermal cell population that expresses collagenase. Stromelysin-1-producing keratinocytes resided on the basement membrane, whereas stromelysin-2-producing keratinocytes were in contact with the dermal matrix. Furthermore, stromelysin-1 expression was prominent in dermal fibroblasts, whereas no signal for stromelysin-2 was seen in any dermal cell. These findings demonstrate that stromelysins-1 and -2 are produced by different populations of basal keratinocytes in response to wounding and suggest that these two matrix metalloproteinases serve distinct roles in tissue repair.

Human T lymphocytes express a member of the Matrix Metalloproteinase gene family

OBJECTIVE

T lymphocytes are known to interact with cellular and structural components of the extracellular matrix. We investigated whether T lymphocytes could also contribute to matrix breakdown by expression of a matrix metalloproteinase (MMP) gene.

METHODS

Complementary DNA (cDNA) was synthesized from messenger RNA extracted from cultured peripheral blood T lymphocytes after exposure to phorbol myristate acetate and calcium ionophore A23187 and amplified by the polymerase chain reaction with primers derived from two conserved domains in MMP genes.

RESULTS

An amplification product of 402 basepairs was generated and cloned; sequence analysis revealed identity to human stromelysin-2 cDNA. Using the amplified stromelysin-2 cDNA as a probe for Northern analyses, we detected a 1.8-kilobase transcript in stimulated T lymphocytes.

CONCLUSION

T lymphocytes are a potential source of stromelysin-2 transcripts and may have a role in the degradation of extracellular matrix constituents.

Phenotypic alterations in fos-transgenic mice correlate with changes in Fos/Jun-dependent collagenase type I expression. Regulation of mouse metalloproteinases by carcinogens, tumor promoters, cAMP, and Fos oncoprotein

Using specific cDNAs isolated from mouse fibroblasts we determined tissue-specific expression of different matrix metalloproteinase genes: both stromelysin-1 and collagenase IV are highly expressed in heart and lung, whereas collagenase I is expressed most abundantly in skeletal muscle, kidney, and bone. High basal level expression of stromelysin-2 is found in heart and kidney. Like in man and rat, the expressions of collagenase I, stromelysin-1, and stromelysin-2 are regulated by the tumor promoter 12-O-tetradecanoyl-phorbol 13-acetate and by UV irradiation, but not by cAMP. In contrast, the expression of the 72-kDa collagenase IV is not affected by either stimuli. We and others have shown previously that under cell culture conditions, the regulation of human collagenase I is regulated by the transcription factor Fos/Jun (AP-1). Here we show that in c-fos transgenic mice transcription of collagenase I is induced in thymus, spleen, and, most dominantly, in bone upon overexpression of Fos. Neither collagenase IV nor stromelysin-1 or stromelysin-2 expression is affected by c-Fos. The sites of induced collagenase I expression correlate with the sites of Fos-induced long-term cellular alterations in transgenic mice including bone remodeling and T cell development. In fact, in the developing bone tumors strongly enhanced levels of collagenase I transcripts were detectable. These results identify collagenase I as a Fos-regulated gene in vivo and suggest a possible role for Fos/Jun heterodimers in establishing the pathological phenotype of c-fos transgenic mice.

Cell type-specific regulation of SL-1 and SL-2 genes. Induction of the SL-2 gene but not the SL-1 gene by human keratinocytes in response to cytokines and phorbolesters

The stromelysin-2 (SL-2) gene is transcriptionally active in normal human keratinocytes and encodes a secreted, catalytically competent but latent matrix metalloproteinase. Phorbolester induction resulted in the emergence of SL-2 (but not SL-1 transcripts), whereas the opposite was true for human mucosal fibroblasts. Expression of keratinocyte SL-2 was also induced by the two keratinocyte growth factors, transforming growth factor-alpha and epidermal growth factor, by the proinflammatory cytokine, tumor necrosis factor-alpha, but, somewhat surprisingly, not by interleukin-1 beta. The latent SL-2 proenzyme was isolated from 12-O-tetradecanoylphorbol-13-acetate-induced keratinocytes by immunoaffinity chromatography using a cross-reactive antibody raised against human SL-1. This procedure led to the recovery of a single M(r) 54,000 molecular species at a level of approximately 0.2 microgram/ml of culture medium. Amino-terminal sequencing identified the protein as SL-2 and verified the predicted signal sequence cleavage site. Conformational activation of latent SL-2 precursor by SDS gave rise to a full-length, uncleaved (M(r) 54,000) active form and at the same time exposed a cryptic thiol group. By contrast, organomercurial activation resulted in autolytic truncation of the molecule with loss of M(r) approximately 10,000 propeptide. SL-2 shared with (human fibroblast) SL-1 the ability to cleave casein, to "superactivate" fibroblast type procollagenase, and to form apparently binary, SDS-resistant complexes with tissue inhibitor of metalloproteinases-1.

Role of zinc-binding- and hemopexin domain-encoded sequences in the substrate specificity of collagenase and stromelysin-2 as revealed by chimeric proteins

The relationship of enzyme structure to substrate specificity for the matrix metalloproteinases interstitial collagenase and stromelysin-2 has been investigated by analysis of the cleavage specificity of recombinant human collagenase-stromelysin-2 hybrid proteins and C terminally truncated collagenase and stromelysin-2. Two series of chimeric proteins were devised by progressive substitution of exon-encoded domains. The recombinant proteins were expressed in COS-7 cells as protein A-fusion proteins and purified on an IgG affinity matrix. Treatment with 4-amino-phenylmercuric acetate released active metalloproteinase of the sizes predicted for the chimeric proteins. Active forms of both the chimeric protein series and the short form enzymes expressed both casein- and gelatin-degrading activities. Like stromelysin, the catalytic activity of stromelysin-2 was contained in the N-terminal domain (encoded by exons 1-5) and was apparently independent of the C-terminal domain (encoded by exons 6-10). Only full-length collagenase displayed a triple helicase (collagenolytic) activity; no combination of N- or C-terminal collagenase domains fused with stromelysin-2 domains had such activity. This suggests that the triple helicase activity is a composite of elements derived from both halves of the collagenase molecule. C terminally truncated collagenase (exons 1-5) and a hybrid of collagenase exons 1-5 and stromelysin-2 exons 6-10 cleaved denatured type I collagen (gelatin) to generate diagnostic peptides in gelatin fingerprint assays. When exon 5 (the exon encoding the zinc-binding domain) was derived from stromelysin-2, the enzyme specificity in the fingerprint assay changed to that of native stromelysin-2. In contrast, when exon 5 was derived from collagenase, the specificity reflected that of the parent enzyme. Our data also suggest that mismatching of exons 2 and 5 destabilizes the enzyme, presumably by altering the geometry of the propeptide-zinc-binding site interaction. We conclude that the loss of triple helicase collagenolytic activity is not accompanied by a shift to the broad specificity characteristic of stromelysin. Rather, the zinc-binding domain confers a distinct cleavage specificity on each metalloproteinase.

The order and orientation of a cluster of metalloproteinase genes, stromelysin 2, collagenase, and stromelysin, together with D11S385, on chromosome 11q22-q23

A cluster of metalloproteinase genes, stromelysin, fibroblast collagenase, and stromelysin 2 together with the anonymous DNA marker D11S385, was mapped using pulsed-field gel electrophoresis to a 135-kb region of chromosome 11q22-q23. The physical proximity of these markers was subsequently confirmed using two YAC clones, and their relative order was established as stromelysin 2-collagenase-stromelysin-D11S385. The pattern of marker representation in a panel of radiation-reduced chromosome 11 hybrids suggests that the metalloproteinase gene/D11S385 cluster is orientated with STMY2 closest to the centromere.