The invasive phenotype in HMT-3522 cells requires increased EGF receptor signaling through both PI 3-kinase and ERK 1,2 pathways

We studied the invasion of HMT-3522 breast epithelial cells in response to epidermal growth factor (EGF), and the associated signaling pathways. HMT-3522 T4-2 cells were shown to invade Matrigel-coated Transwell membranes in response to EGF while HMT-3522 S-1 cells failed to invade when treated with EGF. Studies utilizing specific molecular inhibitors showed the importance of beta1 integrin, phosphatidylinositol 3 kinase (PI 3-kinase), p38, extracellular regulated kinase 1, 2 (Erk 1,2) MAP kinases, and metalloproteinases in invasion and motility. T4-2 cell invasion was shown to be time-dependent and also gene transcription-dependent as shown by inhibition with Actinomycin D. T4-2 cells exhibited an increased activation of MAP kinases Erk 1,2 (2-fold), EGF receptor (3-fold), and PI 3-kinase (3- to 4-fold) when compared to the S-1 cells. In response to EGF, T4-2 cells showed a 5-fold greater secretion of matrix metalloproteinase-9 (MMP-9) as compared to S-1 cells, and this increase was largely dependent on the activity of PI 3-kinase. These findings indicate that expression of the invasive phenotype in these breast epithelial cells requires increased EGF receptor signaling, involving both PI 3-kinase and Erk 1,2 activities, which leads to multiple downstream effects, including enhanced secretion of MMP-9 and transcription of invasion-related genes.

Interleukin-1beta and tumor necrosis factor-alpha induce chemokine and matrix metalloproteinase gene expression in human colonic subepithelial myofibroblasts

BACKGROUND

Colonic subepithelial myofibroblasts may play a role in the inflammatory responses and in extracellular matrix (ECM) metabolism. In this study, we investigated the effects of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha on chemokine (IL-8 and monocyte chemoattractant protein (MCP)-1) and ECM turnover (proliferation of subepithelial myofibroblasts, and secretion of ECM and matrix metalloproteinases (MMPs)) in colonic subepithelial myofibroblasts.

METHODS

Human colonic subepithelial myofibroblasts were isolated using the method described by Mahida et al. Chemokine and MMP expressions were determined by ELISA and Northern blotting. Nuclear factor (NF)-kappaB and NF-IL6 DNA binding activities were evaluated by electrophoretic gel mobility shift assays (EMSA).

RESULTS

IL-1beta and TNF-alpha did not affect the proliferation of subepithelial myofibroblasts, but stimulated the secretion of types I and IV collagens weakly. Unstimulated subepithelial myofibroblasts secreted a large amount of MMP-2, but a small amount of IL-8, MCP-1 and MMP-1. IL-1beta and TNF-alpha both induced a dose- and time-dependent increase in IL-8, MCP-1 and MMP-1 secretion, and weakly stimulated MMP-2 secretion. IL-1beta and TNF-alpha both rapidly evoked NF-kappaB DNA-binding activity. The inhibition of NF-kappaB activation markedly blocked both IL-1beta- and TNF-alpha-induced IL-8 and MCP-1 mRNA expression, but did not affect MMP-1 mRNA expression.

CONCLUSIONS

These observations indicate that chemokine secretion and ECM metabolism are collectively regulated by the proinflammatory cytokines, IL-1beta and TNF-alpha, in colonic subepithelial myofibroblasts. Thus, colonic subepithelial myofibroblasts may play an important role in the pathophysiology of inflammation in the colon.

The vascular endothelial growth factor (VEGF) signaling pathway: a therapeutic target in patients with hematologic malignancies

Angiogenesis is an important component in the progression and metastasis of solid tumors. We now appreciate that angiogenesis is also critically involved in the pathogenesis of hematologic malignancies. Current data suggest important prognostic and therapeutic implications of angiogenesis in a variety of malignancies of the hematopoietic system, including acute and chronic leukemias, myeloproliferative diseases, multiple myeloma, non-Hodgkin's lymphomas, and Hodgkin's disease. Vascular endothelial growth factor (VEGF) is a major angiogenic factor that regulates multiple endothelial cell functions, including mitogenesis. Cellular and circulating levels of VEGF are elevated in hematologic malignancies and are adversely associated with prognosis. Angiogenesis is a very complex, tightly regulated, multistep process, the targeting of which may well prove useful in the creation of novel therapeutic agents. Current approaches being investigated include the inhibition of angiogenesis stimulants (e.g., VEGF), or their receptors, blockade of endothelial cell activation, inhibition of matrix metalloproteinases, and inhibition of tumor vasculature. Preclinical, phase I, and phase II studies of both monoclonal antibodies to VEGF and blockers of the VEGF receptor tyrosine kinase pathway indicate that these agents are safe and offer potential clinical utility in patients with hematologic malignancies.

Atorvastatin reduces the expression of cyclooxygenase-2 in a rabbit model of atherosclerosis and in cultured vascular smooth muscle cells

Inflammation is involved in the genesis and rupture of atherosclerotic plaques. We assessed the effect of atorvastatin (ATV) on the expression of cyclooxygenase-2 (COX-2) and other proinflammatory molecules in a rabbit model of atherosclerosis. Fourteen animals underwent injury of femoral arteries and 2 weeks of atherogenic diet. Afterwards, they were randomized to receive either 5 mg/kg per day of ATV (n=8) or no treatment (NT, n=6) during 4 weeks, and were finally killed. ATV reduced lipid levels, neointimal size (0.13 (0.03-0.29) mm(2) vs 0.65 (0.14-1.81) mm(2), P=0.005) and the percentage of neointimal area positive for macrophages (1% (0-3) vs 19% (5-32), P=0.001), COX-2 (32% (23-39) vs 60% (37-81) P=0.019), interleukin-8 (IL-8) (23% (3-63) vs 63% (25-88) P=0.015), and metalloproteinase-3 (19% (12-34) vs 42% (27-93), P=0.010), without significant differences in COX-1 expression (immunohistochemistry). In situ hybridization confirmed a decreased expression of COX-2 mRNA (22% (5-40) vs 43% (34-59) P=0.038). The activity of nuclear factor-kappaB, which controls many proinflammatory genes including COX-2, was reduced in atherosclerotic lesions (3538 (2663-5094) vs 8696 (5429-11312)) positive nuclei per mm(2), P=0.001) and circulating mononuclear cells (2966 vs 17130 arbitrary units). In cultured vascular smooth muscle cells, ATV reduced the expression of COX-2 mRNA induced by IL-1beta and TNF-alpha without affecting COX-1 expression. In conclusion, ATV, besides decreasing a number of inflammatory mediators in the atherosclerotic lesion, significantly downregulates COX-2 both in vivo and in vitro. These anti-inflammatory actions could partially account for the reduction of acute coronary events achieved by statins.

Expression of matrix metalloproteases (MMP-2, MT1 -MMP) and their tissue inhibitor (TIMP-2) by rat sertoli cells in culture: implications for spermatogenesis

During testicular development and maturation, extracellular matrix (ECM) remodelling is a fundamental process which requires the presence of several proteases and protease inhibitors. Among the proteases, a pivotal role has been proposed for matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs). Here we report an analysis of MMP-2, MT1-MMP and TIMP-2 expression by rat Sertoli cells in culture using RT-PCR and zymographic techniques. Stimulating Sertoli cells with follicle-stimulating hormone (FSH) in vitro induced evident changes in the level of their mRNA in a time-dependent manner. In the case of TIMP-2 and MT1-MMP, the respective transcripts were augmented up to three-fold after 24 h of treatment, and MMP-2 transcripts increased by four times in the same period. MMP-2 activity determined by gelatin zymography showed an increase in enzyme secretion after FSH stimulation. The results of this study suggest that: (i) at the surface of Sertoli cells pro-MMP-2 activation mediated by MT1-MMP may occur, involving TIMP-2 as a receptor; and (ii) the expression of these molecules is not constitutive in this cell type, but may be modulated by FSH and is therefore implicated in spermatogenesis.

Transforming growth factor-alpha promotes mouse blastocyst outgrowth and secretion of matrix metalloproteinases

OBJECTIVE

To study the effect of transforming growth factor-alpha (TGF-alpha) on early stage of embryo implantation.

METHODS

Mouse blastocysts were cultured in vitro in medium containing various concentrations of TGF-alpha. Blastocyst implantation capacity was evaluated by calculating the percentage of embryos with attachment or outgrowth. Matrix metalloproteinases (MMPs) secretion of blastocysts was observed using gelatin zymography.

RESULTS

There was no significant difference in the percentage of attachment between control and TGF-alpha treated groups, but the percentage of outgrowth of TGF-alpha treated groups was significantly higher than that of the control group after 24 h culturing. Gelatin zymography showed that blastocysts cultured in TGF-alpha treated groups started secreting MMPs earlier than those in the control group.

CONCLUSION

TGF-alpha is involved in regulating the mouse embryo implantation process by promoting blastocyst outgrowth and secreting matrix matalloproteinases.

Effects of norepinephrine, HIV type 1 infection, and leukocyte interactions with endothelial cells on the expression of matrix metalloproteinases

The expression of matrix metalloproteinases (MMPs) associated with AIDS-related cardiomypathies and cocaine abuse was examined in an in vitro coculture model. Human peripheral blood mononuclear cells (PBMCs), HIV infected or uninfected, were placed in coculture with primary human cardiac microvascular endothelial cells (HMVEC-C) in the presence or absence of the cocaine-inducible catecholamine norepinephrine (NE). Culture supernatants were assayed for MMP-1, -2, -3, -7, -9, and -13, and for tissue inhibitor of metalloproteinase 1 (TIMP-1) and TIMP-2, by enzyme-linked immunosorbent assay. Low levels of constitutively expressed MMP-1 and -2 were detected in individual cultures of HMVEC-C and PBMCs. NE did not induce MMP or TIMP expression by HMVEC-C and caused modest increases (3- to 4-fold) in MMP-1 and -2 by uninfected PBMCs. Increased levels of NE-induced MMP-1 (5-fold) and MMP -2 (15-fold) were detected in cocultures of HMVEC-C and uninfected PBMCs. HIV infection enhanced MMP-1 (46-fold) and MMP-2 (48-fold) and active MMP-7 (33-fold) and MMP-9 (50-fold) by PBMCs. Coculture of HIV-infected PBMCs with HMVEC-C increased MMP-1 (110-fold) and MMP-2 (307-fold) but not active MMP-7 and -9. The combination of NE, HIV infection, and coculture increased MMP-1 (126-fold) and MMP-2 (467-fold), and active MMP-7 (65-fold) and MMP-9 (75-fold). MMP-3 or-13 was not detected in any of the treatment groups and TIMP-1 and -2 appeared inversely proportional to the observed levels of MMPs. These results suggest that HIV infection, NE, and leukocyte endothelial interactions demonstrate separate and overlapping cooperative effects on the regulation of expression of TIMPs and MMPs associated with AIDS-related cardiomyopathies.

The role of retinoids in the prevention and repair of aged and photoaged skin

Retinoids, either naturally occurring or synthetic, are defined by their ability to bind nuclear retinoid receptors of the steroid/thyroid superfamily. Their protean but key function in physiology is control of cellular proliferation and differentiation. Topical retinoids, namely tretinoin, have been proven to prevent and repair clinical features of photoageing; these processes are facilitated by an ability to prevent loss of collagen from, and stimulate new collagen formation in, the papillary dermis of sun-exposed skin. Emerging evidence indicates that intrinsic, chronological ageing of the skin shares several mechanistic features with photoageing. Indeed aged skin is characterized by retinoid sensitivity and is probably reparable by application of topical retinoids.

Expression and regulation of MMP-20 in human tongue carcinoma cells

Human matrix metalloproteinase-20 (MMP-20, enamelysin) fragments the enamel-specific protein amelogenin and has been shown to be synthesized exclusively by odontoblasts and ameloblasts and in certain odontogenic tumors. Here we demonstrate, for the first time, the expression of MMP-20 mRNA and protein in two carcinoma cell lines originating from the tongue. Treatment of the SCC-25 and HSC-3 cells with phorbol 12-myristate 13-acetate (10 nmol/L) up-regulated MMP-20 mRNA and protein expression by up to 1.6-fold, but transforming growth factor beta (10 ng/mL) had no effect. The latent proform of recombinant (r) human MMP-20 was converted by tumor-related trypsin-2. Activated rMMP-20 did not degrade type I or type II collagen, but efficiently hydrolyzed fibronectin, type IV collagen, laminin-1 and -5, tenascin-C, and beta-casein. This implies that MMP-20 not only participates in dental matrix remodeling but is also present in tongue carcinoma cells.

Effect of hyaluronan on MMP expression and activation

Matrix metalloproteases (MMPs) play a crucial role in tissue remodelling in a variety of physiological and pathological processes. Hyaluronan is also involved in the same processes. Several cytokines and growth factors are involved in the regulation of the biosynthesis of hyaluronan and also of MMPs. The activity of MMPs has been shown to be regulated at the level of transcription and activation of the zymogen form. In order to explore the possible relationship between matrix components and especially hyaluronan, we studied the effect of hyaluronan on MMP expression (biosynthesis and activation) in the culture of human skin fibroblasts and corneal keratocytes (explant cultures and cell cultures). These cells were shown to exhibit distinct phenotypes as far as matrix biosynthesis is concerned. Using a synthetic substrate N-Suc(ala)3pNA, we measured elastase-type endopeptidase activity produced by fibroblasts and keratocytes and characterized the MMPs by zymography. Hyaluronan added to fibroblast cultures stimulated the membrane-bound elastase-type endopeptidase activity in a dose dependent fashion. Similar results were obtained with keratocyte cultures. In the presence of 1 mg/ml hyaluronan there was an increase in MMP expression and also an activation of latent MMPs both by fibroblasts and keratocytes.

Human odontoblast culture method: the expression of collagen and matrix metalloproteinases (MMPs)

Studies on mature human odontoblasts have suffered for the lack of in vitro models. We recently introduced a human odontoblast and pulp tissue organ culture method, in which the odontoblasts are cultured in the pulp chamber after removal of the pulp tissue, and the pulp tissue can be cultured separately (Tjäderhane et al., 1998a). With this method, we have studied the effects of growth factors on the expression of collagen and extracellular matrix (ECM)-degrading enzymes, matrix metalloproteinases (MMPs), in mature human odontoblasts. TGF-beta 1 was selected because of its ability to regulate the response of the dentin-pulp complex to external irritation. The effect of TGF-beta 1 (10 ng/mL) on pro alpha 1(I) collagen mRNA was analyzed by quantitative PCR, and type I procollagen propeptide (PINP) was analyzed from conditioned culture media with RIA. Odontoblast media were also assayed for respective type III procollagen propeptide (PIIINP). TGF-beta had a negligible effect on collagen mRNA expression or protein synthesis, indicating that TGF-beta alone does not markedly induce dentin matrix formation per se in the human dentin-pulp complex (Palosaari et al., 2001). However, TGF-beta 1 seems to regulate MMP expression in mature human odontoblasts differentially. A strong down-regulation of MMP-8 (Palosaari et al., 2000), a modest down-regulation of MMP-20 (Tjäderhane et al., 2000), and considerable up-regulation of MMP-9, with no apparent effect on MMP-2 expression (Tjäderhane et al., 1998b), indicate that growth factors may affect the matrix synthesis by controlling the expression and activity of MMPs instead of collagen synthesis. The altered expression of MMPs may result in altered ECM formation, which in turn may contribute to the formation of atubular reparative dentin.

Subantimicrobial dose doxycycline as an adjunct to scaling and root planing: post-treatment effects

BACKGROUND/OBJECTIVE

Subantimicrobial dose doxycycline (SDD 20 mg bid) plus scaling and root planing (SRP) significantly improved clinical attachment level (CAL) and reduced probing depth (PD) compared with placebo plus SRP in a double-blind, placebo-controlled, multicenter study of patients with adult periodontitis (AP). In a study conducted as a follow-up, the post-treatment effects of SDD were assessed in patients who completed the SRP study.

METHODS

The SRP study was a 9-month, active-treatment study and the follow-up was a 3-month, no-treatment study. In the SRP study, tooth sites in qualifying quadrants were scaled and root planed and patients were randomized to receive twice daily SDD 20 mg or placebo. In the follow-up, patients received no study drug; investigators and patients remained blinded to the previous treatment group assignments. Efficacy measures included the change in CAL and PD from baseline values determined at the start of the SRP study in tooth sites stratified by baseline PD (i.e., 0-3 mm, 4-6 mm, > or =7 mm). Safety was evaluated using adverse event data and the results of clinical laboratory tests, oral pathology examinations, and microbiological assessments.

RESULTS

Within each disease stratum, the incremental improvements in PD and CAL demonstrated in the SDD group over 9 months of active treatment were maintained through 3 additional months of no treatment. Treatment cessation did not result in an accelerated regression of periodontal health. No differences in the incidence of adverse events (including those related to infection) or laboratory or microbiological parameters were noted between the SDD group and the placebo group.

CONCLUSIONS

The administration of SDD 20 mg bid for a period of up to 9 months is not associated with rebound effects or delayed or negative after-effects for a 3-month period after cessation of therapy.

Protein-bound polysaccharide PSK inhibits tumor invasiveness by down-regulation of TGF-beta1 and MMPs

Transforming growth factor beta1 (TGF-beta1) and matrix metalloproteinases (MMPs) produced by tumor cells play important roles in tumor invasion. PSK, a protein-bound polysaccharide, is widely used in Japan as an immunopotentiating biological response modifier for cancer patients. In this study, we focused on the effects of PSK on invasiveness, TGF-beta1 production, and MMPs expression in two human tumor cell lines, pancreatic cancer cell line (NOR-P1) and gastric cancer cell line (MK-1P3). PSK significantly decreased the invasiveness of both cell lines through Matrigel-coated filters but did not affect cell viability, proliferation, or adhesion. Decreased invasion was associated with the inhibition of TGF-beta1, MMP-2, and MMP-9 at both mRNA and protein levels as assessed by reverse transcriptase-polymerase chain reaction, gelatin zymography, and enzyme-linked immunosorbent assay. Antibody against TGF-beta1 neutralized the MMP activities of both cell lines. PSK also suppressed the expression of urokinase plasminogen activator (uPA) and uPA receptor but did not change plasminogen activator inhibitor-1 (PAI-1) expression. Western blot analysis showed that PSK reduced uPA protein expression but not PAI-1 expression in the both cell lines. These results indicate that PSK suppresses tumor cell invasiveness through down-regulation of several invasion-related factors including TGF-beta1, uPA, MMP-2, and MMP-9.

Stimulation of plasminogen activator activity and matrix metalloproteinases of human dental pulp-derived cells by tumor necrosis factor-alpha

The effects of tumor necrosis factor (TNF)-alpha on the plasminogen activator (PA)/plasmin system in human dental pulp (HDP) cells were examined. TNF-alpha treatment induced a significantly high level of PA activity in the conditioned medium of HDP cells in a time- and dose-dependent manner, compared with untreated control cells. Western-blot analysis revealed that tissue type (t)PA protein in conditioned medium was increased by TNF-alpha when compared with control medium. Furthermore the tPA mRNA level had increased in HDP cells treated with TNF-alpha, as determined by reverse transcription-polymerase chain reaction, but urokinase PA and PA inhibitor-1 mRNA levels did not increase. We examined the effects of TNF-alpha against activities of matrix metalloproteinases (MMPs) using zymography. TNF-alpha stimulated MMP-2 activity in conditioned medium and stimulated MMP-9 activity with addition of plasminogen into conditioned medium. The present results suggested that TNF-alpha stimulates PA activity via an enhancement of tPA gene expression in HDP cells and MMP-2 activity, and further that tPA-activated TNF-alpha stimulated MMP-9.

Esculetin inhibits cartilage resorption induced by interleukin 1alpha in combination with oncostatin M

OBJECTIVE

To determine if a new inhibitor, esculetin (EST), can block resorption of cartilage.

METHODS

Interleukin 1alpha (IL1alpha, 0.04-5 ng/ml) and oncostatin M (OSM, 0.4-50 ng/ml) were used to stimulate the release of proteoglycan and collagen from bovine nasal cartilage and human articular cartilage in explant culture. Proteoglycan and collagen loss were assessed by dimethylmethylene blue and hydroxyproline assays, respectively. Collagenase levels were measured by assay of bioactivity and by enzyme linked immunosorbent assay (ELISA). The effects of EST on the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the transformed human chondrocyte cell line T/C28a4 were assessed by northern blot analysis. TIMP-1 protein levels were assayed by ELISA. The effect of EST on the MMP-1 promoter was assessed using a promoter-luciferase construct in transient transfection studies.

RESULTS

EST inhibited proteoglycan and collagen resorption in a dose dependent manner with significant decreases seen at 66 microM and 100 microM EST, respectively. Collagenolytic activity was significantly decreased in bovine nasal cartilage cultures. In human articular cartilage, EST also inhibited IL1alpha + OSM stimulated resorption and decreased MMP-1 levels. TIMP-1 levels were not altered compared with controls. In T/C28a4 chondrocytes the IL1alpha + OSM induced expression of MMP-1, MMP-3, and MMP-13 mRNA was reduced to control levels by 250 microM EST. TIMP-1 mRNA levels were unaffected by EST treatment. All cytokine stimulation of an MMP-1 luciferase-promoter construct was lost in the presence of the inhibitor.

CONCLUSION

EST inhibits degradation of bovine nasal cartilage and human articular cartilage stimulated to resorb with IL1alpha + OSM.

Effects of genistein on the periovulatory expression of messenger ribonucleic acid for matrix metalloproteinases and tissue inhibitors of metalloproteinases in the rat ovary

The matrix metalloproteinases (MMPs) play critical roles in the ovulatory process. Their expression and activity, together with those of the endogenous tissue inhibitors of metalloproteinases (TIMPs), are stimulated by LH. The LH surge initiates a cascade of events resulting in ovulation and formation of the corpus luteum via activation of protein kinases A and C, as well as tyrosine kinases. In vitro perfused rat ovaries were untreated, or treated with LH (0.2 microg ml(-1)) plus 0.2 mmol 3-isobutyl-1-methylxanthine l(-1) with 0, 10 or 100 micromol genistein l(-1) (an inhibitor of tyrosine kinases) to assess whether tyrosine kinases are mediators of the LH-stimulated increase in ovarian expression of the MMPs and TIMPs. After 10 h of perfusion, ovaries were collected and frozen until RNA isolation. Northern and RNase protection analyses were used to measure mRNA encoding collagenase 3, gelatinases A and B, and TIMPs-1, -2 and -3. Treatment with LH plus 3-isobutyl-1-methylxanthine resulted in a two- and fivefold increase in mRNA encoding collagenase 3 and TIMP-1, respectively (P < 0.05). Treatment with 100 micromol genistein l(-1) blocked the LH-stimulated increase in collagenase 3 (0.012 +/- 0.002 versus 0.028 +/- 0.005 relative units for 100 micromol genistein l(-1) versus LH; P < 0.05), whereas neither dose of genistein affected LH-induced TIMP-1 expression. LH alone or with genistein did not alter the expression of mRNA encoding TIMP-2 and TIMP-3, or mRNA encoding gelatinases A and B. These data indicate that tyrosine kinases play a role in the LH-induced tissue remodelling required for ovulation by mediating the LH-stimulated expression of collagenase 3.

Rhein, an active metabolite of diacerein, suppresses the interleukin-1alpha-induced proteoglycan degradation in cultured rabbit articular chondrocytes

Diacerein has proved to be effective in the treatment of osteoarthritis. We investigated the effects of rhein, an active metabolite of diacerein, on the degradation of recombinant human interleukin-1alpha (rhIL-1alpha)-induced proteoglycan and matrix metalloproteinases (MMPs) release from rabbit articular chondrocytes. Chondrocytes were treated for 24 h with rhein in the presence of rhIL-1alpha. Rhein suppressed the rhIL-1alpha-induced proteoglycan degradation. In addition, rhein decreased the rhIL-1alpha-induced proMMP-3 production and reduced the MMPs activity. These results suggested that diacerein might have a protective effect on proteoglycan degradation via the suppressive effect of rhein on the production of proMMPs.

Hepatocyte growth factor/scatter factor enhances the invasion of mesothelioma cell lines and the expression of matrix metalloproteinases

Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional factor involved both in development and tissue repair, as well as pathological processes such as cancer and metastasis. It has been identified in vivo in many types of tumours together with its tyrosine kinase receptor, Met. We show here that exogenous HGF/SF acts as a strong chemoattractant for human mesothelioma cell lines. The factor also enhanced cell adhesion to and invasion into Matrigel. The mesothelioma cell lines synthesized a panel of matrix metalloproteinases critical for tumour progression such as MMP-1, 2, 3, 9 and membrane-bound MT1-MMP. HGF/SF stimulated the expression of MMP-1, 9 and MT1-MMP and had a slight effect on expression of the MMP inhibitor TIMP-1 but not TIMP-2. However, there was no simple correlation between the levels of MMPs and TIMPs of the cell lines and their different invasion properties or between HGF/SF stimulatory effects on MMP expression and invasion. In addition, effects of protease inhibitors on invasion suggested that serine proteases were also expressed in human mesothelioma cell lines and were involved in HGF/SF-induced invasion. The results show a predominant role for HGF/SF in mesothelioma cell invasion, stimulating simultaneously adhesion, motility, invasion and regulation of MMP and TIMP levels.

Ovulation: a multi-gene, multi-step process

The luteinizing hormone (LH) surge initiates a cascade of proteolytic events that control ovulation. One of the genes induced by LH is the progesterone receptor (PR). Because mice with a mutant PR gene (PRKO) fail to ovulate and are infertile, we have used them as a model in which to determine PR target genes that might mediate the ovulatory process. The matrix metalloproteinases (MMPs: MMP2, MMP9, and MMP13) appear to be expressed in ovaries of PRKO mice in a manner similar to that in their wild-type littermates. However, the expression of two other types of proteases, cathepsin L (a member of the papain family) and ADAMTS-1 (A Disintegrin And Metalloproteinase with Thrombospondin-like motifs), are selectively induced in granulosa cells of preovulatory follicles by the LH surge. Maximal levels of these proteases are observed at 12-16 h after an LH surge, the time of ovulation. Furthermore, mRNAs encoding cathepsin L and ADAMTS-1 are reduced in the PRKO mice compared to their wild-type littermates. These novel observations indicate that these two proteases regulate some key step(s) controlling ovulation.

Production and regulation of matrix metalloproteinases and their inhibitors by human peritoneal mesothelial cells

OBJECTIVE

Human peritoneal mesothelial cells (HPMC) are likely to be involved in maintenance of the peritoneal membrane. We determined whether these cells were able to synthesize the matrix degrading enzymes, matrix metalloproteinases (MMPs), likely to be responsible for the breakdown of this membrane, and whether this secretion could be modulated by cytokines involved in the inflammatory response.

DESIGN

MMP activity in conditioned medium of growth-arrested HPMC was measured by zymography. Cultures were incubated in the presence and absence of the cytokines transforming growth factor-beta (TGFbeta) and interleukin (IL)-1beta in order to determine the effects of these cytokines on this process. The mRNA for these MMPs, together with that of their specific inhibitors, tissue inhibitors of metalloproteinases (TIMPs), was also examined by reverse transcriptase polymerase chain reaction

RESULTS

HPMC were shown to constitutively secrete the metalloproteinases MMP-2 and MMP-3 in vitro. In response to the proinflammatory cytokine IL-1beta , the protein and mRNA for MMP-9 was induced, while secretion of MMP-2 was unaltered. Similarly, the mRNA for MMP-3 was also increased relative to actin following the addition of IL-1beta. TGFbeta was shown to slightly induce the secretion of MMP-2 together with the mRNA for TIMP I, TIMP II, and, to a greater extent, TIMP III. Used peritoneal dialysate was also shown to induce MMP-9 secretion, and this effect was blocked by the co-incubation of IL-1 receptor antagonist. The secretion of enzyme activity was shown to be from the apical surface of the cells.

CONCLUSION

HPMC have the ability to control the accumulation of extracellular matrix by secreting the matrix degrading molecules MMP-2, MMP-3, and MMP-9. In addition, the secretion of these enzymes, together with that of their inhibitors (TIMPs) is regulated by the cytokines IL-1beta and TGFbeta. This process is likely to be important in both the normal maintenance of the integrity of the peritoneal membrane and in the changes that occur following prolonged peritoneal dialysis.

Effective adenoviral transfer of IkappaBalpha into human fibroblasts and chondrosarcoma cells reveals that the induction of matrix metalloproteinases and proinflammatory cytokines is nuclear factor-kappaB dependent

OBJECTIVE

To determine whether, in human fibroblasts and chondrosarcoma cells, the regulation of interleukins (IL)-6, 8, and 11 and matrix metalloproteinases (MMP)-1, 3, and 13, and their tissue inhibitor TIMP-1, depends on the transcription factor nuclear factor-kappaB (NF-kappaB).

METHODS

Fibroblasts and chondrosarcoma cells were effectively infected with an adenovirus encoding human IkappaBalpha, and inhibition of NF-kappaB function was observed. The induction of MMP and IL-6, 8, and 11 by various stimuli was assessed by ELISA.

RESULTS

The induction of IL-6 and IL-8 clearly depended on NF-kappaB in both fibroblasts and chondrosarcoma cells, irrespective of stimulus, but IkappaBalpha overexpression had little effect on IL-11. MMP-1, -3, and -13 were also inhibited, but TIMP-1 was unaffected.

CONCLUSION

NF-kappaB appears to play an important and selective role in MMP induction in human fibroblasts and chondrosarcoma cells. This suggests there are NF-kappaB dependent mechanisms of cartilage destruction in rheumatoid arthritis, and supports the concept that there are similarities in the regulation of inflammatory and destructive pathways in that disease.

4'-Hydroxy aceclofenac suppresses the interleukin-1-induced production of promatrix metalloproteinases and release of sulfated-glycosaminoglycans from rabbit articular chondrocytes

This study demonstrates the novel actions of a non-steroidal anti-inflammatory drug aceclofenac, which is frequently used for rheumatoid arthritis and osteoarthritis. 4'-Hydroxy aceclofenac, a main metabolite of aceclofenac in humans, down-regulated the production of promatrix metalloproteinase-1/procollagenase 1 and promatrix metalloproteinase-3/prostromelysin 1 along with a decrease in their mRNAs in rabbit articular chondrocytes and synoviocytes, and interfered with the release of sulfated-glycosaminoglycans (proteoglycans) from the chondrocytes. 4'-Hydroxy aceclofenac also suppressed the proliferation of rabbit synoviocytes. In contrast, aceclofenac itself and its other metabolites, diclofenac and 4'-hydroxy declofenac, did not exert obvious actions on cellular functions. Therefore, it is suggested that the therapeutic effects of aceclofenac on rheumatoid arthritis and osteoarthrits are, at least in part, due to the novel chondroprotective effect of 4'-hydroxy aceclofenac via the suppression of promatrix metalloproteinase production and proteoglycan release. There is also evidence that inhibition of synoviocyte proliferation and the known inhibitory action on prostaglandin E(2) production play a role.

Effect of danazol and ovariectomy on matrix metalloproteinases in rat uteri

The experiments described in this report were designed to study the effects of danazol on matrix metalloproteinases in the rat uterus. Proteinases were analyzed by zymography in gels copolymerized with either gelatin or transferrin. There were no apparent effects of danazol on proteinases from rat uteri when analyzed in gelatin gels. However, in transferrin gels, not only did more bands appear in control samples but also there was a clear negative effect of danazol on the production of these proteinases. Similar results were obtained from uteri of ovariectomized rats. Again no differences were observed in gelatin gels but the control bands which appeared only on transferrin gels were missing in transferrin gels as a result of ovariectomy. These results indicate that there is an effect of estrogen on the synthesis of specific matrix metalloproteinases in the rat uterus and that these proteinases are only observed by zymography when gels are developed in transferrin but not collagen.

Synthesis pattern of matrix metalloproteinases (MMPs) and inhibitors (TIMPs) in human explant organ cultures after treatment with latanoprost and dexamethasone

PURPOSE

To determine changes in production of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) in the ciliary body, the trabecular meshwork and the retinal pigment epithelium induced by both prostaglandins and corticosteroids.

METHODS

Explant organ cultures were removed by a scleral incision 3 mm posterior to the limbus. Retinal pigment epithelium was grown to confluence. Organ and cell cultures were treated with latanoprost and/or dexamethasone for 72 h. The activity of MMP-2, -3 and -9 was assessed using zymography. The synthesis pattern of MMPs and TIMP-1 and -2 was identified using immunostaining.

RESULTS

Treatment of explant organ cultures with 10 micrograms/ml of latanoprost induced a mean upregulation of MMP-2 by 36%, MMP-3 by 112% and MMP-9 by 156% as seen by zymography. Dexamethasone 500 nm reduced the amounts of secreted MMP-2 by 13%, MMP-3 by 69%. MMP-9 was not detectable in the media of corticosteroid-treated explant organ cultures. The addition of 10 micrograms/ml of latanoprost to dexamethasone-treated cultures increased MMP-2 by 14%, MMP-3 by 43% and MMP-9 by 49%. Using immunohistochemistry we found staining with antibodies against MMP-2, -3, -9 and TIMP-1 and -2 within the ciliary body, and only to a lesser degree in the trabecular meshwork. Latanoprost treatment caused an increase of 29% in MMP-2 (p < 0.0001), 98% in MMP-3 (p < 0.0001) and 108% in MMP-9 (p < 0.0001). Dexamethasone reduced the staining for MMP-2 by 32% (p < 0.0001), for MMP-3 by 33% (p < 0.0001) and for MMP-9 by 83% (p < 0.0001). Almost no change in staining for MMPs was detectable in the trabecular meshwork. Neither latanoprost treatment nor dexamethasone induced significant changes (p < 0.93) in the secretion of TIMPs. In the media of non-treated retinal pigment epithelium (RPE) cells the only MMP detected was MMP-2. RPE cells in culture did not respond to either treatment with a change in their MMP secretion.

CONCLUSION

We detected a profound upregulation of both MMP-3 and MMP-9 and a mild induction of MMP-2 through latanoprost in the ciliary body, but not the trabecular meshwork or RPE cells. Corticosteroids, on the other hand, downregulated MMP expression in both tissues. This inhibiting effect of corticosteroids on MMP production was reversed by latanoprost.

The effect of mifepristone administration on leukocyte populations, matrix metalloproteinases and inflammatory mediators in the first trimester cervix

Cervical ripening is analogous to an inflammatory reaction characterized by an influx of inflammatory cells and an increase in inflammatory mediators. The anti-gestogen mifepristone is highly effective in inducing cervical ripening in women throughout gestation. However, its mechanism of action is largely unknown. The aim of the study was to investigate the effect of in-vivo administration of mifepristone on inflammatory cells and mediators in the cervix. Cervical biopsies were taken from women undergoing a first trimester termination of pregnancy at 0, 6, 12, 24 and 36 h (n = 6 per group) after mifepristone administration. Biopsies were fixed for immunohistochemistry and also cultured for subsequent analysis of culture media by radioimmunoassay or enzyme-linked immunosorbent assay. After administration of mifepristone (6-24 h), there was an increase in immunostaining for leukocyte common antigen (CD45), neutrophil elastase, monocytes (CD68), and matrix metalloproteinases (MMP)-1, -8 and -9. Immunostaining for MMP-2 and tissue inhibitor of metalloproteinases (TIMP)-1, -2 and -4 were unaffected by mifepristone treatment. Secretion of monocyte chemotactic protein (MCP-1) was significantly (P < 0.05) increased from biopsies taken 6-24 h after mifepristone administration. Cervical biopsies also released interleukin-8 (IL-8), prostaglandin (PG) E(2), PGF(2alpha) and prostaglandin metabolites (PGEM and PGFM) although their secretion was unaffected by mifepristone treatment. This study suggests that mifepristone may, in part, effect cervical ripening by modulating the influx of inflammatory cells into the cervix, up-regulating MMP expression and inducing chemokine secretion by cervical tissue.