Degradation of intact basement membranes by human and murine tumor enzymes

Terazosin Modifies the Content of Glycosaminoglycans and the Activity of Matrix Metalloproteinase 2 in the Rat Ventral Prostate

OBJECTIVES

We have investigated the effects of terazosin on the content of glycosaminoglycans (GAGs), the activity of matrix metalloproteinase 2 (MMP-2) and MMP-9, and the content of tissue inhibitors of MMP (TIMP) in the ventral prostate of Wistar rats.

METHODS

Rats were treated with terazosin (0.12, 1.2mg/kg orally every second day) for 120 d. GAGs were isolated and purified from ventral prostate homogenates by lipid extraction, ethanol precipitation, and extensive digestion with pronase and DNAse, separated by electrophoresis, and characterised using specific enzymes. The activity of MMP-2 and MMP-9 was estimated using gelatin zymography and TIMP-1 and TIMP-2 were measured by enzyme-linked immunosorbent assay.

RESULTS

Terazosin treatment did not affect the weight of the ventral prostate gland. The prostate contains hyaluronic acid, chondroitin sulfate (CS), dermatan sulfate (DS), and heparan sulfate (HS), MMP-2, TIMP-1, and TIMP-2, but not MMP-9. Terazosin caused a significant increase in the relative content of DS and a significant decrease in the relative content of CS and to a lesser extent of HS. Terazosin evoked a significant increase in the activity of proMMP-2 and MMP-2 but did not affect TIMP.

CONCLUSIONS

The differential effect of terazosin treatment in GAG molecules of the rat prostate may be beneficial because CS is known to induce and DS to inhibit cell proliferation. The effect of terazosin on GAGs and MMP-2 may contribute in the molecular mechanisms of terazosin-induced apoptosis because HS and CS have a proapoptotic effect, whereas DS and MMP-2 are antiapoptotic.

Matrix metalloproteinases of epithelial origin in facial sebum of patients with acne and their regulation by isotretinoin

Acne vulgaris is a skin disorder of the sebaceous follicles, involving hyperkeratinization and perifollicular inflammation. Matrix metalloproteinases (MMP) have a predominant role in inflammatory matrix remodeling and hyperproliferative skin disorders. We investigated the expression of MMP and tissue inhibitors of MMP (TIMP) in facial sebum specimens from acne patients, before and after treatment with isotretinoin. Gelatin zymography and Western-blot analysis revealed that sebum contains proMMP-9, which was decreased following per os or topical treatment with isotretinoin and in parallel to the clinical improvement of acne. Sebum also contains MMP-1, MMP-13, TIMP-1, and TIMP-2, as assessed by ELISA and western blot, but only MMP-13 was decreased following treatment with isotretinoin. The origin of MMP and TIMP in sebum is attributed to keratinocytes and sebocytes, since we found that HaCaT keratinocytes in culture secrete proMMP-2, proMMP-9, MMP-1, MMP-13, TIMP-1, and TIMP-2. SZ95 sebocytes in culture secreted proMMP-2 and proMMP-9, which was also confirmed by microarray analysis. Isotretinoin inhibited the arachidonic acid-induced secretion and mRNA expression of proMMP-2 and -9 in both cell types and of MMP-13 in HaCaT keratinocytes. These data indicate that MMP and TIMP of epithelial origin may be involved in acne pathogenesis, and that isotretinoin-induced reduction in MMP-9 and -13 may contribute to the therapeutic effects of the agent in acne.

Analysis of N-acetyl and N-glycolylneuraminic acid in rat serum and tissues with Walker 256 carcinoma by high-performance liquid chromatography

Serum and tissue specimens from healthy Wistar rats and from rats with Walker 256 carcinoma were analysed for N-acetyl and N-glycolylneuraminic acid by high performance liquid chromatography (HPLC) as per-O-benzoylated derivatives. Both neuraminic acids were identified, while N-acetylneuraminic acid was the predominant sialic acid. Samples from rats with generalized metastasis showed a significant increase (45-80%) of total sialic acids. This phenomenon in serum is caused by the overproduction of sialic acids, as a result of synthesis of both types of neuraminic acids to a similar molar ratio. The increase of sialic acids in rat bones with metastatic cancer is mainly because of increased N-acetylneuraminic acid synthesis. These results suggest that the molecular mechanisms responsible for cancer metastasis in different tissues may be closely associated with increased synthesis of dominating neuraminic acid.

Treatment of central nervous system inflammation with inhibitors of basement membrane degradation

Currently available anti-inflammatory drugs for the treatment of multiple sclerosis (MS) and other inflammatory diseases are generally inadequate, with disease progression not being arrested by the treatments and undesirable side effects posing problems. In response to these deficiencies our laboratories have, over the past 10 years, been developing novel drugs that interfere with the entry of leucocytes into inflammatory sites by inhibiting their passage through the subendothelial basement membrane (BM). This review initially summarizes evidence supporting the hypothesis that the subendothelial BM is a major barrier to the accumulation of leucocytes in inflammatory sites. An important point that has emerged is that breaching of the BM is probably a cooperative process, involving activation- and cytokine-induced degradative enzymes contributed by leucocytes, endothelial cells and platelets. The review then discusses the properties of three separate classes of anti-inflammatory compounds we have developed, namely sulfated polysaccharides/oligosaccharides, phosphosugars, and castanospermine (CS), which inhibit the passage of leukocytes through BM. Each drug type appears to prevent BM degradation by a different mechanism. Sulfated polysaccharides/oligosaccharides mediate their anti-inflammatory effect by inhibiting the endoglycosidase, heparanase, which plays a key role in the solubilization of BM by invading leucocytes. In fact, our studies have highlighted the heparanase enzyme as a major target for future drug development. Phosphosugars probably inhibit inflammation by displacing lysosomal enzymes, which are involved in BM degradation, from cell surface mannose 6-phosphate receptors. This mechanism of expressing degradative enzymes on the cell surface is particularly evident with activated T lymphocytes. On the other hand, CS interferes with appropriate targeting of lysosomal enzymes involved in BM degradation. For reasons which are still unclear, CS specifically inhibits BM degradation by endothelial cells, which results in a characteristic perivascular arrest of leucocytes in inflammatory sites. Overall, our studies have established that inhibitors of subendothelial BM degradation represent viable anti-inflammatory agents. It is hoped that future work will result in the development of a totally new class of highly effective, subtle and non-toxic anti-inflammatory drugs for the treatment of MS and other inflammatory diseases.

Comparative analysis of the ability of leucocytes, endothelial cells and platelets to degrade the subendothelial basement membrane: evidence for cytokine dependence and detection of a novel sulfatase

The subendothelial basement membrane (BM) is regarded as an important barrier to the entry of leucocytes into inflammatory sites. This study compares the ability of leucocytes, platelets and endothelial cells (EC) to degrade a [35SO4]-labelled subendothelial extracellular matrix (ECM) and assesses the effect of PMA and various pro-inflammatory cytokines on this degradative activity. The different products of degradation, identified by fast protein liquid chromatography (FPLC) gel filtration chromatography, were indicative of protease, endoglycosidase (heparanase) and exoglycosidase and/or sulfatase activity. In terms of ECM degradation, EC and platelets were the most active, with PMA stimulation further enhancing the degradative activity of these two cell types. Platelets exhibited predominantly heparanase activity whereas the EC degradation products suggested a range of enzymic activities, namely proteases, heparanases and sulfatases. Interestingly, EC in suspension expressed these three enzymic activities whereas confluent EC monolayers only exhibited sulfatase activity, suggesting that the former situation might represent an angiogenic response. In the case of leucocytes, neutrophils and lymphocytes degraded the ECM to a much greater extent than monocytes. Each cell type also differed in the predominant enzymic activities it expressed, for example, heparanase activity by lymphocytes, protease activity by neutrophils and sulfatase activity by monocytes. Furthermore, PMA stimulation was shown to have differential effects on these enzymic activities. Some pro-inflammatory cytokines were found to be cell-type specific in their effects on ECM degradation. Thus, IL-1 + TNF enhanced neutrophil and EC degradation of the ECM but inhibited lymphocyte ECM degradation. In contrast, the chemokine IL-8 enhanced ECM degradation by neutrophils, lymphocytes and EC. Of particular interest was the unique sulfatase activity expressed by EC and monocytes which was induced in EC by TNF + IL-1 and IL-8, whereas in monocytes the sulfatase activity was exclusively induced by the chemokine monocyte chemotactic and activating factor (MCAF). Collectively, the results of this study show that leucocytes differ markedly in the enzymes they express to degrade the BM during extravasation and that PMA and cytokines are cell-type specific in their induction of hydrolytic enzyme activity. These results also indicate that EC may play an important role, not only in the recruitment of leucocytes, but also via sulfatase activity in the preparation of vascular BM for leucocyte extravasion.

Inhibition of angiogenesis by anthracyclines and titanocene dichloride

The anthracycline antibiotics, daunorubicin, doxorubicin, and epirubicin, which are widely used for treatment of malignancies, have been evaluated for their effect on angiogenesis in relation to the inhibition of collagenase type IV reported previously. In the chick chorioallantoic membrane (CAM) system of angiogenesis, anthracyclines inhibited vascular density at doses of 5-20 micrograms/disc as well as collagenous protein biosynthesis, which is a reliable index of angiogenesis. Similarly, all three anthracyclines inhibited tube formation in the in vitro system of angiogenesis using human umbilical vein endothelial cells (HUVECs) plated on Matrigel. The inhibition was dose-dependent and caused 50% inhibition at concentrations of 2.5-15 micrograms/mL. At concentrations of anthracyclines which prevented tube formation and angiogenesis, there were no cytotoxic effects, as evidenced by methylene blue uptake, and the growth of these endothelial cells was not inhibited. The experimental antitumor agent titanocene dichloride inhibited collagenase type IV from Walker 256 carcinosarcoma with IC50 approximately 0.2 mM. Titanocene also prevented angiogenesis in the CAM and tube formation by HUVECs on Matrigel at concentrations that were without effect on growth or cytotoxicity of endothelial cells or Walker 256 cells in culture. The antiangiogenic effect of the aforementioned antitumor agents at therapeutically attainable concentrations may explain, at least in part, their antitumor properties because angiogenesis is an essential process for tumor growth and metastasis. The antiangiogenic effect is, however, unrelated to metalloproteinase inhibition because higher concentrations are required for that effect than for inhibition of angiogenesis.

Suppression of angiogenesis by the antitumor agent titanocene dichloride

Titanocene dichloride, which is an active antitumor agent against solid but not blood-borne tumors, suppresses angiogenesis and inhibits biosynthesis of collagenous proteins in the in vivo system of the chorioallantoic membrane of the chick embryo. The agent does not affect total protein biosynthesis in the same system. At non-toxic dose regimens titanocene dichloride retards the growth of Walker 256 carcinosarcoma transplants in rats and reduces the number of seeded implants in the mesenteric bed. At concentrations which suppress angiogenesis and inhibit biosynthesis of collagenous proteins, the agent does not affect the viability of Walker 256 carcinosarcoma cells, or the attachment and proliferation of human A549 lung adenocarcinoma or human umbilical vein endothelial cells in culture. It appears that the antitumor activity of titanocene dichloride may be attributed, at least in part, to its ability to suppress angiogenesis.

"In vitro" study of basement membrane degradation by the cysteine proteinases, cathepsins B, B-like and L. Digestion of collagen IV, laminin, fibronectin, and release of gelatinase activities from basement membrane fibronectin

We have studied the soluble fragments obtained from bovine lens capsules after digestion by the cysteine proteinases cathepsins B, B-like and L. These proteinases liberated collagen IV, laminin and fibronectin fragments, as shown by immunoblotting. Sodium dodecyl sulfate treatment of digested capsules gave a soluble material used for subsequent fractionation and immunochemical study. Comparison of both results demonstrate the ability of these cathepsins to degrade a basement membrane at near neutral pH values. The differences observed in the size and the number of fragments suggest that the three proteinases exhibit similar specificities in basement membrane digestion, as shown previously. Nevertheless, cathepsin L seems to be more effective than cathepsins B and B-like. From this study, cysteine proteinases could be associated to basement membrane destruction. Soluble cysteine proteinase digests of bovine lens capsules showed several bands of gelatinolytic activity by gelatin zymography. Three major bands of 77, 60 and 45 kDa were seen whatever the cysteine proteinase used. These bands were identified as fibronectin fragments. Thus cysteine proteinases can activate the latent proteinase fibronectin from basement membrane leading to a new "metastatic cascade". This would be an important factor in the "in vivo" basement membrane dissolution observed during tumor invasion.

Substratum acidification and proteinase activation by murine B16F10 melanoma cultures

Murine B16F10 melanoma cells, cultured within 0.7% agarose gels containing the fluorescent proteinase substrate acetamidofluorescein-BSA, catalyze the hydrolysis of the substrate in the region immediately surrounding the cell. Fluorescence ratio measurements on hydrolyzed substrate correlate with an average pH of 5.5 +/- 0.2 in the adjacent substratum region. Enzymatic activity within the gel is partially inhibited by leupeptin, pepstatin, phenylmethylsulfonyl fluoride. EDTA and by anti-human cathepsin B, suggesting potential roles for thiol-, aspartic- and metalloproteinases. The time-course of fluorescence intensity, correlated with substratum pH measurements, suggest that substrate hydrolysis is catalyzed by enzymes with pH optima of < 5.5. Invasion by these cells through thin barriers of reconstituted basement membrane gel (Matrigel) is totally blocked by the thiol proteinase inhibitor, leupeptin. It is suggested that secreted or cell-surface acid proteinase enzymes, activated by the cell-mediated local hyperacidity, are involved in substrate hydrolysis and that these enzymes may be important in invasiveness by this cell-line.

Expression of type IV collagen-degrading activity during early embryonal development in the sea urchin and the arresting effects of collagen synthesis inhibitors on embryogenesis

Type IV collagen-degrading activity was expressed in homogenates of Lytechinus pictus embryos during embryogenesis. Activity was concentrated 1,600-fold by ammonium sulfate fractionation, ion exchange, and gel chromatography and could not be activated further upon trypsin or organomercurial treatment. This enzyme activity could also degrade gelatin but had no affinity for type I, III, and V collagens. Activity was inhibited by addition of excess type IV collagen or gelatin, but was unaffected by addition of excess amounts of non-collagenous proteins of the extracellular matrix. Chelators such as 1,10-phenanthroline or Na2EDTA reduced activity to control levels. Inhibitors of plasmin and of serine and thiol proteases were without effect. Type IV collagen-degrading activity first became apparent at the stage of early mesenchyme blastula. It then increased by a small increment and remained stable up to the stage of late mesenchyme blastula, coinciding with first detection of collagen synthesis and the appearance of the archenteron. Thereafter, a sharp increase in activity was observed, concurrently with remodelling of the archenteron. Maximum activity was attained at prism stage and was retained throughout to pluteus-larva stage. The specific inhibitors of collagen biosynthesis 8,9-dihydroxy-7-methyl-benzo[b]quinolizinium bromide and tricyclodecane-9-yl xanthate arrested sea urchin embryo development at early blastula, prevented the invagination of the archenteron, and reverted the expression of type IV collagen-degrading activity to non-detectable levels. Removal of the inhibitors allowed embryos to gastrulate and express type IV collagen-degrading activity.

Basement membrane biosynthesis as a target for developing inhibitors of angiogenesis with anti-tumor properties

Basement membrane (BM) exerts profound influence on endothelial cell (EC) behavior. In addition BM is a structural element of blood vessels; in fact at some point of their formation blood vessels are bare EC tubes lined with the BM produced by these EC. We thought, therefore, that a quantitative relationship must exist between the rate of BM synthesis and angiogenesis, and that interfering with BM synthesis must have an effect on angiogenesis. This was found experimentally in the chick chorioallantoic membrane (CAM) system. It was shown that the rate of BM collagen biosynthesis can serve as a biochemical index of angiogenesis and that inhibitors of BM synthesis prevent angiogenesis. GPA 1734 (8,9-dihydroxy-70-methyl-benzo(b)quinolizinium bromide), which inhibits proline and lysine hydroxylations in type IV collagen formation, suppresses angiogenesis in the CAM. Similarly, D609 (tricyclodecan-9-yl-xanthate), which inhibits BM synthesis by an as yet unknown mechanism, also prevents angiogenesis. Structurally related analogs of GPA 1734 and D609 that have no effect on BM biosynthesis are also without effect on angiogenesis. The aforementioned inhibitors of angiogenesis GPA 1734 and D609 have a dose-dependent inhibitory effect on tumor growth in rats bearing Walker 256 carcinosarcoma, without any obvious toxic effects. This effect is probably related to angiosuppression, since structurally related analogs that do not inhibit angiogenesis are without antitumor properties. Also GPA 1734 and D609 have no direct cytotoxic effects on Walker 256 cells in vitro. These results suggest that a search for agents that are specific inhibitors of BM synthesis may provide novel angiosuppressors with potential application in tumor chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Penetration of the uterine epithelial basement membrane during blastocyst implantation in the mouse

For many species, blastocyst implantation is associated with a reduction in the number of cellular and extracellular matrix layers which separate the trophoblast from maternal vasculature. Following loss of uterine epithelial cells along the distal mural trophoblast, the mouse blastocyst encounters the residual epithelial basement membrane. This sheet of extracellular matrix must be breached and later removed prior to trophoblast invasion of the uterine stroma and formation of the placenta. The interactions between the trophoblast, luminal epithelial basement membrane, and decidual cells during the time when embryonic and uterine stromal cells first achieve contact were examined in this study. Distal mural trophoblast of activated delay blastocysts was in contact with the residual luminal epithelial basement membrane 36 hr after estrogen administration. This portion of the basement membrane contained areas in which the usual linear appearance was changed to an irregular, tortuous profile. The lamina densa frequently appeared flocculent and diffuse. Cytoplasmic processes from trophoblast and decidual cells simultaneously perforated the basement membrane at multiple discrete loci. With further development the basement membrane was lost, leaving trophoblast and decidual cells in close contact over large areas. In normally implanting blastocysts a similar stage of embryonic development, as described above, was attained by 0400 hr on day 6 of pregnancy. Regions of convoluted epithelial basement membrane were also seen in these implantation sites. However, only decidual cell processes were seen penetrating the residual basement membrane. These processes extended to the fetal side of the basement membrane and separated that matrix from overlying trophoblast. They contained organelles and formed rudimentary intercellular junctions with the trophoblast.(ABSTRACT TRUNCATED AT 250 WORDS)

Basement membrane collagen-degrading activity from a malignant tumor is inhibited by anthracycline antibiotics

Type IV collagenase activity was previously identified and purified to 7500-fold in homogenates from murine Walker 256 carcinoma, using acetylated [3H]-type IV collagen as a substrate. Anthracycline antibiotics daunorubicin, doxorubicin and epirubicin exhibited a non-competitive, reversible inhibition with Ki 92, 49 and 40 microM, respectively. This inhibitory effect, at therapeutically attainable concentrations of the forementioned antineoplastic drugs, may contribute, at least in part, to their antimetastatic properties. The anthracycline derivatives: 4-demethoxydaunorubicin, 4'-iododoxorubicin and 4-demethoxy-3'-deamino-3'-hydroxyepirubicin were without inhibitory effects at comparable concentrations. Other antineoplastic agents, such as belomycin, carmustine, cisplatine, etoposide, methotrexate, mitotane and teniposide did not exhibit any inhibitory effect at concentrations up to 1.0 mM.

Angiogenesis is associated with collagenous protein synthesis and degradation in the chick chorioallantoic membrane

Extracts of the chick embryo chorioallantoic membrane (CAM) obtained from 7-20 day old embryos, contained enzyme activity that could degrade type IV collagen. Peak enzyme activity was observed on days 8-10 of embryogenesis, which coincides with the stage of maximum angiogenesis. This activity decreased to lowest values at days 13-15 and increased thereafter up to day 20. Maximum rate of collagen biosynthesis in CAM was observed between days 7 and 10, with a drastic decrease at day 12, when vascular density has reached a plateau. The type IV collagen-degrading activity of CAM was of the metalloprotease type, since it was inhibited by 1,10-phenanthroline and EDTA but was also partially inhibited by serine and thiol protease inhibitors.