Inhibition of Invasion by Polyphenols from Citrus Fruit and Berries in Human Malignant Glioma Cells In Vitro.

BACKGROUND/AIM: The outlook for patients with high grade glioma (HGG) remains dismal. Hence, attention has focused on numerous innovative treatments. Our group has proposed a strategy on the use of a combination of polyphenols, as anti-invasive agents for the management of these neoplasms. MATERIALS AND METHODS: The aim of this study was to evaluate the in vitro effects of citrus flavonoids (tangeretin, nobiletin, naringin and limonin) and berry extracts (chokeberry, elderberry and bilberry) on selected mediators of invasion in 2 HGG cell cultures. RESULTS: The IC50 values could only be determined for tangeretin and chokeberry extract. The rest were non-functional in this context. Immunocytochemistry and flow cytometry results showed that chokeberry extract was most effective in down-regulating the expression of CD44. Similarly, RT-PCR data supported its ability to reduce gene expression of MMP-14 and EGFR. 2D invasion assays confirmed that inhibition is greater with chokeberry extract. CONCLUSION: Both polyphenols have anti-invasive potential but chokeberry extract is a stronger agent for glioma management.

Preclinical Efficacy of Endoglin-Targeting Antibody-Drug Conjugates for the Treatment of Ewing Sarcoma.

PURPOSE: Endoglin (ENG; CD105) is a coreceptor of the TGFß family that is highly expressed in proliferating endothelial cells. Often coopted by cancer cells, ENG can lead to neo-angiogenesis and vasculogenic mimicry in aggressive malignancies. It exists both as a transmembrane cell surface protein, where it primarily interacts with TGFß, and as a soluble matricellular protein (sENG) when cleaved by matrix metalloproteinase 14 (MMP14). High ENG expression has been associated with poor prognosis in Ewing sarcoma, an aggressive bone cancer that primarily occurs in adolescents and young adults. However, the therapeutic value of ENG targeting has not been fully explored in this disease. EXPERIMENTAL DESIGN: We characterized the expression pattern of transmembrane ENG, sENG, and MMP14 in preclinical and clinical samples. Subsequently, the antineoplastic potential of two novel ENG-targeting monoclonal antibody-drug conjugates (ADC), OMTX503 and OMTX703, which differed only by their drug payload (nigrin-b A chain and cytolysin, respectively), was assessed in cell lines and preclinical animal models of Ewing sarcoma. RESULTS: Both ADCs suppressed cell proliferation in proportion to the endogenous levels of ENG observed in vitro. Moreover, the ADCs significantly delayed tumor growth in Ewing sarcoma cell line-derived xenografts and patient-derived xenografts in a dose-dependent manner. CONCLUSIONS: Taken together, these studies demonstrate potent preclinical activity of first-in-class anti-ENG ADCs as a nascent strategy to eradicate Ewing sarcoma.

Involvement of Catechols in Acteoside in the Activation of Promatrix Metalloproteinase-2 and Membrane Type-1-Matrix Metalloproteinase Expression via a Phosphatidylinositol-3-Kinase Pathway in Human Dermal Fibroblasts.

Granulation tissue formation during skin wound healing requires the migration and proliferation of dermal fibroblasts in the wound site, where a subsequent remodeling of extracellular matrices (ECM) occurs. An abnormality of ECM remodeling within the healing wound leads to fibrosis and a contracted scar. To evaluate whether acteoside, a phenylethanoid glycoside isolated from the leaves of Rehmannia glutinosa LIBOSCH., exhibits wound-healing actions, we examined the effect of acteoside on the expression of matrix metalloproteinases (MMPs) in normal human dermal fibroblasts (NHDF). Acteoside dose- and time-dependently augmented the activation of the precursor of MMP-2 (proMMP-2/progelatinase A) in untreated- and interleukin-1ß-treated NHDF, while the alteration of the MMP-2 gene expression was negligible. The acteoside-induced proMMP-2 activation was associated with the augmented membrane-type 1 MMP (MT1-MMP) expression in the NHDF. In addition, the proMMP-2 activation was enhanced by two aglycones in acteoside: caffeic acid and 3,4-dihydroxyphenylethanol, which consist of catechol. However, there was no change in the proMMP-2 activation in other catechol derivatives: homovanillyl alcohol- and homovanillic acid-treated NHDF, indicating that catechols in acteoside were requisite for the regulation of the MMP activation and expression in NHDF. Furthermore, the proMMP-2 activation by acteoside was selectively inhibited by LY294002, a potent phosphatidylinositol-3-kinase (PI3K) inhibitor. These results provide novel evidence that acteoside augments proMMP-2 activation along with an increase in MT1-MMP expression through a PI3K signal pathway in NHDF. Thus, acteoside is likely to be an attractive candidate that facilitates ECM remodeling in the skin wound repair process.

Melatonin reduces two-cell block via nonreceptor pathway in mice.

Embryo development block seriously limits the success of in vitro embryo production and assisted reproductive technology. Although numerous researchers have explored this problem, it remains to be solved. In this study, we found that melatonin supplementation at 10-8 and 10-9 M in M16 significantly reduced two-cell block of mouse embryos. When those melatonin-treated four-cell embryos were transplanted into the oviducts of female recipient mice, the litter sizes were significantly increased compared with those of the controls. Mechanism study discovered that melatonin treatment markedly reduced reactive oxygen species and mitochondrial superoxide. Quantitative polymerase chain reaction revealed that melatonin significantly upregulated the transcription of catalase, superoxide dismutase 2, glutathione peroxidase, and the antiapoptotic factors Bcl-2 and Bcl-x while downregulated the transcription of pro-apoptotic genes p53 and Bax. In addition, we found Dux, an important gene which promotes zygotic genome activation, and zygotic genes (zinc finger and SCAN4B and eukaryotic translation initiation factor 1A) were all increased after melatonin treatment. Melatonin membrane receptors have two isoforms, melatonin receptor 1 and 2 (MT1, MT2). Further studies with luzindole (a nonselective MT1 and MT2 antagonist) demonstrated that the beneficial effects of melatonin on reducing two-cell block were not mediated by the melatonin membrane receptors. This study shows that melatonin can be used for improving the embryo quality and production efficiency cultured in vitro and also identifies the underlying mechanism by which melatonin decreases two-cell block.

Epitope-specific affinity maturation improved stability of potent protease inhibitory antibodies.

Targeting effectual epitopes is essential for therapeutic antibodies to accomplish their desired biological functions. This study developed a competitive dual color fluorescence-activated cell sorting (FACS) to maturate a matrix metalloprotease 14 (MMP-14) inhibitory antibody. Epitope-specific screening was achieved by selection on MMP-14 during competition with N-terminal domain of tissue inhibitor of metalloproteinase-2 (TIMP-2) (nTIMP-2), a native inhibitor of MMP-14 binding strongly to its catalytic cleft. 3A2 variants with high potency, selectivity, and improved affinity and proteolytic stability were isolated from a random mutagenesis library. Binding kinetics indicated that the affinity improvements were mainly from slower dissociation rates. In vitro degradation tests suggested the isolated variants had half lives 6-11-fold longer than the wt. Inhibition kinetics suggested they were competitive inhibitors which showed excellent selectivity toward MMP-14 over highly homologous MMP-9. Alanine scanning revealed that they bound to the vicinity of MMP-14 catalytic cleft especially residues F204 and F260, suggesting that the desired epitope was maintained during maturation. When converted to immunoglobulin G, B3 showed 5.0 nM binding affinity and 6.5 nM inhibition potency with in vivo half-life of 4.6 days in mice. In addition to protease inhibitory antibodies, the competitive FACS described here can be applied for discovery and engineering biosimilars, and in general for other circumstances where epitope-specific modulation is needed.

Statin treatment reduces matrix degradation capacity of proinflammatory polarized macrophages.

BACKGROUND AND AIMS: Macrophages are versatile immune cells involved in tissue degradation and remodeling. Proinflammatory macrophages have the highest capacity of matrix degradation and proteolysis. Within atherosclerotic lesions, proinflammatory macrophages are associated with unstable plaques. Statins have been demonstrated to increase plaque stability. Possible changes of polarized macrophage tissue degradation behavior under statin treatment are currently unknown. METHODS: Polarized macrophages were tested in vitro for matrix degradation capacity with or without statin treatment. RESULTS: Proinflammatory macrophages show high matrix degradation capacity, which is lost after statin treatment. Statin concentrations were within a physiological range and did not influence overall macrophage polarization. Proinflammatory macrophages showed however a loss of filopodia where activators of MMPs are located. Loss of matrix degradation in proinflammatory macrophages was associated with changes of MMP14 activation and loss of uPAR localization at filopodia. Supplementation of mevalonate restored localization of uPAR to cellular protrusions and matrix degradation capacity. CONCLUSION: Statins reduce the matrix degradation potential of proinflammatory macrophages by reducing uPAR localization to cellular filopodia and reducing intracellular MMP14 activation.

Biophysical evidence for differential gallated green tea catechins binding to membrane type-1 matrix metalloproteinase and its interactors.

Membrane type-1 matrix metalloproteinase (MT1-MMP) is a transmembrane MMP which triggers intracellular signaling and regulates extracellular matrix proteolysis, two functions that are critical for tumor-associated angiogenesis and inflammation. While green tea catechins, particularly epigallocatechin gallate (EGCG), are considered very effective in preventing MT1-MMP-mediated functions, lack of structure-function studies and evidence regarding their direct interaction with MT1-MMP-mediated biological activities remain. Here, we assessed the impact in both cellular and biophysical assays of four ungallated catechins along with their gallated counterparts on MT1-MMP-mediated functions and molecular binding partners. Concanavalin-A (ConA) was used to trigger MT1-MMP-mediated proMMP-2 activation, expression of MT1-MMP and of endoplasmic reticulum stress biomarker GRP78 in U87 glioblastoma cells. We found that ConA-mediated MT1-MMP induction was inhibited by EGCG and catechin gallate (CG), that GRP78 induction was inhibited by EGCG, CG, and gallocatechin gallate (GCG), whereas proMMP-2 activation was inhibited by EGCG and GCG. Surface plasmon resonance was used to assess direct interaction between catechins and MT1-MMP interactors. We found that gallated catechins interacted better than their ungallated analogs with MT1-MMP as well as with MT1-MMP binding partners MMP-2, TIMP-2, MTCBP-1 and LRP1-clusterIV. Overall, current structure-function evidence supports a role for the galloyl moiety in both direct and indirect interactions of green tea catechins with MT1-MMP-mediated oncogenic processes.

Role of ß-catenin signaling in the anti-invasive effect of the omega-3 fatty acid DHA in human melanoma cells.

BACKGROUND: We previously found that docosahexaenoic acid (DHA), a dietary polyunsaturated fatty acid present at high level in fatty fish, inhibited cell growth and induced differentiation of melanoma cells in vitro by increasing nuclear ß-catenin content. An anti-neoplastic role of nuclear ß-catenin was suggested in melanoma, and related to the presence in the melanocyte lineage of the microphtalmia transcription factor (MITF), which interferes with the transcription of ß-catenin/TCF/LEF pro-invasive target genes. OBJECTIVE: In the present work we investigated if DHA could inhibit the invasive potential of melanoma cells, and if this effect could be related to DHA-induced alterations of the Wnt/ß-catenin signaling, including changes in MITF expression. METHODS: WM115 and WM266-4 human melanoma, and B16-F10 murine melanoma cell lines were used. Cell invasion was evaluated by Wound Healing and Matrigel transwell assays. Protein expression was analyzed by Western Blotting and ß-catenin phosphorylation by immunoprecipitation. The role of MITF in the anti-invasive effect of DHA was analyzed by siRNA gene silencing. RESULTS: We found that DHA inhibited anchorage-independent cell growth, reduced their migration/invasion in vitro and down-regulated several Matrix Metalloproteinases (MMP: MMP-2, MT1-MMP and MMP-13), known to be involved in melanoma invasion. We related these effects to the ß-catenin increased nuclear expression and PKA-dependent phosphorylation, as well as to the increased expression of MITF. CONCLUSION: The data obtained further support the potential role of dietary DHA as suppressor of melanoma progression to invasive malignancy through its ability to enhance MITF expression and PKA-dependent nuclear ß-catenin phosphorylation.

Selective Inhibition of MMP-2 Does Not Alter Neurological Recovery after Spinal Cord Injury.

Matrix metalloproteinase (MMP)-2 knockout (KO) mice show impaired neurological recovery after spinal cord injury (SCI), suggesting that this proteinase is critical to recovery processes. However, this finding in the KO has been confounded by a compensatory increase in MMP-9. We synthesized the thiirane mechanism-based inhibitor ND-378 and document that it is a potent (nanomolar) and selective slow-binding inhibitor of MMP-2 that does not inhibit the closely related MMP-9 and MMP-14. ND-378 crosses the blood-spinal cord barrier, achieving therapeutic concentrations in the injured spinal cord. Spinal-cord injured mice treated with ND-378 showed no change in long-term neurological outcomes, suggesting that MMP-2 is not a key determinant of locomotor recovery.

Angelica acutiloba Kitagawa Extract Attenuates DSS-Induced Murine Colitis.

We examined the protective effects of Angelica acutiloba Kitagawa (AAK) extract on a murine model of acute experimental colitis. Colitis was induced by 4% dextran sulfate sodium (DSS) in the drinking water of male C57BL/6 mice, for 7 consecutive days. Oral administration of AAK extract (500 mg/kg/day) significantly alleviated DSS-induced symptoms such as anorexia, weight loss, events of diarrhea or bloody stools, and colon shortening. Histological damage was also ameliorated, as evidenced by the architectural preservation and suppression of inflammatory cell infiltration in colonic samples. Treatment improved the colonic mRNA expression of different inflammatory markers: cytokines, inducible enzymes, matrix metalloproteinases, and tight junction-related proteins. In the isolated serum, IgE levels were downregulated. Collectively, these findings indicate the therapeutic potentials of AAK as an effective complementary or alternative modality for the treatment of ulcerative colitis.

Direct production of functional matrix metalloproteinase--14 without refolding or activation and its application for in vitro inhibition assays.

Human matrix metalloproteinase (MMP)-14, a membrane-bound zinc endopeptidase, is one of the most important cancer targets because it plays central roles in tumor growth and invasion. Large amounts of active MMP-14 are required for cancer research and the development of chemical or biological MMP-14 inhibitors. Current methods of MMP-14 production through refolding and activation are labor-intensive, time-consuming, and often associated with low recovery rates, lot-to-lot variation and heterogeneous products. Here, we report direct production of the catalytic domain of MMP-14 in the periplasmic space of Escherichia coli. 0.5 mg/L of functional MMP-14 was produced without tedious refolding or problematic activation process. MMP-14 prepared by simple periplasmic treatment can be readily utilized to evaluate the potencies of chemical and antibody-based inhibitors. Furthermore, co-expression of both MMP-14 and antibody Fab fragments in the periplasm facilitated inhibitory antibody screening by avoiding purification of MMP-14 or Fabs. We expect this MMP-14 expression strategy can expedite the development of therapeutic drugs targeting MMPs with biological significance.

Pressure and Temperature Effects on the Activity and Structure of the Catalytic Domain of Human MT1-MMP.

Membrane type 1-matrix metalloproteinase (MT1-MMP or MMP-14) is a zinc-transmembrane metalloprotease involved in the degradation of extracellular matrix and tumor invasion. While changes in solvation of MT1-MMP have been recently studied, little is known about the structural and energetic changes associated with MT1-MMP while interacting with substrates. Steady-state kinetic and thermodynamic data (including activation energies and activation volumes) were measured over a wide range of temperatures and pressures by means of a stopped-flow fluorescence technique. Complementary temperature- and pressure-dependent Fourier-transform infrared measurements provided corresponding structural information of the protein. MT1-MMP is stable and active over a wide range of temperatures (10-55 °C). A small conformational change was detected at 37 °C, which is responsible for the change in activity observed at the same temperature. Pressure decreases the enzymatic activity until complete inactivation occurs at 2 kbar. The inactivation is associated with changes in the rate-limiting step of the reaction caused by additional hydration of the active site upon compression and/or minor conformational changes in the active site region. Based on these data, an energy and volume diagram could be established for the various steps of the enzymatic reaction.

Oryeongsan suppressed high glucose-induced mesangial fibrosis.

BACKGROUND: The pathological change of kidney in diabetic nephropathy is represented hypertrophy, inflammation, and renal fibrosis. Oryeongsan, traditional oriental herbal formula, is widely used for the treatment of nephrosis, dropsy, and uremia. This study was examined whether Oryeongsan attenuate high-glucose (HG)-promoted rat mesangial cell fibrosis and matrix accumulation, major features of diabetic glomerulosclerosis. METHODS: Oryeongsan was mixed traditional herbal medicine, Alisma orientale Juz, Polyporus umbellatus Fries, Atractylodes macrocephala Koidez, Poria cocos Wolf and Cinnamomum Cassia Presl (5:3:3:1). Renoprotective role in diabetic nephropathy of Oryeongsan was evaluated by [(3)H]-thymidine incorporation, Western blot, RT-qPCR and immunofluorescence microscopy assay. RESULTS: Rat mesangial cell proliferation induced by HG was significantly accelerated, which was inhibited by Oryeongsan in a dose dependent manner. HG enhanced expression of fibrosis biomarkers such as collagen IV and connective tissue growth factor (CTGF), which was markedly attenuated by Oryeongsan. Oryeongsan increased HG-inhibited membrane type-1 matrix metalloproteinase expression (MT1-MMP) and MMP-2 promotor activity, whereas suppressed HG-induced tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) expression. Moreover, Oryeongsan promoted extracellular matrix degradation through disturbing transforming growth factor ß (TGF-ß)-Smad signaling. This study further revealed that Oryeongsan ameliorated HG-induced mesangial inflammation accompanying induction of intracellular cell adhesion molecule-1 (ICAM-1) and monocyte chemoattractant protein-1 (MCP-1). Moreover, pretreatment of Oryeongsan inhibited NF-κB translocation in HG-exposed mesangial cell. CONCLUSION: These results demonstrate that Oryeongsan has protective effect against renal proliferation, fibrosis, and inflammation. Therefore Oryeongsan may be specific therapies targeting renal dysfunction leading to diabetic nephropathy.

[Study the effects of Salvia miltiorrhiza monomer IH764-3 on the expression of matrix metalloproteinase in lungs of rats exposed to Paraquat (PQ)].

OBJECTIVE: To observe the expression of the matrix metalloproteinase 2 (MMP-2) and membrane-type 1 metalloproteinase (MT1-MMP) in lung of rats exposed to paraquat (PQ) and the effects of Salvia miltiorrhiza monomer IH764-3 on above expression. METHODS: Ninety adult healthy Sprague-Dawley (SD) rats were randomly divided into the control group (group A, 6 rats), the exposure group (group B, 42 rats) and the group treated by Salvia miltiorrhiza monomer IH764-3 (group C, 42 rats). The group B and C were treated intragastrically with 1ml of PQ (50 mg/kg), and the group A was treated intragastrically with normal saline. The group C was treated intraperitoneally with 1 ml Salvia miltiorrhiza monomer IH764-3 at the dose of 40 mg/kg a day. The group A and B were treated intraperitoneally with 1 ml normal saline day. The expression of MMP-2 and MT1-MMP was detected on the 1st, 3rd, 7th, 14th, 21st, 28th and 35th days after exposure for all groups. RESULTS: As compared with the expression level (0.305 ± 0.045) of MMP-2 mRNA in group A, the expression levels of MMP-2 mRNA in Group B significantly increased, which were 0.654 ± 0.077, 0.623 ± 0.051, 0.637 ± 0.024, 0.533 ± 0.043 and 0.552 ± 0.050 on the 1st, 3rd, 7th, 14th, 21st days after exposure, respectively (P < 0.01). As compared with group A, the the expression levels of MMP-2 mRNA on the 1st, 3rd, 7th days in Group C slightly increased, but the expression levels of MMP-2 mRNA on the 1st, 3rd, 7th, 14th, 21st days in Group C were 0.523 ± 0.074, 0.567 ± 0.097, 0.514 ± 0.058, 0.359 ± 0.018 and 0.374 ± 0.020, respectively, which were significantly lower than those in group B (P < 0.01). As compared with the expression level (0.391 ± 0.058) of MT1-MMP mRNA in group A, the expression levels of MT1-MMP mRNA in Group B significantly increased, which were 0.796 ± 0.021, 0.762 ± 0.043, 0.590 ± 0.010, 0.803 ± 0.076 and 0.680 ± 0.034 on the 1st, 3rd, 7th, 14th and 21st days after exposure, respectively (P < 0.01). As compared with group A, the expression levels of MT1-MMP mRNA in Group C significantly increased, which were 0.594 ± 0.010, 0.653 ± 0.044 and 0.564 ± 0.009 on the 1st, 3rd and 21st days after exposure, respectively (P < 0.01). The expression levels of MT1-MMP mRNA in Group C were significantly lower than those in group B (P < 0.05 or P < 0.01). CONCLUSION: The expression changes of MMP-2 and MT1-MMP genes of lungs in rats intragastrically exposed to PQ could result in the unbalance the synthesis and degradation of ECM, which may be a cause of lung fibrosis. The Salvia miltiorrhiza monomer IH764-3 could affect the expression of MMP-2 and MT1-MMP genes to a certain extent, resulting in the reduction of lung fibrosis.

Anti-atherogenic activity of wild grape (Vitis thunbergii) extract antagonizing smooth muscle cell proliferation and migration promoted by neighboring macrophages.

The proliferation and migration of vascular smooth muscle cells (SMCs) play critical roles in intimal thickening and neointimal hyperplasia in early-phase atherosclerosis. This study tested whether wild grape extract (WGE) suppressed the proliferation and migration of human aortic SMCs induced by neighboring macrophages. Cellular expression of fibrogenic connective tissue growth factor (CTGF) and secretion of collagen IV and matrix metalloproteinase (MMP)-2 were determined in SMCs exposed to THP-1-differentiated macrophage-conditioned media. Proliferation was enhanced in SMCs exposed to macrophage-conditioned media collected during the early stage of differentiation, which was attenuated by treatment with ≥ 10 µg/ml WGE. Increased secretion of CTGF and collagen IV macrophage-conditioned media was suppressed in WGE-supplemented SMCs. TGF-ß1-promoted production of CTGF and collagen IV was suppressed by blocking TGF-ß receptors of R1 and R2 in SMCs. WGE repressed macrophage-conditioned media-upregulated MMP-2 secretion, indicating that WGE had an ability to encumber plaque rupture within atherosclerotic lesions. In addition, ≥ 1 µg/ml WGE ameliorated the migration of SMCs promoted by neighboring macrophages. These results demonstrate that WGE retarded neointimal hyperplasia and thickening within atherosclerotic plaques largely comprising of macrophages and SMCs. Therefore, WGE may be developed as an anti-proliferative and anti-migratory agent targeting SMCs in the proximity of newly differentiated and resident macrophages.

Mechanical forces-induced human osteoblasts differentiation involves MMP-2/MMP-13/MT1-MMP proteolytic cascade.

Matrix metalloproteinase (MMP) family proteins play diverse roles in many aspects of cellular processes such as osteoblastic differentiation. Besides, mechanical forces that occur in 3D collagen gel promote the osteoblastic phenotype and accelerate matrix mineralization. Although MMPs have been involved in bone differentiation, the proteolytic cascades triggered by mechanical forces are still not well characterized. In this study, we have investigated the contribution of both proteolytic cascades, MMP-3/MMP-1 and MMP-2/MMP-13/MT1-MMP in the differentiation of human osteoblasts cultured in a floating type I collagen lattice (FL) versus an attached collagen lattice (AL). Compared to AL, contraction of human osteoblasts-populated FL led to a fast (1 day) induction of alkaline phosphatase (ALP), bone sialoprotein (BSP), osteoprotegerin (OPG), and Runx-2 expression. At day 4, osteocalcin (OC) overexpression preceded the formation of calcium-containing nodule formation as assessed by X-ray analyses. MMP-1 and MMP-3 were produced to similar extent by cells cultured in FL and AL, whereas contraction of collagen lattices triggered both mRNA overexpression of MMP-2, MMP-13, and MT1-MMP (i.e., MMP-14), and their activation as evidenced by Western blotting or zymographic analyses. Down-regulating MT1-MMP expression or activity either by siRNA transfection or supplementation of culture medium with TIMP-1 or TIMP-2 highlighted the contribution of that enzyme in OC, ALP, and OPG expression. MMP-2 and MMP-13 were more directly involved in BSP expression. So, these results suggest that the main proteolytic cascade, MMP-2/MMP-13/MT1-MMP, and more particularly, its initial regulator MT1-MMP is involved in osteoblast differentiation through mechanical forces.

Stromal regulation of vessel stability by MMP14 and TGFbeta.

Innate regulatory networks within organs maintain tissue homeostasis and facilitate rapid responses to damage. We identified a novel pathway regulating vessel stability in tissues that involves matrix metalloproteinase 14 (MMP14) and transforming growth factor beta 1 (TGFbeta(1)). Whereas plasma proteins rapidly extravasate out of vasculature in wild-type mice following acute damage, short-term treatment of mice in vivo with a broad-spectrum metalloproteinase inhibitor, neutralizing antibodies to TGFbeta(1), or an activin-like kinase 5 (ALK5) inhibitor significantly enhanced vessel leakage. By contrast, in a mouse model of age-related dermal fibrosis, where MMP14 activity and TGFbeta bioavailability are chronically elevated, or in mice that ectopically express TGFbeta in the epidermis, cutaneous vessels are resistant to acute leakage. Characteristic responses to tissue damage are reinstated if the fibrotic mice are pretreated with metalloproteinase inhibitors or TGFbeta signaling antagonists. Neoplastic tissues, however, are in a constant state of tissue damage and exhibit altered hemodynamics owing to hyperleaky angiogenic vasculature. In two distinct transgenic mouse tumor models, inhibition of ALK5 further enhanced vascular leakage into the interstitium and facilitated increased delivery of high molecular weight compounds into premalignant tissue and tumors. Taken together, these data define a central pathway involving MMP14 and TGFbeta that mediates vessel stability and vascular response to tissue injury. Antagonists of this pathway could be therapeutically exploited to improve the delivery of therapeutics or molecular contrast agents into tissues where chronic damage or neoplastic disease limits their efficient delivery.

[Expression of MT1-MMP and its significance in rabbit VX2 tumor tissues after transarterial embolization with hydroxyapatite nanoparticles].

OBJECTIVE: To study location of MT1-MMP and effect of its change in expression on rabbit VX2 tumor tissues after transarterial embolization with hydroxyapatite nanoparticles loaded with lipiodol. METHODS: Sixty rabbits implanted with tumor tissue of cell line VX2 were divided into three groups (control group, lipiodol group, hydroxyapatite nanoparticles loaded with lipiodol group). The transarterial embolization was performed super-selectively via gastro- duodenal artery of rabbits, each rabbit in control group was inserted with 1 ml normal saline,that in lipiodol group was inserted with 0.3 lipiodol ml/kg, also 0.3 ml hydroxyapatite nanoparticles loaded with lipiodol per kg for that in the last group. Results of embolization were detected by using CT scanning 3 days after operation. After two weeks, all tumors were took out as specimens to investigate location of MT1-MMP in VX2 tumor tissues,and also to determine the change of its expression in tumor tissues after embolization with different medicines, with three-step immunohistochemical technique (S-P). MT1-MMP mRNA was measured by RT-PCR to determine whether there were differences in three groups. Western blot technique was performed to determine difference of MT1-MMP protein expression of in three groups. RESULTS: Immunohistochemical results exposed that MT1-MMP was expressed on membrane of tumor cells and in extracellular matrix of tumor cells. Comparison of MT1-MMP expression in control group with that in other two groups, showed a significant lower level in control group (P < 0.05). There was no difference in MT1-MMP expression between lipiodol group, hydroxyapatite nanoparticles loaded with lipiodol group (P > 0.05). Western blot supported this conclusion. RT-PCR detecting MT1-MMP mRNA was found no differences among three groups (P > 0.05). CONCLUSIONS: MT1-MMP was mainly expressed on membrane of tumor cells and in extracellular matrix of tumor cells. There was an increasing tendency on expression of MT1-MMP in tumor tissues and extracellular matrix after transarterial embolization with hydroxyapatite nanoparticles loaded with lipiodol,it might be one of important mechanisms provoking high recurrence rate for hepatocellular carcinoma after treatment embolization.

The arthritis severity locus Cia5d is a novel genetic regulator of the invasive properties of synovial fibroblasts.

OBJECTIVE: The synovial fibroblast, or fibroblast-like synoviocyte (FLS), has a central role in pannus invasion and destruction of cartilage and bone in rheumatoid arthritis (RA). However, regulation of the FLS remains incompletely understood. The aim of this study was to determine whether the invasive properties of FLS are genetically regulated by arthritis severity loci. METHODS: DA rats (arthritis susceptible) and rat strains congenic for arthritis-protective intervals were studied. Primary FLS cell lines were generated from each strain and used in a well-established FLS invasion model through a collagen-rich barrier. Cells or culture supernatants were analyzed for gene expression, activity of different matrix metalloproteinases (MMPs), cytoskeleton integrity, and cell proliferation. RESULTS: The median number of FLS from DA.F344(Cia5d) rats that invaded through the collagen-rich barrier was reduced 86.5% compared with the median number of invading FLS from DA rats. Histologic examination showed that DA.F344(Cia5d) rats preserved a normal joint without pannus, hyperplasia, or erosions. FLS from DA.F344(Cia5d) rats produced significantly lower levels of active MMP-2 compared with FLS from DA rats, but the levels of proMMP-2 and MMP-2 messenger RNA in DA.F344(Cia5d) rats were similar to those in DA rats. Treatment of FLS from DA rats with an MMP-2 inhibitor reduced cell invasion to a level similar to that in DA.F344(Cia5d) rats, demonstrating that MMP-2 activity accounted for the difference between FLS from these 2 strains. Analysis of MMP-2-activating pathways revealed increased levels of soluble membrane type 1 (MT1)-MMP in DA rats compared with DA.F344(Cia5d) rats. CONCLUSION: These data represent the first evidence for a genetic component in the regulation of FLS invasion. A gene located within the Cia5d interval accounts for this effect and operates via the regulation of soluble MT1-MMP production and MMP-2 activation. These observations suggest novel potential pathways for prognostication and therapy.

Herbal compound 861 regulates mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells.

AIM: To identify the role of herbal compound 861 (Cpd 861) in the regulation of mRNA expression of collagen synthesis- and degradation-related genes in human hepatic stellate cells (HSCs). METHODS: mRNA levels of collagen types I and III, matrix metalloproteinase 1 (MMP-1), matrix metalloproteinase 2 (MMP-2), membrane type-1 matrix metalloproteinase (MT1-MMP), tissue inhibitor of metalloproteinase 1 (TIMP-1), and transforming growth factor beta1 (TGF-beta1) in cultured-activated HSCs treated with Cpd 861 or interferon-gamma (IFN-gamma) were determined by real-time PCR. RESULTS: Both Cpd 861 and IFN-gamma reduced the mRNA levels of collagen type III, MMP-2 and TGF-beta1. Moreover, Cpd 861 significantly enhanced the MMP-1 mRNA levels while down-regulated the TIMP-1 mRNA expression, increasing the ratio of MMP-1 to TIMP-1 to (6.3 + 0.3)- fold compared to the control group. CONCLUSION: The anti-fibrosis function of Cpd 861 may be mediated by both decreased interstitial collagen sythesis by inhibiting the transcription of collagen type III and TGF-beta1 and increased degradation of these collagens by up-regulating MMP-1 and down-regulating TIMP-1 mRNA levels.