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Expression of membrane-type 1, 2, and 3 matrix metalloproteinases messenger RNA in ovarian carcinoma cells in serous effusions.

We studied the levels of matrix metalloproteinase (MMP)-2, membrane-type (MT)1-MMP, MT2-MMP, and MT3-MMP in 43 malignant pleural and peritoneal effusions using reverse transcription-polymerase chain reaction (RT-PCR) and cellular localization of MT1-MMP in 66 effusion specimens and 85 corresponding primary and metastatic tumors using messenger RNA (mRNA) in situ hybridization (ISH). In 43 effusions, MMP-2 mRNA was detected in 37, MT1-MMP in 25, and MT2-MMP in 32. Expression of MT1-MMP and MT2-MMP was found in 21 specimens; in 16 MT-MMP-positive specimens, mRNA for only 1 of 2 enzymes was expressed. MT3-MMP mRNA was not detected. High levels of MMP-2 mRNA were detected more often in effusions with high MT1-MMP and/or MT2-MMP mRNA expression. Using ISH, MT1-MMP mRNA was localized to cancer cells in 27 of 58 malignant effusions; focal signals were detected in mesothelial cells in 7 of 42. MT1-MMP was localized to tumor cells in 32 of 85 primary and metastatic solid lesions, and stromal cells expressed MT1-MMP in 3. Tumor cell MT1-MMP expression in effusion specimens did not differ from primary or metastatic lesions. MT-MMP expression in tumor cells in effusions showed no association with effusion site or tumor type using ISH and RT-PCR.

Ascitic Fluid↗

Ciprofloxacin enhances the stimulation of matrix metalloproteinase 3 expression by interleukin-1beta in human tendon-derived cells. A potential mechanism of fluoroquinolone-induced tendinopathy.

OBJECTIVE: To determine whether the fluoroquinolone antibiotic ciprofloxacin, which can cause tendon pain and rupture in a proportion of treated patients, affects the expression of matrix metalloproteinases (MMPs) in human tendon-derived cells in culture. METHODS: Cell cultures were derived from 6 separate tendon explants, and were incubated in 6-well culture plates for 2 periods of 48 hours each, with ciprofloxacin (or DMSO in controls) and interleukin-1beta (IL-1beta), alone and in combination. Samples of supernatant medium from the second 48-hour incubation were assayed for MMPs 1, 2, and 3 by Western blotting. RNA was extracted from the cells and assayed for MMP messenger RNA (mRNA) by semiquantitative reverse transcription-polymerase chain reaction, with normalization for GAPDH mRNA. RESULTS: Unstimulated tendon cells expressed low or undetectable levels of MMP-1 and MMP-3, and substantial levels of MMP-2. IL-1beta induced a substantial output of both MMP-1 and MMP-3 into cell supernatants, reflecting increases (typically 100-fold) in MMP mRNA, but had only minor effects on MMP-2 expression. Ciprofloxacin had no detectable effect on MMP output in unstimulated cells. Preincubation with ciprofloxacin potentiated IL-1beta-stimulated MMP-3 output, reflecting a similar effect on MMP-3 mRNA expression. Ciprofloxacin also potentiated IL-1beta-stimulated MMP-1 mRNA expression, but did not potentiate the output of MMP-1, and had no significant effects on MMP-2 mRNA expression or output. CONCLUSION: Ciprofloxacin can selectively enhance MMP expression in tendon-derived cells. Such effects might compromise tendon microstructure and integrity.

Anti-Infective Agents↗

Characterization of collagenase 3 (matrix metalloproteinase 13) messenger RNA expression in the synovial membrane and synovial fibroblasts of patients with rheumatoid arthritis.

OBJECTIVE: To study the localization and cell type-specific expression of collagenase 3 messenger RNA (mRNA) in the synovial membrane, its regulation in primary synovial fibroblasts, and the correlation with systemic markers of inflammation and radiographic damage in rheumatoid arthritis (RA). METHODS: The expression of collagenase 3 mRNA was characterized by Northern blot analysis, reverse transcriptase-polymerase chain reaction, and in situ hybridization. Immunohistochemical detection of cell type-specific antigens was used in combination with in situ hybridization of collagenase 3 mRNA to characterize the cellular origin of collagenase 3 mRNA expression. RESULTS: Collagenase 3 mRNA was detected in synovial membrane specimens of 21 of 36 RA patients (58%) and correlated with an increase in erythrocyte sedimentation rate (P<0.05) and C-reactive protein levels (P<0.005). Collagenase 3 mRNA was localized in fibroblast-like cells of the lining and sublining layers, and at the synovial membrane-cartilage interface. Four of 10 primary synovial fibroblast cell cultures showed basal expression of collagenase 3 mRNA, which was stimulated 2-4-fold upon interleukin-1beta or tumor necrosis factor alpha treatment and, in contrast to interstitial collagenase mRNA, 5-10-fold by increasing the intracellular level of cAMP. The stimulation by cAMP analogs was completely abolished by protein kinase A inhibitors. CONCLUSION: Some RA patients show collagenase 3 mRNA expression in the synovial membrane, which correlates with elevated levels of systemic markers of inflammation in these patients. In synovial fibroblasts, the expression of collagenase 3 and interstitial collagenase mRNA is differentially regulated by distinct protein kinase signal transduction pathways.

1-Methyl-3-isobutylxanthine↗

Autocrine regulation of collagenase 3 (matrix metalloproteinase 13) during osteoarthritis.

OBJECTIVE: To correlate the increased collagenase production previously seen in chondrocytes isolated from osteoarthritic (OA) lesions and the expression of cytokines and cytokine receptors. METHODS: Chondrocytes were isolated from OA cartilage and characterized for synthesis of collagenases, cytokines, and cytokine receptors by Northern and Western blot analyses, RNA protection assay, and flow cytometry. RESULTS: Chondrocytes located in cartilage proximal to the macroscopic OA lesions bound more tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) compared with chondrocytes isolated from morphologically normal cartilage from the same joint. In response to TNFalpha stimulation, messenger RNA (mRNA) levels for the IL-1 receptor I (IL-1RI), IL-1RII, TNF receptor II (TNFR II), and IL-6 receptor as well as the level of proinflammatory cytokines, such as IL-1alpha, IL-1beta, lymphotoxin beta, TNFalpha, and IL-6, also increased. In contrast, treatment with transforming growth factor beta1 (TGFbeta1) resulted in down-regulation of matrix metalloproteinase 1 (MMP-1) and MMP-13 concomitant with a reduction in the levels of mRNA for IL-1RI, IL-1RII, TNFRI, and TNFRII and proinflammatory cytokine levels. In contrast, the levels of mRNA for TGFbeta receptor I, TGFbeta1, and TGFbeta3 were up-regulated. CONCLUSION: These data show that TGFbeta1 has antagonistic effects upon OA chondrocytes, in contrast to the effects seen with TNFalpha. The cyclical course of OA, where a period of active disease is followed by a period of remission, can be explained by a sequential pattern of cytokine stimulation followed by a feedback inhibition of autocrine cytokine production and cytokine receptor expression, thus affecting collagenase synthesis.

Aged↗

Expression and tissue localization of membrane-types 1, 2, and 3 matrix metalloproteinases in rheumatoid synovium.

In vitro, membrane-type matrix metalloproteinases (MT-MMP) are known to activate the zymogen of MMP-2 (proMMP-2, progelatinase A), which is one of the key MMP in joint destruction in rheumatoid arthritis. In the present study, we examined the production and activation of proMMP-2, and the expression of MT1-MMP, MT2-MMP, and MT3-MMP, their correlation with proMMP-2 activation, and their localization in rheumatoid synovial tissue. Using sandwich enzyme immunoassay and gelatin zymography techniques, proMMP-2 production levels and activation ratios were found to be significantly higher in rheumatoid synovium compared with normal synovium (p < 0.01). Quantitative RT-PCR analyses demonstrated that MT1-MMP and MT3-MMP were expressed in all rheumatoid synovial tissue (30 of 30 cases), but that the mean expression level of MT1-MMP was approximately 11-fold higher than MT3-MMP. Significant correlation was found between the mRNA expression level of MT1-MMP and the activation ratio of proMMP-2 (p < 0.01). In situ hybridization indicated that the hyperplastic lining cells of rheumatoid synovium expressed MT1-MMP. Immunohistochemistry demonstrated that MT1-MMP was co-localized with MMP-2 and with a tissue inhibitor of metalloproteinase-2, and was mainly located in the rheumatoid synovial lining cells. In situ zymography of rheumatoid synovium showed gelatinolytic activity, predominantly in the lining cell layer. This activity was blocked when incubated with BB94, a specific MMP inhibitor. These results demonstrate that MT1-MMP plays an important role in the activation of proMMP-2 in the rheumatoid synovial lining cell layer, and suggest that its activity may be involved in the cartilage destruction of rheumatoid arthritis.

Aged↗

Collagenase 3 (matrix metalloproteinase 13) gene expression by HaCaT keratinocytes is enhanced by tumor necrosis factor alpha and transforming growth factor beta.

Collagenase-3 (matrix metalloproteinase 13; MMP-13) is a novel matrix metalloproteinase, the expression of which to date has only been detected in human breast carcinoma tissue and osteoarthritic cartilage. Here, we show that MMP-13 transcripts are expressed by human HaCaT keratinocytes but not by primary human epidermal keratinocytes. The levels of MMP-13 mRNAs in HaCaT cells were enhanced up to 130- and 45-fold by tumor necrosis factor alpha (TNF-alpha) and transforming growth factor beta (TGF-beta), respectively. The maximal induction of MMP-13 mRNAs by TNF-alpha was noted after a 6-h incubation, whereas with TGF-beta, the maximal stimulation was observed after 24 h. The up-regulation of MMP-13 mRNA abundance by TNF-alpha and TGF-beta was dependent on protein synthesis and was prevented partially by dexamethasone and retinoic acid. Nuclear run-on assays demonstrated activation of MMP-13 gene transcription by TNF-alpha maximally at the 2-h time point and by TGF-beta after 12 h of treatment. Incubation of HaCaT keratinocytes with TNF-alpha and TGF-beta also increased production of proMMP-13 into the culture media, as detected by Western blotting. Our data indicate that the MMP-13 gene is expressed by transformed epidermal keratinocytes, suggesting a role for MMP-13 in the invasive capacity of human epidermal malignancies.

Blotting, Northern↗

Elevated expression of membrane-type 1 and 3 matrix metalloproteinases in rat vascular smooth muscle cells activated by arterial injury.

Matrix metalloproteinases (MMPs) play critical roles in tissue remodeling under various physiologic and pathologic conditions. We recently reported the expression of three membrane-type MMPs (MT-MMPs) by cultured vascular smooth muscle cells (SMCs) of rats (Shofuda et al, 1997). To investigate the roles of the MT-MMPs in the matrix remodeling of blood vessels, expression of MT1-MMP and MT3-MMP was examined in normal and balloon-injured rat carotid arteries by in situ hybridization and immunohistochemistry. Both MT-MMP mRNAs were detected in the intimal-dedifferentiated SMCs, but were negligible in the medial SMCs or in any of normal vascular cells. To elucidate the regulatory mechanism for the MT-MMPs expression, effects of various factors on cultured rat SMCs were also examined. MT1-MMP mRNA was constantly expressed at a high level, and its expression was weakly increased by treatment with interleukin-1beta or tumor necrosis factor-alpha. When the cells were incubated with type IV collagen, the MT1 -MMP expression was markedly decreased. On the other hand, expression of MT3-MMP mRNA was strongly increased by platelet-derived growth factor and fibronectin. These results suggest that type IV collagen may act as a negative regulator for the expression of MT1-MMP in the medial SMCs, whereas platelet-derived growth factor and fibronectin may up-regulate MT3-MMP expression under pathologic conditions. Furthermore, the elevated expression of MT1-MMP and MT3-MMP in SMCs was well associated with their dedifferentiated phenotype.

Animals↗

The role of interleukin-1 in the pathogenesis of human intervertebral disc degeneration.

In this study, we investigated the hypotheses that in human intervertebral disc (IVD) degeneration there is local production of the cytokine IL-1, and that this locally produced cytokine can induce the cellular and matrix changes of IVD degeneration. Immunohistochemistry was used to localize five members of the IL-1 family (IL-1alpha, IL-1beta, IL-1Ra (IL-1 receptor antagonist), IL-1RI (IL-1 receptor, type I), and ICE (IL-1beta-converting enzyme)) in non-degenerate and degenerate human IVDs. In addition, cells derived from non-degenerate and degenerate human IVDs were challenged with IL-1 agonists and the response was investigated using real-time PCR for a number of matrix-degrading enzymes, matrix proteins, and members of the IL-1 family. This study has shown that native disc cells from non-degenerate and degenerate discs produced the IL-1 agonists, antagonist, the active receptor, and IL-1beta-converting enzyme. In addition, immunopositivity for these proteins, with the exception of IL-1Ra, increased with severity of degeneration. We have also shown that IL-1 treatment of human IVD cells resulted in increased gene expression for the matrix-degrading enzymes (MMP 3 (matrix metalloproteinase 3), MMP 13 (matrix metalloproteinase 13), and ADAMTS-4 (a disintegrin and metalloproteinase with thrombospondin motifs)) and a decrease in the gene expression for matrix genes (aggrecan, collagen II, collagen I, and SOX6). In conclusion we have shown that IL-1 is produced in the degenerate IVD. It is synthesized by native disc cells, and treatment of human disc cells with IL-1 induces an imbalance between catabolic and anabolic events, responses that represent the changes seen during disc degeneration. Therefore, inhibiting IL-1 could be an important therapeutic target for preventing and reversing disc degeneration.

Adult↗

Differential inhibition of membrane type 3 (MT3)-matrix metalloproteinase (MMP) and MT1-MMP by tissue inhibitor of metalloproteinase (TIMP)-2 and TIMP-3 rgulates pro-MMP-2 activation.

The membrane type (MT)-matrix metalloproteinases (MMPs) constitute a subgroup of membrane-anchored MMPs that are major mediators of pericellular proteolysis and physiological activators of pro-MMP-2. The MT-MMPs also exhibit differential inhibition by members of the tissue inhibitor of metalloproteinase (TIMP) family. Here we investigated the processing, catalytic activity, and TIMP inhibition of MT3-MMP (MMP-16). Inhibitor profile and mutant enzyme studies indicated that MT3-MMP is regulated on the cell surface by autocatalytic processing and ectodomain shedding. Inhibition kinetic studies showed that TIMP-3 is a high affinity inhibitor of MT3-MMP when compared with MT1-MMP (K(i) = 0.008 nm for MT3-MMP versus K(i) = 0.16 nm for MT1-MMP). In contrast, TIMP-2 is a better inhibitor of MT1-MMP. MT3-MMP requires TIMP-2 to accomplish full pro-MMP-2 activation and this process is enhanced in marimastatpretreated cells, consistent with regulation of active enzyme turnover by synthetic MMP inhibitors. TIMP-3 also enhances the activation of pro-MMP-2 by MT3-MMP but not by MT1-MMP. TIMP-4, in contrast, cannot support pro-MMP-2 activation with either enzyme. Affinity chromatography experiments demonstrated that pro-MMP-2 can assemble trimolecular complexes with a catalytic domain of MT3-MMP and TIMP-2 or TIMP-3 suggesting that pro-MMP-2 activation by MT3-MMP involves ternary complex formation on the cell surface. These results demonstrate that TIMP-3 is a major regulator of MT3-MMP activity and further underscores the unique interactions of TIMPs with MT-MMPs in the control of pericellular proteolysis.

Animals↗

Evaluation of the influence of prostaglandin E2 on recombinant equine interleukin-1beta-stimulated matrix metalloproteinases 1, 3, and 13 and tissue inhibitor of matrix metalloproteinase 1 expression in equine chondrocyte cultures.

OBJECTIVE: To determine the effects of prostaglandin E2 (PGE2) on recombinant equine interleukin (IL)-1beta-stimulated expression of matrix metalloproteinases (MMP 1, MMP 3, MMP 13) and tissue inhibitor of matrix metalloproteinase 1 (TIMP 1) in vitro. SAMPLE POPULATION: Cultured equine chondrocytes. PROCEDURE: Stationary monolayers of first-passage chondrocytes were exposed to graduated concentrations of PGE2 with or without a subsaturating dose (50 pg/ml) of recombinant equine IL-1beta (reIL-1beta) to induce expression of MMP 1, MMP 3, MMP 13, and TIMP 1, followed by RNA isolation and northern blotting. In subsequent experiments, gene expression was similarly quantified from mRNA isolated from cultures pretreated with phenylbutazone to quench endogenous PGE2 synthesis, followed by exposure to reIL-1beta and exogenous PGE2 (5 mg/ml) with appropriate controls. RESULTS: Exogenous PGE2 (10 mg/ml) significantly reduced reIL-1beta-induced expression of MMP 1, MMP 3, MMP 13, and TIMP 1. Abrogation of cytokine induction with this dose of PGE2 was comparable to that for dexamethasone (10(-5) M) control. Similarly, pretreatment with phenylbutazone, followed by exposure to relL-1beta and PGE2 (5 mg/ml), was associated with a reduced expression of the genes of interest, an effect that was significant for MMP 1, MMP 13, and TIMP 1. CONCLUSIONS AND CLINICAL RELEVANCE: The MMP and TIMP 1 are important mediators in the pathophysiologic events in osteoarthritis. The potential for physiologically relevant regulation of expression of these genes by PGE2 is a consideration in the use of drugs that inhibit prostanoid synthesis in the treatment of equine arthropathies.

Animals↗

Steps involved in activation of the pro-matrix metalloproteinase 9 (progelatinase B)-tissue inhibitor of metalloproteinases-1 complex by 4-aminophenylmercuric acetate and proteinases.

The precursor of matrix metalloproteinase 9 (pro-MMP-9, progelatinase B) noncovalently binds to tissue inhibitor of metalloproteinases (TIMP)-1 through the C-terminal domain of each molecule. We have isolated the proMMP-9.TIMP-1 complex from the medium of human fibrosarcoma HT-1080 cells and investigated the activation processes of the complex by 4-aminophenylmercuric acetate, trypsin, and matrix metalloproteinase 3 (MMP-3, stromelysin 1). The treatment of the proMMP-9.TIMP-1 complex with 4-aminophenylmercuric acetate or trypsin converts proMMP-9 to lower molecular weight species corresponding to active forms, but no gelatinolytic activity is detected. The lack of enzymic activity results from binding of TIMP-1 to the activated MMP-9. The treatment of the proMMP-9.TIMP-1 complex with a possible physiological proMMP-9 activator, MMP-3, does not reveal any gelatinolytic activity unless the molar ratio of MMP-3 to the complex exceeds 1. This is due to the inhibition of MMP-3 by TIMP-1 forming a ternary proMMP-9.TIMP-1.MMP-3 complex. The formation of the ternary complex weakens the interaction between proMMP-9 and TIMP-1, resulting in partial dissociation of the complex into proMMP-9 and the TIMP-1.MMP-3 complex. When MMP-3 is in excess, the propeptide is completely processed, and the full activity of MMP-9 is detected. Similarly, the proMMP-9.TIMP-1 complex inhibits MMP-1 (interstitial collagenase) and in turn renders the proMMP-9 activable by a catalytic amount of MMP-3. These results suggest that formation of the proMMP-9.TIMP-1 complex regulates extracellular matrix breakdown in tissue by switching the predominant MMP activity from one type to another.

Collagenases↗

Cellular localization of matrix metalloproteinases in the abdominal aortic aneurysm wall.

PURPOSE: This study explores the source(s) of the matrix-degrading proteinases, matrix metalloproteinase 1 (MMP-1; interstitial collagenase), matrix metalloproteinase 3 (MMP-3; stromelysin 1), and matrix metalloproteinase 9 (MMP-9; gelatinase B), previously implicated in abdominal aortic aneurysm (AAA) development. The possible involvement of the plasmin cascade in the activation of these proteinases was also explored by examining the presence of the urokinase-type plasminogen activator (uPA) in aneurysm wall. METHODS: Immunohistochemical techniques were used to detect the presence of MMP-1, MMP-3 and MMP-9 proteins and uPA in fixed, paraffin-embedded tissue sections from AAA (n = 10) and control (n = 2) aortas. RESULTS: The MMP-9 protein was localized to mononuclear cells in the AAA wall. Dual-labeling techniques confirmed the identity of these cells as macrophages. The MMP-3 protein and uPA were also detected primarily in the macrophage-like mononuclear cells infiltrating the aneurysmal aorta. Immunoreactive material to MMP-1 was demonstrated in mesenchymal cells of the AAA wall suggesting alternative expression and delivery of this enzyme in AAA. CONCLUSIONS: This work establishes the role of macrophages in the delivery, expression, and possible activation of matrix destructive proteinases during AAA pathogenesis and suggests a role for the activation of MMPs in the progression of the disease.

Antibodies, Monoclonal↗

Gene expression of matrix metalloproteinases 1, 3, and 9 by chondrocytes in osteoarthritic human knee articular cartilage is zone and grade specific.

OBJECTIVES: Matrix metalloproteinases (MMPs) are thought to be major mediators of cartilage destruction. Osteoarthritis (OA) is characterised by cartilage degradation. This study explores gene expression of three MMPs in articular chondrocytes during the histological development of the cartilage lesion of OA. METHODS: Biopsy specimens of human normal and OA cartilage, classified into four grades on the basis of histology, were probed for MMPs 1, 3, and 9 using 35S-labelled cDNA probes. The signal was measured at four different depths (zones) using an automated image analyser and compared with signal from sections probed with lambda DNA. Rheumatoid synovium was used as a positive control for MMP gene expression. RESULTS: Rheumatoid tissue contained mRNA for all three MMPs. Expression in chondrocytes varied with the depth of the chondrocyte in the cartilage and the histomorphological extent of the OA changes. There was no detectable mRNA signal for these three MMPs in normal cartilage. In general, in OA, MMP-1 gene expression was greatest in the superficial cartilage in established disease. By contrast mRNAs for MMP-3 and 9 were expressed deeper in the cartilage, MMP-9 early in disease and MMP-3 with a biphasic pattern in early and late stage disease, most pronounced in the latter. This was a consequence of differential expression in single cells and chondrocyte clusters in late disease. CONCLUSION: The data indicate that expression of genes for MMPs 1, 3, and 9 is differentially regulated in human articular chondrocytes and, in individual cells, is related to the depth of the chondrocyte below the cartilage surface and the nature and extent of the cartilage lesion.

Cartilage, Articular↗

Effects of interleukin-1beta and tumor necrosis factor-alpha on expression of matrix-related genes by cultured equine articular chondrocytes.

OBJECTIVE: To determine the effects of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) on expression and regulation of several matrix-related genes by equine articular chondrocytes. SAMPLE POPULATION: Articular cartilage harvested from grossly normal joints of 8 foals, 6 yearling horses, and 8 adult horses. PROCEDURE: Chondrocytes maintained in suspension cultures were treated with various doses of human recombinant IL-1beta or TNF-alpha. Northern blots of total RNA from untreated and treated chondrocytes were probed with equine complementary DNA (cDNA) probes for cartilage matrix-related genes. Incorporation of 35S-sulfate, fluorography of 14C-proline labeled medium, zymography, and western blotting were used to confirm effects on protein synthesis. RESULTS: IL-1beta and TNF-alpha increased steady-state amounts of mRNA of matrix metalloproteinases 1, 3, and 13 by up to 100-fold. Amount of mRNA of tissue inhibitor of metalloproteinase-1 also increased but to a lesser extent (1.5- to 2-fold). Amounts of mRNA of type-II collagen and link protein were consistently decreased in a dose-dependent manner. Amount of aggrecan mRNA was decreased slightly; amounts of biglycan and decorin mRNA were minimally affected. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment of cultured equine chondrocytes with IL-1beta or TNF-alpha resulted in marked alterations in expression of various matrix and matrix-related genes consistent with the implicated involvement of these genes in arthritis. Expression of matrix metalloproteinases was increased far more than expression of their putative endogenous inhibitor. Results support the suggestion that IL-1beta and TNF-alpha play a role in the degradation of articular cartilage in arthritis.

Animals↗

Genotypes and haplotypes of matrix metalloproteinase 1, 3 and 12 genes and the risk of lung cancer.

The MMPs (matrix metalloproteinases) are a family of secreted zinc metalloproteases that degrade the collagens of the extracellular matrix important in tissue remodeling and repair during development and inflammation. We investigated the associations between polymorphisms of MMP-1 (-1607 1G/2G, rs1799750), MMP-3 (-1171 5A/6A, rs3025058), and MMP-12 (-82AG, rs2276109, and 1082A/G, rs652438) and the risk of lung cancer in 2014 Caucasian lung cancer patients and 1323 healthy controls. The results were analyzed using logistic regression models, adjusting for covariates. The four polymorphisms were in Hardy-Weinberg disequilibrium. Except for the 1G-1082A, the other linkage disequilibrium tests between the four MMP polymorphisms were statistically significant (P < 0.001). There was no overall association between individual MMP polymorphism and the risk of lung cancer. The MMP polymorphisms jointly were associated with a non-statistically significant higher risk of lung cancer, with the adjusted odds ratio (AOR) of subjects with 5+ variant alleles versus zero variant allele of 1.31 [95% confidence interval (CI), 0.92-1.88]. Stronger associations were observed in never-smokers and males, with the corresponding AORs of 2.44 (95%CI, 1.10-5.43, P(trend) = 0.04) in never smokers and 1.35 (95%CI, 0.79-2.30, P(trend) = 0.04) in men. In haplotype analysis, the 1G-6A-82A-1082G haplotype was associated with higher risk of lung cancer among never smokers, with the AOR of 3.65 (95%CI, 1.62-8.20) when compared with the most common 1G-5A-82A-1082A haplotype. In conclusion, the combined MMP genotypes and associated haplotypes may be associated with higher risk of lung cancer, particularly among never smokers and men.

Adult↗

Immunolocalization of matrix metalloproteinases in partial-thickness defects in pig articular cartilage. A preliminary report.

BACKGROUND: Partial-thickness defects in mature articular cartilage do not heal spontaneously. Attempts at repair often result in limited integration between the repair tissue and the surrounding cartilage, with formation of chondrocyte clusters adjacent to a zone of cartilage necrosis. In wound repair, spatially and temporally controlled expression of matrix metalloproteinases and their inhibitors have been implicated in proteolytic degradation of damaged extracellular matrix components, but the sequence of events following damage to cartilage is unknown. To determine this sequence, we studied the distribution of matrix metalloproteinases and their inhibitors during early in vivo repair of partial-thickness defects in pig articular cartilage. METHODS: With use of a model that elicits the ingrowth of mesenchymal cells into partial-thickness defects, partial-thickness defects were created in knee joint cartilage. The distributions of matrix metalloproteinase-1, 2, 3, 9, 13, and 14; tissue inhibitors of metalloproteinase-1 and 2; and the neoepitope DIPEN341 specifically generated following matrix metalloproteinase cleavage of aggrecan were determined by immunolocalization of repair tissue and surrounding cartilage excised from immature pigs during the first eight weeks of repair and from adult minipigs at eight days and three weeks. RESULTS: Synthesis of matrix metalloproteinase-13 was usually confined to hypertrophic chondrocytes in immature cartilage and to the radial zone in adult cartilage. Following injury, strong induction of matrix metalloproteinase-13 synthesis was observed in chondrocyte clusters surrounding lesions in all of the animals. The migration of macrophages into defects was prominent at two and eight days, with synthesis and deposition of matrix metalloproteinase-9 onto damaged cartilage matrix and newly synthesized matrix in the defect. The DIPEN341 neoepitope was localized to damaged cartilage matrix at eight days and six weeks, indicating partial degradation of aggrecan. Focal synthesis of matrix metalloproteinase-1, 3, and 14 and of tissue inhibitor of metalloproteinase-1 occurred at later times, suggesting continuous remodeling of the increasingly compact repair tissue. CONCLUSIONS: The expression of matrix metalloproteinase-13 by normal hypertrophic chondrocytes and the induction of synthesis in chondrocyte clusters adjacent to the zone of cartilage necrosis suggest that this enzyme participates in the pericellular proteolysis required for lacunar expansion. The localization of matrix metalloproteinase-9 to damaged cartilage matrix suggested matrix proteolysis, which was confirmed with DIPEN341 localization. Reduced matrix metachromasia persisted and was colocalized with DIPEN341 at six weeks. However, under the conditions investigated, there was only limited proteolytic degradation in the zone of cartilage necrosis. This may render the zone mechanically weakened, thereby contributing to subsequent instability of the region, and may form a barrier to integration of repair tissue with viable cartilage. CLINICAL RELEVANCE: Osteoarthritis initially involves the superficial layers of cartilage. The development of procedures to promote the healing or repair of early defects will have major advantages in terms of disease alleviation as well as economic importance. Identification of the enzymes involved in the early repair of partial-thickness defects in articular cartilage is clinically relevant because proteolysis of damaged matrix has to take place in order for repair tissue to integrate with surrounding healthy cartilage.

Aggrecans↗

Distribution pattern of matrix metalloproteinases 1, 2, 3, and 9, tissue inhibitors of matrix metalloproteinases 1 and 2, and alpha 2-macroglobulin in cases of generalized AA- and AL amyloidosis.

Matrix metalloproteinases (MMPs) degrade basement membranes and connective tissue and play an essential role in the homeostasis of the extracellular matrix which is disrupted by the deposition of amyloid. This immunohistochemical study investigated the distribution pattern of matrix metalloproteinases (MMP-1, -2, -3, and -9) and their inhibitors [alpha 2-macroglobulin (alpha 2-M), tissue inhibitors of MMPs (TIMP)-1, and TIMP-2] in human AA- and AL amyloid deposits. Specimens of liver, kidney, and spleen from 22 autopsy cases were investigated. Nine patients had suffered from generalized AA amyloidosis, eight from generalized AL amyloidosis, and five from rheumatoid arthritis or tuberculosis with no histological evidence of amyloid. In all amyloidotic and non-amyloidotic patients, each protease and protease inhibitor was detected in almost every organ investigated. In the amyloidotic cases, there was no indication that a specific protease or protease inhibitor was absent or expressed, but a difference was observed in their spatial distribution patterns. The most noticeable difference was found in immunostaining of amyloid. Only MMP-1, -2, and -3, and alpha 2-M were present in AA amyloid deposits, and only TIMP-1 and TIMP-2 were found in deposits of AL amyloid. This is the first study to show that MMP-1, -2, and -3 are present in AA amyloid deposits. They may be involved in tissue remodeling or in proteolysis of the precursor and fibril proteins.

Adult↗