Diesel exhaust particles activate the matrix-metalloproteinase-1 gene in human bronchial epithelia in a beta-arrestin-dependent manner via activation of RAS

BACKGROUND

Diesel exhaust particles (DEPs) are globally relevant air pollutants that exert a detrimental human health impact. However, mechanisms of damage by DEP exposure to human respiratory health and human susceptibility factors are only partially known. Matrix metalloproteinase-1 (MMP-1) has been implied as an (etio)pathogenic factor in human lung and airway diseases such as emphysema, chronic obstructive pulmonary disease, chronic asthma, tuberculosis, and bronchial carcinoma and has been reported to be regulated by DEPs.

OBJECTIVE

We elucidated the molecular mechanisms of DEPs' up-regulation of MMP-1.

METHODS/RESULTS

Using permanent and primary human bronchial epithelial (HBE) cells at air-liquid interface, we show that DEPs activate the human MMP-1 gene via RAS and subsequent activation of RAF-MEK-ERK1/2 mitogen-activated protein kinase signaling, which can be scaffolded by beta-arrestins. Short interfering RNA mediated beta-arrestin1/2 knockout eliminated formation, subsequent nuclear trafficking of phosphorylated ERK1/2, and resulting MMP-1 transcriptional activation. Transcriptional regulation of the human MMP-1 promoter was strongly influenced by the presence of the -1607GG polymorphism, present in 60-80% of humans, which led to striking up-regulation of MMP-1 transcriptional activation.

CONCLUSION

Our results confirm up-regulation of MMP-1 in response to DEPs in HBE and provide new mechanistic insight into how these epithelia, the first line of protection against environmental insults, up-regulate MMP-1 in response to DEP inhalation. These mechanisms include a role for the human -1607GG polymorphism as a susceptibility factor for an accentuated response, which critically depends on the ability of beta-arrestin1/2 to generate scaffolding and nuclear trafficking of phosphorylated ERK1/2.

Disruption of Vps4 and JNK function in Drosophila causes tumour growth

Several regulators of endocytic trafficking have recently been identified as tumour suppressors in Drosophila. These include components of the endosomal sorting complex required for transport (ESCRT) machinery. Disruption of subunits of ESCRT-I and –II leads to cell-autonomous endosomal accumulation of ubiquitinated receptors, loss of apicobasal polarity and epithelial integrity, and increased cell death. Here we report that disruption of the ATPase dVps4, the most downstream component of the ESCRT machinery, causes the same array of cellular phenotypes. We find that loss of epithelial integrity and increased apoptosis, but not loss of cell polarity, require the activation of JNK signalling. Abrogation of JNK signalling prevents apoptosis in dVps4 deficient cells. Indeed double deficiency in dVps4 and JNK signalling leads to the formation of neoplastic tumours. We conclude that dvps4 is a tumour suppressor in Drosophila and that JNK is central to the cell-autonomous phenotypes of ESCRT-deficient cells.

[Effects of all-trans retinioic acid and tazarotene on MMP-1 and TIMP-1 expression in cultured human fibroblasts after heat shock]

OBJECTIVE

To investigate the molecular mechanism of dermal damage in heat shock-induced skin aging by observing the expressions of metalloproteinase-1 (MMP-1) and tissue inhibitor of MMP-1 (TIMP-1) in retinoic acid-treated cultured human fibroblasts with heat shock.

METHODS

Cultured human fibroblasts were treated with tazarotene or all-trans-retinioic acid (at-RA) after heat shock for 30 min in 43 degrees celsius; water bath. Twenty-four hours later, MMP-1 and TIMP-1 contents in the supernatant of the cell culture medium were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Both tazarotene and at-RA dose-dependently reduced the expression of MMP-1 and increased the expression of TIMP-1 in cultured human fibroblasts exposed to heat shock, and tazarotene produced stronger effect than at-RA.

CONCLUSION

Retinoic acid can reduce the expression of MMP-1 and increase the expression of TIMP-1 in cultured human fibroblasts, suggesting its therapeutic potential for heat shock-induced skin aging.

Inhibition of histone deacetylases antagonized FGF2 and IL-1beta effects on MMP expression in human articular chondrocytes

Fibroblast growth factor-2 (FGF2) and interleukin-1beta (IL-1beta) stimulate the expression of matrix metalloproteinases (MMPs) in articular chondrocytes, which may contribute to cartilage degradation and development of osteoarthritis. Histone deacetylases (HDACs) have recently been implicated in the regulation of MMP gene expression. To investigate the functional involvement of HDACs in the signaling pathway of FGF2 and IL-1beta, we examined the effects of HDAC inhibition on activities of FGF2 or IL-1beta on gene expression of MMP-1, MMP-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS5), collagen type II, and aggrecan. Human articular chondrocyte cultures were treated with FGF2 or IL-1beta in the presence or absence of HDAC inhibitor (trichostatin A, TSA). Gene expression levels after treatments were assessed using quantitative real time PCR. Results showed that FGF2 and IL-1beta both increased MMP-1 and -13 expression, while IL-1beta also increased MMP-3 mRNA levels. These effects were attenuated in the presence of TSA in a dose dependent manner. In contrast to the effects on MMPs, FGF2 decreased mRNA levels of ADAMTS-5, which was not affected by HDAC inhibition. FGF2, IL-1beta, and TSA inhibited expression of aggrecan, while TSA also decreased mRNA levels of collagen type II. These findings showed that HDAC inhibition antagonized FGF2 and IL-1beta induced MMP expression. Combination of FGF2 and the HDAC inhibitor decreases both anabolic and catabolic genes, which may slow the cartilage turnover and be beneficial for maintaining cartilage integrity.

Cranial osteogenesis and suture morphology in Xenopus laevis: a unique model system for studying craniofacial development

Background

The tremendous diversity in vertebrate skull formation illustrates the range of forms and functions generated by varying genetic programs. Understanding the molecular basis for this variety may provide us with insights into mechanisms underlying human craniofacial anomalies. In this study, we provide evidence that the anuran Xenopus laevis can be developed as a simplified model system for the study of cranial ossification and suture patterning. The head structures of Xenopus undergo dramatic remodelling during metamorphosis; as a result, tadpole morphology differs greatly from the adult bony skull. Because of the extended larval period in Xenopus, the molecular basis of these alterations has not been well studied.

Methodology/Principal Findings

We examined late larval, metamorphosing, and post-metamorphosis froglet stages in intact and sectioned animals. Using micro-computed tomography (μCT) and tissue staining of the frontoparietal bone and surrounding cartilage, we observed that bone formation initiates from lateral ossification centers, proceeding from posterior-to-anterior. Histological analyses revealed midline abutting and posterior overlapping sutures. To determine the mechanisms underlying the large-scale cranial changes, we examined proliferation, apoptosis, and proteinase activity during remodelling of the skull roof. We found that tissue turnover during metamorphosis could be accounted for by abundant matrix metalloproteinase (MMP) activity, at least in part by MMP-1 and -13.

Conclusion

A better understanding of the dramatic transformation from cartilaginous head structures to bony skull during Xenopus metamorphosis may provide insights into tissue remodelling and regeneration in other systems. Our studies provide some new molecular insights into this process.

Identification of a cigarette smoke-responsive region in the distal MMP-1 promoter

Tobacco-related diseases are leading causes of death worldwide, and many are associated with expression of matrix metalloproteinase-1 (MMP-1). We have reported extracellular signal-regulated kinase (ERK)1/2-dependent induction of MMP-1 by cigarette smoke in lung epithelial cells. Our objectives were to define regions of the human MMP-1 promoter required for activation by smoke, to identify differences in responses of the 1G/2G -1607 polymorphic promoters to smoke, and to identify relevant transcription factors whose activity in airway epithelial cells is increased by smoke. The responses of deletion and mutant promoter constructs were measured in transfected cells during exposure to cigarette smoke extract (CSE). DNA oligonucleotide arrays were used to identify transcription factors activated after smoke exposure. CSE activated the MMP-1 promoter, and this induction was prevented by PD98059 blockade of ERK1/2 phosphorylation. Deletion studies revealed the distal 1kb promoter region (-4438 to -3280 upstream of the transcription start site) is essential for CSE induction of MMP-1, and confers activation of a minimal promoter. Studies of 1G and 2G MMP-1 polymorphic promoter variants revealed higher 2G allele basal and CSE-responsive activities than the 1G allele. Cotransfection, mithramycin, and electrophoretic mobility shift assay studies identified activating and repressive roles for Sp1 and PEA3 transcription factors, respectively. Oligonucleotide DNA arrays confirmed activation of Sp1 and PEA3 by CSE. These data demonstrate that the MMP-1 promoter is a direct target of cigarette smoke in lung epithelial cells. This characterization of a smoke response region in the distal MMP-1 promoter has implications for smoking-related diseases such as cancer, heart disease, and emphysema.

Development of a piezoelectric immunosensor for matrix metalloproteinase-1 detection

Monoclonal antibodies were immobilized onto the surface of quartz crystals for the development of a piezoelectric biosensor by means of the Layer by Layer self assembly technique (LBL). The immobilization of immunoglobulins specific to the matrix metalloproteinase-1 (MMP-1) was investigated. To this purpose multilayered ultra-thin films composed by precursor layers of cationic poly(dimethyldiallylammonium) chloride and anionic poly(styrenesulfonate) followed by a monolayer of antibodies were assembled by LBL. A quartz crystal microbalance was used to monitor and optimize the assembly process and to test the immunological activity of the deposited antibody molecules. Atomic force microscopy was used to characterize the surface roughness of the multilayers before and after the deposition of the immunoglobulins. The obtained results confirmed the successful deposition of the proposed immunosensor and demonstrated its high potential for the measurement of analytes of clinical interest.

New glycine substitution mutations in type VII collagen underlying epidermolysis bullosa pruriginosa but the phenotype is not explained by a common polymorphism in the matrix metalloproteinase-1 gene promoter

Epidermolysis bullosa (EB) pruriginosa is an unusual variant of dystrophic EB in which intense itching can lead to striking skin changes resembling acquired skin disorders such as nodular prurigo or hypertrophic lichen planus. The molecular pathology involves mutations in the COL7A1 gene, but the nature of the mutations is similar to those seen in other non-pruritic forms of dystrophic EB. The mechanism of the dramatic phenotypic differences is currently unknown. In this study we assessed the incidence of a common functional polymor-phism in the matrix metalloproteinase-1 gene promoter (1G or 2G at nucleotide -1607) in individuals with EB pruriginosa (n = 27) compared with non-itchy dominant dystrophic EB (n = 23), recessive dystrophic EB (n = 25) and normal controls (n = 50). The hypothesis is that the 2G allele, which was previously shown to increase matrix metalloproteinase-1 activity and lead to increased degradation of type VII collagen, could explain the phenotypic heterogeneity encountered in dominant forms of EB, particularly the itchy EB pruriginosa phenotype. The rationale is that increased type VII collagen degradation could trigger an inflammatory response leading to itchy skin characteristic of EB pruriginosa. All 27 individuals with EB pruriginosa were heterozygous for dominant-negative glycine substitution mutations in the COL7A1 gene, six of which have not been reported previously. The frequency of the 2G allele in these subjects (46.3%) was greater than in the controls (42.0%), but less than in non-itchy dominant dystrophic EB (52.2%) or recessive dystrophic EB (62.0%), indicating that variants of a common functional polymorphism in the matrix metalloproteinase-1 gene promoter do not account for the itchy skin phenotype. The pathophysiology of EB pruriginosa remains unexplained.

Glycosaminoglycans modulate inflammation and apoptosis in LPS-treated chondrocytes

Previous studies reported that hyaluronic acid (HA), chondroitin sulphate (CS) and heparan sulphate (HS) were able to reduce the inflammatory process in a variety of cell types after lipopolysaccharide (LPS) stimulation. The aim of this study was to investigate the anti-inflammatory effect of glycosaminoglycans (GAGs) in mouse articular chondrocytes stimulated with LPS. Chondrocyte treatment with LPS (50 microg/ml) generated high levels of TNF-alpha, IL-1beta, IL-6, IFN-gamma, MMP-1, MMP-13, iNOS gene expression and their related proteins, increased NO concentrations (evaluated in terms of nitrites formation), NF-kappaB activation and IkBalpha degradation as well as apoptosis evaluated by the increase in caspase-3 expression and the amount of its related protein. The treatment of chondrocytes using two different doses (0.5 and 1.0 mg/ml) of HA, chondroitin-4-sulphate (C4S), chondroitin-6-sulphate (C6S), HS, keratan sulphate (KS) and dermatan sulphate (DS) produced a number of effects. HA exerted a very small anti-inflammatory and anti-apoptotic effect while it significantly reduced NO levels, although the effect on iNOS expression and activity was extremely slight. C4S and C6S reduced inflammation mediators and the apoptotic process. C6S failed to decrease NO production, although iNOS expression and activity were significantly reduced. HS, like C4S, was able to reduce all the effects stimulated by LPS treatment. KS and DS produced no reduction in any of the parameters considered. These results give further support to the hypothesis that GAGs actively participate in the regulation of inflammatory and apoptotic processes.

[Matrix metalloproteinases regulations of human gingival fibroblasts by Porphyromonas gingivalis with different fimA genotypes]

OBJECTIVE

To investigate the mechanism of matrix metalloproteinases (MMP) regulations of human gingival fibroblasts (HGF) by challenge of Porphyromonas gingivalis (Pg) with different fimA genotypes.

METHODS

Pg ATCC 33277 (type I), WCSP115 (type II), WCSP1.5 (type III), W83 (type IV) were assessed for their inductions of MMP-1 and MMP-2 expression in HGF. MMP mRNA levels of HGF were determined by real-time RT-PCR and MMP protein levels in culture supernatant were determined by ELISA at different time intervals (1, 3, 6 and 12 h) following continuous co-culture of bacteria with HGF.

RESULTS

When co-cultured with Pg, the MMP-1 and MMP-2 mRNA and protein expression of HGF significantly increased compared with the negative control group (P < 0.01). The group of type II showed greater up-regulated than other fimA genotypes in the mRNA and protein expressions of MMP-1 and MMP-2, MMP-1 mRNA [(28.88 +/- 3.12) - (231.01 +/- 24.99)] and protein [(1.35 +/- 0.17) - (3.08 +/- 1.20)] microg/L; MMP-2 mRNA [(20.42 +/- 2.21) - (188.34 +/- 37.37)] and protein [(2.57 +/- 0.76) - (18.08 +/- 1.15)] microg/L for different time periods; While the group of type III was weaker than other fimA genotypes, the level of MMP-1 mRNA was [(5.11 +/- 0.55) - (72.84 +/- 8.84)] and protein [(0.68 +/- 0.13) - (1.46 +/- 0.94)] microg/L, MMP-2 mRNA [(4.55 +/- 0.55) - (25.75 +/- 3.12)] and protein [(2.28 +/- 0.93) - (11.22 +/- 2.46)] microg/L (P < 0.05).

CONCLUSIONS

Pg could induce HGF to over-express MMP, and fimA genotypes of Pg may be related to this pathogenicity, which might indicate fimA genotype is associated with pathogenesis of Pg.

Matrix metalloproteinase-1 is a crucial bone metastasis factor in a human breast cancer-derived highly invasive cell line

Bone metastasis is one of the most severe cancer complications. To analyze the mechanism of bone metastasis, we established highly invasive cell lines from the human breast cancer cell line MDA-MB-231 using an in vitro sequential selection system. The cell lines, MDA-231-S10 and MDA-231-S5, were more invasive and more motile than the parental cell line. Moreover, MDA-231-S10 metastasized to bone more often when inoculated into the arterial circulation of nude mice. MDA-231-S10-bearing nude mice had a significantly poorer prognosis, and their bony metastatic tumors grew more rapidly than those of the mice bearing the parental cell line (MDA-231-P). Given that a high expression of matrix metalloproteinase (MMP) is reported to be associated with cancer invasiveness, we examined MMP expression. Our results showed that the expression of MMP-3, -5, -7, -9, -13 and -14 was decreased on Multiplex real-time quantitative RT-PCR analysis in the two new cell lines. The zymographic analysis showed no MMP-2 activity and a decreased MMP-9 activity in MDA-231-S10. However, the expression of MMP-1 in MDA-231-S10 was increased. We therefore concluded that MMP-1 plays a crucial role in breast cancer bone metastasis. Furthermore, our MDA-231-derived cell lines are useful analytical models of MMP-1- associated breast cancer bone metastasis.

[Expression of MMPs in gingival crevicular fluid of the rats in different age groups with orthodontic appliances]

PURPOSE

To detect the changes of MMP-1 and MMP-9 in gingival crevicular fluid (GCF) of the rats in different age groups with orthodontic appliances.

METHODS

40 female Wistar rats were selected as the animal model, in which there were 20 6-week-old rats and 20 12-week-old rats. The orthodontic appliances were fixed onto the maxilla of the rats after general anesthesia. The maxillary first molar in the experimental side was drawn medially by applying an excess force of 50 g, with both of the maxillary central incisors as anchorage. In the control side, the maxillary first molar was winded around the dental cervix with ligature wire. The GCF was collected every week, and MMP-1 and MMP-9 were assayed in quantitation by SDS-PAGE, Western blot and Gel Doc quantitative analysis system,respectively. The data were analyzed for ANOVA using SPSS11.0 software package.

RESULTS

No statistical difference of the original concentration of MMP-1 and MMP-9 in GCF was found between adolescent group and adult group (P>0.05), but the adult group's contents were a little more than adolescent group's, and is the same as the 1st week's content. The concentration of MMPs in adult group changed more greatly than that in adolescent group. At the beginning of the experiment, the MMPs' increasing speed of adult group was higher than that of adolescent group. But at the end, the rate of descent of adult group was lower than that of adolescent group.

CONCLUSIONS

The expression of MMPs in gingival crevicular fluid of adult rats is higher than that of adolescent rats. It may be more serious of the orthodontic root resorption in adult rats than in adolescent rats. Supported by Shandong Provincial Natural Science Foundation (Grant No.Y2007C023) and Jinan Science and Technology Development Plan (Grant No.200705089-9).

Equine laminitis: membrane type matrix metalloproteinase-1 (MMP-14) is involved in acute phase onset

REASONS FOR PERFORMING STUDY

Enzymatic separation at the hoof lamellar dermal-epidermal interface may play a role in the development of laminitis and characterising and locating matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of MMPs or TIMPs) in lamellar tissues may further understanding of pathogenesis.

OBJECTIVES

To clone and sequence the cDNA encoding lamellar MMP-14 and TIMP-2, and quantify their transcription in normal and laminitic tissue; and to develop antibody to locate MMP-14 in lamellar tissues.

METHODS

Tissue samples were obtained from an oligofructose induced model of laminitis. Total RNA was isolated, amplified by RT-PCR, cloned into a vector and sequenced. Real-time PCR was used to quantify MMP-14 and TIMP-2 expression. Rabbit anti-equine MMP-14 antibody was developed to analyse MMP-14 proteins from hoof tissues.

RESULTS

Immunohistochemistry detected MMP-14 in the cytoplasm of normal lamellar basal and parabasal cells in close proximity to the lamellar basement membrane. In laminitis affected tissue MMP-14 immunostaining was depleted in lamellar basal cells. Quantitative real-time PCR showed MMP-14 and TIMP-2 expression significantly (P<0.05) elevated and lowered respectively in laminitis affected tissues.

CONCLUSION

MMP-14, located in the cytoplasm of normal lamellar basal cells, disappears during laminitis development. The pathology of laminitis is associated with increased and lowered transcription of MMP-14 and TIMP-2, respectively.

POTENTIAL RELEVANCE

Enzymes have a role in laminitis pathology and inhibition of their activity may prevent laminitis.

Matrix metalloproteinase-1 promoter is associated with body mass index in Korean population with aged greater or equal to 50 years

BACKGROUND

Obesity leads to serious medical complications and impairment of quality of life. We investigated whether inter-individual variability in the risk of obesity was associated with a crucial fibrillar collagen-degrading enzyme matrix metalloproteinase (MMP)-1 polymorphisms (MMP1-1607 and MMP1-519).

METHODS

A population-based cohort study consisting of 530 subjects was performed. Body mass index (BMI), systolic and diastolic blood pressures, fasting blood sugar (FBS), HbA1c, total cholesterol, triglyceride, and high density lipoprotein (HDL)-cholesterol were measured. Study subjects divided into 2 groups, one with BMI<25.0 and the other with BMI>or=25.0, were genotyped for MMP1-1607 and MMP1-519 polymorphisms by pyrosequencing analysis.

RESULTS

Analyses of genotype distributions and allele frequencies revealed that both MMP1-1607 and MMP1-519 polymorphisms were associated with BMI (P=0.041 and 0.043, respectively) in individuals with age>or=50 years. We also observed significantly lower BMI and triglyceride in -519 AA individuals with age>or=50 years than in -519 G allele carriers with age>or=50 years. Logistic regression analysis revealed that the odds ratio (OR) for increase in BMI associated with the G vs. A allele in individuals with age>or=50 was 2.02 [95% confidence interval (CI), 1.13-3.60, P=0.01], which strongly implicates protective role of MMP1-519 A allele against increase in BMI.

CONCLUSION

The frequencies of MMP1-1607 G allele and MMP1-519 A allele are significantly higher in subjects with BMI<25.0 and age>or=50 years, suggesting protective roles of MMP1-1607 G allele and MMP1-519 A allele against increase in BMI in Korean population.

Agonist-like SERM effects on ERalpha-mediated repression of MMP1 promoter activity predict in vivo effects on bone and uterus

Estradiol receptors (ER), ERalpha and ERbeta, are ligand-dependent transcription factors that regulate gene expression. Human and murine genetics suggest that ERalpha is the key target for estradiol action on bone, uterus and breast. To date, the molecular mode of action of estradiol and selective estradiol receptor modulators (SERMs) on bone is not fully understood. This is exemplified by a lack of in vitro assays that reliably predict SERM agonist activities in vivo. We hypothesized that ligand-dependent ERalpha transrepression, via protein-protein interactions at AP1, may predict estrogenic effects on bone. We modeled this using the MMP1 promoter, which encodes an AP1 binding site. We show that ICI-182780, raloxifene, 4-hydroxytamoxifen and estradiol all exhibit differential agonistic activities on the MMP1 promoter by suppressing activity by 20-80%. Transrepression efficacy and potency correlated with both uterotrophic (R(2)=0.98) and osteoprotective (R(2)=0.80) potential in the ovariectomized rat. This identifies MMP1 promoter transrepression as an agonist activity commonly shared by AF2 agonists and "antagonists" alike. Mutation analysis showed that the repression by estradiol and SERMs required correct amino acid sequences in the AF-2 domain. For instance, L540Q AF2 mutation did not alter responses to raloxifene, although it greatly increased responses to ICI-182780 (threefold) and reduced estradiol's effect by 20%. Furthermore, all tested ligands repressed the MMP1 promoter through the L540Q mutant with identical efficacy. Together, these data suggest that estradiol and SERMs share common agonist transcriptional activity via protein-protein interactions at AP1.

Expression of matrix metalloproteinase 1 and 2 in congenital choledochal cyst and its clinical significance

BACKGROUND

The pathogenesis of congenital choledochal cyst (CCC) is still not well elucidated. This study was conducted to detect the expression of matrix metalloproteinase-1 and 2 (MMP-1 and MMP-2) in CCC. The roles of MMP-1 and MMP-2 in CCC formation were also discussed.

METHODS

Specimens of CCC and gallbladders were taken from 53 patients with CCC, including 21 boys and 32 girls aged from 4 months to 17 years (mean: 6.5 years old). Twenty-eight normal gallbladders served as controls. Immunohistochemical method was used to detect the expressions of MMP-1 and MMP-2. Image analysis was made to quantitatively analyze the protein expression.

RESULTS

The expressions of MMP-1 and MMP-2 were located in epithelial cells, matrix cells, and inflammatory cells of the CCC wall. Various expressions were also found in the mucosa membrane cells of the CCC gallbladder. The expressions of MMP-1 and MMP-2 were low in the control group. Quantitatively, the expressions of MMP-1 and MMP-2 in the CCC wall were markedly higher than in the CCC gallbladder and the control group (P<0.01). There was no significant difference between the CCC gallbladder and the control group (P>0.05).

CONCLUSIONS

The expression of MMP-1 and MMP -2 in the CCC wall is higher than in the CCC gallbladder and controls. The over-expression of MMP-1 and MMP-2 may be involved in the pathogenesis of CCC.

Hyaluronan inhibits IL-1beta-stimulated collagenase production via down-regulation of phosphorylated p38 in SW-1353 human chondrosarcoma cells

We investigated the intracellular mechanism for the inhibitory effects of hyaluronan (HA) on interleukin-1beta (IL-1beta)-stimulated collagenase-1 and -3 (matrix metalloproteinases (MMPs)-1 and -13) production in a human chondrosarcoma cell line, SW-1353. MMPs-1 and -13 were induced by IL-1beta at 2 ng/ml in SW-1353 cells for 48 h. HA of 800 kDa, which is used clinically, significantly suppressed IL-1beta-stimulated production of MMPs-1 and -13 by immunoblotting. SW-1353 cells express the standard form of CD44 (CD44H), and immunofluorescent cytochemistry demonstrated the association of HA with CD44 on SW-1353 cells. Phosphorylated p38 (Phos-p38) mitogen-activated protein kinase was stimulated in SW-1353 cells by IL-1beta but not by HA alone. SB203580, a p38 MAPK inhibitor, partially blocked the MMP-1 and -13 production stimulated by IL-1beta. 800-kDa HA suppressed IL-1beta-activated Phos-p38 in a dose-dependent manner. CD44 blocking significantly reversed the inhibitory effects of HA on IL-1beta-activated Phos-p38 production. The present study clearly suggests that HA binds CD44 and inhibits IL-1beta-induced MMP-1 and -13 expression via down-regulation of Phos-p38 in SW-1353 cells.

Placental matrix metalloproteinase--1 expression is increased in labor

Matrix metalloproteinases (MMPs) are now known to process a broad spectrum of cell surface molecules and to function in several important biological processes. Testing for differences in gene expression in human placental chorionic villi in the absence or presence of labor, using cDNA microarray analysis, revealed that labor was associated with increased expression of MMP-1 gene expression in 5 placentas collected after term normal spontaneous deliveries compared with 5 placentas collected after term nonlaboring cesarean deliveries. Fibronectin 1 and collagen XVII, 2 other proteins involved in the homeostasis of the extracellular matrix, were also found to be upregulated in labor. MMP-1 was further tested in individual samples and found to be consistently overexpressed in labor. While previous microarray analyses have focused on either uterine tissue or the fetal membranes, the data presented here indicate for the first time that placental chorionic villus genes are likely to affect the initiation of parturition through altered processing of cell surface molecules by MMP-1.

Matrix metalloproteinases and diabetic foot ulcers: the ratio of MMP-1 to TIMP-1 is a predictor of wound healing

AIMS

Matrix metalloproteinases (MMPs) play a major role in wound healing: they can degrade all components of the extracellular matrix. In diabetic foot ulcers there is an excess of MMPs and a decrease of the tissue inhibitors of MMPs (TIMPs). This imbalance is probably one cause of impaired healing. However, little is known about changes in MMPs during wound healing.

METHODS

Sixteen patients with neuropathic diabetic foot ulcers participated. Wound fluid was collected regularly during the 12-week follow-up period, for measurement of MMP-1, MMP-2, MMP-8, MMP-9 and TIMP-1. Results were analysed by the degree of wound healing: good healers (defined by a reduction of at least 82% in initial wound surface at 4 weeks) and poor healers (reduction of less than 82% in wound surface at 4 weeks).

RESULTS

In good healers, levels of MMP-8 and -9 secreted by inflammatory cells decreased earlier. The initial levels of MMP-1 were similar in good and poor healers (P = 0.1) but rose significantly at week 2 in good healers (P = 0.039). There was a significant correlation between a high ratio of MMP-1/TIMP-1 and good healing (r = 0.65, P = 0.008). Receiver Operator Curve (ROC) analysis showed that an MMP-1/TIMP-1 ratio of 0.39 best predicted wound healing (sensitivity = 71%, specificity = 87.5%).

CONCLUSIONS

A high level of MMP-1 seems essential to wound healing, while an excess of MMP-8 and -9 is deleterious, and could be a target for new topical treatments. The MMP-1/TIMP-1 ratio is a predictor of wound healing in diabetic foot ulcers.

Why does menopausal hormone therapy lead to irregular uterine bleeding? Changes to endometrial blood vessels

BACKGROUND

Abnormal bleeding is common in hormone therapy (HT) users. We aimed to determine how HT alters endometrial blood vessels and stromal factors known to regulate vascular growth and integrity.

METHODS

Prospective observational study of 165 post-menopausal women in Western Australia. The following were measured in endometrial biopsies: vascular density (vessels/mm(2)), total vessel area (total area enclosed by peripheral vascular immunostaining for perivascular pericytes in mm(2)), total luminal area (mm(2)) and vessel wall area (total vessel area minus luminal area), stromal expression of matrix metalloproteinases (MMP) -1, -3, -9 and -14, their tissue inhibitors (TIMPs) -1-4 and vascular endothelial growth factor (VEGF) by immunohistochemistry.

RESULTS

Total vessel area was greater during bleeding compared with HT users with no bleeding (P = 0.028) or with a prior irregular bleeding (P = 0.039). Total vessel area was greater in non-HT users compared with HT users with no bleeding (P = 0.021). In HT users, vessel luminal area was greater during bleeding compared with HT users with no bleeding (P = 0.030) and vessel wall area was also increased (P = 0.025). During bleeding there was an increase in stromal TIMP-2 staining (P = 0.044). No significant changes in endometrial MMP or VEGF were seen.

CONCLUSIONS

Abnormal bleeding in HT users is associated with changes in endometrial vessel size and in stromal expression of factors known to regulate vascular growth and integrity. These changes may contribute to abnormal bleeding.

Interleukin 17 levels are increased in juvenile idiopathic arthritis synovial fluid and induce synovial fibroblasts to produce proinflammatory cytokines and matrix metalloproteinases

OBJECTIVE

Cytokines are the major mediators of joint damage in chronic arthritis. Data on synovial fluid (SF) concentration of Th17 cell-derived cytokine interleukin 17 (IL-17) in patients with juvenile idiopathic arthritis (JIA) are sparse. We measured levels of IL-17 in SF specimens from children with enthesitis-related arthritis (ERA) and polyarticular JIA (poly-JIA), and studied the ability of IL-17 to produce matrix metalloproteinases (MMP) and cytokines by fibroblast-like synoviocytes (FLS) from patients with ERA.

METHODS

IL-17 levels were measured in SF of patients with ERA (n = 43), poly-JIA (n = 17), rheumatoid arthritis (RA; n = 35), and osteoarthritis (OA; n = 10) by ELISA. In patients with JIA, 10 paired serum samples were also assayed. FLS were cultured from SF of patients with ERA and subsequently stimulated for 48 h by IL-17 or tumor necrosis factor-alpha. Later the production of IL-6, IL-8, MMP-1, MMP-3, and tissue inhibitor of metalloproteinase (TIMP)-1 was measured in the culture supernatants by ELISA.

RESULTS

Median IL-17 levels in SF were higher in patients with JIA [28 pg/ml (range 0-200)] compared to OA [0 pg/ml (range 0-84); p < 0.001] and RA (p < 0.05). The levels were comparable between poly-JIA patients and the ERA group. The median SF IL-17 levels were significantly higher compared to serum levels in children with JIA (p < 0.005). In ERA, SF IL-17 correlated with number of swollen joints (r = 0.35; p < 0.05), number of joints with limited mobility (r = 0.55; p < 0.001), and number of tender joints (r = 0.46; p < 0.01); however, no correlation was seen with erythrocyte sedimentation rate. IL-17 induced FLS to produce IL-6, IL-8, MMP-3, and MMP-1. However, there was no effect on the production of TIMP.

CONCLUSION

Increased IL-17 levels in ERA SF correlate with disease activity and this may be due to increased production of MMP and cytokines by IL-17.

Berberine induced down-regulation of matrix metalloproteinase-1, -2 and -9 in human gastric cancer cells (SNU-5) in vitro

Berberine, a yellow benzylisoquinoline alkaloid, is a constituent of Coptis chines and is commonly used in Chinese herbal medicine for patients with gastrointestinal disorders. The pharmacological effects of berberine include anti-inflammation, antidiarrhetic, antimalarial, and even antimicrobial activities. However, its mechanism of action on the cell migration of human gastric cancer SNU-5 cells is not fully understood. The effects of berberine on the percentage of viable cells were examined first and it was found that berberine induced dose-dependent inhibition in human gastric cancer SNU-5 cells. The effect of berberine on the levels of reactive oxygen species (ROS) and matrix metalloproteinase-1, -2, -7 and -9 was then examined using Western blotting and the results showed that berberine induced ROS production for up to 6 hours of incubation. It was also found that berberine induced downregulation of MMP-1 -2, and -9 but did not affect the level of MMP-7. The mRNA levels of MMPs in SNU-5 cells after treatment with berberine for 24 hours were investigated using a polymerase chain reaction and the results showed that berberine inhibited the gene expression of MMP-1, -2 and -9 in human SNU-5 cells but it did not affect MMP-7. In conclusion, berberine appears to exert its anticancer properties by inducing ROS production and prevention of cell migration via inhibition of the gene expression of MMP-1, -2 and -9 in human gastric cancer SNU-5 cancer cells.

Prognostic value of protease-activated receptor-1 (PAR-1) and matrix metalloproteinase-1 (MMP-1) in gastric cancer

BACKGROUND

Protease-activated receptors (PARs) are proposed to be involved in the invasive and metastatic processes of various types of cancer. Matrix metalloproteinase-1 (MMP-1) plays a role in cancer invasion and tissue remodelling. It has been reported that MMP-1 can alter the behavior of cancer cells through PAR-1 to promote cell migration and invasion. We considered whether the expression of PAR-1 and MMP-1 has relevance to progression in gastric cancer.

MATERIALS AND METHODS

An immunohistochemical study was carried out on 129 samples of gastric cancer using anti-PAR-1 and anti-MMP-1 mouse monoclonal antibodies. Associations between immunostaining and clinicopathological factors were analyzed statistically.

RESULTS

There were 58 carcinomas positive for PAR-1 expression. The expression of PAR-1 was associated with the depth of wall invasion and peritoneal dissemination. There were 42 carcinomas positive for both PAR-1 and MMP-1 expression which was associated with the histological stage, depth of wall invasion, lymph node metastasis and peritoneal dissemination. These patients had a significantly poorer prognosis than those with expression-negative tumors. Multivariate analysis indicated that PAR-1 expression and combined PAR-1 and MMP-1 expression were independent prognostic factors.

CONCLUSION

The results led us to believe that the expression of PAR-1 and MMP-1 is associated with the progression of gastric cancer and an independent prognostic predictor.