Circulating soluble fibroblast activation protein (FAP) levels are independent of cardiac and extra-cardiac FAP expression determined by targeted molecular imaging in patients with myocardial FAP activation

INTRODUCTION

Tissue Fibroblast Activation Protein alpha (FAP) is overexpressed in various types of acute and chronic cardiovascular disease. A soluble form of FAP has been detected in human plasma, and low circulating FAP concentrations are associated with increased risk of death in patients with acute coronary syndrome. However, little is known about the regulation and release of FAP from fibroblasts, and whether circulating FAP concentration is associated with tissue FAP expression. This study characterizes the release of FAP in human cardiac fibroblasts (CF) and analyzes the association of circulating FAP concentrations with in vivo tissue FAP expression in patients with acute (ST-segment elevation myocardial infarction, STEMI) and chronic (severe aortic stenosis, AS) myocardial FAP expression.

METHODS AND RESULTS

FAP was released from CF in a time- and concentration-dependent manner. FAP concentration was higher in supernatant of TGFβ-stimulated CF, and correlated with cellular FAP concentration. Inhibition of metallo- and serine-proteases diminished FAP release in vitro. Median FAP concentrations of patients with acute (77 ng/mL) and chronic (75 ng/mL, p = 0.50 vs. STEMI) myocardial FAP expression did not correlate with myocardial nor extra-myocardial nor total FAP volume (P ≥ 0.61 in all cases) measured by whole-body FAP-targeted positron emission tomography.

CONCLUSION

We describe a time- and concentration dependent, protease-mediated release of FAP from cardiac fibroblasts. Circulating FAP concentrations were not associated with increased in vivo tissue FAP expression determined by molecular imaging in patients with both chronic and acute myocardial FAP expression. These data suggest that circulating FAP and tissue FAP expression provide complementary, non-interchangeable information.

Imaging of Fibroblast Activation Protein Alpha Expression in a Preclinical Mouse Model of Glioma Using Positron Emission Tomography

Glioblastoma multiforme (GBM) is the most aggressive glioma of the primary central nervous system. Due to the lack of effective treatment options, the prognosis for patients remains bleak. Fibroblast activation protein alpha (FAP), a 170 kDa type II transmembrane serine protease was observed to be expressed on glioma cells and within the glioma tumor microenvironment. To understand the utility of targeting FAP in this tumor type, the immuno-PET radiopharmaceutical [⁸⁹Zr]Zr-Df-Bz-F19 mAb was prepared and Lindmo analysis was used for its in vitro evaluation using the U87MG cell line, which expresses FAP endogenously. Lindmo analysis revealed an association constant (K_a) of 10^-8 M^-1 and an immunoreactivity of 52%. Biodistribution studies in U87MG tumor-bearing mice revealed increasing radiotracer retention in tumors over time, leading to average tumor-to-muscle ratios of 3.1, 7.3, 7.2, and 8.3 at 2, 24, 48 and 72 h, respectively. Small animal PET corroborated the biodistribution studies; tumor-to-muscle ratios at 2, 24, 48, and 72 h were 2.0, 5.0, 6.1 and 7.8, respectively. Autoradiography demonstrated accumulated activity throughout the interior of FAP⁺ tumors, while sequential tumor sections stained positively for FAP expression. Conversely, FAP^- tissues retained minimal radioactivity and were negative for FAP expression by immunohistochemistry. These results demonstrate FAP as a promising biomarker that may be exploited to diagnose and potentially treat GBM and other neuroepithelial cancers.

Major traits of the senescent phenotype of nucleus pulposus intervertebral disc cells persist under the specific microenvironmental conditions of the tissue

Intervertebral discs (IVDs) are the joints of the spine, mainly consisting of extracellular matrix (ECM) with a low number of cells embedded therein. Low cellularity stems from nutrient deprivation due to the lack of blood supply, as well as from the hypoxic and hyperosmotic conditions prevailing in the tissue. Intervertebral disc degeneration (IDD) has been firmly connected with low back pain, a major age-related disease, whereas degenerated discs have been characterized by increased proteolytic activity and accumulation of senescent cells. While the catabolic phenotype of senescent IVD cells has been documented, whether this phenotype is preserved under the harsh conditions met in the IVD milieu has never been investigated. Here we showed that a combination of low glucose, hypoxia, high osmolality and absence of serum is anti-proliferative for young disc cells. In addition, we demonstrated for the first time that classical senescence markers, namely p16^INK4a, p21^WAF1 and ICAM-1, remain up-regulated in senescent cells under these conditions. Finally, up-regulation of the main senescence-associated ECM degrading enzymes, i.e. MMP-1, -2 and -3 was maintained in this strict environment. Conservation of IVD cells' senescent phenotype under the actual conditions these cells are confronted with in vivo further supports their possible implication in IDD.

Imaging fibroblast activation protein to monitor therapeutic effects of neutralizing interleukin-22 in collagen-induced arthritis

Objectives

RA is a chronic autoimmune disease leading to progressive destruction of cartilage and bone. RA patients show elevated IL-22 levels and the amount of IL-22-producing Th cells positively correlates with the extent of erosive disease, suggesting a role for this cytokine in RA pathogenesis. The purpose of this study was to determine the feasibility of SPECT/CT imaging with 111In-labelled anti-fibroblast activation protein antibody (28H1) to monitor the therapeutic effect of neutralizing IL-22 in experimental arthritis.

Methods

Mice (six mice/group) with CIA received anti-IL-22 or isotype control antibodies. To monitor therapeutic effects after treatment, SPECT/CT images were acquired 24 h after injection of 111In-28H1. Imaging results were compared with macroscopic, histologic and radiographic arthritis scores.

Results

Neutralizing IL-22 before CIA onset effectively prevented arthritis development, reaching a disease incidence of only 50%, vs 100% in the control group. SPECT imaging showed significantly lower joint tracer uptake in mice treated early with anti-IL-22 antibodies compared with the control-treated group. Reduction of disease activity in those mice was confirmed by macroscopic, histological and radiographic pathology scores. However, when treatment was initiated in a later phase of CIA, progression of joint pathology could not be prevented.

Conclusion

These findings suggest that IL-22 plays an important role in CIA development, and neutralizing this cytokine seems an attractive new strategy in RA treatment. Most importantly, SPECT/CT imaging with 111In-28H1 can be used to specifically monitor therapy responses, and is potentially more sensitive in disease monitoring than the gold standard method of macroscopic arthritis scoring.

Rhu-Epo down-regulates pro-tumorigenic activity of cancer-associated fibroblasts in multiple myeloma

We have previously demonstrated that recombinant human erythropoietin (rHuEpo) is involved in the regulation of the angiogenic response in multiple myeloma (MM) through a direct effect on macrophages and endothelial cells isolated from the bone marrow of patients with MM. The aim of the present study was designed to determine the effects of rHuEpo on cancer-associated fibroblasts (CAFs) from monoclonal gammopathy of undetermined significance (MGUS) and MM patients by means of in vitro and in vivo assays. rHuEpo treatment reduces the expression of mRNA levels of fibroblast activation markers, namely alpha smooth actin (αSMA) and fibroblast activation protein (FAP) in MGUS and MM CAFs, and of pro-inflammatory and pro-angiogenic cytokines, including interleukin (IL)-6 and IL-8, vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2), and hepatocyte growth factor (HGF) in MM CAFs. Moreover, rHuEpo inhibits the proliferative activity of MM CAFs and increased the apoptosis of MGUS and MM CAFs. Overall, these data suggest that rHu-Epo down-regulates CAFs pro-tumorigenic activity. Moreover, these results are not suggestive for a pro-angiogenic activity of rHuEpo on CAFs. In fact, rHuEpo pre-treatment induces a low angiogenic response in vivo in the chorioallantoic membrane (CAM) assay of MGUS and MM CAFs conditioned medium, not comparable to that of a well-known angiogenic cytokine, VEGF-A, tested in the same assay.

Genotypic and phenotypic diversity in Enterococcus faecalis: is agar invasion a pathogenicity score?

OBJECTIVES

The main objective of the present study is to analyze different genotypic and phenotypic traits related to virulence in Enterococcus faecalis, as well as evaluated the agar invasion phenotype in a collection of isolates with different clinical origins.

MATERIAL AND METHODS

Seventy-nine E. faecalis isolates, with invasive and non-invasive clinical origins, have been used in this work. Presence of cytolysin activator (cylA), gelatinase (gelE), surface protein (esp), aggregation substance (asa1), endocarditis antigen (efaA), and collagen-binding protein (ace) have been analyzed by PCR. Phenotypic characterization included gelatinase activity, haemolysin production, biofilm formation and agar invasion.

RESULTS

All the isolates tested harboured at least one of the virulence determinants. The 95.5% of isolates from haematologic samples were positive for agar invasion test, significantly higher than isolates from non-invasive diseases. A significant reduction in relative invasion area was observed in three selected agar-invasive strains after 15 serial passages.

CONCLUSIONS

It has been observed a significant high prevalence of agar-invasion positive isolates among strains belonged to haematological samples. Agar invasiveness is reduced after adaptation of clinical isolates to laboratory conditions, showing that agar invasion phenotype can be modulate by culture conditions as other virulence factors observed in different bacterial species.

Foramen ovale closure is a process of endothelial-to-mesenchymal transition leading to fibrosis

Patent foramen ovale (PFO) is an atrial septal deformity present in around 25% of the general population. PFO is associated with major causes of morbidity, including stroke and migraine. PFO appears to be heritable but genes involved in the closure of foramen ovale have not been identified. The aim of this study is to determine molecular pathways and genes that are responsible to the postnatal closure of the foramen ovale. Using Sprague-Dawley rat hearts as a model we analysed the dynamic histological changes and gene expressions at the foramen ovale region between embryonic day 20 and postnatal day 7. We observed a gradual loss of the endothelial marker PECAM1, an upregulation of the mesenchymal marker vimentin and α-smooth muscle actin, the elevation of the transcription factor Snail, and an increase of fibroblast activation protein (FAP) in the foramen ovale region as well as the deposition of collagen-rich connective tissues at the closed foramen ovale, suggesting endothelial-to-mesenchymal transition (EndMT) occurring during foramen ovale closure which leads to fibrosis. In addition, Notch1 and Notch3 receptors, Notch ligand Jagged1 and Notch effector HRT1 were highly expressed in the endocardium of the foramen ovale region during EndMT. Activation of Notch3 alone in an endothelial cell culture model was able to drive EndMT and transform endothelial cells to mesenchymal phenotype. Our data demonstrate for the first time that FO closure is a process of EndMT-mediated fibrosis, and Notch signalling is an important player participating in this process. Elucidation of the molecular mechanisms of the closure of foramen ovale informs the pathogenesis of PFO and may provide potential options for screening and prevention of PFO related conditions.

Serum and tissue expression of gelatinase and Twist in breast cancer

OBJECTIVE

This study aimed to investigate the levels of matrix metalloproteinases (MMP)-2, MMP-9 and Twist in tumor tissue and serum from 46 cases of breast cancer patients and 31 cases of benign breast diseases patients by immunohistochemical staining and enzyme-linked immunosorbent assay, respectively. The association of gelatinase and Twist expression with clinicopathological factors was also analyzed in the present study.

PATIENTS AND METHODS

The studied population consisted of 46 breast cancer patients and 31 benign breast disease patients. Serum concentrations of MMP-2, MMP-9 and Twist were measured by using human enzyme-linked immunosorbent assay. The protein expression of Twist, MMP-2 and MMP-9 were determined by immunohistochemical.

RESULTS

The results show that the levels of MMP-2, MMP-9 and Twist expression were significantly increased in tissue and serum from breast cancer group, compared to the group of benign breast lesions diseases (p < 0.05). The pre-operative serum levels of MMP-2, MMP-9 and Twist were positively correlated with their expression in breast cancer tissues, respectively (p < 0.05). We, then, correlated serum and tissue levels of MMP-2, MMP-9 and Twist in breast cancer samples with patients' clinicopathologic characteristics. Compared to low expression, high serum and tissue levels of MMP-2 and Twist were associated with lymph node metastasis and higher TNM stage, high tissue MMP-9 levels were associated with lymph node metastasis and higher TNM stage, and high serum MMP-9 levels were associated with c-erbB-2 expression.

CONCLUSIONS

These data suggest that serum levels of MMP-2, MMP-9 and Twist could be as potential biomarkers for diagnosis and predicting metastasis of breast cancer.

Expression and role of fibroblast activation protein-alpha in microinvasive breast carcinoma

BACKGROUND

Diagnosis of ductal carcinoma in situ (DCIS) in breast cancer cases is challenging for pathologist due to a variety of in situ patterns and artefacts, which could be misinterpreted as stromal invasion. Microinvasion is detected by the presence of cytologically malignant cells outside the confines of the basement membrane and myoepithelium. When malignant cells invade the stroma, there is tissue remodeling induced by perturbed stromal-epithelial interactions. Carcinoma-associated fibroblasts (CAFs) are main cells in the microenvironment of the remodeled tumor-host interface. They are characterized by the expression of the specific fibroblast activation protein-alpha (FAP-α), and differ from that of normal fibroblasts exhibiting an immunophenotype of CD34. We hypothesized that staining for FAP-α may be helpful in determining whether DCIS has microinvasion.

METHODS

349 excised breast specimens were immunostained for smooth muscle actin SMA, CD34, FAP-α, and Calponin. Study material was divided into 5 groups: group 1: normal mammary tissues of healthy women after plastic surgery; group 2: usual ductal hyperplasia (UDH); group 3: DCIS without microinvasion on H & E stain; group 4: DCIS with microinvasion on H & E stain (DCIS-MI), and group 5: invasive ductal carcinoma (IDC). A comparative evaluation of the four immunostains was conducted.

RESULTS

Our results demonstrated that using FAP-α and Calponin adjunctively improved the sensitivity of pathological diagnosis of DCIS-MI by 11.29%, whereas the adjunctive use of FAP-α and Calponin improved the sensitivity of pathological diagnosis of DCIS by 13.6%.

CONCLUSIONS

This study provides the first evidence that immunostaining with FAP-α and Calponin can serve as a novel marker for pathologically diagnosing whether DCIS has microinvasion.

Upregulation of collagenase-1 and -3 in indomethacin-induced gastric ulcer in diabetic rats: role of melatonin

Collagenases are key proteases involved in inflammation and injury. We addressed whether collagenases have an association with the susceptibility of gastric injury under diabetes as well as the effect of melatonin on collagenases in ulcerated gastric tissues. Diabetes was induced in rats by a single dose of streptozotocin (STZ) followed by gastric ulceration using indomethacin, and melatonin's action was studied by its application prior to indomethacin exposure. Ulcer indices and damage were elevated significantly in gastric tissues of diabetic compared with nondiabetic rats. Melatonin reversed the effect of indomethacin during protection of gastric ulcers in diabetic rats. Matrix metalloproteinase (MMP)-13 (i.e., collagenase-3) was upregulated in diabetic gastric mucosa and enhanced further upon ulceration while melatonin ameliorated their activity. In addition, gastric tissues showed enhanced expression of both MMP-1 (i.e., collagenases-1) and -13 significantly in diabetic rats compared with nondiabetic animals and more so during ulceration while tissue inhibitors of metalloproteinase-1 (TIMP-1) showed an opposite trend. MMP-2 activities exhibited a ∼50% downregulation during gastric ulceration which were rescued by melatonin. Moreover, increased expression of both MMP-1 and -13 was mediated by activator protein-1 activation via extracellular signal-regulated kinase 1/2 which were parallel to upregulation of tumor necrosis factor-α, interleukin-1β, and heat shock protein-70 during ulceration. Melatonin arrested collagenase expression by downregulation of these signaling molecules thereby halting the progression of the disease. We conclude that diabetic gastric tissues are susceptible to ulceration and associated with MMP-1 and -13 upregulation in indomethacin-induced injury. Additionally, melatonin protects the gastric damage under diabetes via regulation of both MMP-1 and -13.

Gelatinase-associated phenotypes and genotypes among clinical isolates of Enterococcus faecalis in Poland

Enterococcus faecalis is an important nosocomial pathogen causing serious invasive infections. One of the virulence factors of this pathogen, gelatinase GelE, is a protease whose gene expression is regulated by the Fsr quorum sensing system. In this study, we used a well-characterized collection of 153 clinical E. faecalis isolates to investigate the distribution of genes involved in gelatinase expression. Although 140 isolates (91% of the group) harbored the gelE gene, only 81 isolates (53%) produced active gelatinase. The gelatinase-negative phenotype was found in several unrelated clones, and appeared to be caused by various genetic events. Isolates of the hospital-adapted clonal complex 2 (CC2) and of CC40 were uniformly gelatinase-positive, while all the CC87 isolates contained the 23.9 kb deletion encompassing most of the fsr locus and were gelatinase-negative. No significant differences among isolates of different clinical origin and gelatinase activity or presence of the fsr genes were found with the exception of isolates from cerebrospinal fluid, which were more often gelatinase-positive than colonizing isolates.

Protective role of betulinic acid on TNF-alpha-induced cell adhesion molecules in vascular endothelial cells

Vascular inflammation is an important event in the development of vascular diseases such as tumor progression and atherosclerosis. In the present study, betulinic acid (BA) treatment was found to show potent inhibitory effect on vascular inflammation process by TNF-alpha in human umbilical vein endothelial cells (HUVEC). Pretreatment of HUVEC with BA was blocked TNF-alpha induced expression level of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), endothelial cell selectin (E-selectin) as well as gelatinase in TNF-alpha-activated HUVEC in a dose-dependent manner. When preincubated with BA, the adhesion of HL-60 cells to TNF-alpha-induced HUVEC was significantly decreased in a concentration-dependent manner. TNF-alpha-induced intracellular ROS was markedly decreased by pretreatment with BA. Furthermore, BA significantly inhibited the translocation and transcriptional activity of NF-kappaB increased by TNF-alpha. In conclusion, these results suggested a vascular protective role of BA via inhibition of ROS and NF-kappaB activation in HUVEC.

Subinhibitory concentrations of phenyl lactic acid interfere with the expression of virulence factors in Staphylococcus aureus and Pseudomonas aeruginosa clinical strains

The discovery of intra- and intercellular communication systems (quorum sensing systems) regulating bacterial virulence has afforded a novel opportunity to control infectious bacteria, without interfering with their growth. In this study, we investigated the ability of subinhibitory concentrations (sIC) of phenyl lactic acid (PLA), known to be produced by Lactobacillus probiotic strains, to attenuate the virulence and pathogenicity of Pseudomonas aeruginosa (as experimental model of intercellular bacterial communication in Gram-negative bacteria) and Staphylococcus aureus (as experimental model of intercellular bacterial communication in Gram-positive bacteria) by interfering with the coordinated expression of different virulence factors implicated in the pathogenicity of these opportunistic strains. Our results showed that sIC of PLA decreased the ability of the tested strains to adhere both to the cellular and inert substrata and induced changes in the adherence patterns as well as in the cell morphology. The sIC of PLA induced a significant decrease of sheep red blood cells haemolysins, lecithinase and caseinase and stimulated lipase and gelatinase production by Pseudomonas strains. The sIC of PLA induced an important and constant increase of the Pseudomonas growth inhibition zones diameters for all tested antibiotics, demonstrating the potential use of PLA in the design of new synergic antimicrobial associations active on multiresistant and biofilm-growing P, aeruginosa strains. The present study has proved the role of sIC of PLA released by Lactobacillus probiotic strains in the attenuation of P. aeruginosa and S. aureus virulence and pathogenicity, by interfering with different processes depending on cell density and regulated by quorum sensing (i.e. growth rate, expression of adhesion molecules and secretion of soluble, enzymatic factors) and altering the success of these pathogens in the colonization of a sensitive host and the development of an infectious process. Our results demonstrate that this probiotic soluble products could be used as a new, ecological anti-infective strategy with great therapeutic and preventive value in the biomedical field (especially in the treatment of chronic infections produced by multiresistant and biofilm forming microorganisms), but also in the management of the environmental quality, agriculture and industrial field by reducing the chemical burden delivered in the external medium and by preventing the surfaces colonization with microorganisms and the development of natural biofilms.

Reduced secretion and expression of gelatinase profile in Toxoplasma gondii-infected human monocytic cells

The apicomplexan Toxoplasma gondii, an obligate intracellular parasite, can infect humans and a wide range of vertebrates. Following oral infection, the parasite invades tissues by crossing non-permissive biological barriers such as the placenta or the blood-brain barrier. But the molecular mechanisms underlying migration of T. gondii remain poorly characterized. The crossing of various basal membranes and infiltration into the extracellular matrix by T. gondii could involve matrix metalloproteinases (MMPs). We demonstrated a decrease in proMMP-2 and proMMP-9 secretion by THP-1 cells at 24 and 48h post invasion with regulation at the mRNA level throughout infection. This down regulation was associated with a decrease in TIMP-2 secretion and an inhibition of its expression. Moreover, results showed an activation of MT1-MMP; its expression was regulated after 6, 24, and 48h.

The Influence of Root Canal Sealer on Extended Intracanal Survival of Enterococcus faecalis With and Without Gelatinase Production Ability in Obturated Root Canals

Enterococcus faecalis can survive for extended periods in obturated root canals. In this study, the hypotheses tested were that long-term survival of E. faecalis is dependent on (1) the type of endodontic sealer and (2) the capacity for microbial gelatinase activity, a potential "virulence" trait identified previously in clinical isolates. Root canals of extracted human canines (n=95) were inoculated with either E. faecalis OG1RF or its gelatinase-negative mutant E. faecalis TX5128. After 48 hours of incubation at 37 degrees C, canals were obturated with gutta-percha and either the epoxy-resin-based AH-Plus (Dentsply, De Trey, Konstanz, Germany), the silicone-based RoekoSeal (Coltène/Whaledent, Langenau, Germany), or zinc oxide eugenol-based Roth's sealer (Root Canal Cement Type 801; Roth International Ltd, Chicago, IL). Access cavities were sealed. After 8 months of incubation at 37 degrees C, viable E. faecalis was recovered from more teeth sealed with RoekoSeal (95%) compared with AH-Plus (40%) (p=0.0004, Fisher's exact test) and Roth's sealer (45%) (p=0.0012, Fisher's exact test). In the RoekoSeal groups, viable counts of E. faecalis OG1RF were higher than E. faecalis TX5128 (p=0.03, Mann-Whitney U test) suggesting that gelatinase activity plays a role in long-term survival of E. faecalis in obturated root canals.

Comparative genomic analysis for the presence of potential enterococcal virulence factors in the probiotic Enterococcus faecalis strain Symbioflor 1

Enterococci are members of the natural microbiota of animal and human intestinal tracts and are capable of causing opportunistic infections. They are also used as starter cultures in the food industry as well as in health supplements and probiotics by the pharmaceutical industry. This Janus-faced status requires a careful evaluation on the basis of pathogenic traits to ensure the safety of the strain used to produce food and pharmaceuticals. We performed gapped-genome sequencing of a probiotic strain Enterococcus faecalis Symbioflor 1 and present initial results deriving from comparative genome analysis with that of the previously sequenced pathogenic clinical isolate E. faecalis V583. There was strong overall conservation of synteny between both strains and a detailed analysis revealed the absence of large genomic regions from the chromosome of the probiotic strain, indicating gene loss. Genes absent from the Symbioflor 1 strain included those encoding the enterococcal cytolysin, enterococcal surface protein, and gelatinase (coccolysin) as well as hyaluronidase and the peptide antibiotic AS-48. This data was confirmed using PCR primers specific for the respective genes. However, other enterococcal determinants such as aggregation substance, collagen adhesion protein, the ability to resist oxygen anions as well as capsule formation were detected. The presence of these traits may be advantageous for the strain Symbioflor 1 since they potentially enable colonization and proliferation of the bacterium on mucosal surfaces thereby conferring on it probiotic traits.

Comparative analysis of virulence determinants and mass spectral profiles of Finnish and Lithuanian endodontic Enterococcus faecalis isolates

INTRODUCTION

Putative virulence factors of Enterococcus faecalis have been proposed by several workers and, by analogy, these have been linked to strains of endodontic origin. However, their distribution within the cell population is unknown. In the present study, isolates were taken from the dental root canals of two defined human populations, Lithuanian and Finnish, and examined for a range of virulence properties. In addition, surface-associated molecules and intracellular proteins were compared using matrix-assisted laser desorption-ionization/mass spectrometry (MALDI-TOF-MS) and ProteinChip capture/MS (SELDI-TOF-MS), respectively.

METHODS

Twenty-three Lithuanian and 35 Finnish dental root canal isolates were included. The esp, gelE, ace and efaA genes were detected by polymerase chain reaction, and cytolysin and gelatinase phenotypes were determined by hydrolysis of horse blood agar and gelatine agar, respectively. Protein extracts and surface-associated molecules of whole cells were analysed by SELDI-TOF-MS and MALDI-TOF-MS, respectively.

RESULTS

Presence of esp (n = 15), cytolysin (n = 9), ace (n = 55) and efaA (n = 58) was not statistically different in the two samples, whereas gelE and gelatinase production was detected more frequently in the Finnish material (chi-squared, P < 0.01). Analysis of protein profiles by SELDI-TOF-MS showed clustering of cytolysin-producing strains, whereas MALDI-TOF-MS generated profiles that clustered according to the samples' origin and, furthermore, to atypical quinupristin-dalfopristin susceptibility.

CONCLUSION

A high prevalence of virulence factors was demonstrated in both population types. SELDI-TOF-MS and MALDI-TOF-MS proved useful in distinguishing between different E. faecalis phenotypes and they may be useful technologies for elucidating the eco-distribution of E. faecalis in humans.

Co-expression of aFGF and FGFR-1 is predictive of a poor prognosis in patients with esophageal squamous cell carcinoma

Overexpression of aFGF, bFGF and FGFR-1 has been reported in various cancers, and it has been suggested that it may be a poor prognostic factor in cases with solid tumors. Therefore, we attempted to determine whether overexpression of aFGF, bFGF and FGFR-1 might also be a poor prognostic factor in patients with esophageal squamous cell carcinoma, and examined the expression of aFGF, bFGF and FGFR-1 in esophageal cancer tissue specimens to clarify their clinical significance. Seventy-nine patients with squamous cell carcinoma of the esophagus who underwent resection at the Department of Surgery, Keio University Hospital, were enrolled as the subjects of this study. None of the patients had received any previous treatment. Formalin-fixed and paraffin-embedded sections of esophageal cancer tissue were stained by immunohistochemical methods and examined for expression of the angiogenetic factors and their receptors, and also to determine the microvascular density (MVD). We examined the correlations between the expression of aFGF, bFGF and FGFR-1, and the MVD, clinicopathological background factors and survival of the patients by conducting statistical analyses of the data. The results revealed that positive aFGF expression was associated with a larger tumor area (p=0.009), and co-expression of both aFGF and FGFR-1 was associated with a larger tumor area (p=0.01) and poorer prognosis (p=0.04). There were positive correlations between the expression of aFGF and FGFR-1 (p<0.0001), and between those of bFGF and FGFR-1 (p=0.04). aFGF may promote proliferation of esophageal cancer cells in an angiogenesis-independent and autocrine manner, and may contribute to rapid growth of esophageal cancer on recurrence after esophageal resection.

Activation of EDTA-resistant gelatinases in malignant human tumors

Among the many proteases associated with human cancer, seprase or fibroblast activation protein alpha, a type II transmembrane glycoprotein, has two types of EDTA-resistant protease activities: dipeptidyl peptidase and a 170-kDa gelatinase activity. To test if activation of gelatinases associated with seprase could be involved in malignant tumors, we used a mammalian expression system to generate a soluble recombinant seprase (r-seprase). In the presence of putative EDTA-sensitive activators, r-seprase was converted into 70- to 50-kDa shortened forms of seprase (s-seprase), which exhibited a 7-fold increase in gelatinase activity, whereas levels of dipeptidyl peptidase activity remained unchanged. In malignant human tumors, seprase is expressed predominantly in tumor cells as shown by in situ hybridization and immunohistochemistry. Proteins purified from experimental xenografts and malignant tumors using antibody- or lectin-affinity columns in the presence of 5 mmol/L EDTA were assayed for seprase activation in vivo. Seprase expression and activation occur most prevalently in ovarian carcinoma but were also detected in four other malignant tumor types, including adenocarcinoma of the colon and stomach, invasive ductal carcinoma of the breast, and malignant melanoma. Together, these data show that, in malignant tumors, seprase is proteolytically activated to confer its substrate specificity in collagen proteolysis and tumor invasion.

Pleural injury and pleurisy-induced progelatinase B/proMMP-9 is associated with markers of neutrophil degranulation

OBJECTIVE

Progelatinase B/proMMP-9 has recently been identified as an indicator of pleural inflammation, presumably originating from granulocytes. The aim of this study was to verify the origin of progelatinase B by simultaneous estimation of specific markers of neutrophil recruitment and activation in pleural effusions following induced pleurisy and pleural injury.

MATERIAL AND METHODS

Sixty-three samples of pleural fluid from patients undergoing therapeutic talc pleurodesis (n = 8) and explorative thoracoscopy (n = 3) collected before and at different time intervals after the intervention were analyzed for progelatinase B and neutrophil gelatinase-associated lipocalin (NGAL)-gelatinase complex by substrate electrophoresis, for myeloperoxidase (MPO) and interleukin-8 (IL-8) by immunoadsorbent sandwich assay, as well as for leukocyte count, C-reactive protein (CRP) and total protein (TP).

RESULTS

A significant increase in free and NGAL-complexed progelatinase B, MPO and IL-8 was recorded within 48 h following treatment in all subjects. Progelatinase B was strongly correlated with NGAL-gelatinase complex (r = 0.88, p = 0.001), MPO (r = 0.81, p = 0.001), neutrophil count (r = 0.75, p = 0.01) and IL-8 (r = 0.71, p = 0.001), but not with CRP and TP.

CONCLUSIONS

The results support the neutrophil origin of the proenzyme, which confirms progelatinase B as an indicator of a local inflammatory reaction. Quantifying the inflammatory reaction may be helpful in the evaluation of both the technical variants of therapeutic pleurodesis and finer discrimination of paraneoplastic effusions.

Cytokine-mediated modulation of MMPs and TIMPs in multipotential neural precursor cells

Recent studies have implicated the inflammatory process during experimental allergic encephalomyelitis (EAE) in triggering migration and differentiation of transplanted neural precursors cells (NPCs) into the inflamed white matter. The pro-inflammatory cytokines tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma are key factors in the pathogenesis of brain inflammation in EAE and were shown to enhance NPCs migration in vitro. As cell migration is dependent on extracellular matrix remodeling, involving proteolytic enzyme members of the matrix metalloproteinase (MMPs) family, we characterized the profile of expression of MMPs and their endogenous inhibitors (TIMPs) in rat NPCs, and evaluated the effects of TNF-alpha, IFN-gamma and IFN-beta, a clinically proven modulator of brain inflammation, on the expression of these molecules. Newborn rat striatal NPCs were expanded in spheres as nestin+, PSA-NCAM+ and NG2(-) cells, which can differentiate into astrocytes, oligodendrocytes and neurons. NPCs' gelatinase activities of MMP-2 and MMP-9, as determined by zymography, were increased by TNF-alpha, and to a lesser extent by IFN-gamma. Semi-quantitative RT-PCR indicated that TNF-alpha also upregulated MMP-9 mRNA levels. IFN-beta suppressed the TNF-alpha-induced levels of secreted MMP-9 and MMP-2, while enhancing the expression of TIMP-1 and TIMP-2 mRNA. These results suggest that MMPs activity is induced in NPCs by pro-inflammatory cytokines to mobilize them for promoting reparative processes. IFN-beta, on the other hand, appears to have an anti-proteolytic influence that may attenuate such NPC-mediated repair processes.

Relationship between biofilm formation, the enterococcal surface protein (Esp) and gelatinase in clinical isolates ofEnterococcus faecalisandEnterococcus faecium

One-hundred and twenty-eight enterococcal isolates were examined for their ability to form biofilm in relation to the presence of the gene encoding the enterococcal surface protein (esp), production of gelatinase and to the source of isolation. Neither esp nor gelatinase seemed to be required for biofilm formation: both Enterococcus faecalis and Enterococcus faecium did not show a correlation between the presence of either esp or the production of gelatinase and biofilm formation. However, in E. faecium while esp was found in isolates from either source, the presence of both esp and biofilm together was only found in strains from clinical settings, suggesting that there exists a synergy between these factors which serves as an advantage for the process of infection.

Effect of heat on synthesis of gelatinases and pro-inflammatory cytokines in equine tendinocytes

The aim of this study was to clarify whether matrix metalloproteinases (MMP-2 and -9: gelatinases) and pro-inflammatory cytokines [tumor necrosis factor (TNF) alpha and interleukin (IL)-1beta] are induced by heat in tendon tissue in vitro and to test the hypothesis that heat exposure causes tendinocytes to synthesize pro-inflammatory cytokines and that synthesis of these cytokines, in turn, leads to up-regulation of synthesis of gelatinases. Isolated tendinocytes from equine superficial digital flexor tendons were cultured and all experiments were performed on cells passaged 3 or 4 times. In the cells exposed to heat (37 to 45 degrees C, 0 to 60 min), the survival rate decreased sharply in a temperature- and time-dependent manner, especially at 42 and 45 degrees C. Cells exposed at 40 degrees C, however, showed little change in survival rate and morphology. Gelatin zymograms revealed that proMMP-2 and -9 were the only two MMPs remaining in the supernatant of the cultured tendinocytes, including that of untreated cells. Addition of TNFalpha and IL-1beta to the culture medium of tendinocytes accelerated proMMP-9 synthesis considerably. Heating the tendinocytes (40 degrees C) led to a three-fold increase in proMMP-9 synthesis in a short time. Only TNFalpha was detected in tendinocytes after heat exposure for 30 and 60 min. In contrast, IL-1beta was under the detectable level in ELISA. Cooling of heat-exposed cells from 40 degrees C to 37 degrees C considerably down-regulated cellular proMMP-9 synthesis. Furthermore, proMMP-9 level was greatly reduced in cells treated at lower temperatures, 20 degrees C and 5 degrees C. These findings support our hypothesis that hyperthermia in the horse tendon induces tendinocytes to synthesize pro-inflammatory cytokines and that the synthesis of these cytokines results in the up-regulation of gelatinases.

Immunosuppressant FK506 inhibits matrix metalloproteinase-9 induction in TNF-alpha-stimulated human hepatic stellate cells

Activated hepatic stellate cells (HSCs) play a key role in the pathogenesis of hepatic inflammation and fibrosis through the production of matrix metalloproteinases (MMPs). Cytokines and growth factors are thought to activate HSCs. TNF-alpha has pleiotropic functions in hepatitis, but its role in liver fibrosis remains elusive. In this study we investigated the regulation of tumor necrosis factor-alpha (TNF-alpha) in the expression of MMPs by HSCs. We also examined whether the immunosuppressant FK506 influences the MMPs expression in human HSCs. Human HSCs, LI90, were treated with TNF-alpha in the presence of FK506. Release of MMPs into culture media, levels of MMP-9 mRNA and activation of NF-kappaB were compared between the cells cultured with or without FK506. Stimulation of human HSCs, LI90 cells, with TNF-alpha caused the induction of pro-MMP-9. Further, TNF-alpha stimulation induced the degradation of IkappaB-alpha and resulted in the transcriptional activation of NF-kappaB. FK506 suppressed this TNF-alpha-induced NK-kappaB activation, alone with pro-MMP-9 mRNA and protein induction, in HSC. TNF-alpha contributes to the perpetuation of liver fibrosis through MMP-9 production from HSCs and that FK506 inhibits the induction of MMP-9 through NF-kappaB pathway suggesting the anti-inflammatory properties of FK506.

Inhibition of human leukemia xenograft in nude mice by adenovirus-mediated tissue inhibitor of metalloproteinase-3

Considerable studies have demonstrated the pivotal roles of matrix metalloproteinases (MMPs) in leukemia dissemination and extramedullary infiltration. Tissue inhibitors of matrix metalloproteinases (TIMPs) are multifunctional proteins with MMPs inhibitory effects. However, little is known about the application of TIMPs in the treatment of leukemia. Here, we investigated the effects of TIMP-3 overexpression via adenoviral gene delivery on the in vitro growth and invasiveness of leukemic cells and the in vivo progress of K562-derived xenografts in nude mice. The in vitro invasiveness of K562 cells was markedly impaired by AdTIMP-3 infection. Moreover, TIMP-3 significantly inhibited K562-derived angiogenic factors-induced proliferation, migration and bFGF-induced tube formation of endothelial cells (ECs) in vitro, and reduced VEGF-induced gelatinases expression and activation in ECs. Although TIMP-3 overexpression had no direct effect on the growth of K562 cells in vitro, repeated intratumoral injection of AdTIMP-3 significantly inhibited the growth of K562 xenografts in nude mice. Furthermore, lower microvessel density, less vessel maturity and increased apoptosis were observed in AdTIMP-3-treated K562 xenografts, suggesting the importance of antiangiogenic action of TIMP-3. These data demonstrated the potential of applying AdTIMP-3 as an effective antiangiogenic adjuvant in the treatment of leukemia progression.

Effect of neutrophil depletion on gelatinase expression, edema formation and hemorrhagic transformation after focal ischemic stroke

Background

While gelatinase (MMP-2 and -9) activity is increased after focal ischemia/reperfusion injury in the brain, the relative contribution of neutrophils to the MMP activity and to the development of hemorrhagic transformation remains unknown.

Results

Anti-PMN treatment caused successful depletion of neutrophils in treated animals. There was no difference in either infarct volume or hemorrhage between control and PMN depleted animals. While there were significant increases in gelatinase (MMP-2 and MMP-9) expression and activity and edema formation associated with ischemia, neutrophil depletion failed to cause any change.

Conclusion

The main finding of this study is that, in the absence of circulating neutrophils, MMP-2 and MMP-9 expression and activity are still up-regulated following focal cerebral ischemia. Additionally, neutrophil depletion had no influence on indicators of ischemic brain damage including edema, hemorrhage, and infarct size. These findings indicate that, at least acutely, neutrophils are not a significant contributor of gelatinase activity associated with acute neurovascular damage after stroke.

Virulence, phenotype and genotype characteristics of endodontic Enterococcus spp

BACKGROUND/AIMS

Enterococci have been implicated in persistent root canal infections but their role in the infection process remains unclear. This study investigated the virulence, phenotype and genotype of 33 endodontic enterococcal isolates.

METHODS

Phenotypic tests were conducted for antibiotic resistance, clumping response to pheromone, and production of gelatinase, hemolysin and bacteriocin. Genotype analysis involved polymerase chain reaction amplification of virulence determinants encoding aggregation substances asa and asa373, cytolysin activator cylA, gelatinase gelE, gelatinase-negative phenotype ef1841/fsrC, adherence factors esp and ace, and endocarditis antigen efaA. Physical DNA characterization involved pulsed-field gel electrophoresis of genomic DNA, and plasmid analysis.

RESULTS

Potential virulence traits expressed included production of gelatinase by Enterococcus faecalis (n=23), and response to pheromones in E. faecalis culture filtrate (n=16). Fourteen strains produced bacteriocin. Five strains were resistant to tetracycline and one to gentamicin, whereas all were susceptible to ampicillin, benzylpenicillin, chloramphenicol, erythromycin, fusidic acid, kanamycin, rifampin, streptomycin and vancomycin. Polymerase chain reaction products encoding efaA, ace, and asa were detected in all isolates; esp was detected in 20 isolates, cylA in six isolates, but asa373 was never detected. The gelatinase gene (gelE) was detected in all isolates of E. faecalis (n=31) but not in Enterococcus faecium (n=2); a 23.9 kb deletion sequence corresponding to the gelatinase-negative phenotype was detected in six of the eight E. faecalis isolates that did not produce gelatinase. Pulsed-field gel electrophoresis and plasmid analyses revealed genetic polymorphism with clonal types evident. Plasmid DNA was detected in 25 strains, with up to four plasmids per strain and a similar (5.1 kb) plasmid occurring in 16 isolates.

CONCLUSIONS

Phenotypic and genotypic evidence of potential virulence factors were identified in endodontic Enterococcus spp., specifically production of gelatinase and response to pheromones.

The Enterococcus faecalis fsr two-component system controls biofilm development through production of gelatinase

Bacterial growth as a biofilm on solid surfaces is strongly associated with the development of human infections. Biofilms on native heart valves (infective endocarditis) is a life-threatening disease as a consequence of bacterial resistance to antimicrobials in such a state. Enterococci have emerged as a cause of endocarditis and nosocomial infections despite being normal commensals of the gastrointestinal and female genital tracts. We examined the role of two-component signal transduction systems in biofilm formation by the Enterococcus faecalis V583 clinical isolate and identified the fsr regulatory locus as the sole two-component system affecting this unique mode of bacterial growth. Insertion mutations in the fsr operon affected biofilm formation on two distinct abiotic surfaces. Inactivation of the fsr-controlled gene gelE encoding the zinc-metalloprotease gelatinase was found to prevent biofilm formation, suggesting that this enzyme may present a unique target for therapeutic intervention in enterococcal endocarditis.

Hyperforin Inhibits Cancer Invasion and Metastasis

Hyperforin (Hyp), the major lipophilic constituent of St. John's wort, was assayed as a stable dicyclohexylammonium salt (Hyp-DCHA) for cytotoxicity and inhibition of matrix proteinases, tumor invasion, and metastasis. Hyp-DCHA triggered apoptosis-associated cytotoxic effect in both murine (C-26, B16-LU8, and TRAMP-C1) and human (HT-1080 and SK-N-BE) tumor cells; its effect varied, with B16-LU8, HT-1080, and C-26 the most sensitive (IC50 = 5 to 8 micromol/L). At these concentrations, a marked and progressive decline of growth was observed in HT-1080 cells, whereas untransformed endothelial cells were only marginally affected. Hyp-DCHA inhibited in a dose-dependent and noncompetitive manner various proteinases instrumental to extracellular matrix degradation; the activity of leukocyte elastase was inhibited the most (IC50 = 3 micromol/L), followed by cathepsin G and urokinase-type plasminogen activator, whereas that of the matrix metalloproteinases (MMPs) 2 and 9 showed an IC50 > 100 micromol/L. Nevertheless, inhibition of extracellular signal-regulated kinase 1/2 constitutive activity and reduction of MMP-2 and MMP-9 secretion was triggered by 0.5 micromol/L Hyp-DCHA to various degrees in different cell lines, the most in C-26. Inhibition of C-26 and HT-1080 cell chemoinvasion (80 and 54%, respectively) through reconstituted basement membrane was observed at these doses. Finally, in mice that received i.v. injections of C-26 or B16-LU8 cells, daily i.p. administration of Hyp-DCHA-without reaching tumor-cytotoxic blood levels-remarkably reduced inflammatory infiltration, neovascularization, lung weight (-48%), and size of experimental metastases with C-26 (-38%) and number of lung metastases with B16-LU8 (-22%), with preservation of apparently healthy and active behavior. These observations qualify Hyp-DCHA as an interesting lead compound to prevent and contrast cancer spread and metastatic growth.

Examination of the signal transduction pathways leading to activation of gelatinolytic activity by interleukin-1alpha and Porphyromonas gingivalis in human osteosarcoma cells

BACKGROUND

Recently, evidence show that matrix metalloproteinases (MMP) play an important role in the pathogenesis of periodontal diseases. However, the mechanisms and signal transduction pathways involved in the production of MMPs in human osteosarcoma cells are not fully understood.

OBJECTIVES

The purpose of this study was to investigate the gelatinolytic activity in human osteosarcoma cells stimulated with interleukin-1alpha (IL-1alpha) or Porphyromonas gingivalis in the absence or presence of SB203580 (p38 inhibitor), U0126 [mitogen-activated protein kinase kinase (MEK) inhibitor], and LY294002 [phosphatidylinositaol 3-kinase (PI3K) inhibitor].

METHODS

IL-1alpha and the supernatants of P. gingivalis were used to evaluate gelatinolytic activity in human osteosarcoma cells using gelatin zymography. Furthermore, to search possible signal transduction pathways, SB203580, U0126, and LY294002 were added to test how they modulated the gelatinolytic activity.

RESULTS

Gelatin zymography demonstrated that the latent proforms of gelatinases MMP-2 and MMP-9 were released by human osteosarcoma cells. Secretion of MMP-9 was time-dependent by stimulating with IL-1alpha or P. gingivalis. In addition, SB203580, U0126, and LY294002 significantly reduced the IL-1alpha or P. gingivalis-stimulated MMP-9 production, respectively (p < 0.05). However, none of the kinase inhibitors affected the MMP-2 level compared with the control during the 4-day culture period (p > 0.05).

CONCLUSIONS

Our findings demonstrated that IL-1alpha and P. gingivalis enhance MMP-9 production in human osteosarcoma cells, and the signal transduction pathways p38, MEK, and PI3K are involved in the inhibition of MMP-9. SB203580, U0126, and LY294002 suppress MMP-9 production and/or activity and may therefore be valuable therapeutics in MMP-mediated periodontal destruction, and might be proved clinically useful agents, in combination with standard treatment modalities, in the treatment of periodontitis.

MMPs are required for recruitment of antigen-nonspecific mononuclear cells into the liver by CTLs

We recently showed that antigen-nonspecific inflammatory cells are recruited into the liver when hepatitis B virus (HBV)-specific CTLs are injected into HBV transgenic mice, and that this process amplifies the severity of liver disease. We also showed that the severity of CTL-induced liver disease is ameliorated by the depletion of Gr-1(+) cells (Gr-1 is an antigen highly expressed by neutrophils), which, secondarily, abolishes the intrahepatic recruitment of all antigen-nonspecific Gr-1(-) mononuclear cells (NK and NKT cells, T and B lymphocytes, monocytes, macrophages, dendritic cells) despite the strong induction of chemokine gene expression. Those results suggested that in addition to chemokine expression, CTL-induced functions are necessary for mononuclear cell recruitment to occur. We now report that MMPs known to be produced by Gr-1(+) cells are rapidly induced in the livers of CTL-injected mice. The inhibition of MMP activity reduced the intrahepatic recruitment of antigen-nonspecific mononuclear cells and much of the attending liver disease without affecting the migration or antiviral potential of antigen-specific CTLs. The notion that the inhibition of MMP activity is associated with maintenance of antiviral effects but diminished tissue damage may be significant for the development of immunotherapeutic approaches for the treatment of chronic HBV infection.

Molecular epidemiology of the fsr locus and of gelatinase production among different subsets of Enterococcus faecalis isolates

We examined 215 Enterococcus faecalis isolates and found that neither the two-component regulatory locus fsr (E. faecalis regulator) nor gelatinase production was more common in disease-associated isolates than in isolates colonizing healthy individuals (ca. 60 to 65%). The majority of gelatinase-negative isolates, including 14 endocarditis isolates (of 80 isolates tested), contained the previously described 23.9-kb deletion and lacked fsrA and fsrB. While these findings indicate that neither fsr nor gelatinase is required for E. faecalis to cause infection, this study did not address whether fsr or gelatinase affects the severity of disease, as it does in animal models.

Prevalence, phenotype and genotype of oral enterococci

This study investigated the prevalence, phenotype and genotype of oral enterococci. Enterococci were detected in oral rinse samples from 11% of 100 patients receiving endodontic treatment and 1% of 100 dental students with no history of endodontic treatment (P=0.0027). All enterococcal isolates were identified as Enterococcus faecalis. Viable counts ranged from 1 x 10 to 6 x 103 colony forming units per mL of oral rinse sample. Potential virulence traits expressed by oral E. faecalis strains included production of hemolysin (n=4) and gelatinase (n=4), and response to pheromones in E. faecalis culture filtrate (n=1). Six strains produced bacteriocin. All strains were susceptible to ampicillin, benzylpenicillin, gentamicin and vancomycin. There was no evidence of metal-ion resistance. One isolate produced hemolysin, gelatinase and bacteriocin, was resistant to several antibiotics, and responded to the pheromone cPD1. Pulsed-field gel electrophoresis and plasmid analysis showed that oral E. faecalis exhibited widespread genetic polymorphism, with plasmids detected in seven strains.

Tumor-stromal cell contact promotes invasion of human uterine cervical carcinoma cells by augmenting the expression and activation of stromal matrix metalloproteinases

OBJECTIVE

The augmentation of the expression and activation of matrix metalloproteinases (MMPs) is associated with tumor invasion and metastasis. In addition, tumor-stromal cell contact provides a crucial signal for regulating the pericellular proteolysis for the progression of tumor invasiveness. The present study evaluates the regulation of the expression and activation of MMPs and tissue inhibitors of metalloproteinases (TIMPs) by tumor-stromal cell contact in an in vitro co-culture model of human uterine cervical carcinoma cells and human uterine cervical fibroblasts.

METHODS

When human uterine cervical carcinoma SKG-II cells were co-cultured with human uterine cervical fibroblasts (HUCFs), the invasive activity of SKG-II cells was analyzed using an in vitro invasion assay using Matrigel. The production, mRNA expression and activation of MMPs and TIMPs were monitored by Western blot and Northern blot analyses and gelatin zymography.

RESULTS

SKG-II cells, which constitutively produced membrane-type 1 MMP (MT1-MMP) and a trace of proMMP-2 but neither TIMP-1 nor TIMP-2, showed poor invasiveness in vitro. Upon co-culturing with HUCFs, SKG-II cells were found to transform to the invasive phenotype by enhancing the production and mRNA expression of tumoral MT1-MMP. In addition, a sequential increase in the activation of fibroblast proMMP-2 was observed along with the formation of an MT1-MMP-TIMP-2-proMMP-2 complex on the tumor cell surface. Furthermore, the production and gene expression of fibroblast proMMP-1 and proMMP-3 were augmented under co-culture conditions, whereas mRNA expression of proMMP-2, TIMP-1 and TIMP-2 was unchanged. Moreover, we demonstrated the partial involvement of tumor-cell-derived soluble factors in the augmentation of the production of proMMP-1 and proMMP-3 in HUCFs. However, anti-integrin beta1 and beta3 antibodies failed to abolish the augmentation of fibroblast proMMP-3 production and proMMP-2 activation in the co-culture.

CONCLUSION

Cell-cell contact between cervical carcinoma cells and peripheral stromal fibroblasts augments the production and activation of MMPs, and therefore the subsequent imbalance between MMPs and TIMPs may result in the progression of invasiveness of cervical carcinoma cells in vivo.

Expression and localization of v 6 integrin in extraplacental fetal membranes: possible role in human parturition

Successful outcome of human parturition is dependent upon extensive remodelling of the extracellular matrix (ECM) of the cervix, uterus and fetal membranes, a process that involves adhesion molecules and is also common in tumour invasion and metastasis. To elucidate the role of integrins in human parturition, this study characterizes the expression of the tumour-associated alpha(v)beta(6) integrin in human placenta and extraplacental membranes. Immunohistochemical analysis of the placenta and fetal membranes from normal vaginal deliveries (NVD) (n = 10) exhibited strong intensity of staining for alpha(v)beta(6) integrin (3 = dark brown) in the epithelial layer of the amnion. Weak immunohistochemical staining of alpha(v)beta(6) integrin (1 = pale brown) was detected in the chorion and at the decidual edge. These results were consistent with the immunodetection of alpha(v)beta(6) integrin by western blot analysis that showed 4-fold enhanced expression in the amnion compared to chorion of both NVD and term elective caesarean section (CS) deliveries. Even though there was no difference in the extent of immunohistochemical staining of alpha(v)beta(6) integrin between the amnion of NVD and CS groups, significantly higher intensity of staining was observed in the NVD amniotic epithelium compared to that of CS (n = 10) (chi(2) = 10.25, P = 0.0059). Western blot analysis of the fetal membranes showed no differences in the expression of alpha(v)beta(6) integrin between the NVD and CS groups. Gelatin zymography demonstrated the presence of pro-matrix metalloprotein-9 (MMP-9) and pro-MMP-2 in the amnion and chorion of NVD, whereas in CS only the presence of pro-MMP-2 was observed. These results suggest that in term pregnancy, human fetal membranes express alpha(v)beta(6) integrin and that the expression is significantly higher in amnion compared to chorion. The fact that enhanced expression of alpha(v)beta(6) integrin in fetal membranes correlates with the expression of pro-MMP-9 in NVD is consistent with the invasive role of the integrin in cancer and suggests that the molecule may have a proteolytic role in the initiation and progression of labour.

Survey for virulence determinants among Enterococcus faecalis isolated from different sources

A collection of Enterococcus faecalis strains from clinical isolates, healthy individuals and the environment was screened for the presence of virulence factor genes, such as those for collagen-binding protein (ace), endocarditis antigen (efaA), haemolysin activator (cylA), gelatinase (gelE), aggregation substances (asa1 and asa373), a surface protein (esp) and two novel putative surface antigens (EF0591 and EF3314). Apart from some genes that were present in all strains (ace, efaA and EF3314), the gelE gene was the most common factor, although its presence did not correlate with its expression. The genes that encode Esp and CylA were never detected in endocarditis isolates, whereas an association was noted between the esp gene and isolates from urinary tract infection (UTI) and bacteraemia. An aggregation substance gene was always present in commensal strains. As for gelatinase, the presence of the cylA and asa genes did not correlate completely with their phenotypic expression. Generally, isolates from endocarditis, biliary stents and the environment were equipped with fewer virulence factors than isolates from other sources. UTI strains possessed the highest number of factors.

Elevated hyaluronan production induces mesenchymal and transformed properties in epithelial cells

During carcinoma progression, tumor cells often undergo changes similar (but not identical) to epithelialmesenchymal transitions in embryonic development. In this study, we demonstrate that experimental stimulation of hyaluronan synthesis in normal epithelial cells is sufficient to induce mesenchymal and transformed characteristics. Using recombinant adenoviral expression of hyaluronan synthase-2, we show that increased hyaluronan production promotes anchorage-independent growth and invasiveness, induces gelatinase production, and stimulates phosphoinositide 3-kinase/Akt pathway activity in phenotypically normal Madin-Darby canine kidney and MCF-10A human mammary epithelial cells. Cells infected with hyaluronan synthase-2 adenovirus also acquired mesenchymal characteristics, including up-regulation of vimentin, dispersion of cytokeratin, and loss of organized adhesion proteins at intercellular boundaries. Furthermore, we show that the transforming effects of two well described agents, hepatocyte growth factor (HGF) and beta-catenin, are dependent on hyaluronan-cell interactions. Perturbation of endogenous hyaluronan polymer interactions by treatment with hyaluronan oligomers is shown here to reverse the transforming effects of HGF and beta-catenin in Madin-Darby canine kidney and MCF-10A human mammary epithelial cells. Also, HGF and beta-catenin induced assembly of hyaluronan-dependent pericellular matrices similar to those surrounding mesenchymal cells. Thus, increased expression of hyaluronan is sufficient to induce epithelial-mesenchymal transition and acquisition of transformed properties in phenotypically normal epithelial cells.

Possible roles of thrombin-induced activation of protease-activated receptor 1 in human luteinized granulosa cells

The presence of thrombin and its receptor, protease-activated receptor 1 (PAR 1), in the ovary suggests that thrombin may regulate ovarian function. In particular, to address the possible role of thrombin in ovulation, a phenomenon displaying mimicry of inflammation, we investigated the effects of thrombin and PAR 1 on the production of inflammation-related substances in human luteinized granulosa cells (LGC). Thrombin stimulated the production of IL-8 and monocyte chemoattractant protein-1 by cultured LGC. The stimulatory effects of thrombin were inhibited by both inhibitors of thrombin (hirudin and PPACK) and a protein kinase C inhibitor (calphostin C). The PAR 1 agonist, SFLLRN, also stimulated the production of IL-8 and monocyte chemoattractant protein-1. Thrombin and SFLLRN stimulated the geletinase activities of LGC, the effect of both being inhibited by hirudin and PPACK. Immunocytochemical study showed that thrombin and SFLLRN induced translocation of nuclear factor kappaB to the nucleus from the cytoplasm in LGC. Expression of PAR 1 mRNA was detected in LGC by RT-PCR analysis. These findings suggest that thrombin plays physiological roles in ovulation by enhancing the production of chemoattractive and gelatinolytic substances by granulosa cells by a mechanism involving PAR 1.

Expression patterns of seprase, a membrane serine protease, in cervical carcinoma and cervical intraepithelial neoplasm

BACKGROUND

Seprase is a membrane-bound serine proteinase with gelatinase activity, which may be involved in cancer invasion and metastasis.

PATIENTS AND METHODS

We examined the seprase expression patterns in invasive or preinvasive squamous epithelial lesions.

RESULTS AND CONCLUSION

No seprase immunoreactivity was found in the atypical epithelial cells and subepithelial stromal cells of CIN1 and 2 lesions. No seprase expression could be detected even in CIN3 lesions. However, in contrast to CIN1 and 2, seprase immunoreactivity was occasionally observed in the subepithelial stromal cells that were associated with moderate or severe inflammatory infiltrates. Some microinvasive carcinomas and all invasive carcinomas showed seprase immunoreactivity in the cancer cells with various degrees of seprase-positive stromal cells. Seprase may be an early marker of tumor invasion in squamous lesions of the uterine cervix.

Role of the Enterococcus faecalis GelE protease in determination of cellular chain length, supernatant pheromone levels, and degradation of fibrin and misfolded surface proteins

Gelatinase (GelE), a secreted Zn-metalloprotease of Enterococcus faecalis, has been implicated as a virulence factor by both epidemiological data and animal model studies. Expression of gelE is induced at a high cell density by the fsr quorum-sensing system. In the present study, GelE was shown to be responsible for the instability of a number of Asc10 (aggregation substance) mutant proteins, implying that GelE functions to clear the bacterial cell surface of misfolded proteins. Disruption of GelE production led to increased cell chain length of E. faecalis, from a typical diplococcus morphology to chains of 5 to 10 cells. This function of GelE was also exhibited when the protein was expressed in Streptococcus pyogenes. GelE-expressing E. faecalis strains were more autolytic, suggesting that GelE affects chain length through activation of an autolysin. GelE was also essential for degradation of polymerized fibrin. GelE expression reduced the titer of cCF10, the peptide pheromone that induces conjugation of pCF10, and pCF10 had increased conjugation into non-GelE-expressing strains. These new functions attributed to GelE suggest that it acts to increase the dissemination of E. faecalis in high-density environments.

Regulation of neutrophil and eosinophil secondary granule gene expression by transcription factors C/EBP epsilon and PU.1

In the bone marrow of C/EBP epsilon(-/-) mice, expression of neutrophil secondary and tertiary granule mRNAs is absent for lactoferrin (LF), neutrophil gelatinase (NG), murine cathelin-like protein (MCLP), and the cathelin B9; it is severely reduced for neutrophil collagenase (NC) and neutrophil gelatinase-associated lipocalin (NGAL). In addition, the expression of eosinophil granule genes, major basic protein (MBP), and eosinophil peroxidase (EPX) is absent. These mice express C/EBP alpha, C/EBP beta, and C/EBP delta in the bone marrow at levels similar to those of their wild-type counterparts, suggesting a lack of functional redundancy among the family in vivo. Stable inducible expression of C/EBP epsilon and C/EBP alpha in the murine fibroblast cell line NIH 3T3 activated expression of mRNAs for B9, MCLP, NC, and NGAL but not for LF. In transient transfections of C/EBP epsilon and C/EBP alpha, B9 was strongly induced with weaker induction of the other genes. C/EBP beta and C/EBP delta proteins weakly induced B9 expression, but C/EBP delta induced NC expression more efficiently than the other C/EBPs. The expression of MBP was inefficiently induced by C/EBP epsilon alone and weakly induced with C/EBP epsilon and GATA-1, but the addition of PU.1 resulted in a striking cooperative induction of MBP in NIH 3T3 cells. Mutation of a predicted PU.1 site in the human MBP promoter-luciferase reporter construct abrogated the response to PU.1. Gel-shift analysis demonstrated binding of PU.1 to this site. MBP and EPX mRNAs were absent in a PU.1-null myeloid cell line established from the embryonic liver of PU.1(-/-) mice. Restitution of PU.1 protein expression restored MBP and EPX protein expression. This study demonstrates that C/EBP epsilon is essential and sufficient for the expression of a particular subset of neutrophil secondary granule genes. Furthermore, it indicates the importance of PU.1 in the cooperative activation of eosinophil granule genes.

Differential regulation of the expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases by cytokines and growth factors in bovine endometrial stromal cells and trophoblast cell line BT-1 in vitro

Degradation and reconstitution of extracellular matrix in uterine endometrium is a crucial event for embryonic implantation and is regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). In the present study, we investigated the regulation of MMP and TIMP expression in cultured bovine endometrial stromal cells (BESCs) and a bovine trophoblast cell line BT-1 (BT-1 cells). The production of proMMP-9 was induced by transforming growth factor beta (TGFbeta) and 12-O-tetradecanoylphorbol 13-acetate in the stromal cells. The treatment of BESCs with TGFbeta, insulin-like growth factor-I, and hepatocyte growth factor (HGF) resulted in a significant increase in the level of TIMP-1 in the culture medium. In addition, a significant increase of TIMP-2 production was observed in interleukin (IL)-1alpha and HGF-treated BESCs. However, the expression of TIMP-1 and TIMP-2 mRNA was not augmented by these factors. The treatment of BESCs with 12-O-tetradecanoylphorbol 13-acetate resulted in a significant increase in the level of TIMP-1 but a significant decrease in the level of TIMP-2 in the stromal cells. Membrane type-1 MMP mRNA expression in the stromal cells was augmented by tumor necrosis factor alpha (TNFalpha), IL-6, HGF, and 12-O-tetradecanoylphorbol 13-acetate. On the other hand, BT-1 cells constitutively produced proMMP-9 and proMMP-2, and the treatment of BT-1 cells with TNFalpha, HGF, and 12-O-tetradecanoylphorbol 13-acetate resulted in a significant increase in the level of proMMP-9 but not in the level of proMMP-2. The production of TIMP-1 in BT-1 cells was also augmented by IL-1alpha, TNFalpha, and HGF at the level of translation and was transcriptionally increased by 12-O-tetradecanoylphorbol 13-acetate. However, the level of TIMP-2 mRNA in BT-1 cells was not affected by any of the treatments. These results suggest that the expression of MMPs and TIMPs is differentially regulated by cytokines and growth factors and that the production of TIMP-1 and TIMP-2 may not be accompanied by changes in their mRNA expression in bovine endometrium and trophoblasts. Furthermore, as in humans and rodents, MMPs and TIMPs may contribute to the control of degradation and reconstitution of extracellular matrix in bovine endometrium during embryonic implantation and early placentation.

Anti-angiogenic and anti-tumor invasive activities of tissue inhibitor of metalloproteinase-3 from shark, Scyliorhinus torazame

In order to investigate the anti-angiogenic activity of shark TIMP-3 (sTIMP-3) in endothelial cells, angiogenic assays including in vitro invasion assay, migration assay, zymogram assay and tube formation assay were performed. We observed that the overexpression of sTIMP-3 decreased the invasive capacity by about 70%, the migratory activity by about 50% and the production of gelatinase A in bovine aortic endothelial cells (BAECs). In addition, the overexpression of sTIMP-3 interfered with the formation of capillary-like network in endothelial cells. We also examined whether sTIMP-3 shows the anti-invasive activity in cancer cells. We found that the overexpression of sTIMP-3 diminished the invasive ability of the human fibrosarcoma HT1080 cells by about 40%. Also, the production of specific gelatinases was suppressed in the cancer cells. Therefore, we propose that sTIMP-3 acts as the inhibitor of angiogenesis in endothelial cells and the suppressor of tumor invasion in human fibrosarcoma HT1080 cells.

(-)Epigallocatechin-3-gallate inhibits gelatinase activity of some bacterial isolates from ocular infection, and limits their invasion through gelatine

The objective of this paper is to assess the gelatinase production by some ocular pathogenic bacterial strains, and evaluate the ability of (-)epigallocatechin-3-gallate (EGCg) to inhibit this gelatinase activity and thus limit bacterial invasion. The effect of EGCg on bacterial gelatinase activity was tested by classic zymography methods, while its effect on bacterial invasion was evaluated through the ability of growing bacteria to liquefy and thus penetrate a semisolid gelatine substrate. It was found that EGCg inhibits bacterial gelatinases with an IC(50) of about 0.2 mM, and limits invasion of gelatinase-positive bacteria at concentrations above 2 mM. These results show for the first time that EGCg, as well as having direct antibacterial activity, can also inhibit bacterial gelatinases, thus limiting their invasion on gelatine. Possible use of EGCg is thus suggested as an adjuvant in antibacterial chemotherapy.

Stimulation of Pro-MMP-2 Production and Activation by Native Form of Extracellular Type I Collagen in Cultured Hepatic Stellate Cells

Cultured hepatic stellate cells (HSCs) are known to change their morphology and function with respect to the production of extracellular matrices (ECMs) and matrix metalloproteinases (MMPs) in response to ECM components. We examined the regulatory role of the native form of type I collagen fibrils in pro-MMP-2 production and activation in cultured HSCs. Gelatin zymography of the conditioned media revealed that pro- and active form of MMP-2 was increased in the HSCs cultured on type I collagen gel but not on type I collagen-coated surface, gelatin-coated surface, type IV collagen-coated surface, or Matrigel, suggesting the importance of the native form of type I collagen fibrils in pro-MMP-2 production and activation. The induction of active MMP-2 by extracellular type I collagen was suppressed by the blocking antibody against integrin beta1 subunits, indicating the involvement of integrin signaling in pro-MMP-2 activation. RT-PCR analysis indicated that MMP-2, membrane type-1 MMP (MT1-MMP) and tissue inhibitor of metalloproteinase-2 (TIMP-2) mRNA levels were elevated in HSCs cultured on type I collagen gel. The increased MT1-MMP proteins were localized on the cell surface of HSCs cultured on type I collagen gel. In contrast to the expression of MMP-2, HSCs showed a great decline in MMP-13 expression in HSCs cultured on type I collagen gel. These results indicate that the native fibrillar (polymerized) but not monomeric form of type I collagen induced pro-MMP-2 production and activation through MT1-MMP and TIMP-2 in cultured HSCs, suggesting an important role of HSCs in ECM remodeling in the hepatic perisinusoidal spaces.

Rapid trafficking of membrane type 1-matrix metalloproteinase to the cell surface regulates progelatinase a activation

Pericellular matrix degradation during cancer invasion and inflammation is dependent on activation of progelatinase A by membrane type 1-matrix metalloproteinase (MT1-MMP); a stoichiometric concentration of tissue inhibitor of metalloproteinase-2 (TIMP-2) is required. Activation of progelatinase A has generally been considered to be a slow process occurring as a result of enhanced expression of MT1-MMP. We herein report that ConA treatment of HT1080 fibrosarcoma cells is followed by MT1-MMP-induced activation of progelatinase A on the cell surface within 1 hour. Cell surface biotinylation, immunohistochemistry, and (125)I-labeled TIMP-2 binding to cell surface MT1-MMP were used to characterize the appearance and function of MT1-MMP on the plasma membrane. Treatment of HT1080 cells with ConA resulted in increased specific binding of (125)I-labeled TIMP-2 to cell surface receptors within 5 minutes. TIMP-2 binds almost exclusively to activated MT1-MMP on the surface of HT1080 cells. MT1-MMP function at the cell surface was also accelerated by treatment of cells with cytochalasin D, an inhibitor of actin filaments, PMA, a stimulator of protein kinase C, and bafilomycin A(1), an inhibitor of lysosome/endosome function. A functional pool of intracellular MT1-MMP available for trafficking to the cell surface was demonstrated by repetitive ConA stimulation. ConA-induced expression of MT1-MMP mRNA (Northern blot analysis) in HT1080 cells was a delayed event (>6 hours). These data suggest that presynthesized MT1-MMP is sorted to a transient storage compartment (trans-Golgi network/endosomes), where it is available for rapid trafficking to the plasma membrane and cell surface proteolytic activity.

Molecular characterization and expression analysis of leucine-rich alpha2-glycoprotein, a novel marker of granulocytic differentiation

Using data obtained from cDNA representational difference analysis to identify genes induced during neutrophilic differentiation of the 32D clone 3G (32Dcl3G) cells, we isolated cDNA clones for murine and human leucine-rich alpha2-glycoprotein (hLRG), a protein with unknown function purified 25 years ago. Expression of LRG during differentiation of 32Dcl3G cells preceded the expression of lactoferrin and gelatinase but followed myeloperoxidase. LRG transcripts were also detected in human neutrophils and progenitor cells but not in peripheral blood mononuclear cells. Notably, LRG expression was up-regulated during neutrophilic differentiation of human MPD and HL-60 cells but down-regulated during monocytic differentiation of HL-60 cells. The hLRG gene was localized to chromosome 19p13.3, a region to which the genes for several neutrophil granule enzymes also map. The putative promoter region of LRG was found to contain consensus-binding sites for PU.1, C/EBP, STAT, and MZF1. These results suggest that LRG is a novel marker for early neutrophilic granulocyte differentiation.

Molecular and genetic characterization of a non-metastatic human esophageal cancer cell line, T.Tn expressing non-functional mutated p53

Lymph node metastasis is commonly found in esophageal squamous cell carcinoma (SCC). In this study, we examined the molecular and genetic characteristics of a human esophageal SCC cell line, T.Tn. T.Tn cells formed tumors at s.c. tissue in nude mice when inoculated with Matrigel, but did not metastasize to any organs. T.Tn cells expressed low level of proMMP2 and a trace level of proMMP9. However, T.Tn cells expressed high level of TIMP1 and TIMP2, and beta-catenin and E-cadherin. We found a point mutation of p53 gene at codon 213 (CAT-->CGT) in T.Tn cells. The mutated-p53 protein did not show transcriptional activity on p21(waf1), MDM2 and Bax promoters. Thus, T.Tn cells are low tumorigenic and weakly invasive but not metastasizing in nude mice, and T.Tn cells are suitable parental cells for establishing a model system to study invasion and metastasis of esophageal SCC.

Altered regulation of matrix metalloproteinase-2 in aortic remodeling during aging

To elucidate potential mechanisms of enhanced type 2 matrix metalloprotease levels and activity within the thickened aged rat aorta, the present study measured its mRNA and protein levels and those of its membrane bound activator, MT1-MMP, its endogenous tissue inhibitor, TIMP-2, tissue type, and urokinase plasminogen activators and their receptors, and an inhibitor of plasminogen activation in aortae from Fisher 344X Brown Norway rats, 2 to 30 months of age. Semiquantitative immunohistochemistry, in situ hybridization, and in situ zymography of aortae detected a marked age-associated increase in gelatinolytic activity of type 2 metalloprotease within the thickened intima, internal elastic lamina, and elastic fibers in the inner part of the thickened tunica media, whereas the intimal tissue inhibitor of metalloprotease-2 mRNA and protein levels were not age related. Both activators of plasminogen and their receptors increased approximately 2-fold within the intima between 2 to 30 months. Similar, but not identical, age-associated changes in factors that regulate protease activity within the aortic media were also observed. We conclude that discordant regulation of factors that determine the activation status of type 2 matrix metalloprotease, coupled with an increase in the expression of its zymogen, occur with aging, which lead to an increase in the amount of activated protease. These factors are candidate mechanisms for age-associated vascular remodeling, a potent risk factor for vascular diseases with advancing age.