Differential regulation of matrix metalloproteinase 2 and matrix metalloproteinase 9 by activated protein C: relevance to inflammation in rheumatoid arthritis

Association between matrix metalloproteinase-9-1562C/T gene polymorphism and MMP-9 serum level in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease indicated by joint inflammation and cartilage destruction. Matrix metalloproteinase (MMP) enzymes play an influential role in inflammation by affecting the invasion and degradation of anatomical barriers. In this way, the current study investigated the relationship between the MMP-9-1562C/T gene polymorphism and this enzyme's serum level in RA.

METHODS

The serum levels of MMP-9 in RA patients and healthy controls were measured using the enzyme-linked immunosorbent assay (ELISA). RA was confirmed using rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), and C-reactive protein (CRP). Then the MMP-9-1562C/T gene polymorphism was analyzed utilizing polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Also, multivariate analysis investigated the connection between this polymorphism and the risk of RA.

RESULTS

In this study, the increase of MMP-9 in patients due to the development of single nucleotide polymorphism in the promoter region of this gene (-1562 C→T) was confirmed by increasing the frequency of heterozygous genotype (CT). Logistic regression analysis also demonstrated that the chance of development of RA is higher in people with CT/CC genotype than in other alleles.

CONCLUSIONS

We demonstrated that MMP-9-1562C/T gene polymorphism can play a significant role in the occurrence of RA.

Endothelial Protein C Receptor and Its Impact on Rheumatic Disease

Endothelial Protein C Receptor (EPCR) is a key regulator of the activated protein C anti-coagulation pathway due to its role in the binding and activation of this protein. EPCR also binds to other ligands such as Factor VII and X, γδ T-cells, plasmodium falciparum erythrocyte membrane protein 1, and Secretory group V Phospholipases A2, facilitating ligand-specific functions. The functions of EPCR can also be regulated by soluble (s)EPCR that competes for the binding sites of membrane-bound (m)EPCR. sEPCR is created when mEPCR is shed from the cell surface. The propensity of shedding alters depending on the genetic haplotype of the EPCR gene that an individual may possess. EPCR plays an active role in normal homeostasis, anti-coagulation pathways, inflammation, and cell stemness. Due to these properties, EPCR is considered a potential effector/mediator of inflammatory diseases. Rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus are autoimmune/inflammatory conditions that are associated with elevated EPCR levels and disease activity, potentially driven by EPCR. This review highlights the functions of EPCR and its contribution to rheumatic diseases.

Vitamin A, D, E, and K as Matrix Metalloproteinase-2/9 Regulators That Affect Expression and Enzymatic Activity

Fat-soluble vitamins (vitamin A, D, E, and K) assume a pivotal role in maintaining human homeostasis by virtue of their enzymatic functions. The daily inclusion of these vitamins is imperative to the upkeep of various physiological processes including vision, bone health, immunity, and protection against oxidative stress. Current research highlights fat-soluble vitamins as potential therapeutics for human diseases, especially cancer. Fat-soluble vitamins exert their therapeutic effects through multiple pathways, including regulation of matrix metalloproteinases' (MMPs) expression and enzymatic activity. As MMPs have been reported to be involved in the pathology of various diseases, such as cancers, cardiovascular diseases, and neurological disorders, regulating the expression and/or activity of MMPs could be considered as a potent therapeutic strategy. Here, we summarize the properties of fat-soluble vitamins and their potential as promising candidates capable of effectively modulating MMPs through multiple pathways to treat human diseases.

Matrix Metalloproteinase-9 Level in Synovial Fluid-Association with Joint Destruction in Early Rheumatoid Arthritis

Background and objective: Matrix metalloproteinases (MMPs) are the key enzymes in the pathogenesis of cartilage and joint damage and potentially a new biomarker of the early erosive form of rheumatoid arthritis (RA). Firstly, the study aimed to compare the level of MMP-9 in plasma (PL) and synovial fluid (SF) of patients with RA and osteoarthritis (OA). Secondly, the goal was to examine the association of MMP-9 level in PL and SF with early erosive changes in RA, and finally, to determine the association of MMP-9 level with serological parameters of the disease (rheumatoid factor-RF and anti-citrulline protein antibodies-ACPA). Materials and Methods: A total of 156 subjects were involved in this study (84 patients with RA and 72 patients with OA, who were involved as a control group). MMP-9 level was measured in PL and SF of all subjects by the sandwich enzyme-linked immunosorbent assay (ELISA) method. Standard radiographs of the hands and feet were used to detect joint damage and classification into erosive or non-erosive RA. The Larsen score (LS) was used for the quantitative assessment of joint damage, and its annual change (∆ LS) was used to assess the radiographic progression of the disease. Results: MMP-9 level in PL and SF was significantly higher in RA compared to controls (PL: 19.26 ± 7.54 vs. 14.57 ± 3.11 ng/mL, p< 0.01; SF: 16.17 ± 12.25 vs. 0.75 ± 0.53 ng/mL, p < 0.001) as well as in SF of patients with erosive compared to non-erosive RA (18.43 ± 12.87 vs. 9.36 ± 7.72; p < 0.05). Faster radiographic progression was recorded in erosive compared to non-erosive early RA (11.14 ± 4.75 vs. 6.13 ± 2.72; p < 0.01). MMP-9 level in SF, but not in PL, significantly correlates with the radiographic progression in both erosive and non-erosive RA (ρ = 0.38 and ρ = 0.27). We did not find a significant association between RF and MMP-9 level in early RA, but the ACPA level significantly correlates with MMP-9 level in SF (r = 0.48). Conclusion: The level of MMP-9 in plasma and synovial fluid of patients with RA is significantly higher compared to patients with osteoarthritis. The level of MMP-9 in synovial fluid is significantly higher in erosive than non-erosive early RA. It is significantly associated with the radiographic progression of the disease and the level of anti-citrulline protein antibodies.

Factors of local conversion of iodothyronines correlate with indicators of hormonal, biochemical, and hematological profiles in patients with spinal canal and dural sac stenosis of the lumbar spine

In order to find out the mechanisms of pathogenesis of degenerative-dystrophic diseases of the spine, it is of particular interest to search for body parameters which are directly or indirectly interrelated with the key factors of peripheral conversion of nidus iodothyronines and constitute a system of network interactions, affecting metabolic indicators at the local and systemic level.The aim. To search for correlations of local key factors of peripheral conversion of Ligamentum flavum iodothyronines with indicators of biochemical, hematological and hormonal blood profiles of patients with stenosing processes of the spinal canal and dural sac in the lumbar spine.Materials and methods. 33 patients (15 males, 18 females) with stenosing processes of the spinal canal and dural sac in the lumbar spine were examined (mean age – 45.73 ± 1.95 years). The expression of deiodinase genes and other candidate genes was determined in Ligamentum flavum biopsies collected during surgical treatment. Biochemical, hematological and hormonal parameters were determined in peripheral blood. The resulting data array was processed in order to find correlations between the parameters of systemic and local metabolism.Results. The relationships of deiodinases with the expression of GDF5, MMP1, MMP3 and TIMP1 in Ligamentum flavum (p < 0.05) were found. Of the hormonal profile of the blood serum, the most significant indicators were thyreotropin, free triiodothyronine and thyroperoxidase antibodies. In the biochemical profile, levels of direct bilirubin, total cholesterol, HDL and LDL cholesterol and triglycerides changed along with the expression of deiodinases. Correlative relationships with the expression of deiodinases were found for the following hematological analytes of whole peripheral blood: hemoglobin, mean corpuscular hemoglobin concentration, numbers of granulocytes, lymphocytes, eosinophils, monocytes, band neutrophils, red cell distribution width and platelet crit. The data obtained indicate the involvement of peripheral conversion factors in the pathogenetic process and provide information to form a new view on the pathogenesis of degenerative-dystrophic processes in the Ligamentum flavum of patients with stenosing processes of the spinal canal and the dural sac in the lumbar spine.

Activity of genes of matrix metalloproteinases and their inhibitors in the Ligamentum flavum of patients with stenosing processes in spinal canal and dural sac

New data have been obtained for assessing the expression of genes of metalloproteinases and their tissue inhibitors (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, TIMP-1 and TIMP-2) in the Ligamentum flavum in patients with lumbar stenosis of spinal canal and dural sac. The features of the metabolism of the extracellular matrix (ECM) were revealed, the data obtained were compared with those for previously studied candidate genes. The search for relationships with the features of the ECM metabolic characteristics was carried out.The aim. To study the expression of genes of metalloproteinases and their tissue inhibitors in intraoperative biopsies of the Ligamentum flavum of patients with lumbar stenosis of the spinal canal and dural sac.Materials and methods. A group of 33 people (17 women, 16 men) with lumbar stenosis of the spinal canal and dural sac was studied; the average age is 45.73 ± 1.95 years. RNA was isolated from intraoperative biopsies of the Ligamentum flavum, reverse transcription was performed, and PCR using specific primers was performed.Results. In Ligamentum flavum of patients with stenosing processes of the spinal canal and dural sac, an increased activity of MMP-1 and insufficient response of TIMP-1 and TIMP-2 were found; the expression of MMP-1 increased synchronously with Dio2, and both genes decreased their activity with increasing age of the patient. In patients with Ligamentum flavum ossification, the MMR-8 gene was more actively expressed, and the synthesis of the mRNA of the MMR-9 gene decreased compared to the subgroup without ossification.

[Contribution of endopeptidases to changes in scleral biomechanics in axial elongation of the eye]

The article describes the main properties of the sclera in patients with axial eye elongation depending on the degree of axial myopia, and presents basic information on the structure, mechanism of action and regulatory activity of matrix metalloproteinases (MMPs). MMPs play the key role in the development of abnormal catabolism of extracellular matrix components of the fibrous capsule - the process leading to changes in scleral structure and biomechanical properties in eyes with anterior-posterior axis elongation.

Anti-Inflammatory Effects of Melatonin and 5-Methoxytryptophol on Lipopolysaccharide-Induced Acute Pulpitis in Rats

Aim

The aim of this study was to investigate the possible therapeutic impacts of two pineal hormones, melatonin and 5-methoxytryptophol (5-MTX), in a rat model of acute pulpitis by analyzing biochemical and histopathological parameters.

Methods

This research was done using 32 male and female Wistar albino rats with weight between 200 and 250 g. The rats were randomly divided into four groups: a control group (rats without any treatment), acute pulpitis (AP) group, AP+melatonin group, and AP+5-MTX group. In the AP-induced groups, the crowns of the upper left incisors were removed horizontally. Lipopolysaccharide solution was applied to the exposed pulp tissue before the canal orifices were sealed with a temporary filling material. Melatonin (10 mg/kg) and 5-MTX (5 mg/kg) were administered intraperitoneally. The rats were sacrificed 24 hours after pulp injury, and trunk blood and pulp samples were collected. The concentrations of TNF-α, IL-1β, MMP-1, and MMP-2 in sera and pulp samples were determined using ELISA assay kits.

Results

TNF-α, IL-1β, MMP-1, and MMP-2 levels in the serum and pulp tissues were considerably higher in the AP group than the control group (p < 0.01‐0.001). In the AP+melatonin and AP+5-MTX groups, TNF-α, IL-1β, MMP-1, and MMP-2 levels in the serum and pulp tissues were significantly lower than in the AP group (p < 0.05‐0.001).

Conclusions

Both melatonin and 5-MTX provided protective effects on acute pulpitis, which indicates they may be promising as a therapeutic strategy for oral disease.

Expression of Matrix Metalloproteinases and Their Tissue Inhibitors in Peripheral Blood Leukocytes and Plasma of Children with Nonalcoholic Fatty Liver Disease

Gene expression profiles of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) were evaluated in peripheral blood leukocytes of children with nonalcoholic fatty liver disease (NAFLD). Gene expression patterns were correlated with their plasma protein counterparts, systemic parameters of liver injury, and selected markers of inflammation. The MMP-2, MMP-9, MMP-12, MMP-14, TIMP-1, TIMP-2, TGF-β, and IL-6 transcripts levels were tested by the real-time PCR. Plasma concentrations of MMP-9, TIMP-1, MMP-9/TIMP-1 ratio, MMP-2/TIMP-2 ratio, sCD14, leptin, resistin, IL-1 beta, and IL-6 and serum markers of liver injury were estimated by ELISA. The MMP-9, TIMP-2 expression levels, plasma amounts of MMP-9, TIMP-1, and the MMP-9/TIMP-1 ratio were increased in children with NAFLD. Concentrations of AST, ALT, GGT, and leptin were elevated in serum patients with NAFLD, while concentration of other inflammatory or liver injury markers was unchanged. The MMP-2 and MMP-9 levels correlated with serum liver injury parameters (ALT and GGT concentrations, respectively); there were no other correlations between MMP/TIMP gene expression profiles, their plasma counterparts, and serum inflammatory markers. Association of MMP-2 and MMP-9 expression with serum liver injury parameters (ALT, GGT) may suggest leukocyte engagement in the early stages of NAFLD development which possibly precedes subsequent systemic inflammatory responses.

Destroy to Rebuild: The Connection Between Bone Tissue Remodeling and Matrix Metalloproteinases

Bone is a dynamic organ that undergoes constant remodeling, an energetically costly process by which old bone is replaced and localized bone defects are repaired to renew the skeleton over time, thereby maintaining skeletal health. This review provides a general overview of bone’s main players (bone lining cells, osteocytes, osteoclasts, reversal cells, and osteoblasts) that participate in bone remodeling. Placing emphasis on the family of extracellular matrix metalloproteinases (MMPs), we describe how: (i) Convergence of multiple protease families (including MMPs and cysteine proteinases) ensures complexity and robustness of the bone remodeling process, (ii) Enzymatic activity of MMPs affects bone physiology at the molecular and cellular levels and (iii) Either overexpression or deficiency/insufficiency of individual MMPs impairs healthy bone remodeling and systemic metabolism. Today, it is generally accepted that proteolytic activity is required for the degradation of bone tissue in osteoarthritis and osteoporosis. However, it is increasingly evident that inactivating mutations in MMP genes can also lead to bone pathology including osteolysis and metabolic abnormalities such as delayed growth. We argue that there remains a need to rethink the role played by proteases in bone physiology and pathology.

Loss of Klotho contributes to cartilage damage by derepression of canonical Wnt/β-catenin signaling in osteoarthritis mice

Caducity is known to be an independent risk factor in osteoarthritis (OA), yet the molecular basis behind caducity and OA remains unclear. Klotho, an anti-caducity protein, is an endogenous antagonist of the transduction of Wnt/β-catenin signal which can stimulate the articular cartilage degradation, indicating that deficiency in Klotho may increase Wnt/β-catenin activity and consequently accelerate the development of OA. We found that expression of Klotho was markedly higher in normal mouse cartilage than in the OA model, and in this model the activity of Wnt/β-catenin and its target gene was up-regulated. Decrease in Klotho expression was closely associated with the increase of β-catenin in OA, indicating that there was a negative correlation between Klotho and Wnt signal transduction. In the vitro and in vivo experiments, Klotho was found to bind to multiple Wnt, including Wnt1, Wnt4 and Wnt7a. It was additionally found that cyclic tenisle strain (CTS) inhibited the expression of Klotho and activated β-catenin. On the contrary, over-expression of Klotho would reduce the degradation of articular cartilage induced by CTS. These results suggest that Klotho is an antagonist of endogenous Wnt/β-catenin activity. In OA cartilage, decrease in expression of Klotho can activate Wnt/β-catenin signal transduction and consequently induce cartilage injury.

Dynamics of Matrix Metalloproteinases in Local Cold Injury

The relevance of cold injury is due to its high specific weight in the structure of injuries, complexities of complex therapy, and unsatisfactory results of treatment. It is known that in the pathogenesis of local cold injury, the leading role belongs to endothelial dysfunction, which secretes a huge amount of biologically active substances, including matrix metalloproteinases.Aim: to determine the dynamics of the content of matrix metalloproteinases of the second subfamily (MMP-2, MMP-9) in the serum of patients with local cold injury.Materials and methods. The study included 80 patients (60 men, 20 women) with frostbite of the III–IV degree of the foot to the level of the lower third of the leg in the late reactive period and the period of granulation and epithelization.Results. In the late reactive period in patients with cryopreservation, the level of MMP-2 was 3.4 times higher relative to the control (p = 0.011), on day 30 MMP-2 values did not differ from the control parameters (p = 0.103). The level of collagenase B (MMP-9) in patients with local cold injury on day 5 was 14.5 times higher than the control parameters (p = 0.002), on day 30 – 12.5 times higher compared to the control group (p = 0.000094).Conclusion. During the analysis of the data obtained, we can think about the dual nature of collagenases during the processes of inflammation. In a situation of distress, collagenases prevent endothelial dysfunction by eliminating the cellular structures of the endothelium to ensure adequate metabolism in tissues. Their importance as markers of failure of adequate flow of reparative processes is not excluded.

Diverse characters of Brennan's paw incision model regarding certain parameters in the rat

Background

Brennan’s rodent paw incision model has been extensively used for understanding mechanisms underlying postoperative pain in humans. However, alterations of physiological parameters like blood pressure and heart rate, or even feeding and drinking patterns after the incision have not been documented as yet. Moreover, though eicosanoids like prostaglandins and leukotrienes contribute to inflammation, tissue levels of these inflammatory mediators have never been studied. This work further investigates the antinociceptive effect of protein C after intra-wound administration.

Methods

Separate groups of Sprague–Dawley rats were used for quantitation of cyclooxygenase (COX) activity and leukotriene B4 level by enzyme-linked immunosorbent assay, as well as estimation of cardiovascular parameters and feeding and drinking behavior after paw incision. In the next part, rats were subjected to incision and 10 μg of protein C was locally administered by a micropipette. Both evoked and non-evoked pain parameters were then estimated.

Results

COX, particularly COX-2 activity and leukotriene B4 levels increased after incision. Hemodynamic parameters were normal. Feeding and drinking were affected on days 1 and 3, and on day 1, respectively. Protein C attenuated non-evoked pain behavior alone up to day 2.

Conclusions

Based upon current observations, Brennan’s rodent paw incision model appears to exhibit a prolonged period of nociception similar to that after surgery, with minimal interference of physiological parameters. Protein C, which is likely converted to activated protein C in the wound, attenuated the guarding score, which probably represents pain at rest after surgery in humans.

Leukocyte matrix metalloproteinase and tissue inhibitor gene expression patterns in children with primary hypertension

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) play an important role in cardiovascular remodeling. The aim of the study was to analyze MMP/TIMP genes expression in peripheral blood leukocytes of 80 hypertensive children (15.1 ± 2.0 years) in comparison with age-matched 78 normotensive children (14.6 ± 2.0 years; n.s.). TIMP and MMP expression in peripheral blood leukocytes was assessed by quantitative real-time PCR. Hypertensive children independently of age, sex, and body mass index had greater expression of MMP-2 than normotensive controls (p = 0.0001). Patients with left ventricular hypertrophy had greater expression of MMP-14 than patients with normal left ventricular mass (p = 0.006) and TIMP-2 expression correlated with carotid wall cross-sectional area (p = 0.03; r = 0.238). MMP-14 expression correlated with BMI-SDS (p = 0.001; r = 0.371), waist circumference-SDS (p = 0.016; r = 0.290), hsCRP (p = 0.003; r = 0.350), serum HDL-cholesterol (p = 0.008; r = -0.304), and serum uric acid (p = 0.0001; r = 0.394). In conclusion, hypertensive adolescents presented significant alterations of MMP/TIMP expression pattern in comparison with normotensive peers. Moreover, altered MMP/TIMP expression was associated with hypertensive target organ damage and metabolic abnormalities.

Activated Protein C in Cutaneous Wound Healing: From Bench to Bedside

Independent of its well-known anticoagulation effects, activated protein C (APC) exhibits pleiotropic cytoprotective properties. These include anti-inflammatory actions, anti-apoptosis, and endothelial and epithelial barrier stabilisation. Such beneficial effects have made APC an attractive target of research in a plethora of physiological and pathophysiological processes. Of note, the past decade or so has seen the emergence of its roles in cutaneous wound healing-a complex process involving inflammation, proliferation and remodelling. This review will highlight APC's functions and mechanisms, and detail its pre-clinical and clinical studies on cutaneous wound healing.

Transcription Factor SOX5 Promotes the Migration and Invasion of Fibroblast-Like Synoviocytes in Part by Regulating MMP-9 Expression in Collagen-Induced Arthritis

Objectives

Fibroblast-like synoviocytes (FLS) exhibit a unique aggressive phenotype in rheumatoid arthritis (RA). Increased FLS migration and subsequent invasion of the extracellular matrix are essential to joint destruction in RA. Our previous research reported that transcription factor SOX5 was highly expressed in RA-FLS. Here, the effects of SOX5 in RA-FLS migration and invasion will be investigated.

Methods

The migration and invasion of RA-FLS were evaluated using a transwell chamber assay. The expression of several potential SOX5-targeted genes, including matrix metalloproteinases (MMP-1, 2, 3 and 9), chemokines (CCL4, CCL2, CCR5 and CCR2), and pro-inflammatory cytokines (TNF-α and IL-6), were examined in RA-FLS using SOX5 gain- and loss-of-function study. The molecular mechanisms of SOX5-mediated MMP-9 expressions were assayed by luciferase reporter gene and chromatin immunoprecipitation (ChIP) studies. The in vivo effect of SOX5 on FLS migration and invasion was examined using collagen-induced arthritis (CIA) in DBA/1J mice.

Results

Knockdown SOX5 decreased lamellipodium formation, migration, and invasion of RA-FLS. The expression of MMP-9 was the only gene tested to be concomitantly affected by silencing or overexpressing SOX5. ChIP assay revealed that SOX5 was bound to the MMP-9 promoter in RA-FLS. The overexpression of SOX5 markedly enhanced the MMP-9 promoter activity, and specific deletion of a putative SOX5-binding site in MMP-9 promoter diminished this promoter-driven transcription in FLS. Locally knocked down SOX5 inhibited MMP-9 expression in the joint tissue and reduced pannus migration and invasion into the cartilage in CIA mice.

Conclusion

SOX5 plays a novel role in mediating migration and invasion of FLS in part by regulating MMP-9 expression in RA.

Biodiversity of CS–proteoglycan sulphation motifs: chemical messenger recognition modules with roles in information transfer, control of cellular behaviour and tissue morphogenesis

Chondroitin sulphate (CS) glycosaminoglycan chains on cell and extracellular matrix proteoglycans (PGs) can no longer be regarded as merely hydrodynamic space fillers. Overwhelming evidence over recent years indicates that sulphation motif sequences within the CS chain structure are a source of significant biological information to cells and their surrounding environment. CS sulphation motifs have been shown to interact with a wide variety of bioactive molecules, e.g. cytokines, growth factors, chemokines, morphogenetic proteins, enzymes and enzyme inhibitors, as well as structural components within the extracellular milieu. They are therefore capable of modulating a panoply of signalling pathways, thus controlling diverse cellular behaviours including proliferation, differentiation, migration and matrix synthesis. Consequently, through these motifs, CS PGs play significant roles in the maintenance of tissue homeostasis, morphogenesis, development, growth and disease. Here, we review (i) the biodiversity of CS PGs and their sulphation motif sequences and (ii) the current understanding of the signalling roles they play in regulating cellular behaviour during tissue development, growth, disease and repair.

Proprotein convertase subtilisin/kexin type 6 promotes in vitro proliferation, migration and inflammatory cytokine secretion of synovial fibroblast‑like cells from rheumatoid arthritis via nuclear‑κB, signal transducer and activator of transcription 3 and extracellular signal regulated 1/2 pathways

Our previous studies demonstrated that expression of proprotein convertase subtilisin/kexin type 6 (PCSK6) is greatly enhanced in rheumatoid arthritis fibroblast‑like synoviocytes (RASFs), and that PCSK6 inhibition decreases cell proliferation, migration and invasion. The present study aimed to investigate the functional role of PCSK6 in the hyperplasia of RASFs. Cultured RASFs from RA patients were stimulated with recombinant human (rh)PCSK6. Subsequent changes in proliferation, invasion, migration and the secretion of inflammatory cytokines were measured in vitro using MTT, wound healing and Transwell assays, and ELISA. Cell cycle and apoptosis were analyzed by flow cytometry. Influence on downstream gene expression levels were analyzed using reverse transcription‑quantitative polymerase chain reaction. Specific signaling pathways responsible for these effects were analyzed using western blotting and confirmed with pathway‑specific inhibitors. It was demonstrated that rhPCSK6 significantly increased RASF cell invasion, migration and proliferation, which was influenced through both reduced cell cycle arrest and reduced apoptosis. Furthermore, rhPCSK6 stimulated RASFs to secrete the inflammatory cytokines interleukin (IL)‑1α, IL‑1β and IL‑6, and exhibit altered expression of genes involved in angiogenesis, hypoxia, proliferation and inflammation. These cellular effects were mediated via the nuclear factor (NF)‑κB, signal transducer and activator of transcription 3 (STAT3) and extracellular signal regulated (ERK)1/2 signaling pathways. The results demonstrated that signaling via NF‑κB and STAT3 mediated cell cycle arrest, and signaling through NF‑κB mediated apoptosis in RASF cells stimulated with PCSK6. PCSK6 can activate NF‑κB, STAT3 and ERK1/2 signaling pathways in vitro to enhance cell proliferation, migration, invasion and inflammation in RASF cells. These findings suggest that PCSK6 may be an important therapeutic target in RA.

Synergic and antagonistic relationship between MMP-2 and MMP-9 with fibrosis and inflammation in Chagas' cardiomyopathy

Cardiomyopathy is the most important clinical manifestation in the chronic phase of Chagas' disease because of its frequency, severity and impact on morbidity and mortality. The extracellular matrix degradation during cardiac remodeling in Trypanosoma cruzi infection is driven by matrix metalloproteinases (MMPs), primarily the MMP-2 and MMP-9 gelatinases. MMPs also regulate some molecules related to inflammation, such as growth factors, cytokines and chemokines. The involvement of MMP-2 and MMP-9 is not yet fully understood in Chagas' disease. It has been proposed that the gelatinases may have opposite effect on inflammation/regulation and cardiac remodeling. MMP-2 would participate in regulation, offering a protective role for cardiac damage in asymptomatic patients and would be a good marker for the initiation of changes in the heart. On the other hand, MMP-9 can be used as a marker for serious changes on the heart and would be associated with inflammation and fibrosis. Here, we consolidate all characteristics involving MMP-2 and MMP-9 in Chagas' disease based on current studies to clarify their participation on the inflammation/regulation and fibrosis, and the synergistic or antagonistic role between them.

Role of thrombin-PAR1-PKCθ/δ axis in brain pericytes in thrombin-induced MMP-9 production and blood-brain barrier dysfunction in vitro

Thrombin, an essential component in the coagulation cascade, participates in the pathogenesis of brain diseases, such as ischemic stroke, intracerebral hemorrhage, Alzheimer's disease and Parkinson's disease through blood-brain barrier (BBB) dysfunction. It is thought that the thrombin-matrix metalloproteinase (MMP)-9 axis is an important process in the pathogenesis of neurovascular disease, such as BBB dysfunction. We recently reported that brain pericytes are the most MMP-9-releasing cells in response to thrombin stimulation among the BBB-constituting cells. This thrombin-induced MMP-9 release is partially due to protease-activated receptor (PAR1), one of the specific thrombin receptors. Then, we evaluated the intracellular signaling pathways involved in MMP-9 release and the contribution of thrombin-reactive brain pericytes to BBB dysfunction. PKC activator evoked MMP-9 release from brain pericytes. The thrombin-induced MMP-9 release was inhibited by U0126, LY294002, Go6976, and Go6983. However, Go6976 decreased phosphorylation levels of PKCθ and Akt, and Go6983 decreased phosphorylation levels of PKCδ and extracellular signal-regulated kinase (ERK). Additionally, treatment of pericytes with thrombin or PAR1-activating peptide stimulated PKCδ/θ signaling. These substances impaired brain endothelial barrier function in the presence of brain pericytes. Brain pericytes function through two independent downstream signaling pathways via PAR1 activation to release MMP-9 in response to thrombin - the PKCθ-Akt pathway and the PKCδ-ERK1/2 pathway. These pathways participate in PAR1-mediated MMP-9 release from pericytes, which leads to BBB dysfunction. Brain pericytes and their specific signaling pathways could provide novel therapeutic targets for thrombin-induced neurovascular diseases.

Differential Expression of Matrix Metalloproteinases 2, 9 and Cytokines by Neutrophils and Monocytes in the Clinical Forms of Chagas Disease

Dilated cardiomyopathy, the most severe manifestation in chronic phase of Chagas disease, affects about 30% of patients and is characterized by myocardial dysfunction and interstitial fibrosis due to extracellular matrix (ECM) remodeling. ECM remodeling is regulated by proteolytic enzymes such as matrix metalloproteinases (MMPs) and cytokines produced by immune cells, including phagocytes. We evaluated by flow cytometry the expression of MMP-2, MMP-9, IL-1β, TNF-α, TGF-β and IL-10 by neutrophils and monocytes from patients with indeterminate (IND) and cardiac (CARD) clinical forms of Chagas disease and non-infected individuals (NI), before and after in vitro stimulation with Trypanosoma cruzi antigens. Our results showed an important contribution of neutrophils for MMPs production, while monocytes seemed to be involved in cytokine production. The results showed that neutrophils and monocytes from IND and CARD patients had higher intracellular levels of MMP-2 and MMP-9 than NI individuals. On the other hand, T. cruzi derived-antigens promote a differential expression of MMP-2 and MMP-9 in patients with Chagas disease and may regulate MMPs expression in neutrophils and monocytes, mainly when a cardiac alteration is not present. Our data also showed that in the presence of T. cruzi derived-antigens the production of cytokines by neutrophils and monocytes, but mainly by monocytes, may be intensified. Correlation analysis demonstrated that MMP-2 had a positive correlation with IL-10 and a negative correlation with IL-1β, whereas MMP-9 showed a negative correlation with IL-10. We also observed that IND patients presented a greater percentage of high producer cells of regulatory molecules when compared to CARD patients, indicating a different pattern in the immune response. Our data suggest that MMPs and cytokines produced by neutrophils and monocytes are important contributors for cardiac remodeling and may be an interesting target for new biomarker research.

Extracellular Matrix Reorganization During Wound Healing and Its Impact on Abnormal Scarring

Significance: When a cutaneous injury occurs, the wound heals via a dynamic series of physiological events, including coagulation, granulation tissue formation, re-epithelialization, and extracellular matrix (ECM) remodeling. The final stage can take many months, yet the new ECM forms a scar that never achieves the flexibility or strength of the original tissue. In certain circumstances, the normal scar is replaced by pathological fibrotic tissue, which results in hypertrophic or keloid scars. These scars cause significant morbidity through physical dysfunction and psychological stress. Recent Advances and Critical Issues: The cutaneous ECM comprises a complex assortment of proteins that was traditionally thought to simply provide structural integrity and scaffolding characteristics. However, recent findings show that the ECM has multiple functions, including, storage and delivery of growth factors and cytokines, tissue repair and various physiological functions. Abnormal ECM reconstruction during wound healing contributes to the formation of hypertrophic and keloid scars. Whereas adult wounds heal with scarring, the developing foetus has the ability to heal wounds in a scarless fashion by regenerating skin and restoring the normal ECM architecture, strength, and function. Recent studies show that the lack of inflammation in fetal wounds contributes to this perfect healing. Future Directions: Better understanding of the exact roles of ECM components in scarring will allow us to produce therapeutic agents to prevent hypertrophic and keloid scars. This review will focus on the components of the ECM and their role in both physiological and pathological (hypertrophic and keloid) cutaneous scar formation.

Endogenous MMP-9 and not MMP-2 promotes rheumatoid synovial fibroblast survival, inflammation and cartilage degradation

OBJECTIVE

The aim of this study was to investigate the effect of endogenous matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) on the invasive characteristics of RA synovial fibroblasts.

METHODS

Synovial fibroblasts isolated from patients with RA or OA were treated with MMP small interfering RNA (siRNA), inhibitors and recombinant proteins or TNF-α, with or without cartilage explants. Cell viability and proliferation were measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and 5-bromo-2-deoxyuridine (BrdU) proliferation assays, respectively; apoptosis by an in situ cell death detection kit; migration and invasion by CytoSelect invasion assay, scratch migration and collagen gel assays; cartilage degradation by 1,9-dimethylmethylene blue assay; and inflammatory mediators and MMPs by ELISA, western blot and zymography.

RESULTS

MMP-2 was expressed by both OA and RA synovial fibroblasts, whereas only RA synovial fibroblasts expressed MMP-9. Suppressing MMP-2 or MMP-9 reduced RA synovial fibroblast proliferation equally. However, MMP-9 siRNA had greater effects compared with MMP-2 siRNA on promoting apoptosis and suppressing RA synovial fibroblast viability, migration and invasion. Suppression/inhibition of MMP-9 also decreased the production of IL-1β, IL-6, IL-8 and TNF-α, inactivated nuclear factor κB (NF-κB), extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) and suppressed RA synovial fibroblast-mediated cartilage degradation. In contrast, suppression/inhibition of MMP-2 stimulated TNF-α and IL-17 secretion and activated NF-κB, while recombinant MMP-2 (rMMP-2) inactivated NF-κB and suppressed RA synovial fibroblast-mediated cartilage degradation. Results using specific inhibitors and rMMPs provided supportive evidence for the siRNA results.

CONCLUSION

Endogenous MMP-2 or MMP-9 contribute to RA synovial fibroblast survival, proliferation, migration and invasion, with MMP-9 having more potent effects. Additionally, MMP-9 stimulates RA synovial fibroblast-mediated inflammation and degradation of cartilage, whereas MMP-2 inhibits these parameters. Overall, our data indicate that MMP-9 derived from RA synovial fibroblasts may directly contribute to joint destruction in RA.

Activated protein C: A regulator of human skin epidermal keratinocyte function

Activated protein C (APC) is a physiological anticoagulant, derived from its precursor protein C (PC). Independent of its anticoagulation, APC possesses strong anti-inflammatory, anti-apoptotic and barrier protective properties which appear to be protective in a number of disorders including chronic wound healing. The epidermis is the outermost skin layer and provides the first line of defence against the external environment. Keratinocytes are the most predominant cells in the epidermis and play a critical role in maintaining epidermal barrier function. PC/APC and its receptor, endothelial protein C receptor (EPCR), once thought to be restricted to the endothelium, are abundantly expressed by skin epidermal keratinocytes. These cells respond to APC by upregulating proliferation, migration and matrix metalloproteinase-2 activity and inhibiting apoptosis/inflammation leading to a wound healing phenotype. APC also increases barrier function of keratinocyte monolayers by promoting the expression of tight junction proteins and re-distributing them to cell-cell contacts. These cytoprotective properties of APC are mediated through EPCR, protease-activated receptors, epidermal growth factor receptor or Tie2. Future preventive and therapeutic uses of APC in skin disorders associated with disruption of barrier function and inflammation look promising. This review will focus on APC’s function in skin epidermis/keratinocytes and its therapeutical potential in skin inflammatory conditions.

Activated protein C and its potential applications in prevention of islet β-cell damage and diabetes

Activated protein C (APC) is derived from its precursor, protein C (PC). Originally thought to be synthesized exclusively by the liver, recent reports have shown that PC is also produced by many other cells including pancreatic islet β cells. APC functions as a physiological anticoagulant with anti-inflammatory, anti-apoptotic, and barrier-stabilizing properties. APC exerts its protective effects via an intriguing mechanism requiring combinations of endothelial PC receptor, protease-activated receptors, epidermal growth factor receptor, Tie2 or CD11b, depending on cell types. Diabetes is a chronic condition resulted from the body's inability to produce and/or properly use insulin. The prevalence of diabetes has risen dramatically and has become one of the major causes of premature mortality and morbidity worldwide. Diabetes prevention is an ideal approach to reduce this burden. Type 1 and type 2 diabetes are the major forms of diabetes mellitus, and both are characterized by an autoimmune response, intraislet inflammation, β-cell apoptosis, and progressive β-cell loss. Protecting β-cell from damage is critical in both prevention and treatment of diabetes. Recent in vitro and animal studies show that APC's strong anti-inflammatory and anti-apoptotic properties are beneficial in preventing β-cell destruction and diabetes in the NOD mouse model of type 1 diabetes. Future preventive and therapeutic uses of APC in diabetes look very promising.

Urokinase plasminogen activator system in synovial fibroblasts from osteoarthritis patients: modulation by inflammatory mediators and neuropeptides

Plasminogen activators are specific proteolytic enzymes implicated in a variety of basic biological processes. The expression of the urokinase plasminogen activator system components is increased in some human diseases, including osteoarthritis. We sought to study the effect of two components of the inflamed synovial microenvironment on this system, IL-1β and fibronectin fragments, elucidating whether corticotropin-releasing factor (CRF) and vasoactive intestinal peptide (VIP) neuropeptides modulate it, and analyzing the physiological consequences in joint destruction by measuring matrix metalloproteinases-9 and metalloproteinases-13 levels in osteoarthritis fibroblast-like synoviocytes. We showed that IL-1β and fibronectin fragments stimulated urokinase system contributing to the perpetuation of the destructive cascade in joint. VIP modulated, even at constitutive level, this system, also counteracting the effect of both inflammatory stimuli. However, CRF seemed to be ineffective in controlling the production of these proteinases. Moreover, VIP was able to reduce the constitutive expression of matrix metalloproteinase-13 and the levels of both matrix metalloproteinases after stimulation with the pro-inflammatory stimuli. Our results suggest that the presence of early and later inflammatory mediators, such as IL-1β and fibronectin fragments, increases the urokinase system and the matrix metalloproteinases levels. Whereas CRF did not affect this system, VIP counteracts these actions supporting its therapeutic potential for the treatment of osteoarthritis.

Simultaneous demonstration of gelatinolytic activity, morphology, and immunohistochemical reaction using zymography film

In situ zymography has been used to assess gelatinolytic activity, which is mainly due to matrix metalloproteinases (MMPs) in cancer tissues. MMPs play an important role in cancer invasion and metastasis. Film in situ zymography (FIZ) enables the in situ evaluation of gelatinolytic activity with high reproducibility. In this article, we report a study of FIZ, in a case of breast cancer with an invasive carcinoma component showing clear gelatinolytic activity, and in a non-invasive carcinoma component showing little gelatinolytic activity. Immunohistochemistry on FIZ was also performed. The simultaneous detection of gelatinolytic activity and immunohistochemical reaction was established in a single film. Immunohistochemistry on FIZ may have good potential for the investigation of cancer microenvironment.

Activated protein C inhibits pancreatic islet inflammation, stimulates T regulatory cells, and prevents diabetes in non-obese diabetic (NOD) mice

Activated protein C (aPC) is a natural anticoagulant with strong cyto-protective and anti-inflammatory properties. aPC inhibits pancreatic inflammation and preserves functional islets after intraportal transplantation in mice. Whether aPC prevents the onset or development of type 1 diabetes (T1D) is unknown. In this study, when human recombinant aPC was delivered intraperitoneally, twice weekly for 10 weeks (from week 6 to 15) to non-obese diabetic (NOD) mice, a model for T1D, the incidence of diabetes was reduced from 70% (saline control) to 7.6% by 26 weeks of age. Islets of aPC-treated mice exhibited markedly increased expression of insulin, aPC/protein C, endothelial protein C receptor, and matrix metalloproteinase (MMP)-2 when examined by immunostaining. The insulitis score in aPC-treated mice was 50% less than that in control mice. T regulatory cells (Tregs) in the spleen, pancreatic islets, and pancreatic lymph nodes were increased 37, 53, and 59%, respectively, in NOD mice following aPC treatment. These Tregs had potent suppressor function and, after adoptive transfer, delayed diabetes onset in NOD.severe combined immunodeficiency mice. The culture of NOD mouse spleen cells with aPC reduced the secretion of inflammatory cytokines interleukin (IL)-1β and interferon-γ but increased IL-2 and transforming growth factor-β1, two cytokines required for Treg differentiation. In summary, our results indicate that aPC prevents T1D in the NOD mouse. The aPC mechanism of action is complex, involving induction of Treg differentiation, inhibition of inflammation, and possibly direct cyto-protective effects on β cells.

Pigment epithelium-derived factor regulates early pancreatic fibrotic responses and suppresses the profibrotic cytokine thrombospondin-1

Pigment epithelium-derived factor (PEDF) is important for maintaining the normal extracellular matrix. We hypothesized that the initiation of pancreatic fibrosis is dependent on the loss of PEDF. Pancreatic PEDF expression was assessed in wild-type mice fed either a control or ethanol diet using an intragastric feeding model. Pancreatitis responses were elicited with either a single episode or a repetitive cerulein-induced (50 μg/kg, 6 hourly i.p. injections) protocol in wild-type and PEDF-null mice. Quantitative real-time PCR and immunoblotting were performed to assess fibrogenic responses. In wild-type animals, PEDF expression increased with pancreatitis and was more pronounced in mice fed ethanol. Compared with wild-type mice, α-smooth muscle actin staining and expression levels of fibrogenic markers (eg, transforming growth factor-β1, platelet-derived growth factor, collagen I, and thrombospondin-1) were higher in PEDF-null mice at baseline. Sirius red staining revealed more fibrosis in PEDF-null versus wild-type pancreas 1 week after pancreatitis. Differences in tissue fibrosis resolved with longer recovery periods. PEDF overexpression suppressed thrombospondin-1 levels in vitro. Ethanol feeding and experimental pancreatitis increased PEDF expression in wild-type mice. PEDF-null mice, however, demonstrated enhanced early fibrotic responses compared with wild-type mice with pancreatitis. These findings indicate that PEDF acts as a compensatory antifibrotic cytokine in pancreatitis.

Early joint tissue changes are highly correlated with a set of inflammatory and degradative synovial biomarkers after ACL autograft and its sham surgery in an ovine model

While impossible in humans, the mechanisms of early cartilage, bone and meniscal damage can be quantified after anterior cruciate ligament (ACL) injury in animal models. We utilized an ovine model to determine if the mRNA expression of inflammatory and degradative molecules (IL-1β, IL-6, MMP-1, 2, 3, and 13) in the synovium correlated to changes in joint tissues 2 weeks post-ACL surgery, to test the hypothesis that synovial inflammation is a marker of these changes and possibly their originator. Nine "idealized" ACL autografts were performed and compared with three sham and six normal animals. Using validated protocols, early osteophyte formation, articular cartilage, and meniscal damage were quantified. Synovium was harvested and mRNA expression quantified using qPCR. Multiple linear regression analysis (MLRA) was utilized to correlate synovial mRNA expression in treated and contra-lateral limbs, from all treatment groups with corresponding joint scores. Synovial mRNA expression was significantly elevated in all experimental and sham joints. The MLRA model was a significant predictive tool (p = 0.001, R(2)  = 0.70) of gross tissue scores with significant contributions from IL-1β, IL-6, and MMP-3. Findings suggest that this set of synovial biomarkers is predictive (p < 0.009) of early gross changes of joint tissues after arthrotomy and likely directly involved in the relevant mechanisms, particularly early osteophyte formation, in vivo.

Inhibitory effects of GL-V9 on the invasion of human breast carcinoma cells by downregulating the expression and activity of matrix metalloproteinase-2/9

Cancer cell invasion plays a crucial role in growth and local spreading of tumors. GL-V9 is a newly synthesized flavonoid that has been shown to possess an antitumor effect. However, the mechanism of GL-V9 in preventing tumor growth is still unclear. The purpose of this study is to investigate the anti-invasive and anti-metastatic activity of this novel compound in MDA-MB-231 and MCF-7 human breast carcinoma cells. In this study, GL-V9 caused a concentration-dependent suppression of cell adhesive ability by cell adhesion assay, it also inhibited the migration and invasion of cells by wound healing assay and transwell invasion assay in a concentration-dependent manner. Considering matrix metalloproteinases (MMPs) play an important role in metastatic process, we used western blotting and gelatin zymography to examine the effect of GL-V9 on the expression and activity of MMPs. The mechanism revealed that GL-V9 significantly suppressed the expression and activity of MMP-2 and MMP-9. Furthermore, GL-V9 suppressed their upstream protein kinases activation by reducing phosphorylated forms of serine/threonine kinase AKT and c-Jun N-terminal kinase. These findings suggested that GL-V9 could inhibit the invasion of tumor cells by downregulating the expression and activity of MMP-2 and MMP-9, potentially associating with the suppression of phosphorylation of AKT and JNK.

Elevated plasma matrix metalloproteinases and their tissue inhibitors in patients with severe sepsis

PURPOSE

Matrix metalloproteinases (MMPs) are essential for tissue remodeling. Our objectives were to determine (1) the concentrations of MMPs and their tissue inhibitors (TIMPs) in plasma obtained from patients with severe sepsis, (2) to correlate changes in MMP and TIMP levels with disease severity, and (3) to investigate recombinant activated protein C (rAPC) actions on plasma MMP2, 9 activities from severe sepsis patients.

MATERIALS AND METHODS

Matrix metalloproteinase and TIMP levels were quantified in plasma from patients with severe sepsis using antibody microarrays and gelatin zymography.

RESULTS

Plasma MMPs (3, 7, 8, 9) and TIMPs (1, 2, 4) on microarray were increased in severe sepsis on intensive care unit (ICU) day 1, with more than 3-fold increases in MMP3, MMP7, MMP8, MMP9, and TIMP4. Latent forms of MMP2, 9 on zymography were increased in plasma from patients with severe sepsis, whereas only half of severe sepsis patients showed active MMP9. Elevated MMP7 and MMP9 on ICU days 1 and 3 negatively correlated with multiple organ dysfunctions. The temporal activity patterns of MMP2, 9 during 21 ICU days were not altered in patients treated with rAPC or by the addition of exogenous rAPC to plasma.

CONCLUSION

Most plasma MMPs and TIMPS were elevated in patients with severe sepsis, but only a limited subset of MMPs (7, 9) negatively correlated with disease severity. Recombinant activated protein C does not appear to directly alter MMP2, 9 activities.

Matrix-metalloproteinase-2, -8 and -9 in serum and skin blister fluid in patients with severe sepsis

Introduction

Matrix metalloproteinases (MMPs) have various roles in inflammatory states. They seem to be able to modulate endothelial barriers and regulate the activity of chemokines and cytokines. The timely development of the levels during severe sepsis and thereafter have not been investigated. In addition it was of interest to study alterations of MMP-levels in intact skin, as the skin is the largest barrier against external pathogens and MMPs have not been studied at organ level in human sepsis. The aim of this study was to investigate the timely development of serum and skin MMP-2, -8 and -9 levels in human severe sepsis and their association with disease severity and mortality.

Methods

Forty-four patients with severe sepsis and fifteen healthy controls were included in this prospective longitudinal study. The amounts of MMP-2, -8 and -9 were analyzed from serum at days 1, 4, 6, 8, and 10, and from skin suction blister fluid at days 1 and 5 from the beginning of severe sepsis. Additionally, samples from the survivors were obtained after three and six months.

Results

The levels of MMP-2 and -8 were up-regulated in severe sepsis in comparison to healthy controls in skin blister fluid and serum. Compared to the controls MMP-9 levels were lower in sepsis from the fourth day on in serum and both the first and fifth day in skin blister fluid. Active forms of MMP-2 and -9 were present only in severe sepsis. The non-survivors had higher pro- and active MMP-2 levels than the survivors in skin blister fluid samples. Furthermore, MMP-2 levels were more pronounced in blister fluid and serum samples in patients with more severe organ failures. In the survivors at 3 and 6 month follow-up the MMP levels had returned to normal.

Conclusions

MMP-2 and -8 are elevated in serum and blister fluid in severe sepsis, implying that they may play a significant role in the pathogenesis of severe sepsis and organ dysfunctions. Active forms of MMP-2 and 9 were only present in patients with severe sepsis, and higher MMP-2 levels in skin blister and serum were associated with more severe organ dysfunctions.

MMP-mediated collagen breakdown induced by activated protein C in equine cartilage is reduced by corticosteroids

The plasma serine protease activated protein C (APC) is synthesized by human chondrocytes at sites of pathological cartilage fibrillation. APC levels are increased in osteoarthritis (OA) synovial fluid, and in vitro APC has been shown to synergize with interleukin-1beta (IL-1) to promote degradation from ovine cartilage. A model of equine cartilage degradation was established and used to explore corticosteroid activities. Intraarticular corticosteroids are a commonly prescribed treatment for joint disease, however their role in disease modification remains unclear. APC synergized with IL-1 or tumor necrosis factor-alpha (TNFalpha), promoting significant collagen degradation from equine cartilage explants within 4 days, but did not augment glycoaminoglycan (GAG) release. APC activated pro-matrix metalloproteinases (MMP)-2 but not pro-MMP-9, as assessed by gelatin zymography. APC did not directly activate pro-MMP-13. Dexamethasone, triamcinolone, and methylprednisolone acetate (MPA) were evaluated at concentrations between 10(- 5)M and 10(-10)M. High concentrations significantly increased GAG release from IL-1+APC-treated explants. With the exception of MPA at 10(-10)M, all concentrations of corticosteroids caused significant decreases in IL-1+APC-driven hydroxyproline loss. Treatment with corticosteroids suppressed expression of MMP-1, -3, and -13 mRNA. The collagenolysis associated with IL-1+APC synergy, and the inhibition of this effect by corticosteroids may involve gelatinase activation and downregulation of MMP expression, respectively.

Lymphocytic infiltration leads to degradation of lacrimal gland extracellular matrix structures in NOD mice exhibiting a Sjögren's syndrome-like exocrinopathy

We previously reported that lacrimal glands (LGs) of male non-obese diabetic (NOD) mice, an established mouse model of autoimmune inflammatory LG disease that displays many features of human LGs in patients afflicted with Sjögren's syndrome (SjS), exhibit significant degradation of extracellular matrix (ECM) structures as well as increased expression of matrix metalloproteinases (MMPs). The purpose of the current study was to expand the spectrum of proteases identified, to clarify their probable origin as well as to identify the contribution of these changes to disease pathogenesis. We explored in depth the changes in ECM structures and ECM protease expression at the onset of disease (6 weeks) versus late stage disease (18 weeks) in male NOD mouse LGs, relative to LGs of age-matched male NODscid, a severely immunocompromised congenic strain, and healthy BALB/c mice. LG tissues were examined using routine histological, immunohistochemical, Western Blot and gene expression analyses novel multiphoton imaging technologies. We further characterized the profile of infiltrating immune cells under each condition using flow cytometry. Our results show that the initial infiltrating cells at 6 weeks of age are responsible for increased MMP and cathepsin H expression and therefore initiate the LG ECM degradation in NOD mice. More importantly, NODscid mice exhibited normal LG ECM structures, indicating the lymphocytes seen in the LGs of NOD mice are responsible for the degradation of the LG ECM. The disease-related remodeling of LG ECM structures may play a crucial role in altering the acinar signaling environment, disrupting the signaling scaffolds within the cells, which are required to mobilize the exocytotic trafficking machinery, ultimately leading to a loss of LG function in patients afflicted with SjS.

Incidence and nature of infectious disease in patients treated with anti-TNF agents

Tumor necrosis factor alpha (TNF-alpha) inhibitors offer a targeted therapeutic strategy that contrasts with the nonspecific immunosuppressive agents traditionally used to treat most inflammatory diseases. These biologic agents have had a significant impact in ameliorating the signs and symptoms of inflammatory rheumatoid disease and improving patient function. From the onset of clinical trials, a central concern of cytokine blockade has been a potential increase in susceptibility to infections. Not surprisingly, a variety of infections have been reported in association with the use of TNF-alpha inhibitor agents. In particular, there is evidence suggesting an increased rate of granulomatous infections in patients treated with monoclonal TNF-alpha inhibitors. This review provides the incidence and nature of infections in patients treated with TNF-alpha inhibitor agents and reminds the clinician of the required vigilance in monitoring patients.

Adapted Boolean network models for extracellular matrix formation

BACKGROUND

Due to the rapid data accumulation on pathogenesis and progression of chronic inflammation, there is an increasing demand for approaches to analyse the underlying regulatory networks. For example, rheumatoid arthritis (RA) is a chronic inflammatory disease, characterised by joint destruction and perpetuated by activated synovial fibroblasts (SFB). These abnormally express and/or secrete pro-inflammatory cytokines, collagens causing joint fibrosis, or tissue-degrading enzymes resulting in destruction of the extra-cellular matrix (ECM).We applied three methods to analyse ECM regulation: data discretisation to filter out noise and to reduce complexity, Boolean network construction to implement logic relationships, and formal concept analysis (FCA) for the formation of minimal, but complete rule sets from the data.

RESULTS

First, we extracted literature information to develop an interaction network containing 18 genes representing ECM formation and destruction. Subsequently, we constructed an asynchronous Boolean network with biologically plausible time intervals for mRNA and protein production, secretion, and inactivation. Experimental gene expression data was obtained from SFB stimulated by TGFbeta1 or by TNFalpha and discretised thereafter. The Boolean functions of the initial network were improved iteratively by the comparison of the simulation runs to the experimental data and by exploitation of expert knowledge. This resulted in adapted networks for both cytokine stimulation conditions. The simulations were further analysed by the attribute exploration algorithm of FCA, integrating the observed time series in a fine-tuned and automated manner. The resulting temporal rules yielded new contributions to controversially discussed aspects of fibroblast biology (e.g., considerable expression of TNF and MMP9 by fibroblasts stimulation) and corroborated previously known facts (e.g., co-expression of collagens and MMPs after TNFalpha stimulation), but also revealed some discrepancies to literature knowledge (e.g., MMP1 expression in the absence of FOS).

CONCLUSION

The newly developed method successfully and iteratively integrated expert knowledge at different steps, resulting in a promising solution for the in-depth understanding of regulatory pathways in disease dynamics. The knowledge base containing all the temporal rules may be queried to predict the functional consequences of observed or hypothetical gene expression disturbances. Furthermore, new hypotheses about gene relations were derived which await further experimental validation.

Functional polymorphism of the matrix metalloproteinase-9 (MMP-9) gene in schizophrenia

Matrix metalloproteinase-9 (MMP-9) plays a role in many pathological conditions (e.g. cancer and heart disease). Recently, MMP-9 has been implicated in the activity of the prefrontal cortex and we therefore hypothesized that the MMP-9 gene may be associated with schizophrenia. We genotyped the functional -1562C/T polymorphism in a group of 442 schizophrenia patients and in 558 healthy control subjects. A significant preponderance of C/C genotype and C allele was found in the schizophrenia subjects compared to healthy controls. The results may provide the first evidence for involvement of the MMP-9 gene in the pathogenesis of schizophrenia and could also contribute to explaining a genetic connection between schizophrenia and some somatic illnesses.

New therapeutic applications for the anticoagulant, activated protein C

BACKGROUND

Activated protein C (APC) is derived from its precursor, protein C (PC). Originally thought to be synthesised exclusively by the liver, recent reports have shown that PC is also produced by endothelial cells, smooth muscle cells, keratinocytes and some leukocytes.

OBJECTIVE

To provide an update on the emerging therapeutic effects of APC.

RESULTS/CONCLUSION

APC functions as an anticoagulant with cytoprotective, anti-inflammatory and antiapoptotic properties. In vitro and preclinical data have revealed that APC exerts its protective effects via an intriguing mechanism requiring endothelial protein C receptor and protease activated receptor-1. Approved as a therapeutic agent for severe sepsis, APC is emerging as a potential treatment for a number of autoimmune and inflammatory diseases including spinal cord injury, asthma, chronic wounds and possibly rheumatoid arthritis. The future therapeutic uses of APC look very promising.