Matrix metalloproteinases and TIMPs: properties and implications for the rheumatic diseases

The current landscape of the antimicrobial peptide melittin and its therapeutic potential

Melittin, a main component of bee venom, is a cationic amphiphilic peptide with a linear α-helix structure. It has been reported that melittin can exert pharmacological effects, such as antitumor, antiviral and anti-inflammatory effects in vitro and in vivo. In particular, melittin may be beneficial for the treatment of diseases for which no specific clinical therapeutic agents exist. Melittin can effectively enhance the therapeutic properties of some first-line drugs. Elucidating the mechanism underlying melittin-mediated biological function can provide valuable insights for the application of melittin in disease intervention. However, in melittin, the positively charged amino acids enables it to directly punching holes in cell membranes. The hemolysis in red cells and the cytotoxicity triggered by melittin limit its applications. Melittin-based nanomodification, immuno-conjugation, structural regulation and gene technology strategies have been demonstrated to enhance the specificity, reduce the cytotoxicity and limit the off-target cytolysis of melittin, which suggests the potential of melittin to be used clinically. This article summarizes research progress on antiviral, antitumor and anti-inflammatory properties of melittin, and discusses the strategies of melittin-modification for its future potential clinical applications in preventing drug resistance, enhancing the selectivity to target cells and alleviating cytotoxic effects to normal cells.

Adenosine inhibits TNFα-induced MMP-3 production in MH7A rheumatoid arthritis synoviocytes via A2A receptor signaling

Adenosine causes the anti-inflammatory effect of MTX; however, the contributions of synoviocyte adenosine receptors (AdoRs) are unknown, and matrix metalloproteinase 3 (MMP-3) is released by fibroblast-like synoviocytes in response to inflammatory signaling. To understand the mechanism of the clinical observation that the matrix proteinase-3 concentration of patients with rheumatoid arthritis treated successfully with methotrexate does not usually normalize, we investigated the effects of A_2A AdoR activation and inhibition on tumor necrosis factor-alpha (TNFα)-induced MMP-3 release by MH7A human rheumatoid synovial cells. MH7A cells constitutively expressed membrane-associated A_2A AdoRs, and HENECA enhanced intracellular cAMP. Stimulation with TNFα markedly enhanced release of MMP-3 from MH7A cells, whereas HENECA partially and dose-dependently inhibited TNFα-evoked MMP-3 release. Similarly, dbcAMP partially inhibited TNFα-induced MMP-3 release. Pretreatment with ZM241385 reversed the inhibitory effects of HENECA. Further, TNFα induced p38 MAPK and ATF-2 phosphorylation, whereas HENECA suppressed p38 MAPK and ATF-2 phosphorylation. We concluded that adenosine signaling via A_2A AdoRs, adenylyl cyclase, and cAMP reduces TNFα-induced MMP-3 production by interfering with p38 MAPK/ATF-2 activity. Activation of A_2A AdoR signaling alone using HENECA did not reduce TNFα-induced MMP-3 production to the basal levels, which may explain why MTX usually decreases but does not eliminate serum MMP-3.

Cranial Cruciate Ligament Rupture in Dogs: Review on Biomechanics, Etiopathogenetic Factors and Rehabilitation

Cranial cruciate ligament (CrCL) rupture is one of the most common orthopaedic conditions in veterinary medicine. CrCL plays a fundamental role in the stability and biomechanics of the femoral-tibio-patellar joint, and its incorrect functionality severely impacts on the quality of life of patients. In dogs, the structural weakening of this joint due to the progressive degeneration of the ligament is the most accredited etiopathogenetic hypothesis in relation to the dog signalment (breed, sex and age) and the stifle joint conformation. In humans, this injury is often traumatic and generally occurs during sporting activities. CrCL rupture can be managed conservatively or surgically, and decisions regarding treatment are due to numerous factors: the patient’s age and health, the degree of stifle instability, and cost. Physiotherapy protocols play an important role in rehabilitation, with similar goals in humans and dogs: pain management, physiological articular range of motion recovery, periarticular and core muscle strengthening, and proprioceptive deficit correction. Physiotherapy, even if often neglected in veterinary medicine, is mandatory for the recovery of the correct functionality of the injured limb and for the return to normal daily and sporting activities.

Melanoma-Derived Exosomes Endow Fibroblasts with an Invasive Potential via miR-21 Target Signaling Pathway

Background

Tumor-derived exosomes are messengers that participate in tumor progression. Fibroblasts are associated with the metastasis of cancer depending on their cellular plasticity. We hypothesize that tumor-derived exosomes endow the fibroblasts in tumor microenvironment with invasive phenotype to the benefit of tumor metastasis.

Materials and Methods

Exosomes derived from B16-F10 cells were identified by nanoparticle tracking analyzer (NTA), dynamic light scattering (DLS), Western blot (WB), and transmission electron microscopy (TEM). Cell invasion and migration assays were performed using the xCELLigence real-time cell analyzer (RTCA). Role of tumor-derived exosomal miR-21 in cell invasion was determined by qPCR.

Results

The invasion analysis showed that exosome-treated fibroblast cells had greater invasive capability as compared to untreated fibroblast cells, with the higher expressions of MMP2 and MMP9. miR-21 is at least partially responsible for this effect. After ingestion of melanoma-derived exosomes during incubation, mouse embryonic fibroblasts cells emerged cellular invasiveness with the presentation of a marked increase in miR-21 expression. MiR-21 promoted invasion of fibroblasts by down-regulation of tissue inhibitor of metalloproteinase 3 (TIMP3) expression and increasing of matrix metalloprotein (MMP) expression in fibroblast cells via melanoma-derived exosomes in a time-dependent manner.

Conclusion

Our results suggest that tumor-derived exosomes may facilitate stromal fibroblasts an aggressive phenotype to equip the tumor progression.

Ozone induces autophagy in rat chondrocytes stimulated with IL-1β through the AMPK/mTOR signaling pathway

Background

Ozone injection is generally used for the management of pain in diseases such as osteoarthritis (OA). Recent studies have shown that reduced autophagy in chondrocytes plays an important role in the development of OA. The purpose of this study was to determine whether ozone treats OA by inducing autophagy in OA chondrocytes.

Materials and methods

In this study, primary chondrocytes were stimulated with IL-1β for 24 hours to simulate an OA chondrocyte model, followed by treatment with ozone (30 µg/ mL) or pretreatment with 3-methyladenine or compound C before ozone treatment. Then, cell viability was detected by a CCK-8 kit, and the AMPK/mTOR signaling pathway and autophagy were detected by Western blotting and immunofluorescence. The mRNA expression levels of IL-6, TNF-α, MMP-13 and TIMP-1 were measured by quantitative real-time PCR. Finally, autophagosomes in chondrocytes were observed by transmission electron microscopy.

Results

Ozone improved cell viability in chondrocytes stimulated by IL-1β. The decreased level of autophagy in IL-1β-stimulated chondrocytes improved with ozone treatment through activation of the AMPK/mTOR signaling pathway. In addition, the mRNA expression levels of IL-6 and TNF-α were suppressed by ozone treatment in chondrocytes stimulated with IL-1β. Ozone increased the mRNA level of TIMP-1 and decreased the mRNA level of MMP-13 in chondrocytes stimulated with IL-1β.

Conclusion

These results suggested that ozone improved the decreased level of autophagy in chondrocytes stimulated with IL-1β through activation of the AMPK/mTOR signaling pathway. Moreover, ozone treatment suppressed inflammation and helped maintain metabolic balance in chondrocytes stimulated with IL-1β.

Computational Approaches to Matrix Metalloprotease Drug Design

Matrix metalloproteinases (MMPs) are a family of zinc-containing enzymes required for homeostasis. These enzymes are an important class of drug targets as their over expression is associated with many disease states. Most of the inhibitors reported against this class of proteins have failed in clinical trials due to lack of specificity. In order to assist in drug design endeavors for MMP targets, a computationally tractable pathway is presented, comprising, (1) docking of small molecule inhibitors against the target MMPs, (2) derivation of quantum mechanical charges on the zinc ion in the active site and the amino acids coordinating with zinc including the inhibitor molecule, (3) molecular dynamics simulations on the docked ligand-MMP complexes, and (4) evaluation of binding affinities of the ligand-MMP complexes via an accurate scoring function for zinc containing metalloprotein-ligand complexes. The above pathway was applied to study the interaction of the inhibitor Batimastat with MMPs, which resulted in a high correlation between the predicted and experimental binding free energies, suggesting the potential applicability of the pathway.

Synovial inflammation plays a greater role in post-traumatic osteoarthritis compared to idiopathic osteoarthritis in the Hartley guinea pig knee

Background

The objective of this study was to evaluate the extent of stromal cell-derived factor-1’s (SDF-1) involvement in the pathogenesis of idiopathic versus post-traumatic OA by comparing differences in synovial membrane morphology, SDF-1 synovial fluid (SF) concentrations, and matrix metalloproteinase-13 (MMP-13) SF concentrations.

Methods

Thirty-six 3-month-old Hartley guinea pigs were obtained and divided into 6 groups. Upon sacrifice, India Ink staining was used to evaluate gross morphology, Safranin O/Fast green staining was used to assess cartilage damage, H/E staining was employed to visualize the synovium, and SF samples were obtained for biochemical analyses. Sandwich ELISA was used to quantify the SF concentrations of SDF-1 and MMP-13.

Results

12 month-old, idiopathic OA guinea pigs and 5.5 month-old ACLT animals had comparable cartilage damage when evaluated by the Modified Mankin Score. SDF-1 and MMP-13 concentrations were not statistically different between the two groups. The synovial membrane of the 5.5 month ACLT group had severe synovitis compared to the idiopathic OA group.

Conclusion

In this study, it was found that synovial inflammation, independent of cartilage morphology, SDF-1 concentration, and MMP-13 concentration, was markedly different between idiopathic and post-traumatic OA. These results highlight the differing morphological and biochemical profiles of post-traumatic versus idiopathic osteoarthritis and calls for a more thorough examination of the sole of the synovial membrane in the pathogenesis of post-traumatic osteoarthritis.

The fluence effects of low-level laser therapy on inflammation, fibroblast-like synoviocytes, and synovial apoptosis in rats with adjuvant-induced arthritis

OBJECTIVE

The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) operating at low and high fluences on joint inflammation, fibroblast-like synoviocytes (FLS), and synovial apoptosis in rats with adjuvant-induced arthritis.

BACKGROUND DATA

Rheumatoid arthritis (RA) is characterized by pronounced inflammation and FLS proliferation within affected joints. Certain data indicate that LLLT is effective in patients with inflammation caused by RA; however, the fluence effects of LLLT on synovium are unclear.

METHODS

Monoarthritis was induced in adult male Sprague-Dawley rats (250-300 g) via intraarticular injection of complete Freund's adjuvant (CFA) into the tibiotarsal joint. Animals were irradiated 72 h after CFA administration with a 780 nm GaAlAs laser at 4.5 J/cm2 (30 mW, 30 sec/spot) and 72 J/cm2 (80 mW, 180 sec/spot) daily for 10 days. After LLLT, the animals were euthanized and their arthritic ankles were collected for histopathological analysis, immunoassays of tumor necrosis factor (TNF)-α, matrix metallopeptidase (MMP)3 and 5B5, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays.

RESULTS

LLLT at a fluence of 4.5 J/cm2 significantly reduced infiltration of inflammatory cells and expressions of TNF-α-, MMP3- and 5B5-like immunoreactivities, as well as resulting in more TUNEL-positive apoptotic cells in the synovium. No significant changes were observed in these biochemicals and inflammation in arthritic animals treated with 72 J/cm2.

CONCLUSIONS

LLLT with low fluence is highly effective in reducing inflammation to sites of injury by decreasing the numbers of FLS, inflammatory cells, and mediators in the CFA-induced arthritic model. These data will be of value in designing clinical trials of LLLT for RA.

Characterization, biomedical and agricultural applications of protease inhibitors: A review

This review describes Protease Inhibitors (PIs) which target or inhibit proteases, protein digesting enzymes. These proteases play a crucial task in many biological events including digestion, blood coagulation, apoptosis etc. Regardless of their crucial roles, they need to be checked regularly by PIs as their excess may possibly damage host organism. On basis of amino acid composition of PIs where Protease-PI enzymatic reactions occur i.e. serine, cysteine, and aspartic acid, they are classified. Nowadays, various PIs are being worked upon to fight various parasitic or viral diseases including malaria, schistosomiasis, colds, flu', dengue etc. They prevent an ongoing process begun by carcinogen exposure by keeping a check on metastasis. They also possess potential to reduce carcinogen-induced, increased levels of gene amplification to almost normal levels. Some PIs can principally be used for treatment of hypertension and congestive heart failure by blocking conversion of angiotensin I to angiotensin II for example Angiotensin-converting enzyme inhibitors (ACEIs). Also PIs target amyloid β-peptide (Aβ) level in brain which is prime responsible for development of Alzheimer's Disease (AD). Also, PIs inhibit enzymatic activity of HIV-1 Protease Receptor (PR) by preventing cleavage events in Gag and Gag-Pol that result in production of non-virulent virus particles.

Understanding the binding of inhibitors of matrix metalloproteinases by molecular docking, quantum mechanical calculations, molecular dynamics simulations, and a MMGBSA/MMBappl study

Matrix metalloproteinases (MMPs) consist of a class of proteins required for normal tissue function. Their over expression is associated with many disease states and hence the interest in MMPs as drug targets. Almost all MMP inhibitors have been reported to fail in clinical trials due to lack of specificity. Zinc in the binding site of metalloproteinases performs essential biological functions and contributes to the binding affinity of inhibitors. The multiple possibilities for coordination geometry and the consequent charge on the zinc atom indicate that parameters developed are not directly transferable across different families of zinc metalloproteinases with different zinc coordination geometries, active sites and ligand architectures which makes it difficult to evaluate metal-ligand interactions. In order to assist in drug design endeavors for MMP targets, a computationally tractable pathway is presented, comprising docking of small molecule inhibitors against the target MMPs, derivation of quantum mechanical charges on the zinc ion in the active site and the amino acids coordinating with zinc including the inhibitor molecule, molecular dynamics simulations on the docked ligand-MMP complexes and evaluation of binding affinities of the ligand-MMP complexes via an accurate scoring function for zinc containing metalloprotein-ligand complexes. The above pathway was applied to study the interaction of inhibitor Batimastat with MMPs, which resulted in a high correlation between the predicted binding free energies and experiment, suggesting the potential applicability of the pathway. We then proceeded to formulate a few design principles which identify the key protein residues for generating molecules with high affinity and specificity against each of the MMPs.

Histological, histochemical, and protein changes after induced malocclusion by occlusion alteration of Wistar rats

Although disorders of the stomatognathic system are common, the mechanisms involved are unknown. Our objective was to study the changes in the masseter muscles after unilateral exodontia. Molar extraction was performed on Wistar rats (left side), and the animals were sacrificed after either 14 or 26 days. The masseter muscle was processed for histological analysis, conventional and in situ zymography, and immunohistochemistry. The morphological analysis showed unique and specific characteristics for the experimental group. By conventional zymography no significant values of 72 kDa MMP-2 (P < 0.05) were found in both of the sides of masseter muscle after 14 and 26 days of unilateral extraction. The in situ zymography showed gelatinolytic activity on all deep masseter muscles, with significant increase on the contralateral side after 14 and 26 days (P < 0.05). The immunohistochemistry demonstrated greater expression of MMP-2 than MMP-9 and MMP-14 in all masseter muscles and there were few differences in the staining of 4 TIMPs. This knowledge about morphology and molecular masticatory muscle remodeling following environmental interventions can be used to develop clinically successful treatments.

Hyaluronan modulates accumulation of hypoxia-inducible factor-1 alpha, inducible nitric oxide synthase, and matrix metalloproteinase-3 in the synovium of rat adjuvant-induced arthritis model

Introduction

Hypoxia is a feature of the inflamed synovium in rheumatoid arthritis (RA). Intra-articular injection of hyaluronan (HA) may be considered a potential way to treat RA. However, the exact molecular mechanism of HA on decreased cellular responses to hypoxic environment is unclear. The present study has been designed to use the adjuvant-induced arthritis model to examine the effects of HA on the changes of immunohistochemical expressions of hypoxia-inducible factor-1alpha (HIF-1alpha), inducible nitric oxide synthase (iNOS), and matrix metalloproteinase-3 (MMP3) in the synovial tissues at the early phase of arthritic inflammation.

Methods

Monoarthritis was induced in adult male Sprague-Dawley (250-300 g) via intraarticular injection of complete Freund's adjuvant (CFA) into the tibiotarsal joint. The CFA-induction arthritis animals were divided into three groups: treatment (intraarticular injection of HA), placebo (intraarticular injection of saline) and controls (no treatments). Functional evaluations of edema and pain behavior, histology, and HIF-1alpha, iNOS, and MMP3 immunohistochemistry were performed before, after the first injection, three injections, and on the follow-up injection of the treatments.

Results

Intra-articular injection of HA also significantly suppressed the mechanical allodynia (p < 0.001) and overexpressions of HIF-1alpha (p < 0.001), iNOS (p = 0.004) and MMP3 (p < 0.001) immunoreactivity in synovium.

Conclusions

This study demonstrated that early intervention of HA is an effective protection against accumulation of inflammation-induced HIF-1alpha, iNOS, and MMP3 to limit erosive damage in CFA-induced model of arthritis.

Chondroprotective role of sesamol by inhibiting MMPs expression via retaining NF-κB signaling in activated SW1353 cells

Overexpression of matrix metalloproteinases (MMPs) is a major pathological factor causing cartilage destruction in osteoarthritis (OA). This study aimed to investigate the effects and mechanisms of sesamol on expression of MMPs in activated chondrosarcoma cells. Sesamol significantly attenuated TNF-α- and IL-1β-induced gelatinolysis and expression of MMP-9 in a concentration-dependent manner in SW1353 cells. Additionally, both MMP-1 and -13 stimulated by PMA were inhibited by sesamol. On the other hand, the NF-κB signaling activation through IκB-α degradation was restored by sesamol under TNF-α or PMA stimulation. Furthermore, this bioactive compound exerted the reduction on phosphorylation of ERK1/2 or p38 MAPKs after either PMA or IL-1β stimulation. This study also evaluated whether sesamol down-regulates MMP expression in the joint cartilage of monosodium iodoacetate (MIA)-induced OA in rats. Sesamol prevented the expression of MMP-1 and -9 in the cartilage of MIA-induced OA in rats. The results of this study demonstrate that sesamol inhibits cytokine- or PMA-induced MMPs expression through the signal pathways of either NF-κB or ERK/p38 MAPKs down-regulation. This study also showed that sesamol attenuates destructive factor expression in vivo, providing a potential strategy for the chondroprotective therapy in OA.

Phonoarthrography, musculoskeletal ultrasonography, and biochemical biomarkers for the evaluation of knee cartilage in osteoarthritis

The aim of this study was to examine the relationship among three different parameters used to assess cartilage in osteoarthritis (OA) of the knee. These parameters are phonoarthrography (Phono-A), musculoskeletal ultrasonography (MSUS) from the 4 condyles, and biochemical markers; notably, matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of proteinase (TIMP-1). A total of 100 knees with chronic idiopathic OA diagnosed according to the American College of Rheumatology (ACR) criteria were studied, together with 50 normal knees. The knee sounds were recorded by Phono-A and the cartilage thickness was measured by MSUS. All patients and controls had MMP-3 and TIMP-1 measured in a blood sample, using an enzyme-linked immunosorbent assay (ELISA). Conventional knee X-rays were obtained for diagnosis and for Kellgren-Lawrence (K-L) grading purposes. The results showed that Phono-A values were inversely correlated with cartilage thickness, both of these being sensitive parameters for cartilage degeneration. Phono-A values were higher in patients than in controls, denoting more degeneration of cartilage, and the cartilage thickness of all 4 condyles showed significant reductions in patients compared with normal controls. Most of the patients were categorized as grade 2 (36%) and grade 3 (30%) of the K-L classification. Mean levels of MMP-3 and TIMP-1 were significantly elevated in both groups but they were not correlated with each other. MMP-3 continued to rise with increasing radiological grades until grade 4, where it fell unexpectedly. In conclusion, Phono-A and cartilage thickness measured by MSUS seem to support each other. They can be used as parameters for following up cartilage in OA of the knees. The first deals with the roughness of the cartilage surface and the second with its thickness, complementing each other. MMP-3 continues to rise in early and middle grades of OA, denoting cartilage destruction.

Protease inhibitors: a panacea?

With the increasing evidence of protease involvement in several diseases, novel strategies for drug development involve the use of protease inhibitors (PIs). The local balance between protease inhibitors and proteases is an important determinant of the occurrence and progression of a particular disease. Hence, enzymes and their cognate inhibitors are finding their applications as diagnostic and prognostic markers. PIs are widely implicated for their use in host defense against infection, tissue repair and matrix production, blood coagulation, cancer, and they are, therefore, the current focus as therapeutic alternatives for major diseases such as AIDS and Alzheimer's diseases. This review is a brief summary of the varied role of protein protease inhibitors in controlling the activity of aberrant enzymes in several diseases afflicting mankind today.

Ferritin concentrations in synovial fluid are higher in osteoarthritis patients with HFE gene mutations (C282Y or H63D)

OBJECTIVES

In view of the clinical similarities between polyarticular osteoarthritis (POA) with metacarpophalangeal (MCP) joint involvement and the arthropathy that occurs in hereditary haemochromatosis (HH), it was hypothesized that osteochondral damage in both disorders may be due to localized iron overload. Accordingly, it was predicted that the concentration of ferritin in synovial fluid (SF) would be higher in OA patients with HFE gene mutations than in HFE wild-type (wt) OA patients. The aim of this study was to test this proposition.

METHODS

Sequential patients with physician-diagnosed OA and, for comparison, diverse inflammatory diseases of the joints, who required diagnostic or therapeutic arthrocentesis, were studied. Participants underwent HFE genotyping. SF samples were assayed for ferritin and also for selected cytokines and matrix metalloproteinases (MMPs).

RESULTS

Seventy-three patients with diverse rheumatic disorders were recruited. Of the 29 patients who had knee OA, 15 were wt and 14 were heterozygous for HFE mutations (C282Y or H63D). Mean SF ferritin concentrations in the wt and heterozygous OA groups were 273 and 655 ng/mL, respectively (p = 0.0146).

CONCLUSIONS

A predicted difference in SF ferritin concentrations in patients with knee OA was confirmed. Concentrations of ferritin in the SF were found to be two- to threefold higher in knee OA patients with HFE gene mutations compared to wt patients. This finding is consistent with the possibility that, in OA patients with HFE gene mutations, localized iron overload may contribute either directly or indirectly to osteochondral damage, possibly in a similar way to that which occurs in the arthropathy that complicates HH.

Tissue Engineering of Cartilage; Can Cannabinoids Help?

This review discusses the role of the cannabinoid system in cartilage tissue and endeavors to establish if targeting the cannabinoid system has potential in mesenchymal stem cell based tissue-engineered cartilage repair strategies. The review discusses the potential of cannabinoids to protect against the degradation of cartilage in inflamed arthritic joints and the influence of cannabinoids on the chondrocyte precursors, mesenchymal stem cells (MSCs). We provide experimental evidence to show that activation of the cannabinoid system enhances the survival, migration and chondrogenic differentiation of MSCs, which are three major tenets behind the success of a cell-based tissue-engineered cartilage repair strategy. These findings highlight the potential for cannabinoids to provide a dual function by acting as anti-inflammatory agents as well as regulators of MSC biology in order to enhance tissue engineering strategies aimed at cartilage repair.

A double blind, randomized, placebo controlled study to evaluate the efficacy of erythromycin in patients with knee effusion due to osteoarthritis

OBJECTIVE

The efficacy of erythromycin in treatment of knee effusion due to osteoarthritis was evaluated.

METHOD

We assessed efficacy and safety of erythromycin during 16 weeks in patients enrolled in a randomized double-blind study. One hundred and eight patients with knee effusion due to osteoarthritis (OA) received 12-week courses of erythromycin or placebo allocated randomly, and were followed for 4 months. Acetaminophen 650 mg/day was used in both groups, while they received no other anti-inflammatory drugs (such as corticosteroid or nonsteroidal anti-inflammatory drugs) during the course of the study. Our patients were divided in two groups, erythromycin in doses of 200 mg four times per day was given to the first group (51 patients) over the first 3 months of the study and in the second group we used placebo with the same dosage and schedule (53 patients). Outcomes improvement for the erythromycin-treated group was assessed by a significantly higher mean score from baseline to the end of the trial, compared with placebo group. Patients were examined monthly during the treatment period. Measurement values included recording of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire subscales (pain, stiffness and function), range of motion and knee circumference.

RESULTS

Erythromycin produced a higher response rate than placebo in treatment of knee effusion due to OA. Significant reduction in knee circumference (P < 0.0005) and pain (P < 0.001) with functional improvement (P < 0.0005) were seen. At the first month after treatment, 11.8% (6 patients) in erythromycin and 9.4% (5 patients) in placebo groups had 50% pain reduction, which was not significant (P = 0.75). At the fourth month, 50% reduction of pain was seen in 45.1% (23 patients) of the erythromycin and 11.3% (6 patients) of the placebo group. This was statistically significant (P < 0.0005). Erythromycin treatment was well tolerated and mild adverse events caused no discontinuation during the study.

CONCLUSION

This is a placebo-controlled study of macrolid efficacy on knee effusion due to OA in a short period. Results of this research showed the better efficacy of erythromycin in controlling effusion and pain with functional improvement in patients with knee effusion due to OA.

Arthritis and cannabinoids: HU-210 and Win-55,212–2 prevent IL-1 α-induced matrix degradation in bovine articular chondrocytes in-vitro

Cannabinoids have analgesic, immunomodulatory and anti-inflammatory properties and attenuate joint damage in animal models of arthritis. In this study the mechanisms of action of the synthetic cannabinoid agonists, HU-210 and Win-55,212–2, were studied to determine if they affected interleukin-1 alpha (IL-1α)-induced proteoglycan and collagen degradation in bovine nasal cartilage explant cultures and prostaglandin E2 (PGE2) production in primary cultures of bovine articular chondrocytes. The effects of the inactive enantiomer, Win-55,212–3, were compared with those of the active enantiomer, Win-55,212–2, to determine if the effects were cannabinoid (CB)-receptor mediated. The chondrocytes and explants were stimulated by IL-1α (100 U mL−1 ≡ 0.06 nm and 500 U mL−1 ≡ 0.3 nm, respectively). Proteoglycan breakdown was determined as sulfated glycosaminoglycan (sGAG) release using the dimethylmethylene blue assay. Collagen degradation was determined as hydroxyproline in the conditioned culture media and cartilage digests. PGE2 was determined by ELISA. Expression of cannabinoid receptors, CB1 and CB2; cyclooxygenase-1 and −2 (COX-1 and COX-2); inducible nitric oxide synthase (iNOS); as well as activation of nuclear factor-kappa B (NF-κB) in chondrocytes were studied using immunoblotting techniques and immunofluorescence. The results showed that HU-210 and Win-55,212–2 (5–15 μm) significantly inhibited IL-1α-stimulated proteoglycan (P &lt; 0.001) and collagen degradation (P &lt; 0.001). Win-55,212–2 (5–10 μm) also significantly inhibited PGE2 production (P &lt; 0.01). At 5 μm, Win-55,212–2 inhibited the expression of iNOS and COX-2 and activation of NF-κB. Chondrocytes appeared to constitutively express cannabinoid receptors CB1 and CB2. It is concluded that biologically stable synthetic cannabinoids protect cartilage matrix from degradation induced by cytokines and this effect is possibly CB-receptor mediated and involves effects on prostaglandin and nitric oxide metabolism. Cannabinoids could also be producing these effects via inhibition of NF-κB activation.

PI3Kgamma regulates cartilage damage in chronic inflammatory arthritis

The gamma isoform of phosphoinositide 3-kinase (PI3Kgamma) has been viewed as restricted to leukocytes mediating the regulation of chemokine-induced migration and recruitment of neutrophils, monocytes, and macrophages. In line with the observation that PI3Kgamma-deficient mice display defects in adaptive immunity, inhibition of PI3Kgamma reduces synovial inflammation in the collagen-induced arthritis mouse model of inflammatory arthritis [rheumatoid arthritis (RA)], which has been attributed to reduced influx of inflammatory cells. Challenging the concept of leukocyte-restricted PI3Kgamma function, we report here a novel, nonredundant function of PI3Kgamma as an important regulator of fibroblast-induced cartilage destruction during chronic destructive arthritis. We show that in human tumor necrosis factor transgenic mice, the loss of PI3Kgamma leads to a milder inflammatory arthritis. Interestingly, PI3Kgamma deficiency does not alter the recruitment of inflammatory cells, but significantly reduces cartilage damage through reduced expression of matrix metalloproteinases in fibroblasts and chondrocytes. In vitro analyses demonstrate that the decreased invasiveness of fibroblasts is mediated by reduced phosphorylation of Akt and extracellular signal-regulated kinase. Using a PI3Kgamma specific inhibitor, these data are confirmed in human synovial fibroblasts from patients with RA who exhibit a disease-specific up-regulation of PI3Kgamma. Our data indicate that in addition to mediating the recruitment of inflammatory cells, PI3Kgamma is an important regulator of fibroblast-mediated joint destruction in RA and suggest that specific inhibitors of PI3Kgamma will interfere with the activation of RA synovial fibroblasts and reduce cartilage destruction in RA.

Incorporation of vancomycin-supplemented bone allograftsRadiographical, histopathological and immunohistochemical study in pigs

We compared the incorporation of bone allografts with or without vancomycin in tibial defects of 18 pigs. High-quality radiographs, histological examination, immunological expression of metalloproteinase-13 (MMP-13) and transforming growth factor-beta 2 (TGFbeta2) indicated that there was no significant difference in bone allograft incorporation between up to 220 times the MIC (minimum inhibitory concentration) in bone allografts with 1 g of vancomycin in each 300 g of allograft or without this supplement.

Relative efficacies of omega-3 polyunsaturated fatty acids in reducing expression of key proteins in a model system for studying osteoarthritis

OBJECTIVE

To assess the relative efficacy of three different omega-3 (n-3) polyunsaturated fatty acids (PUFAs) in suppressing the mRNA levels for important proteins involved in the etiology of osteoarthritis (OA).

METHODS

A model cell culture system (bovine chondrocytes) was used. Inflammatory factors and enzymes involved in OA were induced by exposure of the chondrocyte cultures to interleukin-1alpha (IL-1alpha). The effect of pre-incubating cultures with various amounts of exogenous fatty acids on subsequent levels of mRNAs was assessed by reverse transcription-polymerase chain reactions (RT-PCR).

RESULTS

Exposure of cultures to IL-1alpha induced expression of the cartilage proteinases A Disintegrin And Metalloproteinase with ThromboSpondin motifs (ADAMTS)-4 and ADAMTS-5, cyclooxygenase (COX)-2, the matrix metalloproteinase (MMP)-3 and the inflammatory cytokines IL-1alpha, interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha). n-3 PUFAs were able to reduce the levels of mRNA for ADAMTS-4, ADAMTS-5, MMP-3, MMP-13, COX-2 (but not COX-1), IL-1alpha, IL-1beta and TNF-alpha. Eicosapentaenoic acid (EPA) was the most effective, followed by docosahexaenoic (DHA) and then alpha-linolenic (ALA) acid. The n-6 PUFA, arachidonic acid (AA) had no effect.

CONCLUSION

These results show that omega-3 (n-3) PUFAs cause a reduction in the mRNA levels for various proteins known to be important in the pathology of OA. They provide a molecular explanation, at least in part, for beneficial effects of dietary omega-3 PUFAs for the amelioration of symptoms of the disease. The relative efficacy of EPA suggests that this omega-3 PUFA may be especially useful for dietary supplementation in patients with OA.

Multiple matrix metalloproteinases in type II collagen induced arthritis

To study the relative contribution of various matrix degrading enzymes in the pathogenesis of arthritis, changes in the levels of various matrix metalloprtoteinases (MMPs) during the progression of collagen induced arthritis was studied in experimental animals. Arthritis was induced in male wistar rats by injecting an emulsion containing collagen type II and Freund's complete adjuvant. The duration of the experiment was 35 days. Synovial effusate was collected at regular intervals after induction. At the end of the experiment serum and cartilage were collected and analysed. Synovial fluid of osteoarthritic patients was also analyzed. Levels of MMP-2, MMP-3, MMP-9 and MT1-MMP were found to be high in synovial effusate and cartilage of experimental animals. In synovial effusate of arthritic animals the expression of MMP-3 was found to be high during the early stages while increase in MMP-2 and MMP-9 occurred at later stages. Synovial fluid of osteoarthritic patients also showed elevated levels of MMP-2, MMP-3 and MMP-9. Our results indicated that sequential action of MMPs such as MMP-3, MMP-2 and MMP-9 can cause degradation of articular cartilage extracellular matrix.

The effect of prostaglandin analogs and prostamide on central corneal thickness

OBJECTIVE

The aim of this study was to verify the influence of prostaglandin analogs and prostamide on central corneal thickness (CCT).

METHODS

A prospective analysis was done of CCT in glautomatous patients submitted to monotherapy with prostaglandin analogs (latanoprost 0.005% or travoprost 0.004%) or prostamide (bimatoprost 0.03%) during an 8-week period. A control group of patients without any ocular medication was also evaluated. CCT measurements were performed with a commercially available ultrasound pachymeter. A total of 73 patients were included in this study. Mean age was 68.5 +/- 9.2 (range, 48-85) years old.

RESULTS

A statistically significant reduction in CCT was observed in all groups, except the control group (n = 21): Bimatoprost 0.03% group (n = 21): 544.41 +/- 35.4 vs. 540.35 +/- 35.9 microm (P = 0.039); travoprost 0.004% group (n = 17): 538.47 +/- 32.0 vs. 532.25 +/- 30.4 microm (P = 0.009); latanoprost 0.005% group (n = 14): 548.57 +/- 32.4 vs. 543.88 +/- 35.6 microm (P = 0.036).

CONCLUSION

Topical therapy with prostaglandin analogs and bimatoprost is associated with CCT reduction over a period of at least 8 weeks.

A novel paradigm for dendritic cells as effectors of cartilage destruction

OBJECTIVE

Dendritic cells (DCs) are enriched in RA synovium and have been implicated in the pathogenesis of RA primarily through their ability to present autoantigen and activate T cells. However, whether DCs play an effector role in cartilage destruction is unknown. The aim of this study was to investigate whether DCs can induce collagen release from cartilage and the mechanism involved.

METHODS

Human monocyte-derived DCs (mDCs) were activated with CD40 ligand (CD40L) to mimic DC-T-cell interaction, and supernatants were incubated with cartilage explants. Hydroxyproline was assessed as a measure of collagen release and collagenolytic activity was measured by a bioassay using tritiated collagen. TNF-alpha in DC supernatants was measured by specific ELISA.

RESULTS

Supernatants from CD40L-activated mDCs, but not unstimulated mDCs, strongly induced the destruction of cartilage collagen. mDC supernatants did not contain collagenases but did induce collagenolytic activity in cartilage explants. Neutralization of TNF-alpha in mDC supernatants completely abolished collagenolysis.

CONCLUSIONS

This study shows that mDCs, upon CD40-ligation, induce cartilage collagen degradation through an indirect mechanism via the production of TNF-alpha. Our data suggest a potential important role for mDC-derived TNF-alpha in RA, which is in line with the previously reported observations that DCs are a major source of TNF-alpha in early autoimmune lesions and that anti-TNF-alpha therapeutics effectively suppress joint damage in RA patients. We propose that DCs can act as effectors in cartilage destruction, adding a new aspect to the functional role of DCs in RA pathogenesis.

Association of TIMP-4 gene polymorphism with the risk of osteoarthritis in the Korean population

Due to an imbalance in the MMP:TIMP ratio determined a tissue damage in arthritis, it is hypothesized that polymorphic variations of the TIMP genes are associated with regulation of the MMP:TIMP balance. To test this hypothesis, the presence of single nucleotide polymorphisms (SNPs) located in the human TIMP-2 and TIMP-4 genes was confirmed in the Korean RA and OA patients. We performed a case-control study comprising 109 unrelated Korean OA patients, 177 unrelated Korean RA patients and 175 healthy subjects. There were statistically significant differences in the genotype distribution and allele frequencies of the C/T polymorphism of TIMP-4 gene between OA and control groups (P = 0.0002 and P = 0.001, respectively). However, no significant association between TIMP-2 polymorphisms and OA was observed. Also, no difference was observed when allele or genotype frequencies of both TIMP-2 and TIMP-4 gene polymorphisms were compared between RA and controls. We demonstrated that the C/T polymorphism which is located on the 3'-untranslational regions of the TIMP-4 gene might be associated with susceptibility to OA patients.

Effects of melittin on the production of matrix metalloproteinase-1 and -3 in rheumatoid arthritic fibroblast-like synoviocytes

Bee venom (BV) has been used in patients with rheumatoid arthritis, a condition characterized by rheumatoid joint destruction mediated, in large part, by matrix metalloproteinases (MMPs). We investigated the effects of melittin, a major component of bee venom, on the production of MMPs in human rheumatoid arthritic fibroblast-like synoviocytes (FLS). Lipopolysaccharide (LPS)-stimulated MMP3 production was significantly inhibited by melittin, which also inhibited LPS-induced DNA binding by nuclear factor kappaB (NF-kappaB). Mellitin had no effect on IL-1beta- or TNF-alpha-induced MMP1 or MMP3 production and did not decrease LPS-induced secretion of MMP1. Taken together, these findings suggest that melittin may exert its anti-rheumatoid effects, at least in part, by inhibiting MMP3 production, most likely through inhibition of NF-kappaB activity.

Wnt/beta-catenin signaling stimulates matrix catabolic genes and activity in articular chondrocytes: its possible role in joint degeneration

A fine balance between anabolic and catabolic mechanisms maintains extracellular matrix homeostasis in articular cartilage, and shifts toward degradation are associated with joint conditions such as osteoarthritis. To test the possible involvement, relevance and significance of the Wnt/beta-catenin-signaling pathway in those catabolic shifts, rabbit articular chondrocyte cultures were subjected to experimental activation of beta-catenin signaling by Wnt3A treatment or forced expression of constitutive-active beta-catenin (CA-beta-catenin). Both interventions provoked strong gelatinase activity and stimulated gene expression of matrix metalloprotease-3 and -13 and a disintegrin-like and metalloprotease with thrombospondin motif (ADAMTS)-4 and -5 proteases. Furthermore, Wnt3A treatment additively enhanced the effects of intereukin-1beta, a well-known catabolic culprit of proteoglycan matrix loss. To determine whether Wnt/beta-catenin signaling is associated with age-associated osteoarthritic changes in articular cartilage in vivo, we analyzed the presence and intracellular distribution of beta-catenin in a spontaneous guinea pig osteoarthritis model. Healthy articular chondrocytes in young guinea pig knees contained barely detectable levels of beta-catenin. In contrast, the protein was highly abundant in osteoarthritic-like chondrocytes present in older guinea pig joints, and was localized not only in the cytoplasm but also the nucleus, a clear reflection of activated Wnt signaling. These and other data suggest that Wnt/beta-catenin signaling is a powerful stimulator of chondrocyte matrix catabolic action and may be part of mechanisms leading to excessive remodeling and degradation of cartilage matrix in age-associated joint pathologies.

Inhibitory effects of melittin on the production of lipopolysaccharide-induced matrix metalloproteinase 3 in human osteoarthritic chondrocytes

In continuation of our previous study which explored the effect of bee venom (BV) on the global gene expression profiles in lipopolysaccharide (LPS)-treated human chondrosarcoma cells, we investigated herein the effect of melittin, a major component of BV, on the productions of matrix metalloproteinases (MMPs) 1, 3, and 13 in primary cultured human arthritic chondrocytes. Increased generations of MMPs 1, 3, and 13 were observed by MMPs stimulating agents LPS, tumor necrosis factor alpha (TNF-alpha), and interleukin 1beta (IL-1beta). The generations of LPS (1 microg/ml)-induced MMPs 1 and 13 were not decreased by melittin, whereas that of LPS-stimulated MMP 3 was significantly inhibited by melittin. IL-1beta (10ng/ml) and TNF-alpha (10ng/ml)-induced MMPs 1, 3 and 13, however, were not decreased by melittin. Immunoblot analysis revealed that melittin exerted no effect on the LPS-stimulated expression levels of MMPs 1 and 13 but attenuated the LPS-induced MMP 3, which is consistent with the enzyme-linked immunosorbent assay (ELISA) data. Taken together, these findings suggest melittin may exert its anti-arthritic effect, at least in part, by inhibiting LPS-stimulated MMP 3 production in human osteoarthritic chondrocytes.

Intra-articular injection of hyaluronate and indomethacin in rabbits with antigen-induced arthritis

Combined effects of hyaluronate and indomethacin in the treatment of rabbits with antigen-induced arthritis (AIA) were evaluated by assessing joint swelling, C-reactive protein (CRP) and prostaglandin E(2) (PGE(2)) levels with periodic intra-articular (ia) injections of hyaluronate alone (HA group) and with either a low or high concentration of indomethacin (LI-HA or HI-HA group). End-point analyses included matrix metalloproteinases-3 (MMP-3) activity and macroscopic and histological joint examinations. Results demonstrated that treatment in LI-HA and HI-HA groups resulted in statistically significant suppression of CRP, PGE(2, )and MMP-3 in comparison with those of HA group. Inhibition of serum CRP was only observed in LI-HA group. The order of serum MMP-3 inhibition was LI-HA>HI-HA>HA. Based on macroscopic and histological analyses of pannus formation, hyperplasia, inflammation, joint leakage and erosion, and loss of proteoglycan, the only statistically significant improvement was shown in LI-HA group compared to HA group and HI-HA group compared to control group.

A novel approach to measure the contribution of matrix metalloproteinase in the overall net proteolytic activity present in synovial fluids of patients with arthritis

Despite decades of research, only a very limited number of matrix metalloproteinase (MMP) inhibitors have been successful in clinical trials of arthritis. One of the central problems associated with this failure may be our inability to monitor the local activity of proteases in the joints since the integrity of the extracellular matrix results from an equilibrium between noncovalent, 1:1 stoichiometric binding of protease inhibitors to the catalytic site of the activated forms of the enzymes. In the present work, we have measured by flow cytometry the net proteolytic activity in synovial fluids (SF) collected from 95 patients with osteoarthritis and various forms of inflammatory arthritis, including rheumatoid arthritis, spondyloarthropathies, and chronic juvenile arthritis. We found that SF of patients with inflammatory arthritis had significantly higher levels of proteolytic activity than those of osteoarthritis patients. Moreover, the overall activity in inflammatory arthritis patients correlated positively with the number of infiltrated leukocytes and the serum level of C-reactive protein. No such correlations were found in osteoarthritis patients. Members of the MMP family contributed significantly to the proteolytic activity found in SF. Small-molecular-weight MMP inhibitors were indeed effective for inhibiting proteolytic activity in SF, but their effectiveness varied greatly among patients. Interestingly, the contribution of MMPs decreased in patients with very high proteolytic activity, and this was due both to a molar excess of tissue inhibitor of MMP-1 and to an increased contribution of other proteolytic enzymes. These results emphasize the diversity of the MMPs involved in arthritis and, from a clinical perspective, suggest an interesting alternative for testing the potential of new protease inhibitors for the treatment of arthritis.

HIV protease inhibitors selectively induce gene expression alterations associated with reduced calcium deposition in primary human osteoblasts

HIV-infected patients are at increased risk of decreased bone mineral density. Some studies have implicated antiretroviral therapy as a contributor to the decreased bone mineral density seen in treated HIV-1 patients. In this study we explore the interactions between protease inhibitors (PI) and primary human osteoblast gene expression, highlighting a group of dysregulated genes that potentially are key factors in reducing bone formation. Runx-2 mRNA expression, calcium deposition, and alkaline phosphatase (ALP) activity decreased significantly in human osteoblast cultures after exposure to the PIs nelfinavir (NFV) and indinavir (IDV). Saquinavir (SQV), ritonavir (RTV), indinavir (IDV), or nelfinavir (NFV) exposure induced significant changes in genotypic expression as assessed by gene-chip microarray analysis. The altered genes from each group were compared to each other and a list of 8 upregulated and 13 downregulated genes only after NFV and IDV exposure was identified. This set includes TIMP-3, which has previously been demonstrated to be involved in osteoblast differentiation and extracellular matrix development processes. Silencing TIMP-3 mRNA expression using siRNA duplexes enhanced calcium deposition and ALP activity significantly, even after exposure to NFV and IDV. Our data suggest a link between reduced osteoblastic phenotype and a group of 21 altered genes following NFV and IDV treatment, and also suggest TIMP-3 may be involved in the PI-induced inhibition of osteoblast function.

Expression profiling of metalloproteinases and tissue inhibitors of metalloproteinases in normal and degenerate human achilles tendon

OBJECTIVE

To profile the messenger RNA (mRNA) expression for the 23 known genes of matrix metalloproteinases (MMPs), 19 genes of ADAMTS, 4 genes of tissue inhibitors of metalloproteinases (TIMPs), and ADAM genes 8, 10, 12, and 17 in normal, painful, and ruptured Achilles tendons.

METHODS

Tendon samples were obtained from cadavers or from patients undergoing surgical procedures to treat chronic painful tendinopathy or ruptured tendon. Total RNA was extracted and mRNA expression was analyzed by quantitative real-time reverse transcription-polymerase chain reaction, normalized to 18S ribosomal RNA.

RESULTS

In comparing expression of all genes, the normal, painful, and ruptured Achilles tendon groups each had a distinct mRNA expression signature. Three mRNA were not detected and 14 showed no significant difference in expression levels between the groups. Statistically significant (P < 0.05) differences in mRNA expression, when adjusted for age, included lower levels of MMPs 3 and 10 and TIMP-3 and higher levels of ADAM-12 and MMP-23 in painful compared with normal tendons, and lower levels of MMPs 3 and 7 and TIMPs 2, 3, and 4 and higher levels of ADAMs 8 and 12, MMPs 1, 9, 19, and 25, and TIMP-1 in ruptured compared with normal tendons.

CONCLUSION

The distinct mRNA profile of each tendon group suggests differences in extracellular proteolytic activity, which would affect the production and remodeling of the tendon extracellular matrix. Some proteolytic activities are implicated in the maintenance of normal tendon, while chronically painful tendons and ruptured tendons are shown to be distinct groups. These data will provide a foundation for further study of the role and activity of many of these enzymes that underlie the pathologic processes in the tendon.

CD147 overexpression on synoviocytes in rheumatoid arthritis enhances matrix metalloproteinase production and invasiveness of synoviocytes

Macrophage-like synoviocytes and fibroblast-like synoviocytes (FLS) are known as the most active cells of rheumatoid arthritis (RA) and are close to the articular cartilage in a position enabling them to invade the cartilage. Macrophage-like synoviocytes and FLS expression of matrix metalloproteinases (MMPs) and their interaction has aroused great interest. The present article studied the expression of CD147, also called extracellular matrix metalloproteinase inducer, on monocytes/macrophages and FLS from RA patients and its potential role in enhancing MMPs and the invasiveness of synoviocytes. Expression of CD147 on FLS derived from RA patients and from osteoarthritis patients, and expression of CD147 on monocytes/macrophages from rheumatic synovial fluid and healthy peripheral blood were analyzed by flow cytometry. The levels of CD147, MMP-2 and MMP-9 mRNA in FLS were detected by RT-PCR. The role of CD147 in MMP production and the cells' invasiveness in vitro were studied by the co-culture of FLS with the human THP-1 cell line or monocytes/macrophages, by gel zymography and by invasion assay. The results showed that the expression of CD147 was higher on RA FLS than on osteoarthritis FLS and was higher on monocytes/macrophages from rheumatic synovial fluid than on monocytes/macrophages from healthy peripheral blood. RT-PCR showed that the expressions of CD147, MMP-2 and MMP-9 mRNA was higher in RA FLS than in osteoarthritis FLS. A significantly elevated secretion and activation of MMP-2 and MMP-9 were observed in RA FLS co-cultured with differentiated THP-1 cells or RA synovial monocytes/macrophages, compared with those co-cultured with undifferentiated THP-1 cells or healthy control peripheral blood monocytes. Invasion assays showed an increased number of invading cells in the co-cultured RA FLS with differentiated THP-1 cells or RA synovial monocytes/macrophages. CD147 antagonistic peptide inhibited the MMP production and the invasive potential. Our studies demonstrated that the CD147 overexpression on monocytes/macrophages and FLS in RA patients may be responsible for the enhanced MMP secretion and activation and for the invasiveness of synoviocytes. These findings suggest that CD147 may be one of the important factors in progressive joint destruction of RA and that CD147 may be a potential therapeutic target in RA treatment.

Expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 protein in colonic carcinoma

AIM: To analyze the correlation of matrix metallopro-teinase-2(MMP-2) and MMP-9 protein expression with the pathological factors in colonic carcinoma, and to investigate the clinical significance of matrix metallo-proteinases in the occurrence of colonic carcinoma.

METHODS: The expression of MMP-2 and MMP-9 protein were measured by immunohistochemistry in the resected specimens from 31 patients with colonic carcinoma, and their relations with clinicopathologic factors were analyzed by SPSS 10.0 for Windows software. The specimens from ulcerative colitis (n = 20), colon adenoma (n = 21), and normal colon (n = 10) tissues were used as the controls.

RESULTS: The positive rate of MMP-2 protein expres-sion was significantly different between colonic carcinoma and normal colon tissues (10.0% vs 54.8%, P <0.05), while no significant difference was found between other groups. The positive rates of MMP-2 and MMP-9 expression tended to increase in ulcerative colitis, colon adenoma, and colonic carcinoma gradually. The positive rates of MMP-2 and MMP-9 protein expression were significantly correlated with the Dukes's staging and lymph node metastasis (C-D stage vs A-B stage: 76.9% vs 38.9%, P <0.05; 84.6% vs 27.8%, P <0.05; metastasis vs non-metastasis: 76.9% vs 38.9%, P <0.05; 84.6% vs 27.8%, P <0.05).

CONCLUSION: Over-expression of MMP-2 and MMP-9 protein play important roles in the carcinogenesis and metastasis of colonic carcinoma.

Lack of tissue inhibitor of metalloproteinases-3 results in an enhanced inflammatory response in antigen-induced arthritis

Tissue inhibitor of metalloproteinases-3 (TIMP-3) is known to inhibit matrix metalloproteinases, aggrecanases, and tumor necrosis factor (TNF)-alpha-converting enzyme (TACE, ADAM17). These metalloproteases participate in different aspects of joint destruction in inflammatory arthritis. To determine the relative importance of this inhibitor in joint pathology, wild-type and Timp3-/- mice were immunized with methylated bovine serum albumin followed by arthritis induction by intra-articular injection of the same antigen. Animals were monitored for up to 14 days after challenge, and joint tissues were analyzed by routine and Safranin O staining and for the presence of aggrecan neoepitopes produced by metalloprotease cleavage. Serum TNF-alpha was measured by immunoassay. Compared to wild-type animals, Timp3-/- mice showed a dramatic increase in the initial inflammatory response to intra-articular antigen injection, and serum TNF-alpha levels were greatly elevated in the Timp3-/- animals after immunization. However, these differences in clinical features disappeared by days 7 to 14. No difference in Safranin O staining or aggrecan cleavage site neoepitope abundance was seen. Thus, in inflammatory joint disease TIMP-3 likely dampens the inflammatory response of TNF-alpha by reducing ADAM17 activity.

Enhanced angiotensin II-mediated effects in fibroblasts of patients with familial hypercholesterolemia

OBJECTIVE

Familial hypercholesterolemia (FH) is characterized by a high incidence of coronary heart disease. Evidence suggests an important role for angiotensin II (AngII) in the fibrotic response to tissue injury, and in promoting myocardial hypertrophy via paracrine mechanisms mediated by fibroblasts. We sought to determine whether AngII promotes proliferative and pro-atherogenic responses in FH patients.

METHODS

We used primary fibroblasts -- from five patients with heterozygous FH and five control subjects (C) -- to study AngII-induced cell growth, intracellular calcium fluxes, and expression/release of matrix components and pro-inflammatory peptides [transforming growth factor-beta1 (TGFbeta1) and endothelin-1 (ET-1)] and metalloproteinases involved in plaque remodeling and vulnerability.

RESULTS

AngII stimulated cell replication (5.1 +/- 0.03 versus 3.2 +/- 0.04 cells/50 cells per well, P < 0.001), and induced a larger increase in intracellular calcium content in FH cells than in C cells, in a dose-dependent fashion (mean difference = 76 nmol/l, P < 0.001). Similarly, TGFbeta1 and ET-1 expression and release were potentiated (after 24-h incubation with 1 micromol/l AngII: TGFbeta1 was 190 +/- 12 in C and 376 +/- 9 pg/ml per 10(6) cells in FH, and ET-1 was 93 +/- 5 in C and 192 +/- 7 pmol/ml per 10(6) cells in FH; P < 0.001 for both). AngII-induced release of the metalloproteinases MMP-1 and MMP-2 was also increased in FH versus C cells (0.52 +/- 0.04 versus 0.36 +/- 0.05 and 24 +/- 4 versus 13 +/- 3 ng/mg protein with 1 micromol/l AngII). These enhanced responses were likely due to an increased angiotensin receptor 1 (AT1) expression in cells from FH patients induced by AngII, and were prevented by pretreating cells with the selective AT1 antagonist irbesartan.

CONCLUSIONS

These findings show that some AngII-mediated pathways are enhanced in FH subjects irrespective of the presence of low-density lipoprotein (LDL), thus contributing to the development and progression of atherosclerosis in these patients.

Cartilage breakdown in rheumatoid arthritis

Rheumatoid arthritis (RA) is a connective tissue disease characterized by destruction of the joint cartilage and subsequently of the underlying bone. Cartilage destruction is due to proteolysis by enzymes called metalloproteinases (MMPs), whose production and expression are regulated by numerous local mediators such as cytokines, growth factors, prostaglandins, oxygen species, and neuropeptides. MMP activation is largely due to a stimulatory effect of cytokines including IL-1beta and TNFalpha. When these cytokines bind to their membrane receptor, they set off signaling cascades, with activation of TGFbeta-activating kinase (TAK-1), of NF-kappaB by Ikappa-B kinase, of mitogen-activated protein kinases (MAP kinases), and finally of activator protein-1 (AP-1). Tissue inhibitors of MMPs (TIMPs) specifically inhibit MMPs. The interrelations between joint inflammation and joint destruction remain poorly understood. Experimental data suggest that IL-1 may be involved chiefly in joint destruction and TNF in joint inflammation. However, TNF antagonists are potent inhibitors of joint destruction in clinical practice. These results suggest that the mediators function as a network and that inhibition of a single mediator can affect the entire web. Insights gained into the innermost mechanisms of cartilage breakdown in patients with RA have led to major therapeutic breakthroughs. Thus, TNF antagonists have proved highly effective in RA. Future progress will no doubt stem from new knowledge about the extracellular mediators and intracellular signaling pathways that lead to the production and activation of enzymes responsible for cartilage degradation.

The plasminogen activator/plasmin system is essential for development of the joint inflammatory phase of collagen type II-induced arthritis

The plasminogen activator (PA) system has been proposed to have important roles in rheumatoid arthritis. Here we have used the autoimmune collagen type II (CII)-induced arthritis (CIA) model and mice deficient for urokinase-type PA (uPA) or plasminogen to investigate the role of the PA system for development of arthritis. Our data revealed that uPA-deficient mice have a lower severity and incidence of CIA than wild-type mice. Furthermore, although >80% of wild-type control mice developed CIA, we found that none of the 50 plasminogen-deficient littermates that were tested developed CIA within a 40-day period. Antibody generation after CII immunization as well as the binding of labeled anti-CII antibodies to the surface of cartilage were similar in wild-type and plasminogen-deficient mice. No sign of inflammation was seen when plasminogen-deficient mice were injected with a mixture of monoclonal antibodies against CII. However, after daily injections of human plasminogen, these mice developed arthritis within 5 days. Our finding that infiltration of inflammatory cells into the synovial joints was impaired in plasminogen-deficient mice suggests that uPA and plasminogen are important mediators of joint inflammation. Active plasmin is therefore essential for the induction of pathological inflammatory joint destruction in CIA.

Effects of cannabinoids on nitric oxide production by chondrocytes and proteoglycan degradation in cartilage

Cannabinoids have been reported to have anti-inflammatory effects and reduce joint damage in animal models of arthritis. This suggests a potential therapeutic role in arthritis of this group of compounds. Cannabinoids were studied to determine whether they have direct effects on chondrocyte metabolism resulting in cartilage protection. Synthetic cannabinoids, R-(+)-Win-55,212 (Win-2) and S-(-)-Win-55,212 (Win-3) and the endocannabinoid, anandamide, were investigated on unstimulated or IL-1-stimulated nitric oxide (NO) production in bovine articular chondrocytes as well as on cartilage proteoglycan breakdown in bovine nasal cartilage explants. Win-2 significantly inhibited (P < 0.05) NO production in chondrocytes at 1-10 microM concentrations. The combined CB(1) and CB(2) cannabinoid receptor antagonists, AM281 and AM630, respectively, at 100 microM did not block this effect, but instead they potentiated it. Anandamide and Win-2 (5-50 microM) also inhibited the release of sulphated glycosaminoglycans in bovine cartilage explants. The results suggest that some cannabinoids may prevent cartilage resorption, in part, by inhibiting cytokine-induced NO production by chondrocytes and also by inhibiting proteoglycan degradation.

Metabolism and composition of the canine anterior cruciate ligament relate to differences in knee joint mechanics and predisposition to ligament rupture

PURPOSE

The objective of this study was to determine whether differences in the composition and metabolism of the extracellular matrix (ECM) in canine anterior cruciate ligaments (ACLs) might relate to mechanical properties of the canine knee. Variations in ACL biochemistry and knee mechanics could account for divergent predispositions to ligament rupture.

METHODS

Eleven knee joints were obtained from both cadaveric Labrador Retrievers (rupture predisposed) and ex-racing Greyhounds (non-rupture predisposed). Anterioposterior laxity and tensile testing determined mechanical properties of the knee joints and ACL samples respectively. The thermal properties of the collagenous matrix were determined by differential scanning calorimetry (DSC) and the biochemical properties by measuring collagen content, collagen cross-links, glycosaminoglycan (GAG) levels, matrix metalloproteinase-2 (MMP-2), tissue inhibitors of metalloproteinase (TIMP).

RESULTS

The anterioposterior laxity was significantly greater (p = 0.04) in the Labrador Retriever knee joints, and their ACLs tended to be weaker (p = 0.06). Greater collagen turnover was demonstrated by significantly higher (p = 0.02) concentrations of pro-MMP-2, and lower enthalpy of denaturation (p = 0.05) in Labrador Retriever ACLs.

CONCLUSIONS

The different metabolism of the collagenous matrix in the ACLs of dogs predisposed to rupture was related to greater knee joint laxity and lower ligament material properties (ultimate tensile stress). This may be suggestive of a link between ligament rupture and eventual knee osteoarthritis in both dogs and humans.

Microarray analysis of gene expression in chondrosarcoma cells treated with bee venom

Bee venom (BV) has a broad array of clinical applications in Korean medicine, including treatment of inflammatory conditions such as arthritis. The final common pathway of many arthropathies is the destruction of articular cartilage and consequent loss of articular function. Chondrocyte dysfunction plays a key role in the pathogenesis of such disorders. To explore the global gene expression profiles in a human chondrocyte-like cell line treated with BV, microarray analysis was performed. The HTB-94 human chondrosarcoma cells were treated with BV, lipopolysaccharide (LPS), or both. Of the 344 genes profiled in this study, with a cut-off level of 4-fold change in the expression, (1) 35 were downregulated following BV treatment, (2) 16 were upregulated and 7 downregulated following LPS treatment, and (3) 32 were downregulated following co-stimulation of BV and LPS. The results of the present study shows that treatment of BV reversed the LPS-induced upregulation of such genes as interleukin-6 (IL-6) receptor, matrix metalloproteinase 15 (MMP-15), tumor necrosis factor (ligand) superfamily-10, caspase-6 and tissue inhibitor of metalloproteinase-1 (TIMP-1). It is thought that microarrays will play an ever-growing role in the advance of our understanding of the pharmacologic actions of BV in the treatment of arthritis.

Sp1-dependent regulation of the tissue inhibitor of metalloproteinases-1 promoter

Extracellular matrix (ECM) remodeling is involved in many cellular properties such as division, migration, differentiation, and death. The turnover of ECM is regulated by matrix metalloproteinases (MMPs) and the MMPs are inhibited by the tissue inhibitors of metalloproteinases (TIMPs). In this study, the transcriptional regulation of the TIMP-1 promoter was investigated. The 5'-deletion assay showed that the region between -1,200 and -1,101 was responsible for the TIMP-1 promoter activity. The mutations of the two Sp1 sites in this region reduced the transcription activity. In addition, the co-transfection with antisense Sp1 oligonucleotide decreased the promoter activity, suggesting that the transcription of the TIMP-1 promoter is mediated by Sp1. Previously, it was reported that the TIMP-1 expression was enhanced under hypoxia. Therefore, the TIMP-1 promoter activity was investigated with or without cobalt ion, which elicits the same physiological effect as hypoxia. The results showed that the TIMP-1 promoter was induced in the presence of cobalt ion and that the promoter activity was regulated by Sp1 as well as HIF-1. Therefore, this study suggests that Sp1 is involved in the regulation of the TIMP-1 promoter in the presence of cobalt ion as well as in the basal level transcription.

A randomised comparative study of the short term clinical and biological effects of intravenous pulse methylprednisolone and infliximab in patients with active rheumatoid arthritis despite methotrexate treatment

OBJECTIVES

To compare the short term clinical and biological effects of intravenous (i.v.) pulse methylprednisolone (MP) and infliximab (IFX) in patients with severe active rheumatoid arthritis (RA) despite methotrexate (MTX) treatment.

METHODS

Patients with active RA despite MTX treatment were randomly allocated to receive a single i.v. infusion of MP (1 g) or three i.v. infusions of IFX (3 mg/kg) on weeks 0, 2, and 6. Patients were "blindly" evaluated for disease activity measures. Quality of life (QoL) was evaluated through the SF-36 health survey. Serum matrix metalloproteinase-3 (MMP-3) titres were measured at baseline, weeks 2 and 6.

RESULTS

Compared with baseline, significant improvement was noted in all activity measures, including serum C reactive protein (CRP) titres, in the IFX group only. At week 14, 6/9 (67%) and 4/9 (44%) IFX patients met the ACR20 and 50 response criteria, while this was the case in only 1/12 (8%) and 0/12 (0%) MP patients, respectively (p<0.05). None of the QoL scales improved with MP treatment, whereas some did so in the IFX group. Serum MMP-3 titres significantly decreased (41% drop) at week 6 in the IFX group, while no changes were seen in patients given MP.

CONCLUSION

This short term randomised comparative study demonstrates that TNF blockade is better than MP pulse therapy in a subset of patients with severe refractory RA, with improvement in not only clinical parameters of disease activity but also biological inflammatory indices, such as serum CRP and MMP-3 titres.