Induction Of Collagenase Research Articles

Comparative Regenerative Effects of Allogeneic Bone Marrow and Patellar Ligament Fat Pad Mesenchymal Stem Cells on Experimental Superficial Digital Flexor Tendonitis in New Zealand Rabbits

Background: Cell therapy is applied in tendonitis to speed the healing process of tendon tissue and restore its functional properties. Almost all types of stem cells can differentiate from the recipient cells after transplantation. Objectives: The main goal of this study is to compare the effects of two sources of mesenchymal stem cells on tendon regeneration. Methods: This study randomly divided 32 New Zealand rabbits into 4 groups. The bacterial collagenase was induced at the superficial digital flexor tendon (SDFT) of all rabbits, and the treatment was performed 48 hours after collagenase induction. Group 1 was treated with allogeneic bone marrow mesenchymal stem cells (BMMSCs). Group 2 was treated with adipose-derived stem cells (ADSCs) from the patellar ligament fat pad. Group 3 (sham group) was treated with 0.9% normal saline, and group 4 (control group) was left with no treatment. All rabbits were euthanized 2 and 4 weeks after surgery, and tendon samples were harvested. The histopathology was assessed by hematoxylin-eosin, Masson’s trichrome, and Vangieson’s dye, and tendon structure, fiber arrangement, cell nuclei, tissue inflammation, vascularity (angiogenesis), and density were surveyed. Results: The tendon healing process in the BMMSC and ADSC groups revealed better regeneration than the control and sham groups (P≤0.05). Significant changes (P≤0.05) in some microscopic parameters were seen by comparing the BMMSC and ADSC groups. Conclusion: According to the present study, the injection of mesenchymal stem cells (BMMSCs or ADSCs) showed beneficial results in tendon tissue healing. Furthermore, ADSCs showed better regeneration of the injured tendon tissue than BMMSCs.

BMSCs-derived Mitochondria Improve Osteoarthritis by Ameliorating Mitochondrial Dysfunction and Promoting Mitochondrial Biogenesis in Chondrocytes

Bone marrow mesenchymal stem cells (BMSCs)-derived exosomes and microvesicles can effectively improve knee osteoarthritis. We found that microvesicles performed a superior effect on improving mitochondrial function in chondrocytes than exosomes, which may be related to the ability of microvesicles carrying active mitochondria to replace damaged ones in chondrocytes. This study investigated the therapeutic effect of direct mitochondrial transplantation (MT) on knee osteoarthritis. IL-1β stimulated the osteoarthritis phenotype of rat chondrocytes, and the effect of BMSCs-derived mitochondria transplantation was observed in vitro. Knee osteoarthritis rat model was established by collagenase induction to observe the effect of intra-articular injection of mitochondria. Results showed that the mitochondria of BMSCs could be ingested by rat chondrocytes via co-incubation in vitro, and significantly improved osteoarthritis phenotype and mitochondrial function, and inhibited chondrocytes apoptosis. In vivo, BMSCs-derived mitochondria could be ingested by cartilage via intra-articular injection, ameliorated pathological cartilage injury, suppressed inflammation, inhibited chondrocytes apoptosis, and improved osteoarthritis phenotype. In addition, MT promoted mitochondrial biogenesis in chondrocytes by activating PGC-1α signaling. All above results suggest that BMSCs-derived mitochondria transplantation ameliorates knee osteoarthritis by improving chondrocytes mitochondrial dysfunction and promoting mitochondrial biogenesis.

Mechanism of Baicalein in Brain Injury After Intracerebral Hemorrhage by Inhibiting the ROS/NLRP3 Inflammasome Pathway.

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke with high disability/mortality. Baicalein has strong anti-inflammatory activity. This study aims to explore the mechanism of baicalein on brain injury after ICH. The model of brain injury after ICH was established by collagenase induction, followed by the evaluation of neurological severity, brain water content, the degenerated neurons, neuronal apoptosis, and reactive oxygen species (ROS). The ICH model was treated with baicalein or silencing NLRP3 to detect brain injury. The expression of NLRP3 inflammasome was detected after treatment with ROS scavenger. The expressions of oxidative stress markers and inflammatory factors were detected, and the levels of components in NLRP3 inflammasome were detected. Baicalein reduced the damage of nervous system, lesion surface, brain water content, and apoptosis. Baicalein inhibited malondialdehyde and increased IL-10 by inhibiting ROS in brain tissue after ICH. Baicalein inhibited the high expression of NLRP3 inflammasome in ICH. ROS scavenger inhibited the NLRP3 inflammatory response by inhibiting ROS levels. Silencing NLRP3 alleviated the brain injury after ICH by inhibiting excessive oxidative stress and inflammatory factors. Overall, baicalein alleviated the brain injury after ICH by inhibiting ROS and NLRP3 inflammasome.

Intratendon delivery of leukocyte-rich platelet-rich plasma at early stage promotes tendon repair in a rabbit Achilles tendinopathy model.

Tendinopathy is a great obstacle in clinical practice due to its poor regenerative capacity. The influence of different stages of tendinopathy on effects of leukocyte-rich platelet-rich plasma (Lr-PRP) has not been elucidated. The aim of this study is to investigate the optimal time point for delivery of Lr-PRP on tendinopathy. A tendinopathy model was established by local collagenase injection on the rabbit Achilles tendon. Then after collagenase induction, following treatments were applied randomly on the lesion: (a) 200 μl of Lr-PRP at 1 week (PRP-1 group), (b) 200 μl of saline at 1 week (Saline-1 group), (c) 200 μl of Lr-PRP at 4 weeks (PRP-2 group), and (d) 200 μl of saline at 4 weeks (Saline-2 group). Six weeks after collagenase induction, outcomes were assessed by magnetic resonance imaging, cytokine quantification, gene expression, histology, and transmission electron microscopy. Our results demonstrated that PRP-1 group had the least cross-sectional area and lesion percent of the involved tendon, as well as the lowest signal intensity in magnetic resonance imaging among all groups. However, the PRP-2 group showed larger cross-sectional area than saline groups. Enzyme-linked immunosorbent assay indicated that PRP-1 group had a higher level of interleukin-10 but lower level of interleukin-6 when compared with PRP-2 and saline groups. Meanwhile, the highest expression of collagen (Col) 1 in PRP-1 and Col 3, matrix metalloproteinase (MMP)-1, and MMP-3 in PRP-2 was found. Histologically, the PRP-1 showed better general scores than PRP-2, and no significant difference was found between the PRP-2 and saline groups. For transmission electron microscopy, PRP-1 had the largest mean collagen fibril diameter, and the PRP-2 group showed even smaller mean collagen fibril diameter than saline groups. In conclusion, intratendon delivery of Lr-PRP at early stage showed beneficial effect for repair of tendinopathy but not at late stage. For translation of our results to clinical circumstances, further studies are still needed.

Implication of IL-17 in Bone Loss and Structural Damage in Inflammatory Rheumatic Diseases.

Proinflammatory cytokines play an important role in the systemic and focal bone loss associated with chronic inflammatory diseases. Targeting these cytokines with biologics and small molecules has led to a major improvement of the bone health of patients with inflammatory arthritis. Cytokines from the IL-17 family have been shown to be involved in the pathogenesis of several diseases such as spondyloarthritis, psoriatic arthritis, or psoriasis. IL-17A has been the first described and the most studied. The recent development of targeted therapies against IL-17A or its receptor and their efficacy has confirmed the importance of this cytokine in the development of inflammatory diseases. The aim of this review was to describe the effects of the IL-17 family and more particularly of IL-17A on bone and cartilage tissues. At the cellular level, IL-17A is proosteoclastogenic whereas its effects on osteoblasts depend on the stage of differentiation of these cells. In vivo, IL-17A is not required for normal bone homeostasis but plays an important role in bone loss notably in an ovariectomized mouse model of osteoporosis. Preliminary data from clinical trials showed a stabilisation of bone density in patients treated with anti-IL-17A antibodies. IL-17A plays a central role in the cartilage damage through the induction of collagenases and by decreasing the expression of their inhibitors in synergy with the other proinflammatory cytokines. The prevention of structural damage by anti-IL-17A therapies has been demonstrated in several pivotal clinical trials. Overall, blocking the IL-17A pathway seems to have a positive effect on the bone and cartilage damage observed in inflammatory arthritis. Differences and specificity of these effects compared to those already described with other biologics such as anti-TNF therapies remain to be explored.

A Brief History of IL-1 and IL-1 Ra in Rheumatology.

The history of what, in 1979, was called interleukin-1 (IL-1), orchestrator of leukocyte inter-communication, began many years before then, initially by the observation of fever induction via the endogenous pyrogen (EP) (1974) and then in rheumatology on the role in tissue destruction in rheumatoid diseases via the induction of collagenase and PGE2 in human synovial cells by a mononuclear cell factor (MCF) (1977). Since then, the family has exploded to presently 11 members as well as many membrane-bound and soluble receptor forms. The discovery of a natural Interleukin-1 receptor antagonist (IL-1Ra) in human biological fluids has highlighted the importance of IL-1 and IL-1Ra in human diseases. Evidence delineating its role in autoinflammatory syndromes and the elucidation of the macromolecular complex referred to as “inflammasome” have been instrumental to our understanding of the link with IL-1. At present, the IL-1blockade as therapeutic approach is crucial for many hereditary autoinflammatory diseases, as well as for adult-onset Still’s disease, crystal-induced arthropathies, certain skin diseases including neutrophil-triggered skin diseases, Behçet’s disease and deficiency of IL-1Ra and other rare fever syndromes. Its role is only marginally important in rheumatoid arthritis and is still under debate with regard to osteoarthritis, type 2 diabetes mellitus, cardiovascular diseases and cancer. This brief historical review focuses on some aspects of IL-1, mainly IL-1β and IL-Ra, in rheumatology. There are many excellent reviews focusing on the IL-1 family in general or with regard to specific diseases or biological discoveries.

Matrix metalloproteinases and their endogenous regulators in squamous cervical carcinoma (A review of own results)

Own results of long-term studies of expression of matrix metalloproteinases (MMPs) and their endogenous regulators examined in fibroblasts transformed by oncogene E7 HPV16 (TF), immortalized fibroblasts (IF), cell lines associated with HPV16 and HPV18, and tumor tissue samples from patients with squamous cervical carcinoma (SCC) associated with HPV16 have been summarized. Transfection of fibroblasts with the E7 HPV16 oncogen was accompanied by induction of collagenase (MMP-1, MMP-14) and gelatinase (MMP-9) gene expression and the increase in catalytic activity of these MMP, while gelatinase MMP-2 expression remained unchanged. MMP expression correlated with the tumorigenic of transformed clones. Expression of MMP-9 was found only in TF. In TF expression mRNA TIMP-1 decreased, while expression of the genatinase inhibitor, TIMP-2, increased. Collagenase activity and expression of the MMP-14 (collagenase) mRNA increased, while gelatinase activity remained unchanged. The destructive potential of TF is associated with induction of collagenases, gelatinase MMP-9 and decreased levels of MMP inhibitors. MMP-9 may serve as a TF marker. Invasive potential of cell lines associated with HPV18 (HeLa and S4-1) was more pronounced than that of cell lines associated with HPV16 (SiHa and Caski). In most cell lines mRNA levels of collagenases MMP-1 and MMP-14 and the activator (uPA) increased, while gelatinase MMP-2 mRNA and tissue inhibitors mRNAs changed insignificantly. MMP-2 activity significantly increased in Caski and HeLa cell lines, while MMP-9 expression in these cell lines was not detected. The comparative study of expression MMP of and their endogenous regulators performed using SCC tumor samples associated with HPV16 has shown that the invasive and metastatic potentials of tumor tissue in SCC is obviously associated with increased expression of collagenases MMP-1, MMP-14 and gelatinase MMP-9, as well as decreased expression of inhibitors (TIMP-1 and TIMP-2), and to a lesser extent with increased expression of MMP-2. MMP-1 and MMP-9 can serve as markers of invasive and metastatic potential of the SCC tumor. The morphologically normal tissue adjacent to the tumor tissue is characterized by significant expression of MMP-1, MMP-2, and MMP-9. This also contributes to the increased destructive potential of the tumor.

Effects of Egg Shell Membrane Hydrolysates on UVB-radiation-induced Wrinkle Formation in SKH-1 Hairless Mice.

This study was conducted to examine the effect of egg shell membrane hydrolysates (ESMH) on wrinkle, UV, and moisture protection for cosmetic use. ESMH were fragmented as whole ESMH (before fractioning), Fraction I (> 10 kDa), Fraction II (3-10 kDa), and Fraction III (< 3 kDa). In order to test whether fractionated ESMH can be used for functional cosmetic materials, we examined not only the level of hyaluronic acid and collagen production, but also the MMP-1 activity using a HaCaT and CCD-986Sk cell line. Our study treated each sample of fractionated ESMH with different concentrations (0.01, 0.1, 1 mg/mL). In our in vivo research, we used hairless mice that had been exposed to UV-B to induce wrinkles for 7 wk, then applied Fraction I to the treatment group for 5 wk and then tested skin thickness, minimum erythema dose and moisture content. In addition, Fraction I was high in collagen and HA biosynthesis and it was better than TGF-β in improving of the skin. When TNF-α caused MMP-1 activity in the CCD-986Sk cells, the whole ESMH and Fraction I proved to be effective in hindering the induction of collagenase depending on the concentration, and also showed outstanding effects in the suppression of skin aging. We found that the treatment group mice’s UV-B radiation-induced skin damage was largely mitigated compared to that of the non-treatment group mice. Thus, we have concluded that EMSH helps to mitigate UV-B radiation-induced wrinkles, collagen, HA, MMP-1 activity and can be used for functional cosmetic materials.

Matrix metalloproteinases and their endogenous regulators in squamous cervical carcinoma (review of the own data)

Expression of matrix metalloproteinases (MMPs) and their endogenous regulators has been investigated in squamous cervical carcinoma (SCC). The study included (i) immortalized fibroblasts (IF) and three clones of fibroblasts transformed by oncogene E7 HPV-16 (TF); (ii) cell lines associated with HPV-16 and HPV-18; (iii) tumor tissue samples from patients with SCC, associated with gene E7 HPV-16. Transfection of fibroblasts with the E7 HPV16 oncogen was accompanied by induction of collagenase (MMP-1, MMP-14) and gelatinase (MMP-9) gene expression and the increase in catalytic activity of these MMP, while gelatinase MMP-2 expression remained unchanged. Expression of MMP-9 was found only inTF. MMP-9 may serve as a TF marker. In TF expression mRNA TIMP-1 was decreased. The level of free endogenous inhibitors in TF was significantly lower then the level in IF. Expression MMP correlated with the tumorigenic potential of TF. Invasive potential of cell lines associated with HPV18 (HeLa and S4-1) was more pronounced than that of cell lines associated with HPV16 (SiHa and Caski). The cell lines differed substantially in the level of expression of MMPI and their endogenous regulators. In most cell lines mRNA levels of collagenases MMP-1 and MMP-14 and the activator (uPA) increased, while gelatinase MMP-2 mRNA and tissue inhibitors mRNAs changed insignificantly. MMP-9 expression in cell lines was not detected. Results of studies on these cell lines suggest existence of an imbalance in the system enzyme/inhibitor/activator, that increases destructive potential of these cells. The study of expression of MMP and their endogenous regulators performed using SCC tumor samples associated with HPV16 has shown that the invasive and metastatic potentials of tumor tissue in SCC is obviously determined by the increase of expression of collagenases MMP-1, MT1-MMP and gelatinase MMP-9, decreased expression of inhibitors (TIMP-1 and TIMP-2), and to a lesser extent to increased expression of MMP-2. MMP-1 and MMP-9 can serve as markers of invasive and metastatic potential of the SCC tumor. In adjacent to the tumor normal tissue revealed a significant expression of MMP-1,-2,-9.

Comparison of the effect of intra‐tendon applications of recombinant human platelet‐derived growth factor‐BB, platelet‐rich plasma, steroids in a rat achilles tendon collagenase model

This study compared the effect of intra-tendon (IT) delivery of recombinant human platelet-derived growth factor-BB (rhPDGF-BB), platelet-rich plasma (PRP) and corticosteroids in a rat tendinopathy model. Seven days after collagenase induction of tendinopathy, a 30-µl IT injection was administered. Treatments included: saline; 3 µg rhPDGF-BB; 10 µg rhPDGF-BB; PRP; and 300 µg triamcinolone acetonide (TCA). Outcomes were assessed 7 and 21 days after treatment. All groups exhibited good to excellent repair. Relative to saline, cell proliferation increased 65% in the 10 µg rhPDGF-BB group and decreased 74% in the TCA group; inflammation decreased 65% in the TCA group. At 7 days, maximum load-to-failure was increased in the 3 µg rhPDGF-BB group relative to saline, PRP, and TCA (p < 0.025). On day 21, maximum load-to-rupture was increased in the 10 µg rhPDGF-BB group relative to saline, PRP, and TCA (p < 0.035) and in the 3 µg rhPDGF-BB group compared to saline and TCA (p < 0.027). Stiffness in the 10 µg rhPDGF-BB group was increased compared to saline, PRP, and TCA (p < 0.038). Histology demonstrated similar repair in all groups. PRP and TCA did not improve mechanical properties compared to saline. Injections of rhPDGF-BB increased maximum load-to-failure (3 and 10 µg) and stiffness (10 µg) relative to controls and commonly used treatments. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:145-150, 2014.

SAT0003 Microarray studies of synovial tissue of early human (CHECK) and experimental OA identify pathways and processes associated with cartilage damage

BackgroundMany osteoarthritis (OA) patients show synovial inflammation, even relatively early during the disease. Mechanisms through which synovial activation contributes to the joint pathology that characterizes OA, are not known.ObjectivesTo identify...

Dose–response effect of an intra‐tendon application of recombinant human platelet‐derived growth factor‐BB (rhPDGF‐BB) in a rat Achilles tendinopathy model

The purpose of this study was to assess whether intra-tendon delivery of recombinant human platelet-derived growth factor-BB (rhPDGF-BB) would improve Achilles tendon repair in a rat collagenase-induced tendinopathy model. Seven days following collagenase induction of tendinopathy, one of four intra-tendinous treatments was administered: (i) Vehicle control (sodium acetate buffer), (ii) 1.02 µg rhPDGF-BB, (iii) 10.2 µg rhPDGF-BB, or (iv) 102 µg rhPDGF-BB. Treated tendons were assessed for histopathological (e.g., proliferation, tendon thickness, collagen fiber density/orientation) and biomechanical (e.g., maximum load-to-failure and stiffness) outcomes. By 7 days post-treatment, there was a significant increase in cell proliferation with the 10.2 and 102 µg rhPDGF-BB-treated groups (p=0.049 and 0.015, respectively) and in thickness at the tendon midsubstance in the 10.2 µg of rhPDGF-BB group (p=0.005), compared to controls. All groups had equivalent outcomes by Day 21. There was a dose-dependent effect on the maximum load-to-failure, with no significant difference in the 1.02 and 102 µg rhPDGF-BB doses but the 10.2 µg rhPDGF-BB group had a significant increase in load-to-failure at 7 (p=0.003) and 21 days (p=0.019) compared to controls. The rhPDGF-BB treatment resulted in a dose-dependent, transient increase in cell proliferation and sustained improvement in biomechanical properties in a rat Achilles tendinopathy model, demonstrating the potential of rhPDGF-BB treatment in a tendinopathy application. Consequently, in this model, data suggest that rhPDGF-BB treatment is an effective therapy and thus, may be an option for clinical applications to treat tendinopathy.

Microarray studies of synovial specimen of early human (check) and experimental OA identify pathways and processes associated with cartilage damage

Purpose: Over 50% of osteoarthritis (OA) patients show synovial inflammation, even relatively early during the disease. However, the mechanisms through which this synovial activation contributes to the irreversible joint pathology that characterizes OA, are not known. In the present study we used microarray analysis of synovial tissue of early OA patients and of experimental OA, to identify common pathways that determine cartilage damage in this disease. Methods: From a subpopulation of patients that entered the CHECK Cohort study (Cohort Hip and Cohort Knee), synovial biopsies were collected. CHECK is a prospective 10-year follow-up study that was initiated by the Dutch Arthritis Association on participants with early osteoarthritis-related complaints of hip and/or knee. Radiographs are taken in a standardized manner and scored (Kellgren&Lawrence KL) at inclusion (n=18). In addition, biopsies of 7 control synovia were collected. A longitudinal expression analysis was performed on murine synovial tissue at day 7, day 21 and day 42 after induction of collagenase induced OA (CIOA). CIOA was induced by intra-articular injection of collagenase, which causes joint instability, and contra lateral knee joints served as controls. Initial analysis of microarray data was performed using Partek software and functional annotation clustering (FAC) and pathway analysis was done using DAVID. Results: Gene expression profiles of control synovia were compared to CHECK synovia. Analysis using DAVID indicated enrichment of several biological processes and signaling pathways, including regulation of macrophage differentiation, innate immune responses, cell migration, TGFβ-, BMP- and wnt-signaling. This indicates clear activation of the synovium in the CHECK patients compared to controls. Next we compared synovial tissue of CHECK-patients with radiological damage (KL≥1) with CHECK-patients without joint damage (KL=0). Among the top 30 genes that were strongest associated with cartilage damage were MMP-1 (18-fold), MMP-3 (10-fold), S100A8 (6-fold) and cartilage glycoprotein-39 (6-fold), all of which have been associated with cartilage damage. Immunohistochemical staining revealed that expression of MMP-1 and MMP-3 was highest in the synovial lining layer. FAC analysis showed that, among others, response to wounding, chemotaxis, innate immune response and metalloproteases were strongly and significantly enriched and thus associated with joint damage. Pathway analysis demonstrated that in the synovium of patients with joint damage the complement-activation pathway, TGFβ- and BMP-signaling and TLR-activation were significantly upregulated. These results were further underlined by analysis of synovium from experimental OA. Among the genes that were strongly upregulated on all 3 time points after induction were MMP-3 (6-fold), MMP-13 (16-fold), MMP-14 (6-fold) and COMP (13-fold). Again, wound healing, innate immune response and metalloproteases were significantly enriched, as were the complement pathway, the TLR-, TGFβ, BMP and wnt-signaling pathways. In a recent publication, complement was demonstrated to be essential in experimental OA. We therefore determined whether the synovium expressed complement activating proteins, and found a strong upregulation of COMP, lumican, osteomodulin, biglycan, decorin and fibromodulin. In addition, biglycan expression was strongly enhanced (2.5-fold) in human CHECK-samples from patients with joint damage. Conclusions: All in all, these data suggest an active role for the synovium in OA pathology, and identifies pathways that are likely to be involved. One of the strongest associations was of the complement-pathway with cartilage damage. In addition, TGFβ-, BMP- and wnt-signaling in the synovium, may contribute to further joint damage. The enhanced expression of cartilage damaging MMP-1, MMP-3 and MMP-13 again suggests an active role of the synovium in OA pathology. Future studies will focus on association of gene expression patterns with progression of damage of CHECK-patients.

A collagenase gel/physical defect model for controlled induction of superficial digital flexor tendonitis

A consistent and clinically relevant model for the induction of core lesions confined to the mid-metacarpal superficial digital flexor tendon (SDFT) has not been previously reported. Injection of bacterial collagenase is commonly used but often results in large, irregular and inconsistent lesions that disrupt the superficial tendon layers and epitenon. To develop and evaluate a new injection technique for collagenase induction of SDFT injury. Collagenase gel was injected into a physical columnar defect created by longitudinally placing a curved 16 gauge 8.89 cm needle in the mid-metacarpal SDFT in a randomly selected forelimb of 10 horses. A placebo treatment injection was performed 1 week later. Serial ultrasound examinations were performed. Horses were subjected to euthanasia at 2 (n = 2), 4 (n = 2), 8 (n = 4) and 16 (n = 2) weeks post treatment injection. Post mortem magnetic resonance imaging and histological analysis were performed. Gene expression (18S, SCX, TNC, TNMD, COL1A1, COL3A1, COMP, DCN, MMP1, MMP3 and MMP13), total DNA, glycosaminoglycan and collagen content were determined for experimental tendons (n = 10) and unaffected tendons (n = 9). Mid-metacarpal SDFT core lesion induction was successful in all tendons with consistent lesion cross-sectional area and minimal epitenon disruption. Histology confirmed loss of normal tendon architecture after tendonitis induction and subsequent healing of the tendon core lesion. Compared with gene expression in unaffected tendons, several tested genes were significantly upregulated (COL1A1, COL3A1, TNMD, SCX, TNC, MMP13), while others showed significant downregulation (COMP, DCN, and MMP3). Compared with the previously used direct injection of collagenase, this injection technique was easily performed and induced more consistent lesions that were mid-metacarpal and did not disrupt the epitenon. This model will allow for objective assessment of therapies for tendon regeneration in the mid-metacarpal SDFT prior to clinical trials and routine clinical application.

Protein Kinase C Isoforms ζ and ι Mediate Collagenase Expression and Cartilage Destruction via STAT3- and ERK-dependent c-fos Induction

The protein kinase C (PKC) signaling pathway is a major regulator of cellular functions and is implicated in pathologies involving extracellular matrix remodeling. Inflammatory joint disease is characterized by excessive extracellular matrix catabolism, and here we assess the role of PKC in the induction of the collagenases, matrix metalloproteinase (MMP)-1 and MMP-13, in human chondrocytes by the potent cytokine stimulus interleukin-1 (IL-1) in combination with oncostatin M (OSM). IL-1 + OSM-stimulated collagenolysis and gelatinase activity were ameliorated by pharmacological PKC inhibition in bovine cartilage, as was collagenase gene induction in human chondrocytes. Small interfering RNA-mediated silencing of PKC gene expression showed that both novel (nPKC delta, nPKC eta) and atypical (aPKC zeta, aPKC iota) isoforms were involved in collagenase induction by IL-1. However, MMP1 and MMP13 induction by IL-1 + OSM was inhibited only by aPKC silencing, suggesting that only atypical isoforms play a significant role in complex inflammatory milieus. Silencing of either aPKC led to diminished IL-1 + OSM-dependent extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription (STAT) 3 phosphorylation, and c-fos expression. STAT3 gene silencing or ERK pathway inhibition also resulted in loss of IL-1 + OSM-stimulated c-fos and collagenase expression. Silencing of c-fos and c-jun expression was sufficient to abrogate IL-1 + OSM-stimulated collagenase gene induction, and overexpression of both c-fos and c-jun was sufficient to drive transcription from the MMP1 promoter in the absence of a stimulus. Our data identify atypical PKC isozymes as STAT and ERK activators that mediate c-fos and collagenase expression during IL-1 + OSM synergy in human chondrocytes. aPKCs may constitute potential therapeutic targets for inflammatory joint diseases involving increased collagenase expression.

Diversity of Denizens of the Atherosclerotic Plaque

The atherosclerotic plaque typically harbors cells of several lineages whose conversations, mediated by extracellular or cell surface–associated messengers, influence decisively the biology and clinical consequences of the lesion. Early vascular biology studies defined the resting state of the endothelium, characterized by the elaboration of antithrombotic and vasodilatory mediators. The activated endothelium recruits inflammatory leukocytes, favors clot accumulation, participates in angiogenesis, and can influence the behavior of subjacent smooth muscle cells in ways that favor atherogenesis and vasoconstriction (Figure). More recently, we have come to appreciate that the endothelial cell not only can exhibit a spectrum of functions, but that some may arise postnatally from bone marrow–derived precursors.1 Thus, the heterogeneity of endothelial cells depends not only on the mutability of their function but also on their origin. The diversity of endothelium depends not only on lineage but also location, with increasingly well-understood differences between arterial, microvascular, and venous endothelial cells. Figure. Heterogeneity of major cell types in atherosclerotic plaques. Vascular biologists have long recognized heterogeneity of endothelial cells and smooth muscle cells, now understood to result from local mediator milieu, biomechanical stimuli, and different embryological origins. Indeed, recent data suggest that both of these intrinsic vascular cell types can arise in postnatal life from bone marrow–derived precursors. Immunological dogma recognizes several T-cell populations, exemplified here by the Th1 and Th2 subsets, which on the balance exert opposing influences on atherogenesis. New data now establish the relevance to atherosclerosis and hyperlipidemia of monocyte heterogeneity. Monocytes that bear high levels of the markers Ly6c/Gr-1 and P-selectin glycoprotein ligand exhibit more proinflammatory functions than their …

Differential Toll-like receptor-dependent collagenase expression in chondrocytes

Objectives:To characterise the catabolic response of osteoarthritic chondrocytes to Toll-like receptor (TLR) ligands.Methods:Induction of the collagenases, matrix metalloproteinase (MMP)1 and MMP13, by TLR ligands was assessed in chondrocytes by real-time...

Induction of Host Matrix Metalloproteinases byBorrelia burgdorferiDiffers in Human and Murine Lyme Arthritis

Matrix metalloproteinases (MMPs) are induced from host tissues in response to Borrelia burgdorferi. Upregulation of MMPs may play a role in the dissemination of the organism through extracellular matrix tissues, but it can also result in destructive pathology. Although mice are a well-accepted model for Lyme arthritis, there are significant differences compared to human disease. We sought to determine whether MMP expression could account for some of these differences. MMP expression patterns following B. burgdorferi infection were analyzed in primary human chondrocytes, synovial fluid samples from patients with Lyme arthritis, and cartilage tissue from Lyme arthritis-susceptible and -resistant mice by using a gene array, real-time PCR, an enzyme-linked immunosorbent assay, and immunohistochemistry. B. burgdorferi infection significantly induced transcription of MMP-1, -3, -13, and -19 from primary human chondrocyte cells. Transcription of MMP-10 and tissue inhibitor of metalloprotease 1 was increased with B. burgdorferi infection, but protein expression was only minimally increased. The synovial fluid levels of MMPs from patients with high and low spirochete burdens were consistent with results seen in the in vitro studies. B. burgdorferi-susceptible C3H/HeN mice infected with B. burgdorferi showed induction of MMP-3 and MMP-19 but no other MMP or tissue inhibitor of metalloprotease. As determined by immunohistochemistry, MMP-3 expression was increased only in chondrocytes near the articular surface. The levels of MMPs were significantly lower in the more Lyme arthritis-resistant BALB/c and C57BL/6 mice. Differences between human and murine Lyme arthritis may be related to the lack of induction of collagenases, such MMP-1 and MMP-13, in mouse joints.

UVA/UVA1 phototherapy and PUVA photochemotherapy in connective tissue diseases and related disorders: a research based review.

BackgroundBroad-band UVA, long-wave UVA1 and PUVA treatment have been described as an alternative/adjunct therapeutic option in a number of inflammatory and malignant skin diseases. Nevertheless, controlled studies investigating the efficacy of UVA irradiation in connective tissue diseases and related disorders are rare.MethodsSearching the PubMed database the current article systematically reviews established and innovative therapeutic approaches of broad-band UVA irradiation, UVA1 phototherapy and PUVA photochemotherapy in a variety of different connective tissue disorders.ResultsPotential pathways include immunomodulation of inflammation, induction of collagenases and initiation of apoptosis. Even though holding the risk of carcinogenesis, photoaging or UV-induced exacerbation, UVA phototherapy seems to exhibit a tolerable risk/benefit ratio at least in systemic sclerosis, localized scleroderma, extragenital lichen sclerosus et atrophicus, sclerodermoid graft-versus-host disease, lupus erythematosus and a number of sclerotic rarities.ConclusionsBased on the data retrieved from the literature, therapeutic UVA exposure seems to be effective in connective tissue diseases and related disorders. However, more controlled investigations are needed in order to establish a clear-cut catalogue of indications.

UVA1-induced decrease in dermal neuron-specific enolase (NSE) in acrosclerosis.

Besides its role in small-cell carcinoma of the lung, elevated serum levels of neuron-specific enolase (NSE) have recently been reported to be associated with autoimmune rheumatic disorders such as systemic sclerosis. Serum NSE seems to correlate with disease activity as well as Rodnan skin score. The aim of the study was to assess the neuromodulatory effects of conventional UVA1 phototherapy on acrosclerosis as an additional mechanism besides an assumed T cell apoptosis, collagenase induction and angiogenesis. Punch skin biopsies of acrosclerotic skin lesions taken before and after treatment from four patients were evaluated immunohistochemically for the presence of NSE, S100 and neurofilament. Immunolabeling revealed a UVA-induced decrease in dermal NSE expression. In contrast, no alteration in neurofilament+ cells could be detected. In line with the findings of a previous investigation, a high number of S100+ cells were detected in most specimens. We demonstrated a UVA1-induced reduction in dermal NSE levels correlating with a softening of former sclerotic lesions. Even though the origin and the functional mechanisms remain obscure, NSE might be relevant directly within sclerotic skin lesions and may possibly be used as a diagnostic marker at least in SSc-associated acrosclerotic skin.