endothelin-1 and Osteoarthritis

Mounting evidence suggests reconceptualizing osteoarthritis (OA) as an inflammatory disorder. Trauma and obesity, the common risk factors of OA, could trigger the local or systemic inflammatory cytokines cascade. Inflammatory bone loss has been well documented; yet it remains largely unknown about the link between the inflammation and hypertrophic changes of subchondral bone seen in OA, such as osteophytosis and sclerosis. Amid a cohort of inflammatory cytokines, endothelin-1 (ET-1) could stimulate the osteoblast-mediated bone formation in both physiological (postnatal growth of trabecular bone) and pathological conditions (bone metastasis of prostate or breast cancer). Also, ET-1 is known as a mitogen and contributes to fibrosis in various organs, e.g., skin, liver, lung, kidney heart and etc., as a result of inflammatory or metabolic disorders. Subchondral bone sclerosis shared the similarity with fibrosis in terms of the overproduction of collagen type I. We postulated that ET-1 might have a hand in the subchondral bone sclerosis of OA. Meanwhile, ET-1 was also able to stimulate the production of matrix metalloproteinase (MMP)-1 and 13 by articular chondrocytes and synoviocytes, by which it might trigger the enzymatic degradation of articular cartilage. Taken together, ET-1 signaling may play a role in destruction of bone-cartilage unit in the pathogenesis of OA; it warrants further investigations to potentiate ET-1 as a novel diagnostic biomarker and therapeutic target for rescue of OA.

Topics: Bone Remodeling; Cartilage; Chondrocytes; Cytokines; Endothelin-1; Humans; Matrix Metalloproteinase 1; Matrix Metalloproteinase 13; Osteoarthritis; Osteogenesis; Sclerosis; Signal Transduction

Osteoarthritis (OA) is a degenerative and heterogeneous disease that affects all types of joint structures. Current clinical treatments are only symptomatic and do not manage the degenerative process in animals or humans. One of the new orthobiological treatment strategies being developed to treat OA is the use of drug delivery systems (DDS) to release bioactive molecules over a long period of time directly into the joint to limit inflammation, control pain, and reduce cartilage degradation. Two vasoactive peptides, endothelin-1 and bradykinin, play important roles in OA pathogenesis. In this study, we investigated the effects of two functionalized nanogels as DDS. We assessed the effect of chitosan functionalized with a type A endothelin receptor antagonist (BQ-123-CHI) and/or hyaluronic acid functionalized with a type B

Topics: Animals; Bradykinin Receptor Antagonists; Cartilage; Cartilage, Articular; Cells, Cultured; Chondrocytes; Endothelin-1; Horses; Humans; Interleukin-1beta; Nanogels; Organoids; Osteoarthritis

This study aimed to investigate the role of endothelin-1 (ET-1), originally known as the potent vasoconstrictor, and its receptors in chondrocyte senescence and osteoarthritis (OA) development.. Temporal changes of ET-1 and its receptors with OA development were characterized in a posttraumatic OA (PTOA) mouse model at time zero, 1-month and 4-month after surgical induction via destabilization of medial meniscus (DMM). A transgenic ET-1 overexpression (TET-1) mouse model was deployed to assess the impact of upregulated ET-1 on chondrocyte senescence and cartilage degradation. Effects of endothelin receptor blockade on chondrocyte senescence and OA development were further examined both in vitro and in vivo.. Local expression of ET-1 in subchondral bone and synovium upregulated after DMM with an increase of plasma ET-1 level from 3.18 ± 0.21 pg/ml at time zero to 6.47 ± 0.34 pg/ml at 4-month post-surgery. Meanwhile, endothelin type B receptor (ET. ET-1 could induce chondrocytes senescence and cartilage damages via ET

Topics: Animals; Antioxidants; Ascorbic Acid; Cartilage, Articular; Cellular Senescence; Chondrocytes; Cyclin-Dependent Kinase Inhibitor p16; Disease Models, Animal; Endothelin-1; Mice, Transgenic; Osteoarthritis; Receptors, Endothelin; Up-Regulation

Clearance of particles from the knee is an essential mechanism to maintain healthy joint homeostasis and critical to the delivery of drugs and therapeutics. One of the limitations in developing disease modifying drugs for joint diseases, such as osteoarthritis (OA), has been poor local retention of the drugs. Enhancing drug retention within the joint has been a target of biomaterial development, however, a fundamental understanding of joint clearance pathways has not been characterized. We applied near-infrared (NIR) imaging techniques to assess size-dependent in vivo clearance mechanisms of intra-articular injected, fluorescently-labelled polyethylene glycol (PEG-NIR) conjugates. The clearance of 2 kDa PEG-NIR (τ = 171 ± 11 min) was faster than 40 kDa PEG-NIR (τ = 243 ± 16 min). 40 kDa PEG-NIR signal was found in lumbar lymph node while 2 kDa PEG-NIR signal was not. Thus, these two conjugates may be cleared through different pathways, i.e. lymphatics for 40 kDa PEG-NIR and venous for 2 kDa PEG-NIR. Endothelin-1 (ET-1), a potent vasoconstrictor of vessels, is elevated in synovial fluid of OA patients but, its effects on joint clearance are unknown. Intra-articular injection of ET-1 dose-dependently inhibited the clearance of both 2 kDa and 40 kDa PEG-NIR. ET-1 caused a 1.63 ± 0.17-fold increase in peak fluorescence for 2 kDa PEG-NIR and a 1.85 ± 0.15-fold increase for 40 kDa PEG-NIR; and ET-1 doubled their clearance time constants. The effects of ET-1 were blocked by co-injection of ET receptor antagonists, bosentan or BQ-123. These findings provide fundamental insight into retention and clearance mechanisms that should be considered in the development and delivery of drugs and biomaterial carriers for joint diseases. STATEMENT OF SIGNIFICANCE: This study demonstrates that in vivo knee clearance can be measured using NIR technology and that key factors, such as size of materials and biologics, can be investigated to define joint clearance mechanisms. Therapies targeting regulation of joint clearance may be an approach to treat joint diseases like osteoarthritis. Additionally, in vivo functional assessment of clearance may be used as diagnostics to monitor progression of joint diseases.

Topics: Animals; Biocompatible Materials; Bosentan; Drug Carriers; Drug Liberation; Endothelin-1; Fluorescent Dyes; Injections, Intra-Articular; Kinetics; Knee Joint; Lymphatic Vessels; Male; Optical Imaging; Osteoarthritis; Peptides, Cyclic; Polyethylene Glycols; Rats; Rats, Sprague-Dawley; Synovial Fluid; Tissue Distribution

Oncostatin M (OSM) contributes to cartilage degeneration in osteoarthritis (OA) and was demonstrated to be expressed in OA osteoblasts. Endothelin‑1 (ET‑1) is implicated in the degradation of OA articular cartilage, and osteoblast proliferation and bone development. In the present study, the effects of ET‑1 on OSM expression in human OA osteoblasts were investigated, to the best of our knowledge, for the first time. Primary human OA osteoblasts were treated with ET‑1 (1, 5, 10, 20 and 30 nM) for 0.5, 1, 2, 3 and 4 h with or without the selective ETA receptor (ETAR) antagonist, BQ123, ETB receptor antagonist, BQ788 or the phosphatidylinositol 3‑kinase (PI3K) inhibitor, BKM120. ET‑1 treatment induced OSM mRNA expression, and the intracellular and secreted protein levels of OA osteoblasts in a dose‑dependent manner. This effect was suppressed by BQ123 and BKM120, but not BQ788 administration. In combination with electrophoretic mobility shift assays, deletional and mutational analyses on the activity of a human OSM promoter/luciferase reporter demonstrated that ET‑1 induced OSM expression in OA osteoblasts by trans‑activating the OSM gene promoter through specific binding of Ets‑1 to an Ets‑1 binding site in the OSM promoter in an ETAR‑ and PI3K‑dependent manner. Furthermore, ET‑1 treatment increased the expression of Ets‑1 in a dose‑dependent manner, however the knockdown of Ets‑1 suppressed the ET1‑induced expression of OSM in OA osteoblasts. In conclusion, the present study demonstrated that ET‑1 induces the expression of OSM in OA osteoblasts by trans‑activating the OSM gene promoter primarily through increasing the expression level of Ets‑1 in an ETAR‑ and PI3K‑dependent manner. The current study suggested novel insights into the mechanistic role of ET‑1 in the pathophysiology of OA.

Topics: Aminopyridines; Base Sequence; Binding Sites; Cells, Cultured; Endothelin-1; Genes, Reporter; Humans; Molecular Sequence Data; Morpholines; Oligopeptides; Oncostatin M; Osteoarthritis; Osteoblasts; Peptides, Cyclic; Piperidines; Promoter Regions, Genetic; Protein Binding; Proto-Oncogene Protein c-ets-1; RNA Interference; RNA, Messenger; RNA, Small Interfering; Transcriptional Activation

Osteoarthritis (OA), the most prevalent form of arthritis that results from breakdown of joint cartilage and underlying bone, has been viewed as a chronic condition manifested by persistence of inflammatory responses and infiltration of lymphocytes. Regulation of the inflammatory responses in synovial fibroblasts might be useful to prevent the development and deterioration of osteoarthritis. WY-14643, a potent peroxisome proliferator activator receptor-α (PPAR-α) agonist, has been described to beneficially regulate inflammation in many mammalian cells. Here, we investigate the potential anti-inflammatory role of WY-14643 in lipopolysaccharide (LPS)-induced synovial fibroblasts. WY-14643 greatly inhibited the production of NO and PGE2 induced by LPS. In addition, the mRNA expression of intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), endothelin-1 (ET-1), and tissue factor (TF) was significantly suppressed by WY-14643, as well as the secretion of pro-inflammatory cytokines including interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1). Furthermore, the transcription activity and nuclear translocation of NF-kB were found to be markedly decreased by WY-14643, while the phosphorylation of IkB was enhanced, indicating that the anti-inflammatory role of WY-14643 was meditated by NF-kB-dependent pathway. The application of WY-14643 failed to carry out its anti-inflammatory function in PPAR-α silenced cells, suggesting the role of PPAR-α. These findings may facilitate further studies investigating the translation of pharmacological PPAR-α activation into clinical therapy of OA.

Topics: Anti-Inflammatory Agents; Cells, Cultured; Chemokine CCL2; Dinoprostone; Endothelin-1; Fibroblasts; Humans; Intercellular Adhesion Molecule-1; Interleukin-1beta; Joint Capsule; Lipopolysaccharides; NF-kappa B; Nitric Oxide; Osteoarthritis; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Pyrimidines; Signal Transduction; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1

Recent understandings of the vascular contribution of pathophysiology of osteoarthritis (OA) mount new evidence of cross-talking between subchondral bone tissue and articular cartilage that might have a decisive role in a pathophysiology of Osteoarthritis (OA). These understandings include blood flow (or interstitial fluid) impairment in subchondral bone. With regard to the mentioned role of the vasculature, the absence of custom nourishing to articular cartilage, and established, vasoconstrictive role of endothelin-1 (ET-1) it was reasonable to assume that ET-1 has an inconvertible role in pathophysiology of OA. Another moment in pathophysiology of OA is apoptosis of subchondral osteocytes, what induces osteoclastic resorption and at least temporarily reduces the bony support for the overlying cartilage. Since regional dependence of this protein's expression was presumed, we suggest a regional division of subchondral bone by histomorphometrical analysis and quantification of identified protein by Real Time Polymerase Chain Reaction Analysis (RT-PCR). Obtained results should be compared to serum levels of soluble ET-1, what would enforce this methods validity. Herewith, a new screening marker of patients with osteoarthritis would be established. This would enable detection and follow-up of groups threatened by this, growing, cause of disability and decreased quality of life.

Topics: Bone and Bones; Endothelin-1; Humans; Osteoarthritis; Real-Time Polymerase Chain Reaction; RNA, Messenger

Topics: Adrenomedullin; Arthritis, Rheumatoid; Cells, Cultured; Depression, Chemical; Dose-Response Relationship, Drug; Endothelin-1; Humans; Immunohistochemistry; Interleukin-6; Osteoarthritis; Peptides; Synovial Fluid; Synovial Membrane

Degradation of the collagenous extracellular matrix by metalloproteases (MMPs) plays an important role in the pathogenesis of osteoarthritis (OA). Recently, it was suggested that endothelin 1 (ET-1), a potent vasoconstrictor, may be involved in MMP regulation. This study investigated the role of ET-1 in OA cartilage degradation.. We explored ET-1 expression and synthesis in normal and OA cartilage and synovial membrane by reverse transcription-polymerase chain reaction and immunohistochemistry. MMP-1 and MMP-13 gene expression and protein synthesis were investigated using Northern blotting and enzyme-linked immunosorbent assays. Additionally, ET-1-induced collagenase activity, type II collagen metabolites, and tissue inhibitor of metalloproteases 1 (TIMP-1) protein were evaluated.. We found expression and synthesis of ET-1, in situ, in both normal and OA cartilage and synovial membrane. We demonstrated that ET-1 induced gene expression and protein synthesis of both MMP-1 and MMP-13. These enzymes were produced in OA chondrocyte cultures, and the production increased in a dose-dependent manner in the presence of ET-1. In OA cartilage, ET-1 also induced type II collagen-derived neoepitopes concomitantly with an increase in collagenase activity and a decrease in TIMP-1 protein.. Our results provide strong evidence of the catabolic role of ET-1 in OA cartilage via MMP-1 and MMP-13 up-regulation. As well, ET-1 increased the net MMP/TIMP balance and secondarily increased collagen degradation. Hence, ET-1 becomes an attractive factor to target in the conception of new therapeutic approaches for OA and other diseases in which MMP-13 and MMP-1 actions are crucial in tissue alteration.

Topics: Adult; Cartilage; Collagen Type II; Collagenases; Endothelin-1; Epitopes; Gene Expression Regulation, Enzymologic; Humans; Matrix Metalloproteinase 1; Matrix Metalloproteinase 13; Middle Aged; Osteoarthritis; Synovial Membrane

To study the effect of endothelin-1 (ET-1) on the expression of intercellular adhesion molecule-1 (ICAM-1) by synovial fibroblasts derived from individuals with rheumatoid arthritis (RA) or osteoarthritis (OA).. The expression of ICAM-1 protein and the abundance of ICAM-1 mRNA in synovial fibroblasts derived from individuals with RA or OA, or healthy controls, was assessed by flow cytometry and Northern blot analysis, respectively. mRNA expression of ET type A (ETA) and ET type B (ETB) receptors was assessed by reverse transcription polymerase chain reaction.. Tumor necrosis factor-alpha (TNF-alpha) increased the expression of ICAM-1 by RA and OA fibroblasts. While ET-1 alone had no significant effect on ICAM-1 expression by either cell type, it inhibited the TNF-alpha induced increase in ICAM-1 expression, and this effect was more marked in RA fibroblasts. TNF-alpha also increased the amount of ICAM-1 mRNA in both cell types, and ET-1 inhibited this increase to a greater extent in RA fibroblasts than in OA fibroblasts. This inhibitory effect of ET-1 was reversed by addition of specific antagonist of ETA receptor. mRNA expression of ETA and ETB receptors was significantly greater in RA fibroblasts stimulated with TNF-alpha or even medium alone than in OA fibroblasts.. These results suggest that ICAM-1 expression by fibroblasts is regulated not only by proinflammatory cytokines such as TNF-alpha and interleukin-1beta, but also by the vasoactive peptide ET-1, and that ET-1 may play an important role in inflammatory responses, especially in rheumatoid synovitis.

Topics: Aged; Arthritis, Rheumatoid; Cells, Cultured; Cycloheximide; Dactinomycin; DNA Primers; Dose-Response Relationship, Drug; Down-Regulation; Endothelin-1; Female; Fibroblasts; Flow Cytometry; Humans; Immunoenzyme Techniques; Intercellular Adhesion Molecule-1; Interleukin-1; Male; Middle Aged; Osteoarthritis; Receptor, Endothelin A; Receptor, Endothelin B; Receptors, Endothelin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Synovial Membrane; Tumor Necrosis Factor-alpha

Immunoreactive (ir)-endothelin (ET)-1 concentrations in serum samples and synovial fluids from patients with rheumatoid arthritis were higher than concentrations in sera obtained from healthy volunteers. No significant difference in ir-ET-1 concentrations in synovial fluid was observed between rheumatoid arthritis patients and osteoarthritis patients. Cultured fluids of synovial cells collected from synovial tissues and leucocytes from synovial fluids of rheumatoid arthritis patients were studied to determine the origin of ir-ET-1 in synovial fluids. Ir-ET-1 was detected in the cultured fluids of synovial macrophage-like type A cells, but not in those of fibroblast-like type B cells from the synovial tissues or leucocytes from the synovial fluids. Longitudinal studies showed that the ir-ET-1 concentration in the cultured fluid reached a peak around 24 h after starting the culture. ET-1 secreted from macrophage-like synoviocytes may be involved in the pathogenesis of inflammatory arthritis.

Topics: Arthritis, Rheumatoid; Cells, Cultured; Endothelin-1; Female; Humans; Macrophages; Middle Aged; Osteoarthritis; Synovial Fluid