Expression Of ADAMTS-5 Research Articles

TGFβ loss activates ADAMTS-1-mediated EGF-dependent invasion in a model of esophageal cell invasion

The TGFβ signaling pathway is essential to epithelial homeostasis and is often inhibited during progression of esophageal squamous cell carcinoma. Recently, an important role for TGFβ signaling has been described in the crosstalk between epithelial and stromal cells regulating squamous tumor cell invasion in mouse models of head-and-neck squamous cell carcinoma (HNSCC). Loss of TGFβ signaling, in either compartment, leads to HNSCC however, the mechanisms involved are not well understood. Using organotypic reconstruct cultures (OTC) to model the interaction between epithelial and stromal cells that occur in dysplastic lesions, we show that loss of TGFβ signaling promotes an invasive phenotype in both fibroblast and epithelial compartments. Employing immortalized esophageal keratinocytes established to reproduce common mutations of esophageal squamous cell carcinoma, we show that treatment of OTC with inhibitors of TGFβ signaling (A83-01 or SB431542) enhances invasion of epithelial cells into a fibroblast-embedded Matrigel/collagen I matrix. Invasion induced by A83-01 is independent of proliferation but relies on protease activity and expression of ADAMTS-1 and can be altered by matrix density. This invasion was associated with increased expression of pro-inflammatory cytokines, IL1 and EGFR ligands HB-EGF and TGFα. Altering EGF signaling prevented or induced epithelial cell invasion in this model. Loss of expression of the TGFβ target gene ROBO1 suggested that chemorepulsion may regulate keratinocyte invasion. Taken together, our data show increased invasion through inhibition of TGFβ signaling altered epithelial-fibroblasts interactions, repressing markers of activated fibroblasts, and altering integrin-fibronectin interactions. These results suggest that inhibition of TGFβ signaling modulates an array of pathways that combined promote multiple aspects of tumor invasion.

Expression of ADAMTS-1 in AAA

Objectives: Accelerated breakdown of connective tissue, i.e. extracellular matrix, is a feature of many pathological conditions involving inflammation. Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease involving leukocyte infiltration that produce and secrete cytokines and proteases responsible for degradation of the extracellular matrix. Matrix components of the vessel wall include elastin, collagens and proteoglycans such as versican. A disintegrin and metalloprotease with thrombospondin motif type I (ADAMTS-1) is highly expressed in the aorta and cleaves versican, promoting VSMC migration.

SAT0572 The Effect of Interleukin-4 on Mechanical Stress-Induced Protease Expressions by Human Chondrocytes

BackgroundWe previously reported that runt-related transcription factor 2 (RUNX-2) has an important role in regulation of mechanical stress-induced expression of ADAMTS aggrecanases in chondrocytes. Interleukin-4 (IL-4) is an anti-inflammatory cytokine,...

Upregulation of tumor necrosis factor α and ADAMTS-5, but not ADAMTS-4, in human intervertebral cartilage endplate with modic changes.

This study investigated the expression of 2 types of ADAMTS in human intervertebral cartilage endplate (CEP) and related mechanisms concerning tumor necrosis factor α (TNF-α)-induced nuclear factor κB signaling pathway. To determine which type of ADAMTS is more strongly expressed and the role of TNF-α in CEP. ADAMTS-4 and ADAMTS-5 were proven to be essential in the degeneration of articular cartilage and intervertebral disc. CEP is an important structure adjacent to the disc. However, the activities of ADAMTS in CEP are unclear. CEPs were obtained from subjects after spinal surgery and categorized as members of either the Modic change group or the control group. Sections of these tissues were stained with hematoxylin-eosin, safranin O, and immunohistochemistry procedures for ADAMTS-4, ADAMTS-5, and TNF-α. Transcriptional levels of aggrecan, type I collagen, type II collagen, type X collagen, ADAMTS-4, ADAMTS-5, and TNF-α were investigated by quantitative real-time polymerase chain reaction. In addition, the effect of TNF-α on ADAMTS-5 and its potential mechanisms are investigated in cultured bovine endplate chondrocytes in vitro. Our data demonstrated that the degenerative changes associated with the expression of extracellular matrix proteins were correlated with increased levels of ADAMTS-5, but not ADAMTS-4, in the CEP of patients with Modic changes. The expression levels of TNF-α in the Modic change group were significantly increased, which was correlated with the enhanced expression of ADAMTS-5. Additional in vitro investigation confirmed that TNF-α could upregulate the expression of ADAMTS-5 by activating nuclear factor κB pathway in cultured bovine endplate chondrocytes. We conclude that the upregulation of TNF-α and ADAMTS-5, but not ADAMTS-4, may play an important role in degenerative CEP-induced low back pain. N/A.

FRI0009 Adamts5, Which Has Negative Correlation with IL-6, is A Biomarker for the Efficacy Prediction of TOCILIZUMAB in Rheumatoid Arthritis

BackgroundA disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) has been reported to play a key role in aggrecan degradation in cartilage. On the other hand, IL-6 has been shown...

Novel Treatment of Radiculopathy with Fullerol Nanoparticles

Introduction Back pain is ubiquitous and costs the United States an estimated $100 billion each year, second only to the common cold. Degeneration of intervertebral discs (IVDs) is considered to be the major cause of back pain, yet despite decades of efforts focused around treatment of disc degeneration, the predominant treatment option continues to be symptomatic care. Moreover, the mechanisms underlying degeneration are poorly lucidated. Compelling evidence suggests that reactive oxygen species (ROS) plays a pivotal role in disc degeneration. In disc tissues, oxidative stress may initiate or participate in matrix destruction and cell apoptosis that ultimately result in disc degeneration. Fullerol nanoparticles have been demonstrated outstanding ability to scavenge ROS. The goal of this study is to investigate the role of its antioxidative and anti-inflammatory in preventing and antagonizing disc degeneration. Materials and Methods Fullerol, a water soluble fullerene derivative, was characterized with UV-Vis spectrometry, dynamic light scattering, and zeta-potential analyses. The scavenging efficiencies against superoxide anions, hydroxyl radicals, and nitric oxide were determined by the pyrogallol auto-oxidation, Fenton-type reaction, and Griess reaction, respectively. For in vitro cellular experiments, a pro-oxidant H2O2 or an inflammatory cytokine interleukin (IL)-1β was employed to induce degenerated phenotypes in human nucleus pulposus (NP) cells encapsulated in alginate beads, and the effects of fullerol on matrix, ROS, and cell viability were assessed with real-time reverse-transcriptase polymerase chain reaction (RT-PCR), biochemistry, and immunofluorescence microscopy. In the animal study, an annulus degeneration model was induced with needle puncture method, and then 25 μL of fullerol (40 μg/mL) or phosphate-buffered saline (PBS) was injected intradiscally. The outcome was evaluated with magnetic resonance imaging (MRI), histology, and biochemistry. Results The absorption peak of fullerol suspension is 293 nm (UV-Vis spectrum), particle size is between 25 and 45 nm (dynamic light scattering), and average potential between − 40 and − 60 mV (zeta-potential analyzer). The nanofullerol suspension eliminated the radical and hydroxyl radicals in a dose-dependent manner, which is comparable to SOD and mannitol in high concentrations. Furthermore, nitric oxide was decreased by nanofullerol in a dose-dependent fashion. In alginate bead culture, H2O2 treatment significantly reduced the glycosaminoglycan content and the cellular amount of aggrecan in human NP cells. However, cotreatment with nanofullerol reversed the adverse effects of H2O2. Similar results were obtained in the case of type II collagen. While H2O2 caused a significant elevation in messenger RNA (mRNA) expression of matrix degradation enzymes MMP3, MMP9, and ADAMTS5, nanofullerol stopped the effect. The protective effects of fullerol on IL-1β-induced degeneration were also assessed in human NP cells. Human NP cells were treated with 10 ng/mL of IL-1β for up to 7 days in the presence or absence of fullerol. IL-1β caused an increase in nitric oxide secretion at day 3, as well as a decrease in cellular proteoglycan content at both day 3 and day 7. Fullerol elicited a significant counteraction against the IL-1b. Gene expression analysis by real-time RT-PCR showed that IL-1β induced a robust decrease in mRNA levels of aggrecan, type I and II collagens at day 7. Cotreatment with fullerol rescued the decreased mRNA expression of aggrecan and type II collagen but not type I. In addition, with nanofullerol itself, the expression of type II collagen was significantly upregulated. In the in vivo study, the anterior surfaces of rabbit lumbar IVDs were exposed under general anesthesia. Selected discs were punctured with an 18G needle and 25 µL of a nanofullerene suspension, or PBS, injected into the disc. The images from a morphological study and the X-ray and MRI scans showed that discs that were punctured and then injected with PBS showed a blurred annulus fibrosus (AF)/NP junction, narrowed disc space and a lower T2-weighted MRI signal, which indicated disc degeneration. However, discs punctured and then treated with fullerene showed a distinct AF/NP junction, improved disc height and strong T2-weighted MRI signals. Conclusion This study presented both in vitro and in vivo evidences supporting that the potent antioxidant fullerol rescues disc degeneration, which could be a novel therapeutic remedy for disc degeneration. Disclosure of Interest None declared

Chondroprotective Effect of Kartogenin on CD44-Mediated Functions in Articular Cartilage and Chondrocytes.

Objective:A recent report identified the small molecule kartogenin as a chondrogenic and chondroprotective agent. Since changes in hyaluronan metabolism occur during cartilage degeneration in osteoarthritis, we began studies to determine whether there was a connection between extracellular hyaluronan, CD44–hyaluronan interactions and the effects of kartogenin on articular chondrocytes.Methods:Chondrocytes cultured in monolayers, bioengineered neocartilages, or cartilage explants were treated with kartogenin with or without stimulation by IL-1β. Accumulation of matrix was visualized by a particle exclusion assay or by safranin O staining and release of sulfated glycosaminoglycans was determined. Production of aggrecanases and aggrecan G1-ITEGE neoepitope, fragmentation of CD44 and the SMAD1/5/8 signaling pathway were evaluated by western blotting.Results:Kartogenin treatment enhanced chondrocyte pericellular matrix assembly and retention in the presence of IL-1β. The chondroprotective effects of kartogenin on IL-1β-induced release of sulfated glycosaminoglycans from articular cartilage explants, reduction in safranin O staining of neocartilage discs as well as a reduction in aggrecan G1-ITEGE neoepitope in chondrocyte and explant cartilage cultures were observed. Kartogenin partially blocked the IL-1β-induced increased expression of ADAMTS-5. Additionally, kartogenin-treated articular chondrocytes exhibited a decrease in CD44 proteolytic fragmentation. However, kartogenin treatment did not enhance proteoglycan in control, non-IL-1β-treated cultures. Similarly, kartogenin enhanced the SMAD1 phosphorylation but only following pretreatment with IL-1β.Conclusion:These studies provide novel information on the chondroprotective function of kartogenin in adult articular cartilage. The effects of kartogenin are significant after activation of chondrocytic chondrolysis, which may occur following disruption of homeostasis maintained by hyaluronan–CD44 interactions.

Chip is a critical regulator of traf6 degradation and osteoclast formation

Chip is a critical regulator of traf6 degradation and osteoclast formation

Galectin fingerprinting in oa cartilage

Galectin fingerprinting in oa cartilage

Lack of sclerostin promotes osteoarthritis by activating canonical and non-canonical WNT pathways

Lack of sclerostin promotes osteoarthritis by activating canonical and non-canonical WNT pathways

Evidence for Decreased Expression of ADAMTS-1 Associated With Impaired Oocyte Quality in PCOS Patients

Polycystic ovary syndrome (PCOS) is the most common cause of dysfunctional ovulation-affecting female fertility. A disintegrin and metalloproteinase with thrombospondin-like motifs (ADAMTS-1) is required for normal ovulation and subsequent fertilization, and the expression of ADAMTS-1 may be altered in PCOS granulosa cell (GC)-reflecting abnormalities in ovulatory signaling. The purpose of this paper is to analyze the differential expression of ADAMTS-1 in PCOS patients associated with impaired oocyte quality. A prospective comparative experimental study was performed at a clinical reproductive medicine center. Women with PCOS (n = 40) and normovulatory controls (n = 40) undergoing controlled ovarian hyperstimulation and in vitro fertilization were recruited in our study. Differential expression of ADAMTS-1 in GCs was analyzed with immunocytochemistry in PCOS patients and normal controls, and ADAMTS-1 mRNA expression was quantified by RT-PCR. Furthermore, the correlation between ADAMTS-1 mRNA and oocyte quality was analyzed. The expression of ADAMTS-1 was decreased in PCOS patients compared with normally ovulating women and was closely related to lower oocyte recovery, oocyte maturity, and fertilization rate. Our study provides evidence that the dysregulated expression of ADAMTS-1 in PCOS may influence oocyte quality-via GCs-oocyte paracrine and endocrine mechanism.

Expression of ADAMTs-5 and TIMP-3 in the condylar cartilage of rats induced by experimentally created osteoarthritis

ObjectiveTo study the expression of ADAMTs-5 and TIMP-3 in temporomandibular joint osteoarthritis (TMJOA) model rats, to explore and confer the possible effects of ADAMTs-5 and TIMP-3 involved in the degradation of the early stage of OA. Design32 SD rats were divided into four groups: 2-week control group (NC1), 2-week OA group (OA1), 4-week control group (NC2) and 4-week OA group (OA2). Each group had 8 rats. Injection of collagenase was used to build up the TMJOA model. HE staining was used to analyze the structural change of condyle cartilage. Western blot and RT-PCR were used to measure the expression of ADAMTs-5 and TIMP-3 in protein and mRNA levels respectively. ResultsHE analysis revealed that no significant changes were observed in NC1, NC2 and OA1 groups, while mild damages appeared in OA2 group. No significant differences were achieved in the expression of ADAMTs-5 in protein levels between NC1 and OA1, but the expression of ADAMTs-5 in 4-week group increased significantly compared to that in the NC2 group. On mRNA level, the expression of ADAMTs-5 in 2-week and 4-week OA groups increased significantly compared to that in the matched control group. Meanwhile, the expression of TIMP-3 decreased significantly, showing a completely different trend. ConclusionsThe expression of ADAMTs-5 and TIMP-3 changed significantly in the early stage of TMJOA, which indicated that ADAMTs-5 and TIMP-3 may be play an important part in the initial stage of condylar cartilage degradation.

Pentosan Polysulfate Decreases Myocardial Expression of the Extracellular Matrix Enzyme ADAMTS4 and Improves Cardiac Function In Vivo in Rats Subjected to Pressure Overload by Aortic Banding

BackgroundWe hypothesized that cleavage of the extracellular matrix (ECM) proteoglycans versican and aggrecan by ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) proteases, which contributes to stress-induced ECM-reorganization in atherogenesis and osteoarthritis, also play a role in heart failure development.ObjectivesThe primary objective was to identify alterations in expression of ADAMTS versicanases and aggrecanases during development of heart failure, while evaluation of the effects of in vivo modulation of relevant changes in ADAMTS activity constituted the secondary objective.MethodsMyocardial levels of versican, aggrecan, and their ADAMTS cleaving proteases were examined in Wistar rats six weeks after aortic banding (AB), and versican and selected ADAMTS versicanases were further analyzed in neonatal cardiomyocytes (NCM) and cardiac fibroblasts (NFB) after stimulation by inflammatory mediators. Based on the initial findings, ADAMTS4 was selected the most promising therapeutic target. Thus, rats with AB were treated with pentosan polysulfate (PPS), a polysaccharide with known ADAMTS4-inhibitory properties, and effects on versican fragmentation, left ventricular function and geometry were evaluated.ResultsWe discovered that myocardial mRNA and protein levels of ADAMTS1 and -4, and mRNA levels of versican, aggrecan, and ADAMTS8 increased after AB, and TNF-α and IL-1β synergistically increased mRNA of versican and ADAMTS4 in NCM and NFB and secretion of ADAMTS4 from NCM. Furthermore, PPS-treatment improved systolic function, demonstrated by an improved fractional shortening (vehicle 48±3% versus PPS 60±1%, p<0.01) after AB. Following PPS-treatment, we observed an ∼80% reduction in myocardial ADAMTS4 mRNA (p = 0.03), and ∼50% reduction in the extracellular amount of the p150 versican fragments (p = 0.05), suggesting reduced versicanase activity.ConclusionsOur findings suggest that AB induces an increase in myocardial ADAMTS4 versicanase activity, and that PPS-treatment improved systolic function in the pressure-overloaded heart, holding promise as a novel therapeutic agent in heart failure.

A5.9 Sphingosine-1-phosphate counteracts interleukin-1β in human chondrocytes.

Background and ObjectivesThe lipid mediator Sphingosine-1-phosphate (S1P) is found in the synovial fluid of osteoarthritis (OA) patients. S1P protects bovine cartilage by counteracting interleukin-1β (IL-1β). Here we examine the interaction...

The amelioration of cartilage degeneration by ADAMTS-5 inhibitor delivered in a hyaluronic acid hydrogel

Degradation of proteoglycan is the key early event in the development of osteoarthritis (OA). The aggrecanase ADAMTS-5 has been identified as the major enzyme responsible for the degradation and thus is an attractive therapeutic target for OA. However, currently there is no report on using an ADAMTS-5 inhibition strategy for OA treatment. The present study aimed to investigate the synergic effect of combining an ADAMTS-5 inhibitor (114810) with a hyaluronic acid hydrogel (HAX) for OA therapeutics. Two OA models were induced by surgically creating an osteochondral defect or removing the anterior cruciate ligament (ACL) in Sprague–Dawley rats. Human OA cartilage was obtained from total joint replacement patients. Both human and rat OA cartilage showed marked proteoglycan loss with significantly increased ADAMTS-5 expression. The effectiveness of ADAMTS-5 inhibition by 114810 was confirmed by a cartilage explants assay in vitro, which showed that the 114810 halted the aggrecanase-mediated 374ARGS neoepitope released from aggrecan induced by IL-1β stimulation. The in vivo effect of ADAMTS-5 inhibition was assessed by the articular injection of HAX with 114810 into OA knee joints. Evaluated eight weeks after injection, 114810 with HAX significantly promoted the in vivo cartilage healing in the osteochondral defect model, and prevented the progression of degenerative changes in the ACL model. Our results confirmed that ADAMTS-5 is an effective target for OA treatment, and the intra-articular injection of an ADAMTS-5 inhibitor within HAX gel could be a promising strategy for OA treatment.

Exosomes from IL-1β stimulated synovial fibroblasts induce osteoarthritic changes in articular chondrocytes.

IntroductionOsteoarthritis (OA) is a whole joint disease, and characterized by progressive degradation of articular cartilage, synovial hyperplasia, bone remodeling and angiogenesis in various joint tissues. Exosomes are a type of microvesicles (MVs) that may play a role in tissue-tissue and cell-cell communication in homeostasis and diseases. We hypothesized that exosomes function in a novel regulatory network that contributes to OA pathogenesis and examined the function of exosomes in communication among joint tissue cells.MethodsHuman synovial fibroblasts (SFB) and articular chondrocytes were obtained from normal knee joints. Exosomes isolated from conditioned medium of SFB were analyzed for size, numbers, markers and function. Normal articular chondrocytes were treated with exosomes from SFB, and Interleukin-1β (IL-1β) stimulated SFB. OA-related genes expression was quantified using real-time PCR. To analyze exosome effects on cartilage tissue, we performed glycosaminoglycan release assay. Angiogenic activity of these exosomes was tested in migration and tube formation assays. Cytokines and miRNAs in exosomes were analyzed by Bio-Plex multiplex assay and NanoString analysis.ResultsExosomes from IL-1β stimulated SFB significantly up-regulated MMP-13 and ADAMTS-5 expression in articular chondrocytes, and down-regulated COL2A1 and ACAN compared with SFB derived exosomes. Migration and tube formation activity were significantly higher in human umbilical vein endothelial cells (HUVECs) treated with the exosomes from IL-1β stimulated SFB, which also induced significantly more proteoglycan release from cartilage explants. Inflammatory cytokines, IL-6, MMP-3 and VEGF in exosomes were only detectable at low level. IL-1β, TNFα MMP-9 and MMP-13 were not detectable in exosomes. NanoString analysis showed that levels of 50 miRNAs were differentially expressed in exosomes from IL-1β stimulated SFB compared to non-stimulated SFB.ConclusionsExosomes from IL-1β stimulated SFB induce OA-like changes both in vitro and in ex vivo models. Exosomes represent a novel mechanism by which pathogenic signals are communicated among different cell types in OA-affected joints.

Ursodeoxycholic Acid Ameliorates Pain Severity and Cartilage Degeneration in Monosodium Iodoacetate-Induced Osteoarthritis in Rats

Osteoarthritis (OA) is a degenerative joint disease characterized by a progressive loss of cartilage. And, increased oxidative stress plays a relevant role in the pathogenesis of OA. Ursodeoxycholic acid (UDCA) is a used drug for liver diseases known for its free radical-scavenging property. The objectives of this study were to investigate the in vivo effects of UDCA on pain severity and cartilage degeneration using an experimental OA model and to explore its mode of actions. OA was induced in rats by intra-articular injection of monosodium iodoacetate (MIA) to the knee. Oral administration UDCA was initiated on the day of MIA injection. Limb nociception was assessed by measuring the paw withdrawal latency and threshold. Samples were analyzed macroscopically and histologically. Immunohistochemistry was used to investigate the expression of interleukin-1β (IL-1β), IL-6, nitrotyrosine and inducible nitric oxide synthase (iNOS) in knee joints. UDCA showed an antinociceptive property and attenuated cartilage degeneration. OA rats given oral UDCA significantly exhibited a decreased number of osteoclasts in subchondral bone legion compared with the vehicle-treated OA group. UDCA reduced the expression of IL-1β, IL-6, nitrotyrosine and iNOS in articular cartilage. UDCA treatment significantly attenuated the mRNA expression of matrix metalloproteinase-3 (MMP-3), -13, and ADAMTS5 in IL-1β-stimulated human OA chondrocytes. These results show the inhibitory effects of UDCA on pain production and cartilage degeneration in experimentally induced OA. The chondroprotective properties of UDCA were achieved by suppressing oxidative damage and inhibiting catabolic factors that are implicated in the pathogenesis of cartilage damage in OA.

Early induction of ADAMTS 1, -4, -5 and -9 in IL-stimulated mouse astrocytes.

Astrocytes and extracellular matrix molecules have important roles in regulating synaptic functions between neurons in the central nervous system. However, under pathological conditions, these constituents are activated to form glial scar that is thought to be harmful for neuronal regeneration. The aim of this study was to evaluate the expression pattern of ADAMTS1, -4, -5 and -9 in IL-1 stimulated astrocyte cultures obtained from postnatal day zero mouse brains. Real time PCR analyses were performed. An overexpression of ADAMTS1, -4, -5 and -9 at the 3-h time point after IL-1 stimulation was found. IL-1 stimulation induced aggrecaneses and this effect was time dependent. Maximum increase was detected at 3-h (six fold increase). Interestingly the expression of ADAMTS1 and -4 appeared to be at the highest expression level but the ADAMTS5 and ADAMTS9 expression level was much weaker (three times and two times respectively). To the best of our knowledge, this is the first report demonstrating induction of ADAMTS in IL-1 induced astrocytes. Aggrecanases may play a role in tissue destruction in the progression of central nervous system (CNS) injury and they are differentially expressed in mouse CNS, suggesting a critical role in the pathogenesis of CNS injury. This can be a very crucial aetiologic factor for some neuropsychiatric disorders.

Role of nuclear factor of activated T-cells in regulating ADAMTS -4 promoter activity in nucleus pulposus cells

Objective To observe the regulatory effect of nuclear factor of activated T-cells( NFAT)-1,4,5 on ADAMTS-4 promoter activity in nucleus pulposus cells,so as to discuss the underlying molecular mechanism of intervertebral disc degeneration. Methods The ADAMTS-4-pβ-gal-Basic was inserted into PGL3-Basic vector after double digestion by the restriction enzyme XhoⅠ and HindⅢ. The purified PGL3-ADAMTS-4 plasmid was obtained through screening. Rat nucleus pulposus cells were cultured in vitro and,via Lipofectamine2000 transfection reagent,transfected with NFAT-1,NFAT-4,NFAT-5 or DN-TonEBP expressing plasmids with or without appropriate backbone vector and 175 ng ADAMTS-4 promoter. The normal cells were taken as controls and transfected cells were taken as treatment group. Dual-LuciferaseTMreporter assay system was used to detect the effect of NFAT-1,4,5( TonEBP) on ADAMTS-4 promoter activity. Results We successfully constructed PGL3-ADAMTS-4 plasmid and identified two NFAT-Bind elements in the promoter. Compared with the control group,ADAMTS-4 promoter activity was significantly inhibited in NFAT-1 group( P 0. 05). While the activities of ADAMTS-4 promoter in NFAT-4,NAFT-5 and DN-TonEBP groups showed no significant changes( P 0. 05). Conclusion NFAT-1 can regulate ADAMTS-4 expression,which may play a role in modulating aggrecan content in the intervertebral disc physiology and / or intervertebral disc degeneration,providing a new strategy for biological treatment of intervertebral disc degeneration.

Depletion of gangliosides enhances cartilage degradation in mice

Glycosphingolipids (GSLs) are ubiquitous membrane components that play a functional role in maintaining chondrocyte homeostasis. We investigated the potential role of gangliosides, one of the major components of GSLs, in osteoarthritis (OA) pathogenesis. Both age-associated and instability-induced OA models were generated using GM3 synthase knockout (GM3S(-/-)) mice. A cartilage degradation model and transiently GM3S-transfected chondrocytes were analyzed to evaluate the function of gangliosides in OA development. The amount of each series of GSLs in chondrocytes after IL-1α stimulation was profiled using mass spectrometry (MS). OA changes in GM3S(-/-) mice were dramatically enhanced with aging compared to those in wild-type (WT) mice. GM3S(-/-) mice showed more severe instability-induced pathologic OA in vivo. Ganglioside deficiency also led to the induction of matrix metalloproteinase (MMP)-13 and ADAMTS-5 secretion and chondrocyte apoptosis in vitro. In contrast, transient GM3S transfection of chondrocytes suppressed MMP-13 and ADAMTS-5 expression after interleukin (IL)-1α stimulation. GSL profiling revealed the presence of abundant gangliosides in chondrocytes after IL-1α stimulation. Gangliosides play a critical role in OA pathogenesis by regulating the expression of MMP-13 and ADAMTS-5 and chondrocyte apoptosis. Based on the obtained results, we propose that gangliosides are potential target molecules for the development of novel OA treatments.