Articular Cartilage In Synovial Joints Research Articles

Enzyme targeted delivery of sivelestat loaded nanomicelle inhibits arthritic severity in experimental arthritis

AimsRheumatoid arthritis (RA) is chronic inflammatory disorder mainly affects the lining of articular cartilage of synovial joints characterized by severe inflammation and joint damage. The expression of proteolytic enzymes like MMP-2 and Neutrophil Elastase (NE) worsens the RA condition. To address this concern, we have synthesized dual enzyme targeted chlorotoxin conjugated nanomicelles loaded with sivelestat as broad spectrum treatment for RA. Materials and methodsConjugation of the chlorotoxin over nanomicelle and incorporation of sivelestat in nanomicelle provide it dual targeting potential. The sivelestat loaded nanomicelle (SLM) evaluated for the drug release and in-vitro cytocompatibility. Further, investigated its in-vivo anti-arthritic potential on collagen-induced arthritis in wistar rats. Key findingsThe microscopic observation of SLM showed spherical ball like appearance with size ranging from 190 to 230 nm. SLM showed good drug loading and encapsulation efficiency along with no cytotoxicity against healthy cell lines. In-vivo therapeutic assessment on collagen induced arthritis rat model showed potential chondroprotection. The microscopic visualization of articular cartilage by staining showed that it restores the cartilage integrity and lowers the expression of pro-inflammatory enzymes showed by Immunohistochemistry and Immunofluorescence. We observed that, it restrain the mediators of synovial inflammation by simultaneous inhibition of the proteolytic enzymes involved in swelling, cartilage destruction and joint damage which provides strong chondroprotection. SignificanceWe report that significant alleviation of inflammation and inhibition of proteolytic enzymes together might provide enhanced potential for the treatment and management of RA.

Promoting health and quality of life of patients with osteoarthritis of knee joint through non-pharmacological treatment strategies: A randomized controlled trial.

BACKGROUND AND OBJECTIVE:Osteoarthritis (OA) is a chronic degenerative disorder which primarily affects the articular cartilage of synovial joints followed by bony remodeling and overgrowth at the margins of these joints. The consequences of OA are pain, joint stiffness, decreased muscle performance, and decreased aerobic capacity, which eventually affect the quality of life (QOL) and increased risk for disability. The objective of the present study was to investigate the effectiveness of two nonpharmacological treatment regimens, that is, yoga and conventional physiotherapy, on QOL in patients suffering from OA of knee joint.MATERIALS AND METHODS:A total of 83 patients with bilateral OA of knee joint, between the age group of 40 and 80 years, both males and females, were assigned into two groups using computer-generated scheme: 43 in the experimental group (yoga with conventional physiotherapy program) and 40 in control group (conventional physiotherapy program). Western Ontario and McMaster Universities OA index (WOMAC) and Short-Form 36 (SF-36) health survey were measured before, after 15 days, and after 30 days of treatment sessions, and the data were analyzed using paired and unpaired t-test.RESULTS:The results of the study show significant improvement in both groups with regard to WOMAC and SF-36 at the end of 15 and 30 days of treatment regimen; however, when compared to the control group, experimental group had more significant improvement (P < 0.05) in WOMAC and SF-36 at the end of 15 and 30 days of treatment.CONCLUSION:Yoga is more beneficial when added to conventional physiotherapy treatment regimen in promoting health and improving QOL in patients with OA of knee joint.

Translational regulation contributes to the secretory response of chondrocytic cells following exposure to interleukin-1β

Osteoarthritis is a chronic disease characterized by the loss of articular cartilage in synovial joints through a process of extracellular matrix destruction that is strongly associated with inflammatory stimuli. Chondrocytes undergo changes to their protein translational capacity during osteoarthritis, but a study of how disease-relevant signals affect chondrocyte protein translation at the transcriptomic level has not previously been performed. In this study, we describe how the inflammatory cytokine interleukin 1-β (IL-1β) rapidly affects protein translation in the chondrocytic cell line SW1353. Using ribosome profiling we demonstrate that IL-1β induced altered translation of inflammatory-associated transcripts such as NFKB1, TNFAIP2, MMP13, CCL2, and CCL7, as well as a number of ribosome-associated transcripts, through differential translation and the use of multiple open reading frames. Proteomic analysis of the cellular layer and the conditioned media of these cells identified changes in a number of the proteins that were differentially translated. Translationally regulated secreted proteins included a number of chemokines and cytokines, underlining the rapid, translationally mediated inflammatory cascade that is initiated by IL-1β. Although fewer cellular proteins were found to be regulated in both ribosome profiling and proteomic data sets, we did find increased levels of SOD2, indicative of redox changes within SW1353 cells being modulated at the translational level. In conclusion, we have produced combined ribosome profiling and proteomic data sets that provide a valuable resource in understanding the processes that occur during cytokine stimulation of chondrocytic cells.

DNA methylation regulates MiR-140 expression in primary osteoarthritic chondrocytes by altering SMAD-3 binding affinity

Purpose: Osteoarthritis (OA) is a whole-joint disorder that is characterized by the loss of articular cartilage of synovial joints. Abnormal expression of miRNAs, through changes of DNA methylation status of their regulatory regions has been suggested to contribute to pathogenic alterations of an OA joint. MiR-140 is specifically expressed in cartilage and its reduced expression has been associated with abnormal chondrocytes’ metabolism in OA. The aim of the present study was to investigate the role of DNA methylation on miR-140 expression in osteoarthritic chondrocytes. Methods: Articular osteoarthritic and normal cartilage were obtained from 16 patients with primary osteoarthritis and 9 individuals with no history of joint disease, respectively. MiR-140 mRNA expression levels were investigated using real-time PCR. The methylation status of miR-140 regulatory region was analysed using quantitative methylation-specific PCR (qMSP) and bisulfite DNA sequencing assay. The effect of 5’-Aza-2-deoxycytidine (5-AzadC) on miR-140 expression was investigated and SMAD-3 binding to miR-140 regulatory region was assessed by chromatin immunoprecipitation (ChΙP). Statistical analysis was performed using the SPSS software 24. MiR-140 relative expression was assessed using Mann-Whitney. Spearman’s rank correlation coefficient was used to analyze correlative relationships. For all comparisons, p values < 0.05 were considered statistically significant and data were expressed as the mean ± standard error of the mean. Results: We observed that miR-140 expression levels were significantly reduced in OA compared with normal chondrocytes. Downregulation of miR-140 was correlated with increased percentage of methylation of miR-140 regulatory region in OA chondrocytes. Bisulfite DNA sequencing of miR-140 regulatory region revealed 6 CpG sites located near SMAD-3 binding sites to be highly methylated in OA compared to normal chondrocytes. We also observed a weaker binding affinity of SMAD-3 in OA chondrocytes compared to normal, whose miR-140 regulatory region was hypermethylated. Treatment of OA chondrocytes with 5-AzadC resulted in significant upregulation of miR-140 compared to untreated, which was associated with demethylation of miR-140 regulatory region and stronger binding of SMAD-3 in this region. Conclusions: We provide novel findings that DNA methylation regulates miR-140 expression in OA chondrocytes, by changing SMAD-3 binding affinity to miR-140 regulatory region. Our results provide strong evidence that abnormal expression of miRNAs observed in OA is regulated by epigenetics, such as DNA methylation, suggesting a new strategy for treating OA patients, as epigenetic mechanisms are reversible processes.

A New Link Between Arthritis and Alzheimer's Disease?

Recently, systemic inflammation has been implicated in the pathogenesis of Alzheimer's disease (AD). This inflammation has the ability to exacerbate both motor and cognitive symptoms of the disease through increasing amounts of inflammatory markers like TNF‐α and C‐Reactive Protein, as well as amyloid plaque depositions within many areas throughout the body, including articular cartilage of synovial joints. These inflammatory markers and amyloid plaques are related to the development of arthritis. In fact, arthritis is a risk factor for cognitive impairment in the elderly. For this reason, we hypothesize inflammatory mediators associated with the development of AD may also affect articular cartilage metabolism, specifically hypertrophy‐like changes induced by chondrocyte activation by inflammatory cytokines. Here, we compare expression of type X collagen (col10a1), a standard marker for chondrocyte hypertrophy, in tibiofemoral joint articular cartilage of 7‐month‐old male wild type mice with mice of the 3xTg‐AD model for AD. Results show that expression of col10a1 in mice with the Alzheimer's phenotype is significantly reduced in comparison with the wild type mice (P &lt; 0.05). This reduction is consistent with inhibited col10a1 expression by chondrocytes identified in arthritic cartilage. Our exploratory study suggests neurodegenerative and arthritogenic changes identified in many AD patients may be linked to a common systemic inflammatory process, and warrants further investigation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Ultra-low friction between boundary layers of hyaluronan-phosphatidylcholine complexes.

Can designed biomaterials emulate the unique lubrication ability of articular cartilage, and thus provide potential alleviation to friction-related joint diseases? This is the motivation behind the present study. The principles of cartilage lubrication have attracted considerable attention for decades, and several models have been proposed to elucidate it, however, the mechanism of this ultralow friction is still not clear. In this paper we explore the recent suggestion that its efficient lubrication arises from boundary layers of hyaluronan-lipid complexes at its surface, in particular exploring a range of different phosphatidylcholines (PCs) mimicking the wide range of PCs in synovial joints. The present study suggests a synergistic lubricating behavior of the different lipids in living joints, and potential treatment directions using such biomaterial complexes for widespread cartilage-friction-related diseases such as osteoarthritis.

Quantitative proteomics at different depths in human articular cartilage reveals unique patterns of protein distribution

The articular cartilage of synovial joints ensures friction-free mobility and attenuates mechanical impact on the joint during movement. These functions are mediated by the complex network of extracellular molecules characteristic for articular cartilage. Zonal differences in the extracellular matrix (ECM) are well recognized. However, knowledge about the precise molecular composition in the different zones remains limited. In the present study, we investigated the distribution of ECM molecules along the surface-to-bone axis, using quantitative non-targeted as well as targeted proteomics.\\In a discovery approach, iTRAQ mass spectrometry was used to identify all extractable ECM proteins in the different layers of a human lateral tibial plateau full thickness cartilage sample. A targeted MRM mass spectrometry approach was then applied to verify these findings and to extend the analysis to four medial tibial plateau samples.In the lateral tibial plateau sample, the unique distribution patterns of 70 ECM proteins were identified, revealing groups of proteins with a preferential distribution to the superficial, intermediate or deep regions of articular cartilage. The detailed analysis of selected 29 proteins confirmed these findings and revealed similar distribution patterns in the four medial tibial plateau samples.The results of this study allow, for the first time, an overview of the zonal distribution of a broad range of cartilage ECM proteins and open up further investigations of the functional roles of matrix proteins in the different zones of articular cartilage in health and disease.

MR cartilage imaging in assessment of the regenerative power of autologous peripheral blood stem cell injection in knee osteoarthritis

BackgroundOsteoarthritis (OA) describes an age-related, heterogeneous group of disorders characterized pathologically by focal areas of loss of articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone change, and synovitis. Currently, cartilage repair remains a major challenge for physicians, being avascular with limited regenerative capacity. Stem cell therapy opened new horizons for hyaline cartilage repair. Peripheral blood stem cells (PBSC) due to their multi-lineage potential, immunosuppressive activities, and limited immunogenicity, were tried as an intra articular injection. Aim of studyTo find out the regenerative effect of repeated intra articular injections of autologous PBSC in knee joints of OA patients using MR cartilage imaging. Methods10 patients (3 males and 7 females) diagnosed with bilateral knee joints OA were included in this study, they underwent history taking, clinical examination and MR cartilage imaging using the semi-quantitative whole joint assessment score of knee for OA (MOAKS). Three intra articular injections of 8ml of autologous PBSC in each knee were administered. Clinical and MRI assessments were repeated after 1year. ResultsA significant reduction was seen in all parameters post injection. MR images analysis showed increased cartilage thickness in 65 knee joint compartments out of 160 affected compartments. ConclusionLimited good level of evidence showed that repeated intra-articular injections of autologous PBSC resulted in an improvement of the quality of articular cartilage repair and physical function as observed by MRI and clinical assessment.

FRI0583-HPR The Effects of Kinesiologic Taping Applied on Quadriceps and Hamstring Muscles on Functions of Lower Extremity in Patients with Knee Osteoarthritis

BackgroundOne of the most common musculoskeletal diseases, osteoarthritis (OA) is characterized by the progressive loss of articular cartilage in synovial joints (1).One of the first and most widely seen symptoms...

AB0792 Regenerative Power of Autologous Peripheral Blood Stem Cell Injection in Knee Osteoarthritis by A NON Invasive Approach - MRI Study-

BackgroundOsteoarthritis (OA) describes age-related, heterogeneous group of disorders characterized pathologically by focal areas of loss of articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone...

Specification of chondrocytes and cartilage tissues from embryonic stem cells

Osteoarthritis primarily affects the articular cartilage of synovial joints. Cell and/or cartilage replacement is a promising therapy, provided there is access to appropriate tissue and sufficient numbers of articular chondrocytes. Embryonic stem cells (ESCs) represent a potentially unlimited source of chondrocytes and tissues as they can generate a broad spectrum of cell types under appropriate conditions in vitro. Here, we demonstrate that mouse ESC-derived chondrogenic mesoderm arises from a Flk-1(-)/Pdgfrα(+) (F(-)P(+)) population that emerges in a defined temporal pattern following the development of an early cardiogenic F(-)P(+) population. Specification of the late-arising F(-)P(+) population with BMP4 generated a highly enriched population of chondrocytes expressing genes associated with growth plate hypertrophic chondrocytes. By contrast, specification with Gdf5, together with inhibition of hedgehog and BMP signaling pathways, generated a population of non-hypertrophic chondrocytes that displayed properties of articular chondrocytes. The two chondrocyte populations retained their hypertrophic and non-hypertrophic properties when induced to generate spatially organized proteoglycan-rich cartilage-like tissue in vitro. Transplantation of either type of chondrocyte, or tissue generated from them, into immunodeficient recipients resulted in the development of cartilage tissue and bone within an 8-week period. Significant ossification was not observed when the tissue was transplanted into osteoblast-depleted mice or into diffusion chambers that prevent vascularization. Thus, through stage-specific manipulation of appropriate signaling pathways it is possible to efficiently and reproducibly derive hypertrophic and non-hypertrophic chondrocyte populations from mouse ESCs that are able to generate distinct cartilage-like tissue in vitro and maintain a cartilage tissue phenotype within an avascular and/or osteoblast-free niche in vivo.

Variations in the progesterone secretion by developing corpora lutea influence the rhythm of follicular growth in bovine ovaries

Ostearthritis (OA) is characterized by focal areas of loss of the articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone change and synovitis. The Asporin (ASPN) gene which encodes a protein of the extracellular cartilage matrix contains a triplet repeat encoding for aspartic acid (D) within exon 2 The D14 allele was found associated with knee and hip osteoarthritis in case-control study in the Japanese population. Genotyping Greek knee OA patients for the D repeats we determined that the D15 allele could be considered a risk allele for our population.

Normal and Shear Interactions between Hyaluronan–Aggrecan Complexes Mimicking Possible Boundary Lubricants in Articular Cartilage in Synovial Joints

Using a surface force balance, normal and shear interactions have been measured between two atomically smooth surfaces coated with hyaluronan (HA), and with HA/aggrecan (Agg) complexes stabilized by cartilage link protein (LP). Such HA/Agg/LP complexes are the most abundant mobile macromolecular species permeating articular cartilage in synovial joints and have been conjectured to be present as boundary lubricants at its surface. The aim of the present study is to gain insight into the extremely efficient lubrication when two cartilage surfaces slide past each other in healthy joints, and in particular to elucidate the possible role in this of the HA/Agg/LP complexes. Within the range of our parameters, our results reveal that the HA/Agg/LP macromolecular surface complexes are much better boundary lubricants than HA alone, likely because of the higher level of hydration, due to the higher charge density, of the HA/Agg/LP layers with respect to the HA alone. However, the friction coefficients (μ) associated with the mutual interactions and sliding of opposing HA/Agg/LP layers (μ ≈ 0.01 up to pressure P of ca. 12 atm, increasing sharply at higher P) suggest that such complexes by themselves cannot account for the remarkable boundary lubrication observed in mammalian joints (up to P > 50 atm).

Identification of a central role for complement in osteoarthritis

Osteoarthritis, characterized by the breakdown of articular cartilage in synovial joints, has long been viewed as the result of “wear and tear”1. Although low-grade inflammation is detected in osteoarthritis, its role is unclear2–4. Here we identify a central role for the inflammatory complement system in the pathogenesis of osteoarthritis. Through proteomic and transcriptomic analyses of synovial fluids and membranes from individuals with osteoarthritis, we find that expression and activation of complement is abnormally high in human osteoarthritic joints. Using mice genetically deficient in C5, C6, or CD59a, we show that complement, and specifically the membrane attack complex (MAC)-mediated arm of complement, is critical to the development of arthritis in three different mouse models of osteoarthritis. Pharmacological modulation of complement in wild-type mice confirmed the results obtained with genetically deficient mice. Expression of inflammatory and degradative molecules was lower in chondrocytes from destabilized joints of C5-deficient mice than C5-sufficient mice, and MAC induced production of these molecules in cultured chondrocytes. Furthermore, MAC co-localized with matrix metalloprotease (MMP)-13 and with activated extracellular signal-regulated kinase (ERK) around chondrocytes in human osteoarthritic cartilage. Our findings indicate that dysregulation of complement in synovial joints plays a critical role in the pathogenesis of osteoarthritis.

Bilayered Scaffolds for Osteochondral Tissue Engineering

Osteoarthritis (OA) is a prevalent degenerative joint disease that places a significant burden on the socioeconomic efficacy of communities around the world. Tissue engineering repair of articular cartilage in synovial joints represents a potential OA treatment strategy superior to current surgical techniques. In particular, osteochondral tissue engineering, which promotes the simultaneous regeneration of articular cartilage and underlining subchondral bone, may be a clinically relevant approach toward impeding OA progression. The unique and complex functional demands of the two contrasting tissues that comprise osteochondral tissue require the use of bilayered scaffolds to promote individual growth of both on a single integrated implant. This paper reviews the three current bilayered scaffold strategies applied to solve this challenging problem, with a focus on the need for an innovative approach to design and fabrication of new optimized scaffold combinations to reinforce materials science as an important element of osteochondral tissue engineering.

Correlation between the surface area of synovial membrane and the surface area of articular cartilage in synovial joints of the mouse and human

Articular cartilage is avascular. Evidence suggests that in mature animals synovial fluid is the dominant source of nutrition for articular cartilage. If so, there might be a direct correlation between the surface area of synovial membrane and the surface area of articular cartilage in synovial joints. The hindlimb joints of young adult Swiss Webster mice were prepared for histology and sagitally sectioned at regular intervals. The surface area of synovial membrane and the surface area and volume of articular cartilage were calculated from serial photomicrographs of knee, ankle, and first metatarsophalangeal (MTP) joints using ImageJ software and Cavalieri's method. Sagittal E12 slices from numerous synovial joints in a single human cadaver were similarly analysed. There was a strong statistically significant positive linear correlation between the surface area of synovial membrane and articular cartilage in the hindlimb joints of the mouse (r = 0.96, 95% CI 0.90-0.98, P < 0.0001). A similarly strong highly statistically significant corelation was observed between the surface area of synovial membrane and volume of articular cartilage. This relationship was also observed across a wider range of synovial joints in the human (r = 0.83, 95% CI 0.48-0.95, P = 0.0009). All analyses remained highly statistically significant after adjusting the standard errors and consequent P values for the linear models based on multiple observations in the same subject. This study demonstrates for the first time that there is a direct positive linear correlation between the surface area of synovial membrane and the surface area of articular cartilage in synovial joints in the mouse and human. These novel findings support the concept that the nutrition of mature articular cartilage is dependent on synovial fluid and may also explain why some joints communicate with surrounding bursae. Perhaps more consideration should be given to synovial membrane when studying the pathology of articular cartilage.

Association of the CALM1 Core Promoter Polymorphism with Knee Osteoarthritis in Patients of Greek Origin

Osteoarthritis (OA) is characterized by focal areas of loss of articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone change, and synovitis. The Calmodulin 1 gene (CALM1) encodes for a ubiquitous eukaryotic Ca2+ binding protein and is the principal mediator of the calcium signal. The protein thus affects the chondrocyte's response to mechanical load. A functional core promoter single nucleotide polymorphism (SNP) -16C/T (rs12885713) was recently associated with hip OA (HOA) in the Japanese population, while no association was found in a British group of patients with HOA. Our objective was to assess whether this SNP was also associated with knee OA (KOA) in a Greek Caucasian population sample. The -16T/C SNP was genotyped in a 351 case-control cohort--158 patients with idiopathic KOA and 193 controls. No significant differences were found in genotype frequencies for the -16T/C SNP of CALM1 gene between cases and controls (p = 0.581). Our data implied that the -16TT (rs12885713) CALM1 core promoter genotype is not a risk factor for OA etiology in Greek Caucasians on its own, but associated with the Asporin (ASPN) D14 or D15 risk allele, it could influence KOA susceptibility.

Chondrotoxicity of Quinolone Antimicrobial Agents

Quinolone antimicrobial agents induce two types of histological changes in the articular cartilage of synovial joints in immature, but not mature, laboratory animals. The first is cavity formation in the middle zone of the articular cartilage in animals of all species examined so far, and this can be induced by a single or several daily doses. The second is osteochondrotic lesions in the caudal femoral condyles of rats when subchronic or chronic treatment is started at a juvenile age, but there seems to be only one reference for this effect. The development process of cavity formation is as follows. Degeneration and necrosis of chondrocytes are first observed, and the surrounding matrix becomes edematous with demasked collagen fibrils and decreased safranin O stainability. A flat cleft or cavity is then formed in the edematous cartilage, and erosion is sometimes produced by detachment of the cavity outer wall. The potency of quinolones to form chelate complexes with Mg2+ is discussed as causal for cavity formation. This could lead to Mg2+ deficiency in the cartilage, resulting in integrin alteration and further radical formation that can finally induce cartilage lesions. On the other hand, an early change of osteochondrosis is a thickened middle zone of the articular cartilage with a thinned deep zone. The thickened cartilage protrudes into the epiphysis and prevents age-dependent thinning of the cartilage. In advanced cases, fissures are formed in the bottom of the thickened cartilage, and extension of the fissures to the cartilage surface induces detachment of the cartilage, subchondral bone necrosis and fibrotic lesions in the marrow space. The lesions are considered to be caused by quinolone-induced inhibition of the differentiation of chondrocytes in the middle zone into those in the deep zone. For chondrotoxicity in juvenile animals, the pediatric use of quinolones is generally contraindicated, but whether or not chondrotoxicity could really occur in pediatric patients is still controversial.

Asporin and knee osteoarthritis in patients of Greek origin

Ostearthritis (OA) is characterized by focal areas of loss of the articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone change and synovitis. The Asporin (ASPN) gene which encodes a protein of the extracellular cartilage matrix contains a triplet repeat encoding for aspartic acid (D) within exon 2 The D14 allele was found associated with knee and hip osteoarthritis in case-control study in the Japanese population. Genotyping Greek knee OA patients for the D repeats we determined that the D15 allele could be considered a risk allele for our population.

Pathogenesis and management of pain in osteoarthritis

The term osteoarthritis describes a common, age-related, heterogeneous group of disorders characterised pathologically by focal areas of loss of articular cartilage in synovial joints, associated with varying degrees of osteophyte formation, subchondral bone change, and synovitis. Joint damage is caused by a mixture of systemic factors that predispose to the disease, and local mechanical factors that dictate its distribution and severity. Various genetic abnormalities have been described, but most sporadic osteoarthritis probably depends on minor contributions from several genetic loci. Osteoarthritic joint damage may be associated with clinical problems, but the severity of joint disease is only weakly related to that of the clinical problem. For this reason the associations and pathogenesis of pain are in as much need of investigation as joint damage. Subchondral bone and synovium may be responsible for nociceptive stimuli, and peripheral neuronal sensitisation is an important feature, and can result in normal activities (such as walking) causing pain. Central pain sensitisation can also occur, and psychosocial factors are important determinants of pain severity. We present a stepwise approach to the management of osteoarthritis.