DigitalUM :: Browsing by Subject "Osteoarthritis"

Browsing by Subject "Osteoarthritis"

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Open Access
Adipose-derived stem cells in articular cartilage regeneration: current concepts and optimization strategies
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Gu, Xingjian; Li, Caixin; Yin, Feng; Yang, Guanghua
Knee osteoarthritis (KOA) is the most common progressive joint disorder associated with disability in the world. As a chronic disease, KOA has multifactorial etiology. However, the poor self-healing ability of the articular cartilage due to its intrinsic tissue hypovascularity and hypocellularity seems to be directly incriminated in the physio-pathological mechanism of KOA. While conventional therapies result in unfavorable clinical outcomes, regenerative cell therapies have shown great promise in articular cartilage regeneration. Adipose-derived stem cells (ASCs) appear to be an ideal alternative to bone-marrow derived stem cells (BMSCs) and autologous chondrocytes, due to their lower immunogenicity, richer source and easier acquisition. Since the first case report in 2011, ASCs have demonstrated safety and efficacy for articular cartilage regeneration in several phase I/II clinical trials. However, different levels of abnormality were found in the regenerated cartilage for most of the patients. A large portion of recent publications investigated different optimization strategies to improve the therapeutic function of ASCs, including cell source selection, preconditioning and co-delivery. Herein, we give an update on the latest research progress on ASCs, with a focus on the most promising optimization strategies for ASC-based therapy.
Open Access
Age-related degeneration of articular cartilage in the pathogenesis of osteoarthritis: molecular markers of senescent chondrocytes
(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Musumeci, Giuseppe; Szychlinska, Marta Anna; Mobasheri, Ali
Aging is a natural process by which every single living organism approaches its twilight of existence in a natural way. However, aging is also linked to the pathogenesis of a number of complex diseases. This is the case for osteoarthritis (OA), where age is considered to be a major risk factor of this important and increasingly common joint disorder. Half of the world's population, aged 65 and older, suffers from OA. Although the relationship between the development of OA and aging has not yet been completely understood, it is thought that age-related changes correlate with other risk factors. The most prominent hypothesis linking aging and OA is that chondrocytes undergo premature aging due to several factors, such as excessive mechanical load or oxidative stress, which induce the so called “stress-induced senescent state”, which is ultimately responsible for the onset of OA. This review focuses on molecular markers and mechanisms implicated in chondrocyte aging and the pathogenesis of OA. We discuss the most important age-related morphological and biological changes that affect articular cartilage and chondrocytes. We also identify the main senescence markers that may be used to recognize molecular alterations in the extracellular matrix of cartilage as related to senescence. Since the aging process is strongly associated with the onset of osteoarthritis, we believe that strategies aimed at preventing chondrocyte senescence, as well as the identification of new increasingly sensitive senescent markers, could have a positive impact on the development of new therapies for this severe disease.
Open Access
Anabolic actions of IGF-I and TGF-B1 on Interleukin-1B-treated human articular chondrocytes: Evaluation in two and three dimensional cultures
(Murcia : F. Hernández, 2009) Seifarth, Claudia; Csaki, Constanze; Shakibaei, Mehdi
Pro-inflammatory cytokines, such as interleukin-1ß (IL-1ß) and tumor necrosis factor-a (TNF-a) play a key role in the pathogenesis of Osteoarthritis (OA). The aim of this study was to investigate the potential anti-inflammatory properties of the growth factors IGF-I and/or TGF-ß1 on IL-1ß signalling pathways and their effect on the chondrogenic potential of dedifferentiated human articular chondrocytes in vitro. Serum-starved human articular chondrocytes were treated with IL-1ß to induce dedifferentiation and further treated with IGF-I and/or TGF-ß1 at various concentrations. The effects of growth factors were evaluated both in monolayer and high-density cultures. Incubation with the cytokine IL-1ß resulted in rapid dedifferentiation of the cells; they lost their chondrocytelike phenotype while down-regulating the expression of collagen type II, integrin, extracellular regulated kinase (Erk 1/2) and the chondrogenic transcription factor Sox9. Co-treatment with IGF-I and/or TGF-ß1 stimulated the cells to redifferentiate, increasing the expression of the above-mentioned cartilage-specific proteins. These events correlated with down-regulation of cyclooxygenase-2 (COX-2) and matrix metalloproteinase- 13 (MMP-13). Furthermore, in high-density cultures, we observed evidence for new cartilage formation after co-treatment with these growth factors. We further detected that all examined proteins were more strongly expressed during combination treatment. These results indicate that IGF-I and TGF-ß1 exert additive anabolic effects on chondrocytes and may stabilize the chondrogenic potential. The additive action of these growth factors on chondrocytes may find practical applications in the fields of OA and cartilage tissue engineering.
Open Access
Catalpol protects mouse ATDC5 chondrocytes against interleukin-1β-induced catabolism
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Cai, Chengkui; Sun, Pengcheng; Chen, Zhihui; Sun, Chao; Tian, Liying
Catalpol is a natural product with promising anti-inflammatory effects, however, its effects on chondrocytes and osteoarthritis (OA) have not been well investigated. OA is a painful and debilitating joint disease that affects people worldwide. Traditional Chinese Medicine has been sought to treat OA, including the Rehmannia extract, Catalpol. Here, we examined the effects of Catalpol, a plant derivative used in traditional Chinese medicine, on ATDC5 chondrocytes originating from mouse teratocarcinoma cells stimulated with interleukin-1β (IL-1β) to mimic the OA cellular environment. Catalpol significantly reduced matrix metalloproteinase-1, -3, -13 (MMP-1, -3, -13), a disintegrin and metalloproteinase with thrombospondin motifs -4, -5 (ADAMTS-4, -5) against IL-1β, demonstrating a likely anti-cartilage degradation activity. We also found that Catalpol exerted a significant antioxidative stress effect by downregulating the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO), reactive oxygen species (ROS), and malondialdehyde (MDA). Catalpol treatment significantly reduced the levels of several key inflammatory factors, including Prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), interleukin-8 (IL8), and monocyte chemoattractant protein-1 (MCP-1). We further demonstrate that the effects of Catalpol were mediated by the nuclear factor -κB (NF-κB) pathway via downregulation of the phosphorylation of inhibitor of nuclear factor κB-α (IκBα). This was confirmed by measuring p38 and p65 protein levels as well as the luciferase activity of NF-κB. Altogether, we demonstrate the potential of Catalpol as a novel treatment agent against cartilage matrix degradation, oxidative stress, and inflammation in OA.
Embargo
Computed tomography-based patient-specific instrumentation loses accuracy with significant varus preoperative misalignment
(Thieme Gruppe, 2020-09-08) León Muñoz, Vicente Jesús; López López, Mirian; Lisón Almagro, Alonso José; Martínez Martínez, Francisco; Santonja Medina, Fernando; Cirugía, Pediatría y Obstetricia y Ginecología
Patient-specific instrumentation (PSI) has been introduced to simplify and make total knee arthroplasty (TKA) surgery more precise, effective, and efficient. We performed this study to determine whether the postoperative coronal alignment is related to preoperative deformity when computed tomography (CT)-based PSI is used for TKA surgery, and how the PSI approach compares with deformity correction obtained with conventional instrumentation. We analyzed pre-and post-operative full length standing hip-knee-ankle (HKA) X-rays of the lower limb in both groups using a convention > 180 degrees for valgus alignment and < 180 degrees for varus alignment. For the PSI group, the mean ( SD) pre-operative HKA angle was 172.09 degrees varus ( 6.69 degrees) with a maximum varus alignment of 21.5 degrees (HKA 158.5) and a maximum valgus alignment of 14.0 degrees. The mean post-operative HKA was 179.43 degrees varus ( 2.32 degrees) with a maximum varus alignment of seven degrees and a maximum valgus alignment of six degrees. There has been a weak correlation among the values of the pre- and postoperative HKA angle. The adjusted odds ratio (aOR) of postoperative alignment outside the range of 180 3 degrees was significantly higher with a preoperative varus misalignment of 15 degrees or more (aOR: 4.18; 95% confidence interval: 1.35–12.96; p ¼ 0.013). In the control group (conventional instrumentation), this loss of accuracy occurs with preoperative misalignment of 10 degrees. Preoperative misalignment below 15 degrees appears to present minimal influence on postoperative alignment when a CT-based PSI system is used. The CT-based PSI tends to lose accuracy with preoperative varus misalignment over 15 degrees.
Open Access
Current knowledge of pituitary adenylate cyclase activating polypeptide (PACAP) in articular cartilage
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Lauretta, Giovanni; Ravalli, Silvia; Szychlinska, Marta Anna; Castorina, Alessandro; Maugeri, Grazia; D'Amico, Agata Grazia; D'Agata, Velia; Musumeci, Giuseppe
Pituitary adenylate cyclase activating polypeptide (PACAP) is an evolutionally well conserved neuropeptide, mainly expressed by neuronal and peripheral cells. It proves to be an interesting object of study both for its trophic functions during the development of several tissues and for its protective effects against oxidative stress, hypoxia, inflammation and apoptosis in different degenerative diseases. This brief review summarises the recent findings concerning the role of PACAP in the articular cartilage. PACAP and its receptors are expressed during chondrogenesis and are shown to activate the pathways involved in regulating cartilage development. Moreover, this neuropeptide proves to be chondroprotective against those stressors that determine cartilage degeneration and contribute to the onset of osteoarthritis (OA), the most common form of degenerative joint disease. Indeed, the degenerated cartilage exhibits low levels of PACAP, suggesting that its endogenous levels in adult cartilage may play an essential role in maintaining physiological properties. Thanks to its peculiar characteristics, exogenous administration of PACAP could be suggested as a potential tool to slow down the progression of OA and for cartilage regeneration approaches.
Open Access
Differentiation of human mesenchymal stromal cells cultured on collagen sponges for cartilage repair
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Sanjurjo Rodríguez, Clara; Martínez Sánchez, Adela Helvia; Hermida Gómez, Tamara; Fuentes Boquete, Isaac; Díaz Prado, Silvia; Blanco, Francisco J.
y. Aim: The aim of this study was to evaluate proliferation and chondrogenic differentiation of human bone-marrow mesenchymal stromal cells (hBMSCs) cultured on collagen biomaterials. Materials and Methods: hBMSCs were seeded on five different collagen (Col) sponges: C1C2 (types I and II Col), C1C2HS (types I and II Col plus heparan sulphate (HS)), C1C2CHS (types I and II Col plus chondroitin sulphate (CHS)), C1-OLH3 (type I Col plus low molecular weight heparin) and C1CHS (type I Col plus CHS). The resulting constructs were analyzed by histological and immunohistochemical staining, molecular biology and electron microscopy. Col released into culture media was measured by a dye-binding method. Results: hBMSCs on biomaterials C1C2, C1C2HS and C1C2CHS had more capacity to attach, proliferate and synthesize Col II and proteoglycans in the extracellular matrix (ECM) than on C1-OLH3 and C1CHS. The presence of aggrecan was detected only at the gene level. Total Col liberated by the cells in the supernatants in all scaffold cultures was detected. The level of Col I in the ECM was lower in C1-OLH3 and that of Col II was highest in C1C2 and C1C2HS. Electron microscopy showed differently shaped cells, from rounded to flattened, in all constructs. Col fibers in bundles were observed in C1C2CHS by transmission electron microscopy. Conclusions: The results show that Col I and Col II (C1C2, C1C2HS and C1C2CHS) biomaterials allowed cell proliferation and chondrogenic-like differentiation of hBMSCs at an early stage. Constructs cultured on C1C2HS and C1C2CHS showed better cartilage-like phenotype than the other ones.
Open Access
Exposure to second-hand cigarette smoke exacerbates the progression of osteoarthritis in a surgical induced murine model
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Rose, Brandon J.; Weyand, Jeffery A.; Liu, Brady; Smith, Jacob F.; Perez, Brian R.; Clark, J. Christian; Goodman, Michael; Budge, Kelsey M. Hirschi; Eggett, Dennis L.; Arroyo, Juan A.; Reynolds, Paul R.; Kooyman, David L.
Osteoarthritis (OA), formerly understood to be a result of passive wear, is now known to be associated with chronic inflammation. Cigarette smoking promotes systemic inflammation and has been implicated in increased joint OA incidence in some studies, though the recent observational data on the association are contradictory. We hypothesize that second-hand smoke (SHS) treatment will increase the incidence of OA in a mouse model that has been subjected to a surgical destabilization of the medial meniscus (DMM). To test this hypothesis, we applied either SHS treatment or room air (RA) to mice for 28 days post-DMM surgery. Histopathology findings indicated that the knees of SHS mice exhibited more severe OA than their control counterparts. Increased expression of matrix metalloprotease-13 (MMP-13), an important extracellular protease known to degrade articular cartilage, and nuclear factor kappa-light-chainenhancer of activated B cells (NF-κB), an intracellular effector of inflammatory pathways, were observed in the SHS group. These findings provide greater understanding and evidence for a detrimental role of cigarette smoke on OA progression and systemic inflammation.
Open Access
Expression of long-chain noncoding RNA GAS5 in osteoarthritis and its effect on apoptosis and autophagy of osteoarthritis chondrocytes
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Ji, Qinghui; Qiao, Xiaofeng; Liu, Yongxiang; Wang, Dawei
Objective. To investigate the expression of long-chain noncoding RNA GAS5 in osteoarthritis(OA) and the effect of silencing GAS5 on autophagy of osteoarthritis chondrocytes (OACs). Methods. OA rat models were constructed by cutting the anterior cruciate ligament, and the expressions of GAS5 in rat cartilage tissues at 4 weeks (early OA) and 12 weeks (late OA) after modeling were detected. The rat chondrocytes were isolated, cultured and transfected with si-GAS5 to silencing GAS5. Then, the changes of apoptosis and autophagy levels of OA chondrocytes were detected by transfection of GFP-LC3 and flow cytometry. Bioinformatic tools were used to analyze the miRNA binding to GAS5 and the downstream target genes, then luciferase reporter assay and GDC-0349 (inhibitor of mTOR) were used to verify their relationships. Results. The expression of GAS5 in cartilage tissue of OA rats was higher than control, which was higher in late OA than that in early OA. After silencing the GAS5, the autophagy ability of OACs was increased and the apoptosis rate was decreased. GAS5 was able to bind to miR-144 and regulate the expressin of mTOR. mTOR inhibitor GDC-0349 could reverse the inhibition of GAS5 on autophagy but could not reverse its effect on apoptosis. Conclusion. GAS5 expresses highly in OA cartilage tissues and increases with the progression of OA. GAS5 inhibits autophagy and promotes the apoptosis of OACs, and the inhibition of autophagy may be related to its regulation of mTOR
Open Access
Histological scoring of articular cartilage alone provides an incomplete picture of osteoarthritic disease progression
(Murcia : F. Hernández, 2010) Barley, R.D.C.; Bagnal, K.M.; Jomha, N.M.
Purpose: To ascertain whether molecularsubcategories of disease progression exist withinestablished histological grades of articular cartilage(AC). Methods: Based on H&E and safranin-O stainingof AC sections obtained from 18 knee arthroplastysurgeries, 30 samples ranging from Mankin ScoringSystem grade 1 through 5 were identified. Immuno-histochemical (IHC) analysis for collagen type II andaggrecan was performed on serial sections of theparaffin-embedded AC samples. Six AC samples fromeach of the five Mankin Scoring System grades wereexamined. Results: Significant IHC differences incollagen type II and aggrecan deposition were seenwithin AC samples from all five histological grades. Therange of IHC differences in collagen type II andaggrecan increased with increasing histological grade. Achange in the pattern of collagen type II deposition wasobserved in MG-3 AC that was consistent with a switchin collagen type II metabolism. Conclusions: IHCstaining of collagen type II and aggrecan can identifydifferences within histological grades of AC that areconsistent with the existence of molecular subcategories.These differences were detectable even within the lowesthistological grades; therefore the use of IHC staining canfurther enhance and refine the scoring of ACdeterioration in early osteoarthritis (OA). Furthermore,the changes seen in the deposition pattern for bothaggrecan and collagen type II suggest that they could beused to monitor key molecular events in OAprogression. These findings also underscore the need forthe development of IHC scoring criteria.
Open Access
Interleukin-1ß-induced expression of the urokinase-type plasminogen activator receptor and its co-localization with MMPs in human articular chondrocytes
(Murcia : F. Hernández, 2004) Schwab, W.; Schulze-Tanzil, G.; Mobasheri, A.; Dressler, J.; Kotzsch, M.; Shakibaei, M.
The urokinase-type plasminogen activator receptor (uPAR) plays a critical role in cartilage degradation during osteoarthritis as it regulates pericellular proteolysis mediated by serine proteinases. Another important family of proteinases responsible for ECM destruction in arthritis are the matrix metalloproteinases (MMPs). MMPs are regulated by IL- 1ß, a cytokine that plays a pivotal role in pathogenesis of osteoarthritis. This study was undertaken to address two questions: 1. Is uPAR-expression regulated by proinflammatory cytokines such as IL-1ß? 2. Does a functional co-localization exist between uPAR and MMPs? By immunohistochemical analysis we observed enhanced expression of uPAR on chondrocytes derived from osteoarthritic human cartilage compared to nonosteoarthritic controls. We found an IL-1ß-mediated expression of uPAR by immunoelectron microscopy. Western blot analysis demonstrated that IL-1ßstimulated expression of uPAR on chondrocytes in vitro increased in a dose-dependent manner. Furthermore, we found a functional co-localization between uPAR and MMP-9 on IL-1ß-stimulated chondrocytes by means of a co-immunoprecipitation assay. Expression of uPAR in osteoarthritic cartilage but not in healthy cartilage suggests that uPAR plays a role in cartilage breakdown. We propose that uPAR-mediated effects e.g. pericellular proteolysis are one of other cytokine (IL-1ß)-mediated events that contribute to the pathogenesis of osteoarthritis. Furthermore, we found that MMPs and uPAR were part of the same cell surface complexes in chondrocytes. This finding underlines a functional interaction between MMPs and the serine proteinase system in the fine regulation of pericellular proteolysis. Interfering with uPAR signaling may present a novel target in arthritis therapy to prevent excessive proteolytic degradation.
Open Access
Latexin expression correlated with mineralization of articular cartilage during progression of post-traumatic osteoarthritis in a rat model
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Martínez Calleja, América; Cruz, Raymundo; Miranda Sánchez, Magdalena; Fragoso Soriano, Rogelio; Vega López, Marco A.; Kour, Juan B.
As latexin has been linked with chondrocyte hypertrophic differentiation it is possible that this protein may also be involved in the mineralization of cartilage in OA. Therefore, we correlated latexin expression with the mineralization marker, alkaline phosphatase and determined the mineral deposition in the articular cartilage by analyzing the Ca/P ratio and the collagen fibrils pattern, during the progression of post-traumatic OA in a rat model. OA was induced by medial meniscectomy and post-surgery exercise for 5, 10, 20 and 45 days. Protein expression in articular cartilage was evaluated by immunofluorescence, histochemistry and Western blot. Minerals and structure of collagen fibrils in the superficial zone of cartilage were analyzed by energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) respectively. Protein expression analysis showed time-dependent up- regulation of latexin during OA progression. In the cartilage, latexin expression correlated with the expression and activity of alkaline phosphatase. EDX of the superficial zone of cartilage showed a Ca/P ratio closer to theoretical values for basic calcium phosphate minerals. The presence of minerals was also analyzed indirectly with AFM, as the collagen fibril pattern was less evident in the mineralized tissue. Latexin is expressed in articular cartilage from the early stages of post-traumatic OA; however, minerals were detected after latexin expression was up-regulated, indicating that its activity precedes and remains during the pathological mineralization of cartilage. Thus, our results contribute to the identification of molecules involved in the mineralization of articular chondrocytes.
Open Access
Mesenchymal stem cells in connective tissue engineering and regenerative medicine: Applications in cartilage repair and osteoarthritis therapy
(Murcia : F. Hernández, 2009) Mobasheri, A.; Csaki, C.; Clutterbuck, A.L.; Rahmanzadeh, M.; Shakibaei, M.
Defects of load-bearing connective tissues such as articular cartilage, often result from trauma, degenerative or age-related disease. Osteoarthritis (OA) presents a major clinical challenge to clinicians due to the limited inherent repair capacity of articular cartilage. Articular cartilage defects are increasingly common among the elderly population causing pain, reduced joint function and significant disability among affected patients. The poor capacity for self-repair of chondral defects has resulted in the development of a large variety of treatment approaches including Autologous Chondrocyte Transplantation (ACT), microfracture and mosaicplasty methods. In ACT, a cartilage biopsy is taken from the patient and articular chondrocytes are isolated. The cells are then expanded after several passages in vitro and used to fill the cartilage defect. Since its introduction, ACT has become a widely applied surgical method with good to excellent clinical outcomes. More recently, classical ACT has been combined with tissue engineering and implantable scaffolds for improved results. However, there are still major problems associated with the ACT technique which relate mainly to chondrocyte de-differentiation during the expansion phase in monolayer culture and the poor integration of the implants into the surrounding cartilage tissue. Novel approaches using mesenchymal stem cells (MSCs) as an alternative cell source to patient derived chondrocytes are currently on trial. MSCs have shown significant potential for chondrogenesis in animal models. This review article discusses the potential of MSCs in tissue engineering and regenerative medicine and highlights their potential for cartilage repair and cell-based therapies for osteoarthritis and a range of related osteoarticular disorders.
Open Access
microRNA-105-5p protects against chondrocyte injury, extracellular matrix degradation, and osteoarthritis progression by targeting SPARCL1
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2024) Jiang, Dong; Cheng, Shigao; Kang, Pengcheng; Li, Tengfei; Li, Xun; Xiao, Jiongzhe; Ren, Lian
Objective. Both microRNA (miR)-105-5p and SPARCL1 were discovered to be differentially expressed in osteoarthritis (OA), but their roles and exact mechanisms have not been entirely elaborated. This paper sets out to probe the impact of miR-105-5p/SPARCL1 on chondrocyte injury, extracellular matrix degradation, and osteoarthritis progression. Methods. C28/I2 cells were stimulated with IL-1β to construct an in vitro OA model. C28/I2 cells were transfected with sh-SPARCL1, oe-SPARCL1, or miR-105-5p mimic before IL-1β induction. CCK-8 assay, flow cytometry, and ELISA were adopted to assess cell viability, apoptosis, and inflammatory factor expression, respectively. The binding relationship of miR-105-5p to SPARCL1 was assessed using dual-luciferase reporter assay. After an OA rat model was established, rats underwent intra-articular injection with ago-miR-105-5p. TUNEL was applied to determine cell apoptosis in vivo. mRNA and protein levels were measured by qRT-PCR and western blot, respectively, in vitro and in vivo. Results. IL-1β treatment diminished miR-105-5p expression and augmented SPARCL1 expression in C28/I2 cells. miR-105-5p decreased SPARCL1 expression by targeting SPARCL1. miR-105-5p overexpression or SPARCL1 silencing prominently reversed the decrease in viability and the promotion of inflammatory factor production, cartilage matrix degradation, and apoptosis in IL-1β-stimulated C28/I2 cells. Furthermore, upregulation of SPARCL1 nullified the influence of miR-105-5p overexpression on viability, apoptosis, inflammation, and cartilage matrix degradation in IL-1β-stimulated C28/I2 cells. miR-105-5p overexpression ameliorated knee cartilage tissue injury in OA rats. Conclusion. Conclusively, miR-105-5p exerted suppressive effects on chondrocyte injury, extracellular matrix degradation, and OA progression by targeting SPARCL1.
Open Access
Molecular regulation of articular chondrocyte function and its significance in osteoarthritis
(Murcia: F. Hernández, 2011) Schroeppel, J.P.; Crist, J.D.; Anderson, H.C.; Wang, J.
Osteoarthritis (OA) is the most common form of joint disease. Histopathologically, OA is characterized by a progressive loss of articular cartilage, osteophyte formation, thickening of subchondral bone, and subchondral cyst formation. All current therapies are aimed at symptomatic control and have limited impacts on impeding or reversing the histopathologic progression to advanced OA. Previous studies have shown that overexpression of matrix-degrading proteinases and proinflammatory cytokines is associated with osteoarthritic cartilage degradation. However, clinical trials applying an inhibitor of proteinases or proinflammatory cytokines have been unsuccessful. A more sophisticated understanding of the regulatory mechanisms that control the function of articular chondrocytes is paramount to developing effective treatments. Since multiple catabolic factors and pathological chondrocyte hypertrophy are involved in the development of OA, it is important to identify which upstream factors regulate the expression of catabolic molecules and/or chondrocyte hypertrophy in articular cartilage. This review summarizes the current studies on the molecular regulation, with a main focus on transcriptional regulation, of the function of adult articular chondrocytes and its significance in the pathogenesis and treatment of OA. Recent studies have discovered that transcription factor Nfat1 may play an important role in maintaining the physiological function of adult articular chondrocytes. Nfat1-deficient mice exhibit normal skeletal development but display most of the features of human OA as adults, including chondrocyte hypertrophy with overexpression of specific matrix-degrading proteinases and proinflammatory cytokines in adult articular cartilage. ß-catenin transcriptional signaling in articular chondrocytes may also be involved in the pathogenesis of OA. Activation of ß-catenin leads to OA-like phenotypes with overexpression of specific matrix-degrading proteinases in articular cartilage of adult mice. These and other regulatory mechanisms described in this review may provide new insights into the pathogenesis of OA and the development of novel therapeutic targets for the treatment of OA.
Open Access
Multichromatic TTF staining characterizes cartilage matrix in osteoarthritis and bone development
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Feng, Yu; Cai, Zhe; Cheung, Wing ki; Yang, Kedi; Xu, Lei; Weijia Lu, William; Yang, Haibo; Chiu, Kwong-Yuen
Various histological staining methods have been explored to detect the joint lesions in osteoarthritis (OA), but these histological stains cannot comprehensively present the comparatively complex structures of articular cartilage in knee OA. In addition, no integrated histological staining method can be used to evaluate efficiently both the subzone region and matrix composition in cartilage containing tissues. Therefore, in this study, a novel multichromatic staining method termed TTF staining, using Toluidine Blue (T), Tartrazine (T) and Fast Green (F) sequential combined staining for histological analysis, has been exploited to characterize the changes of matrix components and contents in cartilage during OA and in the bone development. This specific TTF staining profile can be used to differentiate the major compartments of knee joint region, including the synovium, meniscus, multiple subzones of cartilage and subchondral bone. An anterior cruciate ligament transection induced OA model in rat has been established to profoundly present the alterations of glycosaminoglycans in cartilage degeneration by TTF staining profile. The changes of TTF staining profile in the chondrification and ossification centers of the postnatal rat knee joint indicate the developmental features of cartilage matrix during the growth of bone. In summary, we have developed an effective histological staining method that enables us to identify the subzones of cartilage in detail and to define the matrix features of bone development. Therefore, finally using this new TTF staining method may help us to exploit a histopathological grading system to assess cartilage lesions in clinical disease.
Open Access
New aspects of the pathogenesis of osteoarthritis: the role of fibroblast-like chondrocytes in late stages of the disease
(Murcia : F. Hernández, 2005) Tesche, F.; Miosge, Nicolai
It is thought that the general increase in life expectancy will make osteoarthritis the fourth leading cause of disability by the year 2020. Even though the pathogenesis of idiopathic osteoarthritis has not been fully elucidated, the main features of the disease process are the altered interactions between the chondrocytes and their surrounding extracellular matrix. In the course of these disturbances, three types of chondrocytes are typically present in the pathologically altered extracellular matrix of the articular cartilage: healthy chondrocytes which are continually undergoing degeneration, degenerated cells which are continually being degraded and finally fibroblast-like chondrocytes which seem not to be influenced by this process and, therefore, are found in ever-increasing numbers. These fibroblast-like chondrocytes take part in tissue regeneration even in advanced stages of osteoarthritis, but only in as much as they form fibrocartilaginous or scar tissue, since, as we were able to show, they mainly synthesize collagen type I and not collagen type II, typical for healthy cartilage. However, we were further able to show that fibroblast-like chondrocytes also produce increasing amounts of the proteoglycans decorin and biglycan which physiologically are involved in the formation of collagen type II, as well as perlecan. These multifunctional fibroblast-like chondrocytes could present an ideal therapeutic starting point if they could be modified to synthesize the collagen type II typical for cartilage and to, thereby, contribute to reversing the damage of the joint cartilage that has occurred by the late stages of osteoarthritis.
Open Access
Osteopontin expression and localization of Ca2+ deposits in early stages of osteoarthritis in a rat model
(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2014) Martínez Calleja, América; Velasquillo, Cristina; Vega López, Marco A.; Arellano Jiménez, M. Josefina; Tsutsumi Fujiyoshi, Victor K.; Mondragón Flores, Ricardo; Kouri Flores, Juan B.
Calcium deposits have been related to articular cartilage (AC) degeneration and have been observed in late stages of osteoarthritis (OA). However, the role of those deposits, whether they induce the OA pathogenesis or they appear as a consequence of such process, is still unknown. In this work, we present the kinetics of expression and tissue localisation of osteopontin (OPN), a mineralisation biomarker, and calcium deposits in samples from (normal, sham) and osteoarthritic cartilage (in a rat model). Immunohisto-chemical and Western blot assays for OPN, as well as Alizarin red staining for calcium deposits were performed; superficial, middle, and deep zones of AC were analysed. An increased expression of OPN and calcium deposits was found in the osteoarthritic cartilage compared with that of control groups, particularly in the superficial zone of AC in early stages of OA. In addition, the expression and localisation of OPN and calcium deposits during the OA pathogenesis suggest that the pathological AC mineralisation starts in the superficial zone during OA pathogenesis.
Open Access
Overexpression of hsa_circ_0094742 inhibits IL-1β-induced decline in CHON-001 cell viability by targeting microRNA-127-5p
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Sun, Mingqi; Yang, Junli; Jiang, Dianming; Bao, Guoyu
Osteoarthritis (OA) is a public health problem that affects 240 million people globally; however, the current treatment options for OA are not effective. Therefore, there is still an urgent need to identify novel strategies to reduce the incidence and progression of OA. The circular RNA hsa_circ_0094742 was reported to be downregulated in patients with OA. However, the underlying mechanism remains unclear. The levels of hsa_circ_0094742 in CHON-001 were detected by reverse transcription quantitative polymerase chain reaction. Moreover, Cell Counting Kit-8 assay and Ki67 staining were used to determine the cell viability. The protein expression of biomarkers was detected by western blot analysis. In addition, the putative downstream target of hsa_circ_0094742 was predicted using the Circinteractome and TargetScan online databases. The putative targeting relationship was verified by dual luciferase reporter assay and fluorescence in situ hybridization. Next, cell apoptosis was determined by Annexin V/PI staining. hsa_circ_0094742 overexpression (OE) inhibited interleukin (IL)-1β-induced decline in the viability of CHON-001 cells and primary human chondrocytes. Furthermore, IL-1β-induced alterations in aggrecan, matrix metallopeptidase 13, X-linked inhibitor of apoptosis protein (XIAP), Bax and active caspase 3 were reversed by hsa_circ_0094742 OE. Luciferase reporter assay indicated that miR-127-5p was the downstream target of hsa_circ_0094742, and latexin was the target of miR-127-5p. hsa_circ_0094742 OE inhibited IL-1βinduced decline in CHON-001 cell viability by targeting miRNA-127-5p. The findings of the present study revealed the biological rational of the use of hsa_circ_0094742 OE as an anti-IL-1β effector in human chondrocytes. These findings may prompt further research on hsa_circ_0094742 as a potent circRNA target for the treatment of OA.
Open Access
Protective effects of the pericellular matrix of chondrocyte on articular cartilage against the development of osteoarthritis
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Liu, Chenlu; Wang, Beiyu; Xiao, Li; Li, Yefu; Xu, Lin; Zhao, Zhihe; Zhang, Lin
Understanding the pathogenesis of osteoarthritis (OA) provides invaluable information in the search of therapeutic targets for the development of disease-modifying OA drugs. Emerging results from investigations demonstrate that the pericellular matrix of chondrocytes plays important roles in protecting articular cartilages from being degraded. Thus, maintaining the structural integrity of the pericellular matrix may be an effective approach to prevent the development of osteoarthritic joints. In this review article, we discuss the consequences of lacking one or more components of the pericellular matrix, and biological effects of the destruction of the pericellular matrix in the development of OA. We believe that more attention should be directed towards the pericellular matrix for the identification of novel biomarkers and therapeutic targets for the prevention and treatment of OA.