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
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
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
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.
Open Access
Role of HTRA1, a serine protease, in the progression of articular cartilage degeneration
(Murcia : F. Hernández, 2010) Polur, Llona; Lee, Peter L.; Servais, Jacqueline M.; Xu, Lin; Li, Yefu
This study is to investigate the possible role of high temperature requirement A 1 (HtrA1) in the articular cartilage degeneration. Paraffin sections were prepared from the knee and temporomandibular (TM) joints of four mouse OA models; two of the models had a genetic mutation (type IX collagen-deficient and type XI collagen-haploinsufficient) and two were surgically induced (destabilization of the medial meniscus of knee joint and discectomy of TM joint). The HtrA1 protein expression profiles of the prepared sections were examined by immunohistostaining. The level of HtrA1 mRNA in the articular cartilage taken from the knee joints of one of the genetically mutated OA models was determined by real-time PCR. Double immunohistostaining was used to examine the expression of co-localization of HtrA1 with type VI collagen and HtrA1 with discoidin domain receptor 2 (Ddr2) in the articular cartilage of knee joints from the genetically mutated OA model. The expression of HtrA1 was found to be increased in the knee and TM joints of these four models at early stages of the disease. An examination of the knee joint of a mutant mouse indicated an 8-fold increase in the level of HtrA1 mRNA, when compared to the levels observed in the knee joints of its wild-type littermates. Pericellular type VI collagen was not present in chondrocytes expressing HtrA1. Meanwhile, the expression of HtrA1 was associated with the expression of Ddr2 in the chondrocytes. Results indicate that HtrA1 may disrupt the pericellular matrix network, resulting in alteration of chondrocyte metabolisms. This eventually leads to OA
Open Access
Roles of TGF-beta 1 signaling in the development of osteoarthritis
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Fang, Jie; Xu, Lin; Li, Yefu; Zhao, Zhihe
Osteoarthritis (OA) is a degenerative joint disorder characterized by the destruction of articular cartilage, subchondral bone and other joint tissues. Although multiple growth factors and cytokines have been shown to be involved in articular cartilage degeneration and subchondral bone destruction, which eventually leads to OA, the molecular mechanisms underlying the pathogenesis of OA are largely unknown. The canonical transforming growth factor beta 1 (TGFβ1) signaling functions as one of the key factors in cartilage and bone formation, remodeling, and maintenance. However, the effects of TGF-β1 signaling on the development of OA are unclear. Numerous studies provide evidence that TGF-β1 is required for the formation of articular cartilage at early stages of joint development. In contrast, other investigations indicate that TGF-β1 may, in fact, be a factor in joint destruction. Therefore, we, in this review article, discuss the “conflicting” roles of TGF-β1 signaling in the development of OA.
Open Access
Semiquantitative analysis of ECM molecules in the different cartilage layers in early and advanced osteoarthritis of the knee joint
(2012) Lahm, Andreas; Kasch, Richard; Mrosek, Eike; Spank, Heiko; Erggelet, Christoph; Esser, Jan; Merk, Harry
The study was conducted to examine the expression of collagen type I and II in the different cartilage layers in relation to other ECM molecules during the progression of early osteoarthritic degeneration in human articular cartilage (AC). Quantitative real-time (RT)-PCR and colorimetrical techniques were used for calibration of Photoshop-based image analysis in detecting such lesions. Immunohistochemistry and histology were performed with 40 cartilage tissue samples showing mild (ICRS grade 1b) respectively moderate/advanced (ICRS grade 3a or 3b) (20 each) osteoarthritis compared with 15 healthy biopsies. Furthermore, we quantified our results on the gene expression of collagen type I and II and aggrecan with the help of real-time (RT)-PCR. Proteoglycan content was measured colorimetrically. The digitized images of histology and immunohisto-chemistry stains were analyzed with Photoshop software. T-test and Spearman correlation analysis were used for statistical analysis. In the earliest stages of AC deterioration the loss of collagen type II was associated with the appearance of collagen type I, shown by increasing amounts of collagen type I mRNA. During subsequent stages, a progressive loss of structural integrity was associated with increasing deposition of collagen type I as part of a natural healing response. A decrease of collagen type II is visible especially in the upper fibrillated area of the advanced osteoarthritic samples, which then leads to an overall decrease. Analysis of proteoglycan showed losses of the overall content and a loss of the classical zonal formation. Correlation analysis of the proteoglycan Photoshop measurements with the RT-PCR revealed strong correlation for Safranin O and collagen type I, medium for collagen type II, alcian blue and glycoprotein but weak correlation with PCR aggrecan results. Photoshop based image analysis might become a valuable supplement for well known histopathological grading systems of lesioned articular cartilage. The evidence of collagen type I production early in the OA disease process coupled with the ability of chondrocytes to up-regulate collagen type II production suggests that therapeutic agents that suppress collagen type I production and increase collagen type II production may enable chondrocytes to generate a more effective repair response
Open Access
Sodium transport systems in human chondrocytes Morphological and functional expression of the Na+,K+-ATPase a and D subunit isoforms in healthy and arthritic chondrocytes
(Murcia : F. Hernández, 1999) Trujillo, E.; Alvarez de la Rosa, D.; Mobasheri, A.; Ávila, J.; Gonzalez, T.; Martín Vasallo, P.
The chondrocyte is the cell responsible for the maintenance of the articular cartilage matrix. The negative charges of proteoglycans of the matrix draw cations, principally Na+, into the matrix to balance the negative charge distribution. The Na+,Kf -ATPase is the plasma membrane enzyme that maintains the intracellular Na+ and K+ concentrations. The enzyme is composed of an a and a l3 subunit, so far, 4 a and 3 B isoforms have been identified in mammals. Chondrocytes are sensitive to their ionic and osmotic environment and are capable of adaptive responses to ionic environmental perturbations particularly changes to extracellular [Na+]. In this article we show that human fetal and adult chondrocytes express three a ( a l , a 2 and the neural form of a3) and the three l3 isoforms (131, l32 and 83) of the Na+,K+-ATPase. The presence of multiple Na+,K+-ATPase isoforms in the plasma membrane of chondrocytes suggests a variety of kinetic properties that reflects a cartilage specific and very fine specialization in order to maintain the Na+/K+ gradients. Changes in the ionic and osmotic environment of chondrocytes occur in osteoarthritis and rheumatoid arthritis as result of tissue hydration and proteoglycan loss leading to a fall in tissue Na+ and K+ content. Although the expression levels and cellular distribution of the proteins tested do not vary, we detect changes in p-nitrophenylphosphatase activity "in situ" between control and pathological samples. This change in the sodium pump enzymatic activity suggests that the chondrocyte responds to these cationic environmental changes with a variation of the active isozyme types present in the plasma membrane.
Open Access
Sodium transport systems in human chondrocytes II. Expression of ENaC, Na+ K+ 2CI- cotransporter and Na+ H+ exchangers in healthy
(Murcia : F. Hernández, 1999) Trujillo, E.; Alvarez de la Rosa, D.; Mobasheri, A.; Gonzalez, T.; Canessa, C.M.; Martín Vasallo, P.
In this article, the second of two, we continue our studies of sodium-dependent transport systems in human cartilage from healthy individuals and with osteoarthritis (OA) and rheumatoid arthritis (RA). We demonstrate the presence of the epithelia1 sodium channel (ENaC), previously undescribed in chondrocytes. This system is composed of three subunits, a, 13 and y. We have shown that the human chondrocytes express at least the a and the l3 subunit of ENaC. The expression of these subunits is altered in arthritic chondrocytes. In RA samples the quantity of a and B is significantly higher than in control samples. On the other hand, ENaC a and B subunits are absent in the chondrocytes of OA cartilage. Human chondrocytes also possess three isoforms of the Na+/H+ exchanger (NHE), NHE1, NHE2 and NHE3. The NHE system is composed of a single protein and is believed to participate in intracellular pH regulation. Furthermore, our studies indicate that at least one isoform of the electroneutral Naf/K+/2C1- cotransporter (NKCC) is present in human chondrocytes. There are no obvious variations in the relative expression of NHE isoforms or NKCC between healthy and arthritic cartilage. Our data suggests that chondrocytes from arthritic cartilage may adapt to changes in their environmental sodium concentration through variations in ENaC protein levels. ENaC is also likely to serve as a major sodium entry mechanism, a process that, along with cytoskeletal proteins, may be part of mechanotransduction in cartilage.
Open Access
Treatment of osteoarthritis with collagen-based scaffold: A porcine animal model with xenograft mesenchymal stem cells
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2018) Tseng, Wo Jan; Huang, Shu Wei; Fang, Chih Hsiang; Hsu, Lih Tao; Chen, Chih Yu; Shen, Hsin Hsin; Zwei Chieng Chang, Jenny; Sun, Jui Sheng; Lin, Feng Huei
Objective. With the goal to explore a new approach to treat the early degenerative lesions of hyaline cartilage, we implanted in a porcine OA model a collagen-based scaffold containing chondroprogenitor cells derived from human bone marrow mesenchymal stem cells (hBM-MSCs). Experimental design. Porcine knee joints were subjected to anterior cruciate ligament (ACL) transection to surgically induce OA. After 4 months, the time necessary for the development of cartilage surface damage, animals were treated either with trephination bone plug wrapped with the chondroprogenic hBM-MSCs-embedded collagen scaffold or microfractures alone. Histological and histomorphometric evaluations were performed at 5 months after surgery. Results. All animals subjected to ACL transection showed osteoarthritic changes including mild lateral femoral condyle or moderate medial femoral condyle ulcerations. After 14 days’ chondrogenic induction, hBM-MSCs seeded onto the scaffold showed expression of chondroprogenitor markers such as SOX9 and COMP. At 5 months after the implantation, significant differences in the quality of the regenerated tissue were found between the hBM-MSCsembedded scaffold group and the control group. Newly generated tissue was only observed at the site of implantation with the hBM-MSCs-embedded scaffolds. Furthermore, histological examination of the generated tissue revealed evidence of cartilage-like tissue with lacuna formation. In contrast, fibrous layers or fissures were formed on the surface of the control knee joint. Conclusions. This study shows that xenogenic hBMMSC derived chondroprogenitor scaffolds can generate new cartilage tissue in porcine articular cartilage and have the potential as a useful treatment option for osteoarthritis.