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Bone & Joint Research
Vol. 13, Issue 6 | Pages 261 - 271
1 Jun 2024
Udomsinprasert W Mookkhan N Tabtimnark T Aramruang T Ungsudechachai T Saengsiwaritt W Jittikoon J Chaikledkaew U Honsawek S

Aims. This study aimed to determine the expression and clinical significance of a cartilage protein, cartilage oligomeric matrix protein (COMP), in knee osteoarthritis (OA) patients. Methods. A total of 270 knee OA patients and 93 healthy controls were recruited. COMP messenger RNA (mRNA) and protein levels in serum, synovial fluid, synovial tissue, and fibroblast-like synoviocytes (FLSs) of knee OA patients were determined using enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and immunohistochemistry. Results. COMP protein levels were significantly elevated in serum and synovial fluid of knee OA patients, especially those in the advanced stages of the disease. Serum COMP was significantly correlated with radiological severity as well as measures of body composition, physical performance, knee pain, and disability. Receiver operating characteristic curve analysis unveiled a diagnostic value of serum COMP as a biomarker of knee OA (41.64 ng/ml, area under the curve (AUC) = 1.00), with a sensitivity of 99.6% and a specificity of 100.0%. Further analysis uncovered that COMP mRNA expression was markedly upregulated in the inflamed synovium of knee OA, consistent with immunohistochemical staining revealing localization of COMP protein in the lining and sub-lining layers of knee OA inflamed synovium. Most notably, relative COMP mRNA expression in knee OA synovium was positively associated with its protein levels in serum and synovial fluid of knee OA patients. In human knee OA FLSs activated with tumour necrosis factor-alpha, COMP mRNA expression was considerably up-regulated in a time-dependent manner. Conclusion. All results indicate that COMP might serve as a supportive diagnostic marker for knee OA in conjunction with the standard diagnostic methods. Cite this article: Bone Joint Res 2024;13(6):261–271


Bone & Joint Research
Vol. 13, Issue 1 | Pages 4 - 18
2 Jan 2024
Wang Y Wu Z Yan G Li S Zhang Y Li G Wu C

Aims. cAMP response element binding protein (CREB1) is involved in the progression of osteoarthritis (OA). However, available findings about the role of CREB1 in OA are inconsistent. 666-15 is a potent and selective CREB1 inhibitor, but its role in OA is unclear. This study aimed to investigate the precise role of CREB1 in OA, and whether 666-15 exerts an anti-OA effect. Methods. CREB1 activity and expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) in cells and tissues were measured by immunoblotting and immunohistochemical (IHC) staining. The effect of 666-15 on chondrocyte viability and apoptosis was examined by cell counting kit-8 (CCK-8) assay, JC-10, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) staining. The effect of 666-15 on the microstructure of subchondral bone, and the synthesis and catabolism of cartilage, in anterior cruciate ligament transection mice were detected by micro-CT, safranin O and fast green (S/F), immunohistochemical staining, and enzyme-linked immunosorbent assay (ELISA). Results. CREB1 was hyperactive in osteoarthritic articular cartilage, interleukin (IL)-1β-treated cartilage explants, and IL-1β- or carbonyl cyanide 3-chlorophenylhydrazone (CCCP)-treated chondrocytes. 666-15 enhanced cell viability of OA-like chondrocytes and alleviated IL-1β- or CCCP-induced chondrocyte injury through inhibition of mitochondrial dysfunction-associated apoptosis. Moreover, inhibition of CREB1 by 666-15 suppressed expression of ADAMTS4. Additionally, 666-15 alleviated joint degeneration in an ACLT mouse model. Conclusion. Hyperactive CREB1 played a critical role in OA development, and 666-15 exerted anti-IL-1β or anti-CCCP effects in vitro as well as joint-protective effects in vivo. 666-15 may therefore be used as a promising anti-OA drug. Cite this article: Bone Joint Res 2024;13(1):4–18


Bone & Joint Research
Vol. 13, Issue 7 | Pages 342 - 352
9 Jul 2024
Cheng J Jhan S Chen P Hsu S Wang C Moya D Wu Y Huang C Chou W Wu K

Aims. To explore the efficacy of extracorporeal shockwave therapy (ESWT) in the treatment of osteochondral defect (OCD), and its effects on the levels of transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, -3, -4, -5, and -7 in terms of cartilage and bone regeneration. Methods. The OCD lesion was created on the trochlear groove of left articular cartilage of femur per rat (40 rats in total). The experimental groups were Sham, OCD, and ESWT (0.25 mJ/mm. 2. , 800 impulses, 4 Hz). The animals were euthanized at 2, 4, 8, and 12 weeks post-treatment, and histopathological analysis, micro-CT scanning, and immunohistochemical staining were performed for the specimens. Results. In the histopathological analysis, the macro-morphological grading scale showed a significant increase, while the histological score and cartilage repair scale of ESWT exhibited a significant decrease compared to OCD at the 8- and 12-week timepoints. At the 12-week follow-up, ESWT exhibited a significant improvement in the volume of damaged bone compared to OCD. Furthermore, immunohistochemistry analysis revealed a significant decrease in type I collagen and a significant increase in type II collagen within the newly formed hyaline cartilage following ESWT, compared to OCD. Finally, SRY-box transcription factor 9 (SOX9), aggrecan, and TGF-β, BMP-2, -3, -4, -5, and -7 were significantly higher in ESWT than in OCD at 12 weeks. Conclusion. ESWT promoted the effect of TGF-β/BMPs, thereby modulating the production of extracellular matrix proteins and transcription factor involved in the regeneration of articular cartilage and subchondral bone in an OCD rat model. Cite this article: Bone Joint Res 2024;13(7):342–352


Bone & Joint Research
Vol. 11, Issue 7 | Pages 453 - 464
20 Jul 2022
Wang H Shi Y He F Ye T Yu S Miao H Liu Q Zhang M

Aims. Abnormal lipid metabolism is involved in the development of osteoarthritis (OA). Growth differentiation factor 11 (GDF11) is crucial in inhibiting the differentiation of bone marrow mesenchymal stem cells into adipocytes. However, whether GDF11 participates in the abnormal adipogenesis of chondrocytes in OA cartilage is still unclear. Methods. Six-week-old female mice were subjected to unilateral anterior crossbite (UAC) to induce OA in the temporomandibular joint (TMJ). Histochemical staining, immunohistochemical staining (IHC), and quantitative real-time polymerase chain reaction (qRT-PCR) were performed. Primary condylar chondrocytes of rats were stimulated with fluid flow shear stress (FFSS) and collected for oil red staining, immunofluorescence staining, qRT-PCR, and immunoprecipitation analysis. Results. Abnormal adipogenesis, characterized by increased expression of CCAAT/enhancer-binding protein α (CEBPα), fatty acid binding protein 4 (FABP4), Perilipin1, Adiponectin (AdipoQ), and peroxisome proliferator-activated receptor γ (PPARγ), was enhanced in the degenerative cartilage of TMJ OA in UAC mice, accompanied by decreased expression of GDF11. After FFSS stimulation, there were fat droplets in the cytoplasm of cultured cells with increased expression of PPARγ, CEBPα, FABP4, Perilipin1, and AdipoQ and decreased expression of GDF11. Exogenous GDF11 inhibited increased lipid droplets and expression of AdipoQ, CEBPα, and FABP4 induced by FFSS stimulation. GDF11 did not affect the change in PPARγ expression under FFSS, but promoted its post-translational modification by small ubiquitin-related modifier (SUMOylation). Local injection of GDF11 alleviated TMJ OA-related cartilage degeneration and abnormal adipogenesis in UAC mice. Conclusion. Abnormal adipogenesis of chondrocytes and decreased GDF11 expression were observed in degenerative cartilage of TMJ OA. GDF11 supplementation effectively inhibits the adipogenesis of chondrocytes and thus alleviates TMJ condylar cartilage degeneration. GDF11 may inhibit the abnormal adipogenesis of chondrocytes by affecting the SUMOylation of PPARγ. Cite this article: Bone Joint Res 2022;11(7):453–464


Bone & Joint Research
Vol. 10, Issue 3 | Pages 192 - 202
1 Mar 2021
Slimi F Zribi W Trigui M Amri R Gouiaa N Abid C Rebai MA Boudawara T Jebahi S Keskes H

Aims. The present study investigates the effectiveness of platelet-rich plasma (PRP) gel without adjunct to induce cartilage regeneration in large osteochondral defects in a rabbit model. Methods. A bilateral osteochondral defect was created in the femoral trochlear groove of 14 New Zealand white rabbits. The right knees were filled with PRP gel and the contralateral knees remained untreated and served as control sides. Some animals were killed at week 3 and others at week 12 postoperatively. The joints were harvested and assessed by Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) MRI scoring system, and examined using the International Cartilage Repair Society (ICRS) macroscopic and ICRS histological scoring systems. Additionally, the collagen type II content was evaluated by the immunohistochemical staining. Results. After 12 weeks post-surgery, the defects of the PRP group were repaired by hyaline cartilage-like tissue. However, incomplete cartilage regeneration was observed in the PRP group for three weeks. The control groups showed fibrocartilaginous or fibrous tissue, respectively, at each timepoint. Conclusion. Our study proved that the use of PRP gel without any adjuncts could successfully produce a good healing response and resurface the osteochondral defect with a better quality of cartilage in a rabbit model. Cite this article: Bone Joint Res 2021;10(3):192–202


Bone & Joint Research
Vol. 11, Issue 4 | Pages 189 - 199
13 Apr 2022
Yang Y Li Y Pan Q Bai S Wang H Pan X Ling K Li G

Aims. Treatment for delayed wound healing resulting from peripheral vascular diseases and diabetic foot ulcers remains a challenge. A novel surgical technique named ‘tibial cortex transverse transport’ (TTT) has been developed for treating peripheral ischaemia, with encouraging clinical effects. However, its underlying mechanisms remain unclear. In the present study, we explored the potential biological mechanisms of TTT surgery using various techniques in a rat TTT animal model. Methods. A novel rat model of TTT was established with a designed external fixator, and effects on wound healing were investigated. Laser speckle perfusion imaging, vessel perfusion, histology, and immunohistochemistry were used to evaluate the wound healing processes. Results. Gross and histological examinations showed that TTT technique accelerated wound closure and enhanced the quality of the newly formed skin tissues. In the TTT group, haematoxylin and eosin (H&E) staining demonstrated a better epidermis and dermis recovery, while immunohistochemical staining showed that TTT technique promoted local collagen deposition. The TTT technique also benefited to angiogenesis and immunomodulation. In the TTT group, blood flow in the wound area was higher than that of other groups according to laser speckle imaging with more blood vessels observed. Enhanced neovascularization was seen in the TTT group with double immune-labelling of CD31 and α-Smooth Muscle Actin (α-SMA). The number of M2 macrophages at the wound site in the TTT group was also increased. Conclusion. The TTT technique accelerated wound healing through enhanced angiogenesis and immunomodulation. Cite this article: Bone Joint Res 2022;11(4):189–199


Bone & Joint Research
Vol. 9, Issue 3 | Pages 99 - 107
1 Mar 2020
Chang C Jou I Wu T Su F Tai T

Aims. Cigarette smoking has a negative impact on the skeletal system, causes a decrease in bone mass in both young and old patients, and is considered a risk factor for the development of osteoporosis. In addition, it disturbs the bone healing process and prolongs the healing time after fractures. The mechanisms by which cigarette smoking impairs fracture healing are not fully understood. There are few studies reporting the effects of cigarette smoking on new blood vessel formation during the early stage of fracture healing. We tested the hypothesis that cigarette smoke inhalation may suppress angiogenesis and delay fracture healing. Methods. We established a custom-made chamber with airflow for rats to inhale cigarette smoke continuously, and tested our hypothesis using a femoral osteotomy model, radiograph and microCT imaging, and various biomechanical and biological tests. Results. In the smoking group, Western blot analysis and immunohistochemical staining revealed less expression of vascular endothelial growth factor (VEGF) and von Willebrand factor (vWF). The smoking group also had a lower microvessel density than the control group. Image and biochemical analysis also demonstrated delayed bone healing. Conclusion. Cigarette smoke inhalation was associated with decreased expression of angiogenic markers in the early bone healing phase and with impaired bone healing. Cite this article:Bone Joint Res. 2020;9(3):99–107


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 34 - 34
4 Apr 2023
Kaneko Y Minehara H Nakamura M Sekiguchi M Matsushita T Konno S
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Recent researches indicate that both M1 and M2 macrophages play vital roles in tissue repair and foreign body reaction processes. In this study, we investigated the dynamics of M1 macrophages in the induced membrane using a mouse femur critical-sized bone defect model. The Masquelet method (M) and control (C) groups were established using C57BL/6J male mice (n=24). A 3mm-bone defect was created in the right femoral diaphysis followed by a Kirschner wire fixation, and a cement spacer was inserted into the defect in group M. In group C, the bone defect was left uninserted. Tissues around the defect were harvested at 1, 2, 4, and 6 weeks after surgery (n=3 in each group at each time point). Following Hematoxylin and eosin (HE) staining, immunohistochemical staining (IHC) was used to evaluate the CD68 expression as a marker of M1 macrophage. Iron staining was performed additionally to distinguish them from hemosiderin-phagocytosed macrophages. In group M, HE staining revealed a hematoma-like structure, and CD68-positive cells were observed between the spacer and fibroblast layer at 1 week. The number of CD68-positive cells decreased at 2 weeks, while they were observed around the new bone at 4 and 6 weeks. In group C, fibroblast infiltration and fewer CD68-positive cells were observed in the bone defect without hematoma-like structure until 2 weeks, and no CD68-positive cells were observed at 4 and 6 weeks. Iron staining showed hemosiderin deposition in the surrounding area of the new bone in both groups at 4 and 6 weeks. The location of hemosiderin deposition was different from that of macrophage aggregation. This study suggests that M1 macrophage aggregation is involved in the formation of induced membranes and osteogenesis and may be facilitated by the presence of spacers


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_7 | Pages 107 - 107
4 Apr 2023
Li C Ding Y Li S Lin S Wen Z Ouyang Z
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Osteoarthritis, the most common degenerative joint disease, significantly impairs life quality and labor capability of patients. Synovial inflammation, initiated by HMGB1 (High mobility group box 1)-induced activation of macrophage, precedes other pathological changes. As an upstream regulator of NF-κB (nuclear factor-kappa B) and MAPK (mitogen-activated protein kinase) signaling pathway, TAK1 (TGF-β activated kinase 1) participates in macrophage activation, while its function in osteoarthritis remains unveiled. This study aims to investigate the role of TAK1 in the pathogenesis of osteoarthritis via both in vitro and in vivo approaches. We performed immunohistochemical staining for TAK1 in synovial tissue, both in osteoarthritis patients and healthy control. Besides, immunofluorescence staining for F4/80 as macrophage marker and TAK1 were conducted as well. TAK1 expression was examined in RAW264.7 macrophages stimulated by HMGB1 via qPCR (Quantitative polymerase chain reaction) and Western blotting, and the effect of TAK1 inhibitor (5z-7 oxozeaenol) on TNF-α production was evaluated by immunofluorescence staining. Further, we explored the influence of intra-articular shRNA (short hairpin RNA) targeting TAK1 on collagenase-induced osteoarthritis in mice. Immunohistochemical staining confirmed significant elevation of TAK1 in osteoarthritic synovium, and immunofluorescence staining suggested macrophages as predominant residence of TAK1. In HMGB1-stimulated RAW264.7 macrophages, TAK1 expression was up-regulated both in mRNA and protein level. Besides, TAK1 inhibitor significantly impairs the production of TNF-α by macrophages upon HMGB1 stimulation. Moreover, intra-articular injection of lentivirus loaded with shRNA targeting TAK1 (sh-TAK1) reduced peri-articular osteophyte formation in collagenase-induced osteoarthritis in mice. TAK1 exerts a potent role in the pathogenesis of osteoarthritis by mediating the activation of macrophages


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_1 | Pages 35 - 35
2 Jan 2024
Nardini M Gentili C Muraglia A Zanirato A Ferrari P Formica M Cancedda R Mastrogiacomo M
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Degenerative disc disease, associated to low back pain, afflicts more than 50% of humans, and represents a major healthcare problem, especially for the pathology initiation. Current treatments range from conservative strategies to more invasive surgical techniques, such as disc removal and vertebral fusion. In the Intervertebral Disease (IVD) the nucleus pulposus (NP) degeneration is a key factor for the pathology initiation. Several tissue engineering approaches aiming to restore the appropriate NP cell (NPCs) and matrix content, were attempted by using adult stromal cells either from bone marrow or adipose tissue, chondrocytes, notochordal cells and more recently also pluripotent stem cells. However, none was fully satisfactory since the NP acid and a-vascularized environment appeared averse to the implanted heterologous cells. Several studies demonstrated the efficacy of platelet derivatives such as platelet rich plasma (PRP) in promoting the regeneration of connective tissues. We investigated the efficacy of PRP on NPCs proliferation and differentiation with the goal to propose the direct stimulation of resident cells (stimulation of endogenous cells – less invasive surgical procedure) or the implantation of NPCs expanded in vitro in the presence of PRP as therapeutic agents in IVD degeneration. NPCs were isolated from small fragments of NP explants, cultivated in medium supplemented with PRP or FCS (standard condition control) and characterized by FACS analysis for the expression of the typical mesenchymal stem cells markers CD34, CD44, CD45, CD73, CD90 and CD105. NPCs cultured in PL showed a phenotypic profile like the cells cultured in FCS. However, compared to NPCs expanded in the presence of FCS, NPCs expanded in PRP showed a much better proliferation and differentiation capacity. NPCs differentiation was evaluated by the cell ability to produce an organized metachromatic cartilaginous matrix, confirmed by the positive immunohistochemical staining for chondrogenic markers


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_8 | Pages 148 - 148
11 Apr 2023
Kopinski-Grünwald O Guillaume O Arslan A Van Vlierberghe S Ovsianikov A
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In the field of tissue engineering (TE), mainly two approaches have been widely studied and utilised throughout the last two decades. Ovsianikov et al. proposed a third strategy for tissue engineering to combine the advantages of the scaffold-based and scaffold-free approach [1]. We utilise the third strategy for TE by fabrication of cell spheroids that are reinforced by microscaffolds, called tissue units (TUs). Aim of the presented study is to differentiate TUs towards a chondrogenic phenotype to show the self-assembly of a millimetre sized cartilage-like tissue in a bottom-up TE approach in vitro. Two-Photon polymerization (2PP) was utilised to fabricate highly porous microscaffolds with a diameter of 300 µm. The biocompatible and biodegradable, resin Degrad INX (supplied from Xpect INX, Ghent, Belgium) was used for 3D-printing. Each microscaffold was seeded with 4000 human adipose derived stem cells (hASCs) in low-adhesive 96-well plates to allow spheroid formation. TUs were differentiated towards the chondrogenic lineage by application of chondrogenic media, subsequently merged in a cylindrical agarose mold, to fuse into a connected tissue with a diameter of ~1.8 mm and a height of 8 mm. The characterization of TUs differentiated towards the chondrogenic phenotype included gene expression and protein analysis. Furthermore, immunohistochemically staining for Collagen II and Alcian blue staining were performed to investigate the matrix deposition and fusion of the self-assembled tissue. Our results suggest that the utilised method could be a promising approach for a variety of tissue engineering approaches, due to the good applicability to a defect side combined with the self-assembly properties of the TUs. Furthermore, the differentiation potential of hASCs is not limited to chondrogenic lineages only, which could pave the way to further TE applications in the future. Acknowledgements:. This research work was financially supported by the European Research Council (Consolidator Grant 772464 A.O.)


Objectives. The lack of effective treatment for cartilage defects has prompted investigations using tissue engineering techniques for their regeneration and repair. The success of tissue-engineered repair of cartilage may depend on the rapid and efficient adhesion of transplanted cells to a scaffold. Our aim in this study was to repair full-thickness defects in articular cartilage in the weight-bearing area of a porcine model, and to investigate whether the CD44 monoclonal antibody biotin-avidin (CBA) binding technique could provide satisfactory tissue-engineered cartilage. Methods. Cartilage defects were created in the load-bearing region of the lateral femoral condyle of mini-type pigs. The defects were repaired with traditional tissue-engineered cartilage, tissue-engineered cartilage constructed with the biotin-avidin (BA) technique, tissue-engineered cartilage constructed with the CBA technique and with autologous cartilage. The biomechanical properties, Western blot assay, histological findings and immunohistochemical staining were explored. Results. The CBA group showed similar results to the autologous group in biomechanical properties, Moran’s criteria, histological tests and Wakitani histological scoring. Conclusions. These results suggest that tissue-engineered cartilage constructed using the CBA technique could be used effectively to repair cartilage defects in the weight-bearing area of joints. Cite this article: H. Lin, J. Zhou, L. Cao, H. R. Wang, J. Dong, Z. R. Chen. Tissue-engineered cartilage constructed by a biotin-conjugated anti-CD44 avidin binding technique for the repairing of cartilage defects in the weight-bearing area of knee joints in pigs. Bone Joint Res 2017;6:–295. DOI: 10.1302/2046-3758.65.BJR-2016-0277


Bone & Joint Research
Vol. 1, Issue 1 | Pages 1 - 7
1 Jan 2012
Rosenberg N Rosenberg O

Objectives. The need for bone tissue supplementation exists in a wide range of clinical conditions involving surgical reconstruction in limbs, the spine and skull. The bone supplementation materials currently used include autografts, allografts and inorganic matrix components; but these pose potentially serious side-effects. In particular the availability of the autografts is usually limited and their harvesting causes surgical morbidity. Therefore for the purpose of supplementation of autologous bone graft, we have developed a method for autologous extracorporeal bone generation. Methods. Human osteoblast-like cells were seeded on porous granules of tricalcium phosphate and incubated in osteogenic media while exposed to mechanical stimulation by vibration in the infrasonic range of frequencies. The generated tissue was examined microscopically following haematoxylin eosin, trichrome and immunohistochemical staining. Results. Following 14 days of incubation the generated tissue showed histological characteristics of bone-like material due to the characteristic eosinophilic staining, a positive staining for collagen trichrome and a positive specific staining for osteocalcin and collagen 1. Macroscopically, this tissue appeared in aggregates of between 0.5 cm and 2 cm. . Conclusions. We present evidence that the interaction of the cellular, inorganic and mechanical components in vitro can rapidly generate three-dimensional bone-like tissue that might be used as an autologous bone graft


The Journal of Bone & Joint Surgery British Volume
Vol. 83-B, Issue 2 | Pages 289 - 294
1 Mar 2001
Im G Kim D Shin J Hyun C Cho W

In 16 mature New Zealand white rabbits mesenchymal stem cells were aspirated from the bone marrow, cultured in monolayer and implanted on to a full-thickness osteochondral defect artificially made on the patellar groove of the same rabbit. A further 13 rabbits served as a control group. The rabbits were killed after 14 weeks. Healing of the defect was investigated histologically using haematoxylin and eosin and Safranin-O staining and with immunohistochemical staining for type-II collagen. We also used a reverse transcription-polymerase chain reaction (RT-PCR) to detect mRNA of type-I and type-II collagen. The semiquantitative histological scores were significantly higher in the experimental group than in the control group (p < 0.05). In the experimental group immunohistochemical staining on newly formed cartilage was more intense for type-II collagen in the matrix and RT-PCR from regenerated cartilage detected mRNA for type-II collagen in mature chondrocytes. These findings suggest that repair of cartilage defects can be enhanced by the implantation of cultured mesenchymal stem cells


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_13 | Pages 26 - 26
1 Nov 2021
Amado I Hodgkinson T Murphy C Kennedy O
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Introduction and Objective. Traditionally, osteoarthritis (OA) has been associated mostly with degradation of cartilage only. More recently, it has been established that other joint tissues, in particular bone, are also centrally involved. However, the link between these two tissues remains unclear. This relationship is particularly evident in post-traumatic OA (PTOA), where bone marrow lesions (BMLs), as well as fluctuating levels of inflammation, are present long before cartilage degradation begins. The process of bone-cartilage crosstalk has been challenging to study due to its multi-tissue complexity. Thus, the use of explant model systems have been crucial in advancing our knowledge. Thus, we developed a novel patellar explant model, to study bone cartilage crosstalk, in particular related to subchondral bone damage, as an alternative to traditional femoral head explants or cylindrical core specimens. The commonly used osteochondral explant models are limited, for our application, since they involve bone damage during harvest. The specifics aim of this study was to validate this novel patellar explant model by using IL-1B to stimulate the inflammatory response and mechanical stimulation to determine the subsequent developments of PTOA. Materials and Methods. Lewis rats (n=48) were used to obtain patellar and femoral head explants which were harvested under an institutional ethical approval license. Explants were maintained in high glucose media (containing supplements), under sterile culture conditions. Initially, we characterised undamaged patellar explants and compared them with the commonly used femoral head. First, tissue viability was assessed using an assay of metabolic activity and cell damage. Second, we created chemical and mechanical damage in the form of IL-1B treatment, and mechanical stimulation, to replicate damage. Standard biochemical assays, histological assays and microstructural assays were used to evaluate responses. For chemical damage, explants were exposed to 10ng/ml of IL-1B for 24 hours at 0, 1, 3 and 7 days after harvesting. For mechanical damage, tissues were exposed to mechanical compression at 0.5 Hz, 10 % strain for 10 cycles, for 7 days. Contralateral patellae served as controls. In both groups, sGAG, ADAMTS4, and MMP-13 were measured as an assessment of representative cartilage responses while ALP, TRAP and CTSK were assessed as a representative of bone responses. In addition to this, histomorphometric, and immunohistochemical, evaluations of each explant system were also carried out. Results. Our results confirm that the patellar explant system is an excellent ex vivo model system to study bone-cartilage crosstalk, and one which does not induce any bone damage at the time of tissue harvest. We successfully established culture conditions to maintain viability in these explants for up to 28 days. Rat IL-1B treatment resulted in increased both proteoglycan content and bone metabolism markers after 7 days when compared with the controls. To confirm this finding, qualitative immunohistochemical staining showed chondrocytes increased expression of MMP13 after treatment with IL-1B. Furthermore, we observed that the levels of ADAMTS4 decreased in 48 hours after IL-1B exposure. Contrastingly IL-1B treatment had the opposite effect on CTSK markers when compared with the control. Mechanically compressed patellae showed a decrease in compressive moduli from day 3 to day 7, suggesting that tissue remodelling may have taken place as a compensatory mechanism in response to damage. In addition, MMP13 release decreased over 48 hours after mechanical compression, while TRAP levels were increased compared with the control. Conclusions. Thus, we successfully demonstrated that IL-1B and mechanical stimulation affects both bone and cartilage tissues independently in this system, which may have relevance in the understanding of bone-cartilage crosstalk after injury and how this is involved in PTOA development


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_22 | Pages 60 - 60
1 Dec 2017
Jensen LK Henriksen NL Jensen HE
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Aim. Despite the expanding research focusing on bacterial biofilm formation, specific histochemical biofilm stains have not been developed for light microscopy. Therefore, pathologists are often not aware of the presence of biofilm formation when examining slides for diagnosing bacterial infections, including orthopaedic infections. The aim of the present study was to develop a combined histochemical and immunohistochemical biofilm stain for simultaneous visualization of Staphylococcus aureus bacteria and extracellular matrix in different colours using light microscopy. Methods. Infected bone tissue was collected from two different porcine models of osteomyelitis inoculated with the biofilm forming S. aureus strain S54F9. The infection time was 5 and 15 days, respectively. First, 25 common histochemical protocols were used in order to find stains that could identify extracellular biofilm matrix. Hereafter, the histochemical protocols for Alcian Blue pH3, Luna and Methyl-pyronin green were combined with an immunohistochemical protocol based on a specific antibody against S. aureus. Finally, the three new combined protocols were applied to infected bone tissue from a child suffering from chronic staphylococcal osteomyelitis for more than a year. For all combined protocols applied on all types of tissue (porcine and human) the number of double stained bacterial aggregates were counted. On the same sections the percentage of extracellular matrix of representative bacterial aggregates was calculated by image analysis. Results. Simultaneous visualization of bacterial cells and extracellular matrix in different colours was detected in both porcine and human tissue sections with all three combined protocols. The bacterial cells were red to light brown and the extracellular matrix either light blue, blue or orange depending on the histochemical stain i.e. if it was Alcian blue pH3 (colouring polysaccharides), Luna or Methyl green-pyronin (both colouring extracellular DNA), respectively. In the porcine models, 10 percent of the bacterial aggregates in a 10× magnification field revealed both the extracellular matrix and bacteria simultaneously in two different colours. For the human case, this was seen in 90 percent of the bacterial aggregates. The percentage of extracellular matrix of representative bacterial aggregates was 60 and 20 percent in the human and porcine tissues, respectively. Conclusions. The amount of S. aureus biofilm extracellular matrix increased with infection time. A combination of histochemical and immunohistochemical staining is a practical method for identification and evaluation of S. aureus biofilm in orthopaedic infections


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_6 | Pages 16 - 16
1 Apr 2018
Lee K
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Meniscus tears in adult patients do not heal spontaneously and represent a risk factor for OA development. PDGF is well known as an enhancer of meniscal cell biosynthetic activity and also has chemotactic activity for mesenchymal cells. PDGF incorporation into scaffolds should be efficient for recruitment of cells to initiate repair in the injured meniscus. We recently developed decellularized meniscus sheet for use in the treatment of meniscus tears. The aim of this study is to examine the potential of PDGF-coated decellularized meniscus scaffold in mediating integrative healing by endogenous cell migration. Fresh bovine meniscus was chemically decellularized. Round sheets were made from the decellularized tissue. Heparin was covalently conjugated with decellularized meniscus scaffold (DMS). PDGF-BB was immobilized by binding to the heparin-conjugated DMS. In vitro, PDGF release kinetics was analyzed by ELISA. DMS was transplanted into the injured meniscus explants and cultured for 2 and 4 weeks. The numbers of migrated cells at the border between DMS and injured explant were counted on DAPI stained sections and PDGFRb expressing cells were counted after immunohistochemical staining. The newly produced ECM and collagen fiber alignment was detected by histology on Safranin-O and picrosirius red stained sections. The explants were also tested for tensile properties. PDGF release kinetics showed sustained slow release in heparin-conjugated DMS, with 11.2% release at day- 16th compared to 26.1% release from the DMS without heparin. Insertion of the PDGF-treated DMS into the meniscus tears in bovine meniscus explants led to the migration of endogenous meniscus cells to the defect zone. The migrated cells expressed PDGFRb and produced new ECM in the defect area. Safranin-O and pircrosirius red staining showed tissue integration between DMS and injured explants. Moreover, the higher concentration of PDGF promoted cell integration into the DMS. Tensile properties of injured explants treated with PDGF coated DMS were significantly higher than in DMS without PDGF. Heparin-conjugated DMS showed strong immobilization of PDGF, which was released slowly. PDGF coated DMS promoted migration of endogenous meniscus cells to the defect area and into the scaffold. New matrix was formed that bridged the space between the native meniscus and the scaffold and this was associated with improved biomechanical properties. The PDGF coated DMS is a novel, feasible and efficient approach for the treatment of meniscus tears


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XIV | Pages 22 - 22
1 Apr 2012
Gomez-Brouchet A Mourcin F Gourault P Bouvier C De Pinieux G Le Guellec S Brousset P Delisle M Schiff C
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Aim and purpose. The clinical management of osteosarcoma differs significantly from that of chondrosarcoma;. Therefore it is extremely important to diagnose these two types of bone tumour accurately. In the absence of a specific marker, differential diagnosis by histochemistry is sometimes impossible, especially between chondroblastic osteosarcoma and conventional chondrosarcoma. The aim of the study was to find an useful diagnostic marker, simple to use for distinguishes chondroblastic osteosarcoma from conventional chondrosarcoma. Method. We analysed 165 bone sarcomas by immunohistochemical staining of tissue microarrays for expression of the galectin-1 (GAL1) lectin and by Western Blot experiments. Results. We found that GAL1 was abundant in normal human osteoblasts from benign proliferations and in osteosarcomas, including chondroblastic osteosarcomas, but not in chondrosarcomas. There was a highly significant statistical difference in the percentage of stained cells (p<10-4) and in the staining intensity (p<10-3) of chondroblastic osteosarcomas compared to conventional chondrosarcomas. This discriminatory potential of GAL1 staining for osteosarcoma-derived tumours was confirmed by western blotting. We propose a diagnostic test for bone tumours that takes into account the optimal discriminative values for the percentage of cells stained and the intensity of staining. The positive and negative predictive values were 85.7% (trust interval of 63.7-97%) and 90% (trust interval of 80-95.9%), respectively, demonstrating the pertinence of the test. Conclusion. Altogether, our data indicate that GAL1 is a powerful diagnostic marker that distinguishes chondroblastic osteosarcomas from conventional chondrosarcomas


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 136 - 136
1 Mar 2008
O’Gorman D Burry A Faber K Gan B Howard J
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Purpose: Frozen Shoulder Syndrome (FSS) frequently occurs in association with Dupuytren’s Disease (DD). Beta-catenin is a signaling pathway implicated in the pathogenesis of DD. The purpose of this study is to determine if beta-catenin is also associated with FSS. Methods: Tissue obtained during shoulder arthroscopy for capsule release in patients with FSS was subjected to immunohistochemical staining (IHC) and Western Blot analysis. Control tissue was obtained from the rotator cuff interval from patients undergoing arthroscopy for rotator cuff syndrome. Results: IHC analysis showed that the vast majority of cells within lesions expressed b-catenin while cells within marginal tissue stained weakly for b-catenin. Western blotting analysis of FSS specimens showed that lesional tissues expressed increasing amounts of b-catenin compared to RCS tissue. Conclusions: Beta-catenin expression is upregulated in FSS. The current lack of knowledge about the biochemical mechanisms of FSS coupled with the limited therapeutic intervention available emphasizes the need for a better understanding of the basic biology of this fibrosing disorder. Funding: Educational Grant from the Canadian Orthopaedic Foundation


Bone & Joint Research
Vol. 12, Issue 8 | Pages 486 - 493
4 Aug 2023
Yamanaka Y Tajima T Tsujimura Y Naito T Mano Y Tsukamoto M Zenke Y Sakai A

Aims

Dupuytren’s contracture is characterized by increased fibrosis of the palmar aponeurosis, with eventual replacement of the surrounding fatty tissue with palmar fascial fibromatosis. We hypothesized that adipocytokines produced by adipose tissue in contact with the palmar aponeurosis might promote fibrosis of the palmar aponeurosis.

Methods

We compared the expression of the adipocytokines adiponectin and leptin in the adipose tissue surrounding the palmar aponeurosis of male patients with Dupuytren’s contracture, and of male patients with carpal tunnel syndrome (CTS) as the control group. We also examined the effects of adiponectin on fibrosis-related genes and proteins expressed by fibroblasts in the palmar aponeurosis of patients with Dupuytren’s contracture.