After the articular cartilage injury, the metabolic level is increased during the progressive degeneration, the chondrocytes secrete a variety of inflammatory factors, and the original cell phenotype is gradually changed. For a long time, a large number of researchers have done a lot of researches to promote anabolism of chondrocytes and to maintain the stability of chondrocyte phenotype. There are many molecular signaling pathways involved in the process of promoting cartilage repair. This review focuses on the key signaling molecules in articular cartilage repair, such as transforming growth factor-beta and bone morphogenetic protein, and reveals their roles in the process of cartilage injury and repair, so that researchers in related fields can understand the molecular mechanism of cartilage injury and repair widely and deeply. Based on this, they may find promising targets and biological methods for the treatment of cartilage injury.
Bone Morphogenetic Proteins ; physiology ; Cartilage, Articular ; growth & development ; injuries ; Chondrocytes ; physiology ; Humans ; Regeneration ; Signal Transduction ; Transforming Growth Factor beta ; physiology

OBJECTIVETo investigate the effect of eletroacupuncture with close-to-bone needling treatment on expression of Sox9, vascular endothelial growth factor (VEGF) and type X collagen (ColX) in impaired cartilage of rabbits with knee osteoarthritis (KOA) and explore its possible mechanisms.

METHODSForty New Zealand rabbits were randomized equally into normal control group, KOA model group, eletroacupuncture with close-to-bone needling group (CN group), and normal thrust needing group (NTN group). In the latter 3 groups, KOA was induced by Hulth-Telhag treatment and evaluated with X-ray examination, and 6 weeks after the modeling, eletroacupuncture for 20 min was administered in CN and NTN groups at the acupoints "Zusanli", "Waixiyan", "Neixiyan", "Liangqiu" and "Yinlingquan" in the left knee joints once daily for 5 days as a treatment cycle. After 5 treatment cycles, the rabbits were examined for behavioral changes, cartilage morphology, and Mankin scores; The protein and mRNA expressions of S0x9, VEGF, and ColX were examined using Westen blotting, immunohistochemistry, and RT-PCR as appropriate.

RESULTSThe rabbits in the model, CN and NTN groups showed significant changes in behaviors and cartilage histomorphology after the modeling and after the treatments. HE staining showed that cartilage injury was repaired and tended to recovery in CN and NTN groups. The cartilage pathologies was severer in the model group than in the normal control, CN and NTN groups (P<0.01); Sox9 protein increased and VEGF mRNA level decreased in CN and NTN groups after treatment as compared with those in the model group (P<0.01).

CONCLUSIONEletroacupuncture with close-to-bone needling can effectively improve KOA in rabbits probably by enhancing Sox9 and reducing VEGF and ColX expressions in the cartilage to inhibit hypertrophic differentiation of the chondrocytes, maintain chondrogenic phenotype and repair cartilage cells.

Acupuncture Points ; Animals ; Cartilage, Articular ; metabolism ; pathology ; Cell Differentiation ; Chondrocytes ; cytology ; Chondrogenesis ; Collagen Type X ; metabolism ; Electroacupuncture ; Knee Joint ; physiopathology ; Osteoarthritis, Knee ; therapy ; Rabbits ; SOX9 Transcription Factor ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo investigate the effect of Ermiao Recipe (, EMR) with medicinal guide Angelicae Pubescentis Radix (APR) on the homing of bone marrow stem cells (BMSCs) to focal zone in osteoarthritis (OA) rats.

METHODSForty-eight Sprague-Dawley rats were randomly assigned to the sham-operated, model, EMR, and EMR plus APR groups (12 rats in each group). The OA rat model was induced by anterior cruciate ligament transection and medial meniscus resection. All rats were injected with recombinant human granulocyte colonystimulating factor [rhG-CSF, 30 μg/(kg·d) for continuous 7 days], and rats in the EMR and EMR plus APR groups were treated with EMR or EMR plus APR at 1.6 or 1.9 g/(kg·d) for 3 or 6 weeks, respectively. Cartilage histopathologic changes were observed by hematoxylin and eosin staining. Chondrocytes apoptosis and cartilage matrix components were tested by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assay and special staining. Interleukin-1β (IL-1 β), tumor necrosis factor α (TNF-α), bone morphogenetic protein 2 (BMP-2), and transforming growth factor beta-1 (TGF-β1) in serum were detected by enzyme-linked immunosorbent assay or radioimmunoassay assay. Matrix metalloproteinase (MMP)-13, tissue inhibitors of metalloproteinase (TIMP)-1, bromodeoxyuridine (BrdU), cluster of differentiation 34 (CD34), and stromal cell derived factor 1 (SDF-1) were measured by immunohistochemistry assay.

RESULTSEMR and EMR plus APR significantly inhibited articular cartilage damage and synovium inflammation in OA rats at 3 or 6 weeks of treatment, the most obvious changes in these parameters were found in the EMR plus APR group. At 6 weeks, compared with EMR treatment, EMR plus APR remarkably inhibited chondrocytes apoptosis and the release of IL-1β and TNF-α, obviously decreased MMP-13 expression, and significantly increased expressions of proteoglycan, collagen, type II collagen and TIMP-1, serum levels of BMP-2 and TGF-β1 as well as expressions of BrdU, CD34 and SDF-1 in cartilage articular (P<0.01 or P<0.05).

CONCLUSIONThe medicinal guide APR improved the therapeutic effects of EMR on OA rats by promoting directional homing of BMSCs to focal zone.

Animals ; Apoptosis ; drug effects ; Bone Marrow Cells ; drug effects ; Bone Morphogenetic Protein 2 ; blood ; Bromodeoxyuridine ; metabolism ; Cartilage, Articular ; drug effects ; enzymology ; pathology ; Chemokine CXCL12 ; metabolism ; Chondrocytes ; drug effects ; pathology ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Granulocyte Colony-Stimulating Factor ; administration & dosage ; pharmacology ; Humans ; Interleukin-1beta ; blood ; Knee Joint ; drug effects ; pathology ; Male ; Matrix Metalloproteinase 13 ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; blood ; Osteoarthritis ; blood ; drug therapy ; pathology ; Rats, Sprague-Dawley ; Synovial Membrane ; pathology ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Transforming Growth Factor beta1 ; blood ; Tumor Necrosis Factor-alpha ; blood

OBJECTIVETo compare the expressions of programmed cell death 5 (PDCD5) and early growth response protein-1 (EGR-1) in the articular cartilage between Kashin-Beck disease (KBD) and primary osteoarthritis and the roles of these factors in KBD cartilage.

METHODSCartilage specimens were collected from 10 confirmed KBD patients, 15 osteoarthritic patients and 6 healthy subjects. The expression levels of PDCD5 and EGR-1 in the cartilage were detected by immunohistochemistry staining, and the positive chondrocyte counts were recorded in the different layers of KBD and OA cartilages.

RESULTSThe KBD cartilages contained a significantly higher percentage of PDCD5-positive chondrocytes in the middle layer [(41.35 ± 2.97)%] than OA cartilages [(26.48 ± 2.04)%, P=0.001] and normal cartilages [(19.02 ± 1.88)%, P=0.000] with also obvious PDCD5 over-expression in the deeper layer compared to OA (P=0.000) and normal cartilages (P=0.029), but PDCD5 expression in the superficial layer of the cartilages showed no significant difference among the 3 groups(P>0.05). The average EGR-1 positivity rate in the superficial layer of the cartilage was significantly higher in KBD patients than in OA patients (P=0.000) and healthy controls (P=0.000), but in the middle layer, its positivity rate in KBD patients was higher than that in the normal control (P=0.017) but lower than that of OA cartilage (P=0.002); EGR-1 expression in the deeper layer was comparable in KBD and OA cartilages but both was higher than that in normal cartilages. PDCD5 and EGR-1 expressions were not correlated in either KBD or normal cartilages, but were positively correlated in the superficial layer of OA cartilages.

CONCLUSIONSKBD cartilages show a significantly increased PDCD5 expression in the deeper layer and enhanced EGR-1 expression in both superficial and deeper layers, suggesting the involvement of PDCD5 and EGR-1 in the pathogenesis of KBD.

Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Cartilage, Articular ; metabolism ; pathology ; Chondrocytes ; metabolism ; Early Growth Response Protein 1 ; metabolism ; Humans ; Immunohistochemistry ; Kashin-Beck Disease ; metabolism ; Neoplasm Proteins ; metabolism ; Osteoarthritis ; metabolism ; Transcriptome

The anti-inflammatory effects of glycosaminoglycan (GAG) derived from Isaria sinclairii (IS) and of IS extracts were investigated in a complete Freund's adjuvant (CFA)-treated chronic arthritis rat model. Groups of rats were treated orally with 30 mg/kg one of the following: [1] saline control, extracts of [2] water-IS, [3] methanol-IS, [4] butanol-IS, [5] ethyl acetate-IS, or [6] Indomethacin(R) as the positive control for a period of two weeks. The anti-paw edema effects of the individual extracts were in the following order: water-IS ex. > methanol ex. > butanol ex. > ethyl acetate ex. The water/methanol extract from I. sinclairii remarkably inhibited UV-mediated upregulation of NF-kappaB activity in transfected HaCaT cells. GAG as a water-soluble alcohol precipitated fraction also produced a noticeable anti-edema effect. This GAG also inhibited the pro-inflammatory cytokine levels of prostaglandin E2-stimulated lipopolysaccharide in LAW 264.7 cells, cytokine TNF-alpha production in splenocytes, and atherogenesis cytokine levels of vascular endothelial growth factor (VEGF) production in HUVEC cells in a dose-dependent manner. In the histological analysis, the LV dorsal root ganglion, including the articular cartilage, and linked to the paw-treated IS GAG, was repaired against CFA-induced cartilage destruction. Combined treatment with Indomethacin(R) (5 mg/kg) and IS GAG (10 mg/kg) also more effectively inhibited CFA-induced paw edema at 3 hr, 24 hr, and 48 hr to levels comparable to the anti-inflammatory drug, indomethacin. Thus, the IS GAG described here holds great promise as an anti-inflammatory drug in the future.
Acetates ; Animals ; Arthritis* ; Atherosclerosis ; Cartilage ; Cartilage, Articular ; Edema ; Freund's Adjuvant ; Ganglia, Spinal ; Human Umbilical Vein Endothelial Cells ; Indomethacin ; Inflammation ; Jurisprudence ; Methanol ; NF-kappa B ; Rats* ; Tumor Necrosis Factor-alpha ; Up-Regulation ; Vascular Endothelial Growth Factor A

The purpose of this study was to investigate the repair of the osteoarthritis(OA)-induced cartilage injury by transfecting the new TGF-β3 fusion protein (LAP-MMP-mTGF-β3) with targeted therapy function into the bone marrow-derived mesenchymal stem cells (MSCs) in rats. The recombinant of pIRES-EGFP-MMP was constructed by combination of DNA encoding MMP enzyme cutting site and eukaryotic expression vector pIRES-EGFP. LAP and mTGF-β3 fragments were obtained from rat embryos by RT-PCR and inserted into the upstream and downstream of MMP from pIRES-EGFP-MMP respectively, so as to construct the recombinant plasmid of pIRES-EGFP-LAP-MMP-mTGF-β3. pIRES-EGFP-LAP-MMP-mTGF-β3 was transfected into rat MSCs. The genetically modified MSCs were cultured in medium with MMP-1 or not. The transfected MSCs were transplanted in the rat OA models. The OA animal models were surgically induced by anterior cruciate ligament transaction (ACLT). The pathological changes were observed under a microscope by HE staining, Alcian blue, Safranin-fast Green and graded by Mankin's scale. pIRES-EGFP-LAP-MMP-mTGF-β3 was successfully constructed by means of enzyme cutting and sequencing, and the mTGF-β3 fusion protein (39 kD) was certified by Western blotting. Those genetically modified MSCs could differentiate into chondrocytes induced by MMP and secrete the relevant-matrix. The transfected MSCs could promote chondrogenesis and matrix production in rat OA models in vivo. It was concluded that a new fusion protein LAP-MMP-mTGF-β3 was constructed successfully by gene engineering, and could be used to repair the OA-induced cartilage injury.
Animals ; Base Sequence ; Blotting, Western ; Bone Marrow Cells ; metabolism ; Cartilage, Articular ; pathology ; surgery ; Cell Differentiation ; genetics ; Cells, Cultured ; Chondrocytes ; metabolism ; Chondrogenesis ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Matrix Metalloproteinases ; genetics ; metabolism ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stromal Cells ; metabolism ; Microscopy, Fluorescence ; Molecular Sequence Data ; Osteoarthritis ; surgery ; Rats ; Rats, Sprague-Dawley ; Recombinant Fusion Proteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection ; Transforming Growth Factor beta3 ; genetics ; metabolism ; Treatment Outcome

INTRODUCTIONVascular endothelial growth factor (VEGF) is expressed in osteoarthritic articular cartilage. However, the pattern of VEGF expression throughout the whole life cycle of articular cartilage is not well elucidated. The aim of the study was to investigate the spatiotemporal expression of VEGF and its receptors, vascular endothelial growth factor receptor-1 (VEGFR1) and vascular endothelial growth factor receptor-2 (VEGFR2), in articular cartilage during growth, maturation and degeneration, using the guinea pig model of spontaneous osteoarthritis.

MATERIALS AND METHODSSections of tibial plateaus aged 2, 6 and 12 months were obtained, representing growing, mature and osteoarthritic cartilage respectively. Expression of VEGF and its receptors was determined by immunohistochemistry and in situ hybridisation.

RESULTSAt 2 months, VEGF and its receptors were expressed in chondrocytes within the superficial layer of the articular cartilage. At 6 months, no expression of VEGF and its receptors was noted. In the 12-month-old specimens, VEGF and its receptors were expressed in chondrocytes within articular cartilage that exhibited osteoarthritic changes (medial tibial plateaus), but not in the histologically normal lateral plateaus.

CONCLUSIONThis spatiotemporal distribution of VEGF and its receptors suggests that VEGF is expressed during articular cartilage growth, becomes quiescent at maturity, and is re-expressed in osteoarthritis.

Aging ; metabolism ; Animals ; Cartilage, Articular ; growth & development ; metabolism ; Chondrocytes ; metabolism ; Guinea Pigs ; Immunohistochemistry ; In Situ Hybridization ; Knee Joint ; metabolism ; Male ; Osteoarthritis, Knee ; metabolism ; Tibia ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism ; Vascular Endothelial Growth Factor Receptor-1 ; metabolism ; Vascular Endothelial Growth Factor Receptor-2 ; metabolism

OBJECTIVETo evaluate the biocompatibility of polylactic-co-glycolic acid (PLGA) for culturing bFGF gene-transfected bone marrow stromal cells (BMSCs) and assess the feasibility of this cell complex for repairing cartilage defect in rabbits using tissue engineering method.

METHODSBMSCs transfected by bFGF gene were cultured on PLGA matrix to assess the biocompatibility of PLGA. The cell complex was then implanted into the cartilage defect in rabbits, and its effect in cartilage defect repair was evaluated by histological observation and immunohistochemical staining.

RESULTSBMSCs transfected by bFGF gene grew normally on PLGA matrix. After implantation, the complex showed good effect for cartilage defect repair in rabbits.

CONCLUSIONPLGA has good biocompatibility with the transfected BMSCs, and the cell complex can be used for repairing rabbit cartilage defect and may potentially serve as a substitute of cartilage autograft.

Animals ; Biocompatible Materials ; chemistry ; Bone Marrow Cells ; cytology ; Cartilage, Articular ; injuries ; surgery ; Cells, Cultured ; Female ; Fibroblast Growth Factor 2 ; genetics ; Genetic Engineering ; methods ; Implants, Experimental ; Lactic Acid ; chemistry ; Male ; Polyglycolic Acid ; chemistry ; Rabbits ; Random Allocation ; Stromal Cells ; cytology ; Transfection

OBJECTIVE: To explore the effect of insulin-like growth factor (IGF-1) on the concentration of NO and PGE(2) in the supernatant of rabbit articular chondrocytes induced by IL-1, and to explore the mechanism of IGF-1 in the development of osteoarthritis (OA). METHODS: The samples were divided into 7 groups: IL-1beta 10 microg/L group, IL-1beta 10 microg/L+IGF-1 1 microg/L group, IL-1beta 10 microg/L+IGF-1 10 microg/L group, IL-1beta 10 microg/L+IGF-1 50 microg/L group, IL-1beta 10 microg/L+IGF-1 100 microg/L group, IGF-1 50 microg/L group, and a blank control group. The chondrocytes from the articular cartilage of 2 month old rabbits were cultivated and identified, and then co-cultured in the second filial generation chondrocytes on plates with or without recombinant human IGF-1 or IL-1. The concentration of NO was detected by nitrate reductase kit, and that of PGE(2) by enzyme-linked immunosorbent assay (ELISA). The results were analyzed by statistical method. RESULTS: The average value of NO and PGE(2) was (89.971+/-10.224) micromol/L and (22.028+/-8.731) micromol/L in the IL-1beta 10 microg/L group, and (12.404+/-8.809) micromol/L and (1.900+/-0.227) ng/L in the blank control group. The concentration of NO and PGE(2) in IL-1beta 10 microg/L group was significantly higher than that in the blank control group (P<0.05). At the same concentration of 10 microg/L, IGF-1 could dose-dependently decrease the increase of NO and PGE(2) concentration induced by IL-1beta in the chondrocytes supernatant in vitro, and the optimum concentration of IGF-1 was 50 microg/L. CONCLUSION IL-1 can significantly increase the concentration of NO and PGE(2), and IGF-1 can dose-dependently decrease the concentration of NO and PGE(2) in the chondrocytes supernatant in vitro. The optimum concentration of IGF-1 was 50 microg/L.
Animals ; Cartilage, Articular ; cytology ; metabolism ; Cells, Cultured ; Chondrocytes ; drug effects ; metabolism ; Dinoprostone ; metabolism ; Insulin-Like Growth Factor I ; pharmacology ; Interleukin-1 ; pharmacology ; Nitric Oxide ; metabolism ; Osteoarthritis ; metabolism ; Rabbits

OBJECTIVE: To explore whether the growth hormone is effective in the treatment of degenerative cartilage of knee in rabbits. METHOD: Thirty New Zealand white rabbits were administered intra-articular injection with monosodium iodoacetate (Sigma, St. Louis, USA) 2.5 mg and divided into 3 groups. Each group was administered with hyaluronic acid (Hyruan plus(R), LG life science, Seoul, Korea)(group A) 0.6 ml, growth hormone (Declage(R), LG life science, Seoul, Korea) (group B) or saline (group C) 0.6 ml intra-articulary once a week for 4 weeks, beginning 4 weeks after the degeneration induction. All rabbits were killed 9 weeks after degeneration induction. The histologic morphology was observed by optical microscope with knee cartilage. RESULTS: Mankin score was 2.4+/-1.3 in group A, 3.9+/-1.7 in group B, 7.4+/-0.8 in group C. Yoshimi score was 1.5+/-0.7 in group A, 2.2+/-0.9 in group B, 4.4+/-0.6 in group C. Gross and microscopic morphologic findings showed that group C represented the more severe than group A & B (p<0.01), also group A was better than group B (p<0.05). CONCLUSION: Growth hormone is effective on degenerative knee cartilage in rabbit model, but less than the hyaluronic acid.
Biological Science Disciplines ; Cartilage ; Growth Hormone ; Hyaluronic Acid ; Injections, Intra-Articular ; Knee ; Rabbits