Due to the poor repair ability of cartilage tissue, regenerative medicine still faces great challenges in the repair of large articular cartilage defects. Quercetin is widely applied as a traditional Chinese medicine in tissue regeneration including liver, bone and skin tissues. However, the evidence for its effects and internal mechanisms for cartilage regeneration are limited. In the present study, the effects of quercetin on chondrocyte function were systematically evaluated by CCK8 assay, PCR assay, cartilaginous matrix staining assays, immunofluorescence assay, and western blotting. The results showed that quercetin significantly up-regulated the expression of chondrogenesis genes and stimulated the secretion of GAG (glycosaminoglycan) through activating the ERK, P38 and AKT signalling pathways in a dose-dependent manner. Furthermore, in vivo experiments revealed that quercetin-loaded silk protein scaffolds dramatically stimulated the formation of new cartilage-like tissue with higher histological scores in rat femoral cartilage defects. These data suggest that quercetin can effectively stimulate chondrogenesis in vitro and in vivo, demonstrating the potential application of quercetin in the regeneration of cartilage defects.
Animals ; Cartilage/cytology* ; Chondrocytes/drug effects* ; Chondrogenesis/drug effects* ; Extracellular Matrix/metabolism* ; Quercetin/pharmacology* ; Rats ; Signal Transduction/drug effects* ; Tissue Scaffolds

OBJECTIVE: To construct a novel non-viral vector loaded with growth and differentiation factor-5 (GDF-5) plasmid using chitosan, hyaluronic acid, and chondroitin sulfate for osteoarthritis (OA) gene therapy. METHODS: Nano-microspheres (NMPs) were prepared by mixing chitosan, hyaluronic acid, and chondroitin sulfate. GDF-5 plasmid was encapsulated in the NMPs through electrostatic adsorption. The basic characteristics of the NMPs were observed, and then they were co-cultured with chondrocytes to observe their effects on extracellular matrix (ECM) protein expression. Finally, NMPs loaded with GDF-5 were injected into the articular cavities of rabbits to observe their therapeutic effects on OA in vivo. RESULTS: NMPs exhibited good physicochemical properties and low cytotoxicity. Their average diameter was (0.61±0.20) μm, and encapsulation efficiency was (38.19±0.36)%. According to Cell Counting Kit-8 (CCK-8) assay, relative cell viability was 75%-99% when the total weight of NMPs was less than 560 μg. Transfection efficiency was (62.0±2.1)% in a liposome group, and (60.0±1.8)% in the NMP group. There was no significant difference between the two groups (P>0.05). Immunohistochemical staining results suggested that NMPs can successfully transfect chondrocytes and stimulate ECM protein expression in vitro. Compared with the control groups, the NMP group significantly promoted the expression of chondrocyte ECM in vivo (P<0.05), as shown by analysis of the biochemical composition of chondrocyte ECM. When NMPs were injected into OA model rabbits, the expression of ECM proteins in chondrocytes was significantly promoted and the progression of OA was slowed down. CONCLUSIONS Based on these data, we think that these NMPs with excellent physicochemical and biological properties could be promising non-viral vectors for OA gene therapy.
Animals ; Cell Differentiation ; Cell Survival/drug effects* ; Chitosan/chemistry* ; Chondrocytes/cytology* ; Chondroitin Sulfates/chemistry* ; Drug Carriers ; Extracellular Matrix/metabolism* ; Genetic Therapy/methods* ; Growth Differentiation Factor 5/genetics* ; Hyaluronic Acid/chemistry* ; Microspheres ; Nanomedicine ; Osteoarthritis/therapy* ; Plasmids/metabolism* ; Rabbits

OBJECTIVETo investigate chondrocyte apoptosis and the expression of biochemical markers associated with apoptosis in Kashin-Beck disease (KBD) and in an established T-2 toxin- and selenium (Se) deficiency-induced rat model.

METHODSCartilages were collected from the hand phalanges of five patients with KBD and five healthy children. Sprague-Dawley rats were administered a selenium-deficient diet for 4 weeks prior to T-2 toxin exposure. The apoptotic chondrocytes were observed by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Caspase-3, p53, Bcl-2, and Bax proteins in the cartilages were visualized by immunohistochemistry, their protein levels were determined by Western blotting, and mRNA levels were determined by real-time reverse transcription polymerase chain reaction.

RESULTSIncreased chondrocyte apoptosis was observed in the cartilages of children with KBD. Increased apoptotic and caspase-3-stained cells were observed in the cartilages of rats fed with normal and Se-deficient diets plus T-2 toxin exposure compared to those in rats fed with normal and Se-deficient diets. Caspase-3, p53, and Bax proteins and mRNA levels were higher, whereas Bcl-2 levels were lower in rats fed with normal or Se-deficiency diets supplemented with T-2 toxin than the corresponding levels in rats fed with normal diet.

CONCLUSIONT-2 toxin under a selenium-deficient nutritional status induces chondrocyte death, which emphasizes the role of chondrocyte apoptosis in cartilage damage and progression of KBD.

Adolescent ; Animals ; Apoptosis ; drug effects ; Biomarkers ; Cartilage, Articular ; physiopathology ; Child ; Chondrocytes ; physiology ; Female ; Humans ; Kashin-Beck Disease ; etiology ; physiopathology ; Male ; Matrilin Proteins ; genetics ; metabolism ; Models, Animal ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Selenium ; deficiency ; T-2 Toxin ; pharmacology

SRT1720, a new discovered drug, was reported to activate silent information regulator 1 (SIRT1) and inhibit the chondrocyte apoptosis. However, the underlying mechanism remains elusive. In the present study, the chondrocytes were extracted from the cartilage tissues of New Zealand white rabbits, cultured in the presence of sodium nitroprusside (SNP) (2.5 mmol/L) and divided into five groups: 1, 5, 10, and 20 μmol/L SRT1720 groups and blank control group (0 μmol/L SRT1720). MTT assay was used to detect the chondrocyte viability and proliferation, and DAPI staining and flow cytometry to measure the chondrocyte apoptosis. The expression levels of SIRT1, p53, NF-κB/p65, Bax, and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) were detected by Western blotting and the expression levels of SIRT1, type II collagen, and aggrecan mRNA by RT-PCR. The results showed that in the SRT1720-treated groups, the nuclei of chondrocytes were morphologically intact and had uniform chromatin. In the blank control group, nuclear rupture into debris was observed in chondrocytes. With the SRT1720 concentration increasing, the chondrocyte viability increased, the apoptosis rate decreased, the protein expression levels of SIRT1 and PGC-1α and the mRNA expression levels of type II collagen and aggrecan increased ({ptP}<0.05), and the expression levels of p53, NF-κB and bax decreased (P<0.05). It was suggested that SRT1720 inhibits chondrocyte apoptosis by activating the expression of SIRT1 via p53/bax and NF-κB/PGC-1α pathways.
Aggrecans ; genetics ; metabolism ; Animals ; Apoptosis ; drug effects ; Cartilage, Articular ; cytology ; drug effects ; metabolism ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Chondrocytes ; cytology ; drug effects ; metabolism ; Chromatin ; chemistry ; drug effects ; metabolism ; Collagen Type II ; genetics ; metabolism ; Gene Expression Regulation ; Heterocyclic Compounds, 4 or More Rings ; pharmacology ; Nitroprusside ; toxicity ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; genetics ; metabolism ; Primary Cell Culture ; Rabbits ; Signal Transduction ; drug effects ; genetics ; Sirtuin 1 ; genetics ; metabolism ; Transcription Factor RelA ; genetics ; metabolism ; Tumor Suppressor Protein p53 ; genetics ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism

To observe the influence of matrix metalloproteinases-2 (MMP-2), monocyte chemoattractant protein-1 (MCP-1), CD47, L-selectin and advanced oxidation proteinproducts (AOPP) in osteoarthritis and the intervention of curcumin.A total of 20 male C57BL/6 mice (10.05-15.00 g) were randomly divided into control group, OA group, Cur25 group and Cur50 group (intraperitoneal injected 25 μmol/L or 50 μmol/L of curcumin everyday after modeling). After 4 weeks treatment, we observed the morphological changes of the gross specimen by immunohistochemical method, and observed the ultrastructure of cartilage tissue under electron microscope. The expression of MMP-2, MCP-1 and CD47 were detected by western blotting, and L-selectin and AOPP were detected by ELISA and spectrophotometer, respectively.In the cartilage tissue morphology, the chondrocytes of OA group showed obvious change, while Cur25 and Cur50 groups maintained the good cartilage cell membrane intact. Compared with control group, the expressions of MMP-2, MCP-1, L-selectin and AOPP in OA group, Cur25 group and Cur50 group were increased (all<0.05), while CD47 levels were decreased (all<0.05). Compared with OA group, the expressions of MMP-2, MCP-1, L-selectin and AOPP in Cur25 group and Cur50 group were decreased (all<0.05), while CD47 levels were increased (all<0.05), and such changes were more significant in Cur50 group (all<0.05).The MMP-2, MCP-1, CD47, L-selectin and AOPP are closely associated with the pathology course of OA. Curcumin has protection effect on cartilage, which can relieve joint cartilage degeneration, reduce cartilage inflammation and increase the metabolic activity of chondrocytes.
Advanced Oxidation Protein Products ; metabolism ; Animals ; Biomarkers ; CD47 Antigen ; metabolism ; Cartilage ; chemistry ; drug effects ; pathology ; Chemokine CCL2 ; metabolism ; Chondrocytes ; drug effects ; pathology ; Curcumin ; administration & dosage ; pharmacology ; Cytokines ; L-Selectin ; metabolism ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Mice, Inbred C57BL ; Osteoarthritis ; genetics ; pathology ; physiopathology ; Oxidative Stress

To investigate the effect of diosgenin (Dgn) on chondrocytes and its relation to JAK2/STAT3 signaling pathway in mice with osteoarthritis (OA).Fifteen male C57BL/6 mice were randomly divided into three groups:control group, OA group and OA+Dgn group. After 4 weeks of treatment, the histopathological changes of cartilage tissue were observed by toluidine blue staining under light microscopy and the ultrastructure of chondrocytes was observed under electron microscopy. The primarily cultured chondrocytes of OA mice were randomly divided into 4 groups:(1) OA group, (2) Dgn group, (3) Dgn+AG490 group, (4) AG490 group. The expression of p-JAK2, p-STAT3, Bax, succinate dehydrogenase (SDH) and cytochrome c oxidase (COX) were detected by Western blotting, and superoxide dismutase (SOD) was detected using colorimetric method.The morphological observation showed that the chondrocytes of OA group presented considerable pathological changes, while the chondrocytes in OA+Dgn group maintained intact membrane. Electron microscopy observation found obvious injury in cartilage tissues of OA group, while that in OA+Dgn group remained smooth. Compared with OA group, the expressions of p-JAK2 and p-STAT3 in chondrocytes of Dgn group were increased (all<0.05), and the expressions of Bax protein, SDH, COX and SOD were decreased (all<0.05). While compared with Dgn group, the expressions of p-JAK2, p-STAT3, SDH, COX and SOD in chondrocytes of Dgn+AG490 group were decreased (all<0.05), and the expression of Bax protein was increased (<0.05).Diosgenin can inhibit apoptosis and increase mitochondrial oxidative stress capacity of chondrocytes in mice with osteoarthritis, which is closely related to the activation of JAK2/STAT3 signaling pathway.
Animals ; Apoptosis ; drug effects ; Cartilage ; drug effects ; pathology ; Chondrocytes ; chemistry ; drug effects ; pathology ; Diosgenin ; pharmacology ; Electron Transport Complex IV ; metabolism ; Janus Kinase 2 ; drug effects ; Male ; Mice ; Mice, Inbred C57BL ; Mitochondria ; drug effects ; genetics ; Osteoarthritis ; genetics ; physiopathology ; Oxidative Stress ; drug effects ; STAT3 Transcription Factor ; drug effects ; Signal Transduction ; Succinate Dehydrogenase ; metabolism ; Superoxide Dismutase ; metabolism ; Tyrphostins ; pharmacology ; bcl-2-Associated X Protein ; metabolism

OBJECTIVEAlthough chondroprotective activities have been documented for polysaccharides, the potential target of different polysaccharide may differ. The study was aimed to explore the effect of glucan HBP-A in chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs in vivo, especially on the expression of type II collagen.

METHODSChondrocytes isolated from rabbit articular cartilage were cultured and verified by immunocytochemical staining of type II collagen. Chondrocyte viability was assessed after being treated with HBP-A in different concentrations. Morphological status of chondrocytes-alginate hydrogel constructs in vitro was observed by scanning electron microscope (SEM). The constructs were treated with HBP-A and then injected to nude mice subcutaneously. Six weeks after transplantation, the specimens were observed through transmission electron microscopy (TEM). The mRNA expressions of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTs-5), aggrecan and type II collagen in both monolayer culture and constructs were determined by real time polymerase chain reaction (PCR). The expression of type II collagen and matrix metalloproteinases-3 (MMP-3) in chondrocyte monolayer culture was also tested through Western blot and enzyme linked immunosorbent assay (ELISA), respectively.

RESULTSMMP-3 secretion and ADAMTs-5 mRNA expression in vitro were inhibited by HBP-A at 0.3 mg/mL concentration. In morphological study, there were significant appearance of collagen in those constructs treated by HBP-A. Accordingly, in both chondrocyte monolayer culture and chondrocytes-alginate hydrogel constructs, the expression of type II collagen was increased significantly in HBP-A group when compared with control group (P<0.001).

CONCLUSIONSThe study documented that the potential pharmacological target of glucan HBP-A in chondrocytes monolayer culture and tissue engineered cartilage in vivo may be concerned with the inhibition of catabolic enzymes MMP-3, ADAMTs-5, and increasing of type II collagen expression.

ADAM Proteins ; genetics ; metabolism ; Aggrecans ; genetics ; metabolism ; Alginates ; pharmacology ; Animals ; Cartilage, Articular ; drug effects ; physiology ; Cell Proliferation ; drug effects ; Cell Shape ; drug effects ; Cell Survival ; drug effects ; Chondrocytes ; cytology ; drug effects ; metabolism ; ultrastructure ; Collagen Type II ; genetics ; metabolism ; Female ; Glucans ; pharmacology ; Glucuronic Acid ; pharmacology ; Hexuronic Acids ; pharmacology ; Hydrogel, Polyethylene Glycol Dimethacrylate ; pharmacology ; Immunohistochemistry ; Matrix Metalloproteinase 3 ; metabolism ; Mice, Nude ; RNA, Messenger ; genetics ; metabolism ; Rabbits ; Tissue Engineering ; methods

This study investigated effects of Ginsenoside Ro (Ro) on interleukin-1β (IL-1β)-induced apoptosis and inflammation in rat chondrocytes. The rat chondrocytes were co-treated with IL-1β (10 ng·kg(-1)) and Ro (50, 100 and 200 μmol·L(-1)) for 48 h. Chondrocytes viability was detected by the MTT assay and Annexin V-FITC/PI dual staining assay. Caspase 3 activity was measured by using caspase 3 colorimetric assay kit. Apoptosis related proteins Bax, Bad, Bcl-xL, PCNA, p53 and phospho-p53, along with inflammation related protein MMP 3, MMP 9 and COX-2, and the expression of phospho-NF-κB p65 were assayed by western blotting analyses. Ro could improve IL-1β-induced chondrocytes viability. Ro could suppress IL-1β-induced apoptosis by inhibiting levels of Bax and Bad, decreasing p53 phosphorylation and promoting the expression of Bcl-xL and PCNA. Ro inhibited caspase 3 activity. IL-1β-induced inflammation and matrix degration were also alleviated by Ro with down-regulating the expression of MMP 3, MMP 9 and COX-2. Moreover, Ro inhibited NF-κB p65 phosphorylation induced by IL-1β. In conclusion, these results suggested Ro exerted anti-apoptosis and anti-inflammation in IL-1β-induced rat chondrocytes, which might be related to NF-κB signal pathway. Therefore, we propose that Ro might be a potential novel drug for the treatment of osteoarthritis.
Animals ; Anti-Inflammatory Agents ; pharmacology ; Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; drug effects ; metabolism ; Caspase 3 ; metabolism ; Cell Survival ; drug effects ; Chondrocytes ; cytology ; drug effects ; Cyclooxygenase 2 ; drug effects ; metabolism ; Down-Regulation ; drug effects ; Drug Evaluation, Preclinical ; Ginsenosides ; pharmacology ; Inflammation ; chemically induced ; drug therapy ; Interleukin-1beta ; antagonists & inhibitors ; pharmacology ; Matrix Metalloproteinase 3 ; drug effects ; metabolism ; Matrix Metalloproteinase 9 ; drug effects ; NF-kappa B ; antagonists & inhibitors ; drug effects ; metabolism ; Phosphorylation ; drug effects ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects

OBJECTIVETo evaluate the effect of Zhuanggu Jianxi Decoction (, ZGJXD) on interleukin-1 β (IL-1 β)-induced degeneration of chondrocytes (CDs) as well as the activation of caveolin-p38 mitogen-activated protein kinase (MAPK) signal pathway, investigating the possible molecular mechanism that ZGJXD treats osteoarthritis.

METHODSSerum pharmacology was applied in the present study, where ZGJXD was orally administrated to New Zealand rabbits and then ZGJXD containing serum (ZGJXD-S) was collected for following in vitro experiments. CDs were isolated aseptically from New Zealand rabbits and then cultured in vitro. Upon IL-1 β stimulation, the degeneration of CDs was verified by inverted microscope, toluidine blue stain and type II collagen immunocytochemistry. After IL-1 β-stimulated CDs were intervened with blank control serum, ZGJXD-S, together with or without SB203580 (a specific inhibitor of p38 MAPK) for 48 h, caveolin-1 protein expression and the phosphorylation level of p38 were determined by Western blotting, and the mRNA expression of IL-1 β, tumor necrosis factor α (TNF-α), matrix metalloproteinase 3 (MMP-3) and MMP-13 were examined by real-time polymerase chain reaction.

RESULTSIL-1 β stimulation induced degeneration of CDs, increased caveolin-1 expression and p38 phosphorylation, up-regulated the mRNA level of IL-1 β, TNF-α, MMP-3 and MMP-13. However, the IL-1 β-induced activation of caveolin-p38 signaling and alteration in the expression of p38 downstream target genes were suppressed by ZGJXD-S and/or SB203580 in CDs.

CONCLUSIONZGJXD can prevent CDs degeneration via inhibition of caveolin-p38 MAPK signal pathway, which might be one of the mechanisms that ZGJXD treats osteoarthritis.

Animals ; Base Sequence ; Blotting, Western ; Caveolins ; metabolism ; Chondrocytes ; drug effects ; enzymology ; metabolism ; DNA Primers ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Profiling ; Interleukin-1beta ; physiology ; MAP Kinase Signaling System ; Male ; RNA, Messenger ; genetics ; Rabbits ; p38 Mitogen-Activated Protein Kinases ; genetics ; 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