From the perspective of circular RNA forkhead box protein O3(circFOXO3) regulating glycolysis in osteoarthritis(OA) chondrocytes, this study investigated the mechanism by which Tougu Xiaotong Capsules(TGXTC) alleviated OA degeneration. In in vivo experiments, after randomized grouping and relevant interventions, morphological staining was used to observe structural changes in cartilage tissue. The mRNA level of circFOXO3 in cartilage tissue was detected by real-time quantitative PCR(RT-qPCR). Western blot analysis was used to detect changes in the expression of glucose transporter 1(GLUT1), hexokinase 2(HK2), pyruvate kinase M2(PKM2), lactate dehydrogenase A(LDHA), and matrix metalloproteinase 13(MMP13). In in vitro experiments, fluorescence in situ hybridization(FISH) was used to detect circFOXO3 expression in chondrocytes from each group. A lentiviral vector was used to construct circFOXO3-silenced(sh-circFOXO3) chondrocytes. RT-qPCR was used to analyze the changes in circFOXO3 levels after silencing, and Western blot was used to assess the regulatory effects of TGXTC on GLUT1, HK2, PKM2, LDHA, and MMP13 proteins in interleukin-1β(IL-1β)-induced chondrocytes under sh-circFOXO3 conditions. Masson staining and alcian blue staining results showed that the cartilage layer structure in the TGXTC and positive drug groups was improved compared with that in the model group. The mRNA level of circFOXO3 was significantly upregulated in both the TGXTC and positive drug groups, while the expression of the above-mentioned proteins was significantly reduced. FISH results showed that TGXTC upregulated the fluorescence intensity of circFOXO3 in IL-1β-induced chondrocytes. In the circFOXO3 silencing experiment, compared with the IL-1β group, circFOXO3 levels in the IL-1β + sh-circFOXO3 group were significantly decreased. Compared with the IL-1β + TGXTC group, circFOXO3 levels were significantly reduced in the IL-1β + sh-circFOXO3 + TGXTC group. Western blot results indicated that the elevated levels of GLUT1, HK2, PKM2, LDHA, and MMP13 proteins in chondrocytes of the IL-1β group were significantly inhibited by TGXTC intervention. However, this regulatory effect was attenuated after circFOXO3 silencing. In conclusion, TGXTC alleviate glycolytic metabolism disorder in OA chondrocytes and delay OA degeneration by regulating circFOXO3.
Chondrocytes/metabolism* ; Animals ; Drugs, Chinese Herbal/administration & dosage* ; RNA, Circular/metabolism* ; Osteoarthritis/genetics* ; Glycolysis/drug effects* ; Humans ; Forkhead Box Protein O3/metabolism* ; Male ; Capsules ; Matrix Metalloproteinase 13/genetics*

OBJECTIVES: To assess the therapeutic effect of aucubin in mice with knee osteoarthritis (KOA) and investigate the underlying mechanism. METHODS: Sixty C57BL/6J mice were randomized equally into sham operation group, KOA model group, glucosamine (positive control) treatment group, and low-, medium-, and high-dose aucubin treatment groups (2, 4, and 8 mg/kg, respectively). KOA mouse models were established by transection of the anterior cruciate ligament (ACL), and the treatment was initiated on day 1 postoperatively and administered weekly for 8 weeks. Safranin O-fast green staining, immunohistochemistry, and microCT were used to evaluate the changes in cartilage pathology, inflammatory protein expression, and subchondral bone volume fraction (BV/TV). The expression levesl of COL2, SOX9, p-P65, IL-1β and MMP13 proteins in the cartilage tissues were detected using Western blotting. In a chondrocyte model with IL-1β treatment for mimicking KOA, the effect of aucubin on chondrogenic differentiation was observed with Alcian blue and Safranin O staining, and cellular COL2, SOX9 and TNF‑α mRNA expressions were detected with RT-qPCR. RESULTS: Compared with those in the model group, the mouse models receiving aucubin treatment showed significantly upregulated COL2 and SOX9 protein levels and downregulated p-P65, IL-1β and MMP13 expressions in the cartilage tissues. In the IL-1β-induced chondrocyte model, aucubin treatment significantly upregulated the mRNA expressions of SOX9 and COL2 but lowered the mRNA expression of TNF-α. Alcian blue and Safranin O staining confirmed that aucubin promoted the synthesis of cartilage extracellular matrix and enhanced chondrogenic differentiation of the cells. CONCLUSIONS Aucubin can effectively alleviate KOA in mice by inhibiting NF‑κB-mediated cartilage inflammation, promoting cartilage matrix synthesis, and improving subchondral bone microstructure.
Animals ; Mice, Inbred C57BL ; Mice ; Osteoarthritis, Knee/drug therapy* ; Signal Transduction/drug effects* ; NF-kappa B/metabolism* ; Iridoid Glucosides/therapeutic use* ; SOX9 Transcription Factor/metabolism* ; Chondrocytes/drug effects* ; Male ; Interleukin-1beta/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Collagen Type II/metabolism* ; Disease Models, Animal

OBJECTIVE: To investigate the effects and underlying mechanisms of VX765 on osteoarthritis (OA) and chondrocytes inflammation in rats. METHODS: Chondrocytes were isolated from the knee joints of 4-week-old Sprague Dawley (SD) rats. The third-generation cells were subjected to cell counting kit 8 (CCK-8) analysis to assess the impact of various concentrations (0, 1, 5, 10, 20, 50, 100 μmol/L) of VX765 on rat chondrocyte activity. An in vitro lipopolysaccharide (LPS) induced cell inflammation model was employed, dividing cells into control group, LPS group, VX765 concentration 1 group and VX765 concentration 2 group without obvious cytotoxicity. Western blot, real-time fluorescence quantitative PCR, and ELISA were conducted to measure the expression levels of inflammatory factors-transforming growth factor β ₁ (TGF-β ₁), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Additionally, Western blot and immunofluorescence staining were employed to assess the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1). Thirty-two SD rats were randomly assigned to sham surgery group (group A), OA group (group B), OA+VX765 (50 mg/kg) group (group C), and OA+VX765 (100 mg/kg) group (group D), with 8 rats in each group. Group A underwent a sham operation with a medial incision, while groups B to D underwent additional transverse incisions to the medial collateral ligament and anterior cruciate ligament, with removal of the medial meniscus. One week post-surgery, groups C and D were orally administered 50 mg/kg and 100 mg/kg VX765, respectively, while groups A and B received an equivalent volume of saline. Histopathological examination using HE and safranin-fast green staining was performed, and Mankin scoring was utilized for evaluation. Immunohistochemical staining technique was employed to analyze the expressions of matrix metalloproteinase 13 (MMP-13) and collagen type Ⅱ. RESULTS: The CCK-8 assay indicated a significant decrease in cell viability at VX765 concentrations exceeding 10 μmol/L ( P<0.05), so 4 μmol/L and 8 μmol/L VX765 without obvious cytotoxicity were selected for subsequent experiments. Following LPS induction, the expressions of TGF-β ₁, IL-6, and TNF-α in cells significantly increased when compared with the control group ( P<0.05). However, intervention with 4 μmol/L and 8 μmol/L VX765 led to a significant decrease in expression compared to the LPS group ( P<0.05). Western blot and immunofluorescence staining demonstrated a significant upregulation of Nrf2 pathway-related molecules Nrf2 and HO-1 protein expressions by VX765 ( P<0.05), indicating Nrf2 pathway activation. Histopathological examination of rat knee joint tissues and immunohistochemical staining revealed that, compared to group B, treatment with VX765 in groups C and D improved joint structural damage in rat OA, alleviated inflammatory reactions, downregulated MMP-13 expression, and increased collagen type Ⅱ expression. CONCLUSION VX765 can improve rat OA and reduce chondrocyte inflammation, possibly through the activation of the Nrf2 pathway.
Rats ; Animals ; Chondrocytes/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha/metabolism* ; Collagen Type II/metabolism* ; Interleukin-6 ; Lipopolysaccharides/pharmacology* ; NF-E2-Related Factor 2/pharmacology* ; Inflammation/drug therapy* ; Osteoarthritis/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Dipeptides ; para-Aminobenzoates

This study aims to observe the effects of different doses of Astragali Radix on the expression of glucagon(GLP-1) in se-rum and glucagon receptor(GLP-1R) in cartilage tissue in rats with knee osteoarthritis(KOA), explore the effect of Astragali Radix on the inflammation and apoptosis of KOA by regulating GLP-1/GLP-1R signaling axis, and investigate the mechanism of its action in alleviating KOA. Forty-eight male SD rats were randomly divided into six groups: blank group, model group, low-, medium-, and high-dose Astragali Radix groups(3.125, 6.25, and 12.5 g·kg~(-1)), and glucosamine sulfate group(0.1 g·kg~(-1)). Except for the blank group, rats in other groups were injected with sodium iodoacetate(MIA) into the knee joint to establish KOA models. After successful modeling, the rats were continuously treated for five weeks. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of GLP-1, tumor necrosis factor-alpha(TNF-α), and interleukin-1β(IL-1β) in rat serum. Pathological examination was utilized to observe the pathological changes in knee joint cartilage. The mRNA levels of TNF-α and MMP13 in knee joint cartilage were detected by qRT-PCR, and the protein expression levels of GLP-1R, MMP13, and caspase-8 in knee joint cartilage were detected by Western blot. The expression of GLP-1R and MMP13 in the knee joint was detected by immunohistochemistry. Tunel staining was used to observe the apoptosis of chondrocytes in the knee joint. The above experimental results showed that Astragali Radix may raise the serum levels of GLP-1, reduce serum levels of TNF-α and IL-1, and decrease the relative mRNA expression of TNF-α and MMP13 through the GLP-1/GLP-1R axis. It thus activated GLP-1R, reduced the protein expression of MMP13 and caspase-8 in cartilage, and regulated their related signaling pathways to improve inflammation and apoptosis, so as to protect cartilage and improve KOA.
Animals ; Male ; Rats, Sprague-Dawley ; Osteoarthritis, Knee/genetics* ; Rats ; Drugs, Chinese Herbal/pharmacology* ; Glucagon-Like Peptide 1/metabolism* ; Glucagon-Like Peptide-1 Receptor/metabolism* ; Astragalus propinquus/chemistry* ; Humans ; Matrix Metalloproteinase 13/metabolism* ; Signal Transduction/drug effects* ; Tumor Necrosis Factor-alpha/metabolism* ; Astragalus Plant/chemistry* ; Apoptosis/drug effects*

OBJECTIVE: To prepare a novel hyaluronic acid methacrylate (HAMA) hydrogel microspheres loaded polyhedral oligomeric silsesquioxane-diclofenac sodium (POSS-DS) patricles, then investigate its physicochemical characteristics and in vitro and in vivo biological properties. METHODS: Using sulfhydryl POSS (POSS-SH) as a nano-construction platform, polyethylene glycol and DS were chemically linked through the "click chemistry" method to construct functional nanoparticle POSS-DS. The composition was analyzed by nuclear magnetic resonance spectroscopy and the morphology was characterized by transmission electron microscopy. In order to achieve drug sustained release, POSS-DS was encapsulated in HAMA, and hybrid hydrogel microspheres were prepared by microfluidic technology, namely HAMA@POSS-DS. The morphology of the hybrid hydrogel microspheres was characterized by optical microscope and scanning electron microscope. The in vitro degradation and drug release efficiency were observed. Cell counting kit 8 (CCK-8) and live/dead staining were used to detect the effect on chondrocyte proliferation. Moreover, a chondrocyte inflammation model was constructed and cultured with HAMA@POSS-DS. The relevant inflammatory indicators, including collagen type Ⅱ, aggrecan (AGG), matrix metalloproteinase 13 (MMP-13), recombinant A disintegrin and metalloproteinase with thrombospondin 5 (Adamts5), and recombinant tachykinin precursor 1 (TAC1) were detected by immunofluorescence staining and real-time fluorescence quantitative PCR, with normal cultured chondrocytes and the chondrocyte inflammation model without treatment as control group and blank group respectively to further evaluate their anti-inflammatory activity. Finally, by constructing a rat model of knee osteoarthritis, the effectiveness of HAMA@POSS-DS on osteoarthritis was evaluated by X-ray film and Micro-CT examination. RESULTS: The overall particle size of POSS-DS nanoparticles was uniform with a diameter of about 100 nm. HAMA@POSS-DS hydrogel microspheres were opaque spheres with a diameter of about 100 μm and a spherical porous structure. The degradation period was 9 weeks, during which the loaded POSS-DS nanoparticles were slowly released. CCK-8 and live/dead staining showed no obvious cytotoxicity at HAMA@POSS-DS, and POSS-DS released by HAMA@POSS-DS significantly promoted cell proliferation (P<0.05). In the chondrocyte anti-inflammatory experiment, the relative expression of collagen type Ⅱ mRNA in HAMA@POSS-DS group was significantly higher than that in control group and blank group (P<0.05). The relative expression level of AGG mRNA was significantly higher than that of blank group (P<0.05). The relative expressions of MMP-13, Adamts5, and TAC1 mRNA in HAMA@POSS-DS group were significantly lower than those in blank group (P<0.05). In vivo experiments showed that the joint space width decreased after operation in rats with osteoarthritis, but HAMA@POSS-DS delayed the process of joint space narrowing and significantly improved the periarticular osteophytosis (P<0.05). CONCLUSION HAMA@POSS-DS can effectively regulate the local inflammatory microenvironment and significantly promote chondrocyte proliferation, which is conducive to promoting cartilage regeneration and repair in osteoarthritis.
Animals ; Rats ; Matrix Metalloproteinase 13 ; Microspheres ; Hydrogels ; Collagen Type II ; Diclofenac ; Inflammation ; Osteoarthritis, Knee/drug therapy* ; Hyaluronic Acid ; Aggrecans

OBJECTIVE: To explore and verify that transient receptor potential vanilloid 4(TRPV4) affects chondrocyte degeneration. METHODS: Neonatal SD rats were selected, primary chondrocytes were extracted, and identified by toluidine blue staining and alcian blue staining;an in vitro chondrocyte inflammation model was constructed by IL-1β, and TRPV4 inhibitor was used to treat chondrocytes under inflammatory conditions, and the chondrocytes were treated by RT-PCR method was used to detect matrix metallopeptidase 13(MMP-13), a disintegrin and metalloproteinase with thrombospondin 5, (ADAMTS-5)、nitric oxide synthase 2(NOS2)、Collagen, type II alpha 1(Col2α1)and aggrecan (Acan) mRNA in chondrocytes; primary chondrocytes were treated with different concentrations of TRPV4 overexpression plasmid, and the optimal overexpression dose was screened. The mRNA expressions of TRPV4, MMP-13, ADAMTS-5, NOS2, Col2α1 and Acan in chondrocytes under the optimal TRPV4 overexpression dose were detected. RESULTS: Toluidine blue staining and Alcian blue staining identified the extracted cells as primary chondrocytes;RT-PCR showed that TRPV4, MMP-13, ADAMTS-5, NOS2 mRNA in chondrocytes treated with TRPV4 inhibitor under inflammatory conditions. The expression of Col2α1 mRNA was significantly decreased (P<0.05), and the expression of Col2α1 mRNA was increased (P<0.05). Although there was no significant difference in the expression of Acan mRNA, the overall trend was also increasing. The expression of Col2α1 and Acan mRNA in chondrocytes was significantly decreased (P<0.05), and the expression of NOS2 mRNA was increased(P<0.05), but there was no significant difference in MMP-13 and ADAMTS-5 (P>0.05). CONCLUSION Inhibiting the expression of TRPV4 can down-regulate the expression of genes related to chondrocyte degeneration.
Animals ; Rats ; Aggrecans/metabolism* ; Cartilage, Articular ; Cells, Cultured ; Chondrocytes ; Interleukin-1beta/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Rats, Sprague-Dawley ; RNA, Messenger/metabolism* ; TRPV Cation Channels/metabolism*

OBJECTIVE: To explore the effect of miR-143 regulating matrix metalloproteinase(MMP)-13 expression on migration and invasion of osteosarcoma cells. METHODS: The mouse osteosarcoma cell line 143B cells were cultured in 96-well plates, and blank group, negative group, positive group, and intervention group were set up. Then, the blank group did no treatment 50 μg miR-143 mimic was added to positive group, negative group added equal mimic NC (control sequence of miR-143 mimic), the intervention group was added 50 μg miR-143 mimic and 10 μg MMP-13 protein, all groups continued to culture for 3 to 6 hours, and finally the serum was aspirated to treat for half an hour. The protein expressions of miR-143 and MMP-13 in each group were measured by fluorescence quantitative PCR experiment and Western blot experiment, respectively, and the invasion and migration abilities of cells were measured by Transwell and scratch experiments. RESULTS: The expression of MMP-13 protein in the positive group and the intervention group was significantly lower than that in the blank group, and the positive group was lower than the intervention group (P<0.05);The mean numbers of invasive cells in blank group, negative group, positive group and intervention group were (1 000.01±44.77), (959.25±46.32), (245.04±4.33), (634.06±33.78) cells/field, respectively;the scratch healing rate of the positive group and the intervention group was significantly lower than that of the blank group, and the positive group was lower than the intervention group (P<0.05). CONCLUSION MMP-13 is a target of miR-143, which can reduce the migration and invasion ability of osteosarcoma cells by inhibiting the expression of MMP-13.
Osteosarcoma/pathology* ; MicroRNAs/genetics* ; Matrix Metalloproteinase 13/genetics* ; Neoplasm Invasiveness ; Animals ; Mice ; Cell Line, Tumor ; Cell Movement

OBJECTIVE: To investigate the effect of pure Chinese herbal extract Mangiferin on the malignant biological behaviors of multiple myeloma (MM) cells, and to analyze the molecular mechanism of the anti-myeloma effect of Mangiferin, so as to provide experimental basis for MM replacement therapy. METHODS: U266 and RPMI8226 of human MM cell lines were intervened with different concentrations of Mangiferin. Cell proliferation was detected by CCK-8 method. Annexin V/PI double staining flow cytometry was used to detect cell apoptosis. Western blot was used to detect the expression of apoptosis and related signaling pathway proteins, and real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of matrix metalloproteinase (MMP) and CXC chemokine receptor (CXCR) family. RESULTS: Mangiferin could inhibit the proliferation activity of U266 and RPMI8226 cells and induce cells apoptosis. After Mangiferin intervened in U266, RPMI8226 cells for 48 h, the expression of Bcl-2 family pro-apoptotic protein Bax was up-regulated, while the expression of survivin and Bcl-xL proteins was down-regulated and caspase-3 was hydrolyzed and activated to promote cell apoptosis, besides, the expression of Bcl-2 protein in U266 cells was also significantly down-regulated to induce apoptosis (P<0.05). After Mangiferin intervenes in MM cells, it can not only increase the expression level of tumor suppressor p53, but also induce programmed cell death of MM cells by inhibiting the expression of anti-apoptotic molecules and down-regulating the phosphorylation levels of AKT and NF-κB. In addition, after the intervention of Mangiferin, the expressions of CXCR4, MMP2 and MMP9 in U266 cells were down-regulated (P<0.05), while there is no effect on the expressions of CXCR2, CXCR7 and MMP13 (P>0.05). However, the expressions of CXCR4, MMP9, and MMP13 in RPMI8226 cells were down-regulated (P<0.01), the expression of MMP2 was weakly affected, and the expression of CXCR2 and CXCR7 was basically not affected (P>0.05). CONCLUSION Mangiferin can inhibit the proliferation and induce apoptosis of MM cells, and its mechanism may be related to inhibiting the activation of NF-κB signaling pathway, affecting the expression of Bcl-2 family proteins, and inhibiting the expression of core members of MMP and CXCR family.
Humans ; Matrix Metalloproteinase 2 ; Matrix Metalloproteinase 9 ; Matrix Metalloproteinase 13 ; Cell Line, Tumor ; NF-kappa B ; Multiple Myeloma/pathology* ; Cell Proliferation ; Apoptosis ; Proto-Oncogene Proteins c-bcl-2

This study aims to investigate the therapeutic effects of alkaloids in Tibetan medicine Bangna(Aconiti Penduli et Aconiti Flavi Radix) on osteoarthritis(OA) rats in vitro and in vivo and the underlying mechanisms. Chondrocytes were isolated from 2-3 week-old male SD rats and lipopolysaccharide(LPS) was used to induce OA in chondrocytes in vitro. Methyl thiazolyl tetrazolium(MTT) assay was used to investigate the toxicity of seven alkaloids(12-epi-napelline, songorine, benzoylaconine, aconitine, 3-acetylaconitine, mesaconitine, and benzoylmesaconine) to chondrocytes. Chondrocytes were classified into the control group, model group(induced by LPS 5 μg·mL~(-1) for 12 h), and administration groups(induced by LPS 5 μg·mL~(-1) for 12 h and incubated for 24 h). The protein expression of inflammatory factors cyclooxygenase-2(COX-2), inducible nitric oxide synthetase(iNOS), tumor necrosis factor-α(TNF-α), and interleukin-1β(IL-1β) in each group were detected by Western blot, and the protein expression of matrix metalloprotease-13(MMP-13), aggrecan, collagen Ⅱ, fibroblast growth factor 2(FGF2) by immunofluorescence staining. For the in vivo experiment, sodium iodoacetate was used to induce OA in rats, and the expression of MMP-13, TNF-α, and FGF2 in cartilage tissues of rats in each group was detected by immunohistochemistry. The results showed that the viability of chondrocytes could reach more than 90% under the treatment of the seven alkaloids in a certain dose range. Aconitine, 12-epi-napelline, songorine, 3-acetylaconitine, and mesaconitine could decrease the protein expression of inflammatory factors COX-2, iNOS, TNF-α and IL-1β compared with the model group. Moreover, 12-epi-napelline, aconitine, and mesaconitine could down-regulate the expression of MMP-13 and up-regulate the expression of aggrecan and collagen Ⅱ. In addition, compared with the model group and other Bangna alkaloids, 12-epi-napelline significantly up-regulated the expression of FGF2. Therefore, 12-epi-napelline was selected for the animal experiment in vivo. Immunohistochemistry results showed that 12-epi-napelline could significantly reduce the expression of MMP-13 and TNF-α in cartilage tissues, and up-regulate the expression of FGF2 compared with the model group. In conclusion, among the seven Bangna alkaloids, 12-epi-napelline can promote the repair of OA in rats by down-regulating the expression of MMP-13 and TNF-α and up-regulating the expression of FGF2.
Aconitine/therapeutic use* ; Aconitum/chemistry* ; Aggrecans/metabolism* ; Alkaloids/therapeutic use* ; Animals ; Cells, Cultured ; Cyclooxygenase 2/metabolism* ; Fibroblast Growth Factor 2/therapeutic use* ; Interleukin-1beta/metabolism* ; Iodoacetic Acid/therapeutic use* ; Lipopolysaccharides ; Male ; Matrix Metalloproteinase 13/metabolism* ; Medicine, Tibetan Traditional ; NF-kappa B/metabolism* ; Osteoarthritis/drug therapy* ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVE: To investigate the effect of indirubin for relieving joint inflammation and injury in a rat model of osteoarthritis. METHODS: Articular cartilage chondrocytes were isolated from adult rat knee joint and cultured in the presence of interleukin-1β (IL-1β) and 0.1, 0.5, 1.0, or 2.0 μmol/L indirubin. The cells were transfected with NPAS2 siRNA or a non-specific siRNA, and the cell proliferation and apoptosis were evaluated using tetramethylthiazole blue staining and flow cytometry. The protein expression levels of Bax, Bcl-2, ACAN, COL2A1, MMP-13 and NPAS2 were detected with Western blotting, and the levels of NO, PGE2 and TNF-α in the culture supernatant were determined with ELISA. The mRNA expression levels of NPAS2, ACAN, COL2A1 and MMP-13 were detected using fluorescence quantitative PCR. In a C57BL/6 mouse model of osteoarthritis, the effect of indirubin on BAX, Bcl-2, ACAN and MMP-13 protein expressions in the bone and joint tissues were evaluated with Western blotting. RESULTS: Treatment with 0.1 μmol/L indirubin produced no significant changes in chondrocyte proliferation, apoptosis, caspase-3 activity, or BAX and Bcl-2 protein expressions. At higher doses (0.5, 1.0 and 2.0 μmol/L), indirubin significantly promoted cell proliferation, increased Bcl-2 protein expression, and lowered cell apoptosis rate, caspase-3 activity and Bax protein expression (P < 0.05). Indirubin treatment at 0.5 μmol/L up-regulated the protein and mRNA expressions of NPAS2, ACAN and COL2A1, and down-regulated the expressions of MMP-13, NO, PGE2 and TNF-α (P < 0.05). Interference of NPAS2 expression significantly attenuated the protective effect of 0.5 μmol/L indirubin against IL-1β-induced chondrocyte injury. The mouse model of osteoarthritis showed obviously increased protein levels of BAX and MMP-13 (P < 0.01) and decreased levels of Bcl-2 (P < 0.05) and ACAN (P < 0.01) in the knee joint, and indirubin treatment of the mouse models significantly inhibited the increase of BAX and MMP-13 protein expressions (P < 0.01) and up-regulated the protein expressions of Bcl-2 and ACAN (P < 0.05). CONCLUSION Indirubin has a protective effect on osteoarthritis tissue and alleviates inflammation and damage of osteoarthritis chondrocytes possibly through NPAS2.
Animals ; Apoptosis ; Caspase 3/metabolism* ; Cells, Cultured ; Chondrocytes ; Dinoprostone/pharmacology* ; Disease Models, Animal ; Indoles ; Inflammation/drug therapy* ; Interleukin-1beta/metabolism* ; Matrix Metalloproteinase 13/metabolism* ; Mice ; Mice, Inbred C57BL ; Osteoarthritis/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; RNA, Messenger/metabolism* ; RNA, Small Interfering/metabolism* ; Rats ; Tumor Necrosis Factor-alpha/metabolism* ; bcl-2-Associated X Protein/metabolism*