BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent years.However,given the complexity of osteoarthritis pathogenesis,single gene ma...BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent years.However,given the complexity of osteoarthritis pathogenesis,single gene manipulation for the treatment of osteoarthritis may not produce satisfactory results.Previous studies have shown that nuclear factorκB could promote the inflammatory pathway in osteoarthritic chondrocytes,and bone morphogenetic protein 4(BMP4)could promote cartilage regeneration.OBJECTIVE:To test whether combined application of AAV-p65shRNA and AAV-BMP4 will yield the synergistic effect on chondrocytes regeneration and osteoarthritis treatment.METHODS:Viral particles containing AAV-p65-shRNA and AAV-BMP4 were prepared.Their efficacy in inhibiting inflammation in chondrocytes and promoting chondrogenesis was assessed in vitro and in vivo by transfecting AAV-p65-shRNA or AAV-BMP4 into cells.The experiments were divided into five groups:PBS group;osteoarthritis group;AAV-BMP4 group;AAV-p65shRNA group;and BMP4-p65shRNA 1:1 group.Samples were collected at 4,12,and 24 weeks postoperatively.Tissue staining,including safranin O and Alcian blue,was applied after collecting articular tissue.Then,the optimal ratio between the two types of transfected viral particles was further investigated to improve the chondrogenic potential of mixed cells in vivo.RESULTS AND CONCLUSION:The combined application of AAV-p65shRNA and AAV-BMP4 together showed a synergistic effect on cartilage regeneration and osteoarthritis treatment.Mixed cells transfected with AAV-p65shRNA and AAV-BMP4 at a 1:1 ratio produced the most extracellular matrix synthesis(P<0.05).In vivo results also revealed that the combination of the two viruses had the highest regenerative potential for osteoarthritic cartilage(P<0.05).In the present study,we also discovered that the combined therapy had the maximum effect when the two viruses were administered in equal proportions.Decreasing either p65shRNA or BMP4 transfected cells resulted in less collagen II synthesis.This implies that inhibiting inflammation by p65shRNA and promoting regeneration by BMP4 are equally important for osteoarthritis treatment.These findings provide a new strategy for the treatment of early osteoarthritis by simultaneously inhibiting cartilage inflammation and promoting cartilage repair.展开更多
Objective: To investigate the possible effect of nivalenol on metabolism ofthe cultured chondrocytes and the protection of selenium. Methods: The quantitative analyses ofmetabolism in single- layer cultured chondrocyt...Objective: To investigate the possible effect of nivalenol on metabolism ofthe cultured chondrocytes and the protection of selenium. Methods: The quantitative analyses ofmetabolism in single- layer cultured chondrocytes were performed by biocliemical means and theimpairment of DNA was observed by both of the single cell microgel electrophoresis assay and theagarose gel electrophoresis assay. Results: In the media containing different concentrations ofnivalenol (0. 000 5-0. 020 0 mg/L), the amounts of DNA and proteoglycan in matrix of thechondrocytes were decreased. The syn-thesis of protein was reduced and the impairment of DNAdeteriorated with the increase of the concentrations of nivalenol in tlte given dose. When seleniumwas added into the media, the impairment by nivalenol was decreased. In the media containingdifferent concentrations of nivalenol, however, the lipid peroxidation of the chondrocytes was notaffected by nivalenol, yet the amount of lipid peroxides significantly declined. Conclusion:Nivalenol may evidently cause impairment of the chondrocytes when its concentrations are in thepresent experimental range. Selenium can protect cultured cliondrocytes, but cannot prevent theirDNA from being impaired.展开更多
背景:富血小板血浆通过调节自噬和凋亡细胞因子、信号转导通路等方面在干预骨关节炎发展过程中发挥了重要作用。目的:总结近年来富血小板血浆在骨关节炎中发挥作用的细胞因子与信号通路,以及与软骨细胞自噬和凋亡的相关性,为未来治疗骨...背景:富血小板血浆通过调节自噬和凋亡细胞因子、信号转导通路等方面在干预骨关节炎发展过程中发挥了重要作用。目的:总结近年来富血小板血浆在骨关节炎中发挥作用的细胞因子与信号通路,以及与软骨细胞自噬和凋亡的相关性,为未来治疗骨关节炎提供有效的靶点。方法:在中国知网、万方数据库、维普、PubMed、Web of Science和Medline数据库进行文献检索,以“富血小板血浆,软骨细胞,细胞凋亡,细胞自噬,骨关节炎,细胞因子,信号通路”作为中文检索词,以“platelet-rich plasma,chondrocyte,apoptosis,autophagy,osteoarthritis,cytokines,signaling pathway”作为英文检索词,对最终纳入的66篇文献进行了系统性的总结和归纳。结果与结论:现有研究显示富血小板血浆能够通过多种途径促进软骨修复,助力骨组织愈合,其主要分为3个方面:①富血小板血浆参与调控了微自噬小体的延伸、闭合与成熟,并在特定条件下促进软骨细胞巨自噬和分子伴侣介导的细胞自噬,促进LC3Ⅱ/Ⅰ、Beclin1等自噬相关因子的表达,抑制P62/SQSTM1的表达,目前尚未有明确的研究直接探讨富血小板血浆对热休克蛋白的具体作用,未来在这一领域值得进一步研究;②富血小板血浆释放的各类生长因子抑制促凋亡因子Caspase、白细胞介素1β、肿瘤坏死因子α的表达,促进抗凋亡因子Bcl-2的表达,阻止软骨细胞凋亡和变性;③富血小板血浆通过激活PI3K/AKT/mTOR信号通路、NF-κB信号转导通路、死亡受体通路、线粒体应激通路等途径,抑制Bax和Caspase的表达,阻止细胞色素c的释放,从而抑制软骨细胞死亡和坏死性凋亡。综合而言,富血小板血浆促进软骨修复、支持软骨再生及发挥抗炎作用,其在软骨细胞中实现生物效应通常依赖于细胞自噬和凋亡相关细胞因子及信号通路的调控。展开更多
It has been previously reported that small mother against decapentaplegic 3 (Smad3) gene knockout (Smad3^ex8/ex8) mice displays phenotypes similar to human osteoarthritis, as characterized by abnormal hypertrophic...It has been previously reported that small mother against decapentaplegic 3 (Smad3) gene knockout (Smad3^ex8/ex8) mice displays phenotypes similar to human osteoarthritis, as characterized by abnormal hypertrophic differentiation of articular chondrocytes. To further clarify the crucial target genes that mediate transformation growth factor-β (TGF-β)/Smad3 signals on articular chondrocytes differentiation and investigate the underlying molecular mechanism of osteoarthritis, microarrays were used to perform comparative transcriptional profiling in the articular cartilage between Smad3^ex8/ex8and wild-type mice on day five after birth. The gene profding results showed that the activity of bone morphogenetic protein (BMP) and TGF-β/cell division cycle 42 (Cdc42) signaling pathways were enhanced in Smad3^ex8/ex8 chondrocytes. Moreover, there was altered gene expression in growth hormone/insulin-like growth factor 1 (Igfl) axis and fibroblast growth factor (Fgf) signaling pathway. Notably, protein synthesis related genes and electron transport chain related genes were upregulated in Smad3^ex8/ex8 chondrocytes, implying that accelerated protein synthesis and enhanced cellular respiration might contribute to hypertrophic differentiation of articular chondrocytes and the pathogenesis of osteoarthritis.展开更多
Objective To investigate the in vitro effect of caffeic acid phenethyl ester (CAPE), a NF-KB inhibitor, on the apoptosis of osteoarthritic (OA) chondrocytes and on the regulation of the gelatinases matrix metallop...Objective To investigate the in vitro effect of caffeic acid phenethyl ester (CAPE), a NF-KB inhibitor, on the apoptosis of osteoarthritic (OA) chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9). Methods Annexin V-FITC/propidium iodide (PI) labeling and western blotting were used to observe and determine the apoptosis in TNFa-stimulated primary cultured osteoarthritic chondrocytes. Also, gelatin zymography was applied to examine MMP-2 and MMP-9 activities in supernatants. Results it was confirmed by both flow cytometry and western blotting that chondrocytes from OA patients have an apoptotic background. Use of CAPE in combination with 10 ng/mL of TNFa for 24 h facilitated the apoptosis. MMP-9 in the supernatant could be autoactivated (from proMMP-9 to active MMP-9), and the physiologic calcium concentration (2.5 mmol/L) could delay the autoactivation of MMP-9. The activities of MMP-2 and MMP-9 in the fresh supernatant increased significantly in response to stimulation by 10 ng/mL of TNFa for 24 h. The stimulatory effect of TNFa just on proMMP-9 was counteracted significantly by CAPE. Conclusion NF-KB could prevent chondrocytes apoptosis though its activation was attributed to the increase of proMMP-9 activity induced by TNFa (a pro-apoptotic factor). Therefore, therapeutic NF-KB inhibitor was a 'double-edged swords' to the apoptosis of chondrocytes and the secretion of MMP-9.展开更多
Objective:To investigate the effects of T-2 toxin on expressions of Fas,p53,Bcl-xL,Bcl-2,Bax and caspase-3 on human chondrocytes.Methods:Human chondrocytes were treated with T-2 toxin(1~20 ng/ml)for 5 d.Fas,p53 and o...Objective:To investigate the effects of T-2 toxin on expressions of Fas,p53,Bcl-xL,Bcl-2,Bax and caspase-3 on human chondrocytes.Methods:Human chondrocytes were treated with T-2 toxin(1~20 ng/ml)for 5 d.Fas,p53 and other apoptosis-related proteins such as Bax,Bcl-2,Bcl-xL,caspase-3 were determined by Western blot analysis and their mRNA expressions were determined by reverse transcriptase-polymerase chain reaction(RT-PCR).Results:Increases in Fas,p53 and the pro-apoptotic factor Bax protein and mRNA expressions and a decrease of the anti-apoptotic factor Bcl-xL were observed in a dose-dependent manner after exposures to 1~20 ng/ml T-2 toxin,while the expression of the anti-apoptotic factor Bcl-2 was unchanged.Meanwhile,T-2 toxin could also up-regulate the expressions of both pro-caspase-3 and caspase-3 in a dose-dependent manner.Conclusion:These data suggest a possible underlying molecular mechanism for T-2 toxin to induce the apoptosis sig- naling pathway in human chondrocytes by regulation of apoptosis-related proteins.展开更多
Objective To investigate the expression of miRNA-140 in chondrocytes and synovial fluid of osteoarthritis(OA) patients, and explore the relationship between the miRNA-140 expression and OA severity. Methods This study...Objective To investigate the expression of miRNA-140 in chondrocytes and synovial fluid of osteoarthritis(OA) patients, and explore the relationship between the miRNA-140 expression and OA severity. Methods This study enrolled 30 OA patients who underwent total knee arthroplasty for chondrocytes sampling and 30 OA patients who underwent intra-articular injection for synovial fluid sampling. All OA patients were grouped into mild [Kellgren and Lawrence(KL) grade 1-2], moderate(KL grade 3) and severe(KL grade 4), with 10 in each subgroups for each sampling purposes. 7 non-OA patients and 10 patients with knee injury were collected for cartilage and synovial fluid sampling respectively as control groups. Chondrocytes were isolated from the cartilage tissue and cultured in vitro. Quantitative real time PCR for miRNA-140 in chondrocytes and synovial fluid were performed, and the U6 sn RNA was used as internal control. The expression difference of miRNA-140 among groups and correlation between the expression and the KL grade of OA were analysed using one-way ANOVA and Spearman test respectively. Results The expression of miRNA-140 in chondrocytes of knees in OA patients was reduced than that in normal knees, and the between-group difference was statistically significant(F=305.464, P<0.001). miRNA-140 could be detected in synovial fluid of both normal knees and OA knees, its relative expression level was reduced in synovial fluid of OA group compared with normal group, and the between-group difference was statistically significant as well(F=314.245, P<0.001). The relative expression level of miRNA-140 in both chondrocytes and synovial fluid were negatively correlated with the KL grade of OA(r=-0.969, P<0.001; r=-0.970, P<0.001). Conclusion miRNA-140 could be detected in chondrocytes and synovial fluid of OA patients, and its expression was negatively correlated with the severity of OA.展开更多
Osteoarthritis(OA) is an age-related disorder that is strongly associated with chondrocyte senescence. The causal link between disruptive PTEN/Akt signaling and chondrocyte senescence and the underlying mechanism are ...Osteoarthritis(OA) is an age-related disorder that is strongly associated with chondrocyte senescence. The causal link between disruptive PTEN/Akt signaling and chondrocyte senescence and the underlying mechanism are unclear. In this study, we found activated Akt signaling in human OA cartilage as well as in a mouse OA model with surgical destabilization of the medial meniscus.Genetic mouse models mimicking sustained Akt signaling in articular chondrocytes via PTEN deficiency driven by either Col2a1-Cre or Col2a1-Cre^(ERT2) developed OA, whereas restriction of Akt signaling reversed the OA phenotypes in PTEN-deficient mice.Mechanistically, prolonged activation of Akt signaling caused an accumulation of reactive oxygen species and triggered chondrocyte senescence as well as a senescence-associated secretory phenotype, whereas chronic administration of the antioxidant N-acetylcysteine suppressed chondrocyte senescence and mitigated OA progression in PTEN-deficient mice. Therefore,inhibition of Akt signaling by PTEN is required for the maintenance of articular cartilage. Disrupted Akt signaling in articular chondrocytes triggers oxidative stress-induced chondrocyte senescence and causes OA.展开更多
文摘BACKGROUND:Adeno-associated virus(AAV)gene therapy has been proven to be reliable and safe for the treatment of osteoarthritis in recent years.However,given the complexity of osteoarthritis pathogenesis,single gene manipulation for the treatment of osteoarthritis may not produce satisfactory results.Previous studies have shown that nuclear factorκB could promote the inflammatory pathway in osteoarthritic chondrocytes,and bone morphogenetic protein 4(BMP4)could promote cartilage regeneration.OBJECTIVE:To test whether combined application of AAV-p65shRNA and AAV-BMP4 will yield the synergistic effect on chondrocytes regeneration and osteoarthritis treatment.METHODS:Viral particles containing AAV-p65-shRNA and AAV-BMP4 were prepared.Their efficacy in inhibiting inflammation in chondrocytes and promoting chondrogenesis was assessed in vitro and in vivo by transfecting AAV-p65-shRNA or AAV-BMP4 into cells.The experiments were divided into five groups:PBS group;osteoarthritis group;AAV-BMP4 group;AAV-p65shRNA group;and BMP4-p65shRNA 1:1 group.Samples were collected at 4,12,and 24 weeks postoperatively.Tissue staining,including safranin O and Alcian blue,was applied after collecting articular tissue.Then,the optimal ratio between the two types of transfected viral particles was further investigated to improve the chondrogenic potential of mixed cells in vivo.RESULTS AND CONCLUSION:The combined application of AAV-p65shRNA and AAV-BMP4 together showed a synergistic effect on cartilage regeneration and osteoarthritis treatment.Mixed cells transfected with AAV-p65shRNA and AAV-BMP4 at a 1:1 ratio produced the most extracellular matrix synthesis(P<0.05).In vivo results also revealed that the combination of the two viruses had the highest regenerative potential for osteoarthritic cartilage(P<0.05).In the present study,we also discovered that the combined therapy had the maximum effect when the two viruses were administered in equal proportions.Decreasing either p65shRNA or BMP4 transfected cells resulted in less collagen II synthesis.This implies that inhibiting inflammation by p65shRNA and promoting regeneration by BMP4 are equally important for osteoarthritis treatment.These findings provide a new strategy for the treatment of early osteoarthritis by simultaneously inhibiting cartilage inflammation and promoting cartilage repair.
基金Supported by the National Natural Science Foundation of China(30170831)
文摘Objective: To investigate the possible effect of nivalenol on metabolism ofthe cultured chondrocytes and the protection of selenium. Methods: The quantitative analyses ofmetabolism in single- layer cultured chondrocytes were performed by biocliemical means and theimpairment of DNA was observed by both of the single cell microgel electrophoresis assay and theagarose gel electrophoresis assay. Results: In the media containing different concentrations ofnivalenol (0. 000 5-0. 020 0 mg/L), the amounts of DNA and proteoglycan in matrix of thechondrocytes were decreased. The syn-thesis of protein was reduced and the impairment of DNAdeteriorated with the increase of the concentrations of nivalenol in tlte given dose. When seleniumwas added into the media, the impairment by nivalenol was decreased. In the media containingdifferent concentrations of nivalenol, however, the lipid peroxidation of the chondrocytes was notaffected by nivalenol, yet the amount of lipid peroxides significantly declined. Conclusion:Nivalenol may evidently cause impairment of the chondrocytes when its concentrations are in thepresent experimental range. Selenium can protect cultured cliondrocytes, but cannot prevent theirDNA from being impaired.
文摘背景:富血小板血浆通过调节自噬和凋亡细胞因子、信号转导通路等方面在干预骨关节炎发展过程中发挥了重要作用。目的:总结近年来富血小板血浆在骨关节炎中发挥作用的细胞因子与信号通路,以及与软骨细胞自噬和凋亡的相关性,为未来治疗骨关节炎提供有效的靶点。方法:在中国知网、万方数据库、维普、PubMed、Web of Science和Medline数据库进行文献检索,以“富血小板血浆,软骨细胞,细胞凋亡,细胞自噬,骨关节炎,细胞因子,信号通路”作为中文检索词,以“platelet-rich plasma,chondrocyte,apoptosis,autophagy,osteoarthritis,cytokines,signaling pathway”作为英文检索词,对最终纳入的66篇文献进行了系统性的总结和归纳。结果与结论:现有研究显示富血小板血浆能够通过多种途径促进软骨修复,助力骨组织愈合,其主要分为3个方面:①富血小板血浆参与调控了微自噬小体的延伸、闭合与成熟,并在特定条件下促进软骨细胞巨自噬和分子伴侣介导的细胞自噬,促进LC3Ⅱ/Ⅰ、Beclin1等自噬相关因子的表达,抑制P62/SQSTM1的表达,目前尚未有明确的研究直接探讨富血小板血浆对热休克蛋白的具体作用,未来在这一领域值得进一步研究;②富血小板血浆释放的各类生长因子抑制促凋亡因子Caspase、白细胞介素1β、肿瘤坏死因子α的表达,促进抗凋亡因子Bcl-2的表达,阻止软骨细胞凋亡和变性;③富血小板血浆通过激活PI3K/AKT/mTOR信号通路、NF-κB信号转导通路、死亡受体通路、线粒体应激通路等途径,抑制Bax和Caspase的表达,阻止细胞色素c的释放,从而抑制软骨细胞死亡和坏死性凋亡。综合而言,富血小板血浆促进软骨修复、支持软骨再生及发挥抗炎作用,其在软骨细胞中实现生物效应通常依赖于细胞自噬和凋亡相关细胞因子及信号通路的调控。
基金This work was supported by the National Key Program on Basic Research of China (No. 2006BAI23B01-3)National Natural Scie- nce Foundation of China (No. 30430350, 30500)National High-Tech Research and Development Program (No. 2006AA 02Z168, Z000 6303041231).
文摘It has been previously reported that small mother against decapentaplegic 3 (Smad3) gene knockout (Smad3^ex8/ex8) mice displays phenotypes similar to human osteoarthritis, as characterized by abnormal hypertrophic differentiation of articular chondrocytes. To further clarify the crucial target genes that mediate transformation growth factor-β (TGF-β)/Smad3 signals on articular chondrocytes differentiation and investigate the underlying molecular mechanism of osteoarthritis, microarrays were used to perform comparative transcriptional profiling in the articular cartilage between Smad3^ex8/ex8and wild-type mice on day five after birth. The gene profding results showed that the activity of bone morphogenetic protein (BMP) and TGF-β/cell division cycle 42 (Cdc42) signaling pathways were enhanced in Smad3^ex8/ex8 chondrocytes. Moreover, there was altered gene expression in growth hormone/insulin-like growth factor 1 (Igfl) axis and fibroblast growth factor (Fgf) signaling pathway. Notably, protein synthesis related genes and electron transport chain related genes were upregulated in Smad3^ex8/ex8 chondrocytes, implying that accelerated protein synthesis and enhanced cellular respiration might contribute to hypertrophic differentiation of articular chondrocytes and the pathogenesis of osteoarthritis.
文摘Objective To investigate the in vitro effect of caffeic acid phenethyl ester (CAPE), a NF-KB inhibitor, on the apoptosis of osteoarthritic (OA) chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9). Methods Annexin V-FITC/propidium iodide (PI) labeling and western blotting were used to observe and determine the apoptosis in TNFa-stimulated primary cultured osteoarthritic chondrocytes. Also, gelatin zymography was applied to examine MMP-2 and MMP-9 activities in supernatants. Results it was confirmed by both flow cytometry and western blotting that chondrocytes from OA patients have an apoptotic background. Use of CAPE in combination with 10 ng/mL of TNFa for 24 h facilitated the apoptosis. MMP-9 in the supernatant could be autoactivated (from proMMP-9 to active MMP-9), and the physiologic calcium concentration (2.5 mmol/L) could delay the autoactivation of MMP-9. The activities of MMP-2 and MMP-9 in the fresh supernatant increased significantly in response to stimulation by 10 ng/mL of TNFa for 24 h. The stimulatory effect of TNFa just on proMMP-9 was counteracted significantly by CAPE. Conclusion NF-KB could prevent chondrocytes apoptosis though its activation was attributed to the increase of proMMP-9 activity induced by TNFa (a pro-apoptotic factor). Therefore, therapeutic NF-KB inhibitor was a 'double-edged swords' to the apoptosis of chondrocytes and the secretion of MMP-9.
基金Project(Nos.3063058 and 30471499)supported by the National Natural Science Foundation of China
文摘Objective:To investigate the effects of T-2 toxin on expressions of Fas,p53,Bcl-xL,Bcl-2,Bax and caspase-3 on human chondrocytes.Methods:Human chondrocytes were treated with T-2 toxin(1~20 ng/ml)for 5 d.Fas,p53 and other apoptosis-related proteins such as Bax,Bcl-2,Bcl-xL,caspase-3 were determined by Western blot analysis and their mRNA expressions were determined by reverse transcriptase-polymerase chain reaction(RT-PCR).Results:Increases in Fas,p53 and the pro-apoptotic factor Bax protein and mRNA expressions and a decrease of the anti-apoptotic factor Bcl-xL were observed in a dose-dependent manner after exposures to 1~20 ng/ml T-2 toxin,while the expression of the anti-apoptotic factor Bcl-2 was unchanged.Meanwhile,T-2 toxin could also up-regulate the expressions of both pro-caspase-3 and caspase-3 in a dose-dependent manner.Conclusion:These data suggest a possible underlying molecular mechanism for T-2 toxin to induce the apoptosis sig- naling pathway in human chondrocytes by regulation of apoptosis-related proteins.
基金Supported by the National Natural Science Foundation of China(No.81672219No.81601936)the Science and Technology Support Program of Sichuan province(No.2014SZ0023-2)
文摘Objective To investigate the expression of miRNA-140 in chondrocytes and synovial fluid of osteoarthritis(OA) patients, and explore the relationship between the miRNA-140 expression and OA severity. Methods This study enrolled 30 OA patients who underwent total knee arthroplasty for chondrocytes sampling and 30 OA patients who underwent intra-articular injection for synovial fluid sampling. All OA patients were grouped into mild [Kellgren and Lawrence(KL) grade 1-2], moderate(KL grade 3) and severe(KL grade 4), with 10 in each subgroups for each sampling purposes. 7 non-OA patients and 10 patients with knee injury were collected for cartilage and synovial fluid sampling respectively as control groups. Chondrocytes were isolated from the cartilage tissue and cultured in vitro. Quantitative real time PCR for miRNA-140 in chondrocytes and synovial fluid were performed, and the U6 sn RNA was used as internal control. The expression difference of miRNA-140 among groups and correlation between the expression and the KL grade of OA were analysed using one-way ANOVA and Spearman test respectively. Results The expression of miRNA-140 in chondrocytes of knees in OA patients was reduced than that in normal knees, and the between-group difference was statistically significant(F=305.464, P<0.001). miRNA-140 could be detected in synovial fluid of both normal knees and OA knees, its relative expression level was reduced in synovial fluid of OA group compared with normal group, and the between-group difference was statistically significant as well(F=314.245, P<0.001). The relative expression level of miRNA-140 in both chondrocytes and synovial fluid were negatively correlated with the KL grade of OA(r=-0.969, P<0.001; r=-0.970, P<0.001). Conclusion miRNA-140 could be detected in chondrocytes and synovial fluid of OA patients, and its expression was negatively correlated with the severity of OA.
基金supported by grants from the State Key Program of National Natural Science of China (31630093)the National Natural Science Foundation of China (31571512, 31871476, and 81241062)+1 种基金the Beijing Nova Program (Z161100004916146)the National Basic Research Program of China (2012CB966904)
文摘Osteoarthritis(OA) is an age-related disorder that is strongly associated with chondrocyte senescence. The causal link between disruptive PTEN/Akt signaling and chondrocyte senescence and the underlying mechanism are unclear. In this study, we found activated Akt signaling in human OA cartilage as well as in a mouse OA model with surgical destabilization of the medial meniscus.Genetic mouse models mimicking sustained Akt signaling in articular chondrocytes via PTEN deficiency driven by either Col2a1-Cre or Col2a1-Cre^(ERT2) developed OA, whereas restriction of Akt signaling reversed the OA phenotypes in PTEN-deficient mice.Mechanistically, prolonged activation of Akt signaling caused an accumulation of reactive oxygen species and triggered chondrocyte senescence as well as a senescence-associated secretory phenotype, whereas chronic administration of the antioxidant N-acetylcysteine suppressed chondrocyte senescence and mitigated OA progression in PTEN-deficient mice. Therefore,inhibition of Akt signaling by PTEN is required for the maintenance of articular cartilage. Disrupted Akt signaling in articular chondrocytes triggers oxidative stress-induced chondrocyte senescence and causes OA.