RESUMEN
Osteoarthritis (OA) is a common degenerative disease of articular cartilage, and there is currently no effective treatment. Baicalein, a flavonoid extracted from plants of the Scutellaria genus, has frequently been used in the past as an anti-inflammatory and anti-allergic therapy. This study investigated the effect of baicalein on OA development. For in vivo study, a destabilization of the medial meniscus (DMM)-induced OA model was established in 8-week-old wild-type (WT) and AMPKα-knockout (KO) mice, while an in vitro study was performed using chondrocytes in an OA microenvironment induced by interleukin-1ß (IL-1ß) exposure. We found that baicalein alleviated OA development in vivo and exerted a chondroprotective effect in vitro by suppressing chondrocyte ferroptosis. Baicalein reduced OA-related pain sensitivity by inhibiting ferroptosis of chondrocytes in OA mice. Baicalein also facilitated AMPK holoenzyme assembly, stability, and activity and suppressed ferroptosis by inducing AMPKα phosphorylation in chondrocyte. In addition, AMPKα preserved nuclear factor erythroid 2-related factor 2(Nrf2) abundance in chondrocytes and induced Nrf2 into nucleus by promoting Keap1 degradation. Meanwhile, Nrf2 increased expression of heme oxygenase-1(HO-1) to inhibit chondrocyte lipid ROS. Taken together, these results showed that baicalein alleviated OA development by improving the activity of AMPK/Nrf2/HO-1 signaling to inhibit chondrocyte ferroptosis, revealing baicalein to be a potential therapeutic strategy for OA.
Asunto(s)
Ferroptosis , Osteoartritis , Ratones , Animales , Condrocitos/metabolismo , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Osteoartritis/tratamiento farmacológico , Osteoartritis/genética , Osteoartritis/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismoRESUMEN
The relationship between osteoporosis (OP) and knee osteoarthritis (OA) was studied using gold nanomaterial (GNP) contrast agent from the imaging and clinical perspectives. Patients were divided into the OA and OP comorbidity group (experimental), OA group (positive control), and OP group (negative control) and evaluated using the Lysholm knee joint score and traditional Chinese medicine syndrome score. Bone density was measured by parallel X-ray examination, magnetic resonance imaging examination, Recht classification, and arthroscopic Outerbridge classification. GNP contrast agents were used in the medical imaging tests. There were significant differences between the various factors compared between the experimental and positive control groups (P < 0.05). The correlation analysis of the variables and bone mineral density in all patients showed a positive linear relationship (P < 0.05). There was a positive correlation between OP and knee OA. GNP has good clinical value in medical imaging.
Asunto(s)
Nanoestructuras , Osteoartritis de la Rodilla , Osteoporosis , Medios de Contraste , Oro , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoporosis/diagnóstico por imagenRESUMEN
BACKGROUND: Non-coding RNAs are endogenous regulators of gene expression that have been implicated in the pathogenesis of various diseases, including osteoarthritis (OA). Long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) and miR-16-5p are up-regulated in OA tissues; however, their functions have not been clarified. METHODS: Chondrocyte ATDC5 was used as a cell model. NEAT1 overexpression and knockdown cells were established by transfection with lipofectamine. miR-16-5p was also transfected into the cells using lipofectamine. Moreover, cell proliferation was examined using cell counting kit-8 assays. Cell apoptosis was evaluated by flow cytometry. The interaction between NEAT1 and miR-16-5p was validated by a Quantitative real-time RT-PCR (qRT-PCR) and dual-luciferase reporter assays. RESULTS: NEAT1 could increase cell viability and decrease apoptosis of ATDC5 cells, whereas miR-16-5p had the opposite effects. NEAT1 could specifically bind to miR-16-5p and reduce its expression. CONCLUSIONS: The suppression of miR-16-5p, as mediated by NEAT1 overexpression, could promote proliferation and inhibit apoptosis of chondrocytes. It was also revealed that NEAT1 is a "double-edged sword" during the development of OA.
Asunto(s)
Proliferación Celular/genética , MicroARNs/genética , Osteoartritis/genética , ARN Largo no Codificante/genética , Apoptosis/genética , Línea Celular , Condrocitos/metabolismo , Condrocitos/patología , Femenino , Citometría de Flujo , Regulación de la Expresión Génica/genética , Humanos , Masculino , Osteoartritis/patologíaRESUMEN
BACKGROUND: 15-Lipoxygenase-1 (15-LOX-1) belongs to the lipoxygenase family involved in the inflammatory response and pathological process of various diseases, including osteoarthritis (OA). The overexpression of TGF-ß1 in osteoblasts leads to abnormal changes in subchondral bone structure, eventually causing OA. However, the pathogenesis of the disease is poorly defined, and the interaction between 15-LOX-1 and TGF-ß1 in osteoblasts has not been evaluated in OA. In this study, the role of 15-LOX-1 in subchondral bone osteoblasts in OA was evaluated. METHOD: 15-LOX-1 expression in osteoblasts of the subchondral bone of patients with OA was measured by immunohistochemistry, qRT-PCR, and western blotting. Osteoblasts extracted from the subchondral bone of OA were transfected with 15-LOX-1 siRNA and an overexpression vector. The eï¬ ;ect of 15-LOX-1 on the expression of TGF-ß1 in OA osteoblasts was assessed by qRT-PCR and western blotting. The effect of 15-LOX-1 on autophagy via AMPK pathway in OA osteoblasts was evaluated by qRT-PCR, western blotting, and transmission electron microscopy. RESULTS: The expression levels of 15-LOX-1 and TGF-ß1 were higher in OA subchondral bone osteoblast than that in non-OA subchondral bone. 15-LOX-1, which downregulated autophagy by inhibiting AMPK following the activation of mTORC1, upregulated the osteoblast expression of TGF-ß1. Treatment with autophagy inhibitors significantly increased the expression levels of TGF-ß1 in osteoblasts. CONCLUSION: In the present study, our findings suggested that 15-Lipoxygenase-1 in Osteoblasts Promotes TGF-ß1 expression via inhibiting autophagy in human Osteoarthritis. These novel results suggested that 15-Lipoxygenase-1 expressed by subchondral bone osteoblasts might be a promising therapeutic target in human OA.
Asunto(s)
Araquidonato 15-Lipooxigenasa/metabolismo , Osteoartritis/metabolismo , Osteoblastos/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Autofagia/fisiología , Huesos/metabolismo , Células Cultivadas , Regulación hacia Abajo/fisiología , Humanos , Regulación hacia Arriba/fisiologíaRESUMEN
AIMS: 15-lipoxygenase-1 (15-LOX-1) plays a vital role in aggravating the inflammatory response in various pathological processes, including osteoarthritis (OA). Abnormal osteoblast phenotypes including elevated runt-related transcription factor 2 (RUNX2), collagen type 1 alpha 1 (COL1), and osteocalcin (OCN) lead to osteosclerosis of the subchondral bone, which eventually causes OA. However, the pathogenesis of OA is poorly defined, and it is unclear if 15-LOX-1 induces osteoblast abnormal phenotypes in OA. Therefore, this study aimed to determine the roles of 15-LOX-1 on the abnormal phenotypes present in osteoblasts of the subchondral bone in OA. MAIN METHODS: The expression levels of 15-LOX-1 were measured by Immunohistochemistry, qRT-PCR and western blotting from the OA subchondral bone osteoblasts. To further investigate the roles of 15-LOX-1 in abnormal phenotypes of osteoblasts and its mechanisms in OA, 15-LOX-1 siRNA or overexpressing lv-15-lox-1 were transfected into osteoblasts, respectively. The effects of 15-LOX-1 on abnormal phenotypes of osteoblasts in OA were assessed by qRT-PCR, and western blotting. We also examined the role of 15-LOX-1-inhibited autophagy in OA osteoblasts by qRT-PCR, and western blotting, transmission electron microscopy. KEY FINDINGS: The expression levels of 15-LOX-1 along with osteoblast phenotype markers such as RUNX2, COL1, and OCN were significantly increased in OA subchondral bone. Furthermore, 15-LOX-1 inhibited autophagy significantly upregulated the expression levels of RUNX2, COL1 and OCN through activated mTORC1. Similarly, treatment with autophagy inhibitors alleviated osteoblast abnormal phenotypes of osteoblasts in OA. SIGNIFICANCE: In conclusion, our results suggested that the expression of 15-LOX-1 on osteoblasts from the subchondral bone increased in OA. 15-LOX-1 inhibited autophagy by activated mTORC1, which in turn upregulated the markers of abnormal osteoblast phenotypes RUNX2, COL1, and OCN.
Asunto(s)
Araquidonato 15-Lipooxigenasa/metabolismo , Lipooxigenasa/metabolismo , Osteoartritis/metabolismo , Osteoblastos/metabolismo , Araquidonato 15-Lipooxigenasa/sangre , Huesos/metabolismo , Células Cultivadas , Colágeno Tipo I/metabolismo , Cadena alfa 1 del Colágeno Tipo I , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Humanos , Lipooxigenasa/sangre , Osteoblastos/patología , Osteocalcina/metabolismo , FenotipoRESUMEN
AIMS: Previous study indicated that the increase of local bio-availability of 3'3'5-triiodothyronine (T3) influenced osteoarthritis (OA) initiation. We aimed to investigate the role of thyroid hormone receptors (THRs) signaling in OA osteoblasts. MATERIALS AND METHODS: THRs expression in OA was detected by immunohistochemistry, immunofluorescence, RT-qPCR and western blotting. These effects on the expression of angiogenesis-related factors were examined after THRα or THRß knockdown in OA osteoblasts. Fluorescence in situ hybridization was used to confirm the leading receptor for regulating angiogenesis-related factors. Co-culture model was utilized to observe the MMPs expression in chondrocytes after THRα knockdown in osteoblasts. The in vivo effects were also studied after intra-articular injection with THRα siRNA in OA model mice. Micro-CT and immunohistochemistry were employed to evaluate the changes of subchondral bone. KEY FINDINGS: THRs expression and nuclear translocation were upregulated in human OA osteoblasts. Immunohistochemistry showed that angiogenic activities were increased in OA subchondral bone of human and mice. VEGF, HIF-1α and IGF-1, these THR downstream genes were downregulated after THRα knockdown in OA osteoblasts. Fluorescence in situ hybridization further indicated that THRα signaling mainly regulated VEGF expression. Intra-articular injection with THRα siRNA reduced angiogenic activities in OA model mice subchondral bone and ameliorated cartilage degradation. Micro-CT analysis displayed that the aberrant subchondral bone formation in OA was promoted. SIGNIFICANCE: The microangiogenesis in subchondral bone may be partly attributed to abnormal THRα signaling in osteoblasts, and local inhibition of the THRα could be a potential target to treat OA.
Asunto(s)
Neovascularización Fisiológica/fisiología , Osteoblastos/metabolismo , Receptores de Hormona Tiroidea/metabolismo , Anciano , Anciano de 80 o más Años , Animales , Huesos/metabolismo , China , Condrocitos/metabolismo , Femenino , Humanos , Inyecciones Intraarticulares , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Osteoartritis/metabolismo , Osteoartritis de la Rodilla/tratamiento farmacológico , Osteoblastos/efectos de los fármacos , Receptores de Hormona Tiroidea/fisiología , Transducción de Señal/fisiología , Tiroxina/análisis , Tiroxina/sangre , Triyodotironina/análisis , Triyodotironina/sangreRESUMEN
Osteoarthritis (OA) is involved in these pathophysiological changes of articular cartilage, subchondral bone and synovium. As a selective HDAC6 inhibitor, Ricolinostat (ACY-1215) has demonstrated chondroprotective effects in OA. However, its efficacy remains unclear in subchondral bone. In this study, we found that the mRNA and protein levels of HDAC6 were elevated in human OA osteoblasts in vitro. PI3K/AKT signaling pathway was suppressed with downregulation of VEGF expression in osteoblasts after ACY-1215 treatment. ACY-1215 promoted apoptosis of OA osteoblast in a concentration-dependent manner, and the expression of apoptosis-related proteins was also changed by activating caspase pathway. Moreover, western blotting showed decreased expression of MMP9 and MMP13 in IL-1ß-induced chondrocytes after co-culture with ACY-1215-stimulated osteoblasts. These data of immunohistochemistry and micro-CT from OA model mice also demonstrated the weak staining of MMPs in cartilage and prevention of aberrant subchondral bone formation after ACY-1215 injection. Therefore, high expression of HDAC6 in osteoblasts also contributed to the OA progression, and our study provided a new evidence that HDAC6 inhibitor may be a potential therapeutic drug for OA.