Treatment of Chondral Lesions in the Knee / Tratamento das lesões condrais no joelho

Abstract Articular cartilage injuries are common and lead to early joint deterioration and osteoarthritis. Articular cartilage repair techniques aim at forming a cartilaginous neo-tissue to support the articular load and prevent progressive degeneration. Several techniques are available for this purpose, such as microfracture and chondrocyte transplantation. However, the procedural outcome is often fibrocartilage, which does not have the same mechanical resistance as cartilaginous tissue. Procedures with autologous osteochondral graft have a morbidity risk, and tissue availability limits their use. As such, larger lesions undergo osteochondral transplantation using fresh or frozen grafts. New techniques using minced or particulate cartilage fragments or mesenchymal stem cells are promising. This paper aims to update the procedures for treating chondral lesions of the knee.

Resumo As lesões da cartilagem articular são comuns e levam à deterioração precoce da articulação e ao desenvolvimento da osteoartrite. As técnicas de reparo da cartilagem articular visam a formação de um neo-tecido cartilaginoso capaz de suportar carga articular e evitar a progressão da degeneração. Há várias técnicas disponíveis para esse fim, como a microfratura e o transplante de condrócitos. Entretanto muitas vezes o desfecho do procedimento é a formação de fibrocartilagem, que não possui a mesma resistência mecânica do tecido cartilaginoso. Em outros procedimentos, nos quais é realizado enxerto osteocondral autólogo, há risco de morbidade associada ao procedimento, além da disponibilidade limitada de tecido. Por esse motivo, o transplante osteocondral, utilizando enxertos a fresco ou congelados tem sido utilizado para lesões de maior volume. Por fim, novas técnicas utilizando fragmentos de cartilagem picada ou particulada, assim como o uso de células tronco mesenquimais se apresentam como promissores. O objetivo desse artigo é realizar uma atualização dos procedimentos para tratamento das lesões condrais do joelho.

Matrix Stiffness Affects Mitochondrial Heterogeneity of Tibial Plateau Chondrocytes in Knee Osteoarthritis / 医用生物力学

Objective To investigate the difference of matrix stiffness in different regions of tibial plateau in osteoarthritis (OA) and its effects on morphology of the cartilage and mitochondria. Methods The tibial plateau cartilage specimens of OA were obtained for nanoindentation test, transmission electron microscopy and histological analysis. The stiffness of cartilage matrix in different regions of OA tibial plateau was detected by nano-indentation. The morphology of cartilage mitochondria in different regions was observed by transmission electron microscopy, and the changes of mitochondrial plane area, shape and ridge volume density were quantitatively analyzed. Cartilage injury in different regions of OA tibial plateau was observed by histological staining. Results The cartilage of OA tibial plateau showed regional heterogeneity, and the cartilage and mitochondria on medial side of varus knee OA were more severe, and the matrix stiffness was higher. The OA scores were positively correlated with matrix stiffness. There was also a significant correlation between OA scores and mitochondrial morphology: the higher OA scores, the larger and rounder mitochondrial plane area, and the lower cristae volume density. Conclusions The differences of tibial plateau revealed the correlation between cartilage matrix stiffness, OA scores and mitochondrial morphological parameters. The increased cartilage matrix stiffness may be the main cause of chondrocyte mitochondrial injury, and further aggravate the progression of OA.

A study on the biological effects of electromagnetic pulse with different high⁃intensity on condylar cartilage in rats / 口腔疾病防治

Objective@#To explore the biological effects of electromagnetic pulse (EMP) with different high intensities on condylar cartilage in rats. @*Methods@#SD rats were randomly divided into a sham group (Sham) and an irradiation group (EMP1: 500 kV/m, 10 Hz; EMP2: 270 kV/m, 10 Hz). Then, they were sacrificed at 1 h, 3 h, 12 h, 24 h and 3 d after irradiation. The degree of cartilage degeneration was evaluated by HE, safranine O-fast green, type Ⅱ collagen immunohistochemistry and TUNEL staining. Immunohistochemistry and western blot were performed to detect the expression of the matrix degradation factors: matrix metalloproteinase-13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-5) and the apoptosis key factor cleaved-cysteinyl aspartate specific proteinase (cleaved-Caspase3) in condylar cartilage. @*Results @#HE staining showed that, compared with the Sham group, a small amount of exfoliation was found on the fibrous surface layer of the cartilage after irradiation in the EMP1 and EMP2 groups. Compared with the Sham group, the percentage of safranine O-fast green-positive area decreased significantly at 12 h and 24 h (both P<0.01) in the EMP1 group and 12 h and 24 h in the EMP2 group (both P<0.05); the percentage of type Ⅱ collagen-positive area decreased significantly at 3 h and 12 h (P<0.05, P<0.001) in the EMP1 group. In addition, the number of TUNEL-positive apoptotic cells increased significantly at 1 h, 3 h, 12 h, and 24 h in the EMP1 group and 1 h, 3 h, and 12 h in the EMP2 group (P<0.05). Moreover, at different timepoints (except at 3 d) in the EMP1 group and EMP2 group, the percentage of MMP-13, ADAMTS-5- and cleaved Caspase3-positive chondrocytes and their protein levels in condylar cartilage increased significantly after irradiation (P<0.05). @* Conclusion@# EMP with a certain degree of high-intensity can induce early transient damage to condylar cartilage. This effect is dose-and time-dependent.

Fracturas osteocondrales de la rodilla

Introducción: Las fracturas osteocondrales que afectan la articulación de la rodilla se presenta de forma aislada o asociada a otras afecciones traumáticas. El diagnóstico inicial es en ocasiones difícil de realizar por la convergencia de signos clínicos e imagenológicos. Objetivo: Brindar información actualizada sobre los elementos más importantes de esta enfermedad traumática. Métodos: La búsqueda y el análisis de la información se realizó en un periodo de 31 días (del primero al 31 de agosto de 2021) y se emplearon las siguientes palabras del idioma ingles: osteochondral lesions, osteochondral fractures, osteochondral injuries a partir de la información obtenida se realizó una revisión bibliográfica de un total de 315 artículos publicados en las bases de datos PubMed, Hinari, SciELO y Medline mediante el gestor de búsqueda y administrador de referencias EndNote. Resultados: Se hace referencia al mecanismo de producción, aspecto artroscópico, localización, características en cuanto a extensión, profundidad, clasificación y desplazamiento. Se describen las modalidades imagenológicas empleadas en el diagnóstico y su utilidad. Con relación al diagnóstico diferencial se describen un grupo de enfermedades con características similares. Se mencionan las modalidades de tratamiento basadas en el tamaño y tiempo de evolución. Conclusiones: Las fracturas osteocondrales son lesiones frecuentes, para su diagnóstico se necesita de un alto índice de sospecha, ya que el diagnóstico clínico e imagenológico inicial no son concluyentes en la mayoría de los pacientes por estar combinada con otras afecciones.

Introduction: Osteochondral fractures that affect the knee joint occur in isolation or associated with other traumatic conditions. The initial diagnosis is sometimes difficult to make due to the convergence of clinical and imaging signs. Objective: To provide updated information on the most important elements of this traumatic entity. Methods: The search and analysis of the information was carried out in a period of 31 days (from August the first to the 31st, 2021) and the following words of the English language were used: osteochondral lesions, osteochondral fractures, osteochondral injuries from the Information obtained, a bibliographic review of a total of 315 articles published in the PubMed, Hinari, SciELO and Medline databases was carried out using the EndNote search manager and reference manager. Results: Reference is made to the mechanism of production, arthroscopic appearance, location, characteristics in terms of extension, depth, classification and displacement. The imaging modalities used in diagnosis and their usefulness are described. Regarding the differential diagnosis, a group of entities with similar characteristics are described. Treatment modalities based on size and time of evolution are mentioned. Conclusions: Osteochondral fractures are frequent injuries, for their diagnosis a high index of suspicion is needed, since the initial clinical and imaging diagnosis are not conclusive in most patients because they are combined with other conditions.

Effect of aloperine on chondrocyte injury induced by interleukin-1β and its mechanism / 中国生物制品学杂志

@#Objective To investigate the effect of aloperine(ALO)on interleukin-1β(IL-1β)-induced chondrocyte injury and its mechanism. Methods Chondrocytes were randomly divided into control(Con)group,IL-1 β group,IL-1β + ALO-L(25 mg/L)group,IL-1β + ALO-M(50 mg/L)group and IL-1 β + ALO-H(100 mg/L)group;Con group,IL-1βgroup,IL-1β + miR-NC group and IL-1β + miR-16-5p group;Con group,IL-1β group,IL-1β + si-NC group and IL-1β + siSOX5 group. Cells in IL-1β group were treated with 10 ng/mL IL-1β,while no treatment was given in Con group. The transcription levels of miR-16-5p and SOX5 mRNA in chondrocytes were detected by qRT-PCR;The contents of IL-6,TNF-αand IL-1β were detected by ELISA;The expression levels of Bcl-2,Bax and SOX5 protein were detected by Western blot and the apoptosis was detected by flow cytometry. Results Compared with IL-1 β group,the contents of IL-6,TNF-α and IL-1βin IL-1β + ALO-L group,IL-1β + ALO-M group and IL-1β + ALO-H group decreased significantly(t = 5. 002～20. 653,each P < 0. 001),the apoptosis rate decreased significantly(t = 5. 473～17. 371,each P < 0. 001),the expression level of Bcl-2 protein increased significantly(t = 7. 800～16. 100,each P < 0. 001),and the expression level of Bax protein decreased significantly(t = 4. 993～14. 311,each P < 0. 001);The mRNA transcription level of miR-16-5p gene increased significantly(t = 6. 688～16. 545,each P < 0. 001),while the mRNA transcription level and protein expression level of SOX5 gene decreased significantly(t = 4. 609～15. 393,each P < 0. 001). Compared with the IL-1β + miR-NC group,the mRNA transcription level of miR-16-5p in the IL-1β + miR-16-5p group increased significantly(t = 17. 106,P < 0. 001),the contents of IL-6,TNF-α and IL-1 β decreased significantly(t = 15. 030～20. 013,each P < 0. 001),the apoptosis rate decreased significantly(t = 12. 273,P < 0. 001),the expression level of Bcl-2 protein increased significantly(t = 15. 652,P < 0. 001),and the expression level of Bax protein decreased significantly(t = 12. 999,P < 0. 001). Compared with IL-1β +si-NC group,the expression level of SOX5(t = 13. 444,P < 0. 001),IL-6,TNF-α and IL-1β in IL-1β + si-SOX5 group decreased significantly(t = 14. 087～17. 103,each P < 0. 001),the apoptosis rate decreased significantly(t = 11. 991,P < 0. 001),the expression level of Bcl-2 protein increased significantly(t = 13. 864,P < 0. 001),and the expression level of Bax protein decreased significantly(t = 11. 818,P < 0. 001). Conclusion Alo inhibited the apoptosis of chondrocytes induced by IL-1β,thus reducing the injury of chondrocytes,of which the mechanism might be regulating the expression of miR-16-5p and SOX5 and the secretion of inflammatory factors in chondrocytes.

Effects of Tuina on cartilage degradation and chondrocyte terminal differentiation in rats with knee osteoarthritis (KOA) via the Wnt/β-catenin signaling pathway / 针灸推拿医学（英文版）

Objective: To investigate the therapeutic effects of Tuina (Chinese therapeutic massage) in a knee osteoarthritis (KOA) rat model and its influence on proteins associated with the Wnt/β-catenin signaling pathway. Methods: A total of 32 specific-pathogen-free grade Sprague-Dawley rats were used. Eight rats were randomly selected as the control group (CG). The remaining 24 rats underwent intra-articular injections with 0.2 mL of 4％ papain to prepare the KOA rat models. After the model was established, the 24 rats were randomly and equally assigned to 3 groups, including a model group (MG), a Tuina group (TG), and a positive medicine group (PMG), with 8 rats in each group. The Lequesne score was applied to evaluate the success of model development. After the model was successfully established, the CG did not receive any intervention, and the TG was treated with local, clockwise annular Rou-Kneading around the knee joint with the thumbs. The pressure in the longitudinal direction was 3 N, and the frequency was designed to be 120-140 times/min for 15 min, followed by flexing the joint 10 times. The PMG was intragastrically administered with celecoxib [24 mg/(kg·bw)] every day. These interventions were performed once a day, 6 d per week, for a total of 4 weeks. After treatment, the Lequesne score was applied again to assess the severity of the KOA in the rats; hematoxylin-eosin (HE) staining and a mixture of equal volumes of aqueous solutions of safranin O-fast green were used to stain and observe the cartilage morphology and structure; the modified Mankin score was applied to evaluate the pathology; enzyme-linked immunosorbent assay method was used to quantify the C-telopeptide fragments of type Ⅱ collagen (CTX-Ⅱ) and cartilage oligomeric matrix protein (COMP); Western blotting was then applied to quantify Wnt4, β-catenin, matrix metalloproteinase 13 (MMP-13), and bone morphogenetic protein 2 (BMP-2) protein expression; immunohistochemistry was conducted to determine the percentage of collagen type X (ColX)-positive cells. Results: The Lequesne score of the TG and PMG was both lower than that of the MG (P<0.01); the HE staining, safranin O-fast green stained morphology and structure, and modified Mankin scores of the TG and the PMG were also better than those in the MG (P<0.01). Compared with the CG, the amounts of CTX-Ⅱ and COMP in the serum were significantly increased (P<0.01); the expression of Wnt4, β-catenin, MMP-13, and BMP-2 proteins in the cartilage tissue was significantly increased (P<0.01), and the percentage of ColX-positive chondrocytes was significantly increased (P<0.01) in the MG. In comparison with those in the MG, the amounts of CTX-Ⅱ and COMP were significantly decreased (P<0.01), the expression of Wnt4, β-catenin, MMP-13, and BMP-2 proteins was significantly decreased (P<0.01), and the percentage of ColX-positive chondrocytes was significantly decreased (P<0.01) in the TG and PMG. Compared with the PMG, the contents of CTX-Ⅱ and COMP and the expression of Wnt4, β-catenin, MMP-13, and BMP-2 proteins were decreased (P<0.05 or P<0.01); the percentage of ColX-positive chondrocytes was significantly decreased (P<0.01) in the TG. Conclusion: Tuina can relieve the degeneration of KOA, and the mechanism may be related to the down-regulation of the Wnt/β-catenin signaling pathway, the decrease in MMP-13 and BMP-2 protein expression, the reduction in chondrocyte extracellular matrix degradation, and slowing down the terminal cell differentiation.

Research progress of cell transplantation in the treatment of osteochondral lesions of the talus / 中华创伤杂志

Osteochondral lesions of the talus (OLT) frequently manifest following ankle joint trauma, causing ankle pain, swelling and impaired mobility, thereby significantly impeding daily activities of the patients. Presently, clinical treatment approaches encompass both conservative management and surgical intervention. Conservative management endeavors to alleviate symptoms, while patients experiencing persistent symptoms resort to surgical intervention. Commonly employed surgical treatments encompass bone marrow stimulation, autologous osteochondral transplantation, and allogeneic osteochondral transplantation. Bone marrow stimulation is employed as a therapeutic approach for the management of smaller OLT, demonstrating favorable short-term effectiveness; however, the long-term prognosis remains uncertain. Autologous osteochondral transplantation is a viable option for larger OLT lesions, albeit it carries the potential of complications at the donor site. Conversely, allogenic osteochondral transplantation exhibits a diminished success rate. In recent times, the utilization of cell transplantation techniques has garnered escalating interest in the treatment of OLT due to their capacity to regenerate cartilage resembling hyaline and their diverse range of cellular origins. The authors reviewed the progress of cell transplantation in the treatment of OLT, providing a reference for the clinical treatment.

The role and mechanism of MMP13 and LRP1 in abnormal autophagy function of articular chondrocytes in patients with Kashin-Beck disease / 中华地方病学杂志

Objective:To investigate the impact of matrix metalloproteinase 13 (MMP13) and low-density lipoprotein receptor-related protein 1 (LRP1) on autophagy of articular chondrocytes in patients with Kashin-Beck disease (KBD).Methods:Human articular cartilage samples obtained from 4 KBD patients and 4 control subjects were collected from Shaanxi Institute for Endemic Disease Prevention and Control, and the expression levels of MMP13 and LRP1 in cartilage tissue were determined using immunohistochemistry (IHC). Chondrocytes were extracted and cultured in vitro, the mRNA and protein expression levels of LRP1 and the autophagy related genes [Beclin 1 (BECN1), microtubule associated protein 1 light chain 3 (LC3)], cartilage injury related genes [MMP13, caspase-3 (CASP3)], chondrocyte differentiation related genes [collagen type Ⅱ alpha 1 chain (COL2A1), and SRY-box transcription factor 9 (SOX9)] were detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot (WB), respectively. Chondrocytes from 3 KBD patients were extracted, and MMP13 gene silencing experiment was performed by RNA interference (RNAi) technology, the mRNA and protein expression levels of the above genes were detected by qRT-PCR and WB, respectively. In addition, the antagonist receptor associated protein (RAP) of LRP1 was used to block the LRP1 of human normal chondrocytes (C28/I2 cells), and qRT-PCR and WB were used to detect the mRNA and protein expression levels of LRP1, chondrocyte autophagy, differentiation and cartilage injury related genes, respectively. Results:The IHC results showed that the expression levels of MMP13 (1.67 ± 0.21, 0.59 ± 0.15, 0.51 ± 0.12) in the surface, middle, and deep layers of cartilage tissue of KBD patients were significantly higher than those of control subjects (0.25 ± 0.03, 0.26 ± 0.04, 0.06 ± 0.01), and the differences were statistically significant ( t = - 11.38, P < 0.001; t = - 3.82, - 6.26, P = 0.019, 0.003). The expression levels of LRP1 (0.10 ± 0.02, 0.03 ± 0.01, 0.17 ± 0.03) were significantly lower than those of control subjects (1.63 ± 0.40, 0.44 ± 0.12, 0.34 ± 0.08), and the differences were statistically significant ( t = 6.61, 5.61, 3.64, P = 0.003, 0.005, 0.022). The mRNA and protein expression levels of MMP13, CASP3, SOX9 in chondrocytes of KBD patients were significantly higher than those of control subjects, and the differences were statistically significant ( P < 0.05). The mRNA expression levels of LRP1, LC3, COL2A1 were significantly lower than those of control subjects, and the differences were statistically significant ( P < 0.05). After silencing the MMP13 gene in chondrocytes of KBD patients, there were no significant differences in the mRNA and protein expression levels of LRP1, BECN1, LC3, CASP3, COL2A1, and SOX9 ( P > 0.05). After blocking LRP1 with RAP, the protein expression levels of LRP1, BECN1, LC3, MMP13, COL2A1 and SOX9 in chondrocytes were significantly lower than those in control group ( P < 0.05). Conclusions:There is no direct correlation between MMP13 and abnormal autophagy of articular chondrocytes in KBD patients. After blocking LRP1, the expression of the autophagy related genes BECN1 and LC3 in chondrocytes is decreased.

Chitinase-3-like protein 1 plays a role in lumbar facet joint degeneration / 中华骨科杂志

Objective:To investigate the effect of CHI3L1 on the biological function of chondrocytes and its role in lumbar facet joint degeneration.Methods:The human lumbar facet joint articular cartilage were collected, and the relative mRNA expression of CHI3L1 gene detected by quantitative fluorescence PCR. Then explored the correlation between joint degeneration and gender, age and relative mRNA expression of CHI3L1. Human chondrocytes were cultured in vitro. The effects of CHI3L1 on chondrocyte proliferation, cycling, and apoptosis, as well as expression of related inflammatory factors, were investigated. The mechanism by which CHI3L1 regulates the degeneration of articular cartilage was investigated using the signal transduction pathway protein chip.Results:There was a positive correlation between the grade of degeneration in lumbar facet joint and the relative expression of CHI3L1 gene mRNA ( r=0.76, P<0.001). There was no correlation with the patient's gender ( r=-0.12, P=0.500). A positive correlation between the age of patients and the relative expression of CHI3L1 gene mRNA was found ( r=0.47, P=0.005). Compared with the non-degenerative group, the expression of CHI3L1 gene mRNA significantly increased in the degenerative group, and the expression of CHI3L1 gradually increased with the aggravation in the grade of degeneration ( F=18.90, P<0.001). Compared with the non-degenerative group, the chondrocytes in the CHI3L1 group had significantly lower proliferation at 48 h (OD 490/fold=7.132), 72 h (OD 490/fold=4.803), 96 h (OD 490/fold=2.431) and 120 h (OD 490/fold=0.009). The ratio of chondrocytes in G1 phase, S phase and G2/M phase were 85.03%±3.05%, 12.78%±2.29% and 0.90%±0.76% in the CHI3L1 group, and 73.93%±2.73%, 22.81%±1.93% and 0.99%±0.87% in control group, respectively. There were significant differences in the percentage of chondrocytes in G1 phase ( t=4.70, P<0.001) and S phase ( t=5.80, P<0.001) between the two groups. The percentages of apoptosis in chondrocyte in CHI3L1 group and control group were 8.64%±0.76% and 5.68%±1.13%, which has a statistically difference ( t=4.47, P<0.001). The expression of IL-6 in chondrocytes of CHI3L1 group was 49.60±0.01 pg/ml, which was higher than that of 47.88±0.01 pg/ml in the control group ( t=132.70, P<0.001). The expression of TNF-α was 95.93±0.02 pg/ml, which was higher than 90.69±0.02 pg/ml in the control group ( t=376.10, P<0.001). There was significant difference in expression of IL-6 in chondrocytes between the CHI3L1 group and the control group ( t=132.72, P<0.001). The expression of TNF-α ( t=376.10, P<0.001) was statistically difference. Protein chip detected 53 proteins with significant differences in expression and 43 proteins with significant differences in protein phosphorylation levels. Bioinformatics analysis was used to identify 16 signaling pathways in which the above different proteins might be involved, including ErbB, PI3K, Akt, Ras, JAK, STAT3, MAPK pathway. In the MAPK pathway, the expression of MAPK1 and RAF1 proteins was higher in the chondrocytes of the CHI3L1 group than in the control group (1.094±0.00 vs. 0.814±0.00, 0.988±0.00 vs. 0.786±0.00; t=103.16, P<0.001; t=54.32, P<0.001). Compared with the control group, the expression of MAPK1 and RAF1 proteins was significantly increased in the chondrocytes of the CHI3L1 group. Conclusion:The expression of CHI3L1 is corrected to articular cartilage degeneration. CHI3L1 is able to inhibit the proliferation of articular chondrocytes, which regulated the cycling of chondrocytes from G1 phase to S phase, promote the apoptosis of chondrocytes, and promote the expression of IL-6 and TNF-α in chondrocytes. Regulation of chondrocytes biological function through the MAPK pathway, which is a potential biomarker for the clinical diagnosis and treatment of lumbar joint degeneration.

T-2 toxin/DON induced differentially expressed genes in human chondrocytes and its relationship with Kashin-Beck disease / 中华地方病学杂志

Objective:To investigate the relationship between T-2 toxin, deoxynivalenol (DON) induced differentially expressed genes in human chondrocytes and Kashin-Beck disease (KBD), and to search for potential molecular markers of KBD.Methods:Gene microarray profiling was used to analyze the differentially expressed genes induced by T-2 toxin (0.01 μg/ml) and DON (1.0 μg/ml) in normal human chondrocytes, and the differences and similarities between them and the differentially expressed genes in KBD chondrocytes were compared. KEGG pathway enrichment analysis was performed on differentially expressed genes in each group. And the expression patterns of KBD susceptibility genes in T-2 toxin and DON induced human chondrocytes were further compared and analyzed.Results:Gene microarray profiling analysis showed that there were 882 (349 up-regulated genes, 533 down-regulated genes) and 2 118 differentially expressed genes (1 124 up-regulated genes, 994 down-regulated genes) in human chondrocytes induced by T-2 toxin and DON compared with normal control cells, respectively. Compared with differentially expressed genes in KBD chondrocytes, the genes with the same expression trend included B cell translocation gene 1 (BTG1), G protein signaling regulatory protein 5 (RGS5), fatty acid binding protein 4 (FABP4) and key protein senescence 1 (FBLN1), the same KEGG pathway including p53, extracellular matrix receptor interaction and phosphatidylinositol-3-kinase-protein kinase B (PI3K-Akt) signaling pathway. Both T-2 toxin and DON induced human chondrocytes to up-regulate the expression of KBD susceptibility gene growth differentiation factor 5 (GDF5) and down-regulate the expression of collagen type ⅨA1 (COL9A1).Conclusion:The BTG1, RGS5, FABP4, FBLN1, GDF5 and COL9A1 genes play an important role in the pathogenesis of KBD and can be used as potential molecular markers for the pathogenesis of KBD.

Report of a clinical and laboratory management of cell therapy for knee cartilage in the face of mycoplasma contamination

ABSTRACT To describe a case of autologous chondrocyte implantation after cell culture contamination by Mycoplasma pneumoniae and the measures taken to successfully complete cell therapy in a patient with focal chondral lesion. A 45-year-old male patient, complaining of chronic pain on the knee and no history of trauma. He had a chondral lesion in the trochlear region of the femur and clinical tests compatible with pain in the anterior compartment of the knee. Conservative treatment failed to alleviate symptoms. Surgical treatment was indicated, but due to the size of the lesion, membrane-assisted autologous chondrocyte implantation was the technique of choice. Cartilage biopsies were collected from the intercondylar region of the distal femur. After isolation, chondrocytes were expanded ex vivo in a trained laboratory, for three weeks, and seeded onto a commercially available collagen membrane prior to implantation in the knee. Two days before surgery, a cell culture sample tested positive for Mycoplasma pneumoniae. The source of contamination was found to be autologous blood serum, extracted from the patient´s peripheral vein, and used to supplement the cell culture medium. After treating the patient with antibiotics, all procedures were repeated and the new final cell product, free from contaminants, was successfully implanted. We discuss the strategies available to deal with this situation, and describe the results of this particular case, which led to modifications in the autologous chondrocyte implant protocol.

Matrix-assisted autologous chondrocyte transplantation for treatment of focal chondral lesions in the knee: the Hospital Israelita Albert Einstein experience

ABSTRACT Objective Phase 1 clinical trial to determine feasibility, safety, and efficacy of a new advanced cell therapy product for treatment of knee articular cartilage injuries. Methods Three participants with knee focal chondral lesions were included, with no signs of osteoarthritis. Chondrocytes were obtained through knee arthroscopy, cultured in collagen membrane for 3 weeks at the laboratory, subjected to tests to release the cell therapy product, and implanted. All patients underwent a specific 3-month rehabilitation protocol, followed by assessments using functional and imaging scales. The main outcome was the incidence of severe adverse events. Results Three participants were included and completed the 2-year follow-up. There was one severe adverse event, venous thrombosis of distal leg veins, which was no associated with therapy, was treated and left no sequelae. The clinical and radiological scales showed improvement in the three cases. Conclusion The preliminary results, obtained with the described methodology, allow concluding that this product of advanced cell therapy is safe and feasible. ReBEC platform registration number: RBR-6fgy76

Expression of plasma miR-320c in patients with osteoarthritis and its effect on proliferation and apoptosis of chondrocyte / 中华老年医学杂志

Objective:To investigate the expression level of plasma miR-320c in patients with osteoarthritis(OA), and explore the clinical significance and the role in pathogenesis of OA.Methods:The clinical data and peripheral blood of 30 patients with OA, 30 patients with connective tissue diseases and 30 healthy control individuals were collected.The levels of plasma miR-320c were detected byfluorescentquantitative reverse transcription PCR(qRT-PCR). Correlation analysis was used to explore the correlation of plasma miR-320c level with knee X-ray data and VAS pain score in OA patients.Finally the miR-320c mimic, the miR-320c inhibitor, and the control material were transfected to the chondrocyte HC-a.The proliferative capacity of HC-a chondrocytes was examined at different time points as determined by the CCK-8 assay.Results:The expression level of plasma miR-320c was significantly higher in OA group(3.26±0.55)than that in the connective tissue diseases group(1.62±0.50)and in healthy control group(1.21±0.66)( F=107.66, P<0.001). Plasma miR-320c expression was positively correlated with radiographic grade( r=0.830, P<0.001), and had no correlation with VAS pain score in OA group( P>0.05). Through repeated measurement variance analysis, the time effect, the group effect and the interaction effect between group and time showed statistically significant differences in chondrocyte proliferation between NC mimic group and miR-320c mimic group( Ftime=5256.767, Fgroup=1947.436, Ftime×group=114.314, all P<0.001). The level of proliferation was significantly reduced.Apoptosis rate of chondrocytes was significantly increased in the group transfected with miR-320c( t=7.85, P<0.01). Conclusions:The expression level of plasma miR-320c is significantly higher in osteoarthritis patients and associated with knee radiographic severity grade.Furthermore, over-expression of miR-320c could suppress the proliferation of chondrocytes.Plasma miR-320c might be potential bio-marker for osteoarthritis knee severity assessment, and involves in regulating chondrocyte growth in the pathogenesis of osteoarthritis.

IRE1α deficiency impairs autophagy in chondrocytes by upregulating calcium homeostasis endoplasmic reticulum protein / 南方医科大学学报

OBJECTIVE@#To explore the mechanism by which inositol-requiring enzyme-1α (IRE1α) regulates autophagy function of chondrocytes through calcium homeostasis endoplasmic reticulum protein (CHERP).@*METHODS@#Cultured human chondrocytes (C28/I2 cells) were treated with tunicamycin, 4μ8c, rapamycin, or both 4μ8c and rapamycin, and the expressions of endoplasmic reticulum (ER) stress- and autophagy-related proteins were detected with Western blotting. Primary chondrocytes from ERN1 knockout (ERN1 CKO) mice and wild-type mice were examined for ATG5 and ATG7 mRNA expressions, IRE1α and p-IRE1α protein expressions, and intracellular calcium ion content using qPCR, Western blotting and flow cytometry. The effect of bafilomycin A1 treatment on LC3 Ⅱ/LC3 Ⅰ ratio in the isolated chondrocytes was assessed with Western blotting. Changes in autophagic flux of the chondrocytes in response to rapamycin treatment were detected using autophagy dual fluorescent virus. The changes in autophagy level in C28/I2 cells overexpressing CHERP and IRE1α were detected using immunofluorescence assay.@*RESULTS@#Tunicamycin treatment significantly up-regulated ER stress-related proteins and LC3 Ⅱ/LC3 Ⅰ ratio and down-regulated the expression of p62 in C28/I2 cells (P < 0.05). Rapamycin obviously up-regulated LC3 Ⅱ/LC3 Ⅰ ratio (P < 0.001) in C28/I2 cells, but this effect was significantly attenuated by co-treatment with 4μ8c (P < 0.05). Compared with the cells from the wild-type mice, the primary chondrocytes from ERN1 knockout mice showed significantly down-regulated mRNA levels of ERN1 (P < 0.01), ATG5 (P < 0.001) and ATG7 (P < 0.001), lowered or even lost expressions of IRE1α and p-IRE1α proteins (PP < 0.01), and increased expression of CHERP (P < 0.05) and intracellular calcium ion content (P < 0.001). Bafilomycin A1 treatment obviously increased LC3 Ⅱ/ LC3 Ⅰ ratio in the chondrocytes from both wild-type and ERN1 knockout mice (P < 0.01 or 0.05), but the increment was more obvious in the wild-type chondrocytes (P < 0.05). Treatment with autophagy dual-fluorescence virus resulted in a significantly greater fluorescence intensity of LC3-GFP in rapamycin-treated ERN1 CKO chondrocytes than in wild-type chondrocytes (P < 0.05). In C28/I2 cells, overexpression of CHERP obviously decreased the fluorescence intensity of LC3, and overexpression of IRE1α enhanced the fluorescence intensity and partially rescued the fluorescence reduction of LC3 caused by CHERP.@*CONCLUSION@#IRE1α deficiency impairs autophagy in chondrocytes by upregulating CHERP and increasing intracellular calcium ion content.

Effect of Quercetin on LPS-induced Chondrocyte Matrix Metabolism and Inflammation by Activating Autophagy / 中国实验方剂学杂志

ObjectiveTo investigate the mechanism of quercetin in regulating chondrocyte extracellular matrix metabolism and inflammatory response in knee osteoarthritis （KOA） from the perspective of autophagy. MethodChondrocytes were extracted and cultured， and the primary cells were identified by immunofluorescence staining with collagen Ⅱ. The chondrocytes induced by lipopolysaccharide （LPS） were divided into a control group （without any treatment）， a model group （10 mg·L-1 LPS treatment for 48 h）， and low-， medium-， and high-dose quercetin group （10 mg·L-1 LPS treatment for 48 h combined with 50， 100， and 150 mmol·L-1 quercetin for 24 h）. The inhibitory effects of LPS （2.5， 5， 7.5， 10， 12.5 mg·L-1） on the proliferation of chondrocytes for different periods （24， 48， 72 h） were detected by cell counting kit-8 （CCK-8）. The effects of quercetin （50， 100， 150， 200 mmol·L-1） on the LPS-induced proliferation of chondrocytes for different periods （12， 24， and 48 h） were investigated. The expression of microtubule-associated protein 1 light chain 3Ⅱ （LC3Ⅱ） and ubiquitin-binding protein p62 was detected by Western blot. LPS-induced chondrocytes were treated with 3-methyladenine （3-MA）. The resultant cells were divided into a control group （without any treatment）， a model group （10 mg·L-1 LPS）， a quercetin group （model group + 100 mmol·L-1 quercetin）， a 3-MA group （model group + 100 μmol·L-1 3-MA）， and a 3-MA + quercetin group （model group + 100 μmol·L-1 3-MA + 100 mmol·L-1 quercetin， specifically， LPS for 48 h， 3-MA for 2 h， and then quercetin for 24 h）. The content of interleukin （IL）-1β and tumor necrosis factor （TNF）-α was determined by enzyme-linked immunosorbent assay （ELISA）. The protein expression of matrix metalloproteinase 13 （MMP-13） and tissue inhibitor of metalloproteinase 1 （TIMP1） was detected by Western blot. ResultCollagen Ⅱ immunofluorescence staining showed that the extracted cells were consistent with the characteristics of chondrocytes. As revealed by CCK-8， the optimum concentration of LPS was 10 mg·L-1 with an action time of 48 h， and the optimum concentration of quercetin was 100 mmol·L-1 with an action time of 24 h. Western blot results showed that compared with the control group， the model group showed decreased expression of LC3Ⅱ （P<0.01） and increased expression of p62 （P<0.01）. The expression of LC3Ⅱ in the quercetin groups was higher than that in the control group （P<0.01）， especially in the medium-dose quercetin group. The p62 expression in the quercetin groups was lower than that in the control group （P<0.01）， especially in the medium-dose quercetin group. Compared with the control group， the model group showed increased expression of MMP-13 （P<0.05） and decreased expression of TIMP1 （P<0.01）. Compared with the model group， the quercetin groups and the 3-MA + quercetin group showed decreased expression of MMP-13 （P<0.05， P<0.01）， especially the quercetin groups， and increased expression of TIMP1 （P<0.01）， especially the quercetin groups. Morphological changes in chondrocytes under the inverted microscope showed that quercetin could restore the morphology of damaged chondrocytes. CCK-8 showed that compared with the control group， the model group showed inhibited chondrocyte proliferation （P<0.01）， and compared with the model group， the quercetin groups and the 3-MA + quercetin group showed promoted chondrocyte proliferation （P<0.01）， especially the quercetin groups. ELISA results showed that IL-1β and TNF-α levels in the model group were higher than those in the control group （P<0.01）， and the levels of IL-1β and TNF-α in the quercetin groups and the 3-MA + quercetin group were lower than those in the model group （P<0.05， P<0.01）， and the decrease in the quercetin groups was the most significant. ConclusionQuercetin can promote LPS-induced chondrocyte proliferation， regulate chondrocyte extracellular matrix synthesis and metabolic balance， inhibit the inflammatory response， and restore chondrocyte function. The mechanism may be related to the activation of autophagy by quercetin.

Potential effect of hyaluronic acid and triamcinolone acetate, alone or combined, on chondrogenic differentiation of mesenchymal stem cells / Efecto potencial del ácido hialurónico y del acetato de triamcinolona solos o combinados sobre la diferenciación condrogénica de células-tronco mesenquimales / Efeito potencial do ácido hialurônico e triancinolona acetonida, isolados e combinados, na diferenciação condrogênica de células-tronco mensenquimais

Abstract Background: Osteoarthritis is a complex degenerative disease with several factors contributing to joint damage. Objective: To compare the potential effect of hyaluronic acid (HA) and triamcinolone acetonide (TA), alone or combined, on the in vitro chondrogenic differentiation process of mesenchymal stem cells (MSCs). Methods: MSCs were divided into four groups: Control, HA, TA, and HA/TA combined. Each treatment group was cultured for 14 days in chondrogenic differentiation medium. The chondrogenic differentiation potential was assessed by histology and immunohistochemistry. Results: The HA and HA/TA-treated MSCs presented histological characteristics similar to native chondrocytes. The extracellular matrix (ECM) of TA-treated MSCs was compact and organized. Glycosaminoglycan staining was intense in Control, moderate in TA, slight in HA/TA, and undetectable in HA. Type II collagen immunoreactivity was high in the TA-treated ECM and MSCs. Conclusions: Histological analysis shows that HA influences morphological development similar to chondrocytes of the MSCs, but with low expression of specific cartilage molecules. The TA promotes formation of a compact and organized ECM.

Resumen Antecedentes: La osteoartritis es una enfermedad degenerativa compleja en la cual varios factores contribuyen al daño articular. Objetivo: Comparar el efecto del ácido hialurónico (HA) y acetónido de triamcinolona (TA), solos o en combinación, en el proceso de diferenciación condrogénica in vitro de células madre mesenquimales (MSCs). Métodos: Las MSCs fueron divididas en cuatro grupos: Control, HA, TA y HA/TA, y cultivadas por 14 días en medio de diferenciación condrogénica para cada tratamiento. El potencial de diferenciación condrogénica fue analizado por medio de histología e inmunohistoquímica. Resultados: Las MSCs tratadas con HA y HA/TA, presentaron características histológicas similares a los condrocitos nativos, y la matriz extracelular (ECM) de MSCs tratadas con TA fue más compacta y organizada. La tinción de glicosaminoglicanos fue intensa en el Control, moderada en TA, ligera en HA/TA, y sin tinción en HA. La inmunoreactividad para colágeno tipo II fue más alta en las MSCs y ECM tratadas con TA. Conclusión: El análisis histológico muestra que el HA influencia un desarrollo morfológico similar a los condrocitos de las MSCs, pero con baja expresión de moléculas específicas de cartílago. La TA promueve la formación de una ECM compacta y organizada.

Resumo Antecedentes: A osteoartrite é uma doença degenerativa complexa, na qual vários fatores contribuem ao dano articular. Objetivo: Comparar o efeito do ácido hialurônico (HA) e Triancinolona acetonida (TA), só ou combinado no processo de diferenciação condrogênica in vitro de células tronco mesenquimais (MSCs). Métodos: MSCs foram divididas em 4 grupos: Controle, HA, TA y HA/TA e cultivadas por 14 dias com meio de diferenciação condrogênica e seus respectivos tratamentos. O potencial de diferenciação condrogênica foi acessado por meio de histologia e imunohistoquímica. Resultados: Histologicamente, MSCs tratadas com HA e HA/TA apresentaram características semelhantes de condrócitos nativos, e a matriz extracelular de MSCs tratadas com TA foi mais compacta e organizada. A coloração para glicosaminoglicanos foi intensa no Controle, moderada no TA, leve no HA/TA e sem coloração com HA. Para os grupos tratamento, a imunoreatividade para colágeno tipo II foi maior nas células e matriz extracelular tratadas com TA. Conclusão: Mediante análise histológica, o HA influenciou o desenvolvimento morfológico semelhante a condrócitos das MSCs, mas com baixa expressão de moléculas específicas de cartilagem. A TA promoveu a formação de uma matriz extracelular compacta e organizada.

Treatment of Chondral Knee Lesions with Autologous Chondrocytes Embedded in a Fibrin Scaffold. Clinical and Functional Assessment / Tratamento de lesões condrais no joelho com condrócitos autólogos embebidos em arcabouço de fibrina. Avaliação clínica e funcional

Abstract Objective The aim of our study is to analyze the clinical and functional results obtained using autologous chondrocytes embedded in a fibrin scaffold in knee joint injuries. Methods We included 56 patients, 36 men and 20 women, with a mean age 36 years. Six of the patients were professional athletes, with single knee injuries that were either chondral or osteochondral (43 chondral, 9 osteochondral, 2 cases of osteochondritis dissecans and 2 osteochondral fractures), 2 to 10 cm2 in size and ≤ 10 mm deep, with no signs of osteoarthritis. The location of the injury was in the patella (8), the medial femoral condyle (40) and lateral femoral condyle (7) and one in the trochlea. The mean follow-up was 3 (range: 1-6) years. The clinical course was assessed using the Cincinnati and Knee Injury and Osteoarthritis Outcome (KOOS) scores, 6 and 12 months after surgery. The paired Student t-test was used to compare pre-and postoperative results. Results Six months after the implant, patients resumed their everyday activities. On the assessment scores, their condition was improving in comparison with their presurgical state (p < 0.05). They were also able to carry out their sporting activities more easily than prior to surgery (p < 0.05). Conclusion The seeding of chondrocytes in fibrin may provide a favorable microenvironment for the synthesis of extracellular matrix and improved the clinical condition and activity of the patients 1 year after surgery.

Resumo Objetivo O objetivo do nosso estudo é analisar os resultados clínicos e funcionais do tratamento de lesões nas articulações do joelho com condrócitos autólogos embebidos em arcabouço de fibrina. Métodos O estudo foi realizado com 56 pacientes (36 homens e 20 mulheres) com idade média de 36 anos; 6 indivíduos eram atletas profissionais. Os pacientes apresentavam lesões únicas, condrais ou osteocondrais (43 condrais, nove osteocondrais, 2 casos de osteocondrite dissecante e duas fraturas osteocondrais) no joelho, com 2 a 10 cm2 de tamanho e ≤ 10 mm de profundidade, sem sinais de osteoartrite. As lesões estavam localizadas na patela (8), no côndilo femoral medial (40), no côndilo femoral lateral (7) e na tróclea (1). O período médio de acompanhamento foi de 3 anos (faixa de 1-6 anos). A evolução clínica foi avaliada pelos escores de Cincinnati e Knee Injury and Osteoarthritis Outcome (KOOS), 6 e 12 meses após a cirurgia. O teste t de Student pareado foi utilizado para comparação dos achados pré e pós-operatórios. Resultados Os pacientes retomaram suas atividades diárias 6 meses após o implante. Os escores avaliados demonstraram a melhora em comparação ao estado pré-cirúrgico (p < 0,05). Além disso, os pacientes conseguiram realizar suas atividades esportivas com mais facilidade do que antes da cirurgia (p < 0,05). Conclusão A cultura de condrócitos em fibrina pode proporcionar um microambiente favorável para a síntese de matriz extracelular e melhorar a condição clínica e a atividade dos pacientes 1 ano após a cirurgia

Mechanism of highly expressed primary cilia in tibial growth plate chondrocyte accelerating chondrocyte differentiation in young rats with chronic renal failure / 中华肾脏病杂志

Objective:To explore the mechanism of highly expressed primary cilia in tibial growth plate chondrocytes accelerating chondrocytes differentiation in young rats with chronic renal failure (CRF).Methods:Forty male 4-week-old SD rats weighing (98±3) g were randomly divided into control group (intragastric administration with distilled water, n=20) and CRF group (intragastric administration with adenine suspension 150 mg·kg -1·d -1, n=20). All the young rats were sacrificed after continuous gavage for 6 weeks. The length of the growth plate was measured with histological sections. Immunofluorescence (IF) was used to detect the expression rate of primary cilia and the level of β-catenin, the key protein of Wnt/β-catenin signaling pathway in tibial growth plate chondrocytes. Chondrocytes isolated from growth plate in two groups were cultured in vitro to P3 generation, and the expression rate of primary cilia in chondrocytes, the levels of Indian hedgehog (IHH) and glycogen synthase kinase 3β (GSK3β) were detected by IF. Co-immunoprecipitation was used to detect the relationship between IHH and GSK3β. Results:Compared with the control group, the relative length of the growth plate was shorter in histological sections [(0.51±0.11) vs (1.00±0.08), t=16.11, P<0.001], the expression rate of primary cilia was higher [(26.3±5.5)% vs (7.6±1.9)%, t=14.37, P<0.001], and the level of β-catenin increased [(7.1±2.0) scores vs (3.6±1.0) scores, t=7.10, P<0.001] in CRF group. In vitro, the expression rate of primary cilia was higher in CRF group chondrocytes [(31.4±8.2)% vs (12.5±3.1)%, t=9.64, P<0.001] than that in control group. The level of IHH in CRF group increased than that in control group [(1 360±270) vs (310±84), t=16.61, P<0.001]. There was no significant difference in GSK3β level of chondrocytes between the two groups [(850±195) vs (780±140), t=1.30, P=0.200]. There was a direct interaction between IHH and GSK3β in CRF group chondrocytes. Conclusions:The expression levels of primary cilia and related protein IHH increase in tibial growth plate chondrocytes of CRF young rats. The IHH protein plays a direct interaction with GSK3β protein, Wnt/β-catenin signaling pathway antagonist, which leads to the activation of Wnt/β-catenin signaling pathway and final accelerated differentiation of chondrocytes. The rapid differentiation of chondrocytes causes the closing trend of growth plate.

Effect of intra-articular injection of different concentrations of ozonated water on articular cartilage of rabbits with osteoarthritis / 中华麻醉学杂志

Objective:To evaluate the effect of intra-articular injection of different concentrations of ozonated water on articular cartilage of rabbits with osteoarthritis (OA).Methods:Twenty-four clean-grade New Zealand white rabbits of both sexes, weighing 2.0-3.0 kg, aged 6 months, were divided into 4 groups ( n=6 each) using a random number table method: control group (group C), OA group, low concentration ozonated water group (L group) and high concentration ozonated water group (H group). The OA model was established by intra-articular injection of papain.At 2 weeks after the model was successfully established, 10.0 and 20.0 μg/ml ozonated water 1.0 ml was injected into the knee joint of rabbits in L and H groups, respectively, and 0.9% sodium chloride solution 1.0 ml was injected once a week, 3 times in total in OA group.At 1 week after the last injection, the cartilage tissue of the knee joint was removed and stained with toluidine blue for evaluation of Mankin score (under light microscope). The activity of caspase-3 in chondrocyte was detected by enzyme-linked immunosorbent assay. Results:Compared with group C, the Mankin score and caspase-3 activity were significantly increased in the other 3 groups ( P<0.05). Compared with group OA, the Mankin score and caspase-3 activity were significantly decreased in group L and group H ( P<0.05). Compared with group L, the Mankin score was significantly increased, and the activity of caspase-3 was decreased in group H ( P<0.05). Conclusion:Injecting ozonated water 10.0 μg/ml and 20.0 μg/ml into the knee joint cavity both can inhibit the apoptosis in chondrocytes and reduce the damage to articular cartilage, however, high concentration of ozonated water can cause the denaturation of the articular cartilage matrix in rabbits with OA.

Effects of HT-2 toxin on expressions of SIRT1, autophagy and apoptosis pathway related proteins in chondrocytes / 中华地方病学杂志

Objective:To explore the effects of HT-2 toxin on expressions of silent information regulator of transcription 1 (SIRT1) and autophagy and apoptosis pathway related proteins in cultured chondrocytes in vitro. Methods:The third-generation chondrocytes of SD neonatal rats aged 1 to 2 days were cultured in vitro and identified by toluidine blue staining and type Ⅱ collagen immunofluorescence staining. CCK-8 method was used to detect the proliferation of chondrocytes. According to the cell survival rate, 2, 4 and 8 ng/ml HT-2 toxin were selected for subsequent experiments, and the exposure time was 48 h. At the same time, a negative control group and a solvent (absolute ethanol) control group were set up. Western blotting was used to detect the expressions of SIRT1 and autophagy and apoptosis pathway related proteins [microtubule-associated protein 1 light chain 3 (LC3)-Ⅱ, LC3-Ⅰ, p62, Beclin1, Caspase-3, B-cell lymphoma-2 (Bcl-2) and Bcl-2-Associated X protein (Bax)] in each group. Results:After staining, the cells were identified as chondrocytes with high purity. The expression levels of SIRT1 protein in 2, 4, 8 ng/ml HT-2 toxin groups (0.69 ± 0.18, 0.46 ± 0.13, 0.35 ± 0.19) were significantly lower than that in negative control group (1.00 ± 0.39, P < 0.05). In 2, 4 and 8 ng/ml HT-2 toxin groups, the ratios of autophagy pathway related proteins LC3-Ⅱ and LC3-Ⅰ expressions (LC3-Ⅱ/LC3-Ⅰ, 1.47 ± 0.15, 1.37 ± 0.13, 1.81 ± 0.34) were higher than that in negative control group (1.00 ± 0.21, P < 0.05), and the expression levels of p62 protein in 4, 8 ng/ml HT-2 toxin groups (0.70 ± 0.04, 0.57 ± 0.01) were lower than that in negative control group (1.00 ± 0.15, P < 0.05). In 2, 4, 8 ng/ml HT-2 toxin groups, the expression levels of apoptosis pathway related protein Bcl-2 (0.61 ± 0.06, 0.54 ± 0.16, 0.47 ± 0.06) were significantly lower than that in negative control group (1.00 ± 0.14, P < 0.05), and the ratio of Bax to Bcl-2 protein expressions in 8 ng/ml HT-2 toxin group (Bax/Bcl-2, 3.27 ± 0.18) was higher than that in negative control group (1.00 ± 0.27, P < 0.05). The expression level of SIRT1 protein was significantly negatively correlated with the expression level of autophagy pathway related protein LC3-Ⅱ ( r = - 0.819, P < 0.01), and was significantly positively correlated with the expression level of p62 protein( r = 0.772, P < 0.01), but not with the expression level of Beclin1 protein ( r = 0.399 , P > 0.05); there was no correlation between SIRT1 protein expression and apoptosis pathway related protein Caspase-3 and Bax expressions ( r = - 0.297、- 0.284, P > 0.05), but there was a significant positive correlation with Bcl-2 protein expression ( r = 0.755, P < 0.01). Conclusion:HT-2 toxin may increase the expression of autophagy pathway related protein LC3-Ⅱ/LC3-Ⅰ, decrease the expression of p62 protein, and increase the apoptosis pathway related protein Bax/Bcl-2 by inhibiting the expression of SIRT1 protein in chondrocytes, resulting in abnormal autophagy and apoptosis, and finally leads to the injury of chondrocytes.