前交叉韧带损伤后软骨退变和骨性关节炎发生的分子变化

为了探讨凋亡酶的半胱天冬酶3 (Caspase 3)、促炎细胞因子interleukin-1β(IL-1β)、白细胞介素-6(IL-6)和基质金属蛋白酶降解酶-13 (MMP-13)的表达水平,来说明前交叉韧带(anterior cruciate ligament,ACL)损伤后软骨细胞的软骨变性和骨性关节炎的发展情况,本研究通过探讨软骨降解程度与损伤时间或患者年龄之间的关系,应用实时聚合酶链反应检测正常人(n=5)和ACL破裂患者(n=42)软骨细胞中IL-1β、IL-6和MMP-13 mRNA的表达水平,采用Western blotting检测MMP-13和Caspase 3蛋白表达水平。通过趋势分析和相关系数分析,分别得出MMP-13、IL-6、IL-1β基因表达与软骨缺损分级,MMP-13、IL-6、IL-1β基因表达与患者年龄的关系。结果表明,软骨降解程度与损伤时间之间存在相关性。与正常相比,ACL损伤的软骨细胞中,MMP-13、IL-6、IL-1β和Caspase 3的表达水平有显著上调。在ACL缺陷患者中,与ACL缺陷未到18个月的患者相比,在超过18个月的患者中发现MMP-13明显上调,而超过10月的患者软骨细胞中IL-6和IL-1β表达水平要高于未到10个月的ACL缺陷患者。同时,IL-1β、IL-6和MMP-13表达水平和软骨损伤或病人的年龄之间没有关联。研究发现,软骨细胞凋亡、炎症和分解代谢因子水平的升高与损伤时间有关,并可能导致ACL损伤后软骨退变和骨性关节炎的发生。

Molecular Changes of Cartilage Degeneration and Osteoarthritis Development with Anterior Cruciate Ligament Injury

In order to investigate the expression levels of the apoptotic enzyme Caspase 3,pro-inflammatory cytokines interleukin-1β(IL-1β) and interleukin-6(IL-6) and degrading enzyme matrix metalloproteinase 13(MMP-13),all indicative of cartilage degeneration and osteoarthritis development in patients’ chondrocytes after anterior cruciate ligament(ACL) injury,we explored the correlation between grade of cartilage degradation and time from injury or patients’ age.IL-1β,IL-6 and MMP-13 m RNA expression levels were investigated in normal(n=5) and chondrocytes from patients with ACL injury(n=42) using real-time polymerase chain reaction.Moreover,MMP-13 and caspase-3 protein expression levels were evaluated by Western blotting analysis.Trend analysis and correlation coefficient were performed to derive the relations between gene expression(MMP-13,IL-6,IL-1β) and grading of cartilage defects and between gene expression(MMP-13,IL-6,IL-1β) and patients’ age,respectively.Correlations were established between grade of cartilage degradation and time from injury.MMP-13,IL-6,IL-1βand Caspase 3 expression levels were significantly upregulated in chondrocytes from ACL-deficient knee compared to normal.Among the patients with ACL injury knees,a significant upregulation of MMP-13 was observed in patients with ACL injury>18 months from the time of injury to arthroscopy compared to patients with ACL injury up to 18 months,whereas IL-6 and IL-1β expression was higher in chondrocytes from patients with more than 10 months ACL injury compared to those that underwent surgery within the first 10 months after injury.Also,there was no association was observed between IL-1β,IL-6 and MMP-13 expression levels and cartilage defects or patients’ age.The results showed that increased levels of apoptotic,inflammatory and catabolic factors in chondrocytes were associated with time from injury and could contribute to cartilage degradation and osteoarthritis development after ACL rupture.