Li Dapeng, Yue Jiawei, Jiang Lu, Huang Yonghui, Sun Jifu, Wu Yan
Department of Orthopaedics, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China (mainland).
Department of Physiology, Medical College of Jiangsu University, Zhenjiang, Jiangsu, China (mainland).
Med Sci Monit. 2017 Apr 22;23:1940-1946. doi: 10.12659/msm.904018.
BACKGROUND Degrading enzymes play an important role in the process of disc degeneration. The objective of this study was to investigate the correlation between the expression of high temperature requirement serine protease A1 (HtrA1) in the nucleus pulposus and the T2 value of the nucleus pulposus region in magnetic resonance imaging (MRI). MATERIAL AND METHODS Thirty-six patients who had undergone surgical excision of the nucleus pulposus were examined by MRI before surgery. Pfirrmann grading of the target intervertebral disc was performed according to the sagittal T2-weighted imaging, and the T2 value of the target nucleus pulposus was measured according to the median sagittal T2 mapping. The correlation between the Pfirrmann grade and the T2 value was analyzed. The expression of HtrA1 in the nucleus pulposus was analyzed by RT-PCR and Western blot. The correlation between the expression of HtrA1 and the T2 value was analyzed. RESULTS The T2 value of the nucleus pulposus region was 33.11-167.91 ms, with an average of 86.64±38.73 ms. According to Spearman correlation analysis, there was a rank correlation between T2 value and Pfirrmann grade (P<0.0001), and the correlation coefficient (rs)=-0.93617. There was a linear correlation between the mRNA level of HtrA1 and T2 value in nucleus pulposus tissues (a=3.88, b=-0.019, F=112.63, P<0.0001), normalized regression coefficient=-0.88. There was a linear correlation between the expression level of HtrA1 protein and the T2 value in the nucleus pulposus tissues (a=3.30, b=-0.016, F=93.15, P<0.0001) and normalized regression coefficient=-0.86. CONCLUSIONS The expression of HtrA1 was strongly related to the T2 value, suggesting that HtrA1 plays an important role in the pathological process of intervertebral disc degeneration.
背景 降解酶在椎间盘退变过程中起重要作用。本研究的目的是探讨髓核中高温需求丝氨酸蛋白酶A1（HtrA1）的表达与磁共振成像（MRI）中髓核区域T2值之间的相关性。
材料与方法 对36例行髓核手术切除的患者在术前进行MRI检查。根据矢状面T2加权成像对目标椎间盘进行Pfirrmann分级，并根据正中矢状面T2映射测量目标髓核的T2值。分析Pfirrmann分级与T2值之间的相关性。通过RT-PCR和蛋白质印迹法分析髓核中HtrA1的表达。分析HtrA1表达与T2值之间的相关性。
结果 髓核区域的T2值为33.11 - 167.91 ms，平均为86.64±38.73 ms。根据Spearman相关性分析，T2值与Pfirrmann分级之间存在等级相关性（P<0.0001），相关系数（rs）=-0.93617。髓核组织中HtrA1的mRNA水平与T2值之间存在线性相关性（a = 3.88，b = -0.019，F = 112.63，P<0.0001），标准化回归系数=-0.88。髓核组织中HtrA1蛋白的表达水平与T2值之间存在线性相关性（a = 3.30，b = -0.016，F = 93.15，P<0.0001），标准化回归系数=-0.86。
结论 HtrA1的表达与T2值密切相关，提示HtrA1在椎间盘退变的病理过程中起重要作用。
