TGF-β_1和结缔组织生长因子在不同退变程度的腰椎间盘组织中的表达

EXPRESSIONS OF TRANSFORMING GROWTH FACTOR β_1 AND CONNECTIVE TISSUE GROWTH FACTOR IN HUMAN LUMBAR INTERVERTEBRAL DISCS IN DIFFERENT DEGREES OF DEGENERATION

目的通过检测不同退变程度腰椎间盘组织中TGF-β1和结缔组织生长因子(connective tissue growth factor,CTGF)的表达,探讨两种蛋白在人椎间盘退变发生发展中的作用。方法选取2012年11月-2013年4月手术摘除的33例腰椎间盘突出症患者和12例腰椎爆裂性骨折患者的腰椎间盘组织作为实验样本,组织切片行HE染色观察椎间盘组织的退变情况,并根据病理学改变将标本进行分级分组;Western blot法测定各组标本中TGF-β1和CTGF的相对表达量。结果根据病理学改变分级分组为:正常组10例,轻度退变组10例,中度退变组9例,重度退变组16例。组织学观察示正常组椎间盘组织的软骨样基质中分布大小一致的圆形髓核细胞,细胞间质均匀一致,未见胶原纤维增生;轻度退变组椎间盘髓核细胞轻度变大,髓核细胞未见明显减少,基质内有少量炎细胞浸润,细胞间质胶原纤维未见明显增生;中度退变组椎间盘髓核细胞大多数变大,呈空泡样,正常髓核细胞减少,细胞间质内胶原纤维轻度增生,可见小血管长入,炎性细胞浸润;重度退变组椎间盘基质内未见正常的髓核细胞,细胞间质内胶原纤维重度增生伴纤维化。Western blot检测示:各组腰椎间盘组织中均有TGF-β1和CTGF表达,3个退变组TGF-β1相对表达量均显著高于正常组(P<0.05);重度退变组显著高于轻、中度退变组(P<0.05),轻、中度退变组差异无统计学意义(P>0.05)。中、重度退变组CTGF相对表达量显著高于正常组(P<0.05);轻度退变组高于正常组,但差异无统计学意义(P>0.05);轻、中、重度退变组间比较差异均有统计学意义(P<0.05)。结论人腰椎间盘组织中TGF-β1和CTGF的表达量与腰椎间盘退变进展程度密切相关,两种蛋白因子表达增高对促进腰椎间盘的退变可能发挥重要作用。

Objective To investigate the role of transforming growth factor β1（TGF-β1） and connective tissue growth factor（CTGF） in pathogenesis and progression of human intervertebral disc degeneration by detecting the expressions of these two factors in dif erent degrees of degenerative discs. Methods The lumbar intervertebral discs were collected from 33 patients with lumbar disc herniation and 12 patients with lumbar vertebral fracture between November 2012 and April 2013. All samples were observed under the microscope after HE staining, and then were divided into dif erent subgroups according to the degenerative degree. The expressions of TGF-β1 and CTGF were detected by Western blot. Results According to the pathological features, 10 discs were dei ned as normal discs, 10 as mild degenerative discs, 9 as moderate degenerative discs, and 16 as severe degenerative discs. The histological observation showed that rounded nucleus pulposus cells with similar size evenly distributed in the cartilage-like matrix, and no hyperplastic collagenous i ber was seen in normal discs; mild degenerative discs characterized by slightly larger nucleus pulposus cells in the matrix, but cells did not decrease, a small quantity of inl ammatory cells ini ltrated in the matrix, hyperplasia of collagenous i ber was not seen; most of the nucleus pulposus cells became bigger, some showed a bulb form, the number of nucleus pulposus cells was signii cantly reduced, low grade hyperplasia of collagenous i ber emerged in the matrix, new vessels and inl ammatory cells were both found in some specii c areas of discs in moderate degenerative discs; there was no nucleus pulposus cells in the matrix of severe degenerative discs, the hyperplasia of collagenous i ber was obvious. The relative expression of TGF-β1 in 3 degeneration discs was signii cantly higher than that in normal discs（P〈0.05）, and the expression of TGF-β1 was signii cantly higher in severe degenerative discs than in moderate and mild degenerative discs（P〈0.05）, but no signii cant dif erence between moderate and mild degenerative discs（P〈0.05）. The relativeexpression of CTGF in moderate and severe degeneration discs was signii cantly higher than that in normal discs（P〈0.05）; and the expression of CTGF in mild degenerative discs was higher than that in normal discs, but there was no signii cant dif erence（P〈0.05）; and signii cant dif erence in CTGF expression was found among 3 degeneration discs（P〈0.05）. Conclusion The expressions of TGF-β1 and CTGF are closely related to the degree of human lumbar disc degeneration, these two factors may play an important role in promoting lumbar intervertebral disc degeneration.