α-平滑肌肌动蛋白在创伤性神经瘤中的表达及其意义

Expression and significance of alpha-smooth muscle actin in the traumatic neuroma

目的观察α-平滑肌肌动蛋白(α-smoothmuscleactin,α-SMA)在创伤性神经瘤中的表达与分布,探讨其与创伤性神经瘤的形成及其临床表现的关系和意义。方法42例创伤性神经瘤组织标本,分为创伤性神经瘤无疼痛症状组(无症状组,31例)、创伤性神经瘤有疼痛症状组(有症状组11例),与15例正常神经组织标本对照(对照组,15例),采用免疫组化方法辅以计算机图像定量分析技术,对α-SMA的表达进行观察和检测。结果α-SMA在对照组和无症状组中未见明显表达,两者间差异无显著性意义(q=0.36,P>0.05);在有症状组可见明显阳性反应,与无症状组及对照组间差异均有非常显著性意义(q=6.87,P<0.01;q=7.44,P<0.01)。有症状组α-SMA的表达水平与疼痛程度呈高度正相关(rs=0.980,P<0.001)。结论肌成纤维细胞及α-SMA是导致创伤性神经瘤疼痛的重要原因。

Objective To observe the expression and distribution of alpha-smooth muscle actin(α-SMA) in the traumatic neuroma and discuss its significance and relationship with traumatic neuroma pain. Methods Forty two specimens from traumatic neuroma were collected between April 1991 and November 2000, and divided into asymptomatic group(n=31), symptomatic group(n=11) according to clinical manifestation. Fifteen normal nerve samples were harvested as the control group(n=15). All the specimens were fixed in formalin and embedded in paraffin for immunohistochemistry studies. Expression and localization of α-SMA in different groups were assessed after incubation of paraffin sections with a mouse monoclonal anti SMA antibody(Sigma, Missouri, USA). The expression level of α-SMA was detected by computer graph analysis system. Results There was no significant expression of α-SMA in the control group and asymptomatic group(q=0.36, P >0.05) except for the positive reaction in the smooth muscle cells of the small vascular walls. While in the symptomatic group, significant expression of α-SMA was observed besides the expression in the smooth muscle cells of the small blood vessels, and the positive fields were mainly located in the cellular plasm. The positive fields were diffusely distributed between the proliferous nerve fibers and collagen tissues most of which showed the streak or linear shapes together with some dot like expression figures. The difference of the expression level among the three groups was significant(F=289.534, P< 0.01) and q-test showed that the difference between the symptomatic group and asymptomatic group or the control group were significant(q=6.87, P< 0.01; q=7.44,P< 0.01); however there was no significant difference between the control group and the asymptomatic group(q=0.36, P >0.05). Correlation analysis indicated that the expression level of α-SMA was positively correlated with the scale of the pain assessed by means of a 10 point visual analogue scale (VAS)(rs =0.980,P< 0.001) and the linear regression equation was Y=648.498X-298.261(P=0.000). Conclusion Myofibroblast and α-SMA play an important role in the cause of the traumatic neuroma pain.