SM22α和α-SMA在静脉曲张组织中的表达及其意义

Expression and significance of SM22α and α-SnA in varicose veins

目的探讨下肢静脉曲张中平滑肌22α（smooth muscle22 alpha，SM22α）及α-平滑肌肌动蛋白（αsmoothmuscleactin，α-SMA）的表达与下肢静脉曲张的关系。方法收集下肢静脉曲张患者的曲张大隐静脉组织作为实验组，另收集冠脉搭桥术患者正常下肢大隐静脉组织为对照组。RT-PCR方法检测标本中SM22αmRNA的表达水平，免疫组织化学法检测标本中SM22α及α-SMA的表达。结果SM22（xmRNA表达量在实验组和正常对照组中分别为0．2614±0．1168和0．5114±0．1554，差异有统计学意义（t=5．020，P〈0．01）。免疫组化示：SM22α和α-SMA均表达于血管平滑肌细胞（vascular smooth muscle cell，VSMC）胞质中。SM22α阳性蛋白累计吸光度（integrate optical density，IOD）值在实验组和对照组分别为10055±3584和16226±3378，差异有统计学意义（t=4．991，P〈0．01），与PCR结果一致。α-SMA阳性蛋白IOD值在实验组和对照组分别为9746±3903和15371±4318，两组比较差异有统计学意义（t=3．861，P〈0．05）。结论SM22α和α-SMA在曲张静脉中低表达表明曲张静脉发生了VSMC由收缩型向合成型的表型转换，进而导致静脉管壁的重塑和静脉曲张的发生。

Objective To explore the relationship between the expression of smooth muscle 22 alpha （SM22α）, α-smooth muscle actin （ct-SMA） and the development of varicose veins of the lower extremities. Methods We collected tissues of varicose saphenous vein in the experimental group, and what left over of normal saphenous vein tissues harvested for a coronary bypass operation （ control group）. RT-PCR were applied to investigate the expression level of SM22αmRNA and immunohistochemical techniques were applied to investigate the expression level of SM22α and α-SMA protein in normal and varicose veins. Results The expression level of SM22α mRNA in normal and abnormal veins was 0. 2614 ±0. 1168 and 0. 5114± 0. 1554 respectively （ t = 5. 020, P 〈 0. 01 ）. The immunohistochemical staining showed that signals of SM22α and α-SMA protein existed in the cytoplasm of smooth muscle cells. The integrate optical density （IOD） of SM22α in normal and abnormal veins was 10 055 ± 3584 and 16 226 ± 3378 respectively （t = 4. 991 ,P 〈 0.01 ）. The IOD of α-SMA in normal and abnormal veins was 9746 ± 3903 and 15 371± 4318 respectively （t = 3. 861, P 〈 0. 05）. Conclusions SM22α and α-SMA was down-regulated in varicose veins, indicating that the VSMC had transformed the typical contractile phenotype into the typical synthetic phenotype. Phenotype changes of VSMC further promote venous wall remodeling leading to the occurrence of varicose veins.