肌球蛋白在胰胆管合流异常患儿胆总管平滑肌中表达的改变

目的:观察胰胆管合流异常(PBM)患儿胆总管平滑肌肌球蛋白重链(MHC)与磷酸化肌球蛋白20 kD轻链(P-MLC20)表达的情况.方法:收集16例儿童PBM胆总管标本,以16例新生儿尸体胆总管标本为对照,免疫组化染色后用图像分析系统检测分析两种组织中MHC和P-MLC20表达；用Western blot法检测两种组织中P-MLC20的蛋白表达.结果:MHC与P-MLC20蛋白表达免疫组化图像分析系统定量分析结果显示,除两者的平均光密度(MOD)组间无差异外(均P＞0.05),PBM组两者的平均阳性面积比例(MLI)与阳性染色得分(MQS)均明显高于对照组(均P＜0.05)；Western blot显示PBM组中P-MLC20蛋白表达量较对照组明显增高(P＜0.05).结论:PBM患儿胆总管平滑肌MHC与P-MLC20蛋白表达增高,该改变可能导致了胆总管平滑肌的收缩力代偿性增加.

Alterations of myosin expression in smooth muscle of common bile duct in children with pancreaticobiliary maljunction

Objective: To observe the expression of myosin heavy chain (MHC) and phosphorylated 20 kD myosin light chain (P-MLC20) in the smooth muscle of the common bile duct (CBD) from children with pancreaticobiliary maljunction (PBM). Methods: The CBD specimens from 16 PBM pediatric patients were compared with 16 CBD specimens from cadavers of neonates serving as control. The MHC and P-MLC20 protein expressions in the two tissues were examined and analyzed by image analysis system after immunohistochemical staining, and the P-MLC20 protein expression in the two tissues were also determined by Western blot analysis.Results: The immunohistochemical semi-quantitative analysis for the MHC and P-MLC20 protein expressions showed there were no differences in mean optical density (MOD) for both proteins between the two groups (both P>0.05), but the mean labeling intensity (MLI) and minimum qualifying scores (MQS) for both proteins in PBM group were all significantly higher than those in control group (all P<0.05). Western blot results showed that the expression level of P-MLC20 protein in PBM group was significantly increased compared with control group (P<0.05).Conclusion: The MHC and P-MLC20 expressions are increased in CBD smooth muscle of PBM children, which may probably lead to the compensatorily enhanced contractile ability of their CBD smooth muscle.