Objective:To analyze the expression of myosin light chain phosphatase target subunit-1 (MYPT1), protein kinase C-activated phosphatase inhibitor 17 (CPI17), and protein phosphatase 1 catalytic subunit (PP1C) in the biliary epithelium of children with pancreaticobiliary maljunction (PBM).Methods:A total of 22 children with PBM and biliary dilatation from the Children's Hospital of Soochow University from March 2015 to December 2017 were collected as the PBM group ( n=22), including 8 males and 14 females, with an age of 4.2 (2.8, 6.3) years. 21 patients who underwent cholecystectomy for gallstones at the First Affiliated Hospital of Soochow University were collected as the control group ( n=21), including 9 males and 12 females, with an age of 32.2 (23.8, 48.3) years. The expression of tight junction-related proteins pMLC, CPI17, PP1C, and MYPT1 in the PBM group and the control group was analyzed by immunohistochemical staining combined score. Western blot was used to detect the protein expression of MYPT1, PP1C, MLC, pCPI17, CPI17, and pMYPT1 in the PBM group and the control group. Results:The immunohistochemical staining combined score showed that the expression of pMLC protein in the PBM group was higher than that in the control group, while the expression of MYPT1, CPI17, and PP1C proteins was lower than that in the control group, and the differences were statistically significant (all P<0.05). The Western blot detection results showed that the expression values of pMYPT1 (Thr696), pCPI17 (Thr38), MLC, CPI17, MYPT1, and PP1C proteins in the PBM group were (1.187±0.140), (0.455±0.038), (0.181±0.013), (0.246±0.016), (0.459±0.054), and (0.202±0.032), respectively, while those in the control group were (0.238±0.048), (0.144±0.025), (3.268±0.278), (1.462±0.214), (1.138±0.189), and (0.853±0.120), respectively. The expression of MLC, CPI17, MYPT1, and PP1C proteins in the PBM group was lower than that in the control group, while the expression of pMYPT1 and pCPI17 proteins was higher than that in the control group, and the differences were statistically significant (all P<0.05). Conclusion:The increased expression of pMYPT1 and pCPI17 and the decreased expression of PP1C in children with PBM may be related to the disruption of tight junctions in the biliary epithelium of these children.

Objective:To analyze the expression of myosin light chain phosphatase target subunit-1 (MYPT1), protein kinase C-activated phosphatase inhibitor 17 (CPI17), and protein phosphatase 1 catalytic subunit (PP1C) in the biliary epithelium of children with pancreaticobiliary maljunction (PBM).Methods:A total of 22 children with PBM and biliary dilatation from the Children's Hospital of Soochow University from March 2015 to December 2017 were collected as the PBM group ( n=22), including 8 males and 14 females, with an age of 4.2 (2.8, 6.3) years. 21 patients who underwent cholecystectomy for gallstones at the First Affiliated Hospital of Soochow University were collected as the control group ( n=21), including 9 males and 12 females, with an age of 32.2 (23.8, 48.3) years. The expression of tight junction-related proteins pMLC, CPI17, PP1C, and MYPT1 in the PBM group and the control group was analyzed by immunohistochemical staining combined score. Western blot was used to detect the protein expression of MYPT1, PP1C, MLC, pCPI17, CPI17, and pMYPT1 in the PBM group and the control group. Results:The immunohistochemical staining combined score showed that the expression of pMLC protein in the PBM group was higher than that in the control group, while the expression of MYPT1, CPI17, and PP1C proteins was lower than that in the control group, and the differences were statistically significant (all P<0.05). The Western blot detection results showed that the expression values of pMYPT1 (Thr696), pCPI17 (Thr38), MLC, CPI17, MYPT1, and PP1C proteins in the PBM group were (1.187±0.140), (0.455±0.038), (0.181±0.013), (0.246±0.016), (0.459±0.054), and (0.202±0.032), respectively, while those in the control group were (0.238±0.048), (0.144±0.025), (3.268±0.278), (1.462±0.214), (1.138±0.189), and (0.853±0.120), respectively. The expression of MLC, CPI17, MYPT1, and PP1C proteins in the PBM group was lower than that in the control group, while the expression of pMYPT1 and pCPI17 proteins was higher than that in the control group, and the differences were statistically significant (all P<0.05). Conclusion:The increased expression of pMYPT1 and pCPI17 and the decreased expression of PP1C in children with PBM may be related to the disruption of tight junctions in the biliary epithelium of these children.