Signal transducer and activator of transcription-3 (Stat3) is one of the most important molecules involved in the initiation of liver development and regeneration. In order to investigate the hepatoprotective effects of Stat3, we examined whether Stat3 protects against Fas-mediated liver injury in the mouse. A constitutively activated form of Stat3 (Stat3-C) was adenovirally overexpressed in mouse liver by intravenous injection, and then a nonlethal dose of Fas agonist (Jo2) was injected intraperitoneally into the mouse (0.3 μg/g body wt). Stat3-C dramatically suppressed both apoptosis and necrosis induced by Jo2. In contrast, liver-specific Stat3-knockout mice failed to survive following Jo2 injection. Stat3-C upregulated expression of FLICE inhibitor protein (FLIP), Bcl-XL, and Bcl-2, and accordingly downregulated activities of FLICE and caspase-3 that were redox-independent. Interestingly, Stat3-C also upregulated the redox-associated protein redox factor-1 (Ref-1) and reduced apoptosis in liver following Jo2 injection by suppressing oxidative stress and redox-sensitive caspase-3 activity. These findings indicate that Stat3 activation protects against Fas-mediated liver injury by inhibiting caspase activities in redox-dependent and -independent mechanisms.

Congenital esophageal stenosis (CES) is an extremely rare malformation, and standard treatment have not been completely established. By years of clinical research, evidence has been accumulated. We conducted systematic review to assess outcomes of the treatment for CES, especially the role of endoscopic modalities. A total of 144 literatures were screened and reviewed. CES was categorized in fibromuscular thickening, tracheobronchial remnants (TBR) and membranous web, and the frequency was 54%, 30% and 16%, respectively. Therapeutic option includes surgery and dilatation, and surgery tends to be reserved for ineffective dilatation. An essential point is that dilatation for TBR type of CES has low success rate and high rate of perforation. TBR can be distinguished by using endoscopic ultrasonography (EUS). Overall success rate of dilatation for CES with or without case selection by using EUS was 90% and 29%, respectively. Overall rate of perforation with or without case selection was 7% and 24%, respectively. By case selection using EUS, high success rate with low rate of perforation could be achieved. In conclusion, endoscopic dilatation has been established as a primary therapy for CES except TBR type. Repetitive dilatation with gradual step-up might be one of safe ways to minimize the risk of perforation.