TY - JOUR T1 - Treatment of pancreatic fibrosis with siRNA against a collagen-specific chaperone in vitamin A-coupled liposomes JF - Gut JO - Gut SP - 1328 LP - 1339 DO - 10.1136/gutjnl-2011-301746 VL - 62 IS - 9 AU - Hirotoshi Ishiwatari AU - Yasushi Sato AU - Kazuyuki Murase AU - Akihiro Yoneda AU - Ryosuke Fujita AU - Hiroki Nishita AU - Naoko Kubo Birukawa AU - Tsuyoshi Hayashi AU - Tsutomu Sato AU - Koji Miyanishi AU - Rishu Takimoto AU - Masayoshi Kobune AU - Shigenori Ota AU - Yasutoshi Kimura AU - Koichi Hirata AU - Junji Kato AU - Yoshiro Niitsu Y1 - 2013/09/01 UR - http://gut.bmj.com/content/62/9/1328.abstract N2 - Background and objective Fibrosis associated with chronic pancreatitis is an irreversible lesion that can disrupt pancreatic exocrine and endocrine function. Currently, there are no approved treatments for this disease. We previously showed that siRNA against collagen-specific chaperone protein gp46, encapsulated in vitamin A-coupled liposomes (VA-lip-siRNAgp46), resolved fibrosis in a model of liver cirrhosis. This treatment was investigated for pancreatic fibrosis induced by dibutyltin dichloride (DBTC) and cerulein in rats. Methods Specific uptake of VA-lip-siRNAgp46, conjugated with 6′-carboxyfluorescein (FAM) by activated pancreatic stellate cells (aPSCs), was analysed by fluorescence activated cell sorting (FACS). Intracellular distribution of VA-lip-siRNAgp46-FAM was examined by fluorescent microscopy. Suppression of gp46 expression by VA-lip-siRNAgp46 was assessed by immunoblotting. Collagen synthesis in aPSCs was assayed by dye-binding. Specific delivery of VA-lip-siRNAgp46 to aPSCs in DBTC rats was verified following intravenous VA-lip-siRNA-FAM and 3H-VA-lip-siRNAgp46. The effect of VA-lip-siRNA on pancreatic histology in DBTC- and cerulein-treated rats was determined by Azan-Mallory staining and hydroxyproline content. Results FACS analysis revealed specific uptake of VA-lip-siRNAgp46-FAM through the retinol binding protein receptor by aPSCs in vitro. Immunoblotting and collagen assay verified knockdown of gp46 and suppression of collagen secretion, respectively, by aPSCs after transduction of VA-lip-siRNAgp46. Specific delivery of VA-lip-siRNAgp46 to aPSCs in fibrotic areas in DBTC rats was confirmed by fluorescence and radioactivity 24 h after the final injection. 10 systemic VA-lip-siRNAgp46 treatments resolved pancreatic fibrosis, and suppressed tissue hydroxyproline levels in DBTC- and cerulein-treated rats. Conclusion These data suggest the therapeutic potential of the present approach for reversing pancreatic fibrosis. ER -