Glial fibrillary acidic protein promoter targets pancreatic stellate cells

Background. Pancreatic fibrosis is one of the clinical manifestations of chronic pancreatitis and pancreatic cancer. Pancreatic stellate cells (PSCs) have been recognised as principal effector cells in the development of pancreatic fibrosis. The ability to specifically address PSCs might offer a potential for developing a targeted therapy for pancreatic fibrosis. Aim. Characterisation of the 2.2 kb hGFAP (human glial fibrillary acidic protein) promoter for its usefulness to express reporter genes specifically in PSCs in vitro and to vivo. Methods. 2.2 kb hGFAP-LacZ reporter expressions were examined in four immortalised PSC lines and two non-PSCs, meanwhile, GFAP-LacZ transgenic mice were used to detect LacZ reporter in pancreas tissue. Several kinase inhibitors, vitamin A and its metabolites were applied to study the regulation of 2.2 kb hGFAP promoter in PSCs. Results. Our results showed that the 2.2 kb hGFAP promoter is capable of regulating the expression of reporter genes exclusively in immortalised and primary PSCs, as well as in PSCs of transgenic GFAP-LacZ mice. When a PSC cell line transfected with the LacZ reporter (SAM-K/LacZ/C1) was treated with different anti-fibrotic agents and kinase inhibitors, the transgenic beta-galactosidase activity was found to he regulated by multiple signalling pathways known to be involved in the PSC activation. Conclusions. This study provides the proof of concept for using the 2.2 kb hGFAP promoter to specifically manipulate PSCs for the development of targeted gene and/or drug therapy in pancreatic fibrosis, and for the screening of anti-fibrotic agents. (C) 2008 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.