title: Inhibitory effects of somatostatin on tumor necrosis factor-alpha-induced interleukin-6 secretion in human pancreatic periacinar myofibroblasts.
abstract: Pancreatic periacinar myofibroblasts are considered to be therapeutic targets for the suppression of acute pancreatitis. To elucidate the mechanisms mediating the therapeutic actions of somatostatin on acute pancreatitis, we investigated how somatostatin affects the tumor necrosis factor (TNF)-alpha-induced interleukin (IL)-6 and IL-8 secretion from pancreatic myofibroblasts. Cytokine secretion was determined by enzyme-linked immunosorbent assay (ELISA) and Northern blotting. Nuclear factor (NF)-kappaB DNA-binding activity was evaluated by electrophoretic mobility shift assay (EMSAs). The expression of somatostatin receptor (SSTR) mRNA was evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Somatostatin dose-dependently inhibited the TNF-alpha-induced IL-6 secretion. In comparison, the effects on IL-8 secretion were modest. Northern blot analysis demonstrated that somatostatin decreased the TNF-alpha-induced IL-6 mRNA expression, and that this effect was completely blocked by the somatostatin antagonist cyclo-somatostatin. Furthermore, somatostatin suppressed TNF-alpha-induced NF-kappaB activation. These cells bear SSTR subtypes 1 and 2. Somatostatin down-regulated the TNF-alpha-induced IL-6 secretion in human pancreatic periacinar myofibroblasts. These findings suggest that some of the therapeutic actions of somatostatin on acute pancreatitis might be mediated by reducing local IL-6 secretion in the pancreas.
authors.affiliation: Department of Internal Medicine, Shiga University of Medical Science, Seta-Tukinowa, Otsu 520-2192, Japan. andoh@belle.shiga-med.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Andoh
authors.forename: Kazunori
authors.initials: K
authors.lastname: Hata
authors.forename: Mitsue
authors.initials: M
authors.lastname: Shimada
authors.forename: Sanae
authors.initials: S
authors.lastname: Fujino
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Tasaki
authors.forename: Shigeki
authors.initials: S
authors.lastname: Bamba
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Araki
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Fujiyama
authors.forename: Tadao
authors.initials: T
authors.lastname: Bamba
mesh_terms: D000208:Acute Disease; D015152:Blotting, Northern; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D016209:Interleukin-8 / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D010179:Pancreas / Q000187:drug effects* / Q000378:metabolism; D010195:Pancreatitis / Q000188:drug therapy* / Q000378:metabolism; D017481:Receptors, Somatostatin / Q000235:genetics / Q000378:metabolism; D013004:Somatostatin / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D017481:Receptors, Somatostatin; D014409:Tumor Necrosis Factor-alpha; D013004:Somatostatin