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Objectives Pancreatic stellate cells (PSCs) play a crucial role during pancreatic fibrosis development. Hydrogen sulfide (H2S) is a recently discovered gaseous transmitter, whose role in PSCs has not been explored yet. In the present study, we examined the effects of sodium hydrosulfide (NaHS), an H2S donor, on rat PSCs and elucidated the mechanisms involved. Methods Primary PSCs were isolated from rat pancreatic tissue. Lactate dehydrogenase and caspase assays were performed to detect cell death. Pancreatic stellate cell proliferation was determined by cell count analyses, bromodeoxyuridine incorporation, and flow cytometry. The role of heme oxygenase-1 (HO-1) was assessed by pharmacological HO inhibition and transfection of HO-1 small interfering RNA. Pancreatic stellate cell migration was determined by a wound healing assay, and PSC contraction was assessed by a gel contraction assay. α-Smooth muscle actin, collagen type I, and fibronectin messenger RNAs were analyzed by real-time polymerase chain reaction. Results NaHS inhibited PSC proliferation at nontoxic concentrations. This was associated with HO-1–mediated repression of extracellular signal–regulated kinase 1/2 signaling. NaHS suppressed PSC migration and activation as well as extracellular matrix synthesis. Conclusions The results of the present study indicate that NaHS inhibits key cell functions of PSCs. Administration of H2S-releasing compounds might represent a novel strategy in the treatment of pancreatic fibrosis.

Objective Hyperglycemia is implicated in fibrosis in many organs. Exocrine and endocrine pancreas are closely linked both anatomically and physiologically, and pathological conditions in the exocrine gland can cause impairment of endocrine function and vice versa. Chronic pancreatitis causes pancreatic fibrosis and sometimes results in diabetes mellitus. Pancreatic stellate cells (PSCs) play a pivotal role in pancreatic fibrogenesis. However, the effects of high glucose concentrations on PSC activation have not been fully elucidated. Methods Cultured PSCs were incubated in the presence of various concentrations of glucose. Pancreatic stellate cell proliferation, alpha-smooth muscle actin (alpha-SMA) expression, and collagen production were determined by colorimetric conversion assay, Western blot analysis, and Sirius red dye binding assay, respectively. Results High glucose concentrations significantly increased PSC proliferation, alpha-SMA expression, and collagen type I production in PSCs. High glucose concentrations activated protein kinase C (PKC) in PSCs, and PKC inhibitor GF109203X inhibited glucose-stimulated PSC proliferation, alpha-SMA expression, and collagen secretion. High glucose also activated p38 mitogen-activated protein kinase (MAPK) in PSCs, and p38 MAPK inhibitor SB203580 inhibited glucose-stimulated collagen secretion. Conclusions Our results indicate that high glucose concentrations stimulate PSC activation via PKC-p38 MAP kinase pathway and suggest that high glucose may aggravate pancreatic fibrosis.

s / Pancreatology 13 (2013) e1–e94 e84 and 37,418, respectively). Higher islet yield correlated with a greater diabetes free rate and a lesser insulin requirement at the following intervals: pre-operative, post-operative and 6 months after IAT. Conclusion: Prior surgery is strongly correlated with the extent of pancreatic fibrosis, islet yield and insulin requirements in CP patients undergoing TP-IAT. The history of prior pancreatic resection and drainage procedures may be used to predict post-operative islet function and help to determine the optimal timing for TP-IAT in CP patients.

Background Several studies have described an increased cyclooxygenase-2 (COX-2) expression in pancreatic cancer, but the role of COX-2 in tumour development and progression is not clear. The aim of the present study was to examine expression of COX-2 in cancer cells and stromal cells in pancreatic cancer specimens, and to explore the role of PGE2 in pancreatic stellate cell proliferation and collagen synthesis. Methods Immunohistochemistry and immunofluorescence was performed on slides from whole sections of tissue blocks using antibodies against COX-2 and α-smooth muscle actin (αSMA). Pancreatic stellate cells (PSC) were isolated from surgically resected tumour tissue by the outgrowth method. Cells were used between passages 4 and 8. Collagen synthesis was determined by [3H]-proline incorporation, or by enzyme immunoassay measurement of collagen C-peptide. DNA synthesis was measured by incorporation of [3H]-thymidine in DNA. Cyclic AMP (cAMP) was determined by radioimmunoassay. Collagen 1A1 mRNA was determined by RT-qPCR. Results Immunohistochemistry staining showed COX-2 in pancreatic carcinoma cells, but not in stromal cells. All tumours showed positive staining for αSMA in the fibrotic stroma. Cultured PSC expressed COX-2, which could be further induced by interleukin-1β (IL-1β), epidermal growth factor (EGF), thrombin, and PGE2, but not by transforming growth factor-β1 (TGFβ). Indirect coculture with the adenocarcinoma cell line BxPC-3, but not HPAFII or Panc-1, induced COX-2 expression in PSC. Treatment of PSC with PGE2 strongly stimulated cAMP accumulation, mediated by EP2 receptors, and also stimulated phosphorylation of extracellular signal-regulated kinase (ERK). Treatment of PSC with PGE2 or forskolin suppressed both TGFβ-stimulated collagen synthesis and PDGF-stimulated DNA synthesis. Conclusions The present results show that COX-2 is mainly produced in carcinoma cells and suggest that the cancer cells are the main source of PGE2 in pancreatic tumours. PGE2 exerts a suppressive effect on proliferation and fibrogenesis in pancreatic stellate cells. These effects of PGE2 are mediated by the cAMP pathway and suggest a role of EP2 receptors.