Activity of acute pancreatitis is modified by secreted protein acidic and rich in cysteine ablation.

BACKGROUND: Acute pancreatitis (AP) is a frequent cause for hospitalization. However, molecular determinants that modulate severity of experimental pancreatitis are only partially understood. OBJECTIVE: To investigate the role of secreted protein acidic and rich in cysteine (SPARC) during cerulein-induced AP in mice. METHODS: AP was induced by repeated cerulein injections in SPARC knock-out mice (SPARC-/- ) and control littermates (SPARC+/+ ). Secreted protein acidic and rich in cysteine expression and severity of AP were determined by histopathological scoring, immunohistochemistry, and biochemical assays. For functional analysis, primary murine acinar cell cultures with subsequent amylase release assays were employed. Proteome profiler assay and ELISA were conducted from pancreatic tissue lysates, and co-immunofluorescence was performed. RESULTS: Upon cerulein induction, SPARC expression was robustly induced in pancreatic stellate cells (PSCs) but not in acinar cells. Genetic SPARC ablation resulted in attenuated severity of AP with significantly reduced levels of pancreatic necrosis, apoptosis, immune cell infiltration, and reduced fibrosis upon chronic stimulation. However, the release of amylase upon cerulein stimulation in primary acinar cell culture from SPARC+/+ and SPARC-/- was indistinguishable. Notably, immune cell derived C-C Motif Chemokine Ligand 2 (CCL2) was highly elevated in SPARC+/+ pancreatic tissue potentially linking PSC derived SPARC with CCL2 induction in AP. CONCLUSION: SPARC mediates the severity of AP. The potential link between SPARC and the CCL2 axis could open new avenues for tailored therapeutic interventions in AP patients and warrants further investigations.

Gut microbiota and pancreatic diseases.

Changes in diet, lifestyle, and exposure to environmental risk factors account for the increased incidence of pancreatic disorders, including acute and chronic pancreatitis, and pancreatic cancer. The role of the microbiota in the development of pancreatic disorders is increasingly acknowledged. The translocation of gut bacteria and endotoxins following gut barrier failure is a key event contributing to the severity of acute pancreatitis, while small intestine bacterial overgrowth is common in patients with chronic pancreatitis and further worsens their symptoms and malnutrition. Specific molecular mimicry link the microbiota and Helicobacter pylori with autoimmune pancreatitis. Changes in the oral microbiota typical of periodontitis seem to be associated with an increased risk of developing pancreatic cancer. The composition of the gut microbiota is also unbalanced in the presence of risk factors for pancreatic cancer, such as obesity, smoking and diabetes. Helicobacter pylori infection, atrophic body gastritis and related decreased gastric acid secretion also seem associated with the risk of pancreatic cancer, although this area needs further research. The link between dysbiosis, immune response and proinflammatory status is most likely the key for these associations. The present review article will discuss current available evidence on the role of gut microbiota in pancreatic disorders, highlighting potential areas for future research.