We have shown earlier that mouse pancreatic acinar cells produce
hydrogen sulfide (H(2)S) and play a role in the pathogenesis of
acute pancreatitis. It is noteworthy that recent evidence indicates that H(2)S has anti-inflammatory effects. To date, the mechanism by which H(2)S directly reduces
inflammation has not been elucidated. In the present study, we hypothesized that H(2)S inhibits the production of proinflammatory
cytokines by activation of the
phosphatidylinositol 3-kinase (PI3K)/
protein kinase B (AKT) pathway. Pancreatic acinar cells were treated with the H(2)S donor,
sodium hydrogen sulfide (
NaHS) (5, 10, and 30 microM). To better understand the effect of H(2)S in
inflammation, pancreatic acinar cells were stimulated with
caerulein after the addition of
NaHS (5, 10, and 30 microM). We observed that H(2)S at the 5 microM concentration down-regulates the activation of
NF-kappaB and degradation of
IkappaB alpha. However, H(2)S (5 microM) activates PI3K as reflected by AKT phosphorylation. We found that H(2)S-mediated activation of PI3K in
caerulein-treated acinar cells correlated with the down-regulation of
extracellular signal-regulated kinase 1/2 phosphorylation, whereas phosphorylation of p38 and c-Jun NH(2)-terminal
kinase and
mitogen-activated protein kinases was unchanged. The PI3K inhibitor
LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-
benzopyran-4-one hydrochloride] abolished the H(2)S-mediated activation of AKT and increases
tumor necrosis factor alpha and
interleukin 1beta levels in
caerulein-treated acinar cells. These findings indicate that the
phosphatidylinositol 3-kinase plays a negative role in
NaHS-treated pancreatic acinar cells and suggest a role for H(2)S in the PI3K/AKT pathway in
acute pancreatitis.