Pancreatic acinar cells accumulate
amino acids against a marked concentration gradient to synthesize digestive
enzymes. Thus, the function of acinar cells depends on
amino acid uptake mediated by active transport. Despite the importance of this process, pancreatic
amino acid transporter expression and cellular localization is still unclear. We screened mouse pancreas for the expression of genes encoding
amino acid transporters. We showed that the most highly expressed transporters, namely
sodium dependent SNAT3 (Slc38a3) and SNAT5 (Slc38a5) and
sodium independent
neutral amino acids transporters LAT1 (
Slc7a5) and LAT2 (Slc7a8), are expressed in the basolateral membrane of acinar cells. SNAT3 and SNAT5, LAT1 and LAT2 are expressed in acinar cells. Additional evidence that these transporters are expressed in mature acinar cells was gained using acinar cell culture and
acute pancreatitis models. In the acute phase of pancreatic injury, when acinar cell loss occurs, and in an acinar cell culture model, which mimics changes occurring during
pancreatitis, SNAT3 and SNAT5 are strongly down-regulated. LAT1 and LAT2 were down-regulated only in the in vitro model. At
protein level, SNAT3 and SNAT5 expression was also reduced during
pancreatitis. Expression of other
amino acid transporters was also modified in both models of
pancreatitis. The subset of transporters with differential expression patterns during
acute pancreatitis might be involved in the injury/regeneration phases. Further expression, localization and functional studies will follow to better understand changes occurring during
acute pancreatitis. These findings provide insight into pancreatic
amino acid transport in healthy pancreas and during
acute pancreatitis injury.