Influence of PI3K gamma on pancreatic acinar cells autophagy in experimental acute pancreatitis in mice

Objective To investigate the influence of phosphoinositide 3-Kinase-C2-gamma (PI3Kγ)on pancreas acinar cells autophagy in experimental acute pancreatitis in mice and explore its significance.Methods Eighteen C57BL/6 wild type (WT) and eighteen PI3Kγ knockout (KO) mice were randomly divided into control group (n =6) and acute panereatitis (AP) group (n =12),respectively.AP models were induced by intraperitoneal injection of 50 μg cerulein/kg body weight,once the other hour for seven times.The mice were sacrificed 7 hours after model induction.The pathological changes of the pancreas were observed through microscope,LC3 dots were determined by immunofluorescence,the trypsin activity was measured by fluorescence spectrophotometer,and the expression of autophagy related protein beclin1,p62 and LC3- Ⅱ were measured by Western blot.Results The autophagy vacuoles counts in pancreatic tissue of WT mice and KO mice were (5.14 ±0.85),(2.25 ±0.54)/HPF,the LC3 immunofluorescence dots counts were (78.6 ±9.38),( 26.4 ± 4.21 )/HPF,the trypsin activities were ( 0.827 ± 0.126 ),( 0.358 ± 0.098 ) pmol/mg protein,the difference between the two groups was statistically significant ( P ＜ 0.05 ).The p62 protein expression was greatly decreased in WT mice compared with their KO counterpart (0.11 vs 0.92,P ＜ 0.05 ),while the expressions of LC3 Ⅱ,beclin1 were greatly increased in WT mice compared with their KO counterpart ( 1.82 vs 0.93,1.43 vs 1.05,P ＜ 0.05 ).Conclusions PI 3 Kγmay up- regulate autophagy of pancreatic acinar cells during acute pancreatitis in mice,then promote trypsinogen activation and necrosis of acinar cells. Key words: Pancreatitis;  Phosphoinositide 3-Kinase-C2-gamma;  Cerulein;  Autophagy