OBJECTIVE: To examine the effect of downregulation of high mobility group box 1 (HMGB1) on severe acute pancreatitis (SAP) associated with acute lung injury (ALI), and its subsequent effect on disease severity. METHODS: Wistar rats were given an IV injection of pRNA-U6.1/Neo-HMGB1, pRNA-U6.1/Neo-vector or saline before induction of SAP. Then, SAP was induced in rats by the retrograde injection of 5% sodium taurocholate into the pancreatic duct. The control group received only a sham operation. Lung and pancreas samples were harvested after induction of SAP. The protein levels of HMGB1, matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1) in lung tissue were investigated. The severity of pancreatic injury was determined by a histological score of pancreatic injury, serum amylase, and pancreatic water content. The lung injury was evaluated by measurement of pulmonary microvascular permeability, lung myeloperoxidase activity and malondialdehyde levels. RESULTS: The results found that in pRNA-U6.1/Neo-HMGB1 treated rats, serum tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels were decreased and the severity of pancreatic tissue injury was less compared with either untreated SAP or pRNA-U6.1/Neo-vector treated rats (P<0.05). The administration of pRNA-U6.1/Neo-HMGB1 in SAP-induced rats downregulated the DNA binding activity of the nuclear factor-kappa B (NF-κB) and the expressions of MMP-9 and ICAM-1 in lung. Thus, compared with the untreated SAP rats, the inflammatory response and the severity of ALI decreased (P<0.05). CONCLUSIONS: These results demonstrate that HMGB1 could augment Inflammation by inducing nuclear translocation of NF-κB, thus aggratating the severity of SAP associated with ALI.
OBJECTIVE: To examine the effect of downregulation of high mobility group box 1 (HMGB1) on severe acute pancreatitis (SAP) associated with acute lung injury (ALI), and its subsequent effect on disease severity. METHODS:Wistar rats were given an IV injection of pRNA-U6.1/Neo-HMGB1, pRNA-U6.1/Neo-vector or saline before induction of SAP. Then, SAP was induced in rats by the retrograde injection of 5% sodium taurocholate into the pancreatic duct. The control group received only a sham operation. Lung and pancreas samples were harvested after induction of SAP. The protein levels of HMGB1, matrix metalloproteinase-9 (MMP-9) and intercellular adhesion molecule-1 (ICAM-1) in lung tissue were investigated. The severity of pancreatic injury was determined by a histological score of pancreatic injury, serum amylase, and pancreaticwater content. The lung injury was evaluated by measurement of pulmonary microvascular permeability, lung myeloperoxidase activity and malondialdehyde levels. RESULTS: The results found that in pRNA-U6.1/Neo-HMGB1 treated rats, serum tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels were decreased and the severity of pancreatic tissue injury was less compared with either untreated SAP or pRNA-U6.1/Neo-vector treated rats (P<0.05). The administration of pRNA-U6.1/Neo-HMGB1 in SAP-induced rats downregulated the DNA binding activity of the nuclear factor-kappa B (NF-κB) and the expressions of MMP-9 and ICAM-1 in lung. Thus, compared with the untreated SAPrats, the inflammatory response and the severity of ALI decreased (P<0.05). CONCLUSIONS: These results demonstrate that HMGB1 could augment Inflammation by inducing nuclear translocation of NF-κB, thus aggratating the severity of SAP associated with ALI.