Alleviation of acute pancreatitis-associated lung injury by inhibiting the p38 mitogen-activated protein kinase pathway in pulmonary microvascular endothelial cells.

BACKGROUND: Previous reports have suggested that the p38 mitogen-activated protein kinase signaling pathway is involved in the development of severe acute pancreatitis (SAP)-related acute lung injury (ALI). Inhibition of p38 by SB203580 blocked the inflammatory responses in SAP-ALI. However, the precise mechanism associated with p38 is unclear, particularly in pulmonary microvascular endothelial cell (PMVEC) injury. AIM: To determine its role in the tumor necrosis factor-alpha (TNF-α)-induced inflammation and apoptosis of PMVECs in vitro. We then conducted in vivo experiments to confirm the effect of SB203580-mediated p38 inhibition on SAP-ALI. METHODS: In vitro, PMVEC were transfected with mitogen-activated protein kinase kinase 6 (Glu), which constitutively activates p38, and then stimulated with TNF-α. Flow cytometry and western blotting were performed to detect the cell apoptosis and inflammatory cytokine levels, respectively. In vivo, SAP-ALI was induced by 5% sodium taurocholate and three different doses of SB203580 (2.5, 5.0 or 10.0 mg/kg) were intraperitoneally injected prior to SAP induction. SAP-ALI was assessed by performing pulmonary histopathology assays, measuring myeloperoxidase activity, conducting arterial blood gas analyses and measuring TNF-α, interleukin (IL)-1ß and IL-6 levels. Lung microvascular permeability was measured by determining bronchoalveolar lavage fluid protein concentration, Evans blue extravasation and ultrastructural changes in PMVECs. The apoptotic death of pulmonary cells was confirmed by performing a terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling analysis and examining the Bcl2, Bax, Bim and cle-caspase3 levels. The proteins levels of P-p38, NFκB, IκB, P-signal transducer and activator of transcription-3, nuclear factor erythroid 2-related factor 2, HO-1 and Myd88 were detected in the lungs to further evaluate the potential mechanism underlying the protective effect of SB203580. RESULTS: In vitro, mitogen-activated protein kinase (Glu) transfection resulted in higher apoptotic rates and cytokine (IL-1ß and IL-6) levels in TNF-α-treated PMVECs. In vivo, SB2035080 attenuated lung histopathological injury, decreased inflammatory activity (TNF-α, IL-1ß, IL-6 and myeloperoxidase) and preserved pulmonary function. Furthermore, SB203580 significantly reversed changes in the bronchoalveolar lavage fluid protein concentration, Evans blue accumulation, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cell numbers, apoptosis-related proteins (cle-caspase3, Bim and Bax) and endothelial microstructure. Moreover, SB203580 significantly reduced the pulmonary P-p38, NFκB, P-signal transducer and activator of transcription-3 and Myd88 levels but increased the IκB and HO-1 levels. CONCLUSION: p38 inhibition may protect against SAP-ALI by alleviating inflammation and the apoptotic death of PMVECs.

[Protective Effect of a Dihydroflavonol Glycoside from Coreopsis tinctoria Nutt. in Mouse Model of Alcoholic Acute Pancreatitis].

OBJECTIVE: To investigate the protective effect of (2R, 3R)-dihydroquercetin 7-O-ß-D-glucopyranose (C1) extracted from Coreopsis tinctoria Nutt. in a mouse model of alcoholic acute pancreatitis (FAEE-AP) induced byfatty acid ethyl ester (FAEE). METHODS: The 30 healthy SPF mice were randomly divided into control group, model group, low dose group, middle dose group and high dose group, 6 in each group. Alcoholic pancreatitis was induced by ethanol and palmitoleic acid administration (1.75 g/kg ethanol, 200 mg/kg palmitoleic acid, 2 times peritoneal injections). The three treatment groups were given C1 (0 h, 4 h, 8 h) at the dose of 12.5, 25 and 50 mg/kg, respectively. After 24 h of molding, the serum amylase, lipase and IL-6 levels were detected. The trypsin level in pancreatic tissue and myeloperoxidase (MPO) level in pancreatic and lung tissue were detected. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of pancreatic tissue and immunohistochemical (IHC) staining was used to detect the expression of nuclear factor-erythroid 2 related factor 2 (Nrf2) in pancreatic tissue. RESULTS: The pancreatic histopathological scores, serum amylase and lipase activity, trypsin level in pancreatic tissue, serum IL-6 level, MPO level of pancreas and lung were significantly higher in the model group than in the control group (P < 0.01). Compared with the model group, the pancreatic histopathologies of the low dose group was significantly improved (P < 0.05), as well as the serum amylase and lipase activity, trypsin level of pancreas, serum IL-6 level, the pancreas andthe lung's MPO level decreased significantly (P < 0.05), and up-regulate that expression of Nrf2 in pancreatic tissue. CONCLUSION: 12.5 mg/kg of (2R, 3R) -dihydroquercetin 7-O-ß-D-glucopyranose (C1) improved the expression of Nrf2, reduced the expression of inflammatory factor IL-6, and protected acute pancreatitis caused by FAEE.

Genome-Wide Identification and Functional Analysis of NADPH Oxidase Family Genes in Wheat During Development and Environmental Stress Responses.

As the key producers of reactive oxygen species (ROS), NADPH oxidases (NOXs), also known as respiratory burst oxidase homologs (RBOHs), play crucial roles in various biological processes in plants with considerable evolutionary selection and functional diversity in the entire terrestrial plant kingdom. However, only limited resources are available on the phylogenesis and functions of this gene family in wheat. Here, a total of 46 NOX family genes were identified in the wheat genome, and these NOXs could be classified into three subgroups: typical TaNOXs, TaNOX-likes, and ferric reduction oxidases (TaFROs). Phylogenetic analysis indicated that the typical TaNOXs might originate from TaFROs during evolution, and the TaFROs located on Chr 2 might be the most ancient forms of TaNOXs. TaNOXs are highly expressed in wheat with distinct tissue or organ-specificity and stress-inducible diversity. A large-scale expression and/or coexpression analysis demonstrated that TaNOXs can be divided into four functional groups with different expression patterns under a broad range of environmental stresses. Different TaNOXs are coexpressed with different sets of other genes, which widely participate in several important intracellular processes such as cell wall biosynthesis, defence response, and signal transduction, suggesting their vital but diversity of roles in plant growth regulation and stress responses of wheat.