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Objective@#To investigate the effect and underlying mechanisms of p38 mitogen-activated protein kinase inhibitor SB203580 on fetal lung injury in a rat model of acute pancreatitis in late pregnancy.@*Methods@#Twenty-four pregnant Sprague-Dawley rats in last gestation were randomly(random number) divided into the SO group, APILP group, and SB203580 treatment (SB) group. APILP model was induced by retrograde injection of 5% sodium taurocholate into the biliary-pancreatic duct. SB203580 administration (10 mg/kg body weight, intraperitoneal injection) was performed 0.5 h before surgery. All the rats in the SO and APILP groups received intraperitoneal injection of equivoluminal solvent at the same time point. Animals were sacrificed at 12 h after the induction of APILP, then the blood and tissue samples were harvested. Serum levels of AMY and TNF-α were analyzed. Histopathological changes of maternal pancreas and fetal lung were observed and evaluated. The expression and location of NF-κB in fetal lungs were detected by immunohistochemistry and MPO expression in fetal lungs was examined by immunofluorescence. The expression of p-p38MAPK, p38MAPK, TNF-α and ICAM-1 was determined by Western blot. One-way ANOVA and Tukey's multiple comparison tests were used for statistical analysis.@*Results@#The levels of AMY and TNF-α in maternal serum were markedly increased after APILP [(7 871.3±623.5) vs (1 915.3±452.3), (193.8±25.4) vs (107.0±13.3), (P<0.05)]. Obvious pathological changes presented in maternal pancreas and fetal lung after the attack of APILP, and their pathological scores were significantly higher than those of the SO group [(12.44±1.08) vs (1.56±0.56), (2.50±0.53) vs (0.88±0.64), (P<0.05)]. The number of NF-κB and MPO positive cells in fetal lungs were significantly higher than those in the SO group [(150.63±34.58) vs(29.50±8.80), (53.38±8.30) vs (11.75±3.33); P<0.05)]. In addition, the expression and nuclear translocation were pervasive in fetal lungs in the APILP group. Furthermore, the levels of p-p38MAPK [(0.6367±0.0386) vs (0.2282±0.0220)], TNF-α [(0.6313±0.0395) vs (0.0725±0.0076)], ICAM-1 [(0.8958±0.0776) vs (0.1372±0.0388)] and HMGB1 [(0.6478±0.0209) vs (0.2825±0.0533)] expression in fetal lungs were significantly increased after the establishment of APILP model (P<0.05). However, with the pre-administration of SB203580, the pathological scores of maternal pancreases (9.38±1.58) and fetal lungs (1.63±0.52) were decreased significantly (P<0.05), as well as the levels of AMY (4162.1±642.1) and TNF-α (139.6±21.1) in maternal serum (P<0.05). The number of NF-κB (93.00±18.88) and MPO (27.38±4.75) positive cells in fetal lungs were dramatically reduced (P<0.05) and fewer nuclear translocation was observed in the SB group. Interestingly, the expression levels of p-p38MAPK (0.2578±0.0170), TNF-α (0.3240±0.0326), ICAM-1 (0.4177±0.0823) and HMGB1 (0.4923±0.0457) in fetal lungs were markedly decreased with the treatment of SB203580 (P<0.05).@*Conclusions@#P38MAPK and its downstream inflammatory signaling pathway were involved in the process of APILP-related fetal lung injury; SB203580 administration could significantly attenuate fetal lung injury induced by APILP, which may be closely related to the inhibition of p38MAPK phosphorylation and inflammatory cascade caused by the activation of downstream signal pathways.
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Objective To investigate the effect and underlying mechanisms of p38 mitogenactivated protein kinase inhibitor SB203580 on fetal lung injury in a rat model of acute pancreatitis in late pregnancy.Methods Twenty-four pregnant Sprague-Dawley rats in last gestation were randomly(random number) divided into the SO group,APILP group,and SB203580 treatment (SB) group.APILP model was induced by retrograde injection of 5％ sodium taurocholate into the biliary-pancreatic duct.SB203580 administration (10 mg/kg body weight,intraperitoneal injection) was performed 0.5 h before surgery.All the rats in the SO and APILP groups received intraperitoneal injection of equivoluminal solvent at the same time point.Animals were sacrificed at 12 h after the induction of APILP,then the blood and tissue samples were harvested.Serum levels of AMY and TNF-α were analyzed.Histopathological changes of maternal pancreas and fetal lung were observed and evaluated.The expression and location of NF-κB in fetal lungs were detected by immunohistochemistry and MPO expression in fetal lungs was examined by immunofluorescence.The expression ofp-p38MAPK,p38MAPK,TNF-α and ICAM-1 was determined by Western blot.One-way ANOVA and Tukey's multiple comparison tests were used for statistical analysis.Results The levels of AMY and TNF-α in maternal serum were markedly increased after APILP [(7871.3±623.5) vs (1 915.3±452.3),(193.8±25.4) vs (107.0±±13.3),(P＜0.05)].Obvious pathological changes presented in matemal pancreas and fetal lung after the attack of APILP,and their pathological scores were significantly higher than those of the SO group [(12.44±1.08) vs (1.56±0.56),(2.50±0.53) vs (0.88±0.64),(P＜0.05)].The number of NF-κB and MPO positive cells in fetal lungs were significantly higher than those in the SO group [(150.63±34.58) vs(29.50±8.80),(53.38±8.30) vs (11.75±3.33);P＜0.05)].In addition,the expression and nuclear translocation were pervasive in fetal lungs in the APILP group.Furthermore,the levels of p-p38MAPK [(0.6367±0.0386) vs (0.2282±0.0220)],TNF-α [(0.6313±0.0395) vs (0.0725±0.0076)],ICAM-1 [(0.8958±0.0776) vs (0.1372±0.0388)] and HMGB1 [(0.6478±0.0209) vs (0.2825±0.0533)] expression in fetal lungs were significantly increased after the establishment of APILP model (P＜0.05).However,with the pre-administration of SB203580,the pathological scores of matemal pancreases (9.38±1.58) and fetal lungs (1.63±0.52) were decreased significantly (P＜0.05),as well as the levels of AMY (4162.1±642.1) and TNF-α (139.6±21.1) in maternal serum (P＜0.05).The number of NF-κB (93.00±18.88) and MPO (27.38±4.75) positive cells in fetal lungs were dramatically reduced (P＜0.05) and fewer nuclear translocation was observed in the SB group.Interestingly,the expression levels of p-p38MAPK (0.2578±0.0170),TNF-α (0.3240±0.0326),ICAM-1 (0.4177±0.0823) and HMGB1 (0.4923±0.0457) in fetal lungs were markedly decreased with the treatment of SB203580 (P＜0.05).Conclusions P38MAPK and its downstream inflammatory signaling pathway were involved in the process of APILP-related fetal lung injury;SB203580 administration could significantly attenuate fetal lung injury induced by APILP,which may be closely related to the inhibition of p38MAPK phosphorylation and inflammatory cascade caused by the activation of downstream signal pathways.
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Objective To investigate the protective effects and mechanisms of intraperitoneal administration of thymosin β4 on severe acute pancreatitis in rats.Methods Fifty-four male Sprague-Dawley rats were randomly (random number) divided into sham operation (SO) group,severe acute pancreatitis (SAP) group and thymosin β4 (Tβ4) pretreatment group (n =18 in each group).SAP rat model was prepared by retrograde injection of 5％ sodium taurocholate into the biliopancreatic duct.Rats in Tβ4 group were treated with thymosin β4 (6 mg/kg) by intraperitoneal administration prior to SAP modeling.Six rats in each group were sacrificed at 3,6,12 hours,respectively after modeling.The serum levels of amylase,tumor necrosis factor-α (TNF-α),interleukin-1 β (IL-1 β),and interleukin-6 (IL-6)were detected,and pathological scores of the tissue of pancreas head were evaluated under light microscope.Pancreatic nuclear factor-kappa 1B (NF-κB) p65 and IκB α levels were detected by the Western blot.All data were analyzed by using the analysis of variauce or t test.Results The levels of serum amylase of SAP 3,6 and 12 hours groups were (3221 ±394) U/L,(4509 ±474) U/L and (6280 ±728) U/L,which were significantly higher than (2598±416) U/L,(3639 ±373) U/L and (4782 ±466) U/L of the Tβ4 groups (t =-2.666,-3.530,-4.245,P ＜ 0.05).The levels of serum TNF-α of the SAP 3,6 and 12 hours groups were (247.7 ± 18.5) pg/mL,(313.5 ± 17.7) pg/mL and (359.3 ±22.6) pg/mL,which were higher than (182.3 ± 13.6) pg/mL,(258.9 ± 14.9) pg/mL and (278.1 ± 16.3) pg/mL of the Tβ4 groups (t =-6.964,-5.769,-7.152,P ＜ 0.05).The levels of serum IL-1 β of the SAP 3,6 and 12 hours groups were (258.2±10.5) pg/mL,(345.1 ±22.0) pg/mL and (430.9 ±25.4) pg/mL,which were higher than (170.3 ± 12.4) pg/mL,(263.5 ± 13.3) pg/mL and (303.7 ± 16.1) pg/mL of the Tβ4 groups (t =-13.258,-7.762,-10.355,P ＜ 0.05).The levels of serum IL-6 of SAP 3,6 and 12 hours groups were (266.3 ±11.5) pg/mL,(355.0 ±24.4) pg/mL and (429.2 ±33.7) pg/ mL,which were higher than (171.1 ± 13.0) pg/mL,(234.9 ± 19.2) pg/mL and (277.2 ± 19.2) pg/ mL of the Tβ4 groups (t =-13.401,-9.474,-9.582,P ＜ 0.05).The pancreatic pathological scores of the SAP3,6 and 12 hours groups were (6.25 ±0.94),(8.83 ±0.82) and (12.08 ±1.16),which were higher than (4.17 ± 0.93),(6.33 ± 0.82) and (7.33 ± 1.25) of the Tβ4 groups (t =-3.867,-5.303,-6.823,P ＜ 0.05).The relative expression of pancreatic NF-κB p65 in SO group was (0.95 ±0.11),which was significantly lower than (2.40 ±0.17) of the SAP 12 hours group (t =-17.368,P＜ 0.05).The relative expression of pancreatic NF-κB p65 in Tβ4 group was 1.50 ± 0.10,which was significantly lower than SAP 12 hours group (t =10.917,P ＜0.05).The relative expression of pancreatic IκB α in SO group was (1.93 ±0.11),which was significantly higher than (0.78 ±0.18) of the SAP 12 hours group (t =13.260,P ＜ 0.05).The relative expression of pancreatic IκB α in Tβ4 group was (1.12±0.10),which was significantly higher than SAP 12 hours group (t =-4.112,P ＜ 0.05).Conclusions Thymosin β4 has the protective effect on SAP rat model,and the mechanism may be associated with inhibition of NF-κB signaling pathway and decreased proinflammatory cytokines.
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Objective To explore the effects of rosiglitazone (ROSI),a PPAR-γ ligand,on hyperlipidemia with severe acute pancreatitis (SAP) in the rat model induced by sodium taurocholate injected into intra-bile-pancreatic duct and explore their underlying mechanism.Methods A total of 120 male SD rats were randomly divided into two groups,and eighty rats were fed with high fat diet for two weeks to induce experimental hyperlipemia and the rest received normal diet.The rats fed with normal diet were divided into two groups:sham operation group (SO group,n =20) and SAP group (n =20).The hyperlipidemic rats were randomly divided into four groups:sham operation hyperlipidemia rats group (HL group,n =20),hyperlipidemia with acute pancreatitis group (HAP group,n =20),ROSI prevention group (HR group,n =20) and antagonist group (HRI group,n =20).Rats of SAP group and HAP group were induced by a retrograde infusion of 5％ sodium tauroholate into bile-pancreatic duct,whereas the rats in SO group and HL group were induced by saline instead; rats in HR group were administered ROSI (10 mg/kg) intra-peritoneally 1 hour prior to sodium taurocholate; rats in HRI group were administered GW9662 (0.3 mg/kg) intraperitoneally 30 min prior to ROSI.Rats from each group were sacrificed by exsanguination 12 h after the induction of pancreatitis.Blood samples were taken from all animals to measure serum amylase (AMY),total cholesterol (TC),triglycerides (TG).The severity of pancreatitis was evaluated by histological score of pancreatic injury.The level of nuclear factor (NF)-KB p65 protein in pancreas was measured by immunohistochemistry.The levels of intercellular adhesion molecule (ICAM-1) protein and tumor necrosisfactor-α (TNF-α) protein were detected by using Western blot analysis.Results The serum levels of TC and TG in HL group and HAP group were significantly higher than those in SO group and SAP group (10.86 ± 1.47,10.42±0.95vs.1.72±0.13; 1.24±0.28,1.36±0.13 vs.0.61 ±0.12,0.54±0.08; all P＜ O.05).Compared with SAP group,the levels of serum AMY,the pancreas pathological score,the levels of NF-KB p65,ICAM-1 and TNF-α in pancreas in the HAP group were significantly higher in HAP group (P ＜ 0.05).Compared with the HAP group and HRI group,HR group significantly decreased the levels of serum AMY,TC and TG; pancreas pathological score; the levels of NF-KB p65,ICAM-1 and TNF-α in pancreas significantly decreased in HR group (2006.9 ± 331.9 vs.6501.9 ± 3771.0,5892.2 ± 474.3 ; 4.36 ± 0.99 vs.10.42 ±0.95,11.08 ± 1.05; 0.58 ±0.12 vs.1.36 ±0.13,1.58 ±0.12; all P ＜0.05),but there were no statistically significant differences in those biomarkers between HAP group and HRI (P ＞ 0.05).Conclusions Our study demonstrated that hyperlipidemia aggravated the severity of sodium taurocholateinduced severe acute pancreatitis and ROSI exerted anti-hyperlipidemic effect and anti-inflanmatory effect against hyperlipidemia rats with sodium taurocholate-induced severe acute pancreatitis.