Impact of interleukin 6 levels on acute lung injury risk and disease severity in critically ill sepsis patients

BACKGROUND Sepsis is a life-threatening condition characterized by a dysregulation of the host response to infection that can lead to acute lung injury(ALI)and multiple organ dysfunction syndrome(MODS).Interleukin 6(IL-6)is a pro-inflammatory cytokine that plays a crucial role in the pathogenesis of sepsis and its complications.AIM To investigate the relationship among plasma IL-6 levels,risk of ALI,and disease severity in critically ill patients with sepsis.METHODS This prospective and observational study was conducted in the intensive care unit of a tertiary care hospital between January 2021 and December 2022.A total of 83 septic patients were enrolled.Plasma IL-6 levels were measured upon admission using an enzyme-linked immunosorbent assay.The development of ALI and MODS was monitored during hospitalization.Disease severity was evaluated by Acute Physiology and Chronic Health Evaluation II(APACHE II)and Sequential Organ Failure Assessment(SOFA)scores.RESULTS Among the 83 patients with sepsis,38(45.8%)developed ALI and 29(34.9%)developed MODS.Plasma IL-6 levels were significantly higher in patients who developed ALI than in those without ALI(median:125.6 pg/mL vs 48.3 pg/mL;P<0.001).Similarly,patients with MODS had higher IL-6 levels than those without MODS(median:142.9 pg/mL vs 58.7 pg/mL;P<0.001).Plasma IL-6 levels were strongly and positively correlated with APACHE II(r=0.72;P<0.001)and SOFA scores(r=0.68;P<0.001).CONCLUSIONElevated plasma IL-6 levels in critically ill patients with sepsis were associated with an increased risk of ALI andMODS.Higher IL-6 levels were correlated with greater disease severity,as reflected by higher APACHE II andSOFA scores.These findings suggest that IL-6 may serve as a biomarker for predicting the development of ALI anddisease severity in patients with sepsis.

Circulating miRNAs as biomarkers for severe acute pancreatitis associated with acute lung injury

AIM To identify circulating micro(mi)RNAs as biological markers for prediction of severe acute pancreatitis(SAP) with acute lung injury(ALI).METHODS Twenty-four serum samples were respectively collected and classified as SAP associated with ALI and SAP without ALI, and the mi RNA expression profiles were determined by microarray analysis. These mi RNAs were validated by quantitative reverse transcriptionpolymerase chain reaction, and their putative targets were predicted by the online software Target Scan, mi Randa and Pic Tar database. Gene ontology(GO) and Kyoto encyclopedia of genes and genomes(commonly known as KEGG) were used to predict their possible functions and pathways involved.RESULTS We investigated 287 mi RNAs based on microarray data analysis. Twelve mi RNAs were differentially expressed in the patients with SAP with ALI and those with SAP without ALI. Hsa-mi R-1260 b, 762, 22-3 p, 23 b and 23 a were differently up-regulated and hsa-mi R-550 a*, 324-5 p, 484, 331-3 p, 140-3 p, 342-3 p and 150 were differently down-regulated in patients with SAP with ALI compared to those with SAP without ALI. In addition, 85 putative target genes of the significantly dysregulated mi RNAs were found by Target Scan, mi Randa and Pic Tar. Finally, GO and pathway network analysis showed that they were mainly enriched in signal transduction, metabolic processes, cytoplasm and cell membranes.CONCLUSION This is the first study to identify 12 circulating mi RNAs in patients with SAP with ALI, which may be biomarkers for prediction of ALI after SAP.

Interleukin-22 ameliorates acute severe pancreatitisassociated lung injury in mice

AIM: To investigate the potential protective effect of exogenous recombinant interleukin-22(r IL-22) on L-arginine-induced acute severe pancreatitis(SAP)-associated lung injury and the possible signaling pathway involved.METHODS: Balb/c mice were injected intraperitoneally with L-arginine to induce SAP. Recombinant mouse IL-22 was then administered subcutaneously to mice. Serum amylase levels and myeloperoxidase(MPO) activity in the lung tissue were measured after the L-arginine administration. Histopathology of the pancreas and lung was evaluated by hematoxylin and eosin(HE) staining. Expression of B cell lymphoma/leukemia-2(Bcl-2), Bcl-x L and IL-22RA1 m RNAs in the lung tissue was detected by real-time PCR. Expression and phosphorylation of STAT3 were analyzed by Western blot. RESULTS: Serum amylase levels and MPO activity in the lung tissue in the SAP group were significantly higher than those in the normal control group(P < 0.05). In addition, the animals in the SAP group showed significant pancreatic and lung injuries. The expression of Bcl-2 and Bcl-x L m RNAs in the SAP group was decreased markedly, while the IL-22RA1 m RNA expression was increased significantly relative to the normal control group(P < 0.05). Pretreatment with PBS did not significantly affect the serum amylase levels, MPO activity or expression of Bcl-2, Bcl-x L or IL-22RA1 m RNA(P > 0.05). Moreover, no significant differences in the degrees of pancreatic and lung injuries were observed between the PBS and SAP groups. However, the serum amylase levels and lung tissue MPO activity in the r IL-22 group were significantly lower than those in the SAP group(P < 0.05), and the injuries in the pancreas and lung were also improved. Compared with the PBS group, r IL-22 stimulated the expression of Bcl-2, Bcl-x L and IL-22RA1 m RNAs in the lung(P < 0.05). In addition, the ratio of p-STAT3 to STAT3 protein in the r IL-22 group was significantly higher than that in the PBS group(P < 0.05).CONCLUSION: Exogenous recombinant IL-22 protects mice against L-arginine-induced SAP-associated lung injury by enhancing the expression of anti-apoptosis genes through the STAT3 signaling pathway.

Proteasome inhibitor ameliorates severe acute pancreatitis and associated lung injury of rats

AIM: To observe the effect of proteasome inhibitor MG-132 on severe acute pancreatitis (SAP) and associated lung injury of rats. METHODS: Male adult SD rats were randomly divided into SAP group, sham-operation group, and MG-132 treatment group. A model of SAP was established by injection of 5% sodium taurocholate into the biliary- pancreatic duct of rats. The MG-132 group was pretreated with 10 mg/kg MG-132 intraperitoneally (ip) 30 min before the induction of pancreatitis. The changes in serum amylase, myeloperoxidase (MPO) activity of pancreatic and pulmonary tissue were measured. The TNF-α level in pancreatic cytosolic fractions was assayed with an enzyme-linked immunosorbent assay (ELISA) kit. Meanwhile, the pathological changes in both pancreatic and pulmonary tissues were also observed. RESULTS: MG-132 significantly decreased serum amylase, pancreatic weight/body ratio, pancreatic TNF-α level, pancreatic and pulmonary MPO activity (P < 0.05). Histopathological examinations revealed that pancreatic and pulmonary samples from rats pretreated with MG-132 demonstrated milder edema, cellular damage, and inflammatory activity (P < 0.05). CONCLUSION: The proteasome inhibitor MG-132 shows a protective effect on severe acute pancreatitis and associated lung injury of rats.

Risk factors and their interactive effects on severe acute pancreatitis complicated with acute gastrointestinal injury

BACKGROUND There are many risk factors for severe acute pancreatitis(SAP)complicated with acute gastrointestinal injury(AGI),but few reports on the interaction between these risk factors.AIM To analyze the risk factors for SAP complicated with AGI and their interactive effects.METHODS We selected 168 SAP patients admitted to our hospital between December 2019 and June 2022.They were divided into AGI group and non-AGI group according to whether AGI was present.Demographic data and laboratory test data were compared between the two groups.The risk factors for SAP with concomitant AGI were analyzed using multifactorial logistic regression,and an analysis of the interaction of the risk factors was performed.RESULTS The percentage of patients with multiple organ dysfunction syndrome,acute physiological and chronic health scoring system II(APACHE II)score,white blood cell count and creatinine(CRE)level was higher in the AGI group than in the non-AGI group.There was a statistically significant difference between the two groups(P<0.05).Logistic regression analysis indicated that an APACHE II score>15 and CRE>100μmol/L were risk factors for SAP complicating AGI.The interaction index of APACHE II score and CRE level was 3.123.CONCLUSION An APACHE II score>15 and CRE level>100μmol/L are independent risk factors for SAP complicated with AGI,and there is a positive interaction between them.

Calycosin attenuates severe acute pancreatitis-associated acute lung injury by curtailing high mobility group box 1-induced inflammation

BACKGROUND Acute lung injury(ALI)is a common and life-threatening complication of severe acute pancreatitis(SAP).There are currently limited effective treatment options for SAP and associated ALI.Calycosin(Cal),a bioactive constituent extracted from the medicinal herb Radix Astragali exhibits potent anti-inflammatory properties,but its effect on SAP and associated ALI has yet to be determined.AIM To identify the roles of Cal in SAP-ALI and the underlying mechanism.METHODS SAP was induced via two intraperitoneal injections of L-arg(4 g/kg)and Cal(25 or 50 mg/kg)were injected 1 h prior to the first L-arg challenge.Mice were sacrificed 72 h after the induction of SAP and associated ALI was examined histologically and biochemically.An in vitro model of lipopolysaccharide(LPS)-induced ALI was established using A549 cells.Immunofluorescence analysis and western blot were evaluated in cells.Molecular docking analyses were conducted to examine the interaction of Cal with HMGB1.RESULTS Cal treatment substantially reduced the serum amylase levels and alleviated histopathological injury associated with SAP and ALI.Neutrophil infiltration and lung tissue levels of neutrophil mediator myeloperoxidase were reduced in line with protective effects of Cal against ALI in SAP.Cal treatment also attenuated the serum levels and mRNA expression of pro-inflammatory cytokines tumor necrosis factor-α,interleukin-6,IL-1β,HMGB1 and chemokine(CXC motif)ligand 1 in lung tissue.Immunofluorescence and western blot analyses showed that Cal treatment markedly suppressed the expression of HMGB1 and phosphorylated nuclear factor-kappa B(NF-κB)p65 in lung tissues and an in vitro model of LPSinduced ALI in A549 cells suggesting a role for HGMB1 in the pathogenesis of ALI.Furthermore,molecular docking analysis provided evidence for the direct interaction of Cal with HGMB1.CONCLUSION Cal protects mice against L-arg-induced SAP and associated ALI by attenuating local and systemic neutrophil infiltration and inflammatory response via inhibition of HGMB1 and the NF-κB signaling pathway.

Expression of phosphatidylinositol-3 kinase and effects of inhibitor Wortmannin on expression of tumor necrosis factor-α in severe acute pancreatitis associated with acute lung injury

BACKGROUND: Acute lung injury(ALI) is a common and serious complication of severe acute pancreatitis(SAP). The study aimed to investigate the protective effect and mechanism of phosphatidylinositol-3 kinase(PI3K) inhibitor Wortmannin in SAP associated with ALI.METHODS: Ninety rats were randomly divided into three groups: sham operation(SO) group(n=30), SAP group(n=30), and SAP+Wortmannin(SAP+W) group(n=30). SAP model was induced by retrograde injection of 4% sodium taurocholate into the biliopancreatic duct of rats. The rate of lung water content, myeloperoxidase(MPO), matrix metalloproteinase 9(MMP-9), protein kinase B(PKB), abdphosphorylation of protein kinase B(P-PKB) activity in the lung tissue were evaluated.RESULTS: In the SAP group, the p-PKB expression in the lung tissue began to rise at 3 hours after modeling, and peaked at 12 hours(P<0.05); the rate of lung water content, MPO and TNF-α activity were also gradually increased, and the degree of lung lesion gradually increased(P<0.05). In the SAP+Wortmannin group, the p-PKB expression in the lung tissue began to rise at 3 hours after modeling, and peaked at 12 hours; it was higher than that in the SO group(P<0.05), but significantly lower than that in the SAP group(P<0.05). The rest indicators in the SAP+Wortmannin group were also significantly decreased as compared with the SAP group(P<0.05).CONCLUSIONS: The expression of phosphatidylinositol-3 kinase/protein kinase B was elevated in severe pancreatitis rats with lung injury. This suggested that PI3 K signal transduction pathway is involved in the control and release of proinfl ammatory cytokines TNF-α, which may play an important role in the pathogenesis of severe acute pancreatitis associated with lung injury. This finding indicated that Wortmannin can block the PI3 K signal transduction pathway, and inhibit the release of infl ammatory factor TNF-α.

Therapeutic effects of Caspase-1 inhibitors on acute lung injury in experimental severe acute pancreatitis

AIM： To assess the therapeutic effect of Caspase-1 inhibitors （ICE-I） on acute lung injury （ALI） in experimental severe acute pancreatitis （SAP）. METHODS： Forty-two SD rats were randomly divided into 3 groups： healthy controls （HC, n = 6）; SAP-S group （n = 18）; SAP-ICE-i group （n = 18）. SAP was induced by retrograde infusion of 5% sodium taurocholate into the bile-pancreatic duct. HC rats underwent the same surgical procedures and duct cannulation without sodium taurocholate infusion, in SAP-S group, rats received the first intraperitoneal injection of isotonic saline 2 h after induction of acute pancreatitis and a repeated injection after 12 h. In SAP-ICE-I group, the rats were firstly given ICE inhibitors intraperitoneally 2 h after induction of pancreatitis. As in SAP-S group, the injection was repeated at 12 h. Serum 1L-1β was measured by EUSA. Intrapulmonary expression of Caspase-1, IL-1β and IL-18 mRNA were detected by semi-quantitative RT-PCR. The wet/dry weight ratios and histopathological changes of the lungs were also evaluated. RESULTS： Serum IL-1β levels in SAP-S group were 276.77 ± 44.92 pg/mL at 6 h, 308.99 ± 34.95 pg/mL at 12 h, and 311.60 ± 46.51 pg/mL at 18 h, which were increased significantly （P 〈 0.01, vs HC）. in SAP- ICE-I group, those values were decreased significantly （P 〈 0.01, vs SAP-S）. intrapulmonary expression of Caspase-1, IL-1β and IL-18 mRNA were observed in the HC group, while they were increased significantly in the SAP-S group （P 〈 0.01, vs HC）. The expression of IL-lβ and IL-18 mRNA were decreased significantly in the SAP- ICE-I group （P 〈 0.01, vs SAP-S）, whereas Caspase-1 mRNA expression had no significant difference （P 〉 0.05）. The wet/dry weight ratios of the lungs in the SAP-S group were increased significantly （P 〈 0.05 at 6 h, P 〈 0.01 at 12 h and 18 h, vs HC） and they were decreased significantly in the SAP-ICE-I group （P 〈 0.05, vs SAP-S）.Caspase-1 inhibitors ameliorated the severity of ALl in SAP.CONCLUSION： Caspase-1 activation, and overproduction of IL-1β and IL-18 play an important role in the course of ALI, and Caspase-1 inhibition is effective for the treatment of ALI in experimental SAP.

Effect of resveratrol on microcirculation disorder and lung injury following severe acute pancreatitis in rats

AIM: To investigate the mechanism of resveratrol underlying the microcirculation disorder and lung injury following severe acute pancreatitis (SAP). METHODS: Twenty-four rats were divided into 3 groups (SAP, sham and resveratrol groups) randomly. SAP model was established by injecting 4% sodium taurocholate l mL/kg through puncturing pancreatic ducts. Sham (control) group (8 rats) was established by turning over the duodenum. Resveratrol was given at 0.1 mg/kg b.m. intraperitoneally. Rats were sacrificed 9 h after SAP was induced. Blood samples were obtained for hemorrheological examination. Lung tissues were used for pathological observation, and examination of microvascular permeability, dry/wet ratio and myeloperoxidase (MPO) activity. Gene expression of intercellular adhesion molecule-1 (ICAM-1) was detected by RT-PCR. RESULTS: Compared with SAP group, resveratrol relieved the edema and infiltration of leukocytes in the lungs. Resveratrol improved markers of hemorrheology: high VTB (5.77±1.18 mPas vs9.49±1.34 mPas), low VTB (16.12±3.20 mPas vs30.91±7.28 mPas), PV (4.69±1.68 mPas vs 8.00±1.34 mPas), BSR (1.25±0.42 mm/h vs50.03±0.03 mm/h), VPC (54.67±3.08% vs 62.17±3.39%), fibrinogen (203.2?7.8 g/ L vs 51.3±19.1 g/L), original hemolysis (0.45±0.02 vs 0.49±0.02), and complete hemolysis (0.41±0.02 vs 0.43±0.02) (P<0.05). Resveratrol decreased the OD ratio of ICAM-1 gene (0.800±0.03 vs 1.188±0.10), dry/wet ratio (0.74±0.02 vs 0.77±0.03), microvascular permeability (0.079±0.006 vs 0.112±0.004) and MPO activity (4.42±0.32 vs 5.03±0.51) significantly (P<0.05). CONCLUSION: Resveratrol can improve the microcirculation disorder of the lung by decreasing leukocyte-endothelial interaction, reducing blood viscosity, improving the decrease of blood flow, and stabilizing erythrocytes in SAP rats. It may be a potential candidate to treat SAP and its severe complications (ALI).

Pathogenesis of acute lung injury in rats with severe acute pancreatitis

BACKGROUND: Acute lung injury (ALI) is the most common and severe complication of severe acute pancreatitis (SAP). The elucidation of the mechanism of ALI contributes to the diagnosis and treatment of the illness. In this study, we studied the pathogenesis of ALI in rats with severe acute pancreatitis. METHODS: The rats were sacrificed at 1, 3, 5, 6, 9 and 12 hours after the establishment of the model of SAP. Pancreas and lung tissues were obtained for pathological study, and examination of microvascular permeability and myeloperoxidase (MPO) examination. The gene expressions of tumor necrosis factor-α (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) in the pancreas and lung tissues were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: After the establishment of the SAP model, the degree of pancreatic and lung injury increased gradually along with the gradual increase of MPO activity and micro-vascular permeability. Gene expressions of TNF-α and ICAM-1 in the pancreas rose at 1 hour and peaked at 7 hours. In contrast, their gene expression in the lungs rose slightly at 1 hour and peaked at 9-12 hours. CONCLUSION: An obvious time window existed between SAP and lung injury, which is beneficial to the early prevention of the development of ALI.

Melatonin attenuates acute pancreatitis-associated lung injury in rats by modulating interleukin 22

AIM： To investigate whether therapeutic treatment with melatonin could protect rats against acute pan- creatitis and its associated lung injury. METHODS： Seventy-two male Sprague-Dawley rats were randomly divided into three groups： the sham op- eration （SO）, severe acute pancreatitis （SAP）, and mel- atonin treatment （MT） groups. Acute pancreatitis was induced by infusion of 1 mL/kg of sodium taurocholate （4% solution） into the biliopancreatic duct. Melatonin （50 mg/kg） was administered 30 min before pancre- atitis was induced, and the severity of pancreatic and pulmonary injuries was evaluated 1, 4 and 8 h after induction. Serum samples were collected to measure amylase activities, and lung tissues were removed to measure levels of mRNAs encoding interleukin 22 （IL-22） and T helper cell 22 （Th22）, as well as levels of IL-22.ing IL-22 and Th22 were significantly higher （P 〈 0.001） in the MT group than in the SAP group （0.526 ± 0.143 vs 0.156 ± 0.027, respectively, here and throughout, after 1 h; 0.489 ± 0.150 vs 0.113 ± 0.014 after 4 h; 0.524 ± 0.168 vs 0.069 ± 0.013 after 8 h, 0.378 ± 0.134 vs 0.122 ± 0.015 after 1 h; 0.205 ± 0.041 vs 0.076 ± 0.019 after 4 h; 0.302 ± 0.108 vs 0.045 ± 0.013 after 8 h, respectively） and significantly lower （P 〈 0.001） in the SAP group than in the SO group （0.156 ± 0.027 vs 1.000 ± 0.010 after 1 h; 0.113 ± 0.014 vs 1.041 ± 0.235 after 4 h; 0.069 ± 0.013 vs 1.110 ± 0.213 after 8 h, 0.122 ± 0.015 vs 1.000 ± 0.188 after 1 h; 0.076 ± 0.019 vs 0.899 ± 0.125 after 4 h; 0.045 ± 0.013 vs 0.991 ± 0.222 after 8 h, respectively）. The mean pathologi- cal scores for pancreatic tissues in the MT group were significantly higher （P 〈 0.01） than those for samples in the SO group （1.088 ± 0.187 vs 0.488 ± 0.183 after 1 h, 2.450 ± 0.212 vs 0.469 ± 0.242 after 4 h; 4.994 ± 0.184 vs 0.513 ± 0.210 after 8 h）, but were significantly lower （P 〈 0.01） than those for samples in the SAP group at each time point （1.088 ± 0.187 vs 1.969 ± 0.290 after 1 h; 2.450 ± 0.212 vs 3.344 ± 0.386 after 4 h; 4.994 ± 0.184 vs 6.981 ± 0.301 after 8 h）. The severity of SAP increased significantly （P 〈 0.01） over time in the SAP group （1.088 ± 0.187 vs 2.450 ± 0.212 between 1 h and 4 h after inducing pancreatitis; and 2.450 ± 0.212 vs 4.994 ± 0.184 between 4 and 8 h after inducing pan- creatitis）. CONCLUSION： Melatonin protects rats against acute pancreatitis-associated lung injury, probably through the upregulation of IL-22 and Th22, which increases the innate immunity of tissue cells and enhances their regeneration.

Microcirculation disturbance affects rats with acute severe pancreatitis following lung injury

AIM: To study the effects of microcirculation disturbance(MD) on rats with acute severe pancreatitis (ASP).METHODS: We developed ASP rat models, and anatomized separately after 1, 3, 5, 7, and 9 h. We took out blood and did hemorrheologic examination and erythrocyte osmotic fragility test, checked up the water content, capillary permeability, and genetic expression of intercellular adhesion molecule-1 (ICAM-1) in lung tissues, examined the apoptosis degree of blood vessel endothelium while we tested related gene expression of Bax and Bcl-2in lung tissues. We did the same examination in control group.RESULTS: The viscosity of total blood and plasma, the hematocrit, and the erythrocyte osmotic fragility were all increased. Fibrinogen was decreased. The water content in lung tissues and capillary permeability were increased.Apoptosis degree of blood vessel endothelium was increased too. ICAM-1 genetic expression moved up after1 h and reached its peak value after 9 h.CONCLUSION: MD plays an important role in ASP following acute lung injury (ALI). The functional damage of blood vessel endothelium, the apoptosis of capillary vessel endothelium, WBC edging-concentration and the increasing of erythrocyte fragility are the main reasons of ALI.

C/EBP homologous protein deficiency aggravates acute pancreatitis and associated lung injury

AIM:To investigate the pathophysiological role of C/EBP homologous protein(CHOP)in severe acute pancreatitis and associated lung injury.METHODS:A severe acute pancreatitis model was induced with 6 injections of cerulein(Cn,50μg/kg)at 1-h intervals,then intraperitoneal injection of lipopolysaccharide(LPS,7.5 mg/kg)in CHOP-deficient(Chop-/-)mice and wild-type(WT)mice.Animals were sacrificed under anesthesia,3 h or 18 h after LPS injection.Serum amylase,lipase,and cytokines[interleukin(IL)-6 and tumor necrosis factor(TNF)-α],pathological changes,acute lung injury,and apoptosis in the pancreas were evaluated.Serum amylase and lipase activities were detected using a medical automatic chemical analyzer.Enzyme-linked immunosorbent assay kits were used to evaluate TNF-αand IL-6 levels in mouse serum and lung tissue homogenates.Apoptotic cells in sections of pancreatic tissues were determined by terminal deoxynucleotidyl transferase-mediated dUTPbiotin nick-end labeling(TUNEL)analysis.The mouse carotid arteries were cannulated and arterial blood samples were collected for PaO2analysis.The oxygenation index was expressed as PaO2/FiO2.RESULTS:Administration of Cn and LPS for 9 and 24 h induced severe acute pancreatitis in Chop-/-and WT mice.When comparing Chop-/-mice and WT mice,we observed that CHOP-deficient mice had greater increases in serum TNF-α(214.40±19.52 pg/mL vs 150.40±16.70 pg/mL;P=0.037),amylase(4236.40±646.32U/L vs 2535.30±81.83 U/L;P=0.041),lipase(1678.20±170.57 U/L vs 1046.21±35.37 U/L;P=0.008),and IL-6(2054.44±293.81 pg/mL vs 1316.10±108.74pg/mL;P=0.046)than WT mice.The histopathological changes in the pancreases and lungs,decreased PaO2/FiO2ratio,and increased TNF-αand IL-6 levels in the lungs were greater in Chop-/-mice than in WT mice(pancreas:Chop-/-vs WT mice,hemorrhage,P=0.005;edema,P=0.005;inflammatory cells infiltration,P=0.005;total scores,P=0.006;lung:hemorrhage,P=0.017;edema,P=0.017;congestion,P=0.017;neutrophil infiltration,P=0.005,total scores,P=0.001;PaO2/FiO2ratio:393±17.65 vs 453.8,P=0.041;TNF-α:P=0.043;IL-6,P=0.040).Results from TUNEL analysis indicated increased acinar cell apoptosis in mice following the induction of acute pancreatitis.However,Chop-/-mice displayed significantly reduced pancreatic apoptosis compared with the WT mice(201.50±31.43vs 367.00±47.88,P=0.016).CONCLUSION:These results suggest that CHOP can exert protective effects against acute pancreatitis and limit the spread of inflammatory damage to the lungs.

Effects of Yue-Bi-Tang on water metabolism in severe acute pancreatitis rats with acute lung-kidney injury

BACKGROUND The complications acute lung injury and acute kidney injury caused by severe inflammation are the main reasons of high mortality of severe acute pancreatitis(SAP).These two complications can both lead to water metabolism and acid-base balance disorders,which could act as additional critical factors affecting the disease trend.Aquaporins(AQPs),which can regulate the transmembrane water transport,have been proved to participate in the pathophysiological process of SAP and the associated complications,such as acute lung injury and acute kidney injury.Thus,exploring herbs that can effectively regulate the expression of AQP in SAP could benefit the prognosis of this disease.AIM To determine whether Yue-Bi-Tang(YBT)can regulate the water metabolism in rats with severe acute pancreatitis via regulating the expression of aquaporins.METHODS Sprague-Dawley rats were randomly divided into three groups,sham operation group(SOG),model group(MG),and treatment group(TG).SAP was induced with 3.5%sodium taurocholate in the MG and TG.Rats in the TG were administered with YBT while SOG and MG rats were given the same volume of saline.Blood and tissue samples were harvested to detect serum inflammatory cytokines,histopathological changes,malondialdehyde and superoxide dismutase in the lung,and protein and mRNA expression of kidney injury molecule-1,α-smooth muscle actin,and vimentin in the kidney,and AQP1 and 4 in the lung,pancreas,and kidney.RESULTS The serum interleukin-10,tumor necrosis factorα,and creatinine levels were higher in the MG than in the SOG.Tumor necrosis factorαlevel in the TG was lower than that in the MG.Malondialdehyde level in lung tissues was higher than in the SOG.The pathological scores and edema scores of the pancreas,lung,and kidney tissues in the MG were all higher than those in the SOG and TG.The protein expression of AQP4 in lung tissues and AQP1 in kidney tissues in the MG were higher than those in the SOG and TG.The expression of vimentin was significantly higher in the MG than in the SOG.The expression of AQP1 mRNA in the lung and kidney,and AQP4 mRNA in the kidney was up-regulated in the MG compared to the SOG.CONCLUSION YBT might regulate water metabolism to reduce lung and kidney edema of SAP rats via decreasing AQP expression,and alleviate the tissue inflammatory injury.

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)-1βand IL-6 levels.Lung microvascular permeability was measured by determining bronchoalveolar lavage fluid protein concentration,Evans blue 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-1βand IL-6)levels in TNF-α-treated PMVECs.In vivo,SB2035080 attenuated lung histopathological injury,decreased inflammatory activity(TNF-α,IL-1β,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.

Effect of Salvia Miltiorrhiza on Expression of the MMP-2 9 in Tissue of Early Stage Acute Lung Injury in Rats with Severe Acute Pancreatitis

Objective:To investigate the effect of salvia miltiorrhiza on expression of the MMP-2、9 and TIMP-1、TIMP-2 in tissue of acute lung injury of severe acute pancreatitis(SAP).Methods:MMP-2、9 expression and changes of the lung were measured after the SAP rats were induced by retrograde injection of 5%sodium tauocholate into hepatopancreatic duct.The changes of those parameters were also measured after salvia miltiorrhiza was injected intramuscularly just after induction of SAP.Results:The level of MMP-2、9 in pancreas and lung in SAP group were significantly higher than those in sham;The level of MMP-2、9 in salvia miltiorrhiza group were significantly lower than those in SAP group. Conclusion:MMP-2、9 were overexpressed in Acute lung injury (ALI) induced by SAP, salvia miltiorrhiza downregulates MMP-2、9 expression and decreased injury of lung tissue.

Pathogenesis of acute lung injury in severe acute pancreatitis

Objective:To study the pathogenesis of acute lung injury in severe acute pancreatitis (SAP). Methods:Rats were sacrificed at 1, 3, 5, 6, 9 and 12 h after establishment of inducing model. Pancreas and lung tissues were obtained for pathological study, microvascular permeability and MPO examination. Gene expressions of TNF-α and ICAM-1 in pancreas and lung tissues were detected by RT-PCR. Results:After inducing SAP model, the injury degree of the pancreas and the lung increased gradually, accompanied with gradually increased MPO activity and microvascular permeability. Gene expressions of TNF-α and ICAM-1 in pancreas rose at 1 h and reached peak at 7 h. Relatively, their gene expressions in the lungs only rose slightly at 1 h and reached peak at 9-12 h gradually. Conclusion:There is an obvious time window between SAP and lung injury, when earlier protection is beneficial to prevent development of acute lung injury.

Acute lung injury and ARDS in acute pancreatitis: Mechanisms and potential intervention

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in acute pancreatitis still represents a substantial problem,with a mortality rate in the range of 30%-40%.The present review evaluates underlying pathophysiological mechanisms in both ALI and ARDS and potential clinical implications.Several mediators and pathophysiological pathways are involved during the different phases of ALI and ARDS.The initial exudative phase is characterized by diffuse alveolar damage,microvascular injury and influx of inflammatory cells.This phase is followed by a fibro-proliferative phase with lung repair,type Ⅱ pneumocyte hypoplasia and proliferation of fibroblasts.Proteases derived from polymorphonuclear neutrophils,various pro-inflammatory mediators,and phospholipases are all involved,among others.Contributing factors that promote pancreatitis-associated ALI may be found in the gut and mesenteric lymphatics.There is a lack of complete understanding of the underlying mechanisms,and by improving our knowledge,novel tools for prevention and intervention may be developed,thus contributing to improved outcome.

Pathological changes at early stage of multiple organ injury in a rat model of severe acute pancreatitis

BACKGROUND: Severe acute pancreatitis (SAP) is a commonly seen acute abdominal syndrome characterized by sudden onset, rapid progression and high mortality rate. The damage in peripheral organs may be more severe than that in the pancreas, and can even lead to multiple organ dysfunction. It is critical to recognize early pathological changes in multiple organs. This study aimed to assess the early pathological features of damaged organs in a rat model of SAP. METHODS: Thirty clean grade healthy male Sprague-Dawley rats weighing 250-300 g were randomly divided into a model control group (n=15) and a sham-operated group (n=15). The SAP rat model was induced by sodium taurocholate. Samples of blood and from multiple organs were collected 3 hours after operation. We assessed the levels of IL-6, TNF-alpha, PLA2, NO, ET-1, MDA, amylases and endotoxin in blood and observed the early pathological changes in multiple damaged organs. RESULTS: Levels of IL-6, TNF-alpha, PLA2, NO, ET-1 and MDA in serum and of amylase and endotoxin in plasma of the model control group rats were significantly higher than those of the sham-operated group (P<0.01). Different degrees of pathological change were observed in multiple damaged organs. CONCLUSION: Multiple organ injury may occur at the early stage of SAP in rats.

Leptin treatment ameliorates acute lung injury in rats with cerulein-induced acute pancreatitis

AIM:To determine the effect of exogenous leptin on acute lung injury (ALI) in cerulein-induced acute pancreatitis (AP). METHODS:Forty-eight rats were randomly divided into 3 groups. AP was induced by intraperitoneal (i.p.) injection of cerulein (50 μg/kg) four times,at 1 h intervals. The rats received a single i.p. injection of 10 μg/kg leptin (leptin group) or 2 mL saline (AP group) after cerulein injections. In the sham group,animals were given a single i.p. injection of 2 mL saline. Experimental samples were collected for biochemical and histological evaluations at 24 h and 48 h after the induction of AP or saline administration. Blood samples were obtained for the determination of amylase,lipase,tumor necrosis factor (TNF)-a,interleukin (IL)-1β,macrophage inflammatory peptide (MIP)-2 and soluble intercellular adhesion molecule (sICAM)-1 levels,while pancreatic and lung tissues were removed for myeloperoxidase (MPO) activity,nitric oxide (NOx) level,CD40 expression and histological evaluation. RESULTS:Cerulein injection caused severe AP,confirmed by an increase in serum amylase and lipase levels,histopathological findings of severe AP,and pancreatic MPO activity,compared to the values obtained in the sham group. In the leptin group,serum levels of MIP-2,sICMA-1,TNF-a,and IL-1b,pancreatic MPO activity,CD40 expression in pancreas and lung tissues,and NOx level in the lung tissue were lower compared to those in the AP group. Histologically,pancreatic and lungdamage was less severe following leptin administration. CONCLUSION:Exogenous leptin attenuates inflammatory changes,and reduces pro-inflammatory cytokines,nitric oxide levels,and CD40 expression in ceruleininduced AP and may be protective in AP associated ALI.