Response In Acute Pancreatitis Research Articles

Systemic differential gene regulation of the inter-α-trypsin inhibitor family in acute necrotizing pancreatitis in mice

BackgroundTherapy for systemic complications in severe necrotizing pancreatitis remains symptomatic owing to the unavailability of more specific therapeutic targets. We investigated the differential gene expression in typically affected organs in a mouse model of severe necrotizing pancreatitis. MethodsAcute necrotizing pancreatitis was induced in mice by retrograde infusion of taurocholate into the common bile duct. Microarray hybridization was subsequently performed with mRNA isolated from the spleen, liver, intestine, and lungs. Additionally, quantitative real-time polymerase chain reaction was performed to confirm the microarray results. ResultsSevere necrotizing pancreatitis induced widespread changes in gene expression, affecting 27.20% of the genes tested in the spleen and 29.07% in the liver. Fewer genes were differentially regulated in the intestine (10.28%) and the lungs (10.75%). Only 10 genes were found to be upregulated in all 4 organs using microarray analysis. This upregulation in all organs was confirmed by quantitative real-time polymerase chain reaction for only 3 molecules. These molecules were lipocalin 2, insulin-like growth factor binding protein 1, and CD14. Additionally we observed significantly aberrant gene regulation of inter-α-trypsin inhibitor family members in several organs. ConclusionsDifferential gene regulation in severe necrotizing pancreatitis is far more organ specific than anticipated, with only 3 molecules uniformly regulated systemically. The inter-α-trypsin inhibitor family of molecules appears to play a crucial biologic role in the systemic inflammatory response in acute pancreatitis. Finally, owing to its regulation and function, α1-microglobulin (or bikunin) may be a suitable predictive marker of the systemic inflammatory response syndrome in acute pancreatitis.

Acute pancreatitis in aging animals: Loss of pancreatitis-associated protein protection?

To investigate the effect of age on severity of acute pancreatitis (AP) using biochemical markers, histology and expression of the protective pancreatitis-associated proteins (PAPs). AP was induced via intraductal injection of 4% sodium taurocholate in young and old rats. Sera and pancreata were assayed at 24 h for the parameters listed above; we also employed a novel molecular technique to assess bacterial infiltration using polymerase chain reaction to measure bacterial genomic ribosomal RNA. At 24 h after induction of AP, the pancreata of older animals had less edema (mean ± SE histologic score of young vs old: 3.11 ± 0.16 vs 2.50 ± -0.11, P < 0.05), decreased local inflammatory response (histologic score of stromal infiltrate: 3.11 ± 0.27 vs 2.00 ± 0.17, P < 0.05) and increased bacterial infiltration (174% ± 52% increase from sham vs 377% ± 4%, P < 0.05). A decreased expression of PAP1 and PAP2 was demonstrated by Western blotting analysis and immunohistochemical staining. There were no differences in serum amylase and lipase activity, or tissue myeloperoxidase or monocyte chemotactic protein-1 levels. However, in the most-aged group, serum C-reactive protein levels were higher (young vs old: 0.249 ± 0.04 mg/dL vs 2.45 ± 0.68 mg/dL, P < 0.05). In older animals, there is depressed PAP expression related to a blunted inflammatory response in AP which is associated with worsened bacterial infiltration and higher C-reactive protein level; this may explain the more aggressive clinical course.

Effect of Ageing on Systemic Inflammatory Response in Acute Pancreatitis

Elderly patients show increased incidence of multiple organ dysfunction in acute pancreatitis possibly due to bacterial translocation. This is associated with increased susceptibility to infections in older people. Several reports have related this increased susceptibility to a proinflammatory status called inflammaging, which decreases the capacity of the immunological system to respond to antigens. Cellular senescence also contributes to this low-grade chronic inflammation in older subjects. We discuss here the effect of ageing on systemic inflammation, focusing on that induced by acute pancreatitis and some of the mechanisms involved. It is important to understand the immunological changes in the elderly to adjust treatment strategies in order to reduce the morbidity and mortality associated with acute pancreatitis and other conditions that lead to systemic inflammation.

Mannan-Binding Lectin and Mannan-Binding Lectin-Associated Serine Protease 2 in Acute Pancreatitis

Complement activation may play a prominent role in acute pancreatitis (AP). Mannan-binding lectin (MBL) and MBL-associated serine protease 2 (MASP-2) participate in complement activation. The objective of the present study was to evaluate the role of MBL and MASP-2 as markers in AP with regard to etiology, inflammatory activity, severity, and development of multiorgan failure. Sixty patients with AP were included. All patients were diagnosed and treated according to a standardized regimen. Blood samples were obtained immediately on admission and again on days 1, 2, and 14. Both MBL (P < 0.001) and MASP-2 (P = 0.002) levels changed significantly over time, but without any significant relation to severity, multiorgan failure, or mortality. We found significantly higher levels of MBL (P = 0.04) in alcohol- than in gallstone-induced AP, but no significant difference in MASP-2 levels. The MBL and MASP-2 acted as acute-phase reactants, but overall, they were not markers for severity, multiorgan failure, nor for mortality in AP. Our results suggest that MBL and MASP-2 play only a minor role in the inflammatory response in AP.

Anti-Inflammatory Effects of Peritoneal Lavage in Acute Pancreatitis

Intraperitoneal administration of trypsin stimulates the production of cytokines from peritoneal macrophages. Removing the pancreatitis-associated ascitic fluid from the peritoneal cavity may decrease the systemic inflammatory response in acute pancreatitis (AP). We investigated the effect of peritoneal lavage on the systemic inflammatory response in severe AP. Acute pancreatitis was induced in Wistar rats by 5% taurocholate intraductal injection. Peritoneal lavage was performed for 4 hours after onset of AP. At 4 hours after induction of AP, serum samples were assayed for amylase and inflammatory cytokines (tumor necrosis factor α, interleukin-6 [IL-6], and IL-10). Expression of pancreatic cyclooxygenase-2 and inducible nitric oxide synthase, liver mitochondrial function, and pulmonary myeloperoxidase activities were determined. Peritoneal lavage after AP led to a decrease in serum levels of tumor necrosis factor α and IL-6 and an increase in IL-10. In the pancreas, this treatment reduced cyclooxygenase-2 and inducible nitric oxide synthase expression. Liver mitochondrial dysfunction was also reduced. There were no differences on serum amylase levels and pulmonary myeloperoxidase between groups with AP. Peritoneal lavage has a systemic anti-inflammatory effect in severe AP and may be able to decrease the severity of severe AP.

The intervention effects of different drugs on dendritic cells in acute pancreatitis in mouse

To study the immunologic mechanism in pathogenesis of the acute pancreatitis (AP) and the intervention effects of sandostatin and magnolol. Ninety BALB/c mice were divided into negative control group, caerulein-induced model group, sandostatin-treatment group, magnolol-treatment group, combined sandostatin- and magnolol-treatment group by means of random number table, with 18 mice in each group. AP model was reproduced by seven intraperitoneal injections of caerulein at an interval of 1 hour. Every 30 minutes before the caerulein challenge, sandostatin was injected sub- cutaneously. Magnolol was injected intravenously immediately after the AP model was reproduced. Then at 9, 12, 24 hours after modelling, blood was drawn from orbital vein and serum was separated. Serum amylase (SA), interleukin-10 (IL-10) and gamma-interferon (IFN-gamma) were determined after the mice were sacrificed, and pancreas and spleen were harvested . The pathological changes of pancreas were observed, and the number and the ratio of myeloid- dendritic cells (MDCs) to lymphoid dendritic cells (LDCs) were measured with flow cytometry. Compared with control group [SA (1.12 + or - 0.05) kU/L, pancreatic score (PS) 0.09 + or - 0.10], both indexes increased progressively in the model group [SA (26.11 + or - 1.96) kU/L, PS 5.32 + or - 0.19, both P<0.01]. The ratio of MDCs/LDCs showed downward tendency at every time-point especially at 9th hour (0.421 + or - 0.049 vs. 1.712 + or - 0.372, P<0.05), while the ratio of IL-10 to IFN-gamma did not show significant differences. Compared with model group, both SA and PS significantly decreased in all the three drug intervention groups [SA (kU/L): 18.25 + or - 1.09, 17.32 + or - 1.26, 17.62 + or - 0.56, PS: 4.55 + or - 0.15, 4.16 + or - 0.18, 4.10 + or - 0.13, all P<0.01]. There was no significant difference in the two ratios of MDCs/LDCs and IL-10/IFN-gamma between sandostatin-treatment group and model group. However, the ratio of MDCs/LDCs of the magnolol-treatment group was higher than that in sandostatin-treatment group 9, 12, 24 hours after modelling (9 hours: 4.694 + or - 0.527 vs. 0.819 + or - 0.182, 12 hours: 2.566 + or - 0.463 vs. 1.421 + or - 0.163, 24 hours : 2.343 + or - 0.359 vs. 1.421 + or - 0.113, P<0.05 or P<0.01). At every time-point, the ratio of IL-10/IFN-gamma in the magnolol-treatment group was significantly higher compared with the model group, and at the 12-hour point, it was higher than that of sandostatin-treatment group (8.000 + or - 1.738 vs. 3.558 + or - 0.362, P<0.05 ). The combined treatment group showed similar changes as the magnolol-treatment group. When AP occurs, the differentiation from T helper (Th0) to Th1 is augmented, while differentiation of Th0 to Th2 decreases, thus inducing an imbalance in the relationship of pro- and anti-inflammatory response. Magnolol can induce the differentiation from Th0 to Th2 by modulating the different subtype dendritic cells, thus improving the anti-inflammatory response, resulting in attenuating local and systemic inflammatory response in AP. However, sandostatin did not show such effect.

CO2 Abdominal Insufflation Decreases Local and Systemic Inflammatory Response in Experimental Acute Pancreatitis

Acute pancreatitis (AP) is a serious disease that is amplified by an associated systemic inflammatory response. We investigated the effect of CO2 pneumoperitoneum on the local and systemic inflammatory response in AP. Acute pancreatitis was induced in Wistar rats by 5% taurocholate intraductal injection. Carbon dioxide pneumoperitoneum was applied for 30 minutes before the induction of AP. Inflammatory parameters were evaluated in the peritoneum (ascites, cell number, and tumor necrosis factor alpha [TNF-alpha]), serum (amylase, TNF-alpha, interleukin-6 [IL-6], and IL-10), pancreas (myeloperoxidase [MPO] activity, cyclo-oxygenase 2 and inducible nitric oxide synthase expression, and histological diagnosis), liver, and lung (mitochondria dysfunction and MPO activity). Abdominal insufflation with CO2 before induction of AP caused a significant decrease in ascites volume, cells, and TNF-alpha in the peritoneal cavity and in serum TNF-alpha and IL-6 but not IL-10 levels. In the pancreas, this treatment reduced MPO activity, acinar and fat necrosis, and the expression of inducible nitric oxide synthase and cyclo-oxygenase 2. There were no significant differences on serum amylase levels, liver mitochondrial function, and pulmonary MPO between groups. Our data demonstrated that CO2 pneumoperitoneum reduced pancreatic inflammation and attenuated systemic inflammatory response in AP. This article suggests that CO2 pneumoperitoneum plays a critical role on the better outcome in patients undergoing laparoscopic pancreatic surgery.

Inflammatory role of the acinar cells during acute pancreatitis

Pancreatic acinar cells are secretory cells whose main function is to synthesize, store and finally release digestive enzymes into the duodenum. However, in response to noxious stimuli, acinar cells behave like real inflammatory cells because of their ability to activate signalling transduction pathways involved in the expression of inflammatory mediators. Mediated by the kinase cascade, activation of Nuclear factor-κB, Activating factor-1 and Signal transducers and activators of transcription transcription factors has been demonstrated in acinar cells, resulting in overexpression of inflammatory genes. In turn, kinase activity is down-regulated by protein phosphatases and the final balance between kinase and phosphatase activity will determine the capability of the acinar cells to produce inflammatory factors. The kinase/phosphatase pair is a redox-sensitive system in which kinase activation overwhelms phosphatase activity under oxidant conditions. Thus, the oxidative stress developed within acinar cells at early stages of acute pancreatitis triggers the activation of signalling pathways involved in the up-regulation of cytokines, chemokines and adhesion molecules. In this way, acinar cells trigger the release of the first inflammatory signals which can mediate the activation and recruitment of circulating inflammatory cells into the injured pancreas. Accordingly, the role of acinar cells as promoters of the inflammatory response in acute pancreatitis may be considered. This concept leads to amplifying the focus from leukocyte to acinar cells themselves, to explain the local inflammation in early pancreatitis.

Regulation of HSP60 and the role of MK2 in a new model of severe experimental pancreatitis

The objective of this study was to investigate the role of MAPKAP kinase 2 (MK2) and heat shock protein (HSP) HSP60 in the pathogenesis of a new model of severe acute pancreatitis (AP). MK2 plays a significant role in the regulation of cytokines. It has been shown that induction and expression of several HSPs can protect against experimental pancreatitis. Interplay between both systems seems of high interest. Mice with a homozygous deletion of the MK2 gene were used. Severe AP was induced by combined intraperitoneal injections of cerulein with lipopolysaccharide (LPS). Severity of AP was assessed by biochemical markers and histology. The serum IL-6 and lung myeloperoxidase (MPO) levels were determined for assessing the extent of systemic inflammatory response. Expression of HSP25, HSP60, HSP70, and HSP90 was analyzed by Western blotting. Repeated injections of cerulein alone or cerulein plus LPS (Cer+LPS) resulted in local inflammatory responses in the pancreas and corresponding systemic inflammatory changes with pronounced severity in the Cer+LPS group. Compared with the C57Bl wild-type mice, the MK2-/- mice presented with significant milder pancreatitis and attenuated responses of serum amylase and trypsinogen activity. Furthermore, serum IL-6 was decreased as well as lung MPO activity. Injection of LPS alone displayed neither pancreatic inflammatory responses nor alterations of pancreatic enzyme activities but evidently elevated serum IL-6 levels and increased lung MPO activity. In contrast hereto, in the MK2-/- mice, these changes were much milder. Increased expression of HSP25 and HSP60 occurred after induction of AP. Especially, HSP60 was robustly elevated after Cer+LPS treatment, in both MK2-/- and wild-type mice. Thus the homozygous deletion of the MK2 gene ameliorates the severity of acute pancreatitis and accompanying systemic inflammatory reactions in a new model of severe acute pancreatitis. Our data support the hypothesis that MK2 participates in the multifactorial regulation of early inflammatory responses in AP, independently of the regulation of stress proteins like HSP25 and HSP60 and most likely due to its effect on cytokine regulation.

Regulation of Hsp60 and the role of MK2 in a new model of severe experimental pancreatitis

MK2 plays a pivotal role in regulating signal transduction pathways of cytokines. It has been shown that induction and expression of several Heat shock proteins (HSPs) can protect against pancreatitis. Little is known about regulation and potential protective effects of Hsp60. The objective of this study was to investigate the role of MK2 and the regulation of HSP60 in the pathogenesis of a new model of severe acute pancreatitis (AP). To elucidate the role of MK2, mice with a homozygous deletion of the MK2 gene were used (MK2 -/-). Severe AP was induced by combined i.p. injections of cerulein with LPS. Severity of AP was assessed by examination of biochemical parameters and by histological analysis. Repeated injections of cerulein alone or in combination with LPS resulted in local inflammatory responses in the pancreas and in systemic inflammatory changes, with animals in the Cer+LPS group being much more severe. Compared to the C57Bl mice, the MK2-/- mice presented with significant milder pancreatitis, showing lower serum amylase and IL-6 levels, decreased trypsinogen and lung MPO activity. The mice injected with LPS alone displayed neither pancreatic inflammatory responses nor alteration of pancreatic enzyme activities, but evidently elevated serum IL-6 levels and increased lung MPO activity. In contrast, in MK2 -/- mice, these changes were much milder than those in wild-type mice. Analysis of heat shock protein expression showed increased expression of Hsp25 and Hsp60. Especially Hsp60 demonstrated robustly elevated expression in the Cer+LPS treated mice in both, MK2 -/- and wild-type mice compared to saline or cerulein treated animals. The increased levels of HSP60 expression in MK2-/- mice were slightly higher, but not significant, than in wild-type mice. These results revealed that deletion of the MK2 gene ameliorates the severity of acute pancreatitis and systemic inflammation in a more severe systemic inflammatory model of AP with repeated injections of cerulein in combination with injection of LPS. The obtained data support the hypothesis that MK2 signalling pathways participate in the multi-factorial regulation of inflammatory responses in AP, possibly including the regulation of certain stress proteins, in particular HSP25 and HSP60.

Cross-Talk between Oxidative Stress and Pro-Inflammatory Cytokines in Acute Pancreatitis: A Key Role for Protein Phosphatases

Acute pancreatitis is an acute inflammatory process localized in the pancreatic gland that frequently involves peripancreatic tissues. It is still under investigation why an episode of acute pancreatitis remains mild affecting only the pancreas or progresses to a severe form leading to multiple organ failure and death. Proinflammatory cytokines and oxidative stress play a pivotal role in the early pathophysiological events of the disease. Cytokines such as interleukin 1beta and tumor necrosis factor alpha initiate and propagate almost all consequences of the systemic inflammatory response syndrome. On the other hand, depletion of pancreatic glutathione is an early hallmark of acute pancreatitis and reactive oxygen species are also associated with the inflammatory process. Changes in thiol homestasis and redox signaling decisively contribute to amplification of the inflammatory cascade through mitogen activated protein kinase (MAP kinase) pathways. This review focuses on the relationship between oxidative stress, pro-inflammatory cytokines and MAP kinase/protein phosphatase pathways as major modulators of the inflammatory response in acute pancreatitis. Redox sensitive signal transduction mediated by inactivation of protein phosphatases, particularly protein tyrosin phosphatases, is highlighted.

Hyperbaric Oxygen Reduces Inflammatory Response in Acute Pancreatitis by Inhibiting NF-κB Activation

Aim: The mechanism of hyperbaric oxygen (HBO) therapy for acute pancreatitis has not been fully clarified yet. The main purpose of this study was to investigate the effect of HBO on nuclear factor κB (NF-κB) activation and the inflammatory response in rats with acute necrotizing pancreatitis (ANP). Methods: A total of 120 male Sprague-Dawley rats were randomly divided into 3 groups (40 in each): control, ANP and ANP + HBO. ANP rat models were established by a retrograde injection of 5% sodium taurocholate into the pancreatic duct. HBO treatment was performed at 2.5-fold absolute atmospheric pressure in 90% oxygen for 1, 3, 5, and 7 h. The activation of NF-κB and its inhibitor IκBα in peripheral blood neutrophilic granulocytes was measured by electrophoretic mobility shift assay and Western blot, respectively. The inflammatory cytokines [interleukin (IL)-2, IL-6, tumor necrosis factor-α (TNF-α), and intercellular adhesion molecule 1] in the blood were measured by enzyme-linked immunosorbent assay. Results: The blood levels of inflammatory cytokines and NF-κB activation were significantly increased in ANP rats compared to control rats, but IκBα activation was suppressed. The levels of the elevated inflammatory cytokines were positively correlated with the changes in NF-κB activation. After HBO treatment, the blood levels of inflammatory cytokines and NF-κB activation were significantly decreased in the ANP + HBO group in a time-dependent manner, but IκBα activation was increased. Conclusion: Our findings suggest that acute pancreatitis is associated with the upregulation of cytokines in blood as well as upregulation of NF-κB levels and downregulation of IκBα activation in peripheral blood neutrophilic granulocytes. In contrast, HBO plays a role in acute pancreatitis treatment by normalizing these changes.

The adrenocorticotropic hormone-induced cortisol response in acute pancreatitis

The evidence that severe acute pancreatitis can result in critical illness-related corticosteroid insufficiency following impaired adrenal secretion is accumulating. The study by Peng and coworkers in Critical Care certainly contributes to that idea, even though the question whether relative adrenal insufficiency should prompt for treatment by substitution doses of corticosteroids remains unresolved. The study is discussed in terms of the risk factors, circumstances and significance of impaired corticosteroid secretion by adrenals in severe acute pancreatitis.

Targeting peripheral immune response reduces the severity of necrotizing acute pancreatitis

A complex cascade of immunologic events leads to the development of systemic inflammatory response in acute pancreatitis (AP). Our aim was to evaluate the effects of two different immunomodulating treatments: Dexamethasone (Dx) and N-acetylcysteine (NAC), on the progression of necrotizing AP. Prospective, random, and control study. Laboratory animals. University-based research laboratory. Male Wistar rats. Retrograde infusion of 3.5% of sodium taurocholate into pancreatic-biliary duct was used to induce AP in rats. Dx (1 mg/kg) was administered 30 mins before or 1 hr after AP, and NAC (50 mg/kg) was given 1 hr before and 1 hr after inducing AP. Dx and NAC treatments reduced the severity of AP in terms of amylasemia, pancreatic edema, and pancreatic and liver necrosis. Dx, administered before or after AP, and NAC reduced the leukocytosis induced by AP and blocked the ability of circulating monocytes to produce tumor necrosis factor-alpha and monocyte chemoattractant protein-1; however none of them significantly reduced the overexpression of intercellular cell adhesion molecule-1 found in monocytes 6 hrs after inducing AP. Leukocyte infiltration in the pancreas was attenuated in Dx-pretreated rats and significantly reduced 6 hrs after inducing AP in rats treated with NAC. However, neither Dx nor NAC were able to significantly reduce interleukin-6 in plasma or mitigate leukocyte infiltration in the lung. Our data demonstrated that treatments targeting the peripheral immune response reduced the severity of sodium taurocholate -induced AP attenuating pancreatic and liver injury, but they were not effective for limiting the spread of the inflammatory damage to the lung.

Differential Preservation of Lipopolysaccharide-Induced Chemokine/Cytokine Expression during Experimental Pancreatitis-Associated Organ Failure in Rats Shows a Regulatory Expressed Phenotype

Background: Altered lipopolysaccharide (LPS)-responsiveness is a key feature of acute pancreatitis (AP)-associated multiple organ failure (AP-MOF) in rats and humans. Aim:To determine the differential expression of 16 cytokines and chemokines in response to delayed LPS administration in established experimental AP-MOF in rats. Methods: In a cubic factorial group design (12 groups, n = 6 rats/group), 0,6 and 30 μug/kg Escherichia coli 0111:B4 LPS was administered intra-arterially, 18 h into experimental AP-MOF or sham laparotomy. AP was induced by intraductal glycodeoxycholic acid and intravenous caerulein. Central venous serum concentrations of 16 cytokines and chemokines were measured by Searchlight™ multiplex ELISA. Results: Four patterns were observed: (1) TNF-α, IL-Iα, IL-1β, IL-6, IFN-γ, MCP-1, MIP-2α, MIP-3α, fractalkine and RANTES showed a diminished LPS response in AP versus sham (p < 0.001, ANOVA); (2) IL-2, IL-4 and GM-CSF levels were undetectable; (3) CINC-2α and GRO/ KC showed little or no difference between AP and controls, and (4) IL-10 concentrations after 0 and 6 μug/kg, but not 30 μg/kg LPS injection were significantly higher in AP than controls (p < 0.001, ANOVA). Conclusion: Experimental AP-MOF in rats results in differential preservation of the cytokine and chemokine response to LPS challenge, with a predominantly regulatory expressed phenotype.

Obesity and Fat Distribution Imply a Greater Systemic Inflammatory Response and a Worse Prognosis in Acute Pancreatitis

Background and Aims: Acute pancreatitis (AP) is a systemic inflammatory disease. It is already known that obesity and central fat distribution are related to the severity of AP, but the intimate mechanism of this relationship remains unknown. Obesity and central fat distribution are associated with an inflammatory state that could amplify the systemic inflammatory response (SIR) in AP. The aim of this study was to investigate how obesity and body fat distribution correlate with the SIR and severity of AP. Methods: 85 consecutive patients with AP were studied. Body mass index, body fat distribution and previous comorbidity were obtained at admission. The SIR was assessed by the serum levels of interleukin (IL)-Iβ, IL-1ra, IL-6, IL-8, IL-10, IL-12p70, tumor necrosis factor-α (TNF-α) and C-reactive protein. Serum concentrations of the previously mentioned cytokines were also determined in a control group of 40 healthy volunteers. Results: 63 patients (74%) had mild AP and 22 patients (26%) had severe AP. All the cytokines except IL-12p70 and TNF-α were increased in the AP group in comparison with the control group. The SIR was significantly increased in patients with severe AP. Obese patients and patients with central fat distribution had significantly more comorbidity, a higher proportion of severe AP and more intense SIR. Patients with comorbidity had a significantly higher proportion of severe AP and more SIR. Conclusion: The severity of AP in obese patients and in patients with central fat distribution seems to be related to the comorbidity and the amplification of SIR.

Early inflammatory response in acute pancreatitis is little affected by body mass index

Objective. Obesity is a known risk factor for severe acute pancreatitis (AP), but the mechanism by which it affects the severity of AP is not fully understood. The main objective of this study was to investigate the relationship between obesity and inflammatory markers in AP. Material and methods. Thirty patients with AP who developed organ failure (Group I) and 87 patients with AP who survived without organ failure (Group II) were studied. Patients’ height and weight were measured at admission for calculation of body mass index (BMI). Blood samples were taken at admission for measurement of plasma interleukin (IL)-1β, IL-6, IL-10, IL-1 receptor antagonist, procalcitonin, C-reactive protein (CRP) and monocyte human leucocyte antigen (HLA)-DR expression. Results. Group I patients had higher BMI values (median 26.2 kg/m2) than Group II patients (25.2 kg/m2), p=0.033. Both CRP values and monocyte HLA-DR expression showed a significant correlation with BMI (Spearman's rank correlation r=0.32, p=0.003 and r=−0.33, p=0.002, respectively). The correlation between BMI and monocyte HLA-DR expression was significant in Group II patients (r=−0.34, p=0.002) but not in Group I patients (r=−0.02, p>0.05). There was no correlation between BMI and IL-1β, IL-6, IL-10, IL-1 receptor antagonist or procalcitonin. Conclusions. BMI did not affect either pro-inflammatory or anti-inflammatory cytokine levels in early AP. However, in patients with mild AP, BMI correlated positively with CRP levels and inversely with monocyte HLA-DR expression, which might reflect an amplified inflammatory response in these patients. Taken together, acute inflammatory response in AP, which ultimately determines the severity of AP, was little affected by BMI.

Interaction Between Cytokines and Oxidative Stress in Acute Pancreatitis

Acute pancreatitis is an inflammation initially localized in the pancreatic gland which may lead to local and systemic complications. The development of severe acute pancreatitis is mediated by pathophysiological mechanisms involved in the systemic inflammatory response, cytokines and oxidative stress being their components of major importance. Nevertheless, it is still unknown why an episode of acute pancreatitis remains mild or progresses to a severe form. Activated leukocytes are the main source of cytokines. Interleukin 1beta and tumor necrosis factor alpha (TNF-alpha) initiate and propagate almost all the consequences of the systemic inflammatory response syndrome, leading to amplification of the inflammatory response. It is noteworthy that the systemic inflammatory response is restrained and the rate of mortality decreased in acute pancreatitis when TNF-alpha is blocked with specific antibodies or in knock-out mice deficient in its receptors. A synergy between pro-inflammatory cytokines and oxidative stress occurs in the development of the inflammatory response in acute pancreatitis. Pro-inflammatory cytokines and oxidative stress trigger common signal transduction pathways that lead to amplification of the inflammatory cascade, mainly through activation of mitogen-activated protein kinases (MAPK) and nuclear factor kappaB (NF-kappaB). Furthermore, pro-inflammatory cytokines, particularly TNF-alpha, and oxidative stress promote each other generating a vicious circle in acute pancreatitis. This cross-talk that arises between pro-inflammatory cytokines and oxidative stress greatly contributes to amplification of the uncontrolled inflammatory cascade through MAPK and NF-kappaB.

Blockade of neurokinin-1 receptor attenuates CC and CXC chemokine production in experimental acute pancreatitis and associated lung injury

Accumulating evidence suggests the neuropeptide substance P (SP) and its receptor neurokinin-1 receptor (NK-1R) play a pivotal role in the pathogenesis of acute pancreatitis (AP). However, the mechanisms remain unclear. The present study investigated whether chemokines as proinflammatory molecules are involved in SP-NK-1R-related pathogenesis of this condition. We observed temporally and spatially selective chemokine responses in secretagogue caerulein-induced AP in mice. CC chemokines monocyte chemotactic protein (MCP)-1 and macrophage inflammatory protein-1alpha (MIP-1alpha) and CXC chemokine MIP-2 were elevated after AP induction. Time-dependent, tissue-specific analysis of their mRNA and protein expression suggested that they are early mediators in the condition and mediate local as well as systemic inflammatory responses. In contrast, another CC chemokine regulated on activation, T cells expressed and secreted (RANTES) was only involved in local pancreatic inflammation at a later stage of the disease. Either prophylactic or therapeutic treatment with a potent selective NK-1R antagonist CP-96,345 significantly suppressed caerulein-induced increase in MCP-1, MIP-1alpha, and MIP-2 expression but had no apparent effect on RANTES expression. The suppression effect of CP-96,345 on MCP-1, MIP-1alpha, and MIP-2 expression was concordantly demonstrated by immunohistochemistry, which, additionally, suggested that chemokine immunoreactivity was localized to acinar cells and the infiltrating leukocytes in the pancreas and alveolar macrophages, epithelial cells, and endothelial cells in the lungs. Our data suggest that SP, probably by acting via NK-1R on various chemokine-secreting cells in the pancreas and lungs, stimulates the release of chemokines that aggravate local AP and the development of its systemic sequelae.

Development of cerulein-induced acute pancreatitis is independent of cross-tolerance after heat shock in mice

Introduction: It is logical to believe that, as in many inflammatory conditions, the development of acute pancreatitis may be modified by the heat shock response. Data, however, are conflicting regarding the significance of the heat shock response in acute pancreatitis. The purpose of this study was to examine the role of the inducible heat shock response in the pathogenesis of acute pancreatitis by examining the effects of cerulein hyperstimulation, with or without heat shock preconditioning (i.e., cross-tolerance), in a mouse model lacking heat shock transcription factor 1 (Hsf1), the main regulator of the heat shock response (Xiao et al EMBO J.18:5943, 1999). Methods: Wild-type and homozygous mice (for Hsf1+/+ and Hsf1−/−, respectively) were generated and verified by PCR Pancreatitis was induced in mice by intraperitoneal injection of three hourly doses of cerulein (100 mcg/kg). Control groups received a similar course of carrier injections. Preconditioning was accomplished by heating ansesthetized mice from 37 degrees C to 41 degrees C for 15 minutes (HS preconditioning), 12 hours prior to induction of pancreatitis. Experimental groups with (n=9-10 per group) and without heat shock preconditioning (n=4-5 per group) were studied. Pancreatic markers included serum amylase levels, and blinded histologic assessment of pancreata for necrosis, vacuolization and inflammatory cell infiltration. Western blot for heat shock protein 70 (Hsp70) expression in pancreata was evaluated 6 hours after induction of pancreatitis, a time point corresponding to peak amylase release and histologic injury in this model. Results: In response to cerulein, Hsf1+/+ mice had a 2.4 fold increase in peak amylase vs control (p<0.001). Likewise, Hsf1−/− mice had a 2.8 fold increase in peak amylase vs control (p<0.001). There were no significant differences in peak serum amylase (p= 0.85) and cerulein-induced histologic scoring of tissue injury between experimental groups. Both cerulein and heat shock treatments induced Hsp70 expression in Hsf1+/+ mice, but not in Hsf1−/− mice. However, development of pancreatitis after HS preconditioning was similar in Hsf1+/+ compared with Hsf1−/− (2.4 fold increase vs control and 2.0 fold increase vs control, p<0.001, respectively). Conclusions: Neither cross-tolerance by HS preconditioning nor the induction of Hsp70 affords effective protection against cerulein-induced pancreatitis in mice. Futhermore, our findings demonstrate for the first time that Hsf1, the major stress-inducible regulatory pathway of heat shock protein expression, is dispensable for development of acute pancreatitis. We conclude that other compensatory and redundant mechanisms, independent of the heat shock response, play central roles in the pathogenesis of cerulein-induced acute pancreatitis.