Search

Background Antimicrobial autoantigenic glycoprotein 2 (GP2) is an important component of the innate immune system which originates from the exocrine pancreas as well as from the small intestines. The relationship of GP2 with the intestinal microbiome as well as the systemic implications of increased fecal GP2 levels are, however, still unclear. Therefore, fecal samples from 2,812 individuals of the Study of Health in Pomerania (SHIP) were collected to determine GP2 levels (enzyme-linked immunosorbent assay) and gut microbiota profiles (16 S rRNA gene sequencing). These data were correlated and associated with highly standardised and comprehensive phenotypic data of the study participants. Results Fecal GP2 levels were increased in individuals with higher body mass index and smokers, whereas lower levels were found in case of preserved exocrine pancreatic function, female sex or a healthier diet. Moreover, higher GP2 levels were associated with increased serum levels of high-sensitivity C-reactive protein, loss of gut microbial diversity and an increase of potentially detrimental bacteria (Streptococcus, Haemophilus, Clostridium XIVa, or Collinsella). At the same time, predicted microbial pathways for the biosynthesis of beneficial short-chain fatty acids or lactic acid were depleted in individuals with high fecal GP2. Of note, GP2 exhibited a stronger association to overall microbiome variation than calprotectin. Conclusion Fecal GP2 is a biomarker of gut microbiota dysbiosis and associated with increased systemic inflammation. The intestines may be more important as origin for GP2 than pancreatic acinar cells. Future studies need to investigate the potential clinical value in disease specific patient cohorts. Keywords: GP2, Exocrine, Pancreas, Pancreatitis, IBD, Biomarker, Author(s): Fabian Frost[sup.1], Stefan Weiss[sup.1,2], Johannes Hertel[sup.3], Malte Rühlemann[sup.4], Corinna Bang[sup.4], Andre Franke[sup.4], Matthias Nauck[sup.5], Marcus Dörr[sup.6], Henry Völzke[sup.7], Dirk Roggenbuck[sup.8,9], Peter Schierack[sup.8,9], Uwe Völker[sup.2], Georg Homuth[sup.2], Ali A. Aghdassi[sup.1], [...]

Elevated pressure in the pancreatic gland is the central cause of pancreatitis following abdominal trauma, surgery, endoscopic retrograde cholangiopancreatography, and gallstones. In the pancreas, excessive intracellular calcium causes mitochondrial dysfunction, premature zymogen activation, and necrosis, ultimately leading to pancreatitis. Although stimulation of the mechanically activated, calcium-permeable ion channel Piezo1 in the pancreatic acinar cell is the initial step in pressure-induced pancreatitis, activation of Piezo1 produces only transient elevation in intracellular calcium that is insufficient to cause pancreatitis. Therefore, how pressure produces a prolonged calcium elevation necessary to induce pancreatitis is unknown. We demonstrate that Piezo1 activation in pancreatic acinar cells caused a prolonged elevation in intracellular calcium levels, mitochondrial depolarization, intracellular trypsin activation, and cell death. Notably, these effects were dependent on the degree and duration of force applied to the cell. Low or transient force was insufficient to activate these pathological changes, whereas higher and prolonged application of force triggered sustained elevation in intracellular calcium, leading to enzyme activation and cell death. All of these pathological events were rescued in acinar cells treated with a Piezo1 antagonist and in acinar cells from mice with genetic deletion of Piezo1. We discovered that Piezo1 stimulation triggered transient receptor potential vanilloid subfamily 4 (TRPV4) channel opening, which was responsible for the sustained elevation in intracellular calcium that caused intracellular organelle dysfunction. Moreover, TRPV4 gene-KO mice were protected from Piezo1 agonist- and pressure-induced pancreatitis. These studies unveil a calcium signaling pathway in which a Piezo1-induced TRPV4 channel opening causes pancreatitis., Introduction The pancreas is highly sensitive to pressure (1-3), and elevated pancreatic duct pressure is a major cause of acute pancreatitis. A gallstone impacted at the junction of the pancreatic [...]

OBJECTIVE: Chronic pancreatitis (CP) patients have an increased risk of malnutrition. Information about nutritional status of CP outpatients is scarce, and simple, sensitive methods to identify patients at risk are lacking. This explorative cross-sectional study was performed to survey the nutritional status of CP outpatients. SUBJECTS: Fifty patients with chronic or recurrent acute pancreatitis (RAP) had a nutritional assessment performed. Scores on nutritional screening tools and a quality of life questionnaire were assessed. General observations and relations between parameters were described. RESULTS: Thirty-nine patients had CP and eleven patients had RAP. According to the nutritional screening tools, 28-50% of the patients had a moderate or high risk of malnutrition. All domains of the Short Form Health Survey were significantly lowered in CP patients (all P [less than or equal to] 0.001) compared with the Dutch norm values. A considerable number of patients scored below the 5th percentile on anthropometric measures. Mini Nutritional Assessment could not identify all patients with very low anthropometric scores. Substantial weight loss was not a sensitive indicator for functional impairment. CONCLUSION: CP outpatients are at risk of malnutrition. Currently used screening methods (for example, weight loss) are likely to be not sensitive enough to identify all patients with impaired body composition and restricted function. Therefore, some patients with objective decline in nutritional status will remain unidentified. An extended nutritional assessment is recommendable in CP patients. European Journal of Clinical Nutrition (2013) 67, 1271-1276; doi: 10.1038/ejcn.2013.199; published online 16 October 2013 Keywords: chronic pancreatitis; outpatients; malnutrition; nutritional status; nutritional assessment; anthropometry, INTRODUCTION Chronic pancreatitis (CP) is an inflammatory condition of the pancreas that may ultimately lead to endocrine and exocrine insufficiency. This impairs digestive, absorptive and metabolic processes, enhancing the risk [...]

Neutrophils and their chemoattractants, the CXC-ELR chemokines keratinocyte cytokine (KC) and macrophage inflammatory protein-2 (MIP-2), play a critical role in pancreatitis. While acute pancreatitis is initiated in acinar cells, it is unclear if these are a source of CXC-ELR chemokines. KC and MIP-2 have NF-[kappa]B, activator protein-1 (AP-1) sites in their promoter regions. However, previous studies have shown increased basal and reduced caerulein-induced AP-1 activation in harvested pancreatic tissue in vitro, which limits interpreting the caerulein-induced response. Moreover, recent studies suggest that NF-[kappa]B silencing in acinar cells alone may not be sufficient to reduce inflammation in acute pancreatitis. Thus the aim of this study was to determine whether acinar cells are a source of KC and MIP-2 and to understand their transcriptional regulation. Primary overnight-cultured murine pancreatic acini were used after confirming their ability to replicate physiological and pathological acinar cell responses. Upstream signaling resulting in KC, MIP-2 upregulation was studied along with activation of the transcription factors NF-[kappa]B and AP-1. Cultured acini replicated critical responses to physiological and pathological caerulein concentrations. KC and MIP-2 mRNA levels increased in response to supramaximal but not to physiological caerulein doses. This upregulation was calcium and protein kinase C (PKC), but not cAMP, dependent. NF-[kappa]B inhibition completely prevented upregulation of KC but not MIP-2. Complete suppression of MIP-2 upregulation required dual inhibition of NF-[kappa]B and AP-1. Acinar cells are a likely source of KC and MIP-2 upregulation during pancreatitis. This upregulation is dependent on calcium and PKC. MIP-2 upregulation requires both NF-[kappa]B and AP-1 in these cells. Thus dual inhibition of NF-[kappa]B and AP-1 may be a more successful strategy to reduce inflammation in pancreatitis than targeting NF-[kappa]B alone. keratinocyte cytokine; macrophage inflammatory protein-2; activator protein-1; nuclear factor-[kappa]B; acinar doi: 10.1152/ajpgi.00177.2010.

The mechanisms of pancreatic pain, a cardinal symptom of pancreatitis, are unknown. Proinflammatory agents that activate transient receptor potential (TRP) channels in nociceptive neurons can cause neurogenic inflammation and pain. We report a major role for TRPV4, which detects osmotic pressure and arachidonic acid metabolites, and TRPA1, which responds to 4-hydroxynonenal and cyclopentenone prostaglandins, in pancreatic inflammation and pain in mice. Immunoreactive TRPV4 and TRPA1 were detected in pancreatic nerve fibers and in dorsal root ganglia neurons innervating the pancreas, which were identified by retrograde tracing. Agonists of TRPV4 and TRPA1 increased intracellular [Ca.sup.2+] concentration ([[[Ca.sup.2+]].sub.i]) in these neurons in culture, and neurons also responded to the TRPV1 agonist capsaicin and are thus nociceptors. Intraductal injection of TRPV4 and TRPA1 agonists increased c-Fos expression in spinal neurons, indicative of nociceptor activation, and intraductal TRPA1 agonists also caused pancreatic inflammation. The effects of TRPV4 and TRPA1 agonists on [[[Ca.sup.2+]].sub.i], pain and inflammation were markedly diminished or abolished in trpv4 and trpa1 knockout mice. The secretagogue cerulein induced pancreatitis, c-Fos expression in spinal neurons, and pain behavior in wild-type mice. Deletion of trpv4 or trpa1 suppressed c-Fos expression and pain behavior, and deletion of trpa1 attenuated pancreatitis. Thus TRPV4 and TRPAI contribute to pancreatic pain, and TRPA1 also mediates pancreatic inflammation. Our results provide new information about the contributions of TRPV4 and TRPA1 to inflammatory pain and suggest that channel antagonists are an effective therapy for pancreatitis, when multiple proinflammatory agents are generated that can activate and sensitize these channels. neurogenic inflammation; TRP channels doi: 10.1152/ajpgi.00433.2009.

Cytosolic [Ca.sup.2+] ([Ca.sup.2+.sub.i]) flux within the pancreatic acinar cell is important both physiologically and pathologically. We examined the role of cAMP in shaping the apical-to-basal [Ca.sup.2+] wave generated by the [Ca.sup.2+]-activating agonist carbachol. We hypothesized that cAMP modulates intra-acinar [Ca.sup.2+] channel opening by affecting either cAMP-dependent protein kinase (PKA) or exchange protein directly activated by cAMP (Epac). Isolated pancreatic acinar cells from rats were stimulated with carbachol (1 [micro]M) with or without vasoactive intestinal polypeptide (VIP) or 8-bromo-cAMP (8-Br-cAMP), and then [Ca.sup.2+] was monitored by confocal laser-scanning microscopy. The apical-to-basal carbachol (1 [micro]M)-stimulated [Ca.sup.2+] wave was 8.63 [+ or -] 0.68 micro]m/s; it increased to 19.66 [+ or +] 2.22 [micro]m/s (*P < 0.0005) with VIP (100 nM), and similar increases were observed with 8-Br-cAMP (100 [micro]M). The [Ca.sup.2+] rise time after carbachol stimulation was reduced in both regions but to a greater degree in the basal. Lag time and maximal [Ca.sup.2+] elevation were not significantly affected by cAMP. The effect of cAMP on [Ca.sup.2+] waves also did not appear to depend on extracellular [Ca.sup.2+]. However, the ryanodine receptor (RyR) inhibitor dantrolene (100 [micro]M) reduced the cAMP-enhancement of wave speed. It was also reduced by the PKA inhibitor PKI (1 [micro]M). 8-(4-chlorophenylthio)-2'-O-Me-cAMP, a specific agonist of Epac, caused a similar increase as 8-Br-cAMP or VIP. These data suggest that cAMP accelerates the speed of the [Ca.sup.2+] wave in pancreatic acinar cells. A likely target of this modulation is the RyR, and these effects are mediated independently by PKA and Epac pathways. calcium signaling; pancreatitis: zymogen activation; exocrine pancreas

Although alcohol abuse is the major cause of chronic pancreatitis, the pathogenesis of alcoholic chronic pancreatitis (ACP) remains obscure. A critical obstacle to understanding the mechanism of ACP is lack of animal models. Our objective was to develop one such model. Rats were pair-fed for 8 wk ethanol or control Lieber-DeCarli liquid diet. For the last 2 wk, they received cyclosporin A (CsA; 20 mg/kg once daily) or vehicle. After 1 wk on CsA, one episode of acute pancreatitis was induced by four 20 [micro]g/kg injections of cerulein (Cer); controls received saline. Pancreas was analyzed 1 wk after the acute pancreatitis. CsA or Cer treatments alone did not result in pancreatic injury in either control (C)- or ethanol (E)-fed rats. We found, however, that alcohol dramatically aggravated pathological effect of the combined CsA+Cer treatment on pancreas, resulting in massive loss of acinar cells, persistent inflammatory infiltration, and fibrosis. Macrophages were prominent in the inflammatory infiltrate. Compared with control-fed C+CsA+Cer rats, their ethanol-fed E+CsA+Cer counterparts showed marked increases in pancreatic NF-[kappa]B activation and cytokine/chemokine mRNA expression, collagen and fihronectin, the expression and activities of matrix metalloproteinase-2 and -9, and activation of pancreatic stellate cells. Thus we have developed a model of alcohol-mediated postacute pancreatitis that reproduces three key responses of human ACP: loss of parenchyma, sustained inflammation, and fibrosis. The results indicate that alcohol impairs recovery from acute pancreatitis, suggesting a mechanism by which alcohol sensitizes pancreas to chronic injury. ethanol; inflammatory response; pancreatic stellate cells; cerulein; cyclosporin A

Activated pancreatic stellate cells (PSCs) play an important role in pancreatic fibrosis and inflammation, where oxidative stress is implicated in the pathogenesis. NADPH oxidase might be a source of reactive oxygen species (ROS) in the injured pancreas. This study aimed to clarify the expression and regulation of cell functions by NADPH oxidase in PSCs. PSCs were isolated from rat and human pancreas tissues. Expression of NADPH oxidase was assessed by reverse transcription-PCR and immunostaining. Intracellular ROS production was assessed using 2',7'-dichlorofluorescin diacetate. The effects of diphenylene iodonium (DPI) and apocynin, inhibitors of NADPH oxidase, on key parameters of PSC activation were evaluated in vitro. In vivo, DPI (at 1 mg x kg body [wt.sup.-1] x [day.sup.-1]) was administered in drinking water to 10-wk-old male Wistar Bonn/Kobori rats for 10 wk and to rats with chronic pancreatitis induced by dibutyltin dichloride (DBTC). PSCs expressed key components of NADPH oxidase (p[22.sup.phox], p[47.sup.phox], NOXI, gp[91.sup.phox]/NOX2, NOX4, and NOX activator 1). PDGF-BB, IL-1[beta], and angiotensin II induced ROS production, which was abolished by DPI and apocynin. DPI inhibited PDGF-induced proliferation, IL-1[beta]-induced chemokine production, and expression of [alpha]-smooth muscle actin and collagen. DPI inhibited transformation of freshly isolated cells to a myofibroblast-like phenotype. In addition, DPI inhibited the development of pancreatic fibrosis in Wistar Bonn/Kobori rats and in rats with DBTC-induced chronic pancreatitis. In conclusion, PSCs express NADPH oxidase to generate ROS, which mediates key cell functions and activation of PSCs. NADPH oxidase might be a potential target for the treatment of pancreatic fibrosis. pancreatitis; pancreatic fibrosis; oxidative stress

Although it is recognized that neurogenic influences contribute to progression of chronic inflammatory diseases, the molecular basis of neuroimmune interactions in the pathogenesis of chronic pancreatitis (CP) is not well defined. Here we report that responsiveness of peripheral blood mononuclear cells (PBMC) to the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is altered in CP. Expression of PACAP and its receptors in human CP was analyzed with quantitative RT-PCR, laser-capture microdissection, and immunohistochemistry. Regulation of PACAP expression was studied in coculture systems using macrophages and acinar cells. Responsiveness of donor and CP PBMC to PACAP was determined based on cytokine profiles and NF-[kappa]B activation of LPS- or LPS+PACAP-exposed cells. Although donor and CP PBMC responded equally to LPS, PACAP-mediated counteraction of LPS-induced cytokine response was switched from inhibiting TNF-[alpha] to decreasing IL-1[beta] and increasing IL-10 secretion. The change of PACAP-mediated anti-inflammatory pattern was associated with altered activation of NF-[kappa]B: compared with LPS alone, a combination of LPS and PACAP had no effect on NF-[kappa]B p65 nuclear translocation in CP PBMC, whereas NF-[kappa]B was significantly decreased in donor PBMC. According to laser-capture microdissection and coculture experiments, PBMC also contributed to generation of a PACAP-rich intrapancreatic environment by upregulating PACAP expression in macrophages encountering apoptotic pancreatic acini. The nociceptive status of CP patients correlated with pancreatic PACAP levels and with IL-10 bias of PACAP-exposed CP PBMC. Thus the ability of PBMC to produce and to respond to PACAP might influence neuroimmune interactions that regulate pain and inflammation in CP. cytokines; inflammation; pituitary adenylate cyclase-activating polypeptide; peripheral blood mononuclear cells

Alcohol abuse is the major cause of chronic inflammation of the pancreas (i.e., chronic pancreatitis). Although it has long been thought that alcoholic pancreatitis is a chronic disease from the [...]

This study was designed to examine whether continuous pancreatic ductal hypertension (PDH) plays an important role in the onset and development of chronic pancreatitis (CP). Pancreatic, biliary, and duodenal cannulas were implanted in male Wistar rats. PDH was induced by vertically raising the free end of the pancreatic duct cannula to exert a hydrostatic pressure and maintained for 2 wk. PDH was gradually increased, but when the pancreatic juice (PJ) flow was interrupted, PDH was decreased to restore PJ flow. The induction of PDH resulted in a marked reduction of amylase activity in PJ and an increase in serum amylase activity. At 2 wk after persistent PDH, pancreatic exocrine function was markedly decreased in response to a bolus injection of secretin (100 pmol/kg) compared with the control group. Histological examination revealed interlobular as well as intralobular fibrosis in the form of nodular pancreatitis at 2 wk after the induction of PDH. Immunohistochemistry revealed the expression of fibronectin and collagen types I and III. Quantitative real-time RT-PCR showed an increase in transforming growth factor-[[beta].sub.1] mRNA expression in the pancreas during PDH. The present results suggest that PDH plays an important role in the onset and development of CP. Furthermore, our animal model seems useful for investigating the mechanisms of CP in rats. pancreatic fibrosis; pancreatic ductal hypertension

Studies in humans have shown that pancreatic enzyme secretion is reduced during acute pancreatitis. It is not known, however, whether the reduction is due to impaired synthesis or disruption of the secretory pathway. The rate of secretion and turnover of trypsin was measured in 12 patients with acute pancreatitis of variable etiology and severity (median Ranson's score 2.5, range 0-5, 4 with severe necrotizing disease) and eight healthy volunteers by 4-h primed/continuous intravenous infusions of 1-[sup.13]C-labeled L-leucine, and collection of pancreatic secretions by duodenal perfusion and sampling. Trypsin secretion was reduced from 476 [+ or -] 73 to 153 [+ or -] 60 U/h (means [+ or -] SE, P = 0.005) in acute pancreatitis, with the greatest reductions being observed in patients with necrotizing disease (32 [+ or -] 7 U/h, P = 0.003). The time for newly labeled trypsin to first appear in digestive juice was not, however, delayed in pancreatitis patients (87.2 [+ or -] 11.1 vs. 94.7 [+ or -] 4.9 min); on the contrary, there was an early appearance of newly labeled trypsin at 30 min in patients with severe necrotizing pancreatitis (P < 0.05). Calculated zymogen pool turnover was unchanged, but pool size was decreased (P = 0.01). Despite low rates of luminal secretion, trypsin continues to be synthesized in patients with acute pancreatitis. Our findings could be explained by post-Golgi leakage of enzymes from acinar cells or by loss of synthetic function in some cells with preservation in others.

Although NF-[kappa]B plays an important role in pancreatitis, mechanisms underlying its activation remain unclear. We investigated the signaling pathways mediating NF-[kappa]B activation in pancreatic acinar cells induced by high-dose cholecystokinin-8 (CCK-8), which causes pancreatitis in rodent models, and TNF-[alpha], which contributes to inflammatory responses of pancreatitis, especially the role of PKC isoforms. We determined subcellular distribution and kinase activities of PKC isoforms and NF-[kappa]B activation in dispersed rat pancreatic acini. We applied isoform-specific, cell-permeable peptide inhibitors to assess the role of individual PKC isoforms in NF-[kappa]B activation. Both CCK-8 and TNF-[alpha] activated the novel isoforms PKC-[delta] and -[epsilon] and the atypical isoform PKC-[zeta] but not the conventional isoform PKC-[alpha]. Inhibition of the novel PKC isoforms but not the conventional or the atypical isoform resulted in the prevention of NF-[kappa]B activation induced by CCK-8 and TNF-[alpha]. NF-[kappa]B activation by CCK-8 and TNF-[alpha] required translocation but not tyrosine phosphorylation of PKC-[delta]. Activation of PKC-[delta], PKC-[epsilon], and NF-[kappa]B with CCK-8 involved both phosphatidylinositol-specific PLC and phosphatidylcholine (PC)-specific PLC, whereas with TNF-[alpha] they only required PC-specific PLC for activation. Results indicate that CCK-8 and TNF-[alpha] initiate NF-[kappa]B activation by different PLC pathways that converge at the novel PKCs ([delta] and [epsilon]) to mediate NF-[kappa]B activation in pancreatic acinar cells. These findings suggest a key role for the novel PKCs in pancreatitis. phosphatidylcholine-specific phospholipase C; phosphatidylinositol-specific phospholipase C: Src kinases; translocation; tyrosine phosphorylation

Background and aims: Nitric oxide represents a potential key mediator of the local and systemic manifestations of acute pancreatitis (AP) in experimental models but its role in human disease is [...]

Research has been conducted lipid-lipase interactions. The role of hydrophobic loop's lipid interactions in C-terminal domain pancreatic lipase has been investigated via the study of human pancreatic lipase mutant with increased (beta)5' loop hydrophobicity and the results indicate loop's major contribution in the lipid-lipase interaction with their substrates.

We hypothesized that neurogenic inflammation is a common final pathway for parenchymal inflammation in pancreatitis and evaluated the role of primary sensory neurons in secretagogue-induced and obstructive pancreatitis. Neonatal rats received either the primary sensory neuron-denervating agent capsaicin (50 mg/kg sc) or vehicle. At 8 wk of age, pancreatitis was produced by six hourly injections of caerulein (50 [micro]g/kg ip) or by common pancreaticobiliary duct ligation (CPBDL). The severity of pancreatitis was assessed by serum amylase, pancreatic myeloperoxidase (MPO) activity, histological grading, pancreatic plasma extravasation, and wet-to-dry weight ratio. Caerulein significantly increased MPO activity and wet-to-dry weight ratio, produced histological evidence of edematous pancreatitis, induced plasma extravasation, and caused hyperamylasemia. CPBDL increased MPO activity and produced histological evidence of pancreatitis. Neonatal capsaicin administration significantly reduced tissue MPO levels, histological severity scores, and wet-to-dry weight ratio and abolished plasma extravasation. These results demonstrate that primary sensory neurons play a significant role in the inflammatory cascade in experimental pancreatitis and appear to constitute a common final pathway for pancreatic parenchymal inflammation. caerulein; capsaicin; common pancreaticobiliary duct ligation; neurogenic inflammation; substance P

Severe pancreatitis is frequently associated with acute lung injury (ALI) and the respiratory distress syndrome. The role of granulocyte-macrophage colony-stimulating factor (GM-CSF) in mediating the ALI associated with secretagogue-induced experimental pancreatitis was evaluated with GM-CSF knockout mice (GM-CSF -/-). Pancreatitis was induced by hourly (12x) intraperitoneal injection of a supramaximally stimulating dose of the cholecystokinin analog caerulein. The resulting pancreatitis was similar in GM-CSF-sufficient (GM-CSF +/+) control animals and GM-CSF -/- mice. Lung injury, quantitated by measuring lung myeloperoxidase activity (an indicator of neutrophil sequestration), alveolar-capillary permeability, and alveolar membrane thickness was less severe in GM-CSF -/- than in GM-CSF +/+ mice. In GM-CSF +/+ mice, pancreas, lung and serum GM-CSF levels increase during pancreatitis. Lung levels of macrophage inflammatory protein (MIP)-2 are also increased during pancreatitis, but, in this case, the rise is less profound in GM-CSF -/- mice than in GM-CSF +/+ controls. Administration of anti-MIP-2 antibodies was found to reduce the severity of pancreatitis-associated ALI. Our findings indicate that GM-CSF plays a critical role in coupling pancreatitis to ALI and suggest that GM-CSF may act indirectly by regulating the release of other proinflammatory factors including MIP-2. granulocyte-macrophage colony-stimulating factor; caerulein; inflammation; adult respiratory distress syndrome; adhesion molecules; neutrophils

Intrapancreatic activation of trypsinogen is believed to play a critical role in the initiation of acute pancreatitis, but mechanisms responsible for intrapancreatic trypsinogen activation during pancreatitis have not been clearly defined. In previous in vitro studies, we have shown that intra-acinar cell activation of trypsinogen and acinar cell injury in response to supramaximal secretagogue stimulation could be prevented by the cell permeant cathepsin B inhibitor E64d (Saluja A, Donovan EA, Yamanaka K, Yamaguchi Y, Hofbauer B, and Steer ML. Gastroenterology 113: 304-310, 1997). The present studies evaluated the role of intrapancreatic trypsinogen activation, this time under in vivo conditions, in two models of pancreatitis by using another highly soluble cell permeant cathepsin B inhibitor, L-3-trans-(propylcarbamoyl)oxirane-2-carbonyl-u-isoleucyl-L-proline methyl ester (CA-074me). Intravenous administration of CA-074me (10 mg/kg) before induction of either secretagogue-elicited pancreatitis in mice or duct infusion-elicited pancreatitis in rats markedly reduced the extent of intrapancreatic trypsinogen activation and substantially reduced the severity of both pancreatitis models. These observations support the hypothesis that, during the early stages of pancreatitis, trypsinogen activation in the pancreas is mediated by the lysosomal enzyme cathepsin B. Our findings also suggest that pharmacological interventions that inhibit cathepsin B may prove useful in preventing acute pancreatitis or reducing its severity. zymogens

The eukaryotic transcription factor nuclear factor-[kappa]B (NF-[kappa]B)/Rel is activated by a large variety of stimuli. It has been demonstrated that NF-[kappa]B/Rel is induced during the course of cerulein pancreatitis. Here, we show that NF-[kappa]B/Rel is differentially activated in pancreatic lobules. Cerulein induces NF-[kappa]B/Rel via activation of I[kappa]B kinase (IKK), which causes degradation of I[kappa]B[alpha] but not I[kappa]B[alpha]. Tumor necrosis factor-[alpha]-mediated IKK activation leads to I[kappa]B[alpha] and I[kappa]B[beta] degradation. In contrast, oxidative stress induced by [H.sub.2][O.sub.2] activates NF-[kappa]B/Rel independent of IKK activation and I[kappa]B[alpha] degradation; instead I[kappa]B[alpha] is phosphorylated on tyrosine. [H.sub.2][O.sub.2] but not cerulein-mediated NF-[kappa]B/Rel activation can be blocked by stabilizing microtubules with Taxol. Inhibition of tubulin polymerization with nocodazole causes NF-[kappa]B/Rel activation in pancreatic lobules. These results propose three different pathways of NF-[kappa]B/Rel activation in pancreatic acinar cells. Furthermore, these data demonstrate that microtubules play a key role in IKK-independent NF-[kappa]B/Rel activation following oxidative stress. acute pancreatitis; inhibitor protein I[kappa]B; I[kappa]B kinase; inflammation; hydrogen peroxide; tyrosine phosphorylation; cytokines; cerulein

Background: Carboxypeptidase B from the pancreatic gland may exist in three different molecular and immunoreactive forms: the proenzyme, the active enzyme, and the activation peptide. Aims: To investigate levels of [...]

Alcoholic pancreatitis in rats: injury from nonoxidative metabolites of ethanol. Am J Physiol Gastrointest Liver Physiol 283: G65-G73, 2002; 10.1152/ajpgi.00419.2001. The mechanism by which alcohol injures the pancreas remains unknown. Recent investigations suggest a role for fatty acid ethyl ester (FAEE), a nonoxidative metabolite of ethanol, in the pathogenesis of alcohol pancreatitis. In this study, we characterized ethanol-induced injury in rats and evaluated the contribution of oxidative and nonoxidative ethanol metabolites in this form of acute pancreatitis. Pancreatic injury in rats was assessed by edema, intrapancreatic trypsinogen activation, and microscopy after infusing ethanol with or without inhibitors of oxidative ethanol metabolism. Plasma and tissue levels of FAEE and ethanol were measured and correlated with pancreatic injury. Ethanol infusion generated plasma and tissue FAEE and, in a dose-dependent fashion, induced a pancreas specific injury consisting of edema,trypsinogen activation, and formation of vacuoles in the pancreatic acini. Inhibition of the oxidation of ethanol significantly increased both FAEE concentration in plasma and pancreas and worsened the pancreatitis-like injury. This study provides direct evidence that ethanol, through its nonoxidative metabolic pathway, can produce pancreas-specific toxicity in vivo and suggests that FAEE are responsible for the development of early pancreatic cell damage in acute alcohol-induced pancreatitis. pathophysiology; ethanol metabolism; fatty acid ethyl ester

Interleukin (IL)-10, a potent anti-inflammatory cytokine, limits the severity of acute pancreatitis and downregulates transforming growth factor (TGF)-[beta] release by inflammatory cells on stimulation. Proinflammatory mediators, reactive oxygen species, and TGF-[beta] can activate pancreatic stellate cells and their synthesis of collagen I and III. This study evaluates the role of endogenous IL-10 in the modulation of the regeneration phase following acute pancreatitis and in the development of pancreatic fibrosis. IL-10 knockout (KO) mice and their C57BL/6 controls were submitted to repeated courses (3/wk, during 6 wk, followed by 1 wk of recovery) of cerulein-induced acute pancreatitis. TGF-[[beta].sub.1] release was measured on plasma, and its pancreatic expression was assessed by quantitative RT-PCR and immunohistochemistry. Intrapancreatic IL-10 gene expression was assessed by semi-quantitative RT-PCR, and intrapancreatic collagen content was assessed by picrosirius staining. Activated stellate cells were detected by immunohistochemistry. S phase intrapancreatic cells were marked using tritiated thymidine labeling. After repeated acute pancreatitis, IL-10 KO mice had more severe histological lesions and fibrosis (intrapancreatic collagen content) than controls. TGF-[[beta].sub.1] plasma levels, intrapancreatic transcription, and expression by ductal and interstitial cells, as well as the number of activated stellate cells, were significantly higher. IL-10 KO mice disclosed significantly fewer acinar cells in S phase, whereas the opposite was observed for pseudotubular cells. Endogenous IL-10 controls the regeneration phase and limits the severity of fibrosis and glandular atrophy induced by repeated episodes of acute pancreatitis in mice. experimental chronic pancreatitis; pancreatic fibrosis; transforming growth factor-[beta]; pancreatic stellate cells

Activation of zymogens within the pancreatic acinar cell is an early feature of acute pancreatitis. Supraphysiological concentrations of cholecystokinin (CCK) cause zymogen activation and pancreatitis. The effects of the CCK analog, caerulein, and alcohol on trypsin and chymotrypsin activation in isolated pancreatic acini were examined. Caerulein increased markers of zymogen activation in a time- and concentration-dependent manner. Notably, trypsin activity reached a peak value within 30 min, then diminished with time, whereas chymotrypsin activity increased with time. Ethanol (35 mM) sensitized the acinar cells to the effects of caerulein ([10.sup.-10] to [10.sup.-7] M) on zymogen activation but had no effect alone. The effects of ethanol were concentration dependent. Alcohols with a chain length of [greater than or equal to] 2 also sensitized the acinar cell to caerulein; the most potent was butanol. Branched alcohols (2-propanol and 2-butanol) were less potent than aliphatic alcohols (1-propanol and 1-butanol). The structure of an alcohol is related to its ability to sensitize acinar cells to the effects of caerulein on zymogen activation. trypsinogen activation peptide; trypsin; chymotrypsin; ethanol; pancreatitis

Patients with pancreatitis who have high IgG4 levels may have a form of pancreatitis called sclerosing pancreatitis, according to a study of 194 people. This could distinguish this disease from other pancreatic diseases, which may be hard to differentiate otherwise.

A study was conducted to analyze the function of insulin-like growth factor (IGF-I) in pancreatic regeneration after caerulein-induced pancreatitis characterized by transient fibroblast proliferation. Male Wistar rates were utilized to carry out the study. Results indicated that acinar cell proliferation during late regeneration from pancreatitis is influenced by paracrine release of IGF-I from fibroblasts.

A model of secretagogue-induced pancreatitis to determine the identity of the intrapancreatic site of trypsinogen activation and what happens with activated trypsin. Subcellular fractionation and both light and electron microscopy immunolocalization were employed. Findings indicated that in response to supramaximal secretagogue stimulation, trypsinogen is activated in a particulate intracellular site that is most likely made of cytoplasmic vacuoles.

Research was conducted to study the functions of intracellular trypsinogen activation and its association with lysosomal enzyme redistribution in the pathogenesis of acute pancreatitis in rats. The isolation of subcellular acinar fractions was determined by differential centrifugation while the fractional activity of cathepsin B was measured according to the fluorometric technique. Results showed that pancreatic autodigestion did not happen in caerulein pancreatitis.

Research was conducted to examine the effects of bradykinin B2 receptor antagonist icatibant on postcapillary leukostasis, tissue necrosis and microcirculatory stasis in acute pancreatitis in rats. The rats were anesthetized with intraperitoneal injection of pentobarbital sodium and ketamine while the diameter of interlobular arterioles was determined before the induction of acute pancreatitis. Results confirmed the importance of postcapillary venular leukocyte adherence and capillary microcirculatory breakdown in the development of hemorrhagic necrotizing pancreatitis.

The extravasation of plasma proteins was analyzed in murine gastrointestinal tract and pancreas to determine the neurally mediated mechanisms that promote gastric and pancreatic inflammation. Extravasation of plasma proteins from the postcapillary venules of murine stomach, pancreas, small and large intestines was induced by the interaction of bradykinin and substance P with NK1 and B2 receptors. Furthermore, the major sites of elevated plasma extravasation to bradykinin and substance P occurred in the submucosa of the stomach, small intestine and colon.

In vivo microscopy was utilized to determine the effects of retrograde infusions of sodium taurocholate into the pancreatic duct of pancreatic microcirculation in rats. Analysis of acute pancreatitis due to the infusion of sodium taurocholate into the main pancreatic duct of rats indicated the detergent action of bile salts which enhanced pancreatic ductal and capillary permeability. Pancreatic failure in rats was mediated by local pancreatic metabolic acidosis and free radicals after acute inflammation.

The role of prostaglandin E1 (PGE1) in the pathogenesis of pancreatitis-associated lung injury was analyzed in rats with caerulein-induced interstitial edematous acute pancreatitis. Infusions of PGE1 in rats with caerulein-induced interstitial edematous acute pancreatitis reduced lung damage by inhibiting the intrapulmonary sequestration of neutrophils. However, PGE1 infusions did not alter the severity of pancreatitis-associated pancreatic injury.