The pancreatitis-associated protein induces lung inflammation in the rat through activation of TNFalpha expression in hepatocytes

Reg3β: A Potential Therapeutic Target for Tissue Injury and Inflammation-Associated Disorders

Since regenerating islet-derived 3β (Reg3β) was first reported, various studies have been conducted to explore the involvement of Reg3β in a gamut of maladies, such as diabetes, pancreatitis, pancreatic ductal adenocarcinoma, and extrapancreatic maladies such as inflammatory bowel disease, acute liver failure, and myocardial infarction. Surprisingly, there is currently no systematic review of Reg3β. Therefore, we summarize the structural characteristics, transcriptional regulation, putative receptors, and signaling pathways of Reg3β. The exact functional roles in various diseases, especially gastrointestinal and liver diseases, are also discussed. Reg3β plays multiple roles in promoting proliferation, inducing differentiation, preventing apoptosis, and resisting bacteria. The present review may provide new directions for the diagnosis and treatment of gastrointestinal, liver, and pancreatic diseases.

Chest computed tomography semi-quantitative pleural effusion and pulmonary consolidation are early predictors of acute pancreatitis severity

Background

To study the predictive value of semi-quantitative pleural effusion and pulmonary consolidation for acute pancreatitis (AP) severity.

Methods

Thorax-abdominal computed tomography (CT) examinations were performed on 309 consecutive AP patients in a single center. Among them, 196 were male, and 113 were female, and the average age was 50±16 years. The etiology of AP was biliary in 43.7% (n=135), hyperlipidemia in 22.0% (n=68), alcoholic in 7.4% (n=23), trauma in 0.6% (n=2), and postoperative status in 1.6% (n=5) cases; 24.6% (n=76) of patients did not have specified etiologies. The prevalence of pleural effusion and pulmonary consolidation was noted. The pleural effusion volume was quantitatively derived from a CT volume evaluation software tool. The pulmonary consolidation score was based on the number of lobes involved in AP. Each patient's CT severity index (CTSI), acute physiology and chronic health evaluation II (APACHE II) scoring system, and bedside index for severity in acute pancreatitis (BISAP) scores were obtained. The semi-quantitative pleural effusion and pulmonary consolidation were compared to these scores and clinical outcomes by receiver operator characteristic (ROC) curve and area under the curve (AUC) analysis.

Results

In the 309 patients, 39.8% had pleural effusion, and 47.9% had pulmonary consolidation. The mean pleural effusion volume was 41.7±38.0 mL. The mean pulmonary consolidation score was 1.0±1.2 points. The mean CTSI was 3.7±1.8 points, the mean APACHE II score was 5.8±5.1 points, and the mean BISAP score was 1.3±1.0 points; 5.5% of patients developed severe AP, and 13.9% of patients developed organ failure. Pleural effusion volume and pulmonary consolidation scores correlated to the scores for the severity of AP. In predicting severe AP, the accuracy (AUC 0.839) of pleural effusion volume was similar to that of the CTSI score (P=0.961), APACHE II score (P=0.757), and BISAP score (P=0.906). The accuracy (AUC 0.805) of the pulmonary consolidation score was also similar to that of the CTSI score (P=0.503), APACHE II score (P=0.343), and BISAP score (P=0.669). In predicting organ failure, the accuracy (AUC 0.783) of pleural effusion volume was similar to that of the CTSI score (P=0.473), APACHE II score (P=0.119), and BISAP score (P=0.980), and the accuracy (AUC 0.808) of the pulmonary consolidation score was also similar to that of the CTSI score (P=0.236), APACHE II score (P=0.293), and BISAP score (P=0.612).

Conclusions

Pleural effusion and pulmonary consolidation are common in AP and correlated to the severity of AP. Furthermore, the pleural effusion volume and pulmonary consolidation lobes can provide early prediction of severe AP and organ failure.

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

AIM: 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).

METHODS: 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.

RESULTS: 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).

CONCLUSION: 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.

Regenerating proteins and their expression, regulation and signaling

The regenerating (Reg) protein family comprises C-type lectin-like proteins discovered independently during pancreatitis and pancreatic islet regeneration. However, an increasing number of studies provide evidence of participation of Reg proteins in the proliferation and differentiation of diverse cell types. Moreover, Reg family members are associated with various pathologies, including diabetes and forms of gastrointestinal cancer. These findings have led to the emergence of key roles for Reg proteins as anti-inflammatory, antiapoptotic and mitogenic agents in multiple physiologic and disease contexts. Yet, there are significant gaps in our knowledge regarding the regulation of expression of different Reg genes. In addition, the pathways relaying Reg-triggered signals, their targets and potential cross-talk with other cascades are still largely unknown. In this review, the expression patterns of different Reg members in the pancreas and extrapancreatic tissues are described. Moreover, factors known to modulate Reg levels in different cell types are discussed. Several signaling pathways, which have been implicated in conferring the effects of Reg ligands to date, are also delineated. Further efforts are necessary for elucidating the biological processes underlying the action of Reg proteins and their involvement in various maladies. Better understanding of the function of Reg genes and proteins will be beneficial in the design and development of therapies utilizing or targeting this protein group.

Mutational characterization of pancreatitis-associated protein 2 domains involved in mediating cytokine secretion in macrophages and the NF-kappaB pathway

Pancreatitis-associated protein 2 (PAP2) is a member of the Reg3 gene family and is classified as a group 7 C-type lectin-like protein. In rats, each of the three PAP isoforms has independent immunologic functional effects on macrophages. We have previously shown that PAP2 up-regulates inflammatory cytokines in macrophages in a dose-dependent manner and acts through NF-kappaB mechanisms. In this study, we aimed to determine protein domains that are essential for the immunologic function of PAP2 by mutational or chemical analysis. The protein activity for each mutant was determined by measuring TNF-alpha, IL-6, or IL-1 production in macrophages. Truncation of the first 25 residues on the N terminus of PAP2 did not affect protein activity whereas truncation of the last 30 residues of the C terminus of PAP2 completely inactivated the function of PAP2. Additionally, reduction of three disulfide bonds proved to be important for the activity of this protein. Further investigation revealed two invariant disulfide bonds were important for activity of PAP2 while the disulfide bond that is observed in long-form C-type lectin proteins was not essential for activity. Coupling the ability of PAP2 to up-regulate inflammatory cytokines via NF-kappaB with its associated expression in acute pancreatitis, a condition with aberrant concentrations of inflammatory cytokines, we investigated whether PAP2 mutants mechanistically activate the NF-kappaB-signaling pathway and demonstrate that preincubation with select rPAP2 mutant proteins affect translocation of this transcription factor into the nucleus.

Pancreatitis-associated protein 2 modulates inflammatory responses in macrophages

Pancreatitis-associated proteins (PAP) are stress-induced secretory proteins that are implicated in immunoregulation. Previous studies have demonstrated that PAP is up-regulated in acute pancreatitis and that gene knockdown of PAP correlated with worsening severity of pancreatitis, suggesting a protective effect for PAP. In the present study, we investigated the effect of PAP2 in the regulation of macrophage physiology. rPAP2 administration to clonal (NR8383) and primary macrophages were followed by an assessment of cell morphology, inflammatory cytokine expression, and studies of cell-signaling pathways. NR8383 macrophages which were cultured in the presence of PAP2 aggregated and exhibited increased expression of IL-1, IL-6, TNF-alpha, and IL-10; no significant change was observed in IL-12, IL-15, and IL-18 when compared with controls. Chemical inhibition of the NFkappaB pathway abolished cytokine production and PAP facilitated nuclear translocation of NF-kappaB and phosphorylation of IkappaB alpha inhibitory protein suggesting that PAP2 signaling involves this pathway. Cytokine responses were dose dependent. Interestingly, similar findings were observed with primary macrophages derived from lung, peritoneum, and blood but not spleen. Furthermore, PAP2 activity was inhibited by the presence of serum, inhibition which was overcome with increased PAP2. Our results demonstrate a new function for PAP2: it stimulates macrophage activity and likely modulates the inflammatory environment of pancreatitis.

Hepatic gene expression during endotoxemia

PURPOSE

During the course of sepsis, endotoxins and cytokines activate Kupffer cells, induce the liberation and synthesis of adhesion molecules, and damage hepatocytes, which leads to septic liver failure. The interaction of the different hepatic cell types during these processes is not completely understood and may be clarified by microarray technology.

MATERIALS AND METHODS

Seven Sprague Dawley rats received either an intraperitoneal injection of lipopolysaccharides (LPS) of 3 mg/kg body weight (n = 4) or sodium chloride (SC) 0.9% (n = 3). Animals were sacrificed 24 h after LPS or SC injection. RNA from liver tissue was isolated and hybridized on GeneChips (RAE 230A; Affymetrix, Santa Clara, CA). Expression of interleukin-1beta, tumor necrosis factor-alpha, and signal transducer and activator of transcription 3 was controlled by reverse transcription-polymerase chain reaction analysis. Immunohistochemical staining for intercellular adhesion molecule-1 of liver tissue was performed.

RESULTS

We detected 508 differentially expressed genes between LPS and SC. Two hundred forty-eight genes were up-regulated and 260 genes were down-regulated in the LPS versus the SC group. Mainly genes involved in immune response and receptor activity were up-regulated in the LPS group. Genes enrolled in catalytic, transferase activity, and metabolisms were down-regulated in the LPS group. The microarray findings could be verified by reverse transcription-polymerase chain reaction analysis and immunohistochemical staining.

CONCLUSIONS

The contemporaneous differential regulation of genes involved in metabolism, hepatocellular synthesis, and immune response reflect the liver's central role as immune organ during the course of sepsis. A switch from metabolic to immunological activity is obvious, which aggravates the hepatic damage. The functional interaction of the single genes identified during this process must be further clarified.

Small-interference RNA gene knockdown of pancreatitis-associated proteins in rat acute pancreatitis

OBJECTIVES

Pancreatitis-associated proteins (PAPs) are induced in acute pancreatitis and antisense-mediated gene knockdown of PAP decreased PAP gene expression and worsened pancreatitis. Here, we investigated the effect of a more stable inhibition of PAP using small-interference RNA gene knockdown in vitro and in an in vivo model of experimental pancreatitis.

METHODS

Pancreatitis-associated protein-specific siRNA was administered to AR42J cell cultures or rats induced with pancreatitis. Controls included administration of scrambled siRNA or vehicle alone. After 24 hours, cells and pancreata were harvested and assessed for PAP (PAP 1, PAP 2, PAP 3) gene expression and pancreatitis severity.

RESULTS

In vitro, PAP protein, and mRNA levels were reduced (PAP 1, 76%; PAP 2, 8%; PAP 3, 24%) in cells treated with PAP siRNA. In vivo, PAP 1, and PAP 3 expressions were reduced (PAP 1, 36%; PAP 3, 66%) in siRNA-treated rats; there was no difference in PAP 2 isoform mRNA expression and serum protein levels. Serum amylase and lipase levels decreased (> or =50%) after administration of siRNA; interleukin (IL) 1beta, IL-4, and IL-6 increased, whereas C-reactive protein and tumor necrosis factor-alpha decreased when compared with vehicle control. Administration of PAP siRNA correlated with worsening histopathology.

CONCLUSIONS

siRNA-mediated gene knockdown of PAP worsens pancreatitis. Differences in gene knockdown technology may provide different approaches to study gene function.

Comparative genomics of human-like Schistosoma japonicum genes indicates a putative mechanism for host-parasite relationship

Schistosoma japonicum causes schistosomiasis in humans and livestock in the Asia-Pacific region. We assembled more than 43,700 S. japonicum expressed sequence tags and conducted comparative genomic analyses between S. japonicum and its human host. Some schistosome genes showed exceptionally high similarity in nucleotide sequence to their human homologues, of which five exhibited anomalous phylogeny and human codon usage bias. The most plausible explanation for their presence is horizontal gene transfer from host to parasite. Functional evidence suggests that S. japonicum might exploit host endocrine and immune signals for cell development and maturation via these host-like genes.

Pathogenesis and treatment of acute pancreatitis with liver injury

Acute pancreatitis is a frequent acute abdomen in clinic, causes damages not only to pancreas, but also to distant organs. Liver is one of the mainly involved organs. The development of liver injury may aggravate pancreatitis. The pathogenesis of acute pancreatitis with liver injury is mainly related to cytokines, pancreatic enzyme, oxidative stress, microcirculation disturbance, apoptosis and pancreatitis-associated ascitic fluid, etc. Its treatment is also to eradicate these factors. However, more methods are still under animal studies. Their clinical application requires further study.

Pancreas-specific RelA/p65 truncation increases susceptibility of acini to inflammation-associated cell death following cerulein pancreatitis

Activation of the transcription factor NF-kappaB/Rel has been shown to be involved in inflammatory disease. Here we studied the role of RelA/p65, the main transactivating subunit, during acute pancreatitis using a Cre-loxP strategy. Selective truncation of the rela gene in pancreatic exocrine cells led to both severe injury of the acinar cells and systemic complications including lung and liver damage. Our data demonstrated that expression and induction of the protective pancreas-specific acute phase protein pancreatitis-associated protein 1 (PAP1) depended on RelA/p65. Lentiviral gene transfer of PAP1 cDNA reduced the extent of necrosis and infiltration in the pancreata of mice with selective truncation of RelA/p65. These results provide in vivo evidence for RelA/p65 protection of acinar cell death via upregulation of PAP1. Moreover, our data underscore the pancreas-specific role of NF-kappaB/Rel and suggest multidimensional roles of NF-kappaB/Rel in different cells and contexts during inflammation.

Relationship between acute pancreatitis and oxidative stress

Under the imbalance between generation of reactive oxygen species and inadequate antioxidant defense systems, oxidative stress can cause cell damage either directly or indirectly through altering signaling pathways. It is the etiopathogenisis and also the consequence of many diseases. Oxidative injury plays an important role not only in the pathogenesis of acute pancreatitis (AP) but also in pancreatitis-induced damages of other organs such as heart, liver, lung, kidney, alimentary canal and so on. Oxidative stress can produce a higher level of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which induce inflammatory reaction and microcirculation disturbance, and cell necrosis or apoptosis, leading to pancreatic inflammation and multiple organ dysfunction syndromes. The antioxidants can decrease the production of oxygen free radicals (or directly scavenge them), protect the antioxidant enzyme activity, reinforce the antioxidative capacity of bodies, and consequently play an obvious therapeutic effect on AP.

Inhibition of the TPA-induced cutaneous inflammation and hyperplasia by EC-SOD

This study reports the roles of extracellular superoxide dismutase (EC-SOD) in the cutaneous inflammation and hyperplasia with 12-O-tetradecanoylphorbol-3-acetate (TPA) application in EC-SOD transgenic mice (Tg EC-SOD). Topical double TPA treatment induced the various inflammatory changes including the epidermal thickness, elevated the PCNA-labeling index, the edema formation, and increased production of hydrogen peroxide (H2O2) in wild type mice (WT). These changes were markedly suppressed in TPA-treated Tg EC-SOD. The expressions of the inflammatory cytokines, IL-1alpha and IL-1beta, were reduced in the TPA-treated Tg EC-SOD compared with those in TPA-treated WT. The expression of IL-1alpha was significantly increased in the skin of TPA-treated WT, especially in the basal and suprabasal layers, but it was restricted focally in basal layer of the skin of TPA-treated Tg EC-SOD. The number of infiltrating inflammatory cells and the IL-1beta expressing cells was obviously reduced in TPA-treated Tg EC-SOD in comparison with TPA-treated WT. The result suggests that EC-SOD might play an important role in the suppression of TPA-induced cutaneous inflammation and epidermal hyperplasia by regulating the expression of IL-1alpha and IL-1beta, although the mechanisms remain to be elucidated.

Exocrine Meets Endocrine: Pancreatic Stone Protein and Regenerating Protein—Two Sides of the Same Coin

BACKGROUND

Regenerating protein (reg) and pancreatic stone protein (PSP) have been discovered independently in the fields of diabetes and pancreatitis.

MATERIALS AND METHODS

These proteins are identical; however, because of the gap between the endocrine and exocrine field, there was never a consensus and the nomenclature has not been rectified. Since the time of the initial discovery, more isoforms have been unified. Historically, PSP was discovered long before reg, yet, in many areas outside of the pancreatitis research field, reg is being used.

RESULTS

For PSP/reg, a role in proliferation and regeneration of islet cells has been postulated. A hitherto insufficiently understood phenomenon is the massive up-regulation of PSP/reg in pancreatic tissue and juice under conditions of stress. Similarly, PAP (pancreatitis-associated protein)/reg III has been attributed various functional roles. Structurally, the ability to form fibrils after tryptic cleavage is a striking common features of both proteins. However, this biochemical transformation is in itself not enough to gain functional insight. Thus, physiological and genetic approaches are required to further characterize the role of these proteins in the pancreas. Recently, more evidence has been presented in support of the theory that PSP/reg plays a key role in islet neogenesis/regeneration.

CONCLUSIONS

In this review we discuss the debate on the localization and functional roles of PSP/reg and PAP/regIII. Therefore, we have summarized hypotheses and experimental results supporting such hypotheses.

Pancreatitis-associated protein I suppresses NF-kappa B activation through a JAK/STAT-mediated mechanism in epithelial cells

Pancreatitis-associated protein I (PAP I), also known as HIP, p23, or Reg2 protein, has recently been implicated in the endogenous regulation of inflammation. Although it was initially characterized as a protein that is overexpressed in acute pancreatitis, PAP I has also been associated with a number of inflammatory diseases, such as Crohn's disease. Knowing that PAP I and IL-10 responses share several features, we have used a pancreatic acinar cell line (AR42J) to assess the extent to which their expression is reciprocally regulated, and whether the JAK/STAT and NF-kappaB signaling pathways are involved in the suppression of inflammation mediated by PAP I. We observed that PAP I is induced in epithelial cells by IL-10 and by PAP I itself. In contrast, we found phosphorylation and nuclear translocation of STAT3 and induction of suppressor of cytokine signaling 3 in response to PAP I exposure. Finally, a JAK-specific inhibitor, tyrphostin AG490, markedly prevented PAP I-induced NF-kappaB inhibition, pointing to a cross-talk between JAK/STAT3 and NF-kappaB signaling pathways. Together, these findings indicate that PAP I inhibits the inflammatory response by blocking NF-kappaB activation through a STAT3-dependent mechanism. Important functional similarities to the anti-inflammatory cytokine IL-10 suggest that PAP I could play a role similar to that of IL-10 in epithelial cells.

The isolated perfused liver response to a 'second hit' of portal endotoxin during severe acute pancreatitis

BACKGROUND/AIM

During severe acute pancreatitis (AP), the liver may show an exaggerated response to the inflammatory products of gut injury transported in the portal vein. Our aim was to explore liver proinflammatory mediator production after a 'second hit' of portal lipopolysaccharide (LPS) during AP.

METHODS

Twenty-four rats underwent one of three 'first-hit' scenarios: (1) severe AP induced by intraductal glycodeoxycholic acid injection and intravenous caerulein infusion, (2) sham laparotomy, or (3) no first intervention. Eighteen hours later, all animals received a 'second hit' of portal LPS in an isolated liver perfusion system. Tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, and IL-6 concentrations were measured in portal and systemic serum, and in the perfusate 30 and 90 min after the 'second hit'. Neutrophil activation by the perfusate was assayed using dihydrorhodamine-123 fluorescence.

RESULTS

We observed a six-fold increase in IL-6 concentration across the liver during AP. All livers produced TNF-alpha after the portal LPS challenge, but this was not exaggerated by AP. No differential neutrophil activation by the perfusate was seen.

CONCLUSION

TNF-alpha, IL-1beta, IL-6 and neutrophil activator production by the isolated perfused liver, in response to a 'second hit' of portal LPS, does not appear to be enhanced during AP.

A nuclear import inhibitory peptide ameliorates the severity of cholecystokinin-induced acute pancreatitis

AIM: To assess the effect of our novel cell-permeable nuclear factor-kappaB (NF-κB) inhibitor peptide PN50 in an experimental model of acute pancreatitis. PN50 was produced by conjugating the cell-penetrating penetratin peptide with the nuclear localization signal of the NF-κB p50 subunit.

METHODS: Pancreatitis was induced in male Wistar rats by administering 2×100 μg/kg body weight of cholecystokinin-octapeptide (CCK) intraperitoneally (IP) at an interval of 1 h. PN50-treated animals received 1 mg/kg of PN50 IP 30 min before or after the CCK injections. The animals were sacrificed 4 h after the first injection of CCK.

RESULTS: All the examined laboratory (the pancreatic weight/body weight ratio, serum amylase activity, pancreatic levels of TNF-α and IL-6, degree of lipid peroxidation, reduced glutathione levels, NF-κB binding activity, pancreatic and lung myeloperoxidase activity) and morphological parameters of the disease were improved before and after treatment with the PN50 peptide. According to the histological findings, PN50 protected the animals against acute pancreatitis by favoring the induction of apoptotic, as opposed to necrotic acinar cell death associated with severe acute pancreatitis.

CONCLUSION: Our study implies that reversible inhibitors of stress-responsive transcription factors like NF-κB might be clinically useful for the suppression of the severity of acute pancreatitis.

The multifunctional family of secreted proteins containing a C-type lectin-like domain linked to a short N-terminal peptide

PSP/Lithostathine/PTP/regI, PAP/p23/HIP, reg1L, regIV and "similar to PAP" are the members of a multifunctional family of secreted proteins containing a C-type lectin-like domain linked to a short N-terminal peptide. The expression of this group of proteins is controlled by complex mechanisms, some members being constitutively expressed in certain tissues while, in others, they require activation by several factors. These members have several apparently unrelated biological effects, depending on the member studied and the target cell. These proteins may act as mitogenic, antiapoptotic or anti-inflammatory factors, can regulate cellular adhesion, promote bacterial aggregation, inhibit CaCO3 crystal growth or increase resistance to antitumoral agents. The presence of specific receptors for these proteins is suggested because biological effects were observed after the addition of purified protein to culture media or after systemic administration to animals, whereas other biological effects could be explained by their biochemical capacity to form homo or heteromers or to form insoluble fibrils at physiological pH.

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Targeted inhibition of gene expression of pancreatitis-associated proteins exacerbates the severity of acute pancreatitis in rats

BACKGROUND

Pancreatitis-associated protein (PAP) is a secretory protein not normally expressed in healthy pancreas but highly induced during acute pancreatitis. While PAP has been shown to be anti-bacterial and anti-apoptotic in vitro, its definitive biological function in vivo is not clear.

METHODS

To elucidate the function of PAP, antisense oligodeoxyribonucleotides (AS-PAP) targeting all three isoforms of PAP were administered via intrapancreatic injections (5 mg kg day, 2 days) to rats prior to induction of pancreatitis.

RESULTS

Severity of pancreatitis and cytokine gene expression in peripheral blood mononuclear cells (PBMC) were evaluated. Administration of AS-PAP, but not the scrambled oligodeoxyribonucleotide (SC-PAP) control, reduced pancreatitis-induced PAP expression by 55.2 +/- 6.4%, 44.0 +/- 8.9%, and 38.9 +/- 10.7% for PAP isoforms I, II, and III, respectively, compared to saline-treated controls (P < 0.05 for all). Inhibition of PAP expression significantly worsened pancreatitis: serum amylase activity, pancreas wet weight (reflecting edema), and serum C-reactive protein levels all increased in AS-PAP-treated animals compared to SC-PAP-treated controls (by 3.5-, 1.7-, and 1.7-fold, respectively; P < 0.05 for all). Histopathologic evaluation of pancreas revealed worsened edema, elevated leukocyte infiltration, and fat necrosis after AS-PAP treatment. Gene expressions of IL-1 microm and IL-4 were significantly higher in PBMC isolated from AS-PAP-treated rats compared to SC-PAP controls.

CONCLUSION

This is the first in vivo evidence indicating that PAP mediates significant protection against pancreatic injury. Our data suggest that PAP may exert its protective function by suppressing local pancreatic as well as systemic inflammation during acute pancreatitis.

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Differential expression of the trypsin inhibitor SPINK3 mRNA and the mouse ortholog of secretory granule protein ZG-16p mRNA in the mouse pancreas after repetitive injury

A mouse model using repetitive acinar cell injury caused by supraphysiologic doses of cerulein to induce the characteristic fibrosis and loss of acinar cell mass found in human chronic pancreatitis was employed to identify early changes in gene expression. A gene array was used to detect changes in 18,000 expressed sequence tags; changes in specific transcripts were confirmed by RNase protection assays. These methods identified SPINK3, the mouse homologue of human and rat protease inhibitor genes, as being highly expressed in the pancreas and induced after pancreatic injury. Because SPINK3 may be an important serine protease inhibitor, its up-regulation may reflect an important endogenous cytoprotective mechanism in preventing further injury. The up-regulation of SPINK3 was specific; the mouse homologue of the zymogen-processing protein ZG-16p was also highly expressed in the pancreas but sharply down-regulated early in the course of injury. These findings suggest that the pancreatic acinar cell may respond to injury with a program of self-preservation and loss of normal function.

A truncated form of CKbeta8-1 is a potent agonist for human formyl peptide-receptor-like 1 receptor

1. Human formyl peptide-receptor-like-1 (FPRL-1) is a promiscuous G protein-coupled receptor (GPCR), and belongs to a chemoattractant receptor family protein. This receptor has been reported to interact with various host-derived peptides and lipids involved in inflammatory responses. We described here, a novel role for FPRL-1 as a high-affinity beta-chemokine receptor for an N-terminally truncated form of the CKbeta8 (CCL23/MPIF-1) splice variant CKbeta8-1 (22-137 aa). 2. RT-PCR analysis of mRNA derived from human tissues and cells revealed a predominant expression of FPRL-1 in inflammatory cells, particularly in neutrophils. 3. Intracellular calcium mobilisation assay, used as screening tool, in recombinant Chinese hamster ovary (CHO-K1) and human embryonic kidney (HEK293s) cells coexpressing FPRL-1 and Galpha(16), demonstrated FPRL-1 is a functional high-affinity receptor for CKbeta8-1 (46-137 aa, sCKbeta8-1), with pEC(50) values of 9.13 and 8.85, respectively. 4. The FPRL-1 activation in CHO-K1 cells is mediated by Galpha(i)/Galpha(o) proteins, as assessed by pertussis toxin sensitivity and inhibition of forskolin-induced cyclic AMP accumulation. 5. Binding experiments were performed with a radio-iodinated synthetic peptide, [(125-)I]-WKYMVm, a known potent FPRL-1 agonist. CHO-K1 cell membranes expressing FPRL-1 bound [(125-)I]-WKYMVm with a K(d) value of 9.34. Many known FPRL-1 agonists were tested and sCKbeta8-1 was the most effective nonsynthetic ligand in displacing the radiolabelled agonist, with a pIC(50) of 7.97. 6. The functional significance of sCKbeta8-1 interaction with FPRL-1 was further demonstrated by the activation of polymorphonuclear leukocytes (PMNs) calcium mobilisation and chemotaxis. These interactions were shown to be via FPRL-1 by specific blockade of PMNs activation in the presence of an FPRL-1 antibody.