Dexamethasone mediates protection against acute pancreatitis via upregulation of pancreatitis-associated proteins

Association between Severe SARS-CoV-2 Infection and Severe Acute Pancreatitis in Pregnancy and Postpartum

INTRODUCTION

SARS-CoV-2 infection (COVID-19) affects the respiratory system but is not limited to it. The gastrointestinal symptoms are polymorphic, including diarrhea, vomiting, abdominal pain, and even acute pancreatitis (AP). Pregnant women are more vulnerable to SARS-CoV-2 infection and have a higher risk of severe outcomes of COVID-19.

CASE REPORT

We present a case report of a 31-year-old primigravid patient at 30 weeks of gestation, unvaccinated, with a medical history of thrombophilia, chronic nephropathy of unknown origin, hypertension, and optic neuropathy with left eye hemianopsia. She was diagnosed with moderate-to-severe COVID-19 and respiratory failure, with indication for cesarean section. Postpartum, she developed severe acute pancreatitis, complicated by peripancreatic and supradiaphragmatic abscesses. After 3 months of hospitalization and eight surgical interventions, the patient was discharged. A short mini-review of the literature is introduced.

CONCLUSION

Pregnant women with cardiovascular comorbidities are prone to severe complications of SARS-CoV-2 infection. Clinicians should be aware of the association of SARS-CoV-2 and AP in pregnant women.

ACVIM consensus statement on pancreatitis in cats

Background

Pancreatitis in cats, although commonly diagnosed, still presents many diagnostic and management challenges.

Objective

To summarize the current literature as it relates to etiology, pathogenesis, diagnosis, and management of pancreatitis in cats and to arrive at clinically relevant suggestions for veterinary clinicians that are based on evidence, and where such evidence is lacking, based on consensus of experts in the field.

Animals

None.

Methods

A panel of 8 experts in the field (5 internists, 1 radiologist, 1 clinical pathologist, and 1 anatomic pathologist), with support from a librarian, was formed to assess and summarize evidence in the peer reviewed literature and complement it with consensus clinical recommendations.

Results

There was little literature on the etiology and pathogenesis of spontaneous pancreatitis in cats, but there was much in the literature about the disease in humans, along with some experimental evidence in cats and nonfeline species. Most evidence was in the area of diagnosis of pancreatitis in cats, which was summarized carefully. In contrast, there was little evidence on the management of pancreatitis in cats.

Conclusions and Clinical Importance

Pancreatitis is amenable to antemortem diagnosis by integrating all clinical and diagnostic information available, and recognizing that acute pancreatitis is far easier to diagnose than chronic pancreatitis. Although both forms of pancreatitis can be managed successfully in many cats, management measures are far less clearly defined for chronic pancreatitis.

Pitfalls in AR42J-model of cerulein-induced acute pancreatitis

Background

AR42J are immortalized pancreatic adenocarcinoma cells that share similarities with pancreatic acinar cells. AR42J are often used as a cell-culture model of cerulein (CN)-induced acute pancreatitis (AP). Nevertheless, it is controversial how to treat AR42J for reliable induction of AP-like processes. Gene knockout and/or overexpression often remain challenging, as well. In this study, we demonstrate conditions for a reliable induction of proinflammatory markers upon CN treatment in AR42J and high transfection efficacy using Glyoxalase-I (Glo-I) as a target of interest.

Methods

Effects of dexamethasone (dexa) and CN on cell morphology and amylase secretion were analyzed via ELISA of supernatant. IL-6, TNF-α and NF-κB-p65 were measured via qRT-PCR, ELISA and Western Blot (WB). Transfection efficacy was determined by WB, qRT-PCR and immune fluorescence of pEGFP-N1-Glo-I-Vector and Glo-I-siRNA.

Results

Treatment of AR42J with 100 nm dexa is mandatory for differentiation to an acinar-cell-like phenotype and amylase production. CN resulted in secretion of amylase but did not influence amylase production. High levels of CN-induced amylase secretion were detected between 3 and 24 hours of incubation. Treatment with LPS alone or in combination with CN did not influence amylase release compared to control or CN. CN treatment resulted in increased TNF-α production but not secretion and did not influence IL-6 mRNA. CN-induced stimulation of NF-κB was found to be highest on protein levels after 6h of incubation. Transient transfection was able to induce overexpression on protein and mRNA levels, with highest effect after 12 to 24 hours. Gene-knockdown was achieved by using 30 pmol of siRNA leading to effective reduction of protein levels after 72 hours. CN did not induce amylase secretion in AR42J cell passages beyond 35.

Conclusion

AR42J cells demonstrate a reliable in-vitro model of CN-induced AP but specific conditions are mandatory to obtain reproducible data.

Emodin ameliorates acute lung injury induced by severe acute pancreatitis through the up-regulated expressions of AQP1 and AQP5 in lung

The present study investigates the ameliorating effects of emodin on acute lung injury (ALI) induced by severe acute pancreatitis (SAP). An ALI rat model was constructed by sodium ursodeoxycholate and they were divided into four groups: SHAM, ALI, emodin and dexamethasone (DEX) (n=24 per group). Blood samples and lung tissues were collected 6, 12 and 24 hours after the induction of SAP-associated ALI. Lung wet/dry ratio, blood gases, serum amylase and tumor necrosis factor-α (TNF-α) were measured at each time point. The expressions of AQP1 and AQP5 in lung tissue were detected by immunohistochemical staining, western blotting and real-time PCR. As the results show, there were no statistical differences in the levels of serum amylase, lung wet/dry ratio, blood gases indexes, serum TNF-α and pathological changes between emodin and DEX groups. However, significant differences were observed when compared with the ALI group. AQP1 and AQP5 expressions were significantly increased and lung oedemas were alleviated with the treatment of emodin and DEX. The expressions of AQP1 and AQP5 were significantly decreased in SAP-associated ALI rats. Emodin up-regulated the expression of AQP1 and AQP5, it could reduce pulmonary oedema and ameliorate SAP-induced ALI. Regulations on AQP1 and AQP5 expression had a great value in clinical application.

Emodin alleviates severe acute pancreatitis-associated acute lung injury by decreasing pre-B-cell colony-enhancing factor expression and promoting polymorphonuclear neutrophil apoptosis

The present study aimed to evaluate the protective effects of emodin on severe acute pancreatitis (SAP)‑associated acute lung injury (ALI), and investigated the possible mechanism involved. SAP was induced in Sprague‑Dawley rats by retrograde infusion of 5% sodium taurocholate (1 ml/kg), after which, rats were divided into various groups and were administered emodin, FK866 [a competitive inhibitor of pre‑B‑cell colony‑enhancing factor (PBEF)] or dexamethasone (DEX). DEX was used as a positive control. Subsequently, PBEF expression was detected in polymorphonuclear neutrophils (PMNs) isolated from rat peripheral blood by reverse transcription‑quantitative polymerase chain reaction and western blotting. In addition, histological alterations, apoptosis in lung/pancreatic tissues, apoptosis of peripheral blood PMNs and alterations in the expression of apoptosis‑associated proteins were examined by hematoxylin and eosin staining, terminal deoxynucleotidyl‑transferase‑mediated dUTP nick end labeling assay, Annexin V/propidium iodide (PI) assay and western blotting, respectively. Serum amylase activity and wet/dry (W/D) weight ratios were also measured. An in vitro study was also conducted, in which PMNs were obtained from normal Sprague‑Dawley rats and were incubated with emodin, FK866 or DEX in the presence of lipopolysaccharide (LPS). Apoptosis of PMNs and the expression levels of apoptosis‑associated proteins were examined in cultured PMNs in vitro by Annexin V/PI assay and western blotting, respectively. The results demonstrated that emodin, FK866 and DEX significantly downregulated PBEF expression in peripheral blood PMNs. In addition, emodin, FK866 and DEX reduced serum amylase activity, decreased lung and pancreas W/D weight ratios, alleviated lung and pancreatic injuries, and promoted PMN apoptosis by regulating the expression of apoptosis‑associated proteins: Fas, Fas ligand, B‑cell lymphoma (Bcl)‑2‑associated X protein, cleaved caspase‑3 and Bcl‑extra‑large. In addition, the in vitro study demonstrated that emodin, FK866 and DEX significantly reversed the LPS‑induced decrease of apoptosis in PMNs by regulating the expression of apoptosis‑associated proteins. In conclusion, the present study demonstrated that emodin may protect against SAP‑associated ALI by decreasing PBEF expression, and promoting PMN apoptosis via the mitochondrial and death receptor apoptotic pathways.

Management of acute pancreatitis in dogs: a critical appraisal with focus on feeding and analgesia

Knowledge about acute pancreatitis has increased recently in both the medical and veterinary fields. Despite this expansion of knowledge, there are very few studies on treatment interventions in naturally occurring disease in dogs. As a result, treatment recommendations are largely extrapolated from experimental rodent models or general critical care principles. General treatment principles involve replacing fluid losses, maintaining hydrostatic pressure, controlling nausea and providing pain relief. Specific interventions recently advocated in human medicine include the use of neurokinin-1 antagonists for analgesia and early interventional feeding. The premise for early feeding is to improve the health of the intestinal tract, as unhealthy enterocytes are thought to perpetuate systemic inflammation. The evidence for early interventional feeding is not supported by robust clinical trials to date, but in humans there is evidence that it reduces hospitalisation time and in dogs it is well tolerated. This article summarises the major areas of management of acute pancreatitis in dogs and examines the level of evidence for each recommendation.

Microarray analysis of pancreatic gene expression during biotin repletion in biotin-deficient rats

Biotin is a B vitamin involved in multiple metabolic pathways. In humans, biotin deficiency is relatively rare but can cause dermatitis, alopecia, and perosis. Low biotin levels occur in individuals with type-2 diabetes, and supplementation with biotin plus chromium may improve blood sugar control. The acute effect on pancreatic gene expression of biotin repletion following chronic deficiency is unclear, therefore we induced biotin deficiency in adult male rats by feeding them a 20% raw egg white diet for 6 weeks. Animals were then randomized into 2 groups: one group received a single biotin supplement and returned to normal chow lacking egg white, while the second group remained on the depletion diet. After 1 week, pancreata were removed from biotin-deficient (BD) and biotin-repleted (BR) animals and RNA was isolated for microarray analysis. Biotin depletion altered gene expression in a manner indicative of inflammation, fibrosis, and defective pancreatic function. Conversely, biotin repletion activated numerous repair and anti-inflammatory pathways, reduced fibrotic gene expression, and induced multiple genes involved in pancreatic endocrine and exocrine function. A subset of the results was confirmed by quantitative real-time PCR analysis, as well as by treatment of pancreatic AR42J cells with biotin. The results indicate that biotin repletion, even after lengthy deficiency, results in the rapid induction of repair processes in the pancreas.

Lycopene protects pancreatic acinar cells against severe acute pancreatitis by abating the oxidative stress through JNK pathway

This study investigated the anti-oxidative and anti-inflammatory effects of lycopene on severe acute pancreatitis (SAP) in both in vivo and in vitro models. Utilizing a rat model, we found that lycopene administration protected against SAP, as indicated by the decreased levels of serum amylase and C-reactive protein. Pathological changes were alleviated by pretreatment with lycopene. The serum levels of tumor necrosis factor-α, interleukin-6, macrophage inflammatory protein-1α, and monocyte chemotactic protein-1 were decreased by lycopene. The decreased reactive oxygen species (ROS) content in the pancreatic tissues of the lycopene-treated group were indirectly evaluated by measuring the levels of myeloperoxidase, lipid peroxidase, and superoxide dismutase. Lycopene protected acinar cells against necrosis and apoptosis by relieving the mitochondrial and endoplasmic stress caused by ROS which was shown in electron microscopy and immunohistochemistry staining of active nuclear factor-κB p65. The protective effect was also observed in a simulated SAP model in a rat acinar cell line. ROS and apoptotic staining were compared between groups. Lycopene exerts protective effects against SAP in rats that may be related to its anti-inflammatory property through inhibiting the expression of damage-associated molecular patterns, and anti-oxidative property which can thus maintain cellular homeostasis and prevent the phosphorylation of JNK pathway.

Traditional Chinese medicine, Qing Ying Tang, ameliorates the severity of acute lung injury induced by severe acute pancreatitis in rats via the upregulation of aquaporin-1

Aquaporin-1 (AQP-1) is expressed in lung endothelial cells and regulates water transport; thus, AQP-1 plays an important role in a number of edema-associated lung diseases. Qing Yin Tang (QYT), a traditional Chinese medicine, has been shown to effectively reduce the mortality rate of acute lung injury (ALI) induced by severe acute pancreatitis (SAP). The current study aimed to investigate the detailed mechanisms underlying the effects of QYT on ALI induced by SAP, particularly the effects on the expression levels of AQP-1 in the lung tissue. ALI was established in Wister rats who were subsequently divided into four groups: SHAM, ALI, dexamethasone (DEX) and QYT groups (n=8 per group). In the QYT group, 20 ml/kg QYT was administered by gavage immediately following the induction of SAP. Blood and lung tissues were collected 8 h following the induction of pancreatitis. The lung wet/dry ratio, as well as the levels of blood gases, serum amylase and tumor necrosis factor-α (TNF-α), were measured at 4, 8 and 12 h following SAP-associated ALI induction surgery. The expression levels of AQP-1 in the lung tissue were detected by quantitative polymerase chain reaction, immunohistochemistry and western blot analysis. No statistically significant differences were observed with regard to the levels of serum amylase, wet/dry ratio, partial pressure of oxygen, serum TNF-α and pathological changes in the pulmonary tissue between the QYT and DEX groups; however, a statistically significant difference was observed when compared with the ALI group. The expression levels of AQP-1 significantly increased (P<0.05) and lung edema was alleviated in the QYT and DEX groups, when compared with ALI group. Therefore, the expression level of AQP-1 is associated with pulmonary edema. QYT protects the lungs from injury induced by SAP via the upregulation of AQP-1, which suppresses TNF-α expression.

Efficacy of glucocorticoids in rodents of severe acute pancreatitis: a meta-analysis

BACKGROUND

The use of corticosteroid in the management of severe acute pancreatitis (SAP) remains contentious and is still being debated despite many pre-clinical studies demonstrating benefits. The limitations of clinical research on corticosteroid in SAP are disparities with regard to benefit, a lack of adequate safety data and insufficient understanding of its mechanisms of action. Thus, we performed a meta-analysis to assess the effectiveness of corticosteroid in experimental SAP and take a closer look at the relation between the animal studies and prospective trials.

METHODS

Studies investigating corticosteroid use in rodent animal models of SAP were identified by searching multiple three electronic databases through October 2013, and by reviewing references lists of obtained articles. Data on mortality, changes of ascitic fluid and histopathology of pancreas were extracted. A random-effects model was used to compute the pooled efficacy. Publication bias and sensitivity analysis were also performed.

RESULTS

We identified 15 published papers which met our inclusion criteria. Corticosteroid prolonged survival by a factor of 0.35 (95% CI 0.21-0.59). Prophylactic use of corticosteroid showed efficacy with regards to ascitic fluid and histopathology of pancreas, whereas therapeutic use did not. Efficacy was higher in large dose and dexamethasone groups. Study characteristics, namely type of steroids, rout of delivery, genders and strains of animal, accounted for a significant proportion of between-study heterogeneity. No significant publication bias was observed.

CONCLUSIONS

On the whole, corticosteroids have showed beneficial effects in rodent animal models of SAP. Prophylactic use of corticosteroid has failed to validate usefulness in prophylaxis of postendoscopic retrogradcholangiopancreatography pancreatitis. Further appropriate and informative animal experiments should be performed before conducting clinical trials investigating therapeutic use in SAP.

Effects of dexamethasone and Salvia miltiorrhiza on multiple organs in rats with severe acute pancreatitis

OBJECTIVE

To investigate the protective effects and mechanisms of action of dexamethasone and Salvia miltiorrhiza on multiple organs in rats with severe acute pancreatitis (SAP).

METHODS

The rats were divided into sham-operated, model control, dexamethasone treated, and Salvia miltiorrhiza treated groups. At 3, 6, and 12 h after operation, the mortality rate of different groups, pathological changes, Bcl-2-associated X protein (Bax) and nuclear factor-κB (NF-κB) protein expression levels in multiple organs (the pancreas, liver, kidneys, and lungs), toll-like receptor 4 (TLR-4) protein levels (only in the liver), intercellular adhesion molecule 1 (ICAM-1) protein levels (only in the lung), and terminal deoxynucleotidy transferase mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) staining expression levels, as well as the serum contents of amylase, glutamate-pyruvate transaminase (GPT), glutamic-oxaloacetic transaminase (GOT), blood urea nitrogen (BUN), and creatinine (CREA) were observed.

RESULTS

The mortality rate of the dexamethasone treated group was significantly lower than that of the model control group (P<0.05). The pathological changes in multiple organs in the two treated groups were relieved to different degrees (P<0.05 and P<0.01, respectively), the expression levels of Bax and NF-κB proteins, and apoptotic indexes of multiple organs were reduced (P<0.05 and P<0.01, respectively). The contents of amylase, GPT, GOT, BUN, and CREA in the two treated groups were significantly lower than those in model control groups (P<0.05 and P<0.01, respectively). The expression level of ICAM-1 protein in the lungs (at 3 and 12 h) in the dexamethasone treated group was significantly lower than that in the Salvia miltiorrhiza treated group (P<0.05). The serum contents of CREA (at 12 h) and BUN (at 6 h) of the Salvia miltiorrhiza treated group were significantly lower than those in the dexamethasone treated group (P<0.05).

CONCLUSIONS

Both dexamethasone and Salvia miltiorrhiza can reduce the inflammatory reaction, regulate apoptosis, and thus protect multiple organs of rats with SAP.

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.

Study of dexamethasone, baicalin and octreotide on brain injury of rats with severe acute pancreatitis

OBJECTIVE

To investigate the protecting effects of dexamethasone (DXM), baicalin and octreotide on brain injury of rats with severe acute pancreatitis (SAP) and explore their underlying mechanism.

METHODS

This experiment was divided into two different parts: (1) In the first part, 90 SAP rats were randomly divided into a model control group and a DXM treated group (n = 45, respectively). (2) In the second part, 135 SAP rats were randomly divided into a model control group, a baicalin treated group and an octreotide treated group (n = 45, respectively). In two different experiments, the same number of normal rats were considered as the sham-operated group (n = 45, respectively). At 3, 6 and 12 h after operation, the pathological changes in the brain were observed. The expression levels of nuclear factor-κB (NF-κB), Bax and Bcl-2 proteins were detected and apoptosis indexes were calculated, using brain tissue microarray section.

RESULTS

(1) First part: The expression levels of Bax and Bcl-2 were significantly higher in the DXM treated group than those in the model control group at different time points, while the content of NF-κB protein and pathological changes were significantly lower in the treated group than those in the model control group (P < 0.05, P < 0.01 or P < 0.001). But the apoptotic indexes of brain tissue were not significantly different at different time points (P > 0.05). (2) Second part: At all time points after operation, the expression levels of NF-κB in the brain of treated groups were, to varying degrees, significantly lower than those in the model control group while the expression levels of Bcl-2 protein in baicalin and octreotide group were significantly higher than those in model control group (P < 0.01, P < 0.01 and P < 0.05, respectively). At 12 h after operation, the expression level of Bax protein in baicalin treated group was significantly higher than those in model control group and octreotide treated group (P < 0.05 and P < 0.01, respectively).

CONCLUSIONS

Dexamethasone, baicalin and octreotide can exert protective effects against brain injury in SAP rats mainly through inhibiting the expression of NF-κB protein.

Clinical observation on the effect of dexamethasone and Chinese herbal decoction for purgation in severe acute pancreatitis patients

OBJECTIVE

To investigate the effect of dexamethasone (Dx) combined with modified Dachengqi Decoction (DCQD), a Chinese herbal decoction for purgation, on patients with severe acute on patients with severe acute, a Chinese herbal decoction for purgation, on patients with severe acute pancreatitis (SAP) accompanied with systematic inflammatory response syndrome (SIRS).

METHODS

A total of 81 patients diagnosed as SAP were randomly assigned to a control group or treatment group according to a random number table generated from an SPSS software. The patients in the control group (38 cases) received standard treatment and Chinese herbal decoction for purgation; those in the treatment group (43 cases) received additional 1 mg/(kg·d) dexamethasone (Dx) treatment for three days based on the above treatment. The mortality rate, acute respiratory distress syndrome (ARDS), renal failure, hemorrhage, sepsis, pancreatic pseudocyst, pancreatic abscess, operability, and days of hospitalization were compared between the two groups.

RESULTS

Three patients in the control group and eight patients in the treatment group dropped out from the study with a drop-out rate of 7.8% and 18.6%, respectively, and no statistics difference was shown between the two groups (P>0.05). Dx treatment significantly reduced ARDS rate and shortened the length of hospitalization compared to those in the control group (7/35, 20.0% versus 15/35, 42.9%, P=0.0394; 32.5±13.2 days versus 40.2±17.5 days, P=0.0344). Other parameters including the mortality rate were not significant different between the two groups.

CONCLUSION

Dx combined with DCQD could decrease the risk of developing ARDS in SAP patients with SIRS and shorten their length of hospitalization.

Comparison of His and GST tagged versions of recombinant pancreatitis associated protein 2 in modulation of inflammatory responses

OBJECTIVE AND DESIGN

Pancreatitis associated proteins (PAP) are highly upregulated in acute pancreatitis and other inflammatory states and have been shown to possess immunomodulatory properties. However, continued study of PAP has been hampered by the ability to effectively isolate appropriate amounts of protein from pancreatic juice or efficient generation of recombinant proteins. Here we describe two different methods for generating recombinant PAP2 protein (rPAP2), using either His or GST tagged bacterial methodology with comparison of function.

METHODS

His or GST tagged rPAP2 were generated, cultured with clonal (NR8383) macrophages and compared with respect to inflammatory cytokine expression (IL-1alpha, IL-1beta, IL-6, and TNF-alpha) and bacterial (E. coli) agglutination. Significance was determined by student's t test (P<0.05).

RESULTS

PAP2His treatment induced a 3.6, 2.8, 13.0, 3.5 fold induction of IL-1alpha, IL-1beta, TNF-alpha and IL-6, respectively; similar cytokine expression changes were observed with PAP2GST treatment (3.9, 2.6, 12.2, and 3.0 fold induction of IL-1alpha, IL-1beta, TNF-alpha and IL-6, respectively) (P<0.05). Further, incubation with recombinant PAP2 led to a time dependent increase in bacterial aggregates which was absent in controls.

CONCLUSIONS

These data demonstrate that both methods maintain functional immunomodulatory integrity for PAP2 and provide the ability to generate sufficient quantities to further study structure and function.

Protective effect of resveratrol in severe acute pancreatitis-induced brain injury

OBJECTIVES

The aim of this study was to study the effects of resveratrol on severe acute pancreatitis (SAP)-induced brain injury.

METHODS

Ninety-six male Sprague-Dawley rats were randomly divided into 4 equal groups: sham operation, SAP, resveratrol-treated (RES), and dexamethasone-treated. Each group was evaluated at 3, 6, and 12 hours. Levels of serum myelin basic protein and zonula occludens 1 (Zo-1) were determined by enzyme-linked immunosorbent assay. The brain and pancreatic tissues were examined using electron microscopy. Expressions of Bax, Bcl-2, and caspase-3 were observed using immunohistochemistry, reverse transcriptase polymerase chain reaction, and Western blotting. Cytochrome c was detected using Western blotting alone.

RESULTS

Myelin basic protein and Zo-1 levels of the RES group were lower than the SAP group at all time points (P < 0.05). The RES group had significantly improved pathologic brain, increase in Bcl-2 expression, and decrease in Bax and caspases-3 expressions compared with the SAP group.

CONCLUSIONS

The degradation of Zo-1 is involved in the pathophysiology of brain injury in SAP; MBP can be used as a marker of brain injury in SAP. The protective effect of resveratrol might be associated with the up-regulation of Bcl-2 and down-regulation of Bax and caspase-3.

Pancreatic regenerating protein I in chronic pancreatitis and aging: implications for new therapeutic approaches to diabetes

OBJECTIVES

We investigated the relationship of pancreatic regenerating protein (reg) in models of acinar cell atrophy and aging, and the effect of reg I protein replacement on glucose tolerance.

METHODS

Rats underwent pancreatic duct ligation (PDL) and were followed through 12 months. Aging rats were studied at 12 and 20 months. Intraperitoneal glucose tolerance tests (IPGTTs) were performed, pancreatic reg I, reg I receptor, insulin gene expression, and reg I protein levels were measured. Pancreatic duct ligation and aged animals were treated with exogenous reg I protein and assessed for glucose metabolism.

RESULTS

After PDL, chronic atrophic pancreatitis developed, with a progressive loss of acinar cells and pancreatic reg I. During aging, a similar depression of reg I gene expression was also noted. The reg I levels correlated with pancreatic insulin levels. Twelve months after PDL, IPGTT results were abnormal, which were significantly improved by administration of reg I protein. Aged animals demonstrated depressed IPGTT, which marginally improved after reg I administration. Anti-reg antibody administration to young rats depressed IPGTT to elderly levels.

CONCLUSIONS

Depletion of the acinar product reg I is associated with the pathogenesis of impaired glucose tolerance of pancreatitis-associated diabetes and aging, and replacement therapy could be useful in these patients. Reg I is an acinar cell product, which affects islet function.

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.

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.

Use of gene expression profiles in cells of peripheral blood to identify new molecular markers of acute pancreatitis

HYPOTHESIS

Blood leukocytes play a major role in mediating local and systemic inflammation during acute pancreatitis. We hypothesize that peripheral blood mononuclear cells (PBMCs) in circulation exhibit unique changes in gene expression and could provide a "reporter" function that reflects the inflammatory response in the pancreas with acute pancreatitis.

DESIGN

To determine specific changes in blood leukocytes during acute pancreatitis, we studied the gene transcription profile in PBMCs in a rat model of experimental pancreatitis (sodium taurocholate). Normal rats, saline controls, and a model of septic shock were used as a controls. Complementary RNA obtained from PBMCs of each group (n = 3 in each group) were applied to Affymetrix rat genome DNA GeneChip arrays. Main Outcome Measure Changes in gene expression.

RESULTS

From the 8799 rat genes analyzed, 140 genes showed unique significant changes in their expression in PBMCs during the acute phase of pancreatitis, but not in sepsis. Among the 140 genes, 57 were up-regulated, while 69 were down-regulated. Platelet-derived growth factor receptor, prostaglandin E(2) receptor, and phospholipase D(1) were among the top up-regulated genes. Others included genes involved in G protein-coupled receptor and transforming growth factor beta-mediated signaling pathways, while genes associated with apoptosis, glucocorticoid receptors, and even the cholecystokinin receptor were down-regulated.

CONCLUSIONS

Microarray analysis in transcriptional profiling of PBMCs showed that genes that are uniquely related to molecular and pancreatic function display differential expression in acute pancreatitis. Profiling genes obtained from an easily accessible source during severe pancreatitis may identify surrogate markers for disease severity.