The TRIM28/miR133a/CD47 axis acts as a potential therapeutic target in pancreatic necrosis by impairing efferocytosis.

Efferocytosis, the clearance of apoptotic cells by macrophages, plays a crucial role in inflammatory responses and effectively prevents secondary necrosis. However, the mechanisms underlying efferocytosis in acute pancreatitis (AP) remain unclear. In this study, we demonstrated the presence of efferocytosis in injured human and mouse pancreatic tissues. We also observed significant upregulation of CD47, an efferocytosis-related the "do not eat me" molecule in injured acinar cells. Subsequently, we used CRISPR-Cas9 gene editing, anti-adeno-associated virus (AAV) gene modification, and anti-CD47 antibody to investigate the potential therapeutic role of AP. CD47 expression was negatively regulated by upstream miR133a, which is controlled by the transcription factor TRIM28. To further investigate the regulation of efferocytosis and reduction of pancreatic necrosis in AP, we used miR-133a-agomir and pancreas-specific AAV-shTRIM28 to modulate CD47 expression. Our findings confirmed that CD47-mediated efferocytosis is critical for preventing pancreatic necrosis and suggest that targeting the TRIM28-miR133a-CD47 axis is clinically relevant for the treatment of AP.

RanBP2/Nup358 enhances miRNA activity by sumoylating Argonautes.

Mutations in RanBP2 (also known as Nup358), one of the main components of the cytoplasmic filaments of the nuclear pore complex, contribute to the overproduction of acute necrotizing encephalopathy (ANE1)-associated cytokines. Here we report that RanBP2 represses the translation of the interleukin 6 (IL6) mRNA, which encodes a cytokine that is aberrantly up-regulated in ANE1. Our data indicates that soon after its production, the IL6 messenger ribonucleoprotein (mRNP) recruits Argonautes bound to let-7 microRNA. After this mRNP is exported to the cytosol, RanBP2 sumoylates mRNP-associated Argonautes, thereby stabilizing them and enforcing mRNA silencing. Collectively, these results support a model whereby RanBP2 promotes an mRNP remodelling event that is critical for the miRNA-mediated suppression of clinically relevant mRNAs, such as IL6.

Heme Oxygenase-1 Polymorphism Is Associated With the Development of Necrotic Acute Pancreatitis Via Vascular Cell Adhesion Molecule-1 and the E-Selectin Expression Regulation Pathway.

OBJECTIVES: Severe acute pancreatitis can lead to systemic complications. Here, we explore the mechanisms based on our previous study associated with the deregulation of heme oxygenase-1 (HO-1) and development of severe acute pancreatitis. METHODS: Acute pancreatitis patients (n = 135) and age- and sex-matched healthy controls (n = 108) were studied. The polymerase chain reaction products were analyzed with an ABI 3130 genetic analyzer and GeneMapper software. A short allele was defined ≤27 dinucleotide (GT) repeats, whereas a long allele was defined >27 GT. Levels of 12 different cytokines in blood serum were measured by enzyme-linked immunosorbent assay. All samples in this study were consistently stored in -80°C. RESULTS: Patients with the long long genotype expressed E-selectin and vascular cell adhesion molecule-1 at statistically significantly higher levels in serum compared with short short genotype or short long genotypes. Vascular cell adhesion molecule-1 and E-selectin serum levels significantly correlate with the total allele length of the HO-1 promoter region. CONCLUSION: Polymorphism of the GT repeats in the HO-1 promoter region may be a risk factor for developing acute necrotizing pancreatitis due to deregulation of the immune response.

Bone marrow-derived mesenchymal stem cells attenuate severe acute pancreatitis via regulation of microRNA-9 to inhibit necroptosis in rats.

AIMS: Severe acute pancreatitis (SAP) is an acute disease of the digestive system accompanied by pancreatic necrosis. We have found that bone marrow-derived mesenchymal stem cells (BMSCs) can attenuate SAP, but the underlying mechanism remains unclear. The present study was conducted to explore the possible mechanisms by which BMSCs alleviate SAP. MAIN METHODS: BMSCs and BMSCs engineered to overexpress microRNA (miR)-9 (miR-9-BMSCs) were transplanted into rat models of SAP via the tail vein. Pancreatic acinar cells (PACs) were isolated from rat pancreatic tissues and induced by tumor necrosis factor-α (TNF-α) in vitro. KEY FINDINGS: miR-9-BMSCs significantly reduced the systemic inflammatory response, impeded the necroptosis signaling pathway and promoted regeneration of damaged pancreas in vivo. miR-9-BMSCs secreted miR-9, which targeted the gene encoding receptor interacting protein kinase 1 in PACs induced by TNF-α, to inhibit necroptosis and ameliorate SAP. SIGNIFICANCE: miR-9-BMSCs can reduce SAP-induced injury to pancreatic tissues and PACs by regulating miR-9 to suppress necroptosis.

Genistein protects against acute pancreatitis via activation of an apoptotic pathway mediated through endoplasmic reticulum stress in rats.

Acute pancreatitis (AP) is a severe and frequently lethal disorder, but the precise mechanisms are not well understood and there is lack of effective drugs. Therefore, our study examined the in vivo intervention effects of genistein and elucidated its mechanism in acute experimental pancreatitis models. We used cerulein or taurocholate to induce acute pancreatitis (AP) in Sprague-Dawley rats with prior genistein treatment. Histological examination of the pancreas was performed and the expression of unfolded protein response (UPR) components and apoptotic mediators like caspase 12 and c-Jun N-terminal protein kinase (JNK) were measured. The amount of apoptosis in pancreatic acinar cells was also determined. Our studies found that the severity of cerulein- or taurocholate-induced AP was rescued by prior genistein treatment. Genistein stimulated the activation of multiple endoplasmic reticulum (ER) stress-related regulators like GRP78, PERK, eIF2α, and upregulated the expression of the apoptotic genes, caspase 12 and CHOP. Moreover, TUNEL assays showed that genistein treatment promoted acinar cell apoptosis. Taken together, we speculated that ER stress-associated apoptotic pathways in AP are induced by genistein, which showed cytoprotective capacity in the exocrine pancreas. These data suggest novel therapeutic strategies that employ genistein in the prevention of AP.

MicroRNA-9 modified bone marrow-derived mesenchymal stem cells (BMSCs) repair severe acute pancreatitis (SAP) via inducing angiogenesis in rats.

BACKGROUND: Severe acute pancreatitis (SAP) is an acute abdominal disease characterized by pancreatic necrosis and systemic disease. In a previous study, we showed that bone marrow-derived mesenchymal stem cells (BMSCs) can reduce SAP by secreting microRNA (miR)-9; however, the underlying mechanism remains unclear. The present study investigated the mechanism underlying BMSC-induced pancreatic regeneration. METHODS: BMSCs were isolated, and miR-9 modified/antagonized BMSCs (pri-miR-9-BMSCs/TuD-BMSCs) were generated and injected into SAP rats. The levels of inflammatory cytokines and histopathologic changes were examined using ELISA and H&E staining. Angiogenesis was analyzed by qRT-PCR, western blotting, and immunohistochemistry. Cell function tests, dual luciferase reporter assays, cell co-culture, western blotting, and cell tracing were used to explore the mechanisms underlying miR-9 induced angiogenesis. RESULTS: Pri-miR-9-BMSCs induced angiogenesis in SAP rats (Ang-1↑, TIE-2↑, and CD31↑) and repaired damaged vascular endothelial cells (VECs) in vitro, promoting angiogenesis (Ang-1↑, TIE-2↑, PI3K↑, AKT↑, p-AKT↑, CD31↑, and CD34↑). Pri-miR-9-BMSCs released miR-9 into VECs or injured pancreatic tissue, targeting the VE-cadherin gene and promoting PI3K/AKT signaling to treat SAP (VE-cadherin↓, ß-catenin↓, PI3K↑, p-AKT↑), whereas antagonizing miR-9 in BMSCs did not alleviate or aggravated SAP. CONCLUSIONS: Pri-miR-9-BMSCs can repair injured pancreatic tissue by secreting miR-9 and promoting angiogenesis.

MiR-21-3p aggravates injury in rats with acute hemorrhagic necrotizing pancreatitis by activating TRP signaling pathway.

To evaluate the expression and effect of miR-21-3p in pancreas and lung injury of acute hemorrhagic necrotizing pancreatitis (AHNP) rats. AHNP rat model was constructed via retrograde injection of 5% sodium taurocholate into biliary pancreatic duct. Then rats were divided into normal, sham, AHNP, mimics negative control (NC), miR-21-3p mimics, inhibitors NC, miR-21-3p inhibitors, miR-21-3p mimics + phosphate buffer saline and miR-21-3p mimics + Gd3+ groups (N = 10 in each group). The expression of miR-21-3p, TRP signaling pathway factor, apoptosis related protein and histology were studied in pancreatic and lung tissues. Apoptosis of pancreatic acinar cells was detected. Oxidative stress indexes were detected in lung tissues. The level of PaO2 and PaCO2 and the expression of amylase, lipase and inflammatory factors were detected in blood. Compared with normal and sham groups, the miR-21-3p expression was increased in pancreatic and lung tissues of AHNP rats. MiR-21-3p expression was successfully regulated. Down-regulated miR-21-3p promoted apoptosis of pancreatic acinar cells and restored its function in AHNP rats. Up-regulated miR-21-3p reduced the lung oxygenation function, promoted pathological damage, and aggravated oxidative stress injury in AHNP rats. Meanwhile, up-regulated miR-21-3p also promoted the expression of serum enzymes and inflammatory factors, and activated TRP signaling pathway in AHNP rats. And miR-21-3p aggravated pancreatitis and lung injury by activating transient receptor potential (TRP) signaling pathway in AHNP rats. miR-21-3p promoted the pancreatic injury, inhibited apoptosis of necrotic acinar cells and aggravated lung oxidative stress injury by activating TRP signaling pathway in AHNP rats.

The immune imbalance in the second hit of pancreatitis is independent of IL-17A.

BACKGROUND: Severe acute pancreatitis (SAP) is characterised by two distinct clinical phases. Organ dysfunction and death is initially as a result of a systemic inflammatory response syndrome (SIRS). Systemic sepsis from infected pancreatic necrosis characterises the second phase, the so called 'second hit' of acute pancreatitis (AP). An immune imbalance during the second hit is postulated to contribute to the formation of the septic complications that occur in these patients. The pro-inflammatory T-helper (Th) 17 pathway has been shown to be an initiator of early SIRS in AP, however to date its role has not been established in the second hit in AP. METHODS: Thirty-six patients with mild (n = 16), moderate (n = 10) and severe (n = 10) acute pancreatitis were enrolled. Peripheral blood samples were drawn on days 7, 9, 11 and 13 of illness for analysis of routine clinical markers as well as cytokine analysis. Flow cytometry and a IL-17A ELISA was performed to determine cytokine concentrations. RESULTS: There were no significant differences between days 7, 9, 11 and 13 for either the mild/moderate or SAP groups for IL-17A (CBA assay or ELISA), IFN-γ, TNF-α, IL-2 or IL-4. For each of the study days, the mean IL-6 and IL-10 concentrations were significantly higher in the SAP group compared to the mild/moderate group. WCC, CRP and PCT were all significantly higher in severe acute pancreatitis over the study days. CONCLUSIONS: An immune imbalance exists in patients with SAP, however secreted IL-17A is not responsible for the second hit in AP.

Cav 1.2 and Cav 2.2 expression is regulated by different endogenous ghrelin levels in pancreatic acinar cells during acute pancreatitis.

Ghrelin influences pancreatic endocrine and exocrine functions, regulates intracellular calcium [Ca2+]i levels, and has an anti-inflammatory role in acute pancreatitis. This study investigated the role of endogenous ghrelin in the expression of Cav 1.2 (L-type of Ca2+ channel) and Cav 2.2 (N-type of Ca2+ channel) in acute pancreatitis. For this purpose, acute edematous pancreatitis (AEP) and acute necrotizing pancreatitis (ANP) rat models were established. Cav 1.2 and Cav 2.2 expression was assessed by immunohistochemistry in the pancreatic tissues of rats; ghrelin, interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α) serum levels were detected using ELISA. Next, in AR42J cells with either knock-out or overexpression of ghrelin, Cav 1.2 and Cav 2.2 expression was examined using western blot analysis, and intracellular calcium [Ca2+]i was detected with confocal microscopy. In this study, the ghrelin serum level was highest in the ANP group and was higher in the AEP group than the normal group. Expression of Cav 1.2 and Cav 2.2 in the ANP and AEP groups was higher than in the respective control groups. The serum IL-1ß and TNF-α levels were significantly higher in the ANP group compared to the other groups. Cav 1.2 and Cav 2.2 expression and [Ca2+]i decreased in ghrelin knockdown AR42J cells but increased in ghrelin overexpressing cells. In conclusion, Cav 1.2 and Cav 2.2 expression increased in ANP. The [Ca2+]i level, which is mediated by Cav 1.2 and Cav 2.2 expression, is directly regulated by ghrelin in pancreatic acinar cells, and serum ghrelin levels may be involved in the severity of acute pancreatitis.

Inhibition of 5-lipoxygenase represses neutrophils activation and activates apoptosis in pancreatic tissues during acute necrotizing pancreatitis.

Pancreatic glandular necrosis is rapid inflammation of the pancreas and contributes to severe acute pancreatitis in humans. The pathogenesis of pancreatic tissue inflammation during acute pancreatitis is still largely unknown. Recent studies suggest that 5-lipoxygenase (5-LOX) is an essential mediator in modulating cell death pathways in human diseases. In this study, we aimed to evaluate the effects of a 5-LOX inhibitor, zileuton, on tissue apoptosis and neutrophils activation in pancreatic tissues during acute necrotizing pancreatitis (ANP) in a rat model. In this present study, both mRNA and protein levels of 5-LOX are upregulated during ANP and zileuton treatment is shown to repress ANP-induced upregulation of 5-LOX levels. In addition, zileuton treatment is found to repress blood biomarkers of neutrophils activation such as soluble intercellular adhesive molecular 1 (ICAM-1), soluble E-selectin (E-selectin), soluble P-selectin (P-selectin), leukotriene B4 (LTB4), and myeloperoxidase (MPO). Also, zileuton treatment attenuates pancreatic tissue pathology, upregulates caspase-3, downregulates B-cell lymphoma 2 (Bcl-2), and activates tissue apoptosis evaluated by TUNEL staining. Our results show that 5-LOX plays an important role in activating apoptosis and repressing neutrophils activation during ANP. The current study suggests that 5-LOX can be used as a potential target for the treatment of ANP.

Epigenetic Regulation of Early- and Late-Response Genes in Acute Pancreatitis.

Chromatin remodeling seems to regulate the patterns of proinflammatory genes. Our aim was to provide new insights into the epigenetic mechanisms that control transcriptional activation of early- and late-response genes in initiation and development of severe acute pancreatitis as a model of acute inflammation. Chromatin changes were studied by chromatin immunoprecipitation analysis, nucleosome positioning, and determination of histone modifications in promoters of proinflammatory genes in vivo in the course of taurocholate-induced necrotizing pancreatitis in rats and in vitro in rat pancreatic AR42J acinar cells stimulated with taurocholate or TNF-α. Here we show that the upregulation of early and late inflammatory genes rely on histone acetylation associated with recruitment of histone acetyltransferase CBP. Chromatin remodeling of early genes during the inflammatory response in vivo is characterized by a rapid and transient increase in H3K14ac, H3K27ac, and H4K5ac as well as by recruitment of chromatin-remodeling complex containing BRG-1. Chromatin remodeling in late genes is characterized by a late and marked increase in histone methylation, particularly in H3K4. JNK and p38 MAPK drive the recruitment of transcription factors and the subsequent upregulation of early and late inflammatory genes, which is associated with nuclear translocation of the early gene Egr-1 In conclusion, specific and strictly ordered epigenetic markers such as histone acetylation and methylation, as well as recruitment of BRG-1-containing remodeling complex are associated with the upregulation of both early and late proinflammatory genes in acute pancreatitis. Our findings highlight the importance of epigenetic regulatory mechanisms in the control of the inflammatory cascade.

Expression pattern of HMGB1 and its association with autophagy in acute necrotizing pancreatitis.

High-motility group box protein 1 (HMGB1) has an important role in autophagy; however, its exact role in acute necrotizing pancreatitis (ANP) remains unknown. The present study aimed to investigate the expression pattern of HMGB1 in ANP, and to determine its association with autophagy. Sprague Dawley rats (weight, 350±30 g, n=48) were randomly divided into control (n=12) and experimental (n=36) groups. Experimental rats were retrogradely injected with 5% sodium taurocholate into the biliopancreatic duct to induce ANP. Control rats received an equal amount of saline. Serum amylase levels were used to determine whether the model had been successfully generated. Autophagosomes in pancreatic acinar cells were observed under electron microscopy. The expression levels of HMGB1 and Beclin 1 were detected in pancreatic tissues by western blotting, quantitative polymerase chain reaction and immunohistochemistry. HMGB1 levels were also determined in the serum and in isolated nuclei. The results demonstrated that autophagy was detected at 3 h post­ANP induction; however, HMGB1 expression remained unaltered during the early stage (0­6 h; P>0.05). HMGB1 expression was significantly increased at 12 h, and was still increasing at 24 h (P<0.05). Notably, HMGB1 was increased in the nuclei compared with in the cytoplasm at 3­6 h. Furthermore, serum HMGB1 levels began to increase at 3 h, and reached the highest levels at 24 h in the ANP group. In conclusion, in an ANP model, HMGB1 was initially increased in the nuclei to initiate autophagy. Subsequently, it moved into the cytoplasm, where it interacted with Beclin 1 to enhance autophagy, and HMGB1 was released into the blood, leading to the deterioration of ANP.

The immunoproteasomes are key to regulate myokines and MHC class I expression in idiopathic inflammatory myopathies.

Idiopathic inflammatory myopathies (IIMs) are diseases with muscle weakness, morphologically characterized by inflammatory infiltration and increased expression of MHC class I molecule on myofibers. Immunoproteasome, as a proteolytic complex that shapes the repertoire of antigenic peptides, has been previously demonstrated to be over-expressed in IIMs at mRNA level. In this study, we investigated the expression and the function of the immunoproteasome in IIMs in more detail. As shown by immunofluorescence staining, expression of relevant players of the immunoproteasome was detectable in the inflamed skeletal muscle tissue from IIM patients. In fact, two subunits of the immunoproteasome, ß1i or ß5i were upregulated in sporadic inclusion body myositis, immune-mediated necrotizing myopathies and dermatomyositis muscle biopsies and co-localized with the MHC class I expressing myofibers. Double immunofluorescence revealed that both myofibers and muscle infiltrating cells, including CD8+ T-cells and CD68 + macrophages in IIMs expressed ß1i or ß5i. In addition, we have also investigated the role of the immunoproteasome in myoblasts during in vitro inflammatory conditions. Using human primary myoblasts cultures we found that pro-inflammatory cytokines, TNF-α or IFN-γ upregulate ß1i or ß5i. Selective inhibition or depletion of ß5i amplified the TNF-α or IFN-γ mediated expression of cytokines/chemokines (myokines) in myoblasts. Furthermore, we demonstrated that specific inhibitors of ß1i or ß5i reduced the cell surface expression of MHC class I in myoblasts induced by IFN-γ. Taken together, our data suggest that the immunoproteasome is involved in pathologic MHC class I expression and maintenance of myokine production in IIMs. Thus, induction of the immunoproteasome was identified as a pathomechanism underlying inflammation in IIMs.

NF-κB in acute pancreatitis: Mechanisms and therapeutic potential.

The incidence of acute pancreatitis (AP) is increasing globally and mortality could be high among patients with organ failure and infected necrosis. The predominant factors responsible for the morbidity and mortality of AP are systemic inflammatory response syndrome and multiorgan dysfunction. Even though preclinical studies have shown antisecretory agents (somatostatin), antioxidants (S-adenosyl methionine [SAM], selenium), protease inhibitors, platelet activating factor inhibitor (Lexipafant), and anti-inflammatory immunomodulators (eg. prostaglandin E, indomethacin) to benefit AP in terms of reducing the severity and/or mortality, most of these agents have shown heterogeneous results in clinical studies. Several years of experimental studies have implicated nuclear factor-kappa B (NF-κB) activation as an early and central event in the progression of inflammation in AP. In this manuscript, we review the literature on the role of NF-κB in the pathogenesis of AP, its early intraacinar activation, and how it results in progression of the disease. We also discuss why anti-protease, antisecretory, and anti-inflammatory agents are unlikely to be effective in clinical acute pancreatitis. NF-κB, being a central molecule that links the initial acinar injury to systemic inflammation and perpetuate the inflammation, we propose that more studies be focussed towards targeted inhibition of NF-κB activity. Direct NF-κB inhibition strategies have already been attempted in patients with various cancers. So far, peroxisome proliferator activator receptor gamma (PPAR-γ) ligand, pyrrolidine dithiocarbamate (PDTC), proteasome inhibitor and calpain I inhibitor have been shown to have direct inhibitory effects on NF-κB activation in experimental AP.

Association of the HindIII Lipoprotein Lipase Gene Polymorphism with the Development of the Non-Biliary Acute Pancreatitis: a Pilot Study.

We studied the relationship between lipoprotein lipase (LPL) gene HindIII polymorphism and the development of acute pancreatitis in the Russian population. Whole blood samples were collected from 145 patients with acute non-biliary pancreatitis and 191 healthy individuals. Genotyping of LPL gene HindIII (rs320) polymorphism was performed by PCR with TaqMan assay. It was found that allele H+ (OR=0.63, 95%CI 0.41-0.96, p=0.03) and genotype H+/H+ (OR=1.79, 95%CI 1.06-3.04, p=0.03) were associated with the risk of acute non-biliary pancreatitis only in males. In this study, the relationship between HindIII polymorphism of LPL gene with the risk of acute non-biliary pancreatitis was revealed.

Ameliorative Effects of Curcumin on Fibrinogen-Like Protein-2 Gene Expression, Some Oxido-Inflammatory and Apoptotic Markers in a Rat Model of l-Arginine-Induced Acute Pancreatitis.

The aim of the study was to investigate the ameliorative effects of curcumin on fibrinogen like protein-2 (fgl-2), some oxido-inflammatory and apoptotic markers in rat-induced acute pancreatitis (AP). Seventy-five albino rats were divided into control group, l-arginine (l-Arg)-induced AP group, curcumin pre-treated group before AP induction, curcumin post-treated group after AP induction, and curcumin injected group only. AP group showed severe necrotizing pancreatitis confirmed by histopathological changes and elevations in serum amylase and lipase activities, levels of epithelial neutrophil-activating peptide 78, tissue content of protein carbonyls, levels of tumor necrosis factor α, and caspase-3 as well as myeloperoxidase activity. Significant elevation in pancreatic fgl-2 mRNA expression was detected in AP group. Improvement of all parameters was detected with increase of caspase-3 in both curcumin-treated groups that confirmed curcumin ameliorative effects against AP through induction of apoptosis and inhibition of micro-thrombosis, inflammation, and oxidative stress.

Decreased MIZ1 Expression in Severe Experimental Acute Pancreatitis: A Rat Study.

AIM: We tested our hypothesis that Myc-interacting zinc finger protein 1 (MIZ1), a cell cycle regulator, suppressed inflammation, and therefore, represented a useful prognostic marker in patients with acute necrotizing pancreatitis (ANP) complicated by acute lung injury. METHODS: Sprague-Dawley rats were randomly divided into control and ANP groups at different time points. The MIZ1 protein expression was measured by Western blot and ELISA, and confirmed using immunohistochemistry. The severity of pancreatic and lung injury was evaluated by the injury score and wet/dry weight ratio. The severity of disease was evaluated by serum C-reactive protein (CRP). The MPO activity of lung tissue amylase levels and the degree of inflammation were evaluated by serum tumor necrosis factor (TNF)-α and interleukin (IL)-6 expression. The risk due to multiple factors was investigated by relationship analysis. RESULTS: The serum levels of CRP, amylase, TNF-α, and IL-6 were gradually increased at 6, 24, and 48 h in ANP when compared with the control rats. The MIZ1 expressions were greatly decreased in ANP rats, especially at 24 h. Statistical analysis showed that there were time-dependent differences in ANP rats when compared with control rats (6 vs. 24 or 48 h, P < 0.01). MIZ1 showed close negative correlation with the degree of pancreatic and lung injury, serum amylase, CRP, TNF-α, and IL-6 (P < 0.01, respectively). CONCLUSION: The decreasing MIZ1 expression was closely correlated with inflammatory response, and development of ANP. Decreasing MIZ1 levels indicate a risk for ANP.

Cartilage Oligomeric Matrix Protein-Angiopoietin-1 Has a Protective Effect of Vascular Endothelial Barrier in Rat With Acute Necrotizing Pancreatitis.

OBJECTIVE: To investigate the protective effect of angiopoietin-1 (Ang-1) from capillary endothelial damage in rats with acute necrotizing pancreatitis (ANP). METHODS: 96 male Sprague-Dawley rats were randomly averaged and divided into control group, ANP group, Si-Ang-1 group, and COMP (cartilage oligomeric matrix protein)-Ang-1 group. Animals were killed at 6, 12, and 24 hours after molding. Levels of serum amylase, porcine endothelin 1, C-reactive protein, and Ang-1 were detected; histopathological changes in the pancreas were observed; capillary permeability and Ang-1 expression of the pancreatic tissue were detected by Evans Blue extravasation assay, immunohistochemistry, Western blot, and quantitative polymerase chain reaction. RESULTS: (1) Levels of serum amylase, C-reactive protein, and porcine endothelin-1 increased and level of Ang-1 decrease in the ANP group and Si-Ang-1 group compared with the control group, whereas COMP-Ang-1 group could improve the changes. (2) The order of pancreas pathological changes (mild to severe) is: control group, COMP-Ang-1 group, ANP group, and Si-Ang-1 group. (3) Capillary permeability of the pancreatic tissue in the COMP-Ang-1 group was lower than that in the ANP group. (4) Ang-1 mRNA and protein expression in the COMP-Ang-1 group was significantly higher than in the ANP group. CONCLUSIONS: COMP-Ang-1 can upregulate the expression of Ang-1 protein to promote angiogenesis and improve early inflammatory and pathological damage in ANP group.

Loss of Ifnar1 in Pancreatic Acinar Cells Ameliorates the Disease Course of Acute Pancreatitis.

Type I interferon constitutes an essential component of the combinational therapy against viral disease. Acute pancreatitis is one side effect of type I interferon-based therapy, implying that activation of type I interferon signaling affects the homeostasis and integrity of pancreatic acinar cells. Here, we investigated the role of type I interferon signaling in pancreatic acinar cells using a caerulein-induced murine model of acute pancreatitis. Pancreas-specific ablation of interferon (alpha and beta) receptor 1 (Ifnar1) partially protected animals from caerulein-induced pancreatitis, as demonstrated by reduced tissue damage. Profiling of infiltrating immune cells revealed that this dampened tissue damage response correlated with the number of macrophages in the pancreas. Pharmacologic depletion of macrophages reversed the protective effect of Ifnar1 deficiency. Furthermore, expression of chemokine (C-C motif) ligand 2 (Ccl2), a potent factor for macrophage recruitment, was significantly increased in the Ifnar1-deficient pancreas. Thus, type I interferon signaling in pancreatic acinar cells controls pancreatic homeostasis by affecting the macrophage-mediated inflammatory response in the pancreas.

Effect of Chaiqinchengqi decoction on inositol requiring enzyme 1α in alveolar macrophages of dogs with acute necrotising pancreatitis induced by sodium taurocholate.

OBJECTIVE: To investigate the effect of Chaiqinchengqi decoction (CQCQD) on inositol requiring enzyme lα (IRElα) in alveolar macrophages (AMs) of the dog model of acute necrotising pancreatitis (ANP) induced by sodium taurocholate. METHODS: Fifteen beagle dogs were randomised into a control group, ANP group and CQCQD group (n = 5 per group). ANP was induced by a retrograde duct injection of 50 mg/kg of 5% sodium taurocholate. The dogs in the control group received injections of the same volume of saline as the sodium taurocholate. After the models were induced, the dogs in the CQCQD group were administered 10 mL/kg CQCQD every 2 h for 6 h. Two hours after the last administration of either CQCQD or saline, they were sacrificed by anaesthesia. AMs were collected to determine the IRElα and interleukin-1ß (IL-1ß) mRNA and protein expression, and pancreatic tissues were collected for histopathology analysis. RESULTS: Compared with the ANP group, the mRNA and protein expression of IREl a and the protein expression of IL-1ß of AMs in the CQCQD group were significantly down-regulated, and the pancreatic histopathology score of the CQCQD group also was lower. There was no significant difference in the mRNA expression of IL-1ß of AMs between the two groups. CONCLUSION: The CQCQD-induced down-regulation of the IL-1ß protein expression may involve the down-regulation of the mRNA and protein expression of IRElα in AMs.