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Sepsis is a global fatal disease and leads to severe lung injury due to dysfunction of inflammation response. TRIM27 is closely related to the diseased with dysfunction of inflammation response. The aim of this study was to clarify the role and mechanism of TRIM27 in sepsis-induced lung injury.The lipopolysaccharide (LPS)-induced septic mouse model was successfully established. The lung injury was evaluated by lung wet/dry (W/D) ratio and hematoxylin-eosin (HE) staining. The cell apoptosis was evaluated by TUNEL assay. The inflammatory cytokines were measured by quantitative real time-PCR (qRT-PCR) assay and commercial enzyme-linked immunosorbent assay (ELISA). The oxidative stress was assessed by the contents of superoxide dismutase (SOD) and malondialdehyde (MDA), and the expression of dihydroethidium (DHE).In this study, we demonstrated that TRIM27 was up-regulated in LPS-induced septic mice. In loss-of-function experiments, knockdown of TRIM27 alleviated sepsis-induced lung injury, inflammation, apoptosis, and oxidative stress. More importantly, knockdown of TRIM27 was observed to reduce p-p65/NOX4 expression via suppressing ubiquitination of PPARγ. In rescue experiments, overexpression of NOX4 abolished the effect of sh-TRIM27 on alleviating sepsis-induced inflammation, apoptosis, and oxidative stress.These findings highlighted that knockdown of TRIM27 alleviated sepsis-induced inflammation, oxidative stress and apoptosis via suppressing ubiquitination of PPARγ and reducing NOX4 expression, which supports the potential utility of TRIM27 as a therapeutic target in septic lung injury.

The role of skullcapflavone II in pneumonia was investigated using lipopolysaccharide treated human lung fibroblasts WI-38 cells as a model. Lipopolysaccharide treatment led to decreased cell viability, increased cell apoptosis and inflammation. Exposure of these lipopolysaccharide-treated cells to skullcapflavone II resulted in amelioration of cytotoxic effects of the lipopolysaccharide. The reduced IκBα expression and enhanced p-IκBα and p-p65 in WI-38 cells caused by the lipopolysaccharide treatment were reversed by skullcapflavone II. In conclusion, skullcapflavone II exerts antiapoptotic and anti-inflammatory effects on lipopolysaccharide-induced WI-38 through inhibition of NF-κB pathway.

Background & objectives Acute pancreatitis is a common inflammatory disorder of the exocrine pancreas with no specific therapy. Intracellular nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in nicotinamide adenine dinucleotide (NAD) salvage pathway, is involved in many inflammatory disorders. In this study, we investigated the role of NAMPT in experimental acute pancreatitis. Methods Acute pancreatitis was induced in mice using three disparate models: (1) caerulein hyperstimulation, (2) ethanol plus palmitoleic acid, and (3) retrograde biliopancreatic ductal infusion of sodium taurocholate. The NAMPT inhibitor FK866 and NAMPT downstream product nicotinamide mononucleotide (NMN) was administered. Serum and pancreas were collected and analyzed biochemically and histologically. Bone marrow derived macrophages were isolated, cultured with cytokines or pancreatic acini, then analyzed by quantitative PCR and non-targeted metabolomics. Results The levels of pancreatic NAMPT and NAD were down-regulated upon acute pancreatitis. NAMPT inhibitor FK866 suppressed M1 macrophage polarization while NMN boosted it. In co-culture of macrophages with acinar cells, inhibition of NAMPT prevented M1-like macrophage differentiation induced by injured pancreatic acini. The injured pancreatic acinar milieu induced a unique metabolic signature linked to macrophage polarization, and inhibition of NAMPT reversed these metabolites changes. Furthermore, NMN supplementation aggravated caerulein hyperstimulation pancreatitis and alcoholic pancreatitis, and inhibition of NAMPT protected against caerulein hyperstimulation, alcoholic and biliary acute pancreatitis and reducing pancreatic macrophage infiltration in vivo. Conclusions NAMPT inhibition protects against acute pancreatitis via preventing M1 macrophage polarization and restoring the metabolites related to macrophage polarization and that NAMPT could be a promising therapeutic target for acute pancreatitis.

Pancreatic regeneration after acute pancreatitis is critical in the normal restoration of pancreatic exocrine function, the inhibition of which can cause severe complications including pancreatic exocrine insufficiency. However, the regulators of pancreatic regeneration and the underlying mechanisms remain uncovered. Here, using the inducible Tet-on system, we found that regenerating family member 4 (Reg4) knockdown significantly impaired pancreatic regeneration after pancreatitis. Both acinar-to-ductal metaplasia and the resolution of pancreatitis during regeneration were affected by Reg4 knockdown. Further investigations confirmed that Reg4 exerted its function through regulating Notch activation both in vitro and in vivo. Our study revealed Reg4 as a new regulator and potential therapeutic target for pancreatic regeneration.

Acute pancreatitis (AP) was initiated within pancreatic parenchymal cells and sustained by uncontrolled inflammatory responses. AXL and MERTK receptor tyrosine kinases play a crucial role in negatively regulating the innate immunity. Therefore, this study aimed to investigate the role and underlying mechanism of AXL and MERTK in AP.Experimental AP was induced by ten hourly intraperitoneal administration of caerulein in global, hematopoietic- and pancreas-specific Axl and Mertk deficient mice. Pancreatitis severity was assessed biochemically and histologically. Pancreatic transcriptomics and pancreatic infiltrating immune cells were profiled. Some mice were given R428, an antagonist of AXL and MERTK. AXL and MERTK in peripheral leukocytes were measured by flow cytometry.The levels of AXL and MERTK in pancreatic tissue and pancreatic CD45Our findings reveal that specific AXL/MERTK antagonist may be a novel and potential early treatment for AP and the levels of MERTK in peripheral leukocytes may be a promising biomarker for predicting pancreatic severity in patients with AP.National Natural Science Foundation of China, Shanghai Natural Science Foundation, a Shanghai Young Talent Award and a Shanghai Young Orient Scholar Award.Evidence before this study Acute pancreatitis (AP) is a common inflammatory disorder of the exocrine pancreas, the severity of which was determined by the extent of pancreatic necrosis, with no targeted therapy. AP was initiated by signals within pancreatic parenchymal cells and sustained by uncontrolled innate immune responses. One of the three crucial regulatory roles for AXL and MERTK is to negatively regulate innate immune responses. Added value of this study Global and hematopoietic-, but not pancreas-specific Axl and Mertk deficiency protected against pancreatitis, primarily pancreatic necrosis. Deletion of Axl and Mertk selectively inhibited pancreatic neutrophil infiltration that was related to CXCL2 secreted by pro-inflammatory macrophages. AXL and MERTK antagonist similarly reduced pancreatitis severity via limiting CXCL2-mediated pancreatic neutrophil infiltration. Higher levels of MERTK, but not AXL in peripheral leukocytes were correlated with more severe form of acute pancreatitis. Implications of all the available evidence A specific AXL/MERTK antagonist may be a novel and potential early treatment for AP. The level of MERTK on peripheral leukocytes may be a promising biomarker for predicting disease severity in patients with AP.

Sepsis is a whole-body inflammation and main cause of death in intensive care units worldwide. We aimed to investigate the roles of lncRNA MIAT and miR-330-5p in modulating inflammatory responses and oxidative stress in lipopolysachariden (LPS)-induced septic cardiomyopathy. Serum and heart tissue were collected from in vivo septic mice model, ELISA and qRT-PCR were used to measure the expression of pro-inflammation cytokines, MIAT and miR-330-5p, respectively. The knockdown of MIAT and overexpression of miR-330-5p were conducted to assess their effects on regulating inflammation response and intracellular oxidative stress in LPS-stimulated HL-1 cells. The reactive oxygen (ROS) level, mitochondrial membrane potential (MMP), GSH/GSSH ratio, and lipid peroxidation assessment (MDA) were used to evaluate the intracellular oxidative stress. Dual-luciferase reporter assay was performed to identify the association between MIAT and miR-330-5p, TRAF6 and miR-330-5p, respectively. In septic mice, the expression of MIAT and pro-inflammation cytokines was elevated while the expression of miR-330-5p decreased. Knockdown of MIAT or overexpression of miR-330-5p restrained inflammation and oxidative stress induced by LPS in vitro; MIAT directly targeted miR-330-5p to regulate NF-κB signaling, and miR-330-5p targeted against TRAF6 to suppress the activation of NF-κB signaling. We determined that lncRNA MIAT directly binds to miR-330-5p to activate TRAF6/NF-κB signaling axis and further promotes inflammation response as well as oxidative stress in LPS-induced septic cardiomyopathy. This finding suggests the potential therapeutic role of lncRNA MIAT and miR-330-5p in LPS-induced myocardial injury.

Background and purpose Macrophage infiltration and activation is a critical step during acute pancreatitis (AP). We have shown that pancreas-specific D2 receptor signalling protects against AP severity. As it is unclear to what extent myeloid-specific D2 receptor mediates AP, we investigated the role of myeloid-specific D2 receptor signalling in AP. Experimental approach Using wild-type and LysM+/cre D2 fl/fl mice, AP was induced by l-arginine, caerulein and LPS. Murine bone marrow-derived macrophages and human peripheral blood mononuclear cells (PBMCs) were isolated, cultured and then induced to M1 phenotype. AP severity was assessed by measurements of serum amylase and lipase and histological grading. Macrophage phenotype was assessed by flow cytometry and qRT-PCR. NADPH oxidase-induced oxidative stress and NF-κB and NLRP3 inflammasome signalling pathways were also evaluated. Key results We found that dopaminergic system was activated and dopamine reduced inflammatory cytokine expression in M1-polarized macrophages from human PBMCs. Dopaminergic synthesis was also activated, but D2 receptor expression was down-regulated in M1-polarized macrophages from murine bone marrows. During AP, myeloid-specific D2 receptor deletion worsened pancreatic injury, systematic inflammation and promoted macrophages to M1 phenotype. Furthermore, M1 macrophages from LysM+/cre D2 fl/fl mice exhibited increased NADPH oxidase-induced oxidative stress and enhanced NF-κB and NLRP3 inflammasome activation. D2 receptor activation inhibited M1 macrophage polarization, oxidative stress-induced NF-κB and NLRP3 inflammasome activation. Conclusion and implications Our data for the first time showed that myeloid-specific D2 receptor signalling controls pancreatic injury and systemic inflammation via inhibiting M1 macrophage, suggesting D2 receptor activation might serve as therapeutic target for AP.

Acute pancreatitis (AP) is an inflammatory disease that is associated with trypsinogen activation, mitochondrial dysfunction, cell death, and inflammation. Dopamine D2 receptor (DRD2) plays an essential role in alleviating AP, while it is unclear whether it is involved in regulating acinar cell necroptosis. Here, we found that DRD2 agonist quinpirole alleviated acinar cell necroptosis via inhibiting cathepsin B (CTSB). Moreover, CTSB inhibition by CA-074Me ameliorated AP severity by reducing necroptosis. Notably, knockdown of TFAM reversed the therapeutic effect of either quinpirole or CA-074Me. We identified a new mechanism that DRD2 signaling inhibited CTSB and promoted the expression of mitochondrial transcription factor A(TFAM), leading to reduction of ROS production in AP, which attenuated acinar cell necroptosis ultimately. Collectively, our findings provide new evidence that DRD2 agonist could be a new potential therapeutic strategy for AP treatment.

BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with poor prognosis. Karyopherin subunit alpha 4 (KPNA4) is a nuclear transport factor and plays tumor-promoting roles in multiple cancers. However, the roles of KPNA4 in PDAC still remain unknown. This study investigated the prognostic value of KPNA4 and its potential functions in PDAC and tumor microenvironment.MethodsLinkedOmics was utilized to screen genes with survival significance in PDAC. KPNA4 expression was analyzed using multiple datasets and verified in PDAC cells and clinical samples by qRT-PCR and immunohistochemistry. Clinical correlation and survival analyses were conducted to identify the clinical significance and prognostic value of KPNA4 in PDAC patients. Subsequently, KPNA4 was knocked down in PDAC cell lines, and CCK-8, colony formation and wound healing assays were performed to test the functions of KPNA4 in vitro. Immune infiltration analysis was performed to explore the potential roles of KPNA4 in the tumor microenvironment of PDAC. Moreover, functional analyses were conducted to explore the underlying mechanism of KPNA4 in the progression of PDAC.ResultsWe found KPNA4 was significantly upregulated in PDAC cells and tissues. KPNA4 expression was associated with tumor progression in PDAC patients. Survival analyses further revealed that KPNA4 could act as an independent predictor of unfavorable survival for PDAC patients. KPNA4 knockdown suppressed the viability, colony formation and migration of PDAC cells. Moreover, KPNA4 was correlated with immunosuppressive cells infiltration and T cell exhaustion in the tumor microenvironment of PDAC. Finally, functional analyses indicated the association of KPNA4 with focal adhesion kinase (FAK) signaling, and KPNA4 silencing significantly decreased the expression of FAK and PD-L1.ConclusionsThis study revealed that KPNA4 is an independent prognostic biomarker for PDAC and plays a tumor-promoting role by facilitating proliferation and migration of cancer cells and participating in immune infiltration, which may be mediated by FAK signaling and PD-L1 expression. These results provide a novel and potential therapeutic target for pancreatic cancer.

Mild acute pancreatitis (AP) is a self-limiting disease, whereas severe AP has high mortality because of enhanced systemic inflammation and multiple organ failure. In experimental models of AP, infiltration of monocytes and activation of monocyte-derived macrophages largely determine the severity of the disease. Our previous studies have shown that CD11b+Ly-6Chi inflammatory monocytes were mobilized from bone marrow into peripheral blood and inflamed pancreas during the early stage of AP. However, the phenotype and characteristics of circulating monocytes in patients with AP are not well defined. Fifty patients with AP and nine age- and sex-matched healthy volunteers were enrolled in this study. Compared with those of healthy volunteers, the proportion of CD14hiCD16− monocytes and the level of myeloid-related cytokines/chemokines were increased in AP patients within 48 h after disease onset, especially in patients with a severe disease course. Moreover, the increased monocyte proportions were associated with decreased HLA-DR expression and a reduced T cell count. Notably, dynamic changes in circulating CD14hiCD16− monocytes and their HLA-DR expression, as well as in CD4+ T cells, were obviously different between moderate severe AP and severe AP. Last, area under the receiver operating characteristic analysis showed that the combination of CD14hiCD16− monocyte proportions with their HLA-DR level had higher accuracy for predicting the severity of AP. Taken together, the ratio of CD14hiCD16− monocytes and their HLA-DR level might assist in predicting the severity of disease in AP patients at admission and in monitoring patients’ clinical status during recovery.

We present Graph Attention Collaborative Similarity Embedding (GACSE), a new recommendation framework that exploits collaborative information in the user-item bipartite graph for representation learning. Our framework consists of two parts: the first part is to learn explicit graph collaborative filtering information such as user-item association through embedding propagation with attention mechanism, and the second part is to learn implicit graph collaborative information such as user-user similarities and item-item similarities through auxiliary loss. We design a new loss function that combines BPR loss with adaptive margin and similarity loss for the similarities learning. Extensive experiments on three benchmarks show that our model is consistently better than the latest state-of-the-art models.

Acute pancreatitis (AP) is associated with impaired acinar cell autophagic flux, intracellular zymogen activation, cell necrosis and inflammation. Activation of the cholinergic system of vagus nerve has been shown to attenuate AP, but the effect of organ-intrinsic cholinergic system on pancreatitis remains unknown. In this study, we aim to examine the effect of α7 nicotinic acetylcholine receptor (α7nAChR) stimulation within the pancreas during AP. In vivo, AP was induced by caerulein plus LPS or ethanol plus palmitoleic acid in mice. In vitro, pancreatic acini were isolated and subjected to cholecystokinin (CCK) stimulation. Mice or acini were pre-treated with PNU-282987 (selective α7nAChR agonist) or methyllycaconitine citrate salt (selective α7nAChR antagonist). Pancreatitis severity, acinar cell injury, autophagic flux, and transcription factor EB (TFEB) pathway were analyzed. Both caerulein plus LPS in vivo and CCK in vitro led to an up-regulation of α7nAChR, indicating activation of pancreas-intrinsic α7nAChR signaling during AP. PNU-282987 decreased acinar cell injury, trypsinogen activation and pancreatitis severity. Conversely, methyllycaconitine citrate salt increased acinar cell injury and aggravated AP. Moreover, activation of α7nAChR by PNU-282987 promoted autophagic flux as indicated by reduced p62, increased LysoTracker staining and decreased number of autolysosomes with undegraded contents. Furthermore, PNU-282987 treatment significantly increased TFEB activity in pancreatic acinar cells. α7nAChR activation also attenuated pancreatic inflammation and NF-κB activation. Our results showed that activation of α7nAChR protected against experimental pancreatitis through enhancing TFEB-mediated acinar cell autophagy, suggesting that activation of pancreas-intrinsic α7nAChR may serve as an endogenous protective mechanism during AP.

Trypsinogen activation is the hallmark of acute pancreatitis (AP) independent of intra-acinar NF-κB activation and inflammation. We previously found that dopamine (DA) receptor 2 (DRD2) activation controls inflammation during AP via PP2A-dependent NF-κB activation. In this study, we sought to examine whether DRD2 signaling mediates trypsinogen activation and the underlying mechanisms. Pancreatic acinar cells were stimulated with cholecystokinin-8 in vitro. AP was induced by intraperitoneal injections of caerulein and LPS or l-arginine. Pancreatitis severity was assessed biochemically and histologically. We found that activation of DRD2 by quinpirole, a potent DRD2 agonist, resulted in the reduction of trypsinogen activation and the upregulation of HSP70 in vitro and in vivo. Mechanistically, we found that quinpirole induced dephosphorylation of heat shock factor 1 (HSF1), a master transcription factor of HSP70, leading to increased nuclear translocation of HSF1 in a PP2A-dependent pathway. Furthermore, DRD2 activation restored lysosomal pH and, therefore, maintained lysosomal cathepsin B activity in a HSP70-dependent manner. VER155008, a potent HSP70 antagonist, abolished the protective effects observed with DRD2 activation in vitro and in two experimental models of AP. Our data showed that besides controlling NF-κB activation, DRD2 activation prevented trypsinogen activation during acute pancreatitis via PP2A-dependent upregulation of HSP70 and further support that DRD2 agonist could be a promising therapeutic strategy for treating AP.NEW & NOTEWORTHY The current study demonstrated that activation of DRD2 by quinpirole protects against trypsinogen activation in the in vitro and in vivo setting of acute pancreatitis by upregulating HSP70 and restoring lysosomal degradation via a PP2A-dependent manner, therefore leading to reduced pancreatic injury. These findings provide a new mechanistic insight on the protective effect of DRD2 activation in acute pancreatitis.

Chronic pancreatitis (CP) is a major risk factor for pancreatic cancer; however, little is known about the pathogenic mechanisms underlying the development of CP. Legumain (Lgmn) has been linked to some chronic inflammatory diseases. The present study investigated the role of legumain in pancreatic fibrogenesis. We induced CP in wild type C57BL6 (WT), Lgmn-deficient (Lgmn−/−), Lgmnflox/flox and Lgmnflox/flox × LysMCre mice by intraperitoneal injection of caerulein for 4 weeks. Pancreata were collected and analyzed by quantitative reverse transcription polymerase chain reaction, Western blotting, and histology. Pancreatic stellate cells and macrophages were isolated and studied using immunofluorescence, gelatin zymography, and enzyme-linked immunosorbent assay. The effects of inhibition of legumain were investigated in vivo by administration of the specific legumain inhibitor, RR-11a. Legumain was found to be upregulated in the serum and pancreatic tissues of mice with caerulein-induced CP. Mice with global and macrophage-specific legumain deficiency exhibited significantly reduced development of pancreatic fibrosis compared with control mice, based on pancreas size, histology, and expression of fibrosis-associated genes. Our results indicate that legumain promotes activation of pancreatic stellate cells and increases synthesis of extracellular matrix proteins via activation of matrix metalloproteinase-2(MMP-2), which hydrolyzes the transforming growth factor-β1 (TGF-β1) precursor to form active TGF-β1. Administration of RR-11a markedly attenuated pancreatic fibrosis in mice with CP. Deficiency or inhibition of legumain significantly reduces the severity of pancreatic fibrosis by suppressing activation of the TGF-β1 precursor. Our results highlight the potential of legumain as a novel therapeutic target for CP. • Legumain expression was markedly upregulated in CP mice. • Deletion of legumain attenuated pancreatic fibrosis in CP mice. • Legumain promotes fibrosis via MMP-2 activation, which hydrolyzed the TGF-β1 precursor to the active form. • Legumain is a potential therapeutic target for the management of CP.

Background/Objective. Inhibition of matrix metalloproteinases (MMPs), particularly MMP-9, attenuates leukocyte infiltration and pancreatic and distant organ damages in acute pancreatitis (AP). However, it is unclear whether MMPs mediate inflammatory cell activation. In this study, we investigated the effects of inhibition of MMPs on neutrophil and macrophage activation in caerulein-induced pancreatitis. Methods. AP was induced in Balb/C mice by ten hourly intraperitoneal injections of caerulein (100 μg/kg) and LPS (5 mg/kg). The MMP inhibitor, BB-94 (20 mg/kg) was intraperitoneally administered 30 min before AP induction. Pancreatitis was confirmed by histology and serum amylase and lipase. Expression of pancreatic proinflammatory mediators and NF-κB activation were assessed. Bone marrow-derived neutrophils (BMDNs) and macrophages (BMDMs) were isolated. BMDNs were activated by phorbol 12-myristate 13-acetate (PMA, 50 ng/ml) and neutrophil reactive oxygen species (ROS) production was recorded. BMDMs were stimulated with 10 ng/ml IFN-γ and 100 ng/ml LPS to induce M1 macrophage polarization. Results. Pancreatic MMP-9 was markedly upregulated and serum MMP-9 was increased in caerulein-induced pancreatitis. Inhibition of MMP with BB-94 ameliorated pancreatic tissue damage and decreased the expression of proinflammatory cytokines (TNFα and IL-6) or chemokines (CCL2 and CXCL2) and NF-κB activation. Furthermore, using isolated BMDNs and BMDMs, we found that inhibition of MMP with BB-94 markedly decreased neutrophil ROS production, inhibited inflammatory macrophage polarization and NF-κB activation. Conclusions. Our results showed that inhibition of MMP with BB-94 protected against pancreatic inflammatory responses in caerulein-induced pancreatitis via modulating neutrophil and macrophage activation.

Acute pancreatitis (AP) is a sterile inflammation, in which inflammatory monocytes (CD11b+Ly-6Chi) are recruited into the inflamed tissue at the onset of disease. Monocyte infiltration and activation at the site of inflammation are critical to the pathogenesis of AP. Our previous studies have shown a protective role for CO in AP, which is partially mediated by inhibition of macrophage activation via TLR4 signaling. In the current study, to gain a better understanding of CO’s therapeutic effect, we further investigated whether CO could affect inflammatory monocyte trafficking during AP. In a mouse model of AP, we found that treatment with CO-releasing molecule-2 (CORM-2) impaired recruitment of inflammatory monocytes, but not that of neutrophils, from peripheral blood to inflamed pancreas. During the early stage of AP, a single dose of CORM-2 decreased pancreatic CCL2 and soluble ICAM-1 expression. In addition, using in vivo and in vitro experiments, we found that CORM-2 had the ability to inhibit CD11b+Ly-6Chi monocyte migration via blockade of CCR2 endocytosis. Notably, we showed that CORM-2 inhibited CCR2 endocytosis of inflammatory monocytes (CD14hiCD16−) from AP patients. Taken together, our results highlighted CO’s effect on inflammatory monocyte trafficking, shedding additional light on its therapeutic potential in AP.

Background and Purpose Dopamine has multiple anti-inflammatory effects, but its role and molecular mechanism in acute pancreatitis (AP) are unclear. We investigated the role of dopamine signalling in the inflammatory response in AP. Experimental Approach Changes in pancreatic dopaminergic system and effects of dopamine, antagonists and agonists of D1 and D2 dopamine receptors were analysed in wild-type and pancreas-specific Drd2−/− mice with AP (induced by caerulein and LPS or L-arginine) and pancreatic acinar cells with or without cholecystokinin (CCK) stimulation. The severity of pancreatitis was assessed by measuring serum amylase and lipase and histological assessments. The NF-κB signalling pathway was evaluated, and macrophage and neutrophil migration assessed by Transwell assay. Key Results Pancreatic dopamine synthetase and metabolic enzyme levels were increased, whereas D1 and D2 receptors were decreased in AP. Dopamine reduced inflammation in CCK-stimulated pancreatic acinar cells by inhibiting the NF-κB pathway. Moreover, the protective effects of dopamine were blocked by a D2 antagonist, but not a D1 antagonist. A D2 agonist reduced pancreatic damage and levels of p-IκBα, p-NF-κBp65, TNFα, IL-1β and IL-6 in AP. Pancreas-specific Drd2−/− aggravated AP. Also, the D2 agonist activated PP2A and inhibited the phosphorylation of Akt, IKK, IκBα and NF-κB and production of inflammatory cytokines and chemokines. Furthermore, it inhibited the migration of macrophages and neutrophils by reducing the expression of CCL2 and CXCL2. A PP2A inhibitor attenuated these protective effects of the D2 agonist. Conclusions and Implications D2 receptors control pancreatic inflammation in AP by inhibiting NF-κB activation via a PP2A-dependent Akt signalling pathway.

Pancreatic acinar cell necrosis and inflammatory responses are two key pathologic processes in acute pancreatitis (AP), which determines the severity and outcome of the disease. Recent studies suggest that necroptosis, a programed form of necrosis, is involved in the pathogenesis of AP, but the underlying mechanisms remain unknown. We investigated the expression of necrosome components, including receptor-interacting protein (RIP) 1, RIP3, and mixed lineage kinase domain-like (MLKL), and the molecular mechanisms in pancreatitis-associated necroptosis. We found that RIP3 and phosphorylated MLKL expression was positively related to the degree of necrosis, whereas RIP1 expression was negatively related to the degree of necrosis. Pharmacologic inhibition of RIP1 kinase activity exerted no protection against caerulein/cholecystokinin-8-induced AP, but knockdown of RIP1 with siRNA increased acinar cell necrosis and inhibition of NF-κB activation. RIP1 inhibition led to enhanced RIP3 expression. RIP3 and MLKL inhibition decreased acinar cell necrosis, in which the inhibition of RIP3 reduced the phosphorylation level of MLKL. RIP3 inhibition had no effect on trypsinogen activation but partly inhibited inflammasome activation. Our study strongly suggests that the imbalance between RIP1 and RIP3 shifts the cell death to necrosis, which unravels a new molecular pathogenesis of mechanism of AP and may provide insight into the development of novel therapeutic agent for other necrosis-related diseases.

BACKGROUND AND PURPOSE: Macrophage infiltration and activation is a critical step during acute pancreatitis (AP). We have shown that pancreas‐specific D(2) receptor signalling protects against AP severity. As it is unclear to what extent myeloid‐specific D(2) receptor mediates AP, we investigated the role of myeloid‐specific D(2) receptor signalling in AP. EXPERIMENTAL APPROACH: Using wild‐type and LysM(+/cre)D(2) (fl/fl) mice, AP was induced by l‐arginine, caerulein and LPS. Murine bone marrow‐derived macrophages and human peripheral blood mononuclear cells (PBMCs) were isolated, cultured and then induced to M1 phenotype. AP severity was assessed by measurements of serum amylase and lipase and histological grading. Macrophage phenotype was assessed by flow cytometry and qRT‐PCR. NADPH oxidase‐induced oxidative stress and NF‐κB and NLRP3 inflammasome signalling pathways were also evaluated. KEY RESULTS: We found that dopaminergic system was activated and dopamine reduced inflammatory cytokine expression in M1‐polarized macrophages from human PBMCs. Dopaminergic synthesis was also activated, but D(2) receptor expression was down‐regulated in M1‐polarized macrophages from murine bone marrows. During AP, myeloid‐specific D(2) receptor deletion worsened pancreatic injury, systematic inflammation and promoted macrophages to M1 phenotype. Furthermore, M1 macrophages from LysM(+/cre)D(2) (fl/fl) mice exhibited increased NADPH oxidase‐induced oxidative stress and enhanced NF‐κB and NLRP3 inflammasome activation. D(2) receptor activation inhibited M1 macrophage polarization, oxidative stress‐induced NF‐κB and NLRP3 inflammasome activation. CONCLUSION AND IMPLICATIONS: Our data for the first time showed that myeloid‐specific D(2) receptor signalling controls pancreatic injury and systemic inflammation via inhibiting M1 macrophage, suggesting D(2) receptor activation might serve as therapeutic target for AP.

Objectives We aimed to evaluate the values of neutrophil-to-lymphocyte ratio (NLR) and white blood cell (WBC) in predicting severity of acute pancreatitis (AP) with different etiologies. Methods We compared NLR and WBC levels in patients with different etiologies and AP severity. The optimal cutoff value for them to predict severe acute pancreatitis (SAP) was determined by receiver operating characteristic (ROC) curve analysis. Results Both NLR and WBC were elevated in patients with SAP. After subgrouping AP by etiology, NLR was predictive of SAP only in hypertriglyceridemia-induced AP (HTG-AP), while WBC could effectively predict severity in both gallstone and HTG-AP. The best cutoff value of WBC for predicting SAP in gallstone AP patients was 12.81 × 109 /L, with sensitivity and specificity of 78.9% and 70.2%. The best cutoff value for NLR and WBC to differentiate HTG-SAP was more than 5.88 and 15.89 × 109 /L, respectively, with sensitivity and specificity of 87% and 50% for NLR and 56.5% and 75.76% for WBC. Conclusions Our study firstly demonstrated that NLR selectively played a role in HTG-AP, while WBC could predict the severity of both gallstone and HTG-AP. Furthermore, we firstly elucidated that NLR was more sensitive and accurate in judging the severity of HTG-AP compared with WBC.

Reseda odorata L. has long been used in traditional Asian medicine for the treatment of diseases associated with oxidative injury and acute inflammation, such as endotoxemia, acute lung injury, acute myocardial infarction and hepatitis. Luteolin, the main component of Reseda odorata L., which is also widely found in many natural herbs and vege tables, has been shown to induce heme oxygenase-1 (HO-1) expression to exert anti-inflammatory and antioxidant effects. In this study, we aimed to examine the effects of luteolin on mice with severe acute pancreatitis (SAP), and to explore the underlying mechanisms. Cerulein and lipopolysaccharide were used to induce SAP in male Institute of Cancer Research (ICR) mice in the SAP group. The SAP group was divided into 4 subgroups, as follows: the vehicle, luteolin, zinc protoporphyrin (ZnPP) only, and luteolin (Lut) + ZnPP (luteolin plus zinc protoporphyrin treatment) groups. The wet/dry weight ratios, hematoxylin and eosin staining and pathological scores of pancreatic tissues were assessed and compared to those of the control mice. Amylase, lipase, nuclear factor-κB (NF-κB) and myeloperoxidase activities, and malondialdehyde, tumor necrosis factor α (TNFα), interleukin (IL)-6, IL-10 and HO-1 levels, as well as the expression of HO-1 were determined in serum and/or pancreatic tissue samples. SAP was successfully induced in male mice compared to normal control mice. The wet/dry weight ratios, pathological scores, and amylase and lipase activity, as well as the levels of TNFα and IL-6 were significantly reduced in the pancreatic tissues of the mice in the Lut group compared with those of the mice in the vehicle group. The Lut group exhibited a significant increase in HO-1 expression in the pancreas and enhanced serum HO-1 and IL-10 levels compared with the vehicle group. The suppression of HO-1 activity in the ZnPP group significantly abolished the protective effects of luteolin. NF-κB expression in the pancreatic tissues from the mice in the Lut + ZnPP group was significantly increased following the suppression of HO-1 activity. On the whole, our findings demonstrate that luteolin protects mice from SAP by inducing HO-1-mediated anti-inflammatory and antioxidant activities, in association with the suppression of the activation of the NF-κB pathway.

Hypermethylated in cancer 1 (HIC1) is a tumour suppressor gene that is frequently deleted or epigenetically silenced in many human cancers. However, the molecular function of HIC1 in pancreatic cancer has not been fully elucidated, especially in cancer invasion and metastasis. We aimed to clarify the clinical relevance of HIC1 and human pancreatic cancer and the mechanism of its effect on invasion and metastasis .HIC1 was downregulated in pancreatic cancer patient cancer tissue and pancreatic cancer cell lines. A tissue microarray analysis demonstrated that negative HIC1 expression predicted advanced pathological stages and worse patient survival. In addition, HIC1 inhibited the invasion and metastasis of pancreatic cancer cells both in vitro and in vivo. Finally, HIC1 repressed the expression of STAT3 target genes, including c-Myc, VEGF, CyclinD1, MMP2 and MMP9, by binding and interacting with STAT3 to impede its DNA-binding ability but without affecting the protein levels of STAT3 and p-STAT3. Therefore, HIC1 appears to function as a STAT3 inhibitor and may be a promising target for cancer research and for the development of an optimal treatment approach for pancreatic cancer.