Guojian Yin

Shikonin ameliorates cerulein-induced acute pancreatitis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE Shikonin, a highly liposoluble naphthoquinone pigment isolated from the traditional medical herbs Lithospermum erythrorhizon (LE), was considered to exhibit an anti-inflammatory property. While the potential of shikonin to ameliorate acute pancreatitis (AP) is unknown. Our aim was to investigate the effects of shikonin in a murine model of cerulein-induced pancreatitis. MATERIALS AND METHODS AP was induced in mice by six intraperitoneal injection of cerulein (50 μg/kg) at hourly intervals. Vehicle or shikonin (50 mg/kg) was pretreated 2 h before the first cerulein injection. After 6 h, 9 h and 12 h of the first cerulein injection, the severity of acute pancreatitis was assessed by biochemistry, myeloperoxidase activity, histological grading, proinflammatory cytokines levels and nuclear factor kappa B (NF-κB) activity. RESULTS Shikonin administration significantly reduced serum amylase and lipase activities, pancreatic histological scores, TNF-α, IL-1β, IL-6 levels, MPO activity and NF-κB activity. CONCLUSION Taken together, these results suggest that shikonin might protect against experimental pancreatitis by reducing release of inflammatory cytokines via inhibition of NF-κB activity. The therapeutic role of shikonin in AP needs further investigation.

Retinoic Acid Ameliorates Pancreatic Fibrosis and Inhibits the Activation of Pancreatic Stellate Cells in Mice with Experimental Chronic Pancreatitis via Suppressing the Wnt/β-Catenin Signaling Pathway

Pancreatic fibrosis, a prominent feature of chronic pancreatitis (CP), induces persistent and permanent damage in the pancreas. Pancreatic stellate cells (PSCs) provide a major source of extracellular matrix (ECM) deposition during pancreatic injury, and persistent activation of PSCs plays a vital role in the progression of pancreatic fibrosis. Retinoic acid (RA), a retinoid, has a broad range of biological functions, including regulation of cell differentiation and proliferation, attenuating progressive fibrosis of multiple organs. In the present study, we investigated the effects of RA on fibrosis in experimental CP and cultured PSCs. CP was induced in mice by repetitive cerulein injection in vivo, and mouse PSCs were isolated and activated in vitro. Suppression of pancreatic fibrosis upon administration of RA was confirmed based on reduction of histological damage, α-smooth muscle actin (α-SMA) expression and mRNA levels of β-catenin, platelet-derived growth factor (PDGF)-Rβ transforming growth factor (TGF)-βRII and collagen 1α1 in vivo. Wnt 2 and β-catenin protein levels were markedly down-regulated, while Axin 2 expression level was up-regulated in the presence of RA, both in vivo and in vitro. Nuclear translation of β-catenin was significantly decreased following RA treatment, compared with cerulein-induced CP in mice and activated PSCs. Furthermore, RA induced significant PSC apoptosis, inhibited proliferation, suppressed TCF/LEF-dependent transcriptional activity and ECM production of PSC via down-regulation of TGFβRII, PDGFRβ and collagen 1α1 in vitro. These results indicate a critical role of the Wnt/β-catenin signaling pathway in RA-induced effects on CP and PSC regulation and support the potential of RA as a suppressor of pancreatic fibrosis in mice.

Imbalance of Wnt/Dkk negative feedback promotes persistent activation of pancreatic stellate cells in chronic pancreatitis.

The role of persistent activation of pancreatic stellate cells (PSCs) in the fibrosis associated with chronic pancreatitis (CP) is increasingly being recognized. Recent studies have shown that Wnt signaling is involved in the development of fibrosis in multiple organs, however, the role of specific Wnts in pancreatic fibrosis remains unknown. We investigated the role of Wnt signaling during PSC activation in CP and the effect of β-catenin inhibition and Dickkopf-related protein 1 (Dkk1) restoration on the phenotype of PSCs. CP was induced in mice by repetitive caerulein injection and mouse PSCs were isolated and activated in vitro. The expression of Wnts, β-catenin, secreted frizzled-related proteins (sFRPs) and Dkks was analyzed by quantitative RT-PCR and western blotting. The canonical Wnt signaling pathway was examined by immunofluorescence and western blot detection of nuclear β-catenin expression. The effect of recombinant mouse Dkk-1 (rmDkk-1) on cell proliferation and apoptosis was assessed by flow cytometry, immunofluorescence, immunocytochemistry and Cell Counting Kit-8 (CCK-8) analysis. The expression of β-catenin, collagen1α1, TGFβRII, PDGFRβ and α-SMA in PSCs treated with different concentrations of rmDkk-1 or siRNA against β-catenin was determined by quantitative RT-PCR and western blotting. Wnt2 was the only Wnt whose expression was significantly upregulated in response to PSC activation, and Wnt2 and β-catenin protein levels were significantly increased in the pancreas of CP mice, whereas Dkk-1 expression was evidently decreased. Nuclear β-catenin levels were markedly increased in activated PSCs, and rmDkk-1 suppressed the nuclear translocation of β-catenin and the proliferation and extracellular matrix production of PSCs through the downregulation of PDGFRβ and TGFβRII. Upregulation of Dkk-1 expression increased apoptosis in cultured PSCs. These results indicate that Wnt signaling may mediate the profibrotic effect of PSC activation, and Wnt2/Dkk-1 could be potential therapeutic targets for CP.

Rosmarinic Acid Attenuates Sodium Taurocholate-Induced Acute Pancreatitis in Rats by Inhibiting Nuclear Factor-κB Activation

Rosmarinic Acid (RA), a caffeic acid ester, has been shown to exert anti-inflammation, anti-oxidant and antiallergic effects. Our study aimed to investigate the effect of RA in sodium taurocholate ( NaTC )-induced acute pancreatitis, both in vivo and in vitro. In vivo, RA (50 mg/kg) was administered intraperitoneally 2 h before sodium taurocholate injection. Rats were sacrificed 12 h, 24 h or 48 h after sodium taurocholate injection. Pretreatment with RA significantly ameliorated pancreas histopathological changes, decreased amylase and lipase activities in serum, lowered myeloperoxidase activity in the pancreas, reduced systematic and pancreatic interleukin-1 β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) levels, and inhibited NF-κB translocation in pancreas. In vitro, pretreating the fresh rat pancreatic acinar cells with 80 μ mol/L RA 2 h before 3750 nmol/L sodium taurocholate or 10 ng/L TNF-α administration significantly attenuated the reduction of isolated pancreatic acinar cell viability and inhibited the nuclear activation and translocation of NF-κB. Based on our findings, RA appears to attenuate damage in sodium taurocholate-induced acute pancreatitis and reduce the release of inflammatory cytokines by inhibiting the activation of NF-κB. These findings might provide a basis for investigating the therapeutic role of RA in managing acute pancreatits.

Increased interleukin-23/17 axis and C-reactive protein are associated with severity of acute pancreatitis in patients.

Objective The interleukin (IL)-23/IL-17 axis plays an important role in various inflammatory conditions but its function in acute pancreatitis (AP) is not well understood. The present study investigated the relationship between serum levels of IL-23, IL-17, and C-reactive protein (CRP) in patients and the severity of AP. Methods Eighty-five patients with AP were categorized into mild group, moderately severe group, and severe group according to the revised Atlanta classification, 2012. Serum levels of IL-23 and IL-17 were measured by enzyme-linked immunosorbent assay in patients 48 hours after admission. The CRP levels of patients were also measured on admission and 48 hours after admission. Results The serum levels of CRP of patients on admission and 48 hours after admission and levels of IL-23 and IL-17 of patients 48 hours after admission increased alone with the severity of AP, respectively (P < 0.01). The serum levels of IL-23 and IL-17 in the patients were correlated with CRP levels (r2 = 0.234, r2 = 0.552, P < 0.001, respectively). Conclusions The serum levels of IL-17, IL-23, and CRP are correlated with the severity of AP and represent valuable prognostic factors in the assessment of disease severity of patients with AP.

C-reactive protein: rethinking its role in evaluating the severity of hyperlipidemic acute pancreatitis.

Objectives The goal of this study is to evaluate the role of C-reactive protein (CRP) in predicting the severity of hyperlipidemic acute pancreatitis (HLAP) compared with non-HLAP (NHLAP). Methods A total of 1073 episodes of acute pancreatitis between July 2009 and June 2013 were retrospectively studied. The clinical characteristics and laboratory data of HLAP and NHLAP were statistically analyzed on days 1, 2, 3, 4, and 6, especially the CRP level. Results There was a significant difference in CRP levels between HLAP and NHLAP (P < 0.01) on days 1, 2, 3, 4, and 6. The cutoff value for CRP in HLAP should be greater than NHLAP to obtain an accurate prediction of severity. Higher serum CRP levels in HLAP cases were correlated with higher incidences of diabetes and fatty liver and lower incidences in women, elevated very-low-density lipoprotein levels, and lower high-density lipoprotein levels. Conclusions The significant difference in CRP cutoff values in predicting severity between patients with HLAP and NHLAP should be noted in the clinic.

Different Clinical Presentations of Hyperlipidemic Acute Pancreatitis: A Retrospective Study.

Objectives The goal of this study was to summarize the clinical features of hyperlipidemic acute pancreatitis (HLAP), and help clinicians understand the characteristic presentations of HLAP. Methods From July 2009 to June 2013, 1073 cases of acute pancreatitis were retrospectively assessed. The clinical characteristics of HLAP and non-HLAP were statistically analyzed. Results The etiologic ratio of HLAP in acute pancreatitis rose from 13% in 2009 to 25.6% in 2013. Diabetes mellitus, fatty liver, and acute pancreatitis recurrence were positively correlated with HLAP, and female sex, age (>60 years), and alkaline phosphatase level were negatively correlated with HLAP. The diagnostic accuracy of amylase in HLAP was only 40.38%, compared with lipase (91.83%). Different cutoff points of serum triglyceride on day 1 (5.33 mmol/L), day 2 (2.77 mmol/L), and day 3 (2.18 mmol/L) could be used to obtain an accurate diagnosis of HLAP. Higher incidences of acute peripancreatic fluid collection, renal failure, and severe acute pancreatitis were also observed in patients with HLAP. Conclusions Different clinical presentations of HLAP should be applied to be distinguished from non-HLAP in the clinic.

Role of Microvesicles From Bone Marrow Mesenchymal Stem Cells in Acute Pancreatitis

Objectives Mesenchymal stem cells (MSCs) have shown an obvious protective effect on acute pancreatitis (AP). The purpose of the present study was to analyze the effect of bone marrow MSC-derived microvesicles (bmMSC-MVs) on AP and explore the underlying mechanisms. Methods Bone marrow MSCs and bmMSC-MVs were isolated from Sprague-Dawley rats. Cerulein-induced mild AP (MAP) and sodium taurocholate-induced severe AP (SAP) were used as AP models in vivo and in vitro. Pancreatic injury was evaluated by measuring serum levels of amylase, lipase, chemokines, and interleukins, and by pancreatic histology, reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. The effects of bmMSC-MVs on the survival rates of pancreatic acinar cells in vitro were also assessed. Results Bone marrow MSC-MVs attenuated acute pancreatic injury in MAP and SAP by regulating IL-1&agr;, IL-6, and TNF-&agr;, and dramatically attenuated the nuclear translocation of NF-&kgr;B p65 in MAP and SAP. Bone marrow MSC-MVs improved the survival rates of pancreatic acinar cells in MAP and SAP models in vitro. Conclusions Bone marrow MSC-MVs played a protective role in AP by reducing the levels of proinflammatory cytokines and regulating the nuclear translocation of NF-&kgr;B p65. Bone marrow MSC-MVs could be developed as a strategy for the clinical treatment of SAP.OBJECTIVES Mesenchymal stem cells (MSCs) have shown an obvious protective effect on acute pancreatitis (AP). The purpose of the present study was to analyze the effect of bone marrow MSC-derived microvesicles (bmMSC-MVs) on AP and explore the underlying mechanisms. METHODS Bone marrow MSCs and bmMSC-MVs were isolated from Sprague-Dawley rats. Cerulein-induced mild AP (MAP) and sodium taurocholate-induced severe AP (SAP) were used as AP models in vivo and in vitro. Pancreatic injury was evaluated by measuring serum levels of amylase, lipase, chemokines, and interleukins, and by pancreatic histology, reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry. The effects of bmMSC-MVs on the survival rates of pancreatic acinar cells in vitro were also assessed. RESULTS Bone marrow MSC-MVs attenuated acute pancreatic injury in MAP and SAP by regulating IL-1α, IL-6, and TNF-α, and dramatically attenuated the nuclear translocation of NF-κB p65 in MAP and SAP. Bone marrow MSC-MVs improved the survival rates of pancreatic acinar cells in MAP and SAP models in vitro. CONCLUSIONS Bone marrow MSC-MVs played a protective role in AP by reducing the levels of proinflammatory cytokines and regulating the nuclear translocation of NF-κB p65. Bone marrow MSC-MVs could be developed as a strategy for the clinical treatment of SAP.

Pancreatic acinar cells-derived cyclophilin A promotes pancreatic damage by activating NF-κB pathway in experimental pancreatitis

Inflammation triggered by necrotic acinar cells contributes to the pathophysiology of acute pancreatitis (AP), but its precise mechanism remains unclear. Recent studies have shown that Cyclophilin A (CypA) released from necrotic cells is involved in the pathogenesis of several inflammatory diseases. We therefore investigated the role of CypA in experimental AP induced by administration of sodium taurocholate (STC). CypA was markedly upregulated and widely expressed in disrupted acinar cells, infiltrated inflammatory cells, and tubular complexes. In vitro, it was released from damaged acinar cells by cholecystokinin (CCK) induction. rCypA (recombinant CypA) aggravated CCK-induced acinar cell necrosis, promoted nuclear factor (NF)-κB p65 activation, and increased cytokine production. In conclusion, CypA promotes pancreatic damage by upregulating expression of inflammatory cytokines of acinar cells via the NF-κB pathway.

Astragaloside IV ameliorates acute pancreatitis in rats by inhibiting the activation of nuclear factor-κB

This study aimed to investigate the effects of astragaloside IV (AS-IV; 3-O-β-D-xylopyranosyl-6-O-β-D-glucopyranosylcycloastragenol), which has been reported to have comprehensive pharmacological functions, on sodium taurocholate (NaTc)/L-arginine (L-Arg)-induced acute pancreatitis (AP) in rats in vivo and in rat pancreatic acinar cells in vitro. NaTc-induced experimental AP was induced in rats by injecting 4% NaTc (0.1 ml/100 g) in the retrograde direction of the biliopancreatic duct. L-Arg-induced experimental AP was induced in rats by 2 intraperitoneal injections of 20% L-arg (3 g/kg), with an interval of 1 h between the injections. The rats were pre-treated AS-IV (50 mg/kg) or the vehicle (DMSO) 2 h prior to the induction of AP. Enzyme-linked immunosorbent assay, H&E staining, myeloperoxidase (MPO) activity, reverse transcription-quantitative PCR, western blot analysis and immunohistochemistry were used to evaluate the effects of AS-IV on AP. The results revealed that treatment with AS-IV significantly reduced serum amylase and lipase levels, pancreatic pathological alterations, the secretion of pro-inflammatory cytokines, MPO activity, and the protein expression of nuclear factor-κB (NF-κB) in vivo. Moreover, pre-treatment with AS-IV significantly increased the expression levels of manganese superoxide dismutase and cuprum/zinc superoxide dismutase. In the in vitro experiment, treatment of the cells with AS-IV aslo reduced rat pancreatic acinar cell necrosis and nuclear NF-κB activity, and enhanced the protein expression of superoxide dismutase. In conclusion, this study indicates that the protective effects of AS-IV on experimental AP in rats may be closely related to the inhibition of NF-κB. In addition, our results indicate that AS-IV may exert potential antioxidant effects on AP. Therefore, AS-IV may be an effective therapeutic agent for AP.