Pirfenidone alleviates chronic pancreatitis via suppressing the activation of pancreatic stellate cells and the M1 polarization of macrophages.

In the realm of fibroinflammatory conditions, chronic pancreatitis (CP) stands out as a particularly challenging ailment, lacking a dedicated, approved treatment. The potential of Pirfenidone (PFD), a drug originally used for treating idiopathic pulmonary fibrosis (IPF), in addressing CP's fibrotic aspects has sparked new interest. This investigation focused on the role of PFD in diminishing fibrosis and immune response in CP, using a mouse model induced by caerulein. The research extended to in vitro studies examining the influence of PFD on pancreatic stellate cells' (PSCs) behavior and the polarization of macrophages into M1 and M2 types. Advanced techniques like RNA sequencing and comprehensive data analyses were employed to decode the molecular interactions of PFD with PSCs. Supplementary experiments using techniques such as quantitative real-time PCR, western blotting, and immunofluorescence were also implemented. Results showed a notable reduction in pancreatic damage in PFD-treated mice, manifested through decreased acinar cell atrophy, lower collagen deposition, and a reduction in macrophage presence. Further investigation revealed PFD's capacity to hinder PSCs' migration, growth, and activation, alongside a reduction in the production and secretion of extracellular matrix proteins. This effect is primarily achieved by interfering with signaling pathways such as TGF-ß/Smad, Wnt/ß-catenin, and JAK/STAT. Additionally, PFD selectively hampers M1 macrophage polarization through the STAT3 pathway, without impacting M2 polarization. These outcomes highlight PFD's dual mechanism in moderating PSC activity and M1 macrophage polarization, positioning it as a promising candidate for CP therapy.

Chronic exposure to BDE-47 aggravates acute pancreatitis and chronic pancreatitis by promoting acinar cell apoptosis and inflammation.

The effect of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), a persistent environmental pollutant commonly used as a flame retardant in various consumer products, on pancreatitis has not been clearly elucidated, although it has been reported to be toxic to the liver, nervous system, and reproductive system. Acute pancreatitis (AP) and chronic pancreatitis (CP) models were induced in this study by intraperitoneal injection of caerulein. The aim was to investigate the impact of BDE-47 on pancreatitis by exposing the animals to acute (1 week) or chronic (8 weeks) doses of BDE-47 (30 mg/kg in the low-concentration group and 100 mg/kg in the high-concentration group). Additionally, BDE-47 was utilized to stimulate mouse bone marrow-derived macrophages, pancreatic primary stellate cells, and acinar cells in order to investigate the impact of BDE-47 on pancreatitis. In vivo experiments conducted on mice revealed that chronic exposure to BDE-47, rather than acute exposure, exacerbated the histopathological damage of AP and CP, leading to elevated fibrosis in pancreatic tissue and increased infiltration of inflammatory cells in the pancreas. In vitro experiments showed that BDE-47 can promote the expression of the inflammatory cytokines Tnf-α and Il-6 in M1 macrophages, as well as promote acinar cell apoptosis through the activation of the PERK and JNK pathways via endoplasmic reticulum stress. The findings of this study imply chronic exposure to BDE-47 may exacerbate the progression of both AP and CP by inducing acinar cell apoptosis and dysregulating inflammatory responses.

Catechin hydrate ameliorates cerulein­induced chronic pancreatitis via the inactivation of TGF­ß/Smad2 signaling.

Chronic pancreatitis (CP) is a pancreatic inflammatory disease associated with histological changes, including fibrosis, acinar cell loss and immune cell infiltration, and leads to damage of the pancreas, which results in pain, weight loss and loss of pancreas function. Catechin or catechin hydrate (CH) has antioxidant, anticancer and immune­regulatory effects. However, unlike other catechins, the antifibrotic effects of (+)­CH have not been widely studied in many diseases, including CP. Therefore, the anti­fibrotic effects of (+)­CH against CP were evaluated in the present study. To assess the prophylactic effects of CH, (+)­CH (1, 5 or 10 mg/kg) or ethanol was administered 1 h before first cerulein (50 µg/kg) injection. To assess the therapeutic effects, (+)­CH (5 mg/kg) or ethanol was administered after cerulein injection for one or two weeks. In both methods, cerulein was injected intraperitoneally into mice once every hour, six times a day, four times a week, for a total of three weeks, to induce CP. The data showed that (+)­CH markedly inhibited glandular destruction and inflammation during CP. Moreover, (+)­CH prevented pancreatic stellate cell (PSC) activation and the production of extracellular matrix components, such as fibronectin 1 and collagens, which suggested that it may act as a novel therapeutic agent. Furthermore, the mechanism and effectiveness of (+)­CH on pancreatic fibrosis were investigated in isolated PSCs. (+)­CH suppressed the activation of Smad2 and fibrosis factors that act through transforming growth factor­ß (TGF­ß) or platelet­derived growth factor. These findings suggest that (+)­CH exhibits antifibrotic effects in cerulein­induced CP by inactivating TGF­ß/Smad2 signaling.

Pancreatic Acinar Cells-Derived Sphingosine-1-Phosphate Contributes to Fibrosis of Chronic Pancreatitis via Inducing Autophagy and Activation of Pancreatic Stellate Cells.

BACKGROUND & AIMS: Studies have demonstrated that activated pancreatic stellate cells (PSCs) play a crucial role in pancreatic fibrogenesis in chronic pancreatitis (CP); however, the precise mechanism for PSCs activation has not been fully elucidated. We analyzed the role of injured pancreatic acinar cells (iPACs) in the activation of PSCs of CP. METHODS: Sphingosine kinase 1 (SPHK1)/sphingosine-1-phosphate (S1P) signaling was evaluated in experimental CP induced by cerulein injection or pancreatic duct ligation, as well as in PACs injured by cholecystokinin. The activation of PSCs and pancreatic fibrosis in CP samples was evaluated by immunohistochemical and immunofluorescence analyses. In vitro coculture assay of iPACs and PSCs was created to evaluate the effect of the SPHK1/S1P pathway and S1P receptor 2 (SIPR2) on autophagy and activation of PSCs. The pathogenesis of CP was assessed in SPHK1-/- mice or PACs-specific SPHK1-knockdown mice with recombinant adeno-associated virus serotypes 9-SPHK1-knockdown, as well as in mice treated with inhibitor of SPHK1 and S1P receptor 2 (S1PR2). RESULTS: SPHK1/S1P was remarkably increased in iPACs and acinar cells in pancreatic tissues of CP mice. Meanwhile, the pathogenesis, fibrosis, and PSCs activation of CP was significantly prevented in SPHK1-/- mice and recombinant adeno-associated virus serotypes 9-SPHK1-knockdown mice. Meanwhile, iPACs obviously activated PSCs, which was prevented by SPHK1 knockdown in iPACs. Moreover, iPACs-derived S1P specifically combined to S1PR2 of PSCs, by which modulated 5' adenosine monophosphate-activated protein kinase/mechanistic target of rapamycin pathway and consequently induced autophagy and activation of PSCs. Furthermore, hypoxia-inducible factor 1-α and -2α promoted SPHK1 transcription of PACs under hypoxia conditions, which is a distinct characteristic of the CP microenvironment. Coincidently, inhibition of SPHK1 and S1PR2 activity with inhibitor PF-543 and JTE-013 obviously impeded pancreatic fibrogenesis of CP mice. CONCLUSIONS: The activated SPHK1/S1P pathway in iPACs induces autophagy and activation of PSCs by regulating the S1PR2/5' adenosine monophosphate-activated protein kinase/mammalian target of rapamycin pathway, which promotes fibrogenesis of CP. The hypoxia microenvironment might contribute to the cross talk between PACs and PSCs in pathogenesis of CP.

CD73-generated extracellular adenosine promotes resolution of neutrophil-mediated tissue injury and restrains metaplasia in pancreatitis.

Pancreatitis is currently the leading cause of gastrointestinal hospitalizations in the US. This condition occurs in response to abdominal injury, gallstones, chronic alcohol consumption or, less frequently, the cause remains idiopathic. CD73 is a cell surface ecto-5'-nucleotidase that generates extracellular adenosine, which can contribute to resolution of inflammation by binding adenosine receptors on infiltrating immune cells. We hypothesized genetic deletion of CD73 would result in more severe pancreatitis due to decreased generation of extracellular adenosine. CD73 knockout (CD73-/- ) and C57BL/6 (wild type, WT) mice were used to evaluate the progression and response of caerulein-induced acute and chronic pancreatitis. In response to caerulein-mediated chronic or acute pancreatitis, WT mice display resolution of pancreatitis at earlier timepoints than CD73-/- mice. Using immunohistochemistry and analysis of single-cell RNA-seq (scRNA-seq) data, we determined CD73 localization in chronic pancreatitis is primarily observed in mucin/ductal cell populations and immune cells. In murine pancreata challenged with caerulein to induce acute pancreatitis, we compared CD73-/- to WT mice and observed a significant infiltration of Ly6G+, MPO+, and Granzyme B+ cells in CD73-/- compared to WT pancreata and we quantified a significant increase in acinar-to-ductal metaplasia demonstrating sustained metaplasia and inflammation in CD73-/- mice. Using neutrophil depletion in CD73-/- mice, we show neutrophil depletion significantly reduces metaplasia defined by CK19+ cells per field and significantly reduces acute pancreatitis. These data identify CD73 enhancers as a potential therapeutic strategy for patients with acute and chronic pancreatitis as adenosine generation and activation of adenosine receptors is critical to resolve persistent inflammation in the pancreas.

XCHT alleviates the pancreatic fibrosis via VDR/NLRP3 signaling pathway in a mouse model of CP.

ETHNOPHARMACOLOGICAL RELEVANCE: Xiao Chai Hu Tang (XCHT) derived from the classic medical book Shang Han Lun (Treatise on Febrile Diseases) in the Eastern Han Dynasty, which has been widely used in China and other Asian countries for the treatment of inflammation and fibrosis of chronic pancreatitis (CP), but the therapeutic mechanism of XCHT in pancreatic fibrosis remains unclear. AIM OF THE STUDY: This study aimed to evaluate the intervention effects and explore pharmacological mechanism of XCHT on inflammation and fibrosis in cerulein-induced CP model. MATERIALS AND METHODS: Fifty male C57BL/6 mice were randomly divided into five main groups, 10 animals in each: Control, CP model (50 µg/kg cerulein), high dose XCHT-treated CP group (60 g/kg XCHT), medium dose XCHT-treated CP group (30 g/kg XCHT) and low dose XCHT-treated CP group (15 g/kg XCHT). Different doses of XCHT were given to mice by gavage twice a day for 2 weeks after the CP model induction. Pancreatic tissues were harvested and the pancreatic inflammation and fibrosis were evaluated by histological score, Sirius red staining, and alpha-smooth muscle actin (α-SMA) immunohistochemical staining. ELISA, IHC and RT-qPCR were performed to detect the expression of Vitamin D3 (VD3) and Vitamin D receptor (VDR) in serum and pancreatic tissues, respectively. The expressions of NLRP3 inflammasome related genes and molecules were assayed by WB, IHC and RT-qPCR. RESULTS: The pathohistological results demonstrated that XCHT markedly inhibited the fibrosis and chronic inflammation of cerulein-induced CP, indicated by reduction of collagen I, collagen III, α-SMA, and NLRP3 expressions. XCHT significantly increased VD3 and VDR expression while reduced the pancreatic NLRP3 expression. Correspondingly, XCHT decreased the levels of NLRP3 downstream targets IL-1ß, TNF-α and IL-6. CONCLUSIONS: These results revealed that XCHT suppressed the pancreatic fibrosis and chronic inflammation in cerulein-induced CP model by enhancing the VD3/VDR expression and inhibiting the secretion of NLRP3-assoicated inflammatory factors.

P-element-Induced Wimpy-Testis-Like Protein 1 Regulates the Activation of Pancreatic Stellate Cells Through the PI3K/AKT/mTOR Signaling Pathway.

AIM: Pancreatic fibrosis is the main pathological characteristic of chronic pancreatitis (CP) and pancreatic cancer. Pancreatic stellate cells (PSCs) play a critical role in pancreatic fibrosis. Any targets that may have an impact on the activation of PSCs could become potential treatment candidates for CP and pancreatic cancer. Our goal was to investigate the effect of P-element-induced wimpy-testis (PIWI) protein 1 (PIWIL1) on PSC activation. METHODS: Lentivirus-based RNA interference (RNAi) and overexpression vector construction were used to knock down and over-express the PIWIL1 protein. Immunocytofluorescent staining, western blotting, wound healing assay, transwell assay, and phalloidin staining were used to investigate the effects of PIWIL1 on the secretion of extracellular matrix components (EMC), actin cytoskeleton, and on the invasion and migration abilities of primary PSCs isolated from C57BL/6 mice. Moreover, pancreatic fibrosis was induced by L-arginine in C57BL/6 mice. The expression of PIWIL1 and collagen deposition in vivo were tested by western blotting and Sirius red staining. RESULTS: Expression levels of collagen I, collagen III, and α-smooth muscle actin were significantly decreased in the LV-PIWIL1 group. Compared with the si-PIWIL1 group, significant differences were observed in the expression of desmin, p-PI3K, p-AKT, and p-mTOR in the LV-PIWIL1 group. Furthermore, PIWIL1 suppressed the PSCs' invasion and migration abilities. In a rescue experiment, the PI3K/AKT/mTOR signaling pathway was found to be the underlying mechanism in PSCs activation mediated by PIWIL1. CONCLUSIONS: Our findings suggest that PIWIL1 inhibits the activation of PSCs via the PI3K/AKT/mTOR signaling pathway. PIWIL1 is a potential therapeutic target for pancreatic fibrosis.

Development and Characterization of Novel Chronic Eosinophilic Inflammation- Mediated Murine Model of Malignant Pancreatitis.

AIMS: Develop a novel murine models of malignant pancreatitis. BACKGROUND: Although patients with chronic pancreatitis are at a greater risk of developing pancreatic cancer, there is no definitive mouse model that currently develops chronic pancreatitis-induced pancreatic cancer. OBJECTIVE: Characterization of eosinophilic inflammation-mediated malignant pancreatitis in novel murine model. METHODS: We developed a murine model of chronic eosinophilic inflammation associated with pancreatitis that also shows characteristic features of pancreatic malignancy. The mouse received cerulein and azoxymethane via intraperitoneal administration developed pathological malignant phenotype, as well as concomitant lung inflammation. RESULTS: We discovered pathological alterations in the pancreas that were associated with chronic pancreatitis, including a buildup of eosinophilic inflammation. Eosinophil degranulation was reported nearby in the pancreas tissue sections that show acinar-to-ductal metaplasia and acinar cell atrophy, both of which are characteristic of pancreatic malignancies. Additionally, we also observed the formation of PanIN lesions after three initial doses of AOM and eight weeks of cerulein with the AOM treatment regimen. We discovered that persistent pancreatic eosinophilic inflammation linked with a pancreatic malignant phenotype contributes to pulmonary damage. The RNA seq analysis also confirmed the induction of fibro-inflammatory and oncogenic proteins in pancreas and lung tissues. Further, in the current manuscript, we now report the stepwise kinetically time-dependent cellular inflammation, genes and proteins involved in the development of pancreatitis malignancy and associated acute lung injury by analyzing the mice of 3 AOM with 3, 8, and 12 weeks of the cerulein challenged protocol regime. CONCLUSION: We first show that sustained long-term eosinophilic inflammation induces time-dependent proinflammatory, profibrotic and malignancy-associated genes that promote pancreatic malignancy and acute lung injury in mice.

Acinar ATP8b1/LPC pathway promotes macrophage efferocytosis and clearance of inflammation during chronic pancreatitis development.

Noninflammatory clearance of dying cells by professional phagocytes, termed efferocytosis, is fundamental in both homeostasis and inflammatory fibrosis disease but has not been confirmed to occur in chronic pancreatitis (CP). Here, we investigated whether efferocytosis constitutes a novel regulatory target in CP and its mechanisms. PRSS1 transgenic (PRSS1Tg) mice were treated with caerulein to mimic CP development. Phospholipid metabolite profiling and epigenetic assays were performed with PRSS1Tg CP models. The potential functions of Atp8b1 in CP model were clarified using Atp8b1-overexpressing adeno-associated virus, immunofluorescence, enzyme-linked immunosorbent assay(ELISA), and lipid metabolomic approaches. ATAC-seq combined with RNA-seq was then used to identify transcription factors binding to the Atp8b1 promoter, and ChIP-qPCR and luciferase assays were used to confirm that the identified transcription factor bound to the Atp8b1 promoter, and to identify the specific binding site. Flow cytometry was performed to analyze the proportion of pancreatic macrophages. Decreased efferocytosis with aggravated inflammation was identified in CP. The lysophosphatidylcholine (LPC) pathway was the most obviously dysregulated phospholipid pathway, and LPC and Atp8b1 expression gradually decreased during CP development. H3K27me3 ChIP-seq showed that increased Atp8b1 promoter methylation led to transcriptional inhibition. Atp8b1 complementation substantially increased the LPC concentration and improved CP outcomes. Bhlha15 was identified as a transcription factor that binds to the Atp8b1 promoter and regulates phospholipid metabolism. Our study indicates that the acinar Atp8b1/LPC pathway acts as an important "find-me" signal for macrophages and plays a protective role in CP, with Atp8b1 transcription promoted by the acinar cell-specific transcription factor Bhlha15. Bhlha15, Atp8b1, and LPC could be clinically translated into valuable therapeutic targets to overcome the limitations of current CP therapies.

YAP activates pancreatic stellate cells and enhances pancreatic fibrosis.

BACKGROUND: Pancreatic stellate cells (PSCs) foster the progression of pancreatic adenocarcinoma and chronic pancreatitis (CP) by producing a dense fibrotic stroma. However, the incomplete knowledge of PSCs biology hampers the exploration of antifibrotic therapies. Here, we explored the role of the Hippo pathway in the context of PSCs activation and experimental CP. METHODS: CP model was created in rats with the tail vein injection of dibutyltin dichloride (DBTC). The expression of Yes-associated protein (YAP) in CP tissue was assessed. Primary and immortalized rats PSCs were treated with the YAP-inhibitor verteporfin. Furthermore, YAP siRNA was employed. Subsequently, DNA synthesis, cell survival, levels of α-smooth muscle actin (α-SMA) protein, presence of lipid droplets and PSCs gene expression were evaluated. Upstream regulators of YAP signaling were studied by reporter gene assays. RESULTS: In DBTC-induced CP, pronounced expression of YAP in areas of tubular structures and periductal fibrosis was observed. Verteporfin diminished DNA replication in PSCs in a dose-dependent fashion. Knockdown of YAP reduced cell proliferation. Primary cultures of PSCs were characterized by a decrease of lipid droplets and increased synthesis of α-SMA protein. Both processes were not affected by verteporfin. At the non-cytotoxic concentration of 100 nmol/L, verteporfin significantly reduced mRNA levels of transforming growth factor-ß1 (Tgf-ß1) and Ccn family member 1 (Ccn1). YAP signaling was activated by TGF-ß1, but repressed by interferon-γ. CONCLUSIONS: Activated YAP enhanced PSCs proliferation. The antifibrotic potential of Hippo pathway inhibitors warrants further investigation.

Trimetazidine has Promising Preventive Effects on Experimental Chronic Pancreatitis Rat Model.

BACKGROUND: It was aimed to evaluate the preventive efficacy of trimetazidine in an experimental chronic pancreatitis rat model. METHODS: Chronic pancreatitis model was accomplished with caerulein and alcohol administration. In the study, 40 female Sprague Dawley rats were randomized into 5 groups containing 8 animals in each. Group 1 (chronic pancreatitis); group 2 (chronic pancreati- tis+low-dose trimetazidine group); group 3 (chronic pancreatitis+high-dose trimetazidine group); group 4 (placebo group (chronic pancreatitis + saline)); group 5 (sham group). 24 hours after the last injection, all animals were sacrificed. Tumor necrosis factor-alpha, transforming growth factor-ß, malondialdehyde, and glutathione peroxidase levels were tested in blood samples. Histopathologic exam- inations were conducted by a senior pathologist who was unaware of the group allocations. RESULTS: Results of biochemical parameters of the trimetazidine groups (groups 2 and 3) were significantly favorable compared with the chronic pancreatitis group (group 1) (P < .05). The difference between the low-dose- and the high-dose trimetazidine group (group 3) was significant in terms of blood tests (P < .05). The difference between the low-dose trimetazidine group and the chronic pancreatitis group was not significant in terms of histopathologic scores (P > .05); however, the difference was significant between the high-dose trimetazidine group and the chronic pancreatitis group (P < .05). CONCLUSIONS: To the best of our knowledge, this current research is the first study that evaluates trimetazidine's efficacy in the chronic pancreatitis rat model. Trimetazidine has affirmative preventive properties in the chronic pancreatitis course.

Murine Chronic Pancreatitis Model Induced by Partial Ligation of the Pancreatic Duct Encapsulates the Profile of Macrophage in Human Chronic Pancreatitis.

Immune responses are an integral part of the pathogenesis of pancreatitis. Studies applying the mouse model of pancreatitis induced by partial ligation of the pancreatic duct to explore the pancreatic immune microenvironment are still lacking. The aim of the present study is to explore the macrophage profile and associated regulatory mechanisms in mouse pancreatitis, as well as the correlation with human chronic pancreatitis (CP). In the present study, the mouse model of pancreatitis was induced by partial ligation of the pancreatic duct. Mice in the acute phase were sacrificed at 0, 4, 8, 16, 32, 72 h after ligation, while mice in the chronic phase were sacrificed at 7, 14, 21, 28 days after ligation. We found that the pancreatic pathological score, expression of TNF-α and IL-6 were elevated over time and peaked at 72h in the acute phase, while in the chronic phase, the degree of pancreatic fibrosis peaked at day 21 after ligation. Pancreatic M1 macrophages and pyroptotic macrophages showed a decreasing trend over time, whereas M2 macrophages gradually rose and peaked at day 21. IL-4 is involved in the development of CP and is mainly derived from pancreatic stellate cells (PSCs). The murine pancreatitis model constructed by partial ligation of the pancreatic duct, especially the CP model, can ideally simulate human CP caused by obstructive etiologies in terms of morphological alterations and immune microenvironment characteristics.

Piezo1-mediated stellate cell activation causes pressure-induced pancreatic fibrosis in mice.

Pancreatic fibrosis is a complication of chronic pancreatitis and is a prominent feature of pancreatic cancer. Pancreatic fibrosis is commonly observed in patients with prolonged pancreatic duct obstruction, which elevates intrapancreatic pressure. We show here that increased pancreatic duct pressure causes fibrosis and describes the mechanism by which pressure increases deposition of extracellular matrix proteins and fibrosis. We found that pancreatic stellate cells (PSCs), the source of the extracellular matrix proteins in fibrosis, express the mechanically activated ion channel Piezo1. By increasing intracellular calcium, mechanical stress or the Piezo1 agonist Yoda1-activated PSCs manifest by loss of perinuclear fat droplets and increased TGF-ß1, fibronectin, and type I collagen expression. These effects were blocked by the Piezo1 inhibitor GsMTx4 and absent in PSCs from mice with conditional genetic deletion of Piezo1 in stellate cells, as was pancreatic duct ligation-induced fibrosis. Although TRPV4 has been proposed to have direct mechanosensing properties, we discovered that PSCs from Trpv4-KO mice were protected against Yoda1-triggered activation. Moreover, mice devoid of TRPV4 were protected from pancreatic duct ligation-induced fibrosis. Thus, high pressure within the pancreas stimulates Piezo1 channel opening, and subsequent activation of TRPV4 leads to stellate cell activation and pressure-induced chronic pancreatitis and fibrosis.

Evaluating Outcomes and Misuse in Opioid-Dependent Chronic Pancreatitis Using a State-Mandated Monitoring System.

INTRODUCTION: Patients with chronic pancreatitis (CP) often require opioids for pain control. The goal of our study was to characterize opioid use in patients with CP in a real-life practice using a state-mandated online monitoring program and to assess outcomes compared to CP patients without opioid dependency. METHODS: CP patients seen in our Pancreas Center from 2016 to 2021 were divided into two groups-with and without chronic opioid use. Details of opioids and other controlled prescriptions were obtained by review of the Massachusetts Prescription Awareness Tool (MassPat). RESULTS: Of the 442 CP outpatients, 216 used chronic opioids. Patients with opioid use had significantly more recurrent acute pancreatitis (76.6% vs. 52.7%), concurrent alcohol use (11.2% vs. 5.8%), tobacco use (37.8% vs. 19.7%), anxiety (22.4% vs. 16.6%), depression (43.5% vs. 23.5%) and daily pain (59.8% vs. 24.8%) (p < 0.001). They also concurrently used more benzodiazepines (43.7% vs. 12.4%), gabapentinoids (66.4% vs. 31.1%) and medical marijuana (14.9% vs. 4.19%) (p < 0.001). They had more celiac plexus blocks (22.0% vs. 6.67%), surgery (18.3% vs. 8.89%) and more hospitalizations for CP flares (3.6 vs. 1.0 visits) (p < 0.001). Less than 13% patients received opioids by means of ED visits; 81.7% patients received their prescriptions from one facility and 75% received them at regular intervals. CONCLUSION: Opioid-dependent CP patients exhibit polypharmacy and have worse outcomes with higher resource utilization. The state-monitoring program ensures that the majority of patients receive opioids from a single facility, thereby minimizing misuse.

Curative role of mesenchymal stromal cells in chronic pancreatitis: Modulation of MAPK and TGF-ß1/SMAD factors.

BACKGROUND AND OBJECTIVE: Living organisms respond to physical, chemical, and biological threats with a potent inflammatory response which alters organ cell signaling and leads to dysfunction. We evaluated the therapeutic effect of bone marrow-based mesenchymal stromal cell (BM-MSC) transplanted in rats to preserve tissue integrity and to restore homeostasis and function in the pancreatitis experimental pattern. METHODS: This study involved 40 adult male Wister rats. Repeated L-arginine injections caused chronic pancreatitis (CP), leading to the development of pancreatic damage and shifting the intracellular signaling pathways. Rats were then infused with BM-MSC labeled with PKH26 fluorescent linker dye for 12 weeks. RESULTS: Cell-surface indicators of BM-MSCs such as CD 90 and CD29 were expressed with the lack of CD34 expression. BM-MSC treatment considerably improved the alterations induced in a series of inflammatory markers, including IL-18, TNF-α, CRP, PGE2, and MCP-1. Furthermore, improvement was found in digestive enzymes and lipid profile with amelioration in myeloperoxidase activity. BM-MSC treatment also regulated the (TGF-/p-38MPAK/SMAD2/3) signaling factors that enhances repair of damaged pancreatic tissue, confirmed by reversed alteration of histopathological examination. CONCLUSION: our results further bring to light the promise of cell transplant therapy for chronic pancreatitis.

Nicotine facilitates pancreatic fibrosis by promoting activation of pancreatic stellate cells via α7nAChR-mediated JAK2/STAT3 signaling pathway in rats.

AIM: Smoking has been considered as a risk factor of chronic pancreatitis (CP), but the potential mechanism is still unknown. The major pathological feature of CP is pancreatic fibrosis, whose major functional cells are pancreatic stellate cells (PSCs). Nicotine is the major component of cigarette smoke, our recent study suggested that nicotine has the potential to facilitate pancreatic fibrosis in CP. This study was aimed to analyze the function and mechanism of nicotine on PSCs and pancreatic fibrosis in rats. MATERIALS AND METHODS: In vivo, a rat CP model was induced by intraperitoneal injection of 20 % L-arginine hydrochloride (200 mg/100 g) at 1 h intervals twice per week, nicotine was injected subcutaneously at a dose of 1 mg/kg body weight per day. After four weeks, the pancreatic tissue was collected for H&E, Masson and immunohistochemical staining. In vitro, primary rPSCs were isolated from rats and treated with nicotine (0.1 µM and 1 µM). The proliferation、apoptosis、α-SMA expression、extracellular matrix (ECM) metabolism and α7nAChR-mediated JAK2/STAT3 signaling pathway of rPSCs were detected by CCK-8 assay、flow cytometry、real-time Q-PCR and western blotting analysis. The α7nAChR antagonist α-bungarotoxin (α-BTX) was used to perform inhibition experiments. KEY FINDINGS: Nicotine increased pancreatic damage, collagen deposition and activation of PSCs in the CP rat model. In rPSCs, the proliferation, α-SMA expression and ECM formation were significantly promoted by nicotine in a dose-dependent manner. Meanwhile, the apoptosis of rPSCs was significantly reduced after nicotine treatment. Moreover, nicotine also activated the α7nAChR-mediated JAK2/STAT3 signaling pathway in rPSCs. These effects of nicotine on rPSCs were blocked by α-BTX. SIGNIFICANCE: Our finding in this research suggests that nicotine facilitates pancreatic fibrosis by promoting activation of pancreatic stellate cells via α7nAChR-mediated JAK2/STAT3 signaling pathway in rats, partly revealing the mechanism of smoking on chronic pancreatitis.

Neddylation pathway alleviates chronic pancreatitis by reducing HIF1α-CCL5-dependent macrophage infiltration.

Chronic pancreatitis (CP) is characterized by a wide range of irreversible fibro-inflammatory diseases with largely ambiguous pathogenesis. Although neddylation pathway has been implicated in regulating immune responses, whether the dysregulation of neddylation is involved in the progression of CP and how neddylation regulates the inflammatory microenvironment of CP have not yet been reported. Here, we demonstrate that global inactivation of neddylation pathway by MLN4924 significantly exacerbates chronic pancreatitis. The increased M2 macrophage infiltration, mediated by the upregulated chemokine (C-C motif) ligand 5 (CCL5), is responsible for the enhanced pancreatitis-promoting activity of MLN4924. Both CCL5 blockade and macrophage depletion contribute to alleviating pancreatic fibrosis and inflammation in MLN4924-treated CP mice. Mechanistic investigation identifies that inactivation of Cullin-RING ligases (CRLs) stabilizes cellular levels of hypoxia-inducible factor 1α (HIF-1α), which increases CCL5 expression by promoting CCL5 transactivation. Clinically, UBE2M expression remarkably decreases in human CP tissues compared with normal specimens and the levels of CCL5 and M2 marker CD163 are negatively correlated with UBE2M intensity, suggesting that neddylation is involved in the pathogenesis of pancreatitis. Hence, our studies reveal a neddylation-associated immunopathogenesis of chronic pancreatitis and provide new ideas for the disease treatment.

Berberine attenuates severity of chronic pancreatitis and fibrosis via AMPK-mediated inhibition of TGF-ß1/Smad signaling and M2 polarization.

Berberine (BR) acts as an AMP-activated protein kinase (AMPK) activator which possesses antioxidant and anti-inflammatory properties. In this study, we have investigated the effects of BR against cerulein-induced chronic pancreatitis (CP) via inhibition of TGF-ß/Smad signaling and M2 macrophages polarization in AMPK dependent manner. Cerulein-induced CP mice were treated with BR (3 and 10 mg/kg), intraperitoneally every day for 21 days. Our results indicated that, BR treatment (10 mg/kg) significantly reduced oxidative-nitrosative stress, histological alterations, inflammatory cells infiltration and collagen deposition in pancreatic tissue. BR treatment also prevented cerulein-induced pancreatic stellate cells (PSCs) activation and extracellular matrix (ECM) deposition via downregulation of α-SMA, collagen1a, collagen3a and fibronectin expression. Mechanistically, treatment with BR significantly activated AMPK signaling as compared to cerulein-challenged mice. Further, administration of BR also inhibited TGF-ß/Smad signaling and macrophages polarization in cerulein-induced CP in-vivo models and TGF-ß1 stimulated RAW 264.7 macrophages in-vitro. Together, our results strongly suggest that BR treatment protected against cerulein-induced CP and associated fibrosis progression by inhibiting TGF-ß1/Smad signaling and M2 macrophages polarization in an AMPK dependent manner.

Isoliquiritigenin ameliorates caerulein-induced chronic pancreatitis by inhibiting the activation of PSCs and pancreatic infiltration of macrophages.

Chronic pancreatitis (CP) is characterized by persistent inflammation of the pancreas that results in progressive loss of the endocrine and exocrine compartment owing to atrophy and/or replacement with fibrotic tissue. Currently, the clinical therapeutic scheme of CP is mainly symptomatic treatment including pancreatic enzyme replacement, glycaemic control and nutritional support therapy, lacking of specific therapeutic drugs for prevention and suppression of inflammation and fibrosis aggravating in CP. Here, we investigated the effect of isoliquiritigenin (ILG), a chalcone-type dietary compound derived from licorice, on pancreatic fibrosis and inflammation in a model of caerulein-induced murine CP, and the results indicated that ILG notably alleviated pancreatic fibrosis and infiltration of macrophages. Further in vitro studies in human pancreatic stellate cells (hPSCs) showed that ILG exerted significant inhibition on the proliferation and activation of hPSCs, which may be due to negative regulation of the ERK1/2 and JNK1/2 activities. Moreover, ILG significantly restrained the M1 polarization of macrophages (RAW 264.7) via attenuation of the NF-κB signalling pathway, whereas the M2 polarization was hardly affected. These findings indicated that ILG might be a potential anti-inflammatory and anti-fibrotic therapeutic agent for CP.

Adipose­derived mesenchymal stem cells ameliorate dibutyltin dichloride­induced chronic pancreatitis by inhibiting the PI3K/AKT/mTOR signaling pathway.

Adipose­derived mesenchymal stem cells (ASCs) play a positive role in tissue injury repair and regeneration. The aim of this study was to determine whether ASCs could ameliorate chronic pancreatitis (CP) induced by the injection of dibutyltin dichloride (DBTC) and to elucidate its potential mechanisms. Furthermore, this study also explored whether there was a significant difference if the ASCs were injected via the inferior vena cava or the left gastric artery. CP was induced in rats by a single intravenous administration of DBTC, and the accumulation of collagen and apoptotic rates of pancreatic acinar cells were analyzed. According to the results, ASCs markedly reduced DBTC­induced pancreatic damage and collagen deposition in the rat model of CP. Moreover, ASCs significantly decreased pancreatic cell apoptosis by regulating the expression levels of caspase­3, BAX and Bcl­2. These effects were observed regardless of whether the injection was in the inferior vena cava or the left gastric artery. It was also found that the expression levels of phosphorylated PI3K, AKT and mTOR in pancreatic tissues of the DBTC­induced CP model group were significantly increased, while the expression levels of phosphorylated PI3K, AKT and mTOR in the two treatment groups were markedly decreased. ASCs noticeably suppressed the PI3K/AKT/mTOR pathway in the pancreatic tissue of DBTC­induced CP. This study indicated that ASCs protect against pancreatic fibrosis by modulating the PI3K/AKT/mTOR pathway, and have the potential to be a new strategy for the treatment of CP in the future.