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In the pathogenesis of pancreatic adenocarcinoma, tumor stroma plays a key role in both aggressiveness, immune evasion, resistance to chemotherapy, and the ability to metastasize. Among the elements that characterize the behavior of the stroma, extracellular vesicles and, in particular, exosomes play an important role. These extracellular vesicles carry a wide range of bioactive molecules, from transcription factors to microRNAs, which can substantially alter the phenotype of the cellular components of the stroma. Exosomes are involved in the exchange of signals between tumor cells, tumor-associated macrophages, cancer-associated fibroblasts, and also with the healthy cells surrounding the tumor. They can transfer resistance to chemotherapeutic drugs, promote the epithelial-mesenchymal transition, modify the phenotype of macrophages, or induce the expression of molecules that alter the extracellular matrix to facilitate migration and metastasis. On the other hand, all these characteristics make these vesicles first-rate therapeutic targets, as controlling their functionality could greatly enhance the effectiveness of treatments that, today, are still far from be satisfactory.

Pancreatic ductal adenocarcinoma (PDAC) offers an optimal model for discovering “druggable” molecular pathways that participate in inflammation-associated cancer development. Chronic pancreatitis, a common prolonged inflammatory disease, behaves as a well-known premalignant condition that contributes to PDAC development. Although the mechanisms underlying the pancreatitis-to-cancer transition remain to be fully elucidated, emerging evidence supports the hypothesis that the actions of proinflammatory mediators on cells harboring Kras mutations promote neoplastic transformation. Recent elegant studies demonstrated that the IL17 pathway mediates this phenomenon and can be targeted with antibodies, but the downstream mechanisms by which IL17 functions during this transition are currently unclear. In this study, we demonstrate that IL17 induces the expression of REG3β, a well-known mediator of pancreatitis, during acinar-to-ductal metaplasia and in early pancreatic intraepithelial neoplasia (PanIN) lesions. Furthermore, we found that REG3β promotes cell growth and decreases sensitivity to cell death through activation of the gp130-JAK2-STAT3-dependent pathway. Genetic inactivation of REG3β in the context of oncogenic Kras-driven PDAC resulted in reduced PanIN formation, an effect that could be rescued by administration of exogenous REG3β. Taken together, our findings provide mechanistic insight into the pathways underlying inflammation-associated pancreatic cancer, revealing a dual and contextual pathophysiologic role for REG3β during pancreatitis and PDAC initiation. Cancer Res; 75(22); 4852–62. ©2015 AACR.

Legend for Supplemental Figure 1.

Schematic representation of the IL-17A and REG3β signaling pathway and PDAC development.

PDF file, 57K, Primers used for real time qRT-PCR.

7 pages, 5 figures, supplementary materials https://doi.org/10.1016/j.hal.2023.102389.-- Data availability: Data will be made available on request, Extracellular Vesicles (EVs) are likely an important strategy of transport and communication in marine microbial community. Their isolation and characterization from axenic culture of microbial eukaryotes represents a technological challenge not fully solved. Here, for the first time, we isolated EVs from a near-axenic culture of the toxic dinoflagellate Alexandrium minutum. Pictures of the isolated vesicles were done with Cryo TEM (Cryogenic Transmission Electron Microscopy). Based on their morphotype the EVs were clustered in five major groups (rounded, rounded electron-dense, lumen electron-dense, double and irregular) and each EV was measured resulting in an average size of 0.36 µm of diameter. Taking in account that in prokaryotes it has been demonstrated that EVs play an important role in the mechanism of toxicity, this descriptive work aims to be the first step to study the possible role of EVs in the toxicity of dinoflagellates, We thank the Spanish MICINN Project SMART (PID2020-112978GB-I00), and the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019- 000928-S)

As acute pancreatitis progresses to the severe form, a life-threatening systemic inflammation is triggered. Although the mechanisms involved in this process are not yet well understood, it has been proposed that circulating exosomes may be involved in the progression of inflammation from the pancreas to distant organs. Here, the inflammatory capacity and protein profile of plasma exosomes obtained during the first 24 h of hospitalization of patients diagnosed with acute pancreatitis were characterized and compared with the final severity of the disease. We found that the final severity of the disease strongly correlates with the inflammatory capacity of exosomes in the early stages of acute pancreatitis. Exosomes isolated from patients with mild pancreatitis had no effect on macrophages, while exosomes isolated from patients with severe pancreatitis triggered NFκB activation, TNFα and IL1β expression, and free radical generation. To delve deeper into the mechanism involved, we performed a proteomic analysis of the different exosomes that allowed us to identify different groups of proteins whose concentration was also correlated with the clinical classification of pancreatitis. In particular, an increase in the amount of S100A8 and S100A9 carried by exosomes of severe pancreatitis suggests that the mechanism of action of exosomes is mediated by the effect of these proteins on NADPH oxidase. This enzyme is activated by S100A8/S100A9, thus generating free radicals and promoting an inflammatory response. Along these lines, we observed that inhibition of this enzyme abolished all the pro-inflammatory effects of exosomes from severe pancreatitis. All this suggests that the systemic effects, and therefore the final severity of acute pancreatitis, are determined by the content of circulating exosomes generated in the early hours of the process. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland., This work was supported by the projects PI16/00060 from Instituto de Salud Carlos III, 2019AEP057 CVSCI, and a grant ‘Gonzalo Miño’ from the Asociación Española de Gastroenterología. The Biologial and Environmental Proteomics group is a member of Proteored-PRB3 and is supported by Grant PT17/0019/0008 of the PE I+D+I 2013–2016, funded by ISCIII and FEDER.

The crosstalk between the transformed tumoral cells and their microenvironment is a key aspect for pancreatic ductal adenocarcinoma (PDAC) progression. This molecular dialog is intensively studied because it may result in an efficient therapeutic target. Contrary to this near microenvironment, the stromal portion in direct contact with the transformed cells, a far microenvironment, placed at the periphery of the tumor mass, produces factors signaling tumors. Among these factors, REG3β, produced by this part of the pancreas, is an important factor in promoting tumor progression. This paper demonstrated that targeting REG3β protein with specific antibodies limits the PDAC tumor growth in an orthotopic, syngeneic mice model induced by injection of Panc02 cells. Then, we showed that CTGF is over-expressed in response to REG3β in PDAC-derived cells. Moreover, inactivation of REG3β by treating tumors with anti-REG3β antibodies results in a strong decrease of CTGF in PDAC tumors. Lastly, we demonstrated that forced expression of CTGF in xenografted Panc02 cells abolishes the therapeutic effect of the anti-REG3β antibody treatment. Altogether, these results indicate that the effect of REG3β in promoting PDAC progression is mediated by CTGF over-activation. Thus, REG3β is a promising therapeutic target to treat PDAC with an original rationale. In conclusion, we demonstrated that the far microenvironment is essential for PDAC progression by producing active secretory factors, and some of them could be used as therapeutic targets., This work was supported by La Ligue Contre le Cancer, INCa, Canceropole PACA, and INSERM.

In this study we aimed to determine the effect of the exosomes derived from Mesenchymal stromal cells (MSC) on cell proliferation, and to study how pre-conditioning the MSCs to a septic environment, changes their exosomes’ content and consequently, their regenerative capacity. MSC were isolated from male rats’ femora and tibiae and cultured in non pre-stimulated and pre-stimulated (with LPS) conditions. The secreted exosomes were obtained via standard ultracentrifugation protocol. Cell proliferation experiments were conducted by treating an epithelial cell line with exosomes from non pre-stimulated MSC (Control exosomes) and pre-stimulated MSC (LPS exosomes) through an in vitro scratch assay. Exosomal protein profile was analyzed by a liquid chromatography-mass spectrometry analysis. The treatment of epithelial cells with LPS exosomes increases a 10% its capacity to proliferate and to heal the wound in comparison with the cells treated with Control exosomes (Fig.1a). The analysis of the protein content of both types of exosomes confirmed that pre-conditioning MSCs to a septic environment modifies the protein cargo of its exosomes (Fig. 1b), resulting in the appearance proteins related to cell cycle regulation and cell proliferation. In conclusion, pre-stimulating MSC with LPS enhances their paracrine activity and improves the reparative capacity of their secreted exosomes.

Polyethylene glycols (PEGs) are neutral polymers widely used in biomedical applications due to its hydrophilicity and biocompatibility. Exosomes are small vesicles secreted by nearly all cell types and play an important role in normal and pathological conditions. The purpose of this study was to evaluate the role of a 35-kDa molecular weight PEG (PEG35) on the modulation of exosome-mediated inflammation. Human macrophage-like cells THP-1, epithelial BICR-18, and CAPAN-2 cells were exposed to PEG35 prior to incubation with exosomes of different cellular origins. Exosome internalization was evaluated by confocal microscopy and flow cytometry. In another set of experiments, macrophages were treated with increasing concentrations of PEG35 prior to exposure with the appropriate stimuli: lipopolysaccharide, BICR-18-derived exosomes, or exosomes from acute pancreatitis-induced rats. Nuclear Factor Kappa B (NF&kappa, B) and Signal transducer and activator of transcription 3 (STAT3) activation and the expression levels of pro-inflammatory Interleukin 1&beta, (IL1&beta, ) were determined. PEG35 administration significantly enhanced the internalization of exosomes in both macrophages and epithelial cells. Further, PEG35 ameliorated the inflammatory response induced by acute pancreatitis-derived exosomes by reducing the expression of IL1&beta, and p65 nuclear translocation. Our results revealed that PEG35 promotes the cellular uptake of exosomes and modulates the pro-inflammatory effect of acute pancreatitis-derived vesicles through inhibition of NF&kappa, B, thus emphasizing the potential value of PEG35 as an anti-inflammatory agent for biomedical purposes.

Background/Objective: Evidence from basic and clinical studies suggests that unsaturated fatty acids (UFAs) might be relevant mediators of the development of complications in acute pancreatitis (AP). Objective: The aim of this study was to analyze outcomes in patients with AP from regions in Spain with different patterns of dietary fat intake. Materials and Methods: A retrospective analysis was performed with data from 1,655 patients with AP from a Spanish prospective cohort study and regional nutritional data from a Spanish cross-sectional study. Nutritional data considered in the study concern the total lipid consumption, detailing total saturated fatty acids, UFAs and monounsaturated fatty acids (MUFAs) consumption derived from regional data and not from the patient prospective cohort. Two multivariable analysis models were used: (1) a model with the Charlson comorbidity index, sex, alcoholic etiology, and recurrent AP; (2) a model that included these variables plus obesity. Results: In multivariable analysis, patients from regions with high UFA intake had a significantly increased frequency of local complications, persistent organ failure (POF), mortality, and moderate-to-severe disease in the model without obesity and a higher frequency of POF in the model with obesity. Patients from regions with high MUFA intake had significantly more local complications and moderate-to-severe disease; this significance remained for moderate-to-severe disease when obesity was added to the model. Conclusions: Differences in dietary fat patterns could be associated with different outcomes in AP, and dietary fat patterns may be a pre-morbid factor that determines the severity of AP. UFAs, and particulary MUFAs, may influence the pathogenesis of the severity of AP., GG-R was supported by grant from the Instituto de Salud Carlos III and Instituto de Investigación Sanitaria (IIS) Aragón [Río Hortega grant CM17/00145].

A frequent complication of acute pancreatitis is the lung damage associated with the systemic inflammatory response. Although various pro-inflammatory mediators generated at both local and systemic levels have been identified, the pathogenic mechanisms of the disease are still poorly understood. In recent years, exosomes have emerged as a new intercellular communication system able to transfer encapsulated proteins and small RNAs and protect them from degradation. Using an experimental model of taurocholate-induced acute pancreatitis in rats, we aimed to evaluate the role of exosomes in the extent of the systemic inflammatory response. Induction of pancreatitis increased the concentration of circulating exosomes, which showed a different proteomic profile to those obtained from control animals. A series of tracking experiments using PKH26-stained exosomes revealed that circulating exosomes effectively reached the alveolar compartment and were internalized by macrophages. In vitro experiments revealed that exosomes obtained under inflammatory conditions activate and polarize these alveolar macrophages towards a pro-inflammatory phenotype. Interestingly, the proteomic analysis of circulating exosomes during acute pancreatitis suggested a multi-organ origin with a relevant role for the liver as a source of these vesicles. Tracking experiments also revealed that the liver retains the majority of exosomes from the peritoneal cavity. We conclude that exosomes are involved in the lung damage associated with experimental acute pancreatitis and could be relevant mediators in the systemic effects of pancreatitis. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Background Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease with limited response to currently available therapies. Alveolar type II (ATII) cells act as progenitor cells in the adult lung, contributing to alveolar repair during pulmonary injury. However, in IPF, ATII cells die and are replaced by fibroblasts and myofibroblasts. In previous preclinical studies, we demonstrated that ATII-cell intratracheal transplantation was able to reduce pulmonary fibrosis. The main objective of this study was to investigate the safety and tolerability of ATII-cell intratracheal transplantation in patients with IPF. Methods We enrolled 16 patients with moderate and progressive IPF who underwent ATII-cell intratracheal transplantation through fiberoptic bronchoscopy. We evaluated the safety and tolerability of ATII-cell transplantation by assessing the emergent adverse side effects that appeared within 12 months. Moreover, pulmonary function, respiratory symptoms, and disease extent during 12 months of follow-up were evaluated. Results No significant adverse events were associated with the ATII-cell intratracheal transplantation. After 12 months of follow-up, there was no deterioration in pulmonary function, respiratory symptoms, or disease extent. Conclusions Our results support the hypothesis that ATII-cell intratracheal transplantation is safe and well tolerated in patients with IPF. This study opens the door to designing a clinical trial to elucidate the potential beneficial effects of ATII-cell therapy in IPF.

Pancreatic ductal adenocarcinoma (PDAC) offers an optimal model for discovering >druggable> molecular pathways that participate in inflammation-associated cancer development. Chronic pancreatitis, a common prolonged inflammatory disease, behaves as a well-known premalignant condition that contributes to PDAC development. Although the mechanisms underlying the pancreatitis-to-cancer transition remain to be fully elucidated, emerging evidence supports the hypothesis that the actions of proinflammatory mediators on cells harboring Kras mutations promote neoplastic transformation. Recent elegant studies demonstrated that the IL17 pathway mediates this phenomenon and can be targeted with antibodies, but the downstream mechanisms by which IL17 functions during this transition are currently unclear. In this study, we demonstrate that IL17 induces the expression of REG3β, a wellknown mediator of pancreatitis, during acinar-to-ductal metaplasia and in early pancreatic intraepithelial neoplasia (PanIN) lesions. Furthermore, we found that REG3β promotes cell growth and decreases sensitivity to cell death through activation of the gp130-JAK2-STAT3-dependent pathway. Genetic inactivation of REG3β in the context of oncogenic Kras-driven PDAC resulted in reduced PanIN formation, an effect that could be rescued by administration of exogenous REG3β. Taken together, our findings provide mechanistic insight into the pathways underlying inflammation-associated pancreatic cancer, revealing a dual and contextual pathophysiologic role for REG3β during pancreatitis and PDAC initiation., This work was supported by La Ligue Contre le Cancer, INCa, Canceropole PACA, DGOS (labellisation SIRIC), and INSERM to J.L. Iovanna; NIH grants DK52913, the Mayo Clinic Center for Cell Signaling in Gastroenterology (P30DK084567), and the Mayo Foundation to R. Urrutia; by Fraternal Order of Eagles Cancer Award to G. Lomberk; and the FIS grant from Instituto de Salud Carlos III (PI13/01224) to E. Folch-Puy

Extracellular vesicles (EVs), including exosomes and microvesicles, are nano-sized membrane vesicles containing proteins and nucleic acids, which act as intercellular messengers. They play an important role in a variety of physiological processes, as well as in pathological situations such as inflammation or cancer. Here, we show that in the case of pancreatic ductal adenocarcinoma (PDAC), the healthy pancreatic tissue surrounding the tumor releases REG3β, a lectin that binds to the glycoproteins present in the surface of EVs, thus interfering with their uptake and internalization by target cells. In vitro, the disruption of the signaling mediated by EVs due to the presence of REG3β, prevents the EV-induced phenotypic switch in macrophages, inhibits the increased cell migration of cancer cells and reverses a number of metabolomic changes promoted by EVs. In vivo, the uptake of REG3β+ EVs by tumor cells is significantly impaired. Furthermore, it results in an increase of circulating REG3β+ EVs in blood of pancreatic cancer patients. Our findings highlight the effect of a lectin released by the healthy pancreatic tissue surrounding the tumor in modulating the EV-mediated interactions between different cell types in PDAC., This work was supported by the projects FIS PI16/00060 (DC) and FIS PI13/02192 (MG) (co-funded by FEDEREuropean Union) from Instituto de Salud Carlos III; La Ligue Contre le Cancer, INCa, Canceropole PACA, DGOS (labellisation SIRIC) and INSERM (JLI); L. Bonjoch is supported by a predoctoral fellowship from Generalitat de Catalunya (AGAUR, FI DGR 2013); CIBEREHD is funded by the Instituto de Salud Carlos III.

[Background] Little is known regarding the optimal type of fluid resuscitation in acute pancreatitis (AP)., [Objective] The objective of this article was to compare the effect of lactated Ringer’s solution (LR) vs normal saline (NS) in the inflammatory response in AP., [Methods] We conducted a triple-blind, randomized, controlled trial. Patients ≥ 18 admitted with AP were eligible. Patients were randomized to receive LR or NS. Primary outcome variables were number of systemic inflammatory response syndrome (SIRS) criteria at 24 hours, 48 hours and 72 hours and blood C-reactive protein (CRP) levels at 48 hours and 72 hours. In vitro complementary experiments were performed to further explore the interaction between pH, lactate and inflammation., [Results] Nineteen patients receiving LR and 21 receiving NS were analyzed. The median (p25–p75) number of SIRS criteria at 48 hours were 1 (1–2) for NS vs 1 (0–1) for LR, p = 0.060. CRP levels (mg/l) were as follows: at 48 hours NS 166 (78–281) vs LR 28 (3–124), p = 0.037; at 72 hours NS 217 (59–323) vs LR 25 (3–169), p = 0.043. In vitro, LR inhibited the induction of inflammatory phenotype of macrophages and NF-κB activation. This effect was not observed when using Ringer’s solution without lactate, suggesting a direct anti-inflammatory effect of lactate., [Conclusions] Lactated Ringer’s is associated with an anti-inflammatory effect in patients with acute pancreatitis., The RCT was funded by AIGPA, an association of researchers in gastroenterology from the province of Alicante, Spain. In vitro experiments were supported by a national Spanish public grant, project FIS PI13/00019 from Instituto de Salud Carlos III; L.B. is supported by a predoctoral fellowship from Generalitat de Catalunya (AGAUR, FI DGR 2013).

In this article we report the obesogenic role of the acute phase protein PAP/HIP. We found that the transgenic TgPAP/HIP mice develop spontaneous obesity under standard nutritional conditions, with high levels of glucose, leptin, and LDL and low levels of triglycerides and HDL in blood. Accordingly, PAP/HIP-deficient mice are skinny under standard nutritional conditions. We also found that expression of PAP/HIP is induced in intestinal epithelial cells in response to gavage with olive oil and this induction is AG490 sensitive. We demonstrated that incubation of 3T3-L1 preadipocytes with a low concentration as 1 ng/ml of recombinant PAP/HIP results in accelerated BrdU incorporation in vitro. PAP/HIP-dependent adipocytes growth is sensitive to the MEK inhibitor U0126. Finally, patients with severe obesity present higher blood levels of PAP/HIP than non-obese control individuals. Altogether our data suggest that PAP/HIP could be a mediator of fat tissue development, released by the intestine and induced by the presence of food into the gut.

There is a convincing body of evidence that oxidative stress is involved in the pathogenesis of acute pancreatitis. The effects of different radical scavengers suggested that reactive oxygen metabolites are generated at very early stage of disease and contribute to amplify the pancreatic damage. Oxidative stress is also involved in the progression of the disease from a local damage to a systemic organ failure. However, therapeutic use of antioxidants failed to clearly show a clinical benefit in different trials. Therefore, although antioxidants alone seem to be not enough for the treatment of severe acute pancreatitis, future combined therapeutic strategies should include antioxidants in its composition. © 2013 Informa UK, Ltd.

Background Octreotide is generally administered based on the surgeon's interpretation of perceived risk for pancreatic fistula at the time of pancreaticoduodenectomy (PD). Methods A single-institution, prospective randomized trial was conducted between April 2009 and December 2011 involving 62 PD patients who were randomized to receive octreotide (100 μg subcutaneously every 8 h; n = 32) or placebo (n = 30). Pancreatic juice output was measured after the operation using a catheter inserted into the pancreatic duct. Postoperative complications were recorded. Results No significant differences in median output were found between the octreotide (82.5 ml) and placebo (77.5 ml) groups (P = 0.538). Median total output was significantly lower in patients with adenocarcinoma compared with those with periampullary tumours (P = 0.004) and in patients with a duct diameter of >5 mm compared with those with a duct diameter of

International audience; The REG3β protein was identified more than 2 decades ago, but its role in PDAC development was only recently reported. In Pancreatic Ductal Adenocarcinoma (PDAC), REG3β protein is expressed and released by the far microenvironment, which is situated out of the tumor, at the periphery of the tumor mass, and is part of the healthy peri-tumoral region. This compartment is completely unrelated to the classical microenvironment that corresponds to the intra-tumoral stoma. Clinically relevant, the far microenvironment, and the factors released by it, could be novel and original therapeutic targets for treating patients with a PDAC. In this way we recently demonstrated that REG3β is an essential soluble factor necessary for PDAC development which is able to stimulate several simultaneous pro-tumoral mechanisms. We also find that secreted REG3β boosts interactions between epithelial cells and immune cells by activating the CXCL12/CXCR4 signaling cascade, which facilitates tumor escape through evasion of immune surveillance, and promotes metastasis. In addition, REG3β interfere the intercellular communication inside the tumor mediated by extracellular vesicles, resulting in relevant changes in macrophage phenotype or tumor cell migration. Therefore, we are proposing to call as near microenvironment to the classical microenvironment that is constituted by fibroblasts, inflammatory cells and fibers and located into the tumor, and as far microenvironment, which is constituted by the parenchymal non transformed cells located at the periphery of the tumor mass.

Pulmonary macrophages exist in two different anatomical compartments in the lower respiratory tract: alveolar macrophages in the alveoli and interstitial macrophages in the interstitium. Depending on the micro-environmental stimulation, macrophages follow different activation pathways. According to their inflammatory response pattern, activated macrophages have been characterized as pro-inflammatory (M1), wound-healing (M2a) and regulatory (M2b). Since acute pancreatitis occurs in parallel with acute lung injury, the profile of the different macrophage subpopulations could be relevant in the progression of the disease. The activation of lung alveolar and interstitial macrophages was assessed in an experimental model of severe acute pancreatitis induced in rats by intraductal infusion of 3.5% sodium taurocholate. Alveolar and interstitial macrophages were obtained and the expression of markers of different activations was evaluated. Activation of nuclear factors PPARγ and NF-κB, which are involved in the acquisition of different phenoytpes, was also measured. Alveolar macrophages acquired an early M1 phenotype characterized by the expression of inflammatory cytokines and NF-κB activation. In contrast, interstitial macrophages followed the inhibitory M2b pathway. In these macrophages, PPARγ became activated and the anti-inflammatory cytokine IL-10 was expressed. These results suggest that alveolar and interstitial macrophages play different roles in acute lung injury associated with acute pancreatitis. Alveolar macrophages promote an early inflammatory response, whereas interstitial macrophages help resolve inflammation.

Obesity and lipid metabolism are associated with the severity of acute pancreatitis. Fat necrosis appears in the severe acute pancreatitis as a consequence of the release of lipolytic enzymes, but its potential role on the progression of the disease is unclear. In this study, we have examined the role of white adipose tissue as a source of inflammatory mediators that can promote systemic inflammation during experimental taurocholate-induced acute pancreatitis in rats. The inflammatory status and the expression of TNFalpha, iNOS, adiponectin and IL-10 were determined in necrotic and non-necrotic areas of adipose tissue. Samples of adipose tissue were also used to induce the activation of macrophages in vitro. Finally, the release of TNFalpha to mesenterial vessels surrounded by necrotic or non-necrotic fat was evaluated in ex vivo perfused mesenterium. A strong inflammatory infiltrate was observed in the border between necrotic and non-necrotic areas of adipose tissue. In these areas, high expression of TNFalpha and iNOS and a reduced expression of IL-10 were observed, while adiponectin showed only a moderate increase. Necrotic fat strongly activates peritoneal macrophages in vitro. Mesenterial areas with fat necrosis release to the vascular vessels significantly increased amounts of TNFalpha when compared to vessels without necrosis. Altogether, these results indicate that adipose tissue inflammation is a process secondary to acute pancreatitis but also contributes to the generation of mediators potentially involved in the induction of the systemic inflammatory response. In particular, the areas of fat necrosis are important sources of inflammatory mediators.

Oxidative stress has a primary role in the pathogenesis of severe acute pancreatitis. Then, the antioxidant capacity is a critical factor in the progression of this disease. Serum paraoxonase-1 (PON1) is an esterase associated with high-density lipoprotein, which clinical interest resides in its ability to prevent or limit the lipid oxidation. The aim of this study was to investigate changes in PON1 activity in the early stages of acute pancreatitis and to find out if its alteration is related with the severity of the disease. To this purpose, we used an experimental model of taurocholate-induced mild and severe acute pancreatitis. Our results showed that serum activity and PON1 concentration decreased 18 h after the induction of a severe acute pancreatitis. In vitro analysis revealed that incubation with oxidized lipids obtained from pancreatitis samples results in the inactivation of the enzyme in a concentration-dependent manner. In addition to oxidative inactivation, we observed by Western blot, an immunoreactive band suggestive of proteolytic degradation of the enzyme, altogether indicating that during severe acute pancreatitis, there is a significant decrease in serum PON1 activity. This decrease is related with inactivation of the enzyme by oxidized lipids, probably followed by proteolytic degradation of the enzyme.

[Rationale]: Transplantation of stem cells has been proposed as a strategy for repair of lung fibrosis. Nevertheless, many studies have yielded controversial results that currently limit the potential use of these cells as an efficient treatment. Alveolar type II cells are the progenitor cells of the pulmonary epithelium and usually proliferate after epithelial cell injury. During lung fibrosis, however, the altered regeneration process leads to uncontrolled fibroblast proliferation. [Objectives]: To investigate whether intratracheal transplantation of isolated alveolar type II cells can halt and reverse the fibrotic process in an experimental model of bleomycin-induced lung fibrosis in rats. [Methods]: Lung fibrosis was induced in syngeneic female Lewis rats by a single intratracheal instillation of bleomycin (2.5 U/kg). Animals were transplanted with alveolar type II cells from male animals at a dose of 2.5 × 106 cells per animal 3, 7, and 15 days after endotracheal bleomycin instillation. Animals were killed 21 days after the induction of lung fibrosis. [Measurements and Main Results]: Lung fibrosis was assessed by histologic study anddetermination of hydroxyproline content. Engraftment of transplanted cells was measured by real-time polymerase chain reaction for the Y chromosome and by fluorescence in situ hybridization for the Y chromosome. Transplantation of alveolar type II cells into damaged lung 3, 7, or 15 days after bleomycin instillation led to reduced collagen deposition, and reduction in the severity of pulmonary fibrosis. [Conclusions]: This study demonstrates the potential role of alveolar type II cell transplantation in designing future therapies for lung fibrosis., Supported by grant FIS PI060679 from the Spanish Ministry of Health and by grant N-2005-79 from the Sociedad Española de Neumología y Cirugía Torácica (SEPAR).

A frequent complication of acute pancreatitis is the lung damage associated with the systemic inflammatory response. Although various pro-inflammatory mediators generated at both local and systemic levels have been identified, the pathogenic mechanisms of the disease are still poorly understood. In recent years, exosomes have emerged as a new intercellular communication system able to transfer encapsulated proteins and small RNAs and protect them from degradation. Using an experimental model of taurocholate-induced acute pancreatitis in rats, we aimed to evaluate the role of exosomes in the extent of the systemic inflammatory response. Induction of pancreatitis increased the concentration of circulating exosomes, which showed a different proteomic profile to those obtained from control animals. A series of tracking experiments using PKH26-stained exosomes revealed that circulating exosomes effectively reached the alveolar compartment and were internalized by macrophages. In vitro experiments revealed that exosomes obtained under inflammatory conditions activate and polarize these alveolar macrophages towards a pro-inflammatory phenotype. Interestingly, the proteomic analysis of circulating exosomes during acute pancreatitis suggested a multi-organ origin with a relevant role for the liver as a source of these vesicles. Tracking experiments also revealed that the liver retains the majority of exosomes from the peritoneal cavity. We conclude that exosomes are involved in the lung damage associated with experimental acute pancreatitis and could be relevant mediators in the systemic effects of pancreatitis. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John WileySons, Ltd.

Minocycline is a tetracycline antibiotic that, in addition to its antimicrobial function, has been reported to possess a relevant anti-inflammatory activity. Its effects have been extensively evaluated in inflammatory-related neurological diseases. Here, we evaluate its effect on the systemic inflammatory response in a model of experimental acute pancreatitis. Minocycline treatment significantly reduced the inflammation in pancreas and mesenterium, had no effect on the adipose tissue inflammation, and increased the inflammatory response in the lung. These differences seem to be related with different effects exerted on peritoneal and alveolar macrophages. In vitro, minocycline reduced the expression of IL-1β and inhibit the activation of nuclear factor kappa B (NF-κB) on peritoneal macrophages, while it had no effect on alveolar macrophages. Our data indicates that although minocycline may be useful as a tool to control some inflammatory processes, differences on its effects depending on the population of macrophages involved in the process can be expected. In the particular case of acute pancreatitis, it could promote or potentiate inflammation in the lung so that its use does not appear to be recommended., This work was supported by the projects FIS PI13/00019 from Instituto de Salud Carlos III to DC and PEII-2014-053-P from JCCM to JJ. L. Bonjoch is supported by a grant from Generalitat de Catalunya (AGAUR, Grant FI DGR 2013).

Background and aims: Increased pancreatitis associated protein (PAP) mRNA has been reported in active inflammatory bowel disease (IBD). The aims of the current study were to characterise PAP production in IBD and the effects of PAP on inflammation. Patients and methods: Serum PAP levels were determined in healthy controls (n = 29), inflammatory controls (n = 14), and IBD patients (n = 171). Ex vivo PAP secretion in intestinal tissue was measured in 56 IBD patients and 13 healthy controls. Cellular origin of PAP was determined by immunohistochemistry. The effects of exogenous PAP on nuclear factor κB (NFκB) activation, proinflammatory cytokine production, and endothelial adhesion molecule expression were also analysed ex vivo. Results: Patients with active IBD had increased serum PAP levels compared with controls, and these levels correlated with clinical and endoscopic disease severity. Ex vivo intestinal PAP synthesis was increased in active IBD and correlated with endoscopic and histological severity of inflammatory lesions. PAP localised to colonic Paneth cells. Incubation of mucosa from active Crohn's disease with PAP dose dependently reduced proinflammatory cytokines secretion. PAP prevented TNF-α induced NFκB activation in monocytic, epithelial, and endothelial cells and reduced proinflammatory cytokine mRNA levels and adhesion molecule expression. Conclusions: PAP is synthesised by Paneth cells and is overexpressed in colonic tissue of active IBD. PAP inhibits NFκB activation and downregulates cytokine production and adhesion molecule expression in inflamed tissue. It may represent an anti-inflammatory mechanism and new therapeutic strategy in IBD., This work was supported by grants SAF2002/02211 from Ministerio de Ciencia y Tecnología, FIS PI020286, 01/0099-01E, and C03/02 from the Instituto de Salud Carlos III. M Gironella is the recipient of a grant from Fondation Recherche Médicale

In recent years, significant progress has been made in understanding the involvement of pro-inflammatory lipidic mediators in the pathogenesis of allergic diseases. The most relevant lipidic mediator is arachidonic acid and its metabolites. Arachidonic acid is the precursor for biosynthesis of eicosanoids, potent mediators of inflammation that have been implicated in the pathogenesis of diverse disease processes. Eicosanoids are mainly synthesized by the action of cyclo-oxygenase (prostaglandin endoperoxide synthase) that generates prostaglandins and thromboxane, and 5-lipoxygenase, which leads to the production of leukotrienes. In addition, 12- and 15-lipoxygenase are found in mammalian systems. The activity of these enzymes results in the formation of different hydroxyeicosatetraenoic acids, but their functions in vivo have not been clearly established in normal or pathological states. Since several arachidonic acid metabolites clearly play an important role in allergic response, a substantial effort has been directed to understanding the cellular and molecular aspects of these pathways and their pharmacological modulation. This review summarizes some of these aspects based on our current knowledge of the involvement of arachidonic metabolism in the pathogenesis of allergic diseases and outlines the potential therapeutic opportunities that can result from the modulation of these metabolites. © 2005 Bentham Science Publishers Ltd.

1. This study examines the activity of the antioxidant N-acetylcysteine on bleomycin-induced pulmonary fibrosis in rats with emphasis on the early inflammatory phase. 2. Rats receiving N-acetylcysteine (300 mg kg(-1) day(-1), intraperitoneal) had less augmented lung wet weight, and lower levels of proteins, lactate dehydrogenase, neutrophil and macrophage counts in bronchoalveolar lavage fluid and lung myeloperoxidase activity with a betterment of histological score at 3 days postbleomycin. 3. A diminished lung GSH/GSSG ratio and augmented lipid hydroperoxides were observed 3 days postbleomycin. These changes were attenuated by N-acetylcysteine. Alveolar macrophages from bleomycin-exposed rats released augmented amounts of superoxide anion and nitric oxide. N-Acetylcysteine did not modify superoxide anion generation but reduced the increased production of nitric oxide. 4. N-Acetylcysteine suppressed the bleomycin-induced increased activation of lung NF-kappaB (shift assay and immunohistochemistry), and decreased the augmented levels of the early inflammatory cytokines, tumour necrosis factor-alpha, interleukin-beta, interleukin-6 and macrophage inflammatory protein-2 observed in bronchoalveolar lavage fluid at 1 and 3 days postbleomycin exposure. 5. At 15 days postbleomycin, N-acetylcysteine decreased collagen deposition in bleomycin-exposed rats (hydroxyproline content: 6351+/-669 and 4626+/-288 micro g per lung in drug vehicle- and N-acetylcysteine-treated rats, respectively; P