The fibrosis of chronic pancreatitis: new insights into the role of pancreatic stellate cells

Sodium aescinate promotes apoptosis of pancreatic stellate cells and alleviates pancreatic fibrosis by inhibiting the PI3K/Akt/FOXO1 signaling pathways

Chronic pancreatitis (CP) is an inflammatory disease of progressive pancreatic fibrosis, and pancreatic stellate cells (PSCs) are key cells involved in pancreatic fibrosis. To date, there are no clinical therapies available to reverse inflammatory damage or pancreatic fibrosis associated with CP. Sodium Aescinate (SA) is a natural mixture of triterpene saponins extracted from the dried and ripe fruits of horse chestnut tree. It has been shown to have anti-inflammatory and anti-edematous effects. This study aims to explore the therapeutic potential of SA in CP and the molecular mechanism of its modulation. Through in vivo animal models and experiments, we found that SA significantly alleviated pancreatic inflammation and fibrosis in caerulein-induced CP mice model. In addition, SA inhibited the proliferation, migration and activation of PSCs as well as promoted apoptosis of PSCs through a series of experiments on cells in vitro including CCK-8 assay, Western blotting, immunofluorescence staining, wound-healing assay, Transwell migration assays, flow cytometric analysis, etc. Further RNA sequencing and in vitro validation assays revealed that inhibition of the PI3K/AKT/FOXO1 signaling pathway was involved in the SA mediated promotion of PSCs apoptosis, thus alleviating pancreatic fibrosis. In conclusion, this study revealed that SA may have promising potential as therapeutic agent for the treatment of CP, and the PI3K/AKT/FOXO1 pathway is a potential therapeutic target for pancreatic inflammation and fibrosis.

Redox signaling in the pancreas in health and disease

This review addresses oxidative stress and redox signaling in the pancreas under healthy physiological conditions as well as in acute pancreatitis, chronic pancreatitis, pancreatic cancer, and diabetes. Physiological redox homeodynamics is maintained mainly by NRF2/KEAP1, NF-κB, protein tyrosine phosphatases, peroxisome proliferator-activated receptor-γ coactivator 1α (PGC1α), and normal autophagy. Depletion of reduced glutathione (GSH) in the pancreas is a hallmark of acute pancreatitis and is initially accompanied by disulfide stress, which is characterized by protein cysteinylation without increased glutathione oxidation. A cross talk between oxidative stress, MAPKs, and NF-κB amplifies the inflammatory cascade, with PP2A and PGC1α as key redox regulatory nodes. In acute pancreatitis, nitration of cystathionine-β synthase causes blockade of the transsulfuration pathway leading to increased homocysteine levels, whereas p53 triggers necroptosis in the pancreas through downregulation of sulfiredoxin, PGC1α, and peroxiredoxin 3. Chronic pancreatitis exhibits oxidative distress mediated by NADPH oxidase 1 and/or CYP2E1, which promotes cell death, fibrosis, and inflammation. Oxidative stress cooperates with mutant KRAS to initiate and promote pancreatic adenocarcinoma. Mutant KRAS increases mitochondrial reactive oxygen species (ROS), which trigger acinar-to-ductal metaplasia and progression to pancreatic intraepithelial neoplasia (PanIN). ROS are maintained at a sufficient level to promote cell proliferation, while avoiding cell death or senescence through formation of NADPH and GSH and activation of NRF2, HIF-1/2α, and CREB. Redox signaling also plays a fundamental role in differentiation, proliferation, and insulin secretion of β-cells. However, ROS overproduction promotes β-cell dysfunction and apoptosis in type 1 and type 2 diabetes.

Targeted animal models for preclinical assessment of cellular and gene therapies in pancreatic and liver diseases: regulatory and practical insights

Cellular and gene therapy (CGT) products have emerged as a popular approach in regenerative medicine, showing promise in treating various pancreatic and liver diseases in numerous clinical trials. Before these therapies can be tested in human clinical trials, it is essential to evaluate their safety and efficacy in relevant animal models. Such preclinical testing is often required to obtain regulatory approval for investigational new drugs. However, there is a lack of detailed guidance on selecting appropriate animal models for CGT therapies targeting specific pancreatic and liver conditions, such as pancreatitis and chronic liver diseases. In this review, the gastrointestinal committee for the International Society for Cell and Gene Therapy provides a summary of current recommendations for animal species and disease model selection, as outlined by the US Food and Drug Administration, with references to EU EMA and Japan PMDA. We discuss a range of small and large animal models, as well as humanized models, that are suitable for preclinical testing of CGT products aimed at treating pancreatic and liver diseases. For each model, we cover the associated pathophysiology, commonly used metrics for assessing disease status, the pros and limitations of the models, and the relevance of these models to human conditions. We also summarize the use and application of humanized mouse and other animal models in evaluating the safety and efficacy of CGT products. This review aims to provide comprehensive guidance for selecting appropriate animal species and models to help bridge the gap between the preclinical research and clinical trials using CGT therapies for specific pancreatic and liver diseases.

Corynoline protects chronic pancreatitis via binding to PSMA2 and alleviating pancreatic fibrosis

BACKGROUND

Pancreatic fibrosis is the main pathological feature of chronic pancreatitis. There is a lack of medications that effectively alleviate or reverse pancreatic fibrosis and thus cure chronic pancreatitis.

METHODS

We screened drugs that could alleviate pancreatic fibrosis from 80 traditional Chinese medicine monomers and verified their efficacy and mechanisms.

RESULTS

We preliminarily identified corynoline as an antifibrotic candidate by drug screening among 80 compounds. In vitro, corynoline dose-dependently reduces collagen I synthesis in pancreatic stellate cells induced by TGF-β1 and inhibits its activation. Furthermore, we found that corynoline could alleviate the morphological disruption, such as acinar cell atrophy, collagen deposition etc., as well as reduced pancreatic weight in mice with chronic pancreatitis. We further validated the antifibrotic effect of corynoline in mRNA and protein levels. We also found that corynoline could inhibit NF-κB signaling pathway in vitro and in vivo. Next, we identified PSMA2 as the binding protein of corynoline by Lip-SMap and validated it using DARTS. Moreover, the siRNA of PSMA2 disrupts the anti-fibrotic effect of corynoline.

CONCLUSION

In conclusion, corynoline is a promising agent for the treatment of pancreatic fibrosis and chronic pancreatitis.

Role of Sphingosine-1-Phosphate Signaling Pathway in Pancreatic Diseases

Sphingosine-1-phosphate (S1P) is a sphingolipid metabolic product produced via the phosphorylation of sphingosine by sphingosine kinases (SPHKs), serving as a powerful modulator of various cellular processes through its interaction with S1P receptors (S1PRs). Currently, this incompletely understood mechanism in pancreatic diseases including pancreatitis and pancreatic cancer, largely limits therapeutic options for these disorders. Recent evidence indicates that S1P significantly contributes to pancreatic diseases by modulating inflammation, promoting pyroptosis in pancreatic acinar cells, regulating the activation of pancreatic stellate cells, and affecting organelle functions in pancreatic cancer cells. Nevertheless, no review has encapsulated these advancements. Thus, this review compiles information about the involvement of S1P signaling in exocrine pancreatic disorders, including acute pancreatitis, chronic pancreatitis, and pancreatic cancer, as well as prospective treatment strategies to target S1P signaling for these conditions. The insights presented here possess the potential to offer valuable guidance for the implementation of therapies targeting S1P signaling in various pancreatic diseases.

Metabolism and bioenergetics in the pathophysiology of organ fibrosis

Fibrosis is the tissue scarring characterized by excess deposition of extracellular matrix (ECM) proteins, mainly collagens. A fibrotic response can take place in any tissue of the body and is the result of an imbalanced reaction to inflammation and wound healing. Metabolism has emerged as a major driver of fibrotic diseases. While glycolytic shifts appear to be a key metabolic switch in activated stromal ECM-producing cells, several other cell types such as immune cells, whose functions are intricately connected to their metabolic characteristics, form a complex network of pro-fibrotic cellular crosstalk. This review purports to clarify shared and particular cellular responses and mechanisms across organs and etiologies. We discuss the impact of the cell-type specific metabolic reprogramming in fibrotic diseases in both experimental and human pathology settings, providing a rationale for new therapeutic interventions based on metabolism-targeted antifibrotic agents.

Heterozygous Spink1 c.194+2T>C mutation promotes chronic pancreatitis after acute attack in mice

BACKGROUND & AIMS

Mutations in genes, including serine protease inhibitor Kazal-type 1 (SPINK1), influence disease progression following sentinel acute pancreatitis event (SAPE) attacks. SPINK1 c.194+2T > C intron mutation is one of the main mutants of SPINK1，which leads to the impairment of SPINK1 function by causing skipping of exon 3. Research on the pathogenesis of SAPE attacks would contribute to the understanding of the outcomes of acute pancreatitis. Therefore, the aim of the study was to clarify the role of SPINK1 c.194+2T > C mutation in the CP progression after an AP attack.

METHODS

SAPE attacks were induced in wildtype and SPINK mutant (Spink1 c.194+2T > C) mice by cerulein injection. The mice were sacrificed at 24 h, 14 d, 28 d, and 42 d post-SAPE. Data-independent acquisition (DIA) proteomic analysis was performed for the identification of differentially expressed protein in the pancreatic tissues. Functional analyses were performed using THP-1 and HPSCs.

RESULTS

Following SAPE attack, the Spink1 c.194+2T > C mutant mice exhibited a more severe acute pancreatitis phenotype within 24 h. In the chronic phase, the chronic pancreatitis phenotype was more severe in the Spink1 c.194+2T > C mutant mice after SAPE. Proteomic analysis revealed elevated IL-33 level in Spink1 c.194+2T > C mutant mice. Further in vitro analyses revealed that IL-33 induced M2 polarization of macrophages and activation of pancreatic stellate cells.

CONCLUSION

Spink1 c.194+2T > C mutation plays an important role in the prognosis of patients following SAPE. Heterozygous Spink1 c.194+2T > C mutation promotes the development of chronic pancreatitis after an acute attack in mice through elevated IL-33 level and the induction of M2 polarization in coordination with pancreatic stellate cell activation.

Methods of pancreatic fibrosis assessment

Objective. This review provides an in-depth analysis of the current landscape in assessing pancreatic fibrosis. Key points. Pancreatic fibrosis is a common feature in various diseases, including inflammatory and neoplastic conditions, exacerbating their progression. Timely identification of fibrotic changes in pancreatic tissue plays a crucial role in halting or slowing down the advancement of glandular damage. Evaluation methods for fibrosis encompass both invasive and non-invasive approaches. Histological assessment remains the most dependable method for gauging the extent of pancreatic fibrosis. Among the numerous scales for the morphological assessment of pancreatic fibrosis, the system proposed by G. Kloppel, B. Maillet, which evaluates peri- and intralobular fibrosis along with an integrative index, currently stands out as the most applicable for research purposes. In the pursuit of novel non-invasive diagnostic methods for pancreatic tissue fibrosis, researchers are actively developing laboratory biomarkers such as matrix metalloproteinases and specific blood cytokines, as well as instrumental techniques like ultrasound, computed tomography, and magnetic resonance imaging. Conclusion. Each method possesses unique capabilities and limitations associated with the patient’s condition, the prevalence of the fibrotic process, and the presence of comorbidities. The most effective approach involves the integrated use of data obtained from an objective assessment of pancreatic tissue fibrosis. Notably, there is a current lack of standardized scales for the reproducibility of laboratory, instrumental and histological systems in assessing pancreatic fibrosis.

Activation and Regulation of Pancreatic Stellate Cells in Chronic Pancreatic Fibrosis: A Potential Therapeutic Approach for Chronic Pancreatitis

In the complex progression of fibrosis in chronic pancreatitis, pancreatic stellate cells (PSCs) emerge as central figures. These cells, initially in a dormant state characterized by the storage of vitamin A lipid droplets within the chronic pancreatitis microenvironment, undergo a profound transformation into an activated state, typified by the secretion of an abundant extracellular matrix, including α-smooth muscle actin (α-SMA). This review delves into the myriad factors that trigger PSC activation within the context of chronic pancreatitis. These factors encompass alcohol, cigarette smoke, hyperglycemia, mechanical stress, acinar cell injury, and inflammatory cells, with a focus on elucidating their underlying mechanisms. Additionally, we explore the regulatory factors that play significant roles during PSC activation, such as TGF-β, CTGF, IL-10, PDGF, among others. The investigation into these regulatory factors and pathways involved in PSC activation holds promise in identifying potential therapeutic targets for ameliorating fibrosis in chronic pancreatitis. We provide a summary of recent research findings pertaining to the modulation of PSC activation, covering essential genes and innovative regulatory mediators designed to counteract PSC activation. We anticipate that this research will stimulate further insights into PSC activation and the mechanisms of pancreatic fibrosis, ultimately leading to the discovery of groundbreaking therapies targeting cellular and molecular responses within these processes.

A new method for treating chronic pancreatitis and preventing fibrosis using bioactive calcium silicate ion solution

Chronic pancreatitis (CP) is a multifactorial fibroinflammatory syndrome. At present, there is no effective way to treat it clinically. In this study, we proposed a new approach by application of a highly active calcium silicate ion solution derived from calcium silicate (CS) bioceramics, which effectively inhibited the development of CP. This bioceramic derived bioactive ionic solution mainly regulated pancreatic acinar cells (PACs), macrophages and pancreatic stellate cells (PSCs) by SiO32- ions to inhibit inflammation and fibrosis and promote acinar regeneration. The possible mechanism of the therapeutic effect of CS ion solution mainly includes the inhibition of PAC apoptosis by down-regulating the c-caspase3 signal pathway and promotion of the regeneration of PACs by up-regulating the WNT/β-catenin signaling pathway. In addition, the CS ion solution also effectively down-regulated the NF-κB signaling pathway to reduce macrophage infiltration and PAC inflammatory factor secretion, thereby reducing PSC mediated pancreatic fibrosis. This bioceramics-based ion solution provides a new idea for disease treatment using biomaterials, which may have the potential for the development of new therapy for CP.

Gut microbiota controls the development of chronic pancreatitis: A critical role of short-chain fatty acids-producing Gram-positive bacteria

Chronic pancreatitis (CP) is a progressive and irreversible fibroinflammatory disorder, accompanied by pancreatic exocrine insufficiency and dysregulated gut microbiota. Recently, accumulating evidence has supported a correlation between gut dysbiosis and CP development. However, whether gut microbiota dysbiosis contributes to CP pathogenesis remains unclear. Herein, an experimental CP was induced by repeated high-dose caerulein injections. The broad-spectrum antibiotics (ABX) and ABX targeting Gram-positive (G+) or Gram-negative bacteria (G-) were applied to explore the specific roles of these bacteria. Gut dysbiosis was observed in both mice and in CP patients, which was accompanied by a sharply reduced abundance for short-chain fatty acids (SCFAs)-producers, especially G+ bacteria. Broad-spectrum ABX exacerbated the severity of CP, as evidenced by aggravated pancreatic fibrosis and gut dysbiosis, especially the depletion of SCFAs-producing G+ bacteria. Additionally, depletion of SCFAs-producing G+ bacteria rather than G- bacteria intensified CP progression independent of TLR4, which was attenuated by supplementation with exogenous SCFAs. Finally, SCFAs modulated pancreatic fibrosis through inhibition of macrophage infiltration and M2 phenotype switching. The study supports a critical role for SCFAs-producing G+ bacteria in CP. Therefore, modulation of dietary-derived SCFAs or G+ SCFAs-producing bacteria may be considered a novel interventive approach for the management of CP.

Fibrosis induced by resident macrophages has divergent roles in pancreas inflammatory injury and PDAC

Tissue-resident macrophages (TRMs) are long-lived cells that maintain locally and can be phenotypically distinct from monocyte-derived macrophages. Whether TRMs and monocyte-derived macrophages have district roles under differing pathologies is not understood. Here, we showed that a substantial portion of the macrophages that accumulated during pancreatitis and pancreatic cancer in mice had expanded from TRMs. Pancreas TRMs had an extracellular matrix remodeling phenotype that was important for maintaining tissue homeostasis during inflammation. Loss of TRMs led to exacerbation of severe pancreatitis and death, due to impaired acinar cell survival and recovery. During pancreatitis, TRMs elicited protective effects by triggering the accumulation and activation of fibroblasts, which was necessary for initiating fibrosis as a wound healing response. The same TRM-driven fibrosis, however, drove pancreas cancer pathogenesis and progression. Together, these findings indicate that TRMs play divergent roles in the pathogenesis of pancreatitis and cancer through regulation of stromagenesis.

Nintedanib Alleviates Chronic Pancreatitis by Inhibiting the Activation of Pancreatic Stellate Cells via the JAK/STAT3 and ERK1/2 Pathways

BACKGROUND

Nintedanib (Ninte) has been approved for the treatment of pulmonary fibrosis, and whether it can ameliorate chronic pancreatitis (CP) is unknown.

AIMS

This study was conducted to investigate the effect and molecular mechanism of Ninte on pancreatic fibrosis and inflammation in vivo and in vitro.

METHODS

The caerulein-induced CP model of murine was applied, and Ninte was orally administered. Pathological changes in pancreas were evaluated using hematoxylin & eosin, Sirius Red, Masson's trichrome, and anti-Ki-67 staining. For in vitro studies, the effects of Ninte on cell viability, apoptosis, and migration of pancreatic stellate cells (PSCs) were determined by CCK-8, flow cytometry, and wound healing assays, respectively. The potential molecular mechanisms of the effects of Ninte on PSCs were analyzed by RNA-Seq and verified at the gene expression and protein activity levels by qRT-PCR and Western Blot.

RESULTS

Ninte significantly alleviated the weight loss in mice with caerulein-induced CP and simultaneously attenuated the pancreatic damage, as evidenced by reduced acinar atrophy, collagen deposition, infiltration of inflammatory cells, and inhibited cell proliferation/regeneration. Besides, Ninte markedly suppressed the transcription of fibrogenic and proinflammatory genes in pancreatic tissues. Further in vitro studies showed that Ninte significantly inhibited the transcription and protein expression of genes corresponding to fibrogenesis and proliferation in PSCs. The results of RNA-Seq analysis and subsequent verification assays indicated that Ninte inhibited the activation and proliferation of PSCs via the JAK/STAT3 and ERK1/2 pathways.

CONCLUSIONS

These findings indicate that Ninte may be a potential anti-inflammatory and anti-fibrotic therapeutic agent for CP.

Dynamic Contrast-Enhanced MRI Assessing Antifibrotic Therapeutic Effects of Pancreatic Fibrosis with Curcumin - An Experimental Study at 11.7 T

RATIONALE AND OBJECTIVES

Pancreatic fibrosis is the hallmark of chronic pancreatitis (CP), which is associated with microcirculatory disturbance. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can assess the perfusion and permeability of the pancreas by providing information about microcirculation. We hypothesize that DCE-MRI parameters can be utilized to assess pancreatic fibrosis and may furthermore provide an opportunity to evaluate response to antifibrotic treatment with curcumin. Our study was to evaluate the feasibility of quantitative DCE-MRI in assessing pancreatic fibrosis and the antifibrotic effect of curcumin in a rat model of CP.

MATERIALS AND METHODS

Pancreatic fibrosis was induced by injecting dibutyltin dichloride (DBTC). Seventy rats were randomized to five groups: the control group (n = 10); DBTC for 2 weeks (n = 15); DBTC for 4 weeks (n = 15); DBTC + curcumin for 2 weeks (n = 15); DBTC + curcumin for 4 weeks (n = 15). DCE-MRI was performed at an 11.7 T MR scanner. DCE-MRI quantitative parameters (Ktrans, Ve, and Vp) were derived from an extended Tofts model. Fibrosis content and DCE-MRI parameters were compared among the above groups (one-way analysis of variance). The correlations between DCE-MRI parameters and pancreatic fibrosis content as well as the expression of α-SMA were computed by Spearman correlation coefficients.

RESULTS

Fifty-three rats survived and underwent MR imaging. Ktrans in rats 4 weeks after DBTC injection was significantly lower than DBTC 2 weeks rats and control rats (0.30 ± 0.06 min vs 0.49 ± 0.09 vs 0.62 ± 0.09, respectively). Vp in DBTC 4 weeks rats was also significantly lower than control rats (0.048 ± 0.010 min-1 vs 0.065 ± 0.011 min-1, respectively). Ktrans and Vp significantly correlated with fibrosis content of pancreas (r = -0.619 and -0.450, all P < 0.001), and the expression of α-SMA (r = -0.688 and -0.402, all P < 0.01). Ktrans and Vp in rats with daily curcumin treatment for 4 weeks were significantly higher than DBTC 4 weeks rats (Ktrans, 0.51 ± 0.09 vs 0.30 ± 0.06; Vp, 0.064 ± 0.015 vs 0.048 ± 0.010).

CONCLUSION

DCE-MRI parameters (Ktrans and Vp) have the potential to noninvasively assess pancreatic fibrosis and the antifibrotic treatment response of curcumin.

Contrast-Enhanced Computed Tomography and Laboratory Parameters as Non-Invasive Diagnostic Markers of Pancreatic Fibrosis

Pancreatic fibrosis (PF) is a part of the pathogenesis in most pancreatic disorders and plays a crucial role in chronic pancreatitis development. The aim of our study was to investigate a relationship between PF grade and signs in resected pancreatic specimens, and the results of both multidetector computed tomography (MDCT) post-processing parameters and fibronectin (FN), hyaluronic acid (HA), matrix metalloproteinase (MMP)-1, and MMP-9 serum levels. The examination results of 74 patients were analyzed. The unenhanced pancreas density (UPD) value and contrast enhancement ratio (CER) showed statistically significant differences in groups with peri- and intralobular fibrosis grades, an integrative index of fibrosis, inflammation in pancreatic tissue, and pancreatic duct epithelium metaplasia, while the normalized contrast enhancement ratio in the venous phase (NCER VP) significantly differed with the perilobular fibrosis grade, integrative fibrosis index, and inflammation (p < 0.05). The blood FN level showed a weak positive correlation with the intralobular fibrosis grade (rho = 0.32, p = 0.008). The blood level of HA positively correlated with the presence of prominent and enlarged peripheral nerves (rho = 0.28, p = 0.02) and negatively correlated with the unenhanced pancreas density value (rho = -0.42, p = 0.0001). MMP-1 and MMP-9 values' intergroup analysis and correlation did not show any statistical significance. The UPD value, NCER VP, and CER, as well as blood levels of FN and HA, could be used in non-invasive PF diagnosis.

Tcf21 Alleviates Pancreatic Fibrosis by Regulating the Epithelial-Mesenchymal Transformation of Pancreatic Stellate Cells

BACKGROUND AND AIMS

The activation of pancreatic stellate cells (PSCs) plays a key role in the occurrence and development of chronic pancreatitis (CP) and pancreatic fibrosis, which is related to the process of epithelial-mesenchymal transition (EMT). This study was designed to investigate the effect and mechanism of Tcf21 (one of tumor suppressor genes) on pancreatic inflammation and fibrosis in vivo and in vitro.

METHODS

C57BL/6 male mice were intraperitoneally injected with caerulein for 6 weeks to establish CP animal model. Fixed pancreatic tissue paraffin-embedded sections were used for immunohistochemistry staining of Tcf21, fibrosis-related markers (α-SMA), interstitial markers (Vimentin) and epithelial markers (E-cadherin). Western blotting and qRT-PCR assay were performed to analyze the change of expression of the above markers after stimulation of TGF-β1 or overexpressed Tcf21 lentivirus transfection in human pancreatic stellate cells (HPSCs).

RESULTS

The pancreatic expression of α-SMA and Vimentin of CP mice significantly increased, while the expression of Tcf21 and E-cadherin significantly decreased. TGF-β1 could promote activation and EMT process of HPSCs, and inhibited the expression of Tcf21. Overexpression of Tcf21 could significantly down-regulate the expression of α-SMA, Fibronectin and Vimentin, and up-regulated the expression of ZO-1 of HPSCs. Cell Counting Kit-8 assay and scratch wound-healing assay results showed that overexpression of Tcf21 could significantly inhibit the cell migration and proliferation of HPSCs.

CONCLUSIONS

Overexpression of Tcf21 could significantly alleviate the activation, proliferation, migration of PSCs by regulating the EMT process. Tcf21 had a potential prospect of a new target for CP therapy.

Immune cells and immune cell-targeted therapy in chronic pancreatitis

In recent years, studies have attempted to understand the immune cells and mechanisms underlying the pathogenesis of chronic pancreatitis (CP) by constructing a model of CP. Based on these studies, the innate immune response is a key factor in disease pathogenesis and inflammation severity. Novel mechanisms of crosstalk between immune and non-immune pancreatic cells, such as pancreatic stellate cells (PSC), have also been explored. Immune cells, immune responses, and signaling pathways in CP are important factors in the development and progression of pancreatitis. Based on these mechanisms, targeted therapy may provide a feasible scheme to stop or reverse the progression of the disease in the future and provide a new direction for the treatment of CP. This review summarizes the recent advances in research on immune mechanisms in CP and the new advances in treatment based on these mechanisms.

Chronic Pancreatitis and Risk of Atherosclerotic Cardiovascular Disease: A US Cohort Propensity-Matched Study

OBJECTIVES

Worldwide prevalence of chronic pancreatitis (CP) has risen in recent years, with data suggesting an increased risk of atherosclerotic cardiovascular disease (ASCVD) in these patients. We assessed the incidence and risk of ASCVD in patients with CP.

METHODS

We compared the risk of ischemic heart disease, cerebrovascular accident, and peripheral arterial disease between CP and non-CP cohorts after propensity matching of known risk factors of ASCVD using TriNetX, a multi-institutional database. We also evaluated the risk of outcomes of ischemic heart disease including acute coronary syndrome, heart failure, cardiac arrest, and all-cause mortality between CP and non-CP cohorts.

RESULTS

Chronic pancreatitis cohort was also found to have an increased risk of ischemic heart disease (adjusted odds ratio [aOR], 1.08; 95% confidence interval [CI], 1.03-1.12), cerebrovascular accident (aOR, 1.12; 95% CI, 1.05-1.20), and peripheral arterial disease (aOR, 1.17; 95% CI, 1.1-1.24). Chronic pancreatitis patients with ischemic heart disease were also found to have an increased risk of acute coronary syndrome (aOR, 1.16; 95% CI, 1.04-1.30), cardiac arrest (aOR, 1.24; 95% CI, 1.01-1.53), and mortality (aOR, 1.60; 95% CI, 1.45-1.77).

CONCLUSIONS

Chronic pancreatitis patients are at a higher risk of ASCVD when compared with the general population, matched for confounding etiological, pharmacological, and comorbid variables.

Remodeling of imbalanced extracellular matrix homeostasis for reversal of pancreatic fibrosis

Pancreatic fibrosis is mainly manifested by imbalance in extracellular matrix (ECM) homeostasis due to excessive deposition of collagen in pancreas by activated pancreatic stellate cells (PSCs). Recently, some drugs have exhibited therapeutic potentials for the treatment of pancreatic fibrosis; however, currently, no effective clinical strategy is available to remodel imbalanced ECM homeostasis because of inferior targeting abilities of drugs and collagen barriers that hinder the efficient delivery of drugs. Herein, we design and prepare collagen-binding peptide (CBP) and collagenase I co-decorated dual drug-loaded lipid nanoparticles (named AT-CC) for pancreatic fibrosis therapy. Specifically, AT-CC can target fibrotic pancreas via the CBP and degrade excess collagen by the grafted collagenase I, thereby effectively delivering all-trans-retinoic acid (ATRA) and ammonium tetrathiomolybdate (TM) into pancreas. The released ATRA can reduce collagen overproduction by inhibiting the activation of PSCs. Moreover, the released TM can restrain lysyloxidase activation, consequently reducing collagen cross-linking. The combination of ATRA and TM represses collagen synthesis and reduces collagen cross linkages to restore ECM homeostasis. The results of this research suggest that AT-CC is a safe and efficient collagen-targeted degradation drug-delivery system for reversing pancreatic fibrosis. Furthermore, the strategy proposed herein will offer an innovative platform for the treatment of chronic pancreatitis.

[Other specific types of diabetes and exocrine pancreatic insufficiency (update 2023)]

The heterogenous category "specific types of diabetes due to other causes" encompasses disturbances in glucose metabolism due to other endocrine disorders such as acromegaly or hypercortisolism, drug-induced diabetes (e.g. antipsychotic medications, glucocorticoids, immunosuppressive agents, highly active antiretroviral therapy (HAART), checkpoint inhibitors), genetic forms of diabetes (e.g. Maturity Onset Diabetes of the Young (MODY), neonatal diabetes, Down‑, Klinefelter- and Turner Syndrome), pancreatogenic diabetes (e.g. postoperatively, pancreatitis, pancreatic cancer, haemochromatosis, cystic fibrosis), and some rare autoimmune or infectious forms of diabetes. Diagnosis of specific diabetes types might influence therapeutic considerations. Exocrine pancreatic insufficiency is not only found in patients with pancreatogenic diabetes but is also frequently seen in type 1 and long-standing type 2 diabetes.

Combinational Treatment Involving Decellularized Extracellular Matrix Hydrogels With Mesenchymal Stem Cells Increased the Efficacy of Cell Therapy in Pancreatitis

Cell transplantation using mesenchymal stem cells (MSCs) has emerged as a promising approach to repairing and regenerating injured or impaired organs. However, the survival and retention of MSCs following transplantation remain a challenge. Therefore, we investigated the efficacy of co-transplantation of MSCs and decellularized extracellular matrix (dECM) hydrogels, which have high cytocompatibility and biocompatibility. The dECM solution was prepared by enzymatic digestion of an acellular porcine liver scaffold. It could be gelled and formed into porous fibrillar microstructures at physiological temperatures. MSCs expanded three-dimensionally in the hydrogel without cell death. Compared to the 2-dimensional cell culture, MSCs cultured in the hydrogel showed increased secretion of hepatocyte growth factor (HGF) and tumor necrosis factor-inducible gene 6 protein (TSG-6), both of which are major anti-inflammatory and anti-fibrotic paracrine factors of MSCs, under TNFα stimulation. In vivo experiments showed that the co-transplantation of MSCs with dECM hydrogel improved the survival rate of engrafted cells compared to those administered without the hydrogel. MSCs also demonstrated therapeutic effects in improving inflammation and fibrosis of pancreatic tissue in a dibutyltin dichloride (DBTC)-induced rat pancreatitis model. Combinational use of dECM hydrogel with MSCs is a new strategy to overcome the challenges of cell therapy using MSCs and can be used for treating chronic inflammatory diseases in clinical settings.

Lived Experience of Hereditary Chronic Pancreatitis - A Qualitative Interview Study

OBJECTIVES

Hereditary chronic pancreatitis is a rare condition characterized by intermittent acute episodes of pancreatitis and long-term impairment of pancreatic functions. However, the subjective perspective of individuals affected by hereditary chronic pancreatitis has been little studied. This qualitative study investigates the experience of hereditary chronic pancreatitis patients and their relatives because the awareness of the needs of those affected is an essential component of a patient-centered management of chronic conditions.

METHODS

Semi-structured qualitative interviews were conducted with hereditary chronic pancreatitis patients and their relatives. Data were analysed using qualitative content analysis. The concepts of 'biographical contingency,' 'biographical disruption' and the 'shifting perspectives model' served as theoretical frameworks.

RESULTS

A total of 24 participants (17 patients, 7 relatives) were interviewed individually. Four main themes were identified: (1) The unpredictable clinical course of hereditary chronic pancreatitis; (2) hereditary chronic pancreatitis as a devastating experience; (3) hereditary chronic pancreatitis as part of a normal life; and (4) being reduced to hereditary chronic pancreatitis.

DISCUSSION

The 'shifting perspectives model' of chronic illness covers the four dimensions adequately and can serve as a theoretical model to explain hereditary chronic pancreatitis patients' experience. A better understanding of the patients and their families' experience and the shifting character of hereditary chronic pancreatitis can help healthcare professionals to tailor the care to meet the needs of those affected.

Arecae pericarpium water extract alleviates chronic pancreatitis by deactivating pancreatic stellate cells

Chronic pancreatitis (CP) is a chronic inflammatory disease of the pancreas with irreversible morphological changes. Arecae pericarpium (ARP), known to improve gastrointestinal disorders, has not yet been reported to inhibit fibrosis in CP. Therefore, we investigated the beneficial effects of ARP on cerulein-induced CP. Cerulein (50 μg/kg) was administered intraperitoneally to mice every hour, six times a day, four times a week for a total of 3 weeks to induce CP. To ascertain the prophylactic effects of ARP, ARP water extract (50, 100, or 200 mg/kg) or saline was administered intraperitoneally 1 h before the onset of CP. To determine the therapeutic effects of ARP, ARP water extract (200 mg/kg) or saline was administered for a total of 1 week or 2 weeks, starting 2 weeks or 1 week after the onset of CP. The pancreas was collected immediately for histological analysis. Additionally, to determine the effectiveness and mechanism of ARP in alleviating pancreatic fibrosis, pancreatic stellate cells (PSCs) were isolated. ARP treatment considerably improved glandular atrophy and inflammation and repressed collagen deposition in the pancreas. Furthermore, ARP water extract inhibited extracellular matrix (ECM) constituents such as alpha-smooth muscle actin (α-SMA), collagen I, and fibronectin 1 (FN1) in pancreatic tissue and PSCs. ARP also suppressed transforming growth factor-β (TGF-β) signaling by inhibiting Smad2 phosphorylation. Our study suggests that ARP exhibits anti-fibrotic effects in cerulein-induced CP by inhibiting TGF-β/Smad signaling.

The Rabep1-Mediated Endocytosis and Activation of Trypsinogen to Promote Pancreatic Stellate Cell Activation

Background: The pathogenesis of chronic pancreatitis is still unclear. Trypsinogen activation is an active factor in acute pancreatitis that has not been studied in the occurrence of chronic pancreatitis. Methods: Immunofluorescence was used to detect the location and expression of trypsinogen in chronic pancreatitis and normal tissues. Microarray and single-cell RNA-seq (scRNA-seq) were used to screen core genes and pathways in pancreatic stellate cells (PSCs). Western blotting and immunofluorescence were used to verify trypsinogen expression in PSCs after silencing Rabep1. Immunofluorescence and flow cytometry were used to validate trypsinogen activation and PSC activation after intervening in the endocytosis pathway. Results: Endocytosed trypsinogen was found in PSCs in CP clinical samples. Bioinformatic analysis showed that Rabep1 is a core gene that regulates trypsinogen endocytosis through the endocytosis pathway, verified by Western blot and immunofluorescence. Immunofluorescence and flow cytometry analyses confirmed the activation of trypsinogen and PSCs through the endocytosis pathway in PSCs. Conclusion: This study discovered a new mechanism by which trypsinogen affects the activation of PSCs and the occurrence and development of CP. Through communication between pancreatic acinar cells and PSCs, trypsinogen can be endocytosed by PSCs and activated by the Rabep1 gene.

Current Trends and Research Hotspots in Pancreatic Stellate Cells: A Bibliometric Study

BACKGROUND

Pancreatic stellate cells (PSCs) play crucial roles in acute/chronic pancreatitis and pancreatic cancer. In this study, bibliometric analysis was used to quantitatively and qualitatively analyze the literature related to PSCs from 1998-2021 to summarize the current trends and research topics in this field.

METHODS

Relevant literature data were downloaded from the Science Citation Index Expanded Web of Science Core Collection (WoSCC) on April 07, 2021, using Clarivate Analytics. Biblioshiny R packages, VOSviewer, Citespace, BICOMB, gCLUTO, and the Online Analysis Platform of Literature Metrology (http://bibliometric.com) were used to analyze the manually selected data.

RESULTS

A total of 958 relevant studies published in 48 countries or regions were identified. The United States of America (USA) had the highest number of publications, followed by the People's Republic of China, Germany, and Japan. Tohoku University (Japan), the University of New South Wales (Australia), the University of Texas MD Anderson Cancer Center (USA), Technical University of Munich (Germany), and University of Rostock (Germany) were the top five institutions with most publications. Nine major clusters were generated using reference co-citation analysis. Keyword burst detection revealed that progression (2016-2021), microenvironment (2016-2021), and tumor microenvironment (2017-2021) were the current frontier keywords. Biclustering analysis identified five research hotspots in the field of PSCs during 1998-2021.

CONCLUSION

In this study, a scientometric analysis of 958 original documents related to PSCs showed that the research topics of these studies are likely in the transition from acute/chronic pancreatitis to pancreatic cancer. The current research trends regarding PSCs are related to pancreatic cancer, such as tumor microenvironment. This study summarizes five research hotspots in the field of PSCs between 1998 and 2021 and thus may provide insights for future research.

Inflammatory-miR-301a circuitry drives mTOR and Stat3-dependent PSC activation in chronic pancreatitis and PanIN

Activated pancreatic stellate cells (PSCs) are the main cells involved in chronic pancreatitis and pancreatic intraepithelial neoplasia lesion (PanIN). Fine-tuning the precise molecular targets in PSC activation might help the development of PSC-specific therapeutic strategies to tackle progression of pancreatic cancer-related fibrosis. miR-301a is a pro-inflammatory microRNA known to be activated by multiple inflammatory factors in the tumor stroma. Here, we show that miR-301a is highly expressed in activated PSCs in mice, sustained tissue fibrosis in caerulein-induced chronic pancreatitis, and accelerated PanIN formation. Genetic ablation of miR-301a reduced pancreatic fibrosis in mouse models with chronic pancreatitis and PanIN. Cell proliferation and activation of PSCs was inhibited by downregulation of miR-301a via two of its targets, Tsc1 and Gadd45g. Moreover, aberrant PSC expression of miR-301a and Gadd45g restricted the interplay between PSCs and pancreatic cancer cells in tumorigenesis. Our findings suggest that miR-301a activates two major cell proliferation pathways, Tsc1/mTOR and Gadd45g/Stat3, in vivo, to facilitate development of inflammatory-induced PanIN and maintenance of PSC activation and desmoplasia in pancreatic cancer.

Stem bark of Fraxinus rhynchophylla ameliorates the severity of pancreatic fibrosis by regulating the TGF-β/Smad signaling pathway

Chronic pancreatitis (CP) is a pathological fibroinflammatory syndrome of the pancreas. Currently, there are no therapeutic agents available for treating CP-associated pancreatic fibrosis. Fraxinus rhynchophylla (FR) reportedly exhibits anti-inflammatory, antioxidative and antitumor activities. Although FR possesses numerous properties associated with the regulation of diverse diseases, the effects of FR on CP remain unknown. Herein, we examined the effects of FR on CP. For CP induction, mice were intraperitoneally administered cerulein (50 μg/kg) 6 times a day, 4 days per week for 3 weeks. FR extract (100 or 400 mg/kg) or saline (control group) was intraperitoneally injected 1 hour before the first cerulein injection. After 3 weeks, the pancreas was harvested for histological analysis. In addition, pancreatic stellate cells (PSCs) were isolated to examine the antifibrogenic effects and regulatory mechanisms of FR. Administration of FR significantly inhibited histological damage in the pancreas, increased pancreatic acinar cell survival, decreased PSC activation and collagen deposition, and decreased pro-inflammatory cytokines. Moreover, FR treatment inhibited the expression of fibrotic mediators, such as α-smooth muscle actin (α-SMA), collagen, fibronectin 1, and decreased pro-inflammatory cytokines in isolated PSCs stimulated with transforming growth factor (TGF)-β. Furthermore, FR treatment suppressed the phosphorylation of Smad 2/3 but not of Smad 1/5 in TGF-β-stimulated PSCs. Collectively, these results suggest that FR ameliorates pancreatic fibrosis by inhibiting PSC activation during CP.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

The Potential Use of Cannabis in Tissue Fibrosis

Fibrosis is a condition characterized by thickening or/and scarring of various tissues. Fibrosis may develop in almost all tissues and organs, and it may be one of the leading causes of morbidity and mortality. It provokes excessive scarring that excels the usual wound healing response to trauma in numerous organs. Currently, very little can be done to prevent tissue fibrosis, and it is almost impossible to reverse it. Anti-inflammatory and immunosuppressive drugs are among the few treatments that may be efficient in preventing fibrosis. Numerous publications suggest that cannabinoids and extracts of Cannabis sativa have potent anti-inflammatory and anti-fibrogenic properties. In this review, we describe the types and mechanisms of fibrosis in various tissues and discuss various strategies for prevention and dealing with tissue fibrosis. We further introduce cannabinoids and their potential for the prevention and treatment of fibrosis, and therefore for extending healthy lifespan.

Screening and Identification of Key Genes for Activation of Islet Stellate Cell

Background

It has been demonstrated that activated islet stellate cells (ISCs) play a critical role in islet fibrogenesis and significantly contribute to the progression of type 2 diabetes mellitus. However, the key molecules responsible for ISCs activation have not yet been determined. This study aimed to identify the potential key genes involved in diabetes-induced activation of ISCs.

Method

Stellate cells were isolated from three 10-week-old healthy male Wistar rats and three Goto-Kakizaki (GK) rats. Cells from each rat were primary cultured under the same condition. A Genome-wide transcriptional sequence of stellate cells was generated using the Hiseq3000 platform. The identified differentially expressed genes were validated using quantitative real-time PCR and western blotting in GK rats, high fat diet (HFD) rats, and their controls.

Results

A total of 204 differentially expressed genes (DEGs) between GK. ISCs and Wistar ISCs (W.ISCs) were identified, accounting for 0.58% of all the 35,362 genes detected. After the Gene Ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses, the mRNA levels of these genes were further confirmed by real-time PCR in cultured ISCs. We then selected Fos, Pdpn, Bad as the potential key genes for diabetes-induced activation of ISCs. Finally, we confirmed the protein expression levels of FOS, podoplanin, and Bad by western blotting and immunofluorescence in GK rats, HFD rats, and their controls. The results showed that the expression level of FOS was significantly decreased, while podoplanin and Bad were significantly increased in GK.ISCs and HFD rats compared with controls, which were consistent with the expression of α-smooth muscle actin.

Conclusions

A total of 204 DEGs were found between the GK.ISCs and W.ISCs. After validating the expression of potential key genes from GK rats and HFD rats, Fos, Pdpn, and Bad might be potential key genes involved in diabetes-induced activation of ISCs.

Dahuang Danshen Decoction Inhibits Pancreatic Fibrosis by Regulating Oxidative Stress and Endoplasmic Reticulum Stress

Background

In Traditional Chinese Medicine (TCM), Dahuang Danshen decoction (DD) is used to treat pancreatic fibrosis. Pancreatic fibrosis is a typical manifestation of chronic pancreatitis (CP), which affects the digestive system. The therapeutic mechanisms of DD in pancreatic fibrosis are unclear.

Aim

This study aimed to investigate the regulatory mechanisms of DD on oxidative stress and endoplasmic reticulum stress in CP.

Materials and Methods

Experimental rats were intraperitoneally injected with 500 mg/kg BW of diethyldithiocarbamate (DDC) twice a week for six weeks to induce CP. At the same time, DD was administered orally at daily doses of 1.37 g/kg BW, 2.74 g/kg BW, and 5.48 g/kg BW to evaluate its treatment effects on CP. After all treatments, pancreatic tissues were harvested and subjected to H&E staining. Transmission electron microscopy (TEM) was also performed to show the endoplasmic reticulum structure in the pancreatic tissues. Immunohistochemistry was used to detect the α-SMA expression level in the pancreatic tissues. Metabolomics analysis of the serum and proteomics analysis of the pancreatic tissues were performed to reveal the changes of endogenous metabolites and proteins, respectively. Concentrations of GSH, MDA, SOD, ROS, col-1, and col-3 were determined using corresponding kits. The western blotting method was used to determine the protein levels of Keap-1, HO-1, NQO1, Nrf2, GRP, JNK, and caspase 12. The pancreatic mRNA levels of NQO1, GPX1, HO-1, GST-π, GRP, JNK, and caspase 12 were also determined by quantitative PCR. The interactions between TCM components and Keap-1 were investigated by molecular docking modeling.

Results

The pathohistological results demonstrated that DD could ameliorate DDC-induced CP in vivo, indicated by reduction of α-SMA, col-1, col-3, TNF-α, and IL-6. DD increased serum levels of GSH and SOD but reduced pancreatic ROS. DD decreased cytoplasmic Keap-1 and increased Nrf2 nuclear localization. Correspondingly, DD increased the expression levels of Nrf2 downstream antioxidant genes NQO1, GPX1, HO-1, and GST-π. DD also decreased ERS hallmarks caspase 12 cleavage and GRP expression. Eventually, DD inhibited PSC activation by reducing JNK phosphorylation and MMK-3/p38 expression. Molecular docking analysis showed that salvianolic acid B and emodin had a good binding affinity toward Keap-1.

Conclusions

These results demonstrated that DD could ameliorate the oxidative and endoplasmic reticulum stress through releasing Nrf2 from Keap-1 binding and inducing the downstream antioxidant enzymes. As a result, DD could thwart pancreatic fibrosis by inhibiting PSCs activation, which was induced by OS and ERS through JNK and MMK3/p38 pathways.

Targeting Fibrosis: The Bridge That Connects Pancreatitis and Pancreatic Cancer

Pancreatic fibrosis is caused by the excessive deposits of extracellular matrix (ECM) and collagen fibers during repeated necrosis to repair damaged pancreatic tissue. Pancreatic fibrosis is frequently present in chronic pancreatitis (CP) and pancreatic cancer (PC). Clinically, pancreatic fibrosis is a pathological feature of pancreatitis and pancreatic cancer. However, many new studies have found that pancreatic fibrosis is involved in the transformation from pancreatitis to pancreatic cancer. Thus, the role of fibrosis in the crosstalk between pancreatitis and pancreatic cancer is critical and still elusive; therefore, it deserves more attention. Here, we review the development of pancreatic fibrosis in inflammation and cancer, and we discuss the therapeutic strategies for alleviating pancreatic fibrosis. We further propose that cellular stress response might be a key driver that links fibrosis to cancer initiation and progression. Therefore, targeting stress proteins, such as nuclear protein 1 (NUPR1), could be an interesting strategy for pancreatic fibrosis and PC treatment.

The effects of nuclear factor-kappa B in pancreatic stellate cells on inflammation and fibrosis of chronic pancreatitis

The activation of pancreatic stellate cells (PSCs) plays a critical role in the progression of pancreatic fibrosis. Nuclear factor-kappa B (NF-κB) is associated with chronic pancreatitis (CP). Previous evidence indicated that NF-κB in acinar cells played a double-edged role upon pancreatic injury, whereas NF-κB in inflammatory cells promoted the progression of CP. However, the effects of NF-κB in PSCs have not been studied. In the present study, using two CP models and RNAi strategy of p65 in cultured PSCs, we found that the macrophage infiltration and MCP-1 expression were increased, and the NF-κBp65 protein level was elevated. NF-κBp65 was co-expressed with PSCs. In vitro, TGF-β1 induced overexpression of the TGF-β receptor 1, phosphorylated TGF-β1-activated kinase 1 (p-TAK1) and NF-κB in the PSCs. Moreover, the concentration of MCP-1 in the supernatant of activated PSCs was elevated. The migration of BMDMs was promoted by the supernatant of activated PSCs. Further knockdown of NF-κBp65 in PSCs resulted in a decline of BMDM migration, accompanied by a lower production of MCP-1. These findings indicate that TGF-β1 can induce the activation of NF-κB pathway in PSCs by regulating p-TAK1, and the NF-κB pathway in PSCs may be a target of chronic inflammation and fibrosis.

Extracellular vesicles and pancreatitis: mechanisms, status and perspectives

Comprehensive reviews and large population-based cohort studies have played an important role in the diagnosis and treatment of pancreatitis and its sequelae. The incidence and mortality of pancreatitis have been reduced significantly due to substantial advancements in the pathophysiological mechanisms and clinically effective treatments. The study of extracellular vesicles (EVs) has the potential to identify cell-to-cell communication in diseases such as pancreatitis. Exosomes are a subset of EVs with an average diameter of 50~150 nm. Their diverse and unique constituents include nucleic acids, proteins, and lipids, which can be transferred to trigger phenotypic changes of recipient cells. In recent years, many reports have indicated the role of EVs in pancreatitis, including acute pancreatitis, chronic pancreatitis and autoimmune pancreatitis, suggesting their potential influence on the development and progression of pancreatitis. Plasma exosomes of acute pancreatitis can effectively reach the alveolar cavity and activate alveolar macrophages to cause acute lung injury. Furthermore, upregulated exosomal miRNAs can be used as biomarkers for acute pancreatitis. Here, we summarized the current understanding of EVs in pancreatitis with an emphasis on their biological roles and their potential use as diagnostic biomarkers and therapeutic agents for this disease.

The influence of erythropoietin on apoptosis and fibrosis in the early phase of chronic pancreatitis in rats

INTRODUCTION

Chronic pancreatitis (CP) is a continuing, inflammatory process of the pancreas, characterised by irreversible morphological changes. The identification of pancreatic stellate cells resulted in the development of research on the pathogenesis of CP. Erythropoietin (Epo) regulates the interaction between apoptosis and inflammation of the brain, kidney, and heart muscle. Erythropoietin receptors were also found in the pancreas, in particular on the islet cells. Our objective was to evaluate the influence of Epo on fibrosis and apoptosis in experimental CP.

MATERIAL AND METHODS

The experiments were performed on 48 male Wistar rats (250-350 g). The animals were divided into six equal groups (I - control, II - chronic cerulein - induced pancreatitis, III - 1 ml of Epo sc, IV - 0.5 ml of Epo sc, V - CP treated with 1 ml Epo, VI - CP treated with 0.5 ml Epo). The blood for gelatinases and pancreata for the morphological examinations and immunohistochemistry were collected.

RESULTS

A slight reduction of interstitial oedema and less severe fibrosis were noticed in the groups treated with Epo. Reduced expression of caspase-3 and α-actin, and a lack of Bcl-2 expression were observed in areas with inflammation. There was no expression of caspase-9 observed in all groups. There were no statistically significant differences between the groups in the activity of gelatinases.

CONCLUSIONS

Erythropoietin seems to have the effect of reducing fibrosis and apoptosis in an experimental model of CP.

Pathological Mechanisms in Diabetes of the Exocrine Pancreas: What's Known and What's to Know

The clinical significance of diabetes arising in the setting of pancreatic disease (also known as diabetes of the exocrine pancreas, DEP) has drawn more attention in recent years. However, significant improvements still need to be made in the recognition, diagnosis and treatment of the disorder, and in the knowledge of the pathological mechanisms. The clinical course of DEP is different from type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). DEP develops in patients with previous existing exocrine pancreatic disorders which damage both exocrine and endocrine parts of pancreas, and lead to pancreas exocrine insufficiency (PEI) and malnutrition. Therefore, damage in various exocrine and endocrine cell types participating in glucose metabolism regulation likely contribute to the development of DEP. Due to the limited amount of clinical and experimental studies, the pathological mechanism of DEP is poorly defined. In fact, it still not entirely clear whether DEP represents a distinct pathologic entity or is a form of T2DM arising when β cell failure is accelerated by pancreatic disease. In this review, we include findings from related studies in T1DM and T2DM to highlight potential pathological mechanisms involved in initiation and progression of DEP, and to provide directions for future research studies.

Prospect and clinical value of oxymatrine in prevention and treatment of pancreatic fibrosis

Studies have confirmed that pancreatic stellate cell activation is the central event in the initiation and development of pancreatic fibrosis (PF), but the specific mechanism of PF is still unknown, and there is no specific treatment for PF. Some basic studies have confirmed that oxymatrine (OMT) has a certain therapeutic effect on PF, but further research is needed. It can be predicted that OMT has a far-reaching research prospect and good clinical application value for the prevention and treatment of PF, and is also conducive to the better development and utilization of traditional Chinese herbal medicine radix sophorae flavescentis.

The potential roles of exosomes in pancreatic cancer initiation and metastasis

Pancreatic cancer (PaCa) is an insidious and highly metastatic malignancy, with a 5-year survival rate of less than 5%. So far, the pathogenesis and progression mechanisms of PaCa have been poorly characterized. Exosomes correspond to a class of extracellular nanovesicles, produced by a broad range of human somatic and cancerous cells. These particular nanovesicles are mainly composed by proteins, genetic substances and lipids, which mediate signal transduction and material transport. A large number of studies have indicated that exosomes may play decisive roles in the occurrence and metastatic progression of PaCa. This article summarizes the specific functions of exosomes and their underlying molecular mechanisms in mediating the initiation and metastatic capability of PaCa.

Macrophages in pancreatitis: Mechanisms and therapeutic potential

Macrophages play a crucial role in the pathogenesis of pancreatitis that is a common gastrointestinal disease. Particularly, macrophages differentiate into different phenotypes and exert diverse functions in acute pancreatitis (AP) and chronic pancreatitis (CP), respectively. In AP, macrophages in the pancreas and other related organs are mainly activated and differentiated into a pro-inflammatory M1 phenotype, and furthermore secrete inflammatory cytokines and mediators, causing local inflammation of the pancreas, and even intractable systemic inflammatory response or multiple organ failure. In CP, macrophages often exhibit a M2 polarisation and interact with pancreatic stellate cells (PSCs) in an autocrine and paracrine cytokine-dependent manner to promote the progression of pancreatic fibrosis. As the severity of pancreatic fibrosis aggravates, the proportion of M2/M1 macrophage cytokines in the pancreas increases. The discovery of macrophages in the pathogenesis of pancreatitis has promoted the research of targeted drugs, which provides great potential for the effective treatment of pancreatitis. This paper provides an overview of the roles of various macrophages in the pathogenesis of pancreatitis and the current research status of pancreatitis immunotherapy targeting macrophages. The findings addressed in this review are of considerable significance for understanding the pivotal role of macrophages in pancreatitis.

Clinical and Pre-Clinical Evidence of Carbonic Anhydrase IX in Pancreatic Cancer and Its High Expression in Pre-Cancerous Lesions

Hypoxia is a common phenomenon that occurs in most solid tumors. Regardless of tumor origin, the evolution of a hypoxia-adapted phenotype is critical for invasive cancer development. Pancreatic ductal adenocarcinoma is also characterized by hypoxia, desmoplasia, and the presence of necrosis, predicting poor outcome. Carbonic anhydrase IX (CAIX) is one of the most strict hypoxia regulated genes which plays a key role in the adaptation of cancer cells to hypoxia and acidosis. Here, we summarize clinical data showing that CAIX expression is associated with tumor necrosis, vascularization, expression of Frizzled-1, mucins, or proteins involved in glycolysis, and inevitably, poor prognosis of pancreatic cancer patients. We also describe the transcriptional regulation of CAIX in relation to signaling pathways activated in pancreatic cancers. A large part deals with the preclinical evidence supporting the relevance of CAIX in processes leading to the aggressive behavior of pancreatic tumors. Furthermore, we focus on CAIX occurrence in pre-cancerous lesions, and for the first time, we describe CAIX expression within intraductal papillary mucinous neoplasia. Our review concludes with a detailed account of clinical trials implicating that treatment consisting of conventionally used therapies combined with CAIX targeting could result in an improved anti-cancer response in pancreatic cancer patients.

Diffusion Metrics for Staging Pancreatic Fibrosis and Correlating With Epithelial‐Mesenchymal Transition Markers in a Chronic Pancreatitis Rat Model at 11.7T MRI

Background

Chronic pancreatitis (CP) is characterized by pancreatic fibrosis, in which a epithelial‐mesenchymal transition (EMT)‐like process is observed. However, few noninvasive approaches have been reported to evaluate pancreatic fibrosis and EMT in an animal model based on diffusion imaging.

Purpose

To evaluate pancreatic fibrosis in CP by conventional diffusion‐weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) and then explore the correlation between diffusion parameters and the EMT markers in an animal model.

Study Type

Prospective controlled imaging histological correlation.

Population

Forty‐five rats with CP induced by injecting dibutyltin dichloride solution and 10 normal rats comprised the control group.

Field Strength/Sequence

11.7T MR, diffusion imaging with 10 b‐values.

Assessment

Apparent diffusion coefficient (ADC), IVIM‐associated perfusion fraction (f), pseudodiffusion coefficient (D*), diffusion coefficient (D), DKI‐associated mean kurtosis (MK), and mean corrected diffusion coefficient (MD) were quantitatively measured and correlated with pancreatic fibrosis stages as well as the EMT markers E‐cadherin and α‐smooth muscle actin (α‐SMA) expression. The discriminative performance of diffusion parameters for staging fibrosis was compared.

Statistical Tests

Spearman's correlation, Student's t‐test, and a receiver operating characteristic curve was conducted for statistical analysis.

Results

ADC, D, and MD (r = –0.637, –0.688, and –0.535; P < 0.001) were negatively correlated with pancreatic fibrosis staging, but MK (r = 0.740, P < 0.001) had a positive correlation. ADC, D, MD, and MK were significantly correlated with α‐SMA (r = –0.684, –0.728, –0.627, and 0.721, all P < 0.001), while MK was significantly correlated with E‐cadherin (r = –0.606, P < 0.001). The area under the curve (AUC) was not significantly different (P > 0.05) among ADC (0.797, 0.816, 0.873), D (0.862, 0.810, 0.895), MD (0.767, 0.772, 0.801), and MK (0.836, 0.893, 0.951) for F1 or greater, F2 or greater, and F3 pancreatic fibrosis separately.

Data Conclusion

ADC, D, MD, and MK were helpful for assessing pancreatic fibrosis staging, and these diffusion parameters were also significantly correlated with the expression of EMT markers in pancreatic fibrosis.

Level of Evidence: 2

Technical Efficacy Stage: 2

J. Magn. Reson. Imaging 2020;52:197–206.

HDAC inhibitors promote pancreatic stellate cell apoptosis and relieve pancreatic fibrosis by upregulating miR-15/16 in chronic pancreatitis

In chronic pancreatitis, PSCs are activated by proinflammatory cytokines to induce pancreatic fibrogenesis. HDAC inhibition protected against the pancreatic fibrosis and the apoptosis of PSCs through induced apoptosis and depressed inflammation. In our study, we found that miR-15 and miR-16 decreased significantly in chronic pancreatitis and HDAC inhibition could recover the levels of these two miRNAs. HDAC regulated the transcription of miR-15 and miR-16, which then modulate the apoptosis and fibrosis of PSCs. And we proved that Bcl-2 and Smad5 were the target genes of miR-15 and miR-16, which illustrated how HDAC inhibition alleviated the apoptosis and fibrogenesis of PSCs in chronic pancreatitis. These results suggested that HDAC inhibition protects against CP by promoting apoptosis and TGF-β/Smads signaling pathways, and indicated that HDAC inhibition is a potential therapy to alleviate CP patients in clinic, and these need to be explored further.

Preventive Effects of Gardenia jasminoides on Cerulein-Induced Chronic Pancreatitis

Our previous report revealed that Gardenia jasminoides (GJ) has protective effects against acute pancreatitis. So, we examined whether aqueous extract of GJ has anti-inflammation and antifibrotic effects even against cerulein-induced chronic pancreatitis (CP). CP was induced in mice by an intraperitoneal injection of a stable cholecystokinin (CCK) analogue, cerulein, six times a day, four days per week for three weeks. GJ extract (0.1 or 1[Formula: see text]g/kg) or saline (control group) were intraperitoneally injected 1[Formula: see text]h before first cerulein injection. After three weeks of stimulation, the pancreas was harvested for the examination of several fibrotic parameters. In addition, pancreatic stellate cells (PSCs) were isolated using gradient methods to examine the antifibrogenic effects of GJ. In the cerulein-induced CP mice, the histological features of the pancreas showed severe tissue damage such as enlarged interstitial spaces, inflammatory cell infiltrate and glandular atrophy, and tissue fibrosis. However, treatment of GJ reduced the severity of CP such as pancreatic edema and inflammatory cell infiltration. Furthermore, treatment of GJ increased pancreatic acinar cell survival, and reduced pancreatic fibrosis and activation of PSC in vivo and in vitro. In addition, GJ treatment inhibited the activation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated protein kinase (ERK) in the PSCs. These results suggest that GJ attenuated the severity of CP and the pancreatic fibrosis by inhibiting JNK and ERK activation during CP.

Selective phytochemicals targeting pancreatic stellate cells as new anti-fibrotic agents for chronic pancreatitis and pancreatic cancer

Activated pancreatic stellate cells (PSCs) have been widely accepted as a key precursor of excessive pancreatic fibrosis, which is a crucial hallmark of chronic pancreatitis (CP) and its formidable associated disease, pancreatic cancer (PC). Hence, anti-fibrotic therapy has been identified as a novel therapeutic strategy for treating CP and PC by targeting PSCs. Most of the anti-fibrotic agents have been limited to phase I/II clinical trials involving vitamin analogs, which are abundant in medicinal plants and have proved to be promising for clinical application. The use of phytomedicines, as new anti-fibrotic agents, has been applied to a variety of complementary and alternative approaches. The aim of this review was to present a focused update on the selective new potential anti-fibrotic agents, including curcumin, resveratrol, rhein, emodin, green tea catechin derivatives, metformin, eruberin A, and ellagic acid, in combating PSC in CP and PC models. It aimed to describe the mechanism(s) of the phytochemicals used, either alone or in combination, and the associated molecular targets. Most of them were tested in PC models with similar mechanism of actions, and curcumin was tested intensively. Future research may explore the issues of bioavailability, drug design, and nano-formulation, in order to achieve successful clinical outcomes with promising activity and tolerability.

Wingless-type MMTV integration site family member 5a is a key inhibitor of islet stellate cells activation

AIMS/INTRODUCTION

Type 2 diabetes mellitus is a chronic metabolic disorder characterized by islet β-cell dysfunction, which might result from the activation of islet stellate cells (ISCs). Our recent study showed that a specific population of ISCs is prone to be activated in type 2 diabetes mellitus accompanied by reduced secretion of insulin. The wingless-type MMTV integration site family member 5a (Wnt5a)/frizzled-5 signaling pathway might play an important role in this process. The present study aimed to explore the effects of Wnt5a on the activation of ISCs isolated from db/db mice.

MATERIALS AND METHODS

ISCs were isolated from db/db mice and matched db/m mice. Immunohistochemistry and western blotting analysis were applied for the determination of Wnt5a expression. Exogenous Wnt5a and lentivirus containing the target gene Wnt5a short hairpin ribonucleic acid were used as a molecular intervention. The experiment of transwell and wound healing was used to evaluate the migration of the isolated ISCs.

RESULTS

Our data showed that the expression of Wnt5a and frizzled-5 was decreased in the ISCs isolated from db/db mice compared with db/m mice. Both the exogenous Wnt5a and the overexpression of Wnt5a could inhibit the outgrowth rate of ISCs from islets, and its viability, migration and α smooth muscle actin expression. These changes were associated with the inactivation of the Smad2/3 signaling pathway in a frizzled-5-dependent manner.

CONCLUSIONS

Our observations revealed a potential role of Wnt5a in preventing ISC activation. The maintenance of quiescent ISCs might be a desirable outcome of therapeutic strategies for diabetes mellitus.

Diagnosis and Management of Chronic Pancreatitis: A Review

IMPORTANCE

Chronic pancreatitis (CP) is a chronic inflammatory and fibrotic disease of the pancreas with a prevalence of 42 to 73 per 100 000 adults in the United States.

OBSERVATIONS

Both genetic and environmental factors are thought to contribute to the pathogenesis of CP. Environmental factors associated with CP include alcohol abuse (odds ratio [OR], 3.1; 95% CI, 1.87-5.14) for 5 or more drinks per day vs abstainers and light drinkers as well as smoking (OR, 4.59; 95% CI, 2.91-7.25) for more than 35 pack-years in a case-control study involving 971 participants. Between 28% to 80% of patients are classified as having "idiopathic CP." Up to 50% of these individuals have mutations of the trypsin inhibitor gene (SPINK1) or the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Approximately 1% of people diagnosed with CP may have hereditary pancreatitis, associated with cationic trypsinogen (PRSS1) gene mutations. Approximately 80% of people with CP present with recurrent or chronic upper abdominal pain. Long-term sequelae include diabetes in 38% to 40% and exocrine insufficiency in 30% to 48%. The diagnosis is based on pancreatic calcifications, ductal dilatation, and atrophy visualized by imaging with computed tomography, magnetic resonance imaging, or both. Endoscopic ultrasound can assist in making the diagnosis in patients with a high index of suspicion such as recurrent episodes of acute pancreatitis when imaging is normal or equivocal. The first line of therapy consists of advice to discontinue use of alcohol and smoking and taking analgesic agents (nonsteroidal anti-inflammatory drugs and weak opioids such as tramadol). A trial of pancreatic enzymes and antioxidants (a combination of multivitamins, selenium, and methionine) can control symptoms in up to 50% of patients. Patients with pancreatic ductal obstruction due to stones, stricture, or both may benefit from ductal drainage via endoscopic retrograde cholangiopancreatography (ERCP) or surgical drainage procedures, such as pancreaticojejunostomy with or without pancreatic head resection, which may provide better pain relief among people who do not respond to endoscopic therapy.

CONCLUSIONS AND RELEVANCE

Chronic pancreatitis often results in chronic abdominal pain and is most commonly caused by excessive alcohol use, smoking, or genetic mutations. Treatment consists primarily of alcohol and smoking cessation, pain control, replacement of pancreatic insufficiency, or mechanical drainage of obstructed pancreatic ducts for some patients.

[Other specific types of diabetes and exocrine pancreatic insufficiency (Update 2019)]

The heterogenous catagory "specific types of diabetes due to other causes" encompasses disturbances in glucose metabolism due to other endocrine disorders such as acromegaly or hypercortisolism, drug-induced diabetes (e. g. antipsychotic medications, glucocorticoids, immunosuppressive agents, highly active antiretroviral therapy (HAART)), genetic forms of diabetes (e. g. Maturity Onset Diabetes of the Young (MODY), neonatal diabetes, Down Syndrome, Klinefelter Syndrome, Turner Syndrome), pancreatogenic diabetes (e. g. postoperatively, pancreatitis, pancreatic cancer, haemochromatosis, cystic fibrosis), and some rare autoimmune or infectious forms of diabetes. Diagnosis of specific diabetes types might influence therapeutic considerations. Exocrine pancreatic insufficiency is not only found in patients with pancreatogenic diabetes but is also frequently seen in type 1 and long-standing type 2 diabetes.

Piperine ameliorates the severity of fibrosis via inhibition of TGF‑β/SMAD signaling in a mouse model of chronic pancreatitis

Chronic pancreatitis (CP) is characterized by recurrent pancreatic injury, resulting in inflammation and fibrosis. Currently, there are no drugs for the treatment of pancreatic fibrosis associated with CP. Piperine, a natural alkaloid found in black pepper, has been reported to show anti-inflammatory, anti-oxidative, and antitumor activities. Although piperine exhibits numerous properties in regards to the regulation of diverse diseases, the effects of piperine on CP have not been established. To investigate the effects of piperine on CP in vivo, we induced CP in mice through the repetitive administration of cerulein (50 µg/kg) six times at 1-h intervals, 5 times per week, for a total of 3 weeks. In the pre-treatment groups, piperine (1, 5, or 10 mg/kg) or corn oil were administrated orally at 1 h before the first cerulein injection, once a day, 5 times a week, for a total of 3 weeks. In the post-treatment groups, piperine (10 mg/kg) or corn oil was administered orally at 1 or 2 week after the first cerulein injection. Pancreases were collected for histological analysis. In addition, pancreatic stellate cells (PSCs) were isolated to examine the anti-fibrogenic effects and regulatory mechanisms of piperine. Piperine treatment significantly inhibited histological damage in the pancreas, increased the pancreatic acinar cell survival, reduced collagen deposition and reduced pro-inflammatory cytokines and chemokines. In addition, piperine treatment reduced the expression of fibrotic mediators, such as α-smooth muscle actin (α-SMA), collagen, and fibronectin 1 in the pancreas and PSCs. Moreover, piperine treatment reduced the production of transforming growth factor (TGF)-β in the pancreas and PSCs. Furthermore, piperine treatment inhibited TGF-β-induced pSMAD2/3 activation but not pSMAD1/5 in the PSCs. These findings suggest that piperine treatment ameliorates pancreatic fibrosis by inhibiting TGF-β/SMAD2/3 signaling during CP.