Acinar injury and early cytokine response in human acute biliary pancreatitis

Heart rate variability in acute pancreatitis: a narrative review

Background and Objective

Acute pancreatitis (AP) is a complex inflammatory disorder with potential systemic repercussions including sepsis, multiple organ failure and mortality. As such, the development of a prognostic tool to assess the complications and severity of AP is critical as urgent medical intervention is warranted in cases of severe AP to prevent complications and reduce mortality. Despite the plethora of scoring systems such as the Acute Physiology and Chronic Health Evaluation II (APACHE II) score available for prognostication of AP, they often require manual invasive blood testing and lack the ability to monitor the dynamic progression of the disease. To this end, heart rate variability (HRV), a measure of the autonomic nervous system's modulation on cardiac activity, has emerged as a promising tool. Having been previously posited as a tool to monitor the progression of cardiovascular and neurological conditions, the use of HRV as a risk stratification tool for AP is highly plausible. Therefore, this study aims to synthesize the existing literature regarding the usage of HRV as a tool for the prognostication and monitoring of AP.

Methods

A comprehensive literature search was conducted in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, Scopus and Embase from inception to December 2023. Articles with mentions of AP and HRV were reviewed, and the complications of AP and its effects on HRV parameters were analyzed.

Key Content and Findings

Early studies on the use of HRV in AP have revealed the association of decreased HRV parameters with the development of subsequent complications, reflecting the suppression of sympathetic activity as a predominant driving force. In addition, HRV has also been shown to outperform other established scoring systems in predicting outcomes of the complications of AP, but more studies are needed to validate its accuracy.

Conclusions

Preliminary studies have shown that certain parameters of HRV may be used to predict the severity of AP and prognosticate outcomes. Although HRV monitoring demonstrates potential to be superior to existing scoring systems in AP, more research is needed to validate its use as a prognostic tool. Nevertheless, the prospective utility of HRV monitoring in predicting the onset and outcomes of AP and its complications remains optimistic.

The Pathogenesis of Pancreatitis and the Role of Autophagy

The pathogenesis of acute and chronic pancreatitis has recently evolved as new findings demonstrate a complex mechanism operating through various pathways. In this review, the current evidence indicating that several mechanisms act in concert to induce and perpetuate pancreatitis were presented. As autophagy is now considered a fundamental mechanism in the pathophysiology of both acute and chronic pancreatitis, the fundamentals of the autophagy pathway were discussed to allow for a better understanding of the pathophysiological mechanisms of pancreatitis. The various aspects of pathogenesis, including trypsinogen activation, ER stress and mitochondrial dysfunction, the implications of inflammation, and macrophage involvement in innate immunity, as well as the significance of pancreatic stellate cells in the development of fibrosis, were also analyzed. Recent findings on exosomes and the miRNA regulatory role were also presented. Finally, the role of autophagy in the protection and aggravation of pancreatitis and possible therapeutic implications were reviewed.

Comparative transcriptomic analysis reveals the molecular changes of acute pancreatitis in experimental models

BACKGROUND

Acute pancreatitis (AP) encompasses a spectrum of pancreatic inflammatory conditions, ranging from mild inflammation to severe pancreatic necrosis and multisystem organ failure. Given the challenges associated with obtaining human pancreatic samples, research on AP predominantly relies on animal models. In this study, we aimed to elucidate the fundamental molecular mechanisms underlying AP using various AP models.

AIM

To investigate the shared molecular changes underlying the development of AP across varying severity levels.

METHODS

AP was induced in animal models through treatment with caerulein alone or in combination with lipopolysaccharide (LPS). Additionally, using Ptf1α to drive the specific expression of the hM3 promoter in pancreatic acinar cells transgenic C57BL/6J- hM3/Ptf1α(cre) mice were administered Clozapine N-oxide to induce AP. Subsequently, we conducted RNA sequencing of pancreatic tissues and validated the expression of significantly different genes using the Gene Expression Omnibus (GEO) database.

RESULTS

Caerulein-induced AP showed severe inflammation and edema, which were exacerbated when combined with LPS and accompanied by partial pancreatic tissue necrosis. Compared with the control group, RNA sequencing analysis revealed 880 significantly differentially expressed genes in the caerulein model and 885 in the caerulein combined with the LPS model. Kyoto Encyclopedia of Genes and Genomes enrichment analysis and Gene Set Enrichment Analysis indicated substantial enrichment of the TLR and NOD-like receptor signaling pathway, TLR signaling pathway, and NF-κB signaling pathway, alongside elevated levels of apoptosis-related pathways, such as apoptosis, P53 pathway, and phagosome pathway. The significantly elevated genes in the TLR and NOD-like receptor signaling pathways, as well as in the apoptosis pathway, were validated through quantitative real-time PCR experiments in animal models. Validation from the GEO database revealed that only MYD88 concurred in both mouse pancreatic tissue and human AP peripheral blood, while TLR1, TLR7, RIPK3, and OAS2 genes exhibited marked elevation in human AP. The genes TUBA1A and GADD45A played significant roles in apoptosis within human AP. The transgenic mouse model hM3/Ptf1α(cre) successfully validated significant differential genes in the TLR and NOD-like receptor signaling pathways as well as the apoptosis pathway, indicating that these pathways represent shared pathological processes in AP across different models.

CONCLUSION

The TLR and NOD receptor signaling pathways play crucial roles in the inflammatory progression of AP, notably the MYD88 gene. Apoptosis holds a central position in the necrotic processes of AP, with TUBA1A and GADD45A genes exhibiting prominence in human AP.

A non-human primate derived anti-P-selectin glycoprotein ligand-1 antibody curtails acute pancreatitis by alleviating the inflammatory responses

Acute pancreatitis (AP) is a devastating disease characterized by an inflammatory disorder of the pancreas. P-selectin glycoprotein ligand-1 (PSGL-1) plays a crucial role in the initial steps of the adhesive at process to inflammatory sites, blockade of PSGL-1 might confer potent anti-inflammatory effects. In this study, we generated two non-human primate derived monoclonal antibodies capable of efficiently targeting human PSGL-1, RH001-6 and RH001-22, which were screened from immunized rhesus macaques. We found that RH001-6, can effectively block the binding of P-selectin to PSGL-1, and abolish the adhesion of leukocytes to endothelial cells in vitro. In vivo, we verified that RH001-6 relieved inflammatory responses and pancreatic injury in both caerulein and l-arginine induced AP models. We also evaluated the safety profile after RH001-6 treatment in mice, and verified that RH001-6 did not cause any significant pathological damages in vivo. Taken together, we developed a novel non-human primate derived PSGL-1 blocking antibody with high-specificity, named RH001-6, which can interrupt the binding of PSGL-1 and P-selectin and attenuate inflammatory responses during AP. Therefore, RH001-6 is highly potential to be further developed into therapeutics against acute inflammatory diseases, such as AP.

Galantamine ameliorates experimental pancreatitis

BACKGROUND

Acute pancreatitis is a common and serious inflammatory condition currently lacking disease modifying therapy. The cholinergic anti-inflammatory pathway (CAP) is a potent protective anti-inflammatory response activated by vagus nerve-dependent α7 nicotinic acetylcholine receptor (α7nAChR) signaling using splenic CD4+ T cells as an intermediate. Activating the CAP ameliorates experimental acute pancreatitis. Galantamine is an acetylcholinesterase inhibitor (AChEI) which amplifies the CAP via modulation of central muscarinic ACh receptors (mAChRs). However, as mAChRs also activate pancreatitis, it is currently unknown whether galantamine would be beneficial in acute pancreatitis.

METHODS

The effect of galantamine (1-6 mg/kg-body weight) on caerulein-induced acute pancreatitis was evaluated in mice. Two hours following 6 hourly doses of caerulein (50 µg/kg-body weight), organ and serum analyses were performed with accompanying pancreatic histology. Experiments utilizing vagotomy, gene knock out (KO) technology and the use of nAChR antagonists were also performed.

RESULTS

Galantamine attenuated pancreatic histologic injury which was mirrored by a reduction in serum amylase and pancreatic inflammatory cytokines and an increase the anti-inflammatory cytokine IL-10 in the serum. These beneficial effects were not altered by bilateral subdiaphragmatic vagotomy, KO of either choline acetyltransferase+ T cells or α7nAChR, or administration of the nAChR ganglionic blocker mecamylamine or the more selective α7nAChR antagonist methyllycaconitine.

CONCLUSION

Galantamine improves acute pancreatitis via a mechanism which does not involve previously established physiological and molecular components of the CAP. As galantamine is an approved drug in widespread clinical use with an excellent safety record, our findings are of interest for further evaluating the potential benefits of this drug in patients with acute pancreatitis.

Comprehensive review on the pathogenesis of hypertriglyceridaemia-associated acute pancreatitis

It is well known, that the inflammatory process that characterizes acute pancreatitis (AP) can lead to both pancreatic damage and systemic inflammatory response syndrome (SIRS). During the last 20 years, there has been a growing incidence of episodes of acute pancreatitis associated with hypertriglyceridaemia (HTAP). This review provides an overview of triglyceride metabolism and the potential mechanisms that may contribute to developing or exacerbating HTAP. The article comprehensively discusses the various pathological roles of free fatty acid, inflammatory response mechanisms, the involvement of microcirculation, serum calcium overload, oxidative stress and the endoplasmic reticulum, genetic polymorphism, and gut microbiota, which are known to trigger or escalate this condition. Future perspectives on HTAP appear promising, with ongoing research focused on developing more specific and effective treatment strategies.

Optogenetic stimulation of the brainstem dorsal motor nucleus ameliorates acute pancreatitis

Introduction

Inflammation is an inherently self-amplifying process, resulting in progressive tissue damage when unresolved. A brake on this positive feedback system is provided by the nervous system which has evolved to detect inflammatory signals and respond by activating anti-inflammatory processes, including the cholinergic anti-inflammatory pathway mediated by the vagus nerve. Acute pancreatitis, a common and serious condition without effective therapy, develops when acinar cell injury activates intrapancreatic inflammation. Prior study has shown that electrical stimulation of the carotid sheath, which contains the vagus nerve, boosts the endogenous anti-inflammatory response and ameliorates acute pancreatitis, but it remains unknown whether these anti-inflammatory signals originate in the brain.

Methods

Here, we used optogenetics to selectively activate efferent vagus nerve fibers originating in the brainstem dorsal motor nucleus of the vagus (DMN) and evaluated the effects on caerulein-induced pancreatitis.

Results

Stimulation of the cholinergic neurons in the DMN significantly attenuates the severity of pancreatitis as indicated by reduced serum amylase, pancreatic cytokines, tissue damage, and edema. Either vagotomy or silencing cholinergic nicotinic receptor signaling by pre-administration of the antagonist mecamylamine abolishes the beneficial effects.

Discussion

These results provide the first evidence that efferent vagus cholinergic neurons residing in the brainstem DMN can inhibit pancreatic inflammation and implicate the cholinergic anti-inflammatory pathway as a potential therapeutic target for acute pancreatitis.

Systemic Bile Acids Affect the Severity of Acute Pancreatitis in Mice Depending on Their Hydrophobicity and the Disease Pathogenesis

Acute pancreatitis (AP) is a major, globally increasing gastrointestinal disease and a biliary origin is the most common cause. However, the effects of bile acids (BAs), given systemically, on the pancreas and on disease severity remains elusive. In this study, we have investigated the roles of different circulating BAs in animal models for AP to elucidate their impact on disease severity and the underlying pathomechanisms. BAs were incubated on isolated acini and AP was induced through repetitive injections of caerulein or L-arginine; pancreatic duct ligation (PDL); or combined biliopancreatic duct ligation (BPDL). Disease severity was assessed using biochemical and histological parameters. Serum cholecystokinin (CCK) concentrations were determined via enzyme immunoassay. The binding of the CCK1 receptor was measured using fluorescence-labeled CCK. In isolated acini, hydrophobic BAs mitigated the damaging effects of CCK. The same BAs further enhanced pancreatitis in L-arginine- and PDL-based pancreatitis, whereas they ameliorated pancreatic damage in the caerulein and BPDL models. Mechanistically, the binding affinity of the CCK1 receptor was significantly reduced by hydrophobic BAs. The hydrophobicity of BAs and the involvement of CCK seem to be relevant in the course of AP. Systemic BAs may affect the severity of AP by interfering with the CCK1 receptor.

Bifidobacterium spp. and their metabolite lactate protect against acute pancreatitis via inhibition of pancreatic and systemic inflammatory responses

Severe acute pancreatitis (SAP) is a critical illness characterized by a severe systemic inflammatory response resulting in persistent multiple organ failure and sepsis. The intestinal microbiome is increasingly appreciated to play a crucial role in modulation of AP disease outcome, but limited information is available about the identity and mechanism of action for specific commensal bacteria involved in AP-associated inflammation. Here we show that Bifidobacteria, particularly B. animalis, can protect against AP by regulating pancreatic and systemic inflammation in germ-free (GF) and oral antibiotic-treated (Abx) mouse models. Colonization by B. animalis and administration of its metabolite lactate protected Abx and GF mice from AP by reducing serum amylase concentration, ameliorating pancreatic lesions and improving survival rate after retrograde injection of sodium taurocholate. B. animalis relieved macrophage-associated local and systemic inflammation of AP in a TLR4/MyD88- and NLRP3/Caspase1-dependent manner through its metabolite lactate. Supporting our findings from the mouse study, clinical AP patients exhibited a decreased fecal abundance of Bifidobacteria that was inversely correlated with the severity of systemic inflammatory responses. These results may shed light on the heterogeneity of clinical outcomes and drive the development of more efficacious therapeutic interventions for AP, and potentially for other inflammatory disorders.

USP25 Deficiency Exacerbates Acute Pancreatitis via Up-Regulating TBK1-NF-κB Signaling in Macrophages

BACKGROUND & AIMS

Severe acute pancreatitis can easily lead to systemic inflammatory response syndrome and death. Macrophages are known to be involved in the pathophysiology of acute pancreatitis (AP), and macrophage activation correlates with disease severity. In this study, we examined the role of ubiquitin-specific protease 25, a deubiquitinating enzyme and known regulator of macrophages, in the pathogenesis of AP.

METHODS

We used L-arginine, cerulein, and choline-deficient ethionine-supplemented diet-induced models of AP in Usp25^-/- mice and wild-type mice. We also generated bone marrow Usp25^-/- chimeric mice and initiated L-arginine-mediated AP. Primary acinar cells and bone marrow-derived macrophages were isolated from wild-type and Usp25^-/- mice to dissect molecular mechanisms.

RESULTS

Our results show that Usp25 deficiency exacerbates pancreatic and lung injury, neutrophil and macrophage infiltration, and systemic inflammatory responses in L-arginine, cerulein, and choline-deficient ethionine-supplemented diet-induced models of AP. Bone marrow Usp25^-/- chimeric mice challenged with L-arginine show that Usp25 deficiency in macrophages exaggerates AP by up-regulating the TANK-binding kinase 1 (TBK1)-nuclear factor-κB (NF-κB) signaling pathway. Similarly, in vitro data confirm that Usp25 deficiency enhances the TBK1-NF-κB pathway, leading to increased expression of inflammatory cytokines in bone marrow-derived macrophages.

CONCLUSIONS

Usp25 deficiency in macrophages enhances TBK1-NF-κB signaling, and the induction of inflammatory chemokines and type I interferon-related genes exacerbates pancreatic and lung injury in AP.

Exposure to binge ethanol and fatty acid ethyl esters exacerbates chronic ethanol-induced pancreatic injury in hepatic alcohol dehydrogenase-deficient deer mice

Alcoholic chronic pancreatitis (ACP) is a fibroinflammatory disease of the pancreas. However, metabolic basis of ACP is not clearly understood. In this study, we evaluated differential pancreatic injury in hepatic alcohol dehydrogenase-deficient (ADH^-) deer mice fed chronic ethanol (EtOH), chronic plus binge EtOH, and chronic plus binge EtOH and fatty acid ethyl esters (FAEEs, nonoxidative metabolites of EtOH) to understand the metabolic basis of ACP. Hepatic ADH^- and ADH normal (ADH⁺) deer mice were fed Lieber-DeCarli liquid diet containing 3% (wt/vol) EtOH for 3 mo. One week before the euthanization, chronic EtOH-fed mice were further administered with an oral gavage of binge EtOH with/without FAEEs. Blood alcohol concentration (BAC), pancreatic injury, and inflammatory markers were measured. Pancreatic morphology, ultrastructural changes, and endoplasmic reticulum (ER)/oxidative stress were examined using H&E staining, electron microscopy, immunostaining, and/or Western blot, respectively. Overall, BAC was substantially increased in chronic EtOH-fed groups of ADH^- versus ADH⁺ deer mice. A significant change in pancreatic acinar cell morphology, with mild to moderate fibrosis and ultrastructural changes evident by dilatations and disruption of ER cisternae, ER/oxidative stress along with increased levels of inflammatory markers were observed in the pancreas of chronic EtOH-fed groups of ADH^- versus ADH⁺ deer mice. Furthermore, chronic plus binge EtOH and FAEEs exposure elevated BAC, enhanced ER/oxidative stress, and exacerbated chronic EtOH-induced pancreatic injury in ADH^- deer mice suggesting a role of increased body burden of EtOH and its metabolism under reduced hepatic ADH in initiation and progression of ACP.NEW & NOTEWORTHY We established a chronic EtOH feeding model of hepatic alcohol dehydrogenase-deficient (ADH^-) deer mice, which mimics several fibroinflammatory features of human alcoholic chronic pancreatitis (ACP). The fibroinflammatory and morphological features exacerbated by chronic plus binge EtOH and FAEEs exposure provide a strong case for metabolic basis of ACP. Most importantly, several pathological and molecular targets identified in this study provide a much broader understanding of the mechanism and avenues to develop therapeutics for ACP.

Role of Interleukin-17 in Acute Pancreatitis

Acute pancreatitis (AP) is a leading cause of death and is commonly accompanied by systemic manifestations that are generally associated with a poor prognosis. Many cytokines contribute to pancreatic tissue damage and cause systemic injury. Interleukin-17 (IL-17) is a cytokine that may play a vital role in AP. Specifically, IL-17 has important effects on the immune response and causes interactions between different inflammatory mediators in the AP-related microenvironment. In this literature review, we will discuss the existing academic understanding of IL-17 and the impacts of IL-17 in different cells (especially in acinar cells and immune system cells) in AP pathogenesis. The clinical significance and potential mechanisms of IL-17 on AP deterioration are emphasized. The evidence suggests that inhibiting the IL-17 cytokine family could alleviate the pathogenic process of AP, and we highlight therapeutic strategies that directly or indirectly target IL-17 cytokines in acute pancreatitis.

Pancreas Divisum Increases the Risk of Recurrent Acute Pancreatitis in Patients with rs12338 Polymorphism in the Cathepsin B Gene

OBJECTIVES

Pancreas divisum (PD) as a cause of pancreatitis has been debated. In this study, we report the association of multiple gene polymorphisms on the risk of RAP in the presence of PD.

DESIGN

We enrolled 687 individuals (167 IRAP, 276 ICP, and 244 unrelated healthy controls) from May 2015 to September 2016. Patients were divided into those with/without PD. Associations between the significantly prevalent SNPs and IRAP/ICP in the presence of PD were evaluated. Clinical data were analyzed using Mann-Whitney U/Chi-square test. Effect size of association of SNPs with IRAP/ICP was expressed as odds ratio (OR) (95% CI). Gene-gene interaction was assessed by transheterozygosity analyses. Bonferroni-corrected two-tailed "p" value of ≤ 0.01 was considered statistically significant.

RESULTS

Thirty-three (19.8%) and 82 (29.7%) patients with IRAP and ICP, respectively, had PD. Among the patients with IRAP, duration of disease was significantly shorter in those with PD compared to those without (mean [95% CI] duration: 1.6 (1.3-1.9) vs 2.7 (2.3-3.1) years; p = 0.005). There were no differences in gender, race, and diabetes among patients with/without PD in IRAP/ICP groups. Mean (95% CI) pancreatic duct diameter (mm) was significantly higher in the presence of PD in patients with both IRAP [1.6 (1.4-1.9) v/s 1.29 (1.2-1.4); p = 0.03)] and ICP [5.2 (4.5-5.9) v/s 4.5 (3.9-5.1); p = 0.02]. CTSB (rs12338) polymorphisms were significantly associated with IRAP [OR (95% CI) 2.44 (1.41-4.22); p = 0.001] among patients with PD. No association was observed with ICP. Transheterozygosity analysis did not show any significant associations of combination of SNPs with IRAP in the presence of PD.

CONCLUSION

Risk of RAP due to PD increases in patients with rs12338 polymorphism in the cathepsin B gene.

Non-compliance to practice guidelines still exist in the early management of acute pancreatitis: Time for reappraisal?

INTRODUCTION

Earlier national surveys on the management of acute pancreatitis (AP) had reported non-compliance to practice guidelines. In the past decade, several guidelines were revised based on new evidence. In this multicenter international survey, we aimed to evaluate the practice patterns of early management of AP and compliance to the revised treatment guidelines across different disciplines and practice environments.

METHODS

A structured questionnaire was sent via email to a target population of 654 that constituted of medical and surgical gastroenterologists, physicians and general surgeons, paediatricians from academic and non-academic centres across 30 countries. Other than demographic variables, the questionnaire contained items pertaining to early management of AP, such as, assessment at admissions and within first 72 h s, details regarding analgesics, IV hydration, oral/enteral feeding and antibiotic use.

RESULTS

The response rate was 46.2% and after exclusions, a total of 297 participant's responses were analysed. Majority of the participants were from Asia, followed by Europe and the Americas. 181 (60.9%) claimed to follow practice guidelines, out of which 59 (32.6%) followed more than one. On further probing, only 41.9% were actually compliant to feeding and 59.7% to antibiotic guidelines. Even though participants opted for aggressive hydration, early feeding and avoidance of prophylactic antibiotics, there were non-compliance and discrepancies in titration of fluid therapy, indications of feeding and antibiotic use.

DISCUSSION

Discrepancies and non-compliance still appear to exist in the early management of AP due to lack of strong evidence. We discuss ways that could improve compliance to the existing guidelines until stronger evidence comes to the fore.

Sting pathway - A futuristic therapeutic target for acute pancreatitis?

Acute Pancreatitis (AP) refers to the inflammatory state of the pancreatic mass caused by an abnormal release of digestive enzymes characterized by pancreatic acinar cell injury. It is mainly caused by gallstones, which primarily block sphincter of Oddi opening into the duodenum, heavyalcohol use, systemic diseases, etc. Stimulator of interferon genes known as STING uniquely senses the apoptotic and necrotic DNA fragments. Through the expression of TMEM173 (transmembrane protein 173) or STING protein in macrophages, downstream signaling pathways are activated in AP and are responsible for promoting inflammation. STING elicits a cascade of downstream signaling events such as activation of TBK1, IRF-3 phosphorylation, and IFN-β production along with other cytokines, which result in the excessive manufacture of the type-I IFNs and different kinds of proinflammatory cytokines that take part in the immune defense system of the host. Research findings suggest that STING regulates an array of innate immunity pathways, and the absence of proper treatment measures for AP provides the opportunity of evaluating STING as a striking therapeutic target for AP associated inflammation. Although the understanding of STING hyperactivation and its association with inflammation is relative of recent interest among researchers, extensive studies are going on to identify inhibitors that can directly target STING and inhibits the downstream signaling in AP. Therefore, this review aims to collectively compile the available pieces of evidence, which could help to better understand the role of STING signaling in AP and its promising role as a therapeutic target.

Immunomodulation Through Beta-D-glucan in Chemically-induced Necrotizing Pancreatitis

BACKGROUND

Although the ability of β-D-glucan and monophosphoryl lipid A (MPLA) to modulate immune responses has been studied in human primary cells, their effect on sterile inflammation models such as necrotizing pancreatitis has never been investigated.

MATERIALS AND METHODS

85 male New Zealand rabbits were assigned into following groups: A: control, B: pretreatment with β-D-glucan 3 d before pancreatitis, C: pretreatment with MPLA 3 d before pancreatitis, D: pretreatment with β-D-glucan and laminarin 3 d before pancreatitis, E: treatment with β-D-glucan 1 d after pancreatitis, and F: MPLA 1 d after pancreatitis. Pancreatitis was induced by sodium taurocholate injection into the pancreatic duct and parenchyma. Survival was recorded for 21 d. On days 1, 3, and 7, blood was collected for amylase measurement. Peripheral blood mononuclear cells were isolated and stimulated for tumor necrosis factor alpha and interleukin 10 production. Pancreatic necrosis and tissue bacterial load were assessed.

RESULTS

21-d survival was prolonged after pretreatment or treatment with β-D-glucan; this benefit was lost with laminarin administration. At sacrifice, pancreatic inflammatory alterations were more prominent in the control group. Bacterial load was lower after pretreatment or treatment with β-D-glucan and MPLA. Tumor necrosis factor alpha production from stimulated peripheral blood mononuclear cells was significantly decreased, whereas interleukin 10 production remained unaltered after pretreatment or treatment with β-D- glucan.

CONCLUSIONS

β-D-glucan reduces mortality of experimental pancreatitis in vivo. This is mediated through attenuation of cytokine production and prevention of bacterial translocation.

Fatty acid ethyl ester (FAEE) associated acute pancreatitis: An ex-vivo study using human pancreatic acini

BACKGROUND & AIM

Fatty acid ethyl esters (FAEEs), are produced by non-oxidative alcohol metabolism and can cause acinar cell damage and subsequent acute pancreatitis in rodent models. Even though experimental studies have elucidated the FAEE mediated early intra-acinar events, these mechanisms have not been well studied in humans. In the present study, we evaluate the early intra-acinar events and inflammatory response in human pancreatic acinar tissues and cells in an ex-vivo model.

METHODS

Experiments were conducted using normal human pancreatic tissues exposed to FAEE. Subcellular fractionation was performed on tissue homogenates and trypsin and cathepsin B activities were estimated in these fractions. Acinar cell injury was evaluated by histology and immunohistochemistry. Cytokine release from exposed acinar cells was evaluated by performing Immuno-fluorescence. Serum was collected from patients with AP within the first 72 h of symptom onset for cytokine estimation using FACS.

RESULTS

We observed significant trypsin activation and acinar cell injury in FAEE treated tissue. Cathepsin B was redistributed from lysosomal to zymogen compartment at 30 min of FAEE exposure. IHC results indicated the presence of apoptosis in pancreatic tissue at 1 & 2hrs of FAEE exposure. We also observed a time dependent increase in secretion of cytokines IL-6, IL-8, TNF-α from FAEE treated acinar tissue. There was also a significant elevation in plasma cytokines in patents with alcohol associated AP within 72 h of symptom onset.

CONCLUSION

Our data suggest that alcohol metabolites can cause acute acinar cell damage and subsequent cytokine release which could eventually culminant in SIRS.

Drug discovery and formulation development for acute pancreatitis

Acute pancreatitis is a sudden inflammation and only last for a short time, but might lead to a life-threatening emergency. Traditional drug therapy is an essential supportive method for acute pancreatitis treatment, yet, failed to achieve satisfactory therapeutic outcomes. To date, it is still challenging to develop therapeutic medicine to redress the intricate microenvironment promptly in the inflamed pancreas, and more importantly, avoid multi-organ failure. The understanding of the acute pancreatitis, including the causes, mechanism, and severity judgment, could help the scientists bring up more effective intervention and treatment strategies. New formulation approaches have been investigated to precisely deliver therapeutics to inflammatory lesions in the pancreas, and some even could directly attenuate the pancreatic damages. In this review, we will briefly introduce the involved pathogenesis and underlying mechanisms of acute pancreatitis, as well as the traditional Chinese medicine and the new drug option. Most of all, we will summarize the drug delivery strategies to reduce inflammation and potentially prevent the further development of pancreatitis, with an emphasis on the bifunctional nanoparticles that act as both drug delivery carriers and therapeutics.

Impaired autophagy increases susceptibility to endotoxin-induced chronic pancreatitis

Chronic pancreatitis (CP) is associated with elevated plasma levels of bacterial lipopolysaccharide (LPS) and we have demonstrated reduced acinar cell autophagy in human CP tissue. Therefore, we investigated the role of autophagy in experimental endotoxin-induced pancreatic injury and aimed to identify LPS in human CP tissue. Pancreatic Atg7-deficient mice were injected with a single sub-lethal dose of LPS. Expression of autophagy, apoptosis, necroptosis, and inflammatory markers was determined 3 and 24 h later utilizing immunoblotting and immunofluorescence. The presence of LPS in pancreatic tissue from mice and from patients and healthy controls was determined using immunohistochemistry, immunoblots, and chromogenic assay. Mice lacking pancreatic autophagy exhibited local signs of inflammation and were particularly sensitive to the toxic effect of LPS injection as compared to control mice. In response to LPS, Atg7^Δpan mice exhibited enhanced vacuolization of pancreatic acinar cells, increase in TLR4 expression coupled to enhanced expression of NF-κΒ, JNK, and pro-inflammatory cytokines by acinar cells and enhanced infiltration by myeloid cells (but not Atg7^F/F controls). Cell death was enhanced in Atg7^Δpan pancreata, but only necroptosis and trypsin activation was further amplified following LPS injection along with elevated pancreatic LPS. The presence of LPS was identified in the pancreata from all 14 CP patients examined but was absent in the pancreata from all 10 normal controls. Altogether, these results support a potential role for metabolic endotoxemia in the pathogenesis of CP. Moreover, the evidence also supports the notion that autophagy plays a major cytoprotective and anti-inflammatory role in the pancreas, and blunting metabolic endotoxemia-induced CP.

A rare case of acute pancreatitis: a diagnostic conundrum and unusual complications

A 63-year-old man with a history of recurrent idiopathic acute pancreatitis (AP) was admitted to our surgical ward due to severe abdominal pain. He denied chronic excessive alcohol use. Other typical causes of AP, such as gallstones, hypertriglyceridemia, and trauma, were ruled out. After considering all possible etiologies, the most likely factor producing AP was medication that had been administered to him two weeks before the very first episode of the disease. Medication should always be considered as a possible trigger of AP, especially if the first episode occurs shortly after drug administration and the etiology is unclear. During patient’s hospitalization, laboratory reports revealed significant fluctuations in the serum levels of pancreatic enzymes, which can be attributed to recurrent bacteremia. After the 30-day period of hospitalization and long-lasting antibiotic therapy, he was discharged in a good condition with normal levels of serum pancreatic enzymes.

Association between contrast-induced nephrotoxicity and contrast enhanced computed tomography followed by endoscopic retrograde cholangiopancreatography

PURPOSE

To determine if endoscopic retrograde cholangiopancreatography (ERCP) performed within 72 h after contrast enhanced computed tomography (CECT) increases contrast-induced nephrotoxicity (CIN) risk in patients with abdominal complaints.

METHOD

This single-center retrospective cohort study included consecutive adult patients with abdominal complaints who underwent CECT between October 1, 2016, and June 30, 2019 at an emergency department (ED). CIN was diagnosed based on serum creatinine (SCr) level >0.5 mg/dL within 72 h after CECT or that increased >25 % compared to pre-CECT level. Logistic regression analysis was performed to determine independent risk factors for CIN, including age, sex, body mass index, comorbidities, medication, pre-CECT SCr level >1.5 mg/dL, and ERCP performed within 72 h after CECT. For persistent CIN, SCr level was obtained after 3 months at the earliest and compared to data obtained within 72 h after ERCP and CECT.

RESULTS

Of 1457 patients with CECT, 90 (6.2 %) underwent ERCP within 72 h after CECT and 93 (6.4 %) developed CIN. Multivariate analysis revealed that ERCP performed within 72 h after CECT (odds ratio, 3.31; 95 % confidence interval, 1.74, 6.29; p < 0.001) and pre-CECT SCr level >1.5 mg/dL (odds ratio, 9.86; 95 % confidence interval, 5.08, 19.2; p < 0.001) were independent risk factors for CIN. Of 93 patients with CIN, 10 (11 %) had persistent CIN. No specific factors were correlated with persistent CIN in the 3-month time frame.

CONCLUSION

ERCP performed within 72 h after CECT and pre-CECT SCr level >1.5 mg/dL are associated with CIN development.

Early Systemic Inflammatory Response Syndrome Duration Predicts Infected Pancreatic Necrosis

BACKGROUND AND PURPOSE

Systemic inflammatory response syndrome (SIRS) was considered to play an important role in the progress of acute pancreatitis, but its specific relation with infected pancreatic necrosis remains largely unclear. We aimed to investigate the correlation between SIRS duration and infected pancreatic necrosis, and its application in prediction of infected pancreatic necrosis.

METHODS

A prospective observational cohort study of 2130 patients with acute pancreatitis from 2012 to 2017. The SIRS duration at the first week was registered daily, and demographic, radiology, and all clinical laboratory data were prospectively collected and retrospectively reviewed.

RESULTS

A significant upward tendency of infected pancreatic necrosis incidence was observed with increased SIRS duration. In multivariate logistic regression, SIRS duration (odds ratio, 1.305; 95% CI, 1.161-1.468) was independently associated with infected pancreatic necrosis. ROC analysis demonstrated that the areas under curves of SIRS duration for predicting persistent multi-organ failure, pancreatic infection, and mortality were 0.97 (95% CI, 0.96-0.98), 0.92 (95% CI, 0.91-0.94), and 0.86 (95% CI, 0.83-0.90), respectively, which were comparable to, or even greater than, the area under curves of APACHE II and CT severity index scores.

CONCLUSIONS

Early SIRS duration was strongly associated with infected pancreatic necrosis and could serve as an easy bedside indicator to predict pancreatic infection.

Progress in research of liver injury induced by acute biliary pancreatitis

Acute biliary pancreatitis (ABP) not only causes acute inflammation of the pancreas, but also leads to obstruction or infection of the biliary system. Liver injury is one of the most common complications of ABP. The pathological mechanisms mainly include infection and endotoxin, cholestasis, pancreatic enzyme damage, microcirculatory disorders, and oxidative stress, and the research conclusions are mostly derived from animal experiments. On the basis of routine medical treatment of ABP, active anti-infective treatment and rapid relief of biliary obstruction can promote the recovery of ABP-related liver injury.

Serum TLR9 and NF-κB Biochemical Markers in Patients with Acute Pancreatitis on Admission

Aim

The aim of this study was to investigate the serum TLR9 and NF-κB levels in patients for the diagnosis and prognostication of AP in the emergency department.

Methods

In the current study, we looked at the TLR9 and NF-κB levels in patients for the diagnosis and prognostication of AP in the emergency department.

Results

Of the patients with acute pancreatitis, 22 (49%) were male and 23 (51%) were female. The mean age of the patient group was 62 years, with a range of 25-95 years. The control group consisted of 19 (43.1%) male and 25 (56.9%) female patients. The serum TLR9 and NF-κB levels in patients for the diagnosis and prognostication of AP in the emergency department. p < 0.001 and 8.04 ± 1.76 vs. 4.76 ± 1.13; p < 0.001 and 8.04 ± 1.76 vs. 4.76 ± 1.13; κB levels in patients for the diagnosis and prognostication of AP in the emergency department. p < 0.001 and 8.04 ± 1.76 vs. 4.76 ± 1.13; κB levels in patients for the diagnosis and prognostication of AP in the emergency department. p < 0.001 and 8.04 ± 1.76 vs. 4.76 ± 1.13.

Conclusion

We demonstrated that the TLR9 and NF-κB pathway is activated in acute pancreatitis and increases the inflammatory process. This may help to further understand the pathogenesis of disorder, diagnosis, and clinical severity. We proposed that blockage of these inflammatory pathways may play a role in the prevention of the disease progression and development of inflammatory complications.κB levels in patients for the diagnosis and prognostication of AP in the emergency department.

8α-Hydroxypinoresinol isolated from Nardostachys jatamansi ameliorates cerulein-induced acute pancreatitis through inhibition of NF-κB activation

Acute pancreatitis (AP) is a severe inflammatory condition of the pancreas, with no specific treatment available. We have previously reported that Nardostachys jatamansi (NJ) ameliorates cerulein-induced AP. However, the specific compound responsible for this inhibitory effect has not been identified. Therefore, in the present study, we focused on a single compound, 8α-hydroxypinoresinol (HP), from NJ. The aim of this study was to determine the effect of HP on the development of pancreatitis in mice and to explore the underlying mechanism(s). AP was induced by the injection of cerulein (50 μg/kg/h) for 6 h. HP (0.5, 5 or 10 mg/kg, i.p.) was administered 1 h prior to and 1, 3 or 5 h after the first cerulein injection, with vehicle- and DMSO-treated groups as controls. Blood samples were collected to determine serum levels of amylase, lipase, and cytokines. The pancreas was removed for morphological examination, myeloperoxidase (MPO) assays, cytokine assays, and assessment of nuclear factor (NF)-κB activation. The lungs were removed for morphological examination and MPO assays. Administration of HP dramatically improved pancreatic damage and pancreatitis-associated lung damage and also reduced amylase and lipase activities in serum. Moreover, administration of HP reduced the production of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in the pancreas and serum during AP. In addition, the administration of HP inhibited degradation of inhibitory κ-Bα (Iκ-Bα), NF-κB p65 translocation into nucleus and NF-κB binding activity in the pancreas. Our results suggest that HP exerted therapeutic effects on pancreatitis and these beneficial effects may be due to the inhibition of NF-κB activation.

Protective effects of maresin 1 against inflammation in experimentally induced acute pancreatitis and related lung injury

Severe acute pancreatitis (SAP) is an inflammatory disorder that progresses with local and systemic difficulties accompanied by a relatively high mortality rate. In recent years, maresin 1 (MaR1) has been shown to be a macrophage mediator with effective proresolving and anti-inflammatory properties that prevents the occurrence of various inflammatory conditions. The purpose of this study was to investigate the role of MaR1 in SAP and related lung injury. Experimental SAP was induced in mice with a combination of cerulean and lipopolysaccharide. MaR1 was administered 30 min before the primary injection of cerulean. Biochemical markers and histological injury scores were used to evaluate the severity of acute pancreatitis. To determine the degree of inflammation, serum cytokines and myeloperoxidase activity in pancreas and lung tissues were measured. Western blot analysis detected the activation of NF-κB. After MaR1 pretreatment, the activities of amylase, lipase, TNF-α, IL-1β, and IL-6 were decreased in serum, and the myeloperoxidase activity both in pancreas and in lung tissues significantly decreased, whereas the activity of anti-inflammatory cytokine IL-10 in serum was increased. MaR1-pretreated mice reduced the activation of pancreatic NF-κB and decreased the severity of pancreatic and lung-related injuries. These results confirm that MaR1 alleviated inflammation of the pancreas and lung by inhibiting the activity of NF-κB in experimentally induced acute pancreatitis and exerted anti-inflammatory effects. These findings suggest that MaR1 could be a new and useful drug in the treatment of SAP.NEW & NOTEWORTHY These results provided us evidence to confirm that maresin 1 (MaR1) can alleviate inflammation of the pancreas and lung by inhibiting the activity of NF-κB in experimental induced acute pancreatitis and exerts certain anti-inflammatory effects. These findings suggest that MaR1 could be a new and useful drug in the treatment of severe acute pancreatitis.

Oxidative stress induces apoptosis via calpain- and caspase-3-mediated cleavage of ATM in pancreatic acinar cells

Oxidative stress-induced DNA cleavage and apoptosis in pancreatic acinar cells has been implicated in the pathogenesis of acute pancreatitis. Thus, an efficient DNA repair process is key to prevention of apoptotic pancreatic acinar cell death. Ataxia telangiectasia mutated (ATM), a sensor of DNA breaks, functions by recruiting DNA repair proteins to initiate the DNA repair process. In the present study, we investigated whether H₂O₂ produced by the action of glucose oxidase on α-D-glucose (G/GO) induces apoptosis in pancreatic acinar AR42J cells through an alteration of the level of ATM. As a result, G/GO induced apoptosis by promoting a loss of cell viability, increase in Bax, decrease in Bcl-2, cleavage of poly (ADP-ribose) polymerase (PARP) and fragmentation of DNA. In addition, ATM cleavage along with elevated levels of calpain and caspase-3 activity was induced by G/GO. By using ATM siRNA, we demonstrated that reduction in ATM levels enhanced G/GO-induced apoptosis. Moreover, inhibition of calpain activity by calpeptin or calpastatin, or by inhibition of caspase-3 with z-DEVD, suppressed G/GO-induced apoptosis and ATM cleavage. Collectively, these findings suggest that proteolysis of ATM is the underlying mechanism of apoptosis of pancreatic acinar cells caused by exposure to oxidative stress.

New insights into acute pancreatitis

The incidence of acute pancreatitis continues to increase worldwide, and it is one of the most common gastrointestinal causes for hospital admission in the USA. In the past decade, substantial advancements have been made in our understanding of the pathophysiological mechanisms of acute pancreatitis. Studies have elucidated mechanisms of calcium-mediated acinar cell injury and death and the importance of store-operated calcium entry channels and mitochondrial permeability transition pores. The cytoprotective role of the unfolded protein response and autophagy in preventing sustained endoplasmic reticulum stress, apoptosis and necrosis has also been characterized, as has the central role of unsaturated fatty acids in causing pancreatic organ failure. Characterization of these pathways has led to the identification of potential molecular targets for future therapeutic trials. At the patient level, two classification systems have been developed to classify the severity of acute pancreatitis into prognostically meaningful groups, and several landmark clinical trials have informed management strategies in areas of nutritional support and interventions for infected pancreatic necrosis that have resulted in important changes to acute pancreatitis management paradigms. In this Review, we provide a summary of recent advances in acute pancreatitis with a special emphasis on pathophysiological mechanisms and clinical management of the disorder.

TSG-6 secreted by human adipose tissue-derived mesenchymal stem cells ameliorates severe acute pancreatitis via ER stress downregulation in mice

Background

Through recent studies, the onset of acute pancreatitis in pancreatic acinar cells (PACs) and the regulatory role of PACs in severe acute pancreatitis (SAP) have been revealed. During the early stages of pancreatitis, the endoplasmic reticulum (ER) in PACs undergoes significant changes, including swelling and vacuolization. In response to an increase in the extracellular stress in ER, PACs lose their functions, leading to cell apoptosis and inflammation response. The beneficial effects of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) on SAP have been well documented in previous studies. However, the underlying mechanism of their action remains controversial.

Methods

In this study, the therapeutic effects of intraperitoneally administered hAT-MSCs in a caerulein (50 μg/kg)- and lipopolysaccharide (LPS) (10 mg/kg)-co-induced SAP mouse model were evaluated. Inflammatory response and ER stress were measured in pancreatic tissue samples, and the beneficial effects were evaluated through quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blot, and immunofluorescence analysis.

Results

Inflammatory response and ER stress were ameliorated following hAT-MSC injection, and the beneficial effects were observed in the absence of significant engraftment of hAT-MSCs. hAT-MSCs transfected with siRNA-targeting tumour necrosis factor-α-induced gene/protein 6 (TSG-6) were unable to inhibit ER stress and inflammation. In addition, TSG-6 from hAT-MSCs significantly suppressed ER stress-induced apoptosis and nuclear factor kappa B (NF-κB) activity in SAP model mice.

Conclusions

TSG-6 secreted by hAT-MSCs protects PACs in SAP model mice via the inhibition of ER stress, as well as inflammatory responses. This study has revealed a new area for ER stress-targeted therapy in SAP patients.

Graphical abstract

Electronic supplementary material

The online version of this article (10.1186/s13287-018-1009-8) contains supplementary material, which is available to authorized users.