The causality between use of glucocorticoids and risk of pancreatitis: a Mendelian randomization study.

Background and aim: To date, the association between glucocorticoid use and the risk of pancreatitis remains controversial. The aim of this study was the investigation of this possible relationship. Methods: We carried out a two-sample Mendelian randomization (MR) analysis using GWAS data from European ancestry, East Asian descendants and the FinnGen Biobank Consortium to evaluate this potential causal relationship. Genetic variants associated with glucocorticoid use were selected based on genome-wide significance (p < 5×10-8). Results: Our MR analysis of European ancestry data revealed no significant causal relationship between glucocorticoid use and AP (IVW: OR=1.084, 95% CI= 0.945-1.242, P=0.249; MR-Egger: OR=1.049, 95% CI= 0.686-1.603, P=0.828; weighted median: OR=1.026, 95% CI= 0.863-1.219, P=0.775) or CP (IVW: OR=1.027, 95% CI= 0.850-1.240, P=0.785; MR-Egger: OR= 1.625, 95% CI= 0.913-2.890, P= 0.111; weighted median: OR= 1.176, 95% CI= 0.909-1.523, P= 0.218). Sensitivity analyses, including MR-Egger and MR-PRESSO, indicated no evidence of pleiotropy or heterogeneity, confirming the robustness of our findings. Multivariable MR analysis adjusted for alcohol consumption, BMI, cholelithiasis and C-reactive protein levels supported these findings. Replicated analysis was performed on datasets from the FinnGen Biobank Consortium and East Asian descendants, and similar results were obtained. Conclusions: This MR analysis suggests that there is no causal association between glucocorticoid use and the risk of pancreatitis.

mTORC2 knockdown mediates lipid metabolism to alleviate hyperlipidemic pancreatitis through PPARα.

Hyperlipidemic pancreatitis (HP) is an inflammatory injury of the pancreas triggered by elevated serum triglyceride (TG) levels. The mechanistic target of rapamycin (mTOR) signaling pathway plays a crucial role in regulating lipid homeostasis and inflammation. This study aimed to investigate whether the activity of mTOR complex 2 (mTORC2) affects the progression of HP and its underlying mechanisms. In vivo, a high-fat diet and retrograde administration of sodium taurocholate were employed to establish the HP models in rats, with pancreatic tissue pathology evaluated. The expression of Rictor and peroxisome proliferator-activator receptor (PPAR) was examined. The serum levels of TG, fatty acid metabolites, inflammatory and lipid metabolism-related factors were determined. In vitro, pancreatic acinar cells (PACs) were exposed to palmitic acid and cholecystokinin-8. PAC apoptosis, pyroptosis, and ferroptosis were assessed. In the HP models, rats and PACs exhibited upregulated Rictor and downregulated PPARα, and Rictor knockdown promoted PPARα expression. In vivo, Rictor knockdown decreased the serum levels of TG, α-amylase, total cholesterol, low-density lipoprotein cholesterol, lactate dehydrogenase, and inflammatory factors, while increasing high-density lipoprotein cholesterol levels. Rictor knockdown increased ACOX1 and CPT1α and decreased SREBP-1, CD36, SCD1, ACLY, and ACACA. Rictor knockdown reduced damage to pancreatic tissue structure. In vitro, Rictor knockdown inhibited PAC apoptosis, pyroptosis, and ferroptosis. Treatment with the PPARα antagonist GW6471 abolished the beneficial effects of Rictor knockdown. Rictor/mTORC2 deficiency reduces serum TG levels, maintains lipid homeostasis, and suppresses inflammation by inhibiting PPARα expression. Weakening mTORC2 activity holds promise as a novel therapeutic strategy for HP.

Regulatory axis of circular RNA DTNB, microRNA-485-5p, and myeloid cell leukemia 1 attenuates inflammation and apoptosis in caerulein-treated AR42J cells.

Acute pancreatitis (AP) is an inflammatory disease of the pancreas and the main cause of hospital admissions for gastrointestinal diseases. Here, the work studied the circular RNA DTNB/microRNA-485-5p/MCL1 axis in AP and hoped to unravel the related mechanism. Caerulein exposure replicated an AP model in AR42J cells, and caerulein-mediated expression of circDTNB, miR-485-5p, and MCL1 was recorded. After exposure, cells were intervened with transfection plasmids and tested for LDH release, apoptosis, and inflammation. To determine the interwork of circDTNB, miR-485-5p, and MCL1, prediction results and verification experiments were conducted. Caerulein exposure reduced circDTNB and MCL1, while elevated miR-485-5p levels in AR42J cells. Upregulating circDTNB protected AR42J cells from caerulein-induced LDH cytotoxicity, apoptosis, and inflammation, but circDTNB upregulation-induced protections could be muffled by inhibiting MCL1. On the contrary, downregulating circDTNB further damaged AR42J cells under caerulein exposure, however, this phenomenon could be partially rescued after silencing miR-485-5p. miR-485-5p was mechanistically verified to be a target of circDTNB to mediate MCL1. Overall, the circDTNB/miR-485-5p/MCL1 axis protects inflammatory response and apoptosis in caerulein-exposed AR42J cells, promisingly identifying circDTNB as a novel molecule for AP treatment.

Protective effects of forsythoside A against severe acute pancreatitis- induced brain injury in mice.

OBJECTIVES: This study aimed to evaluate the therapeutic effects of forsythoside A (FA) on brain injury induced by severe acute pancreatitis (SAP) using a murine model. METHODS: Mice were induced with 3.5 % sodium taurocholate to model SAP-induced brain injury (SAP-IBI) and were randomly assigned to four distinct treatment regimens: the SAP-IBI model group (SAP-IBI), low-dose FA treatment group (FA L+SI), middle-dose FA treatment group (FA M+SI), and high-dose FA treatment group (FA H+SI). A sham-operation group (SO) served as a negative control. Serum levels of interleukin-1ß (IL-1ß) and IL-18 were quantified via ELISA, and serum amylase levels were assessed using optical turbidimetry. mRNA expression levels of AIM2, ASC, Caspase-1, and GAPDH in hippocampal brain tissue were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Protein levels of NLRP3, GSDMD, IL-1ß, and IL-18 in hippocampal brain tissue were evaluated using Western blotting. Neurological function in surviving mice was assessed through modified neurological severity scores (mNSS). Transmission electron microscopy (TEM) provided ultrastructural analysis of the hippocampus. Additionally, water content and pathological changes in hippocampal brain tissue were examined 24 hours post-operation, along with other relevant indicators. RESULTS: At 24 hours post-operation, the FA H+SI group exhibited significantly reduced levels of serum amylase, IL-1ß, and IL-18, along with decreased expression of AIM2, ASC, and Caspase-1 mRNA. Furthermore, NLRP3 protein levels, water content, pancreas and hippocampal brain pathological scores, and mNSS were significantly lower compared to the SAP-IBI group (P<0.01). CONCLUSIONS: FA demonstrates protective effects against SAP-IBI in mice, suggesting potential therapeutic benefits.

The incidence of acute pancreatitis with GLP-1 receptor agonist therapy in individuals with a known history of pancreatitis.

Glucagon-like peptide-1 receptor agonists (GLP-1RA) have been reported to increase the risk of acute pancreatitis (AP). This real-world study did not observe a higher frequency of AP with GLP-1RA exposure in adults with T2D and a prior history of AP regardless of etiology.

Pancreatitis and Pancreatic Cancer Risk Among Patients With Type 2 Diabetes Receiving Dipeptidyl Peptidase 4 Inhibitors: An Updated Meta-Analysis of Randomized Controlled Trials.

PURPOSE: This meta-analysis sought to assess the relationship between dipeptidyl peptidase-4 inhibitors (DPP-4) and the risk of pancreatitis and pancreatic cancer by synthesizing data from randomized, controlled trials, in light of the conflicting findings from observational studies and previous meta-analyses. METHODS: Cochrane, Embase, ClinicalTrials.gov, and PubMed databases that compared the use of DPP-4 inhibitors and that reported pancreatitis and pancreatic cancer events in patients with diabetes mellitus Type 2 (T2DM) were searched using specific terms. Studies were included if they satisfied the following inclusion criteria: They were randomized trials comparing DPP-4 inhibitors use in patients with T2DM; The study's duration was longer than 24 weeks; And they reported pancreatitis and pancreatic cancer events. Stata 15 MP was used to analyze the data, and odds ratios (OR) with 95% confidence intervals (CI) were used to represent the results. FINDINGS: A total of 81,737 participants with T2DM were included in the analysis. The results showed that during a mean follow-up period of 24 to 520 weeks, The use of DPP-4 inhibitors was not associated with an increased risk of pancreatitis (Peto-OR 0.97; 95% CI: 0.74, 1.27) or pancreatic cancer (Peto-OR = 0.88; 95% CI: 0.59, 1.30). IMPLICATIONS: Current evidence fails to validate a significant correlation between DPP-4 therapy and pancreatitis or pancreatic cancer. However, subgroup analyses showed that sitagliptin was associated with a significant reduction in pancreatitis risk compared to the control group; furthermore, when comparing different types of control medications, a significant decrease in pancreatic cancer risk was observed among DPP-4 users compared to GLP-1 users.

Secretagogue-induced pancreatitis in mice devoid of chymotrypsin.

The serine protease chymotrypsin protects the pancreas against pancreatitis by degrading trypsinogen, the precursor to the digestive protease trypsin. Taking advantage of previously generated mouse models with either the Ctrb1 gene (encoding chymotrypsin B1) or the Ctrl gene (encoding chymotrypsin-like protease) disrupted, here we generated the novel Ctrb1-del × Ctrl-KO strain in the C57BL/6N genetic background, which harbors a naturally inactivated Ctrc gene (encoding chymotrypsin C). The newly created mice are devoid of chymotrypsin, yet the animals develop normally, breed well, and show no spontaneous phenotype, indicating that chymotrypsin is dispensable under laboratory conditions. When given cerulein, the Ctrb1-del × Ctrl-KO strain exhibited markedly increased intrapancreatic trypsin activation and more severe acute pancreatitis, relative to wild-type C57BL/6N mice. After the acute episode, Ctrb1-del × Ctrl-KO mice spontaneously progressed to chronic pancreatitis, whereas C57BL/6N mice recovered rapidly. The cerulein-induced pancreas pathology in Ctrb1-del × Ctrl-KO mice was highly similar to that previously observed in Ctrb1-del mice; however, trypsin activation was more robust and pancreatitis severity was increased. Taken together, the results confirm and extend prior observations demonstrating that chymotrypsin safeguards the pancreas against pancreatitis by limiting pathologic trypsin activity. In mice, the CTRB1 isoform, which constitutes about 90% of the total chymotrypsin content, is responsible primarily for the anti-trypsin defenses and protection against pancreatitis; however, the minor isoform CTRL also contributes to an appreciable extent.NEW & NOTEWORTHY Chymotrypsins defend the pancreas against the inflammatory disorder pancreatitis by degrading harmful trypsinogen. This study demonstrates that mice devoid of pancreatic chymotrypsins are phenotypically normal but become sensitized to secretagogue hyperstimulation and exhibit increased intrapancreatic trypsin activation, more severe acute pancreatitis, and rapid progression to chronic pancreatitis. The observations confirm and extend the essential role of chymotrypsins in pancreas health.

Certolizumab Has Favorable Efficacy on Preventing Pancreas and Target Organs Damage in Acute Pancreatitis.

OBJECTIVE: It was targeted to assess the efficacy of certolizumab on pancreas and target organs via biochemical parameters and histopathologic scores in experimental acute pancreatitis (AP). MATERIALS AND METHODS: Forty male Sprague Dawley rats were divided into the following 5 equal groups: group 1 (sham group), group 2 (AP group), group 3 (AP + low-dose certolizumab group), group 4 (AP + high-dose certolizumab group), and group 5 (placebo group). Rats in all groups were sacrificed 24 hours after the last injection and amylase, tumor necrosis factor α, transforming growth factor ß, interleukin 1ß, malondialdehyde, superoxide dismutase, and glutathione peroxidase levels were studied in blood samples. Histopathological investigation of both the pancreas and target organs (lungs, liver, heart, kidneys) was performed by a pathologist blind to the groups. In silico analysis were also accomplished. RESULTS: The biochemical results in the certolizumab treatment groups were identified to be significantly favorable compared to the AP group (P < 0.001). The difference between the high-dose group (group 4) and low-dose treatment group (group 3) was found to be significant in terms of biochemical parameters and histopathological scores (P < 0.001). In terms of the effect of certolizumab treatment on the target organs (especially on lung tissue), the differences between the low-dose treatment group (group 3) and high-dose treatment group (group 4) with the AP group (group 2) were significant. CONCLUSIONS: Certolizumab has favorable protective effects on pancreas and target organs in AP. It may be a beneficial agent for AP treatment and may prevent target organ damage.

Incretin mimetics and acute pancreatitis: enemy or innocent bystander?

PURPOSE OF REVIEW: The incretin enhancers and mimetics, including dipeptidyl peptidase-4 (DPP-4) inhibitors, GLP-1 receptor agonists (GLP-1RA) and GLP-1/GIP co-agonists, have become mainstays in the treatment of type 2 diabetes (T2D). Recently, the approval of certain GLP-1RA and GLP-1/GIP co-agonists for the treatment of obesity has broadened their popularity and use. In this review, we summarize the evidence for an association of these drugs with acute pancreatitis and other adverse events of special interest to gastroenterologists. RECENT FINDINGS: In addition to pancreatic islets, GLP-1 receptors are expressed in the exocrine cells of the pancreas. There is inconsistent evidence for an association of DPP-4 inhibitors, GLP-1RA and co-agonists with risk for acute pancreatitis in individual trials. Meta-analyses of long-term randomized controlled trials indicate a small risk of acute pancreatitis associated with DPP-4 inhibitors but not GLP-1RA or co-agonists. Cholecystitis and cholelithiasis may be more common among those treated with GLP-1RA and GLP-1/GIP co-agonists. There is no evidence that any of these drugs are associated with an increased risk of pancreatic cancer. SUMMARY: While drugs that leverage the incretin system are increasingly being used for patients with T2D and obesity, caution in warranted in those with a history of pancreatitis and gallbladder disease.

RASEF/Rab45 regulates the formation and sorting of zymogen granules and secretion of digestive enzymes by pancreatic acinar cells.

The pancreas is a glandular organ with both endocrine and exocrine functions. Researchers have investigated the roles of several Rab proteins, which are major regulators of membrane trafficking, in pancreatic exocytosis of zymogen granules in exocrine cells, also known as acinar cells. However, detailed molecular mechanisms mediated by Rab proteins are not fully understood. RASEF/Rab45 is an atypical Rab GTPase that contains N-terminal EF-hand and coiled-coil domains, as well as a C-terminal Rab-GTPase domain. In this study, we investigated the in vivo role of RASEF in pancreatic acinar cells using RASEF-knockout (KO) mice. Morphological analyses revealed that pancreatic acinar cells in RASEF-KO mice had an increased number of zymogen granules and abnormal formations of organelles, such as the endoplasmic reticulum (ER) and lysosomes. Biochemical analyses showed that ER proteins were decreased, but digestive enzymes were increased in the RASEF-KO pancreas. Moreover, trypsinogen was activated and co-localized with the endo-lysosomal marker LAMP1 in RASEF-KO pancreas. Upon cerulein administration to induce acute pancreatitis, impaired enzyme release from the pancreas was observed in the serum of RASEF-KO mice. These findings suggest that RASEF likely regulates the formation and sorting of zymogen granules and secretion of digestive enzymes by pancreatic acinar cells.

Aging- and alcohol-associated spatial transcriptomic signature in mouse acute pancreatitis reveals heterogeneity of inflammation and potential pathogenic factors.

The rapidly aging population is consuming more alcohol, leading to increased alcohol-associated acute pancreatitis (AAP) with high mortality. However, the mechanisms remain undefined, and currently there are no effective therapies available. This study aims to elucidate aging- and alcohol-associated spatial transcriptomic signature by establishing an aging AAP mouse model and applying Visium spatial transcriptomics for understanding of the mechanisms in the context of the pancreatic tissue. Upon alcohol diet feeding and caerulein treatment, aging mice (18 months) developed significantly more severe AAP with 5.0-fold increase of injury score and 2.4-fold increase of amylase compared to young mice (3 months). Via Visium spatial transcriptomics, eight distinct tissue clusters were revealed from aggregated transcriptomes of aging and young AAP mice: five acinar, two stromal, and one islet, which were then merged into three clusters: acinar, stromal, and islet for the comparative analysis. Compared to young AAP mice, > 1300 differentially expressed genes (DEGs) and approximately 3000 differentially regulated pathways were identified in aging AAP mice. The top five DEGs upregulated in aging AAP mice include Mmp8, Ppbp, Serpina3m, Cxcl13, and Hamp with heterogeneous distributions among the clusters. Taken together, this study demonstrates spatial heterogeneity of inflammatory processes in aging AAP mice, offering novel insights into the mechanisms and potential drivers for AAP development. KEY MESSAGES: Mechanisms regarding high mortality of AAP in aging remain undefined. An aging AAP mouse model was developed recapturing clinical exhibition in humans. Spatial transcriptomics identified contrasted DEGs in aging vs. young AAP mice. Top five DEGs were Mmp8, Ppbp, Serpina3m, Cxcl13, and Hamp in aging vs. young AAP mice. Our findings shed insights for identification of molecular drivers in aging AAP.

The correlation of asparaginase enzyme activity levels after PEG-asparaginase administration with clinical characteristics and adverse effects in Chinese paediatric patients with acute lymphoblastic leukaemia.

Studies on asparaginase enzyme activity (AEA) monitoring in Chinese patients receiving PEG-asparaginase remain limited. We monitored AEA in paediatric patients diagnosed with acute lymphoblastic leukaemia (ALL) and treated according to the Chinese Children's Cancer Group study protocols, CCCG-ALL-2015/CCCG-ALL-2020 protocols. We measured the AEA at days 7 ± 1 and 14 ± 1 and analysed their association with patient characteristics and PEG-asparaginase-related adverse effects (AEs). We measured 2147 samples from 329 patients. Mean AEA levels (interquartile range) were 931 iu/L (654-1174 iu/L) at day 7 ± 1 and 664 iu/L (463-860 iu/L) at day 14 ± 1. The AEA levels were higher in younger children and increased with the cumulative dose numbers. PEG-asparaginase inactivation rate was 19.1%, and the silent inactivation (SI) rate was 12.5%. Nine patients were identified with allergic-like reactions. Hypofibrinogenaemia, hypertriglyceridaemia, pancreatitis and thrombosis were associated with older age, whereas hypoglycaemia was associated with younger age. The risk of hypertriglyceridaemia and hypoglycaemia increased with cumulative dose numbers of PEG-asparaginase. Except for hypofibrinogenaemia, elevated AEA levels did not increase the risk of PEG-asparaginase-related AEs. Drug monitoring can be utilized as guidance for treatment decision-making. Individualizing asparaginase doses do not reduce toxicities. The treatment target of PEG-asparaginase remains to achieve sustained and adequate activity.

Clinical characteristics, treatment and outcome of pembrolizumab-induced acute pancreatitis.

Acute pancreatitis (AP) is a rare adverse event of pembrolizumab with unclear clinical features. This study investigated the clinical features of pembrolizumab-induced AP to provide a reference for prevention and treatment. Case reports, case series and clinical studies of pembrolizumab-induced AP were collected by searching Chinese and English databases up to January 31, 2024. Thirty-one patients were included, with a median age of 59 years (range 39, 82). The median time from administration to onset of AP was 5.05 months (range 0.5, 16) and the median cycle was 7 cycles (range 1, 35). Twenty-two (71.0%) patients had elevated pancreatic amylase with a median value of 860 IU/L (range 105-12562), and 16 (51.6%) patients had elevated lipase with a median value of 282 IU/L (range 153-1034). Pancreatic biopsy showed neutrophil infiltration (9.7%) and lymphocyte infiltration (6.5%). Immunohistochemical staining showed CD8 dominated inflammatory infiltration (6.5%). The computed tomography showed diffuse enlargement (51.6%) and focal enlargement (51.6%) of the pancreas. Endoscopic ultrasound showed enlarged hypoechoic pancreas(16.1%). PET/CT showed increased FDG uptake (16.1%). The magnetic resonance cholangial pancreatography showed narrowing of main pancreatic duct (12.9%). AP symptoms and pancreatic enzymes improved after discontinuation of pembrolizumab and administration of steroids and infliximab. Clinicians should be aware that AP is a rare adverse reaction to pembrolizumab. Pembrolizumab induced AP can be initiated with steroids for control, and infliximab can be initiated with steroid-refractory AP.

Acute pancreatitis in an ulcerative colitis patient treated with vedolizumab and budesonide.

Acute pancreatitis (AP) is a sudden inflammation of the pancreas which often manifests as a mild disease but can be associated with high morbidity and mortality. Drug-induced AP is rare and most likely underdiagnosed. Vedolizumab is a human monoclonal antibody with gut-selective integrin antagonist effect, and it is used for treatment of inflammatory bowel disease (IBD). Budesonid is a glucocorticoid which is released in the colon and it is also used in IBD treatment. This is a case report where vedolizumab or budesonide caused acute pancreatitis in a young man with ulcerative colitis.

Role of ulinastatin in steroid-induced pancreatitis.

Steroid-induced acute pancreatitis is a rare form of pancreatitis that requires intensive care and has a high morbidity and mortality rate as there is no specific treatment. Management of steroid-induced pancreatitis is generally non-specific and supportive. Here, we are presenting a man in his 40s presented with epigastric pain, fever and vomiting. The patient was diagnosed case of rheumatoid arthritis, for which he was receiving regular 5 mg oral prednisolone therapy. Based on history, and clinical, biochemical and radiological imaging a diagnosis of steroid-induced pancreatitis was made, which was successfully managed with the help of ulinastatin and other supportive treatments. A serine protease inhibitor like ulinastatin may be used early in the clinical management of steroid-induced pancreatitis.

S1PR2 participates in intestinal injury in severe acute pancreatitis by regulating macrophage pyroptosis.

Background: Severe acute pancreatitis (SAP) is an inflammatory disorder affecting the gastrointestinal system. Intestinal injury plays an important role in the treatment of severe acute pancreatitis. In this study, we mainly investigated the role of S1PR2 in regulating macrophage pyroptosis in the intestinal injury of severe acute pancreatitis. Methods: The SAP model was constructed using cerulein and lipopolysaccharide, and the expression of S1PR2 was inhibited by JTE-013 to detect the degree of pancreatitis and intestinal tissue damage in mice. Meanwhile, the level of pyroptosis-related protein was detected by western blot, the level of related mRNA was detected by PCR, and the level of serum inflammatory factors was detected by ELISA. In vitro experiments, LPS+ATP was used to construct the pyroptosis model of THP-1. After knockdown and overexpression of S1PR2, the pyroptosis proteins level was detected by western blot, the related mRNA level was detected by PCR, and the level of cell supernatant inflammatory factors were detected by ELISA. A rescue experiment was used to verify the sufficient necessity of the RhoA/ROCK pathway in S1PR2-induced pyroptosis. Meanwhile, THP-1 and FHC were co-cultured to verify that cytokines released by THP-1 after damage could regulate FHC damage. Results: Our results demonstrated that JTE-013 effectively attenuated intestinal injury and inflammation in mice with SAP. Furthermore, we observed a significant reduction in the expression of pyroptosis-related proteins within the intestinal tissue of SAP mice upon treatment with JTE-013. We confirmed the involvement of S1PR2 in THP-1 cell pyroptosis in vitro. Specifically, activation of S1PR2 triggered pyroptosis in THP-1 cells through the RhoA/ROCK signaling pathway. Moreover, it was observed that inflammatory factors released during THP-1 cell pyroptosis exerted an impact on cohesin expression in FHC cells. Conclusion: The involvement of S1PR2 in SAP-induced intestinal mucosal injury may be attributed to its regulation of macrophage pyroptosis.

Myricetin ameliorates the severity of pancreatitis in mice by regulating cathepsin B activity and inflammatory cytokine production.

Cathepsin B (CTSB) and inflammatory cytokines are critical in initiating and developing pancreatitis. Calcineurin, a central calcium (Ca2+)-responsive signaling molecule, mediates acinar cell death and inflammatory responses leading to pancreatitis. However, the detailed mechanisms for regulating CTSB activity and inflammatory cytokine production are unknown. Myricetin (MC) exhibits various biological activities, including anti-inflammatory effects. Here, we aimed to investigate MC effects on pancreatitis and the underlying mechanisms. Prophylactic and therapeutic MC treatment ameliorated the severity of cerulein-, L-arginine-, and PDL-induced acute pancreatitis (AP). The inhibition of CTSB activity by MC was mediated via decreased calcineurin activity and macrophage infiltration, not neutrophils infiltration, into the pancreas. Additionally, calcineurin activity inhibition by MC prevented the phosphorylation of Ca2+/CaM-dependent protein kinase kinase 2 (CaMKK2) during AP, resulting in the inhibition of CaMKIV phosphorylation and adenosine monophosphate-activated protein kinase (AMPK) dephosphorylation. Furthermore, MC reduced nuclear factor-κB activation by modulating the calcineurin-CaMKIV-IKKα/ß-Iκ-Bα and calcineurin-AMPK-sirtuin1 axes, resulting in reduced production of tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6. Our results showed that MC alleviated AP severity by inhibiting acinar cell death and inflammatory responses, suggesting that MC as a calcineurin and CaMKK2 signaling modulator may be a potential treatment for AP.

Soluble Fibrinogen-Like Protein 2 Downregulation and Th17/Treg Imbalance in a Taurocholate-Induced Murine Experimental Model of Severe Acute Pancreatitis.

BACKGROUND: Severe acute pancreatitis (SAP) is associated with tremendous systemic inflammation, T-helper 17 (Th17) cells, and regulatory T (Treg) cells play an essential role in the inflammatory responses. Meanwhile, soluble fibrinogen-like protein 2 (Sfgl2) is a critical immunosuppressive effector cytokine of Treg cells and modulates immune responses. However, the impact of SAP induction on Sfgl2 expression and the role of Sfgl2 in immunomodulation under SAP conditions are largely unknown. METHODS: A taurocholate-induced mouse SAP model was established. The ratios of CD4+CD25+Foxp3+ Treg cells or CD4+IL-17+ Th17 cells in blood and pancreatic tissues as well as surface expression of CD80, CD86, and major histocompatibility complex class II (MHC-II) were determined by flow cytometry. Gene mRNA expression was determined by qPCR. Serum amylase and soluble factors were quantitated by commercial kits. Bone marrow-derived dendritic cells (DCs) were generated, and NF-κB/p65 translocation was measured by immunofluorescence staining. RESULTS: SAP induction in mice decreased the Th17/Treg ratio in the pancreatic tissue and increased the Th17/Treg ratio in the peripheral blood. In addition, SAP was associated with a reduced level of Sfgl2 in the pancreatic tissue and blood: higher levels of serum IL-17, IL-2, IFN-α, and TNF-α, and lower levels of serum IL-4 and IL-10. Furthermore, the SAP-induced reduction in Sfgl2 expression was accompanied by dysregulated maturation of bone marrow-derived DCs. CONCLUSIONS: SAP causes reduced Sfgl2 expression and Th17/Treg imbalance, thus providing critical insights for the development of Sfgl2- and Th17/Treg balance-targeted immunotherapies for patients with SAP.

Pinocembrin's protective effect against acute pancreatitis in a rat model: The correlation between TLR4/NF-κB/NLRP3 and miR-34a-5p/SIRT1/Nrf2/HO-1 pathways.

BACKGROUND: Acute pancreatitis (APS) is a prevalent acute pancreatic inflammation, where oxidative stress, inflammatory signaling pathways, and apoptosis activation contribute to pancreatic injury. METHODS: Pinocembrin, the predominant flavonoid in propolis, was explored for its likely shielding effect against APS provoked by two intraperitoneal doses of L-arginine (250 mg / 100 g) in a rat model. RESULTS: Pinocembrin ameliorated the histological and immunohistochemical changes in pancreatic tissues and lowered the activities of pancreatic amylase and lipase that were markedly elevated with L-arginine administration. Moreover, pinocembrin reinstated the oxidant/antioxidant equilibrium, which was perturbed by L-arginine, and boosted the pancreatic levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Pinocembrin markedly reduced the elevation in serum C-reactive protein (CRP) level induced by L-arginine. Additionally, it decreased the expression of high motility group box protein 1 (HMGB1), toll-like receptor 4 (TLR4), nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and NOD-like receptor (NLR) Family Pyrin Domain Containing 3 (NLRP3) inflammasome in the pancreas. Furthermore, it also reduced myeloperoxidase (MPO) activity. Pinocembrin markedly downregulated miR-34a-5p expression and upregulated the protein levels of peroxisome proliferator-activated receptor alpha (PPAR-α) and Sirtuin 1 (SIRT1) and the gene expression level of the inhibitor protein of NF-κB (IκB-α), along with normalizing the Bax/Bcl-2 ratio. CONCLUSIONS: Pinocembrin notably improved L-arginine-induced APS by its antioxidant, anti-inflammatory, and anti-apoptotic activities. Pinocembrin exhibited a protective role in APS by suppressing inflammatory signaling via the TLR4/NF-κB/NLRP3 pathway and enhancing cytoprotective signaling via the miR-34a-5p/SIRT1/Nrf2/HO-1 pathway.