Calpain Inhibitor Calpeptin Improves Pancreatic Fibrosis in Mice with Chronic Pancreatitis by Inhibiting the Activation of Pancreatic Stellate Cells.

BACKGROUND: Pancreatic fibrosis is a hallmark feature of chronic pancreatitis (CP), resulting in persistent damage to the pancreas. The sustained activation of pancreatic stellate cells (PSCs) plays a pivotal role in the progression of pancreatic fibrosis and is a major source of extracellular matrix (ECM) deposition during pancreatic injury. METHODS: Calpain is a calcium-independent lysosomal neutral cysteine endopeptidase and was found to be correlated to various fibrotic diseases. Studies have revealed that calpeptin, a calpain inhibitor, can improve the fibrosis process of multiple organs. This study investigated the effect of the calpain inhibitor, calpeptin, on fibrosis in experimental CP and activation of cultured PSCs in mice. CP was induced in mice by repeated injections of cerulein for four weeks in vivo, and the activation process of mouse PSCs was isolated and cultured in vitro. Then, the inhibitory effect of calpeptin on pancreatic fibrosis was confirmed based on the histological damage of CP, the expression of α-smooth muscle actin (α-SMA) and collagen-Iα1(Col1α1), and the decrease in mRNA levels of calpain-1 and calpain-2. RESULTS: In addition, it was revealed that calpeptin can inhibit the activation process of PSCs and induce significant PSCs apoptosis by downregulating the expression of calpain-1, calpain-2 and TGF-ß1, and the expression and phosphorylation of smad3 in vitro. CONCLUSION: These results suggest that the calpain inhibitor, calpeptin, plays a key role in the regulation of PSC activation by inhibiting the TGF-ß1/smad3 signaling pathway, which supports the potential of calpeptin as an inhibitor of pancreatic fibrosis in mice by interfering with calpain.

Qing Xia Jie Yi Formula granules alleviated acute pancreatitis through inhibition of M1 macrophage polarization by suppressing glycolysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Herbal formulas from Traditional Chinese Medicine are common and well-established practice for treating acute pancreatitis (AP) patients. However, little is known about their bioactive ingredients and mechanisms, such as their targets and pathways to inhibit inflammation. AIM OF THE STUDY: This study aimed to evaluate the effect of Qing Xia Jie Yi Formula (QXJYF) granules on AP and discuss the molecular mechanisms involved. MATERIALS AND METHODS: Major compounds in QXJYF granules were identified using UPLC-quadrupole-Orbitrap mass spectrometry (UPLC-Q-Orbitrap MS). The effect of QXJYF granules on experimental AP models both in vitro and in vivo, and detailed mechanisms were clarified. Two AP models were induced in mice by intraperitoneally injections of caerulein or L-arginine, and QXJYF granules were used to treat AP mice in vivo. Histological evaluation of pancreas and lung, serum amylase and lipase levels, serum inflammatory cytokines, inflammatory cell infiltration and macrophage phenotype were assessed. Bone marrow derived macrophages (BMDMs) were cultured and treated with QXJYF granules in vitro. BMDM phenotype and glycolysis levels were measured. Lastly, clinical effect of QXJYF granules on AP patients was verified. Predicted severe AP (pSAP) patients eligible for inclusion were assessed for enrollment. RESULTS: Nine major compounds were identified in QXJYF granules. Data showed that QXJYF granules significantly alleviated AP severity both in caerulein and L-arginine-induced AP models in vivo, pancreatic injury and inflammatory cell infiltration, systematic inflammation, lung injury and inflammatory cell infiltration were all improved after QXJYF treatment. QXJYF granules significantly reduced M1 macrophages during AP both in vivo and in vitro; besides, the mRNA expression levels of M1 genes such as inos, Tnfα, Il1ß and Il6 were significantly lower after QXJYF treatment in M1 macrophages. Mechanistically, we found that HK2, PFKFB3, PKM, LDHα levels were increased in M1 macrophages, but significantly decreased after QXJYF treatment. Clinical data indicated that QXJYF granules could significantly reduce CRP levels and shorten the duration of organ failure, thereby reducing the incidence of SAP and preventing pSAP patients from progressing to SAP. CONCLUSION: QXJYF granules alleviated AP through the inhibition of M1 macrophage polarization by suppressing glycolysis.

Predictive value of serum retinol binding protein in severity and complications of acute pancreatitis: a retrospective cohort study.

OBJECTIVES: Retinol binding protein (RBP) is associated with an increased risk of insulin resistance, metabolic syndrome, atherosclerosis and hypertension. This study aimed to evaluate serum RBP levels in patients with acute pancreatitis (AP). METHODS: The study included 1,871 AP patients, including 1,411 with mild AP (MAP), 244 with moderately severe AP (MSAP), and 186 with severe AP (SAP). Retrospective analysis was conducted on RBP concentrations and other clinical data of AP patients. RESULTS: AP patients were subgrouped by RBP level into low RBP (LRBP), normal RBP (NRBP), and high RBP (HRBP) groups. The LRBP group showed a significantly higher proportion of SAP patients than NRBP and HRBP groups. Additionally, the LRBP group had the highest BISAP and CTSI scores among the three groups; WBC and CRP levels in the NRBP group were significantly lower than those in the LRBP and HRBP groups. RBP was better at predicting acute necrotic collection (ANC) than other local complications, with an area under the curve (AUC) of 0.821. RBP was also an independent risk factor for acute lung injury (ALI) and ANC in AP patients. The AUC of RBP for predicting ALI was 0.829, with 30.45 mg/L as the optimal cutoff value, and the sensitivity and specificity were 59.70% and 96.50%, respectively. The AUC of RBP for predicting ANC was 0.821, with 28.35 mg/L as the optimal cutoff value, and the sensitivity and specificity were 61.20% and 95.50%, respectively. CONCLUSIONS: Serum RBP had predictive value for AP severity, local and systemic complications.

Corrigendum: Systematic characterization of the clinical relevance of KPNA4 in pancreatic ductal adenocarcinoma.

[This corrects the article DOI: 10.3389/fonc.2022.834728.].

The long-term efficacy of transoral incisionless fundoplication with Medigus Ultrasonic Surgical Endostapler (MUSE) for gastroesophageal reflux disease.

BACKGROUND: To evaluate the long-term efficacy of transoral incisionless fundoplication (TIF) with Medigus Ultrasonic Surgical Endostapler (MUSE) for gastroesophageal reflux disease (GERD). METHODS: A total of 16 patients with proton pump inhibitor-dependent gastroesophageal reflux disease had undergone TIF by MUSE in Shanghai General Hospital （Shanghai, China）from March 2017 to December 2018. Patients were followed up at 6 months, and the GERD-health-related quality of life (GERD-HRQL) questionnaire score, the GERD questionnaire (GERD-Q) score, high-resolution esophageal manometry (HREM) and 24 h esophageal pH parameters, the Hill grade of the gastroesophageal flap valve (GEFV) and daily Proton pump inhibitor (PPI) consumption before and after procedure were compared. Patients also were followed up at 3 years and 5 years using a structured questionnaire via phone which evaluated symptoms of reflux, dose of PPI medication and side effects. RESULTS: Follow-up data were collected from 13 patients, ranging from 38 to 63 months, 53 months on average. 10/13 patients reported symptomatic improvement and daily PPI consumption was stopped or halved in 11/13. After procedure, the mean scores of GERD-HRQL and GERD-Q were significantly increased. The mean DeMeester score, the mean acid exposure time percentage and the mean number of acid reflux episodes were significantly lower. The mean rest pressure at lower esophageal sphincter (LES) had no significant difference. CONCLUSION: TIF by MUSE has significant efficacy in the treatment of PPI-dependent GERD, which can improve symptoms and life quality of patients, and reduce the acid exposure time for long-term. Chictr.org.cn. TRIAL REGISTRATION: ChiCTR2000034350.

Endoplasmic reticulum stress promoted acinar cell necroptosis in acute pancreatitis through cathepsinB-mediated AP-1 activation.

Acinar cell death and inflammatory response are two important events which determine the severity of acute pancreatitis (AP). Endoplasmic reticulum (ER) stress and necroptosis are involved in this process, but the relationships between them remain unknown. Here, we analyzed the interaction between ER stress and necroptosis and the underlying mechanisms during AP. Experimental pancreatitis was induced in Balb/C mice by caerulein (Cae) and lipopolysaccharide (LPS) or L-arginine (L-Arg) in vivo, and pancreatic acinar cells were also used to follow cellular mechanisms during cholecystokinin (CCK) stimulation in vitro. AP severity was assessed by serum amylase, lipase levels and histological examination. Changes in ER stress, trypsinogen activation and necroptosis levels were analyzed by western blotting, enzyme-linked immunosorbent assay (ELISA), adenosine triphosphate (ATP) analysis or lactate dehydrogenase (LDH) assay. The protein kinase C (PKC)α -mitogen-activated protein kinase (MAPK) -cJun pathway and cathepsin B (CTSB) activation were evaluated by western blotting. Activating protein 1 (AP-1) binding activity was detected by electrophoretic mobility shift assay (EMSA). We found that ER stress is initiated before necroptosis in CCK-stimulated acinar cells in vitro. Inhibition of ER stress by 4-phenylbutyrate (4-PBA) can significantly alleviate AP severity both in two AP models in vivo. 4-PBA markedly inhibited ER stress and necroptosis of pancreatic acinar cells both in vitro and in vivo. Mechanistically, we found that 4-PBA significantly reduced CTSB maturation and PKCα-JNK-cJun pathway -mediated AP-1 activation during AP. Besides, CTSB inhibitor CA074Me markedly blocked PKCα-JNK-cJun pathway -mediated AP-1 activation and necroptosis in AP. However, pharmacologic inhibition of trypsin activity with benzamidine hydrochloride had no effect on PKCα-JNK-cJun pathway and necroptosis in CCK-stimulated pancreatic acinar cells. Furthermore, SR11302, the inhibitor of AP-1, significantly lowered tumor necrosis factor (TNF) α levels, and its subsequent receptor interacting protein kinases (RIP)3 and phosphorylated mixed lineagekinase domain-like (pMLKL) levels, ATP depletion and LDH release rate in CCK-stimulated pancreatic acinar cells. To sum up, all the results indicated that during AP, ER stress promoted pancreatic acinar cell necroptosis through CTSB maturation, thus induced AP-1 activation and TNFα secretion via PKCα-JNK-cJun pathway, not related with trypsin activity. These findings provided potential therapeutic target and treatment strategies for AP or other cell death-related diseases.

Dopamine D2 Receptor Signaling Attenuates Acinar Cell Necroptosis in Acute Pancreatitis through the Cathepsin B/TFAM/ROS Pathway.

Acute pancreatitis (AP) is an inflammatory disease that is associated with trypsinogen activation, mitochondrial dysfunction, cell death, and inflammation. Dopamine D2 receptor (DRD2) plays an essential role in alleviating AP, while it is unclear whether it is involved in regulating acinar cell necroptosis. Here, we found that DRD2 agonist quinpirole alleviated acinar cell necroptosis via inhibiting cathepsin B (CTSB). Moreover, CTSB inhibition by CA-074Me ameliorated AP severity by reducing necroptosis. Notably, knockdown of TFAM reversed the therapeutic effect of either quinpirole or CA-074Me. We identified a new mechanism that DRD2 signaling inhibited CTSB and promoted the expression of mitochondrial transcription factor A(TFAM), leading to reduction of ROS production in AP, which attenuated acinar cell necroptosis ultimately. Collectively, our findings provide new evidence that DRD2 agonist could be a new potential therapeutic strategy for AP treatment.

AXL and MERTK receptor tyrosine kinases inhibition protects against pancreatic necrosis via selectively limiting CXCL2-related neutrophil infiltration.

BACKGROUND: Acute pancreatitis (AP) was initiated within pancreatic parenchymal cells and sustained by uncontrolled inflammatory responses. AXL and MERTK receptor tyrosine kinases play a crucial role in negatively regulating the innate immunity. Therefore, this study aimed to investigate the role and underlying mechanism of AXL and MERTK in AP. METHODS: Experimental AP was induced by ten hourly intraperitoneal administration of caerulein in global, hematopoietic- and pancreas-specific Axl and Mertk deficient mice. Pancreatitis severity was assessed biochemically and histologically. Pancreatic transcriptomics and pancreatic infiltrating immune cells were profiled. Some mice were given R428, an antagonist of AXL and MERTK. AXL and MERTK in peripheral leukocytes were measured by flow cytometry. FINDINGS: The levels of AXL and MERTK in pancreatic tissue and pancreatic CD45+ cells were dynamically altered at 6 h and 12 h after the 1st injection of caerulein. Global and hematopoietic-specific, but not pancreas-specific deletion of Axl and Mertk protected against pancreatic necrosis and trypsinogen activation. Pancreatic transcriptomic analysis revealed that differentially expressed gene signatures were mainly related to metabolic and inflammatory pathways. Furthermore, deletion or inhibition of Axl and Mertk selectively inhibited pancreatic neutrophil infiltration, which was primarily related to CXCL2 secreted by pro-inflammatory macrophages. Increased levels of MERTK in peripheral leukocytes were correlated with more severe form of AP. INTERPRETATION: Our findings reveal that specific AXL/MERTK antagonist may be a novel and potential early treatment for AP and the levels of MERTK in peripheral leukocytes may be a promising biomarker for predicting pancreatic severity in patients with AP. FUNDING: National Natural Science Foundation of China, Shanghai Natural Science Foundation, a Shanghai Young Talent Award and a Shanghai Young Orient Scholar Award. RESEARCH IN CONTEXT: Evidence before this study Acute pancreatitis (AP) is a common inflammatory disorder of the exocrine pancreas, the severity of which was determined by the extent of pancreatic necrosis, with no targeted therapy. AP was initiated by signals within pancreatic parenchymal cells and sustained by uncontrolled innate immune responses. One of the three crucial regulatory roles for AXL and MERTK is to negatively regulate innate immune responses. Added value of this study Global and hematopoietic-, but not pancreas-specific Axl and Mertk deficiency protected against pancreatitis, primarily pancreatic necrosis. Deletion of Axl and Mertk selectively inhibited pancreatic neutrophil infiltration that was related to CXCL2 secreted by pro-inflammatory macrophages. AXL and MERTK antagonist similarly reduced pancreatitis severity via limiting CXCL2-mediated pancreatic neutrophil infiltration. Higher levels of MERTK, but not AXL in peripheral leukocytes were correlated with more severe form of acute pancreatitis. Implications of all the available evidence A specific AXL/MERTK antagonist may be a novel and potential early treatment for AP. The level of MERTK on peripheral leukocytes may be a promising biomarker for predicting disease severity in patients with AP.

Systematic Characterization of the Clinical Relevance of KPNA4 in Pancreatic Ductal Adenocarcinoma.

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with poor prognosis. Karyopherin subunit alpha 4 (KPNA4) is a nuclear transport factor and plays tumor-promoting roles in multiple cancers. However, the roles of KPNA4 in PDAC still remain unknown. This study investigated the prognostic value of KPNA4 and its potential functions in PDAC and tumor microenvironment. Methods: LinkedOmics was utilized to screen genes with survival significance in PDAC. KPNA4 expression was analyzed using multiple datasets and verified in PDAC cells and clinical samples by qRT-PCR and immunohistochemistry. Clinical correlation and survival analyses were conducted to identify the clinical significance and prognostic value of KPNA4 in PDAC patients. Subsequently, KPNA4 was knocked down in PDAC cell lines, and CCK-8, colony formation and wound healing assays were performed to test the functions of KPNA4 in vitro. Immune infiltration analysis was performed to explore the potential roles of KPNA4 in the tumor microenvironment of PDAC. Moreover, functional analyses were conducted to explore the underlying mechanism of KPNA4 in the progression of PDAC. Results: We found KPNA4 was significantly upregulated in PDAC cells and tissues. KPNA4 expression was associated with tumor progression in PDAC patients. Survival analyses further revealed that KPNA4 could act as an independent predictor of unfavorable survival for PDAC patients. KPNA4 knockdown suppressed the viability, colony formation and migration of PDAC cells. Moreover, KPNA4 was correlated with immunosuppressive cells infiltration and T cell exhaustion in the tumor microenvironment of PDAC. Finally, functional analyses indicated the association of KPNA4 with focal adhesion kinase (FAK) signaling, and KPNA4 silencing significantly decreased the expression of FAK and PD-L1. Conclusions: This study revealed that KPNA4 is an independent prognostic biomarker for PDAC and plays a tumor-promoting role by facilitating proliferation and migration of cancer cells and participating in immune infiltration, which may be mediated by FAK signaling and PD-L1 expression. These results provide a novel and potential therapeutic target for pancreatic cancer.

Reg4 regulates pancreatic regeneration following pancreatitis via modulating the Notch signaling.

Pancreatic regeneration after acute pancreatitis is critical in the normal restoration of pancreatic exocrine function, the inhibition of which can cause severe complications including pancreatic exocrine insufficiency. However, the regulators of pancreatic regeneration and the underlying mechanisms remain uncovered. Here, using the inducible Tet-on system, we found that regenerating family member 4 (Reg4) knockdown significantly impaired pancreatic regeneration after pancreatitis. Both acinar-to-ductal metaplasia and the resolution of pancreatitis during regeneration were affected by Reg4 knockdown. Further investigations confirmed that Reg4 exerted its function through regulating Notch activation both in vitro and in vivo. Our study revealed Reg4 as a new regulator and potential therapeutic target for pancreatic regeneration.

Inhibition of nicotinamide phosphoribosyltransferase protects against acute pancreatitis via modulating macrophage polarization and its related metabolites.

BACKGROUND & OBJECTIVES: Acute pancreatitis is a common inflammatory disorder of the exocrine pancreas with no specific therapy. Intracellular nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in nicotinamide adenine dinucleotide (NAD) salvage pathway, is involved in many inflammatory disorders. In this study, we investigated the role of NAMPT in experimental acute pancreatitis. METHODS: Acute pancreatitis was induced in mice using three disparate models: (1) caerulein hyperstimulation, (2) ethanol plus palmitoleic acid, and (3) retrograde biliopancreatic ductal infusion of sodium taurocholate. The NAMPT inhibitor FK866 and NAMPT downstream product nicotinamide mononucleotide (NMN) was administered. Serum and pancreas were collected and analyzed biochemically and histologically. Bone marrow derived macrophages were isolated, cultured with cytokines or pancreatic acini, then analyzed by quantitative PCR and non-targeted metabolomics. RESULTS: The levels of pancreatic NAMPT and NAD were down-regulated upon acute pancreatitis. NAMPT inhibitor FK866 suppressed M1 macrophage polarization while NMN boosted it. In co-culture of macrophages with acinar cells, inhibition of NAMPT prevented M1-like macrophage differentiation induced by injured pancreatic acini. The injured pancreatic acinar milieu induced a unique metabolic signature linked to macrophage polarization, and inhibition of NAMPT reversed these metabolites changes. Furthermore, NMN supplementation aggravated caerulein hyperstimulation pancreatitis and alcoholic pancreatitis, and inhibition of NAMPT protected against caerulein hyperstimulation, alcoholic and biliary acute pancreatitis and reducing pancreatic macrophage infiltration in vivo. CONCLUSIONS: NAMPT inhibition protects against acute pancreatitis via preventing M1 macrophage polarization and restoring the metabolites related to macrophage polarization and that NAMPT could be a promising therapeutic target for acute pancreatitis.

Activation of α7nACh receptor protects against acute pancreatitis through enhancing TFEB-regulated autophagy.

Acute pancreatitis (AP) is associated with impaired acinar cell autophagic flux, intracellular zymogen activation, cell necrosis and inflammation. Activation of the cholinergic system of vagus nerve has been shown to attenuate AP, but the effect of organ-intrinsic cholinergic system on pancreatitis remains unknown. In this study, we aim to examine the effect of α7 nicotinic acetylcholine receptor (α7nAChR) stimulation within the pancreas during AP. In vivo, AP was induced by caerulein plus LPS or ethanol plus palmitoleic acid in mice. In vitro, pancreatic acini were isolated and subjected to cholecystokinin (CCK) stimulation. Mice or acini were pre-treated with PNU-282987 (selective α7nAChR agonist) or methyllycaconitine citrate salt (selective α7nAChR antagonist). Pancreatitis severity, acinar cell injury, autophagic flux, and transcription factor EB (TFEB) pathway were analyzed. Both caerulein plus LPS in vivo and CCK in vitro led to an up-regulation of α7nAChR, indicating activation of pancreas-intrinsic α7nAChR signaling during AP. PNU-282987 decreased acinar cell injury, trypsinogen activation and pancreatitis severity. Conversely, methyllycaconitine citrate salt increased acinar cell injury and aggravated AP. Moreover, activation of α7nAChR by PNU-282987 promoted autophagic flux as indicated by reduced p62, increased LysoTracker staining and decreased number of autolysosomes with undegraded contents. Furthermore, PNU-282987 treatment significantly increased TFEB activity in pancreatic acinar cells. α7nAChR activation also attenuated pancreatic inflammation and NF-κB activation. Our results showed that activation of α7nAChR protected against experimental pancreatitis through enhancing TFEB-mediated acinar cell autophagy, suggesting that activation of pancreas-intrinsic α7nAChR may serve as an endogenous protective mechanism during AP.