Pancreatic acinar cells-derived cyclophilin A promotes pancreatic damage by activating NF-κB pathway in experimental pancreatitis

The effect of cyclosporin a on ischemia-reperfusion damage in a mouse model of ischemic stroke

OBJECTIVES

We aimed to investigate the protective effects of cyclosporin A (CsA) against ischemia-reperfusion (I/R) damage in a mouse ischemia model and the possible underlying mechanism.

METHODS

Mice were divided equally into five groups: Sham, I/R, Vehicle, I/R plus CsA (10 mg/kg), and I/R plus CsA (20 mg/kg). Nerve function scores, infarct volume, brain water content, and Evans blue (EB) leakage were evaluated, and western blotting was performed to analyze the changes in CypA, p-Akt, NF-κB, MMP-9, and Claudin-5 expression.

RESULTS

CsA can attenuate I/R damage in a mouse ischemic stroke model, as indicated by improved neurological function scores and decreased infarct volume, brain water content, and EB leakage. Additionally, high-dose CsA showed better protective effects than low-dose. The molecular mechanisms underlying the effects of CsA were explored, and it was found that CsA could inhibit the increase in CypA, p-Akt, NF-κB, and MMP-9 protein expression after middle cerebral artery occlusion, while Claudin-5 expression was decreased.

DISCUSSION

CsA showed potential as a neuroprotective drug for the treatment of ischemic stroke patients; besides interfering with the typical NF-κB signaling pathway, the Akt pathway may also be involved in the effects of CsA.

Activation of the Nuclear Factor-kappa B Signaling Pathway Damages the Epithelial Barrier in the Human Pancreatic Ductal Adenocarcinoma Cell Line HPAF-II

OBJECTIVES

Injury of the pancreatic duct epithelial barrier plays a critical role in the development of acute pancreatitis. The activity of the nuclear factor-kappa B (NF-κB) pathway is involved in the disruption of the pancreatic duct epithelial barrier. This study investigated how NF-κB impacts the dysfunction of the pancreatic duct epithelial barrier.

METHODS

A human pancreatic ductal adenocarcinoma cell line was treated with tumor necrosis factor-alpha (TNF-α) and pyrrolidine dithiocarbamate. The expression levels of p65 and p-p65 were detected to evaluate NF-κB activity. Tricellulin (TRIC) expression levels were measured to assess the change in tight junction (TJ)-related proteins. The expression and localization of myosin light chain kinase (MLCK) were investigated. The structure of TJs and monolayer permeability were also examined.

RESULTS

NF-κB was activated by TNF-α and suppressed by pyrrolidine dithiocarbamate. Activation of NF-κB upregulated the expression levels of TRIC and MLCK. Broadened TJs were observed after NF-κB was activated. Lower monolayer permeability was observed when NF-κB was suppressed.

CONCLUSIONS

Activation of the NF-κB pathway induced by TNF-α leads to increased TRIC and MLCK expression, resulting in broadened TJs and high permeability, which contribute to damage to the pancreatic duct epithelial barrier.

Predictive value of serum cyclophilin A concentrations after acute pancreatitis

BACKGROUND

Cyclophilin A is identified as a biomarker for inflammation. We elucidated prognostic significance of serum cyclophilin A (CypA) concentrations in acute pancreatitis (AP).

METHODS

In this prospective and observational study, serum CypA concentrations were quantified in 210 AP patients and 100 healthy controls. We recorded local complication, in-hospital mortality and organ failure. Disease severity was assessed using the traditional predictors, namely Acute Physiology and Chronic Health Care Evaluation II score, Ranson score, multiple organ dysfunction score and sequential organ failure assessment score.

RESULTS

Serum CypA concentrations were significantly lower in controls than in AP group. CypA concentrations after AP were highly correlated with the traditional predictors and other inflammatory mediators, including blood erythrocyte sedimentation rate, procalcitonin levels, white blood cell count and C-reactive protein levels. Serum CypA emerged as an independent predictor for in-hospital local complication, organ failure and mortality. Under receiver operating characteristic curve, serum CypA possessed similar prognostic ability, as compared to the traditional predictors. Its predictive ability was almost similar to that of procalcitonin levels and significantly exceeded those of the other inflammatory mediators. Also, it significantly improved prognostic performance of the traditional predictors.

CONCLUSIONS

Increased serum CypA concentrations have close relation to the severity, inflammation and prognosis, substantializing CypA as a potential prognostic biomarker of AP.

Role of the c-Jun N-terminal kinase signaling pathway in the activation of trypsinogen in rat pancreatic acinar cells

Bile acid causes trypsinogen activation in pancreatic acinar cells through a complex process. Additional research is required to further elucidate which signaling pathways affect trypsinogen activation when activated. the changes in the whole‑genome expression profile of AR42J cells under the effect of taurolithocholic acid 3‑sulfate (TLC‑S) were investigated. Furthermore, gene groups that may play a regulatory role were analyzed using the modular approach of biological networks. The aim of the present study was to improve our understanding of the changes in TLC‑S‑stimulated AR42J cells through a genetic functional modular analysis. whole‑genome expression profile chip arrays were applied to detect genes that were differentially expressed in pancreatic acinar AR42J cells treated with TLC‑S for 20 min. Based on the human protein reference database, a protein‑protein interaction network was obtained, which was then processed by CFinder software to derive 14 modules. Among these 14 modules, the gene ontology biological processes enrichment analysis identified two as modules of interest. Kyoto encyclopedia of genes and genomes map analysis revealed that MAP2K4, MAPK8 and FLNA are part of the c-Jun N-terminal kinase (JNK) pathway. The JNK signaling pathway is involved in regulating trypsinogen activation in rat pancreatic AR42J cells. Next, a regulatory network of seven kinase inhibitors was constructed. SP600125 is an ATP‑competitive, efficient, selective and reversible inhibitor of JNK. the results were verified by four sets of experiments and demonstrated that trypsinogen activation is mediated by the JNK signaling pathway in the pathogenesis of acute pancreatitis (AP). The present study provided a useful reference for better understanding the pathogenesis of AP and identifying new targets to regulate trypsinogen activation, in addition to providing valuable information for the treatment of AP.

Anti-B7-H3 monoclonal antibody ameliorates the damage of acute experimental pancreatitis by attenuating the inflammatory response

B7-H3, a recently discovered B7 family member, is documented as a regulator in the inflammatory response as well as T cell-mediated immune responses. In this paper, we find that patients with acute pancreatitis revealed overwhelming levels of serum soluble B7-H3 (sB7-H3) associated with the clinical outcomes. Furthermore, B7-H3 protein was marked increased in l-arginine-induced acute experimental pancreatitis. Anti-B7-H3 monoclonal antibody treatment attenuated the proinflammatory cytokine production, downregulated the activation of the NF-κB signaling pathway, and ameliorated the pancreas disruption in l-arginine-induced pancreatitis. In addition, although l-arginine alone failed to induce the production of proinflammatory cytokine and anti-B7-H3 mAb had no effect on the proinflammatory cytokine production of acinar cells, administration of anti-B7-H3 mAb in the coculture model of acinar cells and macrophages stimulated by l-arginine displayed the similar effects. On the whole, B7-H3 participates in the development of acute pancreatitis, and anti-B7-H3 monoclonal antibody ameliorates severity of acute experimental pancreatitis via attenuation of the inflammatory response.

Current and future intratumoral targeted treatment for pancreatic cancer

Pancreatic cancer is an insidious type of cancer with its symptoms manifested upon extensive disease. The overall 5-year survival rates between 0.4 and 4%. Surgical resection is an option for only 10% of the patients with pancreatic cancer. Local recurrence and hepatic metastases occur within 2 years after surgery. There are currently several molecular pathways investigated and novel targeted treatments are on the market. However; the nature of pancreatic cancer with its ability to spread locally in the primary site and lymph nodes indicates that further experimentation with local interventional therapies could be a future treatment proposal as palliative care or adjunct to gene therapy and chemotherapy/radiotherapy. In the current review, we will summarize the molecular pathways and present the interventional treatment options for pancreatic cancer.

CypA, a gene downstream of HIF-1α, promotes the development of PDAC

Hypoxia-inducible factor-1α (HIF-1α) is a highly important transcription factor involved in cell metabolism. HIF-1α promotes glycolysis and inhibits of mitochondrial respiration in pancreatic ductal adenocarcinoma (PDAC). In response to tumor hypoxia, cyclophilin A (CypA) is over-expressed in various cancer types, and is associated with cell apoptosis, tumor invasion, metastasis, and chemoresistance in PDAC. In this study, we showed that both HIF-1α and CypA expression were significantly associated with lymph node metastasis and tumor stage. The expression of CypA was correlated with HIF-1α. Moreover, the mRNA and protein expression of CypA markedly decreased or increased following the suppression or over-expression of HIF-1α in vitro. Chromatin immunoprecipitation analysis showed that HIF-1α could directly bind to the hypoxia response element (HRE) in the CypA promoter regions and regulated CypA expression. Consistent with other studies, HIF-1α and CypA promoted PDAC cell proliferation and invasion, and suppressed apoptosis in vitro. Furthermore, we proved the combination effect of 2-methoxyestradiol and cyclosporin A both in vitro and in vivo. These results suggested that,CypA, a gene downstream of HIF-1α, could promote the development of PDAC. Thus, CypA might serve as a potential therapeutic target for PDAC.