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.

Elevated CK-MB levels are associated with adverse clinical outcomes in acute pancreatitis: a propensity score-matched study

Aim

Cardiac injury, reflected by the measured concentrations of chemicals released from injured cardiac muscle, is common in acute pancreatitis (AP). However, there is no adequate evidence assessing the impact of cardiac injury on AP-related outcomes. Creatine kinase-myocardial band (CK-MB) mainly exists in the myocardium. Therefore, we sought to evaluate the relationship between the increase in CK-MB and the adverse clinical outcomes of AP.

Methods

This propensity score-matched study analyzed AP patients admitted to the Department of Gastroenterology in the First Affiliated Hospital of Nanchang University from June 2017 to July 2022. Propensity score matching and multivariate logistic regression analysis were used to explore the relationship between CK-MB elevation and AP outcome variables.

Results

A total of 5,944 patients were screened for eligibility, of whom 4,802 were ultimately enrolled. Overall, 896 (18.66%) of AP patients had elevated (>24 U/ml) CK-MB levels, and 895 (99.89%) were paired with controls using propensity score matching. The propensity score-matched cohort analysis demonstrated that mortality (OR, 5.87; 95% CI, 3.89-8.84; P < 0.001), severe acute pancreatitis (SAP) (OR, 2.74; 95% CI, 2.23-3.35; P < 0.001), and infected necrotizing pancreatitis (INP) (OR, 3.40; 95% CI, 2.34-4.94; P < 0.001) were more frequent in the elevated CK-MB (>24 U/ml) group than in the normal CK-MB (≤ 24 U/ml) group. Using the multivariate logistic regression analysis, elevated CK-MB levels were independently associated with increased mortality (OR, 2.753, 95% CI, 2.095-3.617, P < 0.001), SAP incidence (OR, 2.223, CI, 1.870-2.643, P < 0.001), and INP incidence (OR, 1.913, 95% CI, 1.467-2.494, P < 0.001). CK-MB elevation was an independent risk factor for adverse clinical outcomes in AP patients.

Conclusion

CK-MB elevation was significantly related to adverse outcomes in AP patients, which makes it a potentially useful laboratory parameter for predicting adverse clinical outcomes of AP.

Study on the Mechanism of MicroRNA551b-5p in Severe Acute Pancreatitis Capillary Leakage Syndrome

Objective

This study focused on investigating the effects of microRNA551b-5p (miR-551b-5p) on severe acute pancreatitis.

Methods

Initially, quantitative real-time polymerase chain reaction (qPCR) is employed to determine the expression of miR-551b-5p in differentiated human umbilical vein endothelial cells (HUVECs). Further, the effects of aberrantly expressed miR-551b-5p in HUVECs Transwell assay. The expressions of proteins associated with severe acute pancreatitis capillary leakage syndrome are determined by Western blot, FITC-phalloidin, and immunofluorescence stainings. Finally, the correlative factor and the target genes of miR-551b-5p, as well as their contributions, are assessed.

Results

We observed that overexpression of miR-551b-5p distinctly promoted the expression of EGFR, AKT3, and AQP5, while it suppressed the expression of JAM3, AQP1, and occludin. Functionally, the cytoskeleton of the miR-551b-5p overexpression was relatively loose with apparent vacuoles, and overexpression of miR-551b-5p increased the permeability of HUVECs.

Conclusion

miR-551b-5p overexpression promoted changes in vascular endothelial permeability via upregulation of the EGFR/AKT3 pathway and downregulation of occludin and JAM3.

Effects of Snake-Derived Phospholipase A2 Inhibitors on Acute Pancreatitis: In vitro and in vivo Characterization

Objective

We aimed to investigate the effects of snake-derived phospholipase A2 inhibitor (PLA2) from Sinonatrix percarinata and Bungarus multicinctus on acute pancreatitis in vivo and in vitro and assess the mechanisms.

Methods

The levels of platelet-activating factor (PAF) and tumor necrosis factor (TNF)-α were detected by ELISA, and the characteristics of autophagy were detected by transmission electron microscopy and Western blotting (LC3, p62, and ATG5).

Results

In vitro experiments showed that PLA2 treatment caused obvious formation of autophagic bodies. By contrast, Sinonatrix and Bungarus peptides reduced the number of autophagic bodies. The concentrations of PAF and TNF-α, and the expressions of p62, autophagy-related 5 (ATG5), and microtubule-associated protein 1A/1B-light chain 3 (LC3)II/LC3I in the PLA2-treated group were significantly higher than in the control group (P<0.05). The concentrations of PAF and TNF-α, and the expressions of p62, ATG5, and LC3II/LC3I in the Sinonatrix or Bungarus peptide treatment groups were significantly lower than in the PLA2-treated cells (P<0.05). In the pancreatic tissue, autophagic bodies were observed in the model group; autophagic bodies were remarkably reduced in Sinonatrix or Bungarus peptide-treated groups compared with the model group. In vivo experiments also showed that the levels of PAF and TNF-α, and the expressions of p62, ATG5, and LC3II/LC3I were significantly higher in the model group than in the control group (P<0.05). The levels of PAF and TNF-α in the model group, and the expressions of p62, ATG5, and LC3II/LC3I in Sinonatrix or Bungarus peptide-treated groups were significantly lower than in the model group (P<0.05).

Conclusion

Sinonatrix or Bungarus peptide could ameliorate the features of acute pancreatitis, likely through regulating autophagy.

Double-catheter lavage combined with percutaneous flexible endoscopic debridement for infected pancreatic necrosis failed to percutaneous catheter drainage

Background

Infected pancreatic necrosis (IPN) is a serious local complication of acute pancreatitis, with high mortality. Minimally invasive therapy including percutaneous catheter drainage (PCD) has become the preferred method for IPN instead of traditional open necrosectomy. However, the efficacy of double-catheter lavage in combination with percutaneous flexible endoscopic debridement after PCD failure is unknown compared with surgical necrosectomy.

Methods

A total of 27 cases of IPN patients with failure PCD between Jan 2014 and Dec 2015 were enrolled in this retrospective cohort study. Fifteen patients received double-catheter lavage in combination with percutaneous flexible endoscopic debridement, and 12 patients underwent open necrosectomy. The primary endpoint was the composite end point of major complications or death. The secondary endpoint included mortality, major complication rate, ICU admission length of stay, and overall length of stay.

Results

The primary endpoint occurrence rate in double-catheter lavage in combination with percutaneous flexible endoscopic debridement group (8/15, 53%) was significantly lower than that in open necrosectomy group (11/12, 92%) (RR = 1.71, 95% CI = 1.04 – 2.84, P < 0.05). Though the mortality between two groups showed no statistical significance (0% vs. 17%, P = 0.19), the rate of new-onset multiple organ failure and ICU admission length of stay in the experimental group was significantly lower than that in open necrosectomy group (13% vs. 58%, P = 0.04; 0 vs. 17, P = 0.02, respectively). Only 40% of patients required ICU admission after percutaneous debridement, which was markedly lower than the patients who underwent surgery (83%; P < 0.05).

Conclusions

Double-catheter lavage in combination with percutaneous flexible endoscopic debridement showed superior effectiveness, safety, and convenience in patients with IPN after PCD failure as compared to open necrosectomy.

Electronic supplementary material

The online version of this article (10.1186/s12876-017-0717-3) contains supplementary material, which is available to authorized users.

miR-551b-5p increases intracellular Ca2+ concentration but does not alter c-Kit expression in rat interstitial cells of Cajal

OBJECTIVE

To investigate the effect of the severe acute pancreatitis (SAP)-related miR-551b-5p on intracellular Ca²⁺ concentration and c-Kit expression and distribution in rat interstitial cells of Cajal (ICCs) in vitro.

METHODS

ICCs were isolated from 5-10-day-old rats and cultured in vitro. The cultured ICCs were divided into five groups: a normal control group; a group transfected with an miR-551b-5p mimic; a group transfected with an miR-551b-5p inhibitor; a group transfected with a negative control for the miR-551b-5p mimic; and a group transfected with a negative control for the miR-551b-5p inhibitor. After transfection, real-time PCR was used to detect miR-551b-5p and c-Kit expression. A Western blot analysis was used to determine the expression of c-Kit protein. Confocal microscopy combined with immunofluorescence and Fluo 3-acetoxymethyl (AM) fluorescence were used to determine the localization of c-Kit and intracellular Ca²⁺ concentration, respectively.

RESULTS

Transfection with the miR-551b-5p mimic or inhibitor resulted in overexpression or downregulation of miR-551b-5p in ICCs, respectively. The overexpression or downregulation of miR-551b-5p had no significant influence on c-Kit mRNA or protein levels. The overexpression of miR-551b-5p significantly increased the intracellular Ca²⁺ concentration, and the downregulation of miR-551b-5p significantly decreased the intracellular Ca²⁺ concentration.

CONCLUSION

miR-551b-5p increases intracellular Ca²⁺ concentration but does not alter c-Kit expression in rat ICCs, suggesting that it functions in ICCs by regulating the intracellular Ca²⁺ concentration downstream or independently of c-Kit signaling.