Identification of Significant Genes and Pathways in Acute Pancreatitis via Bioinformatical Analysis

Expression and Targeted Application of Claudins Family in Hepatobiliary and Pancreatic Diseases

Hepatobiliary and pancreatic diseases are becoming increasingly common worldwide and associated cancers are prone to recurrence and metastasis. For a more accurate treatment, new therapeutic strategies are urgently needed. The claudins (CLDN) family comprises a class of membrane proteins that are the main components of tight junctions, and are essential for forming intercellular barriers and maintaining cellular polarity. In mammals, the claudin family contains at least 27 transmembrane proteins and plays a major role in mediating cell adhesion and paracellular permeability. Multiple claudin proteins are altered in various cancers, including gastric cancer (GC), esophageal cancer (EC), hepatocellular carcinoma (HCC), pancreatic cancer (PC), colorectal cancer (CRC) and breast cancer (BC). An increasing number of studies have shown that claudins are closely associated with the occurrence and development of hepatobiliary and pancreatic diseases. Interestingly, claudin proteins exhibit different effects on cancer progression in different tumor tissues, including tumor suppression and promotion. In addition, various claudin proteins are currently being studied as potential diagnostic and therapeutic targets, including claudin-3, claudin-4, claudin-18.2, etc. In this article, the functional phenotype, molecular mechanism, and targeted application of the claudin family in hepatobiliary and pancreatic diseases are reviewed, with an emphasis on claudin-1, claudin-4, claudin-7 and claudin-18.2, and the current situation and future prospects are proposed.

Identification of novel biomarkers based on lipid metabolism-related molecular subtypes for moderately severe and severe acute pancreatitis

BACKGROUND

Acute pancreatitis (AP) is an unpredictable and potentially fatal disorder. A derailed or unbalanced immune response may be the root of the disease's severe course. Disorders of lipid metabolism are highly correlated with the occurrence and severity of AP. We aimed to characterize the contribution and immunological characteristics of lipid metabolism-related genes (LMRGs) in non-mild acute pancreatitis (NMAP) and identify a robust subtype and biomarker for NMAP.

METHODS

The expression mode of LMRGs and immune characteristics in NMAP were examined. Then LMRG-derived subtypes were identified using consensus clustering. The weighted gene co-expression network analysis (WGCNA) was utilized to determine hub genes and perform functional enrichment analyses. Multiple machine learning methods were used to build the diagnostic model for NMAP patients. To validate the predictive effectiveness, nomograms, receiver operating characteristic (ROC), calibration, and decision curve analysis (DCA) were used. Using gene set variation analysis (GSVA) and single-cell analysis to study the biological roles of model genes.

RESULTS

Dysregulated LMRGs and immunological responses were identified between NMAP and normal individuals. NMAP individuals were divided into two LMRG-related subtypes with significant differences in biological function. The cluster-specific genes are primarily engaged in the regulation of defense response, T cell activation, and positive regulation of cytokine production. Moreover, we constructed a two-gene prediction model with good performance. The expression of CARD16 and MSGT1 was significantly increased in NMAP samples and positively correlated with neutrophil and mast cell infiltration. GSVA results showed that they are mainly upregulated in the T cell receptor complex, immunoglobulin complex circulating, and some immune-related routes. Single-cell analysis indicated that CARD16 was mainly distributed in mixed immune cells and macrophages, and MGST1 was mainly distributed in exocrine glandular cells.

CONCLUSIONS

This study presents a novel approach to categorizing NMAP into different clusters based on LMRGs and developing a reliable two-gene biomarker for NMAP.

Fabp5 is a common gene between a high-cholesterol diet and acute pancreatitis

BACKGROUND AND AIMS

Hypercholesterolemia has been identified as risk factor for severe acute pancreatitis (AP). We aimed to identify the common differentially expressed genes (DEGs) between a high-cholesterol diet and AP.

METHODS

We retrived gene expression profiles from the GEO database. DEGs were assessed using GEO2R. For AP hub genes, we conducted functional enrichment analysis and protein-protein interaction (PPI) analysis. GeneMANIA and correlation analysis were employed to predict potential DEG mechanisms. Validation was done across various healthy human tissues, pancreatic adenocarcinoma, peripheral blood in AP patients, and Sprague-Dawley rats with AP.

RESULTS

The gene "Fabp5" emerged as the sole common DEG shared by a high-cholesterol diet and AP. Using the 12 topological analysis methods in PPI network analysis, Rela, Actb, Cdh1, and Vcl were identified as hub DEGs. GeneMANIA revealed 77.6% physical interactions among Fabp5, TLR4, and Rela, while genetic correlation analysis indicated moderate associations among them. Peripheral blood analysis yielded area under the ROC curve (AUC) values of 0.71, 0.63, 0.74, 0.64, and 0.91 for Fabp5, TLR4, Actb, Cdh1 genes, and artificial neural network (ANN) model respectively, in predicting severe AP. In vivo immunohistochemical analysis demonstrated higher Fabp5 expression in the hyperlipidemia-associated AP group compared to the AP and control groups.

CONCLUSION

Fabp5 emerged as the common DEG connecting a high-cholesterol diet and AP. Rela was highlighted as a crucial hub gene in AP. Genetic interactions were observed among Fabp5, TLR4, and Rela. An ANN model consisting of Fabp5, TLR4, Actb, and Cdh1 was helpful in predicting severe AP.

Polystyrene microplastics aggravate acute pancreatitis in mice

Microplastics (MPs) with a diameter of < 5mm are emerging as a new type of environmental pollutants. With the discovery of MPs in human tissues, the health risks of MPs have attracted considerable attention in recent years. In this study, we aimed to investigate the impact of MPs on acute pancreatitis (AP). We exposed male mice to 100 and 1000μg/L polystyrene MPs for 28 days, then intraperitoneally injected mice with cerulein to develop acute pancreatitis (AP). The results demonstrated that MPs dose-dependently exacerbated pancreatic injuries and inflammation in AP. High-dose MPs significantly increased intestinal barrier disruption in AP mice, which may be partly responsible for the aggravation of AP. Moreover, through tandem mass tag (TMT)- based proteomics of pancreatic tissues, we screened 101 differentially expressed proteins (DEPs) between AP mice and high-dose MPs-treated AP mice. Gene Ontology and KEGG Pathway analysis revealed that the DEPs were mainly implicated in the molecular events including cytoskeleton organization, acute inflammatory response, arginine metabolism, etc. These mechanisms may also contribute to the aggravating AP effects of MPs. Collectively, our data provide new evidence for the harmful potential of MPs.

Claudin-4: A New Molecular Target for Epithelial Cancer Therapy

Claudin-4 (CLDN4) is a key component of tight junctions (TJs) in epithelial cells. CLDN4 is overexpressed in many epithelial malignancies and correlates with cancer progression. Changes in CLDN4 expression have been associated with epigenetic factors (such as hypomethylation of promoter DNA), inflammation associated with infection and cytokines, and growth factor signaling. CLDN4 helps to maintain the tumor microenvironment by forming TJs and acts as a barrier to the entry of anticancer drugs into tumors. Decreased expression of CLDN4 is a potential marker of epithelial-mesenchymal transition (EMT), and decreased epithelial differentiation due to reduced CLDN4 activity is involved in EMT induction. Non-TJ CLDN4 also activates integrin beta 1 and YAP to promote proliferation, EMT, and stemness. These roles in cancer have led to investigations of molecular therapies targeting CLDN4 using anti-CLDN4 extracellular domain antibodies, gene knockdown, clostridium perfringens enterotoxin (CPE), and C-terminus domain of CPE (C-CPE), which have demonstrated the experimental efficacy of this approach. CLDN4 is strongly involved in promoting malignant phenotypes in many epithelial cancers and is regarded as a promising molecular therapeutic target.

Serum metabolomics study for acute attack of chronic pancreatitis

BACKGROUND & AIMS

Chronic pancreatitis (CP) is an inflammatory disease characterized by irreversible changes. However, acute CP attacks can lead to various complications and affect patient prognosis. Therefore, this study aimed to identify reliable candidate metabolic biomarkers for diagnosing acute CP attacks and complement candidate diagnostic markers for CP.

METHODS

A total of 139 serum specimens were prospectively included in three consecutive exploratory, identification, and validation studies. All samples were analyzed for candidate diagnostic biomarkers and metabolic pathways using a liquid chromatography-mass spectrometer.

RESULTS

Serum metabolic profiles differed between patients with CP and non-pancreatic disease controls, and 239 potential metabolic biomarkers for diagnosing CP were identified. Based on identification and validation studies, Diacylglycerol(16:0/18:4), 16-F1-PhytoP, N-(hexacosanoyl)-tetradecasphing-4-enine, carnosic acid, and Auxin b were identified as biomarkers for distinguishing acute attacks from non-acute attacks in patients with CP. The area under the curve of the Diacylglycerol(16:0/18:4) was 0.969 (95% confidence interval, 0.869-1) in the validation study.

CONCLUSIONS

To the best of our knowledge, this is the first prospective cohort study to identify and validate a metabolomic signature in serum for diagnosing acute attacks of CP. In addition, our study identified 239 potential biomarkers for CP diagnosis.

Claudin and pancreatic cancer

Due to the lack of timely and accurate screening modalities and treatments, most pancreatic cancer (PCa) patients undergo fatal PCa progression within a short period since diagnosis. The claudin(CLDN) family is expressed specifically as tight junction structure in a variety of tumors, including PCa, and affects tumor progression by changing the cell junctions. Thus far, many of the 27 members of the claudin family, including claudin-18.2 and claudin-4, have significantly aberrantly expression in pancreatic tumors. In addition, some studies have confirmed the role of some claudin proteins in the diagnosis and treatment of pancreatic tumors. By targeting different targets of claudin protein and combining chemotherapy, further enhance tumor cell necrosis and inhibit tumor invasion and metastasis. Claudins can either promote or inhibit the development of pancreatic cancer, which indicates that the diagnosis and treatment of different kinds of claudins require to consider different biological characteristics. This literature summarizes the functional characteristics and clinical applications of various claudin proteins in Pca cells, with a focus on claudin-18.2 and claudin-4.

Polypharmacology-based approach for screening TCM against coinfection of Mycoplasma gallisepticum and Escherichia coli

Natural products and their unique polypharmacology offer significant advantages for finding novel therapeutics particularly for the treatment of complex diseases. Meanwhile, Traditional Chinese Medicine exerts overall clinical benefits through a multi-component and multi-target approach. In this study, we used the previously established co-infection model of Mycoplasma gallisepticum and Escherichia coli as a representative of complex diseases. A new combination consisting of 6 herbs were obtained by using network pharmacology combined with transcriptomic analysis to reverse screen TCMs from the Chinese medicine database, containing Isatdis Radix, Forsythia Fructus, Ginkgo Folium, Mori Cortex, Licorice, and Radix Salviae. The results of therapeutic trials showed that the Chinese herbal compounds screened by the target network played a good therapeutic effect in the case of co-infection. In summary, these data suggested a new method to validate target combinations of natural products that can be used to optimize their multiple structure-activity relationships to obtain drug-like natural product derivatives.

FXYD domain containing ion transport regulator 5 (FXYD5) silencing promotes cell viability and alleviates inflammatory response in cerulein-induced AR42J cells by blocking JAK2/STAT3 signaling pathway

Acute pancreatitis (AP), which causes severe morbidity and mortality, is a heavy burden for people clinically and financially. This study was designed to explore the mechanism of AP and try to find effective therapies against AP. The expression of FXYD5 was interfered by performing transfection. RT-qPCR and Western blot were utilized to measure FXYD5 expression. In addition, the viability, apoptosis and inflammatory response were evaluated using CCK-8, TUNEL and ELISA, respectively. Moreover, Western blot was employed to measure the expressions of apoptosis-, inflammation- and signaling pathway-related proteins. FXYD5 was found to be overexpressed in AP patients and AP cell model. The results showed that in cerulein-induced AR42J cells, cell viability was remarkably increased, and apoptosis was inhibited compared to the normal FXYD5-expressing group because FXYD5 was downregulated. Similarly, in such cells, interference with FXYD5 significantly suppressed the inflammatory response. In addition, Western blot analysis revealed that JAK2/STAT3 signaling was also strongly inhibited by FXYD5 interference. However, the effect of FXYD5 downregulation was reversed upon simultaneous activation of JAK2/STAT3 signaling. In conclusion, downregulation of FXYD5 could promote cell viability and alleviate inflammatory response in cerulein-induced AP via blocking JAK2/STAT3 signaling pathway.

TSPAN1 silencing protects against cerulein-induced pancreatic acinar cell injury via targeting AGR2

Acute pancreatitis (AP) is an inflammatory gastrointestinal disorder affecting the pancreas. Previous study reported that tetraspanin 1 (TSPAN1) expression was significantly upregulated in the pancreas of AP patients. However, the underlying molecular mechanism of TSPAN1 in the pathogenesis of AP remains unclear. Thus, the aim of the present study was to investigate the potential role of TSPAN1 in development of AP. RT-qPCR was carried out to quantify the relative mRNA levels of TSPAN1 and anterior gradient-2 (AGR2). The CCK-8 assay was used to detect the cell viability. The TUNEL assay was performed to visualize the apoptotic cells. Western blot was performed to determine the expressions of proteins related to endoplasmic reticulum (ER) stress and apoptosis. ELISA kits were adopted to detect the concentration of inflammatory cytokines including TNF-α and IL-6. Finally, immunoprecipitation (IP) was used to verify the interaction between TSPAN1 and AGR2. TSPAN1 was upregulated in serum of AP patients and AP cell models. TSPAN1 silencing promoted the cell proliferation and inhibited inflammatory response in cerulein-induced AR42J cells. Moreover, TSPAN1 induced endoplasmic reticulum stress by binding AGR2. Interestingly, the overexpression of AGR2 abolished the effects of TSPAN1 silencing on cell proliferation and inflammatory response in cerulein-induced AR42J cells. In summary, TSPAN1 silencing protects against cerulein-induced pancreatic acinar cell injury through inhibiting ER stress-mediated by AGR2. Hence, TSPAN1 may serve as a promising therapeutic target for AP treatment.