The adult-onset form of T1D is not rare in China. The registry participants were characterized by older age at onset, lower BMI, and a higher prevalence of DKA at onset compared with those in regions with a high incidence of T1D, such as northern Europe. These findings contribute to a better understanding of the heterogeneity of T1D in different populations and so will help healthcare providers to develop management models that are more suitable for these patients.

Objective The CagA (cytotoxin-related gene A, CagA) protein is an important factor for the pathogenicity of Helicobacter pylori (H. pylori). Although H. pylori has previously been shown to activate the NLRP3 inflammasome, it remains unclear what role CagA plays in this process. In the current study, we aimed to investigate the effect of CagA on NLRP3 activation and how it is linked to gastric cancer cell migration and invasion. Methods CagA positive H. pylori strain (Hp/CagA + ) and CagA gene knockout mutant (Hp/ΔCagA) infected and the pcDNA3.1/CagA plasmid transfected gastric epithelial cell lines, respectively. The morphological alterations of cells under a microscope; the NLRP3 inflammasome-related markers: NLRP3, caspase-1, and ASC protein levels were detected by Western blot, IL-1β and IL-18 levels were determined by ELISA; cell migration and invasion were determined by transwell assay; and the pyroptosis levels and intracellular ROS were determined by flow cytometry analysis. Then, pretreated with 5 mM NAC for 2 h and subsequently transfected with the pcDNA3.1/CagA plasmid for 48 h, the effects of NAC pretreatment on CagA-induced NLRP3 inflammasome-related markers expression and cell pyroptosis were examined, finally assessed the effect of CagA on migration and invasion in NLRP3-silenced cells. Results We found that Hp/CagA + strain infection and pcDNA3.1/CagA vector transfection result in NLRP3 inflammasome activation, generation of intracellular ROS, and increased invasion and migration of gastric cancer cells. Moreover, we found that ROS inhibition via NAC effectively blocks NLRP3 activation and pyroptosis. Silencing of NLRP3 reduces the effects of CagA on gastric cancer cell migration and invasion. ConclusionOur study shows that CagA can promote the invasion and migration of gastric cancer cells by activating NLRP3 inflammasome pathway. These findings provide novel insights into the mechanism of gastric cancer induction by H. pylori.

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Aim Helicobacter pylori cytotoxin-associated protein A (CagA) is an important virulence factor known to induce gastric cancer development. However, the cause and the underlying molecular events of CagA induction remain unclear. Here, we applied integrated bioinformatics to identify the key genes involved in the process of CagA-induced gastric epithelial cell inflammation and can ceration to comprehend the potential molecular mechanisms involved. Materials and Methods AGS cells were transected with pcDNA3.1 and pcDNA3.1::CagA for 24 h. The transfected cells were subjected to transcriptome sequencing to obtain the expressed genes. Differentially expressed genes (DEG) with adjusted P value < 0.05, — logFC —> 2 were screened, and the R package was applied for gene ontology (GO) enrichment and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The differential gene protein–protein interaction (PPI) network was constructed using the STRING Cytoscape application, which conducted visual analysis to create the key function networks and identify the key genes. Next, the Kaplan–Meier plotter survival analysis tool was employed to analyze the survival of the key genes derived from the PPI network. Further analysis of the key gene expressions in gastric cancer and normal tissues were performed based on The Cancer Genome Atlas (TCGA) database and RT-qPCR verification. Results After transfection of AGS cells, the cell morphology changes in a hummingbird shape and causes the level of CagA phosphorylation to increase. Transcriptomics identified 6882 DEG, of which 4052 were upregulated and 2830 were downregulated, among which q-value < 0.05, FC > 2, and FC under the condition of ≤2. Accordingly, 1062 DEG were screened, of which 594 were upregulated and 468 were downregulated. The DEG participated in a total of 151 biological processes, 56 cell components, and 40 molecular functions. The KEGG pathway analysis revealed that the DEG were involved in 21 pathways. The PPI network analysis revealed three highly interconnected clusters. In addition, 30 DEG with the highest degree were analyzed in the TCGA database. As a result, 12 DEG were found to be highly expressed in gastric cancer, while seven DEG were related to the poor prognosis of gastric cancer. RT-qPCR verification results showed that Helicobacter pylori CagA caused up-regulation of BPTF, caspase3, CDH1, CTNNB1, and POLR2A expression. Conclusion The current comprehensive analysis provides new insights for exploring the effect of CagA in human gastric cancer, which could help us understand the molecular mechanism underlying the occurrence and development of gastric cancer caused by Helicobacter pylori.

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Background H. pylori is the most prevalent bacterial infection in the world, and its crucial virulence component CagA is the primary cause of gastric cancer. Mitophagy is a form of selective autophagy that eliminates damaged mitochondria and is essential for some viruses and bacteria to evade the immune system. However, the potential impact of H.pylori CagA in the crosstalk between mitophagy and NLRP3 inflammasome is not completely known.Objective In this study, we aimed to understand the impact of H. pylori and its CagA on the induction of mitochondrial dysfunction and mitophagy and the interactions between mitophagy induction and NLRP3 inflammasome activation in the survival of H. pylori-infected cells.Methods We co-cultured gastric epithelial cells (GES)-1 and human gastric adenocarcinoma cell line (AGS) with H. pylori CagA mutant strain (GZ7/ΔCagA) and CagA-positive wild-type strain (GZ7/CagA) for 48 h at the multiplication of infection (MOI) of 60, respectively. Afterward, mitochondrial membrane potential, adenosine triphosphate production levels, and cell apoptosis detection were performed. Furthermore, western blotting was used to detect the expression of mitochondrial fusion and fission proteins, mitophagy-related proteins, and NLRP3 inflammasome-related proteins; immunofluorescence staining was used to assess the localization and expression of LC3; transmission electron microscope (TEM) was used to obtain digital images of mitophagy. Additionally, immunochemistry was used to identify the expression of mitophagy-related proteins in the gastric tissues of H. pylori-infected mice. Next, we used green fluorescent protein-mCherry-LC3 as a tandem reporter to explore the effect of H. pylori infection on autophagic flux. Furthermore, the expression of associated proteins for mitophagy and the NLRP3 inflammasome in each group of cells was examined after pretreatment with mitophagy inducer (Olaparib), mitophagy inhibitor (BafA1), and NLRP3 inflammasome inhibitor (MCC950) for 24 h and subsequent infection with GZ7/ΔCagA and GZ7/CagA at an MOI of 60–48 h, respectively. Finally, we assessed the effect of mitophagy inhibition on apoptosis and viability in H. pylori-infected cells.Results We discovered that H. pylori primarily used its CagA to cause mitochondrial oxidative damage, induce mitochondrial dysfunction, dynamic imbalance, and mitophagy, and impede the autophagic flux. Although NLRP3 inflammasome inhibition hinders the induction of mitophagy, mitophagy activation can reduce NLRP3 inflammasome activation caused by H. pylori infection. Conversely, mitophagy inhibition can increase NLRP3 inflammasome activation caused by H. pylori infection. CagA plays an evident role in these processes. Moreover, inhibiting mitophagy can also increase apoptosis and reduce the viability of H. pylori-infected cells.Conclusion Our findings suggested that H. pylori, primarily via CagA, is required for the induction of mitochondrial dysfunction and mitophagy, which not only reduced NLRP3 inflammasome activation to evade host immune surveillance and increased infected cell survival and viability but also caused abnormal mitochondrial accumulation, possibly leading to the occurrence and development of gastric cancer.)