H. pylori CagA activates the NLRP3 inflammasome to promote gastric cancer cell migration and invasion.

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-1ß 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. CONCLUSION: Our 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.

Prevention of systemic inflammation and neuroprotective effects of Qingda granules against angiotensin II-mediated hypertension.

Qingxuan Jiangya Decoction (QXJYD), prescribed by academician Ke-ji Chen, has long been used as a Traditional Chinese Medicine formula in blood pressure control and has achieved good clinical outcomes in hypertensive patients. Qingda granules (QDGs), which is a formula simplified from QXJYD, might serve as a novel anti-hypertensive pharmaceutical. However, the functional mechanism of QDGs remains unclear. This study aimed to evaluate the effect of QDGs against the elevation of blood pressure, systemic inflammation and brain injury in Ang II-mediated hypertensive mice. Ang II-mediated hypertensive mice were treated with 28.63mg QDG of per mouse every day. The blood pressure of all mice was measured on days 0, 1, 3, 5, 7, 14 and 28 by using the tail-cuff plethysmograph method. Following 28 days of treatment, the mice were sacrificed and their whole blood and brain tissues were used for analysis. The results showed that QDGs significantly decreased elevated systolic and diastolic blood pressure in Ang II-mediated hypertensive mice while body weight did not change, which demonstrated anti-hypertensive activities of QDGs without obvious toxicity. QDGs significantly attenuated the level of serum cytokines (IL-6, TNF-a) and chemokines (MCP-1, MIP-1a, RANTES) in the Ang II-mediated hypertensive mice. Moreover, pathological staining showed that QDGs significantly ameliorated cerebral histopathology changes, reduced the loss of neurons and activations of astrocytes. Additionally, QDGs inhibited neuronal apoptosis by down-regulation of Bax expression and up-regulation of Bcl-2 expression. These results suggested that QDGs exhibited excellent anti-hypertensive properties by preventing systemic inflammation and providing neuroprotective effects against Ang II-mediated hypertension.

Serological and molecular survey of Toxoplasma gondii infection and associated risk factors in urban cats in Kunming, Southwest China.

Toxoplasma gondii (T. gondii) is a worldwide zoonotic parasite that can infect almost warm-blood animals, including humans, which seriously affect the health of host. Cats are known to be the only definitive host of T. gondii and continuously excrete highly infectious oocysts. This parasite carried by the companion animals leads to a great public health risk. However, there is little information on epidemiology of T. gondii in urban cats in Kunming, Southwest China. In the present study, a total of 231 serum and fecal samples were collected in Kunming aera, and then seroprevalence of T. gondii IgG antibodies in serum and molecular investigation in feces were analyzed to elucidate T. gondii infection in urban cats. The results revealed that 168 of 231 cats (72.7%) were positive for T. gondii antibodies, and 1 of 74 cat feces (1.4%) also showed a positive PCR for T. gondii DNA. The positive fecal sample was sequenced and then phylogenetically analyzed, and the isolate of T. gondii in the present study was closely related to T. gondii strain CN. In addition, the food, water and age of cats were identified as the risk factor for seropositivity. Overall, our findings indicate the widespread occurrence of T. gondii infection in urban cats in Kunming, Southwest China and identify food, water and age are the risk factors associated with T. gondii infection, which can provide effective information for developing strategies to prevent and control this zoonosis.

A prominent role of LncRNA H19 in H. pylori CagA induced DNA damage response and cell malignancy.

Helicobacter pylori (H. pylori), together with its CagA, has been implicated in causing DNA damage, cell cycle arrest, apoptosis, and the development of gastric cancer. Although lncRNA H19 is abundantly expressed in gastric cancer and functions as a pro-oncogene, it remains unclear whether lncRNA H19 contributes to the oncogenic process of H. pylori CagA. This study investigates the role of H19 in the DNA damage response and malignancy induced by H. pylori. It was observed that cells infected with CagA+ H. pylori strain (GZ7/cagA) showed significantly higher H19 expression, resulting in increased γH2A.X and p-ATM expression and decreased p53 and Rad51 expression. Faster cell migration and invasion was also observed, which was reversed by H19 knockdown in H. pylori. YWHAZ was identified as an H19 target protein, and its expression was increased in H19 knockdown cells. GZ7/cagA infection responded to the increased YWHAZ expression induced by H19 knockdown. In addition, H19 knockdown stimulated cells to enter the G2-phase and attenuated the effect of GZ7/cagA infection on the cellular S-phase barrier. The results suggest that H. pylori CagA can upregulate H19 expression, participate in the DNA damage response and promote cell migration and invasion, and possibly affect cell cycle arrest via regulation of YWHAZ.

Helicobacter pylori CagA mediated mitophagy to attenuate the NLRP3 inflammasome activation and enhance the survival of infected cells.

Helicobacter pylori (H. pylori) is one of the most common bacterial infections in the world, and its key virulence component CagA is the leading 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 mechanisms by which CagA mediates H. pylori-induced mitophagy and NLRP3 inflammasome activation remain elusive. In this study, we reported that H. pylori primarily uses its CagA to induce mitochondrial oxidative damage, mitochondrial dysfunction, dynamic imbalance, and to block autophagic flux. Inhibition of mitophagy led to an increase in NLRP3 inflammasome activation and apoptosis and a decrease in the viability of H. pylori-infected cells. Our findings suggested that H. pylori induces mitochondrial dysfunction and mitophagy primarily via CagA. It reduces NLRP3 inflammasome activation to evade host immune surveillance and increases the survival and viability of infected cells, potentially leading to gastric cancer initiation and development. Our findings provide new insights into the pathogenesis of H. pylori-induced gastric cancer, and inhibition of mitophagy may be one of the novel techniques for the prevention and treatment of this disease.

Effects of Helicobacter pylori on the expression of the FTO gene and its biological role in gastric cancer.

Helicobacter pylori (Hp) is a primary risk factor for gastric cancer. The fat mass and obesity-associated (FTO) gene is associated with the development and progression of various cancer types such as glioma, leukemia, breast cancer and colorectal cancer. The aim of the present study was to investigate the effect of Hp infection on the expression of FTO and its roles in gastric cancer. It was found that the expression levels of both FTO mRNA and protein were significantly increased in Hp-infected human gastric mucosal epithelial cells and Mongolian gerbil gastric tissues. The expression of FTO in gastric cancer tissues was higher than that in para-cancer tissues. Data from The Cancer Genome Atlas demonstrated that FTO expression in gastric cancer tissues was significantly higher than that in normal tissues. Patient survival rate was significantly decreased in patients with high expression levels of FTO. It was also demonstrated that FTO expression was associated with several pathological parameters, such as tumor stage, metastasis stage and the American Joint Committee on Cancer stage. The FTO gene was positively correlated with 16,601 genes in gastric cancer and negatively correlated with 3,623 genes. Gene Ontology enrichment analysis demonstrated that FTO was significantly enriched in the regulation of gene expression and oxidative RNA demethylase activity, and it was associated with components such as the RNA N6-methyladenosine methyltransferase complex and nuclear speckle. In addition, knockdown of the FTO gene inhibited the migration and invasion of Hp-infected cells. In conclusion, the data suggests that Hp infection leads to upregulation of the FTO gene, which may be related to patient survival rate, tumor staging and other pathological parameters of patients with gastric cancer. It also suggests that FTO promotes proliferation and migration of gastric cancer cells, which may be involved in the pathogenesis of Hp-induced gastric cancer.

Gastrin-17 induces gastric cancer cell epithelial-mesenchymal transition via the Wnt/ß-catenin signaling pathway.

Gastric cancer (GC) is one of the most common cancers, with most patients often succumbing to death as a result of tumor metastasis. Recent work has demonstrated that gastrin is closely associated with GC metastasis. However, the specific molecular mechanisms underlying this relationship remain to be unveiled. In this study, we assessed the impact of gastrin and the Wnt/ß-catenin inhibitor XAV939 on the epithelial-mesenchymal transition (EMT) of the SGC-7901 and MKN45 GC cell lines, and we determined that gastrin-17 significantly decreased E-cadherin expression and upregulated the expression of Snail1 and N-cadherin in GC cells. In addition, gastrin 17 also significantly increased the expression of Wnt3α in a dose-dependent manner. Consistent with these results, gastrin-17 promoted GC cell invasion, proliferation, and migration in a dose-dependent fashion, and these effects were inhibited by XAV939. Together, these results indicated that gastrin-17 induced GC cell EMT, migration, and invasion via the Wnt/ß-catenin signaling pathway, which suggests that this gastrin/Wnt/ß-catenin signaling axis may represent a therapeutic target for the prevention of GC metastasis.

Qingda granules attenuate hypertensive cardiac remodeling and inflammation in spontaneously hypertensive rats.

Qingda granules (QDG) are derived from QingXuanJiangYa Decoction (QXJYD) a traditional Chinese medication that has been used to treat hypertension for more than 60 years. QXJYD has been shown to be effective in rat models of hypertension. However, the effects of QDG on hypertension remain largely unknown. In the current study, baicalin was identified as one of the main components of QDG using Ultra Performance Liquid Chromatography (UPLC) analysis. We investigated the effects of QDG on blood pressure, cardiac remodeling, and cardiac inflammation. QDG (0.8 g/kg/day) treatment attenuated the elevated blood pressure in spontaneously hypertensive rats (SHRs). Moreover, QDG treatment reduced the degree of myocardial fiber disarray, degeneration and necrosis of myocardial cells, expression of ANP and BNP, as well as collagen content of SHRs. Moreover, we further assessed the effect of QDG treatment on cardiac inflammation and found that QDG treatment reduced CD68 protein expression, decreased levels of IL-6 and TNF-α in both serum and cardiac tissues, as well as suppressed activation of NF-κB pathway in cardiac tissues of SHRs. Differential expressed metabolites (DEMs) analysis identified 41 increased and 51 decreased metabolites in the cardiac tissues of SHRs after QDG treatment. In summary, QDG treatment of SHRs attenuated the elevated blood pressure and ameliorated cardiac remodeling and inflammation, in part, through suppression of NF-κB pathway and DEMs, which provide a basis for other therapeutic uses of this TCM.

Alkaloids from Nelumbinis Plumula (AFNP) ameliorate aortic remodeling via RhoA/ROCK pathway.

The protective role of alkaloids from Nelumbinis Plumula (AFNP) on the aorta during hypertension is not yet fully understood. We hypothesize that AFNP exerts protective effects against Ang II-induced hypertension by mediating RhoA/ROCK pathway and phenotypic switching during hypertension. In the present study, we evaluated the effect of AFNP on angiotensin II (Ang II)-induced actin cytoskeleton reorganization and aorta remodeling, as well as the involvement of RhoA/Rho-associated coiled kinase (ROCK) pathway in protecting against hypertension. We used rat aortic tissues to investigate the vasodilatation effect of AFNP on Ang II-induced constriction. AFNP was shown to significantly relax the endothelium-intact arteries induced by Ang II. We further investigated the vasodilation effect of AFNP in endothelium denuded arteries, which showed that the action of AFNP was endothelial independent. Male SHR rats were treated with saline or AFNP and morphological changes were examined following 8 weeks. AFNP treatment normalized the effects of hypertension in SHRs. HE staining showed that AFNP treatment improved the tunica media and wall thickness and ratio of MT/LD and MA/LA. Western blotting showed that AFNP treatment markedly decreased the Ang II-induced expression of collagen I and increased α-SMA in aorta. Furthermore, MTT assay showed that AFNP inhibited the proliferation of Ang II treated VSMCs in a concentration-dependent manner. AFNP treatment also ameliorated F-actin cytoskeleton remodeling in Ang II treated VSMCs, as visualized under fluorescence microscopy. Western blot analysis showed that RhoA transposition and ROCK activation and phosphorylation of MYPT1 was increased following Ang II treatment but were inhibited by AFNP treatment, showing that the cardio-protective effect of AFNP is likely mediated by the RhoA/ROCK signaling pathway. The anti-hypertension and aortic protection effects of AFNP are due to non-endothelial dependent inhibition of the VSMC cytoskeleton remodeling and regulation of RhoA/ROCK pathway.