Effect and mechanism of Qingre Huashi decoction on drug-resistant Helicobacter pylori.

BACKGROUND: Helicobacter pylori (HP), the most common pathogenic microorganism in the stomach, can induce inflammatory reactions in the gastric mucosa, causing chronic gastritis and even gastric cancer. HP infection affects over 4.4 billion people globally, with a worldwide infection rate of up to 50%. The multidrug resistance of HP poses a serious challenge to eradication. It has been de-monstrated that compared to bismuth quadruple therapy, Qingre Huashi decoction (QHD) combined with triple therapy exhibits comparable eradication rates but with a lower incidence of adverse reactions; in addition, QHD can directly inhibit and kill HP in vitro. AIM: To explore the effect and mechanism of QHD on clinically multidrug-resistant and strong biofilm-forming HP. METHODS: In this study, 12 HP strains were isolated in vitro after biopsy during gastroscopy of HP-infected patients. In vitro, the minimum inhibitory concentration (MIC) values for clinical HP strains and biofilm quantification were determined through the E-test method and crystal violet staining, respectively. The most robust biofilm-forming strain of HP was selected, and QHD was evaluated for its inhibitory and bactericidal effects on the strain with strong biofilm formation. This assessment was performed using agar dilution, E-test, killing dynamics, and transmission electron microscopy (TEM). The study also explored the impact of QHD on antibiotic resistance in these HP strains with strong biofilm formation. Crystalline violet method, scanning electron microscopy, laser confocal scanning microscopy, and (p)ppGpp chromatographic identification were employed to evaluate the effect of QHD on biofilm in strong biofilm-forming HP strains. The effect of QHD on biofilm and efflux pump-related gene expression was evaluated by quantitative polymerase chain reaction. Non-targeted metabolomics with UHPLC-MS/MS was used to identify potential metabolic pathways and biomarkers which were different between the NC and QHD groups. RESULTS: HP could form biofilms of different degrees in vitro, and the intensity of formation was associated with the drug resistance of the strain. QHD had strong bacteriostatic and bactericidal effects on HP, with MICs of 32-64 mg/mL. QHD could inhibit the biofilm formation of the strong biofilm-forming HP strains, disrupt the biofilm structure, lower the accumulation of (p)ppGpp, decrease the expression of biofilm-related genes including LuxS, Spot, glup (HP1174), NapA, and CagE, and reduce the expression of efflux pump-related genes such as HP0605, HP0971, HP1327, and HP1489. Based on metabolomic analysis, QHD induced oxidative stress in HP, enhanced metabolism, and potentially inhibited relevant signaling pathways by upregulating adenosine monophosphate (AMP), thereby affecting HP growth, metabolism, and protein synthesis. CONCLUSION: QHD exerts bacteriostatic and bactericidal effects on HP, and reduces HP drug resistance by inhibiting HP biofilm formation, destroying its biofilm structure, inhibiting the expression of biofilm-related genes and efflux pump-related genes, enhancing HP metabolism, and activating AMP in HP.

Correction: Biofunctional Janus particles promote phagocytosis of tumor cells by macrophages.

[This corrects the article DOI: 10.1039/D0SC01146K.].

Fuzheng Nizeng Decoction regulated ferroptosis and endoplasmic reticulum stress in the treatment of gastric precancerous lesions: A mechanistic study based on metabolomics coupled with transcriptomics.

Background: Fuzheng Nizeng Decoction (FZNZ) has a history of decades in gastric precancerous lesions (GPL) treatment, which has shown clear clinical efficacy. Blocking GPL is a key measure to reduce the incidence of gastric cancer (GC). Therefore, we aim to investigate the mechanism of FZNZ-induced ferroptosis and endoplasmic reticulum (ER) in MNNG-induced gastric precancerous lesion (MC) cells, which has been rarely studied in Traditional Chinese Medicine (TCM). Methods: First, CCK8 and lactate dehydrogenase assays were conducted to study the potential effect of FZNZ on MC cells. Second, combined transcriptomic and metabolomic analysis were used to explore the effect and mechanism of FZNZ. Functionally, the occurrence of ferroptosis was assessed by transmission electron microscopy morphological observation and measurement of ferrous iron levels, lipid peroxidation, and glutathione levels. Finally, the expression levels of mRNAs or proteins related to ferroptosis and ER stress were determined by qPCR or western blot assays, respectively. Results: FZNZ inhibited MC cells viability and induced cell death. By metabolomics coupled with transcriptomics analysis, we found that the mechanism of FZNZ treatment induced ferroptosis and was related to glutathione metabolism and ER stress. We then, for the first time, found that FZNZ induced ferroptosis, which contributed to an increase in intracellular ferrous iron, reactive oxygen species, and malondialdehyde and a decrease in glutathione. Meanwhile, the protein level of glutathione peroxidase 4 (GPX4) was decreased. The mRNA levels of ATF3/CHOP/CHAC1, which are related to ferroptosis and ER stress, were also upregulated. Conclusion: Our results elaborate that FZNZ could induce ferroptosis and ER stress in MC cells, and reduce GPX4/GSH. ATF3/CHOP/CHAC1 may play a crosstalk role, which provides a new molecular mechanism for the treatment of GPL.

Engineering nanoparticles to tackle tumor barriers.

Engineering nanoparticles (NPs) as delivery systems of anticancer therapeutics has attracted tremendous attention in recent decades, and some nanoscale drug formulations have been approved for clinical use. However, their therapeutic efficacies are still limited by the presence of a series of biological barriers during the delivery process. Among these obstacles, tumor barriers are generally recognized as the bottleneck, because they dominate the NP extravasation from the tumor vasculature and penetration into the tumor parenchyma. Therefore, this review first discussed tumor barriers from two aspects: tumor vascular barriers and tumor stromal barriers. Pathological features of the two sets of barriers as well as their influence on the delivery efficacy were described. Then, we outlined strategies for engineering NPs to overcome these challenges: increasing extravasation through physical property optimization and tumor vascular targeting; and facilitating deep penetration through particle size manipulation, modulation of the tumor extracellular matrix, and some new mechanisms. This review will provide a critical perspective on engineering strategies for more efficient nanomedicine in oncology.

Biofunctional Janus particles promote phagocytosis of tumor cells by macrophages.

Herein, a versatile strategy for the construction of biofunctional Janus particles (JPs) through the combination of Pickering emulsion and copper-free click chemistry is developed for the study of particle-mediated cell-cell interactions. A variety of biomolecules including bovine serum albumin (BSA), ferritin, transferrin (Tf), and anti-signal regulatory protein alpha antibodies (aSIRPα), etc., can be incorporated into the Janus platform in a spatially defined manner. JPs consisting of Tf and aSIRPα (Tf-SPA1-aSIRPα JPs) demonstrate a significantly improved binding affinity to either macrophages or tumor cells compared to their uniformly modified counterparts. More importantly, Tf-SPA1-aSIRPα JPs mediate more efficient phagocytosis of tumor cells by macrophages as revealed by real-time high-content confocal microscopy. This study demonstrates the potential advantages of JPs in mediating cell-cell interactions and may contribute to the emerging cancer immunotherapy.