ClyA enhances LPS-induced IL-1β secretion in human macrophages through TLR4 and NLRP3 signaling

Intervention effects and related mechanisms of glycyrrhizic acid on zebrafish with Hirschsprung-associated enterocolitis

BACKGROUND

The prevention and treatment of Hirschsprung-associated enterocolitis (HAEC) is a serious challenge in pediatric surgery. Exploring the mechanism of HAEC is conducive to the prevention of this disease.

AIM

To explore the possible mechanism of glycyrrhizic acid (GA) and its therapeutic effect on HAEC.

METHODS

We developed a model of enteritis induced by trinitrobenzenesulfonic acid (TNBS) in zebrafish, and treated it with different concentrations of GA. We analyzed the effect of GA on the phenotype and inflammation of zebrafish.

RESULTS

After treatment with TNBS, the area of the intestinal lumen in zebrafish was significantly increased, but the number of goblet cells in the intestinal lumen was significantly reduced, but these did not increase the mortality of zebrafish, indicating that the zebrafish enteritis model was successfully developed. Different concentrations of GA protected zebrafish with enteritis. In particular, high concentrations of GA were important for the prevention and control of HAEC because it significantly reduced the intestinal luminal area, increased the number of goblet cells in the intestinal lumen, and reduced the levels of interleukin (IL)-1β and IL-8.

CONCLUSION

GA significantly reduced the intestinal luminal area, increased the number of intestinal goblet cells, and decreased IL-1β and IL-8 in zebrafish, and is important for prevention and control of HAEC.

Peitu Shengjin Recipe Attenuates Airway Inflammation via the TLR4/NF-kB Signaling Pathway on Chronic Obstructive Pulmonary Disease

Background

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease, but there is no specific medicine for COPD. In this study, we aimed to evaluate the effects of Peitu Shengjin Recipe (PSR) and Biostime Probiotic Powder on COPD rats.

Methods

UPLC-Q/TOF-MS was used to detect the chemical constituents in PSR. The COPD rat model was established by cigarette smoke combined with tracheal injection of lipopolysaccharide. We assessed lung function by calculating FEV_0.3/FVC%, dynamic lung compliance (Cdyn), and resistance of inspiration (RI). Histological analysis was performed by HE staining. The levels of TNF-α, IFN-γ, IL-1β, IL-4, and IL-10 were detected by the ELISA. The mRNA and protein expressions of the TLR4/NF-kB signaling pathway were detected by the qRT-PCR and western blotting, respectively.

Results

There were 53 ESI⁺ and 50 ESI⁻ components in PSR. After high-dose PSR treatment, FEV_0.3/FVC% and Cdyn increased significantly, while RI decreased. Compared with the COPD model, the RI of the Biostime Probiotic Powder group was significantly lower. HE staining showed that the inflammatory cell infiltration was reduced to varying degrees, the bronchial tube wall was not thickened, and the alveoli were relatively intact after treatment with PSR and Biostime Probiotic Powder. Compared with the model group, the levels of TNF-α, IFN-γ, IL-1β, IL-4, and IL-10 in the PSR group and the Biostime Probiotic Powder group were reversed. The mRNA and protein expressions of TLR4 and NF-kB were significantly decreased after PSR and Biostime Probiotic Powder treatment.

Conclusion

Our findings suggest that PSR and Biostime Probiotic Powder have protective effects on COPD rats, which may be achieved by modulating the TLR4/NF-kB signaling pathway.

Tumor-Associated Macrophages: Key Players in Triple-Negative Breast Cancer

Triple negative breast cancer (TNBC) refers to the subtype of breast cancer which is negative for ER, PR, and HER-2 receptors. Tumor-associated macrophages (TAMs) refer to the leukocyte infiltrating tumor, derived from circulating blood mononuclear cells and differentiating into macrophages after exuding tissues. TAMs are divided into typical activated M1 subtype and alternately activated M2 subtype, which have different expressions of receptors, cytokines and chemokines. M1 is characterized by expressing a large amount of inducible nitric oxide synthase and TNF-α, and exert anti-tumor activity by promoting pro-inflammatory and immune responses. M2 usually expresses Arginase 1 and high levels of cytokines, growth factors and proteases to support their carcinogenic function. Recent studies demonstrate that TAMs participate in the process of TNBC from occurrence to metastasis, and might serve as potential biomarkers for prognosis prediction.

Cytolysin A (ClyA): A Bacterial Virulence Factor with Potential Applications in Nanopore Technology, Vaccine Development, and Tumor Therapy

Cytolysin A (ClyA) is a pore-forming toxin that is produced by some bacteria from the Enterobacteriaceae family. This review provides an overview of the current state of knowledge regarding ClyA, including the prevalence of the encoding gene and its transcriptional regulation, the secretion pathway used by the protein, and the mechanism of protein assembly, and highlights potential applications of ClyA in biotechnology. ClyA expression is regulated at the transcriptional level, primarily in response to environmental stressors, and ClyA can exist stably both as a soluble monomer and as an oligomeric membrane complex. At high concentrations, ClyA induces cytolysis, whereas at low concentrations ClyA can affect intracellular signaling. ClyA is secreted in outer membrane vesicles (OMVs), which has important implications for biotechnology applications. For example, the native pore-forming ability of ClyA suggests that it could be used as a component of nanopore-based technologies, such as sequencing platforms. ClyA has also been exploited in vaccine development owing to its ability to present antigens on the OMV surface and provoke a robust immune response. In addition, ClyA alone or OMVs carrying ClyA fusion proteins have been investigated for their potential use as anti-tumor agents.