Downregulation of adaptor protein MyD88 compromises the angiogenic potential of B16 murine melanoma

A cold-water extracted polysaccharide-protein complex from Grifola frondosa exhibited anti-tumor activity via TLR4-NF-κB signaling activation and gut microbiota modification in H22 tumor-bearing mice

Grifola frondosa polysaccharide-protein complex (G. frondosa PPC) is a polymer which consists of polysaccharides and proteins/peptides linked by covalent bonds. In our previous ex vivo research, it has been demonstrated that a cold-water extracted G. frondosa PPC has stronger antitumor activity than a G. frondosa PPC extracted from boiling water. The main purpose of the current study was to further evaluate the anti-hepatocellular carcinoma and gut microbiota regulation effects of two PPCs isolated from G. frondosa at 4 °C (GFG-4) and 100 °C (GFG-100) in vivo. The results exhibited that GFG-4 remarkably upregulated the expression of related proteins in TLR4-NF-κB and apoptosis pathway, thereby inhibiting the development of H22 tumors. Additionally, GFG-4 increased the abundance of norank_f__Muribaculaceae and Bacillus and reduced the abundance of Lactobacillus. Short chain fatty acids (SCFAs) analysis suggested that GFG-4 promoted SCFAs production, particularly butyric acid. Conclusively, the present experiments revealed GFG-4 has the potential of anti-hepatocellular carcinoma growth via activating TLR4-NF-κB pathway and regulating gut microbiota. Therefore, G. frondosa PPCs could be considered as safe and effective natural ingredient for treatment of hepatocellular carcinoma. The present study also provides a theoretical foundation for the regulation of gut microbiota by G. frondosa PPCs.

Mesenchymal stromal cells induce inhibitory effects on hepatocellular carcinoma through various signaling pathways

Hepatocellular carcinoma (HCC) is the most prevalent type of malignant liver disease worldwide. Molecular changes in HCC collectively contribute to Wnt/β-catenin, as a tumor proliferative signaling pathway, toll-like receptors (TLRs), nuclear factor-kappa B (NF-κB), as well as the c-Jun NH2-terminal kinase (JNK), predominant signaling pathways linked to the release of tumor-promoting cytokines. It should also be noted that the Hippo signaling pathway plays an important role in organ size control, particularly in promoting tumorigenesis and HCC development. Nowadays, mesenchymal stromal cells (MSCs)-based therapies have been the subject of in vitro, in vivo, and clinical studies for liver such as cirrhosis, liver failure, and HCC. At present, despite the importance of basic molecular pathways of malignancies, limited information has been obtained on this background. Therefore, it can be difficult to determine the true concept of interactions between MSCs and tumor cells. What is known, these cells could migrate toward tumor sites so apply effects via paracrine interaction on HCC cells. For example, one of the inhibitory effects of MSCs is the overexpression of dickkopf-related protein 1 (DKK-1) as an important antagonist of the Wnt signaling pathway. A growing body of research challenging the therapeutic roles of MSCs through the secretion of various trophic factors in HCC. This review illustrates the complex behavior of MSCs and precisely how their inhibitory signals interface with HCC tumor cells.

Myeloid differentiation primary response gene (MyD) 88 signalling is not essential for intestinal fibrosis development

Dysregulation of the immune response to microbiota is associated with inflammatory bowel disease (IBD), which can trigger intestinal fibrosis. MyD88 is a key component of microbiota signalling but its influence on intestinal fibrosis has not been clarified. Small bowel resections from donor-mice were transplanted subcutaneously into the neck of recipients C57BL/6 B6-MyD88tm1 Aki (MyD88^-/-) and C57BL/6-Tg(UBC-green fluorescence protein (GFP))30Scha/J (GFP-Tg). Grafts were explanted up to 21 days after transplantation. Collagen layer thickness was determined using Sirius Red stained slides. In the mouse model of fibrosis collagen deposition and transforming growth factor-beta 1 (TGF-β1) expression was equal in MyD88^+/+ and MyD88^-/-, indicating that MyD88 was not essential for fibrogenesis. Matrix metalloproteinase (Mmp)9 expression was significantly decreased in grafts transplanted into MyD88^-/- recipients compared to MyD88^+/+ recipients (0.2 ± 0.1 vs. 153.0 ± 23.1, respectively, p < 0.05), similarly recruitment of neutrophils was significantly reduced (16.3 ± 4.5 vs. 25.4 ± 3.1, respectively, p < 0.05). Development of intestinal fibrosis appears to be independent of MyD88 signalling indicating a minor role of bacterial wall compounds in the process which is in contrast to published concepts and theories. Development of fibrosis appears to be uncoupled from acute inflammation.