Gut microbiota and the tumor microenvironment are thought to be critical factors that modulate the processes of liver diseases, including hepatocellular carcinoma (HCC). Interleukin-25 (IL-25) promotes type 2 immunity via alternative activation of macrophages, and is closely associated with inflammation-related diseases, even malignancies. However, it is not clear which role IL-25 plays in the development of HCC, and whether gut microbiota are involved. IL-25 was detected by ELISA, Western blotting (WB), and immunohistochemistry. Chemokines were measured by RT-qPCR and WB. After co-culture with IL-25-stimulated macrophages, the cell growth, migration, invasion and EMT marker of HCC cell lines (MHCC97L and HepG2) were evaluated by Brdu proliferation, Transwell assays and WB. An antibody neutralization assay of chemokine CXCL10 was performed to confirm its role in HCC development. Furthermore, the effects of IL-25 in HCC were investigated in vivo. Dysbiosis of gut microflora was induced by antibiotics (vancomycin, cefoperazone or combination of ampicillin, neomycin, metronidazole, and vancomycin). We used feces suspension to treat colonic epithelial NCM460 cells, and detected IL-25 and tuft cell marker DCLK1 using WB and immunofluorescence staining. We found that the level of IL-25 was significantly elevated in HCC patients, and was negatively correlated with survival rate after hepatectomy. However, IL-25 did not directly promote the development of HCC cells. Then, we observed the significant positive correlation between IL-25 level and M2 percentage (CD206/CD68) in HCC tumors. In vitro and in vivo, IL-25 induced alternative activation of macrophages promoted HCC cell migration, invasion and tumorigenesis, increased the expression of vimentin, Snail and phospho-ERK, and decreased the expression of E-cadherin in HCC cells. After IL-25 treatment, chemokine CXCL10 was increased in macrophages. Neutralizing CXCL10 in macrophage-conditioned medium reversed the IL-25-mediated effect on HCC cells. Vancomycin-induced dysbiosis promoted the growth of orthotopic HCC homograft. Surprisedly, we found the hyperplasia of colonic epithelial tuft cells, from which more IL-25 was secreted . IL-25 promotes the progression of HCC through inducing alternative activation and CXCL10 secretion of macrophages in tumor microenvironment, and IL-25 secretion may partly result from hyperplastic epithelial tuft cells in colon, induced by gut microbiota dysbiosis.

Background: The use of keratinocytes derived from induced pluripotent stem cells (iPSCs-KCs) may represent a novel cell therapy strategy for burn treatment. There is growing evidence that extracellular vesicles, including exosomes, are primary mediators of the benefits of stem cell therapy. Herein, we thus explored the effects of exosomes produced by iPSCs-derived keratinocytes (iPSCs-KCs-Exos) in a model of deep second-degree burn wound healing and evaluated the mechanistic basis for the observed activity. Methods: iPSCs-KCs-Exos were isolated from conditioned medium of iPSCs-KCs and verified by electron micrograph and size distribution. Next, iPSCs-KCs-Exos were injected subcutaneously around wound sites, and its efficacy was evaluated by measuring wound closure areas, histological examination, and immunohistochemistry staining. The effects of iPSCs-KCs-Exos on proliferation and migration of keratinocytes and endothelial cells in vitro were assessed by EdU staining, wound healing assays, and transwell assay. Then, high-throughput microRNA sequencing was used to explore the underlying mechanisms. We assessed the roles of miR-762 in iPSCs-KCs-Exos-induced regulation of keratinocytes and endothelial cells migration. Furthermore, the target gene which mediated the biological effects of miR-762 in keratinocytes and endothelial cells was also been detected. Results: The analysis revealed that iPSCs-KCs-Exos application to the burn wound drove the acceleration of wound closure, with more robust angiogenesis and re-epithelialization being evident. Such iPSCs-KCs-Exos treatment effectively enhanced endothelial cell and keratinocyte migration in vitro. Moreover, the enrichment of miR-762 was detected in iPSCs-KCs-Exos and was found to target promyelocytic leukemia (PML) as a means of regulating cell migration through a mechanism tie to integrin beta1 (ITGB1). Conclusion: These results thus provide a foundation for the further study of iPSCs-KCs-Exos as novel cell-free treatments for deep second-degree burns. Graphical

Background: Induced pluripotent stem cells (iPSCs) have emerged as a promising treatment paradigm for skin wounds. Extracellular vesicles are now recognized as key mediators of beneficial stem cells paracrine effects. In this study, we investigated the effect of iPSCs-derived microvesicles (iPSCs-MVs) on deep second-degree burn wound healing and explored the underlying mechanism.

Background: Neuromedin U (NMU) is a neuropeptide belonging to the neuromedin family. Recently, significant associations between NMU and several cancers have been reported. However, no studies have examined the association between NMU and hepatocellular carcinoma (HCC). The purpose of this study was to examine the role of NMU in HCC. Methods: An enzyme-linked immunosorbent assay was used to measure the level of NMU protein in the sera of patients with hepatic hemangioma and HCC. NMU and cytokine mRNA expression was assessed in HCC samples via RT-qPCR. A tissue microarray consisting of 228 HCC peri- and intra-tumor tissues was used to detect NMU expression via immunohistochemical analysis. The association between NMU expression and overall survival (OS) and disease-free survival (DFS) was analyzed by Kaplan-Meier curves, the log-rank test, and Cox proportional hazard model. Results: The level of NMU protein was increased in the sera of HCC patients (p = 0.006). NMU was expressed in intercellular space, rather than in hepatocytes or HCC cells. The prognosis of HCC patients with high NMU expression in peri-tumor tissue was significantly poorer than that of patients with low NMU expression (OS: p = 0.002, DFS: p = 0.033). Peri-tumor NMU expression was also a significant independent prognostic factor for OS (hazard ratio: 1.541, 95% confidence interval: 1.092–2.175, p = 0.014). The level of NMU expression was positively associated with M2 macrophage percentage and the levels of type-2 inflammatory cytokines in HCC tissue. Conclusions: NMU may serve as a novel prognostic biomarker for HCC patients, although further validation is needed in the future. The activation of M2 macrophages and a type-2 inflammatory response may involve in the role of NMU in patients with HCC.