In this study, exosomes used to encapsulate curcumin (Exo-cur) or a signal transducer and activator of transcription 3 (Stat3) inhibitor, i.e., JSI124 (Exo-JSI124) were delivered noninvasively to microglia cells via an intranasal route. The results generated from three inflammation-mediated disease models, i.e., a lipopolysaccharide (LPS)-induced brain inflammation model, experimental autoimmune encephalitis and a GL26 brain tumor model, showed that mice treated intranasally with Exo-cur or Exo-JSI124 are protected from LPS-induced brain inflammation, the progression of myelin oligodendrocyte glycoprotein (MOG) peptide induced experimental autoimmune encephalomyelitis (EAE), and had significantly delayed brain tumor growth in the GL26 tumor model. Intranasal administration of Exo-cur or Exo-JSI124 led to rapid delivery of exosome encapsulated drug to the brain that was selectively taken up by microglial cells, and subsequently induced apoptosis of microglial cells. Our results demonstrate that this strategy may provide a noninvasive and novel therapeutic approach for treating brain inflammatory-related diseases.

Food-derived exosome-like nanoparticles pass through the intestinal tract throughout our lives, but little is known about their impact or function. Here, as a proof of concept, we show that the cells targeted by grape exosome-like nanoparticles (GELNs) are intestinal stem cells whose responses underlie the GELN-mediated intestinal tissue remodeling and protection against dextran sulfate sodium (DSS)-induced colitis. This finding is further supported by the fact that coculturing of crypt or sorted Lgr5⁺ stem cells with GELNs markedly improved organoid formation. GELN lipids play a role in induction of Lgr5⁺ stem cells, and the liposome-like nanoparticles (LLNs) assembled with lipids from GELNs are required for in vivo targeting of intestinal stem cells. Blocking β-catenin-mediated signaling pathways of GELN recipient cells attenuates the production of Lgr5⁺ stem cells. Thus, GELNs not only modulate intestinal tissue renewal processes, but can participate in the remodeling of it in response to pathological triggers.

Until now the essential transcription factor that determines the epithelial phenotype of breast cancer has not been identified and its role in epithelial-to-mesenchymal transition (EMT) and tumor progression remain unclear. Here, by analyzing large expression profiles of human breast cancer cells, we found an extraordinary correlation between the expression of Grainyhead transcription factor Grhl2 and epithelial marker E-cadherin. Knockdown of Grhl2 expression by shRNA in human mammary epithelial cell MCF10A leads to down-regulation of E-cadherin and EMT. Grhl2 is down-regulated in disseminated cancer cells that have undergone EMT, and over-expression of Grhl2 is sufficient to induce epithelial gene expression. Large clinical datasets reveal that expression of Grhl2 is significantly associated with poor relapse free survival and increased risk of metastasis in breast cancer patients. In mouse models, over-expression of Grhl2 significantly promotes tumor growth and metastasis. Further testing of several Grhl2 regulated genes leads to the same conclusions that the tumorigenic and metastatic potentials of tumor cells are linked to epithelial phenotype but not mesenchymal phenotype. In conclusion, our findings indicate that Grhl2 plays an essential role in the determination of epithelial phenotype of breast cancers, EMT and tumor progression.

Regulation and induction of anergy in natural killer T (NKT) cells of the liver can inhibit autoimmune and anti-tumor responses by mechanisms that are poorly understood. We investigated the effects of prostaglandin E2 (PGE2), delivered by intestinal, mucus-derived, exosome-like nanoparticles (IDENs), on NKT cells in mice. Here, we demonstrate that IDENs migrate to the liver where they induce NKT cell anergy. These effects were mediated by an IDENs PGE2. Blocking PGE2 synthesis attenuated IDENs inhibition of induction of IFN-γ and IL-4 by α-GalCer stimulated liver NKT cells in a PGE2 EP2/EP4 receptor mediated manner. Pro-inflammatory conditions enhanced the migration of IDENs to the liver where α-GalCer and PGE2 induced NKT anergy in response to subsequent α-GalCer stimulation. These findings demonstrate that IDENs carrying PGE2 can be transferred from the intestine to the liver, where they act as immune modulators, inducing an anergic-like state of NKT cells. These reagents might be developed as therapeutics for autoimmune liver diseases.

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Background: Recent studies suggest that there is a link between the gut microbiota and glucose metabolism. This study aimed to compare the gut microbiota during early pregnancy of women with hyperglycymia to those with normal blood glucose. Methods: Gut microbial composition was analysed in 22 women with hyperglycaemia and 28 age-matched healthy controls during their first prenatal visits (< 20 weeks) using high throughput sequencing of the V3-V4 region of the 16S ribosomal RNA gene. Hyperglycemia was diagnosed based on the criteria recommended by the International Association of Diabetes and Pregnancy Study Groups in 2010. Results: Women with hyperglycemia in pregnancy (HIP) had significantly lower microbial richness and diversity compared with healthy pregnant women. The proportions of the Firmicutes and Bacteroidetes phyla and the ratio of Firmicutes:Bacteroidetes were not different between the two groups. We observed that individuals with HIP had an increased abundance of Nocardiaceae, Fusobacteriaceae, etc., whereas healthy controls had significantly higher levels of Christensenellaceae, Clostridiales_vadinBB60_group, Coriobacteriaceae, etc. Similarly, levels of the members of the Ruminococcaceae family, including Ruminococcaceae_UCG-014, Ruminococcaceae_UCG-003, and Ruminococcaceae_ UCG-002, were significantly reduced in the HIP group and were negatively correlated with HbA1c. HbA1c levels were positively correlated with Bacteroidaceae and Enterobacteriaceae and negatively correlated with Christensenellaceae, etc. CRP was positively correlated with the Bacteroidaceae and Fusobacteriaceae families and the Fusobacterium genus. Conclusions: Our study revealed that individuals with HIP have gut microbial dysbiosis and that certain bacterial groups are associated with glucose metabolism during pregnancy. Further study is needed to provide new ideas to control glucose by modifying the gut microbiota.

The Wnt/β-catenin pathway has been known to play a role in induction of immune tolerance, but its role in the induction and maintenance of NKT cell anergy is unknown. We found that activation of the Wnt pathway(s) in the liver microenvironment is important for induction of NKT cell anergy. We identified a number of stimuli triggering Wnt/β-catenin pathway activation, including exogenous NKT cell activator, glycolipid α-GalCer, and endogenous PGE2. Glycolipid α-GalCer treatment of mice induced the expression of wnt3a and wnt5a in the liver, and subsequently resulted in a liver microenvironment that induced NKT cell anergy to α-GalCer restimulation. We also found that circulating PGE2 carried by nanoparticles is stable, and that these nanoparticles are A33+. A33+ is a marker of intestinal epithelial cells, which suggests that the nanoparticles are derived from the intestine. Mice treated with PGE2 associated with intestinal mucus-derived exosome-like nanoparticles (IDEN) induced NKT cell anergy. PGE2 treatment leads to activation of the Wnt/β-catenin pathway by inactivation of GSK-3β of NKT cells. IDEN-associated PGE2 also induces NKT cell anergy through modification of the ability of DCs to induce IL-12 and IFN-β in the context of both glycolipid presentation and TLR-mediated pathways. These findings demonstrate that IDEN associated PGE2 serves as an endogenous immune modulator between the liver and intestines and maintains liver NKT cell homeostasis and this finding has implications for development of NKT cell–based immunotherapies.

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