Scope Milk‐derived extracellular vesicles (mEVs) as nanoparticles are being developed as novel drug vehicles due to their pivotal role in cell–cell communication. As an important bioactive component in milk, little is known about their effect on the gut microbiota and intestinal immunity. Therefore, the effects of mEVs on gut microbiota and intestinal immunity in mice are investigated. Methods and results First, a new method to obtain high‐yield mEVs is developed. Afterward, the colonic contents from C57BL/6 mice fed different doses of mEVs (8 weeks) are collected and the microbial composition via 16S rRNA gene sequencing is analyzed. It is found that mEVs could alter the gut microbiota composition and modulate their metabolites—short‐chain fatty acids (SCFAs). Furthermore, the effects of mEVs on intestinal immunity are evaluated. It is observed that the expression levels of Muc2, RegIIIγ, Myd88, GATA4 genes, and IgA, sIgA are increased in the intestine, which are significant for the integrity of the mucus layer. Conclusion These findings reveal that the genes with critical importance for intestinal barrier function and immune regulation are modified in mice by oral administration mEVs, which also result in the changes of the relative composition of gut microbiome and SCFAs.
Rationale: Bovine milk constitutes an essential part of human diet, especially for children, due to its enrichment of various nutrients. We recently developed an effective protocol for the isolation of extracellular vesicles from milk (mEVs) and discovered that mEVs contained large amounts of immune-active proteins and modulated the gut immunity and microbiota in healthy mice. Here, we aimed to explore the therapeutic effects of mEVs on inflammatory bowel disease. Methods: MicroRNAs and protein content in mEVs were analyzed by RNA sequencing and proteomics, respectively, followed by functional annotation. Ulcerative colitis (UC) was induced by feeding mice with dextran sulfate sodium. Intestinal immune cell populations were phenotyped by flow cytometry, and the gut microbiota was analyzed via 16S rRNA sequencing. Results: We showed that abundant proteins and microRNAs in mEVs were involved in the regulation of immune and inflammatory pathways and that oral administration of mEVs prevented colon shortening, reduced intestinal epithelium disruption, inhibited infiltration of inflammatory cells and tissue fibrosis in a mouse UC model. Mechanistically, mEVs attenuated inflammatory response via inhibiting TLR4-NF-κB signaling pathway and NLRP3 inflammasome activation. Furthermore, mEVs were able to correct cytokine production disorder and restore the balance between T helper type 17 (Th17) cells and interleukin-10 + Foxp3 + regulatory T (Treg) cells in the inflamed colon. The disturbed gut microbiota in UC was also partially recovered upon treatment with mEVs. The correlation between the gut microbiota and cytokines suggests that mEVs may modulate intestinal immunity via influencing the gut microbiota. Conclusions: These findings reveal that mEVs alleviate colitis by regulating intestinal immune homeostasis via inhibiting TLR4-NF-κB and NLRP3 signaling pathways, restoring Treg/Th17 cell balance, and reshaping the gut microbiota.
Circular RNAs are non-coding RNAs, and are enriched in the CNS. Dorsal horn neurons of the spinal cord contribute to pain-like hypersensitivity after nerve injury in rodents. Here we show that spinal nerve ligation is associated with an increase in expression of circAnks1a in dorsal horn neurons, in both the cytoplasm and the nucleus. Downregulation of circAnks1a by siRNA attenuates pain-like behaviour induced by nerve injury. In the cytoplasm, we show that circAnks1a promotes the interaction between transcription factor YBX1 and transportin-1, thus facilitating the nucleus translocation of YBX1. In the nucleus, circAnks1a binds directly to the Vegfb promoter, increases YBX1 recruitment to the Vegfb promoter, thereby facilitating transcription. Furthermore, cytoplasmic circAnks1a acts as a miRNA sponge in miR-324-3p-mediated posttranscriptional regulation of VEGFB expression. The upregulation of VEGFB contributes to increased excitability of dorsal horn neurons and pain behaviour induced by nerve injury. We propose that circAnks1a and VEGFB are regulators of neuropathic pain.
BackgroundStudies showed that upregulation of Nav1.6 increased the neuronal excitability and participated in neuropathic pain in the dorsal root ganglion (DRG). However, the molecular mechanisms underlying Nav1.6 upregulation were not reported yet.MethodsThe paw withdrawal threshold was measured in the rodents following lumbar 5 ventral root transection (L5-VRT). Then qPCR, western blotting, immunoprecipitation, immunohistochemistry, and chromatin immunoprecipitation assays were performed to explore the molecular mechanisms in vivo and in vitro.ResultsWe found that the levels of Nav1.6 and phosphorylated STAT3 were significantly increased in DRG neurons following L5-VRT, and TNF-α incubation also upregulated the Nav1.6 expression in cultured DRG neurons. Furthermore, immunoprecipitation and chromatin immunoprecipitation assays demonstrated that L5-VRT increased the binding of STAT3 to the Scn8a (encoding Nav1.6) promoter and the interaction between STAT3 and p300, which contributed to the enhanced transcription of Scn8a by increasing histone H4 acetylation in Scn8a promoter in DRG. Importantly, intraperitoneal injection of the TNF-α inhibitor thalidomide reduced the phosphorylation of STAT3 and decreased the recruitment of STAT3 and histone H4 hyperacetylation in the Scn8a promoter, thus subsequently attenuating Nav1.6 upregulation in DRG neurons and mechanical allodynia induced by L5-VRT.ConclusionThese results suggested a new mechanism for Nav1.6 upregulation involving TNF-α/STAT3 pathway activation and subsequent STAT3-mediated histone H4 hyperacetylation in the Scn8a promoter region in DRG, which contributed to L5-VRT-induced neuropathic pain.
Even though ER-positive, HER2-negative breast tumors represent a subset of breast cancers with a better clinical outcome, approximately 12.7 % of patients in this subgroup ultimately develop cancer-related mortality. Recent studies had confirmed that hypoxia-induced autophagy-related gene Beclin 1 expression might be important for disease progression and be correlated with patient outcome in several tumors. Here, we examined the autophagic Beclin 1 and hypoxic HIF-1α levels in 378 ER-positive, HER2-negative breast cancer patients by immunohistochemistry using tissue microarray. We found that Beclin 1 was highly expressed in normal mammary gland epithelia. In contrast, it was either not expressed or only moderately expressed in 78.0 % of breast adenocarcinoma tissue. Compared to the subset overexpressing Beclin 1, the subset in which Beclin 1 levels were reduced had a poor 5-year overall survival rate (OS, 85.1 % vs. 94.1 %, P = 0.005) and a poor distant metastasis-free survival (DMFS, 79.1 % vs. 89.3 %, P = 0.037). Cox multivariate analysis confirmed that Beclin 1 was indeed an independent prognostic factor for OS and DMFS. Additionally, Beclin 1 positively correlated with HIF-1α expression (r = 0.206, P < 0.001). Importantly, among patients with HIF-1α overexpression, low levels of Beclin 1 predicted a worse OS. Our study confirmed that deficiency of Beclin 1 was a negative prognostic factor for OS and DMFS in ER-positive, HER2-negative breast cancer. The combination of Beclin 1 and HIF-1α refined the risk definition of the patient subset and provided a novel way to identify those with a high risk of relapse.
The present study assessed the effects of the tankyrase (TNKS) small molecule inhibitor XAV939 on the proliferation and migration of lung adenocarcinoma A549 cells and the possible underlying mechanism. To do this, the association between TNKS and the WNT/β-catenin signaling pathway in lung acinar adenocarcinoma was investigated. Immunohistochemistry was performed, which demonstrated that TNKS, β-catenin and Myc proto-oncogene protein (c-Myc) proteins are positively expressed in lung adenocarcinoma tissue; this expression was significantly higher than that in normal adjacent non-carcinoma tissues. A549 cell proliferation was inhibited in all XAV939-intervention groups examined. In the wound-healing assay, cells treated with different concentrations of XAV939 exhibited a significantly increased scratch width compared with the control group. Reverse transcription-semi-quantitative polymerase chain reaction analysis revealed that β-catenin mRNA expression was significantly decreased in A549 cells in response to different XAV939 concentrations compared with the control group. Immunofluorescence revealed that β-catenin protein, initially localized in the nucleus/cytoplasm, gradually translocated to the cytoplasm/membrane, an effect that was associated with increased drug concentration. TNKS, β-catenin and c-Myc protein expression in A549 cells treated with XAV939 was reduced compared with that in untreated cells. Therefore, abnormally high TNKS expression may promote the occurrence of lung cancer. The TNKS inhibitor XAV939 inhibited lung adenocarcinoma A549 cell proliferation and migration in vitro. The underlying mechanism by which XAV939 exerted its inhibitory effects may be associated with attenuation of the WNT signaling pathway.
Previously, we and others showed that hypoxia-inducible factor-1a (HIF-1a) and transcriptionally upregulated Aurora-A were required for disease progression in several tumors. Here, we address the clinicopathologic value of Aurora-A and HIF-1a in locally advanced nasopharyngeal carcinoma (NPC). Aurora-A and HIF-1a expression was semiquantitatively evaluated by immunohistochemistry staining in 144 cases from a randomized controlled trial. Of these patients, 69 received neoadjuvant chemotherapy plus concurrent chemoradiotherapy, and acted as the training set, and 75 cases treated with neoadjuvant chemotherapy plus radiotherapy were used as the testing set to validate the prognostic effect of Aurora-A and HIF-1a. We found that Aurora-A and HIF-1a were highly expressed in NPC, but were deficient in normal adjacent epithelia. In the testing set, Aurora-A overexpression predicted a shortened 5-year overall survival (59.1% vs 82.5%, P = 0.024), progressionfree survival (44.8% vs 79.8%, P = 0.004), and distant metastasisfree survival (43.0% vs 17.3%, P = 0.016). Multivariate regression analysis confirmed that Aurora-A was indeed an independent prognostic factor for death, recurrence, and distant metastasis both in the testing set and overall patients. Moreover, a positive correlation between Aurora-A and HIF-1a was detected (P = 0.037). Importantly, although HIF-1a did not show any prognostic effect for patient outcome, the subset with Aurora-A and HIF-1a co-overexpression had the poorest overall, progression-free, and distant metastasis-free survival (all P < 0.05). Our results confirmed that Aurora-A was an independent prognostic factor for NPC. Aurora-A combined with HIF-1a refined the risk definition of the patient subset, thus potentially directing locally advanced NPC patients for more selective therapy. (Cancer Sci 2012; 103: 1586-1594
Purpose: The separation of Luminal A-like from Luminal B-like breast cancer subtypes in surrogate assay relies on Ki67 scores assessed by immunohistochemistry (IHC), a method known to be associated with subjectivity and inconsistency. We attempted to measure Ki67 levels absolutely, quantitatively and objectively in Formalin Fixed Paraffin Embedded (FFPE) specimens, and evaluate its influence on the performance of surrogate assay for breast cancer patients. Methods: The Ki67 protein levels were assessed using both IHC and Quantitative Dot Blot (QDB) methods respectively in 253 specimens. These patients were assigned into Luminal A-like and Luminal B-like subtypes using either Ki67 score of 14% as cutoff in surrogate assay, or 2.31 nmole/g from QDB method as cutoff in adjusted surrogate assay. These two subtyping methods were compared with the Kaplan-Meier, univariate and multivariate survival analyses of the overall survival (OS) of Luminal-like patients. Results: Ki67 levels measured using QDB method was highly correlated with those by IHC analysis (r=0.7, p<0.0001). The survival prediction for Luminal A-like patients was improved significantly in adjusted surrogate assay than surrogate assay (p=0.03 vs p<0.00052). The prediction of Hazard Ratio (HR) was also improve from 2.14 (95%CI: 0.89-5.11, p=0.087) to 6.89 (95%CI: 2.66-17.84, p<0.00001) in multivariate survival analysis. Conclusion: Our study demonstrated that the inherent subjectivity and inconsistency associated with IHC analysis has adverse effect on the performance of surrogate assay. This issue can be improved by objective and quantitative measurement of Ki67 levels with QDB method in daily clinical practice.
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