Core Fucosylation of the T Cell Receptor Is Required for T Cell Activation

CD4+ T cell activation promotes the pathogenic process of systemic lupus erythematosus (SLE). T cell receptor (TCR) complex are highly core fucosylated glycoproteins, which play important roles in T cell activation. In this study, we found that the core fucosylation of CD4+ T cells was significantly increased in SLE patients. Loss of core fucosyltransferase (Fut8), the sole enzyme for catalyzing the core fucosylation of N-glycan, significantly reduced CD4+ T cell activation and ameliorated the experimental autoimmune encephalomyelitis-induced syndrome in Fut8−/− mice. T cell activation with OVA323–339 loaded major histocompatibility complex II (pMHC-II) on B cell was dramatically attenuated in Fut8−/−OT-II CD4+ T cells compared with Fut8+/+OT-II CD4+ T cells. Moreover, the phosphorylation of ZAP-70 was significantly reduced in Fut8+/+OT-II CD4+ T cells by the treatment of fucosidase. Our results suggest that core fucosylation is required for efficient TCR–pMHC-II contacts in CD4+ T cell activation, and hyper core fucosylation may serve as a potential novel biomarker in the sera from SLE patients

Genistein Ameliorates Non-alcoholic Fatty Liver Disease by Targeting the Thromboxane A₂ Pathway

Non-alcoholic fatty liver disease (NAFLD) is now a public health issue worldwide, but no drug has yet received approval. Genistein, an isoflavonoid derived from soybean, ameliorates high-fat-diet-induced NAFLD in mice, but the molecular underpinnings remain largely elusive. Arachidonic acid (AA) is a major ingredient of animal fats, and the AA cascade has been implicated in chronic inflammation. In this study, we investigated whether genistein was against NAFLD by targeting the AA cascade. Using a mouse model, we showed that genistein supplementation improved high-fat-diet-induced NAFLD by normalizing hepatomegaly, liver steatosis, aminotransferase abnormalities, and glucose tolerance. The thromboxane A₂ (TXA₂) pathway was aberrantly active in NAFLD, evidenced by an elevation of circulating TXA₂ and hepatic thromboxane A₂ receptor expression. Mechanistically, we found that genistein directly targeted cyclooxygenase-1 activity as well as its downstream TXA₂ biosynthesis, while the TXA₂ pathway might mediate NAFLD progression by impairing insulin sensitivity. Taken together, our study revealed a crucial pathophysiological role of the TXA₂ pathway in NAFLD and provided an explanation as to how genistein was against NAFLD progression

Genistein Ameliorates Non-alcoholic Fatty Liver Disease by Targeting the Thromboxane A₂ Pathway

Non-alcoholic fatty liver disease (NAFLD) is now a public health issue worldwide, but no drug has yet received approval. Genistein, an isoflavonoid derived from soybean, ameliorates high-fat-diet-induced NAFLD in mice, but the molecular underpinnings remain largely elusive. Arachidonic acid (AA) is a major ingredient of animal fats, and the AA cascade has been implicated in chronic inflammation. In this study, we investigated whether genistein was against NAFLD by targeting the AA cascade. Using a mouse model, we showed that genistein supplementation improved high-fat-diet-induced NAFLD by normalizing hepatomegaly, liver steatosis, aminotransferase abnormalities, and glucose tolerance. The thromboxane A₂ (TXA₂) pathway was aberrantly active in NAFLD, evidenced by an elevation of circulating TXA₂ and hepatic thromboxane A₂ receptor expression. Mechanistically, we found that genistein directly targeted cyclooxygenase-1 activity as well as its downstream TXA₂ biosynthesis, while the TXA₂ pathway might mediate NAFLD progression by impairing insulin sensitivity. Taken together, our study revealed a crucial pathophysiological role of the TXA₂ pathway in NAFLD and provided an explanation as to how genistein was against NAFLD progression

LincK contributes to breast tumorigenesis by promoting proliferation and epithelial-to-mesenchymal transition

Abstract Background Increasing evidence has demonstrated that mesenchymal stem cells (MSCs) play a role in the construction of tumor microenvironments. Co-culture between tumor cells and MSCs provides an easy and useful platform for mimicking tumor microenvironments and identifying the important members involved in tumor progress. The long non-coding RNAs (lncRNAs) have been shown to regulate different tumorigenic processes. In this study, we aimed to examine functional lncRNA deregulations associated with breast cancer malignancy instigated by MSC-MCF-7 co-culture. Methods The microarrays were used to profile the expression changes of lncRNAs in MCF-7 cells during epithelial-mesenchymal transition (EMT) induced by co-culture with MSCs. We found that an intergenic lncRNA KB-1732A1.1 (termed LincK, partly overlapped with GASL1) was significantly elevated. To investigate the biological function of LincK, the expression of EMT markers, cell migration, invasion, proliferation, and colony formation were evaluated in vitro and xenograft assay in nude mice were performed in vivo. Furthermore, we detected LincK expression in clinical samples using RNAscope® technology and verified aberrant expression of LincK in breast cancer data sets from The Cancer Genome Atlas (TCGA) by bioinformatic analysis. The underlying mechanisms of LincK were investigated using mRNA microarray analyses, Western blot, RNA pull down, and RNA immunoprecipitation. Results LincK induced an EMT progress in breast cancer cells (BCC) MCF-7, MDA-MB-453, and MDA-MB-231. The depletion of LincK decreased the growth, migration, and invasion in BCC, whereas the overexpression of LincK exerted the opposite effects. Moreover, knockdown of LincK repressed tumorigenesis, and ectopic expression of LincK promoted tumor growth in MCF-7 xenograft model. LincK ablation in MDA-MB-231 cells dramatically impaired lung metastasis when incubated intravenously into nude mice. Further, LincK was frequently elevated in breast cancer compared with normal breast tissue in clinical samples. Mechanistically, LincK may share common miRNA response elements with PBK and ZEB1 and regulate the effects of miR-200 s. Conclusion LincK plays a significant role in regulating EMT and tumor growth and could be a potential therapeutic target in breast cancer

Pb-rich Cu grain boundary sites for selective CO-to-n-propanol electroconversion

Electrochemical carbon monoxide (CO) reduction to high-energy-density fuels provides a potential way for chemical production and intermittent energy storage. As a valuable C3 species, n-propanol still suffers from a relatively low Faradaic efficiency (FE), sluggish conversion rate and poor stability. Herein, we introduce an “atomic size misfit” strategy to modulate active sites, and report a facile synthesis of a Pb-doped Cu catalyst with numerous atomic Pb-concentrated grain boundaries. Operando spectroscopy studies demonstrate that these Pb-rich Cu-grain boundary sites exhibit stable low coordination and can achieve a stronger CO adsorption for a higher surface CO coverage. Using this Pb-Cu catalyst, we achieve a CO-to-n-propanol FE (FEpropanol) of 47 ± 3% and a half-cell energy conversion efficiency (EE) of 25% in a flow cell. When applied in a membrane electrode assembly (MEA) device, a stable FEpropanol above 30% and the corresponding full-cell EE of over 16% are maintained for over 100 h with the n-propanol partial current above 300 mA (5 cm2 electrode). Furthermore, operando X-ray absorption spectroscopy and theoretical studies reveal that the structurally-flexible Pb-Cu surface can adaptively stabilize the key intermediates, which strengthens the *CO binding while maintaining the C–C coupling ability, thus promoting the CO-to-n-propanol conversion