The parasitic helminthTrichinella spiralis, which poses a serious health risk to animals and humans, can be found worldwide. Recent findings indicate that a rare type of gut epithelial cell, tuft cells, can detect the helminth, triggering type 2 immune responses. However, the underlying molecular mechanisms remain to be fully understood. Here we show that both excretory–secretory products (E–S) and extract ofT. spiraliscan stimulate the release of the cytokine interleukin 25 (IL-25) from the mouse small intestinal villi and evoke calcium responses from tuft cells in the intestinal organoids, which can be blocked by a bitter-taste receptor inhibitor, allyl isothiocyanate. Heterologously expressed mouse Tas2r bitter-taste receptors, the expression of which is augmented during tuft-cell hyperplasia, can respond to the E–S and extract as well as to the bitter compound salicin whereas salicin in turn can induce IL-25 release from tuft cells. Furthermore, abolishment of the G-protein γ13 subunit, application of the inhibitors for G-protein αo/i, Gβγ subunits, and phospholipase Cβ2 dramatically reduces the IL-25 release. Finally, tuft cells are found to utilize the inositol triphosphate receptor type 2 (Ip3r2) to regulate cytosolic calcium and thus Trpm5 activity, while potentiation of Trpm5 by a sweet-tasting compound, stevioside, enhances tuft cell IL-25 release and hyperplasia in vivo. Taken together,T. spiralisinfection activates a signaling pathway in intestinal tuft cells similar to that of taste-bud cells, but with some key differences, to initiate type 2 immunity.

Cold stress has been shown to induce the production of reactive oxygen species (ROS), which can elicit a potentially damaging oxidative burden on cellular metabolism. Here, the expression of a metallothionein gene (AtMT2a) was upregulated under low temperature and hydrogen peroxide (H 2 O 2 ) stresses. The Arabidopsis T-DNA insertion mutant, mt2a, exhibited more sensitivity to cold stress compared to WT plants during the seed germination, and H 2 O 2 levels in mt2a mutant were higher than that in WT plants during the cold stress. Synthetic GFP fused to AtMT2a was observed to be localized in cytosol. These results indicated that AtMT2a functions in tolerance against cold stress by mediating the ROS balance in the cytosol. Interestingly, mRNA level of AtMT2a was increased in seedlings of Arabidopsis cat2 mutant after cold treatment compared to WT seedlings, and overexpression of AtMT2a in cat2 could improve CAT activity under chilling stress. Moreover, the enzymatic activity of CAT in mt2a was higher than that in WT plants after cold treatment, suggesting that AtMT2a and CAT might complement each other in antioxidative process potentially in Arabidopsis. Taken together, our results provided a novel insight into the relationship between MTs and antioxidative enzymes in the ROS-scavenging system in plants.

Background/Aims: Triptolide (TP) is a diterpenoid triepoxide extracted from the traditional Chinese medical herb Tripterygium wilfordii that exerts prominent broad-spectrum anticancer activity to repress proliferation and induce cancer cell apoptosis through various molecular pathways. We previously observed that TP inhibits the progression of A549 cells and pancreatic cancer cells (PNCA-1) in vitro. However, the complex molecular mechanism underlying the anticancer activity of TP is not well understood. Methods: To explore the molecular mechanisms by which TP induces lung cancer cell apoptosis, we investigated changes in the protein profile of A549 cells treated with TP using a proteomics approach (iTRAQ [isobaric tags for relative and absolute quantitation] combined with NanoLC-MS/MS [nano liquid chromatographymass spectrometry]). Changes in the profiles of the expressed proteins were analyzed using the bioinformatics tools OmicsBean and the Kyoto Encyclopedia of Genes and Genomes (KEGG) and were verified using western blotting. Apoptosis and cell cycle effects were analyzed using flow cytometry. Results: TP induced apoptosis in A549 cells and blocked A549 cells at the G2/M phase. Using iTRAQ technology, we observed 312 differentially expressed proteins associated in networks and implicated in different KEGG pathways. Gene Ontology (GO) analysis showed the overviews of dysregulated proteins in the biological process (BP), cell component (CC), and molecular function (MF) categories. Moreover, some candidate proteins involved in PARP1/AIF and nuclear Akt signaling pathways or metastasis processes were validated by western blotting. Conclusion: TP exerted anti-tumor activity on non-small cell lung cancer (NSCLC) A549 lung adenocarcinoma cells by dysregulating tumor-related protein expression. Herein, we provide a preliminary study of TP-related cytotoxicity on A549 cells using proteomics tools. These findings may improve the current understanding of the anti-tumor effects of TP on lung cancer cells and may reveal candidate proteins as potential targets for the treatment of lung cancer.

MicroRNAs (miRNAs) function as genetic modulators that regulate gene expression and are involved in a wide range of biological roles, including tumor cell migration and invasion. In the present study, we demonstrated that the migration and invasion activity in MDA-MB-231 breast cancer cells could be directly influenced by altering miR-146a expression. The expression of RhoA and miR-146a in the breast cancer cells showed an inverse correlation. Upregulation of miR-146a in the MDA-MB-231 breast cancer cells by transfection of miR-146a mimics resulted in decreased RhoA protein levels. Conversely, downregulation of miR-146a by transfection of miR-146a inhibitor resulted in increased RhoA protein levels. To confirm the fact that RhoA is a potential target of miR-146a, luciferase reporter containing the RhoA 3′ untranslated region (3′UTR) was constructed. The results demonstrated that the luciferase reporter activity was reduced after overexpression of miR-146a. Moreover, the luciferase reporter which was constructed with the RhoA 3′UTR mutant did not show significantly altered luciferase reporter activity. Furthermore, after treatment with the RhoA inhibitor exoenzyme C3 transferase protein, the migratory capacity of the MDA-MB-231 cells was not significantly altered even though the amount of miR-146a was changed. Our results indicate that miR-146a functions as a tumor suppressor in breast cancer cells. Downregulation of the expression of miR-146a increased the migration of MDA-MB-231 cells, due to the upregulation of RhoA expression.

SAG encodes a MDN1 domain containing protein in Arabidopsis. Seeds of a T-DNA insertion line of this gene exhibited hypersensitivity to ABA, mannitol and NaCl during seed germination and early seedling development. SAG was genetically epistatic to ABI3 and ABI5