Project description:TA inhibits cellulose synthesis but its actual mode of action is unknown. Addition of TA to hybrid poplar (Populus trichocarpa x Populus deltoides) cell suspensions can activate a cellular program leading to cell death. In contrast, it is possible to habituate hybrid poplar cell cultures to grow in the presence of TA levels that would normally induce cell death. This habituation was performed by adding increasing levels of TA to cell cultures at the time of subculture over a period of 12 months. TA-habituated cells were then cultured in the absence of TA for more than 18 months. These cells displayed a reduced size and growth compared to control cells and had fragmented vacuoles filled with electron-dense material. Habituation to TA was associated with changes in the cell wall composition, with a reduction in cellulose and an increase in pectin levels. Remarkably, high level of resistance to TA was maintained in TA-habituated cells even after being cultured in the absence of TA. Moreover, these cells exhibited enhanced resistance to two other inhibitors of cellulose biosynthesis, dichlobenil and isoxaben. Analysis of gene expression in TA-habituated cells using Affymetrix GeneChip Poplar Genome Array revealed that durable resistance to TA is associated with a major and complex reprogramming of gene expression implicating processes such as cell wall synthesis and modification, lignin and flavonoid synthesis, as well as DNA and chromatin modifications.
Project description:TA inhibits cellulose synthesis but its actual mode of action is unknown. Addition of TA to hybrid poplar (Populus trichocarpa x Populus deltoides) cell suspensions can activate a cellular program leading to cell death. In contrast, it is possible to habituate hybrid poplar cell cultures to grow in the presence of TA levels that would normally induce cell death. This habituation was performed by adding increasing levels of TA to cell cultures at the time of subculture over a period of 12 months. TA-habituated cells were then cultured in the absence of TA for more than 18 months. These cells displayed a reduced size and growth compared to control cells and had fragmented vacuoles filled with electron-dense material. Habituation to TA was associated with changes in the cell wall composition, with a reduction in cellulose and an increase in pectin levels. Remarkably, high level of resistance to TA was maintained in TA-habituated cells even after being cultured in the absence of TA. Moreover, these cells exhibited enhanced resistance to two other inhibitors of cellulose biosynthesis, dichlobenil and isoxaben. Analysis of gene expression in TA-habituated cells using Affymetrix GeneChip Poplar Genome Array revealed that durable resistance to TA is associated with a major and complex reprogramming of gene expression implicating processes such as cell wall synthesis and modification, lignin and flavonoid synthesis, as well as DNA and chromatin modifications. Experiment Overall Design: Each sample was taken from an individual flask of control cells or TA-habituated resistant cells grown without the toxin for 18 months (TA(-)hab cells) that had grown for 5 d after subculture. Six arrays were hybridized, representing 3 arrays per cell type.
Project description:Six different Solanaceae species, Potato (Solanum tubersosum), Tomato (Lycopersicum esculentum), Pepper (Capsicum annuum), Tobacco (Nicotiana tabaccum), Petunia and Nicotiana benthiamana were grown at 25C, 16h light and 8h darkness. Mature leaves were harvested after 4-6 weeks. RNA was isolated using Qiagen RNeasy. Tomato, pepper, petunia, tobacco and N. benthamiana samples were hybridized against potato samples. Keywords: Solanaceae comparative gene expression profiling
Project description:High endothelial venules (HEVs) are specialized postcapillary venules that mediate lymphocyte trafficking from the blood into lymph nodes. HEV-like blood vessels are found in solid tumors in association with CD8+ T cell infiltration.This study uses single cell RNA-sequencing using the Fluidigm C1 system as a method to evaluate the transcriptome in lymph node and tumor-associated HEV endothelial cells (LN-HECs and TA-HECs). We isolated MECA-79+ TA-HECs and CD31+MECA-79- tumor-associated endothelial cells (TA-ECs) by cell sorting and we compared their transcriptome to those of their counterparts in homeostatic (LN-HECs and LN-ECs) or inflamed (iLN-HECs) lymph nodes. TA-HECs express high levels of endothelial cell markers Cdh5 and Pecam1 (CD31), post-capillary venule marker Ackr1 (DARC) and venous transcription factor Nr2f2, indicating that they correspond to post-capillary venule endothelium, like their lymph node counterparts. The genes encoding HEV sialomucins decorated by the sulfated MECA-79 epitope (CD34 and Emcn, endomucin) and the core 1 branching enzyme B3gnt3 that is essential for its biosynthesis, are equally expressed in all HEC populations, whereas sulfotransferases Chst2 and Chst4 are expressed at lower levels in TA-HECs. Although TA-HECs are molecularly distinct from lymph node HECs, they share several important characteristics with iLN-HECs, including the upregulation of endothelial selectins (Selp, Sele) and inflammatory chemokines CXCL9 and CXCL10, the ligands for chemokine receptor CXCR3 on effector T cells. Finally, endothelial cell adhesion molecules ICAM1, ICAM2 and VCAM1 that are important for lymphocyte sticking to HEVs, are expressed at similar levels in all HECs. Together, these findings indicated that MECA-79+ TA-HECs, similar to HECs in immune-stimulated lymph nodes, exhibit an inflamed phenotype characterized by co-expression of MECA-79+ antigens with endothelial selectins and inflammatory chemokines.
Project description:Lycium barbarum, a member of the Solanaceae family, has been used for more than 2000 years in the traditional Chinese medicine. L. ruthenicum, endemic to northwestern China, is also used as medicine and has had a great influence on the development of Minority Medicine. Previous studies revealed there are many differences between two species, including morphological and phytochemical differences. However, the molecular mechanism of formation of its fruit and associated medicinal and nutritional components is unexplored. In the present studies, for transcriptomic analyses, fruits from 5 developmental stages L. barbarum and L. ruthenicum were collected. KEGG analyses for the DEGs between L. barbarum and L. ruthenicum, revealed that molecular mechanism of fruit formation were distinct obviously during the development process. Moreover, we found that multiple DEGs enriched in “Phenylpropanoid biosynthesis (ID: ko00940”, “Flavonoid biosynthesis” (ID: ko00941) were up-regulated in L. ruthenicum at different developmental stages of fruit. It suggested that biotic and abiotic stress might be responsible for high abundance of antioxidant capacities in L. ruthenicum.
Project description:Global identification of activated GR and p65 binding sites and target genes using ChIP-seq in HeLa B2 cells. generation genome-wide chromatin state-maps of GR, p65 and RNAPII in HeLa B2 cells under conditions 1) DMSO (control); 2) TA 1M-BM-5M 4hr; 3) TNFM-NM-1 10ng/ml ; 4) TA 1M-BM-5M 4hr at at third hour 10ng/ml TNF M-NM-1 was added
Project description:The mechanism of egress of mature regulatory T cells (Tregs) from the thymus to the periphery remains enigmatic, as does the nature of those factors expressed in the thymic environment. Here, we examined the fate of thymic Tregs in TNFα/RelA double-knockout (TA-KO) mice, because TA-KO mice retain a Treg population in the thymus but have only a small Treg population at the periphery. Transplantation of whole TA-KO thymus to under the kidney capsule of Rag1 null mice failed to induce the production of donor-derived splenic Tregs expressing neuropilin-1 (Nrp1), which was reported to be a marker of naturally occurring Tregs, indicating that TA-KO thymic Tregs either do not leave the thymus or are lost at the periphery. We next transplanted enriched TA-KO thymic Tregs to the peripheries of TA-KO mice and traced mouse survival. Transplantation of TA-KO thymic Tregs rescued the lethality in TA-KO mice, demonstrating that TA-KO thymic Tregs remain functional at the periphery. The TA-KO thymic Treg population had highly demethylated CpG motifs in the foxp3 locus, indicating that the cells were arrested at a late-mature stage. Also, the population included a large subpopulation of Tregs expressing IL-7Rα, which is a possible marker of late-mature Tregs. Finally, TA-KO fetal liver chimeric mice developed an Nrp1+ splenic Treg population from TA-KO cells, suggesting that Treg arrest is caused by a lack of RelA in the thymic environment. Together, these results suggest that egress of mature Tregs from the thymus depends on RelA in the thymic environment.