Project description:Background: MicroRNAs play important roles in the adaptive responses of plants to nutrient deficiencies. Here, we sequenced two small RNA libraries from B-deficient and -sufficient (control) Citrus sinensis leaves, respectively, using Illumina sequencing in order to identify the potential miRNAs related to the tolerance of citrus to B-deficiency. Results: Ninety one (83 known and 8 novel) up- and 81 (75 known and 6 novel) downregulated miRNAs were isolated from B-deficient leaves. The great alteration of miRNA expression might contribute to the tolerance of citrus to B-deficiency. The adaptive responses of miRNAs to B-deficiency might related to several aspects: (a) attenuation of plant growth and development by repressing auxin signaling due to decreased TIR1 level and ARF-mediated gene expression by altering the expression of miR393, miR160 and miR3946; (b) maintaining leaf phenotype and enhancing the stress tolerance by up-regulating NACs targeted by miR159, miR782, miR3946 and miR7539; (c) activation of the stress responses and antioxidant system through down-regulating the expression of miR164, miR6260, miR5929, miR6214, miR3946 and miR3446; (d) decreasing the expression of major facilitator superfamily protein genes targeted by miR5037, thus lowering B export from plants. Also, B-deficiency-induced downregulation of miR408 might play a role in plant tolerance to B-deficiency by regulating Cu homeostasis and enhancing superoxide dismutase activity. Conclusions: Our study reveals some novel responses of citrus to B-deficiency, which increase our understanding of the adaptive mechanisms of citrus to B-deficiency at the miRNA (post-transcriptional) level.
Project description:In China, magnesium (Mg)-deficiency often occurs in citrus orchards, and is responsible for the loss of yield and poor fruit quality. However, very limited data are available on Mg-deficiency-responsive microRNAs (miRNAs) in higher plants. Using Illumina sequencing, we isolated 93 (91 known and 2 novel) up- and 90 (83 known and 7 novel) down-regulated miRNAs from Mg-deficient Citrus sinensis leaves. In addition to the remarkable metabolic flexibility as indicated by the great alteration of miRNA expression, the adaptive responses of leaf miRNAs to Mg-deficiency might also involve the following aspects: (a) accelerating protein turnover and amino acid biosynthesis by repressing the expression of miR2919, miR7812, miR5904 and miR5742; (b) up-regulating stress-related genes by down-regulating miR2919, miR164 and miR7812; (c) enhancing cell transport due to decreased expression of miR2919, miR3946, miR7533, miR1222, miR779, miR6143 and miR2868 and increased expression of miR395, miR1077, miR1160 and miR8019; (d) activating lipid metabolism-related genes by repressing miR158, miR1222, miR7533 and miR3946; (e) inducing cell wall-related genes by decreasing miR7533, miR779 and miR2868 expression; and (f) maintaing primary meristems by down-regulating miR6135. To conclude, we identified some candidate miRNAs that might contribute to Mg-deficiency tolerance. Our results are usefult not only for increasing our understaning of the molecular mechanisms on plant Mg-deficiency tolerance at post-transcriptional level, but also for obtaining the key miRNAs for plant Mg-deficiency tolerance.
Project description:a novel orphan peptide, IRON-REGULATED PROTEIN1 (IRP1) that is rapidly induced by Fe deficiency and improves growth on Fe-deplete media. In Arabidopsis, ectopic expression of IRP1 affected the activity of several genes involved in Fe acquisition and homeostasis, causing a dramatic increase of Fe in leaves and enhanced seed Fe loading. Heterologous expression of IRP1 in tomato plants resulted in increased Fe levels in fruits. Integration of AtIRP1 into the genome of crop plants may represent a novel strategy for Fe biofortification. wild type Col-0 and transgenic overexpressor IRP1-OE plants were grown under normal conditions or subjected to and iron-starvation for 3 days. Roots and shoots were collected with 3 biological replicates.
Project description:NF1 deficiency drives metabolic reprogramming in ER+ breast cancer. This reprogramming is characterized by oxidative ATP constraints, glutamine TCA influx, and lipid pool expansion, and these metabolic changes introduce novel metabolic-to-targeted inhibitor synergies.
Project description:ApoE exerts pleiotropic properties in controlling inflammation and myeloid cell activation. We here uncover microRNA regulation as yet another mechanism that ApoE acts upon to control immune cell activity and inflammatory response. We compared the expression of microRNAs in BMDM derived from ApoE-KO (EKO) or WIldtype (WT) mice and identified 78 microRNAs to be differentially expressed between these two groups. Among these microRNAs, we identified miR-146a-5p to be highly upregulated in WT BMDM as compared to EKO BMDM. This is consistent with our prior study that reports a role of ApoE in promoting the biogenesis of this microRNA via the transcription of its host gene PU.1 (Spi1) in monocytes/macrophages. Of note, miR-146a-5p is recognized as a potent inhibitor of the NF-κB signaling pathway via the inactivation of IRAK1 and TRAF6. Furthermore, we identified mIR-142a-3p as downregulated in WT BMDM as compared to EKO BMDM. This microRNA has been reported to control important metabolic functions in myeloid cells by targeting the long chain fatty acid transporter CPT1A, thereby inhibiting fatty acid oxidation. Our data thus uncovers another novel of ApoE in controlling lipid metabolism in myeloid cells by suppressing the expression of miR-142a-3p. Taken together, our data provide a novel framework for the microRNA signatures regulated by ApoE in myeloid cells. Moreover, we uncovered an important mechanism of which ApoE can regulate myeloid cell immunometabolism via the regulation of miR-146a-5p and miR-142a-3p.
Project description:Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is silenced by promoter methylation in many types of tumors, yet ASC’s role in most cancers remains unknown. Here, we show that ASC is highly expressed in a model of medulloblastoma, the most common malignant pediatric brain cancer. Importantly, while ASC deficiency did not affect normal cerebellar development, ASC knock-out mice in the Smoothened (ND2:SmoA1) transgenic model of medulloblastoma exhibited a profound reduction in medulloblastoma incidence and delayed tumor onset. Premalignant lesions in cerebella of ASC-/-;ND2:SmoA1 mice displayed a striking decrease in number of ectopic progenitors. While proliferation rates decreased with ASC deletion, apoptosis and differentiation markers remained unchanged. Interestingly, ASC deficiency disrupted expression of genes in the TGF-ß pathway and increased the level of nuclear Smad3 in this medulloblastoma model. Together, these results demonstrate an unexpected requirement for ASC in Sonic hedgehog-driven medulloblastoma tumorigenesis, thus identifying ASC as a promising novel target for anti-tumor therapy. reference x sample
Project description:Background: Since chemical assays of soil nutrients are unreliable the UK horticultural and agricultural industries routinely apply large amounts of inorganic fertiliser to maintain crop yields and quality. Excessive fertiliser applications are both costly and can lead to unnecessary pollution. A possible solution to this problem is to use sensor (GM or non-GM) technologies that exploit the changes in plant gene expression profiles under incipient nutrient deficiency. The aim of this project is to identify genes upregulated in the early stages of nutrient depletion. Methods: Arabidopsis ecotype Col-5 (N1644) will be grown hydroponically using established techniques. In parallel experiments NP and K will be withdrawn individually after 21 d growth. RNA will be extracted from shoots of nutrient replete (control) and nutrient depleted plants 24 h after the removal of nutrients. Shoot nutrient content will be assayed by ICP-EMS as a reference. By comparing expression profiles we will be able to differentiate between genes that are upregulated by lack of specific nutrients and those upregulated by a universal stress-response system. Promoters and transcripts of these genes will underpin the development of novel sensor technologies and knowledge of the gene expression profiles will improve our understanding of the physiology of plant mineral nutrition. Experiment Overall Design: 4 samples
Project description:miRNAs play an important role in growth, development, stress resilience and epigenetic modifications of plants. However, the effect of calcium nutrition on miRNA expression in orphan crops such as tef ((Eragrostis tef) remained unknown. In this study, we analyzed genome-wise miRNAs of roots and shoots in response to long-term calcium deficiency in tef. MiRNA-seq followed by bioinformatic analysis identified a large number of small RNAs with size ranging from 17bp to 35bp. A total 1380 miRNAs were identified in plants experiencing long-term Ca deficiency, while 1495 miRNAs were identified in the control plants. Among the miRNAs identified in this study, 161 miRNAs were known, and 348 miRNAs were novel while the remaining miRNAs were uncharacterized. Putative target genes and their functions were predicted for all the known and novel miRNAs. Based on gene ontology (GO) analysis, the target genes were found to have various biological and molecular functions including calcium uptake and transport. Pairwise comparison of differentially expressed miRNAs revealed that some of the miRNAs were specifically enriched in roots or shoots of low calcium treated plants as compared to control plants. Further characterization of the miRNAs and their targets detected in this study will help in identifying Ca deficiency responses not only in tef but also in related orphan crops