Project description:Significant occupational and environmental exposures to hexavalent chromium, a metal with broad toxicity potential in humans, have been reported. In order to understand the mechanisms of dermal toxicity induced by hexavalent chromium, global gene expression profiling of human dermal fibroblasts exposed to a toxic concentration of potassium dichromate was performed. Microarray analysis of the gene expression profile in the fibroblasts treated with potassium dichromate identified significant differential expression of approximately 1,200 transcripts compared with the control cells. Hierarchical cluster analysis of the gene expression profile demonstrated a clear separation of the treated cells from the control group of cells. Functional categorization of the differentially expressed genes identified the enrichment of genes involved in several cellular processes, including apoptosis and oxidative stress, in the fibroblasts exposed to hexavalent chromium. Induction of apoptosis and generation of hydroxyl radicals indicative of oxidative stress in the dermal fibroblasts in response to their exposure to hexavalent chromium were independently confirmed by TUNEL assay and electron spin resonance (ESR) analysis, respectively. The potassium dichromate-induced cytotoxicity, differential gene expression, apoptosis, and oxidative stress were significantly blocked by the addition of ferrous sulfate, an agent known for its ability to reduce hexavalent chromium to the insoluble and therefore impermeable trivalent form, to the cell culture medium. Taken together, our data provide insights into the potential mechanisms underlying the dermal toxicity of hexavalent chromium and suggest a definite role for apoptosis and oxidative stress in Cr(VI)-induced cytotoxicity in human dermal fibroblasts. 16 samples were analyzed in this experiment. Exponentially growing human dermal fibroblasts (3x105 cells) were cultured in T25 cell culture flasks. When the cells were approximately 70% confluent, hexavalent potassium dichromate (5µM) was added to the medium with or without 40µM ferrous sulfate. Following 16 hours of culturing at 37oC, total RNA was isolated for gene expression studies. Details of the samples are: Control 4 Samples: Cr(0)-1, Cr(0)-2, Cr(0)-3, Cr(0)-4 Cr 5 µM 4 Samples: Cr(5)-5, Cr(5)-6, Cr(5)-7, Cr(5)-8 FeSO4 40 µM 4 Samples: Fe(40)-9, Fe(40)-10, Fe(40)-11, Fe(40)-12 Cr 5 µM + FeSO4 40 µM 4 Samples: Cr(5)+Fe(40)-13,Cr(5)+Fe(40)-14, Cr(5)+Fe(40)-15, Cr(5)+Fe(40)-16
Project description:au10-14_fer - response of ein3eil1 mutants to fe deficiency - Response of ein3eil1 mutants to Fe deficiency - Wild type seedlings and ethylene insensitive ein3eil1 seedlings were germinated and grown in the presence of 50 µM Fe or absence of Fe (0 µM) on Hoagland medium agar plates until the age of 6 days. Under these growth conditions symptoms of Fe deficiency develop in the 0 Fe plants. Ethylene is known to promote Fe acquisition responses. Whole seedlings were harvested for transcriptome analysis, in a total of three biological replicates.
Project description:Several phytohormones and other small molecules have been demonstrated to be involved in iron (Fe) homeostasis. However, how salicylic acid (SA), an essential hormone in plant immunity and defense responses, participates in Fe-deficiency responses in plants is largely unknown. Here, we took advantage of a SA biosynthesis defect mutant phytoalexin deficient 4 (pad4: T-DNA Salk_089936) to explore the possible effects of endogenous SA on the morphological and physiological responses to Fe deprivation. Under a Fe-deficiency treatment, Col-0 showed more severe leaf chlorosis and root growth inhibition compared with the pad4 mutant. The soluble Fe concentrations were significant higher in pad4 than Col-0 under the Fe-deficiency treatment, suggesting that a mutation in the PAD4 gene may alleviate the Fe-deficiency-induced symptoms by regulating the soluble Fe concentrations. Furthermore, a SA signaling maker line (PR1promoter: GUS) was used to investigate how Fe deficiency affects endogenous SA biosynthesis and metabolism. The data showed that Fe deficiency significantly induced SA accumulation in Col-0, and the loss function of PAD4 blocked this process. The requirement of endogenous SA accumulation for Fe-deficiency responses was confirmed using a series of SA biosynthetic mutants and transgenic lines.
Project description:RNAseq transcriptome of leaves and roots of Arabidopsis thaliana Columbia-0 grown under control (ES media) and Fe-deficiency (-Fe +100 µM FRZ) conditions.
Project description:Calorie restriction (CR) extends lifespan by modulating the mechanisms involved in aging. We quantified the hepatic proteome of male C57BL/6 mice exposed to graded levels of CR (0% to 40% CR) for three months, and evaluated which signaling pathways were most affected.
Project description:Arabidopsis wild-type plants (Col-0 accession) were grown on control (+Fe+P) for 7 days on 0.1X MS then transferred to three different medium: control (+Fe+P), iron deficiency (-Fe+P), and iron and phosphate deficiency conditions (-Fe-P). Shoots were collected 39 h, 52 h and 76 h after the transfer. For RNA-seq experiments, three biological replicates were used for each time point (39h, 52h and 76h) and each condition (+Fe+P, -Fe+P and -Fe-P) for a total of 27 samples.
Project description:We reported the flg22-triggered immune responses in roots affect the iron deficiency responses and may link to the function of FLS2 and IMA1 in the root. To identify the underlying mechanism of how the root transcriptome profiles respond to +Fe, +Fe+flg22, -Fe, -Fe+flg22 respectively, and if the flg22 responses is dependent on the function of FLS2 and IMA1 in the root, we performed an mRNA-seq experiments in Col-0, fls2 and UBQ10::mCitrine-IMA1 with different treatments. The differentially expressed genes in response to +Fe, +Fe+flg22, -Fe, -Fe+flg22 were analyzed. It has 36 samples in total, with 3 biogical replicates for each condition and each genotype.
Project description:Iron (Fe) and copper (Cu) are essential metal micronutrients that are necessary for many redox reactions. The uptake of these metals is tightly regulated in plants. Some redox processes can alternatively use Fe-containing proteins or Cu-containing proteins, depending on nutritional status. Copper deficiency can rescue a Cucumis melo Fe uptake deficient mutant, and Fe deficiency can result in increased accumulation of Cu. However, the system responsible for Fe-deficiency-regulated Cu-uptake is unknown. To understand the genes and gene networks associated with Fe-deficiency regulated Cu uptake and Fe-Cu cross-talk, we conducted transcriptomic profiling of roots and rosettes of spl7 (a Cu uptake deficient mutant in arabidopsis) and Col-0 (WT) grown under Fe, Cu and simultaneous Fe and Cu deficiency conditions.
Project description:au13-07_ox - comparison 39ox and wt samples with or without fe - Differential gene expression between 39Ox and WT at +Fe and -Fe - WT (Col-0) and 39Ox seeds were surface sterilized and grown directly on +Fe or -Fe Hoagland medium for 6 days. 60 whole seedlings were harvested in liquid nitrogen and grinded to a fine powder. Total RNA was extracted with the Spectrum Plant total RNA kit (Sigma-Aldrich). 8 µg total RNA was sent to analysis. For validation of the results, RT-qPCR was performed using the same RNA samples.