Project description:We studied the application of transcriptome technology in alfalfa selenium treatment. After spraying sodium selenite on the leaves, the process of selenium absorption and assimilation of alfalfa is unknown. The time point of transcriptome determination was determined by measuring the change of selenium content. Our results showed that 12 h was the key point of the change of selenium content in alfalfa, that is, the selenium content increased continuously before 12 h, decreased gradually after 12 h, and remained stable after 48 h. Transcriptome sequencing showed that phosphorus transporter and endocytosis related genes may be involved in selenium absorption at 12 h compared with 0 H. 12-48 h, some thiometabolic pathways may be involved in selenium metabolism and ubiquitination pathway, which may be the detoxification pathway of selenoprotein.
Project description:Methanococcus maripaludis utilizes selenocysteine-(Sec-) containing proteins (selenoproteins), mostly active in the organism’s primary energy metabolism, methanogenesis. Under selenium depletion, M. maripaludis employs a set of enzymes containing cysteine (Cys) instead of Sec. The genes coding for these Sec-/Cys-containing isoforms are the only genes known expression of which is influenced by the selenium status of the cell. Using quantitative proteomics and transcriptomics approx. 7% and 12%, respectively, of all genes/proteins were differentially expressed/synthesized in response to the selenium supply. Some of the genes identified involve methanogenesis, nitrogenase functions, and putative transporters. An increase of transcript abundance for putative transporters under selenium-depleted conditions indicated the organism’s effort to tap into alternative sources of selenium. Selenium sources M. maripaludis is known to utilize are selenite and dimethylselenide. To expand this list, a selenium responsive reporter strain was assessed with nine other, environmentally relevant selenium species. While some had a similar biological window as selenite, others were effectively utilized at lower concentrations. Conversely, selenate and seleno-amino acids were only utilized at unphysiologically high concentrations and two compounds were not utilized at all. To address the role of the selenium-regulated putative transporters in selenium transport, M. maripaludis mutant strains lacking one or two of the putative transporters were tested for the capability to utilize the different selenium species. Of the five putative transporters analyzed by loss-of-function mutagenesis, none appeared to be absolutely required for utilizing any of the selenium species tested, indicating they have redundant and/or overlapping specificities, or are not dedicated selenium transporters.
Project description:To better understand the immunosuppressor mechanism of ptaquiloside in splenic NK cells and the reversion of this effect by selenium, we have employed whole genome microarray expression profile to identify genes associated with immunosuppression. Among 89 genes induced by ptaquiloside treatment in splenic NK cells only two genes (Mt1 and Mt2) were identified as related with its immunosuppressor effect. Moreover this augmented expression of Mt1 and Mt2 was totally abrogated by selenium co-treatment. These results were confirmed by flow cytometry in splenic cells harvested from other six mice and treated in vitro for 1 hour with ptaquiloside and/or selenium.
Project description:Evidence from biochemical indicators suggested that selenium could effectively repair the liver injury caused by beta-cypermethrin (β-CYP). However, the molecular mechanisms of selenium against liver injury induced by β-CYP remains unclear. In the present study, dynamic changes in gene expression profiles before and after the treatment of Na2SeO3 in liver injury mice were analyzed by using RNA sequencing. As a result, several essential genes and pathways were identified to be significantly associated with this process.
Project description:To better understand the immunosuppressor mechanism of ptaquiloside in splenic NK cells and the reversion of this effect by selenium, we have employed whole genome microarray expression profile to identify genes associated with immunosuppression. Among 89 genes induced by ptaquiloside treatment in splenic NK cells only two genes (Mt1 and Mt2) were identified as related with its immunosuppressor effect. Moreover this augmented expression of Mt1 and Mt2 was totally abrogated by selenium co-treatment. These results were confirmed by flow cytometry in splenic cells harvested from other six mice and treated in vitro for 1 hour with ptaquiloside and/or selenium. Twenty mice were separated randomly into four groups as Control (water), Pt (ptaquiloside 5.3 mg/kg), PtSe (ptaquiloside 5.3 mg/kg and selenium 1.3 mg/kg) and Se (selenium 1.3 mg/kg) and were treated daily by gavage for 14 days. After treatment, untouched NK cells were isolated using the NK cell isolation kit, LS columns, and QuadroMACS cell separator system (Miltenyi Biotec, Inc.) to perform RNA isolation and whole-genome gene expression profile. Thereby, five independent experiments were performed per group using different donors for each experiment. To confirm the increase of metallothionein protein induced by ptaquiloside, splenic cells were harvested from other six mice and treated in vitro for 1 hour with ptaquiloside [4.4 M-BM-5g/mL] and/or selenium [0.1 mM] and analyzed by flow cytometry.
Project description:We studied the application of transcriptome technology in alfalfa selenium (Se) treatment. Alfalfa had different states after different concentrations of Se treatment. It shows that lower concentration promoted growth and higher concentration produced toxicity. The positive regulatory effects of moderate Se (100 mg / kg) on alfalfa was determined through preliminary experiments, and the gene expression of Alfalfa under this treatment was further analyzed by transcriptome.
Project description:We used selenium as a photodynamic anti-tumor synergist of phycocyanin to explore its inhibitory effect on lung cancer and its molecular mechanism in vitro. First of all, we used LLC-luc mouse lung cancer cells to establish a tumor-bearing model. Selenium-enriched phycocyanin was injected next to the tumor. When it was absorbed by the tumor tissue, the tumor site was irradiated by a 620nm wavelength laser. The changes in tumor size were monitored in real-time and the physiological indexes of mice were measured. It was found that selenium phycocyanin photodynamic therapy could enhance the inhibitory effect of tumors and improve the level of antioxidation in tumor-bearing mice. In addition, the pathological section observation and electron microscope microstructure analysis of the tumor tissue showed that the effect of the selenium-enriched phycocyanin photodynamic treatment group was more significant. At the same time, the tumor tissue transcriptional group sequencing analysis and qRT-PCR verification analysis showed that selenium-enriched phycocyanin photodynamic treatment group could reduce the expression of Mmp13, Serpine1, Vegfa, and Ppbp genes inhibit tumor cell metastasis and proliferation, up-regulate the expression of Ccl2, Ccl3, Cxcl2 and down-regulate the expression of Ccl24 chemokine, and promote tumor local immunity. Our results show that selenium phycocyanin photodynamic therapy plays an anti-tumor effect by promoting tumor cell apoptosis, reducing inflammation, and promoting tumor immunity.
Project description:Moderate selenium deficiency may lead to an impaired capacity to cope with health challenges. Functional effects of suboptimal selenium intake are not fully known, and biomarkers for an insufficient selenium supply are inadequate. We therefore fed mice diets of moderately deficient or adequate selenium intake for 6 weeks. Changes in global gene expression were monitored by microarray analysis in splenic leukocytes. Genes for four selenoproteins, Sepw1, Gpx1, Selh and Sep15, were the most significantly down-regulated in moderate selenium deficiency, and this was confirmed by quantitative polymerase chain reaction (qPCR). Classification of significantly affected genes revealed that processes related to inflammation, heme biosynthesis, DNA replication and transcription, cell cycle and transport were affected by selenium restriction. Down-regulation by moderate selenium deficiency of specific genes involved in inflammation and heme biosynthesis was confirmed by qPCR. Myeloperoxidase and lysozyme activities were decreased in selenium-restricted leukocytes, providing evidence for functional consequences. Genes for 31 nuclear factor (NF)-κB targets were down-regulated in moderate selenium deficiency, indicating an impaired NF-κB signaling. Together, the observed changes point to a disturbance in inflammatory response. The selenoproteins found here to be sensitive to selenium intake in murine leukocytes might also be useful as biomarkers for a moderate selenium deficiency in humans.