Project description:In this study we show that cAMP helps regulate cytosine demethylation through augmenting the intracellular labile ferrous iron pool.
Project description:Liver iron overload can induce hepatic expression of hepcidin and regulates iron metabolism. However, the mechanism of iron regulating iron metabolism remains known. Intracellular labile iron represents the nonferritin-bound, redox-active iron which is transitory and serves as a crossroad of cell iron metabolism. The role of intracellular labile iron played in iron metabolism has largely been elucidated. Here we show that intracellular labile iron of hepatocytes has dual function in iron metabolism. It can induce hepatocytes expressing hepcidin via ER stress induced transcription factors on the one hand, on the other hand stimulate BMP2 and BMP6 expression of liver sinusoidal endothelial cells (LSECs) though TNFα secreted by hepatocytes to further regulate iron metabolism. Blockade of TNFα could dysregulate the iron metabolism during iron overload. Our findings reveal the important role of intracellular labile iron in iron metabolism and represent a novel way to modulate iron metabolism during iron overload.
Project description:Systemic iron metabolism is disrupted in chronic kidney disease (CKD). However, little is known about local kidney iron homeostasis and its role in kidney fibrosis. Kidney-specific effects of iron therapy in CKD also remain elusive. Here, we elucidate the role of macrophage iron status in kidney fibrosis and demonstrate that it is a potential therapeutic target. In CKD, kidney macrophages exhibited depletion of labile iron pool (LIP) and induction of transferrin receptor 1, indicating intracellular iron deficiency. Low LIP in kidney macrophages was associated with their defective antioxidant response and proinflammatory polarization. Repletion of LIP in kidney macrophages through knockout of ferritin heavy chain (Fth1) reduced oxidative stress and mitigated fibrosis. Similar to Fth1 knockout, iron dextran therapy, through replenishing macrophage LIP, reduced oxidative stress, decreased the production of proinflammatory cytokines, and alleviated kidney fibrosis. Interestingly, iron markedly decreased TGF-β expression and suppressed TGF-β–driven fibrotic response of macrophages. Iron dextran therapy and FtH suppression had an additive protective effect against fibrosis. Adoptive transfer of iron-loaded macrophages alleviated kidney fibrosis, validating the protective effect of iron-replete macrophages in CKD. Thus, targeting intracellular iron deficiency of kidney macrophages in CKD can serve as a therapeutic opportunity to mitigate disease progression.
Project description:We explored the transcriptome change of Streptococcus suis in the presence of ferrous iron and cobalt by RNA sequencing. The data revealed that expression of a lot of genes was altered to respond to ferrous iron and cobalt toxicity. Moreover, most of the genes differentially expressed in response to cobalt are the same as those in response to ferrous iron.
Project description:Aspartyl-tRNA synthetase 2 (Dars2) is involved in the regulation of mitochondrial protein synthesis and tissue-specific mitochondrial unfolded protein response (UPRmt). The role of Dars2 in the self-renewal and differentiation of hematopoietic stem cells (HSCs) is unknown. Here we show that knockout (KO) of Dars2 significantly impairs the maintenance of HSCs and progenitor cells (HSPCs) without involving its tRNA synthetase activity. Dars2 KO results in significantly reduced expression of Srsf2/3/6 and impairs multiple events of mRNA alternative splicing (AS). Dars2 directly localizes to Srsf3 labeled spliceosomes in HSPCs and regulates the stability of Srsf3. Dars2-deficient HSPCs exhibit aberrant AS of mTOR and Slc22a17. Dars2 KO greatly suppresses the levels of labile ferrous iron and iron-sulfur cluster containing proteins, which dampens mitochondrial metabolic activity and DNA damage repair pathway in HSPCs. Our study reveals that Dars2 plays an unprecedented role in the iron-sulfur metabolism and maintenance of HSPCs by modulating RNA splicing.
Project description:transcriptomic study of the impact of iron toxicity on rice plant (Oryza sativa L.; cv M-bM-^@M-^XI Kong PaoM-bM-^@M-^Y ) after short term (3 days) or long term (3 weeks) exposure to ferrous iron (125 ppm). Twenty five days old rice seedlings were exposed to 0 or 125 mg/L ferrous iron for 3 days and 3 weeks in hydroponic culture. Comparison between control and iron stressed plants were done at the shoot and the root levels. The assays were replicated twice on two independent plant cultures. 8 samples, Two-condition experiment, control (0 ppm ferrous iron) vs. iron treated (125 ppm ferrous iron). Biological replicates: 2 replicates for comparison shoot 3 days of stress, root 3 days of stress, shoot 3 weeks of stress and root 3 weeks of stress.
Project description:Adipocyte differentiation has been shown to require iron, but the underlying mechanism remains elusive. Ferrous iron ion is known to function as a co-factor for alpha-ketoglutarate-dependent dioxygenases, including demethylases for histones, DNA, and RNA. Previously we reported several alpha-ketoglutarate-dependent histone demethylases as critical epigenetic regulators during adipogenesis. These lines of evidence led us to hypothesize that iron orchestrates epigenetic/epitranscriptional regulations during adipogenesis by controlling demethylation activities. In this study, we conducted genome-wide analysis on methylation landscapes of histones, DNA, and RNA in differentiation of 3T3-L1 pre-adipocytes. Using the iron chelator deferoxamine, we demonstrate here how dynamically methylation levels of histones, DNA, and RNA are regulated by iron during adipogenesis.
Project description:Adipocyte differentiation has been shown to require iron, but the underlying mechanism remains elusive. Ferrous iron ion is known to function as a co-factor for alpha-ketoglutarate-dependent dioxygenases, including demethylases for histones, DNA, and RNA. Previously we reported several alpha-ketoglutarate-dependent histone demethylases as critical epigenetic regulators during adipogenesis. These lines of evidence led us to hypothesize that iron orchestrates epigenetic/epitranscriptional regulations during adipogenesis by controlling demethylation activities. In this study, we conducted genome-wide analysis on methylation landscapes of histones, DNA, and RNA in differentiation of 3T3-L1 pre-adipocytes. Using the iron chelator deferoxamine, we demonstrate here how dynamically methylation levels of histones, DNA, and RNA are regulated by iron during adipogenesis.
Project description:Adipocyte differentiation has been shown to require iron, but the underlying mechanism remains elusive. Ferrous iron ion is known to function as a co-factor for alpha-ketoglutarate-dependent dioxygenases, including demethylases for histones, DNA, and RNA. Previously we reported several alpha-ketoglutarate-dependent histone demethylases as critical epigenetic regulators during adipogenesis. These lines of evidence led us to hypothesize that iron orchestrates epigenetic/epitranscriptional regulations during adipogenesis by controlling demethylation activities. In this study, we conducted genome-wide analysis on methylation landscapes of histones, DNA, and RNA in differentiation of 3T3-L1 pre-adipocytes. Using the iron chelator deferoxamine, we demonstrate here how dynamically methylation levels of histones, DNA, and RNA are regulated by iron during adipogenesis.
Project description:Abstract: The crenarchaeal order Sulfolobales collectively contains at least five major terminal oxidase complexes. Based on genome sequence information, all five complexes are found only in Metallosphaera sedula and Sulfolobus tokodaii, the two sequenced Sulfolobales capable of iron oxidization. While specific respiratory complexes in certain Sulfolobales have been characterized previously as proton pumps for maintaining intracellular pH and generating proton motive force (pmf), their contribution to sulfur and iron biooxidation has not been considered. For M. sedula growing in the presence of ferrous iron and reduced inorganic sulfur compounds (RISCs), global transcriptional analysis was used to track the response of specific genes associated with these complexes, as well as other known and putative respiratory electron transport chain elements. ORFs from all five terminal oxidase or bc1-like complexes were stimulated on one or more conditions tested. Components of the fox (Msed0467-0489) and soxNL-cbsABA (Msed0500-0505) terminal/quinol oxidase clusters were triggered by ferrous iron, while the soxABCDD' terminal oxidase cluster (Msed0285-0291) were induced by tetrathionate and S°. Chemolithotrophic electron transport elements, including a putative tetrathionate hydrolase (Msed0804), a novel polysulfide/sulfur/DMSO reductase-like complex (Msed0812-0818), and a novel heterodisulfide reductase-like complex (Msed1542-1550), were also stimulated by RISCs. Furthermore, several hypothetical proteins were found to have strong responses to ferrous iron or RISCs, suggesting additional candidates in iron or sulfur oxidation-related pathways. From this analysis, a comprehensive model for electron transport in M. sedula could be proposed as the basis for examining specific details of iron and sulfur oxidation in this bioleaching archaeon.