Reticulocyte 3 timepoints
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE16174 | GEO | 2009/10/12
SECONDARY ACCESSION(S): PRJNA115061
REPOSITORIES: GEO
Similar Datasets
Project description:Mouse models have proven invaluable for understanding erythropoiesis. Here, we describe an autosomal recessive inherited anemia in the mouse mutant hem6. Hematologic and transplantation analyses revealed a mild, congenital, hypochromic, microcytic anemia intrinsic to the hematopoietic system that is associated with a decreased red blood cell zinc protoporphyrin to heme ratio, indicative of porphyrin insufficiency. Iron uptake experiments showed that hem6 reticulocytes are defective in heme production, but not cellular iron uptake defects. Male hem6 mice are infertile due to defects in sperm structure and motility. Through positional cloning and BAC complementation, we identified the gene responsible for the hem6 anemia. We hypothesized that the relative deficiency in erythroid-specific mRNAs in hem6 reticulocytes might be due to decreased mRNA stability. Indeed, serial microarray analysis of reticulocytes aged in vitro showed that numerous, abundantly expressed erythroid-specific transcripts decayed at faster rates in hem6 reticulocytes compared to control reticulocytes. Furthermore, these mRNAs also have progressively shorter poly (A) tails, suggesting a mechanism for the increased rate of decay. Keywords: serial time points Reticulocyte rich blood were collected and cultured ex vivo for 24 hours, samples were collected at 0, 12,24 hours for microarray analysis. There are 3 wild type (wt) biological replicates and 5 mutant (mut) biological replicates in each time point.
2009-10-12 | E-GEOD-16174 | biostudies-arrayexpress
Project description:Hematopoietic stem cells (HSCs) are capable of regenerating the blood system, but the instructive cues that direct HSCs to regenerate particular lineages lost to the injury remain elusive. Here, we show that iron is increasingly taken up by HSCs during anemia and induces erythroid gene expression and regeneration in a Tet2-dependent manner. Lineage tracing of HSCs revealed that HSCs respond to hemolytic anemia by increasing erythroid output. The number of HSCs in the spleen, but not bone marrow, increased upon anemia and these HSCs exhibited enhanced proliferation, erythroid differentiation, iron uptake, and TET2 protein expression. Increased iron in HSCs promoted DNA demethylation and expression of erythroid genes. Suppressing iron uptake or TET2 expression impaired erythroid genes expression and erythroid differentiation of HSCs; iron supplementation, however, augmented these processes. These results establish that the physiological level of iron taken up by HSCs has an instructive role in promoting erythroid-biased differentiation of HSCs.
2023-12-04 | GSE178215 | GEO
Project description:Hematopoietic stem cells (HSCs) are capable of regenerating the blood system, but the instructive cues that direct HSCs to regenerate particular lineages lost to the injury remain elusive. Here, we show that iron is increasingly taken up by HSCs during anemia and induces erythroid gene expression and regeneration in a Tet2-dependent manner. Lineage tracing of HSCs revealed that HSCs respond to hemolytic anemia by increasing erythroid output. The number of HSCs in the spleen, but not bone marrow, increased upon anemia and these HSCs exhibited enhanced proliferation, erythroid differentiation, iron uptake, and TET2 protein expression. Increased iron in HSCs promoted DNA demethylation and expression of erythroid genes. Suppressing iron uptake or TET2 expression impaired erythroid genes expression and erythroid differentiation of HSCs; iron supplementation, however, augmented these processes. These results establish that the physiological level of iron taken up by HSCs has an instructive role in promoting erythroid-biased differentiation of HSCs.
2023-12-04 | GSE182058 | GEO
Project description:Haemophilus influenzae frequently causes human disease, and humans are it’s sole niche. This bacterium has an absolute requirement for both a porphyrin and an iron source for aerobic growth, and exogenous heme can satisfy both requirements. Heme and iron can be acquired by H. influenzae from free or human protein-bound sources. The ability to selectively regulate the acquisition of heme and iron from physiological sources is a major virulence determinant for this microorganism. We utilized whole genome arrays to identify the full set of H. influenzae Rd KW20 iron and heme regulated genes. Condition specific RNA was derived from cells starved for both heme and iron and cells from the same culture 20 mins after the addition of exogenous iron and heme. The results identified 162 genes with a change in transcription ≥ 1.5 fold. Eighty genes in 42 operons were preferentially expressed under iron/ heme starvation; 82 genes in 50 operons were preferentially expressed under iron/heme replete conditions. In each case, all genes contained within the operon were co-regulated. The former group included genes encoding proteins known to have a role in iron and heme uptake as well as several hypothetical ORFs. Enzymes involved in the gluconeogenesis pathway and glycogen biosynthesis were also upregulated. The genes showing increased transcription immediately after the addition of iron and heme primarily encode proteins involved with aerobic respiration and protein biosynthesis, consistent with a relaxation of starvation. Genomic transcriptional profiling provides a more complete understanding of the effects of iron and heme availability. Keywords: Transcription analyses
2006-07-28 | GSE5061 | GEO
Project description:Porphyromonas gingivalis is a major pathogen associated with the microbial biofilm-mediated disease chronic periodontitis. P. gingivalis has an obligate requirement for iron and protoporphyrin IX which it satisfies by transporting heme and iron liberated from the human host. The level of cellular iron in P. gingivalis affects the expression of a distinct iron-associated regulon of 64 genes and low iron invokes an iron sparing response. Iron homeostasis is usually mediated in Gram-negative bacteria at the transcriptional level by the Ferric Uptake Regulator (Fur). There is a single predicted P. gingivalis Fur superfamily orthologue named Har (heme associated regulator) that lacks the conserved metal binding residues found in other Fur orthologues. We show that Har binds both heme and ferrous iron resulting in a conformational change in the protein. Har was unable to complement the Escherichia coli H1780 fur mutant and there was no change in cellular metal content in a P. gingivalis Har mutant compared with the wild-type. The Har regulon of 44 genes is not predicted to play a role in iron homeostasis. Together these data indicated that Har does not regulate iron homeostasis in P. gingivalis. However, Har was required for heme-responsive biofilm development and its regulon overlapped P. gingivalis regulons previously identified after growth in heme limitation or as a homotypic biofilm. P. gingivalis is unique as an iron-dependent Gram-negative bacterium with a single heme-binding Fur superfamily orthologue, Har, that does not regulate iron homeostasis.
2015-04-01 | GSE37099 | GEO
Project description:Ineffective erythropoiesis, the death of maturing erythroid cells, is a common cause of anemia. To better understand why this occurs, we studied the fates and adaptations of single erythroid marrow cells from individuals with Diamond Blackfan anemia (DBA), del(5q) myelodysplastic syndrome (del(5q) MDS), and normal controls, and defined an unhealthy (vs. healthy) differentiation trajectory, using velocity pseudotime and cell surface protein assessment. The pseudotime trajectories diverge immediately after the cells upregulate transferrin receptor (CD71), import iron, and initiate heme synthesis, although cell death occurs much later. Cells destined to die highly express heme-responsive genes, including ribosomal protein and globin genes. In contrast, surviving cells downregulate heme synthesis, while upregulating DNA damage response, hypoxia, and HIF1 pathways. Surprisingly, 24±12% of cells from controls follow the unhealthy trajectory, implying that heme also regulates cell fate decisions during normal red cell production. Del(5q) MDS (unlike DBA) results from somatic mutations, so many normal (unmutated) erythroid cells persist. By independently tracking their trajectory, we gained insight into why they cannot expand to prevent anemia. In addition, we show that intron retention is especially prominent during red cell differentiation. The additional information provided by messages with retained introns also allowed us to align data from multiple independent experiments and thus accurately query the transcriptomic changes that occur as single erythroid cells mature.
2023-09-06 | GSE222368 | GEO
Project description:Porphyromonas gingivalis is a major pathogen associated with the microbial biofilm-mediated disease chronic periodontitis. P. gingivalis has an obligate requirement for iron and protoporphyrin IX which it satisfies by transporting heme and iron liberated from the human host. The level of cellular iron in P. gingivalis affects the expression of a distinct iron-associated regulon of 64 genes and low iron invokes an iron sparing response. Iron homeostasis is usually mediated in Gram-negative bacteria at the transcriptional level by the Ferric Uptake Regulator (Fur). There is a single predicted P. gingivalis Fur superfamily orthologue named Har (heme associated regulator) that lacks the conserved metal binding residues found in other Fur orthologues. We show that Har binds both heme and ferrous iron resulting in a conformational change in the protein. Har was unable to complement the Escherichia coli H1780 fur mutant and there was no change in cellular metal content in a P. gingivalis Har mutant compared with the wild-type. The Har regulon of 44 genes is not predicted to play a role in iron homeostasis. Together these data indicated that Har does not regulate iron homeostasis in P. gingivalis. However, Har was required for heme-responsive biofilm development and its regulon overlapped P. gingivalis regulons previously identified after growth in heme limitation or as a homotypic biofilm. P. gingivalis is unique as an iron-dependent Gram-negative bacterium with a single heme-binding Fur superfamily orthologue, Har, that does not regulate iron homeostasis. Paired samples were compared on the same microarray using a two-colour system. A total of 6 paired microarray hybridizations were performed representing 6 biological replicates, where a balanced dye design was used, with the overall analysis including three microarrays where P. gingivalis 33277 samples were labeled with Cy3 and the paired ECR455 samples were labeled with Cy5 and three other microarrays where samples were labeled with the opposite combination of fluorophores.
2015-04-01 | E-GEOD-37099 | biostudies-arrayexpress
Project description:Iron is essential for all cells but is toxic in excess, so iron absorption and distribution are tightly regulated. Serum iron is bound to transferrin and primarily enters erythroid cells via receptor-mediated endocytosis of the transferrin receptor (Tfr1). Tfr1 is essential for developing erythrocytes and reduced Tfr1 expression is associated with anemia. The transcription factors STAT5A/B are activated by many cytokines, including erythropoietin. Stat5a/b-/- mice are severely anemic and die perinatally, but no link has been made to iron homeostasis. To study the function of STAT5A/B in vivo, we deleted the floxed Stat5a/b locus in hematopoietic cells with a Tie2-Cre transgene. These mice exhibited microcytic, hypochromic anemia, as did lethally irradiated mice transplanted with Stat5a/b-/- fetal liver cells. Flow cytometry and RNA analyses of erythroid cells from mutant mice revealed a 50% reduction in Tfr1 mRNA and protein. We detected STAT5A/B binding sites in the first intron of the Tfr1 gene and found that expression of constitutively active STAT5A in an erythroid cell line increased Tfr1 levels. Chromatin immunoprecipitation experiments confirmed the binding of STAT5A/B to these sites. We conclude that STAT5A/B is an important regulator of erythroid progenitor iron uptake via its control of Tfr1 transcription. Keywords: genetic modification
2008-06-13 | GSE11777 | GEO
Project description:During erythropoiesis, erythroid progenitor cells proliferate in response to erythropoietin (Epo) and progressively differentiate, which encompasses an increasing accumulation of iron-bound hemoglobin. The impact of Epo on these dynamic processes remained to be resolved. By combining the development of a time-collapsed super SILAC method with transcriptome analysis we examined Epo-induced alterations in the proteome of erythroid progenitor cells at the colony-forming unit erythroid stage (CFU E). We showed that the timing of a major increase in the transcription factors GATA1 and TAL1 precedes the cessation of cell cycle progression but coincides with a massive upregulation of enzymes of the heme biosynthetic pathway. A failure of this upregulation due to the absence of the Epo receptor resulted in massive iron accumulation in the fetal liver and dilation of the maternal vasculature in the placenta. Thus, Epo-induced dynamic proteome adaptations in CFU E cells not only prevent anemia but also severe iron-intoxication in embryos.
2022-09-22 | GSE108696 | GEO
Project description:The increased heme biosynthesis long observed in leukemia was previously of unknown significance. Heme, synthesized from porphyrin precursors, plays a central role in oxygen metabolism and mitochondrial function, yet little is known about its role in leukemogenesis. Here we show increased expression of heme biosynthetic genes, including UROD, only in pediatric AML with high MYCN expression. Both high UROD and MYCN expression predict poor overall survival and unfavorable outcomes in adult AML. Murine leukemic progenitors derived from hematopoietic progenitor cells (HPCs) overexpressing a MYCN cDNA (MYCN-HPC) require heme/porphyrin biosynthesis, accompanied by increased oxygen consumption, to fully engage in self-renewal and oncogenic transformation. Blocking heme biosynthesis reduced mitochondrial oxygen consumption and markedly suppressed self-renewal. Leukemic progenitors rely on balanced production of heme and heme intermediates, the porphyrins. Porphyrin homeostasis is required because absence of the porphyrin exporter, ABCG2, increased death of leukemic progenitors in vitro and prolonged the survival of mice transplanted with Abcg2-KO MYCN HPCs. Pediatric AML patients with elevated MYCN mRNA display strong activation of TP53 target genes. Abcg2-KO MYCN HPCs were rescued from porphyrin toxicity by p53 loss. This vulnerability was exploited to show that treatment with a porphyrin precursor, coupled with the absence of ABCG2, blocked MYCN-driven leukemogenesis in vivo thereby demonstrating, that porphyrin homeostasis is a pathway crucial to MYCN leukemogenesis. We used microarrays to compare the global transcription profiles of hematopoietic progenitor cells from wild-type and Abcg2-ko mice that after transduction with vector-alone or vector containing MYCN gene.
2020-01-10 | GSE100437 | GEO