Project description:DNA damage response kinase ATM regulates the genetic program of lymphocytes with phsiologically induced DNA DSBs. In bone marrow-derived macrophages, related kinase DNAPKcs is also responsible for activating DNA damage responses after infection with Listeria monocytogenes. Here we show that both ATM and DNA-PKcs regulate the genetic program of Listeria monocytogenes-infected macrophages. Two independent bone marrow-derived macrophage cultures for each genotype (LysMcre/+ and Scid: Atmc/c: LysMcre/+) were infected with Listeria monocytogenes for 24 hrs at an MOI of 5. RNA was isolated using RNeasy (Qiagen). Gene expression profiling was performed using Illumina MouseRef-8 expression microarrays.
Project description:The B-myb (MYBL2) gene is a member of the MYB family of transcription factors and is involved in cell cycle regulation, DNA replication and maintenance of genomic integrity. However, its function during adult development and hematopoiesis is unknown. We show here that conditional inactivation of B-myb in vivo results in depletion of the HSC pool, leading to profound reductions in mature lymphoid, erythroid and myeloid cells. This defect is autonomous to the bone marrow and is first evident in the HSCs, which accumulate in the S and G2/M phases. B-myb inactivation also causes defects in the myeloid progenitor compartment and results in an accumulation of GMPs. Microarray studies indicate that B-myb null LKS+ cells differentially express genes that direct myeloid lineage development and commitment, suggesting that B-myb is a key player in controlling cell fate. Collectively, these studies demonstrate that B-myb is essential for HSC and progenitor maintenance and survival during hematopoiesis. Total RNA was isolated from FACS purified LKS+ cells isolated from pIpC-treated control and B-myb floxed-MxCre mice. Each sample is derived from a pool of 3-5 mice. 2 samples were analyzed for each genotype.
Project description:GABPalpha is an Ets family transcription factor and involved in regulation of both basic cellular functions such as cell cycle progression and tissue-specific biological processes. We found that GABPalpha is critically required for survival and differentiation of hematopoietic stem cells. We used microarrays to detect gene expression changes in Flt3(-) LSK cells (which contains both long-term and short-term hematopoietic stem cells) by GABPalpha deficiency. Mx1Cre-GABPa(FL/+) and Mx1Cre-GABPa(FL/-) mice were treated with pIpC to induce inactivation of GABPalpha in bone marrow cells. Four days after last treatment of pIpC, the bone marrow cells were isolated and the Flt3(-)LSK subset was purified by cell sorting. RNA was extracted and hybridized to GeneChip Mouse GENE 1.0 ST arrays (Affymetrix).
Project description:Reactive Oxygen Species (ROS) could be a stress factor that affects microRNA regulation and function in macrophages. The production of microRNAs (miRNA) is influenced by various stimuli, including environmental stresses. We hypothesized that ROS-associated stress could regulate macrophage miRNA synthesis. p47phox-/- mice have deficient NADPH oxidase activity resulting in decreased ROS production. We cultured bone marrow-derived macrophages (BMDM) from wild type (WT) and p47phox-/- mice and profiled miRNA expression using microarrays. The microarray data reveals that there are differences in the expression levels of different miRs, and our studies suggest functional crosstalk between ROS and miR-451 in the regulation of macrophage oxidant stress. Mouse bone marrow-derived macrophages (BMDMs) were obtained from WT (wild type) and p47phox-/- mice. MicroRNAs were isolated by using the mirVana miRNA kit, and a TaqMan rodent microRNA array (consisting of Megaplex RT Primers, Rodent Pool-A, Applied Biosystems) was used for microarray. The array enables quantitation of the expression levels of up to 380 microRNAs and controls. Rodent Pool A contains reverse transcription (RT) primers for 335 and 238 unique microRNAs for mouse and rat, respectively, plus 4 species-specific controls. The data were analyzed on RQ manager software (Qiagen, SA Biosciences) and normalized to the endogenous controls, and analyzed for fold change of miRs in WT compared to p47phox-/-.
Project description:H3K4me1 binding in murine pre-B cells detected by ChIP-seq. For the ChIP-seq, input and immunoprecipitated DNA was given to the TSRI Next Generation Sequencing Core (the Scripps Research Institute, La Jolla, CA, US), where it was prepared for massively parallel sequencing on Illumina HiSeq2000.
Project description:The purpose of current study is to identify the differentiated gene expression associated with mouse 11B3 deletion, syntenic to human chromosome 17p13.1. We compared four different mouse acute myeloid leukemia cells, freshly isolated from mouse bone marrows with either 11B3fl/p53fl;shNf1;shMll3;Vav1-Cre or p53fl/fl;shNf1;shMll3;Vav1-Cre. The RNA-seq results indicate that genes located on chromosome 11B3 mostly reduce gene expression level in 11B3 deleted leukemia cells. Examination RNA expression level in 11B3-deleted vs p53-loss only samples.
Project description:We discovered that mice with hematopoietic-specific deletion of Lsd1 lacked Gr-1+ Mac1+ neutrophilic granulocytes whereas the numbers of Gr-1dim Mac1+ granulocytic progenitor cells was increased. To determine the genes altered by Lsd1-loss, Gr-1dim Mac1+ granulocytic progenitor cells from Lsd1fl/fl and Lsd1fl/fl Mx1Cre mice were FACS-purified to be analyzed by gene expression profiling. Primary Gr-1dim Mac1+ granulocytic progenitor cells were isolated from the bone marrow of Lsd1fl/fl and Lsd1fl/fl Mx1Cre animals by FACS-sorting, one week after the final p(I:C) dose. Total RNA from three biological replicates per genotype was extracted and used to hybridize to Affymetrix expression arrays using the Mouse Genome 430 2.0 array platform.
Project description:MicroRNAs influence hematopoietic differentiation, but little is known about their effects on the stem cell state. Here, we report that the microRNA processing enzyme Dicer is essential for stem cell persistence in vivo and a specific microRNA, miR-125a controls the size of the stem cell population by regulating stem/progenitor cell (HSPC) apoptosis. Conditional deletion of Dicer revealed an absolute dependence for the multipotent HSPC population in a cell autonomous manner, with increased HSPC apoptosis in mutant animals. An evolutionarily conserved microRNA cluster containing miR-99b, let-7e and miR-125a was preferentially expressed in long term HSCs. miR-125a alone was capable of increasing the number of hematopoietic stem cells in vivo by more than eight fold. This was accomplished through a differentiation stage-specific reduction of apoptosis in immature hematopoietic progenitors, possibly through targeting multiple pro-apoptotic genes. Bak1 was directly down-regulated by miR-125a and expression of a 3’UTR-less Bak1 blocked miR-125a-induced hematopoietic expansion in vivo. These data demonstrate cell-state-specific regulation by microRNA and identify a unique microRNA functioning to regulate the stem cell pool size. Bone marrow populations were FACS-sorted and profiled using a bead-based profiling platform. Long-term HSCs, short-term HSCs, multipotent progenitors, Lin-Kit+Sca+ cells, Lin-Kit+Sca- cells, Lin-Kit-Sca+ cells, Lin- cells and unfractionated whole bone marrow cells were prepared for total RNA using TriZol (Invitrogen) in replicates. For rare populations, cells from multiple mice were pooled. To perform microRNA profiling, 60 ng of total RNA were used for each sample.
Project description:Small RNAs regulate the genetic networks through a ribonucleoprotein complex called the RNA induced silencing complexes (RISC), which in mammals contains at its center one of four Argonaute proteins (Ago1-4). A key regulatory event in the RNAi and miRNA pathways is Ago loading, where double stranded small RNA duplexes are incorporated into RISC (pre-RISC) and then become single stranded (mature-RISC), a process that is not well understood. The Agos contain an evolutionary conserved PAZ (Piwi/Argonaute/Zwille) domain whose primary function is to bind the 3’-end of small RNAs. We created multiple Paz domain disrupted Ago mutant proteins and studied their biochemical properties and biological functionality in cells. We found that the Paz domain is dispensable for Ago loading of slicing-competent RISC. In contrast, in the absence of slicer activity or slicer substrate duplex RNAs, Paz-disrupted Agos bound duplex siRNAs but were unable to unwind/eject the passenger strand and form functional RISC complexes. We have discovered that the highly conserved Paz domain plays an important role in RISC activation, providing new mechanistic insights into how miRNAs regulate genes, as well as new insights for future design of miRNA and RNAi-based therapeutics. Various Argonautes associated small RNA profiles were generated by deep sequencing the Agos-IP samples in HEK293 Cells transfected with corresponding Argonaute.
Project description:A20 is a negative regulator of NF-κB signaling, crucial to control inflammatory responses and ensure tissue homeostasis. A20 is thought to restrict NF-κB activation both by its ubiquitin-editing activity as by non-enzymatic activities. Besides its role in NF-κB signaling, A20 also acts as a protective factor inhibiting apoptosis and necroptosis. Because of the ability of A20 to both ubiquitinate and deubiquitinate substrates and its involvement in many cellular processes, we hypothesized that deletion of A20 might generally impact on protein levels, thereby disrupting cellular processes. We performed a differential proteomics study of bone marrow derived macrophages (BMDMs) from control and myeloid-specific A20 knockout mice, both in untreated conditions and after LPS and TNF treatment, and demonstrate proteome-wide changes in protein expression upon A20 deletion. Several inflammatory proteins are up-regulated in the absence of A20, even without an inflammatory stimulus. Depending on the treatment and the time, more proteins are regulated. Together these changes may affect multiple signaling pathways disturbing tissue homeostasis and inducing (autoimmune) inflammation, as suggested by genetic studies in patients.