Project description:Successful ex vivo expansion of hematopoietic stem cells (HSCs) would greatly benefit the treatment of disease and the understanding of critical questions of stem cell biology. Microarray studies showed that the HSC supportive mouse fetal liver CD3+ cells specifically expressed angiopoietin-like 2 (Angptl2) and angiopoietin-like 3 (Angptl3). When highly enriched HSCs were cultured in the presence of Angptl2 or Angptl3 together with saturating levels of other growth factors for 10 days, a 24 or 30 fold net expansion of long-term HSCs was observed by reconstitution analysis. The coiled-coil domain of Angptl2 mediated the effects of Angptl2 on HSC expansion. Furthermore, angiopoietin-like 5, angiopoietin-like 7, and microfibril-associated glycoprotein 4 also supported expansion of HSCs in culture. Experiment Overall Design: Cultured 3 different cell types Experiment Overall Design: -> Total RNA isolation -> dscDNA -> Biotinylated cRNA -> hybridization to Affymetrix U74Bv2 and U74Cv2 mouse chips
Project description:Successful ex vivo expansion of hematopoietic stem cells (HSCs) would greatly benefit the treatment of disease and the understanding of critical questions of stem cell biology. Microarray studies showed that the HSC supportive mouse fetal liver CD3+ cells specifically expressed angiopoietin-like 2 (Angptl2) and angiopoietin-like 3 (Angptl3). When highly enriched HSCs were cultured in the presence of Angptl2 or Angptl3 together with saturating levels of other growth factors for 10 days, a 24 or 30 fold net expansion of long-term HSCs was observed by reconstitution analysis. The coiled-coil domain of Angptl2 mediated the effects of Angptl2 on HSC expansion. Furthermore, angiopoietin-like 5, angiopoietin-like 7, and microfibril-associated glycoprotein 4 also supported expansion of HSCs in culture. Keywords: Cell type comparison
Project description:To comprehensively understand how dendritic cells (DCs) are reprogrammed by lung fibroblasts- and their derived COX-2/PGE2, we employed lung fibroblasts isolated from WT or Ptgs2-/- mice, and collect their conditioned medium (CM) to stimulate the ex vivo cultured bone marrow (BM)-derived DCs (BM-DCs), with the PGE2 treatment as a control. After the treatment, BM-DCs were harvested for RNA extraction and the transcriptional profiles were analyzed by RNA sequencing (RNA-seq).
Project description:A transcriptome study in mouse hematopoietic stem cells was performed using a sensitive SAGE method, in an attempt to detect medium and low abundant transcripts expressed in these cells. Among a total of 31,380 unique transcript, 17,326 (55%) known genes were detected, 14,054 (45%) low-copy transcripts that have no matches to currently known genes. 3,899 (23%) were alternatively spliced transcripts of the known genes and 3,754 (22%) represent anti-sense transcripts from known genes.
Project description:Osteolineage cell-derived extracellular vesicles (EVs) play a regulatory role in hematopoiesis and have been shown to promote the ex vivo expansion of human hematopoietic stem and progenitor cells (HSPCs). Here, we demonstrate that EVs from different human osteolineage sources do not have the same HSPC expansion promoting potential. Comparison of stimulatory and non-stimulatory osteolineage EVs by next-generation sequencing and mass spectrometry analyses revealed distinct microRNA and protein signatures identifying EV-derived candidate regulators of ex vivo HSPC expansion. Accordingly, the treatment of umbilical cord blood-derived CD34+ HSPCs with stimulatory EVs altered HSPC transcriptome, including genes with known roles in cell proliferation. An integrative bioinformatics approach, which connects the HSPC gene expression data with the candidate cargo in stimulatory EVs, delineated the potentially targeted biological functions and pathways during hematopoietic cell expansion and development. In conclusion, our study gives novel insights into the complex biological role of EVs in osteolineage cell-HSPC crosstalk and promotes the utility of EVs and their cargo as therapeutic agents in regenerative medicine.
Project description:A transcriptome study in mouse hematopoietic stem cells was performed using a sensitive SAGE method, in an attempt to detect medium and low abundant transcripts expressed in these cells. Among a total of 31,380 unique transcript, 17,326 (55%) known genes were detected, 14,054 (45%) low-copy transcripts that have no matches to currently known genes. 3,899 (23%) were alternatively spliced transcripts of the known genes and 3,754 (22%) represent anti-sense transcripts from known genes. Mouse hematopoietic stem cells were purified from bone marrow cells using negative and positive selection with a Magnetic-Activated Cell Sorter (MACS). total RNA and mRNA were purified from the purified cells using Trizol reagent and magnetic oligo dT beads. Double strand cDNAs were synthesized using a cDNA synthesis kit and anchored oligo dT primers. After NlaIII digestion, 3’ cDNAs were isolated and amplified through 16-cycle PCR. SAGE tags were released from the 3’ cDNA after linker ligation. Ditags were formed, concatemerized and cloned into a pZERO vector. Sequencing reactions were performed with the ET sequencing terminator kit. Sequences were collected using a Megabase 1000 sequencer. SAGE tag sequences were extracted using SAGE 2000 software.
Project description:This is an investigation of whole genome gene expression level in tissues of mice stimulated by LPS, FK565 or LPS + FK565 in vivo and ex vivo. We show that parenteral administration of a pure synthetic Nod1 ligand, FK565, induces site-specific vascular inflammation in mice, which is prominent in aortic root including aortic valves, slight in aorta and absent in other arteries. The degree of respective vascular inflammation is associated with persistent high expression of proinflammatory chemokine/cytokine genes in each tissue in vivo by microarray analysis, and not with Nod1 expression levels. The ex vivo production of proinflammatory chemokine/cytokine by Nod1 ligand is higher in aortic root than in other arteries from normal murine vascular tissues, and also higher in human coronary artery endothelial cells (HCAEC) than in human pulmonary artery endothelial cells (HPAEC), suggesting that site-specific vascular inflammation is at least in part ascribed to an intrinsic nature of the vascular tissue/cell itself.
Project description:Bone marrow mesenchymal stromal cells (MSCs) are a major source of secreted factors that control hematopoietic stem and progenitor cell (HSPC) function. We previously reported the generation of revitalized MSCs (rMSCs), which support functional HSCs in culture more effectively than control MSCs. In a secretomic screen using rMSCs, we identified semaphorin 3A (SEM3A) as a secreted factor upregulated as part of a pro-inflammatory signature that may underly HSPC expansion by rMSCs. Similarly, SEM3A expression is upregulated by BM-MSCs in vivo in response to hematopoietic stress. Recombinant SEM3A directly promotes HSPC quiescence ex vivo. Analysis of a SEM3A loss of function mutation in vivo revealed hematopoietic progenitor expansion and accelerated recovery after myeloablation, consistent with a role for SEM3A in regulating the HSPC stress response. This work highlights proteomic screening using rMSCs as a method to identify novel secreted niche factors and uncovers a novel role for SEM3A in promoting HSPC quiescence in stress hematopoiesis.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.