Project description:Macrophage activation must be tightly controlled to prevent overzealous responses that cause self-damage. MicroRNAs have been shown to promote classical macrophage activation by blocking concomitant anti-inflammatory signals and transcription factors, but can also place restraints on activation by preventing excessive TLR-signalling. In contrast, the microRNA profile associated with alternatively activated macrophages and their role in regulating wound-healing or anti-helminthic responses has not yet been described. Utilizing an in vivo model of alternative activation, in which adult Brugia malayi nematodes are surgically implanted in the peritoneal cavity of mice, we examined the profile of microRNA expression in these alternatively activated macrophages and compared this to alternatively activated IL-4 receptor knockout macrophages and thioglycollate elicited macrophages. Peritoneal macrophages from BALB/c wild type or IL-4 receptor knockout mice were elicited with thioglycollate or using nemtodes (peritoneal implant of Brugia malayi). The latter leads to a population of alternatively activated macrophages. Microarray analysis was used to examine the microRNA profile of WT alternatively activated macrophages (n = 4), IL-4 receptor knockout alternatively activated macrophages (n = 4), WT thioglycollate elicited macrophages (n = 3) and IL-4 receptor knockout thioglycollate elicited macrophages (n = 3).
Project description:Macrophage activation must be tightly controlled to prevent overzealous responses that cause self-damage. MicroRNAs have been shown to promote classical macrophage activation by blocking concomitant anti-inflammatory signals and transcription factors, but can also place restraints on activation by preventing excessive TLR-signalling. In contrast, the microRNA profile associated with alternatively activated macrophages and their role in regulating wound-healing or anti-helminthic responses has not yet been described. Utilizing an in vivo model of alternative activation, in which adult Brugia malayi nematodes are surgically implanted in the peritoneal cavity of mice, we examined the profile of microRNA expression in these alternatively activated macrophages and compared this to alternatively activated IL-4 receptor knockout macrophages and thioglycollate elicited macrophages.
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: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:To investigate the differences in microRNA expression profiles between fibrotic and normal livers, we performed microRNA microarrays for total RNA extracts isolated from mouse livers treated with carbontetrachloride (CCl4) or corn-oil for 10 weeks (n=3/group). MicroRNAs were considered to have significant differences in expression level when the expression difference showed more than two-fold change between the experimental and control groups at p<0.05. We found that 12 miRNAs were differentially expressed in CCl4-induced fibrotic liver.