Project description:Esophageal cancer-related gene 4 (Ecrg4), a hormone-like peptide, is thought to be a tumor suppressor, however little is known about the mechanism of how Ecrg4 suppresses tumorigenesis. Using the mouse glioma–initiating cell models, we identified Ecrg4 acts as a tumor suppressor in vivo. To characterize the function of Ecrg4 towards microglia, an innate immune cell in central nervous system, we performed gene expression microarray analysis for primary microglia treated with or without recombinant Fc-fused Ecrg4 fragments. We demonstrate here that Ecrg4 fragments, amino acid residues 71-132 and 133-148, which are produced by the proteolitic cleavage, induced the expression of pro-inflammatory cytokines in microglia. Thus, Ecrg4 acts as a cytokine/chemokine inducer, which activates the immune cells to eradicate tumor.
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.
Project description:We use microarray analysis to compare the expression profiles of glioma-associated microglia/macrophages and naive control cells. Samples were generated from CD11b+ MACS-isolated cells from naïve and GL261-implanted C57BL/6 mouse brains.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:Esophageal cancer-related gene 4 (Ecrg4) encodes a hormone-like peptide, and is thought to be involved in a variety of physiological phenomena including tumor suppressor function. Recent progress of Ecrg4 reveals that Ecrg4 peptides are pro-inflammatory and induce the expression of several cytokines and chemokines. However, detailed molecular mechanisms of Ecrg4 signaling, especially the receptors for Ecrg4 peptides, remain poorly understood. Here, using retrovirus-mediated expression cloning, we identified lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) as a membrane protein bound for amino acid residues 71-132 of Ecrg4, Ecrg4(71-132). Moreover, not only LOX-1 but also several scavenger receptors such as Scarf1, Cd36 and Stabilin-1 efficiently internalized Ecrg4(71-132) into cells. The broad scavenger receptor competitive inhibitor polyinosinic acid reduced both the internalization of Ecrg4(71-132) and activation of NF-kB in microglia. In addition, this activation is dependent on Myd88, an adaptor protein to recruit signaling proteins to TLR and IL-1R receptors with induction of several immune response. These data suggest that multiple scavenger receptors recognize Ecrg4(71-132) and transduce its signals along with TLR/IL-1R receptors in microglia.
Project description:Engrams are considered to be substrates for memory storage, and the functional dysregulation of the engrams leads to cognition impairment.However, the cellular basis for these maladaptive changes lead to the forgetting of memories remains unclear. Here we found that the expression of autophagy protein 7 (Atg7) mRNA was dramatically upregulated in aged DG engrams, and led to the forgetting of contextual fear memory and the activation of surrounding microglia.To determine mechanism by which autophagy in DG engrams activates the surrounding microglia, mice were co-injected AAV-RAM-Cre either with AAV-Dio-Atg7-Flag or AAV-Dio- EYFP in dorsal dentate gyrus to overexpress ATG7 in the DG memory engrams. Microglia were separated using magnetic-activated cell sorting and subjected to RNA-Seq in dorsal hippocampus .Bioinformatics analysis shown overexpression of Atg7 in dorsal DG memory engrams caused an increase in the expression of Tlr2 in the surrounding microglia.Depletion of Toll-like receptor 2/4 (TLR2/4) in DG microglia prohibited excessive microglial activation and synapse elimination induced by the overexpression of ATG7 in DG engrams, and thus prevented forgetting. Furthermore, the expression of Rac1, a Rho-GTPases which regulates active forgetting in both fly and mice, was upregulated in aged engrams. Optogentic activation of Rac1 in DG engrams promoted the autophagy of the engrams, the activation of microglia, and the forgetting of fear memory. Invention of the Atg7 expression and microglia activation attenuated forgetting induced by activation of Rac1 in DG engrams. Together, our findings revealed autophagy-dependent synapse elimination of DG engrams by microglia as a novel forgetting mechanism.
Project description:Analysis of gene expression profiles is an attractive method for discovering how animals respond to environmental challenges in nature. Compared to low altitudes, high altitudes are characterized by reduced partial pressures of oxygen (hypoxia) and cooler ambient temperatures To better understand how mammals cope with high altitudes, we trapped wild house mice (Mus musculus domesticus) from 3 populations in La Paz, Bolivia (3000 - 3600 m) and 3 populations in Lima, Peru (0 – 200 m). Affymetrix GeneChip® Mouse Genome 430 2.0 Arrays were use to measure mRNA abundance in the livers of these mice.