Project description:Wild type tumor cells, producing high levels of prostaglandin E2 (MCG101, EP2 +/+), were inoculated on EP2 knockout (EP2 -/-) and EP2 wild type (EP2 +/+) mice. Solid tumors were dissected into tumor- and tumor-stroma tissue compartments for RNA expression microarray screening, followed by metabolic pathway analyses. The study aims to evaluate simultaneous gene pathway expressions in separate tissue compartments, such as isolated tumor tissue and tumor stroma respectively.
Project description:Effective regeneration after peripheral nerve injury requires macrophage recruitment. We investigated activation of remodeling pathways within the macrophage population when repair is delayed and identified alteration of key upstream regulators of the inflammatory response. We then targeted one of these regulators, using exogenous IL10 to manipulate the response to injury at the repair site. We demonstrate that this approach alters macrophage polarization, promotes macrophage recruitment, axon extension, neuromuscular junction formation and increases the number of regenerating motor units reaching their target. We also demonstrate that this approach can rescue the effects of delayed nerve graft.
Project description:Two types of monocytes, inflammatory and patrolling, infiltrate the hearts in both human myocarditis and murine experimental autoimmune myocarditis (EAM) model. The fates and functions of these infiltrating monocytes governing the progression of heart failure remain unclear. Here, we created parabiotic EAM and naïve mice to show that cardiac inflammation facilitate monocyte-to-macrophage differentiation. Using a combination of flow cytometry, time lapsed imaging and transmission electron microscopy, we demonstrated in vitro that cardiac fibroblasts interact with monocytes and are instrumental in facilitating monocyte-to-macrophage differentiation. Moreover, IL-17A stimulated cardiac fibroblasts completely arrested Ly6Clo monocyte proliferation and inhibited both Ly6Chi and Ly6Clo monocyte-to-macrophage differentiation both in vitro and in vivo after intracardiac injections of monocytes into the hearts. Intriguingly, IL-17A signaling through cardiac fibroblasts also significantly downregulated Mer tyrosine kinase (MerTK) expressions on Ly6Chi monocyte-derived macrophages, thus jeopardizing their phagocytic abilities. Collectively, our results implicate divergent fates and functions of heart-infiltrating monocytes influenced by cardiac fibroblasts.
Project description:Microglia, the innate immune cells of the central nervous system, perform critical inflammatory and non-inflammatory functions to maintain homeostasis and normal neural function. However in Alzheimer’s disease (AD), these beneficial functions become progressively impaired, contributing to synapse and neuron loss and cognitive impairment. The inflammatory cyclooxygenase-PGE2 pathway, including the PGE2 receptor EP2, is implicated in AD development, both in human epidemiology and in transgenic models of AD. To test the transcriptional responses of EP2-deficient microglia to Aβ in vivo, we used mice in which the EP2 receptor is conditionally deleted in microglia using the CD11b-Cre transgene and floxed alleles of the EP2 gene. By injecting these mice with Aβ ICV and isolating microglia from the brains, we have been able to establish the transcriptional response of microglia to Aβ in vivo and test how EP2 deletion in microglia affects this response. 8 month-old C57BL/6 mice, of the genotype CD11b-Cre; EP2+/+ or CD11b-Cre; EP2lox/lox, were injected I.C.V. with either Aβ or vehicle. 48 hours after injection, the mice were sacrificed and transcardially perfused with cold heparinized 0.9% NaCl. Brains were then removed from the mice and pooled, two brains of the same genotype per sample, to ensure adequate cell and RNA yield. The brains were then enzymatically dissociated for microglia isolation using the Neural Tissue Dissociation Kit (P), MACS Separation Columns (LS), and magnetic CD11b Microbeads from Miltenyi Biotec according to the manufacturer's protocol. Immediately after isolating the microglia, RNA was extracted from the cells for microarray analysis.
Project description:Microglia, the innate immune cells of the central nervous system, perform critical inflammatory and non-inflammatory functions to maintain homeostasis and normal neural function. However in Alzheimer’s disease (AD), these beneficial functions become progressively impaired, contributing to synapse and neuron loss and cognitive impairment. The inflammatory cyclooxygenase-PGE2 pathway, including the PGE2 receptor EP2, is implicated in AD development, both in human epidemiology and in transgenic models of AD. To test the transcriptional responses of EP2-deficient microglia to Aβ in vivo, we used mice in which the EP2 receptor is conditionally deleted in microglia using the CD11b-Cre transgene and floxed alleles of the EP2 gene. By injecting these mice with Aβ ICV and isolating microglia from the brains, we have been able to establish the transcriptional response of microglia to Aβ in vivo and test how EP2 deletion in microglia affects this response.