Our study looks at the dirsruption of lung circadian transcriptome that occurs when neutrophils are depleted (by application of antibodies (anti-Ly6G-1A8) to wildtype C57BL/6 mice, or Diphtheria toxin (DT) to neutrophil-specific DT-susceptible mice (MRP8-Cre;iDTR-flox)). Overall design: Lungs were harvested from neutrophil-depleted (antibody or DT) or non-depleted mice, in normal light-controlled mouse facility (ZT4) or 12h inverted light cabinets (ZT16). Experiments were carried out over 3 batches (July 2017, September 2017, and April 2018), with 3 or 4 mice per group. Antibody-depleted and non-depleted mice were tested for the July 2017 and September 2017 batches, whereas DT-depleted mice were tested only in April 2018.
Neutrophils instruct homeostatic and pathological states in naive tissues.
Specimen part, Treatment, Subject
View SamplesTo identify novel LXR target genes, we conducted transcriptional profiling studies using RAW264.7 cells ectopically expressing
Apoptotic cells promote their own clearance and immune tolerance through activation of the nuclear receptor LXR.
Cell line
View SamplesThe liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues. LXRs exert additional biological functions as negative regulators of inflammation, particularly in macrophages. However, the transcriptional responses controlled by LXRs in other myeloid cells, such as dendritic cells (DC), are still poorly understood. Here we used gain- and loss-of-function models to characterize the impact of LXR deficiency on DC activation programs. Our results identified an LXR-dependent pathway that is important for DC chemotaxis. LXR-deficient mature DCs are defective in stimulus-induced migration in vitro and in vivo. Mechanistically, we show that LXRs facilitate DC chemotactic signaling by regulating the expression of CD38, an ectoenzyme important for leukocyte trafficking. Pharmacological or genetic inactivation of CD38 activity abolished LXR-dependent induction of DC chemotaxis. Using the LDLR-/- mouse model of atherosclerosis, we also demonstrated that hematopoietic CD38 expression is important for the accumulation of lipid-laden myeloid cells in lesions, suggesting that CD38 is a key factor in leukocyte migration during atherogenesis. Collectively, our results demonstrate that LXRs are required for efficient emigration of DCs in response to chemotactic signals during inflammation.
LXR nuclear receptors are transcriptional regulators of dendritic cell chemotaxis.
Specimen part
View SamplesMouse BMDCs were differentiated from bone marrow by GM-CSF and IL-4 for 9 days.
LXR nuclear receptors are transcriptional regulators of dendritic cell chemotaxis.
Specimen part
View Samples