Hoxb8 mutant mice show compulsive behavior similar to trichotillomania, a human obsessive-compulsive-spectrum disorder. The only Hoxb8 lineage-labeled cells in the brains of mice are microglia, suggesting that defective Hoxb8 microglia caused the disorder. What is the source of the Hoxb8 microglia? It has been posited that all microglia progenitors arise at embryonic day (E) 7.5 during yolk sac hematopoiesis, and colonize the brain at E9.5. In contrast, we show the presence of two microglia subpopulations: canonical, non-Hoxb8 microglia and Hoxb8 microglia. Unlike non- Hoxb8 microglia, Hoxb8 microglia progenitors appear to be generated during the second wave of yolk sac hematopoiesis, then detected in the aorto-gonad-mesonephros (AGM) and fetal liver, where they are greatly expanded, prior to infiltrating the E12.5 brain. Further, we demonstrate that Hoxb8 hematopoietic progenitor cells taken from fetal liver are competent to give rise to microglia in vivo. Although the two microglial subpopulations are very similar molecularly, and in their response to brain injury and participation in synaptic pruning, they show distinct brain distributions which might contribute to pathological specificity. Non-Hoxb8 microglia significantly outnumber Hoxb8 microglia, but they cannot compensate for the loss of Hoxb8 function in Hoxb8 microglia, suggesting further crucial differences between the two subpopulations. Overall design: Green (non-Hoxb8, control) and yellow (Hoxb8, experimental) microglia data sets
Correction: Two distinct ontogenies confer heterogeneity to mouse brain microglia (doi: 10.1242/dev.152306).
Age, Specimen part, Cell line, Subject
View SamplesBackground/Aims: Ribavirin improves treatment response to pegylated-interferon (PEG-IFN) in chronic hepatitis C but the mechanism remains controversial. We studied correlates of response and mechanism of action of ribavirin in treatment of hepatitis C. Methods: 70 treatment-nave patients were randomized to 4 weeks of ribavirin (1000-1200 mg/d) or none, followed by PEG-IFN alfa-2a and ribavirin at standard doses and durations. Patients were randomized to undergo a liver biopsy either 24 hours before, or 6 hours after starting PEG-IFN. Hepatic gene expression was assessed by microarray and interferon-stimulated gene (ISG) expression quantified by the nCounter platform. Temporal changes in ISG expression were assessed by qPCR in peripheral-blood mononuclear cells (PBMC) and by serum levels of IP-10. Results: After four weeks of ribavirin monotherapy, HCV levels decreased by 0.50.5 log10 (p=0.009 vs. controls) and ALT by 33% (p<0.001). Ribavirin pretreatment, while modestly augmenting the induction of ISGs by PEG-IFN, did not modify the virological response to subsequent PEG-IFN and ribavirin treatment. However, biochemical, but not virological response to ribavirin monotherapy predicted response to subsequent combination treatment (rapid virological response, 71% in biochemical responders vs. 22% non-responders, p=0.01; early virological response, 100% vs. 68%, p=0.03, sustained virological response 83% vs. 41%, p=0.053). Ribavirin monotherapy lowered serum IP-10 levels but had no effect on ISG expression in PBMC. Conclusion: Ribavirin is a weak antiviral but its clinical effect in combination with PEG-IFN seems to be mediated by a separate, indirect mechanism, which may act to reset the interferon responsiveness in HCV-infected liver. Ribavirin pretreatment does not alter the clinical outcome of subsequent combination therapy.
Effect of ribavirin on viral kinetics and liver gene expression in chronic hepatitis C.
Specimen part, Disease, Disease stage, Treatment
View SamplesWe access the activity-dependent genes in olfactory neuron cells with unilateral naris occlusion model with mouse. Overall design: mRNA profile of olfactory epithelia between closed and open sides of mice naris was compared
Activity-Dependent Gene Expression in the Mammalian Olfactory Epithelium.
Specimen part, Cell line, Subject
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency. This series describes 1 of the 5 array experiments.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesConditional deletion of Lhx2, and to a lesser extent, Emx2 in olfactory neurons alters odorant receptor expression frequency.
Lhx2 Determines Odorant Receptor Expression Frequency in Mature Olfactory Sensory Neurons.
Specimen part
View SamplesOdorants are thought to activate sets of odorant receptors in vivo, but capturing sets of responsive receptors in vivo has never been accomplished.
In vivo identification of eugenol-responsive and muscone-responsive mouse odorant receptors.
Specimen part
View Samples