Characterization of the macrophage transcriptome in glomerulonephritis-susceptible and -resistant rat strains

Crescentic glomerulonephritis (CRGN) is a major cause of rapidly progressive renal failure for which the underlying genetic basis is unknown. WKY rats show marked susceptibility to CRGN, while Lewis rats are resistant. Glomerular injury and crescent formation are macrophage-dependent and mainly explained by seven quantitative trait loci (Crgn1-7). Here, we used microarray analysis in basal and lipopolysaccharide (LPS)-stimulated macrophages to identify genes that reside on pathways predisposing WKY rats to CRGN. We detected 97 novel positional candidates for the uncharacterised Crgn3-7. We identified 10 additional secondary effector genes with profound differences in expression between the two strains (>5-fold change, <1% False Discovery Rate) for basal and LPS-stimulated macrophages. Moreover, we identified 8 genes with differentially expressed alternatively spliced isoforms, by using an in depth analysis at probe-level that allowed us to discard false positives due to polymorphisms between the two rat strains. Pathway analysis identified several common linked pathways, enriched for differentially expressed genes, which affect macrophage activation. In summary, our results identify distinct macrophage transcriptome profiles between two rat strains that differ in susceptibility to glomerulonephritis, provide novel positional candidates for Crgn3-7, and define groups of genes that play a significant role in differential regulation of macrophage activity

Coexistence of charge order and antiferromagnetism in (TMTTF)(2)SbF6: NMR study

The electronic state of (TMTTF)(2)SbF6 was investigated by the H-1 and C-13 NMR measurements. The temperature dependence of T-1(-1) in H-1 NMR shows a sharp peak associated with the antiferromagnetic transition at T-AF = 6 K. The temperature dependence of T-1(-1) is described by the power law T-2.4 below T-A. This suggests the nodal gapless spin wave excitation in antiferromagnetic phase. In 13C NMR, two sharp peaks at high temperature region, associated with the inner and the outer carbon sites in TMTTF dimer, split into four peaks below 150 K. It indicates that the charge disproportionation occurs. The degree of charge disproportionation Delta rho is estimated as (025 +/- 0.09)e from the chemical shift difference. This value Delta rho is consistent with that obtained from the infrared spectroscopy. In the antiferromagnetic state (AFI), the observed line shape is well fitted by eight Lorentzian peaks. This suggests that the charge order with the same degree still remains in the AF state. From the line assignment, the AF staggered spin amplitude is obtained as 0.70 mu(B) and 0.24 mu(B) at the charge rich and the poor sites, respectively. These values corresponding to almost 1 mu(B) per (timer are quite different from 0.11 mu(B) of another AF (AFII) state in (TMITF)(2)Br with effective higher pressure. As a result, it is understood that the antiferromagnetic staggered spin order is stabilized on the CO state in the AFI phase of (TMTTF)2(S)bF(6)

Small molecule Toll-like receptor 7 agonists localize to the MHC class II loading compartment of human plasmacytoid dendritic cells

Toll-like receptors (TLRs) 7 and 8 are intracellular sensors activated by single stranded RNA species generated during viral infections. Various synthetic small molecules can also activate TLR7 and/or 8; however the molecular mechanisms governing their TLR7/8 triggering remain largely unknown. To shed light on how small molecule agonists target TLRs, we labeled two imidazoquinolines, resiquimod and imiquimod, and one purine-like compound, SM360320, with two different fluorophores (TAMRA and AlexaFluor488) and monitored their intracellular localization in human plasmacytoid dendritic cells (pDCs). All fluorescent compounds induced the production of IFN TNF and IL-6 and the up-regulation of CD80 and CD86 by pDCs showing they retained TLR7 stimulating activity. Confocal imaging demonstrated that all compounds concentrated in LAMP1+CD63+HLA-DR+ endosomes, which represent the MHC class II loading compartment of pDCs. Moreover, CpG-B, which triggers TLR9 signaling from this endolysosomal compartment, co-localized with all 3 TLR7/8 small molecule agonists. By contrast, treatment of pDCs with bafilomycin A, an antagonist of the vacuolar-type proton ATPase that inhibits TLR7 and TLR9 signaling, prevented the accumulation of imiquimod-TAMRA, but not of CpG-B-TAMRA, in LAMP1+HLA-DR+ endosomes. These results indicate that a pH-driven concentration of small molecule TLR7 agonists in the MHC class II loading compartment is required for pDCs activation

Jund is a determinant of macrophage activation and is associated with glomerulonephritis susceptibility

Crescentic glomerulonephritis is an important cause of human kidney failure for which the underlying molecular basis is largely unknown. In previous studies, we mapped several susceptibility loci, Crgn1-Crgn7, for crescentic glomerulonephritis in the Wistar Kyoto (WKY) rat. Here we show by combined congenic, linkage and microarray studies that the activator protein-1 (AP-1) transcription factor JunD is a major determinant of macrophage activity and is associated with glomerulonephritis susceptibility. Introgression of Crgn2 from the nonsusceptible Lewis strain onto the WKY background leads to significant reductions in crescent formation, macrophage infiltration, Fc receptor-mediated macrophage activation and cytokine production. Haplotype analysis restricted the Crgn2 linkage interval to a 430-kb interval containing Jund, which is markedly overexpressed in WKY macrophages and glomeruli. Jund knockdown in rat and human primary macrophages led to significantly reduced macrophage activity and cytokine secretion, indicating conservation of JunD function in macrophage activation in rats and humans and suggesting in vivo inhibition of Jund as a possible new therapeutic strategy for diseases characterized by inflammation and macrophage activation