Figure 3
From: AhR-deficiency as a cause of demyelinating disease and inflammation
AhR-dependent inflammatory response controls myelin genes. (A) Left: Heatmap of the annotated genes with the highest importance in inflammatory response. Red: increased mRNAs expression; green: decreased mRNA expression (n = 5/group). Right: Connected components of the relevance network after IPA. Thirteen gene probes were analyzed by IPA software and annotated for gene network construction. Both over-expressed and under-expressed genes were mapped to the same network space. The pathway analysis revealed a central regulating role for tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFNγ). Main components of the legend: hatched line: indirect interaction; continuous line: direct interaction; arrow: acts on; line with a perpendicular line at the end: inhibits; square: cytokine (Interferon-γ and TNF-α); horizontal oval (STAT1); transcription regulator; vertical oval (SFRP1): transmembrane receptor; vertical diamond (ASCL1): enzyme; horizontal diamond (CFB): peptidase; circle (Saa3): other. (B) Expression of immunoreactive GFAP, an astrocyte marker, in the optic nerve of WT (top) and AhR KO (bottom) adult mice (Scale bar: 100 µm, n = 4/group). (C) Quantitative Real-Time PCR analysis of Interleukine-1β (IL1β), IL6, RANTES (Regulated on Activated Normal T-cell Expressed and Secreted), MCP1–3 (Monocyte Chemoattractant Protein 1–3), Tumor Necrosis Factor-α (TNF-α) in the WT (black bars) and AhR-KO (blue bars) mice optic nerves (n = 10–22/group). mRNA levels were normalized to GAPDH mRNA expression. (D) Myelin genes (MAG, MBP and PLP) mRNA expression was determined by Quantitative Real-Time PCR analysis in primary mixed glial cell cultures after 3 days-treatment with TNFα (10 ng/mL), IFNγ (10 ng/mL) or both (concentration 10ng/mL of each) or vehicle (control). The relative mRNA expression levels were represented as relative fold change compared to mRNA abundance in cells treated with vehicle. Data are expressed as the mean of four to six independent experiments. Each experiment consists of pool of 2–8 pups. IPA: Ingenuity Pathway Analysis, GFAP: Glial Fibrillary Acidic Protein (***p < 0.001, **p < 0.01; *p < 0.05).
