Outcomes of extended substantial excess fat diet (HFD) feeding on glucose and lipid laws. Glucose tolerance (A),1000413-72-8 supplier insulin secretion (B) and complete and HDL cholesterol (C,D) ended up analysed in C57BL/6J and BALB/c fed HFD or handle diet program. Values are expressed as meansEM.In contrast, genes exhibiting the strongest magnitude of transcriptional reaction to HFD in C57BL/6J ended up specific to this pressure and provided downregulated expression of genes encoding metallothioneins (Mt1, Mt2), insulin-like progress aspect binding protein one (Igfbp1), aspartate aminotransferase (Got1) and glucose-6-phosphatase (G6pc), and upregulation expression of glucokinase (Gck) and adipsin (Adn). We then analysed coordinated expression of genes concerned in related biological procedures pertinent to insulin resistance and NAFLD.These final results underline the complexity of gene transcription adaptation to HFD in BALB/c and C57BL/6J, combining strain certain and conserved mechanisms. They point out that the strongest transcriptional effect of HFD in C57BL/6J concerns genes differentially expressed exclusively in this strain, whilst genes displaying the highest magnitude of transcription changes in BALB/c also exhibit equivalent reaction to HFD in C57BL/6J. These information also suggest a feasible part of coordinated expression of SREBF1 and STARD4 in typical adaptation to HFD feeding.To identify global gene transcription styles related with diet plan-induced resistance (BALB/c) and susceptibility (C57BL/6J) to NAFLD, we utilized GSEA which allowed exploration of alterations in gene pathways (Figure 3) and identification of individual genes driving altered pathway expression (Table one).Determine three. Overview of HFD-induced liver gene transcription modifications determined by GSEA in C57BL/6J and BALB/c mice. Only KEGG organic pathways significantly upregulated (red) or downregulated (green) by HFD in at the very least 1 of the two strains are documented. The (complete) Normalised Enrichment Score (NES) computed by GSEA is plotted (with more substantial values indicLatanoprostative of important enrichment). FDR q-values (<0.05) were used to identify statistically significant effects of fat feeding on the pathways in C57BL/6J (*) and BALB/c ($).Genes contributing to pathway enrichment are listed in Table 1.In both strains adaptation to HFD feeding involved consistent activation of the metabolism of amino and nucleotide sugars, which may reflect adaptive mechanisms unrelated to disease pathogenesis. In contrast, fat feeding induced opposite transcriptional regulation patterns of the proteasome pathway in the two strains (Figure 3), through significant transcription down-regulation of Psma5, Psmb4, Psmd2, Psmd11 in BALB/c and up-regulation of Psma2, Psma4, Psma5, Psma7, Psmb3, Psmc2 in C57BL/6J (Table 1, Figure 4A). Table 1. Effects of fat feeding on hepatic transcription of genes contributing to changes in KEGG pathways conserved or divergent in BALB/c and C57BL/6J mice.Upregulated expression of protein export (NES=2.106, P<0.001), spliceosome (NES=2.054, P<0.001) and Snare interactions in vesicular transport (NES=1.740, P=0.028) was specific to the response of C57BL/6J mice to HFD (Figure 3, Table 1), suggesting activation of cell regeneration processes. Even though the PPAR signalling pathway was not globally affected by HFD in C57BL/6J mice (NES=1.072, P=0.64), expression of key genes in this pathway (Pparg, Ppargc1a, Rxr) was significantly altered (Table S3). These strain-specific alterations in diet-reactive gene expression patterns may directly reflect susceptibility and resistance to genetically determined NAFLD and point to a pivotal role of increased proteasome activity on NAFLD. Validation of altered gene and pathway expression regulation. To test accuracy of Affymetrix-based gene expression data, we performed qRT-PCR analysis of selected genes of the proteasome (Figure 4A), ubiquitin-mediated proteolysis and PPAR signalling pathways. Significant stimulation of liver expression of Psmb9, Psmc4, Rbx1, Anapc2 and Pparg by HFD in C57BL/6J mice and generally unaffected expression of these genes in BALB/c provide support to Affymetrix array results (Figures 4B,C). To investigate the biological consequences of differential regulation of ubiquitin mediated proteolysis by HFD in these mice, we quantified liver ubiquitination of PPARG, which requires ubiquitin-mediated proteolysis for activation. We show that ubiquitin binding to PPARG is increased by HFD specifically in BALB/c in the absence of PPARG transcription changes (Figure 4D). These results suggest that differential regulation of liver proteasome transcription and PPARG expression and ubiquitination may at least partly account for resistance (BALB/c) and susceptibility (C57BL/6J) to HFD-induced NAFLD.We report conserved and divergent HFD-induced liver gene expression in mouse strains, which underlie physiological responses to the dietary stimulus and genetically-determined increased susceptibility (C57BL/6J) or relative resistance (BALB/c) to liver histopathology resembling NAFLD. Analyses of the expression of both individual genes and biological pathways point to molecular mechanisms contributing to NAFLD and underline the etiological role of gene x environment interactions in the disease.
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