Transcriptome Profiling of High Glucose and Glucosamine-Induced Mouse Mesangial Cells

The renal mesangial cells play an important role in the development of diabetic glomerulosclerosis and renal failure. We have previously demonstrated some of the effects of high glucose are mediated via the hexosamine biosynthesis pathway (HBP) in which fructose-6-phosphate is converted to glucosamine-6-phosphate by the rate-limiting enzyme glutamine:fructose-6-phosphate amidotransferase (GFAT). Using Affymetrix murine expression U430 2.0 chips, we examined the global effects of high glucose (HG) and glucosamine (GlcN) on the transcriptomes of a mouse mesangial cell line (MES-13). Of the 34,000 genes on the chip, ~55-60% genes are detected in MES-13 cells. HG induces the expression of ~369 genes at >2-fold where 263 genes are up and 106 genes down regulated. Similarly, GlcN increases the expression of 120 genes and decreases 94 genes. Seventy-two genes are commonly regulated by HG and GlcN, in which 33 genes are up and 39 genes are down. The differential expressions of several genes found in the microarray are also confirmed by quantitative PCR. Significant pathways co-modulated by HG and GlcN are the thioredoxin system (a 20-fold increase in thioredoxin interacting protein expression), endoplasmic reticulum (ER) stress, extracellular matrix and interferon-inducible genes. Furthermore, HG and GlcN target various intracellular pathways including the mitogen-activated protein kinase, TOLL-like receptor, fructose and mannose metabolism, and the biosynthesis of steroids and N-glycans. We conclude from this microarray data and other experimental results that the HBP mediates several effects of high glucose on mesangial cell metabolism, which promotes ER stress, oxidative stress and the interferon-inducible gene expression to cause cell cycle arrest, ECM gene expression and apoptosis.

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