Rosiglitazone Prevents High Glucose-Induced Vascular Endothelial Growth Factor and Collagen IV Expression in Cultured Mesangial Cells

Figure 1

Effect of high glucose on PPAR 𝛾expression. Rat glomerular mesangial cells were cultured in 5.6 mM (NG) or 25 mM D-glucose (HG), or 5.6 mM D-glucose + 24.4 mM L-glucose (LG) for up to 48 hours. (a) PPAR𝛾 was detected by immunobloting in total cell lysates, using 𝛽-actin as the loading controls. The graphs represent PPAR𝛾 protein levels relative to NG. (b) PPAR𝛾 mRNA levels were determined by real-time RT-PCR. (𝑛=4-6, ^∗𝑃<.05 versus NG; ^∗∗𝑃<.01 versus NG). (c) Preincubated with 10 𝜇M rosiglitazone (RSG) or/and 10 𝜇M GW9662, the protein expression of PPAR𝛾 was not affected by RSG or GW6992 in HG (𝑛=5,^∗𝑃<.05 versus NG). Mesangial cells were transiently transfected with a luciferase reporter gene containing three PPAR response elements and then cultured in the above conditions. (d) Luciferase reporter activity was reduced in HG (𝑛=5,^∗𝑃<.05 versus NG, ^∗∗𝑃<.01 versus NG). (e) In NG, PPAR𝛾 promoter activity increased in dose response to RSG (𝑛=4, ^∗𝑃<.01 versus NG). (f) GW6992 blocked the effect of RSG (𝑛=4-6, ^∗𝑃<.01 versus NG alone, ^∗∗𝑃<.05 versus NG or HG alone, ^∗∗∗𝑃<.05 versus NG or HG with RSG).

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