Table 1.
Basic parameters of lean/obese Zucker rats.
Figure 1.
Increased MG accumulation, reduced GSH level and glyoxalase I activity were related to Akt1 expression in obese Zucker rats.
(A) MG levels in kidney, fat, liver of 16-week old Zucker lean or obese rats. *P<0.05, n = 4−8 in each groups. (B) GSH level decreased in the adipose tissue of Zucker obese rats while glyoxalase I activity (C ) remain unchanged compare with Zucker lean rats. GSH level was presented as % of that in control group. *P<0.05, n = 4 in each groups. (D) The expression of p-Akt1 and Akt1 in adipose tissue of lean and obese Zucker rats. *P<0.05, **P<0.01, n = 4 in both groups. The results of Western blotting were quantified by Chemigenus® Bio imaging system company) and presented as the percentage of that from control cells (E). □ Zucker lean rats, ▪ Zucker obese rats.
Figure 2.
The effect of MG on 3T3-L1 cell proliferation, GSH level and glyoxalase I activity.
The relative cell proliferation of each group was presented as the ratio between arbitrary absorbance on 570 nm of each group and that from the control group without treatment. The effect of different MG concentrations on cell proliferation was shown in (A) and the effect of 10 µM MG with/without SH-6 and alagebrium was shown in (B). The reduced GSH level (C ) and unchanged glyoxalase I activity (D) was observed in 3T3-L1 cells treated with 5, 10, 20 and 50 µM MG. *P<0.05, **P<0.01 vs control cells; +P<0.05 vs MG treated cells; n = 12 in each group.
Figure 3.
Effect of MG on cell cycle progression of 3T3-L1 cells.
After 12, 16, 20 h of MG (10 µM) treatment, cellular DNA content was determined by a flow cytometer (A). The effect of MG with/without SH6 (10 µM) or alagebrium (50 µM) on cellular DNA content is shown in (B). *P<0.05 vs control group; +P<0.05 vs MG treated group; n = 6 in each group. The indicated percentage of the cell number is average of three experiments. CT: control; ALA: alagebrium.
Figure 4.
Effect of MG on Akt1 phosphorylation in 3T3-L1 cells.
After 24 h treatment with or without MG (10 µM) in the presence or absence of SH-6 (10 µM)/alagebrium (50 µM), the protein levels of Akt1, (A), Representive Western blot of phospho-Akt1 (p-Akt1(Ser473), p-Akt1(thr308)) and Akt1; (B), The level of phospho-Akt1(Ser473) in 3T3-L1 cells with/without MG treatment; (C ), The level of phospho-Akt1(thr308) in 3T3-L1 cells with/without MG treatment. *P<0.05 vs control (CT) cells; +P<0.05 vs MG treated cells. The results were based on data from three experiments. CT: control; ALA: alagebrium.
Figure 5.
Effect of MG on p21, p-p21, p27, p-p27 and CDK2 activity in 3T3-L1 cells.
After 24 h treatment with or without MG (10 µM) in the presence or absence of SH-6 (10 µM)/alagebrium (50 µM), the protein levels of p21, p-21 and p27, p-p27 (A), and the activity of Cdk2 (B) were determined and compared. *P<0.05 vs control (CT) cells; +P<0.05 vs MG treated cells. The results were based on data from three experiments.
Figure 6.
MG induced adipogenesis in 3T3-L1 adipocytes.
After treated with MG, SH-6 or alagebrium for 48 h, cells were cultured till confluence and differentiation. The Oil Red O staining in adipocytes was shown in (A). The lipid content in adipocytes from different groups was quantified and presented as the percentage of that from control cells (B). The mRNA expression of adiponectin, PPARγ, C/EBPα and leptin in differentiated cells treated with MG alone or with MG and alagebrium were determined by real-time PCR (C). *P<0.05; **P<0.01; n = 3 in each groups. The open square in Figure 6C represents cells treated with MG; the stripped square represents cells treated with MG alagebrium. CT: control; ALA: alagebrium.