Involvement of MAPKs in ICAM-1 Expression in Glomerular Endothelial Cells in Diabetic Nephropathy

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1 Involvement of MPKs in ICM-1 Expression in Glomerular Endothelial Cells in Diabetic Nephropathy a a,b* a a a a c a a a c b

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4 5 Watanabe et al. cta Med. Okayama Vol. 5, No. cholate, and 1mM mercaptoethanol at 7 C for 3min. fter four 1-min washes with TS-T, membranes were incubated with another primary antibody and then visualized again. The amount of detected proteins was analyzed using Image Quant (Molecular Dynamics, Chicago, IL, US) software. Results are expressed as means ± SD of 3 to independent experiments. Stimulated samples were compared with controls by unpaired Studentʼs test. For multiple-group comparisons, one-way analysis of variance (NOV) followed by the post hoc Fisherʼs test was performed using StatView software..5 was considered statistically significant. Results Hb1c and urinary albumin excretion (UE) are significantly higher in diabetic rats compared with nondiabetic rats (Hb1c; 13.ｵ vs 3.ｵ, UE; 9 μg/day vs 5. μg/day,.5). In diabetic rats, ICM-1 expression was increased in glomeruli compared with nondiabetic rats (Fig. 1). On immunofluorescence microscopy, ICM-1 was seen in a fine granular pattern on the surface of GE cells. lthough / To examine whether ERK1/ phosphorylation is mediated by HG and HM in GE cells, the activation of these kinases was assayed by Western blot using an antibody specific for the phosphorylated, active forms of ERK1/. oth HG and HM stimulated phosphorylation of ERK1/ in GE cells (Fig. ). The maximal response was obtained within 1min and then declined. To determine whether p3 phosphorylation is mediated by HG and HM in GE cells, activation of this kinase was assayed by Western blot using an antibody specific for the phosphorylated, active forms of p3. oth HG and HM stimulated phosphorylation of p3 in GE cells (Fig. normal Fig. 1 ICM-1 was expressed at low levels in the basal state (NG), its expression was significantly increased in HG and HM (Fig. ). Western blot analysis also revealed that exposure to HG and HM induced ICM-1 protein expression in a time-dependent manner in GE cells (Fig. 3). Exposure to HG increased ICM-1 protein expression.1 ±.-fold after 1h and 5.3±1.-fold after h compared with that at baseline (Fig. 3). Similarly, exposure to HM increased ICM-1 protein.39 ±. 3-fold after 1h and 5.3 ± 1.51-fold after h (Fig. 3). DM Immunofluorescence staining for ICM-1 in the glomeruli of nondiabetic () and diabetic rats ().

5 ugust 11 MPKs in Diabetic Glomerulus 51 control (NG) C HG HM Fig. Immunofluorescence staining for ICM-1 in GE cells. GE cells were incubated with 5.5 mm D-glucose (), 3 mm D-glucose () and 5.5 mm D-glucose plus.5 mm D-mannitol (C) for h. 5). The maximal response was achieved within 1min and then slightly declined. To examine whether JNK1 phosphorylation is mediated by HG and HM in GE cells, activation of this kinase was assayed by Western blot using an antibody specific for the phosphorylated, active forms of JNK1. oth HG and HM stimulated phosphorylation of JNK1 in GE cells (Fig. ), and the maximal response was obtained within 1 min and then declined. To determine whether ERK, p3 and JNK are involved in HG-induced ICM-1 expression in GE cells, ERK inhibitor II, p3 inhibitor (S35)

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