TY - JOUR
T1 - Apoptosis occurs differentially according to glomerular size in diabetic kidney disease
AU - Jung, Dong Sub
AU - Lee, Sun Ha
AU - Kwak, Seung Jae
AU - Li, Jin Ji
AU - Kim, Do Hee
AU - Nam, Bo Young
AU - Kang, Hye Young
AU - Chang, Tae Ik
AU - Park, Jung Tak
AU - Han, Seung Hyeok
AU - Yoo, Tae Hyun
AU - Kang, Shin Wook
N1 - Funding Information:
Acknowledgements. This work was supported in part by the BK21 (Brain Korea 21) Project for Medical Sciences, Yonsei University, a faculty research grant from Yonsei University College of Medicine for 2009 (6-2009-0064) and the Korea Science and Engineering Foundation (KO-SEF) grant funded by the Korea government (MOST) (R01-2007-000-20263-0 and R13-2002-054-04001-0).
PY - 2012/1
Y1 - 2012/1
N2 - Background.Apoptosis, which is involved in the process of mesangial cell and podocyte loss in diabetic nephropathy, is known to be regulated by protein kinase B/Akt (Akt). A number of studies have therefore investigated the activity of Akt under diabetic conditions, but the results have not been consistent. In this study, we hypothesized that apoptosis may occur differentially and that Akt may be differentially activated according to glomerular size in diabetic kidney disease. Methods.Fifty male Sprague-Dawley rats were injected intraperitoneally with diluent (C, n = 25) or streptozotocin (DM, n = 25). After 3 months, glomeruli were isolated using sieves with pore sizes of 250, 150, 125 and 75 μm and then classified into large glomeruli (on the 125-μm sieve, LG) and small glomeruli (on the 75-μm sieve, SG) groups. Western blot analyses for phospho-Akt, apoptosis-related molecules (Bax, Bcl-2, active fragments of Caspase-3 and phospho-p53) and cyclin-dependent kinase inhibitors were performed. Conclusions.The numbers of total cells and podocytes in isolated glomeruli were determined using transmission electron microscopy. Akt phosphorylation was significantly decreased in DM-LG, while it was significantly increased in DM-SG (P < 0.05). The ratio of Bax/Bcl-2 protein expression and active fragments of Caspase-3 and phospho-p53 protein expression were significantly increased in DM-LG compared to DM-SG and C-SG (P < 0.001 and P < 0.01, respectively). In contrast, the expression of p27 Kip1 and p21 Cip1 was significantly increased in DM-SG compared to DM-LG and C-SG (P < 0.05). The numbers of total glomerular cells and podocytes were significantly decreased in DM-LG (P < 0.05). In conclusion, these data show differential expression of Akt activity and apoptosis-related molecules according to glomerular size in diabetic nephropathy, suggesting that apoptosis may be more operative in more hypertrophic glomeruli, resulting in fewer glomerular cells and podocytes in diabetic nephropathy.
AB - Background.Apoptosis, which is involved in the process of mesangial cell and podocyte loss in diabetic nephropathy, is known to be regulated by protein kinase B/Akt (Akt). A number of studies have therefore investigated the activity of Akt under diabetic conditions, but the results have not been consistent. In this study, we hypothesized that apoptosis may occur differentially and that Akt may be differentially activated according to glomerular size in diabetic kidney disease. Methods.Fifty male Sprague-Dawley rats were injected intraperitoneally with diluent (C, n = 25) or streptozotocin (DM, n = 25). After 3 months, glomeruli were isolated using sieves with pore sizes of 250, 150, 125 and 75 μm and then classified into large glomeruli (on the 125-μm sieve, LG) and small glomeruli (on the 75-μm sieve, SG) groups. Western blot analyses for phospho-Akt, apoptosis-related molecules (Bax, Bcl-2, active fragments of Caspase-3 and phospho-p53) and cyclin-dependent kinase inhibitors were performed. Conclusions.The numbers of total cells and podocytes in isolated glomeruli were determined using transmission electron microscopy. Akt phosphorylation was significantly decreased in DM-LG, while it was significantly increased in DM-SG (P < 0.05). The ratio of Bax/Bcl-2 protein expression and active fragments of Caspase-3 and phospho-p53 protein expression were significantly increased in DM-LG compared to DM-SG and C-SG (P < 0.001 and P < 0.01, respectively). In contrast, the expression of p27 Kip1 and p21 Cip1 was significantly increased in DM-SG compared to DM-LG and C-SG (P < 0.05). The numbers of total glomerular cells and podocytes were significantly decreased in DM-LG (P < 0.05). In conclusion, these data show differential expression of Akt activity and apoptosis-related molecules according to glomerular size in diabetic nephropathy, suggesting that apoptosis may be more operative in more hypertrophic glomeruli, resulting in fewer glomerular cells and podocytes in diabetic nephropathy.
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U2 - 10.1093/ndt/gfr301
DO - 10.1093/ndt/gfr301
M3 - Article
C2 - 21652547
AN - SCOPUS:84863011417
SN - 0931-0509
VL - 27
SP - 259
EP - 266
JO - Proceedings of the European Dialysis and Transplant Association - European Renal Association. European Dialysis and Transplant Association - European Renal Association. Congress
JF - Proceedings of the European Dialysis and Transplant Association - European Renal Association. European Dialysis and Transplant Association - European Renal Association. Congress
IS - 1
ER -
