TY - JOUR
T1 - Accumulation of 8-hydroxy-2′-deoxyguanosine and mitochondrial DNA deletion in kidney of diabetic rats
AU - Kakimoto, Maiko
AU - Inoguchi, Toyoshi
AU - Sonta, Toshiyo
AU - Yu, Hai Yan
AU - Imamura, Minako
AU - Etoh, Takashi
AU - Hashimoto, Toshihiko
AU - Nawata, Hajime
PY - 2002
Y1 - 2002
N2 - Oxidative stress may contribute to the pathogenesis of diabetic nephropathy. However, the detailed molecular mechanism remains uncertain. Here, we report oxidative mitochondrial DNA (mtDNA) damage and accumulation of mtDNA with a 4,834-bp deletion in kidney of streptozotocin-induced diabetic rats. At 8 weeks after the onset of diabetes, levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), which is a marker of oxidative DNA damage, were significantly increased in mtDNA from kidney of diabetic rats but not in nuclear DNA, suggesting the predominant damage of mtDNA. Semiquantitative analysis using PCR showed that the frequency of 4,834-bp deleted mtDNA was markedly increased in kidney of diabetic rats at 8 weeks, but it did not change at 4 weeks. Intervention by insulin treatment starting at 8 weeks rapidly normalized an increase in renal 8-OHdG levels of diabetic rats, but it did not reverse an increase in the frequency of deleted mtDNA. Our study demonstrated for the first time that oxidative mtDNA damage and subsequent mtDNA deletion may be accumulated in kidney of diabetic rats. This may be involved in the pathogenesis of diabetic nephropathy.
AB - Oxidative stress may contribute to the pathogenesis of diabetic nephropathy. However, the detailed molecular mechanism remains uncertain. Here, we report oxidative mitochondrial DNA (mtDNA) damage and accumulation of mtDNA with a 4,834-bp deletion in kidney of streptozotocin-induced diabetic rats. At 8 weeks after the onset of diabetes, levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), which is a marker of oxidative DNA damage, were significantly increased in mtDNA from kidney of diabetic rats but not in nuclear DNA, suggesting the predominant damage of mtDNA. Semiquantitative analysis using PCR showed that the frequency of 4,834-bp deleted mtDNA was markedly increased in kidney of diabetic rats at 8 weeks, but it did not change at 4 weeks. Intervention by insulin treatment starting at 8 weeks rapidly normalized an increase in renal 8-OHdG levels of diabetic rats, but it did not reverse an increase in the frequency of deleted mtDNA. Our study demonstrated for the first time that oxidative mtDNA damage and subsequent mtDNA deletion may be accumulated in kidney of diabetic rats. This may be involved in the pathogenesis of diabetic nephropathy.
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U2 - 10.2337/diabetes.51.5.1588
DO - 10.2337/diabetes.51.5.1588
M3 - Article
C2 - 11978660
AN - SCOPUS:0036317040
VL - 51
SP - 1588
EP - 1595
JO - Diabetes
JF - Diabetes
SN - 0012-1797
IS - 5
ER -