First Author | Brezniceanu ML | Year | 2008 |
Journal | Diabetes | Volume | 57 |
Issue | 2 | Pages | 451-9 |
PubMed ID | 17977949 | Mgi Jnum | J:132449 |
Mgi Id | MGI:3775977 | Doi | 10.2337/db07-0013 |
Citation | Brezniceanu ML, et al. (2008) Attenuation of interstitial fibrosis and tubular apoptosis in db/db transgenic mice overexpressing catalase in renal proximal tubular cells. Diabetes 57(2):451-9 |
abstractText | OBJECTIVE: The present study investigated the relationships between reactive oxygen species (ROS), interstitial fibrosis, and renal proximal tubular cell (RPTC) apoptosis in type 2 diabetic db/db mice and in db/db transgenic (Tg) mice overexpressing rat catalase (rCAT) in their RPTCs (db/db rCAT-Tg). RESEARCH DESIGN AND METHODS: Blood pressure, blood glucose, and albuminuria were monitored for up to 5 months. Kidneys were processed for histology and apoptosis studies (terminal transferase-mediated dUTP nick-end labeling or immunostaining for active caspase-3 and Bax). Real-time quantitative PCR assays were used to quantify angiotensinogen (ANG), p53, and Bax mRNA levels. RESULTS: db/db mice developed obesity, hyperglycemia, hypertension, and albuminuria. In contrast, db/db rCAT-Tg mice became obese and hyperglycemic but had normal blood pressure and attenuated albuminuria compared with db/db mice. Kidneys from db/db mice displayed progressive glomerular hypertrophy, glomerulosclerosis, interstitial fibrosis, and tubular apoptosis and increased expression of collagen type IV, Bax, and active caspase-3, as well as increased ROS production. These changes, except glomerular hypertrophy, were markedly attenuated in kidneys of db/db rCAT-Tg mice. Furthermore, ANG, p53, and Bax mRNA expression was increased in renal proximal tubules of db/db mice but not of db/db rCAT-Tg mice. CONCLUSIONS: Our results indicate a crucial role for intra-renal ROS in the progression of hypertension, albuminuria, interstitial fibrosis, and tubular apoptosis in type 2 diabetes and demonstrate the beneficial effects of suppressing ROS formation. |