Patil 2014 Am J Physiol Renal Physiol
|Patil NK, Parajuli N, Macmillan-Crow LA, Mayeux PR (2014) Inactivation of renal mitochondrial respiratory complexes and manganese superoxide dismutase during sepsis: mitochondria targeted antioxidant mitigates injury. Am J Physiol Renal Physiol 306:F734-43.|
Abstract: Acute kidney injury (AKI) is a complication of sepsis and leads to a high mortality rate. Human and animal studies suggest that mitochondrial dysfunction plays an important role in sepsis-induced multi-organ failure; however, the specific mitochondrial targets damaged during sepsis remain elusive. We used a clinically relevant cecal ligation and puncture (CLP) murine model of sepsis and assessed renal mitochondrial function using high-resolution respirometry, renal microcirculation using intravital microscopy and renal function. CLP caused a time-dependent decrease in mitochondrial complex I and II/III respiration and reduced ATP. By 4 hours after CLP, activity of manganese superoxide dismutase (MnSOD) was decreased by 50% and inhibition was sustained through 36 hours. These events were associated with increased mitochondrial superoxide generation. We then evaluated whether the mitochondria-targeted antioxidant Mito-TEMPO could reverse renal mitochondrial dysfunction and attenuate sepsis-induced AKI. Mito-TEMPO (10 mg/kg) given at 6 hours post CLP decreased mitochondrial superoxide levels, protected complex I and II/III respiration, and restored MnSOD activity by 18 hours. Mito-TEMPO also improved renal microcirculation and glomerular filtration rate. Importantly, even delayed therapy with a single dose of Mito-TEMPO significantly increased 96-hour survival rate from 40% in untreated septic mice to 80%. Thus, sepsis causes sustained inactivation of three mitochondrial targets that can lead to increased mitochondrial superoxide. Importantly, even delayed therapy with Mito-TEMPO alleviated kidney injury, suggesting that it may be a promising approach to treat septic AKI.
• Keywords: Sepsis, Kidney, Mitochondria, Oxidative stress, Mitochondrial antioxidant
• O2k-Network Lab: US AR Little Rock MacMillan-Crow LA
Labels: MiParea: Respiration
Organism: Mouse Tissue;cell: Kidney Preparation: Permeabilized tissue
Coupling state: LEAK, OXPHOS Pathway: N, S, CIV HRR: Oxygraph-2k