TY - JOUR T1 - Role of Mitochondrial Oxidants in an In Vitro Model of Sepsis-Induced Renal Injury JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 192 LP - 201 DO - 10.1124/jpet.111.183756 VL - 340 IS - 1 AU - Elina Pathak AU - Lee Ann MacMillan-Crow AU - Philip R. Mayeux Y1 - 2012/01/01 UR - http://jpet.aspetjournals.org/content/340/1/192.abstract N2 - Oxidative stress has been implicated to play a major role in multiorgan dysfunction during sepsis. To study the mechanism of oxidant generation in acute kidney injury (AKI) during sepsis, we developed an in vitro model of sepsis using primary cultures of mouse cortical tubular epithelial cells exposed to serum (2.5–10%) collected from mice at 4 h after induction of sepsis by cecal ligation and puncture (CLP) or Sham (no sepsis). CLP serum produced a concentration-dependent increase in nitric oxide (NO) (nitrate + nitrite) release at 6 h and cytotoxicity (lactate dehydrogenase release) at 18 h compared with Sham serum treatment. Before cytotoxicity there was a decrease in mitochondrial membrane potential, which was followed by increased superoxide and peroxynitrite levels compared with Sham serum. The role of oxidants was evaluated by using the superoxide dismutase mimetic and peroxynitrite scavenger manganese(III)tetrakis(1-methyl-4-pyridyl)porphyrin tetratosylate hydroxide (MnTmPyP). MnTmPyP (10–100 μM) produced a concentration-dependent preservation of ATP and protection against cytotoxicity. MnTmPyP blocked mitochondrial superoxide and peroxynitrite generation produced by CLP serum but had no effect on NO levels. Although MnTmPyP did not block the initial CLP serum-induced fall in mitochondrial membrane potential, it allowed mitochondrial membrane potential to recover. Data from this in vitro model suggest a time-dependent generation of mitochondrial oxidants, mitochondrial dysfunction, and renal tubular epithelial cell injury and support the therapeutic potential of manganese porphyrin compounds in preventing sepsis-induced AKI. ER -