Oxidative stress and apoptosis are important factors in the etiology of renal ischemia-reperfusion (I/R) injury. The present study tested the hypothesis that the cell-permeant SOD mimetic manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP) protects the kidney from I/R-mediated oxidative stress and apoptosis in vivo. Male Sprague-Dawley rats (175-220 g) underwent renal I/R by bilateral clamping of the renal arteries for 45 min followed by reperfusion for 24 h. To examine the role of reactive oxygen species (ROS) in renal I/R injury, a subset of animals were treated with either saline vehicle (I/R Veh) or MnTMPyP (I/R Mn) (5 mg/kg ip) 30 min before and 6 h after surgery. MnTMPyP significantly attenuated the I/R-mediated increase in serum creatinine levels and decreased tubular epithelial cell damage following I/R. MnTMPyP also decreased TNF-alpha levels, gp(91phox), and lipid peroxidation after I/R. Furthermore, MnTMPyP inhibited the I/R-mediated increase in apoptosis and caspase-3 activation. Interestingly, although MnTMPyP did not increase expression of the antiapoptotic protein Bcl-2, it decreased the expression of the proapoptotic genes Bax and FasL. These results suggest that MnTMPyP is effective in reducing apoptosis associated with renal I/R injury and that multiple signaling mechanisms are involved in ROS-mediated cell death following renal I/R injury.
"Overexpression of extracellular SOD in the transgenic mice neonate brain has been suggested to be associated with significant protection against hyperoxia-induced brain damage (Zaghloul et al., 2012). A cell-permeable SOD mimetic, MnTMPyP is shown to improve tissue functions by reducing oxidative stress caused by free radicals (Kim et al., 2006 and 2010; Liang et al., 2009). MnTMPyP significantly attenuated lypopolisaccharideinduced production of superoxide free radicals and prostaglandin E2 in microglia (T. "
[Show abstract][Hide abstract] ABSTRACT: We investigated the effects of a cell-permeable superoxide dismutase mimetic, manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP) on blood-brain barrier (BBB) integrity following pentylenetetrazole (PTZ)-induced seizures in experimental preeclampsia symptoms induced by N(omega)-nitro-L-arginine methyl ester (L-NAME) in pregnant rats. To show the functional and morphological alterations in BBB integrity, quantitative analysis of sodium fluorescein (NaFlu) extravasation, immunohistochemistry and electron microscopic assessment of horseradish peroxidase (HRP) permeability were performed. Varying degrees of proteinuria were seen and arterial blood pressure increased in L-NAME-treated pregnant rats (p<0.01). MnTMPyP pretreatment and convulsive PTZ challenge significantly decreased the immunoreactivity of occludin in hippocampal capillaries in L-NAME-treated pregnant rats (p<0.01). BBB permeability to NaFlu significantly increased in pregnant rats treated with L-NAME plus PTZ (p<0.01), but MnTMPyP pretreatment did not significantly decrease NaFlu penetration into the brain parenchyma in these animals. Ultrastructurally, frequent vesicles containing HRP reaction products were observed in the capillary endothelial cells in the cerebral cortex and hippocampus of pregnant rats treated with L-NAME and L-NAME plus PTZ with the abundance being more in the latter group. MnTMPyP pretreatment caused a marked reduction in the frequency of HRP reaction product containing vesicles in both experimental settings. In conclusion, the results of the present study provide evidence that MnTMPyP plays an important role in limiting the enhanced vesicle-mediated transcellular transport in BBB endothelium in a rat model of preeclampsia and the differences in the way of transports of NaFlu and HRP might be responsible for the different effects of MnTMPyP on the BBB permeability to these two tracers.
Brain research 05/2014; 1563. DOI:10.1016/j.brainres.2014.03.029 · 2.84 Impact Factor
"This complex may participate in the superoxide anion production by inflammatory cells infiltrating the graft, or directly from the injured tissue. This pro-oxidative milieu was accentuated by a decreased expression of the major antioxidant enzymes: SODs already reported in a rodent model . These results indicate that severe ischemic conditions induce an early pro-oxidative microenvironment and that D3 is a critical time point to evaluate the red/ox balance. "
[Show abstract][Hide abstract] ABSTRACT: Background
Deceased after cardiac arrest donor are an additional source of kidney graft to overcome graft shortage. Deciphering the respective role of renal warm and cold ischemia is of pivotal interest in the transplantation process.
Using a preclinical pig model of renal auto-transplantation, we investigated the consequences of warm and cold ischemia on early innate and adaptive responses as well as graft outcome. Kidneys were subjected to either 60 min-warm ischemia (WI) or auto-transplanted after cold storage for 24 h at 4°C (CS), or both conditions combined (WI + CS). Renal function, immune response and cytokine expression, oxidative stress and cell death were investigated at 3 h, 3 and 7 days (H3, D3 and D7) after reperfusion. At 3 months, we focused on cell infiltration and tissue remodelling.
WI + CS induced a delayed graft function linked to higher tubular damage. Innate response occurred at D3 associated to a pro-oxidative milieu with a level dependent on the severity of ischemic injury whereas adaptive immune response occurred only at D7 mainly due to CS injuries and aggravated by WI. Graft cellular death was an early event detected at H3 and seems to be one of the first ischemia reperfusion injuries. These early injuries affect graft outcome on renal function, cells infiltration and fibrosis development.
The results indicate that the severe ischemic insult found in kidneys from deceased after cardiac arrest donor affects kidney outcome and promotes an uncontrolled deleterious innate and adaptive response not inhibited 3 months after reperfusion.
Journal of Translational Medicine 05/2013; 11(1):129. DOI:10.1186/1479-5876-11-129 · 3.93 Impact Factor
"study inhibited superoxide generation and cytotoxicity in ATP-depleted LLC-PK1 cells (Maenpaa et al., 2008). Although MnTmPyP is not specifically targeted to the mitochondria , it has been shown to protect against the loss of mitochondrial complex activities (Ferrer-Sueta et al., 2006; Nilakantan et al., 2010), block mitochondrial superoxide generation in smooth muscle cells (Zhao et al., 2011), and reduce tubular epithelial injury caused by oxidants during renal ischemic injury (Liang et al., 2009). In addition, similar manganese porphyrin compounds, known to accumulate in mitochondria , decrease oxidative damage, protect the electron transport chain (Ferrer-Sueta et al., 2006; Spasojevicét al., 2007; Kos et al., 2009), and reduce tubular epithelial injury caused by oxidants in animal models of renal ischemic injury (Saba et al., 2007). "
[Show abstract][Hide abstract] ABSTRACT: 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.
Journal of Pharmacology and Experimental Therapeutics 01/2012; 340(1):192-201. DOI:10.1124/jpet.111.183756 · 3.97 Impact Factor
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