Effects of p67phox on the mitochondrial oxidative state in the kidney of Dahl salt-sensitive rats: optical fluorescence 3-D cryoimaging.
The goal of the present study was to quantify and correlate the contribution of the cytosolic p67(phox) subunit of NADPH oxidase 2 to mitochondrial oxidative stress in the kidneys of the Dahl salt-sensitive (SS) hypertensive rat. Whole kidney redox states were uniquely assessed using a custom-designed optical fluorescence three-dimensional cryoimager to acquire multichannel signals of the intrinsic fluorophores NADH and FAD. SS rats were compared with SS rats in which the cytosolic subunit p67(phox) was rendered functionally inactive by zinc finger nuclease mutation of the gene (SS(p67phox)-null rats). Kidneys of SS rats fed a 0.4% NaCl diet exhibited significantly (P = 0.023) lower tissue redox ratio (NADH/FAD; 1.42 ± 0.06, n = 5) than SS(p67phox)-null rats (1.64 ± 0.07, n = 5), indicating reduced levels of mitochondrial electron transport chain metabolic activity and enhanced oxidative stress in SS rats. When fed a 4.0% salt diet for 21 days, both strains exhibited significantly lower tissue redox ratios (P < 0.001; SS rats: 1.03 ± 0.05, n = 9, vs. SS(p67phox)-null rats: 1.46 ± 0.04, n = 7) than when fed a 0.4% salt, but the ratio was still significantly higher in SS(p67phox) rats at the same salt level as SS rats. These results are consistent with results from previous studies that found elevated medullary interstitial fluid concentrations of superoxide and H2O2 in the medulla of SS rats. We conclude that the p67(phox) subunit of NADPH oxidase 2 plays an important role in the excess production of ROS from mitochondria in the renal medulla of the SS rat.
['Salehpour|F|F|', 'Ghanian|Z|Z|', 'Yang|C|C|', 'Zheleznova|N N|NN|', 'Kurth|T|T|', 'Dash|R K|RK|', 'Cowley|A W|AW|', 'Ranji|M|M|']
D000818:Animals D004195:Disease Models, Animal D005182:Flavin-Adenine Dinucleotide D005629:Frozen Sections D005838:Genotype D006973:Hypertension D007091:Image Processing, Computer-Assisted D021621:Imaging, Three-Dimensional D007668:Kidney D008297:Male D008856:Microscopy, Fluorescence D008928:Mitochondria D009243:NAD D010084:Oxidation-Reduction D018384:Oxidative Stress D010641:Phenotype D010750:Phosphoproteins D020303:Rats, Inbred Dahl D055647:Rats, Transgenic D017673:Sodium Chloride, Dietary D013997:Time Factors
p67phox Dahl salt-sensitive rat NADPH oxidase oxidative stress hypertension three-dimensional flavin adenine dinucleotide hicotinamide adenine dinucleotide mitochondrial redox state optical fluorescence cryoimaging