BACKGROUND: The mitochondrial protein frataxin regulates iron metabolism for heme and iron sulfur cluster synthesis in the mitochondria and could be associated with the regulation of oxidative stress. To clarify the expression of frataxin and its association with uremia, we evaluated the mRNA and protein levels of frataxin in the polymorphonuclear leukocytes (PMNLs) of patients on hemodialysis (HD). METHODS: Uremic patients on HD (n = 18) and healthy control subjects (n = 18) were investigated. PMNLs were isolated by differential centrifugation. The mRNA levels of frataxin in isolated leukocytes were quantified by TaqMan real-time polymerase chain reaction. Frataxin protein expression in the cell lysate was evaluated using SDS-polyacrylamide gel electrophoresis and Western blotting. RESULTS: The frataxin/glyceraldehyde-3-phosphate dehydrogenase mRNA ratio in PMNLs from uremic patients was significantly lower than that in control subjects. Frataxin protein expression in uremic patients was also significantly lower than that in controls. Multiple regression analysis showed that frataxin mRNA levels were independently associated with the serum levels of both the oxidative stress marker malondialdehyde and the proinflammatory cytokine tumor necrosis factor-α. CONCLUSION: The downregulation of frataxin seems to be linked with uremic status, which is usually associated with chronic inflammation and the acceleration of oxidative stress. Mitochondrial iron regulation may play a role in several comorbidities and in the poor prognosis in uremic patients. Further investigation is needed to elucidate whether reduced frataxin levels are linked to the pathological status of uremic patients and whether uremic substances affect frataxin expression.
BACKGROUND: The mitochondrial protein frataxin regulates iron metabolism for heme and iron sulfur cluster synthesis in the mitochondria and could be associated with the regulation of oxidative stress. To clarify the expression of frataxin and its association with uremia, we evaluated the mRNA and protein levels of frataxin in the polymorphonuclear leukocytes (PMNLs) of patients on hemodialysis (HD). METHODS: Uremic patients on HD (n = 18) and healthy control subjects (n = 18) were investigated. PMNLs were isolated by differential centrifugation. The mRNA levels of frataxin in isolated leukocytes were quantified by TaqMan real-time polymerase chain reaction. Frataxin protein expression in the cell lysate was evaluated using SDS-polyacrylamide gel electrophoresis and Western blotting. RESULTS: The frataxin/glyceraldehyde-3-phosphate dehydrogenase mRNA ratio in PMNLs from uremic patients was significantly lower than that in control subjects. Frataxin protein expression in uremic patients was also significantly lower than that in controls. Multiple regression analysis showed that frataxin mRNA levels were independently associated with the serum levels of both the oxidative stress marker malondialdehyde and the proinflammatory cytokine tumor necrosis factor-α. CONCLUSION: The downregulation of frataxin seems to be linked with uremic status, which is usually associated with chronic inflammation and the acceleration of oxidative stress. Mitochondrial iron regulation may play a role in several comorbidities and in the poor prognosis in uremic patients. Further investigation is needed to elucidate whether reduced frataxin levels are linked to the pathological status of uremic patients and whether uremic substances affect frataxin expression.
Authors: V Campuzano; L Montermini; Y Lutz; L Cova; C Hindelang; S Jiralerspong; Y Trottier; S J Kish; B Faucheux; P Trouillas; F J Authier; A Dürr; J L Mandel; A Vescovi; M Pandolfo; M Koenig Journal: Hum Mol Genet Date: 1997-10 Impact factor: 6.150
Authors: Wolfgang Nachbauer; Sascha Hering; Markus Seifert; Hannes Steinkellner; Brigitte Sturm; Barbara Scheiber-Mojdehkar; Markus Reindl; Alexander Strasak; Werner Poewe; Guenter Weiss; Sylvia Boesch Journal: Cerebellum Date: 2011-12 Impact factor: 3.847
Authors: John H Willis; Grazia Isaya; Oleksandr Gakh; Roderick A Capaldi; Michael F Marusich Journal: Mol Genet Metab Date: 2008-05-15 Impact factor: 4.797
Authors: M Cossée; A Dürr; M Schmitt; N Dahl; P Trouillas; P Allinson; M Kostrzewa; A Nivelon-Chevallier; K H Gustavson; A Kohlschütter; U Müller; J L Mandel; A Brice; M Koenig; F Cavalcanti; A Tammaro; G De Michele; A Filla; S Cocozza; M Labuda; L Montermini; J Poirier; M Pandolfo Journal: Ann Neurol Date: 1999-02 Impact factor: 10.422