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dc.contributor.advisorJohn Papaconstantinouen_US
dc.creatorChristopher Eric Baileyen_US
dc.date.accessioned2011-12-20T16:04:46Z
dc.date.available2010-09-28en_US
dc.date.available2011-12-20T16:04:46Z
dc.date.created2009-06-24en_US
dc.date.issued2009-06-09en_US
dc.identifier.otheretd-06242009-092534en_US
dc.identifier.urihttp://hdl.handle.net/2152.3/128
dc.description.abstractAging and skeletal muscle ischemia/reperfusion (I/R) injury both lead to skeletal\r\nmuscle dysfunction, evidenced by decreased contractile force generation, particularly in\r\nglycolytic muscle. The deficits in I/R are more severe and persistent in aged animals.\r\nPrevious studies in our lab led us to hypothesize that the expression of the glycolytic\r\nenzyme glyceraldehyde-3-phosphate dehydrogenase may be altered following I/R. We\r\nfurther hypothesized that aging would enhance the oxidative stress and oxidative damage\r\nexperienced by the muscle. GAPDH protein levels were measured by Western blotting.\r\nWe observed that the enzyme is significantly decreased at 3 and 5 days of reperfusion in\r\nthe young muscle, while the enzyme was significantly decreased in the aged muscle at 1,\r\n3, 5, and 7 days. Using PCR, we compared GAPDH mRNA levels at 5 days reperfusion\r\nand found that the I/R tissue from both young and old have significant increases in\r\nGAPDH transcript at this time point compared to control, suggesting that the protein\r\ndeficit is not due to decreased transcription. Finally, we examined tyrosine nitration. A\r\nvii\r\nspot selected following 2D gel electrophoresis and nitrotyrosine western blotting of\r\nyoung and old muscle lysate was identified as GAPDH by mass spectrometry. We\r\ncompared tyrosine nitration over the time course of reperfusion. While total tyrosine\r\nnitration does not increase in the I/R tissue in the young, nitration of GAPDH is\r\nsignificantly increased at 1 and 3 days reperfusion. In contrast to the young, total\r\ntyrosine nitration in the aged muscle was significantly increased at 1, 3, and 5 days of\r\nreperfusion, with significant increases in nitration of GAPDH at the same time points.\r\nWe conclude that GAPDH protein levels are decreased following I/R, which could\r\ninterfere with metabolism and ATP generation. Further, this decrease is not likely\r\ntranscriptionally mediated. Based on the increases in tyrosine nitration, we propose that\r\noxidative modification enhances the degradation of GAPDH following I/R, and that the\r\npersistence of decreased GAPDH in the aged muscle is due to the prolonged increases in\r\noxidative modification seen in that age group. This suggests that the aged muscle\r\nexperiences greater oxidative stress, protein modification, and GAPDH degradation,\r\npossibly contributing to the decreased muscle function reported in the literature.en_US
dc.format.mediumelectronicen_US
dc.language.isoengen_US
dc.rightsCopyright © is held by the author. Presentation of this material on the TDL web site by The University of Texas Medical Branch at Galveston was made possible under a limited license grant from the author who has retained all copyrights in the works.en_US
dc.subjecttyrosine nitrationen_US
dc.subjectskeletal muscleen_US
dc.subjectischemia reperfusionen_US
dc.subjectGAPDHen_US
dc.subjectagingen_US
dc.titleTyrosine nitration and altered protein pool levels of glyceraldehyde-3-phosphate dehydrogenase following ischemia/reperfusion: The influence of aging in glycolytic skeletal muscleen_US
dc.type.materialtexten_US
dc.type.genredissertationen_US
thesis.degree.namePhDen_US
thesis.degree.levelDoctoralen_US
thesis.degree.grantorThe University of Texas Medical Branchen_US
thesis.degree.departmentCell Biologyen_US
dc.contributor.committeeMemberRoger Farraren_US
dc.contributor.committeeMemberJeffrey Rabeken_US
dc.contributor.committeeMemberGolda Leonarden_US
dc.contributor.committeeMemberGiulio Taglialatelaen_US


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