Proteomic profile of acute renal injury by ischemia/reperfusion

Abstract

Incidence of AKI has increased greatly in recent years, particularly in post renal transplant patients, after cardiac surgery and in the ICU. This occurs mainly due to the increase in life expectancy and chronic diseases, added to an improvement in the diagnosis of AKI by the new definition of AKIN. However, this diagnosis is still based on urine output, which can be affected by other non-renal diseases; and serum creatinine, which provides a late diagnosis as amended by several other factors already well established. Although technological and scientific conditions have improved in recent years, there is still no effective therapy for AKI, which consequently increases mortality of these patients. Thus, a better understanding of the LRA may provide new biomarkers earlier than those currently used and new pathways as targets for the prevention and/or intervention in disease. This study aims to analyze the kidney proteome (cortex tubules and glomerulus) and urine and nitroproteoma of kidney, urine and serum in a controlled acute kidney injury model induced by ischemia and reperfusion. For the study, cortices proteins will be extracted by homogenizer and tubules and glomerulus will be separated by laser microdissection. These tissues and urinary proteins will be digested, labeled with different isobars and analyzed by LC/MS Orbitrap. For nitroproteoma analysis, the nitrated proteins will be enriched by immunoprecipitation, digested and analyzed unmarked in the same spectrometer. Proteins identified in the proteomic and nitroproteomas will be available by statistical analysis. The proteins significantly different for this analysis will be analyzed in biological systems Ingenuity. Renal exclusive proteins, nitrated or no nitrated will be selected as candidates for biomarkers. Selected proteins will be validated by immunofluorescence confocal and western blot. Thus, this study can contribute to further discovery of new diagnoses and prognoses of the LRA and to development of new therapeutic targets, facilitating and thus allowing early treatment of the individual. (AU)