Redox Profiling of NAD Kinase in Acute Kidney Injury

Title: Redox Profiling of NAD Kinase in Acute Kidney Injury

Authors: Emily Q. Quach Pharm.D. Candidate 2023, Liang-Jun Yan PhD.

Abstract

Background: Acute kidney injury (AKI) is a common clinical disorder in hospitalized patients and is characterized by a rapid decline in kidney function reflected by a rapid decrease in glomerular filtration rate and a decrease in urine output or anuria. Besides supportive therapy for AKI, there are no effective treatments. Therefore, further understanding of the underlying pathology of this disorder is needed. Purpose: Oxidative stress has been postulated to be one of the major mechanisms underlying AKI; and NAD kinase (NADK), the sole enzyme making NADP from NAD, is a key player in oxidative stress and redox imbalance. Nevertheless, the role of NADK in AKI remains unknown. In this study, we propose to investigate the redox profile of cytosolic NADK in mice models. Methods: AKI-induced mice model by a single intraperitoneal injection of folic acid (250 mg/kg). Three days after the folic acid injection, mice will be euthanized followed by the collection of blood and the kidneys. Kidney function will be measured by quantitation of blood urea nitrogen, serum uric acid, and creatinine. For NADK profiling, we will analyze NADK protein expression, enzymatic activities, and NADK protein oxidative modifications. NADK protein oxidation will be quantitated by Western blot detection of protein carbonyls labeled with biotin-linked reactive aldehyde probes. Results: The NADK protein oxidation is expected to increase upon AKI induction concurrent with a decreased enzymatic activity of NADK. Additionally, we expect to observe changes in NADK protein expression in AKI. Conclusion: the results of our study will provide insights into the role of NADK in AKI and may also indicate that NADK could be a potential target for future prevention and therapy for acute kidney injury.