The kidneys are highly sensitive to metabolic changes. Metabolic phenotyping uncovered a number of pathways associated with high blood pressure and kidney diseases, which sheds light on the complex pathophysiology of hypertension and associated kidney injury. However, the mechanisms underlying the effects of dietary interventions on kidney function and associated changes in cellular metabolic intermediates remain incompletely understood. L-lysine is one of the essential amino acids, which is necessary for many physiological functions. Our recent metabolomics study revealed that intrarenal levels of L-Lysine are reduced in Dahl salt-sensitive (SS) rats when animals are fed an HS diet. This provided further evidence that L-Lysine is critical for metabolic states in the kidney. The main hypothesis of this project is that dietary L-Lysine supplementation significantly enhances cardiorenal protection via acute inhibition of metabolic load and oxidative stress triggered by hypertension and renal damage-induced uptake of albumin in proximal tubule (PT) cells and on a longer scale – via chemically modified entities that provide a sink for essential mitochondrial metabolism and fatty acid biosynthesis. Specifically, we propose that L-Lysine accumulates in the kidneys, inhibits PT reabsorption, and promotes excretion of excessively accumulated intrarenal albumin. These effects of L-Lysine, in conjunction with strong diuretic and natriuretic properties, leads to the protection of PT from metabolic stress. Furthermore, our evidence supports that lysine malonylation (recently described post-translational modification) plays an important role in salt- induced hypertension and kidney injury. Proposed here research strategy represents a pioneering effort to understand the mechanisms regulating metabolic states in the kidney and further pathological changes associated with altered PT function during the development of salt-induced hypertension and chronic kidney disease. Mechanistic insight into the protective effects of L-Lysine and the contribution of Lysine malonylation in these mechanisms will be uncovered. Several innovative approaches and unique rat models will be used to test the following Specific Aims: Aim 1 will define the protective effects of L-Lysine dietary management on PT reabsorption, renal oxidative stress, and the development of renal damage in salt-sensitive hypertension. The hypothesis that Slc7a9 is a key transporter of L-Lysine in PT will also be tested in this aim. Aim 2 will establish the contribution of the Lysine malonylation metabolic pathway in the control of free fatty acid metabolism and mitochondria function. A combination of pharmacological (by using potent MCD inhibitor CBM 301940) and genetic (novel SSMlycd-/- rat model) approaches will be further utilized to understand the role of Malonyl-Lysine in mitochondrial fatty acid oxidation and the regulation of malonyl-CoA in kidney function.