Shifts in cellular energy metabolism impact the development and progression of chronic kidney disease (CKD) through the generation of specific signals that modulate cellular differentiation and function, cell-cell interactions and inflammation. Perivascular renal interstitial cells and pericytes support the renal microvasculature and play a critical role in the pathogenesis of CKD. In kidney injury they represent major cellular sources of myofibroblasts, which promote fibrosis and the progression of CKD through the pathologic production and deposition of collagen and other extracellular matrix components in the interstitial space. Perivascular renal interstitial cells are highly sensitive to changes in tissue pO2 and respond to hypoxia with the production of erythropoietin, an oxygen-regulated erythropoiesis-stimulating glycoprotein hormone that is insufficiently produced in patients with CKD. Despite their importance in renal fibrogenesis and erythropoiesis, perivascular renal interstitial cells are poorly characterized and little is known about their metabolic functions. Here we hypothesize that shifts in energy metabolism plays a critical role in the development of renal fibrosis. Our studies aim at defining the degree of cellular and functional heterogeneity within this perivascular renal interstitial cell population and at defining the molecular mechanisms that link cellular energy and mitochondrial metabolism to fibrosis development. Specifically we a) examine oxygen-regulated metabolism in defined subsets of renal interstitial cells using temporally controlled conditional gene targeting, b) investigate the role of mitochondrial metabolism in renal microvascular homeostasis and differentiation and d) to determine to what degree metabolic reprogramming in perivascular renal interstitial cells impact the development of renal injury, inflammation and repair.