New Insights Into Molecular Mechanisms of Diabetic Kidney Disease Shawn S. Badal, BS, Farhad R. Danesh, MD  American Journal of Kidney Diseases  Volume 63, Issue 2, Pages S63-S83 (February 2014) DOI: 10.1053/j.ajkd.2013.10.047 Copyright © 2014 National Kidney Foundation, Inc. Terms and Conditions

Figure 1 Mitochondrial ROS. The mitochondrial matrix contains the components of the TCA cycle and the β-oxidative pathway, which provide reduced NADH and FADH2 to the electron transport chain, leading to generation of a proton gradient across the inner mitochondrial membrane. Under high-glucose conditions, pyruvate is shuttled to the mitochondria, where it is oxidized by the TCA cycle to produce 4 molecules of NADH and 1 molecule of FADH2. American Journal of Kidney Diseases 2014 63, S63-S83DOI: (10.1053/j.ajkd.2013.10.047) Copyright © 2014 National Kidney Foundation, Inc. Terms and Conditions

Figure 2 Mitochondrial fission and fusion. (A) Mitochondrial networks visualized with MitoTracker Red (Life Technologies) fluorescent dye to monitor mitochondrial morphology under (left) normal or (right) high-glucose conditions. Mitochondria appear as long, tubular, and sometimes branched structures that spread throughout the cytoplasm. However, under high-glucose conditions, they appear dense, small, and fragmented. (B) Mitochondrial fission is driven by Drp1, which resides primarily in the cytoplasm. Under hyperglycemic conditions, Drp1 is activated and recruited to the mitochondria. Drp1 then forms spirals around mitochondria at fission sites, which promote the constriction of mitochondria. American Journal of Kidney Diseases 2014 63, S63-S83DOI: (10.1053/j.ajkd.2013.10.047) Copyright © 2014 National Kidney Foundation, Inc. Terms and Conditions

Figure 3 Assembly and activation of NADPH oxidase. In resting conditions, only heterodimeric NOX-p22phox complex resides in the membrane, whereas the other components of the complex are cytosolic. Activation of the enzyme releases a conformational restriction, which results in association of different components of the complex to the plasma membrane. American Journal of Kidney Diseases 2014 63, S63-S83DOI: (10.1053/j.ajkd.2013.10.047) Copyright © 2014 National Kidney Foundation, Inc. Terms and Conditions

Figure 4 miRNA biogenesis and function. Pri-miRNA transcription is regulated by RNA polymerase II (Pol II). Pri-miRNA, typically several kilobases long, is converted into pre-miRNA by the RNAse III processing enzyme complex Drosha/DGCR8. This pre-miRNA is exported into the cytosol by the exportin 5/RanGTP complex. Pre-miRNAs are processed further through Dicer to form mature miRNAs that are loaded into the RNA-induced silencing complex (RISC) to perform their gene regulatory functions. American Journal of Kidney Diseases 2014 63, S63-S83DOI: (10.1053/j.ajkd.2013.10.047) Copyright © 2014 National Kidney Foundation, Inc. Terms and Conditions

Figure 5 RhoA/ROCK pathway. Rho GTPases cycle between an inactive (GDP)- and an active (GTP)-bound form. American Journal of Kidney Diseases 2014 63, S63-S83DOI: (10.1053/j.ajkd.2013.10.047) Copyright © 2014 National Kidney Foundation, Inc. Terms and Conditions

Figure 6 Regulation of ROCK activation. (A) The catalytic domain of ROCK is located at the amino terminus, followed by a coiled-coil–forming region and a pleckstrin-homology (PH) domain with a cysteine-rich domain (CRD) at the carboxyl terminus. (B) Active Rho binds to the RBD domain of ROCK, resulting in an open conformation and thereby activation of the ROCK. American Journal of Kidney Diseases 2014 63, S63-S83DOI: (10.1053/j.ajkd.2013.10.047) Copyright © 2014 National Kidney Foundation, Inc. Terms and Conditions