Kidney ultrastructure. (a) Ultrastructure of epithelial cell with large and rounded nucleus (N), numerous mitochondria (M), and pronounced microvilli (MV). (b) Necrotic epithelial cell (asterisk) with typical ultrastructural signs of necrosis such as electron pale and disintegrated cytoplasm, disrupted microvilli, and few mitochondria (M). L-lumen of proximal tubule. (c) Details of necrotic epithelial cell with strongly dilated perinuclear space (arrowhead), ruptured Golgi apparatus (asterisk), and highly demolished cytoplasmic integrity with hardly recognizable structures. (d) Epithelial cell with no brush border on apical surface, multilamellar bodies (arrowheads), and extremely large autophagic vacuoles (arrows) and fulfilling the entire cytoplasm. N-nucleus. (e) Apoptotic epithelial cell with condensed chromatin in nuclear fragments (N), lipid droplets (L), disappeared microvilli, and electron dense and condensed cytoplasm (asterisk). (f) Epithelial cells of proximal tubule with normal ultrastructure. Under basal lamina (arrow) of tubule, peritubular cell (asterisk) of connective tissue with typical signs of apoptosis such as cytoplasm condensation and chromatin fragmentation and condensation is present. Representative TEM images of kidney samples taken from control mice (a), mice receiving ATG and cisplatin (b–d), and mice receiving MSCs after ATG and cisplatin (e, f). Original magnifications: ×4400 (a), ×2600 (b), ×5800 (c), ×2600 (d), ×4400 (e), and ×2000 (f).