Comprehensive three-dimensional analysis (CUBIC-kidney) visualizes abnormal renal sympathetic nerves after ischemia/reperfusion injury

• DOI: 10.1016/j.kint.2019.02.011
• Publication Date: 2019-04-09T09:30:32Z
• Authors: Sho Hasegawa; Etsuo A. Susaki; Tetsuhiro Tanaka; Hirotaka Komaba; Takehiko Wada; Masafumi Fukagawa; Hiroki R. Ueda; Masaomi Nangaku
• Keywords: Male; 0301 basic medicine; Histocytological Preparation Techniques; Sympathetic Nervous System; Fluorescent Antibody Technique; Acute Kidney Injury; Kidney; Disease Models, Animal; Mice; Norepinephrine; 03 medical and health sciences; Imaging, Three-Dimensional; Reperfusion Injury; Disease Progression; Animals; Humans; Renal Insufficiency, Chronic

The sympathetic nervous system is critical in maintaining the homeostasis of renal functions. However, its three-dimensional (3D) structures in the kidney have not been elucidated due to limitation of conventional imaging methods. CUBIC (Clear, Unobstructed Brain/Body Imaging Cocktails and Computational analysis) is a newly developed tissue-clearing technique, which enables whole-organ 3D imaging without thin-sectioning. Comprehensive 3D imaging by CUBIC found that sympathetic nerves are primarily distributed around arteries in the mouse kidney. Notably, the sympathetic innervation density was significantly decreased 10 days after ischemia-reperfusion injury (voluminal ratio of innervation area to kidney) by about 70%. Moreover, norepinephrine levels in kidney tissue (output of sympathetic nerves) were significantly reduced in injured kidneys by 77%, confirming sympathetic denervation after ischemia-reperfusion injury. Time-course imaging indicated that innervation partially recovered although overall denervation persisted 28 days after injury, indicating a continuous sympathetic nervous abnormality during the progression of chronic kidney disease. Thus, CUBIC-kidney, the 3D imaging analysis, can be a strong imaging tool, providing comprehensive, macroscopic perspectives for kidney research.