The use of tissue clearing to study renal transport mechanisms and kidney remodelling

Purpose of review Tissue clearing enables examination of biological structures at subcellular resolution in three dimensions. It uncovered the spatial and temporal plasticity of multicellular kidney structures that occur during homeostatic stress. This article will review the recent development in tissue clearing protocols and how it facilitated the study of renal transport mechanisms and remodelling of the kidney. Recent findings Tissue clearing methods have evolved from primarily labelling proteins in thin tissue or individual organs to visualizing both RNA and protein simultaneously in whole animals or human organs. The use of small antibody fragments and innovative imaging techniques improved immunolabelling and resolution. These advances opened up new avenues for studying organ crosstalk and diseases that affect multiple parts of the organism. Accumulating evidence suggests that tubule remodelling can occur rapidly in response to homeostatic stress or injury, allowing for adjustments in the quantitative expression of renal transporters. Tissue clearing helped to better understand the development of tubule cystogenesis, renal hypertension and salt wasting syndromes, and revealed potential progenitor cells in the kidney. Summary The continued evolution and improvement of tissue clearing methods can help to gain deep biological insights into the structure and function of the kidney, which will have clinical implications.