Abstract
Traditional histologic methods are limited in detecting dynamic changes in immune cells during acute kidney injury (AKI). Recently, optical tissue clearing combined with multiphoton microscopy (MPM) or light sheet fluorescence microscopy (LSFM) has become an emerging method for deep tissue evaluation and three-dimensional visualization. These new approaches have helped expand our understanding of tissue injury and repair processes, including tracing the changes in immune cells. We designed this study to investigate the morphological and functional alterations of renal mononuclear phagocytes (MNPs) in lipopolysaccharide (LPS)-induced AKI using renal clearing in CD11c-YFP mice. We also evaluated the effect of the NLRP3 inhibitor MCC950 to determine whether NLRP3 inhibition attenuates the activation of CD11c+ cells in an LPS-induced AKI model. Transverse sectioned whole mouse kidney imaging by LSFM showed that CD11c+ cells were mainly distributed in the cortex, especially the tubulointerstitial area. The number of CD11c+ cells was significantly more densely interspersed, particularly in periglomerular and perivascular lesions, in the saline-treated LPS-exposed kidney than in the control kidney. Deep imaging of the kidney cortex by MPM demonstrated an increased number of CD11c+ cells in the saline-treated LPS group compared with the control group. This quantitative alteration of CD11c+ cells in AKI was accompanied by morphological changes at high resolution, showing an increased number and level of dendrites. These morphological and behavioral changes in the saline-treated LPS group were accompanied by increased MHC class II and CD86 on CD11c-YFP+ cells. MCC950 attenuated the activation of CD11c+ cells after AKI and improved renal function. In conclusion, wide and deep three-dimensional visualization using MPM or LSFM combined with kidney clearing uncovers dynamic changes of renal MNPs, which are directly linked to renal function in AKI.
Highlights
Acute kidney injury (AKI) is a complex syndrome implicated in various clinical conditions and etiologies
3D morphological assessment with light sheet fluorescence microscopy (LSFM) and MFM after tissue clearing highlighted vital changes in the spatial distribution and morphometric measurements of individual mononuclear phagocytes (MNPs) compared to 2D assessment
We tested the effect of MCC950, a specific NLRP3 inhibitor, on intrarenal CD11c+ MNPs and confirmed that MCC950 attenuated LPS-induced functional changes of CD11c+ MNPs involving T cell activation along with suppression of MHC class II and costimulatory molecule expression
Summary
Acute kidney injury (AKI) is a complex syndrome implicated in various clinical conditions and etiologies. The processes of histological analysis, such as embedding, sectioning, staining, and manual counting, are laborious and time-consuming This approach has difficulty providing precise morphological information and results in loss of spatial data of renal MNPs. The development of clearing techniques and analysis of cleared organs with various microscopies, such as light sheet fluorescence microscopy (LSFM) or multiphoton microscopy (MPM), has enabled us to overcome the current unmet needs of histological analytic methods. The development of clearing techniques and analysis of cleared organs with various microscopies, such as light sheet fluorescence microscopy (LSFM) or multiphoton microscopy (MPM), has enabled us to overcome the current unmet needs of histological analytic methods These techniques have led to brain research on the 3D shape and the route of neurons and blood vessels in the whole brain from the cortex to the pituitary gland [4]. The kidney is an anatomically complicated organ for evaluating the morphological and functional changes of each cell type after injury, even inside the cortex
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
