A fast and simple clearing and swelling protocol for 3D in-situ imaging of the kidney across scales

David Unnersjö-Jess; Linus Butt; Martin Höhne; Anna Witasp; Lucas Kühne; Peter F Hoyer; Jaakko Patrakka; Paul T Brinkkötter; Annika Wernerson; Bernhard Schermer; Thomas Benzing; Lena Scott; Hjalmar Brismar; Hans Blom

doi:10.1016/j.kint.2020.10.039

A fast and simple clearing and swelling protocol for 3D in-situ imaging of the kidney across scales

Kidney Int. 2021 Apr;99(4):1010-1020. doi: 10.1016/j.kint.2020.10.039. Epub 2020 Dec 5.

Authors

Affiliations

¹ Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden; Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany. Electronic address: david.unnersjoe-jess@uk-koeln.de.
² Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.
³ Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, Cologne, Germany.
⁴ Division of Renal Medicine, Department of Clinical Sciences, Intervention, and Technology, Karolinska Institutet, Stockholm, Sweden.
⁵ Pediatric Nephrology, Pediatrics II, University of Duisburg-Essen, Essen, Germany.
⁶ KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden.
⁷ Division of Renal Medicine, Department of Clinical Sciences, Intervention, and Technology, Karolinska Institutet, Stockholm, Sweden; Clinical Pathology and Cytology, Karolinska University Hospital Huddinge, Stockholm, Sweden.
⁸ Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden.
⁹ Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden; Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, Solna, Sweden.
¹⁰ Science for Life Laboratory, Department of Applied Physics, Royal Institute of Technology, Solna, Sweden.

PMID: 33285146
DOI: 10.1016/j.kint.2020.10.039

Abstract

In recent years, many light-microscopy protocols have been published for visualization of nanoscale structures in the kidney. These protocols present researchers with new tools to evaluate both foot process anatomy and effacement, as well as protein distributions in foot processes, the slit diaphragm and in the glomerular basement membrane. However, these protocols either involve the application of different complicated super resolution microscopes or lengthy sample preparation protocols. Here, we present a fast and simple, five-hour long procedure for three-dimensional visualization of kidney morphology on all length scales. The protocol combines optical clearing and tissue expansion concepts to produce a mild swelling, sufficient for resolving nanoscale structures using a conventional confocal microscope. We show that the protocol can be applied to visualize a wide variety of pathologic features in both mouse and human kidneys. Thus, our fast and simple protocol can be beneficial for conventional microscopic evaluation of kidney tissue integrity both in research and possibly in future clinical routines.

Keywords: IgA nephropathy; focal segmental glomerulosclerosis; podocyte; renal biopsy; renal pathology.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Kidney Glomerulus*
Kidney* / diagnostic imaging
Mice
Microscopy