Three-Dimensional Super-Resolved Imaging of Paraffin-Embedded Kidney Samples. Issue 3 (31st March 2022)

• Record Type: Journal Article
• Authors: Unnersjö-Jess, David; Ramdedovic, Amer; Höhne, Martin; Butt, Linus; Koehler, Felix C.; Müller, Roman-Ulrich; Hoyer, Peter F.; Blom, Hans; Schermer, Bernhard; Benzing, Thomas
• Is Part Of: Kidney360. Volume 3:Issue 3(2022)
• Page Start: 446
• Page End: 454
• Publication Date: 2022-03-31
• Subjects: CKD -- diagnostic imaging -- foot processes -- microscopy -- paraffin embedding -- renal pathology routine diagnostic tests; 616.61
• DOI: 10.34067/KID.0005882021
• Languages: English
• ISSNs: 2641-7650

Abstract

Key Points: Our previous protocols for 3D super-resolution kidney imaging have not been optimized to be compatible with paraffin-embedded samples. This study overcomes these limitations, allowing 3D super-resolved imaging in FFPE kidney blocks. This advancement opens up for 3D super-resolution kidney imaging of biobank material and in clinical settings. Visual Abstract: Abstract : Background: Diseases of the glomeruli, the renal filtration units, are a leading cause of progressive kidney disease. Assessment of the ultrastructure of podocytes at the glomerular filtration barrier is essential for diagnosing diverse disease entities, providing insight into the disease pathogenesis, and monitoring treatment responses. Methods: Here we apply previously published sample preparation methods together with stimulated emission depletion and confocal microscopy for resolving nanoscale podocyte substructure. The protocols are modified and optimized in order to be applied to formalin-fixed paraffin-embedded (FFPE) samples. Results: We successfully modified our protocols to allow for deep three-dimensional stimulated emission depletion and confocal imaging of FFPE kidney tissue with similar staining and image quality compared with our previous approaches. We further show that quantitative analysis can be applied to extract morphometrics from healthy and diseased samples from both mice and humans. Conclusions: The results from this study could increase the feasibility of implementing optical kidney imaging protocols in clinical routines because FFPE is the gold-standard method for storage of patient samples.