Journal of Molecular Biomarkers and Clinical Trials

Automated Image Analysis of Podocyte Desmin Immunostaining in a Rat Model of Sub-Acute Doxorubicin-Induced Glomerulopathy

Published on: 2016-11-15

Abstract

Remarkable histopathology findings first identified by light microscopic examination of hematoxylin and eosin stained tissues often warrant further characterization. Recent advancements in the field of molecular diagnostic pathology include fully automated whole-slide imaging. Such tools support best practices for digital imaging and quantification of positive immunohistochemical staining. Consequently, we developed a novel computational method to automatically detect total glomeruli in whole-tissue sections and to quantify areas and intensities of desmin immunolabeling in podocytes. We propose that our method represents a feasible, accurate and efficient alternative to semi-automated quantitative methods which require tedious manual tracing of glomerular borders and allow operator bias (e.g., random selection of glomeruli with enhanced staining) when evaluating glomerular alterations and associated changes in marker localization. Real-time quantitative polymerase chain reaction analysis of adjacent tissues may reveal simultaneous changes in nephron-specific genomic biomarkers. Indeed, samples from the same rats with evidence of doxorubicin-induced primary glomerular toxicity, revealed increased gene expression changes in podocyte markers (desmin and podocin) concurrent to upregulated microRNA-34c3p in macrodissected flash-frozen kidney cortices (anatomic site for podocytes). We demonstrated innovative approaches to consider when monitoring for invasive changes in glomerular-specific kidney safety biomarkers following nephrotoxicant exposure

Keywords

Doxorubicin, Podocyte, Glomeruli, Automated Image Analysis, Rat