Related Experiment Video
Updated: Jun 18, 2026

Glomerular Outgrowth as an Ex Vivo Assay to Analyze Pathways Involved in Parietal Epithelial Cell Activation
Published on: August 19, 2020
Tracing the origin of glomerular extracapillary lesions from parietal epithelial cells
Bart Smeets1, Sandra Uhlig, Astrid Fuss
1Department of Nephrology and Immunology, University Hospital of the Aachen University of Technology, Pauwelsstrasse 30, Aachen, Germany. b.smeets@pathol.umcn.nl
Abstract:
Cellular lesions form in Bowman's space in both crescentic glomerulonephritis and collapsing glomerulopathy. The pathomechanism and origin of the proliferating cells in these lesions are unknown. In this study, we examined proliferating cells by lineage tracing of either podocytes or parietal epithelial cells (PECs) in the nephrotoxic nephritis model of inflammatory crescentic glomerulonephritis. In addition, we traced the fate of genetically labeled PECs in the Thy-1.1 transgenic mouse model of collapsing glomerulopathy. In both models, cellular bridges composed of PECs were observed between Bowman's capsule and the glomerular tuft. Genetically labeled PECs also populated larger, more advanced cellular lesions. In these lesions, we detected de novo expression of CD44 in activated PECs. In contrast, we rarely identified genetically labeled podocytes within the cellular lesions of crescentic glomerulonephritis. In conclusion, PECs constitute the majority of cells that compose early extracapillary proliferative lesions in both crescentic glomerulonephritis and collapsing glomerulopathy, suggesting similar pathomechanisms in both diseases.
Related Concept Videos
Renal Corpuscle
Glomerulus: Structure and Function
The glomerulus is a tiny, intricate network of capillaries located at the beginning of the nephron. It's enveloped by the Bowman's capsule and receives its blood supply from an afferent arteriole, which divides into numerous capillaries...
Glomerular Filtration
Components of the Filtration Membrane
The filtration process involves three key layers: the glomerular endothelial cells, the basement membrane, and the podocyte-formed filtration slits.
Nephrons
Renal Drug Excretion: Glomerular Filtration
Drugs gain access to the kidney via the renal artery, which progressively branches off into afferent arterioles.
Acute Kidney Injury II: Pathophysiology
Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...

