Glomerular permeability is altered by loss of P0, a myelin protein expressed in glomerular epithelial cells.

Abstract

The myelin protein 0 (MPZ or P0) is a transmembrane glycoprotein that represents the most abundant myelin component. Mutations in the P0 gene are associated with one form of autosomal dominant demyelinating peripheral neuropathy, Charcot-Marie-Tooth disease type 1B (CMT1B). Because CMT1 may be associated with renal involvement, mostly focal segmental glomerulosclerosis, we hypothesized that P0 could be expressed in the kidney. P0 mRNA was detected by reverse transcriptase-PCR in the human and mouse renal cortex. P0 transcripts were identified by in situ hybridization at different stages of the mouse kidney development, especially in embryonic structures that give rise to the glomerulus. P0 protein was also detected by Western blot in human and rat glomerular extracts and in a human podocyte cell line using a monoclonal anti-P0 antibody. Immunofluorescence studies on human kidney sections showed that the podocytes were intensely labeled. Immunogold electron microscopy disclosed a predominant staining of the membranes of intracellular vesicles in podocytes. P0 was also detected in the podocyte cell membrane, including at the foot processes. P0(-/-) mice exhibited mild growth retardation and demyelinating neuropathy similar to the one observed in patients with CMT1B. They also presented mild albuminuria, without significant ultrastructural change of the glomerular basement membrane or the podocytes. These results demonstrate that P0, the major myelin protein, is also expressed during nephrogenesis and in mature kidney, mostly in podocytes. They suggest that P0 gene mutations might be involved in renal diseases.

• Authors: Emmanuelle Plaisier, Béatrice Mougenot, Marie Christine Verpont, Chantal Jouanneau, Joan J Archelos, Rudolf Martini, Dontscho Kerjaschki, Pierre Ronco
• Journal: Journal of the American Society of Nephrology : JASN (J Am Soc Nephrol) Vol. 16 Issue 11 Pg. 3350-6 (Nov 2005) ISSN: 1046-6673 [Print] United States
• PMID: 16162811 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA Primers
• Myelin P0 Protein

Topics

• Adult
• Animals
• Base Sequence
• DNA Primers
• Humans
• In Situ Hybridization
• Kidney Cortex (physiology)
• Kidney Glomerulus (physiology, ultrastructure)
• Mice
• Microscopy, Immunoelectron
• Myelin P0 Protein (deficiency, genetics, physiology)
• Podocytes (physiology)
• Rats
• Reverse Transcriptase Polymerase Chain Reaction
• Urothelium (physiology)