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

Area of Science:

• Nephrology
• Neuroscience
• Genetics

Background:

• Myelin protein zero (P0) is the primary component of peripheral nervous system myelin.
• Mutations in the P0 gene cause Charcot-Marie-Tooth disease type 1B (CMT1B), a demyelinating neuropathy.
• Renal involvement, including focal segmental glomerulosclerosis, is observed in some CMT1 patients.

Purpose of the Study:

• To investigate the expression of P0 in the kidney.
• To determine if P0 plays a role in kidney development and function.
• To explore the potential link between P0 gene mutations and renal diseases.

Main Methods:

• Reverse transcriptase-PCR to detect P0 mRNA in human and mouse kidneys.
• In situ hybridization to localize P0 transcripts during mouse kidney development.
• Western blot and immunofluorescence to detect P0 protein in human and rat kidney tissues and podocyte cell lines.
• Immunogold electron microscopy to identify the subcellular localization of P0 in podocytes.
• Analysis of P0 knockout (P0-/-) mice for renal phenotypes.

Main Results:

• P0 mRNA and protein are expressed in the human and mouse renal cortex, particularly in podocytes.
• P0 is detected in embryonic kidney structures and mature podocytes, including foot processes.
• P0 knockout mice show mild albuminuria, but no significant glomerular basement membrane or podocyte ultrastructural changes.
• P0(-/-) mice exhibit growth retardation and demyelinating neuropathy consistent with CMT1B.

Conclusions:

• The major myelin protein P0 is expressed in the kidney, predominantly in podocytes, during development and in mature organs.
• These findings suggest a potential role for P0 in kidney physiology and pathology.
• P0 gene mutations may be implicated in certain renal diseases, warranting further investigation.