Human diabetic perineurial cell basement membrane thickening

Area of Science:

• Neuroscience
• Cell Biology
• Diabetology

Background:

• The perineurium, a cellular sheath of peripheral nerves, isolates the endoneurium from the epineurium.
• Perineurial cells are enveloped by basement membranes on both inner and outer surfaces.
• Diabetic microvasculature is known to exhibit basement membrane thickening.

Purpose of the Study:

• To investigate ultrastructural thickness of human sural nerve perineurial cell basement membranes.
• To compare basement membrane thickness in diabetic and non-diabetic individuals.
• To assess the impact of insulin treatment on basement membrane thickness in diabetics.

Main Methods:

• Ultrastructural thickness measurements of perineurial cell basement membranes from human sural nerves.
• Comparison of measurements between diabetic patients and non-diabetic controls.
• Subgroup analysis of diabetic patients based on insulin treatment status.

Main Results:

• Diabetic patients (n=24) exhibited significantly greater mean perineurial cell basement membrane thickness (174.1 ± 76.2 nm) than non-diabetics (n=19) (67.1 ± 12.8 nm; p < 0.001).
• Diabetics on insulin (n=13) showed further exaggerated thickening (208.4 ± 78.1 nm) compared to those not on insulin (133.5 ± 51.8 nm; p = 0.01).
• No significant differences were found based on sex or tissue source (autopsy vs. biopsy).

Conclusions:

• Diabetes mellitus is associated with thickening of the perineurial cell basement membrane, a non-vascular component of peripheral nerves.
• Insulin treatment in diabetics exacerbates this perineurial basement membrane thickening.
• Quantitation of perineurial cell basement membrane thickness may serve as a valuable biomarker for distinguishing diabetic from non-diabetic distal symmetrical neuropathy.