Aberrant microRNA expression in patients with painful peripheral neuropathies

Area of Science:

• Neuroscience
• Immunology
• Genetics

Background:

• Neuro-immune balance is crucial in neuropathic pain development.
• MicroRNAs (miRNAs) regulate immune processes and cytokine expression.
• Previous studies identified cytokine alterations in peripheral neuropathies.

Purpose of the Study:

• To characterize inflammation-regulating miRNA profiles in patients with peripheral neuropathies.
• To identify potential master regulators of the neuro-immune balance in neuropathic pain.
• To investigate systemic and local miRNA expression patterns in relation to pain.

Main Methods:

• Analysis of an unselected cohort of polyneuropathy patients (2014-2015).
• Quantification of systemic (white blood cells) and local (sural nerve, skin) miRNA expression (miR-21-5p, miR-146a, miR-155).
• Comparison of miRNA expression between patients and healthy controls, and between painful and painless neuropathies.

Main Results:

• Peripheral neuropathies exhibited distinct miRNA expression in white blood cells compared to controls: higher miR-21 and miR-146a, lower miR-155.
• Sural nerve miR-21 expression was elevated in painful neuropathies.
• Skin biopsies from painful neuropathies showed reduced miR-146a and miR-155 expression in the lower leg compared to the thigh.

Conclusions:

• Peripheral neuropathies are associated with aberrant miRNA expression across systemic and local tissues.
• Identified miRNA patterns correlate with neuropathic pain and may indicate factors determining pain severity.
• These miRNA profiles represent potential druggable targets for novel neuropathic pain therapies.