Catecholamine-mediated release of miR-133a-3p from adipocytes regulates the onset of chronic primary pain.

Chronic primary pain conditions (CPPCs), such as fibromyalgia and vestibulodynia, affect over 100 million Americans, predominantly women, and pose a substantial healthcare challenge. CPPCs arise from genetic and environmental factors that enhance catecholamine tone, potentially through miRNA dysregulation following catecholamine activation of β-adrenergic receptors. Here, we identified miR-133a-3p as a biomarker of CPPC status and investigated its functions using in vivo and in vitro approaches. Plasma levels of miR-133a-3p were consistently downregulated in humans with ≥ 1 CPPC and in rat and mouse models of primary pain. Our data suggest that miR-133a-3p is packaged in extracellular vesicles that are secreted by adipocytes and trafficked to the spinal cord. Activation of adrenergic receptors on white adipocytes resulted in downregulation of miR-133a-3p, negatively regulating pain-related genes in the spinal cord, such as MAP3K3, which is critical for sensory neuron activation. Adipose-specific overexpression of miR-133a-3p in a mouse model of primary pain reversed mechanical hypersensitivity in both sexes. These findings implicate miR-133a-3p dysregulation in primary pain across conditions and species and establish its role in multisite mechanical hypersensitivity. Furthermore, miR-133a-3p overexpression shows therapeutic potential for the millions of individuals with CPPCs.