# Pain Hypersensitivity in a Mouse Model of Marfan Syndrome

## TL;DR

This study shows that a mouse model of Marfan syndrome exhibits pain hypersensitivity and muscle weakness, with differences based on age and sex.

## Contribution

The study identifies age- and sex-dependent pain mechanisms in a mouse model of Marfan syndrome, linking spinal excitatory signaling and inflammation.

## Key findings

- MFS mice show progressive mechanical and thermal hypersensitivity, with cold allodynia as the earliest symptom.
- Spinal cord of aged MFS mice shows increased excitatory and nociceptive markers, along with sex-specific inflammatory and oxidative stress profiles.
- The Fbn1C1041G/+ mouse model reproduces pain hypersensitivity and muscle deficits seen in MFS patients.

## Abstract

Marfan syndrome (MFS) is a genetic disorder caused by mutations in the fibrillin-1 (Fbn1) gene, leading to structurally abnormal elastic fibers and diverse clinical manifestations. Aortic root dilation represents the most serious threat, often requiring prophylactic surgical repair. Emerging evidence suggests that MFS patients experience increased pain sensitivity, contributing to functional impairment and reduced quality of life. Here, we used C57BL/6 wild-type and Fbn1C1041G/+ (MFS) mice to examine brain transcriptomics, aortic histology, nociceptive behaviors, grip strength, and spinal cord gene expression in both sexes at 2, 4, 6, 8, and 16 months of age. Transcriptomic analysis revealed reduced activation of pain-related pathways in young males and aged females, with a reversal in aged males, suggesting age- and sex-dependent differences in pain modulation. Behavioral testing showed progressive mechanical and thermal hypersensitivity in MFS mice, with cold allodynia as the earliest manifestation with late-onset muscle weakness. In the spinal cord of 16-month-old MFS mice, increased expression of key excitatory and nociceptive markers was observed, consistent with the pain hypersensitivity phenotype. In addition, aged female MFS mice exhibited elevated spinal expression of pro-inflammatory cytokines, inducible nitric oxide synthase, and Nox4, whereas males showed increased transforming growth factor-β1 and Nox1, reflecting distinct inflammatory and oxidative stress profiles. These findings demonstrate that Fbn1C1041G/+ mice reproduce pain hypersensitivity and muscle deficits observed in MFS patients, supporting their use as a preclinical model. Our results suggest that enhanced spinal excitatory/nociceptive signaling, together with neuroinflammation and oxidative stress, contributes to sex- and age-specific pain mechanisms in MFS.