Hypothyroidism impairs skeletal muscle regeneration after injury by altering myogenic and nonmyogenic pathways - PubMed
5 hours ago
- #myopathy
- #muscle regeneration
- #hypothyroidism
- Hypothyroidism impairs skeletal muscle regeneration after injury by altering myogenic and nonmyogenic pathways.
- Thyroid hormone signaling is essential for skeletal muscle development, function, and metabolism, but its role in muscle regeneration is not fully defined.
- Using scRNA-seq and FUCCI reporter mice, researchers found hypothyroid muscles had smaller myofibers and a shift to slower oxidative fiber types up to 2 months post-injury.
- Hypothyroidism reduced myogenic-lineage diversity and delayed cell cycle progression in skeletal muscle stem cells, stalling them at the G1/S transition.
- Transcriptomic data showed altered nonmyogenic dynamics, including elevated fibro-adipogenic progenitors (FAPs) early in repair and persistent proinflammatory macrophages.
- Triiodothyronine (T3) acts through direct transcriptional control of myogenic cell cycle and oxidative programs and indirect paracrine remodeling via FAP and immune signaling networks.
- The study provides novel insights into hypothyroidism's effects on myogenic heterogeneity and impaired tissue repair, relevant to hypothyroidism-associated myopathy and sarcopenia.