Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, P. R. China.
Beijing Institute for Stem Cell and Regenerative Medicine, Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, P. R. China.
Adv Sci (Weinh). 2023 Jul;10(21):e2301519. doi: 10.1002/advs.202301519. Epub 2023 May 4.
It is well-known that muscle regeneration declines with aging, and aged muscles undergo degenerative atrophy or sarcopenia. While exercise and acute injury are both known to induce muscle regeneration, the molecular signals that help trigger muscle regeneration have remained unclear. Here, mass spectrometry imaging (MSI) is used to show that injured muscles induce a specific subset of prostanoids during regeneration, including PGG1, PGD2, and the prostacyclin PGI2. The spike in prostacyclin promotes skeletal muscle regeneration via myoblasts, and declines with aging. Mechanistically, the prostacyclin spike promotes a spike in PPARγ/PGC1a signaling, which induces a spike in fatty acid oxidation (FAO) to control myogenesis. LC-MS/MS and MSI further confirm that an early FAO spike is associated with normal regeneration, but muscle FAO became dysregulated during aging. Functional experiments demonstrate that the prostacyclin-PPARγ/PGC1a-FAO spike is necessary and sufficient to promote both young and aged muscle regeneration, and that prostacyclin can synergize with PPARγ/PGC1a-FAO signaling to restore aged muscles' regeneration and physical function. Given that the post-injury prostacyclin-PPARγ-FAO spike can be modulated pharmacologically and via post-exercise nutrition, this work has implications for how prostacyclin-PPARγ-FAO might be fine-tuned to promote regeneration and treat muscle diseases of aging.
众所周知,肌肉再生能力会随着年龄的增长而下降,衰老的肌肉会发生退行性萎缩或肌肉减少症。虽然运动和急性损伤都已知能诱导肌肉再生,但帮助触发肌肉再生的分子信号仍不清楚。在这里,我们利用质谱成像(MSI)技术显示,在再生过程中,受损肌肉会诱导特定的前列腺素类物质,包括 PGG1、PGD2 和前列环素 PGI2。前列环素的激增通过成肌细胞促进骨骼肌再生,并随着年龄的增长而下降。从机制上讲,前列环素的激增会促进 PPARγ/PGC1a 信号的激增,从而诱导脂肪酸氧化(FAO)的激增,以控制肌发生。LC-MS/MS 和 MSI 进一步证实,早期 FAO 激增与正常再生有关,但在衰老过程中肌肉 FAO 变得失调。功能实验表明,前列环素-PPARγ/PGC1a-FAO 激增是促进年轻和衰老肌肉再生所必需和充分的,前列环素可以与 PPARγ/PGC1a-FAO 信号协同作用,恢复衰老肌肉的再生和功能。鉴于损伤后前列环素-PPARγ-FAO 激增可以通过药理学和运动后的营养来调节,这项工作对于如何微调前列环素-PPARγ-FAO 以促进再生和治疗衰老相关的肌肉疾病具有重要意义。