Gheller Brandon J, Blum Jamie E, Merritt Edward K, Cummings Bethany P, Thalacker-Mercer Anna E
Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States.
Department of Kinesiology, Southwestern University, Georgetown, TX, United States.
Front Physiol. 2019 Mar 5;10:188. doi: 10.3389/fphys.2019.00188. eCollection 2019.
Peptide YY (PYY) is considered a gut peptide with roles in post-prandial appetite and glucose regulation. Circulating PYY protein levels increase during aerobic exercise. Furthermore, people who have greater increases in muscle progenitor cells (MPCs), the adult stem cell population responsible for skeletal muscle (SkM) repair, after resistance training have higher PYY transcript levels in SkM prior to training. Currently, examination of PYY expression patterns in SkM and/or MPCs is lacking. Our objective was to identify the expression patterns of PYY in SkM and MPCs. PYY and the associated Y receptors were analyzed in SkM biopsy tissue and cultured MPCs from young and old human participants. Additional experiments to assess the role and regulation of PYY in MPCs were performed. In SkM, PYY and one of the three Y receptors (Y1r) were detectable, but expression patterns were not affected by age. In expanding MPCs, PYY and all three Y receptor (Y1r, Y2r, and Y5r) proteins were expressed in a temporal fashion with young MPCs having greater levels of Y receptors at various time points. Exogenous PYY did not affect MPC population expansion. MPC PYY levels increased following the metabolic stimulus, 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR), but were not affected by the inflammatory stimulus, tumor necrosis factor alpha (TNFα). In conclusion, PYY and Y receptor expression are not impacted by age in SkM tissue but are reduced in old young expanding MPCs. Furthermore, endogenous PYY production is stimulated by low energy states and thus may be integral for skeletal muscle and MPC responses to metabolic stimuli.
肽YY（PYY）被认为是一种肠道肽，在餐后食欲和葡萄糖调节中发挥作用。有氧运动期间，循环中的PYY蛋白水平会升高。此外，在进行抗阻训练后，肌肉祖细胞（MPC，负责骨骼肌修复的成体干细胞群体）增加幅度更大的人，训练前骨骼肌中的PYY转录水平更高。目前，尚缺乏对骨骼肌和/或MPC中PYY表达模式的研究。我们的目的是确定PYY在骨骼肌和MPC中的表达模式。对年轻和老年人类参与者的骨骼肌活检组织及培养的MPC进行PYY及相关Y受体分析，并开展其他实验以评估PYY在MPC中的作用和调节机制。在骨骼肌中，可检测到PYY和三种Y受体之一（Y1r），但其表达模式不受年龄影响。在增殖的MPC中，PYY和所有三种Y受体（Y1r、Y2r和Y5r）蛋白呈时间依赖性表达，年轻MPC在各个时间点的Y受体水平更高。外源性PYY不影响MPC群体的扩增。代谢刺激物5-氨基咪唑-4-甲酰胺核糖核苷酸（AICAR）可使MPC中的PYY水平升高，但炎症刺激物肿瘤坏死因子α（TNFα）对其无影响。总之，PYY和Y受体的表达在骨骼肌组织中不受年龄影响，但在老年与年轻的增殖MPC中会降低。此外，低能量状态会刺激内源性PYY的产生，因此它可能是骨骼肌和MPC对代谢刺激作出反应所不可或缺的。
