Single-nucleus profiling unveils a geroprotective role of the FOXO3 in primate skeletal muscle aging

Abstract

Age-dependent loss of skeletal muscle mass and function is a feature of sarcopenia, and increases the risk of many aging-related metabolic diseases. Here, we report phenotypic and single-nucleus transcriptomic analyses of non-human primate skeletal muscle aging. A higher transcriptional fluctuation was observed in myonuclei relative to other interstitial cell types, indicating a higher susceptibility of skeletal muscle fiber to aging. We found a downregulation of FOXO3 in aged primate skeletal muscle, and identified FOXO3 as a hub transcription factor maintaining skeletal muscle homeostasis. Through establishment of a complementary experimental pipeline based on a human pluripotent stem cell-derived myotube model, we revealed that silence of FOXO3 accelerates human myotube senescence, whereas genetic activation of endogenous FOXO3 alleviates human myotube aging. Altogether, based on a combination of monkey skeletal muscle and human myotube aging research models, we unraveled the pivotal role of the FOXO3 in safeguarding primate skeletal muscle from aging, providing a comprehensive resource for development of clinical diagnosis and targeted therapeutic interventions against human skeletal muscle aging and the onset of sarcopenia along with aging-related disorders.

A single-cell transcriptomic atlas of exercise-induced anti-inflammatory and geroprotective effects across the body

“…Since both aging and exercise involve distinct organs, tissues, and cell types, 4 , 6 , 21 , 22 , 23 , 24 a systemic and integrative study across multiple tissues, dissecting the molecular programs in tissue- and cell type-specific manner, is of critical importance. 25 , 26 , 27 , 28 , 29 In the past few years, high-throughput single-cell transcriptomes have been constructed for aging and its interventions, 30 , 31 , 32 such as caloric restriction and heterochronic parabiosis in mammalian species, 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 providing unprecedented resolution of the cellular and molecular changes in aged animals. However, whether and how exercise rewires the transcriptome at the systemic level, especially in aged animals, remains largely unexplored.…”

SESN1 is a FOXO3 effector that counteracts human skeletal muscle ageing

“…The hESC culture medium contained Dulbecco's Modified Eagle Medium (DMEM)/F12 (Gibco), 20% Knockout Serum Replacement (Gibco), 2 mM GlutaMAX (Gibco), 0.1 mM non‐essential amino acids (Gibco), 55 μM β‐mercaptoethanol (Invitrogen), 10 ng/mL basic fibroblast growth factor (Joint Protein Central) and 1% penicillin/streptomycin (Gibco). Human myotubes (hMyotubes) were cultured in high‐glucose DMEM medium (Hyclone) containing 2% horse serum (Gibco) and 2 mM GlutaMAX (Gibco) at 37°C with 5% CO 2 and 3%–5% O 2 19,20 . HEK293T cells were cultured in high‐glucose DMEM (Hyclone) supplemented with 10% fetal bovine serum (FBS, Gibco) at 37°C with 5% CO 2 .…”

“…A transcription factor regulatory network of ageing‐associated DEGs in cynomolgus monkey skeletal muscle was established under SCENIC (Single‐Cell Regulatory Network Inference and Clustering) standard workflow following previous work 20,41 . At first, the candidate target genes co‐expressed with FOXO3 were identified using Genie3.…”

Biomarkers of aging

“…Studies based on human and mouse models have revealed numerous hallmarks accompanying or driving MuSC senescence. Intrinsically, increased p16 fragmentation (Baker et al, 2022;Tezze et al, 2017), reduced autophagy (García-Prat et al, 2016) and functional heterogeneity (Tierney et al, 2018), loss of ciliation (Palla et al, 2022), decreased CD34 (García-Prat et al, 2020), FOXO (García-Prat et al, 2020;Jing et al, 2022) and Notch (Carlson et al, 2008;Conboy et al, 2003) signaling, elevated activation of CD47 (Porpiglia et al, 2022) and JAK-STAT signaling (Price et al, 2014;Tierney et al, 2014), have all been proven to be the prominent detriments to MuSC stemness and cause regenerative failure. Aging in the MuSC niche contributes another core source releasing secreted factors that drive MuSC senescence.…”

“…While plenty of elaborate mechanisms have been revealed towards understanding the cellular aging of muscle, it is still a narrow horizon for capturing the overall hallmarks. In the past ten years, the advanced single-cell transcriptomics analyses have enabled systemically dissecting and monitoring all cell type heterogeneity and their aging dynamics both in human (Barruet et al, 2020;De Micheli et al, 2020;Perez et al, 2022;Rubenstein et al, 2020) and model organisms (Dos Santos et al, 2020;Jing et al, 2022;Kim et al, 2020b;Petrany et al, 2020;Zhang et al, 2022d). With mammalian aging, skeletal muscle exhibits decrease in MuSCs, Schwann cells, and vascular cells but infiltration of various immune cells and fibroblasts (Kedlian et al, 2022), in parallel with physiological dysfunction and chronic inflammation.…”