GSDME–IL-18 pyroptotic axis prevents myosteatosis by expanding tissue-resident macrophages to promote muscle regeneration
Qi Cao, Jian Liu, Gang Huang, Su-Yuan Wang, Guo-Dong Lu, Yong Huang, Yi-Ting Chen, Zhen Zhang, Jiang-Tao Fu, Si-Jia Sun, Xiao-Fei Chen, Chunlin Zhuang, Chunquan Sheng, Fu-Ming Shen, Dong-Jie Li, Pei Wang
Qi Cao, Jian Liu, Gang Huang, Su-Yuan Wang, Guo-Dong Lu, Yong Huang, Yi-Ting Chen, Zhen Zhang, Jiang-Tao Fu, Si-Jia Sun, Xiao-Fei Chen, Chunlin Zhuang, Chunquan Sheng, Fu-Ming Shen, Dong-Jie Li, Pei Wang
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Research Article Immunology Inflammation Metabolism

GSDME–IL-18 pyroptotic axis prevents myosteatosis by expanding tissue-resident macrophages to promote muscle regeneration

Abstract

Metabolic–inflammatory crosstalk orchestrates muscle repair. Although pyroptosis typically aggravates sterile injury, we demonstrated that GSDME-dependent pyroptotic signaling associated with recruited myeloid cells paradoxically supported regeneration. GSDME expression was induced in postsurgical human muscle injury and murine damage models. Gsdme deficiency delayed functional recovery and exacerbated injury-induced myosteatosis, a pathological form of intramuscular ectopic fat deposition. Time-series and scRNA-seq analyses revealed that GSDME loss shifted the transcriptional program from oxidative metabolism to lipid storage and adipogenesis. Lipidomics confirmed aberrant accumulation of triacylglycerols (TAGs) and sphingolipids in Gsdme-deficient muscle. Single-cell profiling further identified divergent fibro-adipogenic progenitor (FAP) states skewed toward adipogenesis, accompanied by impaired expansion of restorative Lyve1+Cd163+Txnip+ tissue-resident macrophages (TRMs), as validated by multiplex flow cytometry. Blocking CCR2-dependent monocyte recruitment produced regenerative defects comparable with those caused by Gsdme deficiency. Myeloid-specific Gsdme reintroduction rescued TRM expansion and function and curbed FAP adipogenic reprogramming, whereas FAP-specific expression proved ineffective. Mechanistically, IL-18 downstream of GSDME-dependent signaling engaged KLF4/JUN signaling in TRMs, sustaining their reparative and lipid-clearing capacity. This GSDME–IL-18–TRM axis was compromised in aged muscle, yet exogenous IL-18 reversed myosteatosis and accelerated regeneration. Together, these findings suggest that GSDME-dependent pyroptotic signaling can act as a metabolic checkpoint that sustains TRM-driven lipid homeostasis to support muscle regeneration.

Authors

Qi Cao, Jian Liu, Gang Huang, Su-Yuan Wang, Guo-Dong Lu, Yong Huang, Yi-Ting Chen, Zhen Zhang, Jiang-Tao Fu, Si-Jia Sun, Xiao-Fei Chen, Chunlin Zhuang, Chunquan Sheng, Fu-Ming Shen, Dong-Jie Li, Pei Wang

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Figure 7

GSDME controls the recruitment and expansion of intramuscular immune cells, especially TRMs.

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GSDME controls the recruitment and expansion of intramuscular immune cel...
(A) Experimental design for flow cytometry analysis of injured gastrocnemius muscles from WT and KO mice at D4, D7, and D14. Muscle tissues were digested into single-cell suspensions, and CD45+ cells were isolated using magnetic activated cell sorting. (B) High-dimensional analysis of multiplexed flow cytometry using an unbiased nonlinear dimensionality reduction algorithm to identify the immune cell populations in injured skeletal muscle of WT and KO mice. A total of 1,481,156 CD45+ leukocytes from injured muscle of WT and KO mice at D4, D7, and D14 after injury were analyzed. The mice at different days after injury were arranged to undergo euthanasia simultaneously to avoid batch effect. Full spectral panels and key antibodies are shown in Supplemental Figure 8A. (C) A UMAP visualization of dynamic changes in intramuscular immune cell populations between WT and KO mice at D4, D7, and D14 after injury. The regions with obvious differences between WT and KO mice are indicated with hollow elliptical shapes. (D) Time-series analyses of CD45+ leukocytes within the total cell population of injured skeletal muscle using flow cytometry with manual gating. (E) Time-series analyses of F4/80+CD64+ macrophages within the CD45+ leukocytes of injured skeletal muscle. (F and G) Time-series analyses of proportions of CCR2+Ly6C+ monocytes (F) and CCR2–LYVE1+ macrophages (G) within the CD11b+ myeloid of injured skeletal muscle. (H) Time-series analyses of proportions of CD86+ and CD163+ cells within the macrophages of injured skeletal muscle tissue. (I) The proportion of cDC2 within total DC (CD11c+MHC-II+) population of injured skeletal muscle. Data are presented as mean ± SEM. For D, E, H, and I, by unpaired 2-tailed Student’s t test; for F and G, by 2-way ANOVA with Tukey’s post hoc test. *P < 0.05, **P < 0.01, ***P < 0.001.