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 4

scRNA-seq reveals a coordinated regulation of GSDME in intramuscular TRMs and FAPs.

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scRNA-seq reveals a coordinated regulation of GSDME in intramuscular TRM...
(A) scRNA-seq UMAP plot showing clustering of endothelial cells, FAPs, macrophages, monocytes, MuSCs, Schwann cells, T cells, B cells, skeletal muscle (mature), and pericytes in the injured skeletal muscle tissue of WT and KO mice at D14. (B) Proportions of each cell cluster in injured skeletal muscle of WT and KO mice. (C) Analysis of incoming and outgoing interaction strength between the cell types in a 2-dimensional graph using the CellChat algorithm in R. (D) Circle plot showing the strength of ligand-receptor interactions between pairwise cell populations among the major cell populations in WT and KO groups. (E) Differences in ligand-receptor pairs among these cell types between WT and KO mice. (F) UMAP plot of FAP subgroups. (G) Proportions of each subcluster of FAPs in injured skeletal muscle of WT and KO mice. (H) Trajectory analysis of FAP differentiation according to pseudotime algorithms in injured skeletal muscle of WT and KO mice. (I) GO enrichment analysis of 3 crucial FAP subclusters between WT and KO muscle. (J) UMAP plot of macrophage subgroups. (K) Proportions of each subcluster of macrophages in injured skeletal muscle of WT and KO mice. (L) Expression of TRM and infiltrating macrophage marker genes across the 4 macrophage subclusters. (M) GO enrichment analysis showing the major biological functions enriched in the 4 subgroups of macrophages. (N) Multiplex IHC showing the proportion of Lyve1+CD11b+ macrophages within the total CD11b+ macrophage population in injured muscle (white arrows). Nuclei were stained with DAPI. Scale bars: 100 μm (lower magnification, 50 μm (higher magnification). Data are presented as mean ± SEM and were analyzed by unpaired 2-tailed Student’s t test. ***P < 0.001.