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 1

GSDME is activated in injured skeletal muscle, while its KO hinders tissue recovery by inducing dysmetabolism and fatty accumulation.

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GSDME is activated in injured skeletal muscle, while its KO hinders tiss...
(A) Scheme of GSDME analysis in rectus abdominis during surgical stress, comparing reoperation cases (5–8 days after initial biliary surgery for bile leakage, n = 5) with controls (initial biliary surgery, n = 5); all samples were histologically normal and unaffected by pathology. (B) Transcriptomic expression of gasdermin family members (GSDMB, GSDMC, GSDMD, and GSDME) in initial surgery (IS) versus reoperation (Ro) groups. (C) Transmission electron microscopy of CTX-injured skeletal muscle showing membrane pores and release of intracellular contents. Pink arrows: pore formation; blue arrows: released intracellular organelles; green arrows: cellular debris within the intercellular spaces of damaged muscle fibers. Scale bars: 2 mm (lower magnification), 0.5 mm (higher magnification). (D) Evaluation of gasdermin family members (Gsdmb, Gsdmc, Gsdmd, and Gsdme) in CTX-injured muscle of mice. (E) Evaluation of the cleavage of GSDME proteins in CTX-injured muscle of mice. (F) Experimental design for the CTX-induced muscle injury model and functional recovery in WT and GSDME-KO mice. (G) Gastrocnemius (Gast) weight/body weight ratio in WT and KO mice at D4, D7, and D14 after injury. Data are shown as the mean ± SD with n = 6 (from 6 WT independent mice) and n = 6 (from 6 Gsdme-KO independent mice). (H) Representative images of injured gastrocnemius in WT and KO mice. Cyan arrows indicate fatty degeneration. (I) Gastrocnemius strength at baseline (0 min) and 5 min later (5 min). (J) Representative images and quantification of CSA of myofibers stained with H&E. Scale bars: 100 μm. (K) Total ATP production and proportions of ATP produced via OXPHOS and glycolysis were calculated. (L) Representative images of Oil Red O staining and quantification of lipid accumulation. Scale bars, original images: 500 μm; enlargements: 200 μm. For B, D, and L, by unpaired 2-tailed Student’s t test; for G, I, and K, by 2-way ANOVA with Tukey’s post hoc test. Data are presented as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001.