ZBED6 Knockout Prevents Ageing‐ and Dexamethasone‐Induced Muscle Atrophy via Dkk3 in Pig and Mice
ABSTRACT Background Effective treatments for skeletal muscle atrophy, a debilitating condition linked to ageing and glucocorticoid therapy, remain lacking. Zinc finger BED‐type containing 6 (ZBED6), a transcriptional repressor, enhances muscle growth and protects against sepsis‐induced atrophy, but...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2025-06-01
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| Series: | Journal of Cachexia, Sarcopenia and Muscle |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/jcsm.13829 |
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| Summary: | ABSTRACT Background Effective treatments for skeletal muscle atrophy, a debilitating condition linked to ageing and glucocorticoid therapy, remain lacking. Zinc finger BED‐type containing 6 (ZBED6), a transcriptional repressor, enhances muscle growth and protects against sepsis‐induced atrophy, but its role in ageing‐ and dexamethasone (Dex)‐induced muscle atrophy remains unknown. This study investigated the protective role of ZBED6 knockout (KO) against muscle atrophy through the Dkk3‐Fbxo32 pathway. Methods The muscle mass, ratio and myofibrillar morphology of 5‐day‐old (wild‐type (WT): KO, n = 5:3), 5‐month‐old (n = 8:9) and 8‐month‐old (n = 3:3) ZBED6‐KO pigs and 18‐month‐old mice (n = 3:3) were analysed. A model of Dex‐induced muscle atrophy was established using 3‐month‐old mice (n = 6:6) via intraperitoneal injections (15 mg/kg/day for 10 days). C2C12 myotubes were treated with 100 μM Dex for 24 h. Muscle morphology was analysed through H&E and immunofluorescence staining. Gene expression was assessed through RNA‐seq, qRT‐PCR and western blotting. The downstream targets were identified through ChIP‐seq using anti‐ZBED6 antibodies and RNA‐seq analysis of the gastrocnemius muscle from ZBED6‐KO and WT pigs. Dkk3 was overexpressed by injecting AAV9‐myo2A‐Dkk3 (2 × 1011) into the tibialis anterior muscle of 3‐month‐old ZBED6‐KO mice (n = 4), which were harvested 1 month postinjection. ZBED6‐KO C2C12 cells were generated via CRISPR/Cas9 and treated with Dex to assess the effects on myotube diameter and gene expression. Results The muscle mass and muscle‐to‐carcass ratio in ZBED6‐KO pigs increased by 27% and 12%, respectively (p < 0.05), while the Dkk3‐Fbxo32 pathway was suppressed by 50% (p < 0.01). ChIP‐seq/RNA‐seq identified Dkk3 as the most significant ZBED6 target (log2FC = −3.38, p < 0.01). The myofibrillar cross‐sectional areas (CSAs) increased twofold in aged ZBED6‐KO mice, while fibrosis and the Dkk3‐Fbxo32 pathway were suppressed by 76% and 50%, respectively (all p < 0.01). Dkk3 overexpression reduced the tibialis anterior muscle weight and CSA in ZBED6‐KO mice by 31% and 61%, respectively (p < 0.01). Dex reduced the CSA in WT mice (45%, p < 0.01), but ZBED6‐KO mice resisted atrophy (CSA similar to untreated WT). ZBED6‐KO increased myotube diameter by twofold (p < 0.01) and inhibited the activation of the Dkk3‐Fbxo32 pathway (p < 0.01). Conversely, Zbed6 overexpression reduced the CSA and myotube diameter by 32% and 64%, respectively (p < 0.01) and rescued by Dkk3 silencing (50% recovery, p < 0.01). Conclusions ZBED6 depletion mitigates ageing‐ and Dex‐induced muscle atrophy via the Dkk3‐Fbxo32 axis, highlighting its therapeutic potential. |
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| ISSN: | 2190-5991 2190-6009 |