Cardiomyocyte ßII spectrin plays a critical role in maintaining cardiac function by regulating mitochondrial respiratory function.
Cardiovasc Res
; 120(11): 1312-1326, 2024 Sep 21.
Article
de En
| MEDLINE
| ID: mdl-38832923
ABSTRACT
AIMS:
ßII spectrin is a cytoskeletal protein known to be tightly linked to heart development and cardiovascular electrophysiology. However, the roles of ßII spectrin in cardiac contractile function and pathological post-myocardial infarction remodelling remain unclear. Here, we investigated whether and how ßII spectrin, the most common isoform of non-erythrocytic spectrin in cardiomyocytes, is involved in cardiac contractile function and ischaemia/reperfusion (I/R) injury. METHODS ANDRESULTS:
We observed that the levels of serum ßII spectrin breakdown products (ßII SBDPs) were significantly increased in patients with acute myocardial infarction (AMI). Concordantly, ßII spectrin was degraded into ßII SBDPs by calpain in mouse hearts after I/R injury. Using tamoxifen-inducible cardiac-specific ßII spectrin knockout mice, we found that deletion of ßII spectrin in the adult heart resulted in spontaneous development of cardiac contractile dysfunction, cardiac hypertrophy, and fibrosis at 5 weeks after tamoxifen treatment. Moreover, at 1 week after tamoxifen treatment, although spontaneous cardiac dysfunction in cardiac-specific ßII spectrin knockout mice had not developed, deletion of ßII spectrin in the heart exacerbated I/R-induced cardiomyocyte death and heart failure. Furthermore, restoration of ßII spectrin expression via adenoviral small activating RNA (saRNA) delivery into the heart reduced I/R injury. Immunoprecipitation coupled with mass spectrometry (IP-LC-MS/MS) analyses and functional studies revealed that ßII spectrin is indispensable for mitochondrial complex I activity and respiratory function. Mechanistically, ßII spectrin promotes translocation of NADHubiquinone oxidoreductase 75-kDa Fe-S protein 1 (NDUFS1) from the cytosol to mitochondria by crosslinking with actin filaments (F-actin) to maintain F-actin stability.CONCLUSION:
ßII spectrin is an essential cytoskeletal element for preserving mitochondrial homeostasis and cardiac function. Defects in ßII spectrin exacerbate cardiac I/R injury.Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Lésion de reperfusion myocardique
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Spectrine
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Myocytes cardiaques
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Modèles animaux de maladie humaine
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Mitochondries du myocarde
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Contraction myocardique
Langue:
En
Journal:
Cardiovasc Res
Année:
2024
Type de document:
Article
Pays d'affiliation:
Chine
Pays de publication:
Royaume-Uni