Journal article
Sustained over-expression of calpain-2 induces age-dependent dilated cardiomyopathy in mice through aberrant autophagy
Acta pharmacologica Sinica, Vol.43(11), pp.2873-2884
11/2022
DOI: 10.1038/s41401-022-00965-9
PMCID: PMC9622835
PMID: 35986214
Abstract
Calpains have been implicated in heart diseases. While calpain-1 has been detrimental to the heart, the role of calpain-2 in cardiac pathology remains controversial. In this study we investigated whether sustained over-expression of calpain-2 had any adverse effects on the heart and the underlying mechanisms. Double transgenic mice (Tg-Capn2/tTA) were generated, which express human CAPN2 restricted to cardiomyocytes. The mice were subjected to echocardiography at age 3, 6, 8 and 12 months, and their heart tissues and sera were collected for analyses. We showed that transgenic mice over-expressing calpain-2 restricted to cardiomyocytes had normal heart function with no evidence of cardiac pathological remodeling at age 3 months. However, they exhibited features of dilated cardiomyopathy including increased heart size, enlarged heart chambers and heart dysfunction from age 8 months; histological analysis revealed loss of cardiomyocytes replaced by myocardial fibrosis and cardiomyocyte hypertrophy in transgenic mice from age 8 months. These cardiac alterations closely correlated with aberrant autophagy evidenced by significantly increased LC3BII and p62 protein levels and accumulation of autophagosomes in the hearts of transgenic mice. Notably, injection of 3-methyladenine, a well-established inhibitor of autophagy (30 mg/kg, i.p. once every 3 days starting from age 6 months for 2 months) prevented aberrant autophagy, attenuated myocardial injury and improved heart function in the transgenic mice. In cultured cardiomyocytes, over-expression of calpain-2 blocked autophagic flux by impairing lysosomal function. Furthermore, over-expression of calpain-2 resulted in lower levels of junctophilin-2 protein in the heart of transgenic mice and in cultured cardiomyocytes, which was attenuated by 3-methyladenine. In addition, blockade of autophagic flux by bafilomycin A (100 nM) induced a reduction of junctophilin-2 protein in cardiomyocytes. In summary, transgenic over-expression of calpain-2 induces age-dependent dilated cardiomyopathy in mice, which may be mediated through aberrant autophagy and a reduction of junctophilin-2. Thus, a sustained increase in calpain-2 may be detrimental to the heart.
Details
- Title: Subtitle
- Sustained over-expression of calpain-2 induces age-dependent dilated cardiomyopathy in mice through aberrant autophagy
- Creators
- Xiao-Yun Ji - Jiangsu UniversityDong ZhengRui NiJin-Xi WangJian-Qiang ShaoZer VueAntentor Hinton JrLong-Sheng SongGuo-Chang FanSubrata ChakrabartiZhao-Liang SuTian-Qing Peng
- Resource Type
- Journal article
- Publication Details
- Acta pharmacologica Sinica, Vol.43(11), pp.2873-2884
- DOI
- 10.1038/s41401-022-00965-9
- PMID
- 35986214
- PMCID
- PMC9622835
- NLM abbreviation
- Acta Pharmacol Sin
- ISSN
- 1671-4083
- eISSN
- 1745-7254
- Language
- English
- Electronic publication date
- 08/19/2022
- Date published
- 11/2022
- Academic Unit
- Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984297354102771
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