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JNK-dependent phosphorylation and nuclear translocation of EGR-1 promotes cardiomyocyte apoptosis. Apoptosis 2022; 27:246-260. [PMID: 35103892 DOI: 10.1007/s10495-022-01714-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2022] [Indexed: 01/27/2023]
Abstract
Myocardial apoptosis induced by myocardial ischemia and hyperlipemia are the main causes of high mortality of cardiovascular diseases. It is not clear whether there is a common mechanism responsible for these two kinds of cardiomyocyte apoptosis. Previous studies demonstrated that early growth response protein 1 (EGR-1) has a pro-apoptotic effect on cardiomyocytes under various stress conditions. Here, we found that EGR-1 is also involved in cardiomyocyte apoptosis induced by both ischemia and high-fat, but how EGR-1 enters the nucleus and whether nuclear EGR-1 (nEGR-1) has a universal effect on cardiomyocyte apoptosis are still unknown. By analyzing the phosphorylation sites and nucleation information of EGR-1, we constructed different mutant plasmids to confirm that the nucleus location of EGR-1 requires Ser501 phosphorylation and regulated by JNK. Furthermore, the pro-apoptotic effect of nEGR-1 was further explored through genetic methods. The results showed that EGR-1 positively regulates the mRNA levels of apoptosis-related proteins (ATF2, CTCF, HAND2, ELK1), which may be the downstream targets of EGR-1 to promote the cardiomyocyte apoptosis. Our research announced the universal pro-apoptotic function of nEGR-1 and explored the mechanism of its nucleus location in cardiomyocytes, providing a new target for the "homotherapy for heteropathy" to cardiovascular diseases.
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Wang Y, Yin C, Chen Z, Li Y, Zou Y, Wang X, An Y, Wu F, Zhang G, Yang C, Tang H, Zou Y, Gong H. Cardiac-specific LRP6 knockout induces lipid accumulation through Drp1/CPT1b pathway in adult mice. Cell Tissue Res 2019; 380:143-153. [PMID: 31811407 DOI: 10.1007/s00441-019-03126-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 10/21/2019] [Indexed: 01/05/2023]
Abstract
We recently reported low-density lipoprotein receptor-related protein 6 (LRP6) decreased in dilated cardiomyopathy hearts, and cardiac-specific knockout mice displayed lethal heart failure through activation of dynamin-related protein 1 (Drp1). We also observed lipid accumulation in LRP6 deficiency hearts, but the detailed molecular mechanisms are unclear. Here, we detected fatty acids components in LRP6 deficiency hearts and explored the potential molecular mechanisms. Fatty acid analysis by GC-FID/MS revealed cardiac-specific LRP6 knockout induced the higher level of total fatty acids and some medium-long-chain fatty acids (C16:0, C18:1n9 and C18:2n6) than in control hearts. Carnitine palmitoyltransferase 1b (CPT1b), a rate-limiting enzyme of mitochondrial β-oxidation in adult heart, was sharply decreased in LRP6 deficiency hearts, coincident with the activation of Drp1. Drp1 inhibitor greatly improved cardiac dysfunction and attenuated the increase in total fatty acids and fatty acids C16:0, C18:1n9 in LRP6 deficiency hearts. It also greatly inhibited the decrease in the cardiac expression of CPT1b and the transcriptional factors CCCTC-binding factor (CTCF) and c-Myc induced by cardiac-specific LRP6 knockout in mice. C-Myc but not CTCF was identified to regulate CPT1b expression and lipid accumulation in cardiomyocytes in vitro. The present study indicated cardiac-specific LRP6 knockout induced lipid accumulation by Drp1/CPT1b pathway in adult mice, and c-Myc is involved in the process. It suggests that LRP6 regulates fatty acid metabolism in adult heart.
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Affiliation(s)
- Ying Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Chao Yin
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Zhidan Chen
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Yang Li
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Yan Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Xiang Wang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Yanpeng An
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Sciences, International Centre for Molecular Phenomics, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, 200438, China
| | - Feizhen Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Guoping Zhang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Chunjie Yang
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China
| | - Huiru Tang
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital and School of Life Sciences, International Centre for Molecular Phenomics, Collaborative Innovation Center for Genetics and Development, Fudan University, Shanghai, 200438, China
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China.
| | - Hui Gong
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, and Institutes of Biomedical Sciences, Fudan University, 180 Feng Lin Road, Shanghai, 200032, China.
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