Abstract
Background In order to explore the molecular mechanism of cardiomyocyte-dependent myocardial gene expression and cardiomyocyte differentiation in cardiac hypertrophy, and to provide new insights for cardiac hypertrophy.
Methods Cardiac myocytes were isolated from day 1-3 Sprague-Dawley rat pups. Real time quantitative PCR, western blot and immunocytochemistry Assay were used to detect the expression and localization of related genes. CO-IP was used to detect direct protein interactions between Myocardin and STAT3. Luciferase reporter assay and chromatin immunoprecipitation were used to detect the binding of Myocardin to the promoter of a downstream target gene. Microinjection of zebrafish embryos was used to examine the effects of STAT3 and Myocardin interactions on cardiac development in vivo
Results The N-terminus of STAT3 directly binds to the basic domain of myocardin and inhibits the transcriptional activity of Myocardin-mediated cardiac-specific genes ANF and α-actinin, thereby inhibiting their expression, and further inhibit myocardin-mediated cardiac hypertrophy in vivo.
Conclusions In summary, our report states that signal transduction and transcriptional activation factor 3 (STAT3) are inhibitors of the major cardiac hypertrophic transcription factor Myocardiin, which is required for cardiomyocyte differentiation. The STAT3-cardiacin interaction identified nuclear hormone receptor-mediated and cardiac-specific gene-regulated convergence sites and suggested a possible mechanism for cardioprotective effects.
- Abbreviations
- STAT3
- signal transducer and activator of transcription 3;
- SRF
- serum response factor;
- IL-6
- interleukin-6;
- LIF
- leukemia inhibitory factor;
- DMEM
- Dulbecco’s modified Eagle’s medium;
- DAPI
- 4’,6’-diamidino-2-phenylindole;
- RT-PCR
- semi-quantitative reverse-transcription polymerase chain reaction;
- qPCR
- real time quantitative polymerase chain reaction;
- GAPDH
- Glyceraldehyde-3-phosphate dehydrogenase;
- PAGE
- sodium dodecyl sulfate-polyacrylamide gel electrophoresis;
- ChIP
- Chromatin Immunoprecipitation;
- JAK
- Janus kinase;
- LPS
- lipopolysaccharide;
- ERK1/2
- extracellular regulated protein kinases;
- PIAS1
- protein inhibitor of activated STAT 1;
- SUMO1
- small uniquitin-like modifier 1;
- MO
- Morpholino