Transcription factor Sp1 ameliorates sepsis-induced myocardial injury via ZFAS1/Notch signaling in H9C2 cells.

Purpose: To investigate whether Sp1 can ameliorate sepsis-induced myocardial injury and explore the potential molecular mechanism.

Methods: The embryonic cardiomyocyte cell line H9C2 and primary cultured mouse neonatal cardiomyocytes (CMNCs) were treated with LPS or phosphate-buffered saline (PBS). A mouse model of LPS-induced sepsis was established using male C57BL/6J mice and their cardiomyocytes were collected. Real-time reverse transcription-PCR (qRT-PCR) assay was used to detect the expression levels of Sp1 and ZFAS1 in cardiomyocytes. Western blotting analysis was used to assess the protein expression levels of Sp1, apoptosis-associated proteins and Notch signaling pathway related proteins. Luciferase assay was used to detect the interaction between Sp1 and ZFAS1. Cell transfection was used to generate H9C2 cells with overexpressed or knocked down of Sp1 or ZFAS1. MTT assay and flow cytometry analysis were used to test the cell proliferation and cell apoptosis ratio.

Results: Our data revealed that the expressions of ZFAS1 and Sp1 were significantly reduced in LPS-treated H9C2 cells and primary CMNCs. The downregulation of ZFAS1 and Sp1 were also found in cardiomyocytes obtained from LPS-challenged mice. LPS induced H9C2 cell apoptosis and depressed cell proliferation was ameliorated by ZFAS1 overexpression and aggravated by ZFAS1 knockdown. Mechanistically, Luciferase assay indicated that Sp1 could bind to ZFAS1, and positively regulated ZFAS1 expression. Moreover, Notch signaling pathway participates in H9C2 cell apoptosis mediated by Sp1.

Conclusion: The present study demonstrates that Sp1 regulates LPS-induced cardiomyocyte apoptosis via ZFAS1/Notch signaling pathway, which may serve as therapeutic targets for sepsis-induced myocardial injury.