e0140 Endoplasmic reticulum stress induced-apoptotic model by tunicamycin in cultured neonatal rat cardiomyocytes

Introduction: We aimed to test the mechanism of protective effects of tauroursodeoxycholic acid (TUDCA) on cardiovascular disease using cultured cardiomyocytes. Methods: Neonatal rat cardiomyocytes (NRCMs) were isolated and cultured and then the cells were divided into 4 groups based on the treatments: control group (cells treated with culture medium), H2O2/thapsigargin (TG) group (cells treated with oxidative stress and endoplasmic reticulum [ER] stress inducer), TUDCA group, and H2O2/TG + TUDCA group. The treated NRCMs were then subjected to serial analyses including flow cytometry, enzyme-linked immunosorbent assay, and Western blotting. Results: Tauroursodeoxycholic acid significantly attenuated H2O2-induced reactive oxygen species generation and lactate dehydrogenase release and restored H2O2-induced reductions of glutathione and superoxide dismutase levels in NRCMs. Tauroursodeoxycholic acid also alleviated H2O2-induced cardiomyocytes apoptosis, as well as the Bax/Bcl2 ratio compared with that of H2O2 treated alone. In addition, TUDCA suppressed TG-induced ER stress as reflected by inversing cell viability and the expression levels of glucose-regulated protein 78 kDa and C/enhancer-binding protein homologous protein. Conclusion: Our data indicated that TUDCA-mediated inhibition on H2O2-induced oxidative stress and cardiomyocytes apoptosis was through suppressing ER stress, and TUDCA possesses the potential to be developed as therapeutic tool in clinical use for cardiovascular diseases.

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Tanshinone IIA ameliorates apoptosis of cardiomyocytes induced by endoplasmic reticulum stress

Experimental Biology and Medicine ◽

10.1177/1535370216660634 ◽

2016 ◽

Vol 241 (18) ◽

pp. 2042-2048 ◽

Cited By ~ 4

Author(s):

Jun Feng ◽

Shusheng Li ◽

Huawen Chen

Keyword(s):

Endoplasmic Reticulum ◽

Endoplasmic Reticulum Stress ◽

Caspase 3 ◽

Primary Cultures ◽

Tanshinone Iia ◽

Cardioprotective Effect ◽

Neonatal Rat ◽

Rat Cardiomyocytes ◽

Polymerase Chain ◽

Hoechst Staining

The fat-soluble diterpenoids tanshinone IIA (TSA) is the major active element of Danshen, which has widespread cardioprotective effect. However, the mechanism of its beneficial effect on cardiomyocytes has not been fully investigated. Here, we aim to demonstrate that TSA ameliorates apoptosis of cardiomyocytes activated by endoplasmic reticulum stress (ERS). Primary cultures of neonatal rat cardiomyocytes are used, in which ERS-mediated apoptosis is induced by tunicamycin (Tm). Apoptosis of cardiomyocytes are detected by Hoechst staining and caspase 3 activity analysis. Protein expression of ERS markers are detected by Western blot, and level of miroRNA-133 (miR-133) is detected by real-time polymerase chain reaction. Tm treatment significantly triggers the apoptosis and ERS of cardiomyocytes. TSA dramatically ameliorates apoptosis and ERS of cardiomyocytes induced by Tm. Interestingly, level of miR-133 is reduced by Tm treatment, which is reversed by TSA. The cardioprotective effect of TSA on apoptosis and ERS of cardiomyocytes is blocked by anti-miR-133. These results suggest that TSA protects cardiomyocytes through ameliorated ERS-mediated apoptosis, which may be resulted from upregulation of miR-133.

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