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Urotensin II Protects Cardiomyocytes from Apoptosis Induced by Oxidative Stress through the CSE/H2S Pathway.

Gong H, Chen Z, Zhang X, Li Y, Zhang J, Chen Y, Ding Y, Zhang G, Yang C, Zhu Y, Zou Y - Int J Mol Sci (2015)

Bottom Line: UII pretreatment significantly reduced the number of apoptotic cardiomyocytes induced by H2O2; and it partly abolished the increase of pro-apoptotic protein Bax and the decrease of anti-apoptotic protein Bcl-2 in cardiomyocytes induced by H2O2.SiRNA targeted to the urotensin II receptor (UT) greatly inhibited these effects.In conclusion, UII rapidly promoted the phosphorylation of ERK and upregulated CSE level and H2S production, which in turn activated ERK signaling to protect cardiomyocytes from apoptosis under oxidative stress.

View Article: PubMed Central - PubMed

Affiliation: Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China. ghui1975@163.com.

ABSTRACT
Plasma urotensin II (UII) has been observed to be raised in patients with acute myocardial infarction; suggesting a possible cardiac protective role for this peptide. However, the molecular mechanism is unclear. Here, we treated cultured cardiomyocytes with H2O2 to induce oxidative stress; observed the effect of UII on H2O2-induced apoptosis and explored potential mechanisms. UII pretreatment significantly reduced the number of apoptotic cardiomyocytes induced by H2O2; and it partly abolished the increase of pro-apoptotic protein Bax and the decrease of anti-apoptotic protein Bcl-2 in cardiomyocytes induced by H2O2. SiRNA targeted to the urotensin II receptor (UT) greatly inhibited these effects. Further analysis revealed that UII increased the production of hydrogen sulfide (H2S) and the level of cystathionine-γ-lyase (CSE) by activating the ERK signaling in H2O2-treated-cardiomyocytes. Si-CSE or ERK inhibitor not only greatly inhibited the increase in CSE level or the phosphorylation of ERK induced by UII but also reversed anti-apoptosis of UII in H2O2-treated-cadiomyocytes. In conclusion, UII rapidly promoted the phosphorylation of ERK and upregulated CSE level and H2S production, which in turn activated ERK signaling to protect cardiomyocytes from apoptosis under oxidative stress. These results suggest that increased plasma UII level may protect cardiomyocytes at the early-phase of acute myocardial infarction in patients.

No MeSH data available.


Related in: MedlinePlus

Si-CSE or ERK inhibitor partly abolishes the downregulation of Bax/Bcl-2 induced by UII on H2O2-treated-cardiomyocytes. Representative image of Bax and Bcl-2 (A) and quantitative analysis of Bax/Bcl-2 (B) by Western blot analysis in cultured cardiomyocytes transfected with si-scramble or si-CSE for 48 h, treated with UII or PBS for 30 min, then exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. *p < 0.05, **p < 0.01, UII + si-scram vs. Si-scram or UII + si-CSE vs. Si-CSE. #p < 0.05 UII + si-CSE vs. UII + si-scram. Representative image of Bax and Bcl-2 (C) and quantitative analysis of Bax/Bcl-2 (D) by Western blot analysis in cultured cardiomyocytes treated with DMSO or U0126 with or without UII for 30 min and exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. **p < 0.01, UII + DMSO vs. DMSO or UII + U0126 vs. UII + DMSO. #p < 0.05, UII + U0126 vs. UII + DMSO. All experiments were repeated independently at least three times.
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ijms-16-12482-f005: Si-CSE or ERK inhibitor partly abolishes the downregulation of Bax/Bcl-2 induced by UII on H2O2-treated-cardiomyocytes. Representative image of Bax and Bcl-2 (A) and quantitative analysis of Bax/Bcl-2 (B) by Western blot analysis in cultured cardiomyocytes transfected with si-scramble or si-CSE for 48 h, treated with UII or PBS for 30 min, then exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. *p < 0.05, **p < 0.01, UII + si-scram vs. Si-scram or UII + si-CSE vs. Si-CSE. #p < 0.05 UII + si-CSE vs. UII + si-scram. Representative image of Bax and Bcl-2 (C) and quantitative analysis of Bax/Bcl-2 (D) by Western blot analysis in cultured cardiomyocytes treated with DMSO or U0126 with or without UII for 30 min and exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. **p < 0.01, UII + DMSO vs. DMSO or UII + U0126 vs. UII + DMSO. #p < 0.05, UII + U0126 vs. UII + DMSO. All experiments were repeated independently at least three times.

Mentions: Cardiomyocytes were transfected with si-CSE, and treated with ERK inhibitor, U0126, respectively. The levels of Bax and Bcl-2 were detected in H2O2-treated-cardiomyocytes with or without UII pretreatment. Cardiomyocyte apoptosis was analyzed by TUNEL analysis. The results revealed that ERK inhibitor, U0126, or si-CSE reversed the increase in Bcl-2 level and decrease in Bax level induced by UII in cardiomyocytes exposed to H2O2 (Figure 5A–D). TUNEL analysis showed that UII greatly decreased the number of TUNEL positive cardiomyocytes, but the effect was significantly inhibited by si-CSE or ERK inhibitor in H2O2-treated-cardiomyocytes (Figure 6A–C).


Urotensin II Protects Cardiomyocytes from Apoptosis Induced by Oxidative Stress through the CSE/H2S Pathway.

Gong H, Chen Z, Zhang X, Li Y, Zhang J, Chen Y, Ding Y, Zhang G, Yang C, Zhu Y, Zou Y - Int J Mol Sci (2015)

Si-CSE or ERK inhibitor partly abolishes the downregulation of Bax/Bcl-2 induced by UII on H2O2-treated-cardiomyocytes. Representative image of Bax and Bcl-2 (A) and quantitative analysis of Bax/Bcl-2 (B) by Western blot analysis in cultured cardiomyocytes transfected with si-scramble or si-CSE for 48 h, treated with UII or PBS for 30 min, then exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. *p < 0.05, **p < 0.01, UII + si-scram vs. Si-scram or UII + si-CSE vs. Si-CSE. #p < 0.05 UII + si-CSE vs. UII + si-scram. Representative image of Bax and Bcl-2 (C) and quantitative analysis of Bax/Bcl-2 (D) by Western blot analysis in cultured cardiomyocytes treated with DMSO or U0126 with or without UII for 30 min and exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. **p < 0.01, UII + DMSO vs. DMSO or UII + U0126 vs. UII + DMSO. #p < 0.05, UII + U0126 vs. UII + DMSO. All experiments were repeated independently at least three times.
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Related In: Results  -  Collection

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ijms-16-12482-f005: Si-CSE or ERK inhibitor partly abolishes the downregulation of Bax/Bcl-2 induced by UII on H2O2-treated-cardiomyocytes. Representative image of Bax and Bcl-2 (A) and quantitative analysis of Bax/Bcl-2 (B) by Western blot analysis in cultured cardiomyocytes transfected with si-scramble or si-CSE for 48 h, treated with UII or PBS for 30 min, then exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. *p < 0.05, **p < 0.01, UII + si-scram vs. Si-scram or UII + si-CSE vs. Si-CSE. #p < 0.05 UII + si-CSE vs. UII + si-scram. Representative image of Bax and Bcl-2 (C) and quantitative analysis of Bax/Bcl-2 (D) by Western blot analysis in cultured cardiomyocytes treated with DMSO or U0126 with or without UII for 30 min and exposed to 100 μM H2O2 for 24 h. Values are mean ± SEM. **p < 0.01, UII + DMSO vs. DMSO or UII + U0126 vs. UII + DMSO. #p < 0.05, UII + U0126 vs. UII + DMSO. All experiments were repeated independently at least three times.
Mentions: Cardiomyocytes were transfected with si-CSE, and treated with ERK inhibitor, U0126, respectively. The levels of Bax and Bcl-2 were detected in H2O2-treated-cardiomyocytes with or without UII pretreatment. Cardiomyocyte apoptosis was analyzed by TUNEL analysis. The results revealed that ERK inhibitor, U0126, or si-CSE reversed the increase in Bcl-2 level and decrease in Bax level induced by UII in cardiomyocytes exposed to H2O2 (Figure 5A–D). TUNEL analysis showed that UII greatly decreased the number of TUNEL positive cardiomyocytes, but the effect was significantly inhibited by si-CSE or ERK inhibitor in H2O2-treated-cardiomyocytes (Figure 6A–C).

Bottom Line: UII pretreatment significantly reduced the number of apoptotic cardiomyocytes induced by H2O2; and it partly abolished the increase of pro-apoptotic protein Bax and the decrease of anti-apoptotic protein Bcl-2 in cardiomyocytes induced by H2O2.SiRNA targeted to the urotensin II receptor (UT) greatly inhibited these effects.In conclusion, UII rapidly promoted the phosphorylation of ERK and upregulated CSE level and H2S production, which in turn activated ERK signaling to protect cardiomyocytes from apoptosis under oxidative stress.

View Article: PubMed Central - PubMed

Affiliation: Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China. ghui1975@163.com.

ABSTRACT
Plasma urotensin II (UII) has been observed to be raised in patients with acute myocardial infarction; suggesting a possible cardiac protective role for this peptide. However, the molecular mechanism is unclear. Here, we treated cultured cardiomyocytes with H2O2 to induce oxidative stress; observed the effect of UII on H2O2-induced apoptosis and explored potential mechanisms. UII pretreatment significantly reduced the number of apoptotic cardiomyocytes induced by H2O2; and it partly abolished the increase of pro-apoptotic protein Bax and the decrease of anti-apoptotic protein Bcl-2 in cardiomyocytes induced by H2O2. SiRNA targeted to the urotensin II receptor (UT) greatly inhibited these effects. Further analysis revealed that UII increased the production of hydrogen sulfide (H2S) and the level of cystathionine-γ-lyase (CSE) by activating the ERK signaling in H2O2-treated-cardiomyocytes. Si-CSE or ERK inhibitor not only greatly inhibited the increase in CSE level or the phosphorylation of ERK induced by UII but also reversed anti-apoptosis of UII in H2O2-treated-cadiomyocytes. In conclusion, UII rapidly promoted the phosphorylation of ERK and upregulated CSE level and H2S production, which in turn activated ERK signaling to protect cardiomyocytes from apoptosis under oxidative stress. These results suggest that increased plasma UII level may protect cardiomyocytes at the early-phase of acute myocardial infarction in patients.

No MeSH data available.


Related in: MedlinePlus