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A soluble receptor for advanced glycation end-products inhibits hypoxia/reoxygenation-induced apoptosis in rat cardiomyocytes via the mitochondrial pathway.

Guo C, Zeng X, Song J, Zhang M, Wang H, Xu X, Du F, Chen B - Int J Mol Sci (2012)

Bottom Line: Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05).In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2.Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China; E-Mails: songjuan2008@163.com (J.S.); dayanjingzm@sina.com (M.Z.); xuxiaoweittyy@sina.com (X.X.); fhduu@yahoo.com.cn (F.D.); chbux@126.com (B.C.).

ABSTRACT
Severe myocardial dysfunction and tissue damage resulting from ischemia/reperfusion (I/R) is a common clinical scenario in patients with certain types of heart diseases and therapies such as thrombolysis, percutaneous coronary intervention, coronary artery bypass grafting, and cardiac transplantation. The underlining mechanism of endogenous cardiac protection after I/R injury has been a focus of current research. Growing evidences suggests that soluble receptor for advanced glycation end-products (sRAGE) has a cardioprotective effect; however, its role in I/R injury remains unclear. We hypothesized that exogenous administration of sRAGE during hypoxia/reoxygenation (H/R) induces cardioprotection by inhibiting cardiomyocyte apoptosis via multiple signals, involving mitochondrial membrane potential (MMP), the mitochondrial permeability transition pore (mPTP), mitochondrial cytochrome c, caspase-3, Bcl-2 and Bax. Neonatal rat cardiomyocytes underwent hypoxia for 3-h followed by 2-h reoxygenation or were treated with sRAGE for 10 min before H/R. Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05). In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2. Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

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Effect of sRAGE on mitochondrial membrane potential (Δψm) and mitochondrial permeability transition pore (mPTP) opening. To monitor changes in Δψm (A), cells were incubated with 10 μg/mL JC-1 for 20 min at 37 °C. Data is presented as the relative ratio of green to red fluorescence intensity, which indicates ΔΨm depolarization. To reveal mPTP opening (B), cells were co-loaded for 15 min with 2 μM calcein-AM and 4 mM CoCl2 at 37 °C. The rates of calcein-AM loading and exit were measured by fluorescent signal recording every 5 min by confocal microscopy. Con, no treatment; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation; Con-sRAGE, sRAGE alone. Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 vs. the control, # p < 0.01 vs. H/R; n = 8). The scale bar indicates 50 μM for Figure 4A and 100 μM for Figure 4B.
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f4-ijms-13-11923: Effect of sRAGE on mitochondrial membrane potential (Δψm) and mitochondrial permeability transition pore (mPTP) opening. To monitor changes in Δψm (A), cells were incubated with 10 μg/mL JC-1 for 20 min at 37 °C. Data is presented as the relative ratio of green to red fluorescence intensity, which indicates ΔΨm depolarization. To reveal mPTP opening (B), cells were co-loaded for 15 min with 2 μM calcein-AM and 4 mM CoCl2 at 37 °C. The rates of calcein-AM loading and exit were measured by fluorescent signal recording every 5 min by confocal microscopy. Con, no treatment; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation; Con-sRAGE, sRAGE alone. Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 vs. the control, # p < 0.01 vs. H/R; n = 8). The scale bar indicates 50 μM for Figure 4A and 100 μM for Figure 4B.

Mentions: Δψm is an important mediator and monitor of key cellular processes. In addition, it is a highly sensitive indicator of the energetic state of mitochondria and the health of cells [17]. Detection of mitochondrial permeability provided an early indication of the initiation of cellular apoptosis. Using JC-1, H/R increased Δψm depolarization by 37% (n = 8, p < 0.01) compared to the controls. Compared with H/R, sRAGE pre-treatment decreased mitochondrial depolarization from 1.37 ± 0.17 to 1.08 ± 0.02 (n = 8, p < 0.01). sRAGE alone had no effect on Δψm. However, sRAGE changed H/R-induced Δψm (Figure 4A).


A soluble receptor for advanced glycation end-products inhibits hypoxia/reoxygenation-induced apoptosis in rat cardiomyocytes via the mitochondrial pathway.

Guo C, Zeng X, Song J, Zhang M, Wang H, Xu X, Du F, Chen B - Int J Mol Sci (2012)

Effect of sRAGE on mitochondrial membrane potential (Δψm) and mitochondrial permeability transition pore (mPTP) opening. To monitor changes in Δψm (A), cells were incubated with 10 μg/mL JC-1 for 20 min at 37 °C. Data is presented as the relative ratio of green to red fluorescence intensity, which indicates ΔΨm depolarization. To reveal mPTP opening (B), cells were co-loaded for 15 min with 2 μM calcein-AM and 4 mM CoCl2 at 37 °C. The rates of calcein-AM loading and exit were measured by fluorescent signal recording every 5 min by confocal microscopy. Con, no treatment; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation; Con-sRAGE, sRAGE alone. Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 vs. the control, # p < 0.01 vs. H/R; n = 8). The scale bar indicates 50 μM for Figure 4A and 100 μM for Figure 4B.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472784&req=5

f4-ijms-13-11923: Effect of sRAGE on mitochondrial membrane potential (Δψm) and mitochondrial permeability transition pore (mPTP) opening. To monitor changes in Δψm (A), cells were incubated with 10 μg/mL JC-1 for 20 min at 37 °C. Data is presented as the relative ratio of green to red fluorescence intensity, which indicates ΔΨm depolarization. To reveal mPTP opening (B), cells were co-loaded for 15 min with 2 μM calcein-AM and 4 mM CoCl2 at 37 °C. The rates of calcein-AM loading and exit were measured by fluorescent signal recording every 5 min by confocal microscopy. Con, no treatment; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation; Con-sRAGE, sRAGE alone. Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 vs. the control, # p < 0.01 vs. H/R; n = 8). The scale bar indicates 50 μM for Figure 4A and 100 μM for Figure 4B.
Mentions: Δψm is an important mediator and monitor of key cellular processes. In addition, it is a highly sensitive indicator of the energetic state of mitochondria and the health of cells [17]. Detection of mitochondrial permeability provided an early indication of the initiation of cellular apoptosis. Using JC-1, H/R increased Δψm depolarization by 37% (n = 8, p < 0.01) compared to the controls. Compared with H/R, sRAGE pre-treatment decreased mitochondrial depolarization from 1.37 ± 0.17 to 1.08 ± 0.02 (n = 8, p < 0.01). sRAGE alone had no effect on Δψm. However, sRAGE changed H/R-induced Δψm (Figure 4A).

Bottom Line: Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05).In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2.Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China; E-Mails: songjuan2008@163.com (J.S.); dayanjingzm@sina.com (M.Z.); xuxiaoweittyy@sina.com (X.X.); fhduu@yahoo.com.cn (F.D.); chbux@126.com (B.C.).

ABSTRACT
Severe myocardial dysfunction and tissue damage resulting from ischemia/reperfusion (I/R) is a common clinical scenario in patients with certain types of heart diseases and therapies such as thrombolysis, percutaneous coronary intervention, coronary artery bypass grafting, and cardiac transplantation. The underlining mechanism of endogenous cardiac protection after I/R injury has been a focus of current research. Growing evidences suggests that soluble receptor for advanced glycation end-products (sRAGE) has a cardioprotective effect; however, its role in I/R injury remains unclear. We hypothesized that exogenous administration of sRAGE during hypoxia/reoxygenation (H/R) induces cardioprotection by inhibiting cardiomyocyte apoptosis via multiple signals, involving mitochondrial membrane potential (MMP), the mitochondrial permeability transition pore (mPTP), mitochondrial cytochrome c, caspase-3, Bcl-2 and Bax. Neonatal rat cardiomyocytes underwent hypoxia for 3-h followed by 2-h reoxygenation or were treated with sRAGE for 10 min before H/R. Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05). In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2. Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

Show MeSH
Related in: MedlinePlus