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Tumor necrosis factor-α enhances hyperbaric oxygen-induced visfatin expression via JNK pathway in human coronary arterial endothelial cells.

Wang BW, Lin CM, Wu GJ, Shyu KG - J. Biomed. Sci. (2011)

Bottom Line: Visfatin, a adipocytokine with insulin-mimetic effect, plays a role in endothelial angiogenesis.However, the molecular mechanism of beneficial effects of HBO is poorly understood.HBO significantly increased secretion of TNF-α from cultured human CAECs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Cardiology, Shin Kong Wu Ho-Su Memorial Hospital, and School of Medicine, Fu-Jen Catholic University, New Taipei City, Taipei, Taiwan.

ABSTRACT

Background: Visfatin, a adipocytokine with insulin-mimetic effect, plays a role in endothelial angiogenesis. Hyperbaric oxygen (HBO) has been used in medical practice. However, the molecular mechanism of beneficial effects of HBO is poorly understood. We sought to investigate the cellular and molecular mechanisms of regulation of visfatin by HBO in human coronary arterial endothelial cells (CAECs).

Methods: Human CAECs were exposed to 2.5 atmosphere absolute (ATA) of oxygen in a hyperbaric chamber. Western blot, real-time polymerase chain reaction, and promoter activity assay were performed. In vitro glucose uptake and tube formation was detected.

Results: Visfatin protein (2.55-fold) and mRNA (2.53-fold) expression were significantly increased after exposure to 2.5 ATA HBO for 4 to 6 h. Addition of SP600125 and JNK siRNA 30 min before HBO inhibited the induction of visfatin protein. HBO also significantly increased DNA-protein binding activity of AP-1 and visfatin promoter activity. Addition of SP600125 and TNF-α monoclonal antibody 30 min before HBO abolished the DNA-protein binding activity and visfatin promoter activity induced by HBO. HBO significantly increased secretion of TNF-α from cultured human CAECs. Exogenous addition of TNF-α significantly increased visfatin protein expression while TNF-α antibody and TNF-α receptor antibody blocked the induction of visfatin protein expression induced by HBO. HBO increased glucose uptake in human CAECs as HBO and visfatin siRNA and TNF-α antibody attenuated the glucose uptake induced by HBO. HBO significantly increased the tube formation of human CAECs while visfatin siRNA, TNF-α antibody inhibited the tube formation induced by HBO.

Conclusions: HBO activates visfatin expression in cultured human CAECs. HBO-induced visfatin is mediated by TNF-α and at least in part through JNK pathway.

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HBO-induced visfatin expression in human CAECs is via JNK kinase. A, Representative Western blots for visfatin protein levels in human CAECs subjected to HBO stimulation for 6 h in the absence or presence of inhibitors. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.001 vs. HBO. C, Representative Western blots for phosphor-JNK and total JNK protein levels in human CAECs subjected to HBO stimulation for 2 to 6 h in the absence or presence of inhibitor or siRNA. D, Quantitative analysis of phosphor-JNK protein levels (n = 4 per group). *P < 0.001 vs. control. **P < 0.01 vs. control. +P < 0.001 vs. HBO at 4 h.
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Figure 3: HBO-induced visfatin expression in human CAECs is via JNK kinase. A, Representative Western blots for visfatin protein levels in human CAECs subjected to HBO stimulation for 6 h in the absence or presence of inhibitors. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.001 vs. HBO. C, Representative Western blots for phosphor-JNK and total JNK protein levels in human CAECs subjected to HBO stimulation for 2 to 6 h in the absence or presence of inhibitor or siRNA. D, Quantitative analysis of phosphor-JNK protein levels (n = 4 per group). *P < 0.001 vs. control. **P < 0.01 vs. control. +P < 0.001 vs. HBO at 4 h.

Mentions: As shown in Figure 3A and 3B, the Western blot demonstrated that the HBO-induced increase of visfatin protein was significantly reduced after the addition of SB203580, and SP600125, 30 min before HBO treatment. The addition of PD98059 and wortmannin did not inhibit the visfatin protein expression induced by HBO. These findings implicated that JNK and ERK pathways but not p38 MAP kinase and PI-3 kinase mediated the induction of visfatin protein by HBO in human CAECs. Since JNK kinase inhibitor reduced the visfatin protein expression most significantly. We then focused on the JNK kinase pathway on the visfatin protein expression induced by HBO. HBO at 2.5ATA significantly increased the phosphorylation of JNK (Figure 3C and 3D). SP600125, inhibitor of JNK kinase, significantly attenuated the increased phosphorylation of JNK induced by HBO. JNK siRNA significantly attenuated the expression of phosphor-JNK induced by HBO. The scrambled siRNA did not affect the phosphorylation of JNK induced by HBO.


Tumor necrosis factor-α enhances hyperbaric oxygen-induced visfatin expression via JNK pathway in human coronary arterial endothelial cells.

Wang BW, Lin CM, Wu GJ, Shyu KG - J. Biomed. Sci. (2011)

HBO-induced visfatin expression in human CAECs is via JNK kinase. A, Representative Western blots for visfatin protein levels in human CAECs subjected to HBO stimulation for 6 h in the absence or presence of inhibitors. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.001 vs. HBO. C, Representative Western blots for phosphor-JNK and total JNK protein levels in human CAECs subjected to HBO stimulation for 2 to 6 h in the absence or presence of inhibitor or siRNA. D, Quantitative analysis of phosphor-JNK protein levels (n = 4 per group). *P < 0.001 vs. control. **P < 0.01 vs. control. +P < 0.001 vs. HBO at 4 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3113732&req=5

Figure 3: HBO-induced visfatin expression in human CAECs is via JNK kinase. A, Representative Western blots for visfatin protein levels in human CAECs subjected to HBO stimulation for 6 h in the absence or presence of inhibitors. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.001 vs. HBO. C, Representative Western blots for phosphor-JNK and total JNK protein levels in human CAECs subjected to HBO stimulation for 2 to 6 h in the absence or presence of inhibitor or siRNA. D, Quantitative analysis of phosphor-JNK protein levels (n = 4 per group). *P < 0.001 vs. control. **P < 0.01 vs. control. +P < 0.001 vs. HBO at 4 h.
Mentions: As shown in Figure 3A and 3B, the Western blot demonstrated that the HBO-induced increase of visfatin protein was significantly reduced after the addition of SB203580, and SP600125, 30 min before HBO treatment. The addition of PD98059 and wortmannin did not inhibit the visfatin protein expression induced by HBO. These findings implicated that JNK and ERK pathways but not p38 MAP kinase and PI-3 kinase mediated the induction of visfatin protein by HBO in human CAECs. Since JNK kinase inhibitor reduced the visfatin protein expression most significantly. We then focused on the JNK kinase pathway on the visfatin protein expression induced by HBO. HBO at 2.5ATA significantly increased the phosphorylation of JNK (Figure 3C and 3D). SP600125, inhibitor of JNK kinase, significantly attenuated the increased phosphorylation of JNK induced by HBO. JNK siRNA significantly attenuated the expression of phosphor-JNK induced by HBO. The scrambled siRNA did not affect the phosphorylation of JNK induced by HBO.

Bottom Line: Visfatin, a adipocytokine with insulin-mimetic effect, plays a role in endothelial angiogenesis.However, the molecular mechanism of beneficial effects of HBO is poorly understood.HBO significantly increased secretion of TNF-α from cultured human CAECs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Cardiology, Shin Kong Wu Ho-Su Memorial Hospital, and School of Medicine, Fu-Jen Catholic University, New Taipei City, Taipei, Taiwan.

ABSTRACT

Background: Visfatin, a adipocytokine with insulin-mimetic effect, plays a role in endothelial angiogenesis. Hyperbaric oxygen (HBO) has been used in medical practice. However, the molecular mechanism of beneficial effects of HBO is poorly understood. We sought to investigate the cellular and molecular mechanisms of regulation of visfatin by HBO in human coronary arterial endothelial cells (CAECs).

Methods: Human CAECs were exposed to 2.5 atmosphere absolute (ATA) of oxygen in a hyperbaric chamber. Western blot, real-time polymerase chain reaction, and promoter activity assay were performed. In vitro glucose uptake and tube formation was detected.

Results: Visfatin protein (2.55-fold) and mRNA (2.53-fold) expression were significantly increased after exposure to 2.5 ATA HBO for 4 to 6 h. Addition of SP600125 and JNK siRNA 30 min before HBO inhibited the induction of visfatin protein. HBO also significantly increased DNA-protein binding activity of AP-1 and visfatin promoter activity. Addition of SP600125 and TNF-α monoclonal antibody 30 min before HBO abolished the DNA-protein binding activity and visfatin promoter activity induced by HBO. HBO significantly increased secretion of TNF-α from cultured human CAECs. Exogenous addition of TNF-α significantly increased visfatin protein expression while TNF-α antibody and TNF-α receptor antibody blocked the induction of visfatin protein expression induced by HBO. HBO increased glucose uptake in human CAECs as HBO and visfatin siRNA and TNF-α antibody attenuated the glucose uptake induced by HBO. HBO significantly increased the tube formation of human CAECs while visfatin siRNA, TNF-α antibody inhibited the tube formation induced by HBO.

Conclusions: HBO activates visfatin expression in cultured human CAECs. HBO-induced visfatin is mediated by TNF-α and at least in part through JNK pathway.

Show MeSH
Related in: MedlinePlus