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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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Effect of HBO on visfatin protein expression. A, Representative Western blot for visfatin in human CAECs treated with different degrees of HBO for 6 hour. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.05 vs. control. **P < 0.001 vs. control.
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Figure 1: Effect of HBO on visfatin protein expression. A, Representative Western blot for visfatin in human CAECs treated with different degrees of HBO for 6 hour. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.05 vs. control. **P < 0.001 vs. control.

Mentions: To investigate the effect of HBO on the expression of visfatin protein, different degrees of ATA were used. As shown in Figure 1, the visfatin protein was significantly induced by HBO at 1.5, 2, and 2.5 ATA for 6 h. Since 2.5 ATA provided most powerful induction of visfatin protein. The following experiments used 2.5 ATA as the hyperbaric stimulation. The oxygen saturation measured by Oxy-Check (HANNA Instruments, Inc., Woonsocket, WI) and pO2 measured by pHOx Plus C (Nova Biomedical, Waltham, MA) in the medium was 523% and >800 mmHg, respectively after HBO treatment for 6 h and 77% and 175 mmHg, respectively in the control without HBO treatment. The levels of visfatin protein shown by Western blot analysis significantly increased at 4 and 6 h after HBO treatment (Figure 2A and 2B) as compared to control without treatment. Although visfatin protein level still maintained elevated after 8 h of HBO treatment, the level of visfatin protein tended to return to baseline level. Visfatin mRNA significantly increased at 2 h after HBO treatment, increased to maximal at 4 h and returned to baseline level at 8 h after HBO treatment (Figure 2C). Because visfatin protein was maximally induced at 6 h after HBO treatment, the following experiments were set for HBO treatment for 6 hours. To simulate the clinical application of HBO, HBO was also applied intermittently and repeatedly day by day at 1 h per day. The visfatin protein level increased by intermittent and repeat exposure was similar to that by 6 hr HBO exposure (Additional file 2, Figure S2)


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)

Effect of HBO on visfatin protein expression. A, Representative Western blot for visfatin in human CAECs treated with different degrees of HBO for 6 hour. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.05 vs. control. **P < 0.001 vs. control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3113732&req=5

Figure 1: Effect of HBO on visfatin protein expression. A, Representative Western blot for visfatin in human CAECs treated with different degrees of HBO for 6 hour. B, Quantitative analysis of visfatin protein levels (n = 4 per group). *P < 0.05 vs. control. **P < 0.001 vs. control.
Mentions: To investigate the effect of HBO on the expression of visfatin protein, different degrees of ATA were used. As shown in Figure 1, the visfatin protein was significantly induced by HBO at 1.5, 2, and 2.5 ATA for 6 h. Since 2.5 ATA provided most powerful induction of visfatin protein. The following experiments used 2.5 ATA as the hyperbaric stimulation. The oxygen saturation measured by Oxy-Check (HANNA Instruments, Inc., Woonsocket, WI) and pO2 measured by pHOx Plus C (Nova Biomedical, Waltham, MA) in the medium was 523% and >800 mmHg, respectively after HBO treatment for 6 h and 77% and 175 mmHg, respectively in the control without HBO treatment. The levels of visfatin protein shown by Western blot analysis significantly increased at 4 and 6 h after HBO treatment (Figure 2A and 2B) as compared to control without treatment. Although visfatin protein level still maintained elevated after 8 h of HBO treatment, the level of visfatin protein tended to return to baseline level. Visfatin mRNA significantly increased at 2 h after HBO treatment, increased to maximal at 4 h and returned to baseline level at 8 h after HBO treatment (Figure 2C). Because visfatin protein was maximally induced at 6 h after HBO treatment, the following experiments were set for HBO treatment for 6 hours. To simulate the clinical application of HBO, HBO was also applied intermittently and repeatedly day by day at 1 h per day. The visfatin protein level increased by intermittent and repeat exposure was similar to that by 6 hr HBO exposure (Additional file 2, Figure S2)

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