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Local Augmented Angiotensinogen Secreted from Apoptotic Vascular Endothelial Cells Is a Vital Mediator of Vascular Remodelling.

Wu SJ, Soulez M, Yang YH, Chu CS, Shih SC, Hébert MJ, Kuo MC, Hsieh YJ - PLoS ONE (2015)

Bottom Line: After the cells were subjected to SS, we found that the mRNA expression of angiotensinogen (AGT) was increased by >3-fold in HUVECs and by approximately 2.5-fold in VSMCs.Increases in the expression of AGT protein and angiotensin II (Ang II) were found in a serum-free medium conditioned by HUVECs (SSC).In conclusion, we first demonstrated that the augmented AGT released from apoptotic endothelial cells acts as a vital progenitor of Ang II to accelerate vascular remodelling, and we suggest that blocking local augmented Ang II might be an effective strategy for restraining intimal hyperplasia.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan.

ABSTRACT
Vascular remodelling is a critical vasculopathy found in atheromatous diseases and allograft failures. The local renin angiotensin system (RAS) has been implicated in vascular remodelling. However, the mechanisms by which the augmented local RAS is associated with the initial event of endothelial cell apoptosis in injured vasculature remain undefined. We induced the apoptosis of human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs) through serum starvation (SS). After the cells were subjected to SS, we found that the mRNA expression of angiotensinogen (AGT) was increased by >3-fold in HUVECs and by approximately 2.5-fold in VSMCs. In addition, the expression of angiotensin-converting enzyme (ACE) mRNA was increased in VSMCs but decreased to 50% in HUVECs during the same apoptotic process. Increases in the expression of AGT protein and angiotensin II (Ang II) were found in a serum-free medium conditioned by HUVECs (SSC). The increased Ang II was suppressed using lisinopril (an ACE inhibitor) treatment. Moreover, the activation of ERK1/2 induced by the SSC in VSMCs was also suppressed by losartan. In conclusion, we first demonstrated that the augmented AGT released from apoptotic endothelial cells acts as a vital progenitor of Ang II to accelerate vascular remodelling, and we suggest that blocking local augmented Ang II might be an effective strategy for restraining intimal hyperplasia.

No MeSH data available.


Related in: MedlinePlus

AGT and ACE gene expression in apoptotic HUVECs and VSMCs.(A) AGT and ACE gene expression in HUVECs that underwent SS for 6 and 12 h. (B) AGT and ACE gene expression in HUVECs exposed to H2O2 for 3 and 6 h. (C) AGT and ACE gene expression in VSMCs that underwent SS for 12 and 24 h. Real-time PCR was performed in the triplicate on each SS-treated sample for both AGT mRNA and ACE mRNA. The relative mRNA ratios represent the respective ΔCt of AGT or ACE normalised according to the ΔCt of GADPH in each experiment. The relative mRNA ratio in the normal medium was designated as 100%. Each assay was repeated 3 times, and the error bars in each individual figure represent the SE. *P < 0.05, **P < 0.01, and ***P < 0.001 in comparison to the control group. ns, no significance.
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pone.0132583.g003: AGT and ACE gene expression in apoptotic HUVECs and VSMCs.(A) AGT and ACE gene expression in HUVECs that underwent SS for 6 and 12 h. (B) AGT and ACE gene expression in HUVECs exposed to H2O2 for 3 and 6 h. (C) AGT and ACE gene expression in VSMCs that underwent SS for 12 and 24 h. Real-time PCR was performed in the triplicate on each SS-treated sample for both AGT mRNA and ACE mRNA. The relative mRNA ratios represent the respective ΔCt of AGT or ACE normalised according to the ΔCt of GADPH in each experiment. The relative mRNA ratio in the normal medium was designated as 100%. Each assay was repeated 3 times, and the error bars in each individual figure represent the SE. *P < 0.05, **P < 0.01, and ***P < 0.001 in comparison to the control group. ns, no significance.

Mentions: To examine the expression of AGT and ACE genes in response to SS in HUVECs, we extracted the total mRNA from the cells, which were incubated under SS conditions for 6 and 12 h, to perform a real-time qPCR assay. We found that SS significantly increased the expression of AGT mRNA by >3-fold (P < 0.05) in HUVECs compared with that in cells in a normal medium. By contrast, the expression of ACE mRNA decreased to approximately 50% (Fig 3A). A similar result was found when HUVECs were treated with 200 uM H2O2 (Fig 3B). We conducted the same experiment by using VSMCs and found that AGT mRNA was slightly increased in SS-treated VSMCs at the 12th hour and increased to 2.5-fold at the 24th hour compared with the control group. In contrast to the HUVECs, the expression of ACE mRNA in VSMCs incubated in the SS medium for 12 and 24 h was significantly upregulated to approximately 300% (Fig 3C).


Local Augmented Angiotensinogen Secreted from Apoptotic Vascular Endothelial Cells Is a Vital Mediator of Vascular Remodelling.

Wu SJ, Soulez M, Yang YH, Chu CS, Shih SC, Hébert MJ, Kuo MC, Hsieh YJ - PLoS ONE (2015)

AGT and ACE gene expression in apoptotic HUVECs and VSMCs.(A) AGT and ACE gene expression in HUVECs that underwent SS for 6 and 12 h. (B) AGT and ACE gene expression in HUVECs exposed to H2O2 for 3 and 6 h. (C) AGT and ACE gene expression in VSMCs that underwent SS for 12 and 24 h. Real-time PCR was performed in the triplicate on each SS-treated sample for both AGT mRNA and ACE mRNA. The relative mRNA ratios represent the respective ΔCt of AGT or ACE normalised according to the ΔCt of GADPH in each experiment. The relative mRNA ratio in the normal medium was designated as 100%. Each assay was repeated 3 times, and the error bars in each individual figure represent the SE. *P < 0.05, **P < 0.01, and ***P < 0.001 in comparison to the control group. ns, no significance.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492977&req=5

pone.0132583.g003: AGT and ACE gene expression in apoptotic HUVECs and VSMCs.(A) AGT and ACE gene expression in HUVECs that underwent SS for 6 and 12 h. (B) AGT and ACE gene expression in HUVECs exposed to H2O2 for 3 and 6 h. (C) AGT and ACE gene expression in VSMCs that underwent SS for 12 and 24 h. Real-time PCR was performed in the triplicate on each SS-treated sample for both AGT mRNA and ACE mRNA. The relative mRNA ratios represent the respective ΔCt of AGT or ACE normalised according to the ΔCt of GADPH in each experiment. The relative mRNA ratio in the normal medium was designated as 100%. Each assay was repeated 3 times, and the error bars in each individual figure represent the SE. *P < 0.05, **P < 0.01, and ***P < 0.001 in comparison to the control group. ns, no significance.
Mentions: To examine the expression of AGT and ACE genes in response to SS in HUVECs, we extracted the total mRNA from the cells, which were incubated under SS conditions for 6 and 12 h, to perform a real-time qPCR assay. We found that SS significantly increased the expression of AGT mRNA by >3-fold (P < 0.05) in HUVECs compared with that in cells in a normal medium. By contrast, the expression of ACE mRNA decreased to approximately 50% (Fig 3A). A similar result was found when HUVECs were treated with 200 uM H2O2 (Fig 3B). We conducted the same experiment by using VSMCs and found that AGT mRNA was slightly increased in SS-treated VSMCs at the 12th hour and increased to 2.5-fold at the 24th hour compared with the control group. In contrast to the HUVECs, the expression of ACE mRNA in VSMCs incubated in the SS medium for 12 and 24 h was significantly upregulated to approximately 300% (Fig 3C).

Bottom Line: After the cells were subjected to SS, we found that the mRNA expression of angiotensinogen (AGT) was increased by >3-fold in HUVECs and by approximately 2.5-fold in VSMCs.Increases in the expression of AGT protein and angiotensin II (Ang II) were found in a serum-free medium conditioned by HUVECs (SSC).In conclusion, we first demonstrated that the augmented AGT released from apoptotic endothelial cells acts as a vital progenitor of Ang II to accelerate vascular remodelling, and we suggest that blocking local augmented Ang II might be an effective strategy for restraining intimal hyperplasia.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Laboratory Science and Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan.

ABSTRACT
Vascular remodelling is a critical vasculopathy found in atheromatous diseases and allograft failures. The local renin angiotensin system (RAS) has been implicated in vascular remodelling. However, the mechanisms by which the augmented local RAS is associated with the initial event of endothelial cell apoptosis in injured vasculature remain undefined. We induced the apoptosis of human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs) through serum starvation (SS). After the cells were subjected to SS, we found that the mRNA expression of angiotensinogen (AGT) was increased by >3-fold in HUVECs and by approximately 2.5-fold in VSMCs. In addition, the expression of angiotensin-converting enzyme (ACE) mRNA was increased in VSMCs but decreased to 50% in HUVECs during the same apoptotic process. Increases in the expression of AGT protein and angiotensin II (Ang II) were found in a serum-free medium conditioned by HUVECs (SSC). The increased Ang II was suppressed using lisinopril (an ACE inhibitor) treatment. Moreover, the activation of ERK1/2 induced by the SSC in VSMCs was also suppressed by losartan. In conclusion, we first demonstrated that the augmented AGT released from apoptotic endothelial cells acts as a vital progenitor of Ang II to accelerate vascular remodelling, and we suggest that blocking local augmented Ang II might be an effective strategy for restraining intimal hyperplasia.

No MeSH data available.


Related in: MedlinePlus