TY - JOUR
T1 - Real-time pcr study of Ang1, Ang2, Tie-2, VEGF, and KDR expression in human erectile tissue during aging
AU - Figueiredo, António
AU - Cordeiro, Ana Lúcia
AU - Tomada, Nuno
AU - Tomada, Inês
AU - Rodrigues, Adriana
AU - Gouveia, Alexandra
AU - Neves, Delminda
N1 - Funding Information:
The authors thank Dr. Alexandre Magalhães from the Faculty of Sciences of Universidade do Porto for statistical analysis of data, Dr. Paula Magalhães from IBMC of Universidade do Porto for technical help in real-time PCR, and Mrs. Helena Pereira from the Pathology Department of Hospital S. João for technical support in the immunohistochemistry technique. This work was supported by Caixa Geral de Depósitos and Universidade do Porto grant IPG04 2007. Adriana Rodrigues was also supported by POCI 2010, FSE and “Fundação para a Ciência e Tecnologia” (SFRH/BD/41024/2007).
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2011/5
Y1 - 2011/5
N2 - Introduction. Aging is a recognized risk factor for erectile dysfunction (ED), contributing independently to vascular damage of penile tissue. Vascular maintenance depends on angiogenic balance in tissues. Vascular endothelial growth factor (VEGF) is a modulator of endothelial cells functions, after engagement to specific receptor kinase domain region (KDR). Other factors, such as angiopoietins, cross talk with VEGF, modulating its effects. Angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) compete for binding to Tie-2 and, while Ang1 promotes vascular stabilization, Ang2 acts as a partial agonist or antagonist of Ang1 signaling, depending on VEGF bioavailability. Aims. To quantify the expression of Ang1, Ang2, Tie-2, VEGF, and KDR by real-time polymerase chain reaction (PCR) in human corpus cavernosum (CC) from young and aged healthy individuals. Methods. Human CC fragments were obtained from organ donors without known risk factors to ED and divided in two groups: young (16-35 years) and aged (59-74 years). RNA was extracted and converted to cDNA. Real-time PCR reactions employed appropriate primers. KDR, Tie-2, Akt, and phospho-Akt protein levels were also assessed by Western blotting (WB). Computer-assisted evaluation of vascular areas was performed. Main Outcome Measures. Study of angiopoietins-Tie-2 and VEGF-KDR systems in human CC during aging by real-time PCR and WB. The ratios Ang1/Tie-2 and VEGF/KDR and Akt levels were also determined. Results. Real-time PCR results showed a sixfold significant reduction in the Ang1/Tie-2 ratio during aging. Ang2, VEGF, and KDR expression results were highly variable. Nevertheless, the ratio VEGF/KDR was significantly higher in the aged individuals. Akt and phospho-Akt levels were similar in both groups. Immunohistological evaluation revealed a significant decrease in vascular areas and endothelial surface in CC with aging, despite no differences found in vessel number. Conclusions. The obtained results suggest an aging-associated downregulation of angiopoietins/Tie-2 system and an apparent compensatory upregulation of the VEGF/KDR system.
AB - Introduction. Aging is a recognized risk factor for erectile dysfunction (ED), contributing independently to vascular damage of penile tissue. Vascular maintenance depends on angiogenic balance in tissues. Vascular endothelial growth factor (VEGF) is a modulator of endothelial cells functions, after engagement to specific receptor kinase domain region (KDR). Other factors, such as angiopoietins, cross talk with VEGF, modulating its effects. Angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) compete for binding to Tie-2 and, while Ang1 promotes vascular stabilization, Ang2 acts as a partial agonist or antagonist of Ang1 signaling, depending on VEGF bioavailability. Aims. To quantify the expression of Ang1, Ang2, Tie-2, VEGF, and KDR by real-time polymerase chain reaction (PCR) in human corpus cavernosum (CC) from young and aged healthy individuals. Methods. Human CC fragments were obtained from organ donors without known risk factors to ED and divided in two groups: young (16-35 years) and aged (59-74 years). RNA was extracted and converted to cDNA. Real-time PCR reactions employed appropriate primers. KDR, Tie-2, Akt, and phospho-Akt protein levels were also assessed by Western blotting (WB). Computer-assisted evaluation of vascular areas was performed. Main Outcome Measures. Study of angiopoietins-Tie-2 and VEGF-KDR systems in human CC during aging by real-time PCR and WB. The ratios Ang1/Tie-2 and VEGF/KDR and Akt levels were also determined. Results. Real-time PCR results showed a sixfold significant reduction in the Ang1/Tie-2 ratio during aging. Ang2, VEGF, and KDR expression results were highly variable. Nevertheless, the ratio VEGF/KDR was significantly higher in the aged individuals. Akt and phospho-Akt levels were similar in both groups. Immunohistological evaluation revealed a significant decrease in vascular areas and endothelial surface in CC with aging, despite no differences found in vessel number. Conclusions. The obtained results suggest an aging-associated downregulation of angiopoietins/Tie-2 system and an apparent compensatory upregulation of the VEGF/KDR system.
KW - Aging
KW - Angiopoietins
KW - Downstream modulation of angiogenic regulation mechanisms
KW - Erectile dysfunction
KW - Human penile tissue
KW - VEGF
UR - http://www.scopus.com/inward/record.url?scp=79955144117&partnerID=8YFLogxK
U2 - 10.1111/j.1743-6109.2010.02116.x
DO - 10.1111/j.1743-6109.2010.02116.x
M3 - Article
C2 - 21091880
AN - SCOPUS:79955144117
SN - 1743-6095
VL - 8
SP - 1341
EP - 1351
JO - Journal of Sexual Medicine
JF - Journal of Sexual Medicine
IS - 5
ER -