The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells
Indiana University-Purdue University Indianapolis (IUPUI) === 17-β estradiol (E2) exerts protective effects in hypoxia-induced pulmonary hypertension (HPH) via endothelial cell estrogen receptor (ER)-dependent mechanisms. However, the effects of hypoxia on ER expression in the pulmonary-right ventri...
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ndltd-IUPUI-oai-scholarworks.iupui.edu-1805-40872019-05-10T15:21:25Z The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells Selej, Mona M.A. Lahm, Tim Petrache, Irina Schweitzer, Kelly S. ER-β HIF-1α Right Ventricle Lung Pulmonary Artery Endothelial Cell Hypoxia Pulmonary Hypertension 17beta Estradiol Pulmonary hypertension -- Research -- Methodology -- Evaluation Estradiol -- Research -- Methodology -- Evaluation Endothelial cells -- Research Selective estrogen receptor modulators Hypoxia (Water) -- Research Heart -- Right ventricle Heart --Left ventricle Western immunoblotting Pulmonary artery -- Research Cellular signal transduction Blood-vessels -- Diseases Phenotype -- Research Indiana University-Purdue University Indianapolis (IUPUI) 17-β estradiol (E2) exerts protective effects in hypoxia-induced pulmonary hypertension (HPH) via endothelial cell estrogen receptor (ER)-dependent mechanisms. However, the effects of hypoxia on ER expression in the pulmonary-right ventricle (RV) axis remain unknown. Based on previous data suggesting a role of ER-β in mediating E2 protection, we hypothesized that hypoxia selectively up-regulates ER-β in the lung and pulmonary endothelial cells. In our Male Sprague-Dawley rat model, chronic hypoxia exposure (10% FiO2) resulted in a robust HPH phenotype associated with significant increases in ER- β but not ER-α protein in the lung via western blotting. More importantly, this hypoxia-induced ER-β increase was not replicated in the RV, left ventricle (LV) or in the liver. Hence, hypoxia-induced ER-β up-regulation appears to be lung-specific. Ex vivo, hypoxia exposure time-dependently up-regulated ER-β but not ER-α in cultured primary rat pulmonary artery endothelial cells (RPAECs) exposed to hypoxia (1% O2) for 4, 24 or 72h. Furthermore, the hypoxia induced ER-β protein abundance, while not accompanied by increases in its own transcript, was associated with ER-β nuclear translocation, suggesting increase in activity as well as post-transcriptional up-regulation of ER-β. Indeed, the requirement for ER-β activation was indicated in hypoxic ER-βKO mice where administration of E2 failed to inhibit hypoxia-induced pro-proliferative ERK1/2 signaling. Interestingly, HIF-1α accumulation was noted in lung tissue of hypoxic ER-βKO mice; consistent with previously reported negative feedback of ER-β on HIF-1α protein and transcriptional activation. In RAPECs, HIF-1 stabilization and overexpression did not replicate the effects of ER- β up-regulation seen in gas hypoxia; suggestive that HIF-1α is not sufficient for ER-β up- regulation. Similarly, HIF-1 inhibition with chetomin did not result in ER-β down-regulation. HIF-1α knockdown in RPAECs in hypoxic conditions is currently being investigated. Hypoxia increases ER- β, but not ER-α in the lung and lung vascular cells. Interpreted in context of beneficial effects of E2 on hypoxic PA and RV remodeling, our data suggest a protective role for ER-β in HPH. The mechanisms by which hypoxia increases ER-β appears to be post-transcriptional and HIF-1α independent. Elucidating hypoxia-related ER-β signaling pathways in PAECs may reveal novel therapeutic targets in HPH. 2014-03-12T17:09:07Z 2014-03-12T17:09:07Z 2014-03-12 Thesis http://hdl.handle.net/1805/4087 en_US |
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ER-β HIF-1α Right Ventricle Lung Pulmonary Artery Endothelial Cell Hypoxia Pulmonary Hypertension 17beta Estradiol Pulmonary hypertension -- Research -- Methodology -- Evaluation Estradiol -- Research -- Methodology -- Evaluation Endothelial cells -- Research Selective estrogen receptor modulators Hypoxia (Water) -- Research Heart -- Right ventricle Heart --Left ventricle Western immunoblotting Pulmonary artery -- Research Cellular signal transduction Blood-vessels -- Diseases Phenotype -- Research |
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ER-β HIF-1α Right Ventricle Lung Pulmonary Artery Endothelial Cell Hypoxia Pulmonary Hypertension 17beta Estradiol Pulmonary hypertension -- Research -- Methodology -- Evaluation Estradiol -- Research -- Methodology -- Evaluation Endothelial cells -- Research Selective estrogen receptor modulators Hypoxia (Water) -- Research Heart -- Right ventricle Heart --Left ventricle Western immunoblotting Pulmonary artery -- Research Cellular signal transduction Blood-vessels -- Diseases Phenotype -- Research Selej, Mona M.A. The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells |
description |
Indiana University-Purdue University Indianapolis (IUPUI) === 17-β estradiol (E2) exerts protective effects in hypoxia-induced pulmonary hypertension (HPH) via endothelial cell estrogen receptor (ER)-dependent mechanisms. However, the effects of hypoxia on ER expression in the pulmonary-right ventricle (RV) axis remain unknown. Based on previous data suggesting a role of ER-β in mediating E2 protection, we hypothesized that hypoxia selectively up-regulates ER-β in the lung and pulmonary endothelial cells.
In our Male Sprague-Dawley rat model, chronic hypoxia exposure (10% FiO2) resulted in a robust HPH phenotype associated with significant increases in ER- β but not ER-α protein in the lung via western blotting. More importantly, this hypoxia-induced ER-β increase was not replicated in the RV, left ventricle (LV) or in the liver. Hence, hypoxia-induced ER-β up-regulation appears to be lung-specific. Ex vivo, hypoxia exposure time-dependently up-regulated ER-β but not ER-α in cultured primary rat pulmonary artery endothelial cells (RPAECs) exposed to hypoxia (1% O2) for 4, 24 or 72h. Furthermore, the hypoxia induced ER-β protein abundance, while not accompanied by increases in its own transcript, was associated with ER-β nuclear translocation, suggesting increase in activity as well as post-transcriptional up-regulation of ER-β.
Indeed, the requirement for ER-β activation was indicated in hypoxic ER-βKO mice where administration of E2 failed to inhibit hypoxia-induced pro-proliferative ERK1/2 signaling. Interestingly, HIF-1α accumulation was noted in lung tissue of hypoxic ER-βKO mice; consistent with previously reported negative feedback of ER-β on HIF-1α protein and transcriptional activation. In RAPECs, HIF-1 stabilization and overexpression did not replicate the effects of ER- β up-regulation seen in gas hypoxia; suggestive that HIF-1α is not sufficient for ER-β up- regulation. Similarly, HIF-1 inhibition with chetomin did not result in ER-β down-regulation. HIF-1α knockdown in RPAECs in hypoxic conditions is currently being investigated.
Hypoxia increases ER- β, but not ER-α in the lung and lung vascular cells. Interpreted in context of beneficial effects of E2 on hypoxic PA and RV remodeling, our data suggest a protective role for ER-β in HPH. The mechanisms by which hypoxia increases ER-β appears to be post-transcriptional and HIF-1α independent. Elucidating hypoxia-related ER-β signaling pathways in PAECs may reveal novel therapeutic targets in HPH. |
author2 |
Lahm, Tim |
author_facet |
Lahm, Tim Selej, Mona M.A. |
author |
Selej, Mona M.A. |
author_sort |
Selej, Mona M.A. |
title |
The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells |
title_short |
The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells |
title_full |
The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells |
title_fullStr |
The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells |
title_full_unstemmed |
The effect of hypoxia on ER-β expression in the lung and cultured pulmonary artery endothelial cells |
title_sort |
effect of hypoxia on er-β expression in the lung and cultured pulmonary artery endothelial cells |
publishDate |
2014 |
url |
http://hdl.handle.net/1805/4087 |
work_keys_str_mv |
AT selejmonama theeffectofhypoxiaonerbexpressioninthelungandculturedpulmonaryarteryendothelialcells AT selejmonama effectofhypoxiaonerbexpressioninthelungandculturedpulmonaryarteryendothelialcells |
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