Abstract 19126: Endothelial-specific Deletion of Prolyl Hydroxylase Domain Protein 2 (PHD2) Results in Severe Pulmonary Hypertension in Mice by Enhancing the HIF2alpha Signaling Pathway

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Haiyang Tang ◽  
Yali Gu ◽  
Ramon Aryon ◽  
Shanshan Song ◽  
Ruby A Fernandez ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Remodeling ◽  
Normoxic Condition ◽  
Severe Pulmonary Hypertension ◽  
Pulmonary Arterial ◽  
Domain Protein ◽  
Specific Deletion

Rationale: Sustained pulmonary vasoconstriction and excessive vascular remodeling are major causes of elevated pulmonary vascular resistance which leads to increased pulmonary arterial pressure in patients with pulmonary hypertension. Hypoxic-inducible factor (HIF) and its upstream regulators have been linked to the hypoxia response in vascular remodeling and the development of pulmonary hypertension. In this study, we aimed at defining whether increased HIF1α and/or HIF2α, due to endothelial cell specific deletion of prolyl hydroxylase domain protein 2 (PHD2) under normoxic condition are involved in or required for the initiation and progression of pulmonary hypertension. Methods: PHD2, HIF1α and HIF2α conditional knockout mice were created. Right ventricle systolic pressures (RVSP), right ventricular hypertrophy by RV/(LV+S) ratios, and small pulmonary artery smooth muscle layer thickness were measured. Pulmonary arterial smooth muscle cells (PASMCs) and pulmonary arterial endothelial cells (PAECs) were isolated from wild type (WT) or knockout (KO) mice, followed with cell-based assays. Results: We report here that mice with targeted deletion of PHD2 developed severe pulmonary hypertension under normoxic condition. Conditional and inducible deletion of HIF2α in endothelial cells, but not smooth muscle cells, dramatically protected mice from hypoxia-induced pulmonary hypertension. HIF2α KO mice had significantly lower RVSP, RV/(LV+S) ratios, and displayed less pulmonary vascular remodeling when exposed to hypoxia compared to their WT mice. Conclusion: This work shows that the endothelium is responsible for the development of pulmonary hypertension and it demonstrates a crucial role of PHD2/HIF signaling for hypoxic response in pulmonary hypertension. These findings unveil temporally and spatially distinct functions for HIFs in the development of pulmonary hypertension.

scholarly journals Eplerenone Improves Pulmonary Vascular Remodeling and Hypertension by Inhibition of the Mineralocorticoid Receptor in Endothelial Cells

Hypertension ◽  
2021 ◽  
Author(s):  
Jessica Kowalski ◽  
Lisa Deng ◽  
Chiara Suennen ◽  
Duygu Koca ◽  
David Meral ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Remodeling ◽  
Mineralocorticoid Receptor ◽  
Chronic Hypoxia ◽  
Cell Type ◽  
Pulmonary Vascular Remodeling ◽  
Cell Type Specific

Pulmonary hypertension is characterized by progressive remodeling of the pulmonary arteries, however, this is not therapeutically targeted yet. Aldosterone and the MR (mineralocorticoid receptor) are key drivers of cardiovascular disease, and there is a growing body of evidence suggesting a role in pulmonary hypertension. Thus, the aim of this study was to investigate the impact of cell type-specific deletion of MR on pulmonary vascular remodeling. To induce pulmonary hypertension, mice were exposed to chronic hypoxia for 6 weeks. Treatment with the MR antagonist eplerenone attenuated pulmonary vascular remodeling, hypertension, and right ventricular dysfunction. In contrast, aldosterone infusion via osmotic minipumps induced pulmonary vascular remodeling. We created 4 different mouse models with cell type-specific MR deletion in smooth muscle cells, endothelial cells, macrophages, or fibroblasts and exposed them to chronic hypoxia. MR deletion from endothelial cells fully recapitulated the beneficial effects of eplerenone while MR deletion from other cell types had no detectable effect on pulmonary vascular remodeling. RNA-seq from isolated MR-deficient and wildtype pulmonary endothelial cells revealed differentially expressed genes as potential downstream mediators of MR related to pulmonary hypertension, including genes related to the endothelin signaling pathway. MR antagonists improve hypoxia-induced pulmonary vascular remodeling via inhibition of MR in endothelial cells but independent from MR in smooth muscle cells, fibroblasts, or macrophages. The results from this study provide the basis for future investigation of potential downstream mediators of MR involved in pulmonary hypertension and further support the clinical evaluation of MR antagonists in pulmonary hypertension.

Exosomes Derived from Human Pulmonary Artery Endothelial Cells Shift the Balance between Proliferation and Apoptosis of Smooth Muscle Cells

Cardiology ◽  
2017 ◽  
Vol 137 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Lin Zhao ◽  
Hui Luo ◽  
Xiaohui Li ◽  
Tangzhiming Li ◽  
Jingni He ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Muscle Cells ◽  
Apoptosis Resistance ◽  
Proliferation And Apoptosis ◽  
Pulmonary Arterial ◽  
Human Pulmonary Artery

Background: The overproliferation of pulmonary vascular cells is noted in pulmonary hypertension. The role of exosomes from pulmonary artery endothelial cells (PAEC) in the proliferation and apoptosis of pulmonary artery smooth muscle cells (PASMC) remains unclear. Methods: Exosomes were isolated and purified from the culture medium of PAEC using a commercial kit. Lipopolysaccharide (LPS), hypoxia, and hydrogen peroxide were utilized to induce PAEC injury. Coculture of PAEC and PASMC was conducted using Transwell plates, and GW4869 was applied to inhibit exosome release. The proliferation and apoptosis level of PASMC was assayed by MTT assay, apoptosis staining, and cleaved caspase-3 immunoblotting. Plasma exosomes were isolated by differential ultracentrifugation. Results: LPS or hypoxia enhance exosome release from PAEC. Release of PAEC-derived exosomes positively correlates with LPS concentration. The coculture of LPS-disposed PAEC with PASMC leads to overproliferation and apoptosis resistance in PASMC, and the exosome inhibitor GW4869 can partly cancel out this effect. Exosomes derived from PAEC could be internalized into PASMC, and thus promote proliferation and induce apoptosis resistance in PASMC. Idiopathic pulmonary arterial hypertension patients exhibit a higher circulation level of endothelium-derived exosomes. Conclusions: Inflammation and hypoxia could induce PAEC to release exosomes. PAEC- derived exosomes are involved in overproliferation and apoptosis resistance in PASMC, by which they may contribute to the pathogenesis of pulmonary hypertension.

DNA methylation signatures of pulmonary arterial smooth muscle cells in chronic thromboembolic pulmonary hypertension

2018 ◽  
Vol 50 (5) ◽  
pp. 313-322 ◽  
Author(s):  
Ying Wang ◽  
Xiaoxi Huang ◽  
Dong Leng ◽  
Jifeng Li ◽  
Lei Wang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Remodeling ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Arterial ◽  
Arterial Smooth Muscle Cells ◽  
Pulmonary Arterial Smooth Muscle

Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening disease, which is often underpinned by vascular remodeling. Pulmonary arterial smooth muscle cells (PASMCs) are the main participants in vascular remodeling. However, their biological role in CTEPH is not entirely clear. In the present study, we analyzed the whole epigenome-wide DNA methylation profile of cultured PASMCs from CTEPH and control cell lines with the Illumina Human Methylation 450K BeadChip. A total of 6,829 significantly differentially methylated probes (DMPs) were detected between these two groups. Among these, 4,246 DMPs were hypermethylated, while 2,583 DMPs were hypomethylated. The functional enrichment analysis of 1,743 DMPs in the promoter regions and corresponding genes indicated that DNA hypermethylation and hypomethylation might be involved in the regulation of genes that have multifarious biological roles, including roles in cancer-related diseases, the regulation of the actin cytoskeleton, cell adhesion, and pattern specification processes. The observed methylations were categorized into the most important functions, including those involved in cell proliferation, immunity, and migration. We speculate that these methylations were most likely involved in the possible pathophysiology of CTEPH. Gene interaction analysis pertaining to signal networks confirmed that PIK3CA and PIK3R1 were important mediators in these whole networks. The mRNA levels of PIK3CA, HIC1, and SSH1 were verified by qPCR and corresponded with DNA methylation differences. Understanding epigenetic features associated with CTEPH may provide new insights into the mechanism that underlie this condition.

Enhance Smooth Muscle Cells Apoptosis Associated With Pulmonary Arterial Remodeling in Dogs Affected With Pulmonary Hypertension Secondary to Degenerative Mitral Valve Disease

2021 ◽  
Author(s):  
Siriwan Sakarin ◽  
Anudep Rungsipipat ◽  
Sirilak Disatian Surachetpong
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Mitral Valve ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Mitral Valve Disease ◽  
Caspase 3 ◽  
Muscle Cells ◽  
Pulmonary Arterial ◽  
Medial Thickening

Abstract Background: Degenerative mitral valve disease (DMVD) is the most common cause of pulmonary hypertension (PH) in dogs. Medial thickening of the pulmonary artery is a major histopathological change in PH. A decrease in apoptosis of pulmonary arterial smooth muscle cells (SMCs) may be the cause of medial thickening. This study aimed to demonstrate the expression of apoptosis molecules in the pulmonary artery of dogs affected with PH secondary to DMVD (DMVD+PH) compared to DMVD without PH (DMVD) and healthy dogs (control). Lung samples were collected from three groups including control (n=5), DMVD (n=7) and DMVD+PH (n=7) groups. Masson trichrome and apoptotic proteins including Bax, Bcl2 and caspase-3 and -8, were stained. Results: The medial thickness in the DMVD and DMVD+PH groups was greater than in the control group and it was greatest in the DMVD+PH group. Bax, Bcl2 and caspase-3 and -8 were expressed mainly in the medial layer of the pulmonary artery. The percentages of Bax and caspase-3 and -8 positive cells were higher in the DMVD group compared to the DMVD+PH group, whereas the percentage of Bcl2-positive cells was increased in the DMVD and DMVD+PH groups. These findings suggested that apoptosis of pulmonary arterial SMCs occurred mainly in the DMVD group and decreased dramatically in the DMVD+PH group. Conclusions: An increase in the medial thickness in dogs affected with PH secondary to DMVD may occur due to a decrease in apoptosis of pulmonary arterial SMCs.

scholarly journals Untargeted Metabolic Profiling Cell-Based Approach of Pulmonary Artery Smooth Muscle Cells in Response to High Glucose and the Effect of the Antioxidant Vitamins D and E

Metabolites ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 87 ◽  
Author(s):  
Abdulwahab Alamri ◽  
Abdulhadi Burzangi ◽  
Paul Coats ◽  
David Watson
Keyword(s):  
Reactive Oxygen Species ◽  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
High Glucose ◽  
Muscle Cells ◽  
Oxygen Species ◽  
Pulmonary Arterial ◽  
Pulmonary Artery Smooth Muscle

Pulmonary arterial hypertension (PAH) is a multi-factorial disease characterized by the hyperproliferation of pulmonary artery smooth muscle cells (PASMCs). Excessive reactive oxygen species (ROS) formation resulted in alterations of the structure and function of pulmonary arterial walls, leading to right ventricular failure and death. Diabetes mellitus has not yet been implicated in pulmonary hypertension. However, recently, variable studies have shown that diabetes is correlated with pulmonary hypertension pathobiology, which could participate in the modification of pulmonary artery muscles. The metabolomic changes in PASMCs were studied in response to 25 mM of D-glucose (high glucose, or HG) in order to establish a diabetic-like condition in an in vitro setting, and compared to five mM of D-glucose (normal glucose, or LG). The effect of co-culturing these cells with an ideal blood serum concentration of cholecalciferol-D3 and tocopherol was also examined. The current study aimed to examine the role of hyperglycemia in pulmonary arterial hypertension by the quantification and detection of the metabolomic alteration of smooth muscle cells in high-glucose conditions. Untargeted metabolomics was carried out using hydrophilic interaction liquid chromatography and high-resolution mass spectrometry. Cell proliferation was assessed by cell viability and the [3H] thymidine incorporation assay, and the redox state within the cells was examined by measuring reactive oxygen species (ROS) generation. The results demonstrated that PASMCs in high glucose (HG) grew, proliferated faster, and generated higher levels of superoxide anion (O2·−) and hydrogen peroxide (H2O2). The metabolomics of cells cultured in HG showed that the carbohydrate pathway, especially that of the upper glycolytic pathway metabolites, was influenced by the activation of the oxidation pathway: the pentose phosphate pathway (PPP). The amount of amino acids such as aspartate and glutathione reduced via HG, while glutathione disulfide, N6-Acetyl-L-lysine, glutamate, and 5-aminopentanoate increased. Lipids either as fatty acids or glycerophospholipids were downregulated in most of the metabolites, with the exception of docosatetraenoic acid and PG (16:0/16:1(9Z)). Purine and pyrimidine were influenced by hyperglycaemia following PPP oxidation. The results in addition showed that cells exposed to 25 mM of glucose were oxidatively stressed comparing to those cultured in five mM of glucose. Cholecalciferol (D3, or vitamin D) and tocopherol (vitamin E) were shown to restore the redox status of many metabolic pathways.

scholarly journals PPARγ regulates hypoxia-induced Nox4 expression in human pulmonary artery smooth muscle cells through NF-κB

2010 ◽  
Vol 299 (4) ◽  
pp. L559-L566 ◽  
Author(s):  
Xianghuai Lu ◽  
Tamara C. Murphy ◽  
Mark S. Nanes ◽  
C. Michael Hart
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Smooth Muscle Cells ◽  
Vascular Remodeling ◽  
Promoter Activity ◽  
Vascular Wall ◽  
Pulmonary Artery Smooth Muscle ◽  
Human Pulmonary Artery ◽  
Stimulation Of

NADPH oxidases are a major source of superoxide production in the vasculature. The constitutively active Nox4 subunit, which is selectively upregulated in the lungs of human subjects and experimental animals with pulmonary hypertension, is highly expressed in vascular wall cells. We demonstrated that rosiglitazone, a synthetic agonist of the peroxisome proliferator-activated receptor-γ (PPARγ), attenuated hypoxia-induced pulmonary hypertension, vascular remodeling, Nox4 induction, and reactive oxygen species generation in the mouse lung. The current study examined the molecular mechanisms involved in PPARγ-regulated, hypoxia-induced Nox4 expression in human pulmonary artery smooth muscle cells (HPASMC). Exposing HPASMC to 1% oxygen for 72 h increased Nox4 gene expression and H2O2 production, both of which were reduced by treatment with rosiglitazone during the last 24 h of hypoxia exposure or by treatment with small interfering RNA (siRNA) to Nox4. Hypoxia also increased HPASMC proliferation as well as the activity of a Nox4 promoter luciferase reporter, and these increases were attenuated by rosiglitazone. Chromatin immunoprecipitation assays demonstrated that hypoxia increased binding of the NF-κB subunit, p65, to the Nox4 promoter and that binding was attenuated by rosiglitazone treatment. The role of NF-κB in Nox4 regulation was further supported by demonstrating that overexpression of p65 stimulated Nox4 promoter activity, whereas siRNA to p50 or p65 attenuated hypoxic stimulation of Nox4 promoter activity. These results provide novel evidence for NF-κB-mediated stimulation of Nox4 expression in HPASMC that can be negatively regulated by PPARγ. These data provide new insights into potential mechanisms by which PPARγ activation inhibits Nox4 upregulation and the proliferation of cells in the pulmonary vascular wall to ameliorate pulmonary hypertension and vascular remodeling in response to hypoxia.

Sign in / Sign up

Export Citation Format

Share Document