GTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertension
Endothelial progenitor cells (EPCs) are both reduced and dysfunctional in hypertension that correlates inversely with its mortality, but the mechanisms are poorly understood. Endothelial nitric oxide synthase (eNOS) critically regulates EPC mobilization and function but is uncoupled in salt-sensitiv...
| Main Authors: | , , , , , |
|---|---|
| Format: | Journal article |
| Language: | English |
| Published: |
2010
|
| _version_ | 1797053733513723904 |
|---|---|
| author | Xie, H Zhou, S Chen, D Channon, K Su, D Chen, A |
| author_facet | Xie, H Zhou, S Chen, D Channon, K Su, D Chen, A |
| author_sort | Xie, H |
| collection | OXFORD |
| description | Endothelial progenitor cells (EPCs) are both reduced and dysfunctional in hypertension that correlates inversely with its mortality, but the mechanisms are poorly understood. Endothelial nitric oxide synthase (eNOS) critically regulates EPC mobilization and function but is uncoupled in salt-sensitive hypertension because of the reduced cofactor tetrahydrobiopterin (BH4). We tested the hypothesis that GTP cyclohydrolase I (GTPCH I), the rate-limiting enzyme of BH4 de novo synthesis, protects EPCs and its function in deoxycorticosterone acetate (DOCA)-salt mice. EPCs were isolated from peripheral blood and bone marrow of wild-type (WT), WT DOCA-salt, endothelial-specific GTPCH transgenic (Tg-GCH), GTPCH transgenic DOCA-salt, and BH4-deficient hph-1 mice. In WT DOCA-salt and hph-1 mice, EPCs were significantly decreased with impaired angiogenesis and adhesion, which were restored in Tg-GCH DOCA-salt mice. Superoxide (O2) and nitric oxide (NO) levels in EPCs were elevated and reduced, respectively, in WT DOCA-salt and hph-1 mice; both were rescued in Tg-GCH DOCA-salt mice. eNOS-/-GCH+/- hybrid mice demonstrated that GTPCH preserved the circulating EPC number, reduced intracellular O2 in EPCs, and ameliorated EPC dysfunction independent of eNOS in DOCA-salt hypertension. Secreted thrombospondin-1 (TSP-1; a potent angiogenesis inhibitor) from EPCs was elevated in WT DOCA-salt and hph-1 but not DOCA-salt Tg-GCH mice. In vitro treatment with BH4, polyethylene glycol-superoxide dismutase (PEG-SOD), or Nomega-nitro-L-arginine (L-NNA) significantly augmented NO and reduced TSP-1 and O2 levels from EPCs of WT DOCA-salt mice. These results demonstrated, for the first time, that the GTPCH/BH4 pathway critically regulates EPC number and function in DOCA-salt hypertensive mice, at least in part, via suppressing TSP-1 expression and oxidative stress. © 2010 American Heart Association, Inc. |
| first_indexed | 2024-03-06T18:47:50Z |
| format | Journal article |
| id | oxford-uuid:0f22ab98-b8b9-4859-881d-66636fa46b12 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T18:47:50Z |
| publishDate | 2010 |
| record_format | dspace |
| spelling | oxford-uuid:0f22ab98-b8b9-4859-881d-66636fa46b122022-03-26T09:49:45ZGTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertensionJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:0f22ab98-b8b9-4859-881d-66636fa46b12EnglishSymplectic Elements at Oxford2010Xie, HZhou, SChen, DChannon, KSu, DChen, AEndothelial progenitor cells (EPCs) are both reduced and dysfunctional in hypertension that correlates inversely with its mortality, but the mechanisms are poorly understood. Endothelial nitric oxide synthase (eNOS) critically regulates EPC mobilization and function but is uncoupled in salt-sensitive hypertension because of the reduced cofactor tetrahydrobiopterin (BH4). We tested the hypothesis that GTP cyclohydrolase I (GTPCH I), the rate-limiting enzyme of BH4 de novo synthesis, protects EPCs and its function in deoxycorticosterone acetate (DOCA)-salt mice. EPCs were isolated from peripheral blood and bone marrow of wild-type (WT), WT DOCA-salt, endothelial-specific GTPCH transgenic (Tg-GCH), GTPCH transgenic DOCA-salt, and BH4-deficient hph-1 mice. In WT DOCA-salt and hph-1 mice, EPCs were significantly decreased with impaired angiogenesis and adhesion, which were restored in Tg-GCH DOCA-salt mice. Superoxide (O2) and nitric oxide (NO) levels in EPCs were elevated and reduced, respectively, in WT DOCA-salt and hph-1 mice; both were rescued in Tg-GCH DOCA-salt mice. eNOS-/-GCH+/- hybrid mice demonstrated that GTPCH preserved the circulating EPC number, reduced intracellular O2 in EPCs, and ameliorated EPC dysfunction independent of eNOS in DOCA-salt hypertension. Secreted thrombospondin-1 (TSP-1; a potent angiogenesis inhibitor) from EPCs was elevated in WT DOCA-salt and hph-1 but not DOCA-salt Tg-GCH mice. In vitro treatment with BH4, polyethylene glycol-superoxide dismutase (PEG-SOD), or Nomega-nitro-L-arginine (L-NNA) significantly augmented NO and reduced TSP-1 and O2 levels from EPCs of WT DOCA-salt mice. These results demonstrated, for the first time, that the GTPCH/BH4 pathway critically regulates EPC number and function in DOCA-salt hypertensive mice, at least in part, via suppressing TSP-1 expression and oxidative stress. © 2010 American Heart Association, Inc. |
| spellingShingle | Xie, H Zhou, S Chen, D Channon, K Su, D Chen, A GTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertension |
| title | GTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertension |
| title_full | GTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertension |
| title_fullStr | GTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertension |
| title_full_unstemmed | GTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertension |
| title_short | GTP cyclohydrolase I/BH4 pathway protects EPCs via suppressing oxidative stress and thrombospondin-1 in salt-sensitive hypertension |
| title_sort | gtp cyclohydrolase i bh4 pathway protects epcs via suppressing oxidative stress and thrombospondin 1 in salt sensitive hypertension |
| work_keys_str_mv | AT xieh gtpcyclohydrolaseibh4pathwayprotectsepcsviasuppressingoxidativestressandthrombospondin1insaltsensitivehypertension AT zhous gtpcyclohydrolaseibh4pathwayprotectsepcsviasuppressingoxidativestressandthrombospondin1insaltsensitivehypertension AT chend gtpcyclohydrolaseibh4pathwayprotectsepcsviasuppressingoxidativestressandthrombospondin1insaltsensitivehypertension AT channonk gtpcyclohydrolaseibh4pathwayprotectsepcsviasuppressingoxidativestressandthrombospondin1insaltsensitivehypertension AT sud gtpcyclohydrolaseibh4pathwayprotectsepcsviasuppressingoxidativestressandthrombospondin1insaltsensitivehypertension AT chena gtpcyclohydrolaseibh4pathwayprotectsepcsviasuppressingoxidativestressandthrombospondin1insaltsensitivehypertension |