Angiotensin II up-regulates angiotensin I-converting enzyme (ACE), but down-regulates ACE2 via the AT1-ERK/p38 MAP kinase pathway
| Autor: | Vijay Koka, Xiao R. Huang, Arthur Ck Chung, Wansheng Wang, Hui Y. Lan, Luan D. Truong |
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| Rok vydání: | 2008 |
| Předmět: |
MAPK/ERK pathway
Adult Male medicine.medical_specialty Hypertension Renal Biology Peptidyl-Dipeptidase A Kidney p38 Mitogen-Activated Protein Kinases Receptor Angiotensin Type 1 Pathology and Forensic Medicine Cell Line Internal medicine Renin–angiotensin system medicine Humans Aged Aged 80 and over Mitogen-Activated Protein Kinase 1 Angiotensin II receptor type 1 Mitogen-Activated Protein Kinase 3 Angiotensin II Myocardium Kidney metabolism Angiotensin-converting enzyme Middle Aged Losartan Endocrinology Gene Expression Regulation Organ Specificity Angiotensin-converting enzyme 2 Hypertension biology.protein Female Angiotensin-Converting Enzyme 2 hormones hormone substitutes and hormone antagonists medicine.drug Signal Transduction Regular Articles |
| Zdroj: | The American journal of pathology. 172(5) |
| ISSN: | 1525-2191 |
| Popis: | The recent discovery of the angiotensin II (Ang II)-breakdown enzyme, angiotensin I converting enzyme (ACE) 2, suggests the importance of Ang II degradation in hypertension. The present study explored the signaling mechanism by which ACE2 is regulated under hypertensive conditions. Real-time PCR and immunohistochemistry showed that ACE2 mRNA and protein expression levels were high, whereas ACE expression levels were moderate in both normal kidney and heart. In contrast, patients with hypertension showed marked ACE up-regulation and ACE2 down-regulation in both hypertensive cardiopathy and, particularly, hypertensive nephropathy. The inhibition of ACE2 expression was shown to be associated with ACE up-regulation and activation of extracellular regulated (ERK)1/2 and p38 mitogen-activated protein (MAP) kinases. In vitro, Ang II was able to up-regulate ACE and down-regulate ACE2 in human kidney tubular cells, which were blocked by an angiotensin II (AT)1 receptor antagonist (losartan), but not by an AT2 receptor blocker (PD123319). Furthermore, blockade of ERK1/2 or p38 MAP kinases by either specific inhibitors or a dominant-negative adenovirus was able to abolish Ang II-induced ACE2 down-regulation in human kidney tubular cells. In conclusion, Ang II is able to up-regulate ACE and down-regulate ACE2 expression levels under hypertensive conditions both in vivo and in vitro. The AT1 receptor-mediated ERK/p38 MAP kinase signaling pathway may be a key mechanism by which Ang II down-regulates ACE2 expression, implicating an ACE/ACE2 imbalance in hypertensive cardiovascular and renal damage. |
| Databáze: | OpenAIRE |
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