Shear Stress Regulates Angiotensin Type 1 Receptor Expression in Endothelial Cells
Bibliographic record
Abstract
RATIONALE: Shear stress (SS) has an established role in atherosclerotic plaque localization, but how it exerts its protective effect is not fully understood. OBJECTIVE: To test the hypothesis that SS may downregulate angiotensin type 1 receptors (AT(1)Rs). Angiotensin II has been shown to be proinflammatory and to promote atherosclerosis. METHODS AND RESULTS: Using immunohistochemistry, we found a pronounced expression of AT(1)R in the inner, atheroprone regions of the aortic arch of C57BL/6 and endothelial NO synthase-deficient (eNOS(-/-)) mice but not eNOS-overexpressing mice. In human umbilical vein endothelial cells (HUVECs), laminar SS (15 dyn/cm(2)) induced a biphasic decrease in AT(1)R protein expression characterized by a first reduction at 1 hour (31+/-4% of static control, P<0.01), partial recovery at 3 hours (65+/-9%), and a second more prolonged decline at 6, 12, and 24 hours (48+/-9%, 36+/-9%, 33+/-5%, respectively, P<0.05). One and 24 hours of SS significantly reduced fluorescent angiotensin binding compared to static HUVECs. Shear-induced downregulation of AT(1)R was abolished by treatment with protein kinase A and G inhibitors or N(G)-nitro-l-arginine methyl ester (L-NAME). Fittingly, stimulating static HUVECs with an NO donor decreased AT(1)R protein levels. RT-PCR revealed a significant (P<0.05) decrease of AT(1)R mRNA in HUVECs exposed to SS during 3 (6+/-2% of static control), 6 (4+/-1%), 12 (4+/-1%), and 24 hours (15+/-4%), suggesting a transcriptional downregulation of AT(1)R at length. Finally, angiotensin-induced vascular cell adhesion molecule was abated in HUVECs exposed to SS and in the outer aortic arch of mice. CONCLUSIONS: Our results demonstrate that SS may convey some of its atheroprotective effects through downregulation of AT(1)R in endothelial cells.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".