Functional Exploration of Conserved Sequences in the Distal Face of Angiotensinogen-Brief Report.
Arterioscler Thromb Vasc Biol
; 43(8): 1524-1532, 2023 08.
Article
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| MEDLINE
| ID: mdl-37345525
ABSTRACT
BACKGROUND:
Angiotensinogen (AGT) is an essential component in the renin-angiotensin system. AGT has highly conserved sequences in the loop and ß-sheet regions among species; however, their functions have not been studied.METHODS:
Adeno-associated viral vector (AAV) serotype 2/8 encoding mouse AGT with mutations of conserved sequences in the loop (AAV.loop-Mut), ß-sheet (AAV.ßsheet-Mut), or both regions (AAV.loop/ßsheet-Mut) was injected into male hepatocyte-specific AGT-deficient (hepAGT-/-) mice in an LDL (low-density lipoprotein) receptor-deficient background. AAV containing mouse wild-type AGT (AAV.mAGT) or a null vector (AAV.null) were used as controls. Two weeks after AAV administration, all mice were fed a western diet for 12 weeks. To determine how AGT secretion is regulated in hepatocytes, AAVs containing the above mutations were transducted into HepG2 cells.RESULTS:
In hepAGT-/- mice infected with AAV.loop-Mut or ßsheet-Mut, plasma AGT concentrations, systolic blood pressure, and atherosclerosis were comparable to those in AAV.mAGT-infected mice. Interestingly, plasma AGT concentrations, systolic blood pressure, and atherosclerotic lesion size in hepAGT-/- mice infected with AAV.loop/ßsheet-Mut were not different from mice infected with AAV.null. In contrast, hepatic Agt mRNA abundance was elevated to a comparable magnitude as AAV.mAGT-infected mice. Immunostaining showed that AGT protein was accumulated in hepatocytes of mice infected with AAV.loop/ßsheet-Mut or HepG2 cells transducted with AAV.loop/ßsheet-Mut. Accumulated AGT was not located in the endoplasmic reticulum.CONCLUSIONS:
The conserved sequences in either the loop or ß-sheet region individually have no effect on AGT regulation, but the conserved sequences in both regions synergistically contribute to the secretion of AGT from hepatocytes.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Angiotensinógeno
Límite:
Animals
Idioma:
En
Revista:
Arterioscler Thromb Vasc Biol
Asunto de la revista:
ANGIOLOGIA
Año:
2023
Tipo del documento:
Article