Background: Angiotensin I-converting enzyme inhibitors and angiotensin receptor blockers protect podocytes more effectively than other anti-hypertensive drugs. Transgenic rats overexpressing angiotensin II Type 1 (AT1) receptor selectively in podocytes have been shown to develop glomerulosclerosis. The prevailing hypothesis is that angiotensin II has a capacity of directly acting on the AT1 receptor of podocytes to induce injury. We therefore investigated the mechanism of reno-protective effect of AT1 receptor in a mouse model of HIV-1 nephropathy.
Methods: We generated transgenic mice carrying the HIV-1 gene (control/HIV-1) or both HIV-1 gene and podocyte-selectively nullified AT1 gene (AT1KO/HIV-1). In these mice, we measured urinary protein or albumin excretion and performed histological analysis.
Results: At 8 months of age, AT1KO/HIV-1 (n = 13) and control/HIV-1 (n = 15) mice were statistically indistinguishable with respect to urinary albumin/creatinine ratio (median 2.5 versus 9.1 mg/mg), glomerulosclerosis (median 0.63 versus 0.45 on 0-4 scale) and downregulation of nephrin (median 6.90 versus 7.02 on 0-8 scale). In contrast to the observed lack of effect of podocyte-specific AT1KO, systemic AT1 inhibition with AT1 blocker (ARB) significantly attenuated proteinuria and glomerulosclerosis in HIV-1 mice.
Conclusion: These results indicate that the protective effect of ARB is mediated through its receptors on cells other than podocytes, such as efferent arteriolar smooth muscle cells.
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http://dx.doi.org/10.1093/ndt/gfs033 | DOI Listing |
Acta Physiol (Oxf)
February 2025
Department of Molecular Medicine, Cardiovascular and Renal Research Unit, University of Southern Denmark, Odense M, Denmark.
The Renin-Angiotensin System (RAS) is a complex neuroendocrine system consisting of a single precursor protein, angiotensinogen (AGT), which is processed into various peptide hormones, including the angiotensins [Ang I, Ang II, Ang III, Ang IV, Ang-(1-9), Ang-(1-7), Ang-(1-5), etc] and Alamandine-related peptides [Ang A, Alamandine, Ala-(1-5)], through intricate enzymatic pathways. Functionally, the RAS is divided into two axes with opposing effects: the classical axis, primarily consisting of Ang II acting through the AT receptor (ATR), and in contrast the protective axis, which includes the receptors Mas, ATR and MrgD and their respective ligands. A key area of RAS research is to gain a better understanding how signaling cascades elicited by these receptors lead to either "classical" or "protective" effects, as imbalances between the two axes can contribute to disease.
View Article and Find Full Text PDFJ Recept Signal Transduct Res
January 2025
Department of Pharmaceutical Sciences, Barry and Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, USA.
The proliferative effects of angiotensin (Ang) II in vascular smooth muscle cells (VSMCs) through its ability to stimulate extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway have been established. The main goal of this study was to explore whether Ang III induces ERK1/2 MAPK and VSMC proliferation in cultured Wistar VSMCs. Further, the Ang III actions were compared to those observed in VSMCs derived from the spontaneously hypertensive rat (SHR).
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Cardiology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510800, China.
Irbesartan improves ventricular remodeling (VR) following myocardial infarction (MI). This study investigates whether irbesartan attenuates VR by reducing aldosterone production in the heart and its underlying mechanisms. MI was induced in male Sprague-Dawley rats through coronary artery ligation.
View Article and Find Full Text PDFBMC Pregnancy Childbirth
January 2025
Collection Biologique de L'Hôpital de La Mère Et de L'Enfant CB-HME (Mother and Child Biobank), University Hospital Center, 8 Avenue Dominique Larrey, Limoges, France.
Background: Maternal agonistic autoantibodies against the angiotensin II type 1 receptor (AT1-AAs) have been implicated in the pathophysiology of preeclampsia, but their presence in their offsprings and their possible neonatal effects have not been specifically explored. This prospective study aimed to evaluate the presence of AT1-AAs and their potential clinical effects in neonates of AT1-AAs positive mothers.
Methods: Women with preeclampsia and their neonates were included.
Endocr Res
December 2024
Department of Biology, College of Science, Salahaddin University-Erbil, Erbil, Kurdistan Region, Iraq.
Background: In patients with diabetes mellitus (DM), vascular endothelial dysfunction (VED) is the main reason for impaired life expectancy. Melatonin (MEL) demonstrates wide-ranging effects across various organs and exhibits pleiotropic characteristics. The current study aims to investigate the modulatory roles of MEL vascular response to angiotensin II (Ang II) and its receptors including angiotensin type 1 receptor (AT-1 R) and angiotensin type 2 receptor (AT-2 R) in isolated thoracic aorta of non-diabetes (non-DM) and diabetes (DM) rats.
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