Angiotensin GPCR Assays
Background of Angiotensin Receptors
The angiotensin receptors family is a group of G protein-coupled receptors binding to angiotensin II (Ang II), including AT1, AT2, and AT4. However, AT4 has a low affinity for Ang II as well as antagonists of AT1 and AT2. The angiotensin receptors are membrane glycoproteins expressed in conjunction with other receptors or miscellaneous proteins that are responsible for maintaining the functions of corresponding receptors and proteins in the renin–angiotensin system, through the signal transduction of the vasoconstricting stimulus of hormone Ang II.
Fig.1. Structure of the angiotensin receptor revealed by serial femtosecond crystallography. (Cianciulli, 2020)
Distribution and Function of Angiotensin Receptors
The AT1 is distributed mainly in the liver, kidney, adrenal gland, and lung, while the AT2 is expressed in the brain, adrenal medulla, heart, and uterus. AT1 receptors mediate several biological functions, including vasoconstriction, aldosterone synthesis and secretion, renal renin inhibition, increased vasopressin secretion, and so on. AT2 receptors are involved in the inhibition of cell growth, fetal tissue development, modulation of extracellular matrix, neuronal regeneration, apoptosis, cellular differentiation, and so on.
Subtypes and Mechanisms of Angiotensin Receptors
The AT1 and AT2 receptors are subtypes of angiotensin receptors. The AT1 receptor couples Gi/Go and Gq/G11 proteins for signal transduction, while the AT2 receptor couples the Gαi protein.
| Receptor | Gene | Mechanism | Agonists | Antagonists |
| AT1 receptor | AGTR1 |
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| AT2 receptor | AGTR2 |
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Assay List of Angiotensin Receptors
Creative Biolabs can provide a range of assays of angiotensin receptors. You can choose the assay in the list or contact us for more information:
Published Data
| Paper Title | Delayed administration of Angiotensin II Type 2 Receptor (AT2R) agonist compound 21 prevents the development of post-stroke cognitive impairment in diabetes through the modulation of microglia polarization |
| Journal | Translational stroke research |
| Published | 2020 |
| Abstract | Stroke may lead to cognitive impairment, i. e. post-stroke cognitive impairment (PSCI). Stroke patients are often accompanied by hypertension and diabetes. The study used a comorbid disease model, the diabetes transformation model induced by a high-fat diet (HFD) and low-dose streptozotocin (STZ) combination, in the preclinical study of the development of PSCI. Compound 21 is a selective AT2R agonist and has been shown by multiple research projects to ameliorate ischemic damage in different models of stroke. In this study, researchers evaluated the application of angiotensin II Type 2 receptor agonist for the PSCI treatment. The antagonist PD123319 was used to identify if the compound 21 effects were mediated through AT2R agonism. The direct effect of compound 21 on microglia polarization was determined in mouse cell lines. |
| Result |
The AT1R leads to the activation of the AT2R, which is due to the increased amount of unbound Ang II able to bind to the AT2R. Delayed administration of compound 21 3 days post-stroke reduced mortality and improved sensorimotor and cognitive deficits. Compound 21 also reduced inflammation and demyelination through modulation of the M1:M2 ratio in diabetic animals. The study has not proven the direct effect of compound 21 on AT2Rs, as the level of AT2Rs within the brain was still controversial.
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Fig.2. Compound 21 directly modulated microglia partly independent of AT2R activation. (Jackson, 2020)
References
- Cianciulli A.; et al. Complement peptide receptors (version 2020.3) in the IUPHAR/BPS Guide to Pharmacology Database. IUPHAR/BPS Guide to Pharmacology CITE. 2020, 2020(3).
- Jackson, L. et al. Delayed administration of angiotensin II type 2 receptor (AT2R) agonist compound 21 prevents the development of post-stroke cognitive impairment in diabetes through the modulation of microglia polarization. Translational stroke research. 2020, 11(4): 762-775.
