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Mathieu NM, Nakagawa P, Grobe JL, Sigmund CD. Insights Into the Role of Angiotensin-II AT 1 Receptor-Dependent β-Arrestin Signaling in Cardiovascular Disease. Hypertension 2024; 81:6-16. [PMID: 37449411 PMCID: PMC10787814 DOI: 10.1161/hypertensionaha.123.19419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
β-arrestins are a family of intracellular signaling proteins that play a key role in regulating the activity of G protein-coupled receptors. The angiotensin-II type 1 receptor is an important G protein-coupled receptor involved in the regulation of cardiovascular function and has been implicated in the progression of cardiovascular diseases. In addition to canonical G protein signaling, G protein-coupled receptors including the angiotensin-II type 1 receptor can signal via β-arrestin. Dysregulation of β-arrestin signaling has been linked to several cardiovascular diseases including hypertension, atherosclerosis, and heart failure. Understanding the role of β-arrestins in these conditions is critical to provide new therapeutic targets for the treatment of cardiovascular disease. In this review, we will discuss the beneficial and maladaptive physiological outcomes of angiotensin-II type 1 receptor-dependent β-arrestin activation in different cardiovascular diseases.
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Affiliation(s)
| | - Pablo Nakagawa
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI
| | - Justin L. Grobe
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI
- Comprehensive Rodent Metabolic Phenotyping Core, Medical College of Wisconsin, Milwaukee, WI
- Department of Biomedical Engineering, Medical College of Wisconsin, Milwaukee, WI
| | - Curt D. Sigmund
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI
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Endocytosis and signaling of angiotensin II type 1 receptor. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 194:141-157. [PMID: 36631190 DOI: 10.1016/bs.pmbts.2022.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A vasoactive octapeptide angiotensin II (Ang II) hormone is the key regulator of the renin-angiotensin system (RAS). It binds with the two different plasma membrane receptors like angiotensin II type 1 (AT1) and type 2 (AT2) and consequence various biological responses occur. Further, AT1 has two subtypes such as AT1A and AT1B. These angiotensin receptors are classified to be G protein-coupled receptors (GPCRs). The main constituent of RAS is the AT1 receptor (AT1R), and its activation, signal transduction, and regulation have been extensively studied. After Ang II stimulation, the ligand-receptor complexes internalized and trafficked through the early endosome, recycling endosome, and some receptors skipped the recycling endosome and trafficked to the lysosome for metabolic degradation. Moreover, some short sequence motifs located in the carboxyl-terminus (CT) of the receptor play a vital role in the internalization, phosphorylation, subcellular trafficking, signaling, and desensitization. Furthermore, in endocytosis, the various proteins interact with the CT region of the receptor. This chapter highlights the basic mechanism of AT1 receptor internalization, trafficking and signaling in both physiological and pathophysiological conditions.
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Beta-Arrestins in the Treatment of Heart Failure Related to Hypertension: A Comprehensive Review. Pharmaceutics 2021. [DOI: 10.3390/pharmaceutics13060838
expr 929824082 + 956151497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
Heart failure (HF) is a complicated clinical syndrome that is considered an increasingly frequent reason for hospitalization, characterized by a complex therapeutic regimen, reduced quality of life, and high morbidity. Long-standing hypertension ultimately paves the way for HF. Recently, there have been improvements in the treatment of hypertension and overall management not limited to only conventional medications, but several novel pathways and their pharmacological alteration are also conducive to the treatment of hypertension. Beta-arrestin (β-arrestin), a protein responsible for beta-adrenergic receptors’ (β-AR) functioning and trafficking, has recently been discovered as a potential regulator in hypertension. β-arrestin isoforms, namely β-arrestin1 and β-arrestin2, mainly regulate cardiac function. However, there have been some controversies regarding the function of the two β-arrestins in hypertension regarding HF. In the present review, we try to figure out the paradox between the roles of two isoforms of β-arrestin in the treatment of HF.
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Rakib A, Eva TA, Sami SA, Mitra S, Nafiz IH, Das A, Tareq AM, Nainu F, Dhama K, Emran TB, Simal-Gandara J. Beta-Arrestins in the Treatment of Heart Failure Related to Hypertension: A Comprehensive Review. Pharmaceutics 2021; 13:838. [PMID: 34198801 PMCID: PMC8228839 DOI: 10.3390/pharmaceutics13060838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 12/24/2022] Open
Abstract
Heart failure (HF) is a complicated clinical syndrome that is considered an increasingly frequent reason for hospitalization, characterized by a complex therapeutic regimen, reduced quality of life, and high morbidity. Long-standing hypertension ultimately paves the way for HF. Recently, there have been improvements in the treatment of hypertension and overall management not limited to only conventional medications, but several novel pathways and their pharmacological alteration are also conducive to the treatment of hypertension. Beta-arrestin (β-arrestin), a protein responsible for beta-adrenergic receptors' (β-AR) functioning and trafficking, has recently been discovered as a potential regulator in hypertension. β-arrestin isoforms, namely β-arrestin1 and β-arrestin2, mainly regulate cardiac function. However, there have been some controversies regarding the function of the two β-arrestins in hypertension regarding HF. In the present review, we try to figure out the paradox between the roles of two isoforms of β-arrestin in the treatment of HF.
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Affiliation(s)
- Ahmed Rakib
- Department of Pharmacy, Faculty of Biological Sciences, University of Chittagong, Chittagong 4331, Bangladesh; (A.R.); (T.A.E.); (S.A.S.)
| | - Taslima Akter Eva
- Department of Pharmacy, Faculty of Biological Sciences, University of Chittagong, Chittagong 4331, Bangladesh; (A.R.); (T.A.E.); (S.A.S.)
| | - Saad Ahmed Sami
- Department of Pharmacy, Faculty of Biological Sciences, University of Chittagong, Chittagong 4331, Bangladesh; (A.R.); (T.A.E.); (S.A.S.)
| | - Saikat Mitra
- Department of Pharmacy, Faculty of Pharmacy, University of Dhaka, Dhaka 1000, Bangladesh;
| | - Iqbal Hossain Nafiz
- Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Chittagong, Chittagong 4331, Bangladesh; (I.H.N.); (A.D.)
| | - Ayan Das
- Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Chittagong, Chittagong 4331, Bangladesh; (I.H.N.); (A.D.)
| | - Abu Montakim Tareq
- Department of Pharmacy, International Islamic University Chittagong, Chittagong 4318, Bangladesh;
| | - Firzan Nainu
- Faculty of Pharmacy, Hasanuddin University, Tamalanrea, Kota Makassar, Sulawesi Selatan 90245, Indonesia;
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly 243122, Uttar Pradesh, India;
| | - Talha Bin Emran
- Department of Pharmacy, BGC Trust University Bangladesh, Chittagong 4381, Bangladesh
| | - Jesus Simal-Gandara
- Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Faculty of Food Science and Technology, University of Vigo–Ourense Campus, E32004 Ourense, Spain
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Inoue K, Tian X, Velazquez H, Soda K, Wang Z, Pedigo CE, Wang Y, Cross E, Groener M, Shin JW, Li W, Hassan H, Yamamoto K, Mundel P, Ishibe S. Inhibition of Endocytosis of Clathrin-Mediated Angiotensin II Receptor Type 1 in Podocytes Augments Glomerular Injury. J Am Soc Nephrol 2019; 30:2307-2320. [PMID: 31511362 PMCID: PMC6900791 DOI: 10.1681/asn.2019010053] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 08/04/2019] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Inhibition of the renin-angiotensin system remains a cornerstone in reducing proteinuria and progression of kidney failure, effects believed to be the result of reduction in BP and glomerular hyperfiltration. However, studies have yielded conflicting results on whether podocyte-specific angiotensin II (AngII) signaling directly induces podocyte injury. Previous research has found that after AngII stimulation, β-arrestin-bound angiotensin II receptor type 1 (AT1R) is internalized in a clathrin- and dynamin-dependent manner, and that Dynamin1 and Dynamin2 double-knockout mice exhibit impaired clathrin-mediated endocytosis. METHODS We used podocyte-specific Dyn double-knockout mice to examine AngII-stimulated AT1R internalization and signaling in primary podocytes and controls. We also examined the in vivo effect of AngII in these double-knockout mice through renin-angiotensin system blockers and through deletion of Agtr1a (which encodes the predominant AT1R isoform expressed in kidney, AT1aR). We tested calcium influx, Rac1 activation, and lamellipodial extension in control and primary podocytes of Dnm double-knockout mice treated with AngII. RESULTS We confirmed augmented AngII-stimulated AT1R signaling in primary Dnm double-knockout podocytes resulting from arrest of clathrin-coated pit turnover. Genetic ablation of podocyte Agtr1a in Dnm double-knockout mice demonstrated improved albuminuria and kidney function compared with the double-knockout mice. Isolation of podocytes from Dnm double-knockout mice revealed abnormal membrane dynamics, with increased Rac1 activation and lamellipodial extension, which was attenuated in Dnm double-knockout podocytes lacking AT1aR. CONCLUSIONS Our results indicate that inhibiting aberrant podocyte-associated AT1aR signaling pathways has a protective effect in maintaining the integrity of the glomerular filtration barrier.
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Affiliation(s)
- Kazunori Inoue
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Xuefei Tian
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Heino Velazquez
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Keita Soda
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Zhen Wang
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Christopher E Pedigo
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Ying Wang
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Elizabeth Cross
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Marwin Groener
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Jee-Won Shin
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Wei Li
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Hossam Hassan
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
| | - Koichi Yamamoto
- Department of Geriatric Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan; and
| | - Peter Mundel
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Shuta Ishibe
- Section of Nephrology, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut;
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Kim HJ, Jang JH, Zhang YH, Yoo HY, Kim SJ. Fast relaxation and desensitization of angiotensin II contraction in the pulmonary artery via AT1R and Akt-mediated phosphorylation of muscular eNOS. Pflugers Arch 2019; 471:1317-1330. [PMID: 31468138 DOI: 10.1007/s00424-019-02305-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 08/08/2019] [Accepted: 08/14/2019] [Indexed: 11/24/2022]
Abstract
Angiotensin II (AngII) triggers a transient contraction of pulmonary arteries (PAs) followed by protracted desensitization. Based on the unconventional eNOS expression in PA smooth muscle cells (PASMCs), we hypothesized that activation of smooth muscle eNOS by AngII might be responsible for fast relaxation and tachyphylaxis. Using dual-wire myograph, mechanically endothelium-denuded rat PA [E(-)PA] showed AngII concentration-dependent transient contractions (ΔTAngII, 95% decay within 1 min), which were abolished by losartan (AT1R antagonist). Neither PD123319 (AT2R antagonist) nor A779 (MasR antagonist) affected ΔTAngII. When the vessels were pretreated with L-NAME (NOS inhibitor), ODQ (guanylate cyclase inhibitor), or KT5823 (PKG inhibitor), ΔTAngII of E(-)PA became larger and sustained, whereas nNOS or iNOS inhibitors had no such effect. Immunoblotting of human PASMCs (hPASMCs) also showed eNOS expression, and AngII treatment induced activating phosphorylations of Ser1177 in eNOS and of Ser473 in Akt (Ser/Thr protein kinase B), an upstream signal of eNOS phosphorylation. In addition, L-NAME co-treatment promoted AngII-induced Ser19 phosphorylation of myosin light chain. In hPASMCs, AngII abolished plasma membrane expression of AT1R, and recovery by washout took more than 1 h. Consistent with the data from hPASMCs, the second application of AngII to E(-)PA did not induce contraction, and significant recovery of ΔTAngII required prolonged washout (> 2 h) in the myography study. L-NAME treatment before the second application facilitated recovery of ΔTAngII. Muscular eNOS plays an auto-inhibitory role in ΔTAngII of PAs. The molecular changes investigated in hPASMCs revealed eNOS phosphorylation and internalization of AT1R by AngII. We propose that the rat PA smooth muscle eNOS-induced lusitropy and slow recovery of AT1R from tachyphylaxis might counterbalance the excessive contractile response to AngII, contributing to the distinctive low-pressure pulmonary circulation.
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Affiliation(s)
- Hae Jin Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Ji Hyun Jang
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Yin Hua Zhang
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea.,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, 03080, South Korea
| | - Hae Young Yoo
- Chung-Ang University Red Cross College of Nursing, Seoul, 100-031, South Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, South Korea. .,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, South Korea. .,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, 03080, South Korea.
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7
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Xu W, Reith MEA, Liu-Chen LY, Kortagere S. Biased signaling agonist of dopamine D3 receptor induces receptor internalization independent of β-arrestin recruitment. Pharmacol Res 2019; 143:48-57. [PMID: 30844536 DOI: 10.1016/j.phrs.2019.03.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 12/14/2022]
Abstract
Agonist-induced internalization of G protein-coupled receptors (GPCRs) is a significant step in receptor kinetics and is known to be involved in receptor down-regulation. However, the dopamine D3 receptor (D3R) has been an exception wherein agonist induces D3Rs to undergo desensitization followed by pharmacological sequestration - which is defined as the sequestration of cell surface receptors into a more hydrophobic fraction within the plasma membrane without undergoing the process of receptor internalization. Pharmacological sequestration renders the receptor in an inactive state on the membrane. In our previous study we demonstrated that a novel class of D3R agonists exemplified by SK608 have biased signaling properties via the G-protein dependent pathway and do not induce D3R desensitization. In this study, using radioligand binding assay, immunoblot or immunocytochemistry methods, we observed that SK608 induced internalization of human D3R stably expressed in CHO, HEK and SH-SY5Y cells which are derived from neuroblastoma cells, suggesting that it is not a cell-type specific event. Further, we have evaluated the potential mechanism of D3R internalization induced by these biased signaling agonists. SK608-induced D3R internalization was time- and concentration-dependent. In comparison, dopamine induced D3R upregulation and pharmacological sequestration in the same assays. GRK2 and clathrin/dynamin I/II are the key molecular players in the SK608-induced D3R internalization process, while β-arrestin 1/2 and GRK-interacting protein 1(GIT1) are not involved. These results suggest that SK608-promoted D3R internalization is similar to the type II internalization observed among peptide binding GPCRs.
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Affiliation(s)
- Wei Xu
- Department of Microbiology and Immunology, Drexel University College of Medicine, PA 19129, United States
| | - Maarten E A Reith
- Department of Psychiatry, Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, NY 10016, United States
| | - Lee-Yuan Liu-Chen
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, United States
| | - Sandhya Kortagere
- Department of Microbiology and Immunology, Drexel University College of Medicine, PA 19129, United States; Department of Pharmacology and Physiology, Drexel University College of Medicine, PA 19102, United States.
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Liu Y, Shen HJ, Wang XQY, Liu HQ, Zheng LY, Luo JD. EndophilinA2 protects against angiotensin II-induced cardiac hypertrophy by inhibiting angiotensin II type 1 receptor trafficking in neonatal rat cardiomyocytes. J Cell Biochem 2018; 119:8290-8303. [PMID: 29923351 DOI: 10.1002/jcb.26862] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 03/13/2018] [Indexed: 01/12/2023]
Abstract
Cardiac hypertrophy is one of the major risk factors for chronic heart failure. The role of endophilinA2 (EndoA2) in clathrin-mediated endocytosis and clathrin-independent endocytosis is well documented. In the present study, we tested the hypothesis that EndoA2 protects against angiotensin II (Ang II)-induced cardiac hypertrophy by mediating intracellular angiotensin II type 1 receptor (AT1-R) trafficking in neonatal rat cardiomyocytes (NRCMs). Cardiac hypertrophy was evaluated by using cell surface area and quantitative RT-PCR (qPCR) analyses. For the first time, we found that EndoA2 attenuated cardiac hypertrophy and fibrosis induced by Ang II. Moreover, EndoA2 inhibited apoptosis induced by excessive endoplasmic reticulum stress (ERS), which accounted for the beneficial effects of EndoA2 on cardiac hypertrophy. We further revealed that there was an interaction between EndoA2 and AT1-R.The expression levels of EndoA2, which inhibits AT1-R transport from the cytoplasm to the membrane, and the interaction between EndoA2 and AT1-R were obviously decreased after Ang II treatment. Furthermore, Ang II inhibited the co-localization of AT1-R with GRP-78, which was reversed by EndoA2 overexpression. In conclusion, our results suggested that EndoA2 plays a role in protecting against cardiac hypertrophy induced by Ang II, possibly by inhibiting AT1-R transport from the cytoplasm to the membrane to suppress signal transduction.
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Affiliation(s)
- Yun Liu
- Department of Pharmacology, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, P.R. China.,Guangzhou Institute of Cardiovascular Disease, Guangzhou Key Laboratory of Cardiovascular Disease, and the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, P.R. China
| | - Huan-Jia Shen
- Department of Pharmacology, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, P.R. China
| | - Xin-Qiu-Yue Wang
- Department of Pharmacology, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, P.R. China
| | - Hai-Qi Liu
- Department of Pharmacology, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, P.R. China
| | - Ling-Yun Zheng
- School of Basic Course, Guangdong Pharmaceutical University, Guangzhou, P.R. China
| | - Jian-Dong Luo
- Guangzhou Institute of Cardiovascular Disease, Guangzhou Key Laboratory of Cardiovascular Disease, and the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, P.R. China
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Arrestins in the Cardiovascular System: An Update. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 159:27-57. [DOI: 10.1016/bs.pmbts.2018.07.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Des-aspartate-angiotensin I causes specific release of PGE2 and PGI2 in HUVEC via the angiotensin AT1 receptor and biased agonism. Eur J Pharmacol 2015; 768:173-81. [PMID: 26524410 DOI: 10.1016/j.ejphar.2015.10.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 10/23/2015] [Accepted: 10/28/2015] [Indexed: 11/23/2022]
Abstract
DAA-I (des-aspartate-angiotensin I), an endogenous angiotensin, had been shown earlier to ameliorate animal models of cardiovascular diseases via the angiotensin AT1 receptor and prostaglandins. The present study investigated further the action of DAA-I on the release of PGE2, PGI2, PGF2α and TXA2 in HUVEC. 10(-11)-10(-8)M DAA-I and 15min incubation specifically released PGE2 and PGI2. The release was inhibited by losartan and indomethacin but not by PD123319 and NS398 indicating that the angiotensin AT1 receptor and COX-1 mediate the release. At concentrations higher than 10(-7)M, DAA-I mimics the action of angiotensin II by releasing TXA2 but had no effect on the production of PGF2α. At similar concentrations and 4h incubation, DAA-I increased the release of the 4 prostaglandins via the angiotensin AT1 receptor and COX-2, again mimicking the action of angiotensin II. HUVEC that were preincubated with DAA-I or angiotensin II, released similar profiles of prostaglandins when incubated with arachidonic acid after the angiotensin had been washed off. We postulate that the internalized DAA-I/receptor complex remains active and mediates the conversion of arachidonic acid to the respective prostaglandins. The release of PGE2 and PGI2 via the angiotensin AT1 receptor and COX-1 is a novel specific action of DAA-I and is likely responsible for its beneficial effects seen in earlier studies. This specific action is definable as a biased agonism of the angiotensin AT1 receptor, which identifies DAA-I as a novel biased agonist and potential therapeutic that is able to produce specific prostaglandins at nanomolar concentrations.
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Hennig R, Pollinger K, Tessmar J, Goepferich A. Multivalent targeting of AT1 receptors with angiotensin II-functionalized nanoparticles. J Drug Target 2015; 23:681-9. [PMID: 25950599 DOI: 10.3109/1061186x.2015.1035276] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The angiotensin II receptor type 1 (AT1R) is a G protein-coupled receptor of paramount significance since it is overexpressed in a number of diseased tissues that are highly attractive for nanoparticle targeting. However, it is also expressed at physiological levels in healthy tissue. Multivalent interactions mediated by multiple AT1R-binding moieties per nanoparticle could promote a high binding avidity to AT1R overexpressing cells and concomitantly spare off-target tissue. To investigate the feasibility of this approach, angiotensin II was thiolated and conjugated to PEGylated quantum dots. Nanoparticle binding, uptake and affinity to several cell lines was investigated in detail. The colloids were rapidly taken up by clathrin-mediated endocytosis into AT1R-expressing cells and showed no interaction with receptor negative cells. The EC50 of the thiolated angiotensin II was determined to be 261 nM, whereas the ligand-conjugated Qdots activated the receptor with an EC50 of 8.9 nM. This 30-fold higher affinity of the nanoparticles compared to the unconjugated peptide clearly demonstrated the presence of multivalent effects when using agonist-targeted nanoparticles. Our study provides compelling evidence that, despite being immediately endocytosed, Ang II-coupled nanoparticles exert potent multivalent ligand-receptor interactions that can be used to establish high affinities to an AT1R overexpressing cell and tissue.
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Affiliation(s)
- Robert Hennig
- a Department of Pharmaceutical Technology , University of Regensburg , Regensburg , Germany and
| | - Klaus Pollinger
- a Department of Pharmaceutical Technology , University of Regensburg , Regensburg , Germany and
| | - Joerg Tessmar
- b Department for Functional Materials in Medicine and Dentistry , University Hospital of Wuerzburg , Wuerzburg , Germany
| | - Achim Goepferich
- a Department of Pharmaceutical Technology , University of Regensburg , Regensburg , Germany and
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