Dataset Information

β₃ -Adrenoceptor as a potential immuno-suppressor agent in melanoma.

ABSTRACT:

Background and purpose

Stress-related catecholamines have a role in cancer and β-adrenoceptors; specifically, β₂ -adrenoceptors have been identified as new targets in treating melanoma. Recently, β₃ -adrenoceptors have shown a pleiotropic effect on melanoma micro-environment leading to cancer progression. However, the mechanisms by which β₃ -adrenoceptors promote this progression remain poorly understood. Catecholamines affect the immune system by modulating several factors that can alter immune cell sub-population homeostasis. Understanding the mechanisms of cancer immune-tolerance is one of the most intriguing challenges in modern research. This study investigates the potential role of β₃ -adrenoceptors in immune-tolerance regulation.

Experimental approach

A mouse model of melanoma in which syngeneic B16-F10 cells were injected in C57BL-6 mice was used to evaluate the effect of β-adrenoceptor blockade on the number and activity of immune cell sub-populations (Treg, NK, CD8, MDSC, macrophages, and neutrophils). Pharmacological and molecular approaches with β-blockers (propranolol and SR59230A) and specific β-adrenoceptor siRNAs targeting β₂ - or β₃ -adrenoceptors were used.

Key results

Only β₃ -, but not β₂ -adrenoceptors, were up-regulated under hypoxia in peripheral blood mononuclear cells and selectively expressed in immune cell sub-populations including Treg, MDSC, and NK. SR59230A and β₃ -adrenoceptor siRNAs increased NK and CD8 number and cytotoxicity, while they attenuated Treg and MDSC sub-populations in the tumour mass, blood, and spleen. SR59230A and β₃ -adrenoceptor siRNAs increased the ratio of M1/M2 macrophages and N1 granulocytes.

Conclusions and implications

Our data suggest that β₃ -adrenoceptors are involved in immune-tolerance, which opens the way for new strategic therapies to overcome melanoma growth.

Linked articles

This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

SUBMITTER: Calvani M

PROVIDER: S-EPMC6592854 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

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Publications

β<sub>3</sub> -Adrenoceptor as a potential immuno-suppressor agent in melanoma.

Calvani Maura M Bruno Gennaro G Dal Monte Massimo M Nassini Romina R Fontani Filippo F Casini Arianna A Cavallini Lorenzo L Becatti Matteo M Bianchini Francesca F De Logu Francesco F Forni Giulia G la Marca Giancarlo G Calorini Lido L Bagnoli Paola P Chiarugi Paola P Pupi Alberto A Azzari Chiara C Geppetti Pierangelo P Favre Claudio C Filippi Luca L

British journal of pharmacology 20190509 14

<h4>Background and purpose</h4>Stress-related catecholamines have a role in cancer and β-adrenoceptors; specifically, β<sub>2</sub> -adrenoceptors have been identified as new targets in treating melanoma. Recently, β<sub>3</sub> -adrenoceptors have shown a pleiotropic effect on melanoma micro-environment leading to cancer progression. However, the mechanisms by which β<sub>3</sub> -adrenoceptors promote this progression remain poorly understood. Catecholamines affect the immune system by modulat ...[more]

PMID: 30874296

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Project description:The β1-adrenoceptor (β1AR) is a G-protein-coupled receptor (GPCR) that couples1 to the heterotrimeric G protein Gs. G-protein-mediated signalling is terminated by phosphorylation of the C terminus of the receptor by GPCR kinases (GRKs) and by coupling of β-arrestin 1 (βarr1, also known as arrestin 2), which displaces Gs and induces signalling through the MAP kinase pathway2. The ability of synthetic agonists to induce signalling preferentially through either G proteins or arrestins-known as biased agonism3-is important in drug development, because the therapeutic effect may arise from only one signalling cascade, whereas the other pathway may mediate undesirable side effects4. To understand the molecular basis for arrestin coupling, here we determined the cryo-electron microscopy structure of the β1AR-βarr1 complex in lipid nanodiscs bound to the biased agonist formoterol5, and the crystal structure of formoterol-bound β1AR coupled to the G-protein-mimetic nanobody6 Nb80. βarr1 couples to β1AR in a manner distinct to that7 of Gs coupling to β2AR-the finger loop of βarr1 occupies a narrower cleft on the intracellular surface, and is closer to transmembrane helix H7 of the receptor when compared with the C-terminal α5 helix of Gs. The conformation of the finger loop in βarr1 is different from that adopted by the finger loop of visual arrestin when it couples to rhodopsin8. β1AR coupled to βarr1 shows considerable differences in structure compared with β1AR coupled to Nb80, including an inward movement of extracellular loop 3 and the cytoplasmic ends of H5 and H6. We observe weakened interactions between formoterol and two serine residues in H5 at the orthosteric binding site of β1AR, and find that formoterol has a lower affinity for the β1AR-βarr1 complex than for the β1AR-Gs complex. The structural differences between these complexes of β1AR provide a foundation for the design of small molecules that could bias signalling in the β-adrenoceptors.

Project description:Background Autoantibodies against the second extracellular loop of the β1-adrenoceptor (β1- AA ) act similarly to agonist of β1-adrenergic receptor, which plays an important role in the pathophysiological characteristics of ventricular remodeling. Recently, considerable lines of evidence have suggested that CTRP9 (C1q tumor necrosis factor-related protein 9) is a potent cardioprotective cardiokine and protects the heart from ventricular remodeling. The aim of this study was to determine the role of CTRP 9 in ventricular remodeling induced by β1- AA . Methods and Results Blood samples were collected from 131 patients with coronary heart disease and 131 healthy subjects. The serum levels of β1- AA and CTRP 9 were detected using ELISA . The results revealed that CTRP 9 levels in β1- AA -positive patients were lower than those in β1- AA -negative patients, and serum CTRP 9 concentrations were inversely correlated with β1- AA . β1- AA monoclonal antibodies (β1- AA mAbs) were administered in mice with and without rAAV 9- cTnT -Full Ctrp9- FLAG virus for 8 weeks. Reverse transcription-polymerase chain reaction/Western analysis showed that cardiomyocyte CTRP 9 expression was significantly reduced in β1- AA mAb-treated mice. Moreover, compared with the β1- AA mAb alone group, cardiac-specific CTRP 9 overexpression improved cardiac function, attenuated adverse remodeling, and ameliorated cardiomyocyte apoptosis and fibrosis. Mechanistic studies demonstrated that CTRP 9 overexpression decreased the levels of G-protein-coupled receptor kinase 2 and promoted the activation of AMP-dependent kinase pathway. However, cardiac-specific overexpression of CTRP 9 had no effect on the levels of cAMP and protein kinase A activity elevated by β1-AAmAb. Conclusions This study provides the first evidence that the long-term existence of β1- AA mAb suppresses cardiac CTRP 9 expression and exaggerates cardiac remodeling, suggesting that CTRP 9 may be a novel therapeutic target against pathologic remodeling in β1- AA -positive patients with coronary heart disease.

Project description:Objective3',5'-Cyclic adenosine monophosphate (cAMP) is a central second messenger governing brown adipocyte differentiation and function. β-adrenergic receptors (β-ARs) stimulate adenylate cyclases which produce cAMP. Moreover, cyclic nucleotide levels are tightly controlled by phosphodiesterases (PDEs), which can generate subcellular microdomains of cAMP. Since the spatio-temporal organisation of the cAMP signalling pathway in adipocytes is still unclear, we sought to monitor real-time cAMP dynamics by live cell imaging in pre-mature and mature brown adipocytes.MethodsWe measured the real-time dynamics of cAMP in murine pre-mature and mature brown adipocytes during stimulation of individual β-AR subtypes, as well as its regulation by PDEs using a Förster Resonance Energy Transfer based biosensor and pharmacological tools. We also correlated these data with β-AR stimulated lipolysis and analysed the expression of β-ARs and PDEs in brown adipocytes using qPCR and immunoblotting. Furthermore, subcellular distribution of PDEs was studied using cell fractionation and immunoblots.ResultsUsing pre-mature and mature brown adipocytes isolated from transgenic mice expressing a highly sensitive cytosolic biosensor Epac1-camps, we established real-time measurements of cAMP responses. PDE4 turned out to be the major PDE regulating cytosolic cAMP in brown preadipocytes. Upon maturation, PDE3 gets upregulated and contributes with PDE4 to control β1-AR-induced cAMP. Unexpectedly, β3-AR initiated cAMP is resistant to increased PDE3 protein levels and simultaneously, the control of this microdomain by PDE4 is reduced upon brown adipocyte maturation. Therefore we postulate the existence of distinct cAMP pools in brown adipocytes. One cAMP pool is formed by β1-AR associated with PDE3 and PDE4, while another pool is centred around β3-AR and is much less controlled by these PDEs. Functionally, lower control of β3-AR initiated cAMP by PDE3 and PDE4 facilitates brown adipocyte lipolysis, while lipolysis activated by β1-AR and is under tight control of PDE3 and PDE4.ConclusionsWe have established a real-time live cell imaging approach to analyse brown adipocyte cAMP dynamics in real-time using a cAMP biosensor. We showed that during the differentiation from pre-mature to mature murine brown adipocytes, there was a change in PDE-dependent compartmentation of β1-and β3-AR-initiated cAMP responses by PDE3 and PDE4 regulating lipolysis.

Dataset Information

β₃ -Adrenoceptor as a potential immuno-suppressor agent in melanoma.

Background and purpose

Experimental approach

Key results

Conclusions and implications

Linked articles

Publications

β<sub>3</sub> -Adrenoceptor as a potential immuno-suppressor agent in melanoma.

Similar Datasets

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Dataset Information

β3 -Adrenoceptor as a potential immuno-suppressor agent in melanoma.

Background and purpose

Experimental approach

Key results

Conclusions and implications

Linked articles

Publications

β<sub>3</sub> -Adrenoceptor as a potential immuno-suppressor agent in melanoma.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

β₃ -Adrenoceptor as a potential immuno-suppressor agent in melanoma.