scholarly journals Antagonistic Roles of GRK2 and GRK5 in Cardiac Aldosterone Signaling Reveal GRK5-Mediated Cardioprotection via Mineralocorticoid Receptor Inhibition

2020 ◽  
Vol 21 (8) ◽  
pp. 2868
Author(s):  
Jennifer Maning ◽  
Katie A. McCrink ◽  
Celina M. Pollard ◽  
Victoria L. Desimine ◽  
Jennifer Ghandour ◽  
...  
Keyword(s):  
G Protein ◽  
Mineralocorticoid Receptor ◽  
Transcriptional Activity ◽  
Ventricular Myocytes ◽  
Cardiac Injury ◽  
Protective Effects ◽  
Cardiac Mr ◽  
Beneficial Effects ◽  
Adult Rat ◽  
G Protein Coupled

Aldosterone (Aldo), when overproduced, is a cardiotoxic hormone underlying heart failure and hypertension. Aldo exerts damaging effects via the mineralocorticoid receptor (MR) but also activates the antiapoptotic G protein-coupled estrogen receptor (GPER) in the heart. G protein-coupled receptor (GPCR)-kinase (GRK)-2 and -5 are the most abundant cardiac GRKs and phosphorylate GPCRs as well as non-GPCR substrates. Herein, we investigated whether they phosphorylate and regulate cardiac MR and GPER. To this end, we used the cardiomyocyte cell line H9c2 and adult rat ventricular myocytes (ARVMs), in which we manipulated GRK5 protein levels via clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 and GRK2 activity via pharmacological inhibition. We report that GRK5 phosphorylates and inhibits the cardiac MR whereas GRK2 phosphorylates and desensitizes GPER. In H9c2 cardiomyocytes, GRK5 interacts with and phosphorylates the MR upon β2-adrenergic receptor (AR) activation. In contrast, GRK2 opposes agonist-activated GPER signaling. Importantly, GRK5-dependent MR phosphorylation of the MR inhibits transcriptional activity, since aldosterone-induced gene transcription is markedly suppressed in GRK5-overexpressing cardiomyocytes. Conversely, GRK5 gene deletion augments cardiac MR transcriptional activity. β2AR-stimulated GRK5 phosphorylates and inhibits the MR also in ARVMs. Additionally, GRK5 is necessary for the protective effects of the MR antagonist drug eplerenone against Aldo-induced apoptosis and oxidative stress in ARVMs. In conclusion, GRK5 blocks the cardiotoxic MR-dependent effects of Aldo in the heart, whereas GRK2 may hinder beneficial effects of Aldo through GPER. Thus, cardiac GRK5 stimulation (e.g., via β2AR activation) might be of therapeutic value for heart disease treatment via boosting the efficacy of MR antagonists against Aldo-mediated cardiac injury.

Abstract 056: Differential Roles of GRK2 and GRK5 in Cardiac Aldosterone Signaling Suggest GRK5-Mediated Cardio-protection Against Mineralocorticoids

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Anastasios Lymperopoulos ◽  
Katie A McCrink ◽  
Ava Brill ◽  
Jennifer Maning ◽  
Victoria L Desimine ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
G Protein ◽  
Transcriptional Activity ◽  
Ventricular Myocytes ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Luciferase Reporter ◽  
Protective Effects ◽  
Cardio Protection ◽  
G Protein Coupled

Background: Aldosterone (Aldo) contributes significantly to the morbidity & mortality of heart failure (HF). In the heart, Aldo binds the mineralocorticoid receptor (MR) to exert damaging effects, e.g. fibrosis, apoptosis, oxidative stress, etc. Additionally, Aldo can activate the G protein-coupled estrogen receptor (GPER), which may have beneficial, anti-apoptotic effects for cardiomyocytes, e.g. in ischemia/reperfusion injury. GRK2 and GRK5 are the most abundant G protein-coupled receptor (GPCR)-kinases (GRKs) in the heart and both phosphorylate GPCRs but also non-GPCR substrates. The human MR is known to undergo inhibitory phosphorylation at Ser-843, inside its ligand binding domain, which blocks its transcriptional activity. Hypothesis: In the heart, GRK5 phosphorylates and inhibits the MR, whereas GRK2 phosphorylates and desensitizes GPER. Methods: We used the cardiomyocyte cell line H9c2 and isolated adult rat ventricular myocytes (ARVMs). We performed co-immunoprecipitation experiments for GRK interactions with MR or GPER. We measured MR phosphorylation via immunoblotting and MR transcriptional activity via the luciferase reporter assay. We also measured apoptosis and oxidative stress in ARVMs. Results: GRK5, but not GRK2, phosphorylates the MR in H9c2 cardiomyocytes. Beta 2 -adrenoceptor activation stimulates this non-canonical effect of GRK5. In contrast, GRK2, but not GRK5, phosphorylates and desensitizes agonist-activated GPER. The GRK5-phosphorylated MR is incapable of activating gene transcription, since MR transcriptional activity is markedly suppressed upon GRK5 overexpression. Conversely, CRISPR-mediated GRK5 gene deletion augments cardiac MR transcriptional activity. Importantly, GRK5 is necessary for the protective effects of the MR antagonist drug eplerenone against Aldo-induced apoptosis/oxidative stress in ARVMs. Finally, beta 2 -adrenoceptor-stimulated GRK5 phosphorylates and inhibits the MR in ARVMs. Conclusions: GRK5 blocks the cardio-toxic MR-dependent effects of Aldo in the heart, whereas GRK2 may hinder GPER`s cardio-protective effects. Thus, cardiac GRK5 stimulation (e.g. via beta 2 -adrenoceptor activation) enhances the cardio-protection exerted by Aldo inhibitors in HF.

scholarly journals Novel Insights into the Crosstalk between Mineralocorticoid Receptor and G Protein-Coupled Receptors in Heart Adverse Remodeling and Disease

2018 ◽  
Author(s):  
Barbara M. Parker ◽  
Shelby L. Wertz ◽  
Celina M. Pollard ◽  
Victoria L. Desimine ◽  
Jennifer Maning ◽  
...  
Keyword(s):  
Heart Disease ◽  
G Protein ◽  
Mineralocorticoid Receptor ◽  
Animal Studies ◽  
Human Heart Failure ◽  
Gpcr Signaling ◽  
Cardiac Mr ◽  
Disease Therapy ◽  
Adverse Remodeling ◽  
G Protein Coupled

The mineralocorticoid hormone aldosterone regulates sodium and potassium homeostasis but also adversely modulates the maladaptive process of cardiac adverse remodeling post-myocardial infarction. Through activation of its mineralocorticoid receptor (MR), a classic steroid hormone receptor/transcription factor, aldosterone promotes inflammation and fibrosis of the heart, the vasculature, and the kidneys. This is why MR antagonists reduce morbidity and mortality of heart disease patients and are part of the mainstay pharmacotherapy of advanced human heart failure. A plethora of animal studies using cell type–specific targeting of the MR gene have established the importance of MR signaling and function in cardiac myocytes, vascular endothelial and smooth muscle cells, renal cells, and macrophages. In terms of its signaling properties, the MR is distinct from nuclear receptors in that it has, in reality, two physiological hormonal agonists: not only aldosterone but also cortisol. In fact, in several tissues, including in the myocardium, cortisol is the primary hormone activating the MR. There is a considerable amount of evidence indicating that the effects of the MR in each tissue expressing it depend on tissue- and ligand-specific engagement of molecular co-regulators that either activate or suppress its transcriptional activity. Identification of these co-regulators for every ligand that interacts with the MR in the heart (and in other tissues) is of utmost importance therapeutically, since it can not only help elucidate fully the pathophysiological ramifications of the cardiac MR`s actions but also help design and develop novel better MR antagonist drugs for heart disease therapy.  Among the various proteins the MR interacts with are molecules involved in cardiac G protein-coupled receptor (GPCR) signaling. This results in a significant amount of crosstalk between GPCRs and the MR, which can affect the latter`s activity dramatically in the heart and in other cardiovascular tissues. This review summarizes the current experimental evidence for this GPCR-MR crosstalk in the heart and discusses its pathophysiological implications for cardiac adverse remodeling as well as for heart disease therapy. Novel findings revealing non-conventional roles of GPCR signaling molecules, specifically of GPCR-kinase (GRK)-5, in cardiac MR regulation are also highlighted.

scholarly journals GRK5 is an Essential Co-repressor for Cardiac Mineralocorticoid Receptor Antagonism induced by Finerenone but not Eplerenone

2020 ◽  
Author(s):  
Victoria L. Desimine ◽  
Jennifer Ghandour ◽  
Natalie Cora ◽  
Celina M. Pollard ◽  
Rachel Valiente ◽  
...  
Keyword(s):  
Mineralocorticoid Receptor ◽  
Transcriptional Activity ◽  
Ventricular Myocytes ◽  
Neonatal Rat ◽  
Human Heart Failure ◽  
Cardiac Mr ◽  
Inverse Agonism ◽  
Mineralocorticoid Receptor Antagonism ◽  
H9c2 Cardiomyocytes ◽  
Induced Apoptosis

Background: In the heart, aldosterone (Aldo) binds the mineralocorticoid receptor (MR) to exert damaging, adverse remodeling-promoting effects. We recently showed that G protein-coupled receptor (GPCR)-kinase (GRK)-5 blocks the cardiac MR by directly phosphorylating it, thereby repressing its transcriptional activity. MR antagonist (MRA) drugs block the cardiac MR reducing morbidity and mortality of advanced human heart failure. Non-steroidal MRAs, such as finerenone, may provide better cardio-protection against Aldo than classic, steroidal MRAs, like spironolactone and eplerenone. Herein, we sought to investigate potential differences between finerenone and eplerenone at engaging GRK5-dependent cardiac MR phosphorylation and subsequent blockade. Methods: We used the cardiomyocyte cell line H9c2 and neonatal rat ventricular myocytes (NRVMs). Results: GRK5 phosphorylates the MR in H9c2 cardiomyocytes in response to finerenone but not to eplerenone. Unlike eplerenone, finerenone alone potently and efficiently suppresses cardiac MR transcriptional activity, thus displaying inverse agonism. GRK5 is necessary for finerenone`s inverse agonism, since GRK5 genetic deletion renders finerenone incapable of blocking cardiac MR transcriptional activity. Eplerenone alone does not fully suppress cardiac MR basal activity regardless of GRK5 expression levels. Finally in NRVMs, GRK5 is necessary for the anti-apoptotic and anti-fibrotic effects of both finerenone and eplerenone against Aldo, as well as for the higher efficacy and potency of finerenone at blocking Aldo-induced apoptosis and fibrosis. Conclusions: Finerenone, but not eplerenone, induces GRK5-dependent cardiac MR inhibition, which underlies, at least in part, its higher potency and efficacy, compared to eplerenone, as an MRA in the heart. GRK5 acts as a co-repressor of the cardiac MR and is essential for efficient MR antagonism in the myocardium.

scholarly journals The Retinoid and Non-Retinoid Ligands of the Rod Visual G Protein-Coupled Receptor

2019 ◽  
Vol 20 (24) ◽  
pp. 6218 ◽  
Author(s):  
Joseph T. Ortega ◽  
Beata Jastrzebska
Keyword(s):  
Drug Discovery ◽  
G Protein ◽  
Binding Sites ◽  
Binding Pocket ◽  
Biologically Active ◽  
Surface Receptors ◽  
Beneficial Effects ◽  
Light Sensing ◽  
Potential Binding ◽  
G Protein Coupled

G protein-coupled receptors (GPCRs) play a predominant role in the drug discovery effort. These cell surface receptors are activated by a variety of specific ligands that bind to the orthosteric binding pocket located in the extracellular part of the receptor. In addition, the potential binding sites located on the surface of the receptor enable their allosteric modulation with critical consequences for their function and pharmacology. For decades, drug discovery focused on targeting the GPCR orthosteric binding sites. However, finding that GPCRs can be modulated allosterically opened a new venue for developing novel pharmacological modulators with higher specificity. Alternatively, focus on discovering of non-retinoid small molecules beneficial in retinopathies associated with mutations in rhodopsin is currently a fast-growing pharmacological field. In this review, we summarize the accumulated knowledge on retinoid ligands and non-retinoid modulators of the light-sensing GPCR, rhodopsin and their potential in combating the specific vision-related pathologies. Also, recent findings reporting the potential of biologically active compounds derived from natural products as potent rod opsin modulators with beneficial effects against degenerative diseases related to this receptor are highlighted here.

scholarly journals Leucine-rich repeat-containing G-protein-coupled receptor 8 in mature glomeruli of developing and adult rat kidney and inhibition by insulin-like peptide-3 of glomerular cell proliferation

2006 ◽  
Vol 189 (2) ◽  
pp. 397-408 ◽  
Author(s):  
P Fu ◽  
P-J Shen ◽  
C-X Zhao ◽  
D J Scott ◽  
C S Samuel ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
G Protein ◽  
Binding Sites ◽  
Renal Cortex ◽  
Mesangial Cells ◽  
Rat Kidney ◽  
Leucine Rich Repeat ◽  
G Protein Coupled Receptor ◽  
Adult Rat ◽  
G Protein Coupled

Leucine-rich repeat-containing G-protein-coupled receptor 8 (LGR8, or RXFP2) is a member of the type C leucine-rich repeat-containing G protein-coupled receptor family, and its endogenous ligand is insulin-like peptide-3 (INSL3). Although LGR8 expression has been demonstrated in various human tissues, including testis, ovary, brain and kidney, the precise roles of this receptor in many of these tissues are unknown. In an effort to better understand INSL3–LGR8 systems in the rat, we cloned the full-length Lgr8 cDNA and investigated the presence and cellular localization of Lgr8 mRNA expression in adult and developing rat kidney. On the basis of these findings, we investigated the presence and distribution of renal 125I-labelled human INSL3-binding sites and the nature of INSL3–LGR8 signalling in cultured renal cells. Thus, using in situ hybridization histochemistry, cells expressing Lgr8 mRNA were observed in glomeruli of renal cortex from adult rats and were tentatively identified as mesangial cells. Quantitative, real-time PCR analysis of the developmental profile of Lgr8 mRNA expression in kidney revealed highest relative levels at late stage gestation (embryonic day 18), with a sharp decrease after birth and lowest levels in the adult. During development, silver grains associated with Lgr8 mRNA hybridization were observed overlying putative mesangial cells in mature glomeruli, with little or no signal associated with less-mature glomeruli. In adult and developing kidney, specific 125I-INSL3-binding sites were associated with glomeruli throughout the renal cortex. In primary cultures of glomerular cells, synthetic human INSL3 specifically and dose-dependently inhibited cell proliferation over a 48 h period, further suggesting the presence of functional LGR8 (receptors) on these cells (mesangial and others). These findings suggest INSL3–LGR8 signalling may be involved in the genesis and/or developmental maturation of renal glomeruli and possibly in regulating mesangial cell density in adult rat kidney.

scholarly journals Phosphorylation and activation of mitogen- and stress-activated protein kinase-1 in adult rat cardiac myocytes by G-protein-coupled receptor agonists requires both extracellular-signal-regulated kinase and p38 mitogen-activated protein kinase

2002 ◽  
Vol 365 (3) ◽  
pp. 757-763 ◽  
Author(s):  
Thomais MARKOU ◽  
Antigone LAZOU
Keyword(s):  
Protein Kinase ◽  
G Protein ◽  
Cardiac Myocytes ◽  
P38 Mapk ◽  
Mitogen Activated Protein Kinase ◽  
G Protein Coupled Receptor ◽  
Receptor Agonists ◽  
Adult Rat ◽  
G Protein Coupled ◽  
Rat Cardiac Myocytes

G-protein-coupled receptor agonists are powerful stimulators of mitogen-activated protein kinase (MAPK) cascades in cardiac myocytes. However, little is known regarding the physiological activation of enzymes downstream of MAPKs. We examined the activation of mitogen- and stress-activated protein kinase-1 (MSK1), a downstream target of MAPKs, in adult rat cardiac myocytes by phenylephrine and endothelin-1. Both agonists induced the phosphorylation of MSK1 at Thr-581 and Ser-376 but not at Ser-360. Maximal phosphorylation was observed at 10–15min after stimulation and it correlated with increased activity. Maximal activation of MSK1 in adult cardiomyocytes temporally coincided with maximal p38 MAPK activation while activation of the extracellular-signal-regulated kinase (ERK) cascade was more rapid. Phosphorylation and activation of MSK1 was completely inhibited by either PD98059 (ERK1/2 pathway inhibitor) or SB203580 (p38 MAPK inhibitor) alone. These data demonstrate that MSK1 activation in adult rat cardiac myocytes by G-protein-coupled receptor agonists requires the simultaneous activation of both the ERK and p38 MAPK pathways. However, the lack of phosphorylation at Ser-360, an identified phosphorylation site targeted by MAPKs, may indicate that MSK1 is not a direct substrate of ERK1/2 and p38 MAPK in adult rat cardiomyocytes.

Expression of G-protein-coupled receptor kinase 6 (GRK6) after acute spinal cord injury in adult rat

2013 ◽  
Vol 44 (3) ◽  
pp. 259-270 ◽  
Author(s):  
Binbin Sun ◽  
Yilu Gao ◽  
Dong Lou ◽  
Xiujie Wu ◽  
Haixiang Wei ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
G Protein ◽  
Acute Spinal Cord Injury ◽  
Receptor Kinase ◽  
G Protein Coupled Receptor ◽  
Adult Rat ◽  
Cord Injury ◽  
G Protein Coupled

scholarly journals G Protein-Coupled Estrogen Receptor 1 (GPER1) Mediates Aldosterone-Induced Endothelial Inflammation in a Mineralocorticoid Receptor-Independent Manner

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ziwei Tang ◽  
Qifu Li ◽  
Qingfeng Cheng ◽  
Mei Mei ◽  
Ying Song ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Estrogen Receptor ◽  
Inflammatory Response ◽  
G Protein ◽  
Mineralocorticoid Receptor ◽  
Umbilical Vein ◽  
Vascular Inflammation ◽  
Independent Manner ◽  
G Protein Coupled ◽  
Estrogen Receptor 1

Objective. It has been increasingly appreciated that G protein-coupled estrogen receptor 1 (GPER1) mediates both proinflammatory and anti-inflammatory response of estrogen. It is also involved in some rapid vascular effects of aldosterone in a mineralocorticoid receptor (MR) independent manner. However, whether GPER1 mediates aldosterone-induced inflammation response in endothelial cells and its relationship with MR are yet undetermined and therefore require further explanation. Method. Based on the hypothesis that GPER1 plays a role in the aldosterone-related vascular inflammation, the present study utilized a model of human umbilical vein endothelial cells transfected with MR siRNA and induced for inflammatory response with increasing concentration of aldosterone. Results. It was discovered that induction of aldosterone had no effect on the expression of GPER1 but promoted the expression of MR. Suppression of MR did not influence GPER1 expression, and GPER1 was capable of mediating part of aldosterone-induced endothelial inflammatory response. This effect may involve phosphoinositide 3-kinases (PI3K) pathway signaling. Conclusion. These findings not only demonstrated the role of GPER1 in aldosterone-induced vascular inflammation but also suggested an alternative for pharmaceutical treatment of hyperaldosteronism considering the unsatisfying effect on cardiovascular risks with MR antagonists.

Neural Receptors Associated with Depression: A Systematic Review of the Past 10 Years

2020 ◽  
Vol 19 (6) ◽  
pp. 417-436
Author(s):  
Alice Barros Câmara ◽  
Igor Augusto Brandão
Keyword(s):  
Cerebral Cortex ◽  
Basal Ganglia ◽  
Cell Survival ◽  
G Protein ◽  
G Protein Coupled Receptors ◽  
Protective Effects ◽  
Inflammation Response ◽  
The Past ◽  
Open Access Journals ◽  
G Protein Coupled

Over the past few years, experimental research has been carried out to analyze the role of specific receptors in depression to better understand the mechanisms and pathophysiological aspects of the disease. In this paper, we aim to investigate the receptors family most involved in depression, as well as the tissues in which most depression related-receptors are expressed. The article also aims to identify the functions of the main receptors predominantly associated with the pathology. This review used a systematic methodology (Prospero; ID 168584) and followed the PRISMA guidelines. Studies were searched in PubMed/MEDLINE, Scientific Electronic Library Online, Web of Science, and Directory of Open Access Journals databases. Quantitative studies with conclusive results regarding receptors involved in depression were selected. The charts and network were made using R programming language and statistical analyses were carried out using SPSS v25 software. It can be seen that G protein-coupled receptors family is the most studied (p < 0.05). These receptors are expressed in the cerebral cortex, basal ganglia, and can interact with each other. A great number of studies have evaluated receptors related to beneficial effects in the disease (p < 0.05). The inflammation response and cell survival/proliferation are the main functions related to these receptors (p < 0.01) and behavioral tests in mice are the main methodologies applied in these studies (p < 0.05). Finally, the most influential protein on the network of receptors involved in depression is the Bradykinin receptor B1. G protein- coupled receptors located in cell membranes involving especially protective effects in depression and that expressed mainly in the cerebral cortex and basal ganglia have shown significant importance in this review. In addition, inflammation response or cell survival/proliferation are the main functions performed by the receptors related to depression as observed in this work.

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