Dataset Information

Deletion of Osteopontin Enhances ??-Adrenergic Receptor-Dependent Anti-Fibrotic Signaling in Cardiomyocytes.

ABSTRACT: Cardiac ??-adrenergic receptors (ARs) are known to inhibit collagen production and fibrosis in cardiac fibroblasts and myocytes. The ??AR is a Gs protein-coupled receptor (GPCR) and, upon its activation, stimulates the generation of cyclic 3',5'-adenosine monophosphate (cAMP). cAMP has two effectors: protein kinase A (PKA) and the exchange protein directly activated by cAMP (Epac). Epac1 has been shown to inhibit cardiac fibroblast activation and fibrosis. Osteopontin (OPN) is a ubiquitous pro-inflammatory cytokine, which also mediates fibrosis in several tissues, including the heart. OPN underlies several cardiovascular pathologies, including atherosclerosis and cardiac adverse remodeling. We found that the cardiotoxic hormone aldosterone transcriptionally upregulates OPN in H9c2 rat cardiac myoblasts-an effect prevented by endogenous ??AR activation. Additionally, CRISPR-mediated OPN deletion enhanced cAMP generation in response to both ??AR and ??AR activation in H9c2 cardiomyocytes, leading to the upregulation of Epac1 protein levels. These effects rendered ??AR stimulation capable of completely abrogating transforming growth factor (TGF)-?-dependent fibrosis in OPN-lacking H9c2 cardiomyocytes. Finally, OPN interacted constitutively with G_?s subunits in H9c2 cardiac cells. Thus, we uncovered a direct inhibitory role of OPN in cardiac ??AR anti-fibrotic signaling via cAMP/Epac1. OPN blockade could be of value in the treatment and/or prevention of cardiac fibrosis.

SUBMITTER: Pollard CM

PROVIDER: S-EPMC6470638 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Deletion of Osteopontin Enhances β₂-Adrenergic Receptor-Dependent Anti-Fibrotic Signaling in Cardiomyocytes.

Pollard Celina M CM Desimine Victoria L VL Wertz Shelby L SL Perez Arianna A Parker Barbara M BM Maning Jennifer J McCrink Katie A KA Shehadeh Lina A LA Lymperopoulos Anastasios A

International journal of molecular sciences 20190320 6

Cardiac β₂-adrenergic receptors (ARs) are known to inhibit collagen production and fibrosis in cardiac fibroblasts and myocytes. The β₂AR is a Gs protein-coupled receptor (GPCR) and, upon its activation, stimulates the generation of cyclic 3',5'-adenosine monophosphate (cAMP). cAMP has two effectors: protein kinase A (PKA) and the exchange protein directly activated by cAMP (Epac). Epac1 has been shown to inhibit cardiac fibroblast activation and fibrosis. Osteopontin (OPN) is a ubiquitous pro-i ...[more]

PMID: 30897705

Similar Datasets

Project description:BackgroundThe type VI adenylyl cyclase (AC6) is a main contributor of cAMP production in the heart. The amino acid (aa) sequence of AC6 is highly homologous to that of another major cardiac adenylyl cyclase, AC5, except for its N-terminus (AC6-N, aa 1-86). Activation of AC6, rather than AC5, produces cardioprotective effects against heart failure, while the underlying mechanism remains to be unveiled. Using an AC6-null (AC6-/-) mouse and a knockin mouse with AC6-N deletion (AC6 ΔN/ΔN), we aimed to investigate the cardioprotective mechanism of AC6 in the heart.MethodsWestern blot analysis and immunofluorescence staining were performed to determine the intracellular distribution of AC6, AC6-ΔN (a truncated AC6 lacking the first 86 amino acids), and STAT3 activation. Activities of AC6 and AC6-ΔN in the heart were assessed by cAMP assay. Apoptosis of cardiomyocytes were evaluated by the TUNEL assay and a propidium iodine-based survival assay. Fibrosis was examined by collagen staining.ResultsImmunofluorescence staining revealed that cardiac AC6 was mainly anchored on the sarcolemmal membranes, while AC6-ΔN was redistributed to the sarcoplasmic reticulum. AC6ΔN/ΔN and AC6-/- mice had more apoptotic myocytes and cardiac remodeling than WT mice in experimental models of isoproterenol (ISO)-induced myocardial injury. Adult cardiomyocytes isolated from AC6ΔN/ΔN or AC6-/- mice survived poorly after exposure to ISO, which produced no effect on WT cardiomyocytes under the condition tested. Importantly, ISO treatment induced cardiac STAT3 phosphorylation/activation in WT mice, but not in AC6ΔN/ΔN and AC6-/- mice. Pharmacological blockage of PKA-, Src-, or STAT3- pathway markedly reduced the survival of WT myocytes in the presence of ISO, but did not affect those of AC6ΔN/ΔN and AC6-/- myocytes, suggesting an important role of AC6 in mediating cardioprotective action through the activation of PKA-Src-STAT3-signaling.ConclusionsCollectively, AC6-N controls the anchorage of cardiac AC6 on the sarcolemmal membrane, which enables the coupling of AC6 with the pro-survival PKA-STAT3 pathway. Our findings may facilitate the development of novel therapies for heart failure.

Dataset Information

Deletion of Osteopontin Enhances ??-Adrenergic Receptor-Dependent Anti-Fibrotic Signaling in Cardiomyocytes.

Publications

Deletion of Osteopontin Enhances β₂-Adrenergic Receptor-Dependent Anti-Fibrotic Signaling in Cardiomyocytes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets