Regulation of β-adrenoceptor density and mRNA levels in the rat heart cell-line H9c2

Dangel, Volker; Giray, Jeanette; Ratge, D.; Wisser, H.

doi:10.1042/bj3170925

Cited by 49 publications

(24 citation statements)

References 27 publications

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“…This cell line has shown electrophysiological and biochemical properties of both skeletal and cardiac tissues, including depolarization in response to acetylcholine and rapid activation of calcium currents through L-type channels. They have been used extensively in the literature as models for cardiomyoblasts and have been considered as a proper model to study molecular responses of the cardiomyocyte to oxidative damage [17,18]. Cells were grown in DMEM supplemented with 1.5 g l -1 sodium bicarbonate, 10% FBS, 100 U ml -1 of penicillin and 100 lg ml -1 of streptomycin in 75-cm 2 tissue culture flasks, and maintained at 37°C, in a humidified incubator containing 5% CO 2 .…”

Section: H9c2 Cell Culturementioning

confidence: 99%

Nitrogen Compounds Prevent H9c2 Myoblast Oxidative Stress-Induced Mitochondrial Dysfunction and Cell Death

et al. 2010

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Oxidative stress has been connected to various forms of cardiovascular diseases. Previously, we have been investigating the potential of new nitrogen-containing synthetic compounds using a neuronal cell model and different oxidative stress conditions in order to elucidate their potential to ameliorate neurodegenerative diseases. Here, we intended to extend these initial studies and investigate the protective role of four of those new synthetic compounds (FMA4, FMA7, FMA762 and FMA796) against oxidative damage induced to H9c2 cardiomyoblasts by tert-butylhydroperoxide (t-BHP). The data indicates that FMA762 and FMA796 decrease t-BHP-induced cell death, as measured by both sulforhodamine B assay and nuclear chromatin condensation evaluation, at non-toxic concentrations. In addition, the two mentioned compounds inhibit intracellular signalling mechanisms leading to apoptotic cell death, namely those mediated by mitochondria, which was confirmed by their ability to overcome t-BHP-induced morphological changes in the mitochondrial network, loss of mitochondrial membrane potential, increased expression of the pro-apoptotic proteins p53, Bax and AIF and activation of caspases-3 and -9. Importantly, our results indicate that the compounds' ROS scavenging ability plays a crucial role in the protection profile, as a significant decrease in t-BHP-induced oxidative stress occurred in their presence. Data obtained indicates that some of the test compounds may clearly prove valuable in a clinical context by diminishing cardiac injury associated to oxidative stress without any toxicity.

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Section: H9c2 Cell Culturementioning

confidence: 99%

Nitrogen Compounds Prevent H9c2 Myoblast Oxidative Stress-Induced Mitochondrial Dysfunction and Cell Death

et al. 2010

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“…The H9c2 cardiomyocytes have characteristics of electrophysiological elements and signaling pathways of adult cardiomyocytes (12). This cell line provides a useful model for studying the interaction between ␤-AR and PI3K because in these cells, population of ␤-AR subtypes can be readily detected and PI3K has been shown to regulate their differentiation (9,19). We showed that ␤-AR stimulation-induced activation of PI3K is ␤ 2 -AR dependent.…”

Section: Discussionmentioning

confidence: 90%

A novel signaling pathway for β-adrenergic receptor-mediated activation of phosphoinositide 3-kinase in H9c2 cardiomyocytes

Yano

Ianus²,

Zhao³

et al. 2007

American Journal of Physiology-Heart and Circulatory Physiology

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Stimulation of cardiac β-adrenergic receptors (β-AR) activates both the Gs- and Gi-coupled signaling cascades, including the phosphoinositide 3 kinase (PI3K) pathway, that have important physiological implications. Multiple isoforms of PI3K exist in the heart. The goals of this study were to examine the intracellular signaling pathways linking β-AR to PI3K and to identify the PI3K isoform mediating this transactivation in a cardiac context. Acute β-AR stimulation with isoproterenol resulted in increased tyrosine kinase-associated PI3K activity and phosphorylation of Akt and p70S6K in H9c2 cardiomyocytes. Cotreatment with ICI-118,551, but not CGP-20712, abolished the increase in PI3K activity, suggesting a β2-AR-mediated event. PI3K activation was also abrogated by cotreatment with pertussis toxin, 4-amino-5-(4-chlorophenyl)-7-( t-butyl)pyrazolol[3,4-d]pyrimidine (PP2, a selective Src-family tyrosine kinases inhibitor), or AG-1296 [selective platelet-derived growth factor receptor (PDGFR) inhibitor] but not with an inhibitor for protein kinase A, protein kinase C, Ras, adenylyl cyclase, epidermal growth factor receptor, or insulin-like growth factor-1 receptor. β-AR stimulation induced an increase in tyrosine phosphorylation of PDGFR, which was abolished by inhibition of Src either by PP2 or small interfering RNA. Moreover, H9c2 cardiomyocytes stably transfected with a vector expressing a Gβγ sequestrant peptide derived from the COOH-terminus of β-AR kinase-1 failed to activate PI3K after β-AR stimulation, suggesting Gβγ is required for the transactivation. Furthermore, acute β-AR stimulation in vivo resulted in increases in PDGFR-associated PI3K and PI3Kα isoform activities but not the activities of other isoforms (PI3Kβ, -δ, -γ) in adult mouse heart. Taken together, these data provide in vitro and in vivo evidence for a novel mechanism of β-AR-mediated transactivation of cardiac PI3Kα via sequential involvement of Gαi/Gβγ, Src, and PDGFR.

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“…In rat C6 glioma cells exposed to the agonist ISO, down-regulation of both subtypes occurs at similar rates (19,20), but when the cells are exposed to atypical agonists, only ␤ 2 AR levels are reduced (19). When rat H9c2 heart cells are treated with agonist, ␤ 2 AR but not ␤ 1 AR undergoes downregulation (21). Distinctions also are found in vivo.…”

mentioning

confidence: 86%

Resistance of the Human β1-Adrenergic Receptor to Agonist-mediated Down-regulation

Liang

Austin²,

Hoang

et al. 2003

Journal of Biological Chemistry

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Prolonged agonist stimulation results in down-regulation of most G protein-coupled receptors. When we exposed baby hamster kidney cells stably expressing the human ␤ 1 -adrenergic receptor (␤ 1 AR) to agonist over a 24-h period, we instead observed an increase of ϳ30% in both ␤ 1 AR binding activity and immune-detected receptors. In contrast, ␤ 2 AR expressed in these cells exhibited a decrease of >50%. We determined that the basal turnover rates of the two subtypes were similar (t1 ⁄2 ϳ 7 h) and that agonist stimulation increased ␤ 2 AR but not ␤ 1 AR turnover. Blocking receptor trafficking to lysosomes with bafilomycin A 1 had no effect on basal turnover of either subtype but blocked agonist-stimulated ␤ 2 AR turnover. As ␤ 1 AR mRNA levels increased in agonist-stimulated cells, ␤ 1 AR up-regulation appeared to result from increased synthesis with no change in degradation. To explore the basis for the subtype differences, we expressed chimeras in which the C termini had been exchanged. Each chimera responded to persistent agonist stimulation based on the source of its C-tail; ␤ 1 AR with a ␤ 2 AR C-tail underwent down-regulation, and ␤ 2 AR with a ␤ 1 AR C-tail underwent up-regulation. The C-tails had a corresponding effect on agonist-stimulated receptor phosphorylation and internalization with the order being ␤ 2 AR > ␤ 1 AR with ␤ 2 AR C-tail > ␤ 2 AR with a ␤ 1 AR C-tail > ␤ 1 AR. As internalization may be a prerequisite for down-regulation, we addressed this possibility by co-expressing each subtype with arrestin-2. Although ␤ 1 AR internalization was increased to that of ␤ 2 AR, down-regulation still did not occur. Instead, ␤ 1 AR accumulated inside the cells. We conclude that in unstimulated cells, both subtypes appear to be turned over by the same mechanism. Upon agonist stimulation, both subtypes are internalized, and ␤ 2 AR but not ␤ 1 AR undergoes lysosomal degradation, the fate of each subtype being regulated by determinants in its C-tail.

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Regulation of β-adrenoceptor density and mRNA levels in the rat heart cell-line H9c2

Cited by 49 publications

References 27 publications

Nitrogen Compounds Prevent H9c2 Myoblast Oxidative Stress-Induced Mitochondrial Dysfunction and Cell Death

Nitrogen Compounds Prevent H9c2 Myoblast Oxidative Stress-Induced Mitochondrial Dysfunction and Cell Death

A novel signaling pathway for β-adrenergic receptor-mediated activation of phosphoinositide 3-kinase in H9c2 cardiomyocytes

Resistance of the Human β1-Adrenergic Receptor to Agonist-mediated Down-regulation

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