Pertussis toxin treatment prevents 5‐HT5a receptor‐mediated inhibition of cyclic AMP accumulation in rat C6 glioma cells

Thomas, Elizabeth A.; Matli, Jennifer R.; Hu, John L.; Sutcliffe, J. Gregor

doi:10.1002/1097-4547(20000701)61:1<75::aid-jnr9>3.3.co;2-0

Cited by 6 publications

(12 citation statements)

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“…GPCRs signal through heterotrimeric G proteins classified into four protein families: Gs, Gi, Gq and G12/13 (Marinissen and Gutkind, 2001). Pertussis toxin, a specific inhibitor of Gi (Thomas et al, 2000), blocked tropoelastin-mediated migration and actin polymerization of vascular smooth muscle cells (Fig. 4C,D).…”

Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 98%

“…4C). Second, pertussis toxin is composed of two subunits, A and B (Thomas et al, 2000). The A protomer inhibits Gi by ADP ribosylation, while the B protomer facilitates the entry of the toxin into the cell.…”

Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 99%

“…The pertussis toxin-sensitive G protein, Gi, inhibits adenylate cyclase, the enzyme responsible for generating cAMP (Thomas et al, 2000). To obtain direct biochemical evidence that tropoelastin signals through Gi, we measured the level of cAMP in tropoelastin-treated cells.…”

Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 99%

“…To obtain direct biochemical evidence that tropoelastin signals through Gi, we measured the level of cAMP in tropoelastin-treated cells. To measure a reduction in cAMP level, it was necessary to increase the baseline cellular levels of cAMP using either forskolin or cholera toxin, agents that activate adenylate cyclase (Thomas et al, 2000;Coward et al, 1999). When tropoelastin was added to either forskolin or cholera toxin pretreated cells, the reduction in cAMP levels was between 40 and 60%, indicating that Gi was activated and inhibited adenylate cyclase activity (Fig.…”

Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 99%

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A critical role for elastin signaling in vascular morphogenesis and disease

et al. 2003

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Vascular proliferative diseases such as atherosclerosis and coronary restenosis are leading causes of morbidity and mortality in developed nations. Common features associated with these heterogeneous disorders involve phenotypic modulation and subsequent abnormal proliferation and migration of vascular smooth muscle cells into the arterial lumen, leading to neointimal formation and vascular stenosis. This fibrocellular response has largely been attributed to the release of multiple cytokines and growth factors by inflammatory cells. Previously, we demonstrated that the disruption of the elastin matrix leads to defective arterial morphogenesis. Here, we propose that elastin is a potent autocrine regulator of vascular smooth muscle cell activity and that this regulation is important for preventing fibrocellular pathology. Using vascular smooth muscle cells from mice lacking elastin(Eln-/-), we show that elastin induces actin stress fiber organization, inhibits proliferation, regulates migration and signals via a non-integrin, heterotrimeric G-protein-coupled pathway. In a porcine coronary model of restenosis, the therapeutic delivery of exogenous elastin to injured vessels in vivo significantly reduces neointimal formation. These findings indicate that elastin stabilizes the arterial structure by inducing a quiescent contractile state in vascular smooth muscle cells. Together, this work demonstrates that signaling pathways crucial for arterial morphogenesis can play an important role in the pathogenesis and treatment of vascular disease.

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Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 98%

Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 99%

Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 99%

Section: Elastin Signals Via a Non-integrin G-protein Coupled Signalmentioning

confidence: 99%

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A critical role for elastin signaling in vascular morphogenesis and disease

et al. 2003

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“…Initial radioligand binding studies were performed by MDS Pharma Services (Bothell, WA) as previously described for serotonin receptor subtypes 1A, 1B, 2B, 2C, 3, 5A, 6, 7, serotonin transporter [5,6,8,23,31,32,[37][38][39][40][41][43][44][45]47]. Significant binding affinity was only observed at the 5-HT 5a receptor (>50%) for the PE and DCM extracts at a concentration of 50 μg/ml [12].…”

Section: Serotonin Receptor Binding Assaysmentioning

confidence: 99%

Valerian extract and valerenic acid are partial agonists of the 5-HT5a receptor in vitro

Dietz

Mahady

Pauli

et al. 2005

Molecular Brain Research

126

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Insomnia is the most frequently encountered sleep complaint worldwide. While many prescription drugs are used to treat insomnia, extracts of valerian (Valeriana officinalis L., Valerianaceae) are also used for the treatment of insomnia and restlessness. To determine novel mechanisms of action, radioligand binding studies were performed with valerian extracts (100% methanol, 50% methanol, dichloromethane [DCM], and petroleum ether [PE]) at the melatonin, glutamate, and GABA A receptors, and 8 serotonin receptor subtypes. Both DCM and PE extracts had strong binding affinity to the 5-HT 5a receptor, but only weak binding affinity to the 5-HT 2b and the serotonin transporter. Subsequent binding studies focused on the 5-HT 5a receptor due to the distribution of this receptor in the suprachiasmatic nucleus of the brain, which is implicated in the sleep-wake cycle. The PE extract inhibited [ 3 H]lysergic acid diethylamide (LSD) binding to the human 5-HT 5a receptor (86% at 50 μg/ml) and the DCM extract inhibited LSD binding by 51%. Generation of an IC 50 curve for the PE extract produced a biphasic curve, thus GTP shift experiments were also performed. In the absence of GTP, the competition curve was biphasic (two affinity sites) with an IC 50 of 15.7 ng/ml for the high-affinity state and 27.7 μg/ml for the lowaffinity state. The addition of GTP (100 AM) resulted in a right-hand shift of the binding curve with an IC 50 of 11.4 μg/ml. Valerenic acid, the active constituent of both extracts, had an IC 50 of 17.2 AM. These results indicate that valerian and valerenic acid are new partial agonists of the 5-HT 5a receptor.

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Recombinant human serotonin 5A receptors stably expressed in C6 glioma cells couple to multiple signal transduction pathways

Нода

Yasuda

Okada

et al. 2003

Journal of Neurochemistry

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Human serotonin 5A (5-HT 5A ) receptors were stably expressed in undifferentiated C6 glioma. In 5-HT 5A receptors-expressing cells, accumulation of cAMP by forskolin was inhibited by 5-HT as reported previously. Pertussis toxin-sensitive inhibition of ADP-ribosyl cyclase was also observed, indicating a decrease of cyclic ADP ribose, a potential intracellular second messenger mediating ryanodine-sensitive Ca 2+ mobilization. On the other hand, 5-HT-induced outward currents were observed using the patch-clamp technique in whole-cell configuration. The 5-HT-induced outward current was observed in 84% of the patched 5-HT 5A receptor-expressing cells and was concentration-dependent. The 5-HT-induced current was inhibited when intracellular K + was replaced with Cs + but was not significantly inhibited by typical K + channel blockers. The 5-HT-induced current was significantly attenuated by 1,2-bis(2-aminophenoxy)ethane-N,N,N¢,N¢-tetraacetic acid (BAPTA) in the patch pipette. Depleting intracellular Ca 2+ stores by application of caffeine or thapsigargin also blocked the 5-HT-induced current. Blocking G protein, the inositol triphosphate (IP3) receptor, or pretreatment with pertussis toxin, all inhibited the 5-HT-induced current. IP3 showed a transient increase after application of 5-HT in 5-HT 5A receptor-expressing cells. It was concluded that in addition to the inhibition of cAMP accumulation and ADP-ribosyl cyclase activity, 5-HT 5A receptors regulate intracellular Ca 2+ mobilization which is probably a result of the IP3-sensitive Ca 2+ store. These multiple signal transduction systems may induce complex changes in the serotonergic system in brain function. Keywords: adenylyl cyclase, ADP ribosyl cyclase, cAMP, IP3, 5-HT 5A receptors, patch-clamp. The neurotransmitter serotonin (5-HT) is involved in the control of diverse physiological processes including sleep, sexual behavior, food intake, locomotion and mood. At least 13 different 5-HT receptors have been identified to date. The present work concerns one of these, the 5-HT 5 receptor, which belongs to the superfamily of G protein-coupled metabotropic receptors.The two members of the 5-HT 5 receptor subfamily, 5-HT 5A and 5-HT 5B , were identified in mice (Plassat et al. 1992;Matthes et al. 1993) and subsequently in rats (Erlander et al. 1993;Wisden et al. 1993). A cDNA encoding the 5-HT 5A receptor has been cloned from human tissues, while the 5-HT 5B receptor does not seem to be functionally expressed

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Pertussis toxin treatment prevents 5‐HT5a receptor‐mediated inhibition of cyclic AMP accumulation in rat C6 glioma cells

Cited by 6 publications

References 0 publications

A critical role for elastin signaling in vascular morphogenesis and disease

A critical role for elastin signaling in vascular morphogenesis and disease

Valerian extract and valerenic acid are partial agonists of the 5-HT5a receptor in vitro

Recombinant human serotonin 5A receptors stably expressed in C6 glioma cells couple to multiple signal transduction pathways

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