Adenosine effects on the rat pineal gland in vitro: Cyclic adenosine monophosphate levels, N-acetyltransferase, and thyroxine type II 5'-deiodinase activities and melatonin production

In rodents, the melatonin production by the pineal gland is controlled through adrenergic signaling from the suprachiasmatic nuclei and regulation of the principal enzyme in its synthesis, arylalkylamine-N-acetyltransferase (AANAT). In the present study, we identified increased isoprenaline-induced aa-nat expression and nocturnal AANAT activity in the pineal glands in response to the silencing of the signal transducer and activator of transcription 3 (STAT3) with siRNA or STAT3 inhibitors WP1066 and AZD1480. This AANAT activity enhancement in vivo did not interfere with light-induced AANAT suppression. Systemic or in vitro lipopolysaccharide (LPS) administration markedly increased Stat3 expression and STAT3 phosphorylation, but it did not significantly affect AANAT expression or activity. Simultaneous LPS administration and Stat3 silencing enhanced the aa-nat transcription and AANAT activity to a similar extent as Stat3 inhibition without LPS co-administration. Furthermore, we describe the circadian rhythmicity in Stat3 expression and the phosphorylated form of STAT3 protein in the rat pineal gland. Our data suggest that the higher nocturnal endogenous level of STAT3 in the pineal gland decelerates or hampers the process of NA-induced AANAT activation or affects the AANAT enzyme stability.

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PKA-RII subunit phosphorylation precedes activation by cAMP and regulates activity termination

The Journal of Cell Biology ◽

10.1083/jcb.201708053 ◽

2018 ◽

Vol 217 (6) ◽

pp. 2167-2184 ◽

Cited By ~ 15

Author(s):

Jörg Isensee ◽

Melanie Kaufholz ◽

Matthias J. Knape ◽

Jan Hasenauer ◽

Hanna Hammerich ◽

...

Keyword(s):

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Mechanistic Modeling ◽

Type Ii ◽

Dependent Protein Kinase ◽

Catalytic Subunits ◽

Dependent Protein ◽

Inhibitory Domain ◽

Activity Dependent

Type II isoforms of cyclic adenosine monophosphate (cAMP)–dependent protein kinase A (PKA-II) contain a phosphorylatable epitope within the inhibitory domain of RII subunits (pRII) with still unclear function. In vitro, RII phosphorylation occurs in the absence of cAMP, whereas staining of cells with pRII-specific antibodies revealed a cAMP-dependent pattern. In sensory neurons, we found that increased pRII immunoreactivity reflects increased accessibility of the already phosphorylated RII epitope during cAMP-induced opening of the tetrameric RII2:C2 holoenzyme. Accordingly, induction of pRII by cAMP was sensitive to novel inhibitors of dissociation, whereas blocking catalytic activity was ineffective. Also in vitro, cAMP increased the binding of pRII antibodies to RII2:C2 holoenzymes. Identification of an antibody specific for the glycine-rich loop of catalytic subunits facing the pRII-epitope confirmed activity-dependent binding with similar kinetics, proving that the reassociation is rapid and precisely controlled. Mechanistic modeling further supported that RII phosphorylation precedes cAMP binding and controls the inactivation by modulating the reassociation involving the coordinated action of phosphodiesterases and phosphatases.

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Dobutamine Antagonizes Epinephrine's Biochemical and Cardiotonic Effects

Anesthesiology ◽

10.1097/00000542-199807000-00010 ◽

1998 ◽

Vol 89 (1) ◽

pp. 49-57 ◽

Cited By ~ 29

Author(s):

Richard C. Prielipp ◽

Drew A. MacGregor ◽

Roger L. Royster ◽

Neal D. Kon ◽

Michael H. Hines ◽

...

Keyword(s):

Artery Bypass ◽

Phase 1 ◽

Human Lymphocytes ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Camp Production ◽

Isobolographic Analysis ◽

Camp Generation ◽

Vitro Model

Background Patients may receive more than one positive inotropic drug to improve myocardial function and cardiac output, with the assumption that the effects of two drugs are additive. The authors hypothesized that combinations of dobutamine and epinephrine would produce additive biochemical and hemodynamic effects. Methods The study was performed in two parts. Phase 1 used human lymphocytes in an in vitro model of cyclic adenosine monophosphate (cAMP) generation in response to dobutamine (10(-8) to 10(-4) M) or epinephrine (10(-9) M to 10(-5) M), and dobutamine and epinephrine together. Phase 2 was a clinical study in patients after aortocoronary artery bypass in which isobolographic analysis compared the cardiotonic effects of dobutamine (1.25, 2.5, or 5 microg x kg(-1) x min(-1)) or epinephrine (10, 20, or 40 ng x kg(-l) x min(-1)), alone or in combination. Results In phase 1, dobutamine increased cAMP production 41%, whereas epinephrine increased cAMP concentration approximately 200%. However, when epinephrine (10(-6) M) and dobutamine were combined, dobutamine reduced cAMP production at concentrations between 10(-6) to 10(-4) M (P = 0.001). In patients, 1.25 to 5 microg x kg(-1) x min(-1) dobutamine increased the cardiac index (CI) 15-28%. Epinephrine also increased the CI with each increase in dose. However, combining epinephrine with the two larger doses of dobutamine (2.5 and 5microg x kg(-1) x mi(-1)) did not increase the CI beyond that achieved with epinephrine and the lowest dose of dobutamine (1.25 microg x kg(-1) x min(-1)). In addition, the isobolographic analysis for equieffective concentrations of dobutamine and epinephrine suggests subadditive effects. Conclusions Dobutamine inhibits epinephrine-induced production of cAMP in human lymphocytes and appears to be subadditive by clinical and isobolographic analyses of the cardiotonic effects. These findings suggest that combinations of dobutamine and epinephrine may be less than additive.

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The nucleoporin RanBP2 tethers the cAMP effector Epac1 and inhibits its catalytic activity

The Journal of Cell Biology ◽

10.1083/jcb.201011126 ◽

2011 ◽

Vol 193 (6) ◽

pp. 1009-1020 ◽

Cited By ~ 33

Author(s):

Martijn Gloerich ◽

Marjolein J. Vliem ◽

Esther Prummel ◽

Lars A.T. Meijer ◽

Marije G.A. Rensen ◽

...

Keyword(s):

Catalytic Activity ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Negative Regulator ◽

Camp Signaling ◽

Nuclear Pore ◽

Nucleotide Exchange ◽

Nucleotide Exchange Factor ◽

Wide Range

Cyclic adenosine monophosphate (cAMP) is a second messenger that relays a wide range of hormone responses. In this paper, we demonstrate that the nuclear pore component RanBP2 acts as a negative regulator of cAMP signaling through Epac1, a cAMP-regulated guanine nucleotide exchange factor for Rap. We show that Epac1 directly interacts with the zinc fingers (ZNFs) of RanBP2, tethering Epac1 to the nuclear pore complex (NPC). RanBP2 inhibits the catalytic activity of Epac1 in vitro by binding to its catalytic CDC25 homology domain. Accordingly, cellular depletion of RanBP2 releases Epac1 from the NPC and enhances cAMP-induced Rap activation and cell adhesion. Epac1 also is released upon phosphorylation of the ZNFs of RanBP2, demonstrating that the interaction can be regulated by posttranslational modification. These results reveal a novel mechanism of Epac1 regulation and elucidate an unexpected link between the NPC and cAMP signaling.

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Pretranslational Regulation of Rhythmic Type II Iodothyronine Deiodinase Expression by β-Adrenergic Mechanism in the Rat Pineal Gland*

Endocrinology ◽

10.1210/endo.140.3.6594 ◽

1999 ◽

Vol 140 (3) ◽

pp. 1272-1278 ◽

Cited By ~ 19

Author(s):

Yuji Kamiya ◽

Masami Murakami ◽

Osamu Araki ◽

Yasuhiro Hosoi ◽

Takayuki Ogiwara ◽

...

Keyword(s):

Pineal Gland ◽

Type Ii ◽

Iodothyronine Deiodinase ◽

Adrenergic Mechanism ◽

Rat Pineal Gland

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Spatial targeting of type II protein kinase A to filopodia mediates the regulation of growth cone guidance by cAMP

The Journal of Cell Biology ◽

10.1083/jcb.200607128 ◽

2007 ◽

Vol 176 (1) ◽

pp. 101-111 ◽

Cited By ~ 28

Author(s):

Jianzhong Han ◽

Liang Han ◽

Priyanka Tiwari ◽

Zhexing Wen ◽

James Q. Zheng

Keyword(s):

Protein Kinase ◽

Protein Kinase A ◽

Growth Cone ◽

Regulatory Protein ◽

Cyclic Adenosine Monophosphate ◽

Spatial Localization ◽

Adenosine Monophosphate ◽

Type Ii ◽

Regulation Of Growth ◽

Kinase A

The second messenger cyclic adenosine monophosphate (cAMP) plays a pivotal role in axonal growth and guidance, but its downstream mechanisms remain elusive. In this study, we report that type II protein kinase A (PKA) is highly enriched in growth cone filopodia, and this spatial localization enables the coupling of cAMP signaling to its specific effectors to regulate guidance responses. Disrupting the localization of PKA to filopodia impairs cAMP-mediated growth cone attraction and prevents the switching of repulsive responses to attraction by elevated cAMP. Our data further show that PKA targets protein phosphatase-1 (PP1) through the phosphorylation of a regulatory protein inhibitor-1 (I-1) to promote growth cone attraction. Finally, we find that I-1 and PP1 mediate growth cone repulsion induced by myelin-associated glycoprotein. These findings demonstrate that the spatial localization of type II PKA to growth cone filopodia plays an important role in the regulation of growth cone motility and guidance by cAMP.

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Ectopic Growth Hormone-Releasing Factor and Dibutyryl Cyclic Adenosine Monophosphate-Stimulated Growth Hormone Release in Vitro: Effects of Corticosterone and Estradiol*

Endocrinology ◽

10.1210/endo-113-4-1191 ◽

1983 ◽

Vol 113 (4) ◽

pp. 1191-1196 ◽

Cited By ~ 26

Author(s):

CHERYLE B. WEBB ◽

MARTA SZABO ◽

LAWRENCE A. FROHMAN

Keyword(s):

Growth Hormone ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Hormone Release ◽

Growth Hormone Release ◽

Growth Hormone Releasing Factor ◽

Release In Vitro ◽

In Vitro Effects

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Thrombin-induced gap formation in confluent endothelial cell monolayers in vitro

Blood ◽

10.1182/blood.v62.3.549.549 ◽

1983 ◽

Vol 62 (3) ◽

pp. 549-556 ◽

Cited By ~ 109

Author(s):

M Laposata ◽

DK Dovnarsky ◽

HS Shin

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Umbilical Vein ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Gap Formation ◽

Culture Dish ◽

Cell Monolayers ◽

Umbilical Vein Endothelial Cells

Abstract When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer, disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10(-2) U/ml (10(-10)M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plus heparin or by preincubation of the monolayers with dibutyryl cyclic adenosine monophosphate (dbcAMP). Histamine also induced gap formation in endothelial cell monolayers. Both pyrilamine and cimetidine prevented the histamine-induced effect, but they had no effect on thrombin- induced gap formation. Intact monolayers were not disrupted by bradykinin, serotonin, C5a, or C3a. Our results suggest that small amounts of thrombin can induce repeated and transient exposure of the subendothelium, a situation believed to be conducive to atherogenesis and thrombosis.

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