scholarly journals Cyclic AMP-binding protein Epac1 acts as a metabolic sensor to promote cardiomyocyte lipotoxicity

2021 ◽  
Vol 12 (9) ◽  
Author(s):  
Marion Laudette ◽  
Yannis Sainte-Marie ◽  
Grégoire Cousin ◽  
Dorian Bergonnier ◽  
Ismahane Belhabib ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Mitochondrial Dysfunction ◽  
Cyclic Adenosine Monophosphate ◽  
Molecular Complexes ◽  
Adenosine Monophosphate ◽  
Intracellular Camp ◽  
Mitochondrial Enzymes ◽  
Amino Acid Residues ◽  
Α Subunit ◽  
Key Enzyme

AbstractCyclic adenosine monophosphate (cAMP) is a master regulator of mitochondrial metabolism but its precise mechanism of action yet remains unclear. Here, we found that a dietary saturated fatty acid (FA), palmitate increased intracellular cAMP synthesis through the palmitoylation of soluble adenylyl cyclase in cardiomyocytes. cAMP further induced exchange protein directly activated by cyclic AMP 1 (Epac1) activation, which was upregulated in the myocardium of obese patients. Epac1 enhanced the activity of a key enzyme regulating mitochondrial FA uptake, carnitine palmitoyltransferase 1. Consistently, pharmacological or genetic Epac1 inhibition prevented lipid overload, increased FA oxidation (FAO), and protected against mitochondrial dysfunction in cardiomyocytes. In addition, analysis of Epac1 phosphoproteome led us to identify two key mitochondrial enzymes of the the β-oxidation cycle as targets of Epac1, the long-chain FA acyl-CoA dehydrogenase (ACADL) and the 3-ketoacyl-CoA thiolase (3-KAT). Epac1 formed molecular complexes with the Ca2+/calmodulin-dependent protein kinase II (CaMKII), which phosphorylated ACADL and 3-KAT at specific amino acid residues to decrease lipid oxidation. The Epac1-CaMKII axis also interacted with the α subunit of ATP synthase, thereby further impairing mitochondrial energetics. Altogether, these findings indicate that Epac1 disrupts the balance between mitochondrial FA uptake and oxidation leading to lipid accumulation and mitochondrial dysfunction, and ultimately cardiomyocyte death.

scholarly journals . Effect of fluoxetine on the inhibition of adenylate cyclase activity in foskolin-stimulated MLTC-1 leydig cells

2020 ◽  
Vol 17 (4) ◽  
pp. 595-602
Author(s):  
Nguyen Thi Mong Diep ◽  
Nguyen Thi Bich Hang ◽  
Nguyen Le Cong Minh ◽  
Tran Thanh Son ◽  
Nguyen Thuy Duong
Keyword(s):  
Cyclic Amp ◽  
Leydig Cells ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cell Types ◽  
Intracellular Camp ◽  
Atp Levels ◽  
Long Time ◽  
Short Time ◽  
Camp Levels

Fluoxetine (FLX), a widely used antidepressant primarily acting as a selective serotonin reuptake inhibitor, has been shown to exhibit other mechanisms of action in various cell types. Cyclic adenosine monophosphate (cAMP) is a second messenger used for intracellular signal induction. Cyclic AMP is a nucleotide synthesized within the cell from adenosine triphosphate by the adenylyl cyclase enzyme, and is inactivated enzymatically to 5′AMP by hydroxylation with a group of enzymes called phosphodiesterase. The aim of this study was to determine the effects of FLX on MLTC-1 Leydig cells on intracellular cyclic AMP response to forskolin (FSK). MLTC-1 cells were incubated at 37°C in media supplemented with or without different doses of FLX (0, 0.156, 0.3125, 0.625, 1.25, 2.5, 5 and 10 µM). We then looked for how the concentration of FLX for a short-time (2 hours) and a long-time (24 hours) affects the concentration of intracellular cyclic AMP response to FSK and ATP levels on MLTC-1 cells. Our results show that FLX decreased the intracellular cAMP response to FSK depending on FLX concentration. FLX decreased significantly cAMP levels only at 10 µM after 2 hours of incubation but after 24 hours of incubation FLX caused an effect on cAMP levels at 5 µM and at 10 µM. Moreover, as expected, FLX also caused a decline of steroidogenesis, which is under the control of cAMP and ATP levels in the cells. Taken together, these findings demonstrate that the inhibition of cAMP synthesis by FLX is dose-dependent, and that FLX also inhibited hormone-induced steroidogenesis in MLTC-1 cells.

scholarly journals Anti-Allergic and Anti-Inflammatory Effects of Undecane on Mast Cells and Keratinocytes

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1554
Author(s):  
Dabin Choi ◽  
Wesuk Kang ◽  
Taesun Park
Keyword(s):  
Mast Cells ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Allergic Diseases ◽  
Intracellular Camp ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
Skin Conditions ◽  
Factor Α ◽  
Camp Levels

The critical roles of keratinocytes and resident mast cells in skin allergy and inflammation have been highlighted in many studies. Cyclic adenosine monophosphate (cAMP), the intracellular second messenger, has also recently emerged as a target molecule in the immune reaction underlying inflammatory skin conditions. Here, we investigated whether undecane, a naturally occurring plant compound, has anti-allergic and anti-inflammatory activities on sensitized rat basophilic leukemia (RBL-2H3) mast cells and HaCaT keratinocytes and we further explored the potential involvement of the cAMP as a molecular target for undecane. We confirmed that undecane increased intracellular cAMP levels in mast cells and keratinocytes. In sensitized mast cells, undecane inhibited degranulation and the secretion of histamine and tumor necrosis factor α (TNF-α). In addition, in sensitized keratinocytes, undecane reversed the increased levels of p38 phosphorylation, nuclear factor kappaB (NF-κB) transcriptional activity and target cytokine/chemokine genes, including thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC) and interleukin-8 (IL-8). These results suggest that undecane may be useful for the prevention or treatment of skin inflammatory disorders, such as atopic dermatitis, and other allergic diseases.

scholarly journals Rapid Bioassay for Detection of Thyroid-Stimulating Antibodies Using Cyclic Adenosine Monophosphate-Gated Calcium Channel and Aequorin

2015 ◽  
Vol 4 (1) ◽  
pp. 14-19 ◽  
Author(s):  
Naohiro Araki ◽  
Mitsuru Iida ◽  
Nobuyuki Amino ◽  
Shinji Morita ◽  
Akane Ide ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Hormone Receptor ◽  
Chinese Hamster ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Thyroid Stimulating Hormone ◽  
Ovary Cell ◽  
Intracellular Camp ◽  
Thyroid Stimulating Antibodies ◽  
Stimulating Hormone

Background: Thyroid-stimulating antibodies (TSAb) are known to be responsible for hyperthyroidism in Graves' disease (GD). The conventional methods to measure TSAb depend on cell-based assays that require cumbersome procedures and a sterilized tissue culture technique. The aim of the present study was to develop a ready-to-use cell-based assay for measuring TSAb activity without requiring sterilized conditions. Methods: We developed a new assay kit using a frozen Chinese hamster ovary cell line expressing the thyroid-stimulating hormone receptor, cyclic adenosine monophosphate (cAMP)-gated calcium channel and aequorin, tentatively named the aequorin TSAb assay. Activated stimulatory G-protein-coupled adenylate cyclase increases intracellular cAMP, which then binds to the cyclic nucleotide-gated calcium channel. Activation of this channel allows Ca2+ to enter the cell, and the influx of Ca2+ can be measured with aequorin, which is quantified by a luminometer. Results can be obtained in only 4 h without sterilized conditions. TSAb activities were expressed by international units using the NIBSC 08/204 standard. Results: Positive results of aequorin TSAb were obtained in 197 of 199 (98.9%) of untreated patients with GD. Only 1 of 42 (2.3%) patients with painless thyroiditis had a weakly positive aequorin TSAb. All 45 patients with subacute thyroiditis and 185 normal subjects showed negative aequorin TSAb. As for chronic thyroiditis, all 52 euthyroid patients showed negative aequorin TSAb, but 8 of 50 (16.0%) hypothyroid patients had a positive reaction. However, these positive reactions were not induced by serum thyroid-stimulating hormone (TSH) and were thought to be induced by the stimulating activity of anti-TSH receptor immunoglobulins. Conventional porcine TSAb and Elecsys thyroid-stimulating hormone receptor antibodies were positive in 69.3 and 95.5% of GD, respectively. Conclusion: The aequorin TSAb assay was positive in 98.9% of GD and was more sensitive than the conventional assay. This assay can be conducted in only 4 h without sterilized conditions and is practically useful in general clinical laboratories.

scholarly journals SITE OF ACTION OF 3',5'-CYCLIC ADENOSINE MONOPHOSPHATE IN PRODUCTION OF TRYPTOPHANASE IN ESCHERICHIA COLI

Genetics ◽  
1972 ◽  
Vol 70 (1) ◽  
pp. 175-180
Author(s):  
LaDonna Immken ◽  
David Apirion
Keyword(s):  
Escherichia Coli ◽  
Cyclic Amp ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Polypeptide Chain ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Chain Elongation ◽  
Site Of Action

ABSTRACT 3″,5″ cyclic-AMP (cAMP) will stimulate the rate of tryptophanase synthesis in Escherichia coli cultures induced with tryptophan. Adding cAMP after the initiation of messenger RNA synthesis was blocked by rifampicin, did not stimulate tryptophanase synthesis. This indicates that cAMP acts at initiation of either transcription or translation and not at the level of chain elongation of either the messenger or the polypeptide chain.

scholarly journals Cyclic AMP response element-binding protein is required in excitatory neurons in the forebrain to sustain wakefulness

SLEEP ◽  
2020 ◽  
Author(s):  
Mathieu E Wimmer ◽  
Rosa Cui ◽  
Jennifer M Blackwell ◽  
Ted Abel
Keyword(s):  
Cyclic Amp ◽  
Intracellular Signaling ◽  
Target Genes ◽  
Binding Protein ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Response Element ◽  
Creb Phosphorylation ◽  
Element Binding Protein ◽  
And Control

Abstract The molecular and intracellular signaling processes that control sleep and wake states remain largely unknown. A consistent observation is that the cyclic adenosine monophosphate (AMP) response element-binding protein (CREB), an activity-dependent transcription factor, is differentially activated during sleep and wakefulness. CREB is phosphorylated by the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway as well as other kinases, and phosphorylated CREB promotes the transcription of target genes. Genetic studies in flies and mice suggest that CREB signaling influences sleep/wake states by promoting and stabilizing wakefulness. However, it remains unclear where in the brain CREB is required to drive wakefulness. In rats, CREB phosphorylation increases in the cerebral cortex during wakefulness and decreases during sleep, but it is not known if this change is functionally relevant to the maintenance of wakefulness. Here, we used the Cre/lox system to conditionally delete CREB in the forebrain (FB) and in the locus coeruleus (LC), two regions known to be important for the production of arousal and wakefulness. We used polysomnography to measure sleep/wake levels and sleep architecture in conditional CREB mutant mice and control littermates. We found that FB-specific deletion of CREB decreased wakefulness and increased non-rapid eye movement sleep. Mice lacking CREB in the FB were unable to sustain normal periods of wakefulness. On the other hand, deletion of CREB from LC neurons did not change sleep/wake levels or sleep/wake architecture. Taken together, these results suggest that CREB is required in neurons within the FB but not in the LC to promote and stabilize wakefulness.

Lithium administration and phosphate excretion

1976 ◽  
Vol 231 (4) ◽  
pp. 1140-1146 ◽  
Author(s):  
JA Arruda ◽  
JM Richardson ◽  
JA Wolfson ◽  
L Nascimento ◽  
DR Rademacher ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Renal Cortex ◽  
Cyclic Adenosine Monophosphate ◽  
Fractional Excretion ◽  
Adenosine Monophosphate ◽  
Adenyl Cyclase ◽  
Phosphate Excretion ◽  
Camp System

The phosphaturic effect of parathyroid hormone (PTH), cyclic adenosine monophosphate (cAMP), acetazolamide (Az), and HCO3 loading was studied in normal, thyroparathyroidectomized (TPTX), and Li-treated dogs. PTH administration to normal animals markedly increased fractional excretion (F) of PO4 but had a blunted effect on FPO4 in the Li-treated animals. Cyclic AMP likewise markedly increased FPO4 in the normal animals but had a markedly blunted effect in the Li-treated animals. Az led to a significant increase in FNa, FHCO3, and FPO4 in the normal animals. In the Li-treated dogs, Az induced a significant natriuresis and bicarbonaturia but failed to increase phosphaturia. HCO3 loading in normal dogs caused a significant phosphaturia while having little effect on FPO4 in Li-treated dogs. HCO3 loading to TPTX dogs was associated with a lower FPO4 as compared to normal HCO3-loaded animals. These data suggest that Li administration not only blocks the adenyl cyclase-cAMP system in the renal cortex, but it may also interfere with a step distal to the formation of cAMP, since the phosphaturic effect of both PTH and cAMP was markedly diminished in Li-treated animals.

Involvement of Cyclic Adenosine Monophosphate in the Regulation of Pupal Color Adaptation of the Butterfly, Inachis io

1997 ◽  
Vol 52 (3-4) ◽  
pp. 255-258 ◽  
Author(s):  
Gerhard Starnecker
Keyword(s):  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Intracellular Camp ◽  
Dependent Manner ◽  
Color Adaptation ◽  
Yellow Color ◽  
Pde Inhibitors ◽  
Inachis Io ◽  
Yellow Coloration ◽  
Entire Central Nervous System

AbstractIn the butterfly Inachis io, a pupal melanization reducing factor (PMRF) which is located throughout the entire central nervous system controls the intensity of pigmentation of pupal cuticle depending on the background color of the pupation site. PMRF does not only reduce melanization but, in addition, enhances lutein incorporation in a dose-dependent manner to form pupae with yellow color on bright backgrounds.The present paper reports on the effects on pupal pigmentation caused by cyclic nucleo­ tides and phosphodiesterase (PDE) inhibitors which prevent degradation of cyclic nucleo­ tides. The injection of cAMP did not alter pupal coloration whereas its membrane-permeable analog dibutyryl-cAMP mimicked dose-dependently PMRF activity. Thus, pupae of reduced melanization and, in addition, enhanced yellow coloration were formed. This indicates that an increased intracellular cAMP level is capable of mediating PMRF effect. Also, the injection of the PDE inhibitor isobutylmethylxanthine (IBMX) caused dose-dependently pupae of reduced melanization and enhanced lutein incorporation.Theophylline (another PDE inhibitor) was only slightly effective (23% inhibition of melanization) at the highest dose compared to IBMX. The injection of cGMP and its analog dibutyryl-cGMP exhibited no melanization reducing effect.Extracts of abdominal ganglia (AG) which contained PMRF activity caused significantly brighter pupae when injected in combination with IBMX. However, this stimulation by IBMX became no longer effective at higher AG doses. Therefore, the present results are suggestive of an involvement of cAMP as a second messenger in the action of PMRF on pupal color adaptation.

Secondary Messenger Systems in PTSD

2016 ◽  
Author(s):  
Ulrike Schmidt
Keyword(s):  
Second Messengers ◽  
Cyclic Adenosine Monophosphate ◽  
Second Messenger ◽  
Adenosine Monophosphate ◽  
Cyclic Guanosine Monophosphate ◽  
Brain Regions ◽  
Guanosine Monophosphate ◽  
Intracellular Camp ◽  
Post Traumatic Stress ◽  
Secondary Messenger

Second messengers such as cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), inositoltriphosphate, and diacylglycerol (DAG) are a prerequisite for the signal transduction of extracellular receptors. The latter are central for cellular function and thus are implicated in the pathobiology of a variety of disorders, such as schizophrenia, bipolar disorder, major depression, and post-traumatic stress disorder (PTSD). This chapter focuses on the involvement of second messenger molecules and their regulators as direct targets in human and animal PTSD and aims to stimulate the underdeveloped research in this field. The synthesis of literature reveals that second messengers clearly play a central role in PTSD-associated brain regions and processes. In particular, pituitary adenylate cyclase-activating polypeptide (PACAP), an important regulator of intracellular cAMP levels, as well as protein kinase c, the major target of DAG, belong to the hitherto most promising PTSD candidate molecules directly involved in second messenger signaling.

scholarly journals IMMUNOLOGICAL RELEASE OF HISTAMINE AND SLOW REACTING SUBSTANCE OF ANAPHYLAXIS FROM HUMAN LUNG

1972 ◽  
Vol 136 (3) ◽  
pp. 556-567 ◽  
Author(s):  
Michael Kaliner ◽  
Robert P. Orange ◽  
K. Frank Austen
Keyword(s):  
Cyclic Amp ◽  
Cyclic Gmp ◽  
Human Lung ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Target Cells ◽  
Human Lung Tissue ◽  
Adrenergic Agents ◽  
Protein Assay

The immunologic release of histamine and slow reacting substance of anaphylaxis (SRS-A) from human lung tissue can be enhanced by stimulation with either alpha adrenergic agents (phenylephrine or norepinephrine in the presence of propranolol) or cholinergic agents (acetylcholine or Carbachol). The finding that atropine prevents cholinergic but not comparable alpha adrenergic enhancement is consistent with the view that cholinergic and alpha adrenergic agonists interact with separate receptor sites on the target cells involved in the immunologic release of chemical mediators. The consistent qualitative relationship between the antigen-induced release of mediators and the level of cyclic adenosine monophosphate (cyclic AMP) as measured by the isolation of 14C-labeled cyclic AMP after incorporation of adenine-14C into the tissues or by the cyclic AMP binding protein assay suggests that changes in the level of this cyclic nucleotide mediate adrenergic modulation of the release of histamine and SRS-A. The addition of 8-bromo-cyclic guanosine monophosphate (cyclic GMP) produces an enhancement of the immunologic release of mediators while dibutyryl cyclic AMP is inhibitory. As cholinergic-induced enhancement was not associated with a measurable change in the levels of cyclic AMP, the possibility is suggested that cyclic GMP may be the intracellular mediator of cholinergic-induced enhancement of the immunologic release of histamine and SRS-A.

scholarly journals Effect of cAMP Signaling Regulation in Osteogenic Differentiation of Adipose-Derived Mesenchymal Stem Cells

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1587 ◽  
Author(s):  
Sławomir Rumiński ◽  
Ilona Kalaszczyńska ◽  
Małgorzata Lewandowska-Szumieł
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Osteogenic Differentiation ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Camp Signaling ◽  
Intracellular Camp ◽  
Successful Implementation ◽  
Induced Apoptosis ◽  
Inhibitor Of Dna Binding

The successful implementation of adipose-derived mesenchymal stem cells (ADSCs) in bone regeneration depends on efficient osteogenic differentiation. However, a literature survey and our own experience demonstrated that current differentiation methods are not effective enough. Since the differentiation of mesenchymal stem cells (MSCs) into osteoblasts and adipocytes can be regulated by cyclic adenosine monophosphate (cAMP) signaling, we investigated the effects of cAMP activator, forskolin, and inhibitor, SQ 22,536, on the early and late osteogenic differentiation of ADSCs cultured in spheroids or in a monolayer. Intracellular cAMP concentration, protein kinase A (PKA) activity, and inhibitor of DNA binding 2 (ID2) expression examination confirmed cAMP up- and downregulation. cAMP upregulation inhibited the cell cycle and protected ADSCs from osteogenic medium (OM)-induced apoptosis. Surprisingly, the upregulation of cAMP level at the early stages of osteogenic differentiation downregulated the expression of osteogenic markers RUNX2, Osterix, and IBSP, which was more significant in spheroids, and it is used for the more efficient commitment of ADSCs into preosteoblasts, according to the previously reported protocol. However, cAMP upregulation in a culture of ADSCs in spheroids resulted in significantly increased osteocalcin production and mineralization. Thus, undifferentiated and predifferentiated ADSCs respond differently to cAMP pathway stimulation in terms of osteogenesis, which might explain the ambiguous results from the literature.

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