Upregulation of cAMP prevents antibody-mediated thrombus formation in COVID-19

Abstract Thromboembolic events are frequently reported in patients infected with the SARS-CoV-2 virus. The exact mechanisms of COVID-19-associated hypercoagulopathy, however, remain elusive. Recently, we observed that platelets (PLTs) from patients with severe COVID-19 infection express high levels of procoagulant markers, which were found to be associated with increased risk for thrombosis. In the current study, we investigated the time course as well as the mechanisms leading to procoagulant PLTs in COVID-19. Our study demonstrates the presence of PLT-reactive IgG antibodies that induce marked changes in PLTs in terms of increased inner-mitochondrial transmembrane potential (Δψ) depolarization, phosphatidylserine (PS) externalization, and P-selectin expression. The IgG-induced procoagulant PLTs and increased thrombus formation were mediated by ligation of PLT Fc-γ RIIA (FcγRIIA). In addition, contents of calcium and cyclic-adenosine-monophosphate (cAMP) in PLTs were identified to play a central role in antibody-induced procoagulant PLT formation. Most importantly, antibody-induced procoagulant events, as well as increased thrombus formation in severe COVID-19, were inhibited by Iloprost, a clinically approved therapeutic agent that increases the intracellular cAMP levels in PLTs. Our data indicate that upregulation of cAMP could be a potential therapeutic target to prevent antibody-mediated coagulopathy in COVID-19 disease.

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

Molecules ◽

10.3390/molecules25071554 ◽

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.

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Initial accumulation of platelets during arterial thrombus formation in vivo is inhibited by elevation of basal cAMP levels

Blood ◽

10.1182/blood-2003-04-1133 ◽

2004 ◽

Vol 103 (6) ◽

pp. 2127-2134 ◽

Cited By ~ 59

Author(s):

Derek S. Sim ◽

Glenn Merrill-Skoloff ◽

Barbara C. Furie ◽

Bruce Furie ◽

Robert Flaumenhaft

Keyword(s):

Vascular Injury ◽

Intracellular Signaling ◽

Thrombus Formation ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

In Vivo Model ◽

The Status ◽

Platelet Accumulation ◽

Camp Levels

Abstract Platelet accumulation at sites of vascular injury is the primary event in arterial thrombosis. Initial platelet accrual into thrombi is mediated by interactions of platelet adhesion receptors with ligands on the injured endothelium or in the sub-endothelial matrix. The role of intracellular signals in initial platelet accumulation at sites of endothelial injury, however, is the subject of debate. We have used a newly discovered inhibitor of phosphodiesterase 3A (PDE3A) and the well-characterized PDE3A inhibitor, cilostazol, to modulate 3′,5′-cyclic adenosine monophosphate (cAMP) levels in an in vivo model that enables the kinetic analysis of platelet accumulation. These studies demonstrate that elevation of basal cAMP levels results in an overall decline in platelet accumulation at the site of vascular injury. In particular, the initial rate of accumulation of platelets is inhibited by elevation of cAMP. Analysis of the kinetics of individual platelets at injury sites using intravital microscopy demonstrates that cAMP directs the rate at which platelets attach to and detach from thrombi. These studies demonstrate that cAMP in circulating platelets controls attachment to and detachment from sites of arteriolar injury. Thus, the status of the intracellular signaling machinery prior to engagement of platelet receptors influences the rate of platelet accumulation during thrombus formation.

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Genetic Polymorphisms of the ß2-Adrenergic Receptor Relate to Guanosine Protein-coupled Stimulator Receptor Dysfunction in Fibromyalgia Syndrome

The Journal of Rheumatology ◽

10.3899/jrheum.101104 ◽

2011 ◽

Vol 38 (6) ◽

pp. 1095-1103 ◽

Cited By ~ 17

Author(s):

YANGMING XIAO ◽

WEIJING HE ◽

I. JON RUSSELL

Keyword(s):

Adrenergic Receptor ◽

Fibromyalgia Syndrome ◽

Mononuclear Cells ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Intracellular Camp ◽

Peripheral Blood Mononuclear ◽

Genotype Frequencies ◽

Camp Levels

Objective.To determine the genotype frequencies of ß2-adrenergic receptor (ß2AR) gene polymorphisms (Gly16Arg, Glu27Gln) in patients with fibromyalgia syndrome (FM) by comparison with unrelated healthy controls. We sought any clinical association with these polymorphisms and determined whether the polymorphisms would associate with a biologic guanosine protein-coupled stimulator receptor (Gs) dysfunction in FM.Methods.Study subjects included 97 clinically characterized patients with FM and 59 controls. The ß2AR polymorphisms at codons 16 and 27 were determined using polymerase chain reaction-restriction fragment length polymorphism. The Gs functions of peripheral blood mononuclear cells (PBMC) were tested using isoproterenol (ISO) as the adrenergic Gs ligand and measuring intracellular cyclic adenosine monophosphate (cAMP) levels.Results.The frequency of the ß2AR gene polymorphism Gly16Arg in FM (43.5%) was significantly lower than in controls (63.2%), suggesting that this genotype might have some effect on the risk of developing FM. The only clinical association in FM was with sleep dysfunction. Patients with FM who carried the ß2AR polymorphism Arg16Arg also exhibited significantly lower PBMC basal cAMP levels (p < 0.05) and lower ISO-stimulated cAMP levels (p < 0.05) than FM carrying Gly16Gly or Gly16Arg.Conclusion.This confirms a relationship between ß2AR polymorphism and FM. It is the first study to demonstrate ß2AR polymorphism-related differences in intracellular cAMP responses of FM PBMC after ß2AR stimulationin vitro. These findings may explain some of the differences in responsiveness of FM subgroups to the adrenergic agonist medications currently approved for FM treatment.

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Shockwaves Suppress Adipocyte Differentiation via Decrease in PPARγ

Cells ◽

10.3390/cells9010166 ◽

2020 ◽

Vol 9 (1) ◽

pp. 166

Author(s):

Wonkyoung Cho ◽

SeoYeon Kim ◽

Myeongsook Jeong ◽

Young Mi Park

Keyword(s):

Adipocyte Differentiation ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Intracellular Camp ◽

Peroxisome Proliferator ◽

Mechanical Stimuli ◽

Western Blots ◽

Peroxisome Proliferator Activated Receptor ◽

Pparγ Expression ◽

Camp Levels

Adipogenesis is a crucial cellular process that contributes to the expansion of adipose tissue in obesity. Shockwaves are mechanical stimuli that transmit signals to cause biological responses. The purpose of this study is to evaluate the effects of shockwaves on adipogenesis. We treated 3T3L-1 cells and human primary preadipocytes for differentiation with or without shockwaves. Western blots and quantitative real-time reverse transcriptase PCR (qRT-PCR) for adipocyte markers including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT-enhancer-binding proteins (C/EBPα) were performed. Extracellular adenosine triphosphate (ATP) and intracellular cyclic adenosine monophosphate (cAMP) levels, which are known to affect adipocyte differentiation, were measured. Shockwave treatment decreased intracellular lipid droplet accumulation in primary human preadipocytes and 3T3-L1 cells after 11–12 days of differentiation. Levels of key adipogenic transcriptional factors PPARγ and/or C/EBPα were lower in shockwave-treated human primary preadipocytes and 3T3L-1 cells after 12–13 days of differentiation than in shockwave-untreated cells. Shockwave treatment induced release of extracellular ATP from preadipocytes and decreased intracellular cAMP levels. Shockwave-treated preadipocytes showed a higher level of β-catenin and less PPARγ expression than shockwave-untreated cells. Supplementation with 8-bromo-cAMP analog after shockwave treatment rescued adipocyte differentiation by preventing the effect of shockwaves on β-catenin, Wnt10b mRNA, and PPARγ expression. Low-energy shockwaves suppressed adipocyte differentiation by decreasing PPARγ. Our study suggests an insight into potential uses of shockwave-treatment for obesity.

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

Vietnam Journal of Biotechnology ◽

10.15625/1811-4989/17/4/14743 ◽

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.

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Caffeine in the Treatment of Atopic Dermatitis and Psoriasis: A Review

SKIN The Journal of Cutaneous Medicine ◽

10.25251/skin.3.2.38 ◽

2019 ◽

Vol 3 (2) ◽

pp. 59-71 ◽

Cited By ~ 1

Author(s):

Mais Bassam Alashqar

Keyword(s):

Atopic Dermatitis ◽

Skin Diseases ◽

Kinase Inhibitor ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Intracellular Camp ◽

Ataxia Telangiectasia Mutated ◽

Inflammatory Skin Diseases ◽

Camp Levels ◽

Effective Adjunct

Atopic dermatitis (AD) and psoriasis are inflammatory skin diseases. AD is characterized by immune dysregulation and barrier impairment, while psoriasis is by immune dysfunction and resultant keratinocyte hyper-proliferation. Caffeine has shown effective in ameliorating the symptoms of both diseases, but it is not conclusive through which pathways. The aim of this study was to provide a detailed discussion of available work on this topic, as well as known modes of action of caffeine that are relevant to these two conditions. After an extensive review of the literature, we found that both diseases have decreased intracellular cyclic adenosine monophosphate (cAMP) levels in cutaneous leukocytes, so it is very likely that being a methylxanthine, and hence a phosphodiesterase (PDE) inhibitor, caffeine raises intracellular cAMP levels, which suppresses inflammatory pathways and potentiates anti-inflammatory ones. Moreover, caffeine is known to be an ATR (ataxia-telangiectasia mutated) kinase and an ATM (ATM- and Rad3-Related) kinase inhibitor, which promotes prompt apoptosis of damaged cells. It was also found to have anti-necrotic effects in reactive oxygen species (ROS)-damaged cells. These pro-apoptotic and anti-necrotic properties may also be reducing the inflammation. Finally, caffeine's metabolites have shown antioxidising effects against ROS, which certainly would reduce inflammation caused by lipid peroxidation, DNA damage and organelle destruction. We find that caffeine acts in a number of ways to improve symptoms of inflammation and that it is an effective adjunct to therapy in AD and psoriasis.

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

European Thyroid Journal ◽

10.1159/000371740 ◽

2015 ◽

Vol 4 (1) ◽

pp. 14-19 ◽

Cited By ~ 13

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.

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

Zeitschrift für Naturforschung C ◽

10.1515/znc-1997-3-418 ◽

1997 ◽

Vol 52 (3-4) ◽

pp. 255-258 ◽

Cited By ~ 1

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.

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Comparison of Two Nasal Cell Collection Methods in Determining Cyclic Adenosine Monophosphate Levels and its Association with Olfaction: A Feasibility Study

Allergy & Rhinology ◽

10.2500/ar.2014.5.0079 ◽

2014 ◽

Vol 5 (1) ◽

pp. ar.2014.5.0079

Author(s):

Jack J. Liu ◽

Guy C. Chan ◽

Avram S. Hecht ◽

Daniel R. Storm ◽

Greg E. Davis

Keyword(s):

Intraclass Correlation ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Olfactory Function ◽

Secondary Outcome ◽

Initial Visit ◽

Two Samples ◽

Camp Levels ◽

Collection Methods

Cyclic adenosine monophosphate (cAMP) is a second messenger that may be associated with olfactory function. No known studies have compared existing collection methods for determining nasal cAMP levels. This is a prospective study comparing the comfort and reliability of the nasal curette and cytobrush. A secondary outcome collected for feasibility testing was characterizing the association between cAMP and olfactory function. We enrolled 19 normal olfaction and 10 olfactory dysfunction subjects. Olfaction was measured by the University of Pennsylvania Smell Identification Test. Two samples were obtained from each nasal cavity at the initial visit and at 1 week follow-up. Comfort was measured by a visual analog scale (VAS). cAMP levels were determined by an enzyme immunoassay. For the curette and cytobrush, mean VAS scores were 03 and 0.7 cm (p = 0.48). Intraclass correlation coefficients were 0.81 (curette) and 0.65 (cytobrush) for the initial visit and 0.64 and 0.54 between the initial and follow-up visit. Using the curette, mean cAMP was 537 and 480 fmol/(mg/mL) for the normal and dysfunction cohorts (p = 0.18). Using the cytobrush, cAMP was 505 and 477, respectively (p = 0.65). The curette and cytobrush are both comfortable and reliable collection methods for determining nasal cAMP levels.

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Secondary Messenger Systems in PTSD

10.1093/med/9780190215422.003.0014 ◽

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.

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