scholarly journals cAMP Signaling in Pathobiology of Alcohol Associated Liver Disease

Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1433
Author(s):  
Mohamed Elnagdy ◽  
Shirish Barve ◽  
Craig McClain ◽  
Leila Gobejishvili

The importance of cyclic adenosine monophosphate (cAMP) in cellular responses to extracellular signals is well established. Many years after discovery, our understanding of the intricacy of cAMP signaling has improved dramatically. Multiple layers of regulation exist to ensure the specificity of cellular cAMP signaling. Hence, disturbances in cAMP homeostasis could arise at multiple levels, from changes in G protein coupled receptors and production of cAMP to the rate of degradation by phosphodiesterases. cAMP signaling plays critical roles in metabolism, inflammation and development of fibrosis in several tissues. Alcohol-associated liver disease (ALD) is a multifactorial condition ranging from a simple steatosis to steatohepatitis and fibrosis and ultimately cirrhosis, which might lead to hepatocellular cancer. To date, there is no FDA-approved therapy for ALD. Hence, identifying the targets for the treatment of ALD is an important undertaking. Several human studies have reported the changes in cAMP homeostasis in relation to alcohol use disorders. cAMP signaling has also been extensively studied in in vitro and in vivo models of ALD. This review focuses on the role of cAMP in the pathobiology of ALD with emphasis on the therapeutic potential of targeting cAMP signaling for the treatment of various stages of ALD.

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 610
Author(s):  
Robin Park ◽  
Andrew L. Coveler ◽  
Ludimila Cavalcante ◽  
Anwaar Saeed

Glycogen synthase kinase-3 beta is a ubiquitously and constitutively expressed molecule with pleiotropic function. It acts as a protooncogene in the development of several solid tumors including pancreatic cancer through its involvement in various cellular processes including cell proliferation, survival, invasion and metastasis, as well as autophagy. Furthermore, the level of aberrant glycogen synthase kinase-3 beta expression in the nucleus is inversely correlated with tumor differentiation and survival in both in vitro and in vivo models of pancreatic cancer. Small molecule inhibitors of glycogen synthase kinase-3 beta have demonstrated therapeutic potential in pre-clinical models and are currently being evaluated in early phase clinical trials involving pancreatic cancer patients with interim results showing favorable results. Moreover, recent studies support a rationale for the combination of glycogen synthase kinase-3 beta inhibitors with chemotherapy and immunotherapy, warranting the evaluation of novel combination regimens in the future.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 498
Author(s):  
Mariaevelina Alfieri ◽  
Antonietta Leone ◽  
Alfredo Ambrosone

Plants produce different types of nano and micro-sized vesicles. Observed for the first time in the 60s, plant nano and microvesicles (PDVs) and their biological role have been inexplicably under investigated for a long time. Proteomic and metabolomic approaches revealed that PDVs carry numerous proteins with antifungal and antimicrobial activity, as well as bioactive metabolites with high pharmaceutical interest. PDVs have also been shown to be also involved in the intercellular transfer of small non-coding RNAs such as microRNAs, suggesting fascinating mechanisms of long-distance gene regulation and horizontal transfer of regulatory RNAs and inter-kingdom communications. High loading capacity, intrinsic biological activities, biocompatibility, and easy permeabilization in cell compartments make plant-derived vesicles excellent natural or bioengineered nanotools for biomedical applications. Growing evidence indicates that PDVs may exert anti-inflammatory, anti-oxidant, and anticancer activities in different in vitro and in vivo models. In addition, clinical trials are currently in progress to test the effectiveness of plant EVs in reducing insulin resistance and in preventing side effects of chemotherapy treatments. In this review, we concisely introduce PDVs, discuss shortly their most important biological and physiological roles in plants and provide clues on the use and the bioengineering of plant nano and microvesicles to develop innovative therapeutic tools in nanomedicine, able to encompass the current drawbacks in the delivery systems in nutraceutical and pharmaceutical technology. Finally, we predict that the advent of intense research efforts on PDVs may disclose new frontiers in plant biotechnology applied to nanomedicine.


2011 ◽  
Vol 193 (6) ◽  
pp. 1009-1020 ◽  
Author(s):  
Martijn Gloerich ◽  
Marjolein J. Vliem ◽  
Esther Prummel ◽  
Lars A.T. Meijer ◽  
Marije G.A. Rensen ◽  
...  

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.


2021 ◽  
Author(s):  
Kaley M. Wilburn ◽  
Christine R. Montague ◽  
Bo Qin ◽  
Ashley K. Woods ◽  
Melissa S. Love ◽  
...  

There is a growing appreciation for the idea that bacterial utilization of host-derived lipids, including cholesterol, supports Mycobacterium tuberculosis (Mtb) pathogenesis. This has generated interest in identifying novel antibiotics that can disrupt cholesterol utilization by Mtb in vivo. Here we identify a novel small molecule agonist (V-59) of the Mtb adenylyl cyclase Rv1625c, which stimulates 3’, 5’-cyclic adenosine monophosphate (cAMP) synthesis and inhibits cholesterol utilization by Mtb. Similarly, using a complementary genetic approach that induces bacterial cAMP synthesis independent of Rv1625c, we demonstrate that inducing cAMP synthesis is sufficient to inhibit cholesterol utilization in Mtb. Although the physiological roles of individual adenylyl cyclase enzymes in Mtb are largely unknown, here we demonstrate that the transmembrane region of Rv1625c is required for cholesterol metabolism. Finally, in this work the pharmacokinetic properties of Rv1625c agonists are optimized, producing an orally-available Rv1625c agonist that impairs Mtb pathogenesis in infected mice. Collectively, this work demonstrates a novel role for Rv1625c and cAMP signaling in controlling cholesterol metabolism in Mtb and establishes that cAMP signaling can be pharmacologically manipulated for the development of new antibiotic strategies.


2020 ◽  
Vol 4 (6) ◽  
Author(s):  
Lijuan Li ◽  
Lixia An ◽  
Lifang Li ◽  
Yongjuan Zhao

Sphingolipids are formed via the metabolism of sphingomyelin, aconstituent of the plasma membrane, or by denovosynthesis. Enzymatic pathways result in the formation of several different lipid mediators, which are known to have important roles in many cellular processes, including proliferation, apoptosis and migration. Several studies now suggest that these sphingolipid mediators, including ceramide, ceramide 1-phosphate and sphingosine 1-phosphate (S1P), are likely to have an integral role in in?ammation. This can involve, for example, activation of pro-in?ammatory transcription factors in different cell types and induction of cyclooxygenase-2, leading to production of pro-in?ammatory prostaglandins. The mode of action of each sphingolipid is different. Increased ceramide production leads to the formation of ceramide-rich areas of the membrane, which may assemble signalling complexes, whereas S1P acts via high-af?nity G-protein-coupled S1P receptors on the plasma membrane. Recent studies have demonstrated that in vitro effects of sphingolipids on in?ammation can translate into in vivo models. This review will highlight the areas of research where sphingolipids are involved in in?ammation and the mechanisms of action of each mediator. In addition, the therapeutic potential of drugs that alter sphingolipid actions will be examined with reference to disease states, such as asthma and in?ammatory bowel disease, which involve important in?ammatory components. A signi?cant body of research now indicates that sphingolipids are intimately involved in the in?ammatory process and recent studies have demonstrated that these lipids, together with associated enzymes and receptors, can provide effective drug targets for the treatment of pathological in?ammation.


2021 ◽  
Vol 14 (12) ◽  
pp. 1248
Author(s):  
Muhammad Waleed Baig ◽  
Humaira Fatima ◽  
Nosheen Akhtar ◽  
Hidayat Hussain ◽  
Mohammad K. Okla ◽  
...  

Exploration of leads with therapeutic potential in inflammatory disorders is worth pursuing. In line with this, the isolated natural compound daturaolone from Datura innoxia Mill. was evaluated for its anti-inflammatory potential using in silico, in vitro and in vivo models. Daturaolone follows Lipinski’s drug-likeliness rule with a score of 0.33. Absorption, distribution, metabolism, excretion and toxicity prediction show strong plasma protein binding; gastrointestinal absorption (Caco-2 cells permeability = 34.6 nm/s); no blood–brain barrier penetration; CYP1A2, CYP2C19 and CYP3A4 metabolism; a major metabolic reaction, being aliphatic hydroxylation; no hERG inhibition; and non-carcinogenicity. Predicted molecular targets were mainly inflammatory mediators. Molecular docking depicted H-bonding interaction with nuclear factor kappa beta subunit (NF-κB), cyclooxygenase-2, 5-lipoxygenase, phospholipase A2, serotonin transporter, dopamine receptor D1 and 5-hydroxy tryptamine. Its cytotoxicity (IC50) value in normal lymphocytes was >20 µg/mL as compared to cancer cells (Huh7.5; 17.32 ± 1.43 µg/mL). Daturaolone significantly inhibited NF-κB and nitric oxide production with IC50 values of 1.2 ± 0.8 and 4.51 ± 0.92 µg/mL, respectively. It significantly reduced inflammatory paw edema (81.73 ± 3.16%), heat-induced pain (89.47 ± 9.01% antinociception) and stress-induced depression (68 ± 9.22 s immobility time in tail suspension test). This work suggests a possible anti-inflammatory role of daturaolone; however, detailed mechanistic studies are still necessary to corroborate and extrapolate the findings.


Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1572 ◽  
Author(s):  
Daniel Salas-Treviño ◽  
Odila Saucedo-Cárdenas ◽  
María de Jesús Loera-Arias ◽  
Humberto Rodríguez-Rocha ◽  
Aracely García-García ◽  
...  

Carbon nanotubes (CNTs) have emerged in recent years as a potential option for drug delivery, due to their high functionalization capacity. Biocompatibility and selectivity using tissue-specific biomolecules can optimize the specificity, pharmacokinetics and stability of the drug. In this study, we design, develop and characterize a drug nanovector (oxCNTs-HA-CPT) conjugating oxidated multi-wall carbon nanotubes (oxCNTs) with hyaluronate (HA) and carboplatin (CPT) as a treatment in a lung cancer model in vitro. Subsequently, we exposed TC–1 and NIH/3T3 cell lines to the nanovectors and measured cell uptake, cell viability, and oxidative stress induction. The characterization of oxCNTs-HA-CPT reveals that on their surface, they have HA. On the other hand, oxCNTs-HA-CPT were endocytosed in greater proportion by tumor cells than by fibroblasts, and likewise, the cytotoxic effect was significantly higher in tumor cells. These results show the therapeutic potential that nanovectors possess; however, future studies should be carried out to determine the death pathways involved, as well as their effect on in vivo models.


Blood ◽  
2020 ◽  
Author(s):  
Ahmed Aburima ◽  
Martin Berger ◽  
Benjamin EJ Spurgeon ◽  
Beth A Webb ◽  
Katie S Wraith ◽  
...  

Thrombospondin-1 (TSP-1) is released by platelets upon activation and can promote platelet activation, but its role in haemostasis in vivo is unclear. We show that TSP-1 is a critical mediator of haemostasis that promotes platelet activation by modulating inhibitory cAMP signaling. Genetic deletion of TSP-1 did not affect platelet activation in vitro, but in vivo models of haemostasis and thrombosis demonstrated that TSP-1 deficient mice had prolonged bleeding, defective thrombosis and increased sensitivity to the prostacyclin mimetic iloprost. Adoptive transfer of wild type (WT), but not TSP-1-/- platelets, ameliorated the thrombotic phenotype, suggesting a key role for platelet-derived TSP-1. In functional assays, TSP-1-deficient platelets showed an increased sensitivity to cAMP signaling, inhibition of platelet aggregation and arrest under flow by PGI2. Plasma swap experiments showed that plasma TSP-1 did not correct PGI2 hypersensitivity in TSP-1-/- platelets. By contrast, incubation of TSP-1-/- platelets with releasates from WT platelets or purified TSP-1, but not releasates from TSP-1-/- platelets, reduced the inhibitory effects of PGI2. Activation of WT platelets resulted in diminished cAMP accumulation and downstream signaling, which was associated with increased activity of the cAMP hydrolyzing enzyme phosphodiesterase 3A (PDE3A). PDE3A activity and cAMP accumulation were unaffected in platelets from TSP-1-/- mice. Platelets deficient in CD36, a TSP-1 receptor, showed increased sensitivity to PGI2/cAMP signaling and diminished PDE3A activity, which was unaffected by platelet-derived or purified TSP-1. This suggests that the release of TSP-1 regulates haemostasis in vivo through modulation of platelet cAMP signaling at sites of vascular injury.


2015 ◽  
Vol 27 (1) ◽  
pp. 209
Author(s):  
T. Fanti ◽  
N. M. Ortega ◽  
R. Garaguso ◽  
M. J. Franco ◽  
C. Herrera ◽  
...  

In vitro embryo production systems (IVP) try to emulate and enhance molecular events that occur in in vivo reproductive systems in order to increase, not only the number of embryos generated, but also their quality. Despite advances, IVP processes are still inefficient compared with in vivo systems. Several studies have attributed this deficiency to a lack of oocyte competence due to spontaneous premature resumption of meiotic maturation in the oocyte following the removal from its follicular environment. Therefore, our objective was to increase oocyte competence avoiding premature resumption of meiosis by using cyclic adenosine monophosphate modulators. Cumulus-oocyte complexes (COC) were obtained from ovaries of slaughterhouses, washed, and randomly allocated in 2 culture systems. Oocytes in the control group (IVM) were cultured for a period of 24 h in basal medium TCM-199 with EGF (1 µg mL–1) supplemented with rhFSH (25 mIU mL–1). Oocytes in the biphasic in vitro maturation (b-IVM) group were cultured for 2 h in a basal medium supplemented with a phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine (IBMX, 500 µM), and an activator of adenylate cyclase (forskolin, 100 µM). Subsequently, COC were washed and cultured in basal medium supplemented with cilostamide (20 µM) and rhFSH (25 mIU mL–1) for 24 h. Maturation rates were analysed and IVF was performed with a dose of 1 × 106 sperm cells mL–1 in IVF-SOF medium. The presumptive zygotes were cultured in continuous-single-culture medium (Irvine) supplemented with 8 mg mL–1 of BSA until they reached the blastocyst stage. No significant differences in maturation, cleavage, and cryotolerance were observed between b-IVM and IVM groups (P > 0.05; Table 1). This study showed that b-IVM produced a significant increase in IVP compared with the control (IVM) at Days 7 and 8 (P < 0.01). Blastocyst hatching rate was significant (P < 0.05) for both treatment and day of analysis. The b-IVM group yielded an increase of 10 and 7.5% at Days 7 and 8, respectively, of IVP. The biphasic maturation showed an improvement in quality regarding the control group, in the timing analysis of production, and hatching percentages, and these results show that the use of cyclic adenosine monophosphate modulators in the oocyte maturation process enhances oocyte competence, which is reflected in increased productivity and embryo quality. We propose this treatment as an alternative to the standard protocols currently used in IVP of bovine embryos. Table 1.Effect of treatment on maturation, cleavage, and cryotolerance


2014 ◽  
Vol 26 (1) ◽  
pp. 193
Author(s):  
R. Appeltant ◽  
J. Beek ◽  
D. Maes ◽  
A. Van Soom

When using modern maturation conditions for in vitro maturation, pig oocytes yield ~20% blastocysts only. One problem is that cumulus cells, which are normally connected with the immature oocyte by cellular projections penetrating through the zona pellucida and with the oolemma via gap junctions, are prematurely losing these connections after the cumulus–oocyte complex is removed from the follicle. The oocyte possesses a type 3 phosphodiesterase, which degrades 3′,5′-cyclic adenosine monophosphate (cAMP), and this activity is inhibited by supply of 3′,5′-cyclic guanosine monophosphate (cGMP) to the oocyte via the cumulus cells. Consequently, cAMP levels, which are typically high during early stages of oocyte maturation in vivo, decrease, leading to spontaneous nuclear maturation and oocytes of low developmental competence. Therefore, the maintenance of these cumulus-oocyte connections is important to keep cAMP high and the oocyte under meiotic arrest. One way to prevent this drop in cAMP is using N6, 2′-o-dibutyryladenosine 3′,5′-cyclic monophosphate sodium (dbcAMP) that causes an arrest at germinal vesicle (GV) stage II (Funahashi et al. 1997 Biol. Reprod. 57, 49–53). Another option is collecting the oocytes in a medium containing the phoshodiesterase inhibitor, IBMX. The present study investigated the influence of IBMX on the progression of the GV of the oocyte after collection, just before the start of the maturation procedure. The GV stage was defined according to Sun et al. (2004 Mol. Reprod. Dev. 69, 228–234). In parallel with the findings on dbcAMP, we hypothesised an arrest at GV II by the presence of IBMX during collection. One group of oocytes were collected in HEPES-buffered TALP without IBMX (n = 375) and another group in the same medium containing 0.5 mM IBMX (n = 586). An average incubation time of 140 min was applied in both groups, and 3 replicates were performed. The proportions of oocytes before or at GV II and beyond GV II were compared in both groups using logistic regression analysis. The proportion of oocytes was included as dependent variable and group (IBMX addition or not) as independent variable. Replicate was also included in the model. The proportion of oocytes before or at GV II was not statistically significant between the group without and the group with IBMX (59.2 v. 58.7% respectively; P > 0.05). In conclusion, the use of IBMX during oocyte collection did not influence the state of the germinal vesicle of the oocyte during collection, indicating that IBMX did not cause a meiotic arrest in the oocytes during collecting in vitro.


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