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1.
Children (Basel) ; 11(6)2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38929296

ABSTRACT

Respiratory disorders significantly impact adolescents' health, often resulting in hospital admissions. Meteorological elements such as wind patterns have emerged as potential contributors to respiratory symptoms. However, it remains uncertain whether fluctuations in wind characteristics over extended periods have a tangible impact on respiratory health, particularly in regions characterized by distinct annual wind patterns. Crete is situated in the central-eastern Mediterranean Sea and frequently faces southerly winds carrying Sahara Desert sand from Africa and northerly winds from the Aegean Sea. This retrospective study analyzes long-term wind direction data and their relationship to respiratory symptoms observed in children up to 14 years old admitted at the University Hospital of Heraklion between 2002 and 2010. Symptoms such as headache, dyspnea, dry cough, dizziness, tachypnea, throat ache, and earache were predominantly reported during the presence of southern winds. Fever, productive cough, and chest pain were more frequently reported during northern winds. Cough was the most common symptom regardless of the wind pattern. Southern winds were significantly associated with higher probabilities of productive or non-productive cough, headache, dyspnea, tachypnea, dizziness, earache, and throat ache. Northern winds were related to a higher incidence of productive cough. Rhinitis, asthma, allergies, pharyngitis, and sinusitis were related to southern winds, while bronchiolitis and pneumonia were associated with northern winds. These findings underscore the critical role of local climatic factors, emphasizing their potential impact on exacerbating respiratory conditions in children. Moreover, they point out the need for further research to elucidate the underlying mechanisms and develop targeted interventions for at-risk populations.

2.
Int J Emerg Med ; 17(1): 46, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38566013

ABSTRACT

Greece is a parliamentary republic in southeastern Europe populated by over 10 million permanent residents: 9 million reside on the mainland, with almost 4 million in the greater Athens area. The remaining 1 million populate the over 1200 Greek islands. In addition, more than 160,000 asylum-seekers reached Greece in 2022, and more than 25 million tourists have visited Greece in the last two years. Modern Greek Emergency Medicine (EM) is now in its 4th decade. The Greek government has focused the last few years on enhancing the quality of emergency services provided in public hospitals. Emergency Departments (EDs) are being modernized, undergraduate medical education gradually incorporates EM, and a specialty training program in emergency nursing has been established. However, the late recognition of the critical importance of EM as a specialty in Greece has resulted in the subsequent need to create three alternative pathways to EM, none of which are direct from residency. The first is a 24-month Emergency Medicine fellowship after completing a residency in another specialty and then passing the national exam. The second is for physicians who have worked in a public hospital ED (Gr: Ethniko Systima Ygeias (ESY) ESY for at least three years and successfully passed the national exam. The third, which no longer exists, is a 'grandfather' pathway for those physicians who worked in an ESY ED for five years prior to the creation of the fellowship training program. As a result, there is a critical shortage of EM-trained physicians, resulting in most care being provided by physicians without formal training in EM. This is further confounded by the country's challenging geography, with frequent air transfers from the islands to mainland hospitals. Creating an EM Residency training program is a critical next step to overcoming many of the challenges facing EM provision in Greece today: it would address the shortage of EM-trained providers, decrease the need for costly ground and air transfers, and improve the quality of emergency care throughout Greece.

5.
Molecules ; 29(1)2023 Dec 31.
Article in English | MEDLINE | ID: mdl-38202807

ABSTRACT

Chronic inflammation is an important factor in the development of cancer. Macrophages found in tumors, known as tumor associated macrophages (TAMs), are key players in this process, promoting tumor growth through humoral and cellular mechanisms. 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), an arachidonic acid metabolite, has been described to possess a potent chemoattractant activity for human white blood cells (WBCs). The biological actions of 5-oxo-ETE are mediated through the GPCR 5-oxo-6E,8Z,11Z,14Z-eicosatetraenoic acid receptor (OXER1). In addition, we have previously reported OXER1 as one of the membrane androgen receptors with testosterone antagonizing 5-oxo-ETE's actions. OXER1 is highly expressed in inflammatory cells and many normal and cancer tissues and cells, including prostate and breast cancer, promoting cancer cell survival. In the present study we investigate the expression and role of OXER1 in WBCs, THP-1 monocytes, and THP-1 derived macrophages, as well as its possible role in the interaction between macrophages and cancer cells (DU-145 and T47D). We report that OXER1 is differentially expressed between WBCs and macrophages and that receptor expression is modified by LPS treatment. Our results show that testosterone and 5-oxo-ETE can act in an antagonistic way affecting Ca2+ movements, migration, and cytokines' expression in immune-related cells, in a differentiation-dependent manner. Finally, we report that 5-oxo-ETE, through OXER1, can attract macrophages to the tumor site while tumor cells' OXER1 activation in DU-145 prostate and T47D breast cancer cells, by macrophages, induces actin cytoskeletal changes and increases their migration.


Subject(s)
Arachidonic Acids , Breast Neoplasms , Humans , Male , Macrophages , Arachidonic Acid , Testosterone , Receptors, Eicosanoid
6.
Biomedicines ; 10(12)2022 Dec 08.
Article in English | MEDLINE | ID: mdl-36551935

ABSTRACT

Introduction: Liver fibrosis has been extensively studied at the cellular and molecular level, but very few data exist on the final enzymatic stages of collagen synthesis (prolyl hydroxylase, PH) and degradation (matrix metalloproteinases, MMPs), particularly in primary biliary cholangitis (PBC). Aim: We studied enzyme activities in liver tissue from patients with chronic liver diseases and compared them to normal livers. Patients: Eighteen patients with PBC of early and late stages (Ludwig's classification) and seven on treatment with ursodeoxycholate (UDCA) were studied and compared to 34 patients with alcoholic liver disease (ALD), 25 patients with chronic viral liver disease and five normal biopsies. Sera were available from a total of 140 patients. Methods: The tritiated water released from the tritiated proline was measured in PH assessment. 14C intact and heat-denatured collagen substrates were used to measure collagenase and gelatinases, respectively. 3H Elastin was the substrate for elastase. In serum, ELISAs were used for MMP-1, TIMP-1, and TIMP-2 measurements while MMP-2 and MMP-9 were estimated by zymography. Results: PH was significantly increased in early and late PBC. Collagenase was reduced only in the late stages (p < 0.01), where the ratio PH/collagenase was increased. UDCA treatment restored values to almost normal. Gelatinases were reduced in late stages (p < 0.05). In contrast to PBC and ALD fibrosis, collagen synthesis is not increased in viral fibrosis. The balance shifted towards collagen deposition due to reduced degradation. Interestingly, gelatinolytic activity is not impaired in ALD. Elastase was similar to controls in all diseases studied. TIMP-1 was reduced in early PBC and viral and alcoholic hepatitis and cirrhosis (p < 0.001). Conclusions: (1) There is evidence that collagen synthesis increases in the early stages of PBC, but the collagenolytic mechanism may compensate for the increased synthesis. (2) In viral disease, fibrosis may be due to decreased degradation rather than increased synthesis. (3) The final biochemical stages of liver fibrosis may be quantitatively different according to underlying etiology.

8.
Comput Struct Biotechnol J ; 20: 5952-5961, 2022.
Article in English | MEDLINE | ID: mdl-36382187

ABSTRACT

Nuclear translocation of large proteins is mediated through karyopherins, carrier proteins recognizing specific motifs of cargo proteins, known as nuclear localization signals (NLS). However, only few NLS signals have been reported until now. In the present work, NLS signals for Importins 4 and 5 were identified through an unsupervised in silico approach, followed by experimental in vitro validation. The sequences LPPRS(G/P)P and KP(K/Y)LV were identified and are proposed as recognition motifs for Importins 4 and 5 binding, respectively. They are involved in the trafficking of important proteins into the nucleus. These sequences were validated in the breast cancer cell line T47D, which expresses both Importins 4 and 5. Elucidating the complex relationships of the nuclear transporters and their cargo proteins is very important in better understanding the mechanism of nuclear transport of proteins and laying the foundation for the development of novel therapeutics, targeting specific importins.

9.
Sci Total Environ ; 843: 156861, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-35750162

ABSTRACT

In late March 2018, a large part of the Eastern Mediterranean experienced an extraordinary episode of African dust, one of the most intense in recent years, here referred to as the "Minoan Red" event. The episode mainly affected the Greek island of Crete, where the highest aerosol concentrations over the past 15 yeas were recorded, although impacts were also felt well beyond this core area. Our study fills a gap in dust research by assessing the multi-sectoral impacts of sand and dust storms and their socioeconomic implications. Specifically, we provide a multi-sectoral impact assessment of Crete during the occurrence of this exceptional African dust event. During the day of the occurrence of the maximum dust concentration in Crete, i.e. March 22nd, 2018, we identified impacts on meteorological conditions, agriculture, transport, energy, society (including closing of schools and cancellation of social events), and emergency response systems. As a result, the event led to a 3-fold increase in daily emergency responses compare to previous days associated with urban emergencies and wildfires, a 3.5-fold increase in hospital visits and admissions for Chronic Obstructive Pulmonary Disease (COPD) exacerbations and dyspnoea, a reduction of visibility causing aircraft traffic disruptions (eleven cancellations and seven delays), and a reduction of solar energy production. We estimate the cost of direct and indirect effects of the dust episode, considering the most affected socio-economic sectors (e.g. civil protection, aviation, health and solar energy production), to be between 3.4 and 3.8 million EUR for Crete. Since such desert dust transport episodes are natural, meteorology-driven and thus to a large extent unavoidable, we argue that the efficiency of actions to mitigate dust impacts depends on the accuracy of operational dust forecasting and the implementation of relevant early warning systems for social awareness.


Subject(s)
Air Pollutants , Dust , Aerosols , Air Pollutants/analysis , Dust/analysis , Environmental Monitoring , Particulate Matter/analysis
10.
J Clin Med ; 11(9)2022 Apr 24.
Article in English | MEDLINE | ID: mdl-35566513

ABSTRACT

BACKGROUND: Postoperative hypocalcemia is one of the most common complications after total thyroidectomy. Parathormone (PTH) and calcium levels, measured several hours after surgery, have been suggested as valuable markers for detecting patients at risk for post-thyroidectomy hypocalcemia. We aimed to determine if early post-surgery PTH and calcium levels can be used for the early identification of patients at risk for symptomatic hypocalcemia. METHODS: PTH and calcium were measured before surgery and at 10 min and 4 h post-thyroidectomy, in 77 patients. Performance characteristics of PTH and calcium levels and their post/pre-surgery ratios were calculated. RESULTS: Four-hour calcium was a sensitive (93.75%) but not specific (67.61%) indicator of patients at risk for symptomatic hypocalcemia. The 4-h/pre-surgery PTH ratio was the most accurate (90.81%) and the most specific (94.37%) test to identify patients at risk. Serum calcium at 4-h, 4-h/pre-surgery PTH ratio, and PTH at 10 min post-surgery had the higher diagnostic odds ratios (50.86, 32.85, and 29.04, respectively). The 4-h/pre-surgery PTH ratio also had the highest (0.694) Youden's J statistic. CONCLUSIONS: Low serum calcium levels 4 h after thyroidectomy and the 4-h/pre-surgery PTH ratio could be valuable additions to everyday clinical practice in post-thyroidectomy patients.

11.
Mol Cell Endocrinol ; 539: 111487, 2022 01 01.
Article in English | MEDLINE | ID: mdl-34634385

ABSTRACT

In prostate cancer, calcium homeostasis plays a significant role in the disease's development and progression. Intracellular calcium changes are an important secondary signal, triggered by a variety of extracellular stimuli, that controls many cellular functions. One of the main events affecting calcium is androgen signaling. Indeed, via calcium changes, androgens regulate cell processes like cell growth, differentiation and motility. In the present work we explored the nature of the receptor involved in calcium response induced by membrane-acting testosterone in prostate cancer cells. We report that testosterone, independently of the presence of the classical androgen receptor, can rapidly increase intracellular calcium from calcium stores, through the oxoeicosanoid receptor 1 (OXER1) and a specific signaling cascade that triggers calcium release from the endoplasmic reticulum. These findings reveal for the first time the receptor involved in the rapid calcium changes induced by androgens. Moreover, they further support the notion that androgens, even in the absence of AR, can still exert specific effects that regulate cancer cell fate.


Subject(s)
Calcium/metabolism , Prostatic Neoplasms/metabolism , Receptors, Eicosanoid/metabolism , Testosterone/pharmacology , Arachidonic Acids/pharmacology , Calcium Signaling/drug effects , Cell Line, Tumor , Endoplasmic Reticulum/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Humans , Male
12.
ACS Omega ; 6(44): 29664-29674, 2021 Nov 09.
Article in English | MEDLINE | ID: mdl-34778638

ABSTRACT

OXER1 (oxoeicosanoid receptor 1) was deorphanized in 1993 and found to be the specific receptor for the arachidonic acid metabolite 5-oxo-ETE. Recently, we have reported that androgen binds to this receptor also, being a membrane androgen receptor, triggering a number of its membrane-mediated actions (cell migration, apoptosis, cell proliferation, Ca2+ movements). In addition, our previous work suggested that a number of natural monomeric and oligomeric polyphenols interact with OXER1, acting similar to testosterone. Here, we interrogated the natural product chemical space and identified nine polyphenolic molecules with interesting in silico pharmacological activities as putative OXER1 antagonists. The molecule with the best pharmacokinetic-pharmacodynamic properties (ZINC15959779) was purchased and tested on OXER1, in prostate cancer cell cultures. It showed that it has actions similar to those of testosterone in inhibiting cAMP, while it had no action in intracellular Ca2+ mobilization or actin cytoskeleton rearrangement/migration. These results are discussed under the prism of structure-activity relationships and in silico models of the OXER1 binding groove. We suggest that these compounds, together with the previously reported (poly)phenolic compounds, can be lead structures for the exploration of the anti-inflammatory and antiproliferative effects of OXER1 antagonists.

13.
Biochem Biophys Res Commun ; 584: 95-100, 2021 12 20.
Article in English | MEDLINE | ID: mdl-34775286

ABSTRACT

OXER1 is a recently identified receptor, binding the arachidonic acid metabolic product 5-oxo-ETE, considered an inflammatory receptor, implicated in chemoattraction of circulating mononuclear cells, Ca2+ surge in neutrophils, inflammation and cancer. Recently, we have shown that OXER1 is also a membrane androgen receptor in various cancer tissues. It was reported that the presence of OXER1 in leucocytes and the production and release of 5-oxo-ETE by wounded tissues is a wound sensing mechanism, leading to lymphocyte attraction. In view of the similarity of hallmarks of cancer and wound healing, we have explored the role of OXER1 and its endogenous ligand in the control of cell migration of human cancer epithelial cells (DU-145, T47D and Hep3B), mimicking the activation/migration phase of healing. We show that OXER1 is up-regulated only at the leading edge of the wound and its expression is up-regulated by its ligand 5-oxo-ETE, in a time-related manner. Knock-down of OXER1 or inhibition of 5-oxo-ETE synthesis led to decreased migration of cells and a prolongation of healing, in culture prostate cancer cell monolayers, with a substantial modification of actin cytoskeleton and a decreased filopodia formation. Inhibition of cell migration is a phenomenon mediated by Gßγ OXER1 mediated actions. These results provide a novel mechanism of OXER1 implication in cancer progression and might be of value for the design of novel OXER1 antagonists.


Subject(s)
Cell Movement/genetics , Gene Expression Regulation, Neoplastic/genetics , Neoplasms/genetics , Receptors, Eicosanoid/genetics , Arachidonic Acids/metabolism , Arachidonic Acids/pharmacology , Blotting, Western , Cell Line, Tumor , Cell Movement/drug effects , Gene Expression Profiling/methods , Gene Expression Regulation, Neoplastic/drug effects , Humans , Neoplasms/metabolism , Neoplasms/pathology , Receptors, Eicosanoid/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , Signal Transduction/genetics , Up-Regulation/drug effects
14.
Int J Mol Sci ; 22(14)2021 Jul 16.
Article in English | MEDLINE | ID: mdl-34299224

ABSTRACT

Inflammation is important for the initiation and progression of breast cancer. We have previously reported that in monocytes, estrogen regulates TLR4/NFκB-mediated inflammation via the interaction of the Erα isoform ERα36 with GPER1. We therefore investigated whether a similar mechanism is present in breast cancer epithelial cells, and the effect of ERα36 expression on the classic 66 kD ERα isoform (ERα66) functions. We report that estrogen inhibits LPS-induced NFκB activity and the expression of downstream molecules TNFα and IL-6. In the absence of ERα66, ERα36 and GPER1 are both indispensable for this effect. In the presence of ERα66, ERα36 or GPER1 knock-down partially inhibits NFκB-mediated inflammation. In both cases, ERα36 overexpression enhances the inhibitory effect of estrogen on inflammation. We also verify that ERα36 and GPER1 physically interact, especially after LPS treatment, and that GPER1 interacts directly with NFκB. When both ERα66 and ERα36 are expressed, the latter acts as an inhibitor of ERα66 via its binding to estrogen response elements. We also report that the activation of ERα36 leads to the inhibition of breast cancer cell proliferation. Our data support that ERα36 is an inhibitory estrogen receptor that, in collaboration with GPER1, inhibits NFκB-mediated inflammation and ERα66 actions in breast cancer cells.


Subject(s)
Estrogen Receptor alpha/metabolism , Receptors, Estrogen/metabolism , Receptors, G-Protein-Coupled/metabolism , Breast Neoplasms , Cell Line, Tumor , Epithelial Cells/metabolism , Estradiol/pharmacology , Estrogen Receptor alpha/genetics , Estrogen Receptor alpha/physiology , Estrogens/metabolism , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Inflammation/metabolism , Interleukin-6/metabolism , MCF-7 Cells , Monocytes/metabolism , NF-kappa B/genetics , NF-kappa B/metabolism , Receptors, Estrogen/physiology , Receptors, G-Protein-Coupled/physiology , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factor-alpha/metabolism
15.
Pharmacol Res Perspect ; 9(4): e00798, 2021 08.
Article in English | MEDLINE | ID: mdl-34128351

ABSTRACT

Therapeutic regimens for the COVID-19 pandemics remain unmet. In this line, repurposing of existing drugs against known or predicted SARS-CoV-2 protein actions have been advanced, while natural products have also been tested. Here, we propose that p-cymene, a natural monoterpene, can act as a potential novel agent for the treatment of SARS-CoV-2-induced COVID-19 and other RNA-virus-induced diseases (influenza, rabies, Ebola). We show by extensive molecular simulations that SARS-CoV-2 C-terminal structured domain contains a nuclear localization signal (NLS), like SARS-CoV, on which p-cymene binds with low micromolar affinity, impairing nuclear translocation of this protein and inhibiting viral replication, as verified by preliminary in vitro experiments. A similar mechanism may occur in other RNA-viruses (influenza, rabies and Ebola), also verified in vitro for influenza, by interaction of p-cymene with viral nucleoproteins, and structural modification of their NLS site, weakening its interaction with importin A. This common mechanism of action renders therefore p-cymene as a possible antiviral, alone, or in combination with other agents, in a broad spectrum of RNA viruses, from SARS-CoV-2 to influenza A infections.


Subject(s)
Antiviral Agents/pharmacology , Cymenes/pharmacology , Influenza A Virus, H1N1 Subtype/physiology , Nucleocapsid Proteins/metabolism , SARS-CoV-2/physiology , Animals , Antiviral Agents/chemistry , Cell Nucleus/metabolism , Cell Nucleus/virology , Chlorocebus aethiops , Cymenes/chemistry , Dogs , Humans , Influenza A Virus, H1N1 Subtype/drug effects , Madin Darby Canine Kidney Cells , Models, Molecular , Molecular Dynamics Simulation , Nuclear Localization Signals , Nucleocapsid Proteins/chemistry , Protein Conformation , Protein Domains , Protein Transport , SARS-CoV-2/drug effects , Vero Cells , Virus Replication/drug effects
17.
Biochim Biophys Acta Gen Subj ; 1865(5): 129851, 2021 05.
Article in English | MEDLINE | ID: mdl-33482249

ABSTRACT

BACKGROUND: Nuclear translocation of large proteins is mediated through specific protein carriers, collectively named karyopherins (importins, exportins and adaptor proteins). Cargo proteins are recognized by importins through specific motifs, known as nuclear localization signals (NLS). However, only the NLS recognized by importin α and transportin (M9 NLS) have been identified so far METHODS: An unsupervised in silico approach was used, followed by experimental validation. RESULTS: We identified the sequence EKRKI(E/R)(K/L/R/S/T) as an NLS signal for importin 7 recognition. This sequence was validated in the breast cancer cell line T47D, which expresses importin 7. Finally, we verified that importin 7-mediated nuclear protein transport is affected by cargo protein phosphorylation. CONCLUSIONS: The NLS sequence for importin 7 was identified and we propose this approach as an identification method of novel specific NLS sequences for ß-karyopherin family members. GENERAL SIGNIFICANCE: Elucidating the complex relationships of the nuclear transporters and their cargo proteins may help in laying the foundation for the development of novel therapeutics, targeting specific importins, with an immediate translational impact.


Subject(s)
Karyopherins/metabolism , Nuclear Localization Signals , Receptors, Cytoplasmic and Nuclear/metabolism , Active Transport, Cell Nucleus , Amino Acid Sequence , Breast Neoplasms/metabolism , Cell Line, Tumor , Female , Humans , Karyopherins/chemistry , Models, Molecular , Phosphorylation , Receptors, Cytoplasmic and Nuclear/chemistry
18.
NPJ Sci Food ; 4(1): 20, 2020 Nov 09.
Article in English | MEDLINE | ID: mdl-33298942

ABSTRACT

The importance of herbal extracts on health, which was initially based on ethnopharmacological and traditional knowledge, becomes increasingly well documented by numerous experimental and intervention studies. The daily use of beverages from different aromatic plants which becomes more popular nowadays, has been a tradition in Crete, and a habit that has been linked to the longevity seen in the island. Additionally, a certain combination of aromatic plants has been used against common cold and influenza. Interestingly, when such a mixture of essential oils from Cretan herbs (Cretan Aromatic Plants essential oil, CAPeo, from thyme, Greek sage, and Cretan dittany) was formulated, significant antiviral properties were observed in vitro and a significant reduction in the duration and severity of symptoms of patients with upper respiratory tract infections was found in a clinical study. However, since many plants extracts can exert toxic effects, toxicity issues should be properly addressed. In the present work we present an acute and sub-chronic toxicity evaluation for this mixture of aromatic plants' essential oils in rats. In fact, it is the only toxicity study for Cretan dittany. We report absence of toxicity, rendering the use of the mixture of essential oils from Cretan dittany, Greek sage and thyme as safe.

19.
Front Endocrinol (Lausanne) ; 11: 579420, 2020.
Article in English | MEDLINE | ID: mdl-33133022

ABSTRACT

G protein-coupled estrogen receptor 1 (GPER1), is a functional estrogen receptor involved in estrogen related actions on several systems including processes of the nervous, reproductive, metabolic, cardiovascular, and immune system. Regarding the latter, GPER is expressed in peripheral B and T lymphocytes as well as in monocytes, eosinophils, and neutrophils. Several studies have implicated GPER in immune-mediated diseases like multiple sclerosis, Parkinson's disease, and atherosclerosis-related inflammation, while a recent report suggests that its deletion could be responsible for a form of familial immunodeficiency. It has also been suggested that it is a key regulator of immune-mediated events in breast, pancreatic, prostate, and hepatocellular cancer as well as in melanoma. GPER has been also reported to interact with classic ER-alpha or its splice variants in order to modify immune functions. This review aims to present current knowledge relating GPER to immune functions, the cellular and signaling pathways involved, as well as the potential clinical implications of GPER modulation in immune-related diseases.


Subject(s)
Immune System Diseases/immunology , Immune System/immunology , Receptors, Estrogen/metabolism , Receptors, G-Protein-Coupled/metabolism , Humans , Immune System/metabolism , Immune System/pathology , Immune System Diseases/metabolism , Immune System Diseases/pathology
20.
Pharmacol Res Perspect ; 8(4): e00600, 2020 08.
Article in English | MEDLINE | ID: mdl-32662237

ABSTRACT

Drug development is an arduous procedure, necessitating testing the interaction of a large number of potential candidates with potential interacting (macro)molecules. Therefore, any method which could provide an initial screening of potential candidate drugs might be of interest for the acceleration of the procedure, by highlighting interesting compounds, prior to in vitro and in vivo validation. In this line, we present a method which may identify potential hits, with agonistic and/or antagonistic properties on GPCR receptors, integrating the knowledge on signaling events triggered by receptor activation (GPCRs binding to Gα,ß,γ proteins, and activating Gα , exchanging GDP for GTP, leading to a decreased affinity of the Gα for the GPCR). We show that, by integrating GPCR-ligand and Gα -GDP or -GTP binding in docking simulation, which correctly predicts crystallographic data, we can discriminate agonists, partial agonists, and antagonists, through a linear function, based on the ΔG (Gibbs-free energy) of liganded-GPCR/Gα -GDP. We built our model using two Gαs (ß2-adrenergic and prostaglandin-D2 ), four Gαi (µ-opioid, dopamine-D3, adenosine-A1, rhodopsin), and one Gαo (serotonin) receptors and validated it with a series of ligands on a recently deorphanized Gαi receptor (OXER1). This approach could be a valuable tool for initial in silico validation and design of GPRC-interacting ligands.


Subject(s)
Drug Development/methods , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/antagonists & inhibitors , Computational Biology/methods , Crystallography , Guanosine Diphosphate/metabolism , Guanosine Triphosphate/metabolism , Humans , Ligands , Molecular Docking Simulation , Receptors, G-Protein-Coupled/metabolism , Signal Transduction
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