Search results for "agonist"
showing 10 items of 2285 documents
Long-term genomic coevolution of host-parasite interaction in the natural environment
2017
Antagonistic coevolution of parasite infectivity and host resistance may alter the biological functionality of species, yet these dynamics in nature are still poorly understood. Here we show the molecular details of a long-term phage–bacterium arms race in the environment. Bacteria (Flavobacterium columnare) are generally resistant to phages from the past and susceptible to phages isolated in years after bacterial isolation. Bacterial resistance selects for increased phage infectivity and host range, which is also associated with expansion of phage genome size. We identified two CRISPR loci in the bacterial host: a type II-C locus and a type VI-B locus. While maintaining a core set of conse…
Closed-Locked and Apo-Resting State Structures of the Human α7 Nicotinic Receptor: A Computational Study
2018
International audience; Nicotinic acetylcholine receptors, belonging to the Cys-loop super-family of ligand-gated ion channels (LGICs), are membrane proteins present in neurons and at neuromuscular junctions. They are responsible for signal transmission, and their function is regulated by neurotransmitters, agonists and antagonists drugs. A detailed knowledge of their conformational transition in response to ligand binding is critical to understand the basis of ligand-receptor interaction, in view of new pharmacological approaches to control receptor activity. However, the scarcity of experimentally derived structures of human channels makes this perspective extremely challenging. To contri…
A possible desensitized state conformation of the human α7 nicotinic receptor: A molecular dynamics study
2017
International audience; The determination of the conformational states corresponding to diverse functional roles of ligand gated ion channels is subject of intense investigation with various techniques, from X-rays structure determination to electrophysiology and computational modeling. Even with a certain number of structures becoming recently available, only few major structural features distinguishing conductive open channel from the non conductive resting protein have been highlighted, while high-resolution details are still missing. The characterization of the desensitized conformation(s) is even more complex, and only few specific characteristics have been identified. Furthermore, exp…
Antiproliferative and pro-apoptotic activity of melatonin analogues on melanoma and breast cancer cells
2017
// Giuliana Gatti 1, * , Valeria Lucini 2, * , Silvana Dugnani 2 , Angela Calastretti 1 , Gilberto Spadoni 3 , Annalida Bedini 3 , Silvia Rivara 4 , Marco Mor 4 , Gianfranco Canti 1 , Francesco Scaglione 2 and Annamaria Bevilacqua 1 1 Department of Medical Biotechnology and Translational Medicine, Universita degli Studi di Milano, Milan, Italy 2 Department of Oncology and Hemato-oncology, Universita degli Studi di Milano, Milan, Italy 3 Department of Biomolecular Sciences, Universita degli Studi di Urbino “Carlo Bo”, Urbino, Italy 4 Department of Food and Drug, Universita degli Studi di Parma, Parma, Italy * Authors contributed equally to this work Correspondence to: Annamaria Bevilacqua, e…
Blocking oestradiol synthesis pathways with potent and selective coumarin derivatives
2018
A comprehensive set of 3-phenylcoumarin analogues with polar substituents was synthesised for blocking oestradiol synthesis by 17-b-hydroxysteroid dehydrogenase 1 (HSD1) in the latter part of the sulphatase pathway. Five analogues produced 62% HSD1 inhibition at 5 mM and, furthermore, three of them produced 68% inhibition at 1 mM. A docking-based structure-activity relationship analysis was done to determine the molecular basis of the inhibition and the cross-reactivity of the analogues was tested against oestrogen receptor, aromatase, cytochrome P450 1A2, and monoamine oxidases. Most of the analogues are only modestly active with 17-b-hydroxysteroid dehydrogenase 2 – a requirement for lowe…
Age-dependent control of collagen-dependent platelet responses by thrombospondin-1 : Comparative analysis of platelets from neonates, children, adole…
2021
Platelet function is developmentally regulated. Healthy neonates do not spontaneously bleed, but their platelets are hypo-reactive to several agonists. The mechanisms underlying immature platelet function in neonates are incompletely understood. This critical issue remains challenging for the establishment of age-specific reference ranges. In this study, we evaluated platelet reactivity of five pediatric age categories, ranging from healthy full-term neonates up to adolescents (11–18 years) in comparison to healthy adults (>
Bisphenolic compounds alter gene expression in MCF-7 cells through interaction with estrogen receptor α
2020
Plasticizers released from microplastic are increasingly viewed with concern. While adverse health effects induced by bisphenol A and its analogues on marine animals are well documented in the literature, the endocrine potential of bisphenolic compounds on human health remains elusive. We applied next generation sequencing (NGS) with the estrogen receptor α (ERα) positive human breast cancer cell line MCF-7 treated with 17-β-estradiol (E2), bisphenol A (BPA), bisphenol B (BPB), bisphenol Z (BPZ) and tetramethyl bisphenol A (4MeBPA). We used molecular docking, microscale thermophoresis, ERα activation assay, and cell cycle experiments on MCF-7 and ERα overexpressing HEK293 cells to verify th…
Activin and inhibin A in predicting outcome of pregnancies of unknown location after ART
2018
Abstract The aim was to investigate the predictive value of a single serum determination of activin A and inhibin A for classifying pregnancies of unknown location (PUL) after IVF cycles in both own fresh and donated oocytes. A case–control study conducted in a University-affiliated IVF center. Pregnancy outcomes after own fresh oocytes included 12 failing PUL, 12 ectopic pregnancies (EP) and a control group of 24 singleton intrauterine pregnancies (IUP). The same scheme was followed for the oocyte donation recipients. Inhibin A, activin A, β-hCG and Progesterone (P) were determined. In the own fresh oocytes IVF, the AUC for predicting EP vs. f failing PUL were: Activin A: 0.458 and Inhibin…
Evidence That Graves' Ophthalmopathy Immunoglobulins Do Not Directly Activate IGF-1 Receptors
2018
Background: Graves' ophthalmopathy (GO) pathogenesis involves thyrotropin (TSH) receptor (TSHR)-stimulating autoantibodies. Whether there are autoantibodies that directly stimulate insulin-like growth factor 1 receptors (IGF-1Rs), stimulating insulin-like growth factor receptor antibodies (IGFRAbs), remains controversial. This study attempted to determine whether there are stimulating IGFRAbs in patients with GO. Methods: Immunoglobulins (Igs) were purified from normal volunteers (NV-Igs) and patients with GO (GO-Igs). The effects of TSH, IGF-1, NV-Igs, and GO-Igs on pAKT and pERK1/2, members of pathways used by IGF-1R and TSHR, were compared in orbital fibroblasts from GO patients (GOFs) a…
microRNA Expression Profile in Single Hormone Receptor-Positive Breast Cancers is Mainly Dependent on HER2 Status—A Pilot Study
2020
Estrogen (ER) and progesterone (PgR) receptors and HER2 are crucial in the assessment of breast cancer specimens due to their prognostic and predictive significance. Single hormone receptor-positive breast cancers are less common and their clinical course is less favorable than ER(+)/PgR(+) tumors. Their molecular features, especially microRNA (miRNA) profiles, have not been investigated to date. Tumor specimens from 36 chemonaive breast cancer patients with known ER and PgR status (18 ER(+)/PgR(&minus