scholarly journals Simulating CXCR5 Dynamics in Complex Tissue Microenvironments

2021 ◽  
Vol 12 ◽  
Author(s):  
Jason Cosgrove ◽  
Kieran Alden ◽  
Jens V. Stein ◽  
Mark C. Coles ◽  
Jon Timmis

To effectively navigate complex tissue microenvironments, immune cells sense molecular concentration gradients using G-protein coupled receptors. However, due to the complexity of receptor activity, and the multimodal nature of chemokine gradients in vivo, chemokine receptor activity in situ is poorly understood. To address this issue, we apply a modelling and simulation approach that permits analysis of the spatiotemporal dynamics of CXCR5 expression within an in silico B-follicle with single-cell resolution. Using this approach, we show that that in silico B-cell scanning is robust to changes in receptor numbers and changes in individual kinetic rates of receptor activity, but sensitive to global perturbations where multiple parameters are altered simultaneously. Through multi-objective optimization analysis we find that the rapid modulation of CXCR5 activity through receptor binding, desensitization and recycling is required for optimal antigen scanning rates. From these analyses we predict that chemokine receptor signaling dynamics regulate migration in complex tissue microenvironments to a greater extent than the total numbers of receptors on the cell surface.

2013 ◽  
Vol 51 (1) ◽  
pp. 191-202 ◽  
Author(s):  
Patricia M Lenhart ◽  
Stefan Broselid ◽  
Cordelia J Barrick ◽  
L M Fredrik Leeb-Lundberg ◽  
Kathleen M Caron

Receptor activity-modifying protein 3 (RAMP3) is a single-pass transmembrane protein known to interact with and affect the trafficking of several G-protein-coupled receptors (GPCRs). We sought to determine whether RAMP3 interacts with GPR30, also known as G-protein-coupled estrogen receptor 1. GPR30 is a GPCR that binds estradiol and has important roles in cardiovascular and endocrine physiology. Using bioluminescence resonance energy transfer titration studies, co-immunoprecipitation, and confocal microscopy, we show that GPR30 and RAMP3 interact. Furthermore, the presence of GPR30 leads to increased expression of RAMP3 at the plasma membrane in HEK293 cells. In vivo, there are marked sex differences in the subcellular localization of GPR30 in cardiac cells, and the hearts of Ramp3−/− mice also show signs of GPR30 mislocalization. To determine whether this interaction might play a role in cardiovascular disease, we treated Ramp3+/+ and Ramp3−/− mice on a heart disease-prone genetic background with G-1, a specific agonist for GPR30. Importantly, this in vivo activation of GPR30 resulted in a significant reduction in cardiac hypertrophy and perivascular fibrosis that is both RAMP3 and sex dependent. Our results demonstrate that GPR30–RAMP3 interaction has functional consequences on the localization of these proteins both in vitro and in vivo and that RAMP3 is required for GPR30-mediated cardioprotection.


2006 ◽  
Vol 34 (6) ◽  
pp. 1009-1013 ◽  
Author(s):  
C.A.H. Hansell ◽  
C.V. Simpson ◽  
R.J.B. Nibbs

Leucocyte migration is essential for robust immune and inflammatory responses, and plays a critical role in many human diseases. Chemokines, a family of small secreted protein chemoattractants, are of fundamental importance in this process, directing leucocyte trafficking by signalling through heptahelical G-protein-coupled receptors expressed by the migrating cells. However, several mammalian chemokine receptors, including D6 and CCX-CKR (ChemoCentryx chemokine receptor), do not fit existing models of chemokine receptor function, and do not even appear to signal in response to chemokine binding. Instead, these ‘atypical’ chemokine receptors are biochemically specialized for chemokine sequestration, acting to regulate chemokine bioavailability and thereby influence responses through signalling-competent chemokine receptors. This is of critical importance in vivo, as mice lacking D6 show exaggerated cutaneous inflammatory responses and an increased susceptibility to the development of skin cancer. CCX-CKR, on the other hand, is predicted to modulate homoeostatic lymphocyte and dendritic cell trafficking, key migratory events in acquired immune responses that are directed by CCX-CKR-binding chemokines. Thus studies on ‘atypical’ chemokine receptors are revealing functional and biochemical diversity within the chemokine receptor family and providing insights into novel mechanisms of chemokine regulation.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381 ◽  
Author(s):  
B Ovalle-Magallanes ◽  
A Madariaga-Mazón ◽  
A Navarrete ◽  
R Mata

2020 ◽  
Author(s):  
Johannes Karges ◽  
Shi Kuang ◽  
Federica Maschietto ◽  
Olivier Blacque ◽  
Ilaria Ciofini ◽  
...  

<div>The use of photodynamic therapy (PDT) against cancer has received increasing attention overthe recent years. However, the application of the currently approved photosensitizers (PSs) is somehow limited by their poor aqueous solubility, aggregation, photobleaching and slow clearance from the body. To overcome these limitations, there is a need for the development of new classes of PSs with ruthenium(II) polypyridine complexes currently gaining momentum. However, these compounds generally lack significant absorption in the biological spectral window, limiting their application to treat deep-seated or large tumors. To overcome this drawback, ruthenium(II) polypyridine complexes designed in silico with (E,E’)-4,4´-bisstyryl 2,2´-bipyridine ligands showed impressive 1- and 2-Photon absorption up to a magnitude higher than the ones published so far. While non-toxic in the dark, these compounds were found phototoxic in various 2D monolayer cells, 3D multicellular tumor spheroids and be able to eradicate a multiresistant tumor inside a mouse model upon clinically relevant 1-Photon and 2 Photon excitation.</div>


2020 ◽  
Vol 26 ◽  
Author(s):  
John Chen ◽  
Andrew Martin ◽  
Warren H. Finlay

Background: Many drugs are delivered intranasally for local or systemic effect, typically in the form of droplets or aerosols. Because of the high cost of in vivo studies, drug developers and researchers often turn to in vitro or in silico testing when first evaluating the behavior and properties of intranasal drug delivery devices and formulations. Recent advances in manufacturing and computer technologies have allowed for increasingly realistic and sophisticated in vitro and in silico reconstructions of the human nasal airways. Objective: To perform a summary of advances in understanding of intranasal drug delivery based on recent in vitro and in silico studies. Conclusion: The turbinates are a common target for local drug delivery applications, and while nasal sprays are able to reach this region, there is currently no broad consensus across the in vitro and in silico literature concerning optimal parameters for device design, formulation properties and patient technique which would maximize turbinate deposition. Nebulizers are able to more easily target the turbinates, but come with the disadvantage of significant lung deposition. Targeting of the olfactory region of the nasal cavity has been explored for potential treatment of central nervous system conditions. Conventional intranasal devices, such as nasal sprays and nebulizers, deliver very little dose to the olfactory region. Recent progress in our understanding of intranasal delivery will be useful in the development of the next generation of intranasal drug delivery devices.


2018 ◽  
Vol 21 (3) ◽  
pp. 215-221
Author(s):  
Haroon Khan ◽  
Muhammad Zafar ◽  
Helena Den-Haan ◽  
Horacio Perez-Sanchez ◽  
Mohammad Amjad Kamal

Aim and Objective: Lipoxygenase (LOX) enzymes play an important role in the pathophysiology of several inflammatory and allergic diseases including bronchial asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, rheumatoid arthritis and chronic obstructive pulmonary disease. Inhibitors of the LOX are believed to be an ideal approach in the treatment of diseases caused by its over-expression. In this regard, several synthetic and natural agents are under investigation worldwide. Alkaloids are the most thoroughly investigated class of natural compounds with outstanding past in clinically useful drugs. In this article, we have discussed various alkaloids of plant origin that have already shown lipoxygenase inhibition in-vitro with possible correlation in in silico studies. Materials and Methods: Molecular docking studies were performed using MOE (Molecular Operating Environment) software. Among the ten reported LOX alkaloids inhibitors, derived from plant, compounds 4, 2, 3 and 1 showed excellent docking scores and receptor sensitivity. Result and Conclusion: These compounds already exhibited in vitro lipoxygenase inhibition and the MOE results strongly correlated with the experimental results. On the basis of these in vitro assays and computer aided results, we suggest that these compounds need further detail in vivo studies and clinical trial for the discovery of new more effective and safe lipoxygenase inhibitors. In conclusion, these results might be useful in the design of new and potential lipoxygenase (LOX) inhibitors.


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