scholarly journals Neuroepithelial organoid patterning is mediated by Wnt-driven Turing mechanism

2021 ◽  
Author(s):  
Abdel Rahman Abdel Fattah ◽  
Sergei Grebenyuk ◽  
Idris Salmon ◽  
Adrian Ranga

AbstractCell patterning in epithelia is critical for the establishment of tissue function during development. The organization of patterns in these tissues is mediated by the interpretation of signals operating across multiple length scales. How epithelial tissues coordinate changes in cell identity across these length scales to orchestrate cellular rearrangements and fate specification remains poorly understood. Here, we use human neural tube organoids as model systems to interrogate epithelial patterning principles that guide domain specification. In silico modeling of the patterning process by cellular automata, validated by in vitro experiments, reveal that the initial positions of floor plate cells, coupled with activator-inhibitor signaling interactions, deterministically dictate the patterning outcome according to a discretized Turing reaction-diffusion mechanism. This model predicts an enhancement of organoid patterning by modulating inhibitor levels. Receptor-ligand interaction analysis of scRNAseq data from multiple organoid domains reveals WNT-pathway ligands as the specific inhibitory agents, thereby allowing for the experimental validation of model predictions. These results demonstrate that neuroepithelia employ reaction-diffusion-based mechanisms during early embryonic human development to organize cellular identities and morphogen sources to achieve patterning. The wider implementation of such in vitro organoid models in combination with in-silico agent-based modeling coupled to receptor-ligand analysis of scRNAseq data opens avenues for a broader understanding of dynamic tissue patterning processes.

MedChemComm ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 138-146 ◽  
Author(s):  
Daniela Rossi ◽  
Annamaria Marra ◽  
Marta Rui ◽  
Erik Laurini ◽  
Maurizio Fermeglia ◽  
...  

To investigate the role of chirality in the ligand–σ1 receptor interaction, a series of enantiomeric arylalkylaminoalcohols and arylpyrrolidinols was evaluated by means of both in silico and in vitro studies.


2021 ◽  
Vol 16 (5) ◽  
pp. 1934578X2110150
Author(s):  
Gang Li ◽  
Wei Zhou ◽  
Xiurong Zhao ◽  
Ying Xie

The novel coronavirus, 2019-nCoV, has led to a major pandemic in 2020 and is responsible for more than 2.9 million officially recorded deaths worldwide. As well as synthetic anti-viral drugs, there is also a need to explore natural herbal remedies. The Traditional Chinese Medicines (TCMs) system has been used for thousands of years for the prevention, diagnosis, and treatment of several chronic diseases. In this paper, we performed an in silico molecular docking and interaction analysis of TCMs against SARS-CoV-2 receptor RNA-dependent RNA polymerase (RdRp). We obtained the 5 most effective plant compounds which had a better binding affinity towards the target receptor protein. These compounds areforsythoside A, rutin, ginkgolide C, icariside II, and nolinospiroside E. The top-ranked compound, based on docking score, was nolinospiroside, a glycoside found in Ophiopogon japonicas that has antioxidant properties. Protein-ligand interaction analysis discerned that nolinospiroside formed a strong bond between ARG 349 of the protein receptor and the carboxylate group of the ligand, forming a stable complex. Hence, nolinospiroside could be deployed as a lead compound against SARS-CoV-2 infection that can be further investigated for its potential benefits in curbing the viral infection.


Author(s):  
Rushil Pingali ◽  
Sourabh K. Saha

Abstract Two-photon lithography (TPL) is a polymerization-based direct laser writing process that is capable of fabricating arbitrarily complex three-dimensional (3D) structures with submicron features. Traditional TPL techniques have limited scalability due to the slow point-by-point serial writing scheme. The femtosecond projection TPL (FP-TPL) technique increases printing rate by a thousand times by enabling layer-by-layer parallelization. However, parallelization alters the time and the length scales of the underlying polymerization process. It is therefore challenging to apply the models of serial TPL to accurately predict process outcome during FP-TPL. To solve this problem, we have generated a finite element model of the polymerization process on the time and length scales relevant to FP-TPL. The model is based on the reaction-diffusion mechanism that underlies polymerization. We have applied this model to predict the geometry of nanowires printed under a variety of conditions and compared these predictions against empirical data. Our model accurately predicts the nanowire widths. However, accuracy of aspect ratio prediction is hindered by uncertain values of the chemical properties of the photopolymer. Nevertheless, our results demonstrate that the reaction-diffusion model can accurately capture the effect of controllable parameters on FP-TPL process outcome and can therefore be used for process control and optimization.


2016 ◽  
Vol 8 (8) ◽  
pp. 861-868 ◽  
Author(s):  
M. Hagiwara

The mechanisms of 2D pattern formation in bronchial epithelial cells were dynamically analyzed by controlled cell culture and a reaction-diffusion model.


2019 ◽  
Vol 59 (7) ◽  
pp. 3277-3290 ◽  
Author(s):  
Peng Ding ◽  
Ziyang Chen ◽  
Hao Chen ◽  
Zizhen Zhang ◽  
Zhihong Liu ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dan Su ◽  
Yu-Qiao Gao ◽  
Yong-Jie Deng ◽  
Han-Hui Zhang ◽  
You-Ru Wu ◽  
...  

The Janus kinases (JAKs) consist of four similar tyrosine kinases and function as key hubs in the signaling pathways that are implicated in both innate and adaptive immunity. Among the four members, JAK3 is probably the more attractive target for treatment of inflammatory diseases because its inhibition demonstrates the greatest immunosuppression and most profound effect in the treatment of such disorders. Although many JAK3 inhibitors are already available, certain shortcomings have been identified, mostly acquired drug resistance or unwanted side effects. To discover and identify new promising lead candidates, in this study, the structure of JAK3 (3LXK) was obtained from the Protein Data Bank and used for simulation modeling and protein-ligand interaction analysis. The ~36,000 Chinese herbal compounds obtained from TCM Database@Taiwan were virtually screened by AutoDock Vina docking program and filtered with Lipinski’s Rules and ADME/T virtual predictions. Because of high occurrence of fake hits during docking, we selected 12 phytochemicals which have demonstrated modulating JAKs expressions among the top 50 chemicals from docking results. To validate whether these compounds are able to directly mediate JAK3 kinase, we have investigated the inhibitory activity using enzymatic activity assays, western blot, and HEK 293 cell STAT5 transactivity assays. The molecular analysis included docking and molecular dynamics (MD) simulations in order to investigate structural conformations and to explore the key amino acids in the interaction between JAK3 kinase and its putative ligands. The results demonstrated that Cryptotanshinone, Icaritin, and Indirubin exhibited substantial inhibitory activity against JAK3 kinase in vitro. The results also provide binding models of the protein-ligand interaction, detailing the interacting amino acid residues at the active ATP-binding domains of JAK3 kinase. In conclusion, our work discovered 3 potential natural inhibitors of JAK3 kinase and could provide new possibilities and stimulate new insights for the treatment of JAK3-targeted diseases.


2015 ◽  
Vol 77 (2) ◽  
Author(s):  
B. Samuel Thavamani ◽  
Molly Mathew ◽  
Dhanabal S. Palaniswamy

Protein-ligand interaction plays a major role in identification of the possible mechanism by which a ligand can bind with the target and exerts the pharmacological action. The present study aims to identify new possible candidates for treating Hepatocellular Carcinoma (HCC) by docking the reported phytochemicals present in Cissampelos pareira with the well known HCC targets using in-silico techniques. Although C. pareira demonstrated in vitro and in vivo anti-heptatocellular carcinoma activities, the mechanism remains uncertain. Selected compounds from C. pareira were docked using GLIDE software with known targets of hepatocellular carcinoma viz. Aurora Kinase, c-Kit, Fibroblast Growth Factor (FGF), Nuclear Factor kappa B (NF-kB), B-cell lymphoma-extra large (Bcl-xL) and Vascular Endothelial Growth Factor (VEGF). Among the compounds docked, pareitropone and pareirubrine B exhibited good hydrogen bonding interactions and binding energy with the targets of HCC taken in the study. Hence these compounds deserve consideration for further studies towards HCC.


Biochemistry ◽  
2014 ◽  
Vol 53 (18) ◽  
pp. 2993-3003 ◽  
Author(s):  
S. Brune ◽  
D. Schepmann ◽  
K.-H. Klempnauer ◽  
D. Marson ◽  
V. Dal Col ◽  
...  

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