scholarly journals Theory of branching morphogenesis by local interactions and global guidance

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mehmet Can Uçar ◽  
Dmitrii Kamenev ◽  
Kazunori Sunadome ◽  
Dominik Fachet ◽  
Francois Lallemend ◽  
...  

AbstractBranching morphogenesis governs the formation of many organs such as lung, kidney, and the neurovascular system. Many studies have explored system-specific molecular and cellular regulatory mechanisms, as well as self-organizing rules underlying branching morphogenesis. However, in addition to local cues, branched tissue growth can also be influenced by global guidance. Here, we develop a theoretical framework for a stochastic self-organized branching process in the presence of external cues. Combining analytical theory with numerical simulations, we predict differential signatures of global vs. local regulatory mechanisms on the branching pattern, such as angle distributions, domain size, and space-filling efficiency. We find that branch alignment follows a generic scaling law determined by the strength of global guidance, while local interactions influence the tissue density but not its overall territory. Finally, using zebrafish innervation as a model system, we test these key features of the model experimentally. Our work thus provides quantitative predictions to disentangle the role of different types of cues in shaping branched structures across scales.

2021 ◽  
Author(s):  
Mehmet Can Uçar ◽  
Dmitrii Kamenev ◽  
Kazunori Sunadome ◽  
Dominik Fachet ◽  
François Lallemend ◽  
...  

Branching morphogenesis governs the formation of many organs such as lung, kidney, and the neurovascular system. Many studies have explored system-specific molecular and cellular regulatory mechanisms, as well as self-organizing rules underlying branching morphogenesis. However, in addition to local cues, branched tissue growth can also be influenced by global guidance. Here, we develop a theoretical framework for a stochastic self-organized branching process in the presence of external cues. Combining analytical theory with numerical simulations, we predict differential signatures of global vs. local regulatory mechanisms on the branching pattern, such as angle distributions, domain size, and space-filling efficiency. We find that branch alignment follows a generic scaling law determined by the strength of global guidance, while local interactions influence the tissue density but not its overall territory. Finally, using zebrafish innervation as a model system, we test these key features of the model experimentally. Our work thus provides quantitative predictions to disentangle the role of different types of cues in shaping branched structures across scales.


2020 ◽  
Vol 10 (4) ◽  
pp. 254-261
Author(s):  
S. V. Topolyanskaya

Modern concepts about the role of connective tissue growth factor in various physiological and pathological processes are described in the review. Connective tissue growth factor regulates a variety of cellular functions, including proliferation, migration, adhesion, differentiation and synthesis of extracellular matrix proteins in cells of different types. This factor is also involved in more complex biological processes of angiogenesis, chondrogenesis, wound healing, fibrosis and oncogenesis. Increased expression of connective tissue growth factor is observed in different cardiovascular and oncological diseases. Potential role of this growth factor in regulation of cellular senescence and aging processes is also discussed.


2016 ◽  
Vol 86 (3-4) ◽  
pp. 127-151 ◽  
Author(s):  
Zeshan Ali ◽  
Zhenbin Wang ◽  
Rai Muhammad Amir ◽  
Shoaib Younas ◽  
Asif Wali ◽  
...  

While the use of vinegar to fi ght against infections and other crucial conditions dates back to Hippocrates, recent research has found that vinegar consumption has a positive effect on biomarkers for diabetes, cancer, and heart diseases. Different types of vinegar have been used in the world during different time periods. Vinegar is produced by a fermentation process. Foods with a high content of carbohydrates are a good source of vinegar. Review of the results of different studies performed on vinegar components reveals that the daily use of these components has a healthy impact on the physiological and chemical structure of the human body. During the era of Hippocrates, people used vinegar as a medicine to treat wounds, which means that vinegar is one of the ancient foods used as folk medicine. The purpose of the current review paper is to provide a detailed summary of the outcome of previous studies emphasizing the role of vinegar in treatment of different diseases both in acute and chronic conditions, its in vivo mechanism and the active role of different bacteria.


1984 ◽  
Vol 52 (02) ◽  
pp. 172-175 ◽  
Author(s):  
P R Kelsey ◽  
K J Stevenson ◽  
L Poller

SummaryLiposomes of pure phospholipids were used in a modified APTT test system and the role of phosphatidyl serine (PS) in determining the sensitivity of the test system to the presence of lupus anticoagulants was assessed. Six consecutive patients with lupus anticoagulants and seven haemophiliacs with anticoagulants directed at specific coagulation factors, were studied. Increasing the concentration of phospholipid in the test system markedly reduced the sensitivity to lupus anticoagulants but had marginal effect on the specific factor inhibitors. The same effect was achieved when the content of PS alone was increased in a vehicle liposome of constant composition.The results suggest that the lupus anticoagulants can best be detected by a screening method using an APTT test with a reagent of low PS content. The use of a reagent rich in PS will largely abolish the lupus anticoagulant’s effect on the APTT. An approach using the two different types of reagent may facilitate differentiation of lupus inhibitors from other types of anticoagulant.


2020 ◽  
pp. 97-110
Author(s):  
E. N. Mikhailova ◽  
V. A. Telegina

The article is devoted to the study of evaluative tools used in modern French media in order to form the media image of a representative of the political elite. The techniques used in the creation of a memorial media portrait of Jacques Chirac (1932—2019), President of France from 1995 to 2007 are considered. The research material was the most prestigious French print media of various political orientations, published in late September — early October 2019 in connection with the death of the ex-President of the French Republic. The relevance of the research topic is dictated by the close attention of modern linguistics to axiological phenomena, differently presented in different types of discursive practices. The novelty of the study is due to the appeal to the analysis of the complex of evaluation tools used in the French print media when characterizing the former leader of the state during the nation’s farewell period. The estimated potential of the title of the article and its influence on the formation of the estimated vector of the entire text of the publication are shown. A systematic analysis of the assessment expression means, reflected in the memorial media portrait of the politician, is given. The factors that influenced the peculiarities of their use in this type of media portrait are revealed.


2020 ◽  
Author(s):  
Hua Jin ◽  
Lina Jia ◽  
Xiaojuan Yin ◽  
Shilin Wei ◽  
Guiping Xu

Misinformation often continues to influence people’s cognition even after corrected (the ‘continued influence effect of misinformation’, the CIEM). This study investigated the role of information relevance in the CIEM by questionnaire survey and experimental study. The results showed that information with higher relevance to the individuals had a larger CIEM, indicating a role of information relevance in the CIEM. Personal involvement might explain the effects of information relevance on the CIEM. This study provides insightful clues for reducing the CIEM in different types of misinformation and misinformation with varying relevance.


2020 ◽  
Vol 26 (21) ◽  
pp. 2492-2496 ◽  
Author(s):  
Fiammetta Romano ◽  
Giovanna Muscogiuri ◽  
Elea Di Benedetto ◽  
Volha V. Zhukouskaya ◽  
Luigi Barrea ◽  
...  

Background: Vitamin D exerts multiple pleiotropic effects beyond its role in calcium-phosphate metabolism. Growing evidence suggests an association between hypovitaminosis D and sleep disorders, thus increasing the interest in the role of this vitamin in the regulatory mechanisms of the sleep-wake cycle. Objective: The study aimed to explore and summarize the current knowledge about the role of vitamin D in sleep regulation and the impact of vitamin D deficiency on sleep disorders. Methods: The main regulatory mechanisms of vitamin D on sleep are explained in this study. The literature was scanned to identify clinical trials and correlation studies showing an association between vitamin D deficiency and sleep disorders. Results: Vitamin D receptors and the enzymes that control their activation and degradation are expressed in several areas of the brain involved in sleep regulation. Vitamin D is also involved in the pathways of production of Melatonin, the hormone involved in the regulation of human circadian rhythms and sleep. Furthermore, vitamin D can affect sleep indirectly through non-specific pain disorders, correlated with alterations in sleep quality, such as restless legs syndrome and obstructive sleep apnea syndrome. Conclusions: : Vitamin D has both a direct and an indirect role in the regulation of sleep. Although vitamin D deficiency has been associated to sleep disorders, there is still scant evidence to concretely support the role of vitamin D supplementation in the prevention or treatment of sleep disturbances; indeed, more intervention studies are needed to better clarify these aspects.


2019 ◽  
Vol 14 (3) ◽  
pp. 219-225 ◽  
Author(s):  
Cong Tang ◽  
Guodong Zhu

The nuclear factor kappa B (NF-κB) consists of a family of transcription factors involved in the regulation of a wide variety of biological responses. Growing evidence support that NF-κB plays a major role in oncogenesis as well as its well-known function in the regulation of immune responses and inflammation. Therefore, we made a review of the diverse molecular mechanisms by which the NF-κB pathway is constitutively activated in different types of human cancers and the potential role of various oncogenic genes regulated by this transcription factor in cancer development and progression. We also discussed various pharmacological approaches employed to target the deregulated NF-κB signaling pathway and their possible therapeutic potential in cancer therapy. Moreover, Syk (Spleen tyrosine kinase), non-receptor tyrosine kinase which mediates signal transduction downstream of a variety of transmembrane receptors including classical immune-receptors like the B-cell receptor (BCR), which can also activate the inflammasome and NF-κB-mediated transcription of chemokines and cytokines in the presence of pathogens would be discussed as well. The highlight of this review article is to summarize the classic and novel signaling pathways involved in NF-κB and Syk signaling and then raise some possibilities for cancer therapy.


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