scholarly journals Hydrostatic pressure prevents chondrocyte differentiation through heterochromatin remodeling

2020 ◽  
pp. jcs.247643
Author(s):  
Koichiro Maki ◽  
Michele M. Nava ◽  
Clementine Villeneuve ◽  
Minki Chang ◽  
Katsuko S. Furukawa ◽  
...  

Articular cartilage protects and lubricates joints for smooth motion and transmission of loads. Due to its high water content, chondrocytes within the cartilage are exposed to high levels of hydrostatic pressure, which has been shown to promote chondrocyte identity though unknown mechanisms. Here we investigate the effects of hydrostatic pressure on chondrocyte state and behavior, and discover that application of hydrostatic pressure promotes chondrocyte quiescence and prevents maturation towards the hypertrophic state. Mechanistically, hydrostatic pressure reduces H3K9me3-marked constitutive heterochromatin and concomitantly increases H3K27me3-marked facultative heterochromatin. Reduced H3K9me3 attenuates expression of pre-hypertrophic genes, replication, and transcription thereby reducing replicative stress. Conversely, promoting replicative stress by inhibition of topoisomerase II decreases Sox9 expression, suggesting that it enhances chondrocyte maturation. Our results reveal how hydrostatic pressure triggers chromatin remodeling to impact cell fate and function.

Author(s):  
A. Bykov ◽  
D. Palatov ◽  
I. Studenov ◽  
D. Chupov

The article provides information about the features of spring feeding of sterlet in the spawning grounds of the middle course of the Northern Dvina river in may 2019. The main and secondary groups of forage objects in the diet of this species of sturgeon are characterized. The article considers the variability of the sterlet food composition with an increase in the size of fish from 30 to 60 cm. In the process of fish growth in the diet of the Severodvinsk sterlet, the main components in terms of occurrence and mass in all size groups are the larvae of Brooks and chironomids. A minor occurrence was the larvae of midges, biting midges, stoneflies, mayflies and small clams. To random and seasonal food are the larvae of water bugs, butterflies, flies, beetles and eggs of other fish. The feeding intensity of the smaller sterlet (30–40 cm) was significantly higher than that of the fish in the size groups 40–50 and 50–60 cm. Fundamental changes in the diet of the Severodvinsk sterlet for the main food objects for more than sixty years of observations have not been established. During periods of high water content of the Northern Dvina due to seasonal changes in the structure of benthic communities, the value of Brooks in the diet of sterlet increases and the proportion of chironomids decreases.


2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.


2018 ◽  
Vol 4 (2) ◽  
pp. 150
Author(s):  
Rahmadini Darwas

<p><strong><em>Abstract<br /></em></strong><em>Laboratory is one of the supporting facilities in im[roving the learning process. Problems found by students regarding the information system laboratory facilities at STMIK Indonesia Padang are</em><em> the computers that suddenly die when operated, the less cold room, display data is blurred, making the inconvenience in the learning process that causes the students less satisfied with the services provided. Students will feel satisfied if the service is expected to match the received. Therefore, a decision support system is needed to analyze the quality of services provided to the students so that it can support the role and function of the laboratory optimally and what attributes need to be improved the quality of service. The method used is Fuzzy Service Quality (Servqual) method. The results showed that the service quality received was not in accordance with the expected because there is a gap of -1.55 for tangibles dimension. Attributes that need to be improved the quality of services are laboratory space is cool and comfortable, the use of laboratories relevant to the field of science, the responsibility of laboratory assistant, the availability of professional teachers and attitudes and behavior of labor officers.<br /></em></p><p><strong><em>Abstrak<br /></em></strong>Laboratorium merupakan salah satu fasilitas pendukung dalam meningkatkan proses pembelajaran. Permasalahan yang ditemukan mahasiswa mengenai fasilitas laboratorium sistem informasi pada STMIK Indonesia Padang adalah komputer yang tiba-tiba mati saat dioperasikan, ruangan yang kurang dingin, data <em>display</em> yang buram sehingga membuat ketidaknyamanan dalam proses pembelajaran yang menyebabkan mahasiswa kurang puas terhadap layanan yang diberikan. Mahasiswa akan merasa puas apabila layanan yang diharapkan sesuai dengan yang diterima. Oleh sebab itu, diperlukan suatu sistem pendukung keputusan untuk menganalisis kualitas layanan yang diberikan kepada mahasiswa sehingga dapat mendukung peran dan fungsi laboratorium secara optimal serta atribut apa saja yang perlu ditingkatkan kualitas layanannya. Metode yang digunakan adalah metode <em>Fuzzy Service Quality </em>(<em>Servqua</em>l). Hasil penelitian menunjukkan bahwa kualitas layanan yang diterima belum sesuai dengan yang diharapkan karena terdapat <em>gap</em> sebesar -1.55 untuk dimensi <em>tangibles</em>. Atribut yang perlu ditingkatkan kualitas layanannya yaitu ruangan laboratorium yang sejuk dan nyaman, penggunaan laboratorium yang relevan dengan bidang ilmu, tanggungjawab asisten labor, tersedianya tenaga pengajar yang professional dan sikap serta perilaku petugas labor</p><p><strong><em>Kata kunci</em></strong><strong> : sistem pendukung keputusan, laboratorium, <em>fuzzy</em>, <em>servqual</em></strong></p><p><strong><em><br /></em></strong></p>


2020 ◽  
Vol 56 (2) ◽  
pp. 119-122
Author(s):  
Doris Adams Hill ◽  
Theoni Mantzoros ◽  
Jonté C. Taylor

Special educators are often considered the experts in their school when it comes to developing functional behavior assessments (FBA) and behavior intervention plans (BIP), yet rarely are they trained much beyond basic antecedents, behaviors, and consequences (ABC). This column discusses concepts that will expand special education professionals’ knowledge to make better decisions regarding interventions for the students they serve. Specifically, the focus is on motivating operations (MO) and function-based interventions and the implications of these on behavior. Knowledge of the concept of MOs can enhance a teacher’s ability to provide evidence-based interventions and more fully developed behavioral interventions for students in their purview.


2019 ◽  
Vol 67 (7) ◽  
pp. 4803-4810 ◽  
Author(s):  
Xiong Wang ◽  
Tao Qin ◽  
Yexian Qin ◽  
Ahmed H. Abdelrahman ◽  
Russell S. Witte ◽  
...  

Author(s):  
Karolina Punovuori ◽  
Mattias Malaguti ◽  
Sally Lowell

AbstractDuring early neural development, changes in signalling inform the expression of transcription factors that in turn instruct changes in cell identity. At the same time, switches in adhesion molecule expression result in cellular rearrangements that define the morphology of the emerging neural tube. It is becoming increasingly clear that these two processes influence each other; adhesion molecules do not simply operate downstream of or in parallel with changes in cell identity but rather actively feed into cell fate decisions. Why are differentiation and adhesion so tightly linked? It is now over 60 years since Conrad Waddington noted the remarkable "Constancy of the Wild Type” (Waddington in Nature 183: 1654–1655, 1959) yet we still do not fully understand the mechanisms that make development so reproducible. Conversely, we do not understand why directed differentiation of cells in a dish is sometimes unpredictable and difficult to control. It has long been suggested that cells make decisions as 'local cooperatives' rather than as individuals (Gurdon in Nature 336: 772–774, 1988; Lander in Cell 144: 955–969, 2011). Given that the cadherin family of adhesion molecules can simultaneously influence morphogenesis and signalling, it is tempting to speculate that they may help coordinate cell fate decisions between neighbouring cells in the embryo to ensure fidelity of patterning, and that the uncoupling of these processes in a culture dish might underlie some of the problems with controlling cell fate decisions ex-vivo. Here we review the expression and function of cadherins during early neural development and discuss how and why they might modulate signalling and differentiation as neural tissues are formed.


2021 ◽  
Vol 22 (8) ◽  
pp. 3955
Author(s):  
László Bálint ◽  
Zoltán Jakus

Our understanding of the function and development of the lymphatic system is expanding rapidly due to the identification of specific molecular markers and the availability of novel genetic approaches. In connection, it has been demonstrated that mechanical forces contribute to the endothelial cell fate commitment and play a critical role in influencing lymphatic endothelial cell shape and alignment by promoting sprouting, development, maturation of the lymphatic network, and coordinating lymphatic valve morphogenesis and the stabilization of lymphatic valves. However, the mechanosignaling and mechanotransduction pathways involved in these processes are poorly understood. Here, we provide an overview of the impact of mechanical forces on lymphatics and summarize the current understanding of the molecular mechanisms involved in the mechanosensation and mechanotransduction by lymphatic endothelial cells. We also discuss how these mechanosensitive pathways affect endothelial cell fate and regulate lymphatic development and function. A better understanding of these mechanisms may provide a deeper insight into the pathophysiology of various diseases associated with impaired lymphatic function, such as lymphedema and may eventually lead to the discovery of novel therapeutic targets for these conditions.


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