scholarly journals Actin Cytoskeleton as Actor in Upstream and Downstream of Calcium Signaling in Plant Cells

2019 ◽  
Vol 20 (6) ◽  
pp. 1403 ◽  
Author(s):  
Dong Qian ◽  
Yun Xiang

In plant cells, calcium (Ca2+) serves as a versatile intracellular messenger, participating in several fundamental and important biological processes. Recent studies have shown that the actin cytoskeleton is not only an upstream regulator of Ca2+ signaling, but also a downstream regulator. Ca2+ has been shown to regulates actin dynamics and rearrangements via different mechanisms in plants, and on this basis, the upstream signaling encoded within the Ca2+ transient can be decoded. Moreover, actin dynamics have also been proposed to act as an upstream of Ca2+, adjust Ca2+ oscillations, and establish cytosolic Ca2+ ([Ca2+]cyt) gradients in plant cells. In the current review, we focus on the advances in uncovering the relationship between the actin cytoskeleton and calcium in plant cells and summarize our current understanding of this relationship.

2019 ◽  
Vol 19 (20) ◽  
pp. 1707-1716 ◽  
Author(s):  
Miao Li ◽  
Meng Pan ◽  
Chengzhong You ◽  
Jun Dou

MiRNAs play an important role in cancers. As a potent tumor suppressor, miRNA-7(miR-7) has been demonstrated to inhibit the diverse fundamental biological processes in multiple cancer types including initiation, growth and metastasis by targeting a number of molecules and signaling pathways. This current review summarizes and discusses the relationship between miR-7 and cancers and the therapeutic potential of miR-7 in cancers. It may provide new integrative understanding for future study on the role of miR-7 in cancers.


2010 ◽  
Vol 38 (3) ◽  
pp. 823-828 ◽  
Author(s):  
Tijs Ketelaar ◽  
Hannie S. van der Honing ◽  
Anne Mie C. Emons

In interphase plant cells, the actin cytoskeleton is essential for intracellular transport and organization. To fully understand how the actin cytoskeleton functions as the structural basis for cytoplasmic organization, both molecular and physical aspects of the actin organization have to be considered. In the present review, we discuss literature that gives an insight into how cytoplasmic organization is achieved and in which actin-binding proteins have been identified that play a role in this process. We discuss how physical properties of the actin cytoskeleton in the cytoplasm of live plant cells, such as deformability and elasticity, can be probed by using optical tweezers. This technique allows non-invasive manipulation of cytoplasmic organization. Optical tweezers, integrated in a confocal microscope, can be used to manipulate cytoplasmic organization while studying actin dynamics. By combining this with mutant studies and drug applications, insight can be obtained about how the physical properties of the actin cytoskeleton, and thus the cytoplasmic organization, are influenced by different cellular processes.


2020 ◽  
Vol 26 ◽  
Author(s):  
Bei Wang ◽  
Wen Xu ◽  
Yuxuan Cai ◽  
Chong Guo ◽  
Gang Zhou ◽  
...  

Background: CASC15, one of long non-coding RNA, is involved in the regulation of many tumor biological processes, and is expected to become a new biological therapeutic target. This paper aims to elucidate the pathophysiological function of CASC15 in various tumors. Methods: The relationship between CASC15 and tumors was analyzed by searching references, and summarizes the specific pathophysiological mechanism of CASC15. Results: LncRNA CASC15 is closely related to tumor development, and has been shown to be abnormally high expressed in all kinds of tumors, including breast cancer, cervical cancer, lung cancer, hepatocellular carcinoma, gastric cancer, bladder cancer, colon cancer, colorectal cancer, cardiac hypertrophy, intrahepatic cholangiocarcinoma, leukemia, melanoma, tongue squamous cell carcinoma, nasopharyngeal carcinoma. However, CASC15 has been found to be downexpressed abnormally in ovarian cancer, glioma and neuroblastoma. Besides, it is identified that CASC15 can affect the proliferation, invasion and apoptosis of tumors. Conclusion: LncRNA CASC15 has the potential to become a new therapeutic target or marker for a variety of tumors.


2020 ◽  
Vol 15 (7) ◽  
pp. 602-606
Author(s):  
Kun Ji ◽  
Ling Ding ◽  
Xi Chen ◽  
Yun Dai ◽  
Fangfang Sun ◽  
...  

Mesenchymal Stem Cells (MSCs) exhibit enormous therapeutic potential because of their indispensable regenerative, reparative, angiogenic, anti-apoptotic, and immunosuppressive properties. MSCs can best differentiate into mesodermal cell lineages, including osteoblasts, adipocytes, muscle cells, endothelial cells and chondrocytes. Specific differentiation of MSCs could be induced through limited conditions. In addition to the relevant differentiation factors, drastic changes also occur in the microenvironment to conduct it in an optimal manner for particular differentiation. Recent evidence suggests that the mitochondria participate in the regulating of direction and process of MSCs differentiation. Therefore, our current review focuses on how mitochondria participate in both osteogenesis and adipogenesis of MSC differentiation. Besides that, in our current review, we try to provide a further understanding of the relationship between the behavior of mitochondria and the direction of MSC differentiation, which could optimize current cellular culturing protocols for further facilitating tissue engineering by adjusting specific conditions of stem cells.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 868
Author(s):  
Jiayang Zhang ◽  
Ruoyu Sun ◽  
Tingting Jiang ◽  
Guangrui Yang ◽  
Lihong Chen

Blood pressure (BP) follows a circadian rhythm, it increases on waking in the morning and decreases during sleeping at night. Disruption of the circadian BP rhythm has been reported to be associated with worsened cardiovascular and renal outcomes, however the underlying molecular mechanisms are still not clear. In this review, we briefly summarized the current understanding of the circadian BP regulation and provided therapeutic overview of the relationship between circadian BP rhythm and cardiovascular and renal health and disease.


1992 ◽  
Vol 71 (11) ◽  
pp. 1816-1821 ◽  
Author(s):  
C.A. Bibb ◽  
A.G. Pullinger ◽  
F. Baldioceda

Undifferentiated mesenchymal (UM) cells, the progenitor cells of the cartilage layer, have been assigned a significant role in TMJ articular tissue maintenance. This was based on reports of UM cell reduction with increased soft-tissue thickness for the condyle and temporal component. However, the strength of this inverse relationship was not presented and remained unclear. The purpose of the present study was to assess the strength of the correlation between UM cell presence and soft-tissue thickness in young adult TMJs at autopsy. Sagittal histological sections from the central thirds of 50 joints were evaluated with respect to articular soft-tissue thickness, histological character, and UM cell presence in the condyle and temporal component. The superior sector ofthe condyle and the articular eminence showed the greatest variability in soft-tissue thickness and were the only areas to show localized UM cell absence. The eminence was the only location to show an inverse relationship between soft-tissue thickness and UM cell presence, and this was consistent in both an ANOVA (p = 0.0016) and a Spearman correlation analysis. However, the strength of this correlation was only moderate (rho = -0.52), and no such relationship was observed in any other location. This study suggests that the relationship between UM cell presence and soft-tissue thickness is more complex than previously hypothesized and that the contribution of UM cells to articular tissue maintenance has been overstated, while other biological processes were overlooked.


2021 ◽  
Vol 28 ◽  
Author(s):  
Chunyan Ao ◽  
Lin Gao ◽  
Liang Yu

: DNA methylation is an important mode of regulation in epigenetic mechanisms, and it is one of the research foci in the field of epigenetics. DNA methylation modification affects a series of biological processes, such as eukaryotic cell growth, differentiation and transformation mechanisms, by regulating gene expression. In this review, we systematically summarized the DNA methylation databases, prediction tools for DNA methylation modification, machine learning algorithms for predicting DNA methylation modification, and the relationship between DNA methylation modification and diseases such as hypertension, Alzheimer's disease, diabetic nephropathy, and cancer. An in-depth understanding of DNA methylation mechanisms can promote accurate prediction of DNA methylation modifications and the treatment and diagnosis of related diseases.


2000 ◽  
Vol 113 (7) ◽  
pp. 1241-1254 ◽  
Author(s):  
M.K. Shaw ◽  
H.L. Compton ◽  
D.S. Roos ◽  
L.G. Tilney

We have used drugs to examine the role(s) of the actin and microtubule cytoskeletons in the intracellular growth and replication of the intracellular protozoan parasite, Toxoplasma gondii. By using a 5 minute infection period and adding the drugs shortly after entry we can treat parasites at the start of intracellular development and 6–8 hours prior to the onset of daughter cell budding. Using this approach we found, somewhat surprisingly, that reagents that perturb the actin cytoskeleton in different ways (cytochalasin D, latrunculin A and jasplakinolide) had little effect on parasite replication although they had the expected effects on the host cells. These actin inhibitors did, however, disrupt the orderly turnover of the mother cell organelles leading to the formation of a large residual body at the posterior end of each pair of budding parasites. Treating established parasite cultures with the actin inhibitors blocked ionophore-induced egression of tachyzoites from the host cells, demonstrating that intracellular parasites were susceptible to the effects of these inhibitors. In contrast, the anti-microtubule drugs oryzalin and taxol, and to a much lesser extent nocodazole, which affect microtubule dynamics in different ways, blocked parasite replication by disrupting the normal assembly of the apical conoid and the microtubule inner membrane complex (IMC) in the budding daughter parasites. Centrosome replication and assembly of intranuclear spindles, however, occurred normally. Thus, daughter cell budding per se is dependent primarily on the parasite microtubule system and does not require a dynamic actin cytoskeleton, although disruption of actin dynamics causes problems in the turnover of parasite organelles.


Author(s):  
Francis Ansah

The traditional tension between external and internal quality assurance implementation in higher education appears to be declining, based on a rethinking of the relationship between the two concepts. Although there are quality assurance agencies that still consider external and internal quality assurance as separate entities, most quality assurance agencies now regard the two concepts as complementary. In this paper, a case is put that the present rethinking of external and internal quality assurance in most higher education settings is guided by pragmatism, but not explicitly acknowledged in the literature. For a better appreciation of pragmatists’ influence on the current understanding of the relationship between external and internal quality assurance in higher education, this paper provides a further pragmatist conceptualisation of the two concepts to enhance stakeholders’ appreciation of employing a pragmatist approach to quality assurance practices in higher education. The conceptualisation is done through a pragmatist analysis of selected international accounts on higher education quality assurance. The paper concludes that pragmatism helps to understand external and internal quality assurance as nested concepts with reciprocities of accountability and improvement roles, and influences which call for alignment of perspectives through negotiations and settlements in order to focus on their practical relevance for implementation in higher education. La tension traditionnelle entre l’implémentation de systèmes d’assurance qualité interne et externe dans l’enseignement supérieur semble s’affaiblir grâce à la reconsidération de la relation entre ces deux concepts. Bien qu’il existe des agences d’assurance qualité qui continuent à considérer les assurances qualité interne et externe comme deux entités distinctes, la plupart des agences considèrent désormais qu’elles sont complémentaires. Cet article soutient que la nouvelle manière de penser les assurances qualité interne et externe dans l’enseignement supérieur est guidée par un souci de pragmatisme mais est encore peu reconnue dans la littérature. Pour mieux apprécier l’influence des pragmatistes sur la compréhension actuelle de la relation entre les assurances qualité interne et externe, cet article offre une conceptualisation pragmatique approfondie de ces deux concepts dans le but d’augmenter l’appréciation des parties prenantes pour l’utilisation d’une telle approche. La conceptualisation proposée provient d’une analyse pragmatique d’un choix d’expériences internationales en matière d’assurance qualité pour l’enseignement supérieur. En conclusion, cet article affirme que le pragmatisme aide à comprendre les assurances qualité interne et externe comme des concepts imbriqués qui ont des rôles réciproques en ce qui concerne la responsabilisation du système et son amélioration. Ces rôles ainsi que l’influence exercée par ces deux types d’assurance qualité requièrent des négociations et accords, pour s’accorder sur les perspectives et pouvoir ensuite se concentrer pleinement sur la pertinence pratique de leur implémentation dans les systèmes d’enseignement supérieur. 


2003 ◽  
Vol 14 (3) ◽  
pp. 1097-1108 ◽  
Author(s):  
Rihong Zhou ◽  
Zhen Guo ◽  
Charles Watson ◽  
Emily Chen ◽  
Rong Kong ◽  
...  

Actin cytoskeleton plays an important role in the establishment of epithelial cell polarity. Cdc42, a member of Rho GTPase family, modulates actin dynamics via its regulators, such as IQGAP proteins. Gastric parietal cells are polarized epithelial cells in which regulated acid secretion occurs in the apical membrane upon stimulation. We have previously shown that actin isoforms are polarized to different membrane domains and that the integrity of the actin cytoskeleton is essential for acid secretion. Herein, we show that Cdc42 is preferentially distributed to the apical membrane of gastric parietal cells. In addition, we revealed that two Cdc42 regulators, IQGAP1 and IQGAP2, are present in gastric parietal cells. Interestingly, IQGAP2 is polarized to the apical membrane of the parietal cells, whereas IQGAP1 is mainly distributed to the basolateral membrane. An IQGAP peptide that competes with full-length IQGAP proteins for Cdc42-binding in vitro also inhibits acid secretion in streptolysin-O-permeabilized gastric glands. Furthermore, this peptide disrupts the association of IQGAP and Cdc42 with the apical actin cytoskeleton and prevents the apical membrane remodeling upon stimulation. We propose that IQGAP2 forms a link that associates Cdc42 with the apical cytoskeleton and thus allows for activation of polarized secretion in gastric parietal cells.


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