scholarly journals Potential Role of Plasmalogens in the Modulation of Biomembrane Morphology

2021 ◽  
Vol 9 ◽  
Author(s):  
Zakaria A. Almsherqi
Keyword(s):  
Cell Membrane ◽  
Vinyl Ether ◽  
Significant Role ◽  
Potential Role ◽  
Unsaturated Fatty Acids ◽  
Morphological Changes ◽  
Proper Function ◽  
Structural And Functional Properties ◽  
Membrane Transformation

Plasmalogens are a subclass of cell membrane glycerophospholipids that typically include vinyl- ether bond at the sn-1 position and polyunsaturated fatty acid at the sn-2 position. They are highly abundant in the neuronal, immune, and cardiovascular cell membranes. Despite the abundance of plasmalogens in a plethora of cells, tissues, and organs, the role of plasmalogens remains unclear. Plasmalogens are required for the proper function of integral membrane proteins, lipid rafts, cell signaling, and differentiation. More importantly, plasmalogens play a crucial role in the cell as an endogenous antioxidant that protects the cell membrane components such as phospholipids, unsaturated fatty acids, and lipoproteins from oxidative stress. The incorporation of vinyl-ether linked with alkyl chains in phospholipids alter the physicochemical properties (e.g., the hydrophilicity of the headgroup), packing density, and conformational order of the phospholipids within the biomembranes. Thus, plasmalogens play a significant role in determining the physical and chemical properties of the biomembrane such as its fluidity, thickness, and lateral pressure of the biomembrane. Insights on the important structural and functional properties of plasmalogens may help us to understand the molecular mechanism of membrane transformation, vesicle formation, and vesicular fusion, especially at the synaptic vesicles where plasmalogens are rich and essential for neuronal function. Although many aspects of plasmalogen phospholipid involvement in membrane transformation identified through in vitro experiments and membrane mimic systems, remain to be confirmed in vivo, the compiled data show many intriguing properties of vinyl-ether bonded lipids that may play a significant role in the structural and morphological changes of the biomembranes. In this review, we present the current limited knowledge of the emerging potential role of plasmalogens as a modulator of the biomembrane morphology.

scholarly journals The neovasculature homing motif NGR: more than meets the eye

Blood ◽  
2008 ◽  
Vol 112 (7) ◽  
pp. 2628-2635 ◽  
Author(s):  
Angelo Corti ◽  
Flavio Curnis ◽  
Wadih Arap ◽  
Renata Pasqualini
Keyword(s):  
Tumor Growth ◽  
Targeted Delivery ◽  
Binding Sites ◽  
Potential Role ◽  
Time Dependent ◽  
Binding Properties ◽  
Cell Functions ◽  
Structural And Functional Properties ◽  
Asparagine Deamidation

Abstract A growing body of evidence suggests that peptides containing the Asn-Gly-Arg (NGR) motif can selectively recognize tumor neovasculature and can be used, therefore, for ligand-directed targeted delivery of various drugs and particles to tumors or to other tissues with an angiogenesis component. The neovasculature binding properties of these peptides rely on the interaction with an endothelium-associated form of aminopeptidase N (CD13), an enzyme that has been implicated in angiogenesis and tumor growth. Recent studies have shown that NGR can rapidly convert to isoaspartate-glycine-arginine (isoDGR) by asparagine deamidation, generating αvβ3 ligands capable of affecting endothelial cell functions and tumor growth. This review focuses on structural and functional properties of the NGR motif and its application in drug development for angiogenesis-dependent diseases. Furthermore, we discuss the time-dependent transition of NGR to isoDGR in natural proteins, such as fibronectins, and its potential role of as a “molecular timer” for generating new binding sites for integrins impli-cated in angiogenesis.

scholarly journals The computational challenge of lattice chiral symmetry - Is it worth the expense?

2020 ◽  
Vol 245 ◽  
pp. 06034
Author(s):  
Adam Virgili ◽  
Waseem Kamleh ◽  
Derek Leinweber
Keyword(s):  
Energy Spectrum ◽  
Lattice Qcd ◽  
Chiral Symmetry ◽  
Significant Role ◽  
Potential Role ◽  
Roper Resonance ◽  
Nucleon Spectrum ◽  
Significant Interest ◽  
The Subject

The origin of the low-lying position of the Roper resonance in the nucleon energy spectrum has been the subject of significant interest for many years, including several investigations using lattice QCD. It has been claimed that chiral symmetry plays an important role in our understanding of this resonance. We present results from our systematic examination of the potential role of chiral symmetry in the low-lying nucleon spectrum through the direct comparison of the clover and overlap fermion actions. After a brief summary of the background motivation, we specify the computational details of the study and outline our comparison methodologies. We do not find any evidence supporting the claim that chiral symmetry plays a significant role in understanding the Roper resonance on the lattice.

scholarly journals Long-Term Effects of Axotomy on Excitability and Growth of Isolated Aplysia Sensory Neurons in Cell Culture: Potential Role of cAMP

1998 ◽  
Vol 79 (3) ◽  
pp. 1371-1383 ◽  
Author(s):  
Supinder S. Bedi ◽  
Ali Salim ◽  
Shanping Chen ◽  
David L. Glanzman
Keyword(s):  
Cell Culture ◽  
Sensory Neurons ◽  
Potential Role ◽  
Morphological Changes ◽  
Axonal Injury ◽  
Long Term Effects ◽  
Cellular Processes ◽  
Neuritic Outgrowth

Bedi, Supinder S., Ali Salim, Shanping Chen, and David L. Glanzman. Long-term effects of axotomy on excitability and growth of isolated Aplysia sensory neurons in cell culture: potential role of cAMP. J. Neurophysiol. 79: 1371–1383, 1998. Crushing nerves, which contain the axons of central sensory neurons, in Aplysia causes the neurons to become hyperexcitable and to sprout new processes. Previous experiments that examined the effects of axonal injury on Aplysia sensory neurons have been performed in the intact animal or in the semi-intact CNS of Aplysia. It therefore has been unclear to what extent the long-term neuronal consequences of injury are due to intrinsic or extrinsic cellular signals. To determine whether injury-induced changes in Aplysia sensory neurons are due to intrinsic or extrinsic signals, we have developed an in vitro model of axonal injury. Isolated central sensory neurons grown for 2 days in cell culture were axotomized. Approximately 24 h after axotomy, sensory neurons exhibited a greater excitability—reflected, in part, as a significant reduction in spike accommodation—and greater neuritic outgrowth than did control (unaxotomized) neurons. Rp diastereoisomer of the cyclic adenosine 3′,5′-monophosphorothiate (Rp-cAMPS), an inhibitor of protein kinase A, blocked both the reduction in accommodation and increased neuritic outgrowth induced by axotomy. Rp-cAMPS also blocked similar, albeit smaller, alterations observed in control sensory neurons during the 24-h period of our experiments. These results indicate that axonal injury elevates cAMP levels within Aplysia sensory neurons, and that this elevation is directly responsible, in part, for the previously described long-term electrophysiological and morphological changes induced in Aplysia sensory neurons by nerve crush. In addition, the results indicate that control sensory neurons in culture are also undergoing injury-related electrophysiological and structural changes, probably due to cellular processes triggered when the neurons are axotomized during cell culturing. Finally, the results provide support for the idea that the cellular processes activated within Aplysia sensory neurons by injury, and those activated during long-term behavioral sensitization, overlap significantly.

scholarly journals Mechanism of damage to platelet and erythrocyte hemostasis in rats with prolonged hypokinesia

2017 ◽  
Vol 8 (2) ◽  
pp. 135-146
Author(s):  
S. L. Popel’ ◽  
О. V. Kryzаnivskaya ◽  
V. M. Zhurakіvskyi ◽  
R. Y. Chovhan ◽  
U. N. Dutchak ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Relative Content ◽  
Male Rats ◽  
Functional Changes ◽  
Activated Platelets ◽  
Structural And Functional Properties ◽  
Level Of Aggregation ◽  
Platelet Aggregates ◽  
Cellular Aggregates

The aim of the study was to determine the morphological changes in the cellular elements of blood in rats of different ages under conditions of prolonged hypokinesia. Research into the structural and functional properties of platelets and erythrocytes was carried out by electron microscope and by biochemical methods in 90 mature male rats aged 2, 12 and 24 months. We found that in young (2 month animals) there was a significant increase in the relative content of activated platelets while the normal content of aggregated and degranulated forms with the appearance of single platelets was maintained with an imbalance of alpha and delta granules. In 12-month-old animals, platelet hemostasis disorders were manifested by a significant increase in the relative content of activated platelets (by 125.8–134.7%) with an increase in aggregated and degranulated forms, the appearance of numerous platelets with an imbalance of alpha- and delta-granules, and reduction of mitochondria (by 24.9–27.8%). In 24 month old animals there was a sharp violation of platelet hemostasis due to a significant increase in the content of activated, degranulated and aggregated platelets, the release of the majority of granules, the development of intravascular platelet hyperactivation, an increase in the number of reversible and irreversibly transformed erythrocytes, an increase in the level of aggregation, in particular the appearance of complex cellular aggregates and bizarre forms of red blood cells. The greatest degree of manifestation of morpho-functional changes was revealed in animals aged 24 months, with relative stability of the hemostasis system in 2 and 12 month old animals. Our results showed that irrespective of age, the degree of disturbance of platelet-erythrocyte hemostasis rose as the period of hypokinesia increased and also depended on the increase in the level of serum creatinine. Taken together, intravascular platelet hyperactivation, an imbalance in the content of all types of granules, the transformation of surface cytoarchitectonics of erythrocytes, and the formation of platelet aggregates may play the role of an early predictor of the development of hypokinetic disease

scholarly journals Hazai és nemzetközi trendek az olvasásnépszerűsítés terén

2020 ◽  
Author(s):  
Krisztina Radics
Keyword(s):  
Reading Comprehension ◽  
Significant Role ◽  
Potential Role ◽  
Digital Form ◽  
Digital World ◽  
International Trends ◽  
Library Use ◽  
On Line ◽  
Library Profession

Reading, either in the traditional or digital form is a concern, whose importance today’s youth must be aware of. The representative national reading surveys of 2017 and 2019 of reading and library use habits carried out within the framework of the My library project demonstrated the declining popularity of reading. Furthermore, results of international reading comprehension surveys, especially the PISA tests pertaining to the specific ability of Hungarian students confirm this tendency. What can be done? What methods can we use to promote reading for the youth of the digital world? Programs popularizing reading can give potential answers. Since libraries play a significant role and they are perhaps the most influential in popularizing reading the opinion of the library profession related to these programs should be explored. In my presentation I compare domestic and international trends related to the popularization of reading. I will also introduce the results of an on-line questionnaire-based survey concerning the library profession’s views on the efficiency of such programs along with discussing the potential role of libraries and the expectations for the future.

scholarly journals Pathogenesis of Children’s Allergic Diseases: Refocusing the Role of the Gut Microbiota

2021 ◽  
Vol 12 ◽  
Author(s):  
Tingting Hu ◽  
Yinmiao Dong ◽  
Chenghao Yang ◽  
Mingyi Zhao ◽  
Qingnan He
Keyword(s):  
Potential Role ◽  
Mode Of Delivery ◽  
Allergic Diseases ◽  
Antibiotic Use ◽  
Proper Function ◽  
Heterogeneous Cluster ◽  
Infant Diet ◽  
Increasing Trend ◽  
Bacterial Groups

Allergic diseases comprise a genetically heterogeneous cluster of immunologically mediated diseases, including asthma, food allergy (FA), allergic rhinitis (AR) and eczema, that have become major worldwide health problems. Over the past few decades, the spread of allergic diseases has displayed an increasing trend, and it has been reported that 22% of 1.39 billion people in 30 countries have a type of allergic disease. Undoubtedly, allergic diseases, which can be chronic, with significant morbidity, mortality and dynamic progression, impose major economic burdens on society and families; thus, exploring the cause of allergic diseases and reducing their prevalence is a top priority. Recently, it has been reported that the gastrointestinal (GI) microbiota can provide vital signals for the development, function, and regulation of the immune system, and the above-mentioned contributions make the GI microbiota a key player in allergic diseases. Notably, the GI microbiota is highly influenced by the mode of delivery, infant diet, environment, antibiotic use and so on. Specifically, changes in the environment can result in the dysbiosis of the GI microbiota. The proper function of the GI microbiota depends on a stable cellular composition which in the case of the human microbiota consists mainly of bacteria. Large shifts in the ratio between these phyla or the expansion of new bacterial groups lead to a disease-promoting imbalance, which is often referred to as dysbiosis. And the dysbiosis can lead to alterations of the composition of the microbiota and subsequent changes in metabolism. Further, the GI microbiota can affect the physiological characteristics of the human host and modulate the immune response of the host. The objectives of this review are to evaluate the development of the GI microbiota, the main drivers of the colonization of the GI tract, and the potential role of the GI microbiota in allergic diseases and provide a theoretical basis as well as molecular strategies for clinical practice.

scholarly journals Saving-investment Behaviour in Pakistan: An Empirical Investigation

2004 ◽  
Vol 43 (4II) ◽  
pp. 665-682 ◽  
Author(s):  
Shahbaz Nasir ◽  
Mahmood Khalid
Keyword(s):  
Economic Growth ◽  
Significant Role ◽  
Potential Role ◽  
Empirical Investigation ◽  
Policy Implications ◽  
Self Reliance ◽  
Macro Variables ◽  
Micro Foundations ◽  
Investment Behaviour

Saving and investment are two key macro variables with micro foundations which can play a significant role in economic growth, inflation stability and promotion of employment especially if seen in the context of a developing country. For self-reliance and growth objectives, mobilisation of domestic resources and their efficient utilisation are the two major policy oriented focuses today [Khan (1993)]. National savings are critically important to help maintain a higher level of investment which is a key determinant for economic uplift. Thereby, necessitating the analysis of saving-investment behaviour and its determinants for policy implications; this is a demanding area because of continuing debate on the potential role of their determinants.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

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