scholarly journals Pro- and Antioxidant Functions of the Peroxisome-Mitochondria Connection and Its Impact on Aging and Disease

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Amparo Pascual-Ahuir ◽  
Sara Manzanares-Estreder ◽  
Markus Proft
Keyword(s):  
Protein Complexes ◽  
Accelerated Aging ◽  
Redox Balance ◽  
Specific Protein ◽  
Environmental Cues ◽  
Dynamic Feature ◽  
Dynamic Nature ◽  
Functional Connection ◽  
Mitochondrial Homeostasis ◽  
The Impact

Peroxisomes and mitochondria are the main intracellular sources for reactive oxygen species. At the same time, both organelles are critical for the maintenance of a healthy redox balance in the cell. Consequently, failure in the function of both organelles is causally linked to oxidative stress and accelerated aging. However, it has become clear that peroxisomes and mitochondria are much more intimately connected both physiologically and structurally. Both organelles share common fission components to dynamically respond to environmental cues, and the autophagic turnover of both peroxisomes and mitochondria is decisive for cellular homeostasis. Moreover, peroxisomes can physically associate with mitochondria via specific protein complexes. Therefore, the structural and functional connection of both organelles is a critical and dynamic feature in the regulation of oxidative metabolism, whose dynamic nature will be revealed in the future. In this review, we will focus on fundamental aspects of the peroxisome-mitochondria interplay derived from simple models such as yeast and move onto discussing the impact of an impaired peroxisomal and mitochondrial homeostasis on ROS production, aging, and disease in humans.

scholarly journals Evaluation of the Impact of Organic Fillers on Selected Properties of Organosilicon Polymer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1103
Author(s):  
Sara Sarraj ◽  
Małgorzata Szymiczek ◽  
Tomasz Machoczek ◽  
Maciej Mrówka
Keyword(s):  
Tensile Strength ◽  
Natural Fiber ◽  
Accelerated Aging ◽  
Strength Properties ◽  
Visual Observation ◽  
Walnut Shell ◽  
Pistachio Shell ◽  
Thermoplastic Matrix ◽  
Static Tensile ◽  
The Impact

Eco-friendly composites are proposed to substitute commonly available polymers. Currently, wood–plastic composites and natural fiber-reinforced composites are gaining growing recognition in the industry, being mostly on the thermoplastic matrix. However, little data are available about the possibility of producing biocomposites on a silicone matrix. This study focused on assessing selected organic fillers’ impact (ground coffee waste (GCW), walnut shell (WS), brewers’ spent grains (BSG), pistachio shell (PS), and chestnut (CH)) on the physicochemical and mechanical properties of silicone-based materials. Density, hardness, rebound resilience, and static tensile strength of the obtained composites were tested, as well as the effect of accelerated aging under artificial seawater conditions. The results revealed changes in the material’s properties (minimal density changes, hardness variation, overall decreasing resilience, and decreased tensile strength properties). The aging test revealed certain bioactivities of the obtained composites. The degree of material degradation was assessed on the basis of the strength characteristics and visual observation. The investigation carried out indicated the impact of the filler’s type, chemical composition, and grain size on the obtained materials’ properties and shed light on the possibility of acquiring ecological silicone-based materials.

scholarly journals Neurotrophins as Key Regulators of Cell Metabolism: Implications for Cholesterol Homeostasis

2021 ◽  
Vol 22 (11) ◽  
pp. 5692
Author(s):  
Mayra Colardo ◽  
Noemi Martella ◽  
Daniele Pensabene ◽  
Silvia Siteni ◽  
Sabrina Di Bartolomeo ◽  
...  
Keyword(s):  
Growth Factors ◽  
Cholesterol Metabolism ◽  
System Development ◽  
Cell Metabolism ◽  
Redox Balance ◽  
Nervous System Development ◽  
Cholesterol Homeostasis ◽  
Signaling Cascades ◽  
Target Cells ◽  
The Impact

Neurotrophins constitute a family of growth factors initially characterized as predominant mediators of nervous system development, neuronal survival, regeneration and plasticity. Their biological activity is promoted by the binding of two different types of receptors, leading to the generation of multiple and variegated signaling cascades in the target cells. Increasing evidence indicates that neurotrophins are also emerging as crucial regulators of metabolic processes in both neuronal and non-neuronal cells. In this context, it has been reported that neurotrophins affect redox balance, autophagy, glucose homeostasis and energy expenditure. Additionally, the trophic support provided by these secreted factors may involve the regulation of cholesterol metabolism. In this review, we examine the neurotrophins’ signaling pathways and their effects on metabolism by critically discussing the most up-to-date information. In particular, we gather experimental evidence demonstrating the impact of these growth factors on cholesterol metabolism.

scholarly journals Post-Translational Modification and Subcellular Compartmentalization: Emerging Concepts on the Regulation and Physiopathological Relevance of RhoGTPases

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1990
Author(s):  
Inmaculada Navarro-Lérida ◽  
Miguel Sánchez-Álvarez ◽  
Miguel Ángel del Pozo
Keyword(s):  
Rho Gtpases ◽  
Rho Gtpase ◽  
Protein Complexes ◽  
Specific Protein ◽  
Cell Polarization ◽  
Small Gtpase ◽  
Post Translational Modification ◽  
Functional Regulation ◽  
Subcellular Compartmentalization ◽  
Cellular Compartments

Cells and tissues are continuously exposed to both chemical and physical stimuli and dynamically adapt and respond to this variety of external cues to ensure cellular homeostasis, regulated development and tissue-specific differentiation. Alterations of these pathways promote disease progression—a prominent example being cancer. Rho GTPases are key regulators of the remodeling of cytoskeleton and cell membranes and their coordination and integration with different biological processes, including cell polarization and motility, as well as other signaling networks such as growth signaling and proliferation. Apart from the control of GTP–GDP cycling, Rho GTPase activity is spatially and temporally regulated by post-translation modifications (PTMs) and their assembly onto specific protein complexes, which determine their controlled activity at distinct cellular compartments. Although Rho GTPases were traditionally conceived as targeted from the cytosol to the plasma membrane to exert their activity, recent research demonstrates that active pools of different Rho GTPases also localize to endomembranes and the nucleus. In this review, we discuss how PTM-driven modulation of Rho GTPases provides a versatile mechanism for their compartmentalization and functional regulation. Understanding how the subcellular sorting of active small GTPase pools occurs and what its functional significance is could reveal novel therapeutic opportunities.

The Impact of Crowding on Calorie Consumption

2017 ◽  
Vol 44 (5) ◽  
pp. 1123-1140 ◽  
Author(s):  
Stefan J Hock ◽  
Rajesh Bagchi
Keyword(s):  
Consumer Behavior ◽  
Food Item ◽  
Affective Processing ◽  
Environmental Cues ◽  
Calorie Consumption ◽  
Managerial Implications ◽  
The Impact ◽  
Specific Reason ◽  
Human Crowding ◽  
Rule Out

Abstract Consumer behavior is often influenced by subtle environmental cues, such as temperature, color, lighting, scent, or sound. We explore the effects of a not-so-subtle cue—human crowding—on calorie consumption. Although crowding is an omnipresent factor, it has received little attention in the marketing literature. We present six studies showing that crowding increases calorie consumption. These effects occur because crowding increases distraction, which hampers cognitive thinking and evokes more affective processing. When consumers process information affectively, they consume more calories. We show the specific reason for the increase in calories. When given a choice between several different options, people select and eat higher-calorie items, but when presented with only one option, people eat more of the same food item. We document this process, rule out alternative explanations, and discuss theoretical and managerial implications.

scholarly journals A Functional Connection between the Circadian Clock and Hormonal Timing in Arabidopsis

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 567 ◽  
Author(s):  
Manjul Singh ◽  
Paloma Mas
Keyword(s):  
Circadian Clock ◽  
Biological Significance ◽  
Feedback Regulation ◽  
Environmental Cues ◽  
Hormone Signaling ◽  
Functional Connection ◽  
The Earth ◽  
Exogenous Cues ◽  
Rotation Of The Earth ◽  
Molecular Components

The rotation of the Earth entails changes in environmental conditions that pervasively influence an organism’s physiology and metabolism. An internal cellular mechanism known as the circadian clock acts as an internal timekeeper that is able to perceive the changes in environmental cues to generate 24-h rhythms in synchronization with daily and seasonal fluctuations. In plants, the circadian clock function is particularly important and regulates nearly every aspect of plant growth and development as well as proper responses to stresses. The circadian clock does not function in isolation but rather interconnects with an intricate network of different pathways, including those of phytohormones. Here, we describe the interplay of the circadian clock with a subset of hormones in Arabidopsis. The molecular components directly connecting the circadian and hormone pathways are described, highlighting the biological significance of such connections in the control of growth, development, fitness, and survival. We focus on the overlapping as well as contrasting circadian and hormonal functions that together provide a glimpse on how the Arabidopsis circadian system regulates hormone function in response to endogenous and exogenous cues. Examples of feedback regulation from hormone signaling to the clock are also discussed.

Metallocluster transactions: dynamic protein interactions guide the biosynthesis of Fe–S clusters in bacteria

2018 ◽  
Vol 46 (6) ◽  
pp. 1593-1603 ◽  
Author(s):  
Chenkang Zheng ◽  
Patricia C. Dos Santos
Keyword(s):  
Protein Interactions ◽  
Protein Complexes ◽  
Specific Protein ◽  
Biological Synthesis ◽  
Cluster Assembly ◽  
Sequence Motifs ◽  
Protein Protein Interactions ◽  
Cysteine Desulfurase ◽  
Wide Range ◽  
Domains Of Life

Iron–sulfur (Fe–S) clusters are ubiquitous cofactors present in all domains of life. The chemistries catalyzed by these inorganic cofactors are diverse and their associated enzymes are involved in many cellular processes. Despite the wide range of structures reported for Fe–S clusters inserted into proteins, the biological synthesis of all Fe–S clusters starts with the assembly of simple units of 2Fe–2S and 4Fe–4S clusters. Several systems have been associated with the formation of Fe–S clusters in bacteria with varying phylogenetic origins and number of biosynthetic and regulatory components. All systems, however, construct Fe–S clusters through a similar biosynthetic scheme involving three main steps: (1) sulfur activation by a cysteine desulfurase, (2) cluster assembly by a scaffold protein, and (3) guided delivery of Fe–S units to either final acceptors or biosynthetic enzymes involved in the formation of complex metalloclusters. Another unifying feature on the biological formation of Fe–S clusters in bacteria is that these systems are tightly regulated by a network of protein interactions. Thus, the formation of transient protein complexes among biosynthetic components allows for the direct transfer of reactive sulfur and Fe–S intermediates preventing oxygen damage and reactions with non-physiological targets. Recent studies revealed the importance of reciprocal signature sequence motifs that enable specific protein–protein interactions and consequently guide the transactions between physiological donors and acceptors. Such findings provide insights into strategies used by bacteria to regulate the flow of reactive intermediates and provide protein barcodes to uncover yet-unidentified cellular components involved in Fe–S metabolism.

scholarly journals Analysis of Dynamic Magnetoelastic Coupling in Mechanically Driven Magnetoelectric Antennas

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 455
Author(s):  
Kevin Q. T. Luong ◽  
Yuanxun (Ethan) Wang
Keyword(s):  
Material Properties ◽  
New Technology ◽  
Operating Conditions ◽  
Dynamic Nature ◽  
Stepping Stones ◽  
Direct Role ◽  
Antenna Size ◽  
Magnetoelastic Coupling ◽  
The Impact ◽  
Analytical Expressions

Mechanically driven magnetoelectric antennas are a promising new technology that enable a reduction in antenna size by many orders of magnitude, as compared to conventional antennas. The magnetoelastic coupling in these antennas, a phenomenon playing a direct role in determining performance, has been modeled using approaches that are severely lacking in both accuracy and tractability. In response to this problem, we take a physics-based approach to the analysis of magnetoelastic coupling. We find that certain directions of applied stress will maximize the coupling and we derive general expressions to quantify it. Our results are applied in comprehensive simulations that demonstrate the dynamic nature of the coupling as well as the impact of various operating conditions and material properties. Our work contributes analytical expressions and associated insight that can serve not only as guidelines for the design of mechanically driven magnetoelectric antennas, but also as stepping stones towards the development of more accurate models.

scholarly journals Pengembangan Metode Pengusangan Cepat Fisik Benih Pepaya (Carica papaya L.)

2019 ◽  
Vol 2 (3) ◽  
pp. 7
Author(s):  
Dyah Priandini ◽  
Muhamad Rahmad Suhartanto ◽  
Abdul Qadir
Keyword(s):  
Moisture Content ◽  
Aging Time ◽  
Seed Quality ◽  
Block Design ◽  
Accelerated Aging ◽  
Seed Moisture Content ◽  
Accelerated Aging Test ◽  
Aging Test ◽  
The Impact ◽  
Papaya Seed

Development of papaya fruit production is influenced by the availability of seed quality. High seed quality is maintained during seed storage. Estimation of vigor in relation to storability can be detected by accelerated aging test. This research aims to develop physicall accelerated aging test by, 1)determine the impact of physical accelerated aging on vigor and viability parameters on papaya seed variety Callina and Sukma, 2) determine the levels of seed moisture content and effective period of physicall accelerated aging to predict vigor of papaya seed. This research was conducted at the Laboratory of Seed Science and Technology and Green House Leuwikopo, Department of Agronomy and Horticulture, IPB in January-May 2016 using a randomized complete block design with three replications. Seeds aged by the aging equipment MPC IPB 77-1 MMM. The results showed that the aging time decreased germination value in papaya seed variety Callina and Sukma with equation y=-0.1389x3+3.3333x2–25.25x+81.5 and y=0.0171x3+0.2028x2-9.9956x+81.095. Effective imbibition is 96 hour with moisture content 63-70% in both varieties. The effective of aging time treatment at 0x4, 1x4, 2x4, 3x4, dan 4x4 minutes.Keywords:imbibition, moisture content, viability, vigor

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