Changes in the Mitochondria in the Aging Process-Can α-Tocopherol Affect Them?

Aerobic organisms use molecular oxygen in several reactions, including those in which the oxidation of substrate molecules is coupled to oxygen reduction to produce large amounts of metabolic energy. The utilization of oxygen is associated with the production of ROS, which can damage biological macromolecules but also act as signaling molecules, regulating numerous cellular processes. Mitochondria are the cellular sites where most of the metabolic energy is produced and perform numerous physiological functions by acting as regulatory hubs of cellular metabolism. They retain the remnants of their bacterial ancestors, including an independent genome that encodes part of their protein equipment; they have an accurate quality control system; and control of cellular functions also depends on communication with the nucleus. During aging, mitochondria can undergo dysfunctions, some of which are mediated by ROS. In this review, after a description of how aging affects the mitochondrial quality and quality control system and the involvement of mitochondria in inflammation, we report information on how vitamin E, the main fat-soluble antioxidant, can protect mitochondria from age-related changes. The information in this regard is scarce and limited to some tissues and some aspects of mitochondrial alterations in aging. Improving knowledge of the effects of vitamin E on aging is essential to defining an optimal strategy for healthy aging

Feed production for sustainable aquaculture: A Bibliometric Network Analysis

In recent years, aquaculture has played a fundamental role in human nutrition and livestock for the ability to produce different animal and vegetable protein and lipid sources essential for human and animal health. However, the growing increase in aquaculture has led to a greater demand for ingredients composing feed for aquatic organisms, many of which are derived from wild fish making the aquatic feed production an unsustainable process. For this reason, the aquaculture sector has expanded experimentation to search for alternative ingredients to reduce environmental impact. This study explored the global scientific literature on sustainable aquaculture with particular reference to feeding using VOSviewer software, which allows for generating, visualizing, and exploring maps based on bibliometric network data. The results allowed a comprehensive overview of the scientific literature on sustainable aquaculture through network maps displaying the relationships among keywords, authors, countries, and journals. In detail, this paper highlighted that in the last years, particularly in recent decades, the research widely focused attention on different aspects of the sustainable aquaculture field. The first journal that researched sustainable aquaculture was the Aquaculture Journal, and the leading countries that pursued this type of research were the USA, UK, and China. Concerning the co-occurrence, the top keywords were aquaculture, sustainability, animals, nonhuman, and sustainable development, highlighting a growing interest in research on microalgae, diet, fishmeal, and climate change. The description of the current state of the art in sustainable aquaculture reported in this article highlighted that the combined use of social network analysis and bibliometrics allows exploring the development of research in specific fields of science and lays the foundations for delving into questions that have not yet been sufficiently investigated

Towards sustainable aquaculture systems: Biological and environmental impact of replacing fishmeal with Arthrospira platensis (Nordstedt) (spirulina)

Sustainable fish food production is crucial for aquaculture. Microalgae, such as spirulina (Arthrospira platensis), can supplement diet antioxidants or replace expensive fishmeal with high-quality proteins. In this study, we tested fish growth and wellbeing by feeding fish on a diet in which 5% of fishmeal was replaced by spirulina (SP5 diet). The low level of spirulina in the diet was intended as supplementation and was effective in ameliorating the redox state of a model fish species (juvenile Koi Carp, Cyprinus carpio L.) in a preliminary lab protocol in a six-week trial. When compared with both the control diet (no Spirulina) and a diet containing 30% spirulina replacing fishmeal (SP30 diet), SP5 was able to reduce the muscle levels of reactive oxygen species (ROS), oxidative damage, and susceptibility to oxidative stress, while increasing glutathione reductase and peroxidase activity. However, high production costs and impacts still limit the use of spirulina in fish diet. Recent studies focused on growing spirulina on urban or agro-industrial wastewater, with appropriate profiles for the alga growth. Therefore, in a circular economy context, a possibility still to be tested and exploited is feeding farmed fish with spirulina produced on output wastewater recirculated back from the same farming plant. Life Cycle Assessment (LCA) was applied to estimate the sustainability of such “circular” fish farming. The LCA ReCiPe Midpoint (H) impact assessment method was used. Firstly, the LCA environmental impacts associated with the production of spirulina grown on aquaculture wastewater as well as on the standard culture medium (Zarrouk medium) were assessed and compared by means of a “gate to gate” analysis. Then, the LCA impacts of an SP5 diet for fish, in which spirulina grown on aquaculture wastewater was used to replace 5% fishmeal (SP5ww), were compared to the diet containing spirulina grown on a standard medium (SP5st) and that one without spirulina (control diet). Results indicated that SP5ww was significantly less impacting, by avoiding the treatment and disposal of wastewater and the need for the highly impacting standard culture medium. In conclusion, the proposed approach for using spirulina in aquaculture represents a valid solution for aquaculture circular economy scenario while at the same time improving fish welfare

Aluminium exposure affects the morphology of gills and muscles and routine oxygen consumption of zebrafish

Aluminium (Al) is a metal highly diffuse in the Earth's crust. In the last decades, climate change and the associated phenomenon of acid rain are further increasing its environmental concentration. The acidification of water bodies facilitates the solubilization of the inorganic Al and increases its bioavailability for aquatic organisms. Studies carried out with different fish species have revealed that Al can produce toxic effects in fish by interfering with physiological activities and biochemical processes that, in turn, affect fertility, growth, and increase mortality. The neurobehavioral alterations link to the affections of swimming activity. However, until now, relatively scarce information is available about the effects of Al on the tissues relevant for the swimming performance of fish, such as gills and muscles. The gills of fish represent the first organ interacting with the metal in water bodies, and their alterations can affect the whole animal physiology. The impaired functionality of muscle is relevant for swimming behavior. Here we report the effects of the chronic exposure to 11 mg/L of Al for 10, 15, and 20 days on gills and muscle morphology, in vivo routine oxygen consumption (rMO2, a measure of the whole animal resting energy requirement), and routine activity parameters (tail beats) of zebrafish adults. This experimental model is an optimal bioindicator to evaluate environmental pollutants' ecotoxicological effects. The histological analysis highlights that the morphology of gills is altered by the Al treatment, although with different degrees depending on the exposure time. 10 days of Al exposure determines dramatic changes in branchial tissue which shows a disordered structure and a reduced lamellae number. After 15 days of Al exposure the branchial tissue shows signs of recovery, that is a more ordered structure and a higher number of lamellae. In 20 days- Al exposed animals there is a further morphological recovery. The morphological alterations of muscles parallel those of gills. A higher alteration of both white and red muscle tissues is evident in the organisms exposed for less time to Al, while a recovery of the normal morphological characteristics is observed after longer time of exposure. The recovery of muscle morphology is associated with its functionality, as demonstrated by the gradual increase of tail beats during the exposition. These changes reflect in the rMO2 consumption that is maximum after 10 days of exposure, suggesting a stress response for the animals. Then this parameter decreases and reaches the lowest levels after 20 days of treatment. This result suggests an adjustment of the resting metabolic pathways to face the reduced efficiency in the gaseous exchange of gill tissue

Muscle Oxidative Stress Plays a Role in Hyperthyroidism-Linked Insulin Resistance

While a low level of ROS plays a role in cellular regulatory processes, a high level can lead to oxidative stress and cellular dysfunction. Insulin resistance (IR) is one of the dysfunctions in which oxidative stress occurs and, until now, the factors underlying the correlation between oxidative stress and IR were unclear and incomplete. This study aims to explore this correlation in skeletal muscle, a tissue relevant to insulin-mediated glucose disposal, using the hyperthyroid rat as a model of oxidative stress. The development of IR in the liver from hyperthyroid animals has been widely reported, whereas data concerning the muscle are quite controversial. Thus, we investigated whether hyperthyroidism induces IR in skeletal muscle and the role of oxidative stress in this process. Particularly, we compared the effects of hyperthyroidism on IR both in the absence and presence of vitamin E (Vit E), acting as an antioxidant. Putative correlations between ROS production, oxidative stress markers, antioxidant capacity and changes in intracellular signalling pathways related to insulin action (AKT) and cellular stress response (EIF2α; JNK; PGC1α; BIP; and NRF1) were investigated. Moreover, we assessed the effects of hyperthyroidism and Vit E on the expression levels of genes encoding for glucose transporters (Slc2a1; Slc2a4), factors involved in lipid homeostasis and insulin signalling (Pparg; Ppara, Cd36), as well as for one of the IR-related inflammatory factors, i.e., interleukin 1b (Il1b). Our results suggest that hyperthyroidism-linked oxidative stress plays a role in IR development in muscle and that an adequate antioxidant status, obtained by vitamin E supplementation, that mitigates oxidative stress, may prevent IR development

A dedicated simulation chain for Hypervelocity Impacts effects on DISC sensor

Comet Interceptor is an ESA Fast-class space mission, which will be launched in 2029 towards an as-yet undiscovered Dynamically New Comet, i.e. never having approached the Sun before, or even an interstellar body. Comet Interceptor consists of three spacecrafts that will flyby the selected DNC. DISC sensors (part of Dust Field and Plasma suite) will be mounted on board two of the three foreseen S/C, aiming to determine cometary dust dynamical properties retrieving information from the particles impinging its sensitive surface. The DISC sensing plate will be exposed to the cometary dust environment thus subjected to Hypervelocity Impacts (HVI), due to the high speed of the flyby (10 - 70 km/s). Nowadays facilities don't let to test all the possible impact cases DISC will be subjected into the cometary environment (very high relative speed during flyby). To overcome this limitation, we set up a simulations system for the sensor with ANSYS TM software and AUTODYN TM hydrocode, capable of simulating a wide range of impacts characteristics (e.g. speeds, particles sizes) DISC will face during the operative phase. The simulation system involves a hybrid model discretized with both Smooth Particles Hydrodynamic (SPH) and Finite Element methods, and it is organized in two main steps: 1. The first step includes the region very close to the impact point, discretized with SPH. Here is reproduced the impact and the impacted surface evolvement from the generated shockwave, large material deformation and compression, till the formation of Lamb waves and the start of the elastic regime. 2. The second step is a transient structural analysis involving Finite Element discretization. The output of the previous step is used as input for this second one, which is applied to the entire DISC sensing plate to obtain the HVI effects till the plate edges, where PZT sensors are placed. This simulation considers the PZTs characteristics to get as output of the simulation the PZT signals. Impacts by different particles diameters and velocities have been simulated. Here we report the simulations system and some of the most relevant final outputs