THE PHYSIOLOGICAL BASIS OF DORIAN GRAY'S PORTRAIT

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Comments on: Effect of physical activity on long COVID fatigue

The authors of the Comments on: Effect of physical activity on long COVID fatigue by Daungsupawong F. and Wiwanitkit V. (2023) have highlighted certain aspects of future research that need to be considered before any conclusions can be drawn regarding the effect of previous physical activity and/or fitness on the course of long-COVID. We can only agree with this need, although we hope that the effects of SARS-CoV-2 infection will become less and less burdensome to manage. As we hypothesise in the last part of the article by Coscia et al. (2023), we think it is crucial to identify the molecular mechanism underlying the atrophic effect (if any) of the described disease states, which could originate from a local inflammatory storm induced by Spike binding to the ACE-2 receptor in muscle. When studies on muscle from patients will be available in sufficient numbers, we will be able to try to answer the still open questions

Extracellular GTP is a Potent Water- Transport Regulator via Aquaporin 5 Plasma-Membrane Insertion in M1-CCD Epithelial Cortical Collecting Duct Cells

Background/Aims: Extracellular GTP is able to modulate some specific functions in neuron, glia and muscle cell models as it has been demonstrated over the last two decades. In fact, extracellular GTP binds its specific plasma membrane binding sites and induces signal transduction via [Ca(2+)]i increase. We demonstrate, for the first time, that extracellular GTP is able to modulate cell swelling in M1-CCD cortical collecting duct epithelial cells via upregulation of aquaporin 5 (AQP5) expression. Methods: We used videoimaging, immunocitochemistry, flow cytometry, confocal techniques, Western blotting and RT-PCR for protein and gene expression analysis, respectively. Results: We demonstrate that AQP5 mRNA is up-regulated 7 h after the GTP exposure in the cell culture medium, and its protein level is increased after 12-24 h. We show that AQP5 is targeted to the plasma membrane of M1-CCD cells, where it facilitates cell swelling, and that the GTP-dependent AQP5 up-regulation occurs via [Ca(2+)]i increase. Indeed, GTP induces both oscillating and transient [Ca(2+)]i increase, and specifically the oscillating kinetic appears to be responsible for blocking cell cycle in the S-phase while the [Ca(2+)]i influx, with whatever kinetic, seems to be responsible for inducing AQP5 expression. Conclusion: The role of GTP as a regulator of AQP5-mediated water transport in renal cells is of great importance in the physiology of renal epithelia, due to its possible physiopathological implications. GTP-dependent AQP5 expression could act as osmosensor. In addition, the data presented here suggest that GTP might play the same role in other tissues where rapid water transport is required for cell volume regulation and maintenance of the homeostasis. © 2014 S. Karger AG, Basel. ispartof: Cellular Physiology and Biochemistry vol:33 issue:3 pages:731-46 ispartof: location:Germany status: publishe

Oxidative Stress in Skeletal Muscle

The accumulation of ROS, mainly due to increased mitochondrial production and/or decreased scavenger systems, is often associated with the term oxidative stress, used to define a condition judged to be problematic for muscle cells [...

Ten years of the Interuniversity Institute of Myology

The Interuniversity Institute of Myology (IIM) has been formally approved in late autumn 2003 by the University of Chieti Board of the first Director, Giorgio Fanò. Many Italian Myologists, coming from Italian Universities such as Università degli Studi di Chieti, Università degli Studi di Brescia, Università degli Studi di Firenze, Università degli Studi di Messina, Università degli Studi di Milano, Università degli Studi di Padova, Università degli Studi di Pavia, Università degli Studi di Perugia, Università degli Studi di Roma 'La Sapienza', Università degli Studi di Siena, who excel in Myology Research, recognized IIM and its potentiality for international joined collaboration

Editorial for the Special Issue “Molecular Bases of Senescence”

The increasing life expectancy of populations worldwide represents the most evident success of the last century thanks to varying interacting social and medical achievements [...

H2O2/Ca2+/Zn2+ Complex Can Be Considered a “Collaborative Sensor” of the Mitochondrial Capacity?

In order to maintain a state of well-being, the cell needs a functional control center that allows it to respond to changes in the internal and surrounding environments and, at the same time, carry out the necessary metabolic functions. In this review, we identify the mitochondrion as such an “agora”, in which three main messengers are able to collaborate and activate adaptive response mechanisms. Such response generators, which we have identified as H2O2, Ca2+, and Zn2+, are capable of “reading” the environment and talking to each other in cooperation with the mitochondrion. In this manner, these messengers exchange information and generate a holistic response of the whole cell, dependent on its functional state. In this review, to corroborate this claim, we analyzed the role these actors, which in the review we call “sensors”, play in the regulation of skeletal muscle contractile capacities chosen as a model of crosstalk between Ca2+, Zn2+, and H2O2

Physical Activity Effects on Muscle Fatigue in Sport in Active Adults with Long COVID-19: An Observational Study

Long COVID-19-related changes in physiology includes alterations in performing muscle work as fatigue. Data available do not allow us to define the usefulness of physical activity to attenuate long COVID-19 functional modifications. The present observational study investigates the effects of physical activity on the perception of fatigue, maximum power output, sleep, and cognitive modifications in subjects affected by long COVID-19, distinguishing between active and sedentary subjects. The data demonstrated the following: the perception of fatigue 1 year after the end of virus positivity was significantly reduced with respect to that observed after 6 months by more than 50% more in active subjects compared to sedentary ones; 6 months after the end of virus positivity, the force developed by active subjects was reduced (RM factor: p p < 0.001), but the reduction was more pronounced in sedentary ones (mean difference = 38.499 W); poor sleep quality and mild cognitive impairment were assessed in both active and sedentary subjects. In conclusion, the study suggests that the long COVID-19 fatigue was lower in active subjects respect to sedentary ones. A comparative analysis performed due to the overlap of functional alterations between long COVID-19 and ME/CFS showed that in a small percentage of the enrolled subjects (8%), the symptomatology reflected that of ME/CFS and was independent of the individual physical capacities

Is it possible to assess visual–perceptual processes involved in writing through a tablet test?The new title is: Psychological and physiological processes in figure - tracing abilities measured using a tablet computer: a study with 7 - 9 - year - old children

The present study investigated the use of a tablet computer to assess figure-tracing skills and their relationships with psychological (visual–perceptual processes, cognitive processes, handwriting skills) and physiological (body mass index, isometric strength of arms) parameters with school-children of second (7-8-year-olds) and fourth (9-10-year-olds) grades. We were also interested in gender differences. The task required tracing of geometric figures on a template, shown on a tablet screen in light grey, for the segments that make up the target figure, one at a time. This figure-tracing tablet test allows acquisition and automated analysis of four parameters: number of strokes (pen lift) for each segment; oscillations of lines drawn with respect to reference lines; pressure of pen on tablet; and average speed of tracing. The results show a trade-off between speed and quality for the tablet parameters, with higher speed associated with more oscillations with respect to the reference lines, and lower number of strokes for each segment, in both male and female children. The involvement of visual–motor integration on the ability to reduce the oscillations in this tablet test was only seen for the male children, while both the male and female children showed a relationship between oscillations and more general/ abstract visual–spatial processes. These data confirm the role of visual–motor processes in this figure-tracing tablet test only for male children, while more general visual–spatial processes influence the performance in the tablet test for both sexes. We conclude that the test proposed is useful to screen for grapho-motor difficulties

New insights into the relationship between mIGF-1-induced hypertrophy and Ca2+ handling in differentiated satellite cells.

Muscle regeneration involves the activation of satellite cells, is regulated at the genetic and epigenetic levels, and is strongly influenced by gene activation and environmental conditions. The aim of this study was to determine whether the overexpression of mIGF-1 can modify functional features of satellite cells during the differentiation process, particularly in relation to modifications of intracellular Ca2+ handling. Satellite cells were isolated from wild-type and MLC/mIGF-1 transgenic mice. The cells were differentiated in vitro, and morphological analyses, intracellular Ca2+ measurements, and ionic current recordings were performed. mIGF-1 overexpression accelerates satellite cell differentiation and promotes myotube hypertrophy. In addition, mIGF-1 overexpression-induced potentiation of myogenesis triggers both quantitative and qualitative changes to the control of intracellular Ca2+ handling. In particular, the differentiated MLC/mIGF-1 transgenic myotubes have reduced velocity and amplitude of intracellular Ca2+ increases after stimulation with caffeine, KCl and acetylcholine. This appears to be due, at least in part, to changes in the physico-chemical state of the sarcolemma (increased membrane lipid oxidation, increased output currents) and to increased expression of dihydropyridine voltage-operated Ca2+ channels. Interestingly, extracellular ATP and GTP evoke intracellular Ca2+ mobilization to greater extents in the MLC/mIGF-1 transgenic satellite cells, compared to the wild-type cells. These data suggest that these MLC/mIGF-1 transgenic satellite cells are more sensitive to trophic stimuli, which can potentiate the effects of mIGF-1 on the myogenic programme