An aged-related structural study of DHPR tetrads in peripheral couplings of human skeletal muscle.

Among the numerous changes that occur in skeletal muscle during aging, the reduced regeneration potential after an injury is largely due to the impaired ability of satellite cells to proliferate and differentiate. Herein, using the freeze-fracture electron microscopy technique, we analyzed both the incidence and size of dihydropyridine receptors (DHPRs) tetrads (4 particles) in cultured myotubes from a young subject (28 years) after 9 days of differentiation and from an old subject (71 years) after 9 and 12 days of differentiation. Compared to young myotubes, at 9 days of differentiation old myotubes exhibited: i) a lower incidence and a smaller size of DHPR clusters and ii) a lower number of complete tetrads.

Myalgic encephalomyelitis/chronic fatigue syndrome from current evidence to new diagnostic perspectives through skeletal muscle and metabolic disturbances.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a demanding medical condition for patients and society. It has raised much more public awareness after the COVID-19 pandemic since ME/CFS and long-COVID patients share many clinical symptoms such as debilitating chronic fatigue. However, unlike long COVID, the etiopathology of ME/CFS remains a mystery despite several decades' research.

The Immune System Response to in Neurological Diseases.

Previous studies have reported an association between oral microbial dysbiosis and the development and progression of pathologies in the central nervous system. (), the keystone pathogen of the oral cavity, can induce a systemic antibody response measured in patients' sera using enzyme-linked immunosorbent assays. The present case-control study quantified the immune system's response to abundance in the oral cavities of patients affected by different central nervous system pathologies.

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.

Effectiveness of Apigenin, Resveratrol, and Curcumin as Adjuvant Nutraceuticals for Calvarial Bone Defect Healing: An In Vitro and Histological Study on Rats.

Bone healing is a major clinical issue, especially in bone defects of critical dimensions. Some studies have reported in vivo positive effects on bone healing by some bioactive compounds, such as the phenolic derivatives found in vegetables and plants, such as resveratrol, curcumin, and apigenin. The aim of this work was (1) to analyze in vitro in human dental pulp stem cells the effects of these three natural compounds on the gene expression of related genes downstream to and , key factor transcriptions associated with osteoblast differentiation, in order to better understand the positive effects that can occur in vivo in bone healing, and (2) to evaluate in vivo the effects on bone healing of critical-size defects in the calvaria in rats of these three nutraceuticals tested in parallel and for the first time administered by the gastric route.

Osteogenic Potential of Human Dental Pulp Stem Cells Co-Cultured with Equine Bone Substitute Combined with Melatonin.

Bone blocks are proposed in oral bone regeneration for their biocompatibility and osteoconductivity. Human dental pulp stem cells (hDPSCs) have been used with bone substitutes as a biocomplex. Melatonin, produced by the pineal gland, has specific functions in the oral cavity in bone remodeling and enhancing the dual actions on osteoblasts and osteoclasts, the genic expression of bone markers.

Biological Aspects of Selected Myokines in Skeletal Muscle: Focus on Aging.

In the last decade, clear evidence has emerged that the cellular components of skeletal muscle are important sites for the release of proteins and peptides called "myokines", suggesting that skeletal muscle plays the role of a secretory organ. After their secretion by muscles, these factors serve many biological functions, including the exertion of complex autocrine, paracrine and/or endocrine effects. In sum, myokines affect complex multi-organ processes, such as skeletal muscle trophism, metabolism, angiogenesis and immunological response to different physiological (physical activity, aging, etc.

Exploring the Connection between and Neurodegenerative Diseases: A Pilot Quantitative Study on the Bacterium Abundance in Oral Cavity and the Amount of Antibodies in Serum.

Recent studies support the hypothesis that microbes can seed some Alzheimer's disease (AD) cases, leading to inflammation and overproduction of amyloid peptides. (Pg) is a keystone pathogen of chronic periodontitis and has been identified as risk factor for the development and progression of AD. The present preliminary study aimed to quantify Pg abundance in neurodegenerative disease (ND) patients compared with neurologic patients without neurodegenerative disorders (no-ND) and healthy controls (HC) to determine possible association between Pg abundance and neurodegenerative process.

Corrigendum to "Superoxide Anion Production and Bioenergetic Profile in Young and Elderly Human Primary Myoblasts".

[This corrects the article DOI: 10.1155/2018/2615372.].

Guanosine-Based Nucleotides, the Sons of a Lesser God in the Purinergic Signal Scenario of Excitable Tissues.

Purines are nitrogen compounds consisting mainly of a nitrogen base of adenine (ABP) or guanine (GBP) and their derivatives: nucleosides (nitrogen bases plus ribose) and nucleotides (nitrogen bases plus ribose and phosphate). These compounds are very common in nature, especially in a phosphorylated form. There is increasing evidence that purines are involved in the development of different organs such as the heart, skeletal muscle and brain.

Neuromuscular Electrical Stimulation Induces Skeletal Muscle Fiber Remodeling and Specific Gene Expression Profile in Healthy Elderly.

Skeletal muscle aging is a multifactorial process strictly related to progressive weakness. One of the results that were focused on was the fiber phenotype modification and their loss. The physiological muscle recruitment to contraction, basically prosecuted under volitional control, can also be engaged by means of Neuromuscular Electrical Stimulation (NMES).

Superoxide Anion Production and Bioenergetic Profile in Young and Elderly Human Primary Myoblasts.

Sarcopenia is the age-related loss of skeletal muscle mass, strength, and function. It is associated with regenerative difficulties by satellite cells, adult muscle stem cells, and alteration of oxidative management, mainly the increase in superoxide anions (O). We aimed to investigate the relation between regenerative deficit in elderly and increase in O production along with mitochondrial alterations.

HDAC4 preserves skeletal muscle structure following long-term denervation by mediating distinct cellular responses.

Background: Denervation triggers numerous molecular responses in skeletal muscle, including the activation of catabolic pathways and oxidative stress, leading to progressive muscle atrophy. Histone deacetylase 4 (HDAC4) mediates skeletal muscle response to denervation, suggesting the use of HDAC inhibitors as a therapeutic approach to neurogenic muscle atrophy. However, the effects of HDAC4 inhibition in skeletal muscle in response to long-term denervation have not been described yet.

Regular exercise participation improves genomic stability in diabetic patients: an exploratory study to analyse telomere length and DNA damage.

Physical activity has been demonstrated to be effective in the prevention and treatment of different chronic conditions, including type 2 diabetes (T2D). In particular, several studies highlighted how the beneficial effects of physical activity may be related to the stability of the DNA molecule, such as longer telomeric ends. Here we analyze the effect of exercise training on telomere length, spontaneous and HO-induced DNA damage, as well as the apoptosis level in leukocytes from untrained or trained T2D patients vs.

Neuromuscular electrical stimulation improves skeletal muscle regeneration through satellite cell fusion with myofibers in healthy elderly subjects.

The aim of this study was to determine whether neuromuscular electrical stimulation (NMES) affects skeletal muscle regeneration through a reduction of oxidative status in satellite cells of healthy elderly subjects. Satellite cells from the vastus lateralis skeletal muscle of 12 healthy elderly subjects before and after 8 wk of NMES were allowed to proliferate to provide myogenic populations of adult stem cells [myogenic precursor cells (MPCs)]. These MPCs were then investigated in terms of their proliferation, their basal cytoplasmic free Ca concentrations, and their expression of myogenic regulatory factors (, and ) and micro-RNAs (miR-1, miR-133a/b, and miR-206).

Denervation does not Induce Muscle Atrophy Through Oxidative Stress.

Denervation leads to the activation of the catabolic pathways, such as the ubiquitin-proteasome and autophagy, resulting in skeletal muscle atrophy and weakness. Furthermore, denervation induces oxidative stress in skeletal muscle, which is thought to contribute to the induction of skeletal muscle atrophy. Several muscle diseases are characterized by denervation, but the molecular pathways contributing to muscle atrophy have been only partially described.

The Regenerative Potential of Female Skeletal Muscle upon Hypobaric Hypoxic Exposure.

Aim: The aim of this study was to determine whether a 14-day trekking expeditions, in high altitude hypoxic environment, triggers redox disturbance at the level of satellite cells (adult stem cells) in young women.

Methods: We collected muscle biopsies from Vastus Lateralis muscle for both single fiber analysis and satellite cells isolation. The samples collected before (PRE-Hypoxia) and after (POST-Hypoxia) the trekking in the Himalayas were compared.

Myomir dysregulation and reactive oxygen species in aged human satellite cells.

Satellite cells that reside on the myofibre surface are crucial for the muscle homeostasis and regeneration. Aging goes along with a less effective regeneration of skeletal muscle tissue mainly due to the decreased myogenic capability of satellite cells. This phenomenon impedes proper maintenance and contributes to the age-associated decline in muscle mass, known as sarcopenia.

Dental pulp stem cells grown on dental implant titanium surfaces: An in vitro evaluation of differentiation and microRNAs expression.

The surface roughness of dental implants influences the proliferation and differentiation rate of adult mesenchymal stem cells (MSCs). The aim of the present study was to evaluate whether specifically treated titanium implant surfaces influenced human dental pulp stem cells (DPSCs) differentiation in an osteogenic pattern through modulation of microRNAs expression. The degree of differentiation was evaluated after 7, 14, and 21 days, through the expression of microRNAs characterizing the osteogenesis (miR-133 and miR-135), of Runx2 and Smad5 (key factor transcriptions associated with osteoblast differentiation) and Osteocalcin, marker for the bone formation process.

Low Intensity Exercise Training Improves Skeletal Muscle Regeneration Potential.

Purpose: The aim of this study was to determine whether 12 days of low-to-moderate exercise training at low altitude (598 m a.s.l.

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.

Stem cell ageing and apoptosis.

Ageing has been defined as the process of deterioration of many body functions over the lifespan of an individual. In spite of the number of different theories about ageing, there is a general consensus in identifying ageing effects in a reduced capacity to regenerate injured tissues or organs and an increased propensity to infections and cancer. In recent years the stem cell theory of ageing has gained much attention.

Transcriptional profile of GTP-mediated differentiation of C2C12 skeletal muscle cells.

Several purine receptors have been localised on skeletal muscle membranes. Previous data support the hypothesis that extracellular guanosine 5'-triphosphate (GTP) is an important regulatory factor in the development and function of muscle tissue. We have previously described specific extracellular binding sites for GTP on the plasma membrane of mouse skeletal muscle (C2C12) cells.

Tiny percutaneous needle biopsy: An efficient method for studying cellular and molecular aspects of skeletal muscle in humans.

Needle biopsy is widely used to obtain specimens for physiological, anatomical and biochemical studies of skeletal muscle (SM). We optimized a procedure which we termed tiny percutaneous needle biopsy (TPNB), to efficiently gather good numbers of human satellite cells and single dissociated fibers for the functional study of skeletal muscle; these samples permit isolation of high-quality RNA and sufficient amounts of proteins to allow molecular analysis. Moreover, TPNB showed a clear advantage in that the technique was easier than other procedures used on healthy volunteers in human trials.

Human muscle satellite cells show age-related differential expression of S100B protein and RAGE.

During aging, skeletal muscles show reduced mass and functional capacity largely due to loss of the regenerative ability of satellite cells (SCs), the quiescent stem cells located beneath the basal lamina surrounding each myofiber. While both the external environment and intrinsic properties of SCs appear to contribute to the age-related SC deficiency, the latter ones have been poorly investigated especially in humans. In the present work, we analyzed several parameters of SCs derived from biopsies of vastus lateralis muscle from healthy non-trained young (28.