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Nutrients Oct 2023Vitamin D deficiency, prevalent worldwide, is linked to muscle weakness, sarcopenia, and falls. Muscle regeneration is a vital process that allows for skeletal muscle... (Review)
Review
Vitamin D deficiency, prevalent worldwide, is linked to muscle weakness, sarcopenia, and falls. Muscle regeneration is a vital process that allows for skeletal muscle tissue maintenance and repair after injury. PubMed and Web of Science were used to search for studies published prior to May 2023. We assessed eligible studies that discussed the relationship between vitamin D, muscle regeneration in this review. Overall, the literature reports strong associations between vitamin D and skeletal myocyte size, and muscle regeneration. In vitro studies in skeletal muscle cells derived from mice and humans showed vitamin D played a role in regulating myoblast growth, size, and gene expression. Animal studies, primarily in mice, demonstrate vitamin D's positive effects on skeletal muscle function, such as improved grip strength and endurance. These studies encompass vitamin D diet research, genetically modified models, and disease-related mouse models. Relatively few studies looked at muscle function after injury, but these also support a role for vitamin D in muscle recovery. The human studies have also reported that vitamin D deficiency decreases muscle grip strength and gait speed, especially in the elderly population. Finally, human studies reported the benefits of vitamin D supplementation and achieving optimal serum vitamin D levels in muscle recovery after eccentric exercise and surgery. However, there were no benefits in rotator cuff injury studies, suggesting that repair mechanisms for muscle/ligament tears may be less reliant on vitamin D. In summary, vitamin D plays a crucial role in skeletal muscle function, structural integrity, and regeneration, potentially offering therapeutic benefits to patients with musculoskeletal diseases and in post-operative recovery.
Topics: Aged; Humans; Animals; Mice; Vitamin D; Muscle, Skeletal; Vitamins; Vitamin D Deficiency; Muscular Diseases; Models, Animal; Regeneration
PubMed: 37892452
DOI: 10.3390/nu15204377 -
International Journal of Surgery... Jun 2019Although numerous treatments exist for fecal incontinence (FI), no consensus exists on the best treatment strategy. The aim was to review the literature and to compare... (Comparative Study)
Comparative Study Meta-Analysis
BACKGROUND
Although numerous treatments exist for fecal incontinence (FI), no consensus exists on the best treatment strategy. The aim was to review the literature and to compare the clinical outcomes and effectiveness of treatments available for FI.
MATERIALS AND METHOD
A systematic literature review was performed, from inception to May 2018, of the following databases: MEDLINE, EMBASE, Science Citation Index Expanded, Cochrane Library. The search terms used were "faecal incontinence" and "treatment". Only randomized controlled trials (RCTs) comparing treatments for FI were considered. A Bayesian network meta-analysis was performed using the Markov chain Monte Carlo method.
RESULT
Forty-seven RCTs were included comparing 37 treatments and reporting on 3748 participants. No treatment ranked best or worst with high probability for any outcome of interest. No significant difference was identified between treatments for frequency of FI per week, or in changing the resting pressure, maximum resting pressure, squeeze pressure, and maximum squeeze pressure. Radiofrequency resulted in more adverse events compared to placebo. Sacral nerve stimulation (SNS) and zinc-aluminium improved the fecal incontinence quality of life questionnaire (FIQL) lifestyle, coping, and embarrassment domains compared to placebo. Transcutaneous posterior tibial nerve stimulation (TPTNS) improved the FIQL embarrassment domain compared to placebo. Autologous myoblasts and zinc-aluminium improved the FIQL depression domain compared to placebo. SNS, artificial bowel sphincter (ABS), and zinc-aluminium significantly improved incontinence scores compared to placebo. Injection of non-animal stabilized hyaluronic acid/dextranomer (NASHA/Dx) resulted in more patients with ≥50% reduction in FI episodes compared to placebo.
CONCLUSION
SNS, ABS, TPTNS, NASHA/Dx, zinc-aluminium, and autologous myoblasts resulted in isolated improvements in specific outcomes of interest. No difference was identified in incontinence episodes, no treatment ranked best persistently or persistently improved outcomes, and many included treatments did not significantly benefit patients compared to placebo. Large multicentre RCTs with long-term follow-up and standardized inclusion criteria and outcome measures are needed.
Topics: Bayes Theorem; Dextrans; Electric Stimulation Therapy; Fecal Incontinence; Humans; Hyaluronic Acid; Network Meta-Analysis; Outcome Assessment, Health Care; Quality of Life; Randomized Controlled Trials as Topic; Tibial Nerve
PubMed: 31022519
DOI: 10.1016/j.ijsu.2019.04.007 -
Medicine and Science in Sports and... Jul 2018The myonuclear domain theory postulates that myonuclei are added to muscle fibers when increases in fiber cross-sectional area (i.e., hypertrophy) are ≥26%. However,... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
The myonuclear domain theory postulates that myonuclei are added to muscle fibers when increases in fiber cross-sectional area (i.e., hypertrophy) are ≥26%. However, recent studies have reported increased myonuclear content with lower levels (e.g., 12%) of muscle fiber hypertrophy.
PURPOSE
This study aimed to determine whether a muscle fiber hypertrophy "threshold" is required to drive the addition of new myonuclei to existing muscle fibers.
METHODS
Studies of resistance training endurance training with or without nutrient (i.e., protein) supplementation and steroid administration with measures of muscle fiber hypertrophy and myonuclei number as primary or secondary outcomes were considered. Twenty-seven studies incorporating 62 treatment groups and 903 subjects fulfilled the inclusion criteria and were included in the analyses.
RESULTS
Muscle fiber hypertrophy of ≤10% induces increases in myonuclear content, although a significantly higher number of myonuclei are observed when muscle hypertrophy is ~22%. Additional analyses showed that age, sex, and muscle fiber type do not influence muscle fiber hypertrophy or myonuclei addition.
CONCLUSIONS
Although a more consistent myonuclei addition occurs when muscle fiber hypertrophy is >22%, our results challenge the concept of a muscle hypertrophy threshold as significant myonuclei addition occurs with lower muscle hypertrophy (i.e., <10%).
Topics: Cell Nucleus; Humans; Hypertrophy; Muscle Fibers, Skeletal; Muscle, Skeletal; Resistance Training; Satellite Cells, Skeletal Muscle
PubMed: 29509639
DOI: 10.1249/MSS.0000000000001593 -
Frontiers in Physiology 2021In skeletal muscle tissue, oxygen (O) plays a pivotal role in both metabolism and the regulation of several intercellular pathways, which can modify proliferation,...
In skeletal muscle tissue, oxygen (O) plays a pivotal role in both metabolism and the regulation of several intercellular pathways, which can modify proliferation, differentiation and survival of cells within the myogenic lineage. The concentration of oxygen in muscle tissue is reduced during embryogenesis and pathological conditions. Myogenic progenitor cells, namely satellite cells, are necessary for muscular regeneration in adults and are localized in a hypoxic microenvironment under the basal lamina, suggesting that the O level could affect their function. This review presents the effects of reduced oxygen levels (hypoxia) on satellite cell survival, myoblast regeneration and differentiation in vertebrates. Further investigations and understanding of the pathways involved in adult muscle regeneration during hypoxic conditions are maybe clinically relevant to seek for novel drug treatments for patients with severe muscle damage. We especially outlined the effect of hypoxia-inducible factor 1-alpha (HIF1A), the most studied transcriptional regulator of cellular and developmental response to hypoxia, whose investigation has recently been awarded with the Nobel price.
PubMed: 34248671
DOI: 10.3389/fphys.2021.684899 -
Nutrients Jan 2024Epicatechin is a polyphenol compound that promotes skeletal muscle differentiation and counteracts the pathways that participate in the degradation of proteins. Several... (Review)
Review
Epicatechin is a polyphenol compound that promotes skeletal muscle differentiation and counteracts the pathways that participate in the degradation of proteins. Several studies present contradictory results of treatment protocols and therapeutic effects. Therefore, the objective of this systematic review was to investigate the current literature showing the molecular mechanism and clinical protocol of epicatechin in muscle atrophy in humans, animals, and myoblast cell-line. The search was conducted in Embase, PubMed/MEDLINE, Cochrane Library, and Web of Science. The qualitative analysis demonstrated that there is a commonness of epicatechin inhibitory action in myostatin expression and atrogenes MAFbx, FOXO, and MuRF1. Epicatechin showed positive effects on follistatin and on the stimulation of factors related to the myogenic actions (MyoD, Myf5, and myogenin). Furthermore, the literature also showed that epicatechin can interfere with mitochondrias' biosynthesis in muscle fibers, stimulation of the signaling pathways of AKT/mTOR protein production, and amelioration of skeletal musculature performance, particularly when combined with physical exercise. Epicatechin can, for these reasons, exhibit clinical applicability due to the beneficial results under conditions that negatively affect the skeletal musculature. However, there is no protocol standardization or enough clinical evidence to draw more specific conclusions on its therapeutic implementation.
Topics: Animals; Humans; Catechin; Muscle Fibers, Skeletal; Muscle, Skeletal; Muscular Atrophy; MyoD Protein; TOR Serine-Threonine Kinases
PubMed: 38276564
DOI: 10.3390/nu16020326 -
British Journal of Clinical Pharmacology Jun 2021Advanced therapy medicinal products (ATMPs) represent a new category of medicinal products with a potential for transformative improvements in health outcomes but at... (Review)
Review
AIMS
Advanced therapy medicinal products (ATMPs) represent a new category of medicinal products with a potential for transformative improvements in health outcomes but at exceptionally high prices. Routine adoption of ATMPs requires robust evidence of their cost-effectiveness.
METHODS
A systematic literature review of economic evaluations of ATMPs, including gene therapies, somatic cell therapies and tissue-engineered products, was conducted. Literature was searched using MedLine, Embase, PubMed, Cochrane Register, the NHS Economic Evaluation Database and the grey literature of health technology assessment organisations with search terms relating to ATMPs and economic evaluations. Titles were screened independently by 2 reviewers. Articles deemed to meet the inclusion criteria were screened independently on abstract, and full texts reviewed. Study findings were appraised critically.
RESULTS
4514 articles were identified, of which 23 met the inclusion criteria. There was some evidence supporting the cost-effectiveness of: chimeric antigen receptor T-cell therapy axicabtagene-ciloleucel (Yescarta), embryonic neural stem cells, tumour infiltrating lymphocytes, in vitro expanded myoblast, autologous chondrocyte implantation, ex vivo gene therapy (Strimvelis) and voretigene neparvovec (Luxturna). However, estimates of cost-effectiveness were associated with significant uncertainty and high likelihood of bias, resulting from largely unknown long-term outcomes, a paucity of evidence on health state utilities and extensive modelling assumptions.
CONCLUSION
There are critical limitations to the economic evidence for ATMPs, most notably in relation to evidence on the durability of treatment effect, and the reliability of opinion-based assumptions necessary when evidence is absent.
Topics: Cost-Benefit Analysis; Reproducibility of Results; Technology Assessment, Biomedical
PubMed: 32154598
DOI: 10.1111/bcp.14275 -
Frontiers in Medicine 2020Sarcopenia, which is characterized by the loss of skeletal muscle, has been reported to contribute to development of physical disabilities, various illnesses, and...
Sarcopenia, which is characterized by the loss of skeletal muscle, has been reported to contribute to development of physical disabilities, various illnesses, and increasing mortality. MicroRNAs (miRNAs) are small non-coding RNAs that inhibit translation of target messenger RNAs. Previous studies have shown that miRNAs play pivotal roles in the development of sarcopenia. Therefore, this systematic review focuses on miRNAs that regulate sarcopenia.
PubMed: 32549041
DOI: 10.3389/fmed.2020.00180 -
Nutrients Oct 2022The non-classical role of vitamin D has been investigated in recent decades. One of which is related to its role in skeletal muscle. Satellite cells are skeletal muscle... (Review)
Review
The non-classical role of vitamin D has been investigated in recent decades. One of which is related to its role in skeletal muscle. Satellite cells are skeletal muscle stem cells that play a pivotal role in skeletal muscle growth and regeneration. This systematic review aims to investigate the effect of vitamin D on satellite cells. A systematic search was performed in Scopus, MEDLINE, and Google Scholar. In vivo studies assessing the effect of vitamin D on satellite cells, published in English in the last ten years were included. Thirteen in vivo studies were analyzed in this review. Vitamin D increases the proliferation of satellite cells in the early life period. In acute muscle injury, vitamin D deficiency reduces satellite cells differentiation. However, administering high doses of vitamin D impairs skeletal muscle regeneration. Vitamin D may maintain satellite cell quiescence and prevent spontaneous differentiation in aging. Supplementation of vitamin D ameliorates decreased satellite cells' function in chronic disease. Overall, evidence suggests that vitamin D affects satellite cells' function in maintaining skeletal muscle homeostasis. Further research is needed to determine the most appropriate dose of vitamin D supplementation in a specific condition for the optimum satellite cells' function.
Topics: Satellite Cells, Skeletal Muscle; Vitamin D; Regeneration; Muscle Development; Muscle Fibers, Skeletal; Cell Differentiation; Muscle, Skeletal; Vitamins
PubMed: 36364820
DOI: 10.3390/nu14214558 -
Pax7 Satellite Cells in Human Skeletal Muscle After Exercise: A Systematic Review and Meta-analysis.Sports Medicine (Auckland, N.Z.) Feb 2023Skeletal muscle has extraordinary regenerative capabilities against challenge, mainly owing to its resident muscle stem cells, commonly identified by Pax7, which... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Skeletal muscle has extraordinary regenerative capabilities against challenge, mainly owing to its resident muscle stem cells, commonly identified by Pax7, which expediently donate nuclei to the regenerating multinucleated myofibers. This local reserve of stem cells in damaged muscle tissues is replenished by undifferentiated bone marrow stem cells (CD34) permeating into the surrounding vascular system.
OBJECTIVE
The purpose of the study was to provide a quantitative estimate for the changes in Pax7 muscle stem cells (satellite cells) in humans following an acute bout of exercise until 96 h, in temporal relation to circulating CD34 bone marrow stem cells. A subgroup analysis of age was also performed.
METHODS
Four databases (Web of Science, PubMed, Scopus, and BASE) were used for the literature search until February 2022. Pax7 cells in human skeletal muscle were the primary outcome. Circulating CD34 cells were the secondary outcome. The standardized mean difference (SMD) was calculated using a random-effects meta-analysis. Subgroup analyses were conducted to examine the influence of age, training status, type of exercise, and follow-up time after exercise.
RESULTS
The final search identified 20 studies for Pax7 cells comprising a total of 370 participants between the average age of 21 and 74 years and 26 studies for circulating CD34 bone marrow stem cells comprising 494 participants between the average age of 21 and 67 years. Only one study assessed Pax7 cells immediately after aerobic exercise and showed a 32% reduction in exercising muscle followed by a fast repletion to pre-exercise level within 3 h. A large effect on increasing Pax7 cell content in skeletal muscles was observed 24 h after resistance exercise (SMD = 0.89, p < 0.001). Pax7 cells increased to ~ 50% above pre-exercise level 24-72 h after resistance exercise. For a subgroup analysis of age, a large effect (SMD = 0.81, p < 0.001) was observed on increasing Pax7 cells in exercised muscle among adults aged > 50 years, whereas adults at younger age presented a medium effect (SMD = 0.64, p < 0.001). Both resistance exercise and aerobic exercise showed a medium overall effect in increasing circulating CD34 cells (SMD = 0.53, p < 0.001), which declined quickly to the pre-exercise baseline level after exercise within 6 h.
CONCLUSIONS
An immediate depletion of Pax7 cells in exercising skeletal muscle concurrent with a transient release of CD34 cells suggest a replenishment of the local stem cell reserve from bone marrow. A protracted Pax7 cell expansion in the muscle can be observed during 24-72 h after resistance exercise. This result provides a scientific basis for exercise recommendations on weekly cycles allowing for adequate recovery time. Exercise-induced Pax7 cell expansion in muscle remains significant at higher age, despite a lower stem cell reserve after age 50 years. More studies are required to confirm whether Pax7 cell increment can occur after aerobic exercise.
CLINICAL TRIAL REGISTRATION
Registered at the International Prospective Register of Systematic Reviews (PROSPERO) [identification code CRD42021265457].
Topics: Adult; Humans; Young Adult; Middle Aged; Aged; Muscle, Skeletal; Exercise; Satellite Cells, Skeletal Muscle; PAX7 Transcription Factor
PubMed: 36266373
DOI: 10.1007/s40279-022-01767-z -
Orthopaedic Journal of Sports Medicine Feb 2017Meniscus damage can be caused by trauma or degeneration and is therefore common among patients of all ages. Repair or regeneration of the menisci could be of great...
BACKGROUND
Meniscus damage can be caused by trauma or degeneration and is therefore common among patients of all ages. Repair or regeneration of the menisci could be of great importance not only for pain relief or regaining function but also to prevent degenerative disease and osteoarthritis. Current treatment does not offer consistent long-term improvement. Although preclinical research focusing on augmentation of meniscal tear repair and regeneration after meniscectomy is encouraging, clinical translation remains difficult.
PURPOSE
To systematically evaluate the literature on in vivo meniscus regeneration and explore the optimal cell sources and conditions for clinical translation. We aimed at thorough evaluation of current evidence as well as clarifying the challenges for future preclinical and clinical studies.
STUDY DESIGN
Systematic review.
METHODS
A search was conducted using the electronic databases of MEDLINE, Embase, and the Cochrane Collaboration. Search terms included , , and .
RESULTS
After screening 81 articles based on title and abstract, 51 articles on in vivo meniscus regeneration could be included; 2 additional articles were identified from the references. Repair and regeneration of the meniscus has been described by intra-articular injection of multipotent mesenchymal stromal (stem) cells from adipose tissue, bone marrow, synovium, or meniscus or the use of these cell types in combination with implantable or injectable scaffolds. The use of fibrochondrocytes, chondrocytes, and transfected myoblasts for meniscus repair and regeneration is limited to the combination with different scaffolds. The comparative in vitro and in vivo studies mentioned in this review indicate that the use of allogeneic cells is as successful as the use of autologous cells. In addition, the implantation or injection of cell-seeded scaffolds increased tissue regeneration and led to better structural organization compared with scaffold implantation or injection of a scaffold alone. None of the studies mentioned in this review compare the effectiveness of different (cell-seeded) scaffolds.
CONCLUSION
There is heterogeneity in animal models, cell types, and scaffolds used, and limited comparative studies are available. The comparative in vivo research that is currently available is insufficient to draw strong conclusions as to which cell type is the most promising. However, there is a vast amount of in vivo research on the use of different types of multipotent mesenchymal stromal (stem) cells in different experimental settings, and good results are reported in terms of tissue formation. None of these studies compare the effectiveness of different cell-scaffold combinations, making it hard to conclude which scaffold has the greatest potential.
PubMed: 28321424
DOI: 10.1177/2325967117690131