Search Results (49)

Acute coronary syndrome (ACS) refers to a spectrum of conditions characterized by a sudden decrease in blood flow to the heart. This includes unstable angina, the mildest form, as well as non-ST- and ST-segment elevation myocardial infarction. The primary cause of ACS is typically the rupture or erosion of an atherosclerotic plaque in a coronary artery, resulting in the formation of a blood clot that can, partially or completely, block the blood flow to the heart muscle. The ongoing discovery and comprehension of emerging biomarkers for atherosclerosis could enhance our capacity to predict future events, particularly when integrated alongside traditional risk factors in assessing overall risk profiles. With advancements in proteomic technologies, large-scale approaches have been increasingly instrumental in unraveling pathways implicated in atherosclerotic degeneration and identifying novel circulating markers, which may serve as early diagnostic indicators or targets for innovative therapies. Over recent decades, numerous matrices including plasma, urine, microparticles, lipoproteins, atherosclerotic plaque extracts and secretomes, as well as thrombi, have been examined to address these questions. Furthermore, proteomics has been applied to various experimental models of atherosclerosis to deepen our understanding of the mechanisms underlying atherogenesis. This review offers a critical overview of the past two decades of untargeted omics research focused on identifying circulating and tissue biomarkers relevant to ACS. Full article

Retinoic acid (RA), a vitamin A derivative, has been shown to prevent the development of neurological disorders by ensuring the integrity of the physiological structure of the neurovascular unit and regulating the physiological cell’s function. After an ischemia event, RA reduces the effects of blood–brain barrier disruption by blocking the apoptotic signaling pathway. However, the effect of RA on smooth muscle cells (SMCs), which are crucial to maintaining blood perfusion, has never been investigated. This study aimed to evaluate the effect of RA on the vasoactive response of middle cerebral artery SMCs in normal and ischemic contexts (O₂ and glucose deprivation, OGD). For this purpose, SMCs cultures were incubated with RA, and the vasoactive response was evaluated in both conditions (OGD and non-OGD). To simulate OGD, co-cultures of neurons and astrocytes were made and incubated with RA to analyze the effect of the secretome released by these cells on SMCs contractility. In non-OGD conditions, RA induced rapid relaxation of SMCs and, in the long term (24 h), promoted cell contraction. In OGD conditions, SMCs contractility patterns were different when pre-incubated with RA. In these conditions, NA loses its contractility effect, and SNP seems to revert its relaxant effect. However, SMCs pre-incubated with 5 uM RA show the vasorelaxant pattern typical of SNP, despite the OGD condition. These effects demonstrate an effect of RA on the vasoactive profile of SMCs, with therapeutic potential in OGD conditions. Full article

The uterine smooth muscle (myometrium) is an immunomodulatory tissue capable of secreting multiple chemokines during pregnancy. We propose that before term labor, chemokines secreted as a result of mechanical stretch of the uterine walls by the growing fetus(es) induce infiltration of maternal monocytes into myometrium, drive their differentiation into macrophages, and induce pro-inflammatory (M1) polarization, leading to labor contractions. This study used high-throughput proteomic mass-spectrometry to investigate the underlying mechanisms and explored the therapeutic potential of a broad-spectrum chemokine inhibitor (BSCI, FX125L) in modulating these effects. Primary myocytes isolated from the myometrium of term pregnant women were subjected in vitro to static mechanical stretch. Proteomic analysis of stretched myocyte-conditioned media (CM) identified significant upregulation of chemokine-related pathways and ECM degradation proteins. CM induced in vitro differentiation of human monocytes to macrophages and polarization into an M1-like phenotype characterized by elevated ROS production. BSCI treatment altered the myocyte secretome, increasing tissue-remodeling and anti-inflammatory proteins, Annexin A1 and TGF-β. BSCI-treated myocyte secretions induced Annexin A1 expression in macrophages and enhanced their phagocytic activity. We conclude that factors secreted by mechanically stretched myocytes induce pro-inflammatory M1 macrophage polarization, while BSCI modulates myocyte secretome, which reprograms macrophages to a homeostatic M2-like phenotype, thus reducing inflammation. When treated with BSCI, M2-polarized macrophages reduced myocyte-driven collagen gel contraction, whereas M1 macrophages enhanced it. This study reveals novel insights into the myocyte–macrophage interaction and identifies BSCI as a promising drug to modulate myometrial activity. We suggest that uterine macrophages may represent a therapeutic target for preventing preterm labor in women. Full article

Inflammation mechanisms play a critical role in muscle homeostasis, and in Muscular Dystrophies (MDs), the myofiber damage triggers chronic inflammation which significantly controls the disease progression. Immunomodulatory strategies able to target inflammatory pathways and mitigate the immune-mediated damage in MDs may provide new therapeutic options. Owing to its capacity of influencing the immune response and enhancing tissue repair, stem cells’ secretome has been proposed as an adjunct or standalone treatment for MDs. In this review study, we discuss the challenging points related to the inflammation condition characterizing MD pathology and provide a concise summary of the literature supporting the potential of perinatal stem cells in targeting and modulating the MD inflammation. Full article

Telocytes (TCs) are distinctive cells widely localized in the stromal compartment of several human organs, including the skin. By means of their peculiar prolongations named telopodes, skin TCs are organized in networks interconnected with a variety of adjacent cells, being thus supposed to take part in skin homeostasis through both cell-to-cell contacts and the release of extracellular vesicles. A disarrangement/loss of the TC network was shown in human fibrotic skin as well as in the murine model of bleomycin-induced cutaneous fibrosis, but whether such TC alterations may represent just a consequence or a trigger of the fibrotic process still remains to be clarified. Thus, we investigated the effects of skin TC secretome as conditioned medium (TC-CM) on the transition of skin fibroblasts into myofibroblasts promoted by the master profibrotic cytokine transforming growth factor β1 (TGFβ1). Primary cultures of both adult human skin TCs and fibroblasts were obtained by means of immunomagnetic cell separation. Nanoparticle tracking analysis was carried out to measure extracellular vesicles in TC-CM. The combination of multiple morphological, gene/protein expression, and functional assessments demonstrated that TC-CM was able to significantly prevent TGFβ1-induced fibroblast-to-myofibroblast transition. TC-CM did not influence cell viability, while it effectively inhibited TGFβ1-induced fibroblast proliferation, migration, and morphological changes. Indeed, TC-CM was able to reduce TGFβ1-mediated skin fibroblast phenotypic and functional differentiation into myofibroblasts, as shown by a significant decrease in FAP, ACTA2, COL1A1, COL1A2, FN1, and CTGF gene expression, α-smooth muscle actin, N-cadherin, COL1A1, and FN-EDA protein levels, and collagen gel matrix contraction. Furthermore, TC-CM significantly lowered TGFβ1-mediated ERK1/2 signaling pathway activation. This in vitro study proves for the first time that TCs may play an important role in skin homeostasis through the prevention of fibroblast-to-myofibroblast transition via paracrine mechanisms and affords the necessary basis to investigate in the future the feasibility of TC secretome as an innovative antifibrotic therapeutic tool. Full article

As we age, we lose muscle strength and power, a condition commonly referred to as sarcopenia (ICD-10-CM code (M62.84)). The prevalence of sarcopenia is about 5–10% of the elderly population, resulting in varying degrees of disability. In this review we emphasise that sarcopenia does not occur suddenly. It is an aging-induced deterioration that occurs over time and is only recognised as a disease when it manifests clinically in the 6th–7th decade of life. Evidence from animal studies, elite athletes and longitudinal population studies all confirms that the underlying process has been ongoing for decades once sarcopenia has manifested. We present hypotheses about the mechanism(s) underlying this process and their supporting evidence. We briefly review various proposals to impede sarcopenia, including cell therapy, reducing senescent cells and their secretome, utilising targets revealed by the skeletal muscle secretome, and muscle innervation. We conclude that although there are potential candidates and ongoing preclinical and clinical trials with drug treatments, the only evidence-based intervention today for humans is exercise. We present different exercise programmes and discuss to what extent the interindividual susceptibility to developing sarcopenia is due to our genetic predisposition or lifestyle factors. Full article

Galectin-3 (Gal-3) is a pleiotropic lectin produced by most cell types, which regulates multiple cellular processes in various tissues. In bone, depending on its cellular localization, Gal-3 has a dual and opposite role. If, on the one hand, intracellular Gal-3 promotes bone formation, on the other, its circulating form affects bone remodeling, antagonizing osteoblast differentiation and increasing osteoclast activity. From an analysis of the secretome of cultured differentiating myoblasts, we interestingly found the presence of Gal-3. After that, we confirmed that Gal-3 was expressed and released in the extracellular environment from myoblast cells during their differentiation into myotubes, as well as after mechanical strain. An in vivo analysis revealed that Gal-3 was triggered by trained exercise and was specifically produced by fast muscle fibers. Speculating a role for this peptide in the muscle-to-bone cross talk, a direct co-culture in vitro system, simultaneously combining media that were obtained from differentiated myoblasts and osteoblast cells, confirmed that Gal-3 is a mediator of osteoblast differentiation. Molecular and proteomic analyses revealed that the secreted Gal-3 modulated the biochemical processes occurring in the early phases of bone formation, in particular impairing the activity of the STAT3 and PDK1/Akt signaling pathways and, at the same time, triggering that one of Notch. Circulating Gal-3 also affected the expression of the most common factors involved in osteogenetic processes, including BMP-2, -6, and -7. Intriguingly, Gal-3 was able to interfere with the ability of differentiating osteoblasts to interact with the components of the extracellular bone matrix, a crucial condition required for a proper osteoblast differentiation. All in all, our evidence lays the foundation for further studies to present this lectin as a novel myokine involved in muscle-to-bone crosstalk. Full article

Skeletal muscle secretome, through its paracrine and endocrine functions, contributes to the maintenance and regulation of overall physiological health. We conducted a narrative review on the role of skeletal muscle and exercise in maintaining glucose homeostasis, driving insulin resistance (IR), and preventing type 2 diabetes in pediatric populations, especially in the context of overweight and obesity. Myokines such as interleukin (IL)-6, IL-8, and IL-15, as well as irisin, myonectin, and myostatin, appear to play a crucial role in IR. Skeletal muscle can also become a target of obesity-induced and IR-induced inflammation. In the correlation between muscle, IR, and inflammation, the role of infiltration of the immune cells and the microvasculature may also be considered. It remains unclear which exercise approach is the best; however, combining aerobic exercise with resistance training seems to be the most effective strategy for managing IR, with high-intensity activities offering superior metabolic benefits and long-term adherence. Encouraging daily participation in enjoyable and engaging exercise is key for long-term commitment and effective glucose metabolism management. Promoting physical activity in children and adolescents must be a top priority for public health, not only in terms of individual quality of life and well-being but also for community health. Full article

Temporomandibular disorders (TMDs) are a heterogeneous group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint (TMJ), masticatory muscles, and associated structures. Mesenchymal stromal/stem cells (MSCs) have emerged as a promising therapy for TMJ repair. This systematic review aims to consolidate findings from the preclinical animal studies evaluating MSC-based therapies, including MSCs, their secretome, and extracellular vesicles (EVs), for the treatment of TMJ cartilage/osteochondral defects and osteoarthritis (OA). Following the PRISMA guidelines, PubMed, Embase, Scopus, and Cochrane Library databases were searched for relevant studies. A total of 23 studies involving 125 mice, 149 rats, 470 rabbits, and 74 goats were identified. Compliance with the ARRIVE guidelines was evaluated for quality assessment, while the SYRCLE risk of bias tool was used to assess the risk of bias for the studies. Generally, MSC-based therapies demonstrated efficacy in TMJ repair across animal models of TMJ defects and OA. In most studies, animals treated with MSCs, their derived secretome, or EVs displayed improved morphological, histological, molecular, and behavioral pain outcomes, coupled with positive effects on cellular proliferation, migration, and matrix synthesis, as well as immunomodulation. However, unclear risk in bias and incomplete reporting highlight the need for standardized outcome measurements and reporting in future investigations. Full article

Briefly (10 min) exposing C2C12 myotubes to low amplitude (1.5 mT) pulsed electromagnetic fields (PEMFs) generated a conditioned media (pCM) that was capable of mitigating breast cancer cell growth, migration, and invasiveness in vitro, whereas the conditioned media harvested from unexposed myotubes, representing constitutively released secretome (cCM), was less effective. Administering pCM to breast cancer microtumors engrafted onto the chorioallantoic membrane of chicken eggs reduced tumor volume and vascularity. Blood serum collected from PEMF-exposed or exercised mice allayed breast cancer cell growth, migration, and invasiveness. A secretome preconditioning methodology is presented that accentuates the graded anticancer potencies of both the cCM and pCM harvested from myotubes, demonstrating an adaptive response to pCM administered during early myogenesis that emulated secretome-based exercise adaptations observed in vivo. HTRA1 was shown to be upregulated in pCM and was demonstrated to be necessary and sufficient for the anticancer potency of the pCM; recombinant HTRA1 added to basal media recapitulated the anticancer effects of pCM and antibody-based absorption of HTRA1 from pCM precluded its anticancer effects. Brief and non-invasive PEMF stimulation may represent a method to commandeer the secretome response of muscle, both in vitro and in vivo, for clinical exploitation in breast and other cancers. Full article

Cancer-associated muscle wasting is a widespread syndrome in people with cancer and is characterized by weight loss and muscle atrophy, leading to increased morbidity and mortality. However, the tumor-derived factors that affect the development of muscle wasting and the mechanism by which they act remain unknown. To address this knowledge gap, we aimed to delineate differences in tumor molecular characteristics (especially secretion characteristics) between patients with and without sarcopenia across 10 tumor types from The Cancer Genome Atlas (TCGA). We integrated radiological characteristics from CT scans of TCGA cancer patients, which allowed us to calculate skeletal muscle area (SMA) to confirm sarcopenia. We combined TCGA and GTEx (The Genotype-Tissue Expression) data to analyze upregulated secretory genes in 10 tumor types compared with normal tissues. Upregulated secretory genes in the tumor microenvironment and their relation to SMA were analyzed to identify potential muscle wasting biomarkers (560 samples). Meanwhile, their predictive values for patient survival was validated in 3530 samples in 10 tumor types. A total of 560 participants with transcriptomic data and SMA were included. Among those, 136 participants (24.28%) were defined as having sarcopenia based on SMA. Enrichment analysis for upregulated secretory genes in cancers revealed that pathways associated with muscle wasting were strongly enriched in tumor types with a higher prevalence of sarcopenia. A series of SMA-associated secretory protein-coding genes were identified in cancers, which showed distinct gene expression profiles according to tumor type, and could be used to predict prognosis in cancers (p value ≤ 0.002). Unfortunately, those genes were different and rarely overlapped across tumor types. Tumor secretome characteristics were closely related to sarcopenia. Highly expressed secretory mediators in the tumor microenvironment were associated with SMA and could affect the overall survival of cancer patients, which may provide a valuable starting point for the further understanding of the molecular basis of muscle wasting in cancers. More importantly, tumor-derived pro-sarcopenic factors differ across tumor types and genders, which implies that mechanisms of cancer-associated muscle wasting are complex and diverse across tumors, and may require individualized treatment approaches. Full article

Mounting evidence underscores the intricate interplay between the immune system and skeletal muscles in Duchenne muscular dystrophy (DMD), as well as during regular muscle regeneration. While immune cell infiltration into skeletal muscles stands out as a prominent feature in the disease pathophysiology, a myriad of secondary defects involving metabolic and inflammatory pathways persist, with the key players yet to be fully elucidated. Steroids, currently the sole effective therapy for delaying onset and symptom control, come with adverse side effects, limiting their widespread use. Preliminary evidence spotlighting the distinctive features of T cell profiling in DMD prompts the immuno-characterization of circulating cells. A molecular analysis of their transcriptome and secretome holds the promise of identifying a subpopulation of cells suitable as disease biomarkers. Furthermore, it provides a gateway to unraveling new pathological pathways and pinpointing potential therapeutic targets. Simultaneously, the last decade has witnessed the emergence of novel approaches. The development and equilibrium of both innate and adaptive immune systems are intricately linked to the gut microbiota. Modulating microbiota-derived metabolites could potentially exacerbate muscle damage through immune system activation. Concurrently, genome sequencing has conferred clinical utility for rare disease diagnosis since innovative methodologies have been deployed to interpret the functional consequences of genomic variations. Despite numerous genes falling short as clinical targets for MD, the exploration of Tdark genes holds promise for unearthing novel and uncharted therapeutic insights. In the quest to expedite the translation of fundamental knowledge into clinical applications, the identification of novel biomarkers and disease targets is paramount. This initiative not only advances our understanding but also paves the way for the design of innovative therapeutic strategies, contributing to enhanced care for individuals grappling with these incapacitating diseases. Full article

Amyotrophic lateral sclerosis (ALS) is a motor neuron (MN) disease associated with progressive muscle atrophy, paralysis, and eventually death. Growing evidence demonstrates that the pathological process leading to ALS is the result of multiple altered mechanisms occurring not only in MNs but also in other cell types inside and outside the central nervous system. In this context, the involvement of skeletal muscle has been the subject of a few studies on patients and ALS animal models. In this work, by using primary myocytes derived from the ALS transgenic hSOD1(G93A) mouse model, we observed that the myogenic capability of such cells was defective compared to cells derived from control mice expressing the nonpathogenic hSOD1(WT) isoform. The correct in vitro myogenesis of hSOD1(G93A) primary skeletal muscle cells was rescued by the addition of a conditioned medium from healthy hSOD1(WT) myocytes, suggesting the existence of an in trans activity of secreted factors. To define a dataset of molecules participating in such safeguard action, we conducted comparative metabolomic profiling of a culture medium collected from hSOD1(G93A) and hSOD1(WT) primary myocytes and report here an altered secretion of amino acids and lipid-based signaling molecules. These findings support the urgency of better understanding the role of the skeletal muscle secretome in the regulation of the myogenic program and mechanisms of ALS pathogenesis and progression. Full article

Muscle function reflects muscular mitochondrial status, which, in turn, is an adaptive response to physical activity, representing improvements in energy production for de novo biosynthesis or metabolic efficiency. Differences in muscle performance are manifestations of the expression of distinct contractile-protein isoforms and of mitochondrial-energy substrate utilization. Powerful contractures require immediate energy production from carbohydrates outside the mitochondria that exhaust rapidly. Sustained muscle contractions require aerobic energy production from fatty acids by the mitochondria that is slower and produces less force. These two patterns of muscle force generation are broadly classified as glycolytic or oxidative, respectively, and require disparate levels of increased contractile or mitochondrial protein production, respectively, to be effectively executed. Glycolytic muscle, hence, tends towards fibre hypertrophy, whereas oxidative fibres are more disposed towards increased mitochondrial content and efficiency, rather than hypertrophy. Although developmentally predetermined muscle classes exist, a degree of functional plasticity persists across all muscles post-birth that can be modulated by exercise and generally results in an increase in the oxidative character of muscle. Oxidative muscle is most strongly correlated with organismal metabolic balance and longevity because of the propensity of oxidative muscle for fatty-acid oxidation and associated anti-inflammatory ramifications which occur at the expense of glycolytic-muscle development and hypertrophy. This muscle-class size disparity is often at odds with common expectations that muscle mass should scale positively with improved health and longevity. Brief magnetic-field activation of the muscle mitochondrial pool has been shown to recapitulate key aspects of the oxidative-muscle phenotype with similar metabolic hallmarks. This review discusses the common genetic cascades invoked by endurance exercise and magnetic-field therapy and the potential physiological differences with regards to human health and longevity. Future human studies examining the physiological consequences of magnetic-field therapy are warranted. Full article

Duchenne muscular dystrophy (DMD) is a muscle disease caused by mutations in the dystrophin gene characterized by myofiber fragility and progressive muscle degeneration. The genetic defect results in a reduced number of self-renewing muscle stem cells (MuSCs) and an impairment of their activation and differentiation, which lead to the exhaustion of skeletal muscle regeneration potential and muscle replacement by fibrotic and fatty tissue. In this study, we focused on an unexplored strategy to improve MuSC function and to preserve their niche based on the regenerative properties of mesenchymal stromal cells from the amniotic membrane (hAMSCs), that are multipotent cells recognized to have a role in tissue repair in different disease models. We demonstrate that the hAMSC secretome (CM hAMSC) and extracellular vesicles (EVs) isolated thereof directly stimulate the in vitro proliferation and differentiation of human myoblasts and mouse MuSC from dystrophic muscles. Furthermore, we demonstrate that hAMSC secreted factors modulate the muscle stem cell niche in dystrophic–mdx-mice. Interestingly, local injection of EV hAMSC in mdx muscles correlated with an increase in the number of activated Pax7+/Ki67+ MuSCs and in new fiber formation. EV hAMSCs also significantly reduced muscle collagen deposition, thus counteracting fibrosis and MuSCs exhaustion, two hallmarks of DMD. Herein for the first time we demonstrate that CM hAMSC and EVs derived thereof promote muscle regeneration by supporting proliferation and differentiation of resident muscle stem cells. These results pave the way for the development of a novel treatment to counteract DMD progression by reducing fibrosis and enhancing myogenesis in dystrophic muscles. Full article