Search Results (580)

Cancer progression in skeletal muscle (SkM) is very rare, and mechanisms remain unclear. This study assessed the potential of SkM (myocyte)-derived EVs (C2C12-EVs) as anti-cancer agents. Using murine in vitro models, we showed that following treatment with C2C12-EVs, lung carcinoma cells failed to colonise SkM cells, and that C2C12-EVs selectively exerted apoptosis on cancer cells. Uptake of C2C12-EVs by carcinoma cells caused changes in lysosomal function and mitochondrial membrane properties inducing cell death with elevated caspase 3 and 9. The C2C12-EVs also inhibited cell proliferation, affecting cell cycle arrest at S phase and inhibited cell migration. Proteomic analysis of C2C12-EV cargoes highlighted functional enrichment pathways involved in lysozyme function, HIF-1 and PI3K-Akt signalling, regulation of actin cytoskeleton, pyruvate metabolism, platelet activation, and protein processing in ER. Decorin, a muscle cell-specific cytokine released from myocytes in response to stress, was significantly enriched in C2C12-EVs and may contribute to C2C12-EVs’ inhibitory activity on cancer cells. C2C12-EVs may suppress cancer and potentially be used as therapeutic agents for cancer metastasis. Full article

Background: Skeletal muscle is essential not only for structural integrity but also metabolic homeostasis. Muscle atrophy, the loss of muscle mass and function, is closely linked to chronic and metabolic disorders and is driven by chronic inflammation, oxidative stress, impaired myogenesis, and disrupted protein homeostasis. The present study aimed to evaluate the protective effects and underlying mechanisms of Rosa canina extract (RCE), a polyphenol-rich plant known for its antioxidant and anti-inflammatory properties, in vitro and in vivo models of muscle atrophy. Methods: We investigated the effects of RCE in TNF-α-treated L6 myotubes and a mouse model (eight-week-old male C57BL/6N) of immobilization-induced muscle atrophy. Markers of inflammation, oxidative stress, myogenesis, protein turnover, and anabolic signaling were analyzed via RT-PCR, Western blotting and ELISA. Muscle mass, performance, micro-CT imaging, and histological cross-sectional area were assessed in vivo. Results: RCE suppressed pro-inflammatory cytokines, restored antioxidant enzyme expression, and preserved myogenic markers. It inhibited muscle proteolysis by downregulating the genes involved in protein degradation and promoted protein synthesis by via activation of the PI3K/Akt/mTOR pathway. In mice, RCE mitigated muscle mass loss, preserved fiber cross-sectional area, improved strength and endurance, and restored muscle volume. Conclusions: RCE attenuated muscle atrophy by targeting inflammation, oxidative stress, proteolysis, and impaired anabolism. These findings highlight RCE as a promising natural therapeutic for preserving muscle health and metabolic homeostasis. Full article

Background/Objectives: Duchenne muscular dystrophy (DMD) is characterized by progressive skeletal and cardiac muscle degeneration driven by inflammation and fibrosis, ultimately leading to cardiomyopathy and premature death. Deramiocel, an allogeneic cell therapy composed of cardiosphere-derived cells (CDCs), has demonstrated potent anti-fibrotic and immunomodulatory effects in preclinical models and clinical trials, including HOPE-2 and its open-label extension (HOPE-2 OLE), where Deramiocel treatment significantly attenuated progression of skeletal and cardiac muscle dysfunction. Methods: CDCs in Deramiocel were cultured to generate CM enriched with secreted exosomes and factors, which was subsequently applied to primary human dermal fibroblasts (HDFs). Following co-culture, ex-pression of collagen type I alpha 1 (COL1A) and collagen type III alpha 1 (COL3A) was measured by qRT-PCR. Non-conditioned media serves as a control in the assay. Reduction in COL1A and COL3A expression therefore provides a direct and clinically relevant measure of the anti-fibrotic activity of Deramiocel. Results: A novel in vitro potency assay was developed to quantify the anti-fibrotic activity of Deramiocel. Conditioned media (CM) from over one hundred Deramiocel manufacturing lots significantly suppressed expression of collagen type I alpha 1 (COL1A) and collagen type III alpha 1 (COL3A) in primary human dermal fibroblasts compared with non-conditioned media controls, establishing a robust, reproducible readout of anti-fibrotic activity. The effect was dose-dependent and abrogated by sequential depletion of exosomes and soluble proteins, implicating both as critical mediators of Deramiocel’s mechanism of action. Importantly, CDCs in Deramiocel lots classified as potent by this assay were shown to exert a clinically meaningful benefit in DMD patients in the HOPE-2 and HOPE-2 OLE studies. Conclusions: This assay represents a mechanistically informative, therapeutically relevant, reproducible, scalable, and regulatory-compliant approach for assessing Deramiocel potency, enabling consistent manufacturing, and facilitating the continued development of Deramiocel as a disease-modifying therapy for DMD. Full article

Background/Objectives: Dilated cardiomyopathy (DCM) is a prevalent and life-threatening heart muscle disease often caused by titin (TTN) truncating variants (TTNtv). While TTNtvs are the most common genetic cause of heritable DCM, the precise downstream regulatory mechanisms linking TTN deficiency to cardiac dysfunction and maladaptive fibrotic remodeling remain incompletely understood. This study aimed to identify key epigenetic regulators of TTN-mediated gene expression and explore their potential as therapeutic targets, utilizing human patient data and in vitro models. Methods: We analyzed RNA sequencing (RNA-seq) data from left ventricles of non-failing donors and cardiomyopathy patients (DCM, HCM, PPCM) (GSE141910). To model TTN deficiency, we silenced TTN in human iPSC-derived cardiomyocytes (iPSC-CMs) and evaluated changes in cardiac function genes (MYH6, NPPA) and fibrosis-associated genes (COL1A1, COL3A1, COL14A1). We further tested the effects of TMP-195, a class IIa histone deacetylase (HDAC) inhibitor, and individual knockdowns of HDAC4/5/7/9. Results: In both human patient data and the TTN knockdown iPSC-CM model, TTN deficiency suppressed MYH6 and NPPA while upregulating fibrosis-associated genes. Treatment with TMP-195 restored NPPA and MYH6 expression and suppressed collagen genes, without altering TTN expression. Among the HDACs tested, HDAC5 knockdown was most consistently associated with improved cardiac markers and reduced fibrotic gene expression. Co-silencing TTN and HDAC5 replicated these beneficial effects. Furthermore, the administration of TMP-195 enhanced the modulation of NPPA and COL1A1, though its impact on COL3A1 and COL14A1 was not similarly enhanced. Conclusions: Our findings identify HDAC5 as a key epigenetic regulator of maladaptive gene expression in TTN deficiency. Although the precise mechanisms remain to be clarified, the ability of pharmacological HDAC5 inhibition with TMP-195 to reverse TTN-deficiency-induced gene dysregulation highlights its promising translational potential for TTN-related cardiomyopathies. Full article

Pathological vascular remodeling—central to restenosis, atherosclerosis, and vasculo-proliferative diseases—depends on the phenotypic switching of vascular smooth muscle cells (VSMCs) from a quiescent, contractile state to a synthetic, proliferative program. Although the receptor tyrosine kinase c-Kit is implicated in proliferation, migration, and tissue repair, its role in VSMC plasticity has yet to be fully understood. Using c-Kit haploinsufficient mice subjected to right carotid artery ligation (CAL) and primary aortic VSMC cultures, we show that c-Kit is required for the contractile-to-synthetic transition. In vitro, c-Kit haploinsufficiency halved c-Kit expression, reduced 5-bromo-2′-deoxyuridine (BrdU) incorporation, and blunted platelet-derived growth factor BB (PDGF-BB)-induced repression of contractile genes. c-Kit–deficient VSMCs exhibited a senescence program with increased p16^INK4a/p21 expression and upregulated senescence-associated secretory phenotype (SASP) mediators. RNA-Seq of carotid arteries 7 days post-ligation revealed that wild-type arteries activated cell-cycle pathways and suppressed contractile signatures, whereas c-Kit-deficient carotid arteries failed to fully engage proliferative programs and instead maintained contractile gene expression. At 28 days post CAL in vivo, c-Kit haploinsufficiency produced markedly reduced neointima, fewer Ki67+ VSMCs, more p16^INK4a+ cells, and impaired re-endothelialization. Because progenitor-to-VSMC differentiation contributes to remodeling, we tested adult cardiac stem/progenitor cells (CSCs) as a model system of adult progenitor differentiation. Wild-type CSCs efficiently generated induced VSMCs (iVSMCs) with appropriate smooth-muscle gene upregulation; c-Kit–deficient rarely did so. Restoring c-Kit with a BAC transgene rescued both the smooth-muscle differentiation and proliferative competence of c-Kit-deficient iVSMCs. Collectively, our data identified c-Kit as a gatekeeper of reparative VSMC plasticity. Adequate c-Kit enables progenitor-to-VSMC commitment and the expansion of newly formed VSMCs while permitting injury-induced proliferation and matrix synthesis; reduced c-Kit locks cells in a hypercontractile, senescence-prone state and limits neointima formation. Modulating the c-Kit axis may therefore offer a strategy to fine-tune vascular repair while mitigating pathological remodeling. Full article

Dietary polyphenols are recognized as crucial modulators of gastrointestinal motility, holding therapeutic promise for conditions like irritable bowel syndrome, postoperative ileus, and functional dyspepsia. However, their reported effects are heterogeneous, ranging from spasmolytic to prokinetic. This review aims to clarify these inconsistencies by synthesizing experimental evidence on structure–activity relationships and underlying mechanisms. Relevant publications were identified in PubMed and Google Scholar using terms related to polyphenols and gastrointestinal motility. References were selected for relevance, and the narrative review integrates findings from in vitro, ex vivo, in vivo, and clinical studies. Across various experimental models, polyphenols function as multi-target modulators of gastrointestinal smooth muscle. The primary mechanisms identified involve the blockade of voltage-dependent L-type Ca²⁺ channels, activation of K⁺ channels (BK, K_ATP), and modulation of the NO/cGMP and cAMP/PKA pathways. Flavones and multiple flavonols consistently demonstrate spasmolytic activity via Ca²⁺ channel antagonism. In contrast, flavanones engage BK and K_ATP channels to induce membrane hyperpolarization. Complex extracts from plants like ginger and turmeric exhibit mixed pro- or antimotility effects, reflecting the diverse profiles of their constituent compounds. While robust ex vivo pharmacology and some in vivo and human data exist, a high degree of dataset heterogeneity and inconsistent reporting impedes direct translational efforts. Polyphenols are promising multi-mechanistic modulators of gastrointestinal motility with clear structure–activity patterns. To advance their clinical application, future research must focus on establishing standardized in vivo pharmacokinetics, conducting targeted structure–activity studies, employing bioassay-guided fractionation, and designing rigorous clinical trials. Full article

Pediatric type 1 diabetes (T1D) disrupts musculoskeletal development during critical windows of growth, puberty, and peak bone mass accrual. Beyond classic micro- and macrovascular complications, accumulating evidence shows a dual burden of diabetic bone disease—reduced bone mineral density, microarchitectural deterioration, and higher fracture risk—and diabetic myopathy, characterized by loss of muscle mass, diminished strength, and metabolic dysfunction. Mechanistically, chronic hyperglycemia, absolute or functional insulin deficiency, and glycemic variability converge to suppress PI3K–AKT–mTOR signaling, activate FoxO-driven atrogenes (atrogin-1, MuRF1), and impair satellite-cell biology; advanced glycation end-products (AGEs) and RAGE signaling stiffen extracellular matrix and promote low-grade inflammation (IL-6, TNF-α/IKK/NF-κB), while oxidative stress and mitochondrial dysfunction further compromise the bone–muscle unit. In vitro, ex vivo, and human studies consistently link these pathways to lower BMD and trabecular/cortical quality, reduced muscle performance, and increased fractures—associations magnified by poor metabolic control and longer disease duration. Prevention prioritizes tight, stable glycemia, daily physical activity with weight-bearing and progressive resistance training, and optimized nutrition (adequate protein, calcium, vitamin D). Treatment is individualized: supervised exercise-based rehabilitation (including neuromuscular and flexibility training) is the cornerstone of skeletal muscle health. This review provides a comprehensive analysis of the mechanisms underlying the impact of type 1 diabetes on musculoskeletal system. It critically appraises evidence from in vitro studies, animal models, and clinical research in children, it also explores the effects of prevention and treatment. Full article

Postbiotics, as a novel class of functional components, have garnered considerable scholarly and industrial interest due to their distinctive advantages in food processing applications and their positive impact on human health. Although postbiotics have demonstrated potential in alleviating constipation, their specific mechanism of action and bioactive components remain unclear. This study aimed to investigate the ameliorative effects and potential mechanisms of postbiotics derived from Bifidobacterium animalis subsp. lactis BL-99 (BL-99) on FC using both in vivo and in vitro models. The findings revealed that both BL-99 and its postbiotics significantly mitigated FC symptoms, as evidenced by enhanced intestinal motility, and elevated fecal water content. Additionally, treatment with BL-99 postbiotics was associated with an increase in the thickness of the intestinal muscular layer and a reduction in apoptosis of intestinal smooth muscle cells (SMCs). Mechanistically, BL-99 postbiotics were found to enhance the contractile response and promote the proliferation of intestinal SMCs. Furthermore, untargeted metabolomics analysis identified two key bioactive peptides, Glu-Val and Glu-Leu, as the active components in BL-99 responsible for regulating SMC function. Collectively, these findings highlight the potential of BL-99 postbiotics as a promising functional food ingredient for alleviating FC, providing a novel and effective strategy for the developing dietary interventions targeting this condition. Full article

Skeletal muscle, constituting 40–50% of total body mass, is vital for mobility, posture, and systemic homeostasis. Muscle contraction heavily relies on ATP, primarily generated by mitochondrial oxidative phosphorylation. Mitochondria play a key role in decoding intracellular calcium signals. The endocannabinoid system (ECS), including CB₁ receptors (CB₁Rs), broadly influences physiological processes and, in muscles, regulates functions like energy metabolism, development, and repair. While plasma membrane CB₁Rs (pCB₁Rs) are well-established, a distinct mitochondrial CB₁R (mtCB₁R) population also exists in muscles, influencing mitochondrial oxidative activity and quality control. We investigated the role of mtCB₁Rs in skeletal muscle physiology using a novel systemic mitochondrial CB₁ deletion murine model. Our in vivo studies showed no changes in motor function, coordination, or grip strength in mtCB₁ knockout mice. However, in vitro force measurements revealed significantly reduced specific force in both fast-twitch (EDL) and slow-twitch (SOL) muscles following mtCB₁R ablation. Interestingly, knockout EDL muscles exhibited hypertrophy, suggesting a compensatory response to reduced force quality. Electron microscopy revealed significant mitochondrial morphological abnormalities, including enlargement and irregular shapes, correlating with these functional deficits. High-resolution respirometry further demonstrated impaired mitochondrial respiration, with reduced oxidative phosphorylation and electron transport system capacities in knockout mitochondria. Crucially, mitochondrial membrane potential dissipated faster in mtCB₁ knockout muscle fibers, whilst mitochondrial calcium levels were higher at rest. These findings collectively establish that mtCB₁Rs are critical for maintaining mitochondrial health and function, directly impacting muscle energy production and contractile performance. Our results provide new insights into ECS-mediated regulation of skeletal muscle function and open therapeutic opportunities for muscle disorders and aging. Full article

Synthetic biomaterials are widely used as bone graft substitutes, but their osteogenic capacity is limited as they lack osteogenic growth factors. This study aimed to enhance the osteogenesis of a novel hydroxyapatite/aragonite (HAA) biomaterial by incorporating decellularized bone matrix and bone morphogenetic protein (BMP)-2 and BMP-7 (BMP-2/7). Human umbilical mesenchymal stem cells (MSCs) were able to proliferate and differentiate on HAA. HEK-293T cells exogenously expressing BMP-2/7 successfully secreted BMP-2/7, which was assessed by enzyme-linked immunosorbent assay. By establishing a co-culture of MSCs with HEK-293T cells expressing BMP-2/7, we successfully created an artificial allograft that integrates both synthetic biomaterials and functional organic components, offering the potential to enhance osteogenesis. The decellularized (by freeze/thawing) functional HAA was implanted between the tibia and anterior tibialis muscle in murine models and assessed the induced bone formation via micro-computer tomography, histology, and osteogenic markers mRNA expression by a reverse transcription-quantitative polymerase chain reaction. A significant increase in new bone formation was seen in the functional HAA implanted group. In conclusion, this study revealed that bone formation following the HAA implantation can be enhanced by a functional decellularized matrix, comprising BMP-2/7, via in vitro tissue engineering using MSCs and HEK-293T cells expressing BMP-2/7. Full article

Reduced oxygen availability, or hypoxia, is an environmental stress factor that modulates cellular and systemic functions. It plays a significant role in both physiological and pathological conditions, including tissue regeneration, where it influences angiogenesis, metabolic adaptation, inflammation, and stem cell activity. Hypoxia-inducible factors (HIFs) orchestrate these responses by activating genes that promote survival and repair, although HIF-independent mechanisms, particularly those related to mitochondrial function, are also involved. Depending on its duration and severity, hypoxia may exert either beneficial or harmful effects, ranging from enhanced regeneration to fibrosis or maladaptive remodeling. This review explores the systemic and cellular effects of acute, chronic, intermittent, and preconditioning hypoxia in the context of tissue regeneration. Hypoxia-driven responses are examined across tissues, organs, and complex structures, including the heart, muscle, bone, vascular structures, nervous tissue, and appendages such as tails. We analyze findings from animal models and in vitro studies, followed by biomedical and pharmacological strategies designed to modulate hypoxia and their initial exploration in clinical settings. These strategies involve regulatory molecules, signaling pathways, and microRNA activity, which are investigated across species with diverse regenerative capacities to identify mechanisms that may be conserved or divergent among taxa. Lastly, we emphasize the need to standardize hypoxic conditions to improve reproducibility and highlight their therapeutic potential when precisely controlled. Full article

Muscle atrophy is defined as reductions in muscle size and function and represents a critical concern affecting elderly populations, immobilized patients, and individuals following specific dietary regimens, such as fasting and low-protein diets. This study investigated the protective effects of Stellaria dichotoma root extract and its isolated bioactive compounds during muscle atrophy using both in vitro and in vivo experimental models. First, S. dichotoma root extract prevented dexamethasone (DEX)-induced atrophy in C2C12 myotubes. Through systematic solvent partitioning and resin chromatography, five compounds (1–5) were successfully isolated from the n-butanol fraction. Dichotomine B (2) was identified as the most abundant and bioactive constituent. Treatment with dichotomine B significantly preserved the myotube diameter, enhanced the fusion index, and maintained the myosin heavy chain protein level while suppressing key atrophic biomarkers, including FoxO3a, MuRF-1, and Atrogin-1, in DEX-treated myotubes. Furthermore, dichotomine B (2) reduced proteolysis in serum-free cultured C2C12 myotubes and in mice subjected to 48 h of fasting, preserving muscle mass and strength. These findings suggest that S. dichotoma root extract and its principal compound, dichotomine B (2), have promising therapeutic potential and provide an opportunity to develop novel pharmacological interventions against muscle wasting through suppression of proteolysis pathways. Full article

Background: Genioplasty is a well-established surgical technique for reshaping the chin and enhancing facial harmony. However, conventional fixation methods may present biomechanical and aesthetic limitations. Objective: This study introduces and evaluates a novel Anatomical Chin Plate (ACP), designed to enhance mechanical performance and facial aesthetics compared to the conventional chin plate (CP). Methods: A three-dimensional finite element analysis (FEA) was conducted to compare stress distribution in ACP and CP models under a standardized oblique load of 60 N, simulating muscle forces from the mentalis and digastric muscles. Plates were modeled using Blender and analyzed using ANSYS software 2025 r2. Mechanical behavior was assessed based on von Mises stress, concentration sites, and potential for plastic deformation or fatigue failure. Results: The ACP demonstrated a significantly lower maximum von Mises stress (77.19 MPa) compared to the CP (398.48 MPa). Stress distribution in the ACP was homogeneous, particularly around the lateral fixation holes, while the CP exhibited concentrated stress between central screw holes. These findings indicate that the anatomical geometry of the ACP enhances load dispersion, reduces critical stress concentrations, and minimizes fatigue risk. Conclusions: The ACP design offers superior biomechanical behavior and improved aesthetic potential for genioplasty procedures. Its optimized shape allows for better integration with facial anatomy while providing stable fixation. Further studies are recommended to validate in vitro performance and explore clinical applicability in advanced genioplasty and complex osteotomies. Full article

Peripheral artery disease is a common manifestation of atherosclerosis, characterized by insufficient tissue perfusion and chronic ischemia. Arteriogenesis and angiogenesis are essential endogenous mechanisms to restore blood flow and limit ischemic injury. The metalloprotease ADAMTS13, known for cleaving ultra-large von Willebrand factor, has been implicated in thrombotic and inflammatory regulation. However, its role in ischemic vascular remodeling remains unclear. Using a murine hind limb ischemia model, we investigated the effect of ADAMTS13 deficiency on arteriogenesis and angiogenesis by comparing male ADAMTS13^−/− and wild-type control mice. Perfusion recovery, vascular cell proliferation, immune cell infiltration, and thrombotic activity were evaluated using laser Doppler measurements, immunohistochemical analysis of adductor and gastrocnemius muscle tissues, and in vivo microscopy. ADAMTS13 deficiency did not impair perfusion recovery, collateral artery growth, or capillarization. While platelet adhesion was slightly increased in ADAMTS13^−/− mice, no thrombotic occlusions were observed. Inflammatory responses, including macrophage and neutrophil infiltration as well as macrophage polarization, were largely unaffected. Despite previous in vitro evidence indicating an angiogenic role for ADAMTS13, its absence did not compromise angiogenesis in vivo. Our findings suggest that ADAMTS13 does not play a critical role in ischemia-related angiogenesis and arteriogenesis under sterile conditions and may be relevant only in contexts involving acute and sufficiently strong thromboinflammatory stimuli. Full article

Myelin is a lipid-rich membrane that insulates axons, providing support and ensuring efficient nerve impulse conduction. Disruption of this sheath, or demyelination, impairs neural transmission and underlies symptoms like vision loss and muscle weakness in multiple sclerosis (MS). Despite extensive studies using in vitro and in vivo models, the molecular mechanisms driving demyelination remain incompletely understood. To investigate the role of myelin basic protein (MBP) in membrane stability, we prepared model myelin membranes (MMMs) from lipids expectedly undergoing gel-to-fluid phase transition, mimicking both normal and altered myelin, with and without MBP. Differential scanning calorimetry (DSC) revealed that MBP suppresses the main phase transition in normal MMMs, unlike in modified MMMs. FTIR spectra showed strengthening of van der Waals interactions in normal MMMs with MBP upon heating and opposite effects in the analogous modified MMM system. Additionally, phosphate groups were identified as critical sites for MBP–lipid interactions. Circular dichroism (CD) spectroscopy suggests that MBP adopts helical structures that penetrate the bilayer of normal MMMs. These findings offer new insights into the molecular-level interactions between MBP and myelin membranes, with implications for understanding demyelination in diseases like MS. Full article