Search Results (220)

Plant-derived extracellular vesicles (PDEVs) are nanoscale, phospholipid bilayer-enclosed vesicles secreted by living cells through cytokinesis under physiological and pathological conditions. Owing to their high biocompatibility and stability, PDEVs have attracted considerable interest in regenerative medicine applications. They can exhibit the capacity to enhance cellular proliferation, migration, and multi-lineage differentiation through immunomodulation, anti-inflammation effects, antioxidative protection, and tissue regeneration mechanisms. Given their abundant availability, favorable safety profile, and low immunogenicity risks, PDEVs have been successfully employed in therapeutic interventions for skeletal muscle disorders, cardiovascular diseases, neurodegenerative conditions, and tissue regeneration applications. This review mainly provides a comprehensive overview of PDEVs, systematically examining their biological properties, standardized isolation and characterization methodologies, preservation techniques, and current applications in regenerative medicine. Furthermore, we critically discuss future research directions and clinical translation potential, aiming to facilitate the advancement of PDEV-based therapeutic strategies. Full article

Skeletal muscle regeneration requires a reliable source of myogenic progenitor cells capable of forming new fibers and creating a self-renewing satellite cell pool. Human induced pluripotent stem cell (hiPSC)-derived teratomas have emerged as a novel in vivo platform for generating skeletal myogenic progenitors, although in vivo studies to date have provided only an early single-time-point snapshot. In this study, we isolated a specific population of CD82⁺ ERBB3⁺ NGFR⁺ cells from human iPSC-derived teratomas and verified their long-term in vivo regenerative capacity following transplantation into NSG-mdx^4Cv mice. Transplanted cells engrafted, expanded, and generated human Dystrophin⁺ muscle fibers that increased in size over time and persisted stably long-term. A dynamic population of PAX7⁺ human satellite cells was established, initially expanding post-transplantation and declining moderately between 4 and 8 months as fibers matured. MyHC isoform analysis revealed a time-based shift from embryonic to neonatal and slow fiber types, indicating a slow progressive maturation of the graft. We further show that these progenitors can be cryopreserved and maintain their engraftment potential. Together, these findings give insight into the evolution of teratoma-derived human myogenic stem cell grafts, and highlight the long-term regenerative potential of teratoma-derived human skeletal myogenic progenitors. Full article

The postmortem interval (PMI), defined as the time elapsed between death and the discovery or examination of the body, is a crucial parameter in forensic science for estimating the time of death. There are many ways to measure the PMI, such as Henssge’s nomogram, which uses rectal temperature measurement; livor mortis; rigor mortis; and forensic entomology. However, these methods are usually affected by various conditions in the surrounding environment. The purpose of the present study was to compare molecular genetics and histological changes in the brain and skeletal muscle tissues of SD rats over increasing periods of time after death. For the PMIs, we considered 0 h, 6 h, 12 h, 24 h, 36 h, 48 h, 4 days, 6 days, 8 days, 10 days, 14 days, and 21 days and compared them at 4 °C and 26 °C. Hematoxylin and Eosin (H&E) staining was performed to observe tissue changes. Morphological tissue changes were observed in cells for up to 21 days at 4 °C, and cell destruction was visually confirmed after 14 days at 26 °C. Total RNA (tRNA) was isolated from each tissue sample, and complementary DNA (cDNA) was synthesized. A reverse transcription quantitative PCR (RT-qPCR) SYBR Green assay targeting three types of housekeeping genes, including Gapdh, Sort1, B2m, and 5S rRNA, was performed. The results showed that Gapdh and 5S rRNA were highly stable and could be better RNA targets for estimating the PMI in brain and skeletal muscle tissues. Conversely, Sort1 and B2m showed poor stability and low expression levels. In conclusion, these molecular biomarkers could be used as auxiliary indicators of the PMI in human, depending on the stability of the marker. Full article

Echovirus 18, a member of the B group of enteroviruses, is a significant etiological agent of aseptic meningitis and viral encephalitis in children. In this study, we investigated the pathogenicity of E18 by establishing a mouse infection model after comparing various mouse strains and injection methods. Two-day-old IFNAR1 knockout mice infected with clinical isolates of E18 exhibited symptoms such as lethargy, hind limb paralysis, and even mortality. Similarly, some two-day-old C57BL/6J mice displayed comparable symptoms; however, the incidence was lower than that observed in IFNAR1 knockout mice. No similar symptoms were noted in any Balb/c mice. Significant pathological changes were observed in skeletal muscle, brain tissue, and other organs of symptomatic mice; among these tissues, skeletal muscle demonstrated the highest viral load. The established infection model using two-day-old IFNAR1 knockout mice provides valuable insights into further investigations regarding its pathological injury mechanisms as well as the protective effects conferred by antibodies. Full article

Background/Objectives: Previous studies have typically investigated injury risk factors either by body region or sport type in isolation, limiting their practical applicability to real-world settings where multiple factors interact. However, injury risk is inherently multifactorial—shaped by a complex interplay of demographic, physiological, and training-related characteristics that differ by anatomical site and sport context. This study addresses that gap by simultaneously analyzing predictors across multiple body regions and sport-specific environments. This integrated approach is critical for developing more precise, evidence-based injury prevention strategies tailored to the specific demands and risk profiles of amateur athletes. This study aimed to identify key predictors of injury risk across various body regions and sport-specific contexts among amateur athletes. Specifically, we sought to (1) develop predictive models that include demographic and body composition variables, and (2) compare the relative predictive strength of these variables across models, highlighting differences in their influence by injury location and sport type. Methods: A total of 454 amateur athletes (219 males and 235 females) participated. Data on anthropometry, body composition, training load were collected. Injury history was obtained via self-administered questionnaires, with participants reporting injuries that had occurred during the 12 months prior to the time of data collection. Logistic regression models were used to identify significant predictors, and Nagelkerke’s R² was calculated to assess model fit. Results: Overall, 49.78% of athletes experienced injuries, with a higher proportion in females (54.47%) than in males (44.75%). Age demonstrated divergent effects: it was protective against both upper and lower limb injuries in male individual-sport athletes (OR = 0.62 and OR = 0.69, respectively) and in female athletes across sport types (ORs = 0.75–0.64), but conversely increased the risk of upper limb injuries in male team-sport athletes (OR = 1.88). In female individual athletes, higher Skeletal Muscle Index (SMI) predicted upper limb injuries (OR = 1.18, p = 0.034). In female team athletes, higher Muscle-to-Fat Ratio (MFR) (OR = 2.46, p = 0.017) and BMI (OR = 1.67, p = 0.008) predicted upper limb injuries, while higher Fat Mass Index (FMI) predicted lower limb injuries (OR = 1.70, p = 0.009). Models showed moderate explanatory power (Nagelkerke’s R² ranging from 0.03 to 0.33). Conclusions: These findings suggest that injury risk profiles are highly context-dependent. Preventive strategies should be tailored by sex and sport type, for example, younger athletes in team sports may benefit from age-sensitive load monitoring, while in female team athletes, targeted interventions addressing both fat and muscle balance could be essential. Age, body composition, and sport-specific demands should be considered in individualized injury prevention planning. Full article

Fish red blood cells (RBCs) are nucleated, transcriptionally active, and key players in both gas transport and immune responses. They are the primary targets of Orthoreovirus piscis (PRV), the etiological agent of heart and skeletal muscle inflammation (HSMI), which includes three genotypes (PRV-1, PRV-2, and PRV-3), linked to circulatory disorders in farmed salmon. In Chile, PRV-3 affects the coho salmon (Oncorhynchus kisutch), but host–pathogen interactions remain poorly characterized. This study compared the interactions of PRV-3 in coho salmon and PRV-1 in Atlantic salmon (Salmo salar) using RBC infection models. RBCs were isolated from healthy juvenile salmon (n = 3) inoculated with either PRV-1 (Ct = 18.87) or PRV-3 (Ct = 21.86). Poly I:C (50 µg/mL) was used as a positive control for the antiviral response. Cells were monitored for up to 14 days post-infection (dpi). PRV-3 infection in coho salmon RBCs caused significant metabolic disruption, apoptosis from 7 dpi, and correlated with increasing viral loads. In contrast, PRV-1 infection in Atlantic salmon RBCs showed limited apoptosis and maintained cell viability. Coho salmon RBCs upregulated rig-i, mx, and pkr transcripts, indicating activation of the type I interferon pathway, whereas Atlantic salmon RBCs exhibited a more attenuated response. PRV-3 induced notable morphological changes in coho salmon RBCs, although neither PRV-3 nor PRV-1 caused hemolysis. These findings highlight species-specific differences in RBC responses to PRV infection and provide new insights into the pathogenesis of PRV-3 and PRV-1. Full article

Stimulating skeletal muscle satellite cells (SMSCs) with amino acids improves their proliferation and differentiation, enhancing skeletal muscle mass, thereby increasing lean meat rate. This study explored lysine (Lys)’s effects on SMSCs and their protein profiles in Sunit sheep. SMSCs were successfully isolated, assessing their survival and proliferation after Lys stimulation at varying concentrations using the CCK-8 assay. Western blotting revealed Lys-induced changes in myogenic differentiation protein expression, while immunocytochemistry detected α-Actinin and Myostatin within the SMSCs. TMT proteomics identified differentially expressed proteins, which underwent functional and interaction analyses, with RT-qPCR validating the corresponding gene expression. This study revealed that 4 mmol/L of Lys significantly boosted SMSC proliferation. A 24 h stimulation with this concentration reduced Myostatin expression, and increased MYOD1 and α-Actinin levels in the SMSCs. A proteomic analysis identified 577 differentially expressed proteins, primarily associated with lipoblast differentiation and muscle development, as highlighted by the GO enrichment analysis. A pathway analysis further demonstrated these proteins’ involvement in the autophagy–lysosome and NOD-like receptor signaling pathways. Lys enhances SMSC proliferation, differentiation, and adipogenesis in Sunit sheep, exhibiting antioxidant properties and supporting muscle stability and amino acid metabolism. It may also have anti-inflammatory, anti-pyroptotic, and proteolysis-inhibitory effects, offering insights into muscle growth mechanisms through amino acid supplementation in ruminants. Full article

Platycladus orientalis, an evergreen tree belonging to the Cupressaceae family, has been traditionally used to treat various ailments, including fever, cough, diarrhea, diuresis, cold symptoms, and gastrointestinal disorders in folk medicine. As part of our ongoing investigation aimed at discovering bioactive natural products and elucidating their mechanisms of action from various natural sources, we investigated a methanol (MeOH) extract of P. orientalis leaves. This investigation led to the isolation and identification of a labdane-type diterpene, lambertianic acid (LA), via column chromatography and HPLC purification. The structure of LA was elucidated using LC/MS and NMR spectroscopic analyses, including HR-ESIMS, while its absolute configuration was confirmed through electronic circular dichroism (ECD) calculations. Recent studies have reported that labdane-type diterpenes exhibit diverse pharmacological activities, such as anticancer, anti-inflammatory, anti-obesity, and hypolipidemic effects. Notably, LA has been shown to modulate adipocyte metabolism via AMPK signaling; however, its role in skeletal muscle atrophy remains unexplored. Therefore, in this study, we investigated the effects of LA on dexamethasone (Dex)-induced muscle atrophy in C2C12 myotubes. Treatment with LA at concentrations of 25 µM and 50 µM significantly rescued myotube diameter and reduced the expression of atrophy-related proteins, including MuRF-1 and atrogin-1/MAFbx, without compromising cell viability at these moderate concentrations. These findings suggest that LA derived from P. orientalis exerts protective effects against skeletal muscle atrophy, highlighting its potential as a promising natural therapeutic candidate for muscle-wasting disorders. Full article

Low birth weight (LBW) in various species leads to a pronounced skeletal muscle phenotype and can serve as a model to study muscle formation and draw conclusions for normal and pathological development. We aimed to elucidate in detail how the differentiation of muscular stem cells and their progeny are disturbed in piglets born with LBW. We isolated primary muscle cells from LBW piglets and their normal siblings with two different approaches: (1) single cells from two functionally divergent subpopulations (previously named “fast” and “slow”) and (2) cells derived from isolated, intact myofibers. Subsequently, we analyzed their proliferative and differentiative capacity by determining proliferation rate, migration behavior, myotube formation, and myogenic gene and protein expression. LBW led to a decreased proliferation rate and migration potential in cells from the subpopulation fast group. Cells from LBW piglets were generally able to differentiate, but they formed smaller myotubes with less incorporated nuclei, leading to a diminished fusion rate. Myogenic gene expression was also significantly altered due to pig birth weight. Overall, early postnatal muscle development in LBW was disturbed at several crucial steps involving the establishment of a reserve stem cell pool, movement of cells towards existing myofibers, and the ability to form nascent myofibers. Full article

Background: Skeletal muscle, as the largest organ in the body and the main protein pool, is crucial for various physiological processes, but atrophy of skeletal muscle can result from glucocorticoids, including dexamethasone, or from aging. Astaxanthin (AST) is a ketocarotenoid with a variety of physiological activities. However, the clinical application of AST is hampered by its strong hydrophobicity, intense off-flavors, and susceptibility to oxidation. Methods: In this study, we prepared whey protein isolate (WPI)-encapsulated AST nanoemulsion (WPI-AST, W-A) and investigated its alleviating effects on dexamethasone-induced skeletal muscle atrophy. Results: The optimal concentration of astaxanthin was determined to be 30 mg/mL with an oil/water ratio of 1:5. The W-A was a typical oil-in-water (O/W) emulsion with a particle size of about 110 nm. The bioaccessibility of astaxanthin was significantly improved, with the off-flavors of astaxanthin effectively masked. After oral administration, the W-A further ameliorated skeletal muscle atrophy by inhibiting skeletal muscle catabolism, promoting skeletal muscle production, and inhibiting mitochondrial autophagy compared with the same dose of WPI and AST. In addition to this, the W-A further improved the glycometabolism of skeletal muscle by reducing the expression of Foxo3 and increasing the expression of PGC-1α. Conclusions: In conclusion, the W-A nanoemulsion demonstrated good therapeutic value in alleviating skeletal muscle atrophy. Full article

Heart and skeletal muscle inflammation (HSMI) is a significant disease affecting Atlantic salmon (Salmo salar) production in Norway but has had limited impact to production in North America. The causative agent of HSMI is piscine orthoreovirus genotype 1 (PRV-1), and disease variation between regions is suggested to be at least partially driven by genetic variation of the virus. Using controlled laboratory injection challenges, we corroborate variations in disease outcomes for three PRV-1 isolates (PRV-1a from the eastern Pacific, PRV-1a from the western Atlantic, and PRV-1b from the Norwegian sea); however, virus replication dynamics, host recognition, and PRV-1-associated heart inflammation were also discrete relative to the Atlantic salmon stock challenged, irrespective of the viral isolate used. Specifically, New Brunswick Tobique River Atlantic salmon had less (p < 0.01) heart inflammation relative to Mowi-McConnell Atlantic salmon of Western Canada which, in turn, had less (p < 0.01) heart inflammation than Mowi Atlantic salmon of Scotland when cumulatively considering challenges using all three PRV-1 isolates. These data indicate that the presence of PRV-1a or PRV-1b alone is not sufficient to reliably predict disease and highlights at least one potential mechanism (host genotype) for reducing HSMI disease severity. Full article

Leonurus cardiaca L. is known in Europe for its cardioactivity—also in interrelation with known risk factors of the metabolic syndrome—just as L. japonicus Houtt. in East Asia; however, up to now, no active constituents could be identified. The three sub-types of PPARs (α, δ, and γ), are involved in controlling the lipid metabolism in the liver and skeletal muscles. Although PPARδ especially is a potential therapeutic target for the metabolic syndrome, insulin resistance, and obesity, no PPARδ agonists with clinical potential have presently been developed. Therefore, nineteen dominant isolated constituents of both species were screened for activity on the metabolic syndrome related PPAR α, δ, and γ in a newly developed luciferase reporter gene assay. Eight phenylethanoid glycosides not previously detected in L. cardiaca, including the novel cardiaphenyloside A, as well as the iridoids ajugol and harpagide were found via bioassay-guided isolation and structural elucidation of spectroscopic and chemical evidence. For the PPARδ experiment, all nineteen isolated constituents and GW0742 (positive control) were added to the medium of transfected COS-1 cells and further processed according to a standardized luciferase assay protocol. Only the major iridoid 7-chloro-6-desoxy-harpagide displayed significant activity in the PPARδ assay at 50 μg/mL, while the result for 100 μg/mL was higher than for the GW0742 positive control. Rutin, chicoric acid, and cardiaphenyloside A at 100 μg/mL showed PPARα agonistic activity. For PPARγ, no significant effects were observed. This activity of Leonurus extracts and especially of their active constituent 7-chloro-6-desoxy-harpagide on the δ subtype of the PPAR system strongly indicates their potential for anti-obesity therapy. Full article

Methylsulfonylmethane (MSM) is a sulfur-containing molecule with reported anti-inflammatory and antioxidant activities. Exercise causes the formation of free radicals and stimulates inflammatory gene expression in leukocytes and skeletal muscle. The hypothesis that dietary supplementation with MSM alters the exercise-mediated inflammatory and oxidant response was assessed in unfit adult thoroughbred geldings. Ten geldings (6.7 ± 1.6 yr) were assigned to a diet supplemented without (CON, n = 5) or with 21 g of MSM (n = 5) for 30 days. Following the supplementation period, horses performed a standardized exercise test (SET) with blood collections before (t = 0), 10 min, 1 h, 4 h, and 24 h post-SET. Skeletal muscle biopsies were retrieved from the middle gluteus before and 1 h post-SET for total RNA isolation. All horses were rested for 120 days before the experiment was repeated in a cross-over design. Plasma total antioxidant capacity was unaffected (p > 0.05) by either exercise or MSM. Plasma glutathione peroxidase activity was less (p < 0.05) in MSM horses than in the CON. Plasma IL6, IL8, IL10, and TNFα were unaffected (p > 0.05) by either exercise or diet. Transcriptomic analysis of skeletal muscle revealed 35 genes were differentially expressed (DEG; p < 0.05) by 2-fold or more in response to exercise; no MSM DEGs were noted. A comparison of the exercise by diet contrasts revealed that horses supplemented with MSM contained a greater number of exercise-responsive genes (630; logFC > 0.2; q < 0.05) by comparison to the CON (237), with many of these mapping to the immune response (71) and cytokine signal transduction (60) pathways. These results suggest supplementation of MSM as a dietary aid for improved anti-inflammatory responses in skeletal muscle following exercise. Full article

Sarcopenia corresponds to a decrease in muscle mass and strength. CCL5 is a new myokine whose expression, along with the CCR5 receptor, is increased in sarcopenic muscle. Therefore, we evaluated whether CCL5 and CCR5 induce a sarcopenic-like effect on skeletal muscle tissue and cultured muscle cells. Electroporation in the tibialis anterior (TA) muscle of mice was used to overexpress CCL5. The TA muscles were analyzed by measuring the fiber diameter, the content of sarcomeric proteins, and the gene expression of E3-ligases. C₂C₁₂ myotubes and single-isolated flexor digitorum brevis (FDB) fibers were also treated with recombinant CCL5 (rCCL5). The participation of CCR5 was evaluated using the antagonist maraviroc (MVC). Protein and structural analyses were performed. The results showed that TA overexpression of CCL5 led to sarcopenia by reducing muscle strength and mass, muscle-fiber diameter, and sarcomeric protein content, and by upregulating E3-ligases. The same sarcopenic phenotype was observed in myotubes and FDB fibers. We showed increased reactive oxygen species (ROS) production and carbonylated proteins, denoting oxidative stress induced by CCL5. When the CCR5 was antagonized, the effects produced by rCCL5 were prevented. In conclusion, we report for the first time that CCL5 is a novel myokine that exerts a sarcopenic-like effect through the CCR5 receptor. Full article

This study investigated the effects of long-term serum starvation on autophagy, metabolism, and differentiation of porcine skeletal muscle satellite cells (SMSCs) and elucidated the role of autophagy in skeletal muscle development. Our findings provide a theoretical basis for improving meat production in domestic pigs. The SMSCs isolated and preserved in our laboratory were revived and divided into six groups based on the culture medium serum concentration to simulate varying levels of serum starvation: 20% serum (control group), 15% serum (mild serum starvation group), 5% serum (severe serum starvation group), and their autophagy inhibition groups supplemented with 3-methyladenine. After 96 h of culture, the apoptosis rate, mitochondrial membrane potential, reactive oxygen species, and ATP were measured to evaluate the effects of serum starvation on the SMSCs’ metabolism. Additionally, the levels of autophagy-related proteins, autophagosomes, and autolysosomes were measured to investigate the impact of long-term serum starvation on autophagy. The expression of proteins associated with myogenic and adipogenic differentiation (MHC, MyoD1, peroxisome proliferator-activated receptor γ, and lipoprotein lipase) as well as lipid content were also determined to investigate the effects of long-term serum starvation on SMSC differentiation. The results showed that long-term serum starvation induced autophagy through the AMPK/mTOR signaling pathway, accelerated cell metabolism and apoptosis, exacerbated reactive oxygen species accumulation, and inhibited myogenic and adipogenic differentiation of SMSCs. Moreover, these effects were positively correlated with the level of serum starvation. In addition, serum starvation-induced autophagy moderately promoted the myogenic and adipogenic differentiation of SMSCs; however, these effects were insufficient to counteract the inhibition of cell differentiation by long-term serum starvation. This study provides insight into leveraging serum starvation as a stressor to regulate muscle growth and metabolism in domestic pigs. Full article