Search Results (579)

This study aims to investigate asymmetries in muscle activation and co-contraction of main lower limb muscles during flamenco Zap-3 footwork with consideration of the footwork speed and dancer proficiency. Twelve flamenco dancers participated, including six professionals and six amateurs. Each participant performed the Zap-3 sequence under three speed conditions: 160 beats per minute (bpm), 180 bpm and the fastest speed level (F). The normalized surface electromyography was recorded in the gastrocnemius medialis (GM), biceps femoris (BF), tibialis anterior (TA) and rectus femoris (RF) in the dominant (DL) and non-dominant leg (NDL). The co-contraction index was also calculated for selected muscle pairs. The results showed that significant asymmetries occurred only in professional dancers and exclusively at the F speed level. Specifically, the value of the GM in the NDL was higher than that of the DL (p < 0.05, d = 1.97); the value of the BF in the DL was higher than that of the NDL (p < 0.05, d = 1.86) and the co-contraction index of BF/RF in the DL was higher than that of the NDL (p < 0.05, d = 1.87). Understanding these asymmetries may help to inform individualized training strategies aimed at optimizing performance and reducing potential risks. Full article

Background: Accumulating evidence indicates that SARS-CoV-2 infection results in long-term multiorgan complications, with the kidney being a primary target. This study aimed to characterize the long-term transcriptomic changes in the kidney following coronavirus infection using a murine model of MHV-1-induced SARS-like illness and to evaluate the therapeutic efficacy of SPIKENET (SPK). Methods: A/J mice were infected with MHV-1. Renal tissues were collected and subjected to immunofluorescence analysis and Next Generation RNA Sequencing to identify differentially expressed genes associated with acute and chronic infection. Bioinformatic analyses, including PCA, volcano plots, and GO/KEGG pathway enrichment, were performed. A separate cohort received SPK treatment, and comparative transcriptomic profiling was conducted. Gene expression profile was further confirmed using real-time PCR. Results: Acute infection showed the upregulation of genes involved in inflammation and fibrosis. Long-term MHV-1 infection led to the sustained upregulation of genes involved in muscle regeneration, cytoskeletal remodeling, and fibrotic responses. Notably, both expression and variability of SLC22 and SLC22A8, key proximal tubule transporters, were reduced, suggesting a loss of segment-specific identity. Further, SLC12A1, a critical regulator of sodium reabsorption and blood pressure, was downregulated and is associated with the onset of polyuria and hydronephrosis. SLC transporters exhibited expression patterns consistent with tubular dysfunction and inflammation. These findings suggest aberrant activation of myogenic pathways and structural proteins in renal tissues, consistent with a pro-fibrotic phenotype. In contrast, SPK treatment reversed the expression of most genes, thereby restoring the gene profiles to those observed in control mice. Conclusions: MHV-1-induced long COVID is associated with persistent transcriptional reprogramming in the kidney, indicative of chronic inflammation, cytoskeletal dysregulation, and fibrogenesis. SPK demonstrates robust therapeutic potential by normalizing these molecular signatures and preventing long-term renal damage. These findings underscore the relevance of the MHV-1 model and support further investigation of SPK as a candidate therapy for COVID-19-associated renal sequelae. Full article

Idiopathic pulmonary fibrosis (IPF) is characterized by excessive extracellular matrix (ECM) deposition driven by aberrant fibroblast-to-myofibroblast transition (FMT). However, the upstream regulators and downstream effectors of this process remain incompletely understood. Here, we identify acyl-CoA synthetase long-chain family member 4 (ACSL4), a lipid metabolic enzyme, as a critical mediator linking complement component 5a (C5a)/C5a receptor 1 (C5aR1) signaling to FMT via calcium signaling. In bleomycin (BLM)-induced pulmonary fibrosis of C57BL/6JGpt mice, and in C5a-stimulated primary lung fibroblasts, the expression of ACSL4 was markedly upregulated. Pharmacological inhibition of ACSL4 (PRGL493) or C5aR1 (PMX53) attenuated the deposition of ECM and suppressed the expression of fibrotic markers in vivo and in vitro. Mechanistically, the activation of C5a/C5aR1 signaling increased intracellular calcium levels and promoted the expression of ACSL4, while inhibition of calcium signaling (FK506) reversed the upregulation of ACSL4 and FMT-related changes, including the expression of α-smooth muscle actin (αSMA) and the migration of fibroblasts. Notably, inhibition of ACSL4 did not affect the proliferation of fibroblasts, suggesting its specific role in phenotypic transition. These findings demonstrate that ACSL4 functions downstream of C5a/C5aR1-induced calcium signaling to promote FMT and the progression of pulmonary fibrosis. Targeting ACSL4 may therefore offer a novel therapeutic strategy for IPF. Full article

Background: This study investigates differences in muscle co-contraction and peak electromyography (EMG) activity between novice and advanced Taekwondo athletes during consecutive roundhouse (bandal chagui) kicks, examining the influence of body composition and experience level. Methods: Sixteen Taekwondo athletes (12 males, 4 females; mean age: 20.5 ± 4.3 years) were divided into novice (n = 8) and advanced (n = 8) groups. Muscle co-contraction indices and peak EMG activity across 15 consecutive kicks were assessed in key lower limb muscles, including the biceps femoris (BF), lateral gastrocnemius (LG), rectus femoris (RF), soleus (SO), semitendinosus (ST), tibialis anterior (TA), vastus lateralis (VL), and vastus medialis (VM). Results: Advanced athletes exhibited significantly higher co-contraction indices in BF–RF, VM–BF, and SO–TA pairs (p < 0.05) and increased peak EMG trends in the BF and LG (p < 0.05). Novice athletes showed significantly reduced peak EMG increases in the RF, VM, and VL. EMG trends were influenced by body composition, with principal component analysis indicating that higher fat mass and lower muscle mass were associated with greater variations in muscle activation. Conclusions: These findings suggest that advanced athletes refine motor control through increased co-contraction, improving stability and efficiency, while novices exhibit less optimized coordination patterns. This study provides insights into the neuromechanical adaptations associated with expertise development in Taekwondo. Full article

The present study aims to investigate the multi-year effects (5 years) of individualized whole-body vibration (WBV) on locomotion, postural control, and handgrip strength in a 68-year-old man with relapse remitting multiple sclerosis (PwRRMS). The dose–response relationship induced by a single session was quantified by determining the surface electromyographic activity (sEMG) of the participant. The participant wore an orthosis to limit the lack of foot dorsiflexion in the weakest limb during walking in daily life. The gait alteration during walking was assessed at 1, 2 and 3 km/h (without the orthosis) through angle–angle diagrams by quantifying the area, perimeter and shape of the loops, and the sEMG of leg muscles was recorded in both limbs. The evaluation of postural control was conducted during upright standing by quantifying the displacement of the center of pressure (CoP). The handgrip strength was assessed by measuring the force–time profile synchronized with the sEMG activity of upper arm muscles. The participant improved his ability to walk at higher speeds (2–3 km/h) without the orthosis. There were greater improvements in the area and perimeter of angle–angle diagrams for the weakest limb (Δ = 36–51%). The sEMG activity of the shank muscles increased at all speeds, particularly in the tibialis anterior of weakest limbs (Δ = 10–68%). The CoP displacement during upright standing decreased (Δ = 40–60%), whereas the handgrip strength increased (Δ = 32% average). Over the 5-year period of intervention, the individualized WBV improved locomotion, postural control and handgrip strength without side effects. Future studies should consider the possibility of implementing an individualized WBV in PwRRMS. Full article

Background: Chitosan, a family of polysaccharides composed of glucosamine and N-acetyl glucosamine, is a promising adjuvant candidate for eliciting potent immune response. Methods: This study compared the adjuvant effects of chitosan to those of empty lipid nanoparticles (eLNPs) and aluminum hydroxide (alum) following administration of recombinant SARS-CoV-2 spike immunogen in adult mice. Mice received the adjuvanted recombinant protein vaccine in a prime-boost regimen with four weeks interval. Subsequent analyses included serological assessment of antibody responses, evaluation of T cell activity, immune cell recruitment and cytokine profiles at injection site. Results: Compared to alum, chitosan induced a more balanced Th1/Th2 response, akin to that observed with eLNPs, demonstrating its ability to modulate both the humoral and cellular immune pathways. Chitosan induced a different proinflammatory cytokine (e.g., IL-1⍺, IL-2, IL-6, and IL-7) and chemokine (e.g., Eotaxin, IP-10, MIP-1a) profile compared to eLNPs and alum at the injection site and in the draining lymph nodes. Moreover, chitosan potentiated the recruitment of innate immune cells, with neutrophils accounting for about 40% of the infiltrating cells in the muscle, representing a ~10-fold increase compared to alum and a comparable level to eLNPs. Conclusions: These findings collectively indicate that chitosan has the potential to serve as an effective adjuvant, offering comparable, and potentially superior, properties to those of currently approved adjuvants. Full article

In placental mammals, the co-option of vertebrate orthologous ATP1B4 genes has profoundly altered the properties of the encoded BetaM proteins, which function as bona fide β-subunits of Na,K-ATPases in lower vertebrates. Eutherian BetaM acquired an extended Glu-rich N-terminal domain resulting in the complete loss of its ancestral function and became a skeletal and cardiac muscle-specific component of the inner nuclear membrane. BetaM is expressed at the highest level during perinatal development and is implicated in gene regulation. Here we report the long-term consequences of Atp1b4 ablation on metabolic parameters in adult mice. Male BetaM-deficient (Atp1b4−/Y) mice have remarkably lower body weight and adiposity than their wild-type littermates, despite higher food intake. Indirect calorimetry shows higher energy expenditure (heat production and oxygen consumption) with a greater spontaneous locomotor activity in Atp1b4−/Y males. Their lower respiratory exchange ratio suggests a greater reliance on fat metabolism compared to their wild-type counterparts. Consistently, Atp1b4−/Y KO mice exhibit enhanced β-oxidation in skeletal muscle, along with improved glucose and insulin tolerance. These robust metabolic changes induced by Atp1b4 disruption demonstrate that eutherian BetaM plays an important role in regulating adult mouse metabolism. This demonstrates that bypassing the co-option of Atp1b4 potentially reduces susceptibility to obesity. Thus, Atp1b4 ablation leading to the loss of evolutionarily acquired BetaM functions serves as a model for a potential alternative pathway in mammalian evolution. Full article

Background and Objective: This study aimed to examine the possibility of using surface electromyography (sEMG) to aid in assessing the correctness of overhead deep squat performance. Electromyography signals were recorded for 20 athletes from the lower (rectus femoris (RF), vastus medialis (VM), biceps femoris (BF), and gluteus (GM)) and upper (deltoid (D), latissimus dorsi (L)) muscles. The sEMG signals were categorized into three groups based on physiotherapists’ evaluations of deep squat correctness. Methods: The raw sEMG signals were filtering at 10–250 Hz, and then the mean frequency, median frequency, and kurtosis were calculated. Next, the maximum excitation of the muscles expressed in percentage of maximum voluntary contraction (%MVC) and co-activation index (CAI) were estimated. To determine the muscle excitation level, the pulse interference filter and variance analysis of the sEMG signal derivative were applied. Next, analysis of variance (ANOVA) tests, that is, nonparametric Kruskal–Wallis and post hoc tests, were performed. Results: The parameter that most clearly differentiated the groups considered turned out to be %MVC. The statistically significant difference with a large effect size in the excitation of RF & GM (p = 0.0011) and VM & GM (p = 0.0002) in group 3, where the correctness of deep squat execution was the highest and ranged from 85% to 92%, was pointed out. With the decrease in the correctness of deep squat performance, an additional statistically significant difference appeared in the excitation of RF & BF and VM & BF for both groups 2 and 1, which was not present in group 3. However, in group 2, with the correctness of the deep squat execution at 62–77%, the statistically significant differences in muscle excitation found in group 3 were preserved, in contrast to group 1, with the lowest 23–54% correctness of the deep squat execution, where the statistical significance of these differences was not confirmed. Conclusions: The results indicate that sEMG can differentiate muscle activity and provide additional information for physiotherapists when assessing the correctness of deep squat performance. The proposed analysis can be used to evaluate the correctness of physical exercises when physiotherapist access is limited. Full article

Contaminants such as nano-polystyrenes (NPs) and heavy metal cocktail (HMC) have been found to disrupt physiological functions in aquatic organisms. Although HMC and NPs alone induce oxidative stress, their combined effects are not well understood. This study aimed to assess the combined effects of HMC and NPs on the freshwater shrimp (Macrobrachium rosenbergii). Shrimp were divided into seven groups, including the control group, and the experimental groups co-exposed to 0, 50, 100, 150, 200, and 250 µg/L NPs combined with 0.5 mg/L HMC. After 14 days, shrimp were sampled, and their hepatopancreas and muscle tissues were analyzed for oxidative biomarkers, biochemical parameters, and metabolic profiles. Moreover, the bioaccumulation rate of heavy metals was measured. Results showed that co-exposure to NPs and HMC increased superoxide dismutase, glutathione peroxidase, glutathione reductase activities, and malondialdehyde levels, while reducing glutathione and total antioxidant capacity. The integrated biomarker response indicated that co-exposure to HMC and NPs induces oxidative stress. A significant decrease was observed in aspartate aminotransferase, gamma-glutamyl transpeptidase, and alkaline phosphatase activities, glycogen, triglyceride, and total protein levels. However, lactate dehydrogenase activity was significantly increased. Co-exposure to HMC and NPs increased heavy metal bioaccumulation, induced oxidative stress, biochemical changes, and enhanced HMC toxicity in shrimp. Full article

Gynecologic perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms characterized by the co-expression of melanocytic markers (HMB-45 and Melan-A) and smooth muscle markers (SMA, desmin, and caldesmon). The uterus is the most common organ affected, with approximately 110 cases reported worldwide, while occurrences in the cervix, vagina, ovary, and other gynecologic locations are exceptionally rare. These tumors typically present with nonspecific symptoms such as abnormal uterine bleeding and pelvic pain, often mimicking other uterine neoplasms. Histopathologically, PEComas exhibit epithelioid and spindle cell morphology with variable nuclear atypia, mitotic activity, and characteristic immunohistochemical profiles. Although most PEComas behave benignly, a subset demonstrates malignant potential, associated with larger tumor sizes, an increased mitotic index, necrosis, and vascular invasion; however, standardized diagnostic criteria remain scarce. Molecular alterations frequently involve the mTOR signaling pathway through tuberous sclerosis complex (TSC) 1 and TSC2 gene mutations, offering potential targets for therapy. Surgical resection with clear margins remains the cornerstone of treatment. For advanced or metastatic cases, mTOR inhibitors have shown promising efficacy, whereas the role of radiotherapy remains uncertain. This review aims to synthesize current knowledge regarding the epidemiology, clinical presentation, histologic features, malignant potential, and treatment of uterine PEComas, emphasizing the importance of accurate histopathological classification and molecular profiling to guide individualized therapeutic strategies. Full article

Tan sheep outperform Dorper sheep in meat-quality traits, including muscle fiber characteristics and fatty acid composition, while Dorper sheep excel in carcass weight. However, the molecular mechanisms underlying these breed-specific traits, especially gut microbiota–bile acid (BA) interactions, remain poorly understood. As host–microbiota co-metabolites, BAs are converted by colonic microbiota via bile salt hydrolase (BSH) and dehydroxylases into secondary BAs, which activate BA receptors to regulate host lipid and glucose metabolism. This study analyzed colonic BA profiles in 8-month-old Tan and Dorper sheep, integrating microbiome and longissimus dorsi muscle transcriptome data to investigate the gut–muscle axis in meat-quality and carcass trait regulation. Results showed that Tan sheep had 1.6-fold higher secondary BA deoxycholic acid (DHCA) levels than Dorper sheep (p < 0.05), whereas Dorper sheep accumulated conjugated primary BAs glycocholic acid (GCA) and tauro-α-muricholic acid (p < 0.05). Tan sheep exhibited downregulated hepatic BA synthesis genes, including cholesterol 7α-hydroxylase (CYP7A1) and 27-hydroxylase (CYP27A1), alongside upregulated transport genes such as bile salt export pump (BSEP), sodium taurocholate cotransporting polypeptide (NTCP), and ATP-binding cassette subfamily B member 4 (ABCB4), with elevated gut BSH activity (p < 0.05). DHCA was strongly correlated with g_Ruminococcaceae_UCG-014, ENSOARG00000001393, and ENSOARG00000016726, muscle fiber density, diameter, and linoleic acid (C18:2n6t) (|r| > 0.5, p < 0.05). In contrast, GCA was significantly associated with g_Lachnoclostridium_10, g_Rikenellaceae_RC9_gut_group, ENSOARG0000001232, carcass weight, and net meat weight (|r| > 0.5, p < 0.05). In conclusion, breed-specific colonic BA profiles were shaped by host–microbiota interactions, with DHCA potentially promoting meat quality in Tan sheep via regulation of muscle fiber development and fatty acid deposition, and GCA influencing carcass traits in Dorper sheep. This study provides novel insights into the gut microbiota–bile acid axis in modulating ruminant phenotypic traits. Full article

The balanced control of the synthesis of CoQ along the life of the organism is essential to maintain the respiratory capacity at the mitochondria and the antioxidant protection of cell membranes and plasma lipoproteins. For this reason, we determined the levels of the transcripts of the CoQ-synthome along the life of mice in comparison with the levels of antioxidant enzymes and the levels of CoQ in these animals. Surprisingly, we found that some organs such as liver, kidney and heart show great differences in mRNA levels of some COQ-genes along life whereas others such as the brain or gastrocnemius muscle do not show differences. Interestingly, these differences were not related to the total amount of CoQ in these tissues, indicating a discrepancy between the transcript activity of the CoQ-synthome and the level of the product, CoQ. This likely responds to different regulatory levels including mRNA lifespan and CoQ turnover. Further, resveratrol and physical activity in old animals can modulate some transcripts but many of them are in an organ-dependent effect, indicating a different response to the regulators. Full article

Background/Objectives: Asthma, a chronic airway inflammatory disease characterized by bronchial narrowing and caused by an inflammatory response, results in airway obstruction and hyperresponsiveness. Stachydrine (STA), an abundant metabolite found in plants and humans, is recognized for its bioactivity in treating fibrosis, cancer, and inflammation. However, its effects on asthma have not been fully elucidated. We aimed to investigate the ameliorating effects of STA on chronic airway inflammation caused by Dermatophagoides pteronyssinus (house dust mite, HDM). Methods: We used a murine model of HDM-induced airway inflammation to assess the change in metabolite profile by chronic airway inflammation. The mice were challenged with HDM (35 challenges in total) for up to 12 weeks. Serum metabolites were analyzed using capillary electrophoresis time-of-flight mass spectrometry. Results: HDM exposure increased airway hypersensitivity, immune cell infiltration, cytokine production, goblet cell hyperplasia, collagen deposition, and alpha smooth muscle actin and fibronectin expression. Serum metabolite analysis revealed that STA levels were lower in the mice with HDM-induced chronic inflammation than in the controls. In vitro analyses demonstrated that HDM sensitization increased cytokine production (interleukin [IL]-6 and IL-8) and extracellular signal-regulated kinase (ERK) activity. However, STA treatment reduced HDM-induced IL-6 and IL-8 production and ERK activity. Co-treatment with a mitogen-activated protein kinase (MAPK) inhibitor and STA resulted in a more pronounced reduction in cytokine production and MAPK activity. Conclusions: These findings suggest that STA, particularly when used in combination with a MAPK inhibitor, effectively suppresses airway inflammation through ERK pathway inhibition, making it a potential therapeutic agent for asthma treatment. Full article

Background/Objectives: Obesity-related metabolic complications contribute to musculoskeletal disorders and are often associated with muscular fat accumulation. The AMP-activated protein kinase (AMPK) is a therapeutic target that can mitigate these effects. Methods: An in vivo study was conducted to understand the effects of Gryllus bimaculatus (GB), a potent AMPK activator, on metabolic and muscular homeostasis in diet-induced obesity (DIO). Six-week-old male C57BL/6J mice were fed either a normal diet or a high-fat diet (HFD) for eight weeks to induce DIO. Subsequently, HFD-fed mice were divided into four groups: HFD only, HFD with 100 mg/kg/day GB, HFD with 200 mg/kg/day GB, and HFD with 400 mg/kg/day GB for 16 weeks. To assess the effects of GB, we evaluated insulin resistance, muscle strength, muscular fat accumulation, and AMPK activation using an oral glucose tolerance test, grip strength test, histological assessments, serum lipid analyses, western blotting, and quantitative reverse transcription–polymerase chain reaction. Results: The low- and mid-dose GB groups showed a trend toward improved insulin resistance. GB significantly reduced muscle fat accumulation and increased muscle strength. The mid- and high-dose GB groups showed a significantly upregulated expression of the molecular markers of mitochondrial biogenesis and fatty acid oxidation in muscle tissues. Additionally, the high-dose GB group activated AMPK and inhibited the activity of acetyl-CoA carboxylase in the skeletal muscle. Conclusions: The results suggest that GB may serve as a nutraceutical candidate for the management of obesity-associated metabolic complications. Full article

Accurate diagnosis of diseases in patients is crucial, particularly in older individuals, where the focus is often placed primarily on advanced age and its associated symptoms. However, advancements in technology and research have revealed that certain diseases traditionally linked to aging can also manifest in younger populations, demonstrating similar bodily changes. One such condition is sarcopenia, a degenerative disease of skeletal muscle that arises from various pathological processes affecting the tissues. In this study, we developed a liposomal formulation based on 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), in which both nicotinamide mononucleotide (NMN) and Matrigel (Mgel) were co-encapsulated, each playing a distinct role in the management of sarcopenia. NMN is known to stimulate the increase of NAD+ levels, while Matrigel enhances the activity of satellite cells, thereby facilitating muscle fiber regeneration and stabilizing protein levels. Results from the DLS, SEM, and TEM analyses revealed significant differences attributed to the type of therapeutic agent used and the synthesis parameters. Additionally, the drug release profile underscored the complementary nature and significance of selecting the appropriate active substances for effective treatment strategies. The in vitro investigations aimed to assess the potential of DMPC lipid vesicles loaded with NMN, either alone or in combination with Matrigel, to counteract sarcopenia-associated oxidative stress and mitochondrial dysfunction. The results showed that both NMN-based formulations reduced oxidative damage, preserved mitochondrial function, and maintained cytoskeletal integrity in a hydrogen peroxide-induced model of sarcopenia. Importantly, the formulation containing both NMN and Matrigel demonstrated superior protective effects, suggesting a synergistic role of the extracellular matrix components in enhancing muscle cell resilience. These findings support the use of DMPC-based delivery systems as promising candidates for sarcopenia therapy and warrant further investigation into their mechanisms of action in preventing muscle cell degeneration. Full article