-
Kidney & Blood Pressure Research May 2024Background Chronic kidney disease (CKD) is a progressive systemic condition characterized by numerous complications. Among these, alterations in skeletal muscle... (Review)
Review
Background Chronic kidney disease (CKD) is a progressive systemic condition characterized by numerous complications. Among these, alterations in skeletal muscle physiology, such as sarcopenia, are particularly significant, as they are associated with poor outcomes and reduced quality of life. Summary Various interventions, including pharmacological approaches and lifestyle modifications have been investigated to slow CKD progression and prevent or treat its complications. Physical exercise, in particular, has emerged as a promising intervention with multiple beneficial effects. These include improvements in physical functioning, increased muscle mass, modulation of metabolic abnormalities, and reduced cardiovascular risk. However, the pathophysiology of physical exercise in patients with kidney disease is complex and remains only partially understood. A crucial advancement in understanding this phenomenon has been the identification of myokines-molecules expressed and released by skeletal muscle in response to physical activity. These myokines can exert both paracrine and systemic effects, influencing not only skeletal muscle physiology but also other processes such as energy metabolism and lipid regulation. Key Messages The interplay among skeletal muscle, physical activity, and myokines may act as a pivotal regulator in various physiological processes, including aging, as well as in pathological conditions like cachexia and sarcopenia, frequently observed in CKD patients at different stages, including patients on dialysis. Despite the potential importance of this relationship, only a limited number of studies have explored the relationship between exercise and myokine, and the effect of this interaction on experimental models or individuals with kidney disease. In the following sections, we review and discuss this topic.
PubMed: 38815556
DOI: 10.1159/000539489 -
Redox Biology May 2024Cysteine, the rate-controlling amino acid in cellular glutathione synthesis is imported as cystine, by the cystine/glutamate antiporter, xCT, and subsequently reduced to...
Cysteine, the rate-controlling amino acid in cellular glutathione synthesis is imported as cystine, by the cystine/glutamate antiporter, xCT, and subsequently reduced to cysteine. As glutathione redox is important in muscle regeneration in aging, we hypothesized that xCT exerts upstream control over skeletal muscle glutathione redox, metabolism and regeneration. Bioinformatic analyses of publicly available datasets revealed that expression levels of xCT and GSH-related genes are inversely correlated with myogenic differentiation genes. Muscle satellite cells (MuSCs) isolated from Slc7a11 mice, which harbour a mutation in the Slc7a11 gene encoding xCT, required media supplementation with 2-mercaptoethanol to support cell proliferation but not myotube differentiation, despite persistently lower GSH. Slc7a11 primary myotubes were larger compared to WT myotubes, and also exhibited higher glucose uptake and cellular oxidative capacities. Immunostaining of myogenic markers (Pax7, MyoD, and myogenin) in cardiotoxin-damaged tibialis anterior muscle fibres revealed greater MuSC activation and commitment to differentiation in Slc7a11 muscle compared to WT mice, culminating in larger myofiber cross-sectional areas at 21 days post-injury. Slc7a11 mice subjected to a 5-week exercise training protocol demonstrated enhanced insulin tolerance compared to WT mice, but blunted muscle mitochondrial biogenesis and respiration in response to exercise training. Our results demonstrate that the absence of xCT inhibits cell proliferation but promotes myotube differentiation by regulating cellular metabolism and glutathione redox. Altogether, these results support the notion that myogenesis is a redox-regulated process and may help inform novel therapeutic approaches for muscle wasting and dysfunction in aging and disease.
PubMed: 38815331
DOI: 10.1016/j.redox.2024.103213 -
PLoS Neglected Tropical Diseases May 2024Photobiomodulation has exhibited promise in mitigating the local effects induced by Bothrops snakebite envenoming; however, the mechanisms underlying this protection are...
BACKGROUND
Photobiomodulation has exhibited promise in mitigating the local effects induced by Bothrops snakebite envenoming; however, the mechanisms underlying this protection are not yet fully understood. Herein, the effectiveness of photobiomodulation effects on regenerative response of C2C12 myoblast cells following exposure to Bothrops jararacussu venom (BjsuV), as well as the mechanisms involved was investigated.
METHODOLOGY/PRINCIPAL FINDINGS
C2C12 myoblast cells were exposed to BjsuV (12.5 μg/mL) and irradiated once for 10 seconds with laser light of 660 nm (14.08 mW; 0.04 cm2; 352 mW/cm2) or 780 nm (17.6 mW; 0.04 cm2; 440 mW/ cm2) to provide energy densities of 3.52 and 4.4 J/cm2, and total energies of 0.1408 and 0.176 J, respectively. Cell migration was assessed through a wound-healing assay. The expression of MAPK p38-α, NF-Кβ, Myf5, Pax-7, MyoD, and myogenin proteins were assessed by western blotting analysis. In addition, interleukin IL1-β, IL-6, TNF-alfa and IL-10 levels were measured in the supernatant by ELISA. The PBM applied to C2C12 cells exposed to BjsuV promoted cell migration, increase the expression of myogenic factors (Pax7, MyF5, MyoD and myogenin), reduced the levels of proinflammatory cytokines, IL1-β, IL-6, TNF-alfa, and increased the levels of anti-inflammatory cytokine IL-10. In addition, PBM downregulates the expression of NF-kB, and had no effect on p38 MAKP.
CONCLUSION/SIGNIFICANCE
These data demonstrated that protection of the muscle cell by PBM seems to be related to the increase of myogenic factors as well as the modulation of inflammatory mediators. PBM therapy may offer a new therapeutic strategy to address the local effects of snakebite envenoming by promoting muscle regeneration and reducing the inflammatory process.
PubMed: 38814992
DOI: 10.1371/journal.pntd.0012227 -
The Turkish Journal of Pediatrics May 2024Due to their relationship with clinical progression, follow-up of exercise capacity and muscle strength is important for optimal disease management in patients who have...
BACKGROUND
Due to their relationship with clinical progression, follow-up of exercise capacity and muscle strength is important for optimal disease management in patients who have undergone the Fontan procedure. We aimed to retrospectively analyze exercise capacity and muscle strength trajectory over approximately 2 years.
METHODS
Exercise capacity was assessed using an exercise stress test with the modified Bruce protocol on a treadmill, hand grip and knee extensor strength using a hand dynamometer, and body composition using a bioelectrical impedance device. Exercise capacity, muscle strength, and body composition follow-up data recorded between 2020 and 2022 were compared.
RESULTS
Fifteen patients [median age from 17 (first assessment) to 18 years (last assessment), 5 females)] with a 20-month median follow-up time were analyzed retrospectively. There was an increase in weight, height, body mass index, and body fat weight (p<0.05). There was a tendency for increased handgrip strength (%) (p=0.069), but no significant difference was observed in the knee extensor strength of patients during the follow-up period (p>0.05). The changes in heart rate (HR) and oxygen saturation were higher in the last test than in the first test (p<0.05). Maximum HR (HRmax), % predicted HRmax and HR reserve recorded during the test and HR 1 minute after the test were similar between the first and last tests (p>0.05).
CONCLUSIONS
After 20 months of follow-up, exercise capacity and muscle strength did not decline; instead, the body mass index and fat weight increased. Patients who have undergone the Fontan procedure may not be experiencing a decline in exercise capacity and muscle strength over relatively short time periods during childhood, adolescence, and early adulthood.
Topics: Humans; Fontan Procedure; Female; Male; Retrospective Studies; Muscle Strength; Adolescent; Follow-Up Studies; Exercise Tolerance; Exercise Test; Hand Strength; Body Composition
PubMed: 38814303
DOI: 10.24953/turkjpediatr.2024.4570 -
The Turkish Journal of Pediatrics May 2024Malnutrition increases the complications and mortality in critically-ill children. We performed a retrospective analysis to define the impact of malnutrition on the...
BACKGROUND
Malnutrition increases the complications and mortality in critically-ill children. We performed a retrospective analysis to define the impact of malnutrition on the outcomes of multisystem inflammatory syndrome in children (MIS-C) due to COVID-19.
METHODS
Patients with MIS-C were evaluated for demographic features, anthropometric parameters, clinical findings and outcomes. Patients with z scores of body mass index (> 5 years) and weight-for-age (< 5 years) < -2 were considered malnourished. Sarcopenia was defined by total psoas muscle area (tPMA), calculated on abdominal computed tomography (CT) at the level of L3 and L4 vertebrae. The z scores <- 2 for tPMA were considered sarcopenia. The results of patients with and without malnutrition were compared.
RESULTS
Twenty-seven patients were included. Forty-four percent (n=12) of patients had malnutrition. Malnutrition was classified as mild to moderate (1/3), severe (1/3) and overweight (1/3). Eighty-two % of cases had acute malnutrition. Among MIS-C symptom criteria, rash was significantly higher in children with malnutrition (p<0.05). Laboratory investigations showed higher ferritin levels in patients with malnutrition (p<0.05). The median tPMA and sarcopenia were significantly higher in patients with malnutrition when compared to patients without malnutrition (42% vs 7%, p<0.05). The oral feeding time, complication rates, and length of hospital stay were similar in both groups (p>0.05).
CONCLUSION
Children with MIS-C already had mild to severe malnutrition at admission. Rash and higher ferritin levels were more common in patients with malnutrition. In addition to anthropometric parameters, sarcopenia calculated using tPMA can be used to predict malnutrition in critically-ill children.
Topics: Humans; COVID-19; Systemic Inflammatory Response Syndrome; Male; Female; Retrospective Studies; Child, Preschool; Child; Malnutrition; SARS-CoV-2; Sarcopenia; Infant; Length of Stay; Turkey
PubMed: 38814301
DOI: 10.24953/turkjpediatr.2024.4586 -
ELife May 2024A new protocol can customize the flavor of lab-grown meat by controlling the level of fat deposited between muscle cells.
A new protocol can customize the flavor of lab-grown meat by controlling the level of fat deposited between muscle cells.
Topics: Taste; Animals; Meat; In Vitro Meat
PubMed: 38813866
DOI: 10.7554/eLife.98918 -
Arteriosclerosis, Thrombosis, and... May 2024Pulmonary hypertension (PH) represents an important phenotype in heart failure with preserved ejection fraction (HFpEF). However, management of PH-HFpEF is challenging...
BACKGROUND
Pulmonary hypertension (PH) represents an important phenotype in heart failure with preserved ejection fraction (HFpEF). However, management of PH-HFpEF is challenging because mechanisms involved in the regulation of PH-HFpEF remain unclear.
METHODS
We used a mass spectrometry-based comparative plasma proteomics approach as a sensitive and comprehensive hypothesis-generating discovery technique to profile proteins in patients with PH-HFpEF and control subjects. We then validated and investigated the role of one of the identified proteins using in vitro cell cultures, in vivo animal models, and independent cohort of human samples.
RESULTS
Plasma proteomics identified high protein abundance levels of B2M (β2-microglobulin) in patients with PH-HFpEF. Interestingly, both circulating and skeletal muscle levels of B2M were increased in mice with skeletal muscle SIRT3 (sirtuin-3) deficiency or high-fat diet-induced PH-HFpEF. Plasma and muscle biopsies from a validation cohort of PH-HFpEF patients were found to have increased B2M levels, which positively correlated with disease severity, especially pulmonary capillary wedge pressure and right atrial pressure at rest. Not only did the administration of exogenous B2M promote migration/proliferation in pulmonary arterial vascular endothelial cells but it also increased PCNA (proliferating cell nuclear antigen) expression and cell proliferation in pulmonary arterial vascular smooth muscle cells. Finally, deletion improved glucose intolerance, reduced pulmonary vascular remodeling, lowered PH, and attenuated RV hypertrophy in mice with high-fat diet-induced PH-HFpEF.
CONCLUSIONS
Patients with PH-HFpEF display higher circulating and skeletal muscle expression levels of B2M, the magnitude of which correlates with disease severity. Our findings also reveal a previously unknown pathogenic role of B2M in the regulation of pulmonary vascular proliferative remodeling and PH-HFpEF. These data suggest that circulating and skeletal muscle B2M can be promising targets for the management of PH-HFpEF.
PubMed: 38813697
DOI: 10.1161/ATVBAHA.123.320270 -
Annals of the Royal College of Surgeons... May 2024Combined vascular malformation affecting the facial region is an extremely rare clinical entity that is debilitating both functionally and emotionally. Treatment...
Combined vascular malformation affecting the facial region is an extremely rare clinical entity that is debilitating both functionally and emotionally. Treatment warrants a multidisciplinary approach with the aim of removing the vascular anomalies and ameliorating any functional facial disfigurement. Here, we present a case of a 40-year-old female with combined vascular malformation of the face who was treated successfully with surgical intervention accompanying significant resolution of facial disfigurement.
PubMed: 38813653
DOI: 10.1308/rcsann.2022.0073 -
Frontiers in Pediatrics 2024The study aims to analyze the clinical characteristics of acute phase of SARS-CoV-2 infection in children aged 0-17 years with the Omicron variant, and summarize the...
OBJECTIVE
The study aims to analyze the clinical characteristics of acute phase of SARS-CoV-2 infection in children aged 0-17 years with the Omicron variant, and summarize the persistent symptoms or new-onset clinical manifestations from 4 to 12 weeks after acute COVID. Explore the association between the vaccination status and SARS-CoV-2 neutralizing antibody levels post infection among preschool-aged children. The comprehensive study systematically describes the clinical characteristics of children infected with SARS-CoV-2, providing a foundation for diagnosis and evaluating long-term COVID in pediatric populations.
METHODS
The study enrolled children who were referred to the Children's Hospital, Capital Institute of Pediatrics, (Beijing, China) from January 10, 2023 to March 31, 2023. Participants were classified as infant and toddlers, preschool, school-age, and adolescent groups. Children or their legal guardians completed survey questionnaires to provide information of previous SARS-CoV-2 infection history, as well as clinical presentation during the acute phase and long-term symptoms from 4 to 12 weeks following infection. Furthermore, serum samples were collected from children with confirmed history of SARS-CoV-2 infection for serological testing of neutralizing antibodies.
RESULTS
The study recruited a total of 2,001 children aged 0-17 years who had previously tested positive for SARS-CoV-2 through nucleic acid or antigen testing. Fever emerged as the predominant clinical manifestation in 1,902 (95.1%) individuals with body temperature ranging from 37.3 to 40.0°C. Respiratory symptoms were identified as secondary clinical manifestations, with cough being the most common symptom in 777 (38.8%) children, followed by sore throat (22.1%), nasal congestion (17.8%), and runnning nose (17.2%). Fatigue (21.6%), headache (19.8%) and muscle-joint pain (13.5%) were frequently reported systemic symptoms in children. The proportion of children with symptoms of SARS-CoV-2 infection varied across age groups. 1,100 (55.0%) children experienced persistent symptoms from 4 to 12 weeks post the acute phase of infection. Trouble concentrating (22.1%), cough (22.1%), and fatigue (12.1%) were frequently reported across age groups in the extended period. A limited number of children exhibited cardiovascular symptoms with chest tightness, tachycardia, and chest pain reported by 3.5%, 2.5%, and 1.8% of children, respectively. Among 472 children aged 3-5 years, 208 children had received two doses of SARS-CoV-2 vaccine at least 6 months prior to infection, and no association was found between the incidence of long-term COVID and pre-infection vaccination statuses among the 3-5 years age groups ( = 1.136, = 0.286).
CONCLUSIONS
In children aged 0-17 years infected with SARS-CoV-2 Omicron variant, fever was the primary clinical manifestation in the acute phase, followed by respiratory symptoms, systemic non-specific and digestive presentations. In particular, respiratory and digestive system symptoms were more frequent in children aged above 6 years. Regarding the long-term symptoms from 4 to 12 weeks post-infection, the most common presentations were concentrating difficulty, cough, and fatigue. The incidence of persistent symptoms of SARS-CoV-2 did not exhibit a significant correlation with vaccination status, which was attributed to the waning efficacy of the vaccine-induced humoral immune response after 6 months.
PubMed: 38813546
DOI: 10.3389/fped.2024.1332020 -
Frontiers in Aging Neuroscience 2024Age-related motor impairments often cause caregiver dependency or even hospitalization. However, comprehensive investigations of the different motor abilities and the...
Age-related motor impairments often cause caregiver dependency or even hospitalization. However, comprehensive investigations of the different motor abilities and the changes thereof across the adult lifespan remain sparse. We, therefore, extensively assessed essential basic and complex motor functions in 444 healthy adults covering a wide age range (range 21 to 88 years). Basic motor functions, here defined as simple isolated single or repetitive movements in one direction, were assessed by means of maximum grip strength (GS) and maximum finger-tapping frequency (FTF). Complex motor functions, comprising composite sequential movements involving both proximal and distal joints/muscle groups, were evaluated with the Action Research Arm Test (ARAT), the Jebsen-Taylor Hand Function Test (JTT), and the Purdue Pegboard Test. Men achieved higher scores than women concerning GS and FTF, whereas women stacked more pins per time than men during the Purdue Pegboard Test. There was no significant sex effect regarding JTT. We observed a significant but task-specific reduction of basic and complex motor performance scores across the adult lifespan. Linear regression analyses significantly predicted the participants' ages based on motor performance scores ( = 0.502). Of note, the ratio between the left- and right-hand performance remained stable across ages for all tests. Principal Component Analysis (PCA) revealed three across all tests that represented dexterity, force, and speed. These components were consistently present in young (21-40 years), middle-aged (41-60 years), and older (61-88 years) adults, as well as in women and men. Based on the three , -means clustering analysis differentiated high- and low-performing participants across the adult life span. The rich motor data set of 444 healthy participants revealed age- and sex-dependent changes in essential basic and complex motor functions. Notably, the comprehensive assessment allowed for generating robust across the adult lifespan. Our data may serve as a reference for future studies of healthy subjects and patients with motor deficits. Moreover, these findings emphasize the importance of comprehensively assessing different motor functions, including dexterity, force, and speed, to characterize human motor abilities and their age-related decline.
PubMed: 38813530
DOI: 10.3389/fnagi.2024.1368052