Clinical trials with treatments inhibiting myostatin pathways to increase muscle mass are currently ongoing in spinal muscular atrophy. Given evidence of potential myostatin pathway downregulation in Spinal Muscular Atrophy (SMA), restoring sufficient myostatin levels using disease-modifying treatments (DMTs) might arguably be necessary prior to considering myostatin inhibitors as an add-on treatment. This retrospective study assessed pre-treatment myostatin and follistatin levels\' correlation with disease severity and explored their alteration by disease-modifying treatment in SMA. We retrospectively collected clinical characteristics, motor scores, and mysotatin and follistatin levels between 2018 and 2020 in 25 Belgian patients with SMA (SMA1 (n = 13), SMA2 (n = 6), SMA 3 (n = 6)) and treated by nusinersen. Data were collected prior to treatment and after 2, 6, 10, 18, and 30 months of treatment. Myostatin levels correlated with patients\' age, weight, SMA type, and motor function before treatment initiation. After treatment, we observed correlations between myostatin levels and some motor function scores (i.e., MFM32, HFMSE, 6MWT), but no major effect of nusinersen on myostatin or follistatin levels over time. In conclusion, further research is needed to determine if DMTs can impact myostatin and follistatin levels in SMA, and how this could potentially influence patient selection for ongoing myostatin inhibitor trials.

Cuticle quality can affect food safety by protecting poultry eggs from bacterial infection in the modern poultry industry. However, genetic factors related to cuticle nanostructure are not much reported due to limited bird models. In the current study, the genome-edited quail targeting myostatin (MSTN) gene was used to investigate the effect of MSTN mutation on the cuticle nanostructure and quality. To analyze nanostructure of the cuticle layer of the MSTN mutant and wild-type (WT) quail eggs, scanning electron microscope (SEM) images was taken. Thickness of the cuticle layer did not differ between the MSTN mutant and WT groups, but the size of the nanospheres in the surface of the cuticle layer was increased by MSTN mutation. In addition, increased size of the nanospheres in the MSTN mutant group was also shown in the upper region of the cross-sectional cuticle layer. Notably, both groups showed similar small-sized nanospheres in the lower region of the cuticle layer and the size was increased as they ascended to the upper region. The data suggested that MSTN mutation increased the size of the nanosphere in the upper region of the cuticle layer at a late phase rather than increasing the size of nanospheres in the lower region of the cuticle layer at an early phase of cuticle formation. However, the number of Escherichia coli attached to the surface did not differ between the two groups indicating no association between nanosphere size and bacterial attachment in quail eggs. The current study demonstrated a new function of the MSTN gene on regulation of cuticle nanostructure, for the first time. These results advanced our knowledge on the association between genetic factors and cuticle nanostructure and can be served as a reference to study the mechanism of cuticle formation in the future study.

This study aimed to evaluate the influence of combined intermittent fasting (IF) and high-intensity interval training (HIIT) on morphology, caspase-independent apoptosis signaling pathway, and myostatin expression in soleus and gastrocnemius (white portion) muscles from healthy rats. Sixty-day-old male Wistar rats (n = 60) were divided into four groups: control (C), IF, high-intensity-interval training (T), and high-intensity-interval training and intermittent fasting (T-IF). The C and T groups received ad libitum chow daily; IF and T-IF received the same standard chow every other day. Animals from T and T-IF underwent a HIIT protocol five times a week for 12 weeks. IF reduced gastrocnemius mass and increased pro-apoptotic proteins apoptosis-inducing factor (AIF) and endonuclease G (EndoG) in soleus and cleaved-to-non-cleaved PARP-1 ratio and myostatin expression in gastrocnemius white portion. HIIT increased AIF and apoptosis repressor with caspase recruitment domain expression in soleus and cleaved-to-total PARP-1 ratio in gastrocnemius muscle white portion. The combination of IF and HIIT reduced fiber cross-sectional area in both muscles, increased EndoG and AIF expression, and decreased cleaved-to-non-cleaved PARP-1 ratio in gastrocnemius muscle white portion. Muscle responses to IF and HIIT are directly impacted by the muscle fiber type composition and are modulated, at least in part, by myostatin and caspase-independent apoptosis signaling.

Chronic kidney disease (CKD) is linked to an elevated risk of malnutrition and sarcopenia, contributing to the intricate network of CKD-related metabolic disorders. Adipokines and myokines are markers and effectors of sarcopenia and nutritional status. The aim of this study was to assess whether the adipokine-myokine signature in patients on kidney replacement therapy could help identify malnutrition and sarcopenia. The study involved three groups: 84 hemodialysis (HD) patients, 44 peritoneal dialysis (PD) patients, and 52 kidney transplant recipients (KTR). Mean age was 56.1 ± 16.3 years. Malnutrition was defined using the 7-Point Subjective Global Assessment (SGA) and the Malnutrition-Inflammation Score (MIS). Sarcopenia was diagnosed based on reduced handgrip strength (HGS) and diminished muscle mass. Concentrations of adipokines and myokines were determined using the enzyme-linked immunosorbent assay (ELISA). 32.8% of all study participants were identified as malnourished and 20.6% had sarcopenia. For malnutrition, assessed using the 7-Point SGA, in ROC analysis albumin (area under the curve (AUC) 0.67 was the best single biomarker identified. In dialysis patients, myostatin (AUC 0.79) and IL-6 (AUC 0.67) had a high discrimination value for sarcopenia, and we were able to develop a prediction model for sarcopenia, including age, albumin, adiponectin, and myostatin levels, with an AUC of 0.806 (95% CI: 0.721-0.891). Adipokines and myokines appear to be useful laboratory markers for assessing malnutrition and sarcopenia. The formula we propose could contribute to a better understanding of sarcopenia and potentially lead to more effective interventions and management strategies for dialysis patients.

BACKGROUND: Brown adipose tissue (BAT) is a thermogenic tissue that uncouples oxidative phosphorylation from ATP synthesis and increases energy expenditure via non-shivering thermogenesis in mammals. Cold exposure and exercise have been shown to increase BAT and browning of white adipose tissue (WAT) in mice. This study aimed to determine whether there is an additive effect of exercise during cold exposure on markers related to browning of adipose tissue. in Wistar rats.
METHODS: Twenty-four male Wistar rats were randomly divided into three groups: Control (C, 25˚C), Swimming in Neutral (SN, 30˚C) water, and Swimming in Cold (SC, 15˚C) water. Swimming included intervals of 2-3 min, 1 min rest, until exhausted, three days a week for six weeks, with a training load of 3-6% body weight. After the experimental protocol, interscapular BAT and inguinal subcutaneous white adipose tissue (WAT) were excised, weighed, and processed for beiging marker gene expression.
RESULTS: SN and SC resulted in lower body weight gain, associated with reduced WAT and BAT volume and increased BAT number with greater effects observed in SC. Myostatin protein expression was lower in BAT, WAT, soleus muscle, and serum NC and SC compared to the C group. Expression of the interferon regulatory factor-4 (IRF4) gene in both BAT and WAT tissues was significantly greater in the SC than in the C. Expression of the PGC-1α in BAT was significantly increased in the SC compared to C and increased in WAT in NC and SC. Expression of the UCP1 in BAT and WAT increased in the SC group compared to other groups.
CONCLUSIONS: The findings demonstrate that six weeks of swimming training in cold water promotes additive effects of the expression of genes and proteins involved in the browning process of adipose tissue in Wistar rats. Myostatin inhibition may possess a regulator effect on the PGC-1α - UCP1 pathway that mediates adipose tissue browning.

Tibetan sheep are vital to the ecosystem and livelihood of the Tibetan Plateau; however, traditional breeding methods limit their production and growth. Modern molecular breeding techniques are required to improve these traits. This study identified a single nucleotide polymorphism (SNP) in myostatin (MSTN) and Callipyge in Tibetan sheep. The findings indicated notable associations between MSTN genotypes and growth traits including birth weight (BW), body length (BL), chest width (ChW), and chest circumference (ChC), as well as a particularly strong association with cannon circumference (CaC) at 2 months of age. Conversely, Callipyge polymorphisms did not have a significant impact on Tibetan sheep. Moreover, the analyses revealed a significant association between sex and BW or hip width (HW) at 2 months of age and ChW, ChC, and CaC at 4 months of age. Furthermore, the study\'s results suggested that the genotype of MSTN as a GA was associated with a notable sex effect on BW, while the genotype of Callipyge (CC) showed a significant impact of sex on CaC at 2 months of age. These results indicated that the SNP of MSTN could potentially serve as a molecular marker for early growth traits in Tibetan sheep.

OBJECTIVE: Insertion and deletion (indel) analysis of CRISPR-Cas guide RNAs (gRNAs) is crucial in gene editing to assess gRNA efficiency and indel frequency. This study evaluates the utility of CRISPResso2 with Oxford Nanopore sequencing data (nCRISPResso2) for gRNA indel screening, compared to two common Sanger sequencing-based methods, TIDE and ICE. To achieve this, sheep and horse fibroblasts were transfected with Cas9 and a gRNA targeting the myostatin (MSTN) gene. DNA was subsequently extracted, and PCR products exceeding 600 bp were sequenced using both Sanger and Nanopore sequencing. Indel profiling was then conducted using TIDE, ICE, and nCRISPResso2.
RESULTS: Comparison revealed close correspondence in indel formation among methods. For the sheep MSTN gRNA, indel percentages were 52%, 58%, and 64% for TIDE, ICE, and nCRISPResso2, respectively. Horse MSTN gRNA showed 81%, 87%, and 86% edited amplicons for TIDE, ICE, and nCRISPResso2. The frequency of each type of indel was also comparable among the three methods, with nCRISPResso2 and ICE aligning the closest. nCRISPResso2 offers a viable alternative for CRISPR-Cas gRNA indel screening, especially with large amplicons unsuitable for Illumina sequencing. CRISPResso2\'s compatibility with Nanopore data enables cost-effective and efficient indel profiling, yielding results comparable to common Sanger sequencing-based methods.

The aims of current investigation were to study the growth performance, carcass traits, meat quality and expression profile of Myostatin (MSTN), Insulin-like growth factor-1 (IGF-I), Myogenin (MyoG) and Myogenic regulatory factor 4 (MRF4) genes in three commercial broiler strains including Ross (Ross 308), Cobb (Cobb 500), and Arian in 2023. A total number of 240 one-day-old chicks were reared under an equalized standard management condition for 6 weeks. Performance, organ weights, meat quality and the expression level of the myogenic genes in the pectoral muscle were investigated. The lowest body weight (BW), feed intake, weight gain and highest feed conversion ratio (FCR) was observed for Arian at the end of the study. The meat quality was similar between strains. The IGF-I expression level was significantly higher on 42 days of age in Cobb compared to Ross and Arian. The MRF4 expression level was significantly higher on 28 days of age in Cobb compared to Ross. The MyoG expression level was significantly lower in Arian compared to Cobb on 42 days of age. Furthermore, the MSTN expression level was significantly lower in Cobb compared to Ross and Arian on 42 days of age. The remarkable differences in gene expression levels at the end of the rearing period was supported by higher growth performance and BW of Cobb compared to Ross and Arian strains. In conclusion, the findings of current study could conveniently help assess the performance of these broiler strains under similar rearing condition.

UNASSIGNED: Exercise-induced cytokines involved in controlling body composition include myostatin (MST) and follistatin (FST), both of which are influenced by physical activity. This study investigated changes in body composition and physical activity during a weight loss program, as well as the impact on serum MST and FST levels at various weight loss rates.
UNASSIGNED: A total of 126 patients with obesity who completed a 6-month weight loss program were divided into three groups based on weight loss rate (%): low (< 3%), middle (3-10%), and high (≥10%). The International Physical Activity Questionnaire was used for assessing physical activity, whereas dual X-ray absorptiometry was used to determine body composition. Serum MST and FST levels were measured using the enzyme-linked immunosorbent assay.
UNASSIGNED: The middle and high groups showed a significant decrease in percent body fat and a significant increase in percent lean body mass and physical activity. Serum MST levels increased significantly in all three groups, although FST levels reduced significantly only in the middle group. After adjusting for sex and body composition, changes in peak oxygen intake (β = -0.359) and serum FST levels (β = -0.461) were identified as independent factors for the change in MST levels in the low group. Sex (β = -0.420) and changes in MST levels (β = -0.525) were identified as independent factors for the change in serum FST levels in the low group, whereas in the high group, sitting time (β = -0.600) during the weight loss program was identified as an independent factor for change in serum FST levels.
UNASSIGNED: Serum MST levels in patients with obesity increased significantly following the weight loss program, independent of weight loss rate. In contrast, serum FST levels reduced significantly only in the 3-10% weight loss group. These findings indicate that MST and FST secretion dynamics may fluctuate in response to physical activity, while also reflecting feedback regulation of body composition and metabolism during weight reduction.

Skeletal muscle growth is an economically important trait in the cattle industry. Secreted muscle-derived proteins, referred to as myokines, have important roles in regulating the growth, metabolism, and health of skeletal muscle in human and biomedical research models. Accumulating evidence supports the importance of myokines in skeletal muscle and whole-body health, though little is known about the potential presence and functional significance of these proteins in cattle. This study evaluates and confirms that secreted proteins acidic and rich in cysteine (SPARC), fibroblast growth factor 21 (FGF-21), myostatin (MSTN), and decorin (DCN) are expressed and SPARC, FGF-21, and DCN are secreted by primary bovine satellite cells from 3- (BSC3; n = 3) and 11- (BSC11; n = 3) month -old commercial angus steers. Cells were cultured and collected at zero, 12, 24, and 48 hours to characterize temporal expression and secretion from undifferentiated and differentiated cells. The expression of SPARC was higher in the undifferentiated (p = 0.04) and differentiated (p = 0.07) BSC11 than BSC3. The same was observed with protein secretion from undifferentiated (p <0.0001) BSC11 compared to BSC3. Protein secretion of FGF-21 was higher in undifferentiated BSC11 (p < 0.0001) vs. BSC3. DCN expression was higher in differentiated BSC11 (p = 0.006) vs. BSC3. Comparing undifferentiated vs. differentiated BSC, MSTN expression was higher in differentiated BSC3 (p ≤ 0.001) for 0, 12, and 24 hours and in BSC11 (p ≤ 0.03) for 0, 12, 24, and 48 hours. There is also a change over time for SPARC expression (p ≤ 0.03) in undifferentiated and differentiated BSC and protein secretion (p < 0.0001) in undifferentiated BSC, as well as FGF-21 expression (p = 0.007) in differentiated BSC. This study confirms SPARC, FGF-21, and DCN are secreted, and SPARC, FGF-21, MSTN, and DCN are expressed in primary bovine muscle cells with age and temporal differences.