Muscle Tissue Research Articles

Combination therapy of corylifol A and anamorelin attenuates cachexia by decreasing pro-inflammatory cytokines, inhibiting lipolysis and increasing food intake in a murine colon cancer model

PurposeIn our previous study, we found that corylifol A (CYA), an active component derived from Psoralea corylifolia L, exhibited ameliorating effects on cancer cachexia. Anamorelin (AML), a ghrelin receptor agonist, is the only approved drug for the clinical treatment of cancer cachexia. Here, we checked the combination of CYA and AML on muscle atrophy and fat lipolysis in cancer cachexia mice to explore the possible clinic therapeutic potency of the combination on cancer cachexia.MethodsC26 colon tumor-bearing mice, a well-established animal model of cancer cachexia, were used to evaluate the effects of combined therapy involving CYA and AML on cancer cachexia and compared with those of CYA or AML alone. Histological analysis was performed to assess the changes in gastrocnemius (GAS) muscle tissue and epididymal adipose tissue (eWAT) and the possible involved molecular pathways were explored using western blotting and ELISA.ResultsTreatments of CYA, AML, or CYA+AML all significantly ameliorated the body weight decrease, muscle atrophy as well as fat loss in the tumor-bearing mice. Notably, the ameliorating effects of CYA+AML on fat loss were more significant than CYA or AML alone. The eWAT weight of mice in healthy control, C26 model, C26 +CYA, C26 +AML or C26 +CYA +AML group was 0.48 ± 0.07, 0.21 ± 0.10, 0.26 ± 0.10, 0.37 ± 0.10 and 0.48 ± 0.18 g, respectively. CYA+AML could increase food intake, significantly decrease the serum levels of inflammatory cytokines (TNF-α and IL-6) and inhibit the activation (phosphorylation) of hormone-sensitive lipase (HSL) in the eWAT tissues of the C26 tumor-bearing mice. Treatment of CYA along could significantly decrease the serum TNF-α level of the C26 tumor-bearing mice. Treatment of AML alone could increase food intake but could not decrease the serum levels of inflammatory cytokines of the C26 tumor-bearing mice.ConclusionThese results suggested that the effects of CYA+AML include both the appetite-stimulating effects of AML and the anti-inflammatory effects of CYA. CYA+AML was better than CYA or AML alone in ameliorating cancer cachexia, especially fat loss, of C26 tumor-bearing mice and might be a novel and beneficial therapeutic option for cancer cachexia.

Multimodal three-dimensional characterization of murine skeletal muscle micro-scale elasticity, structure, and composition: Impact of dysferlinopathy, Duchenne muscular dystrophy, and age on three hind-limb muscles

Skeletal muscle tissue function is governed by the mechanical properties and organization of its components, including myofibers, extracellular matrix, and adipose tissue, which can be modified by the onset and progression of many disorders. This study used a novel combination of quantitative micro-elastography and clearing-enhanced three-dimensional (3D) microscopy to assess 3D micro-scale elasticity and micro-architecture of muscles from two muscular dystrophies: dysferlinopathy and Duchenne muscular dystrophy, using male BLA/J and mdx mice, respectively, and their wild-type (WT) controls. We examined three muscles with varying proportions of slow- and fast-twitch myofibers: the soleus (predominantly slow), extensor digitorum longus (EDL; fast), and quadriceps (mixed), from BLA/J and WTBLA/J mice aged 3, 10, and 24 months, and mdx and WTmdx mice aged 10 months. Both dysferlin deficiency and age reduced the elasticity and variability of elasticity of the soleus and quadriceps, but not EDL. Overall, the BLA/J soleus was 20% softer than WT and less mechanically heterogeneous (−14% in standard deviation of elasticity). The BLA/J quadriceps at 24 months was 72% softer than WT and less mechanically heterogeneous (−59% in standard deviation), with substantial adipose tissue accumulation. While mdx muscles did not differ quantitatively from WT, regional heterogeneity was evident in micro-scale elasticity and micro-architecture of quadriceps (e.g., 11.2 kPa in a region with marked pathology vs 3.8 kPa in a less affected area). These results demonstrate differing biomechanical changes in hind-limb muscles of two distinct muscular dystrophies, emphasizing the potential for this novel multimodal technique to identify important differences between various myopathies.

Fullerene C60 Decreases Inflammation, Oxidative Stress and Apoptosis Induced by 7,12-Dimethylbenz[a]Anthracene (DMBA) in Muscle Tissue Via Caspase-3 and NRF-2 Protein Signaling Pathway

Fullerene C60 Decreases Inflammation, Oxidative Stress and Apoptosis Induced by 7,12-Dimethylbenz[a]Anthracene (DMBA) in Muscle Tissue Via Caspase-3 and NRF-2 Protein Signaling Pathway

Harvester selection and observed mercury levels in Eastern Beaufort Sea and Western Hudson Bay beluga whales (Delphinapterus leucas)

Mercury in marine biota has been extensively studied across Inuit Nunaat because it bioaccumulates and biomagnifies in high trophic level species, such as the beluga whale (Delphinapterus leucas), or qilalugaq in Inuktut. Qilalugaait (pl) are a staple in many coastal Inuit communities, including Tuktoyaktuk, Northwest Territories and Arviat, Nunavut. We examine how total mercury (THg) concentrations in two beluga populations are influenced by biased sampling resulting from local harvester preferences. We examined historical THg in skin, muscle, and liver (1980's to 2022) together with local qualitative interviews from two beluga-harvesting communities. Age and length bins were used to compare similar sized and aged whales between locations, where males (350 - 400 cm, and 20–30 years) and females (330–400 cm, and 15–30 years) were segregated. The interviews revealed distinct preferences whereby harvesters in Tuktoyaktuk actively sought larger (length) male whales, whereas harvesters in Arviat, selected wide and even range across size and sex. These local preferences were also evident in the historical dataset, with the median age and lengths were 31 years and 389.0 cm in Tuktoyaktuk (n = 461) and 23 and 336.0 cm in Arviat (n = 146). For males, mean and median THg concentrations were higher in beluga harvested from Tuktoyaktuk than Arviat in all three tissues with age and lengths combined, yet in the selected age and length bins, there was no difference in mean and median THg in the muscle tissue, and in median liver THg. There were significant differences in mean and median skin THg and in mean liver THg concentrations between males. In female whales, THg concentrations did not differ between Tuktoyaktuk and Arviat (in ages and lengths combined and in selected age bins across all tissues), excluding median muscle THg concentration. This study indicated that differences in THg concentrations that were previously observed resulted from hunter preferences in these two communities.

External validation of a deep learning model for automatic segmentation of skeletal muscle and adipose tissue on abdominal computed tomography images.

Body composition assessment using computed tomography (CT) images at the L3-level is increasingly applied in cancer research. Robust high-throughput automated segmentation is key to assess large patient cohorts and to support implementation of body composition analysis into routine clinical practice. We trained and externally validated a deep learning neural network (DLNN) to automatically segment L3-CT images. Expert-drawn segmentations of visceral and subcutaneous adipose tissue (VAT/SAT) and skeletal muscle (SM) of L3-CT-images of 3,187 patients undergoing abdominal surgery were used to train a DLNN. The external validation cohort was comprised of 2,535 patients with abdominal cancer. DLNN performance was evaluated with (geometric) Dice Similarity (DS) and Lin's Concordance Correlation Coefficient. There was a strong concordance between automatic and manual segmentations with median DS for SM, VAT, and SAT of 0.97 (interquartile range, IQR: 0.95-0.98), 0.98 (IQR: 0.95-0.98), and 0.95 (IQR: 0.92-0.97), respectively. Concordance correlations were excellent: SM 0.964 (0.959-0.968), VAT 0.998 (0.998-0.998), and SAT 0.992 (0.991-0.993). Bland-Altman metrics indicated only small and clinically insignificant systematic offsets; SM radiodensity: 0.23 hounsfield units (0.5%), SM: 1.26 cm2.m-2 (2.8%), VAT: -1.02 cm2.m-2 (1.7%), and SAT: 3.24 cm2.m-2 (4.6%). A robustly-performing and independently externally validated DLNN for automated body composition analysis was developed. CT-based body composition analysis is highly prognostic for long-term overall survival in oncology. This DLNN was succesfully trained and externally validated on several large patient cohorts and will therefore enable large scale population studies and implementation of body composition analysis into clinical practice.

Benefits of chest wall mobilization on respiratory efficiency and functional exercise capacity in people with severe chronic obstructive pulmonary disease (COPD): A randomized controlled trial.

Coexistence of chest wall hypomobility and lung hyperinflation compromises respiratory muscle function and respiratory efficiency in people with severe chronic obstructive pulmonary disease (COPD). This study aimed to investigate the effect of chest wall mobilization on functional exercise capacity, respiratory muscle activity and respiratory muscle tissue oxygen saturation for people with severe COPD. Thirty male adults (age: 75 ± 6) diagnosed with severe COPD completed a 6-week programme (twice/week) according to intervention randomization (chest wall mobilization group, CWMG, n = 15; control group, CG, n = 15). Both groups received standardized education and walking exercise, while CWMG also received chest wall and thoracic spine mobilization. Electromyography of the essential and accessory respiratory muscles and tissue oxygen saturation of the intercostal muscle (StO2, measured by near-infrared spectroscopy) during incremental cycle exercise test were measured and compared between the two groups at pre-programme, post-programme and 3-month follow-up. Patients in CWMG demonstrated a significant increase in exercise tolerance from <3 METS to 4-6 METS (p = 0.000) after intervention. A significant decrease in activity of scalene, sternocleidomastoids and intercostal muscle during exercise test (p < 0.01) was found in CWMG, as compared to CG. A significant decrease in StO2 (p < 0.05) and greater decline in the slope of oxygenation dissociation (p = 0.000) were seen in CWMG during exercise test. These positive results were maintained at 3-month follow-up in CWMG. Improvements in exercise tolerance, respiratory muscle efficiency and oxygenation extraction ability in CWMG suggest a potential clinical benefit of integrating chest wall and thoracic spine mobilization for rehabilitation of people with severe COPD.

Pre- and post-skeletal muscle biopsy quantitative magnetic resonance imaging reveals correlations with histopathological findings.

Quantitative muscle magnetic resonance imaging (MRI) is a promising non-invasive method in the diagnostic workup as well as follow-up of neuromuscular disorders. The aim of this study was to correlate quantitative MRI (qMRI) parameters to histopathological changes in skeletal muscle tissue and thus to verify the data from our pilot study. Twenty-six patients (eight females, 46.4 ± 15.1 years) were examined within 72 h before and within 24 h after a skeletal muscle biopsy using quantitative muscle MRI. Post-biopsy MRI was employed to pinpoint the exact localization of the biopsy. qMRI parameters including fat fraction, water T2 relaxation time and diffusion metrics including fractional anisotropy, mean diffusivity, axial diffusivity and radial diffusivity were extracted from the localization of the biopsy and correlated with histopathological findings. Additionally, three different segmentation masks were applied to the qMRI dataset, to evaluate whether the whole muscle represents the exact biopsy location. Fat fraction and water T2 relaxation time in qMRI correlated significantly with the fat fraction in the muscle biopsy and histopathological inflammatory markers. Fractional anisotropy correlated with the quantity of type 2 fibres, whilst mean diffusivity correlated with p62. No differences were found using different segmentation masks in qMRI. In this follow-up study, the results from our previous study were verified regarding the correlation of qMRI parameters with histopathological features in muscle biopsies, indicating that qMRI serves as a suitable non-invasive method in the follow-up of patients with neuromuscular disorders. If post-biopsy MRI is not available, whole muscle volume can be used for histopathological correlations.

Abstract B002: Tumor-secreted PTHrP facilitates pancreatic cancer cachexia by regulation of de novo lipogenesis pathway

Abstract Pancreatic cancer is associated with one of the highest and most severe forms of cancer- associated cachexia amongst solid tumors. In an effort to further our understanding of the molecular etiology of pancreatic cancer-associated cachexia, we have developed mouse models to study adipose tissue wasting during Pancreatic Ductal Adenocarcinoma (PDAC) progression. In these pursuits, we have identified a pro-cachectic factor, PTHrP, that is produced and secreted by PDAC tumor cells and directly signals to adipocytes to facilitate wasting. Genetic deletion and pharmacological inhibition of PTHrP significantly extended the survival of tumor-bearing animals and dramatically reduced cachectic phenotypes in these animals, manifesting as decreased adipose and muscle tissue wasting. Mechanistic studies have shown crosstalk between tumor-cell derived PTHrP and adipose tissue PTH1R that drives the cachectic phenotype. Finally, bulk RNA sequencing analysis in PTHrP-driven cachectic models point towards a role for reduced de novo lipogenesis and adipogenesis in cachectic adipose depots, suggesting potential rewiring of the metabolic profile of white adipose tissue in tumor-bearing mice with higher PTHrP expression. Citation Format: Nikita Bhalerao, Jessica Peura, Yamini Ogoti, Calvin Johnson, Qingbo Chen, Ekaterina Korobkina, Faith Keller, Maximillan Wengyn, Robert Norgard, Richard Kremmer, Emma Watson, Marcus Ruscetti, David Guertin, Jason R Pitarresi. Tumor-secreted PTHrP facilitates pancreatic cancer cachexia by regulation of de novo lipogenesis pathway [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B002.

Full genomic profiling of gene expression in selected muscle tissue biopsy specimens from myofascial pain syndrome (pilot comparison of muscle biopsy transcriptomes)

Introduction. Myofascial pain syndrome (MFPS) is one of the most frequent musculoskeletal pathologies causing chronic pain. This type of pain reaches the peak of prevalence in middle-aged individuals, women are affected 2,5 times more often than men. The disease leads to significant disability and is not only a medical but also a social problem. At the same time, a number of authors still note the low clinical efficacy of the applied therapy schemes. In this situation, further study of the pathogenesis of MFPS, in particular, genetic aspects of realization of this condition.The aim of the study was to perform full genomic profiling of gene expression (transcriptome study) in selected muscle tissue biopsy specimens of individual patients and control individuals.Materials and methods. To study the genetic aspects of MFPS realization, gene expression profiling in muscle tissue samples by full genome RNA sequencing (RNA-Seq) was performed in 5 patients suffering from myofascial brachial pain syndrome (2 patients with active form of MFPS, 3 — with latent form).Results. The transcriptome analysis of muscle tissue samples from the MFPS area revealed a statistically significant 6-10-fold increase in the expression of the ENSG00000148677:ANKRD1 (ankyrin repeat domain 1) gene in the subgroup of patients with latent form of MFPS compared to active form of MFPS.Conclusion. The results of the studies allowed to suggest that one of the factors of the latent form of MFPS realization may be adaptive hyperexpression of the gene encoding ANKRD1 protein, which regulates myofibrils tension, myoblasts differentiation, lipid metabolism, affects the development of neuronal connections.

One Copy Number Variation within the Angiopoietin-1 Gene Is Associated with Leizhou Black Goat Meat Quality.

The ANGPT1 gene plays a crucial role in the regulation of angiogenesis and muscle growth, with previous studies identifying copy number variations (CNVs) within this gene among Leizhou black goats. In this study, we investigated three ANGPT1 CNVs in 417 individuals of LZBG using quantitative PCR (qPCR), examining the impact of different CNV types on the ANGPT1 gene expression and their associations with growth and meat quality traits. Notably, the ANGPT1 CNV-1 (ARS1_chr14:24950001-24953600) overlaps with protein-coding regions and conserved domains; its gain-of-copies genotype (copies ≥ 3) was significantly correlated with ANGPT1 mRNA expression in muscle tissue (p < 0.01). Furthermore, the gain-of-copies genotype of CNV-1 demonstrated significant correlations with various phenotypic traits, including carcass weight, body weight, shear stress, chest circumference, and cross-sectional area of longissimus dorsi muscle. These findings indicate that the CNV-1 gain-of-copies genotype in the ANGPT1 gene may serve as a valuable marker for selecting Leizhou black goats exhibiting enhanced growth and muscular development characteristics, thereby holding potential applications in targeted breeding programs aimed at improving meat quality.

Orbital Adipose Tissue: The Optimal Control for Back-Table Fluorescence Imaging of Orbital Tumors.

Control tissue is essential for ensuring the precision of semiquantitative analysis in back-table fluorescence imaging. However, there remains a lack of agreement on the appropriate selection of control tissues. To evaluate the back-table fluorescence imaging performance of different normal tissues and identify the optimal normal tissue, a cohort of 39 patients with orbital tumors were enrolled in the study. Prior to surgery, these patients received indocyanine green (ICG) and following resection, 43 normal control tissues (34 adipose tissues, 3 skin tissues, 3 periosteal tissues, and 3 muscle tissues) were examined using back-table fluorescence imaging. The skin tissue demonstrated significantly elevated fluorescence intensity in comparison to the diseased tissue, whereas the muscle tissue exhibited a broad range and standard deviation of fluorescence signal intensity. Conversely, the adipose and periosteum displayed weak fluorescence signals with a relatively consistent distribution. Additionally, no significant correlations were found between the signal-to-background ratio (SBR) of adipose tissue and patients' ages, genders, weights, disease duration, tumor origins, dosing of administration of ICG infusion, and the time interval between ICG infusion and surgery. However, a positive correlation was observed between the SBR of adipose tissue and its size, with larger adipose tissues (>1 cm) showing an average SBR 27% higher than smaller adipose tissues (≤1 cm). In conclusion, the findings of this study demonstrated that adipose tissue consistently exhibited homogeneous hypofluorescence during back-table fluorescence imaging, regardless of patient clinical variables or imaging parameters. The size of the adipose tissue was identified as the primary factor influencing its fluorescence imaging characteristics, supporting its utility as an ideal control tissue for back-table fluorescence imaging.

Comparative Study of Nutritional Composition, Physiological Indicators, and Genetic Diversity in Litopenaeus vannamei from Different Aquaculture Populations.

This study aimed to evaluate the quality and genetic diversity of farmed Litopenaeus vannamei across three distinct populations from Maoming City (MM), Zhanjiang City (ZJ), and Yangjiang City (YJ) in Guangdong Province. Muscle tissues from L. vannamei were analyzed for phenotypic traits, conventional nutrients, amino acids, and fatty acids, while genetic diversity was assessed using whole genome sequencing techniques. The analysis revealed that the crude protein content in shrimp across the three populations ranged from 20.87 to 21.95 g/100 g, crude fat content ranged from 0.90 to 1.50 g/100 g, essential amino acid content ranged from 5.55 to 5.86 g/100 g, total amino acid content ranged from 14.73 to 15.27 g/100 g, total fatty acid content ranged from 682.73 to 793.97 mg/100 g, total antioxidant capacity (T-AOC) ranged from 2.68 to 2.72 μmol/g, superoxide dismutase (SOD) activity ranged from 1021.97 to 1057.21 U/g, and catalase (CAT) activity ranged from 78.65 to 81.33 μmoL/min. No significant differences were observed in ash and crude fat levels among conventional nutrients, nor in the biochemical indexes T-AOC, CAT, and SOD. Genetic analysis showed that the single nucleotide polymorphism density (SNP/Kb) ranged from 15.323 to 17.461, nucleotide diversity (π) ranged from 2.98 × 10-5 to 15.84 × 10-5, polymorphism information content (PIC) ranged from 0.300 to 0.317, heterozygosity (Ho) ranged from 0.033 to 0.048, and inbreeding coefficients (FIS) ranged from 0.834 to 0.887. The genetic differentiation index (FST) values among the three populations ranged from 0.056 to 0.106. This study provides an evaluation of the germplasm resources and genetic diversity of farmed L. vannamei, offering insights for the efficient management and sustainable utilization of this species' germplasm resources.

Multi-Residue Analysis of Thyreostats in Animal Muscle Tissues by Hydrophilic Interaction Liquid Chromatography Tandem Mass Spectrometry: A Thorough Chromatographic Study

Τhyreostats (TSs) are veterinary drugs used in livestock farming for fattening. Their administration is banned in the European Union since 1981, and their monitoring for food quality and safety control requires sensitive and confirmatory methods. The present study describes the development and validation of a hydrophilic interaction liquid chromatography tandem mass spectrometry (HILIC-MS/MS) method for the simultaneous determination of 2-thiouracil (TU), 6-methyl-2-thiouracil (MTU), 6-propyl-2-thiouracil (PTU), 6-phenyl-2-thiouracil (PhTU), tapazole (TAP), and 2-mercaptobenzimidazole (MBI) in bovine muscle tissues. Investigation of the retention mechanism of the six analytes on the selected amide-based stationary phase showed that hydrophilic partition was the dominant interaction. The sample preparation included extraction with ACN/H2O (80/20), followed by dispersive solid-phase extraction (d-SPE) with C18 sorbent and hexane partitioning. The method was validated according to European guidelines using internal standards, including isotopically labelled ones. The method’s LODs ranged between 2.8 ng g−1 (6-phenyl-2-thiouracil) and 4.1 ng g−1 (2-thiouracil). Application of the proposed method to 48 bovine tissue samples showed non-detectable results.

Targeted Gene Delivery to Muscle Cells In Vitro and In Vivo Using Electrostatically Stabilized DNA—Peptide Complexes

Genetic constructs must be delivered selectively to target tissues and intracellular compartments at the necessary concentrations in order to achieve the maximum therapeutic effect in gene therapy. Development of targeted carriers for non-viral delivery of nucleic acids into cells, including those in muscle, which is one of the most challenging tissues to transfect in vivo, remains a topical issue. We have studied ternary complexes of plasmid DNA and an arginine–histidine-rich peptide-based carrier coated with a glutamate–histidine-rich polymer bearing skeletal muscle targeting peptide (SMTP) for the gene delivery to muscle tissue. The relaxation of the ternary complexes after polyanion treatment was assessed using the ethidium bromide displacement assay. The developed polyplexes were used to transfect C2C12 myoblasts in full-media conditions, followed by analysis of their toxic properties using the Alamar Blue assay and expression analysis of lacZ and GFP reporter genes. After delivering plasmids containing the GFP and lacZ genes into the femoral muscles of mdx mice, which are model of Duchenne muscular dystrophy, GFP fluorescence and β-galactosidase activity were detected. We observed that the modification of ternary polyplexes with 10 mol% of SMTP ligand resulted in a 2.3-fold increase in lacZ gene expression when compared to unmodified control polyplexes in vivo. Thus, we have demonstrated that the developed DNA/carrier complexes and SMTP-modified coating are nontoxic, are stable against polyanion-induced relaxation, and can provide targeted gene delivery to muscle cells and tissues. The results of this study are useful for a range of therapeutic applications, from immunization to amelioration of inherited neuromuscular diseases.

PSXIII-30 Using conventional and slow-growing broilers to determine differences in early life developmental physiology of muscle and adipose tissue

Abstract Optimizing growth and body composition while maintaining health, welfare, and meat quality challenges the broiler industry. The objective of this study is to identify molecular pathways in developing adipose and muscle that underlie differential growth rate and body composition in broiler chickens. A conventional (Cobb700) line and a slow-growing (RedBro) line were compared with lines that represent divergent growth and body composition within the context of commercial broiler genetics. Eggs (n = 60) from each line were obtained from commercial hatcheries and incubated until embryonic d 17 (E17), or until hatch and raised to 5 (D 5) or 10 d (D 10) of age. At each age, breast muscle (BM) and subcutaneous (SQ) fat pad (n = 10) were collected, weighed, and snap frozen. Neck and abdominal (ABD) fat pads (n = 10) were collected at D 10 and D 14. Adipocyte size at E17 and D 10 was determined in H&amp;E-stained tissue sections using ImageJ. T-tests were used to compare body and tissue weights and adipocyte size between lines (α = 0.05). RNA (n = 5 tissue -1ּ age-1 / /age) from adipose and breast was isolated for transcriptomic analyses using 3’ RNAseq. Raw reads were mapped to the chicken genome (bGalGal1.mat.broiler.GRCg7b). Differentially expressed genes (DEGs; fdr P-value &amp;lt; 0.1) were identified using the R package DEseq2 R (version 4.3.1). Sets of DEGs were analyzed for functional annotation using Database for Annotation, Visualization, and Integrated Discovery (david.ncifcrf.gov). Body weight was significantly heavier in Cobb vs. Redbro chicks at each age (P &amp;lt; 0.05). The most notable differences in relative tissue weight occurred for adipose (SQ) at E17 and D5, and for BM at D 10. Relative fat pad weight (SQ) was significantly greater in Cobb vs. Redbro at E17 and D5. In the embryo, this difference was associated with larger adipocytes, suggesting increased capacity for energy storage in fast-growing broilers. In contrast, at D5, Cobb exhibited a significant increase in abundance of small adipocytes, indicating a shift towards adipocyte hyperplasia and/or enhanced mobilization of stored energy post-hatch. Differences in adiposity and adipocyte size were associated with 103 and 153 DEGs at E17 and D5, respectively. These gene sets were enriched in various growth-related functions, including tissue morphogenesis, peptide transport, and mitogenesis. Relative breast weight diverged significantly at D 10, with heavier BM in Cobb chicks. The set of 278 DEGs at this age were enriched in multiple GO categories related to lipid metabolism (16% of genes) and protein metabolism. Although relative breast muscle weight did not differ at E17, 362 DEGs were identified at this age, and were enriched in functions related to skeletal muscle development (n = 43) and mitogenesis, among others. In conclusion, these results identify both phenotypic and transcriptomic differences that underlie, and in some cases precede, divergent growth in broiler chickens. Further investigation is required to determine how these differences affect mature body composition.

280 AntagomiR-22-3p Injection alters miRNA expression and muscle fiber type of intrauterine growth restricted lambs

Abstract microRNAs (miRNA) are small non-coding RNAs that modulate muscle satellite cell proliferation. Previous research identified miR-22-3p as differentially expressed during ovine muscle development and in vitro experiments showed that antagomir-22-3p treatment enhanced satellite cell proliferation. The objective of this study was to test in vivo vascular injection of antagomir-22-3p in lateral saphenous vein on miRNA and HDAC family mRNA expression in intrauterine growth restricted lambs. Pregnant ewes (n = 18) with twins were either fed at 100% of NRC (CON) or nutrient restricted (60% NRC; NR) from gestational d 85 to parturition. On d 12 of age, NR lambs (n = 8) were randomly selected and given a systemic injection of antagomir-22-3p in the lateral saphenous vein of the right leg (MIR-NR). CON lambs (n = 8) were also randomly selected and given a sham injection of PBS in the lateral saphenous vein of the right leg (SHAM-CON). Antagomir-22-3p was reconstituted in phosphate buffered saline (PBS). Injections were given for 3 consecutive days and lambs harvested 24 d later. Blood samples were collected from each lamb weekly to monitor miR-22-3p expression. Lambs were slaughtered 24 d after the first injection and muscle mass measured. Muscle samples were removed for miR-22-3p and mRNA expression of potential targets. Cell-free circulating RNA was isolated from blood samples and miR-22-3p expression examined over time. Cell-free circulating miR-22-3p expression was downregulated (P &amp;lt; 0.05) for MIR-NR compared with SHAM-CON on d 14 after injection. On d 21 after injection, miR-22-3p expression in plasma tended (P = 0.08) to be down-regulated in MIR-NR compared with SHAM-CON. Lamb body weight and muscle weights at harvest were similar between MIR-NR and SHAM-CON treatments. In heart and semimembranosus (SM) muscles, expression of miR-22-3p was down-regulated (P &amp;lt; 0.05) in MIR-NR compared with SHAM-CON. In the gastrocnemius and semitendinosus muscle, miR-22-3p expression was unchanged (P &amp;gt; 0.05). The number of type I and IIa muscle fibers were greater (P &amp;lt; 0.05) for MIR-NR than SHAM-CON. Muscle fiber area of Type I, IIa or IIx fibers did not differ (P &amp;gt; 0.05) by treatment. The number of type IIx fibers did not differ (P &amp;gt; 0.05) between treatments. MIR-NR treatment appears to shift muscle fibers towards more oxidative metabolism and down-regulate HDAC-1, 3, and 11 and SIRT6 in SM. The systemic injection of antagomir-22-3P down-regulated miR-22-3p expression in circulation and in muscle tissues, which altered expression of HDAC/SIRT genes involved in muscle fiber type conversion and hypertrophy.

Biochemical responses of crayfish exposed to imidacloprid: assessment of oxidative stress, osmoregulatory response and neurotoxicity

ABSTRACT Among the nicotinoid insecticides, imidacloprid (IMI) may affect non-target invertebrates like aquatic crustaceans by entering the aquatic environment through rainfall. Nevertheless, there are not sufficient studies on the toxicity mechanism of IMI in crayfish. Here, we investigated the effects of IMI on oxidative stress, osmoregulatory, and neurotoxicity biomarkers. The 96-hour lethal concentration value (96 h-LC50) of IMI was determined to be 0.932 mg AI L−1. Four concentrations of IMI (0.932, 0.466, 0.233 and 0.117 mg AI L−1) were applied to crayfish for 96 h. Na+/K+-ATPase, Mg2+-ATPase, Ca2+-ATPase, and total ATPase activities had almost significantly concentration-related inhibition in both gill and muscle tissues (p < 0.05). Compare with control in hepatopancreas, the activities of GST, SOD and GPx were increased, while the activities of AChE, CES and GR were decreased (p < 0.05). As non-enzymatic parameters, a statistically significant (p < 0.05) increase in MDA levels and a decrease in GSH levels were observed in the hepatopancreas compared to the control group, which was not related to the concentration. In conclusion, it can be said that the study's biomarkers are highly helpful and that commercially consumed crayfish are a significant non-target organism in the assessment of IMI toxicity.

Treatment of chronic ruptures and defects of the Achilles tendon

Achilles tendon ruptures that are older than 4-6weeks or developed over amore extended period are chronic. Two challenges characterize the treatment. First, defect zones over alength of several centimeters must frequently be bridged. Second, aprolonged loss of function of the muscles leads to an irreversible fatty degeneration of the tissue. So that even if the tendon is restored, significant functional deficits remain. If there are doubts about the ability of the calf muscles to regenerate, regardless of the size of the defect, tendon transfers are recommended to use the power of an additional muscle to support the plantar flexion of the ankle. Established concepts are the transposition of the flexor hallucis longus or the peroneus brevis muscle. If the muscle is intact, defects of up to 2 cm can be treated with adirect suture. Defects between 2and 5 cm can be bridged using aVY-plasty or aturndown flap. For larger defects, free tendon transplants can be considered. The technical alternative for larger defects is atendon transfer of the flexor hallucis longus or the peroneus brevis muscle. Besides bridging the defect, another advantage of tendon transfer is that vital muscle tissue is placed in the bed of the Achilles tendon. Both tendons are covered with muscle tissue over nearly the full length, which offers advantages, especially in patients with critical soft tissue or after infection. Follow-up treatment is analogous to an acute Achilles tendon rupture. However, permanent impairments are possible; 75-80% of athletes regain their original performance level.

Localization and Tissue Tropism of Ostreid Herpesvirus 1 in Blood Clam Anadara broughtonii.

OsHV-1 caused detrimental infections in a variety of bivalve species of major importance to aquaculture worldwide. Since 2012, there has been a notable increase in the frequency of mass mortality events of the blood clam associated with OsHV-1 infection. The pathological characteristics, tissue and cellular tropisms of OsHV-1 in A. broughtonii remain unknown. In this study, we sought to investigate the distribution of OsHV-1 in five different organs (mantle, hepatopancreas, gill, foot, and adductor muscle) of A. broughtonii by quantitative PCR, histopathology and in situ hybridization (ISH), to obtain insight into the progression of the viral infection. Our results indicated a continuous increase in viral loads with the progression of OsHV-1 infection, reaching a peak at 48 h or 72 h post-infection according to different tissues. Tissue damage and necrosis, as well as colocalized OsHV-1 ISH signals, were observed primarily in the connective tissues of various organs and gills. Additionally, minor tissue damage accompanied by relatively weak ISH signals was detected in the foot and adductor muscle, which were filled with muscle tissue. The predominant cell types labeled by ISH signals were infiltrated hemocytes, fibroblastic-like cells, and flat cells in the gill filaments. These results collectively illustrated the progressive alterations in pathological confusion and OsHV-1 distribution in A. broughtonii, which represent most of the possible responses of cells and tissues to the virus.

281 Changes in satellite cell number in maternal and fetal muscle with 5-hydroxy tryptophan supplementation during late gestation

Abstract Toxic tall fescue contains ergot alkaloids, which induce vasoconstriction in livestock, leading to fescue toxicosis. This condition can impact muscle development due to altered blood flow. Supplementation with 5-HTP may counteract the vasoconstrictive effects of fescue alkaloids. We aimed to investigate the influence of 5-HTP supplementation on satellite cells, myoblast, and preadipocyte numbers in maternal and fetal muscle during late gestation in Suffolk ewes. We hypothesized that 5-HTP supplementation would mitigate the effects of fescue toxicosis on muscle cell populations, potentially promoting muscle development and regeneration in maternal and fetal tissues. Suffolk ewes (n = 75), naïve to toxic tall fescue, were blocked by body condition score and body weight into 10 groups for synchronization. Ewes were confirmed pregnant using transabdominal ultrasound, and lamb number was estimated at gestational day (gd) 60. Pregnant ewes carrying twins (n = 30) were randomly assigned to one of three treatments: 1) negative control (CON, n = 10), 2) toxic tall fescue seed containing 1.77 mg ewe-1ּ d-1 ergovaline/ergovalinine plus 5-HTP (2.5 mg/kg BW) supplement (5HTP, n = 10), or 3) positive control, fed toxic tall fescue seed containing 1.77 mg ewe-1ּ d-1 ergovaline/ergovalinine (E+, n = 10). Ewes were individually fed a total mixed ration from gd 78 to gd 85 of pregnancy and then TMR plus treatment (CON, E+ or 5HTP) from gd 86 to d 111. On gd 112, terminal necropsies were performed, and semimembranosus muscle (SM) from the ewe and fetus was removed. Weights were obtained, and then samples were digested using pronase (1.5mg/mL) to isolate preadipocyte (PP1), myoblasts (PP2) and satellite cell (PP3) fractions using a pre-plating technique. Cells were quantified using a Neubauer-hemocytometer and trypan blue to also assess cell viability and changes in cell number. Fetal SM had a greater (P &amp;lt; 0.05) number of pre-adipocytes, myoblasts, and satellite cells per gram of tissue digested in comparison with the ewes. Pre-adipocyte and myoblast number per gram of tissue digested did not differ (P &amp;gt; 0.05) by treatment. The 5HTP group had the greater (P &amp;lt; 0.05) number of satellite cells per gram of tissue digested in comparison with the CON group. Satellite cell numbers tended (P &amp;lt; 0.10) to be greater in the 5HTP group in comparison to the E+ group. Satellite cell numbers from CON and E+ treatment groups did not differ (P &amp;gt; 0.05). In conclusion, 5-HTP supplementation during late gestation in Suffolk ewes exposed to toxic tall fescue significantly increased satellite cell numbers in maternal and fetal muscle tissues. This suggests a potential mitigation of the impact of fescue toxicosis on muscle cell populations.