Muscle Of Animals Research Articles

Low-temperature vacuum permeation of sodium tripolyphosphate and trehalose suppresses the denaturation of myofibrillar proteins in peeled shrimp (Litopenaeus vannamei) during frozen storage.

Phosphates and trehalose are widely accepted additives in animal muscle products. In this study, the effects of pre-soaking with sodium tripolyphosphate (STPP) and trehalose under vacuum permeation (VP) conditions on the physicochemical properties of shrimp muscle were evaluated over 120 d of frozen storage. The results indicate the STPP/trehalose-VP treatments significantly reduced the thawing loss and prevented changes in the texture, myofibrillar protein (MP) content, and Ca2+-ATPase activity of shrimp muscle during frozen storage compared with results of control and individual STPP or trehalose soaking treatments. The histological structure analysis revealed the permeated STPP/trehalose distinctly inhibited the dissociation of muscle fibers and reduced physical damage to connective tissues during storage. Furthermore, analysis of the thermal properties indicated STPP/trehalose treatment increased the values of shrimp muscle tissues, likely by restricting the mobility of water molecules in muscle tissues and embedding proteins in the glassy matrix. Thus, the physical destruction caused by ice crystal growth was greatly reduced, due to the absence of water molecules around muscle proteins during frozen storage. Accordingly, the combined STPP/trehalose-VP treatment significantly enhanced the stability of frozen shrimp, and the results support the application of traditional cryoprotective additives. The treated shrimp can be stored at comparatively higher temperatures with limited physicochemical reactions during frozen storage.

Вплив холеретичної терапії на активність експресії мікроРНК-378f та м’язову оболонку стінки жовчного міхура

Functional disorders of the gallbladder and sphincter of Oddi in children remain relevant due to their significant percentage in the structure of diseases of the biliary system. One of the options for choleretic therapy is the use of ursodeoxycholic acid. Purpose - to study the effectiveness of choleretic therapy, namely ursodeoxycholic acid, in children with functional disorders of the gallbladder and sphincter of Oddi by determining the activity of microRNA-378f generation and the impact on the cells of the muscular layer of the gallbladder wall. Materials and methods. A comprehensive examination of 70 children with functional disorders of the gallbladder and sphincter of Oddi. To determine the level of expression of microRNA-378f in the serum used the method of real-time polymerase chain reaction. The experimental part of the study was performed on 30 mice. Ultrastructural analysis was performed according to a standard scheme using a transmission electron microscope. Results. Positive dynamics of gallbladder contractility and significant increase in the expression of microRNA-378f in the serum was observed in children with functional disorders of the gallbladder and sphincter of Oddi after a course of ursodeoxycholic acid therapy (p<0.05). After exposure to ursodeoxycholic acid, the mitotic indices of leiomyocytes of the bottom wall and body of the gallbladder were significantly histologically determined compared to intact mice (р˂0.01); there was a probable increase in the nuclear activity of fibroblasts due to decondensation of chromatin and an increase in the number of nuclear pores (p˂0.01); significant increase in the number of Kahal interstitial cells in the muscular layer of the gallbladder of mice was observed (p˂0.01). Conclusions. In children with functional disorders of the gallbladder and sphincter of Oddi during choleretic therapy under the influence of ursodeoxycholic acid there is an increase in decreased contractility of the gallbladder and the level of expression of microRNA-378f in serum. The use of ursodeoxycholic acid causes leiomyocyte hyperplasia and their intracellular ultrastructural changes, increased fibroblast nuclear activity, and an increase in the number of interstitial Kahal interstitial cells of the gallbladder muscle in experimental animals. These morphological changes are likely to increase the contractile function of the gallbladder. The study was conducted in accordance with the principles of the Declaration of Helsinki. The research protocol was approved by the Local Ethics Committee of the institution mentioned in the work. Informed consent of the children’s parents was obtained for the research. The maintenance of experimental animals was carried out in accordance with the sanitary and hygienic norms of the vivarium of the specified institution and was carried out with the permission of the commission on biomedical ethics. The authors declare no conflict of interest.

An insight into farm animal skeletal muscle metabolism based on a metabolomics approach

Farm animal skeletal muscle, formed through development, growth, and maturation processes, is converted to edible meat during postmortem rigor mortis and aging. Live and postmortem muscle metabolism is the phenotypic determinant of muscle characteristics and meat quality traits such as flavor and color. Meanwhile, animal muscle metabolism, originally programmed by genetic program, is modulated by feeding and environmental conditions through changes in the biosynthetic network. Metabolomics deepens our understanding of metabolisms underlying skeletal muscle growth, maturation, abnormality, and postmortem meat aging. The metabolomics approach is beneficial to explore biomarkers to monitor meat production processes and products, leading to improvements in livestock productivity and meat quality. One of the recent metabolomics findings in animal muscle could be the impact of mitochondrial activity and energy metabolisms on meat quality. The present review overviews the advances in metabolomics studies of farm animal skeletal muscle, to gain an insight into the muscle metabolisms associated with livestock production and meat quality.

Applications of Myostatin in Poultry and Aquaculture - A Review

Polymorphism is an important component of animal genetic improvement. As a result, myostatin gene is largely involved in muscle formation and growth and is a great candidate gene for increased growth of muscle in animals. Myostatin negates the growth of muscle cells and is found across species. Literature shows various applications and importance of myostatin in poultry and aquaculture production. In poultry, variations in the myostatin gene have been linked to growth characteristics. In aquaculture, myostatin influences the enhancement of the muscle tissues of fish. Besides, myostatin plays a role in increasing the lipid content of muscle, lowering circulating glucose levels, and hepatosomatic index in fish. Studies on zebrafish as a model species have confirmed myostatin involvement in the muscle development of fish. Its expression is not limited to skeletal muscle but also occurs in the liver, brain, and other organs. In the myostatin-b-deficient zebrafish, the size of visceral adipose tissues shrank, and more lipids have been observed to accumulate in skeletal muscle than in wild-type fish. The inhibition or complete depletion of functional myostatin is known to cause the “double-muscled” in several cattle breeds and similar traits in other species. However, the “double-muscled” animals have captured the attention of breeders and researchers due to the enhanced muscular tissues; associated with productivity issues. For instance, the effect of myostatin inhibition has been associated with egg production. When compared to wild-type, myostatin homozygous mutant birds had a significantly delayed commencement of egg production in layers. It is therefore imperative to increase the knowledge of myostatin molecular genetics and bioactivity in various tissues in the poultry and aquaculture sector. This will enable improved productivity and enhanced contribution of animal-sourced proteins from both sectors of animal production.

Study of the physico-chemical properties of goat meat in order to justify the production of children's food products

The issue of rational nutrition of children is still extremely relevant and an effective factor ensuring the preservation of life and health of children. Pathological conditions associated with intolerance to certain components of food are increasingly common. Biologically complete products play an important role in the organization of rational nutrition of children, which can be created only in industrial production conditions. When assessing the chemical composition of experimental samples of goat meat (Zaanenskaya, Alpine, Nubian), no abnormal deviations were detected, and all indicators were in the generally accepted contents of this type of animal muscle tissue. The mineral composition showed that goat meat is rich in such elements as potassium - 1693.22-4125.83mg/kg; sodium - 852.27-1518 mg/kg, magnesium - 125.33-295.8 mg/kg; calcium - 79.27-160.79 mg/kg, iron 11.42-87.52 mg/kg. The vitamin composition of goat meat showed that the content of pantothenic acid (B5) was 0.53-0.62 mg/100g, pyridoxine (B6) 0.52-0.64 mg/100g tocopherol 0.27-0.33 mg/100g. The indicators of the mass fraction of goat meat proteins were 2.1 ± 0.3- 2.4 ± 0.4 %. The study of the dynamics of changes in the composition of protein fractions based on the results of comparative studies of the ratio of sarcoplasmic proteins showed the content of water-soluble (1.75-4.06 %), salt-soluble (1.75-2.44 %), alkali-soluble (11.15-15.10 %) proteins. The salt-soluble fraction reflects the total changes in the state of protein fractions, the solubility of which was not the same for the rocks under consideration (the highest concentration was determined in the Nubian rock).

PSIII-A-13 Intramuscular fat and Expression of Genes Involved in Lipid Metabolism and Gluconeogenesis in Nellore Bulls fed Snaplage

Abstract We hypothesized that diets with snaplage would increase the expression of lipogenic genes, resulting in higher marbling fat content, compared to a diet of whole-plant silage and reconstituted corn silage. Therefore, the objective of this study was to analyze the chemical composition, as well as the expression of genes involved in lipid metabolism and liver gluconeogenesis of Nellore bulls fed snaplage. Seventy-two Nellore bulls (24 months, initial body weight 400 ±27.4 kg) were used in a completely randomized design. Animals were stratified by body weight, housed in 24 pens (3 animals per pen), and designed to one of the three treatments (8 pens per treatment). Experimental diets (around 14% of crude protein) were: control (corn silage, ground and reconstituted corn grain, protein sources), snaplage + ground corn, replacing completely corn silage (SNAP65, with 65% snaplage), and snaplage 85, replacing completely corn silage and corn grain (SNAP85, with 85% snaplage). Data were analyzed using MIXED procedure of SAS 9.4 with fixed effects of dietary treatment, and random effects of pen nested within treatment. Overall, diets did not affect (P>0.11) the intramuscular fat. However, animals fed SNAP85 showed higher PPARG expression (P=0.03). The muscle of animals fed snaplage (SNAP65 and SNAP85) also had higher expression of ACACA and SCD1 genes (P≤0.03) than the control animals. The FABP4 expression tended to be higher (P=0.10) in the muscle of animals fed SNAP85 compared with SNAP65. In addition, animals fed control diet tended to have higher (P=0.07) expression of PC in the liver compared with animals fed SNAP65 and SNAP85. Also, PEPCK2 expression was lower (P=0.05) in in the liver of animals fed SNAP65 diet than control SNAP85. We conclude that diets with snaplage increased the expression of genes involved in the muscle lipogenesis, without increase intramuscular fat.

Bioaccumulation of Cu, Fe and Zn in Wild Ruminants in Middle Gemer Region

The aim of this study was to monitor trace metals (copper, iron and zinc) concentrations in parenchymatous organs and muscle tissue of red deer (n=23) and roe deer (n=25) that were hunted down in the middle Gemer region in south central Slovakia. Being expressed in mg kg–1 in all cases, these concentrations assumed the following values: mean renal copper concentration in red deer was 4.36, hepatic 19.65, muscle 1.96; renal iron concentration was 72.5, hepatic 131.9, muscle 45.09; mean zinc concentration in kidney was 27.77, in liver 30.22 and in muscle 29.58 , respectively. In roe deer, mean level of copper in kidney was 4.83, in the liver 26.4, in muscle tissue 2.1; mean concentration of iron in kidney was 66.69, in liver 122.83, in muscle tissue 49.07; mean concentration of zinc in kidney was 27.34, in liver 29.76, and in muscle tissue 24.37, respectively. Concentration of metals under study in different age groups showed that the values rose proportionally with age except for zinc concentration, where the highest Zn concentrations were detected in muscle of young animals. In other trace metal levels no significant differences were detected between age groups, males or females. Based on the given results, the Revuca district does not show itself as the most polluted region considering surveyed heavy metals, but nevertheless the presented results document that the presence of heavy metals in the tissues of game is still an interesting object for the next studies.

Roles of MEF2A and MyoG in the transcriptional regulation of bovine LATS2 gene

As an important downstream effector gene in the hippo signaling pathway, large tumor suppressor gene 2 (LATS2) is involved in cell proliferation and differentiation, organ size and tissue regeneration, and plays an important role in regulating the growth and development of animal muscles. The purpose of this study is to explore the temporal expression of bovine LATS2 gene, and determine the key transcription factors for regulating bovine LATS2 gene. The result showed that bovine LATS2 gene was highly expressed in liver and longissimus dorsi, and was up-regulated in infancy muscle. In addition, it was highly expressed on the 2th day during the differentiation stage of myoblast. The upstream 1.7 Kb sequence of the 5 ‘translation region of bovine LATS2 gene was cloned, and 7 different deletion fragments were amplified by the upstream primers. These fragments were constructed into double luciferase reporter vectors and transfected into myoblasts and myotubes cells, respectively to detect the core promoter regions. In addition, the key transcription factors of the core promoter sequence of the bovine LATS2 gene were analyzed and predicted by online software. Combining with site-directed mutations, siRNA interference and chromatin immunoprecipitation technology, it was identified that MEF2A and MyoG combined in core promoter region (−248/−56) to regulate the transcription activity of bovine LATS2 gene. The results have laid a theoretical foundation for exploring the molecular regulation mechanism of LATS2 gene in the process of muscle growth.

The emerging role of circRNAs on skeletal muscle development in economical animals

CircRNAs are a novel type of closed circular molecules formed through a covalent bond lacking a 5′cap and 3′ end tail, which mainly arise from mRNA precursor. They are widely distributed in plants and animals and are characterized by stable structure, high conservativeness in cells or tissues, and showed the expression specificity at different stages of development in different tissues. CircRNAs have been gradually attracted wide attention with the development of RNA sequencing, which become a new research hotspot in the field of RNA. CircRNAs play an important role in gene expression regulation. Presently, the related circRNAs research in the regulation of animal muscle development is still at the initial stage. In this review, the formation, properties, biological functions of circRNAs were summarized. The recent research progresses of circRNAs in skeletal muscle growth and development from economic animals including livestock, poultry and fishes were introduced. Finally, we proposed a prospective for further studies of circRNAs in muscle development, and we hope our research could provide new ideas, some theoretical supports and helps for new molecular genetic markers exploitation and animal genetic breeding in future.

TWIST1, a gene associated with Saethre-Chotzen syndrome, regulates extraocular muscle organization in mouse

Heterozygous loss of function mutations in TWIST1 cause Saethre-Chotzen syndrome, which is characterized by craniosynostosis, facial asymmetry, ptosis, strabismus, and distinctive ear appearance. Individuals with syndromic craniosynostosis have high rates of strabismus and ptosis, but the underlying pathology is unknown. Some individuals with syndromic craniosynostosis have been noted to have absence of individual extraocular muscles or abnormal insertions of the extraocular muscles on the globe. Using conditional knock-out alleles for Twist1 in cranial mesenchyme, we test the hypothesis that Twist1 is required for extraocular muscle organization and position, attachment to the globe, and/or innervation by the cranial nerves. We examined the extraocular muscles in conditional Twist1 knock-out animals using Twist2-cre and Pdgfrb-cre drivers. Both are expressed in cranial mesoderm and neural crest. Conditional inactivation of Twist1 using these drivers leads to disorganized extraocular muscles that cannot be reliably identified as specific muscles. Tendons do not form normally at the insertion and origin of these dysplastic muscles. Knock-out of Twist1 expression in tendon precursors, using scleraxis-cre, however, does not alter EOM organization. Furthermore, developing motor neurons, which do not express Twist1, display abnormal axonal trajectories in the orbit in the presence of dysplastic extraocular muscles. Strabismus in individuals with TWIST1 mutations may therefore be caused by abnormalities in extraocular muscle development and secondary abnormalities in innervation and tendon formation.

Metabolic and structural changes in the myocardium of rats with hypercholesterolemia after prolonged administration of simvastatin

BACKGROUND: The use of statins in cardiovascular pathologies in some cases is associated with the risk of developing statin-induced myopathy, the mechanisms of which are not fully understood. Only a few studies of molecular changes in the myocardium in statin myopathy are presented in the literature. However, the myocardium, as a type of muscle tissue, can also be involved in the pathological process. In this regard, in our opinion, it is advisable to analyze the biochemical changes in the rat myocardium against the background of the use of simvastatin.
 AIM: To analysis of the dynamics of changes in the end products of glycolysis and the isoform composition of the giant protein titin in the heart muscle in animals with experimental hypercholesterolemia on the background of long-term administration of simvastatin.
 MATERIALS AND METHODS: The study was carried out on outbred male rats divided into 3 groups: control group (35 individuals) intact animals; comparison group (35 animals) intact animals treated with simvastatin for two months; experimental group divided into: subgroup 1 (35 individuals) animals with induced alimentary hypercholesterolemia, subgroup 2 (35 individuals) animals with induced alimentary hypercholesterolemia, which were administered simvastatin for two months. During the experiment, the content of the giant sarcomere protein titin, as well as changes in the concentration of pyruvate and lactic acid in the myocardium of the animals of the studied groups were studied.
 RESULTS: In animals with a physiological course of metabolic processes, the administration of simvastatin caused the accumulation of lactic acid in the myocardium. Under conditions of alimentary hypercholesterolemia under the influence of simvastatin, a decrease in the elevated level of pyruvate and lactic acid was revealed, which is obviously due to a decrease in pathobiochemical shifts in energy metabolism. The determination of the isoform composition of titin made it possible to establish that the administration of simvastatin under conditions of alimentary hypercholesterolemia contributed to the appearance of early dystrophic changes in the myocardium, which is consistent with the results of earlier studies of impaired myocardial contractile activity under the influence of statins.
 CONCLUSIONS: The results obtained indicate the need for a more thorough study of statins in terms of their safe use in patients with cardiovascular pathology.

Antidiabetic effects of Psidium x durbanensis Baijnath & Ramcharun ined. (Myrtaceae) leaf extract on streptozotocin-induced diabetes in rats

Ethnopharmacological relevancePsidium guajava L. leaves are used to treat diabetes in South African folkloric medicine and in other parts of the world. Psidium x durbanensis Baijnath & Ramcharun ined. (PD) is a natural sterile hybrid and congener of Psidium guajava that is expected to share the medicinal properties of the genus Psidium and is widely distributed in South Africa.Aim of the study: This study investigates the antioxidant, antidiabetic effects, and mechanisms of action of hydro-methanolic leaf extracts of PD on streptozotocin-induced diabetes in rats. Material and methodsPhytochemical constituents of hydro-methanolic extract of PD were analyzed by gas chromatography-mass spectrometry (GC-MS). Male Wistar rats 250–300 g body weight (BW) were rendered diabetic after a single intraperitoneal injection with streptozotocin, 45 mg/kg BW. The diabetic rats were treated with hydro-methanolic (20:80 v/v) leaf extracts of PD (400 mg/kg/BW) or subcutaneous injections of regular insulin (2.0U/kg/BW, bid) for 56 days. The body weights of the animals were recorded daily. Fasting blood glucose, glucose tolerance tests, and insulin resistance index were measured. The effects of the extracts on total superoxide dismutase, catalase, and reduced glutathione activities, histopathology, and gene expression of insulin receptor substrate 1 and glucose transporter 4 were determined in the liver, pancreas, and gastrocnemius muscles of the rats. ResultsIn the acute toxicity studies, there were no signs of toxicity observed for PD up to 2000 mg/kg BW doses. Diabetic animals showed significant weight loss, elevated and reduced fasting blood glucose and insulin, respectively, impaired glucose tolerance and diminished antioxidant enzymes’ activities compared to controls. Treatment with PD hydro-methanolic leaf extracts improved body weight, glucose tolerance, insulin resistance, and antioxidant enzymes but not plasma insulin in diabetic animals compared to controls, respectively. GC-MS analysis identified organic acids, alcohols, vitamins, terpenoids, and esters in the extracts. Treatment with PD improved glucose uptake by stimulating mRNA expression of GLUT 4 in gastrocnemius muscles of diabetic animals compared to the untreated control and also restored histological aberrations in the pancreas and liver of diabetic rats compared with the untreated control rats. ConclusionCollectively, the present study suggests that treatment with PD leaf extracts significantly ameliorated diabetes symptoms and oxidative stress in rats, and these effects may be linked to the bioactive phytoconstituents present in the plant. This study further suggests that PD improves insulin resistance by increasing glucose uptake in gastrocnemius muscles in an insulin-independent manner.

DETERMINATION OF PESTICIDE RESIDUES IN MUSCLE AND ORGANS OF COW, CAMEL AND GOAT IN BIRNIN KEBBI, KEBBI STATE, NIGERIA

Pesticide residues in muscle and organs of farm animals (cow, camel and goat) were assessed. Samples of muscle (meat), liver, kidney and heart were collected from central abattoirs in the four emirate councils of Kebbi State in order to determine their level of contamination. Residues were extracted from the samples using standard operating procedures and analysed with GC-MS (Intuvo 9000 model) coupled with ECD. Total pesticide residues in the samples ranged from 0.113 to 2.532µg/Kg (muscle), 0.095 to 2.341µg/Kg (liver), 0.047 to 0.931µg/Kg (kidney and 0.026 to 0.361µg/Kg (heart). Pesticide residues concentrations were in the order; muscle > liver > kidney > heart. Analysis of the results obtained also shown that 12.150% of samples from Yauri emirate were contaminated with pesticide residues, 11.249% were contaminated from Argungu, 7.834% from Zuru and 5.784% from B/Kebbi. Samples of muscle and organs from cow accumulated 47.04% of the detected pesticide residues, Camel accumulated 44.48% of the detected residues and goat muscles and organs accumulated 8.48% of the detected pesticide residues. The concentrations of all the assessed pesticides observed in the muscle and organs were however lower than the recommended maximum residual limits (MRLs).

The potential of goat meat as a nutrition source for schoolchildren

The issue of rational nutrition of children is still extremely relevant and an effective factor in ensuring the preservation of the life and health of children. Pathological conditions associated with intolerance to certain components of food are increasingly common. Biologically complete products play an important role in the organization of rational nutrition of children, which can be created only in industrial production conditions. When assessing the chemical composition of experimental goat meat samples (Zaanenskaya, Alpine, Nubian), no abnormal deviations were detected, and all indicators were in the generally accepted contents of this type of animal muscle tissue. The mineral composition showed that goat meat is rich in such elements as potassium – 1693.22 – 4125.83 mg/kg; sodium – 852.27 – 1518 mg/kg, magnesium – 125.33 – 295.8 mg/kg; calcium – 79.27 – 160.79 mg/kg, iron 11.42-87.52 mg/kg. The vitamin composition of goat meat showed that the content of pantothenic acid (B5) was 0.53 – 0.62 mg / 100g, pyridoxine (B6) 0.52 – 0.64 mg/100g tocopherol 0.27 – 0.33 mg/100g. The mass fraction of goat meat proteins was 2.1 ±0.3 – 2.4 ±0.4%. The study of the dynamics of changes in the composition of protein fractions based on the results of comparative studies of the ratio of sarcoplasmic proteins showed the content of water-soluble (1.75 – 4.06%), salt-soluble (1.75 – 2.44%), alkali-soluble (11.15 – 15.10%) proteins. The salt-soluble fraction reflects the total changes in the state of protein fractions, the solubility of which was not the same for the rocks under consideration (the highest concentration was determined in the Nubian rock).

DAF-2/insulin IGF-1 receptor regulates motility during aging by integrating opposite signaling from muscle and neuronal tissues.

During aging, preservation of locomotion is generally considered an indicator of sustained good health, in elderlies and in animal models. In Caenorhabditis elegans, mutants of the insulin‐IGF‐1 receptor DAF2/IIRc represent a paradigm of healthy aging, as their increased lifespan is accompanied by a delay in age‐related loss of motility. Here, we investigated the DAF‐2/IIRc‐dependent relationship between longevity and motility using an auxin‐inducible degron to trigger tissue‐specific degradation of endogenous DAF‐2/IIRc. As previously reported, inactivation of DAF‐2/IIRc in neurons or intestine was sufficient to extend the lifespan of worms, whereas depletion in epidermis, germline, or muscle was not. However, neither intestinal nor neuronal depletion of DAF‐2/IIRc prevented the age‐related loss of motility. In 1‐day‐old adults, DAF‐2/IIRc depletion in neurons reduced motility in a DAF‐16/FOXO dependent manner, while muscle depletion had no effect. By contrast, DAF‐2 depletion in the muscle of middle‐age animals improved their motility independently of DAF‐16/FOXO but required UNC‐120/SRF. Yet, neuronal or muscle DAF‐2/IIRc depletion both preserved the mitochondria network in aging muscle. Overall, these results show that the motility pattern of daf‐2 mutants is determined by the sequential and opposing impact of neurons and muscle tissues and can be dissociated from the regulation of the lifespan. This work also provides the characterization of a versatile tool to analyze the tissue‐specific contribution of insulin‐like signaling in integrated phenotypes at the whole organism level.

DETERMINATION OF PESTICIDE RESIDUES IN MUSCLE AND ORGANS OF COW, CAMEL AND GOAT IN BIRNIN KEBBI, KEBBI STATE, NIGERIA

Pesticide residues in muscle and organs of farm animals (cow, camel and goat) were assessed. Samples of muscle (meat), liver, kidney and heart were collected from central abattoirs in the four emirate councils of Kebbi State. Residues were extracted from the samples using standard operating procedures and analysed with GC-MS (Intuvo 9000 model) coupled with ECD. Total pesticide residues in the samples ranged from 0.113 to 2.532µg/Kg (muscle), 0.095 to 2.341µg/Kg (liver), 0.047 to 0.931µg/Kg (kidney and 0.026 to 0.361µg/Kg (heart). Pesticide residues concentrations were in the order; muscle > liver > kidney > heart. Analysis of the results obtained also shown that 12.150% of samples from Yauri emirate were contaminated with pesticide residues, 11.249% were contaminated from Argungu, 7.834% from Zuru and 5.784% from B/Kebbi. Samples of muscle and organs from cow accumulated 47.04% of the detected pesticide residues, Camel accumulated 44.48% of the detected residues and goat muscles and organs accumulated 8.48% of the detected pesticide residues. The concentrations of all the assessed pesticides observed in the muscle and organs were however lower than the recommended maximum residual limits (MRLs).

MyoBio: An Automated Bioreactor System Technology for Standardized Perfusion-Decellularization of Whole Skeletal Muscle.

Decellularizing solid organs is a promising top-down process to produce acellular bio-scaffolds for 'de novo' regrowth or application as tissue 'patches' that compensate, e.g., large volumetric muscle loss in reconstructive surgery. Therefore, generating standardized acellular muscle scaffolds marks a pressing area of need. Although animal muscle decellularization protocols were established, those are mostly manually performed and lack defined bioreactor environments and metrologies to assess decellularization quality in real-time. To close this gap, we engineered an automated bioreactor system to provide chemical decellularization solutions to immersed whole rat gastrocnemius medialis muscle through perfusion of the main feeding arteries. Perfusion control is adjustable according to decellularization quality feedback. This was assessed both from (i) ex situ assessment of sarcomeres/nuclei through multiphoton fluorescence and label-free Second Harmonic Generation microscopy and DNA quantification, along with (ii) in situ within the bioreactor environment assessment of the sample's passive mechanical elasticity. We find DNA and sarcomere-free constructs after 72 h of 0.1% SDS perfusion-decellularization. Furthermore, passive elasticity can be implemented as additional online decellularization quality measure, noting a threefold elasticity decrease in acellular constructs. Our MyoBio represents a novel and useful automated bioreactor environment for standardized and controlled generation of acellular whole muscle scaffolds as a valuable source for regenerative medicine.

The In Vitro Cytotoxic Effects of Ionophore Exposure on Selected Cytoskeletal Proteins of C2C12 Myoblasts.

Carboxylic ionophores, such as monensin, salinomycin and lasalocid, are polyether antibiotics used widely in production animals for the control of coccidiosis, as well as for the promotion of growth and feed efficiency. Although the benefits of using ionophores are undisputed, cases of ionophore toxicosis do occur, primarily targeting the cardiac and skeletal muscles of affected animals. The 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl tetrazolium bromide (MTT) viability assay was used to determine the cytotoxicity of monensin, salinomycin and lasalocid on mouse skeletal myoblasts (C2C12). Immunocytochemistry and immunofluorescent techniques were, in turn, performed to investigate the effects of the ionophores on the microfilament, microtubule and intermediate filament, i.e., desmin and synemin networks of the myoblasts. Monensin was the most cytotoxic of the three ionophores, followed by salinomycin and finally lasalocid. Monensin and salinomycin exposure resulted in the aggregation of desmin around the nuclei of affected myoblasts. The synemin, microtubule and microfilament networks were less affected; however, vesicles throughout the myoblast’s cytoplasm produced gaps within the microtubule and, to a limited extent, the synemin and microfilament networks. In conclusion, ionophore exposure disrupted desmin filaments, which could contribute to the myofibrillar degeneration and necrosis seen in the skeletal muscles of animals suffering from ionophore toxicosis.

Pentamethylquercetin Regulates Lipid Metabolism by Modulating Skeletal Muscle-Adipose Tissue Crosstalk in Obese Mice.

Irisin is an exercise-induced hormone that regulates lipid metabolism. The present study investigates whether the anti-obesity effect of the natural flavonoid pentamethylquercetin (PMQ) is related to irisin secretion from skeletal muscle in whole animals and cultured cells. Obese mice induced by monosodium glutamate were administered oral PMQ to determine blood irisin level and in vivo parameters of lipid metabolism, and cultured mouse C2C12 myoblasts and 3T3-L1 preadipocytes were employed to investigate the related molecular identities. PMQ increased circulating irisin and decreased bodyweight, insulin, and lipid levels accompanied with increasing brown-like adipocyte formation in obese mice. The brown adipocyte marker uncoupling protein 1 (UCP-1) and other brown-like adipocyte-specific genes and/or markers were increased in mouse white fat tissue, while PMQ treatment reversed the above changes. PMQ also dose-dependently increased the reduced levels of AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), and fibronectin type III domain-containing 5 (FNDC5) signal molecules in obese mice. Interestingly, the irisin level was increased in the culture medium of C2C12 cells treated with PMQ, and the conditioned medium stimulated the brown-like transition of 3T3-L1 preadipocytes with the increased expression of PGC-1α, FNDC5, UCP-1, and other brown-like adipocyte-specific genes. The effects of conditioned culture medium were abolished in C2C12 cells with silenced PGC-1α. On the other hand, PMQ-induced upregulation of PGC-1α and FNDC5 expression was reduced by AMPK inhibitor Compound C in C2C12 cells. Our results demonstrate the novel information that PMQ-induced irisin secretion from skeletal muscle involves the improvement of metabolic dysfunction in obese mice via activating the AMPK/PGC-1α/FNDC5 signal pathway, suggesting that PMQ modulates skeletal muscle-adipose tissue crosstalk and may be a promising drug candidate for treating obesity and obesity-related metabolic diseases.

Genome-Wide Identification and Characterization of Long Non-Coding RNAs in Longissimus dorsi Skeletal Muscle of Shandong Black Cattle and Luxi Cattle.

There is an increasing understanding of the possible regulatory role of long non-coding RNAs (LncRNA). Studies on livestock have mainly focused on the regulation of cell differentiation, fat synthesis, and embryonic development. However, there has been little study of skeletal muscle of domestic animals and the potential role of lncRNA. In this study, the transcriptome numbers of longissimus muscle of different beef cattle (Shandong black catle and Luxi catlle) were used to construct muscle related lncRNAs-miRNA-mRNA interaction network through bioinformatics analysis. This is helpful to clarify the molecular mechanism of bovine muscle development, and can be used to promote animal husbandry and improve animal husbandry production. According to the screening criteria of |FC|≧2 and q < 0.05, a total of 1,415 transcripts (of which 480 were LncRNAs) were differentially expressed (q < 0.05) in the different breeds. Further, we found that the most differentially expressed LncRNAs were found on chromosome 9, in which the differentially expressed LncRNAs targeted 1,164 protein coding genes (MYORG, Wnt4, PAK1, ADCY7,etc) (upstream and downstream<50 Kb). In addition, Pearson’s correlation coefficients of co-expression levels indicated a potential trans regulatory relationship between the differentially expressed LncRNAs and 43844 mRNAs (r > 0.9). The identified co-expressed mRNAs (MYORG, Dll1, EFNB2, SOX6, MYOCD, and MYLK3) are related to the formation of muscle structure, and enriched in muscle system process, strained muscle cell differentiation, muscle cell development, striated muscle tissue development, calcium signaling, and AMPK signaling. Additionally, we also found that some LncRNAs (LOC112444238, LOC101903367, LOC104975788, LOC112441863, LOC112449549, and LOC101907194) may interact with miRNAs related to cattle muscle growth and development. Based on this, we constructed a LncRNAs-miRNA-mRNA interaction network as the putative basis for biological regulation in cattle skeletal muscle. Interestingly, a candidate differential LncRNA (LOC104975788) and a protein-coding gene (Pax7) contain miR-133a binding sites and binding was confirmed by luciferase reporter assay. LOC104975788 may combined miR-133a competitively with Pax7, thus relieving the inhibitory effect of miR-133a on Pax7 to regulate skeletal muscle development. These results will provide the theoretical basis for further study of LncRNA regulation and activity in different cattle breeds.