Relationship of oxidative stress in skeletal muscle with obesity and obesity-associated hyperinsulinemia in horses

In horses, hyperinsulinemia and insulin resistance (insulin dysregulation) are associated with the development of laminitis. Although obesity is associated with insulin dysregulation, the mechanism of obesity-associated insulin dysregulation remains to be established. We hypothesized that oxidative stress in skeletal muscle is associated with obesity-associated hyperinsulinemia in horses. Thirty-five light breed horses with body condition scores (BCS) of 3/9 to 9/9 were studied, including 7 obese, normoinsulinemic (BCS ≥ 7, resting serum insulin < 30 μIU/mL) and 6 obese, hyperinsulinemic (resting serum insulin ≥ 30 μIU/mL) horses. Markers of oxidative stress (oxidative damage, mitochondrial function, and antioxidant capacity) were evaluated in skeletal muscle biopsies. A Spearman’s rank correlation coefficient was used to determine relationships between markers of oxidative stress and BCS. Furthermore, to assess the role of oxidative stress in obesity-related hyperinsulinemia, markers of antioxidant capacity and oxidative damage were compared among lean, normoinsulinemic (L-NI); obese, normoinsulinemic (O-NI); and obese, hyperinsulinemic (O-HI) horses. Increasing BCS was associated with an increase in gene expression of a mitochondrial protein responsible for mitochondrial biogenesis (estrogen-related receptor alpha, ERRα) and with increased antioxidant enzyme total superoxide dismutase (TotSOD) activity. When groups (L-NI, O-NI, and O-HI) were compared, TotSOD activity was increased and protein carbonyls, a marker of oxidative damage, decreased in the O-HI compared to the L-NI horses. These findings suggest that a protective antioxidant response occurred in the muscle of obese animals and that obesity-associated oxidative damage in skeletal muscle is not central to the pathogenesis of equine hyperinsulinemia.     

Preventive effect of zinc against cadmium-induced oxidative stress in the rat testis

The aim of this study was to investigate the antioxidant role of zinc (Zn) in the Cd-exposed testes of Wistar rats. Subchronic exposure to Cd (CdCl(2), 40 mg/l, per os) for 30 days resulted in a significant reduction in growth rate (-11%) and relative weights of testes (-36%) and seminal vesicles (-80%). Treated rats displayed a decrease in testicular and plasma testosterone levels, respectively (-70%, P<0.05; -48%, P<0.05), epididymal sperm count (-22%, P<0.05), and spermatozoa motility (-35%, P<0.05). In contrast, Cd increased the malondialdehyde (+46%, P<0.05), metallothionein (+200%, P<0.05), and 8-oxodGuo concentrations (+71%, P<0.05) in the testis. In the gonad, Cd decreased the GPx (-30%, P<0.05), CAT (-32%, P<0.05), mitochondrial Mn-SOD (-34%, P<0.05), and cytosolic CuZn-SOD (-32%, P<0.05) activities. Zinc supplementation (ZnCl(2), 40 mg/l, per os) in the Cd-exposed rats restored the activities of GPx, CuZn-SOD, and Mn-SOD in the testes to the levels of the control group. Moreover, zinc administration was capable of reducing the elevated levels of malondialdehyde in the testis. Interestingly, zinc supplementation attenuated DNA oxidation induced by Cd in the gonad and restored the testosterone level and sperm count to the levels of the control group. Zinc administration minimized oxidative damage and reversed the impairment of spermatogenesis and testosterone production induced by Cd in the rat testis.     

Role of the antioxidants in the protection against oxidative stress in cattle--nonenzymatic mechanisms (Part 2)

Antioxidative status consists of two mechanisms: nonenzymatic and enzymatic mechanisms. Nonenzymatic mechanisms are composed of antioxidants, scavengers of free radicals, transition metal ions, sequester transition metal ions, albumins, ceruloplasmin, and metallothioneins. On the other hand, enzymatic mechanisms are composed of superoxide dismutase (SOD), peroxidase, catalase and reductase. In cattle, characteristics of these mechanisms depend on the nutritional status of anti-oxidant minerals, especially copper, zinc, iron, selenium, silicon, and manganese. The nutritional status of the cattle in different regions of the world and in Poland is often characterised by the lack of these minerals; therefore, there is a great potential for changes in the activity of defence mechanisms against free radicals.     

太子参茎叶对断乳仔猪抗氧化和抗应激能力的影响

试验旨在研究太子参茎叶对断乳仔猪抗氧化和抗应激能力的影响。将60头杜-长-大断乳仔猪,随机分为4组,每组3个重复,每个重复5头。空白对照组饲喂基础日粮,试验组分别在基础日粮中添加0.5%、1%和1.5%的太子参茎叶粉,分别于50日龄和70日龄采血,检测血清抗氧化和抗应激指标。结果显示,太子参茎叶添加组试验猪与空白对照组相比,血清中MDA含量显著降低,GSH-Px和SOD活性显著升高,T3、T4和皮质醇含量显著升高。结果表明,太子参茎叶能够显著提高断乳仔猪抗氧化和抗应激能力。     

Role of antioxidants in the protection against oxidative stress in cattle--trace elements and enzymatic mechanisms (Part 3)

The most important enzymatic mechanisms which protect an organism against oxidative stress are superoxide dismutase (SOD), peroxidase (Px), e.g. glutathione peroxidase (GSH-Px) and ascorbate peroxidase, catalase and glutathione reductase. Their activity depends on many trace elements. Enzymatic mechanisms, functioning under physiological conditions, prevent the spread of free radical reactions. New and reoccurring metabolic and infectious diseases of cattle emerge when there is a disproportion in the balance between reactive oxygen species and antioxidative enzymatic barrier.     

Overview of horse body composition and muscle architecture: implications for performance

Locomotion requires skeletal muscle to sustain and generate force. A muscle's force potential is proportional to its weight. Since the larger the muscle the larger its potential power output, a better understanding of the proportion of skeletal muscle a horse possesses may lead to a better understanding of horse performance. Several techniques exist to assess body composition, which include dual energy X-ray absorption, underwater (hydrostatic) weighing, derivation from total body water, bio-electric impedance, air displacement, body condition scoring, cadaver dissection and ultrasound. The relevance of each method to the equine industry will be discussed as will the practical information that the existing horse body composition studies have provided. Attention will be given to the data regarding the implications of body composition on the performance horse. The limited number of studies discussing different varieties of muscle architectures and the functional importance of these muscles will also be addressed. These body composition data may provide a better understanding of important issues in horse care that can lead to more optimal horse care techniques and a healthier and safer environment for horses.     

Genetic immunisation of cattle against bovine herpesvirus 1: glycoprotein gD confers higher protection than glycoprotein gC or tegument protein VP8

Bovine herpesvirus 1 (BoHV-1) has frequently been used as a model for testing parameters affecting DNA immunisation in large animals like cattle. However, the selection of target antigens has been poorly studied, and most of the experiments have been conducted in mice. In the present study, we demonstrated in cattle that a DNA vaccine encoding BoHV-1 glycoprotein gD induces higher neutralising antibody titres than vaccines encoding BoHV-1 gC. Additionally, we show that a DNA vaccine encoding a secreted form of gD induces a higher immune response than a vaccine encoding full-length gD. However, the enhanced immunogenicity associated with the secretion of gD could not be extended to the glycoprotein gC. The current study also describes for the first time the development and the evaluation of a DNA vaccine encoding the major tegument protein VP8. This construct, which is the first BoHV-1 plasmid vaccine candidate that is not directed against a surface glycoprotein, induced a high BoHV-1 specific cellular immunity but no humoral immune response. The calves vaccinated with the constructs encoding full-length and truncated gD showed a non-significant tenfold reduction of virus excretion after challenge. Those calves also excreted virus for significantly (p < 0.05) shorter periods (1.5 days) than the non-vaccinated controls. The other constructs encoding gC and VP8 antigens induced no virological protection as compared to controls. Altogether the DNA vaccines induced weaker immunity and protection than conventional marker vaccines tested previously, confirming the difficulty to develop efficient DNA vaccines in large species.     

Embryo vaccination of specific-pathogen-free chickens with infectious bursal disease virus: tissue distribution of the vaccine virus and protection of hatched chickens against disease

Vaccination of specific-pathogen-free chickens as 18-day embryos with the BVM isolate of infectious bursal disease virus (IBDV) resulted in extensive replication of the vaccine virus in the embryonic tissues. The virus was recovered from lung, thymus, proventriculus, liver, kidney, and spleen of embryos 1 day postvaccination, and recoverable virus persisted for at least 7 days. Replication and spread of the vaccine virus in chickens vaccinated as 18-day embryos was compared with that in chickens vaccinated at hatch. Distribution of the virus in tissues was more extensive, virus levels in tissues were generally higher, and detectable virus persisted longer in chickens vaccinated as 18-day embryos than in those vaccinated at hatch. Effective vaccine response could be initiated with 6.2 median embryo lethal doses, the lowest dose tested. Chickens immunized as embryos developed neutralizing antibody against IBDV and resisted challenge with pathogenic IBDV at 4, 6, 8, and 10 weeks of age.     

Development of a toxin-binding agent as a treatment for tunicaminyluracil toxicity: protection against tunicamycin poisoning of sheep

Objective To assess the ability of certain derivatives of beta-cyclodextrin to treat sheep affected by tunicaminyluracil toxicity, using tunicamycin poisoning as a model system.
Design Controlled treatment trial.
Animals One hundred and sixty Merino wethers were used in the studies.
Procedure Groups of sheep were experimentally poisoned with tunicamycin. Derivatives of beta-cyclodextrin, with or without magnesium sulphate and magnesium gluconate, were administered to treatment groups daily for 2 to 3 days. Treatment groups were compared with untreated groups in terms of survival.
Results A significant increase in survival was observed following treatment of tunicamycin-affected sheep with hydroxypropyl-beta-cyclodextrin (HPb -CD) and magnesium sulphate in solution (P < 0.05). In subsequent trials, formula tion of the cyclodextrin in the form of a magnesium gluconate gel suspension demonstrated significant protection (P < 0.01) and was equally as effective as the cyclodextrin in solution, but required half the frequency of administration, even when the treatment was not commenced until 24 h after the final toxin dose. Beta-cyclodextrin-epichlorohydrin copolymer also improved the survival rate. After toxin administration, the sheep lost significantly less weight if treatment with HPb -CD was commenced early (P < 0.001).
Conclusion Protection studies using these two beta-cyclodextrin derivatives suggest that they may be effective in increasing the survival of sheep poisoned by tunicamycin and warrant further testing in field outbreaks of annual ryegrass toxicity.     

Acute immobilization stress in prone position in susceptible Pietrain and resistant Duroc pigs. I: comparison of protein degradation in Duroc and Pietrain pigs' skeletal muscle and liver

The experiment was conducted to determine the relationship between lysosomal proteinase activities in skeletal muscle and liver of stressed pigs. Six‐month‐old Duroc (D) and Pietrain (P) pigs were randomly assigned to either control (group I) or stressed groups (5 min of stress, group II; 15 min of stress, group III; 30 min of stress, group IV; 60 min of stress, group V). At slaughter, the longissimus dorsi muscle and the liver were taken. The tissues were analysed for cathepsin D, acid autolytic activities without and with pepstatin (inhibitor of cathepsin D) and leupeptin (inhibitor of cysteine proteinases). Both tissues were also analysed for RNA, DNA and protein content. The acute immobilization stress in the prone position caused changes in longissimus dorsi muscle in DNA (26% decrease in D and 35% increase in P pigs), functional cell size, protein/10³DNA (FCS) (34% increase in D and 25% decrease in P pigs), increase in acid autolytic activity (AAA) (by 48.3%), pepstatin insensitive acid autolytic activity (PIA) (by 111.8%), leupeptin insensitive acid autolytic activity (LIA) (by 35.8%) in D, but in P pigs by 13.5%, 16.6% and 54%, respectively. The interaction between strain of pigs and stress was also observed, mostly in DNA and AAA's. In the liver, RNA was decreased by 10% in D and by 12.3% in P pigs, DNA by 13% and 24% in D and P pigs, FCS was increased by 13.2% in D and by 22.7% in P pigs; the activity of cathepsin D (CatD) and pepstatin sensitive cathepsin D (PSCatD) increased after 15 min of stress by 9.2% and 9.3% and LIA by 13.7% in D pigs but in P pigs the maximal increase was after 15 min of stress in AAA by 10.3%, in PIA by 13.6% and in LIA by 3.2%. The experiment showed that the proteinase activities in the two different strains of pigs were different. The highest changes were in AAA's in the longissimus dorsi muscle and in CatD and PSCatD in the liver. There was more CatD in the longissimus dorsi muscle and liver of D than P pigs. Although it should be taken with caution, this suggests that other proteinases may be also responsible for the catabolism of proteins.     

Mitochondrial cytochrome c oxidase subunit 1 (cox1) gene sequence of Spirocerca lupi (Nematoda, Spirurida): avenues for potential implications

Canine spirocercosis is a life-threatening parasitosis caused by Spirocerca lupi (Nematoda, Spirurida) that is presently emerging in several countries. This study characterised an informative region within the mitochondrial (mtDNA) gene encoding for the cytochrome c oxidase subunit 1 (cox1) of S. lupi by Polymerase Chain Reaction (PCR)-coupled sequencing. Specimens from five different countries in Europe, Asia and Africa were examined and two different sequence variants of cox1 (i.e. haplotypes) were determined, displaying nucleotidic variation at 6 of 689 positions. All of these positions were invariable among all the parasite individuals from Europe (haplotype 1) and among the African and Asian individuals (haplotype 2), but differed between Europe and Asia/Africa. The S. lupi cox1 sequences were consistent with those of other common Spirurida previously reported at both nucleotidic and phylogenetic levels. This study provides molecular information essential for identification of the nematode, irrespective of its life cycle stage. Crucial implications for the specific molecular diagnosis of clinical spirocercosis and investigation of the evolution, population genetics, ecology and epidemiology of S. lupi are discussed.     

Impact of the source and serial passaging of goat mesenchymal stem cells on osteogenic differentiation potential:implications for bone tissue engineering

Background: Adult mesenchymal stem cells(MSCs) can be conveniently sampled from bone marrow, peripheral blood, muscle, adipose and connective tissue, harvested from various species, including, rodents, dogs, cats, horses,sheep, goats and human beings. The MSCs isolated from adult tissues vary in their morphological and functional properties. These variations are further complicated when cells are expanded by passaging in culture. These differences and changes in MSCs must be considered prior to their application in the clinic or in a basic research study. Goats are commonly used as animal models for bone tissue engineering to test the potential of stem cells for bone regeneration. As a result, goat MSCs isolated from bone marrow or adipose tissue should be evaluated using in vitro assays, prior to their application in a tissue engineering project.Results: In this study, we compared the stem cell properties of MSCs isolated from goat bone marrow and adipose tissue. We used quantitative and qualitative assays with a focus on osteogenesis, including, colony forming unit, rate of cell proliferation, tri-lineage differentiation and expression profiling of key signal transduction proteins to compare MSCs from low and high passages. Primary cultures generated from each source displayed the stem cell characteristics,with variations in their osteogenic potentials. Most importantly, low passaged bone marrow MSCs displayed a significantly higher and superior osteogenic potential, and hence, will be the preferred choice for bone tissue engineering in future in vivo experiments. In the bone marrow MSCs, this process is potentially mediated by the p38 MAPK pathway. On the other hand, osteogenic differentiation in the adipose tissue MSCs may involve the p44/42 MAPK pathway.Conclusions: Based on these data, we can conclude that bone marrow and fat-derived MSCs undergo osteogenesis via two distinct signaling pathways. Even though the bone marrow MSCs are the preferred source for bone tissue engineering, the adipose tissue MSCs are an attractive alternative source and undergo osteo-differentiation differently from the bone marrow MSCs and hence, might require a cell-based enhancer/inducer to improve their osteogenic regenerative capacity.     

In vitro studies of Lactobacillus delbrueckii subsp. lactis in Atlantic salmon (Salmo salar L.) foregut: tissue responses and evidence of protection against Aeromonas salmonicida subsp. salmonicida epithelial damage

Probiotic bacteria increase the host health status and protect mucosal tissue against pathogen-caused damage in mammalian models. Using an in vitro (intestinal sac) method this study aimed to address (a) the in vitro ability of Lactobacillus delbrueckii subsp. lactis to remain in the gastrointestinal tract of Atlantic salmon (Salmo salar L.) and (b) its ability to prevent cellular damage caused by successive incubation with Aeromonas salmonicida subsp. salmonicida the causative agent of furunculosis. Short in vitro incubation of salmon foregut with (TRITC)-labelled L. delbrueckii subsp. lactis showed that the probiont was able to colonize the enterocyte surface as studied by confocal microscopy. Furthermore, foregut incubated with the probiotic bacteria only, resulted in a healthy intestinal barrier whereas exposure to A. salmonicida disrupted its integrity. However, pre-treatment of salmon intestine with L. delbrueckii subsp. lactis prevented Aeromonas damaging effects. These results are promising in the context of the use of non-autochthonous probiotic bacteria as prophylactic agents against fish bacterial infections in the gastrointestinal tract.