RESUMO
Muscle growth and repair rely on two main mechanisms - myonuclear accretion and subsequent protein accumulation. Altering the ability of muscle resident stem cells (satellite cells) to progress through their myogenic lineage can have a profound effect on lifetime muscle growth and repair. The use of the histone deacetylase (HDAC) inhibitor, butyrate, has had positive outcomes on the in vitro promotion of satellite cell myogenesis. In animal models, the use of butyrate has had promising results in treating myopathic conditions as well as improving growth efficiency, but the impact of dietary butyrate on satellite cells and muscle growth has not been elucidated. We investigated the impact of tributyrin, a butyrate prodrug, on satellite cell activity and muscle growth in a piglet model. Satellite cells from tributyrin-treated piglets had altered myogenic potential, and piglets receiving tributyrin had a ~40% increase in DNA:protein ratio after 21 days, indicating the potential for enhanced muscle growth. To assess muscle growth potential, piglets were supplemented tributyrin (0.5%) during either the neonatal phase (d1-d21) and/or the nursery phase (d21-d58) in a 2 × 2 factorial design. Piglets who received tributyrin during the neonatal phase had improved growth performance at the end of the study and had a ~10% larger loin eye area and muscle fiber cross-sectional area. Tributyrin treatment in the nursery phase alone did not have a significant effect on muscle growth or feed efficiency. These findings suggest that tributyrin is a potent promoter of muscle growth via altered satellite cell myogenesis.
Assuntos
Inibidores de Histona Desacetilases/administração & dosagem , Desenvolvimento Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/crescimento & desenvolvimento , Células Satélites de Músculo Esquelético/efeitos dos fármacos , Células Satélites de Músculo Esquelético/fisiologia , Triglicerídeos/administração & dosagem , Animais , Diferenciação Celular/efeitos dos fármacos , DNA/metabolismo , Suplementos Nutricionais , Feminino , Expressão Gênica/efeitos dos fármacos , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/citologia , Miogenina/metabolismo , SuínosRESUMO
Enterohemorrhagic Escherichia coli (EHEC) is one of the leading causes of bacterial enteric infections worldwide, causing â¼100,000 illnesses, 3,000 hospitalizations, and 90 deaths annually in the United States alone. These illnesses have been linked to consumption of contaminated animal products and vegetables. Currently, other than thermal inactivation, there are no effective methods to eliminate pathogenic bacteria in food. Colicins are nonantibiotic antimicrobial proteins, produced by E. coli strains that kill or inhibit the growth of other E. coli strains. Several colicins are highly effective against key EHEC strains. Here we demonstrate very high levels of colicin expression (up to 3 g/kg of fresh biomass) in tobacco and edible plants (spinach and leafy beets) at costs that will allow commercialization. Among the colicins examined, plant-expressed colicin M had the broadest antimicrobial activity against EHEC and complemented the potency of other colicins. A mixture of colicin M and colicin E7 showed very high activity against all major EHEC strains, as defined by the US Department of Agriculture/Food and Drug Administration. Treatments with low (less than 10 mg colicins per L) concentrations reduced the pathogenic bacterial load in broth culture by 2 to over 6 logs depending on the strain. In experiments using meats spiked with E. coli O157:H7, colicins efficiently reduced the population of the pathogen by at least 2 logs. Plant-produced colicins could be effectively used for the broad control of pathogenic E. coli in both plant- and animal-based food products and, in the United States, colicins could be approved using the generally recognized as safe (GRAS) regulatory approval pathway.
Assuntos
Colicinas/metabolismo , Colicinas/farmacologia , Escherichia coli O157/efeitos dos fármacos , Plantas Comestíveis/metabolismo , Sequência de Aminoácidos , Animais , Beta vulgaris/genética , Beta vulgaris/metabolismo , Colicinas/genética , Eletroforese em Gel de Poliacrilamida , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/crescimento & desenvolvimento , Peixes , Microbiologia de Alimentos , Carne/microbiologia , Dados de Sequência Molecular , Plantas Comestíveis/genética , Plantas Geneticamente Modificadas , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Spinacia oleracea/genética , Spinacia oleracea/metabolismo , Suínos , Nicotiana/genética , Nicotiana/metabolismoRESUMO
BACKGROUND: Organic acids, such as citric and sorbic acid, and pure plant-derived constituents, like monoterpens and aldehydes, have a long history of use in pig feeding as alternatives to antibiotic growth promoters. However, their effects on the intestinal barrier function and inflammation have never been investigated. Therefore, aim of this study was to assess the impact of a microencapsulated mixture of citric acid and sorbic acid (OA) and pure botanicals, namely thymol and vanillin, (PB) on the intestinal integrity and functionality of weaned pigs and in vitro on Caco-2 cells. In the first study 20 piglets were divided in 2 groups and received either a basal diet or the basal diet supplemented with OA + PB (5 g/kg) for 2 weeks post-weaning at the end of which ileum and jejunum samples were collected for Ussing chambers analysis of trans-epithelial electrical resistance (TER), intermittent short-circuit current (I SC), and dextran flux. Scrapings of ileum mucosa were also collected for cytokine analysis (n = 6). In the second study we measured the effect of these compounds directly on TER and permeability of Caco-2 monolayers treated with either 0.2 or 1 g/l of OA + PB. RESULTS: Pigs fed with OA + PB tended to have reduced I SC in the ileum (P = 0.07) and the ileal gene expression of IL-12, TGF-ß, and IL-6 was down regulated. In the in vitro study on Caco-2 cells, TER was increased by the supplementation of 0.2 g/l at 4, 6, and 14 days of the experiment, whereas 1 g/l increased TER at 10 and 12 days of treatment (P < 0.05). Dextran flux was not significantly affected though a decrease was observed at 7 and 14 days (P = 0.10 and P = 0.09, respectively). CONCLUSIONS: Overall, considering the results from both experiments, OA + PB improved the maturation of the intestinal mucosa by modulating the local and systemic inflammatory pressure ultimately resulting in a less permeable intestine, and eventually improving the growth of piglets prematurely weaned.
Assuntos
Benzaldeídos/farmacologia , Ácido Cítrico/farmacologia , Inflamação/veterinária , Ácido Sórbico/farmacologia , Suínos , Timol/farmacologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Benzaldeídos/administração & dosagem , Células CACO-2 , Ácido Cítrico/administração & dosagem , Citocinas/genética , Citocinas/metabolismo , Dieta/veterinária , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamação/prevenção & controle , Intestinos/efeitos dos fármacos , Ácido Sórbico/administração & dosagem , Timol/administração & dosagemRESUMO
Intestinal microbiota of infants differ in response to gestational age, delivery mode and feeding regimen. Dietary supplementation of probiotic bacteria is one method of promoting healthy populations. We examined the impact of a novel probiotic strain of Bifidobacterium longum (AH1206) on the health, growth and development of neonatal pigs as a model for infants. Day-old pigs were fed milk-based formula containing AH1206 at 0, 109, or 10¹¹ CFU/d for 18 d (n=10/treatment). Differences were not detected in growth, organ weights or body temperatures (P>0.1); however pigs fed the high dose showed a small (2%) reduction in feed intake. Bacterial translocation was not affected as indicated by total anaerobic and aerobic counts (CFU) in samples of spleen, liver and mesenteric lymph nodes (P>0.1). Feeding AH1206 had no effects on fecal consistency, but increased the density of B. longum in the cecum. Ileal TNF expression tended to increase (P=0.08) while IL-10 expression increased linearly (P=0.01) with supplementation. Based upon findings in the suckling piglet model, we suggest that dietary supplementation with B. longum (AH1206) may be safe for human infants based on a lack of growth, development or deleterious immune-related effects observed in piglets.
Assuntos
Ração Animal/microbiologia , Bifidobacterium , Ceco/microbiologia , Suplementos Nutricionais , Interleucina-10/metabolismo , Probióticos/administração & dosagem , Animais , Animais Recém-Nascidos , Contagem de Colônia Microbiana , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Interleucina-10/genética , Suínos , Aumento de PesoRESUMO
Although mesenchymal stem cells (MSC) and satellite cells are essential for postnatal muscle and bone development and phosphate (PO(4)) restriction reduces both muscle and skeletal tissue growth, no research to our knowledge has investigated the possible mechanism by which this mineral may affect early cell programming. Twenty piglets obtained at 1 d of age (1.8 +/- 0.3 kg) received either a PO(4)-adequate diet or a 25% less PO(4)-available diet over a 15-d trial. Feed intake and body weight were recorded daily and blood samples collected every 5 d. After 15 d, pigs were given an intraperitoneal injection of bromodeoxyuridine 4 h prior to tissue collection. As expected, PO(4) deficiency resulted in reduced growth (P < 0.05), feed conversion efficiency (P < 0.05), and bone mineral content (P < 0.05), as well as lower plasma concentrations of both PO(4) (P < 0.01) and parathyroid hormone (P < 0.05). In addition to these classical indicators of PO(4) deficiency, there was also reduced proliferation of both MSC (P < 0.01) and satellite cells (P < 0.05) in vivo. The expression of osteocalcin mRNA in bone marrow was also 2-fold greater (P < 0.01) within the PO(4)-adequate treatment group. These data indicate that in addition to reductions in muscle and bone growth, dietary PO(4) affects proliferation of tissue-specific stem cells in vivo. Nutritional programming of tissue-specific stem cells by dietary PO(4) may have profound implications for life-long growth potential.
Assuntos
Ração Animal/análise , Proliferação de Células/efeitos dos fármacos , Dieta/veterinária , Células-Tronco Mesenquimais/efeitos dos fármacos , Fósforo na Dieta/farmacologia , Suínos/crescimento & desenvolvimento , Fenômenos Fisiológicos da Nutrição Animal , Animais , Densidade Óssea/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Medula Óssea/metabolismo , Feminino , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Fósforo/deficiência , Aumento de Peso/efeitos dos fármacosRESUMO
Phytic acid, a major phosphorous storage compound found in foodstuffs, is known to form insoluble complexes with nutritionally essential minerals, including zinc (Zn). Phytases are enzymes that catalyze the removal of these minerals from phytic acid, improving their bioavailability. The objective of the present study was to determine the ability of dietary phytase to affect body weight, body composition, and bone strength in growing rats fed a high phytic acid, low Zn diet. Rats (n = 20) were fed either a control (AIN-93) or phytase supplemented (Natuphos, BASF, 1,500 phytase units (FTU)/kg) diet for a period of 8 weeks. Phytase supplementation resulted in increased (P<.05) bone and plasma Zn, but no change in plasma inorganic phosphorous or bone levels of Ca, Fe, or Mg. The addition of phytase to the diets resulted in a 22.4% increase (P<.05) in body weight at the end of the study as compared with rats fed a control diet. Dual x-ray absorptiometry (DXA) revealed that phytase supplementation resulted in increase lean body mass (LBM, P<.001) and increased bone mineral content (BMC, P<.001) as compared with feeding the control diet. Bone studies indicated that femurs and tibias from phytase supplemented rats had greater mass (P<.05) and were stronger (P<.05) than rats fed the control diet. This data suggest that the addition of phytase to low Zn diets results in improved Zn status, which may be responsible for beneficial effects on growth, body composition, and bone strength.
Assuntos
6-Fitase/administração & dosagem , Composição Corporal/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Dieta , Aumento de Peso/efeitos dos fármacos , Zinco/administração & dosagem , Absorciometria de Fóton , Animais , Fenômenos Biomecânicos , Densidade Óssea/efeitos dos fármacos , Fêmur , Masculino , Ratos , Ratos Sprague-Dawley , TíbiaRESUMO
Dietary phosphorus (P) is essential to bone growth and turnover; however, little research has focused on the genetic mechanisms controlling P utilization. Understanding the interactions between genetics and dietary P that optimize bone integrity could provide novel interventions for osteoporosis. Thirty-six pigs from two sire lines known to differ in bone structure [heavier boned (HB) and lighter boned (LB)] were assigned to one of the three diets (P adequate, P repletion or P deficient). After 14 days, bone marrow and intact radial bones were collected. Differences between these lines in growth rate, bone integrity and gene expression within bone marrow were observed. In HB, but not LB, pigs, the P-deficient diet decreased weight gain (P<.01). For both lines, P deficiency caused a reduction in radial bone strength (P<.01), but HB P-deficient animals had greater (P<.10) bone integrity than P-deficient LB pigs. In HB, but not LB, pigs, dietary treatment affected the expression of CALCR (calcitonin receptor) (P<.05), VDR (vitamin D receptor) (P<.04) and IGFBP3 (insulin-like growth factor binding protein 3) (P<.06). There was also a trend of increased IL6 (interleukin-6), TFIIB (transcription initiation factor IIB) and SOX9 (sex determining region Y-box 9) expression with P deficiency in HB, but not LB, pigs. Both genetic backgrounds responded similarly to P deficiency with an increase in the expression of OXTR (oxytocin receptor) and IGF1 (insulin-like growth factor 1). Differences in growth rate, bone integrity and gene expression within the bone marrow suggest a difference in the homeorhetic control of P utilization between these genetic lines. Understanding these differences could lead to novel treatments for osteoporosis and aid in the development of tests for identifying those at risk for this disease.