RESUMEN
The objective of this study was to investigate the effects of Bacillus subtilis-based probiotic supplementation in broiler chicken diets on growth performance, feed efficiency, intestinal cytokine, and tight junction (TJ) protein mRNA expression. Zero-day-old broiler chicks (n = 140) were randomly assigned to one of five dietary treatments: basal diet (CON); basal diet supplemented with either antibiotic bacitracin methylene disalicylate (BMD); or probiotics, namely, B. subtilis strain 1781 (PB1), a combination of B. subtilis strain 1104 + strain 747 (PB2), or B. subtilis strain 1781 + strain 747 (PB3). Body weight and feed intake were measured at 14 days of age, and the feed conversion ratio (FCR) was calculated. At 14 days of age, ileal samples were collected and used for intestinal cytokine, TJ protein, and mucin gene expression analysis using qRT-PCR. The chickens supplemented with antibiotic (BMD) and B. subtilis strain 1781 alone (PB1) had significantly higher body weights compared to controls of the same age. Dietary supplementation with antibiotic (BMD) or probiotics (PB1, PB2, PB3) significantly improved the feed efficiency as evidenced by decreased FCR compared to controls. No differences were observed in the expression of IL1ß, IL17F, IFNγ, and MUC2 gene among the different treatment groups. However, elevated expression of IL6 (BMD, PB1, PB2), IL8 (PB2), and TNFSF15 (PB1, PB2, PB3) compared to controls was observed in the ileum. IL2 and IL10 expression was upregulated in chicks in the PB2 and PB3 groups, and IL4 was elevated in the PB1 group. IL13 was elevated in all probiotic-fed groups (PB1, PB2, PB3). Probiotic supplementation was also shown to significantly increase the expression of TJ proteins JAM2, ZO1 (PB2, PB3), and occludin (PB1, PB2). Taken together, B. subtilis supplementation altered intestinal immune activity and influenced gut barrier integrity through increased tight junction gene expression.
Asunto(s)
Alimentación Animal/microbiología , Antibacterianos/farmacología , Pollos , Intestinos/microbiología , Probióticos/administración & dosificación , Animales , Bacillus subtilis/clasificación , Bacillus subtilis/metabolismo , Bacitracina/farmacología , Pollos/genética , Pollos/inmunología , Pollos/microbiología , Citocinas/genética , Citocinas/metabolismo , Dieta/veterinaria , Microbioma Gastrointestinal , Regulación de la Expresión Génica , Mucinas/genética , Mucinas/metabolismo , ARN Bacteriano/aislamiento & purificación , ARN Mensajero/genética , ARN Mensajero/metabolismo , Salicilatos/farmacología , Proteínas de Uniones Estrechas/genética , Proteínas de Uniones Estrechas/metabolismo , Uniones Estrechas/microbiologíaRESUMEN
Tumor angiogenesis is a fundamental step in tumor growth and proliferation. Fumagillin is an anti-angiogenic agent which is secreted by Aspergillus, but is also toxic. A fumagillin analogue, TNP-470, has been developed which is a potent angiogenic inhibitor with few side effects. TNP-470 has inhibited tumor growth in Lewis lung cancer and melanoma in animal models. This study was designed to test this proven anti-angiogenic agent's effects on head and neck cancer growth. Fort,v Harlan nude mice were injected subcutaneously with cancer cells from a human oral squamous cell carcinoma. After 3 weeks of tumor growth 25 mice were injected with TNP-470 subcutaneously at a distant site every other day for 30 days while 10 control mice received saline injections. Five mice began TNP-470 injections at the time of tumor injection to determine if TNP-470 can prevent tumor development. The tumor growth and development was unaffected by TNP-470 as compared to the control group. Therefore, the use of an angiogenic inhibitor had no effect on oral cancer growth. Analysis of the cell line utilized found abnormal mRNA expression, which included high p53 expression and low cyclin Dl expression. These results suggest that oral cancers are less dependent on angiogenesis than other tumor types. The genetic abnormalities may explain the angiogenesis independence that was demonstrated. Results found in other tumor types with angiogenic inhibitors cannot be extrapolated to oral cancer since genetic mutations may allow oral tumors to grow without neovascularization.