ABSTRACT
OBJECTIVES: Nutritional aggression in critical periods may lead to epigenetic changes that affect gene expression. The aim of this study was to assess the effect of neonatal malnutrition on the expression of toll-like receptor (TLR)-2, TLR-4, and NLRP3 receptors, caspase-1 enzyme, and interleukin (IL)-1 ß production in macrophages infected with methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) Staphylococcus aureus. METHODS: Wistar rats (N = 24) were divided in two distinct groups: nourished (17% casein) and malnourished (8% casein). Four systems were established after the isolation of mononuclear cells: negative control, positive control, MRSA, and MSSA. The plates were incubated at 37°C for 24 h in humidified atmosphere and 5% carbon dioxide. Tests were performed after this period to analyze the expression of standard recognition receptors, caspase-1 enzyme, and the production of IL-1 ß. Student's t test and analysis of variance were used in the statistical analysis; P < 0.05 was statistically significant. RESULTS: Malnutrition reduced animal growth and the expression of TLR-2, TLR-4, and NLRP3 receptors, the caspase-1 enzyme, and the IL-1 ß levels in macrophages infected with lipopolysaccharides in the present study. However, the interaction between the S. aureus and the macrophages promoted greater gene expression of receptors and enzymes. CONCLUSION: The neonatal malnutrition model compromised the expression of standard recognition receptors, of the caspase-1 enzyme as well as the production of IL-1 ß. However, the S. aureus and neonatal malnutrition combination led to intense transcription of such innate immunity components. Therefore, the deregulation in the expression of TLR and NLRP3 receptors and of the caspase-1 enzyme may induce extensive tissue injury and favor the permanence and spread of these bacteria, especially those that are methicillin resistant.
Subject(s)
Epigenesis, Genetic , Gene Expression Regulation , Immunity, Innate , Inflammasomes/metabolism , Macrophages, Alveolar/metabolism , Malnutrition/complications , Staphylococcal Infections/complications , Animals , Animals, Newborn , Caspase 1/genetics , Caspase 1/metabolism , Cells, Cultured , Diet, Protein-Restricted/adverse effects , Female , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Lactation , Macrophages, Alveolar/immunology , Macrophages, Alveolar/microbiology , Macrophages, Alveolar/pathology , Male , Malnutrition/diet therapy , Malnutrition/etiology , Maternal Nutritional Physiological Phenomena , Methicillin-Resistant Staphylococcus aureus/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Rats, Wistar , Staphylococcal Infections/immunology , Staphylococcal Infections/metabolism , Staphylococcal Infections/microbiology , Toll-Like Receptor 2/genetics , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolismABSTRACT
Objective. To compare the use of Bone Marrow adult Stem Cells (BMSCs), differentiated in vitro into osteoblasts, associated to calcium phosphate versus autogenous bone graft, in the repair process of critical size bone defects. Materials and method. On 36 Wistar adult rats, bilateral full-thickness defects on parietal bone were created. The defects were either repaired with calcium phosphate (group I), calcium phosphate + (BMSCs) (group II) or autogenous bone graft (group III), and the opposite side with blood clot (Control Group). In all cases a collagen membrane was used. The animals were sacrificed at 30 and 60 days, and all specimens were collected for further histological and histomorfometric study. Results. At 30 days, group III (autogenous bone graft) evidences a statistical difference on bone formation when compared to the experimental and control groups (p ≤ 0.05). At 60 days group II (BS + BMSCs) and group III (autogenous bone) showed a similar bone formation and has only a statistical difference when compared to group I (BS) and control group. Conclusion. The use of calcium phosphate in conjunction with BMSCs resulted in a similar behavior in the process of bone repair in critical size defects, when compared with autogenous bone graft (AU)
Objetivo. Comparar el uso de células madre adultas de la médula ósea (CMMO), diferenciadas in vitro en osteoblastos, asociadas a fosfato cálcico, frente a injerto de hueso autólogo, en el proceso de reparación de defectos óseos de tamaño crítico. Material y Método. En 36 ratas adultas Wistar, se crearon defectos bilaterales de todo el grosor en el hueso parietal. Los defectos se repararon con fosfato de calcio (BoneSource®) (grupo I), fosfato de calcio (BoneSource®) + (CMMO) (grupo II) o injerto de hueso autólogo (grupo III), y en el lado contralateral con coágulo de sangre (grupo de control). En todos los casos se utilizó membrana de colágeno. Los animales fueron sacrificados a las 30 y 60 días y se obtuvieron todas las muestras para el estudio histológico y el análisis histomorfométrico. Resultados. A los 30 días, en el grupo III (injerto de hueso autólogo) se puso de manifiesto una diferencia estadísticamente significativa en la formación de hueso en comparación con el grupo experimental y el de control (p < 0,05). A los 60 días, en el grupo II (BoneSource®) + CMMO) y el grupo III (hueso autólogo) se demostró una formación ósea similar, y sólo se evidenció una diferencia estadísticamente significativa en comparación con el grupo I (BoneSource®) y el grupo de control. Conclusión. El uso de fosfato de calcio en combinación con CMMO indujo un comportamiento similar en el proceso de reparación ósea en defectos de tamaño crítico, en comparación con injerto de hueso autólogo (AU)
