Metaloproteinasas de la matriz extracelular y su participación en el proceso de cicatrización

Matrix metalloproteinases are essential for structural maintenance of extracellular matrix enzymes, as well as degradation in situations where tissue repair process is warranted. Objective: To review the most current aspects of matrix metalloproteinases and their role in the healing process. Research Methodology: A review of about 95 papers was conducted during the period from July 18,  2015 to September 20, 2016; PubMed, Scopus, Scielo and Science Direct were used. Results: There are six subfamilies of metalloproteinases: collagenases, stromalysins, elastases, gelatinases, matrilysins and metalloproteinases associated with the plasma membrane. Vascular endothelial cells secrete them where there is epithelial damage and a healing process is required. Conclusions: Metalloproteinases are zinc dependent endopeptidases that are essential for the maintenance and degradation of the extracellular matrix. When the adjustment mechanism fails and matrix metalloproteinases are overexpressed, poor healing processes occur, causing problems such as liver chronic wounds, keloids or hypertrophic scars, pterygium, pulmonary and liver fibrosis, among other clinical conditions. MÉD.UIS. 2017;30(2):55-62.Las metaloproteinasas son enzimas fundamentales para el mantenimiento estructural de la matriz extracelular, así como para su degradación en situaciones donde se requiere un proceso de reparación tisular. Objetivo: realizar una revisión de los aspectos más actuales de las metaloproteinasas y su papel en la cicatrización. Metodología de búsqueda: se realizó una revisión de 95 artículos, durante el período comprendido entre el 18 de julio de 2015 y 20 de septiembre de 2016 se utilizó las bases de datos Medline, Scopus, Scielo y Science Direct. Resultados: existen seis subfamilias de metaloproteinasas: colagenasas, estromalisinas, elastasas, gelatinasas, matrilisinas y las metaloproteinasas asociadas a la membrana plasmática. Las células endoteliales vasculares las secretan en donde hay daño epitelial y serequiere de un proceso de cicatrización. Conclusiones: las metaloproteinasas son endopeptidasas dependientes de zinc fundamentales para el mantenimiento y degradación de la matriz extracelular. Cuando el mecanismo de regulación falla y las metaloproteinasas tiene una sobreexpresión, ocurren procesos de cicatrización deficientes, condicionando la aparición de heridas crónicas, cicatrices hipertróficas o queloides, pterigión, fibrosis pulmonar y hepática, entre otras condiciones. MÉD.UIS. 2017;30(2):55-62

Excessive Refined Carbohydrates and Scarce Micronutrients Intakes Increase Inflammatory Mediators and Insulin Resistance in Prepubertal and Pubertal Obese Children Independently of Obesity

Background. Low-grade inflammation is the link between obesity and insulin resistance. Because physiologic insulin resistance occurs at puberty, obese pubertal children are at higher risk for insulin resistance. Excessive diets in refined carbohydrates and saturated fats are risk factors for insulin resistance, but calcium, magnesium, vitamin-D, and the omega-3 fatty acids likely protect against inflammation and insulin resistance. Objective. To analyze interactions among dietary saturated fat, refined carbohydrates, calcium, magnesium, vitamin D, and omega-3 fatty acids on the risk of inflammation and insulin resistance in a sample of prepubertal and pubertal children. Methods. A sample of 229 children from Mexico City was analyzed in a cross-sectional design. Anthropometric measurements, 24 h recall questionnaires, and blood samples were obtained. Serum insulin, glucose, calcium, magnesium, 25-OHD3, C-reactive protein, leptin, adiponectin, and erythrocytes fatty acids were measured. Parametric and nonparametric statistics were used for analysis. Results. While mean macronutrients intake was excessive, micronutrients intake was deficient (P<0.01). Inflammation determinants were central obesity and magnesium-deficient diets. Determinants of insulin resistance were carbohydrates intake and circulating magnesium and adiponectin. Conclusions. Magnesium-deficient diets are determinants of inflammation, while high intake of refined carbohydrates is a risk factor for insulin resistance, independently of central adiposity