Dissertação
Infecção helmíntica exerce efeito benéfico no desenvolvimento da obesidade experimental e suas consequências metabólicas
Fecha
2017-02-13Autor
Camila Pereira de Queiroz
Institución
Resumen
Obesity is a worldwide disease defined by the excessive amount of fat that can cause damage to
the health. The greatest concern about this disease is associated with the metabolic disorders
developed with it, that can lead to metabolic syndrome. The helminth infection can induce
various mechanisms capable of modulating and regulating the immune response of the host,
ensuring their stay. These modulations, including the activation of T regulatory cells, end up
being beneficial to the host, because it decreases the inflammation and impairs the development
of inflammatory chronic diseases. Considering that, the present study aimed to verify the
influence of the infection by Heligmosomoides polygyrus in the development of obesity and its
consequences. Male C57BL/6, specific pathogen free, were fed a control diet or a high fat diet,
for up to eight weeks, in the presence or not of the infection. Weight gain, caloric intake and egg
counting in the stool were evaluated weekly. At the end of the experiment we also evaluated
parameters related to insulin resistance, cholesterol, secretion of adipokines, inflammation and
cellular migration to the adipose tissue. Despite no difference in the caloric intake between the
animals fed with high fat diet, the infection was able to prevent the weight gain, also decreasing
the weight of epididymal and subcutaneous fat. This effect does not occur due parasite spoliation
because there was no difference between the groups that received control diet. Also, the infection
prevented the development of adipocytes hypertrophy, insulin resistance and deregulation in the
production of adipokines. The inflammation decreased, apparently in a manner independent of
IL-10, and the percentage of T regulatory cells and eosinophils increased in the adipose tissue.
Besides that, the infection was not able to reduce the oxidative stress, neither change the
migration of inflammatory cells (Th17, ILC1, ILC3) to the adipose tissue. Overall, the infection
prevented the exacerbated weight gain and the development of obesity associated consequences,
probably by decreasing the inflammation, associated to the increase of T regulatory cells.