Cytokines and chemokines associated with Treg/Th17 response in chronic inflammatory periapical disease

Abstract Cytokines and chemokines have a fundamental role in the maintenance of inflammation and bone response, which culminate in the development of chronic periapical lesions. Regulatory (Treg) and Th17 cytokines play a key role in regulating the immune response involved in this process. The aim of this study was to investigate the role of Treg and Th17 cells in chronic inflammatory periapical disease, by comparing the expression of the immunoregulatory mediators TGF-β, IL-10, CCL4, and the proinflammatory IL-17 and CCL20 in the periapical tissue of teeth with pulp necrosis, with and without associated chronic lesions. Eighty-six periapical tissue samples were obtained from human teeth. The samples were divided into three groups: pulp necrosis with a periapical lesion (n=26); pulp necrosis without a periapical lesion (n=30), and control (n=30). All samples were submitted to histopathological analysis and cytokine and chemokine measurement through ELISA. Statistical analyses were done with Kruskal-Wallis and Mann-Whitney tests and Spearman correlation. The group with pulp necrosis and a periapical lesion showed a higher expression of CCL4 and TGF-β in comparison with pulp necrosis without a lesion. CCL20 was higher in the group with a periapical lesion when compared to the control. In all groups there was a weak positive correlation between IL-17/CCL20, IL-10/CCL4, and IL-17/TGF-β. Both types of cytokines, pro-inflammatory and immunoregulatory, occur simultaneously in periapical tissue. However, a rise in immunosuppressive cytokines and chemokines (CCL4 and TGF-β) in periapical lesions suggests a role of these cytokines in stable periapical disease.

Mast cell in dental pulp: does it have a role / Mastócitos na polpa dental: eles têm uma função

Os mastócitos desempenham um importante papel em uma variedade de processos biológicos e participam, ativamente, da resposta inflamatória. Existe, no entanto, uma controvérsia na literatura a respeito da presença de mastócitos em polpas dentais. O presente trabalho procurou responder essa controvérsia no que se refere à presença de mastócitos no tecido pulpar de ratos e humanos em condições normais e durante a inflamação. Para isso, polpas inflamadas e não inflamadas de humanos e ratos foram coletadas e analisadas, utilizando-se a técnica histoquímica do azul de toluidina e a técnica de imunohistoquímica. Nossos resultados mostraram a ausência de mastócitos em polpas dentais de ratos e humanos tanto em condições normais quanto durante a inflamação. O papel dos mastócitos na resposta inflamatória da polpa dental não é claro. Fatores de crescimento e citocinas envolvidas na sua migração, desenvolvimento e sobrevivência podem estar ausentes no tecido pulpar e necessitam de futuras investigações.

Mast cells play an important role in a variety of biological processes and actively participate in the inflammatory response. There is a controversy in the literature whether mast cells are present in dental pulp. In this investigation we sought to answer the question concerning the presence of mast cells in human and rat dental pulp tissues, under normal and inflammatory conditions. Human and rat dental pulp under normal and inflammatory conditions were analyzed using toluidine blue histochemistry and immunohistochemistry techniques. Our results showed that inflamed and non-inflamed dental pulps neither from humans nor from rats presented mast cells. The role of mast cells in the inflammatory dental pulp response is not clear. Growth factors and cytokines involved in their migration, development and survival could be absent in this tissue and need further investigations.