Efeito do receptor PPARα na modulação da produção de proteínas de fase aguda e de fatores do complemento em cultivo primário em hepatócitos bovinos in vitro

Abstract

The innate immune modulation is a tool capable of improve the immune system capacity to fight infections by pathogens and other external stimuli. The use of signaling paths with participation of some specific receptors, such as peroxisome proliferator-activated receptor alpha (PPARα) arises as an important hypothesis to modulate the acute phase proteins (APP) and complement proteins in bovine liver cells, where most of these molecules are produced in a systemic level. In this way, this work aimed to establish a protocol of primary culture of bovine hepatocytes suitable to analyze intracellular signaling paths and genetic expression and synthesis of proteins related to innate immune system. For that, bovine hepatocytes from five different animals were isolated, cultivated and activated by a receptor ligand - fenofibrate, both alone and associated with proinflammatory stimuli, in different concentrations. After 48 hours of culture, ribonucleic acid (RNA) was extracted and quantified, complementary deoxyribonucleic acid was synthetized and real-time polymerase chain reactions were setup to verify the acute phase and complement proteins expression and synthesis. The culture supernatant was used to analyze the protein dosage by Enzyme-Linked Immunosorbent Assay (ELISA). The results showed that the hepatocytes isolation and culture were not very effective, since the extracted RNA showed low concentration and bad integrity, indicating that more studies must be performed to standardize this technique. Considering the low quantification and bad quality of RNA, it was not possible to access the role of the receptor PPARα in complement factors and acute phase proteins genetic expression and production, when activated by its specific ligand (fenofibrate). Thus, the development of isolation and culture techniques for bovine hepatocytes must continue to be developed in order to better evaluate the intracellular signaling pathways and the search for new molecules capable to modulate proteins related to the immune system in bovines.