Caracterização dos granulócitos hepáticos no desenvolvimento pós-natal do fígado

Abstract

The liver is a vital organ for the body, performing metabolic, immune, synthesis, secretion and storage functions. It is interposed between the gastrointestinal system and the systemic circulation, and it is the destination of nutrients and microbial products from the intestine. During embryonic development, the liver is a hematopoietic site with different liver progenitor cells and a large number of immune cells at different stages of maturation. The neonatal liver is mostly composed of myeloid cells, while the adult liver is especially a lymphoid organ; hence, the immune and metabolic profiles of the neonatal liver are very different from those of an adult liver. Much is known about embryonic liver development, although studies on the mechanisms that govern structural and immune changes in the liver at different stages after birth are still needed. We found that granulocytes are the main cell types in the liver (~35%), being the majority cell population in the first weeks of life. Although the role of these cells in the adult liver have already been described, little is known about the possible diversity and influence of granulocytes in the postnatal development of the liver, as it undergoes immune, metabolic, gene expression and morphological modifications along life challenges. Therefore, this work aims to characterize the dynamics of hepatic granulocytes and study the possible influence of the immune system on the hepatic postnatal development and on the regulation of the processes that structure the liver into adulthood.