Joanna Górka-Dynysiewicz, Jolanta Zuwała-Jagiełło
Pentraxin 3 and its role in tissue repair
Pentraxin 3 (PTX3) is a member of the long pentraxin family. It is an acute-phase protein produced and released in regions of injury. It belongs to humoral innate immune response. It acts as an indicator and regulator of inflammation, in response to the activity of i.a. proinflammatory cytokines (TNF-α, IL-1β), toll‑like receptor (TLR) agonists and lipopolysaccharides. It is synthesised in different types of cells, such as: monocytes, macrophages, dendritic cells, endothelial cells, smooth muscle cells, fibroblasts or adipocytes. PTX3 is also produced during neutrophil differentiation and stored in specific granules of mature neutrophils, ready to be released upon microbial recognition. This multimeric glycoprotein is composed of 381 amino acid residues. It contains the N-terminal domain (18-178 amino acid residues) and the C-terminal domain (179-381 amino acid residues), including the 17-amino-acid signal peptide. Its modular structure enables its various bioactivity. PTX3 removes apoptotic cells during the immune response. PTX3 interacts with components of the hemostatic system and the fibrinolytic cascade, under acidic conditions that occur in damaged tissues. As a result of the interaction with plasminogen and fibrin in the wound, pentraxin 3 promotes the process of fibrinolysis and plays a role in the tissue repair process. Together with chemokines, PTX3 organises the leukocyte recruitment in the region of injury, contributing to the formation of the inflammatory microenvironment and the suppression of the inflammatory response. In many animal models, it has been shown that PTX3 plays a complex, non-redundant role in pathogen resistance, inflammation control and tissue repair, acting as an onco-suppressor gene as well. The diverse bioactivity of PTX3 is probably a result of its capability to interact with a wide spectrum of ligands, including complement components, adhesion molecules, growth factors and extracellular matrix components. The involvement of PTX3 in many biological processes determines it as a potentially important biomarker of many diseases. These studies will prove that pentraxin 3 is involved in tissue regeneration. The involvement of PTX3 in tissue injury / tissue remodelling will highlight the relationship and interaction between homeostasis and resistance. This information helps us to understand why PTX3 may become a potential diagnostic marker of the severity of illness related to tissue remodeling, as well as it provides sufficient evidence for using this protein as a therapeutic tool. A better understanding of the complex mechanisms, in which pentraxin 3 is involved, should be sought.
Keywords: wound healing, Pentraxin 3, tissue remodeling.
© Farm Pol, 2020, 76(2): 65–72