Lyve1+macrophages crucial for angiogenesis for healing of injured dental pulp tissue
Lyve1+ macrophages play an important role in angiogenesis during wound healing and tissue remodelling of the injured dental pulp tissue, according to a recent study published in the Scientific Reports.
Tissue-resident macrophages populate every tissue, playing important roles in support of tissue development, homeostasis, and remodeling, which makes them attractive therapeutic targets. The functions and phenotypes of tissue-resident macrophages are extremely heterogeneous, depending on the ontogeny, local microenvironment, and inflammation status of the tissue in which they reside.Tissue-resident macrophages expressing lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) are found in multiple tissues and organs.
The researchers aimed to evaluate the dynamics and biological functions of LYVE-1+ macrophages in the dental pulp during post-injury tissue remodelling. Immunofluorescence staining of mouse embryos revealed that LYVE-1+ macrophages colonized dental pulp before birth.
In mature rat molar dental pulp, LYVE-1+ macrophages were the main subset of macrophages expressing CD163, an M2 marker, and were distributed throughout the tissue. In response to dental pulp injury induced by cavity preparation, LYVE-1+ macrophages quickly disappeared from the affected area of the pulp and gradually repopulated during the wound healing process. RAW264.
The results were:
7 mouse macrophages cultured with a mixture of macrophage colony-stimulating factor, interleukin-4, and dexamethasone increased LYVE-1 expression, whereas lipopolysaccharide-stimulation decreased LYVE-1 expression. Enforced expression of Lyve1 in RAW264.7 cells resulted in increased mRNA expression of matrix metalloproteinase 2 (Mmp2), Mmp9, and vascular endothelial growth factor A (Vegfa). Lyve1-expressing macrophages promoted the migration and tube formation of human umbilical vein endothelial cells.
Thus, in conclusion, the study suggests that LYVE-1+ tissue-resident M2-like macrophages in dental pulp showed dynamism in response to pulp injury, and possibly play an important role in angiogenesis during wound healing and tissue remodelling.
Reference:
Kinetics of LYVE-1-positive M2-like macrophages in developing and repairing dental pulp in vivo and their pro-angiogenic activity in vitro by Thoai Quoc Kieu, et al. published in the Scientific Reports.
