Novel Adipokine, FAM19A5, Inhibits Neointima Formation After Injury Through Sphingosine-1-Phosphate Receptor 2

Area of Science:

• Endocrinology
• Cardiovascular Biology
• Molecular Biology

Background:

• Obesity is a significant risk factor for cardiovascular diseases, but the underlying mechanisms are not fully understood.
• Adipokines, signaling molecules from adipose tissue, are implicated in obesity-related cardiovascular complications.
• The novel adipokine Family with sequence similarity 19, member A5 (FAM19A5) was identified, with its role in vascular pathology unexplored.

Purpose of the Study:

• To investigate the function of the novel adipokine FAM19A5 in regulating vascular pathology following injury.
• To identify the molecular mechanisms and receptor through which FAM19A5 exerts its effects on vascular cells.

Main Methods:

• Characterization of FAM19A5 secretion and expression using molecular biology techniques.
• In vivo studies involving balloon and wire injury models in rats and mice to assess neointima formation.
• Identification of the FAM19A5 receptor using bioinformatics, binding assays, and cell signaling analyses.

Main Results:

• FAM19A5 is a secreted protein expressed in adipose tissue, downregulated in obesity.
• Overexpression of FAM19A5 suppressed vascular smooth muscle cell proliferation, migration, and neointima formation.
• Sphingosine-1-phosphate receptor 2 (S1PR2) was identified as the functional receptor for FAM19A5, mediating its effects via the G12/13-RhoA pathway.

Conclusions:

• The novel adipokine FAM19A5 inhibits post-injury neointima formation through the S1PR2-G12/13-RhoA signaling axis.
• Downregulation of FAM19A5 in obesity may be a contributing factor to the development of cardiometabolic diseases.