Rac2 mediate foam cell formation and associated immune responses in THP-1 to promote the process of atherosclerotic plaques

Macrophages play an important role in the pathogenesis of atherosclerosis (AS) by mediating oxidative stress, inflammation and lipid metabolism, which can lead to the formation of vascular plaque. The Rac family isoforms of small molecules GTPase are active by binding to GTPase, but are inactivated by binding to GDP, and play a role in the switch of cell information conduction. This experiment adopts shRNA interference THP-1 cells respectively each subtype expression and inhibiting Rac1, Rac2, Rac3 activity, each subtype of Rac family on lipid metabolism, inflammatory reaction and oxidative stress. THP-1 cells were stimulated with Ox-LDL to establish AS cell models including lipid loading, adhesion, migration and chemotaxis. Oil Red O staining, cell immunofluorescence, scratching test, transwell, Western blot and other experiments were performed. To observe the different effects of three subtypes of Rac family on multiple links in the foaming process of THP-1 cells. ApoE-/- mice on a high-fat diet were used as animal models to examine the effects of Rac subtypes in vivo. The results showed that the activation of immune cells induced by ox-LDL was inhibited when Rac1, Rac2 and Rac3 in THP-1 were decreased, respectively. Thus, Rac1 and Rac3 act in combination with ox-LDL and are associated with cellular oxidative stress and inflammation. This study provides new means and ideas for finding potential intervention targets that have important regulatory effects on atherosclerosis, and provides a new direction for the development of clinical drugs.