Shikonin Up-regulates ABCA1 Expression Through PTEN/RUNX1 Pathway

[Background and Aim] Atherosclerosis(As)is an important pathological factor that induces cardiovascular disease.Adenosine triphosphate binding cassette transporter A1(ATP-binding cassette transporter A1,ABCA1)is a type of membrane protein and a member of the ATP binding cassette transporter(ABC)superfamily.It promotes intracellular cholesterol by consuming ATP.It flows out from the cell to apolipoprotein A-I(apolipoprotein,apo A-I),and is transported to the liver for metabolism to play an anti-atherosclerotic effect.Therefore,exploring the various functions of ABCA1 and promoting the outflow of cholesterol in cells is of great significance for the prevention and treatment of atherosclerosis.Shikonin(Shikonin)is a tea quinone natural pigment extracted from natural plant roots.It contains shikonin and its derivatives.It has anti-inflammatory,antibacterial,antiviral,anti-thrombotic,hypoglycemic,and liver protection properties.Related studies have reported that shikonin can inhibit the formation of AS,but it is not clear whether shikonin reduces atherosclerotic lesions is related to the regulation of ABCA1.This topic uses ABCA1 as the target to explore the effect of shikonin on the levels of ABCA1 in macrophages and its specific mechanism.This study helps to clarify the role of shikonin in regulating AS,and provides a theoretical basis for the clinical use of As.[Methods] First,use qPCR and Western Blot to detect the effect of shikonin on the expression of ABCA1 in macrophages;use a liquid scintillation counter to find the effect of shikonin on lipid efflux;detect the activation of shikonin on the transcription factors RUNX1 and ABCA1 After overexpression of PTEN and RUNX1,detect the influence of PTEN and RUNX1 on the expression of ABCA1,and verify that shikonin affects the expression of ABCA1 through the PTEN/RUNX1 signaling pathway.Finally,apo E-/-mice were given shikonin,oil red O,HE,and Masson staining to determine the area of AS plaques in the mouse aorta.Collect mouse aorta specimens,and measure the expression of ABCA1 in the mouse aorta by qPCR and Western Blot.[Results] WB results showed that shikonin significantly increased the expression of ABCA1 in macrophages.Shikonin can reduce the content of total cholesterol,free cholesterol and cholesterol ester in macrophages.The results of the luciferase reporter gene showed that shikonin activated the ABCA1 promoter;qPCR and Western Blot tests showed that RUNX1 siRNA inhibited the expression of ABCA1,indicating that RUNX1 is a key factor for shikonin to regulate the expression of ABCA1;detection of shikonin on PTEN The results showed that shikonin promoted the expression of PTEN,and after inhibiting PTEN,the activity of RUNX1 and the expression of ABCA1 decreased significantly,which proved that shikonin up-regulated the expression of ABCA1 through the PTEN/RUNX1 pathway;The staining of frozen sections of the aortic valve suggests that shikonin can significantly reduce the formation of plaques;the detection of ABCA1 levels in the aorta and plaques of mice indicates that shikonin can increase the expression of ABCA1.[Conclusions]1.Shikonin promotes the binding of RUNX1 to the ABCA1 promoter region by up-regulating the expression of PTEN,which increases cholesterol efflux,thereby reducing intracellular lipid accumulation.2.Shikonin up-regulates the expression of ABCA1 and inhibits the formation and development of atherosclerosis.