Saeideh Sobati
1,2, Amir Shakouri
1, Mahdi Edalati
3,4, Daryoush Mohammadnejad
1, Reza Parvan
5, Javad Masoumi
6, Jalal Abdolalizadeh
7,4* 
1 Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
2 Department of Biochemistry, Higher Education Institute of Rab-Rashid, Tabriz, Iran.
3 Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
4 Paramedical Faculty, Tabriz University of Medical Sciences, Tabriz, Iran.
5 Department of Biosciences, University of Milan, Via celoria 26, 20133, Milan, Italy.
6 Immunology Department, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
7 Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Abstract
Proprotein convertase subtilisin/kexin type 9 (PCSK9), as a vital modulator of low-density lipoprotein cholesterol (LDL-C) , is raised in hepatocytes and released into plasma where it binds to LDL receptors (LDLR), leading to their cleavage. PCSK9 adheres to the epidermal growth factor-like repeat A (EGF-A) domain of the LDLR which is confirmed by crystallography. LDLR expression is adjusted at the transcriptional level through sterol regulatory element binding protein 2 (SREBP-2) and at the post translational stages, specifically through PCSK9, and the inducible degrader of the LDLR PCSK9 inhibition is an appealing new method for reducing the concentration of LDL-C. In this review the role of PCSK9 in lipid homeostasis was elucidated, the effect of PCSK9 on atherosclerosis was highlighted, and contemporary therapeutic techniques that focused on PCSK9 were summarized. Several restoration methods to inhibit PCSK9 have been proposed which concentrate on both extracellular and intracellular PCSK9, and they include blockage of PCSK9 production by using gene silencing agents and blockage of it’s binding to LDLR through antibodies and inhibition of PCSK9 autocatalytic processes by tiny molecule inhibitors.