Melendez Quantil M, Wooten Catherine J, Krishnaji Sreevidhya T, Knagge Kevin, Kirchner David, Lopez Dayami
Department of Pharmaceutical Sciences, Biomanufacturing Research Institute and Technology Enterprise (BRITE), College of Arts and Sciences, North Carolina Central University, Durham, USA.
Indian Institute of Science Education and Research Bhopal, Madhya Pradesh, India.
Int J Biomed Investig. 2020 Jan-Jun;3(1). doi: 10.31531/2581-4745.1000123. Epub 2020 Feb 27.
High levels of cholesterol, especially as low-density lipoprotein (LDL), are a well-known risk factor for atherosclerotic-related diseases. The key atherogenic property of LDL is its ability to form atherosclerotic plaque. Proprotein convertase subtilisin/kexin-9 (PCSK9) is an indirect regulator of plasma LDL levels by controlling the number of LDL receptor molecules expressed at the plasma membrane, especially in the liver. Herein, we performed a combination of affinity chromatography, mass spectrometry analysis and identification, and gene expression studies to identify proteins that interact with PCSK9. Through these studies, we identified three proteins, alpha-1-antitrypsin (A1AT), alpha-1-microglobulin/bikunin precursor (AMBP), and apolipoprotein H (APOH) expressed by C3A cells that interact with PCSK9. The expression levels of A1AT and APOH increased in cells treated with MITO+ medium, a condition previously shown to affect the function of PCSK9, as compared to treating with Regular (control) medium. However, AMBP expression did not change in response to the treatments. Additional studies are required to determine which of these proteins can modulate the expression/function of PCSK9. The identification of endogenous modulators of PCSK9's function could lead to the development of novel diagnostic tests or treatment options for patients suffering hypercholesterolemia in combination with other chronic metabolic diseases.
高水平的胆固醇，尤其是低密度脂蛋白（LDL），是动脉粥样硬化相关疾病的一个众所周知的危险因素。LDL的关键致动脉粥样硬化特性是其形成动脉粥样硬化斑块的能力。前蛋白转化酶枯草杆菌蛋白酶/kexin-9（PCSK9）是血浆LDL水平的间接调节剂，通过控制质膜上，尤其是肝脏中表达的LDL受体分子数量来实现。在此，我们进行了亲和色谱、质谱分析与鉴定以及基因表达研究的组合，以鉴定与PCSK9相互作用的蛋白质。通过这些研究，我们鉴定出三种由C3A细胞表达的与PCSK9相互作用的蛋白质，即α-1-抗胰蛋白酶（A1AT）、α-1-微球蛋白/ bikunin前体（AMBP）和载脂蛋白H（APOH）。与用常规（对照）培养基处理相比，在用MITO +培养基处理的细胞中，A1AT和APOH的表达水平升高，之前已表明这种条件会影响PCSK9的功能。然而，AMBP的表达在处理后没有变化。需要进一步的研究来确定这些蛋白质中哪些可以调节PCSK9的表达/功能。鉴定PCSK9功能的内源性调节剂可能会为患有高胆固醇血症并伴有其他慢性代谢疾病的患者开发新的诊断测试或治疗方案。
