This is a preview and has not been published.

Gene Expression and Methylation Levels of PCSK9 Gene in Iraqi Patients with Coronary Artery Disease


  • Marwa M. Al-Attar Department of Biology, College of Science, Mustansiriyah University, Baghdad, Iraq.
  • Salwa J. Al-Awadi Al-Awadi Department of Molecular and Medical Genetics Technologies, College of Biotechnology, Al-Nahrain University, Baghdad, Iraq.
  • Shaimaa Y. Abdulfattah Biotechnology Research Center, Al-Nahrain University, Baghdad, Iraq.



Atherosclerotic coronary artery disease, ELISA, Gene expression, Methylation, PCSK9, RT-qPCR


The expression of the Proprotein Convertase Subtilisin/Kexin Type 9 gene (PCSK9) is inextricably related to lipid levels and a risk of atherosclerotic coronary artery disease (ASCAD). The present study aims to measure the quantity of PCSK9 gene expression and the effect of methylation on its expression level taking part in the pathogenesis of acute coronary artery disorder.

A current study included 150 subjects from the Iraqi population, 100 ASCAD patients and 50 healthy controls. The concentration of PCSK9 in each serum sample was determined by the ELISA technique, the expression levels of the PCSK9 gene in whole blood were estimated by RT-qPCR – Quantitative Reverse Transcription PCR method, and DNA methylation level detection in PCSK9 gene by using High Resolution Melting Analysis (HRM) technique.

The expression level of the PCSK9 gene was 6.06 ± 1.84 in ASCAD patients group compared with a control group 1.00 ±0.19. That indicates the up-regulation of the PCSK9 gene in patient with atherosclerosis. In addition, the PCSK9 concentration was higher in patient group in comparison to the healthy controls group P= < 0.01. However, PCSK9 methylation levels, a highly significant distinction between the two study groups p=0.002. In conclusion, serum PCSK9 levels are associated with coronary artery lesions as shown in receiver operating characteristic (ROC) analysis. Suggests that, serum PCSK9 might be a good indicator of coronary artery disease development.


Download data is not yet available.


Tao J, Xia L, Cai Z, Liang L, Chen Y, Meng J, et al. Interaction Between microRNA and DNA Methylation in Atherosclerosis. DNA Cell Biol. 2021 Jan 19; 40(1): 1-15.

Pahwa R, Jialal I. Atherosclerosis. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2022 Jan.

Abdulfattah SY, Al-Awadi SJ. ApoB gene polymorphism (rs676210) and its pharmacogenetics impact on atorvastatin response among Iraqi population with coronary artery disease. J Genet Eng Biotechnol. 2021 June 22; 19(1): 95.

Abdulfattah SY, Al-Awadi SJ, Al-Saffar HB. Plasma oxidized low-density lipoprotein level and miRNA-146a gene expression, as a strong predictor for atherosclerotic coronary artery disease and its associated response to atorvastatin in a sample of the Iraqi population. J Gene Rep. 2020 Mar; 18: 2452-0144.

Abd RK, Abd SN, Raman V. Tracing the Risk Factors of Heart Diseases at Al-Nasiriyah Heart Center in Iraq. J Cardiovasc Dis Res. 2019; 10 (1): 31-34.

Al-Aamood AMK, Al-jubori NH, Al-Tmeme A. Prevalence of Coronary Atherosclerosis in Babylon Governorate;Histopathological, Postmortem Prospective Study. Med J Bab. 2015; 12 (2).

Shapiro MD, Fazio S. PCSK9 and atherosclerosis-lipids and beyond. J Atheroscler Thromb. 2017 Mar 9;24(5): 462-472.

Zhang B, Lai X, Jia S. Epigenetics in Atherosclerosis a Clinical Perspective. Discov Med. 2015 Feb 19; 19(103), 73-80.

Zhang PY. PCSK9 as a therapeutic target for cardiovascular disease. Exp Ther Med. 2017 Jan 17; 13(3), 810-814.

Zayr FH, Dhahi MAR, Abdul-Rasheed OF, Hashim HM. DNA Methylation Patterns of Interferon Gamma Gene Promoter and Serum Level in Pulmonary Tuberculosis: Their Role in Prognosis. Baghdad Sci J. 2019Mar.17; 16(1(Suppl.): 0178.

Shyamala N, Gundapaneni KK, Galimudi RK, Tupurani MA, Padala C, Puranam K, et al. PCSK9 genetic (rs11591147) and epigenetic (DNA methylation) modifications associated with PCSK9 expression and serum proteins in CAD patients. J Gene Med. 2021 Apr 22; 23(8): e3346.

Al-Qazzaz HK, Al-Awadi SJ. Epigenetic alteration in DNA methylation pattern and gene expression level using H19 on oligospermia patients in Iraqi men. J Gene Rep. 2020 Sep; 20: 100780.

Livak KJ, Schmittgen TD. Analysis of relative gene expression data using real-time quantitative PCR and the 2-ΔΔCt method. Methods. 2001 Dec; 25(4): 402-408.

Albanna AMJ, Al-Layla AAH. Using Real-Time PCR to Investigate Some of Antibiotic Resistance Genes from Streptococcus agalactiae Isolates from ewe Mastitis cases in Nineveh province. Baghdad Sci J. 2020 Sep 8; 17(3(Suppl.): 0931.

Al-Rahim AM, AlChalabi R, Al-Saffar AZ, Sulaiman GM, Albukhaty S, Belali T et al. Folate-methotrexate loaded bovine serum albumin nanoparticles preparation: an in vitro drug targeting cytokines overwhelming expressed immune cells from rheumatoid arthritis patients. Anim Biotechnol. 2021Jul 28.

Glover T, Mitchell K. An introduction to Biostatistics, 3ed Edition. Waveland press .Inc. 2008; (847): 634-0081;

Forthofer RN, Lee ES. Introduction to biostatistics: a guide to design, analysis, and discovery, 2nd ed. Elsevier. 2014; p. 1-602.

Zheng W, McLerran DF, Rolland BA, Fu Z, Boffetta P, He J. Burden of total and cause-specific mortality related to tobacco smoking among adults aged ≥ 45 years in Asia: a pooled analysis of 21 cohorts. PLoS Med. 2014 Apr 22; 11: e1001631.

Kim M, Han CH, Lee MY. NADPH Oxidase and the Cardiovascular Toxicity Associated with Smoking. Toxic Res. 2014 Sep. 30(3): 149-157.

Costanzo S, Castelnuovo AD, Donati MB, Iacoviello L, Gaetano GD. Alcohol Consumption and Mortality in Patients with Cardiovascular Disease. J Am Coll Cardiol. 2010 Mar 30; 55(13): 1339–1347. DOI:

Djoussé L, Lee IM, Buring JE Gaziano JM. Alcohol Consumption and Risk of Cardiovascular Disease and Death in Women. Circulation.2009 Jul 13. 120(3): 237-244.

Hajar R. Risk factors for coronary artery disease: historical perspectives. Heart views: the official j Gulf Hea Associa. 2017 Sep; 18(3): 109-114.

Phulukdaree A, Khan S, Moodly D, Chuturgoon AA. GST polymorphisms and early – onset coronary artery disease in young. S Afr Med J. 2012; 102 (7): 15-19.

Whelton S, Deal JA, Zikusoka M, Jacobson LP, Sarkar S, Palella Jr, et al. Associations between lipids and subclinical coronary atherosclerosis. Aids. 2019 May 1; 33(6), 1053-1061.

Chan I, Kwok K, Schooling M. The total and direct effects of systolic and diastolic blood pressure on cardiovascular disease and longevity using Mendelian randomization. Sci Rep. 2021 Nov 8; 11:21799.

Alfred EB, Kerry L, Gail H, Luis P, John F, Michael RG, et al. Limitations of Ejection Fraction for Prediction of Sudden Death Risk in Patients With Coronary Artery Disease: Lessons From the MUSTT Study. J Am Coll Cardiol . 2007 Sep; 50(12): 1150–1157.

Cikes M, Solomon SD. Beyond ejection fraction: an integrative approach for assessment of cardiac structure and function in heart failure. Eur Heart J. 2016 Jun 1; 37(21): 1642–1650.

Dua P, Reeta KH. PCSK9 (Proprotein convertase subtilisin/ kexin type 9): A Narrative Review. Pract Cardiovas Sci. 2020 Dec 23; 6(3): 226-233.

Barale C, Melchionda E, Morotti A, Russo, I. PCSK9 biology and Its role in atherothrombosis. Int J Mol Sci. 2021 May 14; 22(11): 5880.

Burke C, Dron S, Hegele A, Huff W. PCSK9 Regulation and Target for Drug Development for Dyslipidemia. Annu Rev Pharmacol Toxicol. 2017 Jul 31; 6(57): 223-244.

Pott J, Schlegel V, Teren A, Horn K, Kirsten H, Bluecher C, et al. Genetic regulation of PCSK9 (proprotein convertase subtilisin/kexin type 9) plasma levels and its impact on atherosclerotic vascular disease phenotypes. Circ Genom Precis Med. 2018 Jun 18; 11(5): e001992.

Tabaei S, Tabaee S. DNA methylation abnormalities in atherosclerosis. Artif Cells Nanomed Biotechnol. 2019 May 22; 47(1): 2031–2041.