Altered expression of miR-375 and miR-541 in type 2 diabetes patients with and without coronary artery disease (CAD): the potential of miR-375 as a CAD biomarker.

Background: MicroRNAs (miRNAs, miRs) have been linked to beta-cell pathologies and have also shown potential as biomarkers for cardiovascular disease. This study aimed to evaluate the expression of miR-375 and miR-541 in T2D patients with and without CAD, in order to determine the potential of these miRNAs as biomarkers for assessing CAD risk. Methods: This study was conducted on 106 patients with T2D who underwent coronary angiographic examination. Reverse transcription was performed using the cDNA synthesis kit. Real-time PCR was performed using the SYBR Green method and specific primers. The ability to predict which person had developed CAD was evaluated by calculating the area under the receiver-operating characteristic (ROC) curve (AUC). Results: The expression of miR-375 was significantly higher in samples from CAD patients compared to those without CAD (p = 0.009). While the expression of miR-541 was also higher in CAD patients, the difference was not statistically significant. In terms of predicting CAD, miR-375 was found to be a suitable predictor with an AUC of 0.74 (p = 0.01), while miR-541 was not. With a cut-off value of 0.016 for miR-375, the sensitivity was 67% and the specificity was 80%. Conclusion: Our results indicated that circulating levels of miR-375 and miR-541 were elevated in T2D patients with CAD compared to those without CAD. This suggests that miR-375 could potentially be used as a non-invasive biomarker for the diagnosis of CAD in T2D patients.

Pleiotropic functions and clinical importance of circulating HDL-PON1 complex.

High density lipoprotein (HDL) functions are mostly mediated through a complex proteome, particularly its enzymes. HDL can provide a scaffold for the assembly of several proteins that affect each other's function. HDL particles, particularly small, dense HDL3, are rich in paraoxonase 1 (PON1), which is an important enzyme in the functionality of HDL, so the antioxidant and antiatherogenic properties of HDL are largely attributed to this enzyme. There is an increasing need to represent a valid, reproducible, and reliable method to assay HDL function in routine clinical laboratories. In this context, HDL-associated proteins may be key players; notably PON1 activity (its arylesterase activity) may be a proper candidate because its decreased activity can be considered an important risk factor for HDL dysfunctionality. Of note, automated methods have been developed for the measurement of serum PON1 activity that facilitates its assay in large sample numbers. Arylesterase activity is proposed as a preferred activity among the different activities of PON1 for its assay in epidemiological studies. The binding of PON1 to HDL is critical for the maintenance of its activity and it appears apolipoprotein A-I plays an important role in HDL-PON1 interaction as well as in the biochemical and enzymatic properties of PON1. The interrelationships between HDL, PON1, and HDL's other components are complex and incompletely understood. The purpose of this review is to discuss biochemical and clinical evidence considering the interactions of PON1 with HDL and the role of this enzyme as an appropriate biomarker for HDL function as well as a potential therapeutic target.

Can HDL cholesterol be replaced by paraoxonase 1 activity in the prediction of severe coronary artery disease in patients with type 2 diabetes?

BACKGROUND AND AIMS: Novel biomarkers are required to improve cardiovascular disease prediction in patients with type 2 diabetes (T2D) as a high-risk population. This study was conducted to examine whether coronary artery disease (CAD) risk assessment can be improved by substituting high-density lipoprotein (HDL)-bound paraoxonase 1 (PON1) activity for HDL cholesterol (HDL-C) concentration in patients with T2D. METHODS AND RESULTS: In this study, we studied 139 patients with T2D (mean age 64.12 ± 8.17 years) who underwent coronary angiographic examination. The initial rate of substrate hydrolysis was spectrophotometrically assayed in kinetic mode for measuring PON1 activity. Receiver operating characteristic (ROC) graphs are created by plotting true positivity versus false positivity. In patients with HbA1c ≥ 7%, PON1 (AUC = 0.7, p = 0.029) and nonHDL-C/PON1 (AUC = 0.75, p = 0.013) were significantly more capable of differentiating patients with CAD from those without CAD compared to HDL-C and nonHDL-C/HDL-C. Also, the predictive power of PON1 (AUC = 0.64, p = 0.029) and nonHDL-C/PON1 (AUC = 0.71, p = 0.004) were significantly higher in comparison with HDL-C and nonHDL-C/HDL-C for CAD characterization in patients aged ≥50 years. Moreover, PON1 and nonHDL-C/PON1 are associated with the incidence of CAD with an AUC of 0.7 (p = 0.026) and AUC of 0.64 (p = 0.087), respectively, among subjects with low HDL-C. CONCLUSION: PON1 and the ratio of nonHDL-C/PON1 significantly improve the prediction of severe CAD in T2D patients and in patients with HbA1c ≥ 7%, age ≥50 years, or low HDL-C. PON1 activity and lipid ratios using this enzyme may be valuable as substitutes of HDL-C for increasing clinical efficacies in cardiovascular risk assessment.

Paraoxonase 1 Activity is Associated with Interleukin-6 Levels in Type 2 Diabetes: Effects of Age and Gender.

Background: A further understanding of the mechanisms linking inflammation to T2D and related complications can help prevent or control this silent but dangerous disease. This study was conducted to determine the association between paraoxonase 1 (PON1) activity and interleukin-6 (IL-6) in type 2 diabetes (T2D). Furthermore, we have evaluated the role of age and gender in the relationship between the PON1 activity and IL-6. Methods: A total of 105 people with T2D were enrolled in this study. IL-6 levels were determined using ELISA. For the PON1 activity assay, the hydrolysis rate of the substrate phenylacetate was spectrophotometrically assayed in serum at 270 nm. The determined velocities were the initial velocities of substrate hydrolysis. Results: PON1 activity was negatively correlated with IL-6 in total data (r = -0.34, P = 0.001). In both groups with age ≥50 and <50 years, PON1 activity was negatively correlated with IL-6, but the correlation was significant in patients aged 50 years and above (r = -0.358, P = 0.005) compared with patients with age <50 years. In both women and men, PON1 activity was negatively correlated with IL-6, but the correlation was significant in women (r = -0.318, P = 0.006) in comparison with men. Conclusions: Inverse association between PON1 activity and IL-6 in T2D may represent the oxidative-inflammatory interaction in this disease. Our findings highlight that at older ages and in women, the associations between lower PON1 activity and higher IL-6 concentrations are more evident, and this should be considered in patients with T2D.

Association between vitamin D receptor gene polymorphism (rs731236) and aggrecan gene VNTR polymorphism with the risk of lumbar intervertebral disc degeneration.

Background: Low back pain is one of the most common causes of referral to physicians. Lumbar disc degeneration (LDD) is the main cause of back pain in different countries. It seems that genetic factors are more effective than environmental factors in the developing of degenerative phenomena. The aim of this investigation, therefore, was to study the association of the aggrecan gene (ACAN) variable number tandem repeat (VNTR) and the vitamin D receptor (VDR) rs731236 (TaqI) polymorphisms, with lumbar intervertebral disc degeneration in a population in the North of Iran. Methods: In this study, 55 patients with symptomatic intervertebral disk degeneration and 55 control subjects were included. VDR gene polymorphism was genotyped by PCR-based RFLP. The isolated DNA was used to genotype the VNTR of ACAN gene via conventional PCR. Results: For VDR gene polymorphism, the CC genotype (OR=5.337, P=0.019) was significantly higher among the patients compared with the controls, revealing a higher frequency of the C allele in patients compared with controls (OR=2.707, P=0.005). The lower number of frequent repetitions in the VNTR aggrecan gene was associated with a six-time increase of lumbar disc degeneration. Also, high BMI can be considered as an independent factor in the incidence of this disease. Conclusion: Aggrecan gene VNTR polymorphism had an association with degeneration of lumbar intervertebral discs that the shorter VNTR repeats increasing the chance of the disc degeneration in this population in the North of Iran. Moreover, an association between the mutant allele (C) of VDR gene TaqI polymorphism and disc degeneration is found.

Oxidized LDL-regulated microRNAs for evaluating vascular endothelial function: molecular mechanisms and potential biomarker roles in atherosclerosis.

As a simple monolayer, vascular endothelial cells can respond to physicochemical stimuli. In addition to promoting the formation of foam cells, oxidized low-density lipoprotein (ox-LDL) contributes to the atherosclerotic process through different mechanisms, including endothelial cell dysfunction. As conserved noncoding RNAs, microRNAs (miRNAs) naturally lie in different genomic positions and post-transcriptionally regulate the expression of many genes. They participate in integrated networks formed under stress to maintain cellular homeostasis, vascular inflammation, and metabolism. These small RNAs constitute therapeutic targets in different diseases, including atherosclerosis, and their role as biomarkers is crucial given their detectability even years before the emergence of diseases. This review was performed to investigate the role of ox-LDL-regulated miRNAs in atherosclerosis, their molecular mechanisms, and their application as biomarkers of vascular endothelial cell dysfunction.

Noncoding RNA Roles in Pharmacogenomic Responses to Aspirin: New Molecular Mechanisms for an Old Drug.

Aspirin, as one of the most frequently prescribed drugs, can have therapeutic effects on different conditions such as cardiovascular and metabolic disorders and malignancies. The effects of this common cardiovascular drug are exerted through different molecular and cellular pathways. Altered noncoding RNA (ncRNA) expression profiles during aspirin treatments indicate a close relationship between these regulatory molecules and aspirin effects through regulating gene expressions. A better understanding of the molecular networks contributing to aspirin efficacy would help optimize efficient therapies for this very popular drug. This review is aimed at discussing and highlighting the identified interactions between aspirin and ncRNAs and their targeting pathways and better understanding pharmacogenetic responses to aspirin.

Epigenetic alterations and genetic variations of angiotensin-converting enzyme 2 (ACE2) as a functional receptor for SARS-CoV-2: potential clinical implications.

Receptor recognition is a crucial step in viral infection and is a critical factor for cell entry and tissue tropism. In several recent studies, angiotensin-converting enzyme 2 (ACE2) has been demonstrated to be the cellular receptor of SARS-CoV-2 as it was previously well known as the receptor of SARS-CoV. SARS-CoV-2 can bind with high affinity to human ACE2 and engages it as an entry receptor. It seems that the genetic, notably epigenetic variations of ACE2 are less known in different populations, indicating the need for its further investigation. These variations have the potential to affect its contribution to the pathogenicity of COVID-19. The contribution of epigenetics in the interindividual variability of ACE2 merits more attention because epigenetic processes can play important roles in ACE2 alterations in various tissues and different people and populations. Analyzing different DNA methylation patterns and microRNAs, contributing to the ACE2 modulation in the lungs will have a high priority. The epigenetic and genetic variations of ACE2 become even more important when considering that some people have mild clinical symptoms despite having COVID-19. The pathogenicity of SARS-CoV-2 infection is complex; therefore, a better understanding of the underlying pathobiology, especially binding the virus to its receptors, could help improve therapeutic and preventive approaches. This review aims to highlight the importance of evaluating both the epigenetic and genetic variations of ACE2 as a receptor for the deadly SARS-CoV-2.

MicroRNAs may provide new strategies in the treatment and diagnosis of diabetic retinopathy: Importance of VEGF.

Diabetic retinopathy (DR) is ocular microvascular complications of diabetes mellitus. Along with the increasing prevalence of diabetes worldwide, DR has come into the major cause of human blindness. Several studies have demonstrated the important roles of the expression alteration in the proteins contributed to vascular dysfunction during DR, especially vascular endothelial growth factor (VEGF). However, there is a need for further mechanistic research in this context to design new therapeutic and diagnostic programs. MicroRNAs (miRNAs, miRs) have been introduced as key controllers of gene expression in a variety of biological processes including differentiation, proliferation, and metabolism. Altered expression of miRNAs during DR development indicates a close relationship between these regulatory molecules and DR through regulating gene expressions. This review discusses and updates the functions of miRNA-dependent pathways and key roles of VEGF in the DR, which may increase our understanding and ability to target these small but important molecules to efficiently improve therapeutic and diagnostic approaches.

The complex combination of COVID-19 and diabetes: pleiotropic changes in glucose metabolism.

PURPOSE: Angiotensin converting enzyme 2 (ACE2) is the door for SARS-CoV-2, expressed in critical metabolic tissues. So, it is rational that the new virus causes pleiotropic alterations in glucose metabolism, resulting in the complication of pre-existing diabetes's pathophysiology or creating new disease mechanisms. However, it seems that less attention has been paid to this issue. This review aimed to highlight the importance of long-term consequences and pleiotropic alterations in glucose metabolism following COVID-19 and emphasize the need for basic and clinical research in metabolism and endocrinology. RESULTS: SARS-CoV-2 shifts cellular metabolism from oxidative phosphorylation to glycolysis, which leads to a decrease in ATP generation. Together with metabolic imbalance, the impaired immune system elevates the susceptibility of patients with diabetes to this deadly virus. SARS-CoV-2-induced metabolic alterations in immune cells can result in hyper inflammation and a cytokine storm. Metabolic dysfunction may affect therapies against SARS-CoV-2 infection. The effective control of metabolic complications could prove useful therapeutic targets for combating COVID-19. It is also necessary to understand the long-term consequences that will affect patients with diabetes who survived COVID-19. CONCLUSIONS: Since the pathophysiology of COVID-19 is still mostly unknown, identifying the metabolic mechanisms contributing to its progression is essential to provide specific ways to prevent and improve this dangerous virus's detrimental effects. The findings show that the new virus may induce new-onset diabetes with uncertain metabolic and clinical features, supporting a potential role of COVID-19 in the development of diabetes.

Role of microRNAs in the anticancer effects of the flavonoid luteolin: a systematic review.

Flavonoids, a broad class of polyphenolic compounds, can potentially have several therapeutic properties in human diseases, including protective effects against oxidative stress, inflammation, cardiovascular disease, diabetes, neurodegenerative disorders, and cancers. Luteolin as a member of flavonoids has been found to exhibit several anticancer properties mainly through cell apoptosis induction, inhibition of invasion, cell proliferation, network formation, and migration. Recent studies have revealed that phytochemicals such as luteolin may exert therapeutic properties through microRNAs (miRNAs or miRs), which have been emerged as important molecules in cancer biology in recent years. miRNAs, as a class of noncoding RNAs, have several important roles in cancer progression or regression. In this review, we aimed to summarize and discuss the role of miRNAs in the luteolin effects on different cancers. This review can be in line with the studies, which have shown that miRNAs may be potential therapeutic targets in cancer treatment.

Improved risk assessment of coronary artery disease by substituting paraoxonase 1 activity for HDL-C: Novel cardiometabolic biomarkers based on HDL functionality.

BACKGROUND AND AIMS: Developing laboratory assays to evaluate HDL functions and improve cardiovascular disease (CVD) risk assessment has recently emerged as a challenge. The present study was conducted to help predict the risk of coronary artery disease (CAD) by investigating new cardiometabolic risk factors based on substituting paraoxonase 1 (PON1) as a critical enzyme in the functionality of HDL for that of HDL-C. METHODS AND RESULTS: The present study recruited 274 subjects undergoing diagnostic coronary angiography, 92 without significant CAD (non-CAD), and 182 with a severe CAD. The diagnostic accuracy of the new biomarkers in non-CAD versus multi-vessel disease was obtained in descending order of AUC as 0.72 (P < 0.001) for log (TG/PON1), 0.70 (P < 0.001) for nonHDL-C/PON1, and 0.67 (P < 0.001) for LDL-C/PON1. After performing a multivariate adjustment for age, gender, BMI, statin therapy, and diabetes mellitus, the increased odds of CAD remained significant for the new cardiometabolic ratios as independent variables [adjusted OR = 1.47 (1.15-1.88), p = 0.002 for LDL-C/PON1; adjusted OR = 2.15 (1.41-3.5), p = 0.009 for nonHDL-C/PON1; adjusted OR = 5.03 (2.14-13.02), p = 0.004 for log (TG/PON1)]. CAD was diagnosed with an optimal discriminating cutoff of 1.84 for LDL-C/PON1, 2.8 for nonHDL-C/PON1, and 0.48 for log (TG/PON1). CONCLUSIONS: To improve CAD's risk assessment, the PON1 activity was proposed as an alternative to HDL-C in the commonly used atherogenic lipid ratios. Substituting the PON1 activity for the HDL-C concentration can provide an index of the HDL activity. The present study sought to exploit the lipoprotein-related risk factors of CAD from a more effective perspective.

The Atherogenic Index Log (Triglyceride/HDL-Cholesterol) as a Biomarker to Identify Type 2 Diabetes Patients with Poor Glycemic Control.

BACKGROUND: Identifying appropriate biomarkers for predicting type 2 diabetes (T2D) patients with increased HbA1c may prove helpful in preventing increased risk of cardiovascular disease (CVD). The present study was conducted to analyze the diagnostic performance of the atherogenic index log (TG/HDL-C) in T2D patients with increased HbA1c. METHODS: Patients with T2D were classified into two groups according to having an HbA1c <8% or ≥8%. Atherogenic index was calculated from the logarithmic transformation of TG/HDL-C. Receiver operating characteristic curve was used to evaluate the diagnostic performance of log (TG/HDL-C). Insulin and fasting glucose concentrations were used to determine homeostasis model assessment for insulin resistance (HOMA-IR). RESULTS: Compared with the patients with HbA1c <8%, log (TG/HDL-C) was significantly higher in the patients with HbA1c ≥8% (p = 0.025). The atherogenic index was a biomarker for the prediction of T2D patients with HbA1c ≥8% versus patients with HbA1c <8%, as shown in the area under the curve (AUC = 0.61, P = 0.013). The best cut-off point of log (TG/HDL-C) for the discrimination between patients with HbA1c ≥8% versus patients with HbA1c <8% determined to be 0.44. Atherogenic index was significantly and positively correlated with HOMA-IR in female patients (r = 0.313, P = 0.003) and in patients with an age ≥5o (r = 0.253, P = 0.021). CONCLUSION: The log (TG/HDL-C) in addition to its known association with enhanced CVD risk could be considered as a biomarker to predict T2D patients with poor glycemic control. Therefore, the increased ratio may provide a simple and useful way of identifying poor glycemic T2D patients who are possibly to be at elevated risk of CVD.

Association of rs11558471 in SLC30A8 Gene with Interleukin 17 Serum Levels and Insulin Resistance in Iranian Patients with Type 2 Diabetes.

BACKGROUND: According to genome wide association studies, SLC30A8 is among the loci containing SNPs associated with type 2 diabetes (T2D) risk. This gene encodes an islet zinc transporter (ZnT8). OBJECTIVE: To provide new information on the association of the SNP rs11558471 in SLC30A8 gene with IL-17 levels and insulin resistance in an Iranian population with T2D. METHODS: A total of 133 patients with T2D and 128 control subjects were included in this study. Insulin and IL-17 concentrations were determined using ELISA. Insulin and fasting blood glucose levels were employed to determine homeostasis model assessment for insulin resistance (HOMA-IR). PCR-based restriction fragment length polymorphism was performed to determine rs11558471 polymorphism. RESULTS: The risk allele frequency of rs11558471 in studied population was among the highest frequencies in different populations. In T2D patients, compared with the GG genotypes, IL-17 concentrations were significantly higher in the GA+AA group (p=0.042). According to the genotypes of this SNP, IL-17 concentrations, fasting blood glucose and HOMA-IR increased with the following order: GG

Functional mechanisms of miR-192 family in cancer.

By growing research on the mechanisms and functions of microRNAs (miRNAs, miRs), the role of these noncoding RNAs gained more attention in healthcare. Due to the remarkable regulatory role of miRNAs, any dysregulation in their expression causes cellular functional impairment. In recent years, it has become increasingly apparent that these small molecules contribute to development, cell differentiation, proliferation, apoptosis, and tumor growth. In many studies, the miR-192 family has been suggested as a potential prognostic and diagnostic biomarker and even as a possible therapeutic target for several cancers. However, the mechanistic effects of the miR-192 family on cancer cells are still controversial. Here, we have reviewed each family member of the miR-192 including miR-192, miR-194, and miR-215, and discussed their mechanistic roles in various cancers.

Epigenetics of paraoxonases.

PURPOSE OF REVIEW: Studies have shown the three-member paraoxonase (PON) multigene family to be involved in the development of a large variety of diseases with an inflammatory component. Environmental factors such as lifestyle-related factors differ widely between populations and it is important to consider that their impacts may be exerted through the epigenetic mechanisms, which connect genes, the environment and disease development and are a potential therapeutic avenue. RECENT FINDINGS: In the review period, very little was published on epigenetics of PON2 or PON3, mostly on their diagnostic value in cancer by measuring methylation levels of these genes. However, the picture is more promising with PON1. Here, several studies have linked the epigenetic regulation of PON1 to various metabolic processes and particularly to the development of several diseases, including stroke, heart disease, aortic valve stenosis and chronic obstructive pulmonary disease. SUMMARY: Studies into the epigenetic regulation of the PON family are in their infancy. However, recent studies linking epigenetic regulation of PON1 to disease development will encourage further research and open up the possibility for new potential therapeutic interventions.

Importance of paraoxonase 1 (PON1) as an antioxidant and antiatherogenic enzyme in the cardiovascular complications of type 2 diabetes: Genotypic and phenotypic evaluation.

Oxidant-antioxidant imbalance is involved in the etiology of different diseases, including cardiovascular diseases (CVDs), liver disorders, kidney diseases, cancers and diabetes mellitus. Antioxidant enzymes play a key role in striking an oxidant-antioxidant balance. Moreover, paraoxonase 1 (PON1) is an antioxidant enzyme that binds with high-density lipoprotein (HDL) in the circulation, and antioxidant and antiaterogenic properties of this lipoprotein are significantly associated with PON1. Research suggests PON1 contributes to the pathogenesis of certain human diseases such as type 2 diabetes (T2D). The association between PON1 and T2D appear to be reciprocal so that the disease significantly decreases PON1 levels and in turn, the genetics of PON1 may have a role the risk of susceptibility to T2D. Several factors that reduce the activity and concentration of PON1 in patients with T2D include increased glycation and loss-of-function polymorphisms. The genotypic and phenotypic evaluations of PON1 are therefore crucial for assessing the risk of cardiovascular complications in these patients, and strategies for increasing or restoring PON1 levels are useful for reducing or preventing their cardiovascular complications as their main cause of mortality. The present review aimed at discussing and emphasizing the key role of PON1 in T2D as a silent and dangerous disease.

Epigallocatechin-3-gallate Enhances the Efficacy of MicroRNA-34a Mimic and MicroRNA-93 Inhibitor Co-transfection in Prostate Cancer Cell Line.

The potential role of microRNAs (miRNA or MIR) as therapeutic molecules has moved them from basic research to the field of cancer therapy. High expression of miR-93 and low expression of miR-34a have previously been indicated in prostate cancer (PC), which is the second leading cause of cancer-related death in men. Androgen receptor (AR) and prostate-specific antigen (PSA) play key roles in the initiation and progression of this cancer. Therefore, this study aimed to investigate the effects of the transfection and co-transfection of miR-34a mimic and miR-93 inhibitor with or without epigallocatechin-3-gallate (EGCG) on prostate cancer cell line and also to evaluate their effects on the expression of AR, PSA. Human lymph node carcinoma of the prostate (LNCaP) cells were treated with miR-34a mimic or/and miR-93 inhibitor with or without EGCG. Gene or protein expressions were assessed by real-time PCR or western blotting of lysates. The transfection with miR-34a mimics significantly reduced the mRNA expression of AR (p=0.0016), and PSA (p=0.038) compared to the control. Also, the miR-93 inhibitor led to a decrease in the mRNA expression of AR (p=0.0057) and PSA (p>0.05) compared to the control group. Furthermore, the co-transfection, along with EGCG, caused more decrease in both the AR (p<0.001) and the PSA (p=0.003) expression compared with the co-transfection without EGCG. Our study indicates that the reduced expression of AR and PSA in PC cells followed by treatment with miR-34a mimic and miR-93 inhibitor and their combination with EGCG as a natural substance may be a promising therapeutic way for controlling the growth of these malignant cells.

The epigenetic regulation of paraoxonase 1 (PON1) as an important enzyme in HDL function: The missing link between environmental and genetic regulation.

BACKGROUND: Paraoxonase 1 (PON1) is an important antiatherogenic and antioxidant enzyme in the circulation that has been associated with adverse health outcomes particularly cardiovascular disease (CVD) and other metabolic disorders. PON1 is a highly promiscuous enzyme and can hydrolyse a large variety of substrates, however, detailed structure/function studies have concluded that the natural substrates for PON1 are lipophilic lactones. The interindividual variability in PON1 activity has been mainly attributed to genetic determinants; however, it appears that the contribution of epigenetics has been ignored as a result of the lack of adequate research. CONTENT: Epigenetic processes, including the histone modifications in the PON1 gene, the methylation of CpG sites in the promoter region of the PON1 gene and the microRNA modulation of PON1 expression can be responsible for the under researched gap between the environmental and genetic regulation of PON1. Environmental factors, including diet, pollution and lifestyle-related factors widely differ between individuals and populations and can cause large differences in the distribution of PON1 and it is important to note that their effects may be exerted through the epigenetic processes. This review discusses and emphasizes the importance of the epigenetic regulation of PON1 as a less-studied subject to highlight future research landscapes. SUMMARY: Epigenetic regulation is known as an important contributor to the pathogenesis of human diseases, particularly multifactorial diseases such as CVD, which is life-threatening. Due to the importance of PON1 in the functionality of high-density lipoprotein (HDL) and its association with CVD, further explorations of its epigenetic regulation using advanced methods such as Methyl-Seq may lead to the identification of new epigenetic contributors that in turn may lead to targeted therapies.