Modulatory Effect of Lifestyle-Related, Environmental and Genetic Factors on Paraoxonase-1 Activity: A Review

Overview of Oxidative Stress in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that is frequently diagnosed in female patients, caused by multiple interacting factors. It has a complex pathogenesis which can affect almost any organ, from the kidneys to the cardiovascular, pulmonary, neurological, osteoarticular, and hematological systems. The present narrative review seeks to elucidate the role of reactive oxygen species (ROS) in the pathogenesis of SLE. The central question guiding this study is to what extent these serum protein modifications correlate with disease activity and organ damage in SLE. It is characterized by the decreased apoptosis and increased necrosis of T cells and the NETosis of granulocytes. Given the impact of an SLE diagnosis on one's life, this narrative review aims to evaluate the intricacies of oxidative stress and its relevance to the pathogenesis and treatment of the disease. Topics such as understanding processes of oxidative stress, their damaging pathways, oxidative stress biomarkers, and their role in the future assistance of clinical decisions will be discussed in the article. The accurate determination of biomarkers is taught to improve both the diagnosis and the management of the disease, while antioxidant therapy may open a new door for the treatment.

What Dietary Vitamins and Minerals Might Be Associated with Paraoxonase-1 Serum Levels in Patients with Coronary Artery Disease?

Paraoxonase-1 (PON-1) is an antioxidant enzyme inversely associated with atherosclerosis incidence. Dietary antioxidants help to increase PON-1 serum levels. Since most vitamins and minerals have antioxidant properties, this research aimed to examine the association between PON-1 serum levels and dietary intake of vitamins and minerals in patients with coronary artery disease (CAD). In this cross-sectional study, 102 inpatients with CAD and 60 healthy individuals participated. The average dietary vitamins and minerals intake were computed using information from the food frequency questionnaire with the assistance of Nutritionist IV software. The serum PON-1 level was measured using the ELISA method. Regarding minerals, serum PON-1 level was positively correlated with dietary calcium (β = 0.57, p = 0.001), phosphorus (β = 0.52, p = 0.004), and potassium intake (β = 0.40, p = 0.03), but inversely associated with dietary consumption of iron (β =  - 0.43, p = 0.04), and sodium (β =  - 0.41, p = 0.02). Concerning vitamins, serum levels of PON-1 were positively associated with vitamin B6 (β = 0.53, p = 0.01) and riboflavin (β = 0.44, p = 0.03) but inversely correlated with niacin (β =  - 0.49, p = 0.03). The serum level of PON-1 might be associated with the dietary intake of minerals and vitamins. Therefore, a diet rich in certain minerals and vitamins may be advantageous in increasing serum PON-1 levels and preventing CAD.

PON1 Status in Relation to Gulf War Illness: Evidence of Gene-Exposure Interactions from a Multisite Case-Control Study of 1990-1991 Gulf War Veterans

BACKGROUND

Deployment-related neurotoxicant exposures are implicated in the etiology of Gulf War illness (GWI), the multisymptom condition associated with military service in the 1990-1991 Gulf War (GW). A Q/R polymorphism at position 192 of the paraoxonase (PON)-1 enzyme produce PON1192 variants with different capacities for neutralizing specific chemicals, including certain acetylcholinesterase inhibitors.

METHODS

We evaluated PON1192 status and GW exposures in 295 GWI cases and 103 GW veteran controls. Multivariable logistic regression determined independent associations of GWI with GW exposures overall and in PON1192 subgroups. Exact logistic regression explored effects of exposure combinations in PON1192 subgroups.

RESULTS

Hearing chemical alarms (proxy for possible nerve agent exposure) was associated with GWI only among RR status veterans (OR = 8.60, p = 0.014). Deployment-related skin pesticide use was associated with GWI only among QQ (OR = 3.30, p = 0.010) and QR (OR = 4.22, p < 0.001) status veterans. Exploratory assessments indicated that chemical alarms were associated with GWI in the subgroup of RR status veterans who took pyridostigmine bromide (PB) (exact OR = 19.02, p = 0.009) but not RR veterans who did not take PB (exact OR = 0.97, p = 1.00). Similarly, skin pesticide use was associated with GWI among QQ status veterans who took PB (exact OR = 6.34, p = 0.001) but not QQ veterans who did not take PB (exact OR = 0.59, p = 0.782).

CONCLUSION

Study results suggest a complex pattern of PON1192 exposures and exposure-exposure interactions in the development of GWI.

PON1, APOE and SDF-1 Gene Polymorphisms and Risk of Retinal Vein Occlusion: A Case-Control Study

Numerous studies have tried to evaluate the potential role of thrombophilia-related genes in retinal vein occlusion (RVO); however, there is limited research on genes related to different pathophysiological mechanisms involved in RVO. In view of the strong contribution of oxidative stress and inflammation to the pathogenesis of RVO, the purpose of the present study was to investigate the association of inflammation- and oxidative-stress-related polymorphisms from three different genes [apolipoprotein E (APOE), paraoxonase 1 (PON1) and stromal cell-derived factor 1 (SDF-1)] and the risk of RVO in a Greek population. Participants in this case-control study were 50 RVO patients (RVO group) and 50 healthy volunteers (control group). Blood samples were collected on EDTA tubes and genomic DNA was extracted. Genotyping of rs854560 (L55M) and rs662 (Q192R) for the PON1 gene, rs429358 and rs7412 for the APOE gene and rs1801157 [SDF1-3'G(801)A] for SDF-1 gene was performed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Multiple genetic models (codominant, dominant, recessive, overdominant and log-additive) and haplotype analyses were performed using the SNPStats web tool to assess the correlation between the genetic polymorphisms and the risk of RVO. Binary logistic regression analysis was used for the association analysis between APOE gene variants and RVO. Given the multifactorial nature of the disease, our statistical analysis was adjusted for the most important systemic risk factors (age, hypertension and diabetes mellitus). The dominant genetic model for the PON1 Q192R single nucleotide polymorphism (SNP) of the association analysis revealed that there was a statistically significant difference between the RVO group and the control group. Specifically, after adjusting for age and hypertension, the PON1 192 R allele (QR + RR) was found to be associated with a statistically significantly higher risk of RVO compared to the QQ genotype (OR = 2.51; 95% CI = 1.02-6.14, p = 0.04). The statistically significant results were maintained after including diabetes in the multivariate model in addition to age and hypertension (OR = 2.83; 95% CI = 1.01-7.97, p = 0.042). No statistically significant association was revealed between the other studied polymorphisms and the risk of RVO. Haplotype analysis for PON1 SNPs, L55M and Q192R, revealed no statistically significant correlation. In conclusion, PON1 192 R allele carriers (QR + RR) were associated with a statistically significantly increased risk of RVO compared to the QQ homozygotes. These findings suggest that the R allele of the PON1 Q192R is likely to play a role as a risk factor for retinal vein occlusion.

The Role of Polyphenols in Modulating PON1 Activity Regarding Endothelial Dysfunction and Atherosclerosis

The incidence and prevalence of cardiovascular diseases are still rising. The principal mechanism that drives them is atherosclerosis, an affection given by dyslipidemia and a pro-inflammatory state. Paraoxonase enzymes have a protective role due to their ability to contribute to antioxidant and anti-inflammatory pathways, especially paraoxonase 1 (PON1). PON1 binds with HDL (high-density lipoprotein), and high serum levels lead to a protective state against dyslipidemia, cardiovascular diseases, diabetes, stroke, nonalcoholic fatty liver disease, and many others. Modulating PON1 expression might be a treatment objective with significant results in limiting the prevalence of atherosclerosis. Lifestyle including diet and exercise can raise its levels, and some beneficial plants have been found to influence PON1 levels; therefore, more studies on herbal components are needed. Our purpose is to highlight the principal roles of Praoxonase 1, its implications in dyslipidemia, cardiovascular diseases, stroke, and other diseases, and to emphasize plants that can modulate PON1 expression, targeting the potential of some flavonoids that could be introduced as supplements in our diet and to validate the hypothesis that flavonoids have any effects regarding PON1 function.

Combined western diet and bisphenol A exposure induces an oxidative stress-based paraoxonase 1 response in larval zebrafish

Paraoxonase 1 (PON1) is an antioxidant enzyme linked to metabolic disorders by genome-wide association studies in humans. Exposure to metabolic disrupting chemicals (MDCs) such as bisphenol A (BPA), together with genetic and dietary factors, can increase the risk of metabolic disorders. The objective of this study was to investigate how PON1 responds to the metabolic changes and oxidative stress caused by a western diet, and whether exposure to BPA alters the metabolic and PON1 responses. Zebrafish larvae at 14 days post fertilization were fed a custom-made western diet with and without aquatic exposure to two concentrations of BPA for 5 days. A combination of western diet and 150 μg/L BPA exposure resulted in a stepwise increase in weight, length and oxidative stress, suggesting that BPA amplifies the western diet-induced metabolic shift. PON1 arylesterase activity was increased in all western diet and BPA exposure groups and PON1 lactonase activity was increased when western diet was combined with exposure to 1800 μg/L BPA. Both PON1 activities were positively correlated to oxidative stress. Based on our observations we hypothesize that a western diet caused a shift towards fatty acid-based metabolism, which was increased by BPA exposure. This shift resulted in increased oxidative stress, which in turn was associated with a PON1 activity increase as an antioxidant response. This is the first exploration of PON1 responses to metabolic challenges in zebrafish, and the first study of PON1 in the context of MDC exposure in vertebrates.

Paraoxonase 1 activity in patients with Alzheimer disease: Systematic review and meta-analysis

Cumulating evidence links environmental toxicants, such as organophosphate (OP) pesticides, to the pathogenesis of Alzheimer's disease (AD). The calcium-dependent Paraoxonase 1 (PON1) can neutralize these toxicants with good catalytic efficiency, thus protecting from OP-induced biological damage. Although different previous studies have already partially described an association between PON1 activity and AD, this intriguing relationship has not yet been comprehensively examined. To fill this gap, we performed a meta-analysis of existing data comparing the PON1 arylesterase activity in AD and healthy subjects from the general population. Data were obtained by searching MEDLINE, Embase and CENTRAL, Google Scholar, and SCOPUS electronic databases for all studies published at any time up to February 2023, reporting and comparing the PON1- paraoxonase activity between AD patients and controls. Seven studies, based on 615 subjects (281 AD and 356 controls) met the inclusion criteria and were included into the final analysis. A random effect model revealed that PON1 arylesterase activity was significantly lower in the AD group compared to controls, exhibiting low level of heterogeneity (SMD = - 1.62, 95% CI = -2.65 to -0.58, p = 0.0021, I2 = 12%). These findings suggest that PON1 activity might be reduced in AD reflecting a major susceptibility to OPs neurotoxicity. Further studies should be conducted to definitely ascertain this link and to establish the cause-effect relationship between PON1 reduction and AD onset.