Relationship between the paraoxonase 1 gene glutamine 192 to arginine polymorphism and gestational diabetes mellitus in Saudi women

Single-nucleotide polymorphisms as important risk factors of diabetes among Middle East population

Diabetes is a chronic metabolic disorder that leads to the dysfunction of various tissues and organs, including eyes, kidneys, and cardiovascular system. According to the World Health Organization, diabetes prevalence is 8.8% globally among whom about 90% of cases are type 2 diabetes. There are not any significant clinical manifestations in the primary stages of diabetes. Therefore, screening can be an efficient way to reduce the diabetic complications. Over the recent decades, the prevalence of diabetes has increased alarmingly among the Middle East population, which has imposed exorbitant costs on the health care system in this region. Given that the genetic changes are among the important risk factors associated with predisposing people to diabetes, we examined the role of single-nucleotide polymorphisms (SNPs) in the pathogenesis of diabetes among Middle East population. In the present review, we assessed the molecular pathology of diabetes in the Middle East population that paves the way for introducing an efficient SNP-based diagnostic panel for diabetes screening among the Middle East population. Since, the Middle East has a population of 370 million people; the current review can be a reliable model for the introduction of SNP-based diagnostic panels in other populations and countries around the world.

Gestational diabetes mellitus induces placental vasculopathies

Gestational diabetes mellitus (GDM) poses significant long- and short-term risks to both the developing fetus and the mother. GDM can lead to maternal complications during pregnancy and increase the mother's risk of developing type 2 diabetes mellitus and cardiovascular disease later. The present study aimed to evaluate the maternal and fetal vasculopathies in the placenta of Saudi women with GDM. This prospective study examined 84 placentas from full-term pregnant women with no complications other than GDM; 40 placentas were collected from healthy women (controls), and 44 were collected from women diagnosed with GDM. The sampling took place in King Saud University Medical City, Riyadh, between January and August 2019. All placentas were histologically examined according to the Amsterdam Placental Workshop Group (2014, 2015). The results showed that the most common placental changes on the maternal side of the placenta in the GDM group were significant syncytial knots (77%), calcification (70%), villous agglutination (57%), decidual vasculopathy (43%), and retroplacental hemorrhage (34%). Placental infarction was the least common placental change in both groups. On the fetal side, vasculopathies included significant villous fibrinoid necrosis (70.5%), chorangiosis (50%), fibromuscular sclerosis (50%), and villous edema (38.6%). Significant villous fibrinoid necrosis, villous edema, and significant fibromuscular sclerosis were more prevalent in the GDM group. The present study concluded that gestational diabetes mellitus induces histopathological phenotypes in the full-term placenta. Increased decidual vasculopathy, syncytial knots, retroplacental hemorrhage, classification, villous agglutination, chorangiosis, villous edema, villous fibroid necrosis, and fibromuscular sclerosis may indicate GDM in the mother. Such findings in the placenta of a woman who has not been diagnosed with GDM increase the need for GDM examination in future pregnancies.

Organophosphate pesticides and new-onset diabetes mellitus: From molecular mechanisms to a possible therapeutic perspective

Organophosphate is a commonly used pesticide in the agricultural sector. The main action of organophosphate focuses on acetylcholinesterase inhibition, and it therefore contributes to acute cholinergic crisis, intermediate syndrome and delayed neurotoxicity. From sporadic case series to epidemiologic studies, organophosphate has been linked to hyperglycemia and the occurrence of new-onset diabetes mellitus. Organophosphate-mediated direct damage to pancreatic beta cells, insulin resistance related to systemic inflammation and excessive hepatic gluconeogenesis and polymorphisms of the enzyme governing organophosphate elimination are all possible contributors to the development of new-onset diabetes mellitus. To date, a preventive strategy for organophosphate-mediated new-onset diabetes mellitus is still lacking. However, lowering reactive oxygen species levels may be a practical method to reduce the risk of developing hyperglycemia.

Prevalence and mortality of COVID-19 are associated with the L55M functional polymorphism of Paraoxonase 1

Introduction

Accumulating evidence recommends that infectious diseases including coronavirus disease 2019 (COVID-19) are often associated with oxidative stress and inflammation. Paraoxonase 1 (PON1, OMIM: 168,820), a member of the paraoxonase gene family, has antioxidant properties. Enzyme activity of paraoxonase depends on a variety of influencing factors such as polymorphisms of PON1, ethnicity, gender, age, and a number of environmental variables. The PON1 has two common functional polymorphisms, namely, Q192R (rs662) and L55M (rs854560). The R192 and M55 alleles are associated with increase and decrease in enzyme activity, respectively.

Objective

The present study was conducted to investigate the possible association of rs662 and rs854560 polymorphisms with morbidity and mortality of COVID-19.

Methods

Data for the prevalence, mortality, and amount of accomplished diagnostic test (per 10⁶ people) on 25 November 2020 from 48 countries were included in the present study. The Human Development Index (HDI) was used as a potential confounding variable.

Results

The frequency of M55 was positively correlated with the prevalence (partial r = 0.487, df = 36, p = 0.002) and mortality of COVID-19 (partial r = 0.551, df = 36, p < 0.001), after adjustments for HDI and amount of the accomplished diagnostic test as possible confounders.

Conclusions

This means that countries with higher M55 frequency have higher prevalence and mortality of COVID-19.

Gestational Diabetes Mellitus: The Genetic Susceptibility Behind the Disease

Gestational diabetes mellitus (GDM), a type of pregnancy-specific glucose intolerance or hyperglycemia, is one of the most common metabolic disorders in pregnant women with 16.9% of the global prevalence of gestational hyperglycemia. Not only are women with GDM likely to develop T2DM, but their children are also at risk for birth complications or metabolic disease in adulthood. Therefore, identifying the potential risk factors for GDM is very important in the prevention and treatment of GDM. Previous studies have shown that genetic predisposition is an essential component in the occurrence of GDM. In this narrative review, we describe the role of polymorphisms in different functional genes associated with increased risk for GDM, and available evidence on genetic factors in the risk of GDM is summarized and discussed.

Lactonase Activity, Status, and Genetic Variations of Paraoxonase 1 in Women with Gestational Diabetes Mellitus

BACKGROUND

Paraoxonase 1 (PON1) is a calcium-dependent multifunctional enzyme that binds to high-density lipoproteins. The physiological function of PON1 is related to its lactonase activity. However, this activity has not been analyzed in women with gestational diabetes mellitus (GDM). The present study investigated the lactonase activities and status of PON1 and their association with PON1 genetic variants and oxidative stress indices in Chinese women with GDM.

METHODS

This is a case-control study of 347 women with GDM and 288 women with uncomplicated pregnancies. PON1 levels and lactonase activities were analyzed using 7-O-diethylphosphoryl-3-cyano-4-methyl-7-hydroxycoumarin (DEPCyMC) and 5-thiobutyl butyrolactone (TBBL), respectively. A normalized lactonase activity (NLA) was estimated based on the ratio of TBBLase to DEPCyMCase activity. Serum malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC) levels, and PON1 genetic variants and oxidative stress indices in Chinese women with GDM.

RESULTS

PON1 lactonase activity and levels of TOS, TAC, and MDA were higher in the GDM women compared with the control women. The PON1 -108C→T genetic variation decreased the levels and lactonase activities of PON1 in a genotype-dependent manner in the patient and control groups. GDM patients with the PON1 -108TT genotype displayed lower NLA than those with the -108CC or -108CT genotype. GDM patients with the RR genotype of PON1 192Q/R polymorphism had significantly lower PON1 lactonase activities and NLA and tended to have decreased PON1 levels compared with those with the QQ or QR genotype. Multivariable regression analysis revealed that the PON1 -108C/T or 192Q/R variations, apolipoprotein (apo) A1, apoB, TAC, MDA, or age was significant predictors of the levels, lactonase activities, or NLA of PON1.

CONCLUSIONS

The lactonase activities of PON1 are increased in women with GDM. PON1 genetic variants, increased oxidative stress, and abnormalities in lipoproteins may be associated with these changes.PON1 genetic variants and oxidative stress indices in Chinese women with GDM.

Paraoxonase 1 (PON1) Q192R and L55M polymorphisms, lipid profile, lipid peroxidation and lipoprotein-a levels in Turkish patients with pregnancy-related disorders

The aim of this study was to investigate the role of PON1Q192R and L55M single nucleotide polymorphisms(SNPs) and its association with the maternal levels of lipid parameters in gestational diabetes mellitus(GDM) and preeclampsia(PE). Ninety-nine pregnant with GDM, 97 pregnant with PE and 98 healthy pregnant were included in the study. No statistically significant difference was observed in the alleles or in the genotypes frequencies of SNPs between groups. In GDM patients, total cholesterol was higher in MM genotype of L55M gene (p < .05); Lp(a) were lower in LM genotype of the gene compared to their respective control (p < .05). In PE, HDL-C levels were higher in LM genotype (p < .05); LDL-C levels were lower in MM genotype of the gene compared to their respective control (p < .05). In PE patients, malondialdehyde(MDA) were higher in QQ genotype compared to their respective control (p < .05). Triglyceride levels were higher in PE patients with QR genotype compared with GDM patients with QR genotype (p < .05). Our results indicated that lipid profiles, Lp(a) and MDA levels showed significant differences in GDM and PE pregnants. These findings support the importance of the lipid profile, oxidized lipid and Lp(a) in different genotypes of L55M and Q192R in Turkish pregnant women with PE/GDM suggesting their roles in etiopathogenesis in these pregnancy-related disorders.

Heterogeneous impact of type 2 diabetes mellitus-related genetic variants on gestational glycemic traits: review and future research needs

Gestational glucose homeostasis influences mother's metabolic health, pregnancy outcomes, fetal development and offspring growth. To understand the genetic roles in pregnant glucose metabolism and genetic predisposition for gestational diabetes (GDM), we reviewed the recent literature up to Jan, 2018 and evaluated the influence of T2DM-related genetic variants on gestational glycemic traits and glucose tolerance. A total of 140 variants of 89 genes were integrated. Their associations with glycemic traits in and outside pregnancy were compared. The genetic circumstances underlying glucose metabolism exhibit a similarity between pregnant and non-pregnant populations. While, not all of the T2DM-associated genetic variants are related to pregnant glucose tolerance, such as genes involved in fasting insulin/C-peptide regulation. Some genetic variants may have distinct effects on gestational glucose homeostasis. And certain genes may be particularly involved in this process via specific mechanisms, such as HKDC1, MTNR1B, BACE2, genes encoding cell cycle regulators, adipocyte regulators, inflammatory factors and hepatic factors related to gestational glucose sensing and insulin signaling. However, it is currently difficult to evaluate these associations with quantitative synthesis due to inadequate data, different analytical methods, varied measurements for glycemic traits, controversies in diagnosis of GDM, and unknown ethnicity- and/or sex-related influences on pregnant maternal metabolism. In conclusion, different genetic associations with glycemic traits may exist between pregnant and non-pregnant conditions. Comprehensive research on specific genetic regulation in gestation is necessary.

Paraoxonase-1 Q192R polymorphism and its association with hs-CRP and fasting blood glucose levels and risk of coronary artery disease

AIMS

Paraoxonase-1 (PON1) has been shown to protect low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) against oxidative-modification and thereby might protect against coronary-artery-disease (CAD). Here we explored the relationship of a genetic variant (a substitution (R) Arg with (Q) Gln at position 192) of PON1 in 250 patients with/without CAD.

MATERIALS AND METHODS

Genotyping of PON1 Q192R was carried out using Real-Time-PCR TaqMan-based-probe. Demographic-characteristics and biochemical-analyses, including fasting blood sugar (FBS), HDL, LDL, triglycerides (TG) and C-reactive protein (CRP) were evaluated. Univariate/multivariate analyses were performed to determine the association of the genetic polymorphism and CAD as well as with clinical-characteristics of population.

RESULTS

Our findings showed that RR-genotype was more frequent in CAD-patients, compared to the wild-type genotype. Moreover, CAD patients with RR-genotype had an odd ratio of 5.0 (95% CI: 1.3-18.6; p = 0.017), versus wild-type genotype, in multivariate-analysis. Of note we also observed that CAD-patients with QQ-genotype had a significantly lower Hs-CRP level, compared to the RR-genotype.

CONCLUSION

we demonstrate that PON1-Q192R-polymorphism was associated with CRP and FBS levels; R-allele of PON1-Q192R may be an independent risk factor for CAD. Further studies are warranted to determine the value of this marker as a surrogate marker in CAD patients.

Q192R polymorphism in the PON1 gene and familial hypercholesterolemia in a Saudi population

BACKGROUND

Familial hypercholesterolemia (FH) is an autosomal dominant condition characterized by abnormal levels of low-density lipoprotein (LDL) in the blood. FH is a risk factor for atherosclerosis and cardiovascular disease. The relationship between the paraoxonase 1 (PON1) gene, atherosclerosis and coronary artery disease has not been studied in Saudi patients.

OBJECTIVE

To investigate the genetic associations of the Q192R polymorphism in the PON1 gene with FH in Saudi patients.

DESIGN

Case-control study.

SETTING

Tertiary care center, Riyadh.

METHODS

Two hundred Saudi patients were enrolled in this study, including 100 patients with FH and 100 healthy controls, during the period from January 2012 to March 2013. Serum was separated from coagulated blood (3 mL) and used for analysis of lipid profiles. Genomic DNA was isolated from anticoagulant-treated blood (2 mL). Genotyping for the Q192R polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism analysis, followed by 3% agarose gel electrophoresis.

MAIN OUTCOME MEASURE

The strength of association between the Q192R polymorphism and FH in the Saudi population.

RESULTS

We confirmed that QR versus QQ (odds ratio [OR]: 1.55; 95% confidence interval [CI]: 1.05-3.43; P=.03), QR+RR versus QQ (OR: 1.98; 95% CI: 1.13-3.49; P=.01), and R versus Q (OR: 1.68; 95% CI: 1.09- 2.59; P=.01) in the Q192R polymorphism were associated with FH in the Saudi population.

CONCLUSION

In conclusion, the Q192R polymorphism in the PON1 gene is associated with FH in the Saudi population. Our results confirmed that the R allele, QR, and dominant model genotypes were associated with FH.

LIMITATION

Only a single variant (Q192R) was analyzed, and the medical and family histories of the patients were not known.

The Q192R polymorphism of the paraoxonase-1 (PON1) gene is associated with susceptibility to gestational diabetes mellitus in the Greek population

A key factor protecting from oxidative stress in gestational diabetes mellitus (GDM) and in type 2 diabetes (T2D) is paraoxonase-1 (PON1). Inconclusive and limited data exist regarding the effect of a coding polymorphism (Q192R) of the PON1 gene in conferring susceptibility to both states. In the present study, we investigated the association between the PON1 gene and the risk for GDM in the Greek population and assessed for the first time its transcriptional efficiency. We studied 185 women with GDM and 104 non-diabetic controls for the PON1 polymorphism. For PON1 mRNA expression, peripheral leucocytes were harvested from 20 GDM and 20 control women, harboring different genotypes for the polymorphism, using real-time quantitative PCR. The RR genotype and the R allele of the PON1 Q192R polymorphism were significantly associated with an increased risk for GDM (p = 0.012 and p < 0.0001, respectively). Furthermore, there was no statistical correlation between the individual metabolic parameters tested and the three genotypes. Finally, the expression levels of PON1 mRNA in GDM patients did not exhibit any statistical difference compared with normal controls (p = 0.138). These data independently document that the Q192R polymorphism is closely associated with GDM susceptibility, while the PON1 gene expression is not impaired in GDM.

Genetic polymorphisms in paraoxonase 1 and G protein-coupled receptor 77, and the risk of glucose-6-phosphate dehydrogenase deficiency in a Saudi population

Objectives:

To investigate the role of amino acid substitution variants Q192R and C698T in the development of glucose-6-phosphate dehydrogenase (G6PD) deficiency in a Saudi male population.

Methods:

This case-control study was carried out in 200 Saudi male individuals: 100 patients with G6PD deficiency, and 100 control subjects collected between July and August 2011 in the Taif region of Saudi Arabia. A total of 2100 male Saudi individuals were screened by a fluorescence spot test, and 100 with G6PD deficiency were selected. Two common variants PON1 (rs662) and C5L2 (rs149572881) were genotyped using polymerase chain reaction followed by restriction fragment length polymorphism analysis.

Results:

The results showed that the R allele and QR genotype were associated with the Q192R polymorphism in PON1 (R versus Q odds ratio [OR], 1.72; 95% confidence interval [95% CI], 1.1-2.6; p=0.01; and QR versus QQ: OR, 1.98; 95% CI, 1.1-3.6; p=0.02). All the C698T genotypes and allele frequencies in C5L2 were almost similar in both the cases and controls (CT versus CC: OR, 2.04; 95% CI, 0.3-11.4; p=0.40; and T versus C: OR, 2.02; 95% CI, 0.3-11.1; p=0.41).

Conclusions:

These findings suggest the association of PON1 with G6PD deficiency in the Saudi male population studied herein. Future studies, including correlation analyses between the clinical features and genotypes in populations of different ethnicities, are warranted to confirm the disease association with these genetic mutations.

Association of JAZF1 and TSPAN8/LGR5 variants in relation to type 2 diabetes mellitus in a Saudi population

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a chronic and multifactorial disease with a rapidly rising incidence in Saudi Arabia. Various genes including zinc finger protein 1 (JAZF1) and tetraspanin 8/leucine-rich repeat-containing G protein-coupled receptor (TSPAN8/LGR5) have been previously described to be associated with T2DM. This study investigated the association of JAZF1 (rs864745) and TSPAN8 (rs7961581) with T2DM in a Saudi population.

METHODS

Genomic DNA samples from 400 Saudi T2DM patients and 400 healthy controls were genotyped and analyzed using a polymerase chain reaction-restriction fragment length polymorphism method. The difference between the genotype frequencies were carried out with Chi-square test. Odds ratio, 95 % confidence intervals and p values were calculated using multinomial logistic regression. Dominant and recessive models were implemented to show the statistical significances. Analysis of variance was used to compare differences between genotypes for the various parameters.

RESULTS

Distribution frequencies of the AA, AG, and GG genotypes of JAZF1 (rs864745) differed significantly among T2DM patients and healthy controls (p < 0.05). The AG and GG genotypes were independently and significantly associated with a T2DM risk after adjusting for factors such as age, sex, and body mass index [odds ratio (OR) 2.1 (95 % confidence interval (CI) 1.3-3.4); p = 0.002] and [OR 1.9 (95 % CI 1.2-3.1); p = 0.005], respectively. A genotype-based stratification of anthropometric and biochemical data revealed that the AG + GG genotype is associated with waist circumference (p = 0.04) and fasting blood glucose (p = 0.01) and high-density lipoprotein cholesterol levels (p = 0.02). None of the allele or genotype showed the significant association between the T2DM cases and control subjects in rs7961581 polymorphism in TSPAN8/LGR5 gene.

CONCLUSION

The rs864745 variant in JAZF1 gene may act as genetic risk factors for the development of T2DM in a Saudi population.