Paraoxonase 1 status in the Thai population

Human serum paraoxonase 1 (PON1), a high-density lipoprotein (HDL)-associated enzyme, has been shown to reduce the oxidation of low-density lipoprotein (LDL) and HDL by degrading lipid peroxides. This property of PON1 accounts for its ability to protect against atherosclerosis. In this study, we identified four polymorphisms in both the coding (L55M and Q192R) and regulatory regions (T-108C and G-909C) of the human PON1 gene in 202 healthy Thai individuals and investigated the influence of these polymorphisms on serum PON1 activity towards three substrates, namely, paraoxon, phenylacetate and diazoxon. The PON1 L55M, Q192R and G-909C polymorphisms significantly affected the variation in serum PON1 activity towards paraoxon. Serum PON1 activity towards paraoxon was significantly different among the genotype groups, as follows: 55LL > 55LM/55MM, 192RR > 192QR > 192QQ and –909CC > –909CG > –909GG. The PON1 Q192R and G-909C polymorphisms also influenced the variation in serum PON1 activity towards diazoxon but in the opposite direction to the activity towards paraoxon. Only the PON1 L55M polymorphism was associated with significant variation in serum PON1 activity towards phenylacetate while the PON1 T-108C polymorphism had no significant effect on serum PON1 activity towards any substrate. We also found linkage disequilibrium among the polymorphic sites, including Q192R versus L55M, Q192R versus T-108C and Q192R versus G-909C. Serum PON1 activity towards both paraoxon and phenylacetate, but not diazoxon, was positively correlated with HDL cholesterol (HDL-C) and apo AI concentrations. None of the PON1 polymorphisms significantly affected serum lipid, lipoprotein or apolipoprotein concentrations. Our findings suggest that the physiological relevance of the PON1 polymorphisms is that they are associated with significant differences in serum PON1 activity, and the impact of PON1 polymorphisms on this activity is substrate-dependent.     

Polymorphisms in the DNA repair gene XRCC1 and age-related disease

The recent hypothesis that common variants (single nucleotide polymorphisms or SNPs) in the population may contribute significantly to genetic risk for common diseases permits a conceptually straightforward approach to identifying age-related disease-causing mutations. Functional variants of DNA replication and repair genes might be expected to be highly significant to cancer and aging since replication must proceed with high fidelity in a cellular environment where an estimated 10000 nucleotides are damaged daily. Single-strand breaks (SSB) are one of the results of DNA damage either by methylation, oxidation, reduction or fragmentation of bases by ionizing radiation, and arise in cells directly by disintegration of damaged sugars or indirectly as intermediates of base excision repair. Studies have demonstrated a role for XRCC1 both in vitro and in vivo during the repair of SSB. A number of SNPs have been identified for the XRCC1 gene, and several have been associated with age-related diseases, especially cancer. This report provides resequencing data confirming the existence of commonly occurring SNPs, including Arg194Trp and Arg399Gln, and briefly summarizes epidemiological and functional relevance to cancer and other age-related diseases. XRCC1 SNPs will be useful probes for investigating age-associated pathobiology in epidemiological and mechanistic studies.     

Antigen presentation in SARS-CoV-2 infection: the role of class I HLA and ERAP polymorphisms

Given the highly polymorphic nature of Human Leukocyte Antigen (HLA) molecules, it is not surprising that they function as key regulators of the host immune response to almost all invading pathogens, including SARS-CoV-2, the etiological agent responsible for the recent COVID-19 pandemic. Several correlations have already been established between the expression of a specific HLA allele/haplotype and susceptibility/progression of SARS-CoV-2 infection and new ones are continuously emerging. Protective and harmful HLA variants have been described in both mild and severe forms of the disease, but considering the huge amount of existing variants, the data gathered in such a brief span of time are to some extent confusing and contradictory. The aim of this mini-review is to provide a snap-shot of the main findings so far collected on the HLA-SARS-CoV-2 interaction, so as to partially untangle this intricate yarn. As key factors in the generation of antigenic peptides to be presented by HLA molecules, ERAP1 and ERAP2 role in SARS-CoV-2 infection will be revised as well.     

Genetic Variation in the Paraoxonase-3 (PON3) Gene is Associated with Serum PON1 Activity

Low serum paraoxonase1 (PON1) activity determined by paraoxon substrate is associated with coronary heart disease (CHD), diabetes and systemic lupus erythematosus (SLE) risk. In this investigation, we have examined the role of genetic variation in the PON3 gene in relation to PON1 activity and SLE risk in a biracial sample comprising 377 SLE patients and 482 controls from US whites and blacks. We genotyped six PON3 tagging single nucleotide polymorphisms (tagSNPs) and examined their associations with PON1 activity, SLE risk, antiphopholipid autoantibodies (APA), lupus nephritis, carotid vascular disease, and inflammation. With the exception of PON1 activity, no other significant associations were found with PON3 SNPs. Multiple regression analysis including all six PON3 tagSNPs and PON1/Q192R and L55M SNPs revealed significant association of PON1 activity with 4 SNPs: PON3/A10340C (p < 0.0001), PON3/A2115T (p = 0.002), PON1/L55M (p < 0.0001) and PON1/Q192R (p < 0.0001). These four SNPs explained 2%, 1%, 8% and 19% of the variation in PON1 activity, respectively. In summary, our new data indicate that genetic variation in the PON3 gene influences serum PON1 activity independently of the known effect of PON1 genetic variation. To our knowledge, this is the first study reporting the association of the PON3 gene variants with PON1 activity.     

Molecular basis of type I (tryrosinase-related) oculocutaneous albinism: Mutations and polymorphisms of the human tyrosinase gene

Type I (tyrosinase related) oculocutaneous albinism (OCA) results from mutations of the tyrosinase gene on chromosome 11q that lead to reduced or absent melanin pigment synthesis. The phenotype of Type I OCA is broad, ranging from a total lack to only a moderate reduction of melanin, and the phenotypic variation is associated with different mutant alleles at the tyrosinase locus. A total of 36 mutations have been identified in Type I OCA including 24 missense, 4 nonsense, and 8 frameshift mutations. The majority of affected individuals have been compound heterozygotes with different maternal and paternal alleles. Six polymorphic sites for haplotype analysis have been identified in the tyrosinase gene including 2 in the promoter region, 2 in the coding region associated with alternative amino acids in the protein, and 2 RFLPs in the first intron. © 1993 Wiley-Liss, Inc.     

Molecular analysis of HLA-D region genes in seropositive rheumatoid arthritis

Analysis of HLA DRB1 and DQB1 Bam HI RFLPs revealed four DRB1 (4.8, 5.2, 6.0 and 7.0 kb) fragments and a 3.2 kb DQB1 fragment to be significantly increased in Caucasians with seropositive RA compared to healthy individuals. The 4.8, 5.2 and 7.0 kb DRB1 fragments were found in 86.5% of RA patients and in 56% of the controls (p = 10(-3), relative risk (RR) = 5.0), while the 6.0 kb fragment was found in 79% of RA patients compared to 32% of controls (p = 2 x 10(-5), RR = 8.0). The 3.2 kb DQB1 fragment was observed in 63.5% of RA patients versus 38.0% of controls (p = 10(-2), RR = 2.8). Analysis of these fragments relative to HLA phenotypes revealed that the 4.8, 5.2 and 7.0 kb DRB1 fragments were strongly correlated with DR4, -7, -9 and -w53 serotypes, the 6.0 kb RFLP with DR4 and the 3.2 kb DQB1 fragment with DR1 and DQw1. Using probes specific for the 5' or 3' regions of the DRB1 gene, the 5.2 and 6.0 kb DRB RFLPs were mapped to the 5' end and the 4.8 and 7.0 kb RFLPs to the 3' end of the DRB1 gene. A probe generated from the second exon of the DRB4 (DRw53) gene recognized only the 5.2 and the 6.0 kb RFLPs corroborating the 5' location of these RFLPs. Family studies further confirmed that these RFLP's segregated with HLA phenotypes.     

Cholesteryl ester transfer protein gene polymorphisms are associated with coronary artery disease in Corsican population (France)

The aim of the present study was to investigate the association between coronary artery disease (CAD) and Cholesterol Ester Transfer Protein (CETP) (gaaa)n polymorphisms of the CETP gene in Central Corsica island (France). The study group was composed by 300 unrelated Corsican patients with angiographically documented CAD and 300 unrelated healthy blood donors. Significant differences were observed in the distribution of CETP (gaaa)n alleles between the groups under study (p=0.03; chi(2): 16.8, df: 8). The occurrence of a long allele (408 bp) was higher in cases (12%) than in control group (2%), showing a 6.75-fold increased risk for CAD in Corsica patients (p=0.0055; OR=6.750; 95% CIs=1.47-31.00). The correlation of this polymorphism with the lipid profile (cholesterol, low density lipoprotein-cholesterol, high density lipoprotein-cholesterol and triglycerides) in the patients group was determined. There was a significant association of the long alleles of CETP (gaaa)n with HDL-C levels. In the patient and in the control groups the LL genotypes had lower HDL-C compared with the SS and SL genotypes (p<0.0001). In summary our results suggest that the genetic variation at the CETP gene may play an important role in determining CAD in Corsican population.     

Genetic Variants in the Wnt Signaling Pathway Are Not Associated with Survival Outcome of Non-Small Cell Lung Cancer in a Korean Population

Recently, genetic variants in the WNT signaling pathway have been reported to affect the survival outcome of Caucasian patients with early stage non-small cell lung cancer (NSCLC). We therefore attempted to determine whether these same WNT signaling pathway gene variants had similar impacts on the survival outcome of NSCLC patients in a Korean population. A total of 761 patients with stages I–IIIA NSCLC were enrolled in this study. Eight variants of WNT pathway genes were genotyped and their association with overall survival and disease-free survival were analyzed. None of the eight variants were significantly associated with overall survival or disease-free survival. There were no differences in survival outcome after stratifying the subjects according to age, gender, smoking status, and histological type. These results suggest that genetic variants in the WNT signaling pathway may not affect the survival outcome of NSCLC in a Korean population.     

rs2507800、rs4880、rs1799895单核苷酸多态性与中国东北地区汉族妇女子痫前期相关性研究

目的:探讨Ang-1 rs2507800、SOD2 rs4880及SOD3 rs1799895多态性与中国东北地区汉族妇女子痫前期(PE)是否存在关联。方法:采用飞行时间质谱对181例PE患者(病例组)及203例健康孕妇(对照组)的上述3个位点进行分型,分型结果采用SPSS12.0软件进行统计分析。结果:病例组与对照组rs2507800、rs4880、rs1799895等位基因频率和基因型频率均无统计学差异(P0.05)。对rs2507800、rs4880分别在显性、隐性模型下进行分析,两组仍无统计学差异(P0.05)。结论:rs2507800、rs4880、rs1799895多态性与PE不相关。     

Association of α_(2A)-Adrenergic Receptor Genetic Variants with Platelet Reactivity in Chinese Patients on Dual Antiplatelet Therapy Undergoing Percutaneous Coronary Intervention

Objective The alpha 2A‐adrenergic receptor gene(ADRA2A) polymorphism in individuals modifies the antiplatelet response to sympathetic stimulation. The aim of this study was to investigate the effect of ADRA2A variants on platelet reactivity in Chinese patients on dual antiplatelet therapy(DAPT) after undergoing percutaneous coronary intervention(PCI).Methods From March 2011 to March 2013, 1,024 patients were enrolled in this prospective,single‐center, observational study in China. Four single nucleotide polymorphisms(SNPs) of ADRA2A gene(rs11195419, rs3750625, rs13306146, and rs553668) and CYP2 C19*2 were detected by ligase detection reaction(LDR), and adenosine diphosphate(ADP) inhibition was detected by thromboelastography(TEG~?).Results The minor allele frequencies of ADRA2A SNPs were common. Platelet ADP inhibition was significantly different among patients carrying rs11195419(adjusted P = 0.022) and rs3750625(adjusted P = 0.016). The homozygous allele carriers had the lowest ADP inhibition. However, ADP inhibition was not significantly different in rs553668 and rs13306146. At the multivariate analysis, rs11195419(P =0.033), rs3750625(P = 0.020) and CYP2 C19*2(P = 0.002) were independent predictors of ADP inhibition. Subgroups analysis based on sex showed rs11195419(P = 0.003) and rs3750625(P = 0.002)were significantly associated with ADP inhibition in males, but not in females.Conclusion ADRA2A genetic variations were associated with ADP‐induced platelet aggregation during DAPT in Chinese patients undergoing PCI, and the effect was particularly more pronounced in males.