STUDY ON THE RELATIONSHIP BETWEEN PARAOXONASE GENE POLYMORPHISM AND CORONARY ARTERIAL DISEASE IN NIDDM

Objective To ascertain the relationship between paraoxonase gene (PON) and the morbidity of coronary arterial disease (CAD) in Chinese non-insulin-dependent diabetes mellitus (NIDDM) patients. Methods The exons of PON gene were screened by polymerase chain reaction-denaturing gradient gel elec-trophoresis in 49 NIDDM patients complicated with CAD, 49 NIDDM and 101 healthy control cases of Chinese population. Results Gln-Arg191 polymorphism of the PON gene was detected in Chinese with the AIR allele frequency 0.39 and 0. 61 respectively. The genotype distribution (AA, AR and RB) of the PON gene polymor-phism was significantly different between NIDDM patients complicated with CAD and controls (NIDDM and healthy subjects). The former had a significantly higher B allele frequency (0. 79 vs 0. 62 and 0. 61, P < 0. 01). Conclusion Gln-Arg191 polymorphism of the PON gene is associated with CAD morbidity in Chinese NJDDM patients and B allele might be a risk factor.

Paraoxonase gene cluster variations associated with coronary heart disease in Chinese Han women

Background The oxidative modification of low-density lipoprotein in theartery wall is currently believed to be central to the pathogenesis of atherosclerosis. Paraoxonase(PON1), an enzyme located on high-density lipoprotein (HDL) , can prevent low-density lipoprotein(LDL) from oxidation at a certain extent. Recent studies show two other members of paraoxonase genefamily, PON2 and PON3, possess antioxidant properties similar to PON1. The aim of the present studywas to explore the role of PON gene cluster on coronary heart disease (CHD) in Chinese Han women.Methods Seven polymorphisms including PON1 -107C > T, -162G > A, -831G > A, R160G, Q192R, PON2S311C, and PON3 -133C > A were genotyped in 184 female patients with CHD and 239 female controls.The plasma PON1 activity toward phenylacetate was determined in 50 cases and 50 controls randomlyselected. Results The plasma PON1 activities were significantly lower in cases than in controls.Individual SNP analysis showed that cases had significantly higher frequencies of PON1 -107T, -831Gand PON2 311S alleles than controls. The genotype distributions of -107C >T were also significantlydifferent between two groups. The odds ratios for the development of CHD were 1. 66 for -107TCcarriers and 2. 0 for -107TT carriers, compared with -107CC carriers. Haplotype analyses showed thatthe distributions of haplotypes comprised of PON1 -107C > T and PON2 S311C were significantlydifferent between cases and controls, with cases having higher frequency of T-S haplotype (44.8% vs.36.3%, P =0.013). The T-S haplotype remained significantly associated with CHD after adjustingenvironmental risk factors (P = 0.0069). Conclusions This association study suggested that lowerplasma PON1 activity increased the risk of CHD in Chinese woman, which may be mediated by the higherfrequency of -107T allele in cases. Haplotype analyses indicated that there might be somesynergistic effects between the PON1 -107C > T and PON2 S311C polymorphisms.

Human paraoxonase gene cluster overexpression alleviates angiotensin II-induced cardiac hypertrophy in mice

Cardiac hypertrophy is the strongest predictor of the development of heart failure, and anti-hypertrophic treatment holds the key to improving the clinical syndrome and increasing the survival rates for heart failure. The paraoxonase(PON) gene cluster(PC) protects against atherosclerosis and coronary artery diseases. However, the role of PC in the heart is largely unknown. To evaluate the roles of PC in cardiac hypertrophy, transgenic mice carrying the intact human PON1, PON2, and PON3 genes and their flanking sequences were studied. We demonstrated that the PC transgene(PC-Tg) protected mice from cardiac hypertrophy induced by Ang II; these mice had reduced heart weight/body weight ratios, decreased left ventricular wall thicknesses and increased fractional shortening compared with wild-type(WT) control. The same protective tendency was also observed with an Apoe^(-/-)background. Mechanically, PC-Tg normalized the disequilibrium of matrix metalloproteinases(MMPs)/tissue inhibitors of MMPs(TIMPs) in hypertrophic hearts, which might contribute to the protective role of PC-Tg in cardiac fibrosis and, thus, protect against cardiac remodeling. Taken together, our results identify a novel anti-hypertrophic role for the PON gene cluster, suggesting a possible strategy for the treatment of cardiac hypertrophy through elevating the levels of the PON gene family.

Analysis of Single Nucleotide Polymorphism in Human Paraoxonase 1 Gene(Q192R) with Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry

Introduction Single nucleotide polymorphisms （SNPs） are the most abundant DNA markers in the human genome occurring at a frequency of one in every 500--1000 nucleotides. A variety of methods have been used for the analysis of single nucleotide polymorphisms, including restriction fragment length polymorphism （RFLP）, direct sequencing by using laser-induced fluorescence detectionTM, fluorescence energy transfer, MALDI-TOF MS combined with primer extension or invasive cleavage, and fluorescence polarization. During the past two decades, mass spectrometry has become a very popular tool in the analysis of biomolecules and is perfectly suited to the analysis of single nucleotide polymorphisms （SNPs） due to its speed, low cost, and accuracy. In this work, we used MALDI TOF mass spectrometry to detect the fragments of restriction endonuclease hydrolysis of PCR products flanking a SNP located at paraoxonase 1（Q192R）. Compared with electrophoresis, this method requires less time of analysis and possess a higher accuracy.