Insertion-deletion polymorphism of the angiotensin converting enzyme gene and its relationship to serum levels of free amino acids in the patients with connective tissue dysplasias

An association between insertion/deletion polymorphism (IDP) of the Alu repeat in intron 16 of the angiotensin I-converting enzyme (ACE) gene and the serum free amino acid levels in the patients with connective tissue dysplasias was examined. Genotyping of 102 patients (25 II, 51 ID, and 26 DD) was performed using PCR. Serum free amino acids levels in these patients were determined by use of HPLC technique. A statistically significant increase of the leucine-isoleucine (P < 0.05) and phenylalanine (P < 0.01) levels in deletion homozygous patients (DD) relative insertion homozygous (II) patients was observed. The differences in respect of other amino acids were not detected. These findings point to the importance of registration of IDP in the ACE gene at dietary therapy of such patients, as well as in the individual choice of medical preparations containing the amino acids mentioned.     

Association between the Insertion/Deletion Polymorphism of the Angiotensin-Converting Enzyme Gene and Angiopathy in Patients with Non-Insulin Dependent Diabetes Mellitus in Chuvash Republic

Insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene was analyzed in patients with non-insulin-dependent diabetes mellitus (NIDDM) and in the control group consisting of healthy subjects. The insertion allele (I) and genotype II were found to be associated with NIDDM. The frequencies of diabetic retinopathy and nephropathy in NIDDM patients were not associated with this polymorphism. However, an association was found between the DD genotype of the ACE gene and diabetic angiopathy in lower extremities.     

Angiotensin-converting enzyme gene polymorphism and digestive system cancer risk: A meta-analysis based on 9656 subjects

The angiotensin-converting enzyme (ACE) is the major regulator of the renin-angiotensin system, and it has been reported that genetic polymorphisms at this locus are associated with risk in numerous types of human cancers. In the current meta-analysis, we aimed to evaluate the association between the ACE Gene insertion/deletion (I/D) polymorphism (DD vs II) and digestive system cancer susceptibility. A total of 19 case-control studies among 3722 patients with seven different types of cancer were included in this meta-analysis. In the pooled analysis, the relationship between the ACE I/D polymorphism and digestive system cancer risk was not statistically significant (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.68-1.29; P = 0.65; random model). Furthermore, subgroup analyses by cancer type also did not reveal an association between ACE polymorphisms and colorectal cancer (OR, 1.14; 95% CI, 0.823-1.58; P = 0.43; random effect model) and gastric cancer (OR, 0.79; 95% CI, 0.51-1.22; P = 0.28; random effect model). These findings indicate that ACE polymorphisms in the digestive tract may still affect the survival of cancer patients, and future studies into the topic of effect of ACE on cancer prognosis are warranted.     

Angiotensinogen and angiotensin-I converting enzyme gene polymorphisms and the risk of coronary artery disease in Chinese

The homozygous deletion allele (DD) of the angiotensin-I converting enzyme (ACE) gene and the T235 homozygote of the angiotensinogen (AGT) gene have been reported to be correlated with an increased prevalence of coronary artery disease (CAD) and myocardial infarction (MI). The importance of the DD genotype and T235 homozygote as genetic risk factors for CAD in Chinese remains uncertain. This study included 426 patients who underwent coronary angiography and 180 healthy subjects without clinical evidence of CAD. Coronary angiography identified 268 patients with CAD (CAD group) and 158 patients without CAD. The healthy subjects and patients without angiographic evidence of CAD constituted the control group. Three polymorphisms were studied: an insertion/deletion (I/D) polymorphism of the ACE gene and the T174 M and M235T polymorphisms of the AGT gene. No association was found between any of the three studied polymorphisms and the risk of CAD or MI in Chinese using univariate or multivariate analysis. In multivariate analysis, the relative risks were 1.20 (95% confidence interval = 0.91–1.61, P = 0.20) for the DD genotype, 1.05 (95% CI = 0.82–1.35, P = 0.69) for the T174 homozygote, and 1.19 (95% CI = 0.91–1.55, P = 0.20) for the T235 homozygote. Similarly, no significant difference was found in the frequencies of the DD genotype and the T174 and T235 homozygotes between the control group, the CAD group, the non-MI group, and the MI group when analyzed according to sex, age, or degree of risk. Our data suggest that neither the DD genotype of the ACE I/D polymorphism nor the T174 and T235 homozygotes of the AGT gene confer significant risk for CAD or MI in Chinese. Received: 18 December 1996 / Accepted: 27 February 1997     

Angiotensin-converting enzyme (ACE) gene polymorphisms in patients characterised by coronary angiography

The angiotensin converting enzyme (ACE) gene is implicated as a risk factor for coronary artery disease and myocardial infarction (MI). An insertion/deletion (I/D) polymorphism is believed to be in linkage disequilibrium with a functional site elsewhere. Ten polymorphisms have recently been identified in the ACE gene. We screened patients undergoing coronary angiography (n = 258) for six of these polymorphisms (T-5491C, T-93C, A-240T, T1237C, D/I and 4656(CT)_2/3), and identified a further two rare polymorphisms. ACE levels were associated with genotype for all polymorphisms analysed individually by one way ANOVA (P < 0.0005). The polymorphisms occurring in the 5′ region were in negative linkage disequilibrium with the exonic and 3′ region polymorphisms. The A-240T polymorphism had the greatest association with ACE levels (R² = 14%); none of the others were significantly associated with levels when adjustment was made for A-240T. None of the polymorphisms were associated with the extent of coronary atheroma. Two of the promoter polymorphisms (A-240T and T-93C) were weakly related to the occurrence of MI (P = 0.03 and P = 0.05, respectively, by χ² analysis). The TT genotype of A-240T appeared to be protective against MI with an odds ratio of 0.31 (95% confidence interval, 0.12, 0.83). These findings indicate that polymorphisms in the ACE gene promoter region may have a stronger association with disease than the I/D polymorphism. Received: 16 February 1997 / Accepted: 13 May 1997     

Synergism between paraoxonase Arg 192 and the angiotensin converting enzyme D allele is associated with severity of coronary artery disease

We have previously shown that angiotensin-converting enzyme (ACE) gene D allele is an independent risk factor for early onset coronary artery disease (CAD). Little is known about the concomitant presence of the ACE gene D allele and paraoxonase (PON1) codon 192 arginine (Arg) on the severity of CAD. Regarding the high rate of CAD among Iranians the aim of present study was to examine the hypothesis of synergistic effects between ACE-D and PON1-Arg alleles on predisposition and the severity of CAD in our population. The PON1 192 and ACE insertion/deletion (I/D) genotypes were detected by PCR-RFLP and PCR, respectively in 414 individuals undergoing their first coronary angiography. Patients were placed into one of two groups: CAD and control without CAD or diabetes. We mentioned the synergistic effects of both genes and not ACE gene alone is a risk factor for CAD. We found that PON1 Arg 192 and ACE D allele act synergistically to increase the risk of CAD (OR 1.3, P = 0.044). Our results showed a significant correlation between the possession of both PON1 192 Arg and the ACE D allele and the extent of CAD in CAD patients and CAD subjects without diabetes, represented by the increased frequency of three-vessel disease with OR 2.7, P = 0.046; χ² = 4, P = 0.046 and OR 2.4, P = 0.051; χ² = 3.8, P = 0.051, respectively. We found that PON1 Arg 192 and ACE D alleles act synergistically to increase the risk of CAD in CAD patients and CAD subjects without diabetes from west of Iran, who have high frequency of three-vessel disease. Our data suggest that PON1 192 Arg and the ACE D allele in combination with each other can be important independent risk factor for severity of CAD in patients carrying both PON1 192 Arg and the ACE D allele in a west population of Iran.     

Analysis of Deletions in SMN1, SMN2, and NAIPGenes in Spinal Muscular Atrophy Patients from the Northwestern Region of Russia

Polymerase chain reaction with subsequent SSCP (single-strand DNA conformational polymorphism) and restriction (BselI restriction endonuclease) analyses were used to type the DNA samples of affected individuals and their relatives from 23 Russian families with high risk of spinal muscular atrophy (SMA) residing in the northwestern region of Russia. Deletions of exon 7 of the SMN1gene were found in 96% of the individuals examined. The frequency of homozygous deletion of exons 7 and 8 of the SMN1gene was 65%. The frequency of homozygous isolated deletion of the SMN1gene exon 7 among the SMA patients was 4.3%. Homozygous deletion of exon 5 of the NAIPgene was found in 22% of SMA patients. In SMA patients, a total of seven deletion types involving the SMN1, NAIP, and SMN2genes were detected. Deletion of exons 7 and 8 of the SMN1gene was the most common mutation associated with SMA in patients from the northwestern Russia.     

Apolipoprotein B signal peptide insertion/deletion polymorphism is associated with Ag epitopes and involved in the determination of serum triglyceride levels.

We have investigated the insertion/deletion polymorphism in the signal peptide region of the apoB gene in 106 Finnish individuals from North Karelia. The relative frequency of the insertion allele in this sample was 0.73. Strong linkage disequilibrium was detected between this apoB insertion/deletion polymorphism and the Ag(c/g) epitope pair of apoB, while weak linkage disequilibrium was detected between the polymorphism and the four other reported Ag epitope pairs [(a1/d), (x/y), (h/i) and (t/z)], as well as the apoB PvuII and the XbaI RFLPs. Using one-way analysis of variance there was a statistically significant association (P less than 0.05) between the apoB insertion/deletion polymorphism and serum triglyceride levels in this sample. Individuals homozygous for the insertion allele had higher triglyceride levels than individuals homozygous for the deletion allele, while individuals heterozygous for the polymorphism had intermediate levels. These differences were reduced when individuals were consuming a low fat diet but were statistically significant when the individuals returned to their normal diet. It is possible that insertion or deletion of three hydrophobic amino acids (leu-ala-leu) from the signal peptide of apoB may have a direct effect on plasma triglyceride levels by altering the intracellular processing of apoB or apoB-containing lipoproteins in the liver or intestine.     

Differential ACE expression among tissues in allele-specific Wistar rat lines

In humans, the insertion/deletion polymorphism in the angiotensin converting enzyme (ACE) gene accounts for half of the variance in plasma ACE activity. The deletion allele is associated with high plasma ACE activity, cardiovascular disease, and renal disease. In rat, a similar association is found between the B and L alleles of a microsatellite marker in the ACE gene. We identified the B/L variation in the Wistar outbred rat and bred two lines homozygous for the two alleles (WU-B and WU-L). ACE activity was measured in serum, heart, kidney, and aorta homogenates. Immunohistochemistry and ACE mRNA expression were performed in heart, kidney, and aortic tissue. Aortic rings were collected and stimulated with AngI, AngII, and AngI with Lisinopril to measure ACE functional activity by vasoconstrictor response. Serum, heart, and kidney ACE activity and kidney mRNA expression were two-fold higher in WU-B. Kidney staining showed a clear difference in tubular ACE expression, with more staining in WU-B. While in aorta ACE activity and mRNA expression was twofold higher in WU-L, functional conversion of AngI was higher in WU-B, indicating either a functional difference in AngI to AngII conversion between the two alleles due to different splicing or the presence of other factors involved in the conversion that are differentially expressed as the result of differences in the ACE alleles. The newly developed WU-B and WU-L lines show tissue-specific differences in ACE expression and activity. This provides an experimental tool to study the pathophysiologic consequences of differences in ACE alleles in renal and cardiovascular disease. J. Kamilic and A. T. Lely contributed equally to this work.     

Polymorphisms of the apolipoprotein and angiotensin converting enzyme genes in young North Karelian patients with coronary heart disease

The genes encoding apolipoproteins (apos) A-I, B, C-III and E as well as that encoding the angiotensin converting enyzme (ACE) have been proposed as candidate genes for coronary heart disease (CHD). We determined the common polymorphisms of the apo genes, previously found to influence serum lipid levels at the population level, and the insertion/deletion polymorphism of the ACE gene, recently reported to reflect the risk of myocardial infarction, in 82 very young (mean, 41 years) North Karelian Finns with symptomatic CHD and 50 controls of similar age. Patients with familial hypercholesterolemia had been excluded from this material. None of the polymorphisms examined, including the apo A-I promoter MspI, apo C-III SstI and apo B XbaI restriction fragment polymorphisms, a common variation of apo E (2, 3 and 4 alleles) and an ACE insertion/deletion (I/D) polymorphism, was significantly associated with the risk of premature CHD. Patients with CHD had a higher mean serum LDL cholesterol/HDL cholesterol ratio than controls (3.15±1.30 vs 2.72±0.98, P < 0.05), but no significant associations between the common apo gene polymorphisms and serum lipid levels were disclosed in either group. It is possible that other genetic loci than those proposed to be associated with accelerated atherosclerosis may be more important as risk factors of symptomatic CHD at the age of 40 years.     

Evidence for two chemosensory pathways in Rhodobacter sphaeroides

In contrast to enteric bacteria, chemotaxis in Rhodobacter sphaeroides requires transport and partial metabolism of chemoattractants. Although a chemotaxis operon has been identified containing homologues of the enteric cheA, cheW, cheR genes and two homologues of the cheY gene, deletion of the entire chemotaxis operon had only minor effects on chemotactic behaviour under the conditions tested. Responses to sugars were enhanced in tethered cells but in all other chemotaxis assays behaviour of the operon deletion mutant was wild type. The mutant also showed wild-type responses to weak organic acids such as acetate and propionate, the dominant chemoattractants for this organism, under all conditions. This is in direct contrast to the enterics in which CheA, CheW and CheY are absolutely essential for taxis to PTS sugars, oxygen and MCP-dependent chemoeffectors. The operon deletion mutant was subjected to Tn5 transposon mutagenesis and new mutants selected using a chemotaxis and phototaxis screen. One mutant, JPA203, was non-chemotactic on swarm plates and showed inverted responses when tethered or subjected to changes in light intensity. Characterization of the Tn5 insertion in JPA203 identified a second chemotaxis operon in R. sphaeroides that contains homologues of cheY, cheA and cheR, the first homologue of cheB and two homologues of cheW. The new genes were labelled orf10, cheY_III, cheA_II, cheW_II, cheW_III, cheR_II, cheB and tlpC. When introduced into a wild-type background, deletion of cheA_II produced a chemotaxis minus phenotype in R. sphaeroides, suggesting that cheA_II forms part of a dominant chemotactic pathway, whereas the earlier identified operon plays only a minor role under laboratory conditions. The data presented here support the existence of two chemosensory pathways in R. sphaeroides, a feature that so far is unique in bacterial chemotaxis.     

Renin-angiotensin system polymorphisms in relation to hypertension status and obesity in a Tunisian population

Essential hypertension (HTA) is the clinical expression of a disordered interaction between the genetic, physiological, and biochemical systems that under usual conditions maintain cardiovascular homeostasis. We studied the effects of the angiotensinogen M235T, angiotensin converting enzyme insertion/deletion (ACE I/D), and angiotensin II receptor 1 (AT1R) A1166C gene polymorphisms on the risk of HTA and to evaluate the relationship between these polymorphisms and obesity. We performed AGT, ACE and AGTR genotyping in 142 hypertensive patients and 191 control subjects using PCR-RFLP methods and PCR, respectively. The three polymorphisms were significantly associated with HTA. Individuals carrying the mutated TT of AGT, DD of ACE and CC of AT1R genotypes had an 1.67 (P = 0.032), 3.09 (P < 0.001) and 3.45 (P < 0.001)-fold increased risk of HTA. After adjustment for sex, smoking, diabetes, dyslipidemia, BMI, triglycerides and DD, TT and CC genotypes, BMI was independent risk factor of HTA (OR = 3.14; P < 0.001). An association of BMI with ACE gene polymorphism (P = 0.035), whereas no association with AGT and AT1R gene polymorphisms was obtained. The proportion of hypertensives is as high as 21.8 and 13.4% in the overweight and the obese DD group. The present study implies that the genotyping for the variants of RAS gene could in the future become an important part of the clinical process of risk identification for HTA.     

Selection and characterization of a rice mutant resistant to 5-methyltryptophan

Summary A rice plant resistant to 5-methyltryptophan (5MT) was selected from mutagenized M3 seeds (Oryza sativa L. var. Sasanishiki) originating from panicles treated with ethylene imine (0.2%) 2 h after flowering. When germinated on 5MT-containing medium, the seeds (M4) from selfed plants segregated with a 3 resistant:1 sensitive ratio, indicating that the plant was heterozygous for a resistance gene and that the resistance was dominant. The resistance was also expressed in callus derived from seeds. Analysis of the free amino acids in seeds, seedlings, and calli showed that homozygous resistant plants (TR1) contained higher levels of total free amino acids than sensitive plants. In particular the levels of tryptophan, phenylalanine, and histidine were, respectively, 8.5, 5.4, and 4.9 times higher than those in the sensitive plants.     

Relationship of the angiotensin-converting enzyme gene polymorphism to glucose intolerance, insulin resistance, and hypertension in NIDDM

The deletion (D) allele of the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been shown to be associated with cardiovascular and renal diseases in diabetes mellitus, but the mechanism underlying this association is not known. In addition, recent studies of the effect of the ACE gene on blood pressure have yielded conflicting results. Therefore, we studied the association of the ACE gene I/D polymorphism with glucose intolerance and insulin resistance, and the contribution of this locus to genetic susceptibility to hypertension in non-insulin-dependent diabetic mellitus (NIDDM). We analysed the ACE genotype in 84unrelated NIDDM patients with a known disease duration of less than 1year and in 115age- and sex-matched controls. The I/D polymorphism was determined by the polymerase chain reaction. There were no differences in ACE genotype distribution and allele frequencies between patients with NIDDM and nondiabetic controls. The frequencies of the D and Ialleles in both groups were identical, viz., 0.65 and 0.35, respectively. The NIDDM patients with the DD genotype had significantly higher blood glucose levels in the oral glucose tolerance test than those with the other genotypes; the incremental glucose area under the curve in the order of II, ID, and DD was 7.2 ± 2.4, 9.2 ± 4.0, and 10.7 ± 2.7mmol/l · h (II vs ID vs DD, P=0.0066 by ANOVA). No significant difference was found between the ACE genotype and serum insulin values. Similarly, there were no differences in body mass index, blood pressure, or serum lipids between the three genotypes. Among the nondiabetic controls, there was no statistically significant association of the I/D polymorphism with serum lipids, blood glucose levels, serum insulin concentrations, or blood pressure values. In conclusion, NIDDM patients with the DD genotype have higher blood glucose levels and are more glucose intolerant; this may help to explain the reported association between the Dallele and vascular complications in NIDDM. Received: 15 September 1997 / Accepted: 13 November 1997     

The genetic map of transfer RNA genes of yeast mitochondria: Correction and extension

Summary Ninety five rho^- mitochondrial DNA's of Saccharomyces cerevisiae were compared for their deletion structure by means of 15 genetic markers and 22 tRNA genes. The patterns of co-deletion and coretention of different tRNA genes allowed us to determine their positions with respect to each other. The deduced order of tRNA genes was consistent with the order of the genetic markers established by independent genetic approaches. Our previously proposed mitochondrial tRNA gene map has been revised and extended. Transfer RNA genes, corresponding to all 20 aminoacids, and two isoacceptor tRNA genes were localized. The possible position of each tRNA gene has been indicated on the physical map of mitochondrial DNA. Seventeen tRNA genes are carried by a narrow region representing less than 20% of the wild type genome.Abbreviations tRNA transfer RNA - mRNA messenger RNA - rRNA ribosomal RNA - mitDNA mitochondrial DNA - nucDNA nuclear DNA - EDTA ethylenediaminetetraacetate - C, E, O_I, O_II and P drug resistance genetic loci - Rib I, Rib III O_I, O_II and P_I respectively. The three letter symbols for amino acids (ala, cys, etc...) designate tRNA genes corresponding to each amino acid Formerly Fondation Curie, Institut du Radium     

C677T Methylentetrahydrofulate Reductase and Angiotensin Converting Enzyme Gene Polymorphisms in Patients with Alzheimer’s Disease in Iranian Population

In recent years numerous data suggest that vascular risk factors may be play a role in Alzheimer’s disease (AD). To determine the association of AD with methylentetrahydrofulate reductase (MTHFR) and angiotensin converting enzyme (ACE) as two main vascular risk factors, we examined MTHFR C677T and ACE insertion/deletion (I/D) gene polymorphism in 117 late-onset AD cases and 125 controls. We found no difference in ACE I/D genotype distribution between AD cases and control (P > 0.05) but there was a significant association between AD and the common MTHFR polymorphism C677T. The T allele conferred an increased risk of AD compared to carrying a C allele (P = 0.001, OR = 1.97, 95% CI: 1.3–2.09). Our result suggests a significant increase in risk of AD in cases with the MTHFR T allele, atleast in the Iranian population.     

Identification of the Klebsiella pneumoniae glnB gene: nucleotide sequence of wild-type and mutant alleles

Summary The glnB gene of Klebsiella pneumoniae, which encodes the nitrogen regulation protein P_II has been cloned and sequenced. The gene encodes a 12429 dalton polypeptide and is highly homologous to the Escherichia coli glnB gene. The sequences of a glnB mutation which causes glutamine auxotrophy and of a Tn5 induced Gln⁺ suppressor of this mutation were also determined. The glutamine auxotrophy was deduced to be the result of a modification of the uridylylation site of P_II and the suppression was shown to be caused by Tn5 insertion in glnB. The 3 end of an open reading frame of unknown function was identified upstream of glnB and may be part of an operon containing glnB. Potential homologues of glnB encoding polypeptides extremely similar in sequence to P_II were identified upstream of published sequences of the glutamine synthetase structural gene (glnA) in Rhizobium leguminosarum, Bradyrhizobium japonicum and Azospirillum brasilense.     

Association of deep venous thrombosis with prothrombotic gene polymorphism identified in lung cancer cases

Venous thrombosis is a significant cause of morbidity and mortality in patients with malignancies. We aimed to investigate the association between prothrombotic gene polymorphisms detected in lung cancer cases and deep venous thrombosis (DVT). Totally 66 patients with an established diagnosis of lung cancer, of which 33 developed DVT, were enrolled. Multiplex PCR technique and reverse hybridization strip assay were performed on DNA extracted from peripheral blood, in order to analyze prothrombin G20210A, factor V G1691A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, angiotensin converting enzyme (ACE), plasminogen activator inhibitor-1 (PAI-1), and glycoprotein IIIa (Gp IIIa) gene mutations. Among prothrombotic gene polymorphisms investigated in this study, the commonest ones were PAI-1 4G/5G (56% heterozygous, 39% homozygous) and ACE gene mutations (58% heterozygous, 17% homozygous). The presence of homozygous MTHFR A1298C mutation was significantly associated with DVT (P = 0.020). Comparing the lung cancer patients with and without DVT, only MTHFR A1298C gene polymorphism differed significantly (P = 0.040). We determined a higher rate of prothrombotic gene mutations in lung cancer patients who developed DVT. However, statistical significance was achieved only for MTHFR A1298C gene mutation. Therefore, nongenetic factors for disturbance of hemostatic metabolism should also be considered in lung cancer patients.