Association between Angiotensin I-Converting Enzyme Insertion/Deletion Polymorphism and Prognosis of Kidney Transplantation: A Meta-Analysis

PurposeAngiotensin I-converting enzyme (ACE) is crucial in the renin–angiotensin–aldosterone system. ACE insertion/deletion (I/D) polymorphism is a common genetic variation of this gene and is associated with several disease phenotypes. However, the results of published studies on the influence of this polymorphism on renal transplantation are inconsistent. Therefore, a meta-analysis was performed to evaluate the association between ACE I/D polymorphism and prognosis of kidney transplantation.MethodsA meta-analysis was performed based on 21 case–control studies from 12 publications (1497 cases and 2029 controls) and 10 studies with quantitative values from 5 publications (814 patients). Pooled odds ratios (ORs) and weighted mean differences (WMDs) with their corresponding 95% confidence intervals (CIs) were used to estimate associations.ResultsACE I/D polymorphism was found to be associated with acute rejection (AR) in genotypes DD+ID versus II (OR = 1.62, 95% CI = 1.14–2.29) and with serum creatinine concentration after renal transplantation in genotypes DD versus ID (WMD = 13.12, 95% CI = 8.09–18.16). Stratified analysis revealed that recipients transplanted within a year had higher serum creatinine concentrations in the DD versus ID model. No significant association was found between hypertension and ACE I/D polymorphism.ConclusionACE I/D polymorphism is associated with AR and allograft function after kidney transplantation.     

The frequency of factor V Leiden mutation,ACE gene polymorphism,serum ACE activity and response to ACE inhibitor and angiotensin II receptor antagonist drugs in Iranians type II diabetic patients with microalbuminuria

The aim of present study was to determine if factor V Leiden (FVL) mutation and angiotensin converting enzyme insertion/deletion (ACE I/D) polymorphism are associated with diabetic nephropathy (DN) among Kurdish population from Western Iran. This case–control study comprised 144 unrelated adult type 2 diabetic mellitus patients (T2DM) including 72 patients with microalbuminuria and 72 age and sex matched patients without nephropathy. The ACE I/D polymorphism and FVL mutation were detected by polymerase chain reaction (PCR) and PCR–RFLP, respectively. The frequency of FVL G1691A and ACE D allele in T2DM patients with microalbuminuria were 1.6 and 57%, respectively and in normoalbuminuric T2DM patients were 4.9 and 58.3%, respectively (P > 0.05). ACE genotypes affected on serum ACE activity and a better response to ACE inhibitor therapy (captopril) compared to angiotensin II receptor antagonist (losartan) was obtained with significant reduction of ACE activity in diabetic patients without nephropathy carrying DD genotype. However, the beneficial effect of losartan therapy was observed in microalbuminuric patients with II genotype compared to ID and DD genotypes.     

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     

Insertion/Deletion Polymorphism and Serum Activity of the Angiotensin-Converting Enzyme in Turkish Patients with Obstructive Sleep Apnea Syndrome

This study determined the allelic frequency and genotypic distribution of an angiotensin-converting enzyme (ACE) polymorphism and serum ACE activity in Turkish patients with obstructive sleep apnea syndrome (OSAS). A colorimetric assay measured serum ACE activity in 73 of 97 subjects. Frequencies for II, ID, and DD genotypes were 19.6, 53.6, and 26.8% in the OSAS group and 15, 38, and 47% in the control group, respectively (P = 0.02). The I allele frequency was higher in the OSAS group than in the healthy control group (P = 0.02). Carrying the I allele (II or ID genotypes) increased OSAS risk 2.41 times in the Turkish population. Mean ACE activity was significantly lower in patients with the II genotype than in the DD genotype (P = 0.011), and ACE activity was significantly lower in patients with severe OSAS than in those with mild OSAS (P = 0.006). Our results suggest that II and ID genotypes of the ACE gene increase the risk of developing OSAS in the Turkish population.     

Glyceryl trinitrate-induced angiotensin-converting enzyme (ACE) inhibition in healthy volunteers is dependent on ACE genotype

Evidence concerning the importance of angiotensin-converting enzyme (ACE) genotype in cardiovascular diseases is accumulating. The aim of this study was to investigate if nitric oxide (NO), generated from glyceryl trinitrate (GTN), affects human serum ACE activity in vivo, and if so, whether this effect was dependent on ACE genotype and (or) reflected in blood pressure reduction. A tablet containing 5 mg GTN was bucally administered for 5 minutes to 17 healthy volunteers. Blood pressure (BP) was recorded, and serum ACE activity, ACE genotype, and plasma cGMP was analyzed. GTN administration significantly reduced BP only in individuals with the deletion/deletion (DD) genotype. Sixty minutes after GTN administration, serum ACE activity was reduced in individuals with the insertion/insertion (II) and insertion/deletion (ID) genotypes, but not the DD genotype. Comparing the change in ACE activity over time between the genotypes resulted in the following: II vs. DD, p < 0.01; II vs. ID, p < 0.05; and ID vs. DD, p < 0.05. There was no significant difference in plasma cGMP content neither between the ACE genotypes nor before and after GTN administration. In conclusion, GTN inhibits serum ACE in vivo in individuals with the II and ID, but not the DD genotype.     

Association of angiotensin I-converting enzyme gene insertion/deletion polymorphism with rheumatic heart disease in Indian population and meta-analysis

Rheumatic heart disease (RHD) is one of the most severe consequences of rheumatic fever. It has been suggested that angiotensin I-converting enzyme (ACE) may be involved in the increased valvular fibrosis and calcification in the pathogenesis of RHD. We conducted a case–control study to look for association of ACE I/D polymorphism with RHD in Indian population. The study incorporated 300 patients (170 males and 130 females) with RHD, and 200 controls (118 males and 82 females). We also subgrouped RHD patients into mitral valve lesion (MVL) and combined valve lesion (CVL). ACE I/D polymorphism was identified using polymerase chain reaction method. We also performed a meta-analysis of three published studies and the present study (636 RHD cases and 533 controls) to evaluate the association between the ACE I/D polymorphisms and RHD risk. A significant difference in ACE ID and DD genotypes distribution between RHD cases (OR = 1.62, 95 % CI = 1.11–2.36 and OR = 2.08, 95 % CI = 1.02–4.15, respectively) and corresponding controls was observed. On comparing the ACE genotypes of MVL and CVL subgroups with controls, ID and DD genotypes were also significantly associated with CVL (FDR Pcorr = 0.009, OR = 2.19 and FDR Pcorr = 0.014, OR = 3.29, respectively). Meta-analysis also suggested association of the ACE D allele (FDR Pcorr = 0.036, OR—1.22, 95 % CI 1.02–1.45) with RHD. In conclusion, ACE ID and DD genotypes are associated with an increased risk of RHD, particularly CVL. This suggests that the ACE I/D gene polymorphism may play an important role in the pathogenesis of RHD.     

Beneficial role of D allele in controlling ACE levels: a study among Brahmins of north India

India being a country with vast diversity is expected to have different dietary and life style patterns which in turn may lead to population-specific environmental risk factors. Further, the interaction of these risk factors with the genetic makeup of population makes it either susceptible or resistant to cardiovascular disease. One such candidate gene is angiotensin converting enzyme (ACE) for various cardiovascular mechanisms. ACE is the key enzyme of the renin angiotensin aldosterone system pathway which maintains homeostasis blood pressure in the body and any variation in the levels is reported to be associated with various complex diseases. The DD genotype is found to increase ACE levels, which is associated with cardiovascular diseases and decrease in ACE levels are associated with kidney diseases. The aim of this study was to understand the distribution of ACE I/D polymorphism and ACE levels among Brahmins of National Capital Region (NCR) north India, with respect to age and sex ratio distribution. In this study, 136 subjects of which 50 males and 86 females, who were unrelated up to first cousin, aged 25 to70 years were studied. ACE gene was found to be polymorphic with high frequency of heterozygote (ID) followed by II and DD genotypes. The studied population was found to be in Hardy–Weinberg equilibrium with respect to ACE I/D polymorphism (P = 0.55). I allele frequency was found to be higher (0.560) than the D allele (0.44). The median level of ACE was found to be 65.96 ng/mL (48.12–86.24) which is towards lower side of the normal range. ACE levels were found to be increased among individual having either of the homozygotes that is II or DD and higher frequency of heterozygote (ID) is indicative of advantage in the population by maintaining lower ACE levels. The limitation of the present study is low sample size, however, the merit is that the subjects belonged to a Mendalian population with a common gene pool.     

Angiotensin converting enzyme I/D,angiotensinogen M235T and AT1-R A/C1166 gene polymorphisms in patients with acromegaly

Acromegaly is associated with increased morbidity and mortality related to cardiovascular disease. Hypertension is one of the most common cardiovascular risk factors in acromegalic patients. The aim of this study was to investigate association between the frequencies of angiotensin converting enzyme (ACE) I/D, angiotensinogen (AGT) M235T and the angiotensin II type 1 receptor (AT1-R) A/C1166 gene polymorphisms and some clinical parameters of acromegalic patients. Total of 33 acromegalic patients and 63 controls were enrolled to study. We determined the ACE I/D, AGT M235T and AT1-R A/C1166 gene polymorphisms. Serum insulin, glucose, triglyceride, HDL-cholesterol, LDL-cholesterol, growth hormone and Insulin-like growth factor I (IGF-I) levels of subjects were analyzed. The frequencies of ACE and M235T AGT genotype were not significantly different between control and patients. The distribution of AT1R A/C1166 genotypes was significantly different between patients and control subjects (P = 0.016). None of the three ACE genotypes, DD, ID and II displayed significant difference in acromegalic patients. A significant difference in systolic blood pressure and the serum IGF-I levels among the three AGT genotype, MM, MT and TT genotypes was found in patient group. Individuals with MT genotypes had significantly higher serum IGF-I levels and systolic blood pressure than MM and TT genotype subjects, P < 0.05. In addition, serum triglyceride and HDL levels differed significantly between MM and MT genotypes, P < 0.05. However, systolic blood pressure of patients with CC genotypes was found to be significantly higher than AA genotypes individuals in acromegaly group, P < 0.05. It can be said that the angiotensinojen MT and AT1R CC1166 genotype carriers may have more risk than other genotypes in the development of hypertension in acromegaly.     

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 of angiotensin-converting enzyme and endothelial Nitric Oxide synthase gene polymorphisms with vascular disease in ESRD patients in a Chinese population

Background The effect of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and endothelial Nitric Oxide synthase (eNOS) gene G894 → T on vascular disease in end-stage renal disease (ESRD) patients was rarely studied previously. We investigated such effect in a Chinese population. Methods A total of 153 ESRD patients with vascular disease (88 men and 65 women; mean age ± SD: 54.0 ± 13.2) were recruited. Polymerase chain reaction was used to classify the ACE genotypes as II, ID and DD and the eNOS genotypes as GG, GT, and TT. Analyses were performed in ESRD patients with vascular disease (n = 153) and the age-matched controls (n = 148). Results The frequencies of ACE DD and eNOS TT genotypes and ACE D and eNOS T alleles in ESRD patients with vascular disease were significantly higher than those in the controls (P < 0.05). There was a significant interaction between ACE I/D alleles and eNOS G894 → T polymorphism: adjusted odds ratio 2.128 (95%CI 1.022–4.434, P = 0.017). Conclusions These results indicated that the etiology of vascular disease in ESRD patients is associated with ACE and eNOS (G894 → T) gene polymorphisms. Our data also suggest that an interaction effect may exist between ACE (I/D) and eNOS (G894 → T) polymorphism in increasing the risk of vascular complications in ESRD patients     

ACE gene polymorphism in peripheral vascular disease.

Peripheral vascular disease is an atherosclerotic process. It has been suggested that angiotensin converting enzyme insertion/deletion polymorphism is associated with atherosclerosis. The aim of this study was to investigate the role of the insertion/deletion polymorphism of the angiotensin-converting enzyme in Turkish patients with peripheral vascular disease in Western part of Turkey. We also investigated the relationship between serum angiotensin converting enzyme activity and distribution of genotypes in both patients and control group. The study group consisted of 78 patients with peripheral vascular disease. The control group consisted of 73 healthy adults. Serum angiotensin converting enzyme activities in patients were higher than those of the control group (p<0.05). Angiotensin converting enzyme genotype frequencies in patients were observed as 28.2%, 18% and 53.8% for DD, II and ID polymorphism, respectively. These frequencies in controls were 42.5%, 20.5% and 37% for DD, II and ID, respectively. Serum angiotensin converting enzyme activities in both groups with II genotype were significantly lower than those with ID and DD genotype (p<0.05). Although conflicting results have been reported about this polymorphism in patients with peripheral vascular disease, we suggest that the angiotensin converting enzyme ID genotype may be a risk factor for peripheral vascular disease.     

Angiotensin-converting enzyme gene polymorphism is associated with anemia in non small-cell lung cancer

The angiotensin-converting enzyme (ACE) plays an important role not only in the regulation of vascular homeostasis but also in stimulation of hematopoiesis. We aimed to evaluate the association between insertion/deletion (I/D) polymorphism of the ACE gene and anemia at the time of the diagnosis. We enrolled 75 patients with non-small-cell lung cancer (NSCLC) and 85 age- and sex-matched healthy control participants. The I/D polymorphism of ACE was identified by using polymerase chain reaction from peripheral blood samples. Statistical analyses were performed with SPSS for Windows. The distributions of the ACE genotypes and alleles are similar in patients and in healthy participants (P=0.29 and P=0.08, respectively). In patients with NSCLC, 34 (45.3%) had anemia; of whom 3 (8.8%) had genotype II, 24 (70.6%) had genotype ID, and 7 (20.6%) had genotype DD (P=0.001). The patients with the II and ID genotypes had more frequent anemia at the time of the diagnosis (odds ratio = 6.02; P=0.001). Our findings suggest that I/D polymorphism of the ACE gene may influence the development of anemia in patients with NSCLC.     

ACE基因多态性与高血压肾脏损害及PAI-1的关系

为探讨血管紧张素转换酶（ACE）基因多态性与高血压肾损害和纤溶酶原激活物抑制物-1（PAI-1）的关系,应用聚合酶链反应（PCR）检测96例正常人、67例高血压无肾脏损害患者和70例高血压伴肾损害患者的ACE基因型,采用ELISA法检测血浆PAI-1。ACE基因I/D多态性与高血压病无明显相关,但高血压肾损害患者DD基因型频率及D等位基因频率显著高于对照组和高血压无肾脏损害组,χ2值分别为6.8589、5.6162 和5.9085、5372。血浆PAI-1在DD型、ID型、II型高血压患者之间亦有显著性差异（P＜0.05）。ACE基因DD型可能是高血压肾损害的危险因素;ACE基因多态性与血浆PAI-1水平相关。 Abstract:The work is to explore the relationship between the polymorphism of angiotensin converting enzyme(ACE) gene and hypertensive kidney lesion/PAI-1 in hypertension patients.ACE genotyping with polymorase chain reaction (PCR) was performed in 96 unrelated healthy controls,67 hypertensives without kidney lesion and 70 hypertensives complicated with kidney lesion.The plasma PAI-1 were determined with ELISA.No significant differences could be detected between ACE gene I/D polymorphism and hypertension.However,the frequencies of DD genotype and deletion allele among the hypertensives complicated with kidney lesion were higher than those among the healthy controls and those among the hypertensives without kidney lesion."χ2" values were 6.8589,5.6162 and 5.9085,5.372 respectively.The plasma PAI-1 level showed significant differences among DD genotype,ID genotype and II genotype(P＜0.05).The DD genotype of ACE gene may be a risk for hypertensive kidney lesion.The plasma PAI-1 level is associated with ACE gene polymorphism.     

Polymorphism of genes of the renin-angiotensin system ACE, AT1R, and AT2R in patients with pulmonary tuberculosis

The goal of this work was to verify the hypothesis about the possible role of some genes of the renin-angiotensin system in the innate immunity to tuberculosis. The insertion/deletion polymorphism (I/D) of the gene of the angiotensin-converting enzyme (ACE) is known to have an effect on the concentration of the angiotensin II in human body and also an indirect effect on various branches of metabolism. On the one hand, people with homozygote deletion of the ACE gene (DD genotype) are vulnerable to adiposity, arterial hypertension, hypercholesterolemia, and a number of other pathological conditions. On the other hand, it was shown that hypocholesterolemia is the general phenomenon for the patients with pulmonary tuberculosis (Perez-Guzman C. et al., Chest (2005)). In this work, we studied the I/D polymorphism of the gene ACE (genotypes DD, ID, and II), single nucleotide polymorphism (SNP) of the gene AT1R (1166 A/C), and SNP in 3123 positions of the gene AT2R (3123 A/C) in 200 patients with tuberculosis, 202 patients with essential hypertension, and 208 apparently healthy subjects. A group of patients with essential hypertension was used as a contrast group. According to the hypothesis stated above, the excess in the number of patients with the DD genotype (ACE) should be statistically significant in the group of patients with hypertension as compared to the group of patients with tuberculosis (chi2 = 9.64; chi2 = 0.0019; OR = 2.0; CI 1.2-3.3). There was a trend toward an increase in the rate of the DD genotype in the group of patients with tuberculosis relative to healthy subjects. Similar trend was observed in healthy subjects relative to the group of patients with hypertension. However, this difference was found to be statistically insignificant. The genotypes and allelotypes were compared in the group of patients with tuberculosis versus both the two control groups (healthy subjects and patients with hypertension). The significant difference from control was observed only in male rather than female patients with tuberculosis. It was shown that the greatest contribution to the distinction between groups was due to the genes ACE and AT2R. The combination of the genotypes of genes ACE and AT2R (ID+3123C) was met significantly more frequently in male patients with tuberculosis as compared to control group of healthy subjects (chi2 = 9.70; chi2 = 0.002; OR = 2.3; CI 1.2-4.3). The results obtained in this work are discussed in terms of the hypothesis stated above.     

ACE gene polymorphism and serum ACE activity in Iranians type II diabetic patients with macroalbuminuria

There are controversial results related to the contribution of insertion (I)/deletion (D) polymorphism of the angiotensin I-converting enzyme (ACE) in the development of diabetic nephropathy. To assess the distribution of this polymorphism in diabetic patients with and without nephropathy we studied 140 unrelated type 2 diabetic patients from the Kermanshah Province of Iran with ethnic background of Kurds including 68 patients with macroalbuminuria and 72 normoalbuinuric diabetic patients as controls. Genotyping was done by polymerase chain reaction (PCR). The frequency of D allele in nephropathic and normoalbuminuric patients were 69.1 and 58.3%, respectively (P = 0.061). In individuals with DD genotype the risk of macroalbuminuria increased 2.87-fold (P = 0.057). Significant lower level of serum ACE activity was found in the normoalbuminuric (59.76 IU/l) compared to macroalbuminuric (97.43 IU/l) patients. The serum ACE activity was significantly higher in macroalbuminuric patients with ID (105.7 IU/l) and ID + DD (100.7 IU/l) genotypes compared to normoalbuminuric patients with the same genotypes (63.5 and 64.2 IU/l, respectively). Treatment with captopril significantly (P = 0.045) reduced the serum ACE activity in normoalbuminuric patients with DD genotype compared to macroalbuminuric patients with the same genotype (33.6 vs. 73.8 IU/l). However, the greatest benefit effect of losartan therapy on ACE activity was observed only in macroalbuminuric patients with DD genotype compared to that in normoalbuminuric patients (61.0 vs. 109.0 IU/l, P = 0.06). Our study suggests the importance of ethnic origin in the development of diabetic nephropathy and demonstrates different responses to therapy according to genotype and stage of diabetes.     

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.     

Association of LncRNA-GAS5 gene polymorphisms and PBMC LncRNA-GAS5 level with risk of systemic lupus erythematosus in Chinese population

Growth arrest-specific 5 (GAS5) is a kind of long non-coding RNAs (lncRNAs). Previous studies showed that down-regulation of LncRNA-GAS5 was involved in the development of systemic lupus erythematosus (SLE). However, the regulatory mechanism of down-expressed LncRNA-GAS5 in SLE remains obscure. In this study, we aimed to investigate the association of LncRNA-GAS5 polymorphism with SLE risk. And further explore how LncRNA-GAS5 is involved in the occurrence of SLE. Here, we evaluated the relationship between the risk for the development of SLE and the 5-base pair (AGGCA/-) insertion/deletion (I/D) polymorphism (rs145204276) in the LncRNA-GAS5 promoter region. A custom 36-Plex SNPscan kit was used for genotyping the LncRNA-GAS5 polymorphisms. The LncRNA-GAS5 and miR-21 target prediction was performed using bioinformatics software. Enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qRT-PCR) were performed to assess GAS5 and miR-21 mRNA expression and PTEN protein expression. The results revealed that rs145204276 resulted in a decreased risk of SLE (DD genotypes vs II genotypes: adjusted OR = 0.538, 95% CI, 0.30-0.97, P = .039; ID genotypes vs II genotypes: adjusted OR = 0.641, 95% CI, 0.46-0.89, P = .007; ID/DD genotypes vs II genotypes: adjusted OR = 0.621, 95% CI, 0.46-0.84, P = .002; D alleles vs I alleles: adjusted OR = 0.680, 95% CI, 0.53-0.87, P = .002). A reduced incidence of renal disorders in SLE was found to be related to ID/DD genotypes and D alleles (ID/DD genotypes vs II genotypes: OR = 0.57, 95% CI, 0.36-0.92, P = .020; D alleles vs I alleles: OR = 0.63, 95% CI, 0.43-0.93, P = .019). However, no significant association of rs2235095, rs6790, rs2067079 and rs1951625 polymorphisms with SLE risk was observed (P > .05). Additionally, haplotype analysis showed that a decreased SLE risk resulted from the A-A-C-G-D haplotype (OR = 0.67, 95% CI, 0.49-0.91, P = .010). Also, patients in the SLE group showed a down-regulated expression of LncRNA-GAS5 and PTEN than the healthy volunteers; however, patients with rs145204276 ID/DD genotypes showed up-regulated expression of LncRNA-GAS5 and PTEN compared with patients carrying the II genotype. Furthermore, the miR-21 levels were considerably up-regulated in the SLE group than the healthy volunteers, and patients with rs145204276 ID/DD genotype had lower miR-21 levels than the ones with the II genotype. Thus, we found that the LncRNA-GAS5/miR-21/PTEN signalling pathway was involved in the development of SLE, where LncRNA-GAS5 acted as an miR-21 target, and miR-21 regulated the expression of PTEN. These findings indicated that the rs145204276 ID/DD genotypes in the LncRNA-GAS5 gene promoter region may be protected against SLE by up-regulating the expression of LncRNA-GAS5, which consecutively regulated miR-21 and PTEN levels.     

ACE ID genotype affects blood creatine kinase response to eccentric exercise.

Unaccustomed exercise may cause muscle breakdown with marked increase in serum creatine kinase (CK) activity. The skeletal muscle renin-angiotensin system (RAS) plays an important role in exercise metabolism and tissue injury. A functional insertion (I)/deletion (D) polymorphism in the angiotensin I-converting enzyme (ACE) gene (rs4646994) has been associated with ACE activity. We hypothesized that ACE ID genotype may contribute to the wide variability in individuals' CK response to a given exercise. Young individuals performed maximal eccentric contractions of the elbow flexor muscles. Pre- and postexercise CK activity was determined. ACE genotype was significantly associated with postexercise CK increase and peak CK activity. Individuals harboring one or more of the I allele had a greater increase and higher peak CK values than individuals with the DD genotype. This response was dose-dependent (mean +/- SE U/L: II, 8,882 +/- 2,362; ID, 4,454 +/- 1,105; DD, 2,937 +/- 753, ANOVA, P = 0.02; P = 0.009 for linear trend). Multivariate stepwise regression analysis, which included age, sex, body mass index, and genotype subtypes, revealed that ACE genotype was the most powerful independent determinant of peak CK activity (adjusted odds ratio 1.3, 95% confidence interval 1.03-1.64, P = 0.02). In conclusion, we indicate a positive association of the ACE ID genotype with CK response to strenuous exercise. We suggest that the II genotype imposes increased risk for developing muscle damage, whereas the DD genotype may have protective effects. These findings support the role of local RAS in the regulation of exertional muscle injury.     

Prevalence of the Angiotensin I Converting Enzyme Gene Insertion/Deletion Polymorphism in a Healthy Turkish Population

Angiotensin converting enzyme (ACE) plays an essential role in the renin–angiotensin system. It converts angiotensin I to angiotensin II and inactivates bradykinin and tachykinins. Numerous studies have been published investigating associations of the ACE gene I/D polymorphism with various pathophysiological conditions. We examined the prevalence of the ACE I/D polymorphism in a sample of healthy volunteers from western Turkey, including 1063 healthy Turkish controls. Analysis of the ACE I/D gene polymorphisms by polymerase chain reaction found frequencies of 16.1% for the II genotype, 47.7% for the ID genotype, and 36.2% for the DD genotype. The allele frequency was 39.9% for the I alleles and 60.1% for the D allele. This study demonstrates that the allele and genotype frequency values for the Turkish population are similar to previously published frequencies for Caucasian populations.