Jingzhou Chen

Effect of oral isoflavone supplementation on vascular endothelial function in postmenopausal women: a meta-analysis of randomized placebo-controlled trials

BACKGROUND The effect of isoflavone on endothelial function in postmenopausal women is controversial. OBJECTIVE The objective of this study was to evaluate the effect of oral isoflavone supplementation on endothelial function, as measured by flow-mediated dilation (FMD), in postmenopausal women. DESIGN A meta-analysis of randomized placebo-controlled trials was conducted to evaluate the effect of oral isoflavone supplementation on endothelial function in postmenopausal women. Trials were searched in PubMed, Embase, the Cochrane Library database, and reviews and reference lists of relevant articles. Summary estimates of weighted mean differences (WMDs) and 95% CIs were obtained by using random-effects models. Meta-regression and subgroup analyses were performed to identify the source of heterogeneity. RESULTS A total of 9 trials were reviewed in the present meta-analysis. Overall, the results of the 9 trials showed that isoflavone significantly increased FMD (WMD: 1.75%; 95% CI: 0.83%, 2.67%; P = 0.0002). Meta-regression analysis indicated that the age-adjusted baseline FMD was inversely related to effect size. Subgroup analysis showed that oral supplementation of isoflavone had no influence on FMD if the age-adjusted baseline FMD was > or = 5.2% (4 trials; WMD: 0.24%; 95% CI: -0.94%, 1.42%; P = 0.69). This improvement seemed to be significant when the age-adjusted baseline FMD levels were <5.2% (5 trials; WMD: 2.22%; 95% CI: 1.15%, 3.30%; P < 0.0001), although significant heterogeneity was still detected in this low-baseline-FMD subgroup. CONCLUSIONS Oral isoflavone supplementation does not improve endothelial function in postmenopausal women with high baseline FMD levels but leads to significant improvement in women with low baseline FMD levels.

Increase in fasting vascular endothelial function after short-term oral l-arginine is effective when baseline flow-mediated dilation is low: a meta-analysis of randomized controlled trials

BACKGROUND Previous trials suggest that oral l-arginine administration affects endothelial function. However, most of these studies were small, the conclusions were inconsistent, and the precise effects are therefore debatable. OBJECTIVE The objective was to assess the effect of oral l-arginine supplementation on endothelial function, as measured with the use of fasting flow-mediated dilation (FMD). DESIGN We conducted a meta-analysis of randomized, placebo-controlled l-arginine supplementation trials that evaluated endothelial function. Trials were identified in PubMed, Cochrane Library, Embase, reviews, and reference lists of relevant papers. The weighted mean difference (WMD) was calculated for net changes in FMD by using random-effect models. Previously defined subgroup analyses and meta-regression analyses were performed to explore the influence of study characteristics. RESULTS Thirteen trials were included and evaluated. Because there was only one long-term study, we focused on short-term effects of l-arginine (12 studies, 492 participants). In an overall pooled estimate, l-arginine significantly increased FMD (WMD: 1.98%; 95% CI: 0.47, 3.48; P = 0.01). Meta-regression analysis indicated that the baseline FMD was inversely related to effect size (regression coefficient = -0.55; 95% CI: -1.00, -0.1; P = 0.016). A subgroup analysis suggested that l-arginine supplementation significantly increased FMD when the baseline FMD levels were <7% (WMD: 2.56%; 95% CI: 0.87, 4.25; P = 0.003), but had no effect on FMD when baseline FMD was >7% (WMD: -0.27%; 95% CI: -1.52, 0.97; P = 0.67). CONCLUSION Short-term oral l-arginine is effective at improving the fasting vascular endothelial function when the baseline FMD is low.

Variants on Chromosome 9p21.3 Correlated With ANRIL Expression Contribute to Stroke Risk and Recurrence in a Large Prospective Stroke Population

Background and Purpose— ANRIL encodes a long antisense noncoding RNA in the INK4 locus. Although ANRIL has been proven to be associated with coronary heart disease, its roles in stroke are inconsistent, and sparse data are available regarding hemorrhagic stroke. Methods— A Chinese case-control study was conducted, comprising 1657 cases (724 atherothrombosis, 466 lacunar infarction, and 462 hemorrhagic strokes) and 1664 controls. Stroke patients were prospectively followed-up for a median of 4.5 (range, 0.1–6.0) years. Expression of ANRIL transcripts was examined in 42 human atherosclerotic plaques. Results— After adjustment for vascular risk factors and correction for multiple comparisons, subjects carrying the GG genotype of rs10757278 had 1.47-fold (95% CI, 1.11–1.89; P=0.05) and 1.60-fold (95% CI, 1.16–2.15; P=0.04) increased risk for atherothrombotic and hemorrhagic strokes, respectively. During the follow-up, 317 recurrent strokes and 301 deaths from all causes were documented. Subjects carrying rs10757278GG had higher risk for stroke recurrence (relative risk [RR],1.56; 95% CI,1.15–2.12; P=0.005) and cardiovascular mortality (RR, 2.0; 95% CI, 1.26–3.18; P=0.003), respectively. Rs10757274 was also associated with stroke risk and recurrence. Family history of stroke further increased the stroke risk by 2.37-fold (95% CI, 1.38–4.06; P=0.01) and recurrent stroke risk by 2.45-fold (95% CI, 1.56–3.86; P<0.0001) respectively, when compared with those carrying none of G-alleles and without family history. Finally, rs10757278 was associated with differential expression of the ANRIL transcripts. Conclusions— Our findings indicated that the ANRIL may serve as a novel genetic marker for the risk of atherothrombotic and hemorrhagic stroke and their recurrence.

Association of Intergenic Polymorphism of Organic Anion Transporter 1 and 3 Genes With Hypertension and Blood Pressure Response to Hydrochlorothiazide

BACKGROUND Organic anion transporter (OAT) 1 and OAT3, encoded by a tightly linked gene pair, play a key role in renal secretion of diuretics. However, no study has yet examined the influence of OAT1 and OAT3 polymorphisms on high blood pressure (BP) and the response to thiazide diuretics. We hypothesized that intergenic polymorphisms between OAT1 and OAT3 might be associated with adult hypertension and the antihypertensive effects of hydrochlorothiazide (HCTZ). METHODS The association of an intergenic polymorphism (rs10792367) with hypertension risk was investigated in two independent case-control studies (n = 1,592 and 602), and then a combined analysis was performed for improving power (1,106 cases and 1,088 controls) with adjustment for geographic location. Two clinical trials (n = 542 and 274) were conducted in untreated hypertensive patients for the association of rs10792367 with antihypertensive responses to 4 and 8 weeks of HCTZ treatment. RESULTS No significant association was found between rs10792367 and hypertension after adjustment for conventional risk factors in either the two populations, respectively, or the combined two population. After adjustment for pretreatment BP and other confounders, HCTZ-induced reduction in systolic BP was 4.8 mm Hg (P = 0.006, first trial) and 6.1 mm Hg (P = 0.003, in second trial) lower, respectively, in C allele carriers than in GG carriers in the two clinical trials. CONCLUSIONS Intergenic polymorphism rs10792367 between OAT1 and OAT3 is not associated with hypertension, but appears to be involved in between-individual variations in antihypertensive responses to HCTZ.

Vitamin k epoxide reductase: a protein involved in angiogenesis.

Vitamin K epoxide reductase (VKOR) is a newly identified protein which has been reported to convert the epoxide of vitamin K back to vitamin K, a cofactor essential for the posttranslational γ-carboxylation of several blood coagulation factors. We found that the gene is expressed ubiquitously including vascular endothelial cells, smooth muscle cells, fibroblasts and cardiomyocytes, and is overexpressed in 11 tumor tissues on microarray. Stable transfection of VKOR cDNA into tumor cell line A549 and H7402 did not promote the cell proliferation. These results promoted us to hypothesize that VKOR may also be involved in angiogenesis. To test this hypothesis, the expression of VKOR was studied in different vascular cells in developmental and pathologic heart tissues. The effects of overexpression and suppressing expression of VKOR on endothelial cell proliferation, migration, adhesion, and tubular network formation were explored. We found that VKOR expression in arteries was prominent in vascular endothelial cells and was high in the ventricular aneurysm tissue of human heart and human fetal heart. In vitro studies showed that overexpression of VKOR slightly but significantly stimulated human umbilical vein endothelial cell proliferation (by 120%), migration (by 118%), adhesion (by 117%), as well as tubular network formation. Antisense to VKOR gene inhibited the proliferation (by 67%), migration (by 64%), adhesion (by 50%), and tubular network formation. Our findings support the impact of VKOR in the process of angiogenesis; hence, the molecule may have a potential application in cardiovascular disease and cancer therapy.

The haplotype of the growth-differentiation factor 15 gene is associated with left ventricular hypertrophy in human essential hypertension

GDF15 (growth-differentiation factor 15) is a novel antihypertrophic factor which is induced in the heart in response to pressure overload and plays an important regulatory role in the process of hypertrophy. In the present study, we have investigated the relationship between GDF15 gene variants and left ventricular hypertrophy in human essential hypertension. A community-based hypertensive population sample of 1527 individuals (506 men and 1021 women) was genotyped for three GDF15 genetic variants, including one tag variant -3148C>G (rs4808793) and two exonic variants +157A>T (rs1059369) and +2438C>G (rs1058587). The effects of those variants on gene expression were studied by use of luciferase reporter assays and the determination of plasma GDF15 levels. Only the tag variant -3148G was significantly associated with a lower risk of left ventricular hypertrophy [odds ratio=0.75 (95% confidence interval, 0.63-0.89); P=0.0009]. Multiple regression analyses confirmed that -3148G predicted the decrease in left ventricular end-diastolic diameter (beta=-0.10, P=0.0001), end-systolic diameter (beta=-0.09, P=0.0007), mass (beta=-0.11, P<0.0001) and indexed mass (beta=-0.12, P<0.0001). These effects were independent of conventional factors, including gender, age, body surface area, blood pressure, diabetes, cigarette smoking and alcohol consumption. The transcription activity of the -3148G-containing construct was increased 1.45-fold (P=0.015) at baseline and 1.73-fold (P=0.008) after stimulation with phenylephrine when compared with the -3148C construct. The -3148G allele was also associated with a significant increase in the plasma GDF15 level in hypertensive subjects (P=0.04). In conclusion, the results show that a promoter haplotype containing the -3148G variant increases GDF15 transcription activity and is associated with favourable left ventricular remodelling in human essential hypertension.

Lack of association between lymphotoxin-α, galectin-2 polymorphisms and coronary artery disease: A meta-analysis

OBJECTIVE Previous case-control studies suggested the single nucleotide polymorphisms of lymphotoxin-alpha (LTA) gene and galectin-2 (LGASL2) gene are associated with coronary artery disease and myocardial infarction. However, other studies did not confirm this relationship. The objective was to assess the relationship of LTA gene, LGALS2 gene and coronary artery disease, using a meta-analysis. METHODS Databases, including PubMed, EMbase, CBM and CNKI, were searched to get the genetic association studies. Data were extracted by two authors and pooled odds ratio (OR) and 95% confidence interval (CI) were calculated. RESULT The meta-analysis included 20640 (LTA-A252G) and 10552 (LGALS2-C3279T) cases, 15388 (A252G) and 10545 (C3279T) controls. The pooled OR of 252G was 1.02 (95%CI: 0.97-1.07) compared to wild type allele in dominant model, and was 1.00 (95%CI: 0.94-1.07) in recessive model. The pooled OR of 3279T was 0.95 (95%CI: 0.89-1.01) compared to wild type allele in dominant model, and was 0.89 (95%CI: 0.78-1.00) in recessive model. None of the polymorphisms was found to associate with coronary artery disease. CONCLUSION In present study, the LTA gene and LGALS2-C3279T are not associated with coronary artery disease.

CARP is a novel caspase recruitment domain containing pro-apoptotic protein

Many CARD-containing caspase mediators interact with CARD-containing caspases and participate in activation or suppression of caspases. We cloned a novel CARD-containing protein from our EST database, named CARP. Computational characterization revealed that CARP encoded 445 amino acids with predicted MW 49.7 kDa, localized at chromosome 10p13 with 15 exons, and four putative function domains, one CARD domain (aa 160-243), one nuclear receptor-binding motif, two EF-hand motifs, and 42% alpha-helix content. Stable transfection of CARP into lung carcinoma A549 and HEK293S cells leads to 23% of the cells undergoing apoptosis, but only 3% in the cells transfected with empty control vector. The cell proliferation was significantly inhibited by 1.2-5 folds (P<0.02) in seven CARP-transfected tumor cell lines-lung carcinoma A549 and PG, melanoma WM451, prostate cancer PC-3 and PC-3M, liver cancer H7402, and bladder cancer BIU87. Our results suggest that CARP is a novel CARD-containing pro-apoptotic protein.

Promoter variant of angiopoietin-2 and plasma angiopoietin-2 are associated with risk of stroke recurrence in lacunar infarct patients.

Angiopoietin-2 has been reported to regulate the inflammation process, which is associated with recurrence of stroke. The purpose of this study was to test the hypothesis that plasma levels of angiopoietin-2 and variants of angiopoietin-2 will confer risk of stroke recurrence. The association of plasma angiopoietin-2 (determined by using ELISA) and the variants in angiopoietin-2 promoter with stroke recurrence was tested in 1735 patients with stroke of three subtypes, lacunar infarct (n=475), atherothrombotic (n=794) and hemorrhage (n=466), for a period of following-up 4.5 years (mean), the association was evaluated by using Kaplan-Meier analysis and the Cox regression models. We found that angiopoietin-2 levels were associated with risk of stroke recurrence in lacunar infarct patients. Taking the lowest quartile as reference, the adjusted hazard ratio (HR) and 95% confidence intervals (CI) for stroke recurrence was 1.48 (0.74-2.95) for the second quartile, 2.56 (1.35-4.86) for the third and 2.15 (1.11-4.17) for the fourth. Allele T of rs3739391 in angiopoietin-2 promoter was associated with elevated angiopoietin-2 levels and increased risk of stroke recurrence in patients with lacunar infarct with HR 1.67 (1.06-2.63) relative to the allele C, but neither in those with atherothrombotic nor in those with hemorrhagic stroke. Our results indicate that both angiopoietin-2 and allele T of rs3739391 might be the risk marker for stroke recurrence in the patients with lacunar infarction. These findings may help to improve future prevention or therapy strategies for stroke. Even some conventional risk factors have been identified responsible for stroke recurrence, but these factors could not fully explain all the recurrent stroke events. Our study opens a new page for the first time that angiopoietin/tie2 pathway has a potential role in lacunar stroke recurrence. Since several strategies are available for blocking or neutralizing plasma angiopoietin-2, especially eicosapentaenoic acid rich in sea food. Our finding obviously has its clinical implication if it was proved by large, prospective clinical studies.

A novel gene IC53 stimulates ECV304 cell proliferation and is upregulated in failing heart.

C53, cloned from rat brain cDNA library, can bind to p35, the precursor of activator of Cdk5. A novel gene with 84% homolog to C53, named IC53, was cloned from our 5300 EST database of human aorta cDNA library (GenBank Accession No. AF110322). Computational analysis showed that IC53 cDNA is 2538 bp long, encoding 419 amino acids, mapped to chromosome 17q21.31 with 12 exons, ubiquitously expressed in 12 tested normal tissues and 8 tumor cell lines from MTN membranes and vascular endothelial cells by Northern blot and in situ hybridization, and upregulated in the rat models of subacute heart failure and chronic ischemic heart failure by left coronary ligation. Stable transfection of IC53 stimulates ECV304 cell proliferation by 2.1-fold compared to cells with empty vector (P<0.05). The results support that IC53 is a novel gene, mainly expressed in vascular endothelial cells and mediates cell proliferation.