High molecular weight hyaluronan decreases oxidative DNA damage induced by EDTA in human corneal epithelial cells

PURPOSE

To investigate the toxic effects of ethylenediaminetetraacetic acid disodium salt (EDTA), a corneal penetration enhancer in topical ophthalmic formulations, on DNA in human corneal epithelial cells (HCEs), and to investigate whether the effect induced by EDTA can be inhibited by high molecular weight hyaluronan (HA).

METHODS

Cells were exposed to EDTA in concentrations ranging from 0.00001 to 0.01% for 60 min, or 30 min high molecular weight HA pretreatment followed by EDTA treatment. The cell viability was measured by the MTT test. Cell apoptosis was determined with annexin V staining by flow cytometry. The DNA single- and double-strand breaks of HCEs were examined by alkaline comet assay and by immunofluorescence microscope detection of the phosphorylated form of histone variant H2AX (γH2AX) foci, respectively. Reactive oxygen species (ROS) production was assessed by the fluorescent probe, 2', 7'-dichlorodihydrofluorescein diacetate.

RESULTS

EDTA exhibited no adverse effect on cell viability and did not induce cell apoptosis in human corneal epithelial cells at concentrations lower than 0.01%. However, a significant increase of DNA single- and double-strand breaks was observed in a dose-dependent manner with all the concentrations of EDTA tested in HCEs. In addition, EDTA treatment led to elevated ROS generation. Moreover, 30 min preincubation with high molecular weight HA significantly decreased EDTA-induced ROS generation and DNA damage.

CONCLUSIONS

EDTA could induce DNA damage in HCEs, probably through oxidative stress. Furthermore, high molecular weight HA was an effective protective agent that had antioxidant properties and decreased DNA damage induced by EDTA.

Interaction with Suv39H1 is critical for Snail-mediated E-cadherin repression in breast cancer

Expression of E-cadherin, a hallmark of epithelial-mesenchymal transition (EMT), is often lost due to promoter DNA methylation in basal-like breast cancer (BLBC), which contributes to the metastatic advantage of this disease; however, the underlying mechanism remains unclear. Here, we identified that Snail interacted with Suv39H1 (suppressor of variegation 3-9 homolog 1), a major methyltransferase responsible for H3K9me3 that intimately links to DNA methylation. We demonstrated that the SNAG domain of Snail and the SET domain of Suv39H1 were required for their mutual interactions. We found that H3K9me3 and DNA methylation on the E-cadherin promoter were higher in BLBC cell lines. We showed that Snail interacted with Suv39H1 and recruited it to the E-cadherin promoter for transcriptional repression. Knockdown of Suv39H1 restored E-cadherin expression by blocking H3K9me3 and DNA methylation and resulted in the inhibition of cell migration, invasion and metastasis of BLBC. Our study not only reveals a critical mechanism underlying the epigenetic regulation of EMT, but also paves a way for the development of new treatment strategies against this disease.

Prevalence, awareness, treatment, and control of hypertension among herdsmen living at 4,300 m in Tibet

BACKGROUND

Studies on blood pressure (BP) in high-altitude areas are scarce and the results are controversial. Tibetans live in regions at high altitudes, and data on the prevalence of hypertension in this population is not currently well known.

METHODS

All Tibetans aged 40 years and older living in the township of Yangbajing (4,300 m) in Tibet, China were invited to participate in the 2009 survey. BP was measured with electronic sphygmomanometers (calibrated by the results of a previous study). Histories of hypertension and medication use were collected through face-to-face interviews. Hypertension was defined as systolic BP (SBP) ≥140 mm Hg and/or diastolic BP (DBP) ≥90 mm Hg, or antihypertensive medication use in the past 2 weeks.

RESULTS

A total of 701 adults (aged 40-89, 42.9% male, 94.9% herdsmen) were recruited. The mean (s.d.) SBP/DBP was 146.6 (31.3)/92.0 (15.7) mm Hg and the prevalence of hypertension was 55.9%. Of note, 61.2% of those with hypertension had stage 2 hypertension (SBP ≥160 or DBP ≥100 mm Hg). At age 70 years and older, the mean (s.d.) SBP/DBP were 182.8 (30.9)/102.6 (13.4) mm Hg. Among those with hypertension (n = 392), only 19.9% were aware of their condition, 2.6% were taking medication, and only one participant had controlled BP.

CONCLUSION

According to our survey in Yangbajing, Tibetan adults aged 40 years and older living at high altitudes had high BP and prevalence of hypertension with low awareness, treatment, and control. Future studies are needed to clarify the association between BP, altitude, and other possible causes.

One novel SNP of growth hormone gene and its associations with growth and carcass traits in ducks

In this study, the growth hormone (GH) gene was studied as a candidate gene for growth and carcass traits of three duck populations (Cherry Valley duck, Muscovy duck and Jingjiang duck). Three pairs of primers were designed to detect single nucleotide polymorphisms of introns 2, 3 and 4 of the GH gene by polymerase chain reaction-restriction fragment length polymorphism and sequencing methods. Only the products amplified from intron 2 displayed polymorphism. The results showed one novel polymorphism: a variation in intron 2 of GH gene (C172T, JN408701 and JN408702). It was associated with some growth and carcass traits in three duck populations including birth weight, 8-week weight, carcass weight, breast muscle weight, leg muscle weight, eviscerated weight, lean meat rate, dressing percentage, etc. And the TT and CT genotypes were associated with superior growth and carcass traits in carcass weight, dressing percentage and percentage of eviscerated weight. Therefore, the variation in intron 2 of GH may be a molecular marker for superior growth and carcass traits in above duck populations.

Hemodynamic changes in patients with arteriovenous malformations assessed using high-resolution 3D radial phase-contrast MR angiography

BACKGROUND AND PURPOSE

Arteriovenous malformations have a high lifetime risk of hemorrhage; however, treatment carries a significant risk of morbidity and mortality, including permanent neurologic sequelae. WSS and other hemodynamic parameters are altered in patients with symptomatic AVMs, and analysis of hemodynamics may have value in stratifying patients into different risk groups. In this study, we examined hemodynamic data from patients with stable symptoms and those who presented with acute symptoms to identify trends which may help in risk stratification.

MATERIALS AND METHODS

Phase-contrast MRA using a radial readout (PC-VIPR) is a fast, high-resolution technique that can acquire whole-brain velocity-encoded angiograms with scan times of approximately 5 minutes. Ten patients with AVMs were scanned using PC-VIPR; velocity, area, flow, and WSS in vessels feeding the AVMs and normal contralateral vessels were calculated using velocity data from the phase-contrast acquisition.

RESULTS

Patients with an asymptomatic presentation or mild symptoms (n = 4) had no significant difference in WSS in feeding vessels compared with normal contralateral vessels, whereas patients presenting with hemorrhage, severe headaches/seizures, or focal neurologic deficits (n = 6) had significantly higher WSS in feeding vessels compared with contralateral vessels.

CONCLUSIONS

In this study, we demonstrate that estimates of WSS and other hemodynamic parameters can be obtained noninvasively in patients with AVMs in clinically useful imaging times. Variation in WSS between feeders and normal vessels appears to relate to the clinical presentation of the patient. Further analysis of hemodynamic changes may improve characterization and staging of AVM patients, when combined with existing risk factors.

Expression and functional analysis of NUCLEAR FACTOR-Y, subunit B genes in barley

NUCLEAR FACTOR-Y, subunit B (NF-YB) comprises a multigene family in plants and has been shown to play important roles in growth, development, and response to environmental stress. In this study, five NF-YBs containing the full-length coding region were obtained from barley (Hordeum vulgare) through database sequence analysis, cloning, and sequencing. Sequence alignment and phylogenetic analysis showed that HvNF-YB3 and HvNF-YB1 were clustered with NF-YB2 and NF-YB3 in Arabidopsis, suggesting these NF-YBs are evolutionary and functionally related. To test this hypothesis, HvNF-YB3 and HvNF-YB1 were overexpressed in Arabidopsis. Overexpression of HvNF-YB1 greatly promoted early flowering in Arabidopsis, supporting that HvNF-YB1may have conserved gene function in flowering time control as NF-YB2 and NF-YB3 in Arabidopsis. Overexpression of HvNF-YB3 in Arabidopsis had no effect on flowering time. An analysis of barley single-nucleotide polymorphism (SNP) data, however, revealed a significant association between an HvNF-YB3 SNP and heading date. While it is unknown whether HvNF-YB3 directly contributes to heading date regulation, the results implied that HvNF-YB3 may also have conserved function in flowering time (heading date in barley) control. Further studies are needed to directly verify these gene functions in barley. Barley NF-YBs showed different expression patterns associated with tissue types, developmental stages, and response to different stress treatments, suggesting that barley NF-YBs may be involved in other physiological processes.

Association of genetic variation in FTO with risk of obesity and type 2 diabetes with data from 96,551 East and South Asians

AIMS/HYPOTHESIS

FTO harbours the strongest known obesity-susceptibility locus in Europeans. While there is growing evidence for a role for FTO in obesity risk in Asians, its association with type 2 diabetes, independently of BMI, remains inconsistent. To test whether there is an association of the FTO locus with obesity and type 2 diabetes, we conducted a meta-analysis of 32 populations including 96,551 East and South Asians.

METHODS

All studies published on the association between FTO-rs9939609 (or proxy [r (2) > 0.98]) and BMI, obesity or type 2 diabetes in East or South Asians were invited. Each study group analysed their data according to a standardised analysis plan. Association with type 2 diabetes was also adjusted for BMI. Random-effects meta-analyses were performed to pool all effect sizes.

RESULTS

The FTO-rs9939609 minor allele increased risk of obesity by 1.25-fold/allele (p = 9.0 × 10(-19)), overweight by 1.13-fold/allele (p = 1.0 × 10(-11)) and type 2 diabetes by 1.15-fold/allele (p = 5.5 × 10(-8)). The association with type 2 diabetes was attenuated after adjustment for BMI (OR 1.10-fold/allele, p = 6.6 × 10(-5)). The FTO-rs9939609 minor allele increased BMI by 0.26 kg/m(2) per allele (p = 2.8 × 10(-17)), WHR by 0.003/allele (p = 1.2 × 10(-6)), and body fat percentage by 0.31%/allele (p = 0.0005). Associations were similar using dominant models. While the minor allele is less common in East Asians (12-20%) than South Asians (30-33%), the effect of FTO variation on obesity-related traits and type 2 diabetes was similar in the two populations.

CONCLUSIONS/INTERPRETATION

FTO is associated with increased risk of obesity and type 2 diabetes, with effect sizes similar in East and South Asians and similar to those observed in Europeans. Furthermore, FTO is also associated with type 2 diabetes independently of BMI.

Longitudinal vitamin D status in pregnancy and the risk of pre-eclampsia

OBJECTIVE

Whether vitamin D deficiency in pregnancy is a cause of pre-eclampsia remains controversial. Most previous studies to date have assessed exposure at only one time-point in pregnancy. We assessed longitudinal vitamin D status during pregnancy and the risk of pre-eclampsia.

DESIGN

Prospective cohort study.

SETTING

Seventeen urban obstetric hospitals, Canada.

POPULATION

Pregnant women who were participants in a trial of vitamin C and E supplementation for the prevention of pre-eclampsia. Canadian participants who consented to participate in a biobank with plasma specimens available at the baseline visit were included (n = 697).

METHODS

Maternal plasma 25-hydroxyvitamin D (25(OH)D) concentrations were measured at 12-18 and 24-26 weeks of gestation using chemiluminescence immunoassay.

MAIN OUTCOME MEASURES

Pre-eclampsia.

RESULTS

Of the women, 39% were vitamin D deficient (25(OH)D <50 nmol/l). A strong positive correlation was observed in maternal 25(OH)D concentrations between the two gestational age windows (r = 0.69, P < 0.0001). Mean maternal 25(OH)D concentrations at 24-26 weeks of gestation were significantly lower in women who subsequently developed pre-eclampsia compared with those who did not (mean ± SD: 48.9 ± 16.8 versus 57.0 ± 19.1 nmol/l, P = 0.03). Women with 25(OH)D < 50 nmol/l at 24-26 weeks gestation experienced an increased risk of pre-eclampsia (adjusted odds ratio 3.24, 95% confidence interval 1.37-7.69), whereas the association was not statistically significant for maternal 25(OH)D level at 12-18 weeks of gestation.

CONCLUSIONS

Lower maternal 25(OH)D levels at late mid-trimester were associated with an increased risk of pre-eclampsia.

Species-specific identification of seven vegetable oils based on suspension bead array

Species adulteration of vegetable oils has become a main form of adulteration in vegetable oils, severely violating consumer rights and causing disorder in the market. A reliable method of species authentication of vegetable oils is desirable. This paper reports a novel method for identification of seven species of vegetable oils based on suspension bead array. One pair of universal primers and seven species-specific probes were designed targeting rbcl gene of the chloroplast. Each probe was coupled to a unique color-coded microsphere. Biotinylated PCR amplicons of seven oils were hybridized to the complementary probes on microsphere sets. Bound amplicons were detected fluorometrically using a reporter dye, streptavidin-R-phycoeryt hrin (SA-PE). A sample could be analyzed less than 1 h after PCR amplification. With the exception of olive probe, all probes showed no cross-reactivity with other species. Absolute detection limit of the seven probes ranged from 0.01 ng/μL to 0.0001 ng/μL. Detection limit in DNA mixture was from 10% to 5%. Detection of vegetable oils validated the effectiveness of the method. The suspension bead array as a rapid, sensitive, and high-throughput technology has potential to identify more species of vegetable oils with increased species of probes.

Association among serum uric acid, cardiovascular risk, and arterial stiffness: a cross-sectional study in She ethnic minority group of Fujian Province in China

OBJECTIVES

To investigate the association between serum uric acid levels, cardiovascular risk, and arterial stiffness in She ethnic minority in South China's Fujian Province.

METHODS

5109 participants aged 20-79 yr were enrolled in analysis. Tpeak-Tend interval (Tp-e), QT interval, and height of the R wave in lead aVL (aVLR) were measured on 12-lead electrocardiogram (ECG), and Minnesota code-indicated major abnormal ECG MA-ECG was used as a risk indicator of cardiovascular disease. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV).

RESULTS

Longer Tp-e interval, greater Tp-e/QT ratio, and higher aVLR were observed in the highest quartile of uric acid level. The incidence of MA-ECG was gradually increased from lowest to highest quartile of serum uric acid in males (p for trend <0.01). After adjusting traditional cardiovascular risk factors, multivariate analysis revealed that the fourth quartile of serum uric acid level was independently associated with MA-ECG in males [odds ratios (OR) (95% confidence interval): 2.129 (1.376-3.295)] but not in females. Serum uric acid was also associated with abnormal baPWV, when adjusted for atherogenic confounders. Compared with the lowest serum uric acid quartile, the OR (95% confidence interval) of the second, third, and fourth quartile were 1.920 (1.246-2.957), 1.650 (1.064-2.558), and 2.501 (1.600-3.908) in males.

CONCLUSION

Among China's She ethnic minority, uric acid level was independently related to arterial stiffness assessed by baPWV in both genders. The evaluation of uric acid level was related to higher cardiovascular risk in males but not in females.