Efficacy of Immediate Antihypertensive Treatment in Patients With Acute Ischemic Stroke With Different Blood Pressure Genetic Variants.

BACKGROUND: It remains unclear whether blood pressure (BP) genetic variants could modify the efficacy of immediate antihypertensive treatment after acute ischemic stroke. We conducted a secondary analysis of the CATIS (China Antihypertensive Trial in Acute Ischemic Stroke) to investigate the effect of early antihypertensive treatment on clinical outcomes among patients with acute ischemic stroke according to 5 BP-associated genetic variants. METHODS: The CATIS randomized 4071 patients with acute ischemic stroke with elevated systolic BP to receive antihypertensive treatment or discontinue all antihypertensive agents during hospitalization. Randomization was conducted centrally and was stratified by participating hospitals and use of antihypertensive medications. Five BP-associated single nucleotide polymorphisms (rs16849225, rs17030613, rs1173766, rs6825911, and rs35444 in FIGN-GRB14, ST7L-CAPZA1, NPR3, ENPEP, and near TBX3, respectively) were genotyped among 2590 patients. The primary outcome was a combination of death and major disability at 14 days or hospital discharge. A weighted BP genetic risk score was constructed by the 5 single nucleotide polymorphisms. RESULTS: At 14 days or hospital discharge, the primary outcome was not significantly different between antihypertensive treatment and control groups based on genotype subgroups for all 5 single nucleotide polymorphisms (all P>0.05 for interaction). In addition, the BP genetic risk score did not modify the effect of antihypertensive treatment. The odds ratios (95% CIs) for the primary outcome were 0.95 (0.71-1.26), 1.08 (0.80-1.44), and 0.91 (0.69-1.22) in patients with low, intermediate, and high BP genetic risk score, respectively (P=0.88 for interaction). CONCLUSIONS: Early antihypertensive treatment had a neutral effect on clinical outcomes among patients with acute ischemic stroke according to 5 BP-associated genetic variants. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01840072.

Multivitamin/mineral supplementation and the risk of cardiovascular disease: a large prospective study using UK Biobank data.

PURPOSE: Despite the widespread use of multivitamin/mineral supplements, the effects of multivitamin/mineral on cardiovascular disease (CVD) remain inconclusive. We aimed to prospectively investigate how multivitamin/mineral use is associated with CVD. METHODS: This population-based cohort study included 465,278 men and women who participated in the UK Biobank and were free from CVD at baseline. Participants were enrolled between 2006 and 2010 and followed-up until the end of 2018. Data on supplement use including multivitamin/mineral were collected using self-reported questionnaires. Cox proportional hazards models were used to estimate the hazard ratios of CVD events in relation to multivitamin/mineral use. RESULTS: During the follow-up, we identified 25,772 cases of CVD events, 4754 cases of CVD mortality, 18,728 cases of coronary heart disease, 6726 cases of myocardial infarction, and 4561 cases of stroke. The multivariable-adjusted hazard ratios associated with multivitamin/mineral use were 0.96 (95% CI: 0.93, 0.99) for CVD events, 0.92 (0.86, 1.00) for CVD mortality, 0.96 (0.93, 0.99) for coronary heart disease, and 0.92 (0.86, 0.97) for myocardial infarction. Subgroup analysis suggested that multivitamin/mineral use was associated with a significantly lower risk of CVD events in participants aged < 60 years and in former and current smokers (P for interaction ≤ 0.01). Sensitivity analyses showed no substantial change in the results when we excluded participants who developed CVD events during the first 2 years of follow-up. CONCLUSION: Multivitamin/mineral supplementation was associated with very modest reductions in CVD events. Age and smoking might modify these associations.

Plasma choline and betaine and risks of cardiovascular events and recurrent stroke after ischemic stroke.

BACKGROUND: Choline and betaine have been suggested to play a pivotal role in neurotransmitter synthesis, cell membrane integrity, and methyl-group metabolism, exerting neuroprotective effects in patients with various neurological disorders. However, population-based evidence on choline and betaine with subsequent cardiovascular events after stroke is rare. OBJECTIVES: We aimed to prospectively investigate the relationships of circulating choline and betaine with cardiovascular events and recurrent stroke in patients with ischemic stroke. METHODS: We performed a nested case-control study within the China Antihypertensive Trial in Acute Ischemic Stroke. A total of 323 cardiovascular events (including 264 recurrent strokes) and 323 controls (free of recurrent cardiovascular events) matched for age (±1 y), sex, and treatment group were included. The primary endpoint was a composite of cardiovascular events after ischemic stroke. Plasma choline and betaine were measured at baseline by ultra-high-performance LC-MS/MS. Conditional logistic regression models were applied, and discrimination, reclassification, and calibration of models with choline pathway metabolites were evaluated. RESULTS: Plasma choline and betaine were inversely associated with cardiovascular events and recurrent stroke after ischemic stroke. Specifically, in fully adjusted models, each additional SD of choline and betaine was associated with 35% (95% CI: 20%-48%) and 30% (95% CI: 14%-43%) decreased risks of subsequent cardiovascular events, respectively, and 34% (95% CI: 16%-48%) and 29% (95% CI: 12%-43%) decreased risks of recurrent stroke, respectively. In addition, both choline and betaine offered substantial risk discrimination and reclassification improvement for cardiovascular events and recurrent stroke beyond traditional risk factors, as evidenced by an increase in C statistics, the net reclassification index, and integrated discrimination improvement. CONCLUSIONS: Plasma choline pathway metabolites, including choline and betaine, were associated with decreased risks of cardiovascular events and recurrent stroke and provided incremental value in risk discrimination and stratification in patients with ischemic stroke. This nested case-control study was based on the China Antihypertensive Trial in Acute Ischemic Stroke, which is registered at clinicaltrials.gov as NCT01840072.

1,25-Dihydroxy Vitamin D3 Attenuates the Oxidative Stress-Mediated Inflammation Induced by PM2.5via the p38/NF-κB/NLRP3 Pathway.

Vitamin D3 is reported to be involved in the regulation of inflammatory processes. In this study, biomarkers related to oxidative stress and inflammation were investigated to clarify the protective effects and possible mechanism of 1,25-dihydroxy vitamin D3 (1,25-(OH)2D3) on PM2.5-induced inflammatory response. In the in vitro study using human bronchial epithelial (HBE) cells, aqueous extracts of PM2.5 could induce oxidative damage which is characterized by significant increases in production of reactive oxygen species, malonaldehyde concentration, and protein expression of HSPA1A and HO-1. Meanwhile, PM2.5 caused secretion of inflammatory factors (IL-6, IL-8) in the culture medium as well as phosphorylation of p38, nuclear factor-kappa B (NF-κB) inhibitor alpha (IκBα), and NF-κB p65 proteins. Increases in NLRP3 expression was also observed in HBE cells after PM2.5 exposure. However, all these biomarkers were remarkably attenuated by a 24-h pretreatment of 1 nM 1,25-(OH)2D3. Furthermore, 1,25-(OH)2D3 also reduced transcriptional activation of NF-κB induced by PM2.5 as indicated by a significant decrease in luciferase activity in HBE cells stably transfected with the NF-κB response element (RE)-driven luciferase reporter. Taken together, our findings provided novel experimental evidences supporting that vitamin D3 could reduce the predominantly oxidative stress-mediated inflammation induced by PM2.5via the p38/NF-κB/NLRP3 signaling pathway.

Cytotoxicity and genotoxicity of nanosilver in stable GADD45α promoter-driven luciferase reporter HepG2 and A549 cells.

OBJECTIVES: The intense commercial application of silver nanoparticles (AgNPs) has been raising concerns about their potential adverse health effects to human. This study aimed to explore the potency of AgNPs to induce GADD45α gene, an important stress sensor, and its relationships with the cytotoxicity and genotoxicity elicited by AgNPs. METHODS: Two established HepG2 and A549 cell lines containing the GADD45α promoter-driven luciferase reporter were treated with increasing concentrations of AgNPs for 48 hours. After the treatment, transcriptional activation of GADD45α indicated by luciferase activity, cell viability, cell cycle arrest, and levels of genotoxicity were determined. The uptake and intracellular localization of AgNPs, cellular Ag doses as well as Ag+ release were also detected. RESULTS: AgNPs could activate GADD45α gene at the transcriptional level as demonstrated by the dose-dependent increases in luciferase activity in both the reporter cells. The relative luciferase activity was greater than 12× the control level in HepG2-luciferase cells at the highest concentration tested where the cell viability decreased to 17.0% of the control. These results was generally in accordance with the positive responses in cytotoxicity, cell cycle arrest of Sub G1 and G2/M phase, Olive tail moment, micronuclei frequency, and the cellular Ag content. CONCLUSIONS: The cytotoxicity and genotoxicity of AgNPs seems to occur mainly via particles uptake and the subsequent liberation of ions inside the cells. And furthermore, the GADD45α promoter-driven luciferase reporter cells, especially the HepG2-luciferase cells, could provide a new and valuable tool for predicting nanomaterials genotoxicity in humans.

Development of HSPA1A promoter-driven luciferase reporter gene assays in human cells for assessing the oxidative damage induced by silver nanoparticles.

The exponential increase in the total number of engineered nanoparticles in consumer products requires novel tools for rapid and cost-effective toxicology screening. In order to assess the oxidative damage induced by nanoparticles, toxicity test systems based on a human HSPA1A promoter-driven luciferase reporter in HepG2, LO2, A549, and HBE cells were established. After treated with heat shock and a group of silver nanoparticles (AgNPs) with different primary particle sizes, the cell viability, oxidative damage, and luciferase activity were determined. The time-dependent Ag(+) ions release from AgNPs in cell medium was also evaluated. Our results showed that heat shock produced a strong time-dependent induction of relative luciferase activity in the four luciferase reporter cells. Surprisingly, at 4h of recovery, the relative luciferase activity was >98× the control level in HepG2-luciferase cells. Exposure to different sizes of AgNPs resulted in activation of the HSPA1A promoter in a dose-dependent manner, even at low cytotoxic or non-cytotoxic doses. The smaller (5nm) AgNPs were more potent in luciferase induction than the larger (50 and 75nm) AgNPs. These results were generally in accordance with the oxidative damage indicated by malondialdehyde concentration, reactive oxygen species induction and glutathione depletion, and Ag(+) ions release in cell medium. Compared with the other three luciferase reporter cells, the luciferase signal in HepG2-luciferase cells is obviously more sensitive and stable. We conclude that the luciferase reporter cells, especially the HepG2-luciferase cells, could provide a valuable tool for rapid screening of the oxidative damage induced by AgNPs.

Oxidative stress and mitochondrial injury-mediated cytotoxicity induced by silver nanoparticles in human A549 and HepG2 cells.

OBJECTIVES: Considering the increasing applications of silver nanoparticles (AgNPs) in food- and cosmetic-related products worldwide, the aim of this study was to investigate the potential adverse health effects induced by AgNPs exposure in terms of cytotoxicity, oxidative stress, and mitochondrial injury in human A549 and HepG2 cells. METHODS: After a 48 h AgNPs treatment, the cell viability was measured by MTT assay. Oxidative damage was determined by assays of malondialdehyde (MDA), 8-epi-PGF2α and 8-hydroxy-2'-deoxyguanosine (8-oxo-dG). The protein expression of HSPA1A and HO-1 was analyzed by western blot analysis. Mitochondrial membrane potential (MMP) was detected by using JC-1 as fluorescent probes. The uptake and intracellular localization of AgNPs was measured by transmission electron microscopy (TEM), and cellular AgNPs was determined by inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: A dose-dependent decrease in cell viability after AgNPs treatment was observed, which was associated correspondingly with oxidative damage as indicated by increases in MDA amount, 8-epi-PGF2α and 8-oxo-dG levels, HSPA1A and HO-1 expression, as well as mitochondrial injury as indicated by decreased MMP. The cellular uptake of AgNPs measured by ICP-MS analysis was correlated correspondingly with the oxidative damage and mitochondrial injury. CONCLUSIONS: The dose-dependent cytotoxicity induced by AgNPs may result from an interaction of oxidative stress, DNA damage and mitochondrial injury in A549 and HepG2 cells. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1691-1699, 2016.