Biosynthesis of Nanoparticles with Green Tea for Inhibition of ß-Amyloid Fibrillation Coupled with Ligands Analysis.

Background: Inhibition of amyloid ß protein fragment (Aß) aggregation is considered to be one of the most effective strategies for the treatment of Alzheimer's disease. (-)-Epigallocatechin-3-gallate (EGCG) has been found to be effective in this regard; however, owing to its low bioavailability, nanodelivery is recommended for practical applications. Compared to chemical reduction methods, biosynthesis avoids possible biotoxicity and cumbersome preparation processes. Materials and Methods: The interaction between EGCG and Aß42 was simulated by molecular docking, and green tea-conjugated gold nanoparticles (GT-Au NPs) and EGCG-Au NPs were synthesized using EGCG-enriched green tea and EGCG solutions, respectively. Surface active molecules of the particles were identified and analyzed using various liquid chromatography-tandem triple quadrupole mass spectrometry methods. ThT fluorescence assay, circular dichroism, and TEM were used to investigate the effect of synthesized particles on the inhibition of Aß42 aggregation. Results: EGCG as well as apigenin, quercetin, baicalin, and glutathione were identified as capping ligands stabilized on the surface of GT-Au NPs. They more or less inhibited Aß42 aggregation or promoted fibril disaggregation, with EGCG being the most effective, which bound to Aß42 through hydrogen bonding, hydrophobic interactions, etc. resulting in 39.86% and 88.50% inhibition of aggregation and disaggregation effects, respectively. EGCG-Au NPs were not as effective as free EGCG, whereas multiple thiols and polyphenols in green tea accelerated and optimized heavy metal detoxification. The synthesized GT-Au NPs conferred the efficacy of diverse ligands to the particles, with inhibition of aggregation and disaggregation effects of 54.69% and 88.75%, respectively, while increasing the yield, enhancing water solubility, and decreasing cost. Conclusion: Biosynthesis of nanoparticles using green tea is a promising simple and economical drug-carrying approach to confer multiple pharmacophore molecules to Au NPs. This could be used to design new drug candidates to treat Alzheimer's disease.

Development and validation of genome-wide SSR molecular markers of Tapes dorsatus.

BACKGROUND: Tapes dorsatus is an economically important benthic animal in the Beibu Gulf of China. However, the deficiency of microsatellite markers has hindered the study of its genetics. The development of microsatellite markers will provide useful tools for genetic improvement, variety identification, phylogenetic analysis and resource conservation. METHODS AND RESULTS: Within the genome sequence, 145,008 simple sequence repeats (SSRs) were identified, and 29,691 primer pairs were designed successfully. A total of 100 primer pairs were randomly synthesized for testing, and 93 primers yielded products. Sixty highly polymorphic primers were used to reveal the genetic diversity of 50 T. dorsatus individuals. The average number of alleles (Na) of the population was 10.40; the average number of effective alleles was 6.16, the average expected heterozygosity (He) was 0.82, and the average polymorphic information content was 0.80. The genetic structure of the population was detected, by which the population could be divided into three subpopulations. CONCLUSION: We identified 145,008 SSRs in the genome of T. dorsatus and designed 29,691 primer pairs in this study. Of 100 synthesized primers, 60 were highly polymorphic and used to reveal the genetic diversity and structure of the population. The SSR markers identified here will provide useful tools and a foundation for genetic diversity, linkage mapping and molecular marker-aided breeding in T. dorsatus.

A programmable oral bacterial hydrogel for controllable production and release of nanovaccine for tumor immunotherapy.

Oral protein vaccines are mainly used to prevent the infection of intestinal pathogens in clinic due to their high safety and strong compliance. However, it is necessary to design the efficient delivery systems to overcome the harsh gastrointestinal environment in the application process. Here we established a programmable oral bacterial hydrogel system for spatiotemporally controllable production and release of nanovaccines. The system was divided into three parts: (1) Engineered bacteria were encapsulated in chitosan-sodium alginate microcapsules, which offered protection against the extreme acid conditions in the stomach. (2) Microcapsules were dissolved, and then engineered bacteria were released and colonized in the intestine. (3) The release of nanovaccines was controlled periodically by a synchronous lysis genetic circuit for tumor immunotherapy. Compared to control groups, tumor volume of subcutaneous tumor-bearing mice treated with bacterial microgels releasing optimized nanovaccine was almost inhibited by 75% and T cell response was activated at least 2-fold. We believe that this programmable bacterial hydrogel will offer a promising way for the application of oral nanovaccines.

Hydrogel microcapsules containing engineered bacteria for sustained production and release of protein drugs.

Subcutaneous administration of sustained-release formulations is a common strategy for protein drugs, which avoids first pass effect and has high bioavailability. However, conventional sustained-release strategies can only load a limited amount of drug, leading to insufficient durability. Herein, we developed microcapsules based on engineered bacteria for sustained release of protein drugs. Engineered bacteria were carried in microcapsules for subcutaneous administration, with a production-lysis circuit for sustained protein production and release. Administrated in diabetic rats, engineered bacteria microcapsules was observed to smoothly release Exendin-4 for 2 weeks and reduce blood glucose. In another example, by releasing subunit vaccines with bacterial microcomponents as vehicles, engineered bacterial microcapsules activated specific immunity in mice and achieved tumor prevention. The engineered bacteria microcapsules have potential to durably release protein drugs and show versatility on the size of drugs. It might be a promising design strategy for long-acting in situ drug factory.

Formation Mechanism of Monodispersed Polysilsesquioxane Spheres in One-Step Sol-Gel Method.

Monodispersed polysilsesquioxane (PSQ) spheres with diameters from hundreds of nanometers to several microns have been successfully synthesized; however, the knowledge of their formation mechanism still lags behind. Herein, with methyltrimethoxysilane and 3-mercaptopropyl trimethoxysilane as model silicon sources, the formation process of PSQ spheres in the one-step sol-gel method was revealed for the first time by monitoring the time evolution of particle morphology, size, and size distribution via transmission electron microscopy and dynamic light scattering. A four-stage formation mechanism was proposed: rapid hydrolysis of organic silicon source and subsequent oligomer micelle nucleation, fast growing of nuclei particles and formation of their aggregates, followed by a further relatively fast growth of dispersed particles, and finally a slow growth to form monodispersed PSQ spheres. Due to the reversibility of hydrolysis and condensation reactions, thermodynamically unstable particles gradually transformed to hydrolytic monomers/oligomers and then regrew on the thermodynamically stable particles until the concentration of hydrolytic oligomers reached the dissolution equilibrium in the alkaline reaction solution. The variation of growth rate during the formation process and the effects of NH4OH concentration on the yield and particle size were investigated to facilitate analyses and understanding of the formation mechanism.

Flow-mediated dilation can be used to predict incident hypertension in patients with hyperuricemia.

INTRODUCTION: The aim of the study was to evaluate whether flow-mediated dilation (FMD) can be used to predict incident hypertension in patients with hyperuricemia. MATERIAL AND METHODS: Normotensive participants with and without hyperuricemia at baseline were prospectively enrolled. Flow-mediated dilation was assessed at baseline, and after 1 year's follow-up the incidence of hypertension was compared between those with and without hyperuricemia. The predictive value of baseline FMD for incident hypertension among hyperuricemia patients was evaluated. RESULTS: A total of 222 participants were included. Mean systolic and diastolic blood pressure (BP) was 129.5 ±8.4 mm Hg and 78.3 ±7.9 mm Hg. Mean serum uric acid (UA) level was 4.4 ±2.8 mg/dl. Mean FMD was 5.1 ±2.7%. Compared to normal UA group, hyperuricemia group had higher proportion of male (58.4% vs. 61.2%), higher systolic BP (125.4 ±7.9 mm Hg vs. 132.1 ±7.3 mm Hg), serum high sensitivity C-reactive protein (3.9 ±2.2 mg/dl vs. 4.5 ±3.0 mg/dl) and UA (3.5 ±1.4 mg/dl vs. 5.7 ±0.7 mg/dl) levels, but lower mean FMD (5.6 ±2.4% vs. 4.8 ±2.0%) (p < 0.05 for all comparisons). No participant in normal UA group developed hypertension, while in hyperuricemia group, 6 participants developed hypertension. In hyperuricemia participants, after adjusted for covariates, per 1-standard deviation decrease in baseline FMD remained significantly associated with 15% increased risk of incident hypertension. CONCLUSIONS: Patients with hyperuricemia have an increased risk of developing hypertension, and low baseline FMD in hyperuricemia patients is associated with significantly increased risk of incident hypertension.

miR-29a promotes myocardial cell apoptosis induced by high glucose through down-regulating IGF-1.

This study was aimed to investigate the role of miR-29a in myocardial cell apoptosis induced by high glucose. Myocardial cells were cultured in normal (5.6 mmol/l) or high glucose medium (30 mmol/l). The apoptotic rate of myocardial cells was evaluated using flow cytometry. The mRNA levels of Bax, Bcl-2, miR-29a, and IGF-1 were determined using real-time quantitative PCR (RT-qPCR). The level of IGF-1 in the culture medium was analyzed using enzyme-linked immunosorbent assay (ELISA). The interaction sites between miR-29a and IGF-1 was analyzed using the the Targetscan program. The regulatory effect of miR-29a on the expression of IGF-1 was investigated using dual luciferase reporter system. The results showed that the expression of miR-29a and the Bax/Bcl-2 ratio in myocardial cells were significantly increased after the cells were cultured in high glucose medium for 72 h, which was consistent with increased apoptosis of myocardial cells. The expression of IGF-1 in myocardial cells was significantly decreased after the cells were cultured in high glucose medium for 72 and 96 h. Targetscan identified a potential binding site on the 3'-UTR of IGF-1 for miR-29a. We also observed that miR-29a mimic and miR-29a inhibitor reduced and increased the expression of IGF-1 in myocardial cells cultured in high glucose medium, respectively. Dual luciferase reporter analysis showed that miR-29a significantly reduced the fluorescence intensity of wild-type psichek2-IGF-1-3'UTR-WT but the fluorescence intensity of mutant psichek2-IGF-1-3'UTR-MT was not significantly affected. In conclusions, the expression of miR-29a in myocardial cells cultured in high glucose medium was significantly increased, which down-regulated IGF-1 and increased myocardial cell apoptosis.

A meta-analysis of relationship between beta-fibrinogen gene -148C/T polymorphism and susceptibility to cerebral infarction in Han Chinese.

OBJECTIVE: The results of studies on association between -148C/T polymorphism in promoter region of beta-fibrinogen gene and susceptibility to cerebral infarction in Chinese population are controversial. In this study, we summarize the results of published works in this field by a meta-analysis. Data sources Genetic association studies evaluating the beta-fibrinogen gene -148C/T polymorphisms and cerebral infarction involving Chinese population published before December 2005 were collected from PubMed, EMBASE and CNKI. Study selection Case control studies involving unrelated, Han subjects aged from 18 to 80 years, and the internationally recognized diagnostic standard of cerebral infarction and genotype frequencies in control group consistent with Hardy-Weinberg equilibrium were used. Publication bias was tested by funnel plot and the odds ratios of all studies were combined dependent on the result of heterogeneity test among the individual studies. The software Review Manager (Version 4.2) was used for meta-analysis. RESULTS: Eleven studies including 1223 patients and 1433 controls met the selection criteria. There was no heterogeneity among the odds ratios (ORs) of individual studies (chi(2) = 17.82, P = 0.06). The combined OR of susceptibility to cerebral infarction in -148T allele carriers compared to the wild homozygote was 1.32 (95% CI 1.12 to 1.55, P = 0.0008). In the patients with cerebral infarction, the average plasma fibrinogen level of allele T carrier was 0.42 g/L (95% CI 0.29 to 0.54, P < 0.001), higher than that of -148C/C homozygous ones. CONCLUSIONS: beta-fibrinogen gene -148C/T polymorphism might contribute to susceptibility to cerebral infarction in Han Chinese. To reach a definitive conclusion, further gene to gene and gene to environment interactions studies on beta-fibrinogen polymorphisms and cerebral infarction with large sample size are required.

A meta-analysis of beta-fibrinogen gene-455G/A polymorphism and plasma fibrinogen level in Chinese cerebral infarction patients.

OBJECTIVE: To evaluate the correlation between the beta-fibrinogen gene-455G/A polymorphism and cerebral infarction in Chinese population by means of meta-analysis. METHODS: Genetic association studies on evaluating the beta-fibrinogen gene -455G/A polymorphism and cerebral infarction involving Chinese population published before December 2005 were collected from database of PubMed, EMBASE, and CNKI. All the data in literature were abstracted based on the defined selection criteria by two independent investigators. Publication bias was tested by funnel plot and the odd ratios of all studies were combined dependent on the result of heterogeneity test among the individual studies. The software Review Manager (Version 4.2) was used for meta-analysis. RESULTS: Eleven studies including 1405 patients and 1600 controls met the selection criteria. There was no publication bias in 11 reviewed studies. Heterogeneity test of reviewed studies showed statistically significant differences (chi2=24.58, P=0.006) among the ORs of individual studies. The combined OR of 11 studies of susceptibility to cerebral infarction in -455A allele carriers compared with the -455G/G wild homozygotes was 1.33 (95%CI 1.04-1.71, P=0.02). In the patients with cerebral infarction in 6 studies, the summarized average plasma fibrinogen level of allele A carrier was 0.29 g/L (95%CI 0.14-0.44, P=0.0002) higher than that of -455G/G homozygous ones. CONCLUSIONS: beta-fibrinogen gene -455G/A polymorphism might contribute to susceptibility of cerebral infarction in Chinese population; allele A increases the individual susceptibility to the disease.