维生素E琥珀酸酯诱导人胃腺癌细胞凋亡途径

目的　探讨维生素E琥珀酸酯 (VES)诱导人胃腺癌SGC -790 1细胞凋亡的死亡受体 (Fas)信号转导途径。方法　人胃腺癌SGC -790 1细胞经不同剂量VES(5,10 ,2 0 μg/ml)处理 ,同时做琥珀酸、维生素E和空白对照 ,采用DAPI(4,6-贰脒基 -2 -苯基吲哚 )荧光染色法观察细胞凋亡情况 ,用WesternBlot法检测Fas、带有死亡结构域的Fas相关蛋白 (FADD)和天冬氨酸特异性半胱氨酸蛋白酶 (caspase -8)蛋白表达情况 ,Fas和FADD反义寡聚核苷分别转染SGC -790 1细胞后 ,用荧光法检测caspase -8活性。 结果　经VES处理后的细胞DAPI染色可见凋亡的形态学改变 ,2 0 μg/mlVES处理 48h后的细胞凋亡率为 89.6% ;VES处理 48h后Fas、FADD和caspase -8蛋白表达明显增加 ,且呈剂量 -效应关系 ;阻断Fas可明显抑制FADD蛋白表达 ,Fas和FADD反义寡聚核苷转染细胞后caspase -8活性明显降低 (P <0 .0 1) ,其中阻断Fas的效果高于阻断FADD。结论　维生素E琥珀酸酯诱导人胃腺癌SGC -790 1细胞凋亡过程中启动了Fas信号转导途径 ,VES启动Fas后 ,FADD将Fas和caspase -8联接起来 ,活化caspases级联反应 ,从而构成Fas/FADD/caspase -8的凋亡信号途径     

Rutin exhibits hepatoprotective effects in a mouse model of non-alcoholic fatty liver disease by reducing hepatic lipid levels and mitigating lipid-induced oxidative injuries

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of hepatic lipids and oxidative injury of hepatocytes. Rutin is a natural flavonoid with significant roles in combating cellular oxidative stress and regulating lipid metabolism. The current study aims to investigate the molecular mechanisms underlying rutin's hypolipidemic and hepatoprotective effects in nonalcoholic fatty liver disease. Rutin treatment was applied to male C57BL/6 mice maintained on a high-fat diet and HepG2 cells challenged with oleic acid. Hepatic lipid accumulation was evaluated by triglyceride assay and Oil Red O staining. Oxidative hepatic injury was assessed by malondialdehyde assay, superoxide dismutase assay and reactive oxygen species assay. The expression levels of various lipogenic and lipolytic genes were determined by quantitative real-time polymerase chain reactions. In addition, liver autophagy was investigated by enzyme-linked immunosorbent assay. In both fat-challenged murine liver tissues and HepG2 cells, rutin treatment was shown to significantly lower triglyceride content and the abundance of lipid droplets. Rutin was also found to reduce cellular malondialdehyde level and restore superoxide dismutase activity in hepatocytes. Among the various lipid-related genes, rutin treatment was able to restore the expression of peroxisome proliferator-activated receptor alpha (PPAR-α) and its downstream targets, carnitine palmitoyltransferase 1 and 2 (CPT-1 and CPT-2), while suppressing those of sterol regulatory element-binding protein 1c (SREBP-1c), diglyceride acyltransfase 1 and 2 (DGAT-1 and 2), as well as acyl-CoA carboxylase (ACC). In addition, rutin was shown to repress the autophagic function of liver tissues by down-regulating key autophagy biomarkers, including tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β). The experimental data demonstrated that rutin could reduce triglyceride content and mitigate oxidative injuries in fat-enriched hepatocytes. The hypolipidemic properties of rutin could be attributed to its ability to simultaneously facilitate fatty acid metabolism and inhibit lipogenesis.     

Studies on the L-2-hydroxy-acid oxidase 2 catalyzed metabolism of S-mandelic acid and its analogues

Mandelic acid (MA) is generally used as a biomarker of the exposure of styrene, which is classified as a class of hazardous environmental pollutants, and also used as an important chiral intermediate in pharmaceutical industry. The previous studies have found the excretion of phenylglyoxylic acid (PGA) in human and rat, a metabolite of MA, was mainly from S-MA rather than R-MA. The metabolic mechanism, however, is not clear. In order to explore the possible metabolic mechanism, the enzyme types involved in the stereoselectivity metabolism of MA were firstly studied, and then human and rat long-chain 2-hydroxy-acid oxidase 2 (HAO2) were recombinantly expressed to study the metabolic profiles of S-MA and its analogues. The results indicated that HAO2 might catalyze the stereoselectivity metabolism of S-MA in rats. Human HAO2 (hHAO2) and rat HAO2 (rHAO2) isozymes β₁ and β₂ were successfully cloned and expressed with high purity and good enzyme activities. The enzyme kinetic profiles of these enzymes were different for S-MA and analogues. The order of catalytic efficiency for hHAO2 and rHAO2, however, was reverse. It might be relevance to the difference in active amino acid residues and loop 4 in human and rat L-2-hydroxy acid oxidase isozyme B crystal structures.     

Metabonomics analysis of serum from rats given long-term and low-level cadmium by ultra-performance liquid chromatography–mass spectrometry

1. This study evaluated the toxicity of chronic exposure to low-level cadmium (Cd) in rats using ultra-performance liquid chromatography–mass spectrometry (UPLC–MS). Forty male Sprague–Dawley rats were randomly assigned to four groups, namely, the control group, low-dose group (0.13?mg/kg·bw), middle-dose group (0.8?mg/kg·bw) and high-dose group (4.89?mg/kg·bw). The rats continuously received CdCl₂ via drinking water for 24?weeks. Serum samples were collected for metabonomics analysis. The data generated from the UPLC–MS was analysed using principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). PLS-DA model with satisfactory explanatory and predictive ability is capable of discriminating the treatment groups from the control group.

2. Finally, the 10 metabolites were identified and showed significant changes in some treatment groups compared with that in the control group (p?p?3. Results suggest that exposure to Cd can cause disturbances in the lipid metabolism, amino acid metabolism, nervous system, antioxidant defence system, liver and kidney function.     

The metabolomic profiling of serum in rats exposed to arsenic using UPLC/Q-TOF MS

Chronic arsenicosis induced by excessive arsenic intake can cause damages to multi-organ systems, skin cancer and various internal cancers. However, the key metabolic changes and biomarkers which can reflect these changes remain unclear resulting in a lack of effective prevention and treatments. The aim of this study is to determine the impact of chronic arsenic exposure on the metabolism of organism, and find the metabolites changes by using metabolomic techniques. Thirty male Wistar rats were randomly divided into three groups. The arsenite was administered in water, and the doses were 0, 10, and 50 mg/L, respectively. The exposure lasted for 6 months. The endogenous metabolite profile of serum was investigated by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Partial least squares discriminant analysis (PLS-DA) enabled clusters to be visualized. Nine serum principal metabolites contributing to the clusters were identified, which were CPA (18:2(9Z,12Z)/0:0), LysoPC (14:0), LysoPC (18:4 (6Z,9Z,12Z,15Z)), LysoPC (P-18:0), l-palmitoylcarnitine, LysoPC (20:2(11Z,14Z)) in positive ESI mode and deoxygcholylglycine, LysoPE (0:0/20:2(11Z,14Z)), 15(S)-hydroxyeicosatrienoic acid in negative ESI. These changes of metabolites in rats suggested the changed metabolism in rats exposed to arsenic. These findings may further aid diagnose and serve as targets for therapeutic intervention of arsenicosis.     

Beyond direct impact: Evidence synthesis towards a better understanding of effectiveness of environmental health interventions

Systematic reviews are a cornerstone of evidence-based public health, and there is much discussion on how this method may need to be modified to do justice to complex interventions, such as environmental health interventions. This paper asserts that intervention effectiveness is influenced by variability in five distinct layers – direct (intrinsic) impact, user compliance, delivery, programming and policy measures – which are embedded in the broader geographical, socio-economic, political and cultural context. The multi-component, multi-sectoral nature of most environmental health interventions results in a complex relationship between these layers of influence, involving systemic interactions. As illustrated with examples, understanding environmental health interventions critically relies on considering all of these layers. These distinct layers of influence can serve as a framework towards the comprehensive analysis of environmental health interventions in systematic reviews, drawing on quantitative and qualitative methods and a variety of disciplines.     

A systematic review of air pollution as a risk factor for cardiovascular disease in South Asia: Limited evidence from India and Pakistan

Cardiovascular diseases (CVD) are major contributors to mortality and morbidity in South Asia. Chronic exposure to air pollution is an important risk factor for cardiovascular diseases, although the majority of studies to date have been conducted in developed countries. Both indoor and outdoor air pollution are growing problems in developing countries in South Asia yet the impact on rising rates of CVD in these regions has largely been ignored. We aimed to assess the evidence available regarding air pollution effects on CVD and CVD risk factors in lower income countries in South Asia. A literature search was conducted in PubMed and Web of Science. Our inclusion criteria included peer-reviewed, original, empirical articles published in English between the years 1990 and 2012, conducted in the World Bank South Asia region (Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka). This resulted in 30 articles. Nine articles met our inclusion criteria and were assessed for this systematic review. Most of the studies were cross-sectional and examined measured particulate matter effects on CVD outcomes and indicators. We observed a bias as nearly all of the studies were from India. Hypertension and CVD deaths were positively associated with higher particulate matter levels. Biomarkers of oxidative stress such as increased levels of P-selection expressing platelets, depleted superoxide dismutase and reactive oxygen species generation as well as elevated levels of inflammatory-related C-reactive protein, interleukin-6 and interleukin-8 were also positively associated with biomass use or elevated particulate matter levels. An important outcome of this investigation was the evidence suggesting important air pollution effects regarding CVD risk in South Asia. However, too few studies have been conducted. There is as an urgent need for longer term investigations using robust measures of air pollution with different population groups that include a wider range of air pollutants and outcomes, including early indicators of CVD. These regions are facing burdens from increasing urbanization, air pollution and populations, generally weaker health infrastructure, aging populations and increased incidence of non-communicable diseases, included CVD. The extent to which the problem of air pollution and CVD will impact these countries will depend largely on the information available to inform policy and programs, which are still lacking, political will as well as social and economic development.     

Prevalence analysis of different human bocavirus genotypes in pediatric patients revealed intra-genotype recombination

BackgroundHuman bocavirus (HBoV) genotypes 1–4 have been detected worldwide in respiratory samples and stool samples, and are increasingly associated with respiratory and intestinal infections of previously unknown etiology in young children. Several studies revealed evidence of extensive recombination among HBoV genotypes at the NP1 and VP1 gene boundary region. This study explored the prevalence of HBoV genotypes in pediatric patients in Beijing, and studied their phylogeny.MethodsA total of 4941 respiratory specimens and 1121 fecal specimens were collected from pediatric patients with respiratory infections from January 2006 to December 2013, or with acute diarrhea from October 2010 to December 2012. Conventional PCR was used to detect HBoV1–4 within these samples. Gene fragments at the NP1 and VP1 gene boundary were amplified from HBoV-positive specimens, sequenced, and their phylogenetic inferences constructed using MEGA 6.0 software. Recombination events were identified with SimPlot software.ResultsHuman bocavirus 1, 2, and 3 were detected in 9 (0.80%), 15 (1.33%), and 1 (0.08%) of 1121 stool samples, respectively. However, only HBoV1 (82, 1.65%) was detected in respiratory specimens. Phylogenetic analysis of gene fragments at the HBoV NP1 and VP1 gene boundary indicated that HBoV1 sequences obtained from fecal or respiratory specimens across 8 years were highly conserved (99–100%), while 15 HBoV2 sequences collected across 2 years in Beijing were more diverse with up to 4.40% variation. Of the 15 HBoV2 sequences, 14 clustered into a new lineage divergent from other HBoV2 sequences in GenBank. Five HBoV2 genomic sequences were analyzed for recombination, revealing intra-genotype recombination between HBoV2A and HBoV2B.ConclusionsMore HBoV1 were detected in children with respiratory tract diseases, and HBoV2 in patients with acute diarrhea. Phylogenetic analysis revealed a new cluster of HBoV2 was prevalent in China, which may be the result of intra-genotype recombination between HBoV2A and HBoV2B.