Hepatic Premalignant Alterations Triggered by Human Nephrotoxin Aristolochic Acid I in Canines.

Aristolochic acid I (AAI) existing in plant drugs from Aristolochia species is an environmental human carcinogen associated with urothelial cancer. Although gene association network analysis demonstrated gene expression profile changes in the liver of human TP53 knock-in mice after acute AAI exposure, to date, whether AAI causes hepatic tumorigenesis is still not confirmed. Here, we show that hepatic premalignant alterations appeared in canines after a 10-day AAI oral administration (3 mg/kg/day). We observed c-Myc oncoprotein and oncofetal RNA-binding protein Lin28B overexpressions accompanied by cancer progenitor-like cell formation in the liver by AAI exposure. Meanwhile, we found that forkhead box O1 (FOXO1) was robustly phosphorylated, thereby shuttling into the cytoplasm of hepatocytes. Furthermore, utilizing microarray and qRT-PCR analysis, we confirmed that microRNA expression significantly dysregulated in the liver treated with AAI. Among them, we particularly focused on the members in let-7 miRNAs and miR-23a clusters, the downstream of c-Myc and IL6 receptor (IL6R) signaling pathway linking the premalignant alteration. Strikingly, when IL6 was added in vitro, IL6R/NF-κB signaling activation contributed to the increase of FOXO1 phosphorylation by the let-7b inhibitor. Therefore, it highlights the new insight into the interplay of the network in hepatic tumorigenesis by AAI exposure, and also suggests that anti-premalignant therapy may be crucial for preventing AAI-induced hepatocarcinogenesis.

CXCL1 Triggers Caspase-3 Dependent Tau Cleavage in Long-Term Neuronal Cultures and in the Hippocampus of Aged Mice: Implications in Alzheimer's Disease.

Truncation of tau protein is considered an early event in Alzheimer's disease (AD) and is believed to play a major pathogenic role in sporadic AD. However, causative factors that trigger tau truncation in AD remain poorly understood. In the present study, we demonstrate that CXCL1 (C-X-C motif ligand 1), a specific ligand for the chemokine receptor CXCR2, induced cleavage of tau at ASP421 in a caspase-3-dependent manner in long-term but not short-term cultured neurons. The cleaved tau formed varicosities or bead-like structures along the neurites, an abnormal distribution of tau induced by CXCL1 that has not been observed previously. CXCL1-induced activation of GSK3ß and the subsequent phosphorylation of tau preceded and were required for caspase-3 activation and tau cleavage. Moreover, intrahippocampal microinjection of lentiviral CXCL1 induced tau cleavage in hippocampal neurons in aged (15-18 months of age) but not adult mice (5-10 months of age). Our data highlight a new role of CXCR2 in tau cleavage and suggest that targeting CXCR2 may offer therapeutic benefits to patients with AD and potentially other tauopathies.

Pharmacokinetic and pharmacodynamic analysis of ferulic acid-puerarin-astragaloside in combination with neuroprotective in cerebral ischemia/reperfusion injury in rats.

OBJECTIVE: To investigate the effects of the active ingredients combined therapy on inflammatory factors interleukin 1 beta (IL-1ß) and neuropeptide Y (NPY) based on pharmacodynamics in rats. METHODS: The animal model was built by transient middle cerebral artery occlusion (MCAO). The method for evaluating the concentrations of the FA-Pr-Al components in rat plasma was established by using HPLC and the expression levels of IL-1ß and NPY were determined by ELISA. A new mathematics method of the trend of percentage rate of change (PRC) was used to assess the correlation between pharmacokinetics (PK) and pharmacodynamics (PD). RESULTS: FA-Pr-Al in combination reduced neurological deficits, decreased infarct volume and inhibited the expression levels of IL-1ß and NPY (all P<0.05) compared with the model group. FA, Pr and Al all displayed two compartment open models in rats. Clockwise hysteresis loops were obtained by time-concentration-effect curves. IL-1ß and NPY level changes in the plasma followed an opposite trend to the plasma concentration tendency after Cmax was reached. Astragaloside's PRC value was significantly higher than those of FA and puerarin between 120 to 180 min. CONCLUSIONS: The pharmacokinetics of FA-Pr-Al in combination were closely related its pharmacodynamics in treating ischemia/reperfusion injury, and the components of FA-Pr-Al may have a synergistic pharmacological effect. Astragaloside may play a more pronounced role in regulating IL-1ßand NPY levels compared with puerarin or FA.

Effect of ligustrazine on levels of amino acid neurotransmitters in rat striatum after cerebral ischemia-reperfusion injury.

This study aimed to evaluate the effect of ligustrazine on levels of amino acid transmitters in the extracellular fluid of striatum following cerebral ischemia/reperfusion (I/R) in male Sprague-Dawley rats. A microdialysis cannula guide was implanted into the right striatum. After recovery, animals underwent a sham operation or middle cerebral artery occlusion (MCAO). Those that developed cerebral ischemia after MCAO were randomized to receive propylene glycol salt water and ligustrazine respectively. Striatal fluid samples were collected from all animals at 15-min intervals after treatment and were subjected to HPLC analysis of aspartic acid, glutamic acid, taurine, and γ-amino butyric acid. Upon the last sample collection, animals were sacrificed and brain tissue specimens were collected for triphenyltetrazolium chloride staining and NeuN staining. Compared with the sham operation, MCAO induced significant neurological deficits and increased striatal concentrations of the four neurotransmitters assessed in a time-dependent manner (P < 0.01). Ligustrazine effectively attenuated the detrimental effects of MCAO on the brain. These observations suggest that ligustrazine as a novel cerebral infarction-protective agent may have potential clinical implications for I/R-related brain damage.

The association of interleukin 6-634C/G polymorphism with left atrial thrombus and severe spontaneous echocontrast in patients with atrial fibrillation.

Atrial fibrillation (AF) not only is an independent risk factor for death but also confers significant risk of morbidity from stroke associated with left atrial thrombus. The association of interleukin 6 (IL-6) polymorphism with thrombus in AF has not been investigated before. We carried out a case-control study in Han Chinese. The IL-6 -634C/G genotypes of 31 patients with thrombus and 45 patients without thrombus were detected by polymerase chain reaction and restriction fragment length polymorphism. The frequencies of the IL-6 genotypes (CC, CG, and GG) were 29.03%, 54.54%, and 16.13% for the patients with thrombus, and 55.56%, 40.00%, and 4.44% for the patients without thrombus, respectively (P = .0391). Compared with the CC genotype, the G allele carriers (CG + GG) had a 2.79-fold increased risk of thrombus or severe spontaneous echocontrast (SEC). These results suggest that IL-6 -634C/G polymorphism is associated with thrombus and severe SEC, and the G allele is an independent risk for thrombus and severe SEC in Han Chinese patients with AF.

[Study on transport of Yangyin Tongnao granules in main effective fractions].

OBJECTIVE: To investigate the absorption characteristics and transportation mechanism Yangyin Tongnao granules in main effective fractions in Caco-2 cell model. METHOD: The safety concentrations of Yangyin Tongnao granules in main effective fractions in Caco-2 cells. A Caco-2 cell model was established to study the transport situations after the compatibility of Yangyin Tongnao granules in main effective fractions, and the content was determined by high performance liquid chromatography (HPLC). RESULT: P(app) of puerarin, ligustrazine and astragaloside were less than 1.0 x 10(-6) cm x s(-1), and their P(app) were hard to be close to atenolol. The oral absorption in descending order is shown as the following: puerarin, ligustrazine, astragaloside. After the compatibility between saponins and flavonoids, P(app) of astragaloside was improved obviously, which promoted the transport from apical (AP) to basolateral (BL); the compatibility of puerarin, ligustrazine and astragaloside showed a significant effect in the efflux of astragaloside and no change in the absorption transport of ligustrazine and puerarin at the same time. There is a great difference in bidirectional transport of representative component of each effective fraction, and P(app)(B --> A) was significantly greater than Papp(A --> B), which suggested that the efflux transport from BL side to AP side had an advantage in the three representative components of the three effective fractions in Caco-2 cell monolayer model. CONCLUSION: Astragaloside, ligustrazine and puerarin may be malabsorptive compounds, and the three compounds may be discharged by the transport protein in small intestine membrane.

The G to A polymorphism at -597 of the interleukin-6 gene is extremely rare in southern Han Chinese.

Interleukin-6 (IL-6) is a cytokine involved in different physiologic and pathophysiologic processes including essential hypertension (EH). Associations of the IL-6 promoter region polymorphisms with circulating level of IL-6 have been reported in various studies. We detected the IL-6-597G/A polymorphism in 246 EH patients and 194 healthy controls from Jiangsu area (south of China). Individuals all carried the GG wild genotype, no GA or AA genotypes were found. Our results suggest that IL-6-597G/A polymorphism is extremely rare and unlikely to be contributing significantly to disease susceptibility in southern Han Chinese.

Interleukin-6 -634C>G polymorphism in hypertensive patients with and without left ventricular hypertrophy.

There is an accumulating body of evidence indicating that inflammation plays a pivotal role in the pathogenesis of cardiovascular disease. Interleukin-6 (IL-6) is a pleiotropic cytokine secreted by many cells of the immune system, cardiovascular components and adipose tissue, and functions as a mediator of inflammatory response with both pro- and anti-inflammatory properties. Circulating levels of IL-6 differ greatly between individuals due to both genetic and environmental factors. The IL-6 -634C>G polymorphism is common in eastern Asian populations. The aim of the present study was to investigate the association of this polymorphism with essential hypertension (EH) and left ventricular hypertrophy (LVH) in 440 subjects (246 EH patients and 194 controls) from a Han Chinese population. In this study, IL-6 -634C>G genotypes were identified by polymerase chain reaction and restriction digestion in all study participants, and left ventricular mass was assessed by 2-mode echocardiography in 178 untreated EH patients. There was no significant difference in either genotype distribution (p=0.9528) or allele frequency (p=0.7775) between the EH and control groups. In addition, the -634C>G polymorphism had no effect on blood pressure in either the controls or the untreated EH patients. No significant differences in genotype distribution (p=0.7998) or allele frequency distribution (p=0.5468) were found between EH patients with and without LVH. Moreover, the echocardiographic parameters were not statistically different between the CC and CG+GG genotypes. These findings suggest that there is no association of the IL-6 -634C>G polymorphism and EH with LVH in EH patients.