Exosomal HMGA2 protein from EBV-positive NPC cells destroys vascular endothelial barriers and induces endothelial-to-mesenchymal transition to promote metastasis.

Increased vascular permeability facilitates metastasis. Cancer-secreted exosomes are emerging mediators of cancer-host crosstalk. Epstein-Barr virus (EBV), identified as the first human tumor-associated virus, plays a crucial role in metastatic tumors, especially in nasopharyngeal carcinoma (NPC). To date, whether and how exosomes from EBV-infected NPC cells affect vascular permeability remains unclear. Here, we show that exosomes from EBV-positive NPC cells, but not exosomes from EBV-negative NPC cells, destroy endothelial cell tight junction (TJ) proteins, which are natural barriers against metastasis, and promote endothelial-to-mesenchymal transition (EndMT) in endothelial cells. Proteomic analysis revealed that the level of HMGA2 protein was higher in exosomes derived from EBV-positive NPC cells compared with that in exosomes derived from EBV-negative NPC cells. Depletion of HMGA2 in exosomes derived from EBV-positive NPC cells attenuates endothelial cell dysfunction and tumor cell metastasis. In contrast, exosomes from HMGA2 overexpressing EBV-negative NPC cells promoted these processes. Furthermore, we showed that HMGA2 upregulates the expression of Snail, which contributes to TJ proteins reduction and EndMT in endothelial cells. Moreover, the level of HMGA2 in circulating exosomes is significantly higher in NPC patients with metastasis than in those without metastasis and healthy negative controls, and the level of HMGA2 in tumor cells is associated with TJ and EndMT protein expression in endothelial cells. Collectively, our findings suggest exosomal HMGA2 from EBV-positive NPC cells promotes tumor metastasis by targeting multiple endothelial TJ and promoting EndMT, which highlights secreted HMGA2 as a potential therapeutic target and a predictive marker for NPC metastasis.

Inhibition of CYP3A4 enhances aloe-emodin induced hepatocyte injury.

Aloe-emodin (AE) is a natural hydroxyanthraquinone derivative that was found in many medicinal plants and ethnic medicines. AE showed a wide array of pharmacological activities including anticancer, antifungal, laxative, antiviral, and antibacterial effects. However, increasing number of published studies have shown that AE may have some hepatotoxicity effects but the mechanism is not fully understood. Studies have shown that the liver injury induced by some free hydroxyanthraquinone compounds is associated with the inhibition of some metabolic enzymes. In this study, the CYP3A4 and CYP3A1 were found to be the main metabolic enzymes of AE in human and rat liver microsomes respectively. And AE was metabolized by liver microsomes to produce hydroxyl metabolites and rhein. When CYP3A4 was knocked down in L02 and HepaRG cells, the cytotoxicity of AE was increased significantly. Furthermore, AE increased the rates of apoptosis of L02 and HepaRG cells, accompanied by Ca2+ elevation, mitochondrial membrane potential (MMP) loss and reactive oxygen species (ROS) overproduction. The mRNA expression of heme oxygenase-1 in L02 and HepaRG cells increased significantly in the high-dose of AE (40 µmol/L) group, and the mRNA expression of quinone oxidoreductase-1 was activated by AE in all concentrations. Taken together, the inhibition of CYP3A4 enhances the hepatocyte injury of AE. AE can induce mitochondrial injury and the imbalance of oxidative stress of hepatocytes, which results in hepatocyte apoptosis.

Epstein-Barr Virus Induces Lymphangiogenesis and Lympth Node Metastasis via Upregulation of VEGF-C in Nasopharyngeal Carcinoma.

Lymphatic metastasis is a common clinical symptom in nasopharyngeal carcinoma (NPC), the most common Epstein-Barr virus (EBV)-associated head and neck malignancy. However, the effect of EBV on NPC lymph node (LN) metastasis is still unclear. In this study, we demonstrated that EBV infection is strongly associated with advanced clinical N stage and lymphangiogenesis of NPC. We found that NPC cells infected with EBV promote LN metastasis by inducing cancer-associated lymphangiogenesis, whereas these changes were abolished upon clearance of EBV genomes. Mechanistically, EBV-induced VEGF-C contributed to lymphangiogenesis and LN metastasis, and PHLPP1, a target of miR-BART15, partially contributed to AKT/HIF1a hyperactivity and subsequent VEGF-C transcriptional activation. In addition, administration of anti-VEGF-C antibody or HIF1α inhibitors attenuated the lymphangiogenesis and LN metastasis induced by EBV. Finally, we verified the clinical significance of this prometastatic EBV/VEGF-C axis by determining the expression of PHLPP1, AKT, HIF1a, and VEGF-C in NPC specimens with and without EBV. These results uncover a reasonable mechanism for the EBV-modulated LN metastasis microenvironment in NPC, indicating that EBV is a potential therapeutic target for NPC with lymphatic metastasis. IMPLICATIONS: This research demonstrates that EBV induces lymphangiogenesis in NPC by regulating PHLPP1/p-AKT/HIF1a/VEGF-C, providing a new therapeutic target for NPC with lymphatic metastasis.

Exploration of components and mechanisms of Polygoni Multiflori Radix-induced hepatotoxicity using siRNA -mediated CYP3A4 or UGT1A1 knockdown liver cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygoni Multiflori Radix, the dried root of Polygonum multiflorum Thunb., and its processed products have been used as restoratives for centuries in China. However, the reports of Polygoni Multiflori Radix-induced liver injury (PMR-ILI) have received wide attention in recent years, and the components and mechanism of PMR-ILI are not completely clear yet. Our previous studies found that the PMR-ILI was related to the down-regulation of some drug metabolism enzymes (DME). AIM OF THE STUDY: To explore the effect of the inhibition of CYP3A4 or UGT1A1 on PMR-ILI, screen the relevant hepatotoxic components and unveil its mechanism. METHODS: RT-qPCR was used to detect the effects of water extract of Polygoni Multiflori Radix (PMR) and its main components on the mRNA expression of CYP3A4 and UGT1A1 in human hepatic parenchyma cell line L02. High-performance liquid chromatography (HPLC) was employed to detect the content of major components in the PMR. And then, the stable CYP3A4 or UGT1A1 knockdown cells were generated using short hairpin RNAs (shRNA) in L02 and HepaRG cells. Hepatotoxic components were identified by cell viability assay when PMR and its four representative components, 2,3,5,4'-tetrahydroxy stilbene glycoside (TSG), emodin (EM), emodin-8-O-ß-D-glucoside (EG), and gallic acid (GA), acted on CYP3A4 or UGT1A1 knockdown cell lines. The PMR-ILI mechanism of oxidative stress injury and apoptosis in L02 and HepaRG cells were detected by flow cytometry. Finally, the network toxicology prediction analysis was employed to excavate the targets of its possible toxic components and the influence on the metabolic pathway. RESULTS: PMR and EM significantly inhibited the mRNA expression of CYP3A4 and UGT1A1 in L02 cells, while TSG and GA activated the mRNA expression of CYP3A4 and UGT1A1, and EG activated CYP3A4 expression while inhibited UGT1A1 expression. The contents of TSG, EG, EM and GA were 34.93 mg/g, 1.39 mg/g, 0.43 mg/g and 0.44 mg/g, respectively. The CYP3A4 or UGT1A1 knockdown cells were successfully constructed in both L02 and HepaRG cells. Low expression of CYP3A4 or UGT1A1 increased PMR cytotoxicity remarkably. Same as PMR, the toxicity of EM and GA increased in shCYP3A4 and shUGT1A1 cells, which suggested EM and GA may be the main components of hepatotoxicity in PMR. Besides, EM not only inhibited the expression of metabolic enzymes but also reduced the cytotoxicity threshold. EM and GA affected the level of ROS, mitochondrial membrane potential, Ca2+ concentration, and dose-dependent induced hepatocyte apoptosis in L02 and HepaRG cells. The network toxicology analysis showed that PMR-ILI was related to drug metabolism-cytochrome P450, glutathione metabolism, and steroid hormone biosynthesis. CONCLUSION: The inhibition of mRNA expression of CYP3A4 or UGT1A1 enhanced hepatotoxicity of PMR. EM and GA, especially EM, may be the main hepatotoxic components in PMR. The mechanism of PMR, EM and GA induced hepatotoxicity was proved to be related to elevated levels of ROS, mitochondrial membrane potential, Ca2+ concentration, and induction of apoptosis in liver cells.

[Spatial-temporal distribution of vegetation net primary productivity and its driving factors from 2000 to 2015 in Shaanxi, China.] / 2000­2015å¹´é™•è¥¿æ¤è¢«å‡€åˆçº§ç”Ÿäº§åŠ›æ—¶ç©ºåˆ†å¸ƒç‰¹å¾åŠå ¶é©±åŠ¨å› ç´ .

Using MOD17A3 NPP time series data, surface cover type data, weather data, MOD16 evapotranspiration products and terrain data, the temporal and spatial variability of vegetation net primary productivity (NPP) in Shaanxi Province from 2000 to 2015 was analyzed, and its response to each influencing factor were discussed. The results showed that the NPP of Shaanxi had a significant upward trend in the past 16 years with a slope of 5.02 g C·m-2·a-1. The annual average of NPP was 344 g C·m-2·a-1 with a range from 247 to 390 g C·m-2·a-1. The NPP at 61.2% area of Shaanxi Province showed a significant increasing trend, which were mainly distributed at northern part of Shaanxi, Weibei area and western part of Qinba Mountain. There was a decrease trend of NPP for the area around Xi'an and Baoji City, accounting for only 2.5% of the whole province. During the study period, the variation of annual mean temperature and annual precipitation in Shaanxi showed no significance. The temperature showed a increase trend and the precipitation showed a decrease trend, implying a drier and warmer climate trend in Shaanxi Province. The areas with significant correlation between NPP and precipitation and temperature accounted for 9.4% and 1.5% of the total area of the province. The frequent intervention of human activities reduced the impact of climate on the changes of NPP, so human activity had gradually become the dominant factor. NPP in northern Shaanxi and Guanzhong areas was significantly correlated with evapotranspiration. The increases of NPP in these areas would have great influence on the water and heat balance. The average NPP at different land cover was farmland > forestland > grassland > garden, increasing rate of NPP at different land cover was garden > grassland > forestland > farmland, and proportional changes of NPP was grassland > garden > forestland > farmland. The increasing percentage of NPP at three gradient ranges were 14.6% (0°-5°), 25.7% (5°-25°) and 35.9% (>25°), respectively.

Hepatotoxicity in Rats Induced by Aqueous Extract of Polygoni Multiflori Radix, Root of Polygonum multiflorum Related to the Activity Inhibition of CYP1A2 or CYP2E1.

The objective of this study is to investigate the relationship between the hepatotoxicity induced by Polygoni Multiflori Radix (PMR, root of Polygonum multiflorum Thunb., He Shou Wu) and the activity of CYP1A2 or CYP2E1 in the rat liver. Levels of rat serum transaminases ALT and AST were not altered but the activity of CYP1A2 or CYP2E1 in the rat liver was significantly inhibited after oral administration of aqueous extract of PMR under the experimental dosage. However, levels of ALT and AST were significantly increased and the activity of CYP1A2 or CYP2E1 was significantly decreased after injection of specific inhibitor for CYP1A2 or CYP2E1 combined with oral administration of aqueous extract of PMR, especially under the repeated treatment over interval times. Liver histopathological observation showed that a moderate liver injury occurred in rats receiving PMR treatment with the activity of CYP1A2 or CYP2E1 inhibited, but there was no significant liver damage in rats receiving PMR treatment or CYP inhibitor alone. These suggested that low level activity of CYP1A2 or CYP2E1 from genetic polymorphism among people might be one of the important reasons for the hepatotoxicity induced by PMR in clinical practice.

[Study on inhibitory effect of water extract of Polygonum multiflorum on CYP1A2 and CYP2E1 enzymatic activities and mRNA expressions in rat liver].

Rats were continuously given different doses of water extract of Polygonum multiflorum (1, 10 g x kg(-1)) for 7 days to prepare liver microsomes. Cocktail in vitro incubation approach and Real-time quantitative PCR technology were used to observe the effect of water extract of P. multiflorum on CYP450 enzymatic activities and mRNA expressions in rat liver. Compared with the blank control group, both 1, 10 g x kg(-1) water extract of P. multiflorum treated groups showed significant inhibitions in CYP2E1 enzymatic activities and mRNA expressions (enzymatic activities of CYP2E1, P < 0.01; mRNA expression of CYP2E1, P < 0.05 in 1 g x kg(-1) group, P < 0.01 in 10 g x kg(-1) group). They revealed a significant increase in the enzymatic activity of CYP3A1 (P < 0.01), but without significant change in mRNA expressions. The 10 g x kg(-1) group showed a significant inhibition in CYP1A2 enzymatic activities and mRNA expressions in rat livers (P < 0.01).

TMPRSS4 facilitates epithelial-mesenchymal transition of hepatocellular carcinoma and is a predictive marker for poor prognosis of patients after curative resection.

TMPRSS4 (Transmembrane protease serine 4) is up-regulated in a broad spectrum of cancers. However, little is known about the biological effects of TMPRSS4 on hepatocellular carcinoma (HCC) and the related mechanisms. In the present study, we found that overexpression of TMPRSS4 significantly promoted the invasion, migration, adhesion and metastasis of HCC. Further more, TMPRSS4 induced EMT of HCC, which was mediated via snail and slug as a result of Raf/MEK/ERK1/2 activation, and inhibition of ERK1/2 activation by its inhibitor was associated with reduced cell invasion and reversion of EMT. In addition, we demonstrated that TMPRSS4 remarkably suppressed the expression of RECK, an inhibitor of angiogenesis, and drastically induced tumor angiogenesis and growth. More important, in clinical HCC specimens, TMPRSS4 expression was significantly correlated with tumor staging and was inversely correlated with E-cadherin and RECKS expression. Expression of TMPRSS4 is significantly associated with HCC progression and is an independent prognostic factor for postoperative worse survival and recurrence. In conclusion, TMPRSS4 functions as a positive regulator of Raf/MEK/ERK1/2 pathway and promotes HCC progression by inducing EMT and angiogenesis. The increase of TMPRSS4 expression may be a key event for HCC progression and may be regarded as a potential prognostic marker for HCC.

Mannose-mediated inhibitory effects of PA-MSHA on invasion and metastasis of hepatocellular carcinoma via EGFR/Akt/IκBß/NF-κB pathway.

BACKGROUND & AIMS: Elevation of high-mannose glycans is a common feature of malignant cells and has been suggested to be the basis for alternative cancer therapy for several years. Here we want to investigate the antitumour effect of pseudomonas aeruginosa-mannosesensitive haemagglutinin (PA-MSHA), a genetically engineered heat-inactivated PA strain with mannose-sensitive binding activity, on hepatocellular carcinoma (HCC). METHODS: Tumourigenicity and metastatic potentials of HCC were studied after PA-MSHA treatment by utilizing the in vitro/in vivo model of HCC. Expression of apoptosis-associated proteins and epithelial-mesenchymal transition (EMT) related genes were evaluated, and possible signalling pathways involved were investigated. RESULTS: PA-MSHA induced significant cell proliferation inhibition and cell cycle arrest of HCC through decreasing the levels of cyclins D1, cyclins E, CDK2, CDK4, proliferating cell nuclear antigen (PCNA), and increasing the level of p21 and p27. Moreover, PA-MSHA suppressed the invasion, migration and adhesion of HCC through inhibiting epithelial-mesenchymal transition (EMT). PA-MSHA also inhibited EGFR/Akt/IκBß/NF-κB pathway and overexpression of NF-κB significantly abrogated PA-MSHA induced EMT inhibition. In addition, competitive inhibition of the mannose binding activity of PA-MSHA by D-mannose significantly blocked its effect on cell cycle arrest and EMT. PA-MSHA also abrogated lung metastasis of HCC and significantly inhibited tumour growth in the in vivo study. CONCLUSIONS: Our study demonstrated the essential role of EGFR/Akt/IκBß/NF-κB pathway in the inhibitory effect of PA-MSHA on invasion and metastasis of HCC through suppressing EMT, and revealed an attractive prospect of PA-MSHA as a novel candidate agent in the treatment of HCC.

Migration and differentiation of mouse embryonic stem cells transplanted into mature cochlea of rats with aminoglycoside-induced hearing loss.

CONCLUSION: Mouse embryonic stem cells (ESCs) transplanted into the scala tympani are able to migrate in the cochlea of rats deafened with aminoglycoside and partly restore the structure of sensory epithelia of the inner ear. OBJECTIVES: To explore the migration and differentiation of enhanced green fluorescence protein (EGFP)-expressing ESCs by transplanting them into the scala tympani of rats with amikacin sulfate-induced hearing loss. METHODS: Adult Sprague-Dawley (SD) rats were deafened with amikacin sulfate. Mouse ESCs expressing EGFP (EGFP-ESCs) were transplanted into the scala tympani. The migration and differentiation were observed at different time points. RESULTS: EGFP-ESCs transplanted into normal cochlea did not migrate, but those in the amikacin-damaged cochlea could survive and migrate into the scala media and the vestibular cisterna. For the first time, we observed that the EGFP-ESCs migrated into the scala media, took the place of the organ of Corti, and formed a structure just like the cochlear tunnel. Some grafted stem cells even expressed myosin VIIa, the molecular marker of hair cells. Some nerve fibers reached to the bottom of the hair cell-like cells. The ESCs migrated into the vestibule and restored the sensory epithelia of the ampullary crest. The number of the transplanted ESCs reduced over the 6 week period of the study.

[Change characteristics and their causes of fractional vegetation coverage (FVC) in Shaanxi Province].

Based on the sub-pixel analysis model, and by using 2000-2009 MODIS NDVI (250 m resolution), this paper quantitatively analyzed the spatiotemporal change characteristics and their causes of fractional vegetation coverage (FVC) in Shannxi Province. From 2000 to 2009, the FVC in the Province had a significant increasing trend, with the great magnitude of 35.0%. During that period, the vegetation coverage increased from 56.9% in 2000 to 68.9% in 2009 in the provincial scale, and the increment was much higher in northern Shannxi, being 21.6% in Yulin and 22.0% in Yan' an. Though the vegetation coverage had an overall increase, it was locally degraded in some areas. The areas with improved vegetation coverage at the significance levels of < 0.01, and < 0.05 were 37.8% and 11.9%, while those with non-improved and degraded vegetation coverage were 46.1% and 4.2%, respectively. The areas whose vegetation coverage had a change rate of 200%, 200%-100%, 100%-10%, 10%-10%, and < -10% occupied 12.2%, 13.3%, 38.8%, 29.3%, and 6.4% of the total, respectively. During the study period, the structure of vegetation coverage in the Province also improved. The areas with high and normal vegetation density increased significantly by 10% and 8.4%, respectively, while the area with low vegetation density decreased significantly by 18.4%. The improvement of the FVC in Shaanxi Province was the interactive effect of natural factors and human activities, but the main cause was the implementation of a series of ecological construction projects such as closing hill for forestation and restoring farmland into forestland and grassland.

[Study on embryo development and somatic embryogenesis of jujube].

The results of embryological observation on embryo development in the thirteen cultivars of jujube indicated that they shared the same experience from proembryo to globular embryo, heart-shaped embryo, torpedo-shaped embryo and cotyledon stage embryo. Embryo began aborting from globular or heart-shaped embryo period in most of cultivars of jujube, but in few of them embryo could keep synchronous developing to cotyledon stage embryo. And the courses of embryo development were not synchronous.