VIEWS: 9 PAGES: 15 POSTED ON: 1/30/2010
Atherosclerosis is the leading cause of death in the cardiovascular disease. It is a systemic disease, a huge number of studies have revealed several risk factors involving in the progression of atherosclerosis. In early atherogenesis, oxidative modification hypothesis of atherosclerosis proposes that LDL oxidation and proliferation of vascular smooth muscle cell (VSMC) in the intima plays a causative role. If agents that can prevent LDL oxidation and proliferation of VSMC, it could possibly attenuate the development of atherosclerosis. Flavonoids are a group of naturally occurring polyphenolic compounds ubiquitously found in plants, fruits and vegetables. It has shown potential antioxidative effects. In this study, we evaluated the effects of mulberry leaf extracts (MLE) to inbibit LDL oxidation and VSMC proliferation. In the Cu2+-induced LDL oxidation model, we observed that MLE were able to apparently reduce the Apo B fragmentation, relative electrophoretic mobility (EM) and the products of lipid peroxide-MDA formation. MLE possessed the best ability of DPPH radical scavenging. Taken together, MLE showed a strong potency to inhibit the LDL oxidation induced by Cu2+. In our previous studies, in cultured cells experiments, have demonstrated that MLE could induce VSMC apoptosis. Nevertheless, does the lower dose of MLE effect ? In this study, we focus on that is MLE able to inhibit VSMC on cell cycle progression and migration? First, MLE effectively inhibit VSMC growth on the dose of 1~1.5 mg/ml MLE which can’t induce cell apoptosis. In the experiments of flow cytometry assay, we also evaluated the proportion of S and G2/M phase of cell cycle were decreased, but G1 phase were increased abundantly on treatment VSMC with 1.0 mg/ml MLE. The western blot have revealed that cyclinD1, CDK4, p-p53, p27, p21, p16 were increased and cyclinA, cyclinE, CDK2, p-Rb were reduced. In the experiments of immunoprecipitation, we analyzed attenuation of cyclinD/CDK4 complexes following the advancement of MLE dose. It means MLE inhibited cell proliferation by interferencing the mechanism of VSMC cell cycle progress to S phase. In addition, the best ability of MLE inhibited VSMC migration by wound healing assay and Boyden chamber assay. The expression of MMP-9, MMP-2, small GTPase, p-FAK and NF-κB were decrease progressively by gelatin zymography assay and westerb blotting. In conclusion, mulberry leaf extracts (MLE) possess ability to inhibit LDL oxidation and abnormal proliferation of vascular smooth muscle cell. Therefore, it is suggestive the mulberry leaves that may have multiple benefical effects on cardiovascular health, and the potential clinical application of these fascinating natural substance. Abstract Cardiovascular disease has been a major cause of mortality in human and hyperlipidemia plays an important role contributing to atherosclerosis. Oxidated LDL (oxLDL) has known to damage the endothelial cells and cause endothelial dysfunction. And oxLDL-mediated foam cell formation by macrophage initiates the cascade of atherosclerosis. This study was to evaluate the anti-oxidative and anti-atherosclerotic effects of the MLE by a model of in vitro antioxdation and cell culture. As shown in previous studies Morus alba L. leaves extract is a nature plant containing a lot of pigments that was found to possess antioxidative activity. In this study, we evaluated the antioxidative activity of the Morus alba L. leaves extract (MLE) by measuring their effects on LDL oxidation and anti-atherosclerotic abilities. MLE possessed the ability of DPPH radical scavenging. The antioxidative activity of the MLE on LDL oxidation was defined by apoB fragmentation, relative electrophoretic mobility (REM) and thiobarbituric acid-relative substances (TBARS) assay. Our results showed that MLE was able to protect the apoB, to reduce REM and to inhibit TBARS assay in the Cu2+-mediated oxidative LDL. Taken together, low concentration of MLE could reduce marked the cellular cholesterol and triglycerides accumulation in macrophage and inhibit the formation of foam cells. MLE inhibits oxLDL-induced CD36 and SR-A expression. We found MLE also recovered oxLDL-mediated NF-κB activity loss. MLE reduces macrophage phagocytosis by latex beads. Our study demonstrates the MLE can inhibit the oxidation of LDL and has the anti-oxidatic and anti-atherosclerotic properties. Abstract It’s a popular topic of discussing how to prevent the formation of cancer. The development of new drugs are both safe and effective will be important for the future of cancer chemoprevention. Many studies demonstrate that Anthocyanins and Polyphenol widely in many plants have the effects of antioxidation, hypolipidemic, anti-atherosclerotic and anti-carcinogenesis, such as the Anthocyanins in the Hibiscus sabdariffa L. Our previous reports demonstrated that anthocyanins extracted from Hibiscus sabdariffa Linne, Hibiscus anthocyanins (HAs) and Hibiscus polyphenol（HPE）induced apoptosis effect on human cancer cells. In this study, we explored the anti-cancer effect and the particularly mechanism of HAs on human colon cancer cell. The Chinese herbal medicine has already been continued to use for many years at many disease, has also included directing against the treatment of the cancer. On the other hand, the research in recent years shows the cancer cell grows and spreads because of being unable to wither and die normally. It’s an important subject to detect the cancer cells with specially mechanism in cancer therapy. We used MTT assay, DAPI staining, flow cytometery, mitochondria membrane potential analysis and western blot to detect and found that HAs treatment markedly induced apoptosis in LoVo cells in a dose- and time-dependent manner. The results also reveal inhibited NF-kB, induced by members of the death receptor such as Fas/FasL that leads to the formation of pro-caspase-8, increased cytochrome C release, and expression of Bcl-2 family protein via mitochondrial death pathway. Followed, the mechanism of apoptosis is associated with activation of the caspase cascade in the HAs-treated LoVo cells. We suggested that HAs could promote colon cancer cell apoptosis and prevent or delay cancer cell progression. According to these results, HAs has a potential in anticancer effect that could be developed as chemopreventive materials. ABSTRACT Chondrocyte is the sole cell type of the cartilage. At the joint, cartilage covers the end of the bone. The extracellular matrix (ECM), a structure of highly hydrated matrix, is consisted of collagen, and glycosaminoglycan (GAG) which is made of hyauronic acid back bone with many other chondroitin sulfate, keratan sulfate and protein components. Chondrocytes are embedded in this ECM structure and produce new collagen and GAGs in cartilage. When chondrocytes are serially expanded, they progressively lose their original phenotype, this process typically described as dedifferentiation. According to previous studies in our laboratory, exogenous type II collagen promoted re-expression of type II collagen mRNA and GAG accumulation in near quiescent rabbit chondrocytes. In this study, we treat human chondrocytes with various exogenous extracellular matrix components (i.e. type II collagen, hyaluronic acid, or chondroitin sulfate). The results demonstrated that exogenous type II collagen indeed induced the re-expression of type II collagen and aggrecan mRNAs, and glycosaminoglycan (GAG) levels. Since exogenous type II collagen indeed make near quiescent chondrocytes re-differentiate, therefore, its preparations maybe be applied to osteoarthritis therapy in the future. In addition, integrins are the principal receptors on animal cells for the most of extracellular matrix proteins ― including collagens, fibronectin, and laminins. Consequently, this study also examined the related signal pathway of integrin. We found that the extracellular signal-regulared protein kinase (ERK) was activated during the induction of the differentiation of dedifferentiated chondrocytes. 英文摘要 Recent advances in molecular genetics have revealed that multiple genetic alterations including activation of oncogenes and inactivation of tumor suppressor genes are required for tumor development and progression. K-ras is frequently mutated in colorectal cancer. Previous studies have shown that prostaglandin E2 (PGE2) is involved in intestinal carcinogenesis through its binding to the PGE2 receptor subtypes EP1 and EP4 and activation of downstream pathways. But the molecular mechanisms that link K-ras and PGE2 receptor are currently undefined. The aim of the present work was to study the association between K-ras and PGE2 receptor .We transfer pcDNA3.1 and pcDNA-K-ras in to HT29 colon cancer cells. The transfected cells and the control cells (empty vector) were analyzed by MTT assay and Western blot. Our data showed overexpression Ras protein led to cell proliferation with activation of the phosphatidylinosotol-3 Kinase (PI3K)/Akt pathway, an effect likely to be due to inhibits GSK3β(Glycogen synthase kinase 3β)activity. Inhibition of GSK3 stabilizes β-catenin (decrease its degradation) and promotes β-catenin nuclear translocation and transcriptional activation of TCF-regulated gene further induction of COX-2 and activation EP1/EP4. We also used COX-2 inhibitor (NS398) and EP4 inhibitor (AH23848) to confirm this pathway. At the same time, we collected colorectal tumor tissues as well as to confirm tumor tissues were overexpression Ras, pAkt and EP1/EP4 protein. Our result provided colorectal cancer causes K-ras mutation which one newly thinks in the treatment. In addition, EP1/EP4 inhibitor use regarding the colorectal cancer prevention also is the choice which may consider. 英文摘要： Atherosclerosis, a disease occurring in arteries, is one of the primary causes of heart diseases, stroke and often cause of death in the cardiovascular disease. The oxidative modification hypothesis of atherosclerosis proposes that LDL oxidation or proliferation and migration of vascular smooth muscle cell (VSMC) in the intima plays a causative role in early stage. Mulberry is a nature fruit containing a lot of pigments that was found to possess antioxidative activity. The mulberry water extracts (MWEs) can effectively inhibit LDL oxidation, may prevent atherosclerosis via reducing early atherogenesis, and slowing down the progression to advance stages.In these experiments, mulberry water extracts (MWEs) and polyphenol extracts (MPEs) were able to inhibit the Apo B fragmentation, MDA formation (TBARS assay) and possessed the ability of DPPH radical scavenging. We demonstrated that MWEs and MPEs could inhibit ASMC (A7r5 cell) migration cause apoptosis by down regulation of Ras/PI3K/Akt and anti-apoptosis pathway strongly , and cell cycle arrest by attenuating of cyclinD/CDK4, cyclin A、E/CDK2 , p53/Mdm2 complexes. In conclusion, we not only evaluated the antioxidative activity of the mulberry extracts, but also observed the mulberry water extracts (MWEs) and mulberry polyphenol extracts (MPEs) can inhibit proliferation and migration of vascular smooth muscle cell by inhibite NFκB transcription activity. FAK, RhoA , Rac-1, Cdc42, and Ras protein ,which facilitates integrin signaling, regulating cell cycle progression, cell survival and cell migration , also can be inhibit by treatment of mulberry extracts. Therefore, it is suggested that mulberry could be a healthy food to prevent individuals from atherosclerosis . Abstract: Background: Diabetic patients have a higher propensity for in-stent restenosis after percutaneous coronary intervention (PCI) as compared with normal subjects. Beyond lipid-lowering effects, statins were reported to reduce intimal hyperplasia by inhibiting smooth muscle cells (SMC) proliferation and migration and may improve outcomes after PCI. We will investigate the mechanism of simvastatin to inhibit vascular SMC at high glucose status mimicking diabetes. Methods: A7r5, a rat smooth muscle of thoracic aorta, were used. Before simvastatin treatment, the cells were pre-culture in starvation medium for 48 hours. Simvastatin were added to the cells which were cultured in high glucose（25 mM）medium to achieve the indicated concentrations (0-60 μM) for 48 hours. We used MTT assay to evaluate the cell viability, flow cytometric analysis to analyze the cell cycle. We also used western blot, immunoblotting, and immunoprecipitation analyses to evaluate the effect of simastatin on the cyclin dependent kinase activity and cell cycle regulatory proteins (Rb, p53, p16, p21, p27). Results: Following a 48 hr incubation with 0.5-60.0 μM of simvastatin treatment in the cells at high glucose level, the percentage of survival cells was around 10~50％. Furthermore, a time-dependent increase in simvastatin-induced cytotoxicity was also detected at dose of 40.0 μM. Simvastatin induced accumulation of significant numbers of cells around 8~18% in the G0/G1 phase of the cell cycle in a concentration-dependent manner, while the cell numbers was significantly decreased in the S and G2/M phases after simvastatin treatment. We also found that simvastatin can inhibit phosphorylation of Rb and promote expression of p53, increase the CDK inhibitory protein (p16, p21, p27) levels, and decrease the CDK2/4 activities. Conclusions: Simvatatin inhibits vascular SMC proliferation at high glucose status mimicking diabetes, which induces a G0/G1 phase growth arrest of the cell cycle by acting on multiple steps upstream of pRb, inhibition of CDK2/4 expression and upregulation of p53 and other CDK inhibitory proteins (p21, p16, p27). Hence, statins should be used in diabetic patients even without dyslipidemia. 英文摘要： Glutathione S-transferase (GST), an important detoxification dimeric enzyme in mammalian cells, includes six isoforms: alpha, pi, mu, theta, zeta and sigma classes. Previous investigations showed that GST would conjugate xenobiotics with the sulfhydry group of GSH (glutathione) to increase the solubility of these xenobiotics. On the other hand, GST has anti-oxidation function, which protect lipid or nucleic acid from the attack of toxins. Therefore, GST plays an important role in the mechanism of detoxification and anti-carcinogenesis. Among the isoforms, GST mu is thought to be related to cancer susceptibility. It is also suggested that GSTM1 could serve as a predictive marker for invasive bladder cancer. After the treatment of carcinogens, the expression of GST mu would increase in the hepatocytes. In order to clarify the role of GST mu, a transient expression system of GST mu was set up to study how the overexpression of GST mu affects the hepatotoxicity and genotoxicity of carcinogen. We used the primary cultured hepatocytes of SD rat to establish the transient transfection system of rGST mu (Yb1), and challenged the cells with Aflatoxin B1. We found that the transfected rGST mu would attenuate the damage of hepatocytes caused by Aflatoxin B1. The treatment of Aflatoxin B1 for 12hr increased the cytosolic GST activity in both GST and control vector-transfected cells in a dose-dependent manner. The GST activity in the cells transfected with rGST mu was higher than those transfected with pcDNA3. The releases of AST and LDH activity, from the Aflatoxin B1-treated cells were inhibited by the transfection of rGST mu as compared to the control. Abstract Colorectal cancer arises through the stepwise, progressive disruption of cellular signaling cascades which control cell proliferation, survival and differentiation. A number of genes have been implicated in tumorigenesis. However, the mechanisms for controlling cancer progression have not been elucidated.In order to further understand whether disease progression is associated with altered gene expression, we collected tumor tissues as well as their surrounding normal tissues resected from patients with different stages of colorectal cancer. Tumor tissues were firstly graded into B, C or D stage according to Duke classification, and the expression of several proteins involved in anti-apoptosis and proliferation, including Mcl-1, Bcl-2, IAP, NF-κB, PI3-K, phospho-Bad, p38, cpp32 and p21, were examined by Western blotting. Expression levels in tumors were normalized to those in normal tissues of the same patients and then compared to other tumor samples derived from different stages of disease. We found that expression levels of PI3-K, Bcl-2 and phospho-Bad were elevated as cancer progressed, suggesting that anti-apoptotic proteins were involved in the regulation of colorectal cancer progression. 進階科技英文寫作測驗 1. estrogen receptor alpha 或 the estrogen receptor alpha 2. tumor suppressor protein p53 或 the tumor suppressor protein p53 3. They exert opposing effect on cellular proliferation. 或 They exert opposing effects on cellular proliferation. 或 They exert opposing effects on the cellular proliferation. 4. As a transcriptional regulator, p53 is ... 或 As transcriptional regulator, p53 is ... 5. P53 is capable of activating various target genes. 或 P53 is capable of the activating various target genes. 或 P53 is capable of the activating of various target genes. P53 is capable of activation various target genes. P53 is capable of activation of various target genes. 或 P53 is capable of the activation of various target genes. 6. P53 is capable of activating or repressing various target genes. 或 P53 is capable of activating or repressing the various target genes. 或 P53 is able to activate or repress various target genes. 7. We have previously reported that ... 或 We previously reported that ... 或 We have previous reported that ... 或 We have a previous report that ... 8. ERalpha binds directly to p53. 或 ERalpha is bound directly to p53. 9. ERalpha binds directly to p53, leading to ... 或 ERalpha binds directly to p53, leads to ... 10. ERalpha binds directly to p53, leading to down-regulation of transcriptional activation by p53. 或 ERalpha binds directly to p53, leading to the down-regulation of the transcriptional activation of p53. 11. In addition to transcriptional activation, transcriptional repression plays important role in diverse biological process. 或 In addition to transcriptional activation, transcriptional repression plays important roles in diverse biological processes. 12. Transcriptional repression of a subset of target genes by p53 plays ... 或 Transcriptional repression by a subset of target genes of p53 play ... 13. ... in diverse biological processes, such as apoptosis. 或 ... in diverse biological processes such as the apoptosis. 14. Here, we report that ... 或 Here, we reported that ... 15. Here, we report that ERalpha inhibited p53-mediating transcriptional repression. 或 Here, we report that ERalpha inhibits p53-mediated transcriptional repression. 16. Chromatin immunoprecipitation assays reveal that ... 或 Chromatin immunoprecipitation assay revealed that ... 17. ... assays reveal that ERalpha interacts in vivo with p53 bound to promoters of Survivin. 或 ... assays reveal that ERalpha interacted in vivo with p53 binding to promoters of Survivin. 18. ERalpha interacts in vivo with p53 bound to promoters of Survivin and multidrug resistance gene 1. 或 ERalpha interacts in vivo with p53 bound to promoters of Survivin and of multidrug resistance gene 1. 19. ... Survivin and multidrug resistance gene 1, both targets for transcriptional repression by p53. 或 ... Survivin and multidrug resistance gene 1, both being targets for transcriptional repression by p53. 20. ERalpha binding to p53 leads to inhibition of p53-mediated transcriptional regulation of these genes in human cancer cells. 或 ERalpha binds to p53 leading to inhibition of p53-mediated transcriptional regulation of these gene in human cancer cell. Writing test 1. Transcriptional derepression of Survivin by ERalpha is depend on the p53-binding site on Survivin promoter. 或 Transcriptional derepression of Survivin by ERalpha is dependent on the p53-binding site on the Survivin promoter. 2. A is dependent on B, consistent with our observation that … 或 A is dependent on B, which is consistent with our observation that … 3. … our observation that p53 is necessary for ERalpha to access the romoters. 或 … our observation that p53 is necessary to ERalpha for access the promoters. 4. Important, mutagenic conversion of this site for an activation element enabled ERalpha for repress p53-mediated transcriptional activation. 或 Importantly, mutagenic conversion of this site to an activation element enabled ERalpha to repress p53-mediated transcriptional activation. 5. Further, RNA interference-mediated knockdown of ERalpha resulted in reduced Survivin expression and enhanced the propensity of MCF-7 cells to undergo apoptosis in response to staurosporine treatment. 或 Furthermore, RNA interference-mediated knockdown of ERalpha resulted reduced Survivin expression and enhanced in the propensity of MCF-7 cells for undergoing apoptosis in response to staurosporine treatment. 6. A resulted in B, an effect that was blocked by exogenous expression of Survivin. 或 A resulted in B, that was an effect blocked by exogenous expression of Survivin. 7. These results unravel a novel mechanism which ERalpha opposes to p53-mediated apoptosis in breast cancer cell. 或 These results unravel a novel mechanism by which ERalpha opposes p53-mediated apoptosis in breast cancer cells. 8. The findings could have translational implications in developing new therapeutic and prevention strategies. 或 The findings can have translational implication in developing new therapeutic and prevention strategy. 9. Studies on retinoblastoma have been at the heart of many of the landmark discoveries in cancer genetics over the past 35 years. 或 Studies of retinoblastoma have been in the heart of many of the landmark discoveries on cancer genetics for the past 35 years. 10. However, these advances in the laboratory have had a little effect in the treatment of children with retinoblastoma. 或 However, these advances in the laboratory have had little effect on the treatment of children with retinoblastoma. 11. One of the reasons for this has been the lack of preclinical models that recapitulated the genetic and histopathologic features of human retinoblastoma. 或 One of the reasons of this have been the lack of preclinical models which recapitulated genetic and histopathologic features of human retinoblastoma. 英文摘要： Polyphenols are widely distributed antioxidant agents in plants, and they have antitumor effects. Anthocyanins, one of the biofalvonols, also have strong antioxidant effects. In previous studies, Hibiscus protocatechuic acid (HPCA), a phenolic compound extracted from Hibiscus sabdariffa L., was found to protect rat primary hepatocytes from oxidative damage by scavenging free radicals. HPCA is also able to inhibit tumor promotion in mouse skin. In addition, Hibiscus Anthocyanins (HACs) were also shown to protect rats from tert-butyl hydroperoxide-induced hepatic toxicity. In this study, we used Hibiscus polyphenolic acid (HPAs) to evalute the molecular mechanism by which the phenolic extracts and the flavonid extracts of Hibiscus sabdariffa inbibit the growth of cancer cells. Moreover the effects of the mutant mitochondrial DNA (mtDNA) on the mechanism were also investigated. The results revealed that HPAs have the capacity of scavenging reactive oxygen species. Moreover, they inhibited the growth of cancer cells, even induced cell death. The cells harboring high proportions of the 4977 bp-deleted mtDNA were more sensitive to HPAs, and in a dose- dependent manner. In addition, after treatment of cybrids with HPAs for 24 hrs, the cells were arrested at G2/M phase through a p53independent pathway. Furthermore, HPAs can respectively activate caspase 8, caspase 9 and caspase 3 in the cybrids haboring only wild-type mtDNA, but the activations of caspase 8 and caspase 3 induced by HPAs were repressed in the cybrids harboring high proportions of the 4977 bp-deleted mtDNA. On the other hand, HACs was also shown to inhibit the growth of cancer cells, but the effects are lower than those of HPAs. Taken together, the results suggest that HPAs and HACs can respectively prevent the growth and activation of the caspases in cancer cells, and that the 4977 bp-deleted mtDNA in cancer cells can affect the mechanism. 英文摘要： Human hepatocellular carcinoma（HCC） is one of the most common cancers in Asia﹒Our recent data had also showed that the decreased levels of membrane-bound PKC activity and PKCα protein in HCC were correlated with tumor stage and tumor size﹒To verify the role of PKC in HCC﹐this study was further determined the mRNA level of PKC isoforms and cell proliferation markers in HCC by use RT-PCR﹒The total mRNA was isolated from the surgical specimens of 43 patients of HCC and adjacent normal tissues﹒The product of RT-PCR was also checked by DNA sequence analysis﹒ The result showed that the level PKCα mRNA in the cancer tissue were significantly higher than that in the adjacent normal tissue﹐specifying that the alteraions in the PKCα may signify their activation in liver cancer﹒Inaddition﹐the level of PKCδ、PKCε、 PKCμ and PKCζ mRNA in the cancer tissue were also significantly higher than that in the adjacent normal tissue﹒Moreover﹐the protein expressions of the PKC down-stream gene （c-raf、MEK、MAPK） and the mRNA expression of the cell proliferation markers were also increased in cancer tissues. Thus , we suggested that the over-expression of PKC isoforms may be involved in the malignant progression of HCC. 進階英文科技寫作練習 Class ( ) Number ( ) 模仿造句： 1. The opium-induced sleep is unnatural and harmful. Name ( ) 2. Good luck is coupled to kindness. 3. The mechanisms by which the ants defend their territories are not yet fully understood. 4. His behavior is associated with his childhood traumatic experience. 5. She rejected him again and again, suggesting that she felt no pity for him. 6. Our results show that this is indeed a good therapy. 7. Jogging is considered to be health-promoting exercise. 8. This disease has been linked to excessive drinking. 9. To understand its side effect, we did a thorough study of this new drug. 10. We assayed using the new method to analyze the data. 11. When compared with John’s weaknesses, Peter’s strengths are even more noteworthy. 12. The effect was most marked among aged patients. 13. They are enjoying their power-derived profits. 14. He delivered a speech in response to the ruling party’s questioning and the opposition party’s attack respectively. 15. When he found the majority of people were on his side, his boldness and his confidence were enhanced.
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