化工、纺织印染与农药化肥等产业的蓬勃发展推动着人类社会的进步,但同时也给环境治理带来了巨大难题。目前,光催化降解局限于在特定波长下针对单一有机污染物进行降解,然而现实中的情况往往更复杂。因此,开发一种多功能光催化材料用于...化工、纺织印染与农药化肥等产业的蓬勃发展推动着人类社会的进步,但同时也给环境治理带来了巨大难题。目前,光催化降解局限于在特定波长下针对单一有机污染物进行降解,然而现实中的情况往往更复杂。因此,开发一种多功能光催化材料用于光催化降解不同有机污染物显得尤为重要。采用一步无模板溶剂热法合成了核壳结构的C-TiO_(2)复合材料前驱体,并在氩气气氛下煅烧得到高结晶度的C-TiO_(2)复合光催化材料。运用SEM、TEM、XRD和TG等表征手段对材料进行表征,结论如下:550℃煅烧时的样品为包含少量碳的高结晶度的锐钛矿相TiO 2,且550℃煅烧时的样品依然保持了完整的核壳结构。此外,C-TiO_(2)复合材料的比表面积高达85.69 m 2·g^(-1),平均孔径为16.4 nm以及孔体积为0.423 m 3·g^(-1)。在UV-Vis光照射下,C-TiO_(2)复合材料分别对罗丹明B(RhB)、亚甲基蓝(MB)和刚果红(CR)3种染料显示出增强的光催化降解活性。展开更多
BACKGROUND: Hepatitis C virus (HCV) is believed to be an important human pathogen causing carcinoma. But the effect of HCV infection on the alteration of cellular pro- liferation and apoptosis and the relationship bet...BACKGROUND: Hepatitis C virus (HCV) is believed to be an important human pathogen causing carcinoma. But the effect of HCV infection on the alteration of cellular pro- liferation and apoptosis and the relationship between the effect and the development of hilar cholangiocarcinoma are largely unknown. The aim of this study was to assess the effect of HCV core protein on proliferation and apoptosis of hilar cholangiocarcinoma. METHODS: HCV core protein (HCV C protein) was de- tected by peroxidase-antiperoxidase assay in surgical speci- mens from 48 patients with hilar cholangiocarcinoma. The apoptosis index ( AI) and PCNA index ( PI) in hilar cholangiocarcinoma were detected by in situ end labeling assay and streptavidin-biotin assay respectively. RESULTS: The expression of HCV C protein was observed in 32 (67.7%) of the 48 specimens of hilar cholangiocarci- noma. The mean ± standard deviation for AI and PI was 3.52%±0.64% and 46.24%±11.46% respectively. The AI of hilar cholangiocarcinoma specimens with HCV C protein expression was significantly lower than that of HCV C pro- tein negative specimens (P<0.01), whereas the PI of HCV C protein positive specimens was significantly higher than that of HCV C protein negative specimens (P<0.01). CONCLUSION: HCV C protein may promote the cellular proliferation of hilar cholangiocarcinoma and inhibit its cel- lular apoptosis.展开更多
Hepatitis C virus(HCV)is a major cause of chronic liver diseases,including steatosis,cirrhosis and hepatocellular carcinoma,and its infection is also associated with insulin resistance and type 2 diabetes mellitus.HCV...Hepatitis C virus(HCV)is a major cause of chronic liver diseases,including steatosis,cirrhosis and hepatocellular carcinoma,and its infection is also associated with insulin resistance and type 2 diabetes mellitus.HCV,belonging to the Flaviviridae family,is a small enveloped virus whose positive-stranded RNA genome encoding a polyprotein.The HCV core protein is cleaved first at residue 191 by the host signal peptidase and further cleaved by the host signal peptide peptidase at about residue 177 to generate the mature core protein(a.a.1-177)and the cleaved peptide(a.a.178-191).Core protein could induce insulin resistance,steatosis and even hepatocellular carcinoma through various mechanisms.The peptide(a.a.178-191)may play a role in the immune response.The polymorphism of this peptide is associated with the cellular lipid drop accumulation,contributing to steatosis development.In addition to the conventional open reading frame(ORF),in the+1 frame,an ORF overlaps with the core proteincoding sequence and encodes the alternative reading frame proteins(ARFP or core+1).ARFP/core+1/F protein could enhance hepatocyte growth and may regulate iron metabolism.In this review,we briefly summarized the current knowledge regarding the production of different core gene products and their roles in viral pathogenesis.展开更多
AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cell...AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.展开更多
OBJECTIVE: To establish a mouse model of HCV core expression and investigate the toxicity of HCV core protein or the possible pathogenic effects. METHODS: A series of vaccinia viral expression vectors were engineered ...OBJECTIVE: To establish a mouse model of HCV core expression and investigate the toxicity of HCV core protein or the possible pathogenic effects. METHODS: A series of vaccinia viral expression vectors were engineered to express 5' portion of HCV genes including 5' non-translated region (NTR), core protein, and portion of the E1 gene. These HCV sequences were fused to a luciferase reporter gene and inserted into a vaccinia virus expression vector (pSC11) adjacent to the vaccinia virus promoter, p7.5. The recombinant DNA constructs were packed into infectious recombinant chimeric viruses. The expression of HCV core protein was examined in cultured cells after infection with these viruses. Death of the infected mice was investigated by specific correlation to the expression of HCV core protein and its expression levels. RESULTS: The recombinant virus (VNCE-LUA) expressed HCV core protein and an envelope-luciferase fusion protein in cultured cells. When Balb/c mice were inoculated intraperitoneally with more than 10~7 pfu per mouse of VNCE-LUA, death occurred immediately. The mortality was dependent on the amount of VNCE-LUA virus inoculated. All mice inoculated with 3×10~8 pfu of VNCE-LUA died within 4 days of infection and 50% of mice inoculated with 3×10~7 pfu of VNCE-LUA died within 7 days of infection. No death occurred in mice inoculated with 3×10~8 pfu of a control recombinant vaccinia virus, which expressed luciferase but not the HCV core and envelope proteins. Deletion of core sequences from VNCE-LUA rapidly reduced the mortality of infected mice whereas deletion of envelope sequence did not. SCID mice infected with VNCE-LUA died 2-3 days after infection, suggesting that the HCV-core induced mortality is not dependent on host T-or B-cell responses to core protein. CONCLUSIONS: HCV core protein can be lethal to mice when expressed in vivo and this specific lethality is independent of T-cells or B-cells. The findings and model itself provide a useful tool for further investigation on potential pathological effects as well as the potential toxicity of the HCV core protein.展开更多
Hepatocellular carcinoma(HCC) is the fifth most common cancer, and hepatitis C virus(HCV) infection plays a major role in HCC development. The molecular mechanisms by which HCV infection leads to HCC are varied. HCV c...Hepatocellular carcinoma(HCC) is the fifth most common cancer, and hepatitis C virus(HCV) infection plays a major role in HCC development. The molecular mechanisms by which HCV infection leads to HCC are varied. HCV core protein is an important risk factor in HCV-associated liver pathogenesis and can modulate several signaling pathways involved in cell cycle regulation, cell growth promotion, cell proliferation, apoptosis, oxidative stress and lipid metabolism. The dysregulation of signaling pathways such as transforming growth factor β(TGF-β), vascular endothelial growth factor(VEGF), Wnt/β-catenin(WNT), cyclooxygenase-2(COX-2) and peroxisome proliferator-activated receptor α(PPARα) by HCV core protein is implicated in the development of HCC. Therefore, it has been suggested that this protein be considered a favorable target for further studies in the development of HCC. In addition, considering the axial role of these signaling pathways in HCC, they are considered druggable targets for cancer therapy. Therefore, using strategies to limit the dysregulation effects of core protein on these signaling pathways seems necessary to prevent HCV-related HCC.展开更多
文摘化工、纺织印染与农药化肥等产业的蓬勃发展推动着人类社会的进步,但同时也给环境治理带来了巨大难题。目前,光催化降解局限于在特定波长下针对单一有机污染物进行降解,然而现实中的情况往往更复杂。因此,开发一种多功能光催化材料用于光催化降解不同有机污染物显得尤为重要。采用一步无模板溶剂热法合成了核壳结构的C-TiO_(2)复合材料前驱体,并在氩气气氛下煅烧得到高结晶度的C-TiO_(2)复合光催化材料。运用SEM、TEM、XRD和TG等表征手段对材料进行表征,结论如下:550℃煅烧时的样品为包含少量碳的高结晶度的锐钛矿相TiO 2,且550℃煅烧时的样品依然保持了完整的核壳结构。此外,C-TiO_(2)复合材料的比表面积高达85.69 m 2·g^(-1),平均孔径为16.4 nm以及孔体积为0.423 m 3·g^(-1)。在UV-Vis光照射下,C-TiO_(2)复合材料分别对罗丹明B(RhB)、亚甲基蓝(MB)和刚果红(CR)3种染料显示出增强的光催化降解活性。
文摘BACKGROUND: Hepatitis C virus (HCV) is believed to be an important human pathogen causing carcinoma. But the effect of HCV infection on the alteration of cellular pro- liferation and apoptosis and the relationship between the effect and the development of hilar cholangiocarcinoma are largely unknown. The aim of this study was to assess the effect of HCV core protein on proliferation and apoptosis of hilar cholangiocarcinoma. METHODS: HCV core protein (HCV C protein) was de- tected by peroxidase-antiperoxidase assay in surgical speci- mens from 48 patients with hilar cholangiocarcinoma. The apoptosis index ( AI) and PCNA index ( PI) in hilar cholangiocarcinoma were detected by in situ end labeling assay and streptavidin-biotin assay respectively. RESULTS: The expression of HCV C protein was observed in 32 (67.7%) of the 48 specimens of hilar cholangiocarci- noma. The mean ± standard deviation for AI and PI was 3.52%±0.64% and 46.24%±11.46% respectively. The AI of hilar cholangiocarcinoma specimens with HCV C protein expression was significantly lower than that of HCV C pro- tein negative specimens (P<0.01), whereas the PI of HCV C protein positive specimens was significantly higher than that of HCV C protein negative specimens (P<0.01). CONCLUSION: HCV C protein may promote the cellular proliferation of hilar cholangiocarcinoma and inhibit its cel- lular apoptosis.
基金Supported by Grants from the National Science Council of Taiwan,NSC 101-2320-B-320-011 to Lo SYfrom the Tzu Chi University,TCMRC-P-101015 and TCRPP101017 to Li HC and Lo SY
文摘Hepatitis C virus(HCV)is a major cause of chronic liver diseases,including steatosis,cirrhosis and hepatocellular carcinoma,and its infection is also associated with insulin resistance and type 2 diabetes mellitus.HCV,belonging to the Flaviviridae family,is a small enveloped virus whose positive-stranded RNA genome encoding a polyprotein.The HCV core protein is cleaved first at residue 191 by the host signal peptidase and further cleaved by the host signal peptide peptidase at about residue 177 to generate the mature core protein(a.a.1-177)and the cleaved peptide(a.a.178-191).Core protein could induce insulin resistance,steatosis and even hepatocellular carcinoma through various mechanisms.The peptide(a.a.178-191)may play a role in the immune response.The polymorphism of this peptide is associated with the cellular lipid drop accumulation,contributing to steatosis development.In addition to the conventional open reading frame(ORF),in the+1 frame,an ORF overlaps with the core proteincoding sequence and encodes the alternative reading frame proteins(ARFP or core+1).ARFP/core+1/F protein could enhance hepatocyte growth and may regulate iron metabolism.In this review,we briefly summarized the current knowledge regarding the production of different core gene products and their roles in viral pathogenesis.
基金Supported by Medical Specialty Development Projects of Beijing Municipal Administration of Hospitals,No.ZYLX201402Ministry of Education of The People’s Republic of China,No.20121107110012+1 种基金Beijing Municipal Commission of Education,No.11320016Collaborative Innovation Center of Infectious Diseases and Beijing Key Laboratory of Emerging Infectious Diseases,Beijing,China
文摘AIM: To investigate the molecular mechanism for regulation of cholesterol metabolism by hepatitis C virus(HCV) core protein in Hep G2 cells.METHODS: HCV genotype 1b core protein was cloned and expressed in Hep G2 cells. The cholesterol content was determined after transfection. The expression of sterol regulatory element binding protein 2(SREBP2) and the rate-limiting enzyme in cholesterol synthesis(HMGCR) was measured by quantitative real-time PCR and immunoblotting after transfection. The effects of core protein on the SREBP2 promoter and 3'-untranslated region were analyzed by luciferase assay. We used different target predictive algorithms, micro RNA(mi RNA) mimics/inhibitors, and site-directed mutation to identify a putative target of a particular mi RNA.RESULTS: HCV core protein expression in Hep G2 cells increased the total intracellular cholesterol level(4.05 ± 0.17 vs 6.47 ± 0.68, P = 0.001), and this increase corresponded to an increase in SREBP2 and HMGCR m RNA levels(P = 0.009 and 0.037, respectively) and protein expression. The molecular mechanism studyrevealed that the HCV core protein increased the expression of SREBP2 by enhancing its promoter activity(P = 0.004). In addition, mi R-185-5p expression was tightly regulated by the HCV core protein(P = 0.041). Moreover, overexpression of mi R-185-5p repressed the SREBP2 m RNA level(P = 0.022) and protein expression. In contrast, inhibition of mi R-185-5p caused upregulation of SREBP2 protein expression. mi R-185-5p was involved in the regulation of SREBP2 expression by HCV core protein. CONCLUSION: HCV core protein disturbs the cholesterol homeostasis in Hep G2 cells via the SREBP2 pathway; mi R-185-5p is involved in the regulation of SREBP2 by the core protein.
文摘OBJECTIVE: To establish a mouse model of HCV core expression and investigate the toxicity of HCV core protein or the possible pathogenic effects. METHODS: A series of vaccinia viral expression vectors were engineered to express 5' portion of HCV genes including 5' non-translated region (NTR), core protein, and portion of the E1 gene. These HCV sequences were fused to a luciferase reporter gene and inserted into a vaccinia virus expression vector (pSC11) adjacent to the vaccinia virus promoter, p7.5. The recombinant DNA constructs were packed into infectious recombinant chimeric viruses. The expression of HCV core protein was examined in cultured cells after infection with these viruses. Death of the infected mice was investigated by specific correlation to the expression of HCV core protein and its expression levels. RESULTS: The recombinant virus (VNCE-LUA) expressed HCV core protein and an envelope-luciferase fusion protein in cultured cells. When Balb/c mice were inoculated intraperitoneally with more than 10~7 pfu per mouse of VNCE-LUA, death occurred immediately. The mortality was dependent on the amount of VNCE-LUA virus inoculated. All mice inoculated with 3×10~8 pfu of VNCE-LUA died within 4 days of infection and 50% of mice inoculated with 3×10~7 pfu of VNCE-LUA died within 7 days of infection. No death occurred in mice inoculated with 3×10~8 pfu of a control recombinant vaccinia virus, which expressed luciferase but not the HCV core and envelope proteins. Deletion of core sequences from VNCE-LUA rapidly reduced the mortality of infected mice whereas deletion of envelope sequence did not. SCID mice infected with VNCE-LUA died 2-3 days after infection, suggesting that the HCV-core induced mortality is not dependent on host T-or B-cell responses to core protein. CONCLUSIONS: HCV core protein can be lethal to mice when expressed in vivo and this specific lethality is independent of T-cells or B-cells. The findings and model itself provide a useful tool for further investigation on potential pathological effects as well as the potential toxicity of the HCV core protein.
文摘Hepatocellular carcinoma(HCC) is the fifth most common cancer, and hepatitis C virus(HCV) infection plays a major role in HCC development. The molecular mechanisms by which HCV infection leads to HCC are varied. HCV core protein is an important risk factor in HCV-associated liver pathogenesis and can modulate several signaling pathways involved in cell cycle regulation, cell growth promotion, cell proliferation, apoptosis, oxidative stress and lipid metabolism. The dysregulation of signaling pathways such as transforming growth factor β(TGF-β), vascular endothelial growth factor(VEGF), Wnt/β-catenin(WNT), cyclooxygenase-2(COX-2) and peroxisome proliferator-activated receptor α(PPARα) by HCV core protein is implicated in the development of HCC. Therefore, it has been suggested that this protein be considered a favorable target for further studies in the development of HCC. In addition, considering the axial role of these signaling pathways in HCC, they are considered druggable targets for cancer therapy. Therefore, using strategies to limit the dysregulation effects of core protein on these signaling pathways seems necessary to prevent HCV-related HCC.
