The effects of angiotensin Ⅱ on the synthesis of albumin and type Ⅰ collagen in human hepatic cells

Objective To investigate the effects of angiotensin Ⅱ (AngⅡ) on the expression of albumin and the synthesis of type Ⅰ collagen in human normal hepatic cells. Methods HL-7702 cells (human normal hepatocyte) were cultured and divided into control group, Ang Ⅱ treated group, an AngⅡ+irbesartan (co-stimulated) group. The expressions of albumin and type Ⅰ collagen were detected by immunofluorescence and Western blotting, respectively. The mRNA level of type Ⅰ collagen was measured by real time-PCR(qRT-PCR). Results After stimulated with 10-7 mol/L Ang Ⅱ for 72 hours, the expression of albumin significantly decreased in Ang Ⅱ treated group compared with control group (0.85±0.11 vs 1. 41±0.23,P=0.000), while the mRNA expression increased in AngⅡ treated group compared with control group (1.00±0.08 vs 3.72±0.19,P=0.000). In costimulated group, however, the expression of albumin significantly increased (0.85 ± 0.11 vs 1.38 ±0.32,P=0.000),and mRNA expression (3. 72±0.19 vs 2.86±0.13,P=0.000) and synthesis of type Ⅰ collagen were reduced when compared with Ang Ⅱ treated group. Conclusions The reduction of albumin and elevated systhesis of type Ⅰ collagen in HL-7702 cells are induced via Ang Ⅱ AT1 receptor.     

The effects of angiotensin Ⅱ on the synthesis of albumin and type Ⅰ collagen in human hepatic cells

Objective To investigate the effects of angiotensin Ⅱ (AngⅡ) on the expression of albumin and the synthesis of type Ⅰ collagen in human normal hepatic cells. Methods HL-7702 cells (human normal hepatocyte) were cultured and divided into control group, Ang Ⅱ treated group, an AngⅡ+irbesartan (co-stimulated) group. The expressions of albumin and type Ⅰ collagen were detected by immunofluorescence and Western blotting, respectively. The mRNA level of type Ⅰ collagen was measured by real time-PCR(qRT-PCR). Results After stimulated with 10-7 mol/L Ang Ⅱ for 72 hours, the expression of albumin significantly decreased in Ang Ⅱ treated group compared with control group (0.85±0.11 vs 1. 41±0.23,P=0.000), while the mRNA expression increased in AngⅡ treated group compared with control group (1.00±0.08 vs 3.72±0.19,P=0.000). In costimulated group, however, the expression of albumin significantly increased (0.85 ± 0.11 vs 1.38 ±0.32,P=0.000),and mRNA expression (3. 72±0.19 vs 2.86±0.13,P=0.000) and synthesis of type Ⅰ collagen were reduced when compared with Ang Ⅱ treated group. Conclusions The reduction of albumin and elevated systhesis of type Ⅰ collagen in HL-7702 cells are induced via Ang Ⅱ AT1 receptor.     

Inhibition effect of captopril and losartan on expression of matrix metalloproteinase-1,-9 induced by angiotensin Ⅱ in rat vascular smooth muscle cells

Objective To investigate the effect of angiotensin converting enzyme inhibitor (ACEI) captopril and angiotensin Ⅱ receptor antagonist losartan on the mRNA expression of matrix metalloproteinase (MMP)-1 and MMP-9 in vascular smooth muscle cells induced by angiotensin Ⅱ (Ang Ⅱ ).Methods Male Wistar rats' thoracic aortic vascular smooth muscle cells were cultured in vitro.The cultured cells were divided in to control group,Ang Ⅱ group,captopril group,losartan group,and captopril plus losartan group.Cells in all groups were collected at the culture end-point.MMP-1 and MMP-9 mRNA expressions were detected by RT-PCR method in the collected specimens,and the effects of Ang Ⅱ on MMP-1 and MMP-9 mRNA expression and the intervention effects of captopril and losartan were observed in different Ang Ⅱ concentrations and different action times to vascular smooth muscle cells.Results ( 1 ) MMP-1 mRNA expression gradually increased along with the increments of Ang Ⅱ concentration and the action time (P＜0.05),and the most significant concentration was 10-6 mol/L (P＜0.01).(2)Captopril (5 × 10-6 mol/L) and losartan (5 × 10-6mol/L) inhibited the action of AngⅡ (P＜0.05,P＜0.01).MMP-9 mRNA expression was 0.47±0.03 ,0.86 ± 0.04,0.94±0.14 and 1.12±0.19 vs.0.10±0.04 (P＜0.05,P＜0.01) respectively when Ang Ⅱ concentration was 10-7 ,10-6 ,10-5 and 10-4 mol/L respectively.Captopril (5 × 10-6mol/L) and losartan (5 × 10-6 mol/I) significantly inhibited the MMP-9 mRNA expression which was stimulated by Ang Ⅱ (P＜0.05,P＜0.01),especially in captopril plus losartan group.The MMP-9 mRNA expression increased with the prolonging of stimulating time of Ang Ⅱ,MMP-9 mRNA expression was earlier than that of MMP-1.Conclusions AngⅡ increases the expression of MMP-1 and MMP-9 of vascular smooth muscle cells in a dose-and time-dependence manner.Captopril and losartan inhibit the MMP-1 and MMP-9 mRNA expression of vascular smooth muscle cells induced by Ang Ⅱ ,and the inhibition is the strongest when losartan was combined with captopril.The inhibitive effects is positively correlated to action time.     

Inhibition effect of captopril and losartan on expression of matrix metalloproteinase-1,-9 induced by angiotensin Ⅱ in rat vascular smooth muscle cells

Objective To investigate the effect of angiotensin converting enzyme inhibitor (ACEI) captopril and angiotensin Ⅱ receptor antagonist losartan on the mRNA expression of matrix metalloproteinase (MMP)-1 and MMP-9 in vascular smooth muscle cells induced by angiotensin Ⅱ (Ang Ⅱ ).Methods Male Wistar rats' thoracic aortic vascular smooth muscle cells were cultured in vitro.The cultured cells were divided in to control group,Ang Ⅱ group,captopril group,losartan group,and captopril plus losartan group.Cells in all groups were collected at the culture end-point.MMP-1 and MMP-9 mRNA expressions were detected by RT-PCR method in the collected specimens,and the effects of Ang Ⅱ on MMP-1 and MMP-9 mRNA expression and the intervention effects of captopril and losartan were observed in different Ang Ⅱ concentrations and different action times to vascular smooth muscle cells.Results ( 1 ) MMP-1 mRNA expression gradually increased along with the increments of Ang Ⅱ concentration and the action time (P＜0.05),and the most significant concentration was 10-6 mol/L (P＜0.01).(2)Captopril (5 × 10-6 mol/L) and losartan (5 × 10-6mol/L) inhibited the action of AngⅡ (P＜0.05,P＜0.01).MMP-9 mRNA expression was 0.47±0.03 ,0.86 ± 0.04,0.94±0.14 and 1.12±0.19 vs.0.10±0.04 (P＜0.05,P＜0.01) respectively when Ang Ⅱ concentration was 10-7 ,10-6 ,10-5 and 10-4 mol/L respectively.Captopril (5 × 10-6mol/L) and losartan (5 × 10-6 mol/I) significantly inhibited the MMP-9 mRNA expression which was stimulated by Ang Ⅱ (P＜0.05,P＜0.01),especially in captopril plus losartan group.The MMP-9 mRNA expression increased with the prolonging of stimulating time of Ang Ⅱ,MMP-9 mRNA expression was earlier than that of MMP-1.Conclusions AngⅡ increases the expression of MMP-1 and MMP-9 of vascular smooth muscle cells in a dose-and time-dependence manner.Captopril and losartan inhibit the MMP-1 and MMP-9 mRNA expression of vascular smooth muscle cells induced by Ang Ⅱ ,and the inhibition is the strongest when losartan was combined with captopril.The inhibitive effects is positively correlated to action time.     

Inhibition effect of captopril and losartan on expression of matrix metalloproteinase-1,-9 induced by angiotensin Ⅱ in rat vascular smooth muscle cells

Objective To investigate the effect of angiotensin converting enzyme inhibitor (ACEI) captopril and angiotensin Ⅱ receptor antagonist losartan on the mRNA expression of matrix metalloproteinase (MMP)-1 and MMP-9 in vascular smooth muscle cells induced by angiotensin Ⅱ (Ang Ⅱ ).Methods Male Wistar rats' thoracic aortic vascular smooth muscle cells were cultured in vitro.The cultured cells were divided in to control group,Ang Ⅱ group,captopril group,losartan group,and captopril plus losartan group.Cells in all groups were collected at the culture end-point.MMP-1 and MMP-9 mRNA expressions were detected by RT-PCR method in the collected specimens,and the effects of Ang Ⅱ on MMP-1 and MMP-9 mRNA expression and the intervention effects of captopril and losartan were observed in different Ang Ⅱ concentrations and different action times to vascular smooth muscle cells.Results ( 1 ) MMP-1 mRNA expression gradually increased along with the increments of Ang Ⅱ concentration and the action time (P＜0.05),and the most significant concentration was 10-6 mol/L (P＜0.01).(2)Captopril (5 × 10-6 mol/L) and losartan (5 × 10-6mol/L) inhibited the action of AngⅡ (P＜0.05,P＜0.01).MMP-9 mRNA expression was 0.47±0.03 ,0.86 ± 0.04,0.94±0.14 and 1.12±0.19 vs.0.10±0.04 (P＜0.05,P＜0.01) respectively when Ang Ⅱ concentration was 10-7 ,10-6 ,10-5 and 10-4 mol/L respectively.Captopril (5 × 10-6mol/L) and losartan (5 × 10-6 mol/I) significantly inhibited the MMP-9 mRNA expression which was stimulated by Ang Ⅱ (P＜0.05,P＜0.01),especially in captopril plus losartan group.The MMP-9 mRNA expression increased with the prolonging of stimulating time of Ang Ⅱ,MMP-9 mRNA expression was earlier than that of MMP-1.Conclusions AngⅡ increases the expression of MMP-1 and MMP-9 of vascular smooth muscle cells in a dose-and time-dependence manner.Captopril and losartan inhibit the MMP-1 and MMP-9 mRNA expression of vascular smooth muscle cells induced by Ang Ⅱ ,and the inhibition is the strongest when losartan was combined with captopril.The inhibitive effects is positively correlated to action time.     

Effects of different levels of iodine concentration on insulin-like growth factors Ⅰ mRNA expression of thyroid and breast in lactating rats

Objective To study the effects of different levels of iodine concentration on insulin-like growth factors Ⅰ (IGF-1) mRNA expression of thyroid and breast in lactating rats. Methods Thirty Wistar female rats, having been weaned for 1 month, were randomly divided into three groups according to their body weights, i. e. :low iodine(LI) group,adequate iodine(AI) group, high iodine(HI) group, 10 rats in each group. Synthetic fodder and deionized water containing iodine of 0,150,3000 μg/L was respectively fed to these rats. After fed for 3 months, the rats mated and had offspring. Their mammary glands, thyroids and serum were sampled at lactation day 5. The serum iodine of lactating rats were determined by moderate acid digestion method, level of T3 and T4 were determined by radioimmunoassay method, and the expressions of IGF-1 mRNA of mammary glands and thyroids were determined by real-time fluorescence quantitative PCR assay. Results The value of serum iodine of LI group [(17.38±3.27) μg/L] was lower than that of AI group [(43.42±6.92) μg/L, P<0.05], and the value of serum iodine of HI group[(350.10±38.46)μg/L] was higher than that of AI group (P<0.05). The level of T3 of LI group and HI group[ (1.11±0.25), (1.61±0.33)μg/L] reduced obviously compared with that of AI group[(2.18±0.46) μg/L, P<0.05]. The mean of T4 of LI group and HI group[(33.40±11.11),(56.54±10.38)μg/L] had no statistical significance compared with AI group(44.02±12.51)μg/L, P>0.05), but the level of T4 of LI group was lower than that of HI group(P<0.05). The level of IGF-1 mRNA expression of thyroid in LI group and HI group (0.34±0.08, 0.23±0.08) was higher than that of AI group(0.15±0.03, P<0.05). The level of IGF-1 mRNA expression of lactating mammary in LI group(0.59±0.18) was higher than that of AI group(0.40±0.10, P<0.05). The level of IGF-1 mRNA expression of thyroid was lower than that of breast between the same group(t=3.54, 6.44,2.62, all P<0.05). Conclusion Iodine could affect IGF-1 mRNA expression of thyroid and lactating mammary, and IGF-1 mRNA expression of lactating mammary was stronger than that of the thyroid.     

Effects of augmentation of liver regeneration recombinant plasmid on rat hepatic fibrosis

AIM: To investigate the effects of eukaryotic expression of plasmid on augmentation of liver regeneration (ALR) in rat hepatic fibrosis and to explore their mechanisms. METHODS: Ten rats were randomly selected from 50 Wistar rats as normal control group. The rest were administered intraperitoneally with porcine serum twice weekly. After 8 wk, they were randomly divided into: model control group, colchicine group (Col), first ALR group (ALR1), second ALR group (ALR2). Then colchicine ALR recombinant plasmid were used to treat them respectively. At the end of the 4th wk, rats were killed. Serum indicators were detected and histopathological changes were graded. Expression of type Ⅰ, Ⅲ, collagen and TIMP-1 were detected by immunohisto-chemistry and expression of TIMP-1 mRNA was detected by semi-quantified RT-PCR. RESULTS: The histologic examination showed that the degree of the rat hepatic fibrosis in two ALR groups was lower than those in model control group. Compared with model group, ALR significantly reduced the serum levels of ALT, AST, HA, LN, PCIII and IV (P<0.05). Immunohistochemical staining showed that expression of type Ⅰ, Ⅲ, collagen and TIMP-1 in two ALR groups was ameliorated dramatically compared with model group (I collagen: 6.94±1.42,5.80±1.66 and 10.83±3.58 in ALR1, ALR2 and model groups, respectively; Ⅲ collagen: 7.18±1.95, 4.50±1.67 and 10.25±2.61, respectively; TIMP-1: 0.39±0.05,0.20±0.06 and 0.53±0.12, respectively,P<0.05 or P<0.01). The expression level of TIMP-1 mRNA in the liver tissues was markedly decreased in two ALR groups compared with model group (TIMP-1 mRNA/β-actin: 0.89±0.08, 0.65±0.11 and 1.36±0.11 in ALR1, ALR2 and model groups respectively, P<0.01). CONCLUSION: ALR recombinant plasmid has beneficial effects on rat hepatic fibrosis by enhancing regeneration of injured liver cells and inhibiting TIMP-1 expressions.     

Effect of levocarnitine on TIMP-1,ICAM-1 expression of rats with coronary heart disease and its myocardial protection effect

Objective:To study the effect of levocarnitine(L-CN) on tissue inhibitor of metalloproteinase-1(TIMP-1) and intercellular adhesion molecule-1(ICAM-1) expression of rats with coronary heart disease and evaluate the protective effect of L-CN on myocardial cells.Methods:Highfat diet feeding and intraperitoneal injection of pituitrin was performed on rats in model group and CHD Model of rats was built.Rats with successful model-building were selected and divided into L-CN group and Ctrl group randomly.Rats in L-CN group were given L-CN treatment,with intraperitoneal injection of 200 mg·kg~(-1)?d~(-1) and successive administration for 3 d.Rats in Ctrl group were given equal volumes of normal saline.Blood was collected from carotid artery at different time and expression quantity of creatine kinase-MB(CK-MB) and Troponin Ⅰ(Tn Ⅰ)in serum was detected.Rats in each group were put to death and were separated to obtain the myocardial tissue.Real-time PCR and Western Blotting hybridization were performed to detect the TIMP-1.ICAM-1 expression in myocardial tissue in each group.Statistical analysis was employed to explore the expression changes of TIMP-1 and ICAM-1.and ELISA test was used lo analyse the expression changes of myocardial necrosis marker- CK-MB and Tn I to learn the effect of L-CN and its myocardial protective effect.Results:The total cholesterol,triglyceride and blood glucose levels of rats in model group were significantly higher than that in control group,which indicated that due to high-fat diet feeding,blood lipid of rats in model group was obviously higher than that in control group.In myocardial tissue of rats in model group,TIMP-I level significantly reduced and ICAM-1 level significantly increased(P0.0l).In model group,after L-CN treatment.TTMP-I level had double increase,while ICAM-1 level had 43%of decrease in L-CN group compared with Ctrl group.After L-CN intervention treatment.CK-MB and Tn Ⅰ content in L-CN group relatively reduced compared with Ctrl group.The difference among groups was obvious(P0.01).Condusions:L-CN could increase the TTMP-I expression level and inhibit the ICAM-1 expression level.L-CN has a certain myocardial protective effect     

Effect of endogenous insulin-like growth factor and stem cell factor on diabetic colonic dysmotility

AIM: To investigate whether the reduction of stem cell factor (SCF) is mediated by decreased endogenous insulin-like growth factor (IGF)-1 in diabetic rat colon smooth muscle. METHODS: Sixteen Sprague-Dawley rats were randomly divided into two groups: control group and streptozotocin-induced diabetic group. After 8 wk of streptozotocin administration, colonic motility function and contractility of circular muscle strips were measured. The expression of endogenous IGF-1 and SCF was tested in colonic tissues. Colonic smooth muscle cells were cultured from normal adult rats. IGF-1 siRNA transfection was used to investigate whether SCF expression was affected by endogenous IGF-1 expression in smooth muscle cells, and IGF-1 induced SCF expression effects were studied. The effect of high glucose on the expression of endogenous IGF-1 and SCF was also investigated. RESULTS: Diabetic rats showed prolonged colonic transit time (252 ± 16 min vs 168 ± 9 min, P < 0.01) and weakness of circular muscle contraction (0.81 ± 0.09 g vs 2.48 ± 0.23 g, P < 0.01) compared with the control group. Endogenous IGF-1 and SCF protein expression was significantly reduced in the diabetic colonic muscle tissues. IGF-1 and SCF mRNA expression also showed a paralleled reduction in diabetic rats. In the IGF-1 siRNA transfected smooth muscle cells, SCF mRNA and protein expression was significantly decreased. IGF-1 could induce SCF expression in a concentration and time-dependent manner, mainly through the extracellular-signal-regulated kinase 1/2 signal pathway. High glucose inhibited endogenous IGF-1 and SCF expression and the addition of IGF-1 to the medium reversed the SCF expression. CONCLUSION: Myopathy may resolve in colonic motility dysfunction in diabetic rats. Deficiency of endogenous IGF-1 in colonic smooth muscle cells leads to reduction of SCF expression.     

Effects of Ang Ⅱ perfusion on transmural heterogeneous of Cx43 in acute myocardial ischemia reperfusion

Objective:To observe the effects of angiotensin Ⅱ(Ang Ⅱ) pefusion on transmural heterogeneity of Cx43 expression in the rabbit model with acute myocardial ischemia reperfusion(MIR),and investigate the role of rennin-angiotensin system in malignant ventricular arrhythmia induced by MIR.Methods:Twenty rabbits were randomly divided into MIR group(n=10) and Ang Ⅱ group(n=10).MIR model was produced with traditional ligation and opening of the anterior descending coronary artery in all animal.The hearts in vitro in the MIR group and the Ang Ⅱ group were perfused with simply improved Tyrode's solution and containing Ang Ⅱ Tyrode's solution respectively.90%monophasic action potential repolarization duration,transmural dispersion of repolarization.Cx43 protein(Cx43-pro) and mRNA(Cx43-Cq) expression in subepicardial,midmyocardial and subendocardial myocardium were measured in both groups.The greatest differences of Cx43-pro and Cx43-Cq among three myocardial layers were calculated and shown with △Cx43-pro and △Cx43-Cq respectively.Results:After Ang Ⅱ perfusion,90%monophasic action potential repolarization duration among three myocardial layer were significantly prolonged(P 0.05 and P 0.01),and transmural dispersion of repolarization also significantly increased compared with the MIR group(P 0.05).Compare with the MIR group,three myocardial Cx43-pro and Cx43-Cq expression in the Ang Ⅱ group were significantly decreased(P 0.05 and P 0.01).but△Cx43-pro and △Cx43-Cq were significant increased.Conclusions:Renin-angiotensin system increases transmural heterogeneity of Cx43 expression in the rabbit model with MIR by Ang Ⅱ,and enlarge transmural dispersion of repolarization among three myocardial layers of left ventricular which induces malignant ventricular arrhythmia.     

1-Naphthyl isocyanate and 1-naphthylamine as metabolites of 1-naphthylisothiocyanate

Abstract: The importance of the bioactivation of 1-naphthylisothiocyanate was studied. Forty minutes after 1-naphthylisothiocyanate administration to rats, bile was collected over a 2.5-h period; the liver was then excised and homogenized. 1-naphthylisothiocyanate and its metabolites in bile and liver of rats were identified and quantified using coupled gas chromatography-mass spectrometry. Three main compounds were found in all 1-naphthylisothiocyanate-treated animals. They were identified as 1-naphthyl isocyanate, 1-naphthylamine and the parent compound, 1-naphthylisothiocyanate. When rats were given cycloheximide, which attenuates 1-naphthylisothiocyanate toxicity, 30 min before 1-naphthylisothiocyanate (300 mg/kg), 1-naphthyl isocyanate concentration was significantly lower than in rats receiving only 1-naphthylisothiocyanate. The appearance of 1-naphthylamine was also inhibited by cycloheximide, although not to the same extent as 1-naphthyl isocyanate. On the other hand, phenobarbital, which potentiates 1-naphthylisothiocyanate hepatotoxicity, enhanced 1-naphthyl isocyanate and 1-naphthylamine formation. It is suggested that 1-naphthyl isocyanate, 1-naphthylamine and the highly reactive sulfur released from 1-naphthylisothiocyanate might be involved in the hepatotoxic effect of 1-naphthylisothiocyanate.     

The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1)

Ezetimibe is a potent inhibitor of cholesterol absorption that has been approved for the treatment of hypercholesterolemia, but its molecular target has been elusive. Using a genetic approach, we recently identified Niemann-Pick C1-Like 1 (NPC1L1) as a critical mediator of cholesterol absorption and an essential component of the ezetimibe-sensitive pathway. To determine whether NPC1L1 is the direct molecular target of ezetimibe, we have developed a binding assay and shown that labeled ezetimibe glucuronide binds specifically to a single site in brush border membranes and to human embryonic kidney 293 cells expressing NPC1L1. Moreover, the binding affinities of ezetimibe and several key analogs to recombinant NPC1L1 are virtually identical to those observed for native enterocyte membranes. KD values of ezetimibe glucuronide for mouse, rat, rhesus monkey, and human NPC1L1 are 12,000, 540, 40, and 220 nM, respectively. Last, ezetimibe no longer binds to membranes from NPC1L1 knockout mice. These results unequivocally establish NPC1L1 as the direct target of ezetimibe and should facilitate efforts to identify the molecular mechanism of cholesterol transport.     

Inhibition of procarcinogen-bioactivating human CYP1A1, CYP1A2 and CYP1B1 enzymes by melatonin

Abstract:  Administration of melatonin to rodents decreases the incidence of tumorigenesis initiated by benzo[ a ]pyrene or 7,12-dimethylbenz[ a ]anthracene, which requires bioactivation by cytochrome P450 enzymes, such as CYP1A1, CYP1A2 and CYP1B1, to produce carcinogenic metabolites. The present study tested the hypothesis that melatonin is a modulator of human CYP1 catalytic activity and gene expression. As a comparison, we also investigated the effect of melatonin on the catalytic activity of CYP2A6, which is also a procarcinogen-bioactivating enzyme. Melatonin (3–300 μ m ) decreased 7-ethoxyresorufin O -dealkylation catalyzed by human hepatic microsomes and recombinant CYP1A1, CYP1A2 and CYP1B1, whereas it did not affect coumarin 7-hydroxylation catalyzed by hepatic microsomes or recombinant CYP2A6. Melatonin inhibited CYP1 enzymes by mixed inhibition, with apparent K _i values (mean ± S.E.M.) of 59 ± 1 (CYP1A1), 12 ± 1 (CYP1A2), 14 ± 2 (CYP1B1) and 46 ± 8 μ m (hepatic microsomes). Additional experiments indicated that melatonin decreased benzo[ a ]pyrene hydroxylation catalyzed by hepatic microsomes and CYP1A2 but not by CYP1A1 or CYP1B1. Treatment of MCF-10A human mammary epithelial cells with melatonin (up to 300 μ m ) did not affect basal or benzo[ a ]pyrene-inducible CYP1A1 or CYP1B1 gene expression. Consistent with this finding, melatonin did not influence reporter activity in aryl hydrocarbon receptor-dependent pGudluc6.1-transfected MCF-10A cells treated with or without benzo[ a ]pyrene, as assessed in an in vitro cell-based luciferase reporter gene assay. Overall, melatonin is an in vitro inhibitor of human CYP1 catalytic activity, and it may be useful to develop potent analogues of melatonin as potential cancer chemopreventive agents that block CYP1-mediated chemical carcinogenesis.     

甲型H1N1与季节性H1N1流感病毒血凝素基因比较分析

目的分析泰安市2008～2009年度季节性流感与2009年度甲型H1N1流感病原学检测结果 ,比较季节性H1N1与甲型H1N1血凝素基因变异情况。方法选择国家级流感监测哨点医院以及暴发疫情的疫点,采集流感样病例的鼻咽拭子标本,通过RealtimePCR进行病毒检测,用MDCK细胞进行病毒分离,通过RT-PCR扩增血凝素HA1片段的基因并测序,利用生物信息学进行序列分析。结果 2008～2009年共检测鼻咽拭子标本283份,分离出流感病毒33株,分离阳性率为11.67%,其中季节性H1N1亚型31株。2009年5月1日～12月31日,检测鼻咽拭子标本996份,流感核酸检测阳性417份,阳性率为41.86%,其中甲型H1N1337份,季节性H1N1亚型1份。6株季节性H1N1病毒均在多个氨基酸位点上发生变异,与疫苗株A/Brisbane/59/2007(H1N1)比较,有11个位点发生了突变,其中5个位点位于抗原决定簇上;测序成功的6株甲型H1N1病毒在多个氨基酸位点发生变异,与疫苗株A/California/07/2009(H1N1)比较,有6个位点发生突变,其中1个位点位于抗原决定簇的B区。结论 2008～2009年度季节性H1N1为优势株,甲流暴发后,甲型H1N1成为绝对优势毒株。季节性H1N1分离株有多处氨基酸替换,抗原决定簇B区变异频繁;甲型H1N1病毒分离株的基因有变异,但关键位点第222位仍为D(天冬氨酸),与疫苗株相比抗原决定簇的关键位点变化不大。