通讯机构：
[Tang, Chao-ke] U;Univ S China, Inst Cardiovasc Res, Hengyang 421001, Hunan, Peoples R China.
关键词：
liver x receptor;ABCA1;NPC1;T0901317;atherosclerosis
摘要：
Although a range of studies indicated Liver X receptor (LXR) activation inhibited the development of atherosclerosis in animal models, the mechanism of this effect for LXR agonists has not been fully understood. A recent study has suggested LXR activators increased the amount of free cholesterol in the plasma membrane of human macrophages by inducing Niemann-Pick type C1 (NPC1) gene expression. Therefore, we hypothesize that LXRs may also promote NPC1 expression in vivo. Here we investigated the effect of a synthetic LXR agonist T0901317 on ATP-binding cassette transporter A1 (ABCA1) and NPC1 in apolipoprotein E knockout (apoE−/−) mice. Male apoE−/− mice were randomized into four groups: baseline group (n = 10), vehicle group (n = 14), prevention group (n = 14), and treatment group (n = 14). En face analysis and Oil red O staining were used to examine the aortic atherosclerotic lesions. Macrophage content of aortic root atherosclerotic lesions and cholesterol efflux form peritoneal macrophages were measured. Gene and protein expression was analyzed by real-time quantitative polymerase chain reaction and Western blotting, respectively. T0901317 treatment reduced aortic atherosclerotic lesion area by 64.2% in prevention group (P < 0.001) and 58.3% in treatment group (P < 0.001) and resulted in a reduction in macrophage content. Plasma triglyceride, total cholesterol, high-density lipoprotein cholesterol, and apoA-I concentrations were markedly increased in T0901317-treated groups. T0901317 also promoted ABCA1 and NPC1 gene and protein levels in the aorta, liver, and small intestine of apoE−/− mice and significantly increased cholesterol efflux from peritoneal macrophages. T0901317 upregulates ABCA1 and NPC1. This study gives us a new insight into the mechanism for antiatherogenic effect of LXR synthetic agonists.
关键词：
familial hypercholesterolemia;LDL receptor;gene mutation;gene function
摘要：
Background: Familial hypercholesterolemia (FH), caused by low density lipoprotein (LDL) receptor (LDL-R) gene mutations, is associated with increased risk of premature coronary heart disease. Until now, limited molecular data concerning FH are available in China. The present study described the clinical profiles and cell biological defects of a Chinese FH kindred with novel LDL-R gene mutation. Methods: The patient's LDL-R gene coding region was sequenced. The patient's lymphocytes were isolated and the LDL-R expression, binding and up-take functions were observed by immunohistochemistry staining and flow cytometry detection. The patient's heart and the major large vessels were detected by vessel ultrasound examination and myocardial perfusion imaging (MPI). Results: The patient's LDL-R expression, LDL binding and up-take functions were significantly lower than normal control (39%, 63% and 76% respectively). A novel homozygous 1439 C→T mutation of the LDL-R gene was detected in the patient and his family. ECG showed atypical angina pectoris. Echocardiogram showed stenosis of the coronary artery and calcification of the aortic valve and its root. Blood vessel ultrasound examination showed the thickness of large vessel intima, and the vessel lumen was narrowed by 71%. MPI showed ischemic changes. Conclusions: The LDL-R synthesis dysfunction of FH patients leads to arterial stenosis and calcification, which are the major phenotype of the clinical disorder. The mutation of the LDL-R gene is determined. These data increase the mutational spectrum of FH in China.
作者机构：
[Yang, Ze Hua] Yiyang Med Coll, Dept Physiol, Yiyang, Peoples R China.;[Cui, Ya Lan; Cao, Shi Yun] Nanhua Univ, Coll Med, Dept Physiol, Hengyang, Peoples R China.
作者机构：
[Ye, Yan Ping; Yi, Guang Hui; Guo, Peng Cheng; Li, Xia; Feng, Jin Tao; Zeng, De Xing] Univ S China, Cardiovasc Res Inst, Hengyang City, Hunan, Peoples R China.;[Mo, Zhong Cheng; Long, Zhi Feng; Shi, Jin Feng] Univ S China, Dept Histol & Embryol, Hengyang City, Hunan, Peoples R China.
通讯机构：
[Wu, YM ] ;Univ S China, Pathogenic Biol Inst, Hengyang 421001, Peoples R China.
摘要：
This study was designed to investigate the molecular mechanisms responsible for the induction of proinflammatory cytokines gene expression and apoptosis in human monocytic cell line THP-1 stimulated by lipoproteins ( LPs) prepared from Mycoplasma genitalium. Cultured cells were stimulated with M. genitalium LP to analyze the production of proinflammatory cytokines and expression of their mRNA by ELISA and RT-PCR, respectively. Cell apoptosis was also detected by Annexin V-FITC-propidium iodide ( PI) staining and acridine orange ( AO)-ethidium bromide ( EB) staining. The DNA-binding activity of nuclear factor-kappa B ( NF-kappa B) was assessed by electrophoretic mobility shift assay ( EMSA). Results showed that LP stimulated THP-1 cells to produce tumor necrosis factor-alpha ( TNF-alpha), interleukin-1 beta ( IL-1 beta), and IL-6 in a dose-dependent manner. The mRNA levels were also upregulated in response to LP stimulation. LPs were also found to increase the DNA-binding activity of NF-kappa B, a possible mechanism for the induction of cytokine mRNA expression and the cell apoptosis. These effects were abrogated by PDTC, an inhibitor of NF-kappa B. Our results indicate that M. genitalium-derived LP may be an important etiological factor of certain diseases due to the ability of LP to produce proinflammatory cytokines and induction of apoptosis, which is probably mediated through the activation of NF-kappa B. Copyright (C) 2008 YimouWu et al.
摘要：
AIM: To isolate and analyze the DNA sequences which are methylated differentially between gastric cancer and normal gastric mucosa. METHODS: The differentially methylated DNA sequences between gastric cancer and normal gastric mucosa were isolated by methylation-sensitive representational difference analysis (MS-RDA). Similarities between the separated fragments and the human genomic DNA were analyzed with Basic Local Alignment Search Tool (BLAST). RESULTS: Three differentially methylated DNA sequences were obtained, two of which have been accepted by GenBank. The accession numbers are AY887106 and AY887107. AY887107 was highly similar to the 11th exon of LOC440683 (98%), 3' end of LOC440887 (99%), and promoter and exon regions of DRDS (94%). AY887106 was consistent (98%) with a CpG island in ribosomal RNA isolated from colorectal cancer by Minoru Toyota in 1999. CONCLUSION: The methylation degree is different between gastric cancer and normal gastric mucosa. The differentially methylated DNA sequences can be isolated effectively by MS-RDA. (c) 2008 WJG. All rights reserved.
摘要：
AIM: To investigate the effects of the sensitizer rosiglitazone on the proliferation of vascular smooth muscle cell (VSMC) induced by high glucose administration. METHODS: VSMCs were isolated from rat thoracic aortas and cultured in 10% fetal bovine serum (FBS). VSMC proliferation was evaluated by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and cell counting. The cell cycle was examined by flow cytometry. The protein expressions of proliferating cell nuclear antigen (PCNA) and matrix metalloproteinases-2 (MMP-2) were evaluated by Western blotting. MMP-2 mRNA expression was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and gelatinolytic activity was determined by zymography. RESULTS: Promoted VSMC proliferation significantly increased the number of VSMCs in the S phase, the expressions of PCNA and MMP-2, and MMP-2 activity, as well as decreased the proportion of VSMCs in the G(0)/G(1) phase. Rosiglitazone at a concentration of 10 mumol/L markedly inhibited glucose-induced VSMC proliferation (1.869 +/- 0.22 vs 0.820 +/- 0.15, P < 0.01). Concomitantly, rosiglitazone inhibited PCNA expression (0.96 +/- 0.07 vs 0.75 +/- 0.06, P < 0.05) and cell cycle progression from G(0)/G(1) to S phase (the proportion of VSMCs in the G(0)/G(1) and S phase were 69.6 +/- 3.96% vs 84.3 +/- 1.73% and 25.2 +/- 1.73% vs 10.1 +/- 1.42% (P < 0.01), respectively). Furthermore, rosiglitazone significantly decreased MMP-2 mRNA expression (0.98 +/- 0.08 vs 0.71 +/- 0.05, P < 0.05), protein expression (0.80 +/- 0.04 vs 0.64 +/- 0.03, P < 0.05) and MMP-2 activity (320 +/- 25% vs 248 +/- 21%, P < 0.05). CONCLUSION: Rosiglitazone significantly inhibited VSMC proliferation, at least in part by inhibiting high glucose-induced G(1)-->S phase transition, PCNA expression and MMP-2 synthesis.
摘要：
Aim: This study was conducted to reveal new proteins involved in acute myeloid leukemia (AML) cell apoptosis. Methods: Using camptothecin analog NSC606985-induced leukemic U937 cell apoptosis as a model, this study performed a differential proteomic analysis during apoptosis induction. The significantly modulated protein was underwent further investigation in the apoptotic process. Results: We found that β-actin protein presented two different spots on the two-dimensional electrophoresis (2-DE) map, which shared similar molecular weight and different pI. Those two spots demonstrated contrary changes (disappeared on the basic-end and increased on the acid-end spot) during apoptosis induction, although the total level of β-actin kept constant. This observation was further confirmed by immunoblot analysis on 2-DE gel. When NSC606985-treated cell lysate was incubated with alkaline phosphotase, β-actin on the basic-end spot was restored, indicating increased phosphorylation of β-actin during NSC606985-induced apoptosis. Moreover, the polymerization of actin also decreased after NSC606985 treatment. The increased β-actin phosphorylation and decreased actin polymerization was antagonized by pre-treatment of rottlerin, a specific protein kinase C-delta (PKCδ) inhibitor. Conclusion: All these results indicate that β-actin was phosphorylated during apoptosis induction, which was mediated by activated PKCδ.
摘要：
Previous studies demonstrated the EGF-targeted phagemid particles carrying siRNA against Akt could be expressed efficiently in the presence of hydroxycamptothecin (HCPT). However, no significant cell growth inhibition was obtained. This study was to further investigate whether the EGF-targeted phagemid particles carrying siRNA would be a promising tool for anti-cancer siRNA delivery. We found that pSi4.1-siFAK phagemid particles could significantly inhibit the expression of focal adhesion kinase in the HCPT-treated cells. Moreover, we also observed that the particles could potently suppress cell growth and cell invasion. These results indicated that EGF-targeted phagemid particles might be a promising tool for anti-cancer siRNA delivery in the presence of HCPT.
作者机构：
[Chen Lin; Yu Min-jun; Wan Yan-ping; Zhu Cui-ming; Cao Qing-xiang; Liu An-yuan; Chan Xi] Univ S China, Inst Pathogen Biol, Hengyang 421001, Peoples R China.
通讯机构：
[Wan Yan-ping] U;Univ S China, Inst Pathogen Biol, Hengyang 421001, Peoples R China.
关键词：
human cytomegalovirus ( HCMV);IE1;macrophages;IL-1 beta;TNF-alpha;apoptosis
摘要：
Objective: To investigate the effect of human cytomegalovirus (HCMV) IE1 protein on the secretory activity and apoptosis of macrophages. Methods: The eukaryotic expression vector pEGFP-C1/IE1 was used to transfect THP-1-macrophages. 48 h after transfection, the expression and localization of GFP or GFP-IE1 was observed under fluorescent microscope. The levels of IL-1β and TNF-α in the culture media were examined by ELISA, and the mRNA expression of them was analyzed by RT-PCR. Cell undergoing apoptosis were determined by flow cytometry using the propidium iodide (PI) staining method. The data were analyzed by SPSS 13.0. Results: As observed under fluorescent microscope, the expressions of GFP-IE1 and GFP by plasmid pEGFP-C1/IE1 or pEGFP-C1 in THP-1-macrophages could be found in nuclei or whole cells. Conclusion: As demonstrated by RT-PCR and ELISA, mRNA and protein expressions of IL-1β and TNF-α and promotes apoptosis in THP-1-macrophages.
