101
|
Ren S, Zhou S, Zhang L., Chen X, Zhou C. Individualized chemotherapy in the advanced NSCLC patients based on the mRNA level of BRCA1 and RRM1. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e18029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
102
|
Pearce J, Li M, Ren S, Li G, Chen W, Vincent C, Kirk K. CO2 storage capacity estimates for selected regions of China - results from the China-UK Near Zero Emissions Coal (NZEC) Initiative. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.egypro.2011.02.608] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
103
|
Jia Y, Liu M, Cao L, Zhao X, Wu J, Lu F, Li Y, He Y, Ren S, Ju Y, Wang Y, Li Z. Recombinant human endostatin, Endostar, enhances the effects of chemo-radiotherapy in a mouse cervical cancer xenograft model. EUR J GYNAECOL ONCOL 2011; 32:316-324. [PMID: 21797125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND The effects of recombinant human endostatin, Endostar, combined with concurrent chemo-radiotherapy (CCRT) on tumor growth, angiogenesis and lymphangiogenesis in a mouse xenograft model of cervical cancer was investigated. METHODS HeLa cells were injected subcutaneously to establish mouse xenograft models and mice were treated with normal saline (control), CCRT with cisplatin (CDDP), Endostar, or a combination of Endostar and CCRT. Growth, metastasis, and angiogenesis of tumors was monitored. RESULTS Tumorogenic activity of tumor cells in the CCRT, Endostar and combination Endostar-CCRT treatment groups was markedly decreased compared with the activity in the NS group (p < 0.05). The most significant inhibition of tumor growth was observed in the Endostar with CCRT group. Lymph node metastases in the Endostar with CCRT group (12.5%) and Endostar alone group (25%) were lower compared to the CCRT group (42.8%) and NS group (66.7%; p < 0.05). Endostar was also found to inhibit tumor angiogenesis. Endostar induced apoptosis of HeLa cells in vivo, and inhibited expression of VEGF and HIF-1alpha in vivo and in vitro. CONCLUSION Endostar enhanced the anti-cancer effect of CCRT in a mouse xenograft model of cervical cancer. These findings thus provide a new strategy to treat cervical cancer.
Collapse
|
104
|
Ren S, Ma SL. A novel oxo-bridged Mn4 mixed salt, {[(n-Bu4N)(ClO4)]2[Mn4O6(Tacn)4](ClO4)4} · 2H2O and its analogue Mn4 cluster [Mn4O6(Tacn)4](ClO4)4 · 2H2O (Tacn = 1,4,7-triazacyclononane). RUSS J COORD CHEM+ 2010. [DOI: 10.1134/s1070328410110126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
105
|
Ma SL, Ren S. Magnetic study of a cyano-bridged bimetallic complex with Cu2+ macrocycle and [Fe(CN)6]3− ions as building blocks. RUSS J INORG CHEM+ 2010. [DOI: 10.1134/s0036023610080206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
106
|
Su C, Zhou S, Zhang L, Ren S, Zhou C. ERCC1, RRM1, and BRCA1 mRNA expression levels and clinical outcome of advanced non-small cell lung cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e18045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
107
|
Zhou S, Ren S, Yan L, Zhang J, Zhou C. The relationship of EGFR intron 1 (CA) and microsatellite polymorphism and the efficacy of EGFR-TKI in advanced NSCLC patients. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.e18051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
108
|
Zhou C, Wu Y, Chen G, Feng J, Liu X, Wang C, Zhang S, Wang J, Zhou S, Ren S. Preliminary results of randomized phase III study comparing efficacy and safety of first-line erlotinib versus carboplatin (CBDCA) plus gemcitabine (GEM) in Chinese advanced non-small cell lung cancer (NSCLC) patients (pts) with EGFR-activating mutations (OPTIMAL). J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.7575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
109
|
Ma SL, Ren S. Novel ladder-like structure motif assembled from edge-sharing rhombus and square of Mo2Dy2 based on [Mo(CN)8]4− and Dy3+ ions as building blocks. RUSS J COORD CHEM+ 2010. [DOI: 10.1134/s1070328410010100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
110
|
Ma SL, Ren S. Two octacyanomolybdate(IV)-M(II) (M = Mn, Co) bimetallic assemblies: Crystal structures and magnetic properties. RUSS J COORD CHEM+ 2009. [DOI: 10.1134/s1070328409100091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
111
|
Zhou S, Ren S, Zhang L, Sun H, Zhou C. The efficacy of chemotherapy in the advanced NSCLC patients who failed with the treatment of EGFR-TKI. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e19078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e19078 Background: EGFR-TKI such as gefitinib and erlotinib were used as standard 2nd/3rd line therapy in previously treated NSCLC. However, those who benefit from EGFR-TKI will inevitably progress from the disease. We reported the efficacy of chemotherapy(CT) in the advanced NSCLC pts failed with the previously 2nd/3rd line treatment of EGFR-TKIs. Methods: Eligibility criteria included advanced NSCLC pts who got disease control(included CR, PR or SD) initially from TKI therapy and then progressed, PS = 0–2, and normal fatal organ function. Pts received systemic CT (docetaxal, pemetrexed, gemicitabine, novelbine or combined with platinum agent) until disease progression or unacceptable toxicity. Results: 32 pts were enrolled from Oct 15 2007 to Nov 30 2008. Demographics: M 56.3%/F 43.7%; median age 56 y [range 34–72]; stage IV 100%; PS 0/1/2: 3 (9.4%)/22(68.8%)/7(21.8%); adenocarcinoma/non-adenocarcinoma 29(90.6%)/3(9.4%); EGFR-TKI treatment duration >6 m 20(62.5%) /< 6 m 12(37.5%); monotherapy 16 (50%)/ doublets 16 (50%). All pts were evaluable for efficacy; partial response in 5 cases (15.6%), stable disease in 21 cases(37.5%), progressive disease in 15 (46.9%) ( Table ). The response of CT was not related with gender, age, regimens, but these with TKI treatment > 6 m achieved a significantly better response than those < 6 m(p=0.01) and these with PS 0–1 got a marginally significantly better response than PS 2(p=0.095). The toxicity was acceptable. Median progression free survival was 3.4 months and it was not correlated with the gender, age and regimens, but PFS were significant longer in the pts received > 6 m of TKI (median 4.8 vs 1.9, p=0.009) and with PS 0–1 (median 4.7 vs 1.9, p=0.002). Conclusions: Pts benefited from TKI therapy and developed progressive disease could also benefit from CT. The response duration of EGFR-TKI and performance status could be predictive for the better efficacy of CT. [Table: see text] No significant financial relationships to disclose.
Collapse
|
112
|
Ren S. A tiered approach for aquatic risk assessment of alcohol ethoxylates. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2008; 71:187-199. [PMID: 18022692 DOI: 10.1016/j.ecoenv.2007.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 09/13/2007] [Accepted: 10/03/2007] [Indexed: 05/25/2023]
Abstract
An environmental risk assessment approach for alcohol ethoxylate (AE) mixtures was recently published which required the concentrations of the AE homologues in a mixture. The application of this approach can be limited in certain circumstances because AE homologue concentrations would generally not be available without environmental monitoring and would be difficult to estimate by exposure modeling. A tiered assessment approach was proposed in this study which required AE homologue concentrations only in the last tier. A key parameter in the tiered approach was based on Monte Carlo simulation in which simulated AE mixtures were decomposed into plausible combinations of homologues. The value of this parameter was determined so that the probability of false-negative conclusions in the tiered risk assessment approach was minimized. The use of the tiered approach was demonstrated.
Collapse
|
113
|
Ren S, Zhang L, Zhou C, Zhou S, Sun H. The efficacy and safety of loading dose ibandronate in the treatment of non-small cell lung cancer metastatic bone pain(MBP). J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.19127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
114
|
Zhou C, Ren S, Zhou S, Zhang L, Zhang Z, Deng Q, Zhang J. Genotyping single-nucleotide polymorphisms (SNPs) in ERCC1 and XRCC3 genes for efficacy prediction in chemotherapy of non-small cell lung cancer (NSCLC). J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.8098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
115
|
Guo J, Zhou C, Deng Q, Ren S, Zhang J. Effect of EGFR mutations on gefitinib in advanced previous treated non-small-cell lung cancer. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.19132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
116
|
Zhou S, Zhou C, Ren S, Yan L, Zhang L. Predictive effects of serum VEGF, TGF-a and EGFR mutations in advanced non-small cell lung cancer treated by erlotinib. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.19133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
117
|
Ren S. Probabilistic risk assessment for zinc in some commercial dishwashing detergents: the anaerobic digestion processes in US POTWs. CHEMOSPHERE 2008; 71:589-600. [PMID: 17959223 DOI: 10.1016/j.chemosphere.2007.09.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 08/31/2007] [Accepted: 09/12/2007] [Indexed: 05/25/2023]
Abstract
A US patent was issued to a commercial dishwashing detergent composition in which soluble zinc serves as an anti-corrosion agent. Since the detergents are used in a down-the-drain fashion, some of the detergents are discharged as wastewater and treated in publicly owned treatment works (POTWs). A risk assessment was previously conducted which focused on the nitrification processes in US POTWs. As a conservative pollutant, zinc removed from wastewater during treatment is transferred to sludges and at sufficiently high concentrations may inhibit the sludge treatment processes. In the present assessment, a probabilistic risk assessment was conducted to quantitatively determine the risk of zinc in the detergents to the anaerobic digestion processes in US POTWs. The procedure for POTW local limit development designed by the US Environmental Protection Agency (EPA) was used as a reference when conducting the risk assessment. The assessment took into account the background zinc concentrations in POTW influents and was conducted at different market penetration rates (MPRs) for the US market of detergents based on the patented formula. Several factors were present that contributed to the conservativeness of the assessment. Results indicate that zinc in detergents does not present a significant risk to the anaerobic digestion processes in POTWs at a MPR up to 10%, with a probability of anaerobic digestion inhibition of below 1%.
Collapse
|
118
|
Zhou G, Ren S, Chen N, Duan L, Zhang Z, Fang S, Zhao W. Cerebral White Matter Lesions and Cognitive Function in a Non-demented Chinese Veteran Cohort. J Int Med Res 2008; 36:115-22. [PMID: 18230275 DOI: 10.1177/147323000803600115] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This study examined the association between cerebral white matter lesions (WMLs) and cognitive function in a male, non-demented Chinese veteran cohort. A total of 662 participants underwent CT scan and cognitive function assessments; 51 were excluded from the analysis because they exhibited non-lacunar infarcts or suspected dementia. Subjects were allocated to one of four groups according to WML status and between-group comparisons were made for seven cognitive function tests. Logistic regression was used to assess odds ratios for impaired performance associated with WML status. In all cognitive tests, subjects with severe WMLs differed significantly from those without WMLs or with mild WMLs, and in three tests subjects with severe WMLs differed significantly from those with moderate WMLs. For each cognitive test severe WMLs were strongly associated with increased risk of impaired performance. Severe WMLs were associated with greater diminished cognitive function and there may be a WML threshold after which, in elderly Chinese subjects, an impact on cognitive function occurs.
Collapse
|
119
|
Sun Y, Kong F, Ren S, Yuan F, Liang F, Liu N, Jin L, Xi Y. Severe acute graft-vs-host disease in a patient with acute monocytic leukemia having a recombination event between HLA-A/B loci from a multiple recombinant family. ACTA ACUST UNITED AC 2007; 70:499-505. [PMID: 17990988 DOI: 10.1111/j.1399-0039.2007.00953.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Human leukocyte antigen (HLA) recombination, particularly multiple recombinations can produce novel haplotypes, thereby complicating donor-recipient selection and possibly inducing severe graft-vs-host disease (GVHD) after nonfully matched allogeneic hematopoietic stem cell transplantation. Here, we report for the first time that a 30-year-old female acute monocytic leukemia patient with an HLA-A/B recombinant haplotype, who has three unmatched and one HLA-B/DRB1 recombinant haplotype siblings, presented grade IV acute GVHD (aGVHD) after transplantation from a sibling with a single allele only mismatch at the classical HLA-A locus. Furthermore, using a new three-dimensional structure modeling application, we inferred that the structural differences in peptide-binding and T-cell receptor interaction sites can significantly change the immunogenicity of mismatched HLA molecules, potentially one of the main causes of aGVHD.
Collapse
|
120
|
Wu S, Ren S, Nguyen L, Adams JS, Hewison M. Splice variants of the CYP27b1 gene and the regulation of 1,25-dihydroxyvitamin D3 production. Endocrinology 2007; 148:3410-8. [PMID: 17395703 DOI: 10.1210/en.2006-1388] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The cytochrome P450 25-hydroxyvitamin D3-1alpha-hydroxylase (CYP27b1) plays a pivotal role in vitamin D physiology by catalyzing synthesis of active 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. In common with other P450s, CYP27b1 is known to exhibit alternative splicing. Here we have cloned and sequenced several novel intron 2-containing, noncoding splice variant mRNAs for CYP27b1 in 1,25(OH)2D3-producing HKC-8 human proximal tubule and THP-1 monocytic cells. Regulation of 1,25(OH)2D3 synthesis in these cell lines by calciotropic and noncalciotropic factors was associated with altered expression of the CYP27b1 splice variants. To assess the functional significance of this, HKC-8 cells were transfected with short hairpin RNA (shRNA) to inhibit mRNAs containing sequences from intron 2. This resulted in a significant increase in the expression of CYP27b1 protein and synthesis of 1,25(OH)2D3 by HKC-8 cells compared with control cells for two different intron 2-containing shRNAs (both P<0.001). shRNA to intron 2 had no significant effect on the levels of wild-type CYP27b1 mRNA, suggesting a posttranscriptional mechanism of action. By contrast, shRNA to wild-type CYP27b1 suppressed transcription and activity of the enzyme by 70 and 31%, respectively (both P<0.01). These data indicate that noncoding splice variants of CYP27b1 are functionally active and may play a significant role in the regulation of 1,25(OH)2D3 synthesis during normal physiology.
Collapse
|
121
|
Ren S. Probabilistic risk assessment for zinc in some commercial dishwashing detergents: the nitrification processes in US POTWs. CHEMOSPHERE 2007; 68:1474-88. [PMID: 17512032 DOI: 10.1016/j.chemosphere.2007.03.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2006] [Revised: 03/16/2007] [Accepted: 03/20/2007] [Indexed: 05/15/2023]
Abstract
A US patent was issued to a commercial dishwashing detergent composition in which soluble zinc is used to protect glassware from corrosion. Some of the consumed detergents are discharged as wastewater and treated in publicly owned treatment works (POTWs). A probabilistic risk assessment was conducted to quantitatively determine the risk of zinc in the detergents to the nitrification processes in US POTWs. The procedure for POTW local limit development designed by the US Environmental Protection Agency (EPA) was used as a reference when conducting the risk assessment. The assessment took into account the background zinc concentrations in POTW influents and potential shock loading patterns, and was conducted at different market penetration rates (MPRs) for the US market of detergents based on the patented formula. The assessment involved several conservative factors including conservative determination of primary treatment efficiency, bioavailability, inhibition concentration, configuration of the nitrification process, as well as background zinc concentration in wastewater. With the conservative factors in the assessment, it was found that zinc in detergents does not present a significant risk to the nitrification processes in POTWs at a MPR up to 10%. It was noted that additional analyses would be required when the MPR is higher than 10% to adequately account for the effects of the conservative factors on the result of the assessment.
Collapse
|
122
|
Xin C, Ren S, Eberhardt W, Pfeilschifter J, Huwiler A. FTY720 suppresses interleukin-1beta-induced secretory phospholipase A2 expression in renal mesangial cells by a transcriptional mechanism. Br J Pharmacol 2007; 150:943-50. [PMID: 17325654 PMCID: PMC2013874 DOI: 10.1038/sj.bjp.0707171] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE FTY720 is a potent immunomodulatory prodrug that is converted to its active phosphorylated form by a sphingosine kinase. Here we have studied whether FTY720 mimicked the action of sphingosine-1-phosphate (S1P) and exerted an anti-inflammatory potential in renal mesangial cells. EXPERIMENTAL APPROACH Prostaglandin E(2) (PGE(2)) was quantified by an enzyme-linked immunosorbent-assay. Secretory phospholipase A(2) (sPLA(2)) protein was detected by Western blot analyses. mRNA expression was determined by Northern blot analysis and sPLA(2)-promoter activity was measured by a luciferase-reporter-gene assay. KEY RESULTS Stimulation of cells for 24 h with interleukin-1beta (IL-1beta) is known to trigger increased PGE(2) formation which coincides with an induction of the mRNA for group-IIA-sPLA(2) and protein expression. FTY720 dose-dependently suppressed IL-1beta-induced IIA-sPLA(2) protein secretion and activity in the supernatant. This effect is due to a suppression of cytokine-induced sPLA(2) mRNA expression which results from a reduced promoter activity. As a consequence of suppressed sPLA(2) activity, PGE(2) formation is also reduced by FTY720. Mechanistically, the FTY720-suppressed sPLA(2) expression results from an activation of the TGFbeta/Smad signalling cascade since inhibition of the TGFbeta receptor type I by a specific kinase inhibitor reverses the FTY720-mediated decrease of sPLA(2) protein expression and sPLA(2) promoter activity. CONCLUSIONS AND IMPLICATIONS In summary, our data show that FTY720 was able to mimic the anti-inflammatory activity of TGFbeta and blocked cytokine-triggered sPLA(2) expression and subsequent PGE(2) formation. Thus, FTY720 may exert additional in vivo effects besides the well reported immunomodulation and its anti-inflammatory potential should be considered.
Collapse
|
123
|
Ren S, Hesk D, McNamara P, Koharski D. A simple and efficient synthesis of [3α-3H]5α-androst-16-en-3β-ol. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.1117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
124
|
Sangle G, Zhu F, Ren S, Shen G. Mo-P2:188 Involvement of RAF/ERK pathway in production of plasminogen activator inhibitor-1 in vascular endothelial cells induced by oxidized or glycated LDL. ATHEROSCLEROSIS SUPP 2006. [DOI: 10.1016/s1567-5688(06)80323-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
125
|
Hall EA, Ren S, Hylemon PB, Redford K, del Castillo A, Gil G, Pandak WM. Mitochondrial cholesterol transport: A possible target in the management of hyperlipidemia. Lipids 2005; 40:1237-44. [PMID: 16477808 DOI: 10.1007/s11745-005-1491-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sterol 27-hydroxylase (CYP27A1) may defend cells against accumulation of excess cholesterol, making this enzyme a possible target in the management of hyperlipidemia. The study objective was to analyze cholesterol homeostatic responses to increases in CYP27A1 activity in HepG2 cells and primary human hepatocytes. Increasing CYP27A1 activity by increasing enzyme expression led to significant increases in bile acid synthesis with compensatory increases in HMG-CoA reductase (HMGR) activity/protein, LDL receptor (LDLR) mRNA, and LDLR-mediated cholesterol uptake. Under these conditions, only a small increase in cellular 27-hydroxycholesterol (27OH-Chol) concentration was observed. No changes were detected in mature sterol regulatory element-binding proteins (SREBP) 1 or 2. Increasing CYP27A1 activity by increasing mitochondrial cholesterol transport (i.e., substrate availability) led to greater increases in bile acid synthesis with significant increases in cellular 27OH-Chol concentration. Mature SREBP 2 protein decreased significantly with compensatory decreases in HMGR protein. No change was detected in mature SREBP 1 protein. Despite increasing 27OH-Chol and lowering SREBP 2 protein concentrations, LDLR mRNA increased significantly, suggesting alternative mechanisms of LDLR transcriptional regulation. These findings suggest that regulation of liver mitochondrial cholesterol transport represents a potential therapeutic strategy in the treatment of hyperlipidemia and atherosclerosis.
Collapse
|
126
|
Takimoto E, Champion HC, Li M, Ren S, Rodriguez ER, Tavazzi B, Lazzarino G, Paolocci N, Gabrielson KL, Wang Y, Kass DA. Pressure Overload and Cardiac Remodelling—A Smoking Gun Points to Uncoupled Nitric Oxide Synthase. J Am Soc Nephrol 2005; 16:2820-2823. [PMID: 37000921 DOI: 10.1681/01.asn.0000926756.36912.0b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
|
127
|
Hall EA, Ren S, Hylemon PB, Rodriguez-Agudo D, Redford K, Marques D, Kang D, Gil G, Pandak WM. Detection of the steroidogenic acute regulatory protein, StAR, in human liver cells. Biochim Biophys Acta Mol Cell Biol Lipids 2005; 1733:111-9. [PMID: 15863358 DOI: 10.1016/j.bbalip.2005.01.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 12/16/2004] [Accepted: 01/20/2005] [Indexed: 11/30/2022]
Abstract
Overexpressing StAR (a mitochondrial cholesterol transporter) increases (>5-fold) the rate of 27-hydroxylation of cholesterol and the rates of bile acid synthesis in primary rat hepatocytes; suggesting that the transport of cholesterol into mitochondria is rate-limiting for bile acid biosynthesis via the CYP27A1 initiated 'acidic' pathway. Our objective was to determine the level of StAR expression in human liver and whether changes in StAR would correlate with changes in CYP27A1 activity/bile acid synthesis rates in human liver tissues. StAR mRNA and protein were detected in primary human hepatocytes and HepG2 cells by RT-PCR/Northern analysis and by Western analysis, respectively. In immunocompetition assays, liver StAR was competed away with the addition of purified human adrenal StAR. Overexpressing CYP27A1 in both cell types led to >2-fold increases in liver StAR concentration. StAR protein levels also increased approximately 2-fold with the addition of 27-hydroxycholesterol to HepG2 cell culture medium. Overexpressing StAR increased the rates of 27-hydroxylation of cholesterol/bile acid synthesis in both cell lines and increased intracellular levels of 27-hydroxycholesterol. In conclusion, human liver cells contain regulable StAR protein whose level of expression appears capable of regulating cellular cholesterol homeostasis, representing a potential therapeutic target in the management of hyperlipidemia.
Collapse
|
128
|
Jacquard AC, Nassal M, Pichoud C, Ren S, Schultz U, Guerret S, Chevallier M, Werle B, Peyrol S, Jamard C, Rimsky LT, Trepo C, Zoulim F. Effect of a combination of clevudine and emtricitabine with adenovirus-mediated delivery of gamma interferon in the woodchuck model of hepatitis B virus infection. Antimicrob Agents Chemother 2004; 48:2683-92. [PMID: 15215126 PMCID: PMC434178 DOI: 10.1128/aac.48.7.2683-2692.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Our aim was to evaluate the antiviral effect of a combination of two nucleoside reverse transcriptase inhibitors, emtricitabine (FTC) and clevudine (L-FMAU), with the addition of an adenovirus-driven delivery of recombinant gamma interferon (IFN-gamma) in the woodchuck model of hepatitis B virus infection. Six woodchuck hepatitis virus (WHV)-infected woodchucks received L-FMAU (10 mg/kg) plus FTC (30 mg/kg) intraperitoneally for 8 weeks; six other animals received in addition an intravenous injection of a recombinant adenovirus vector expressing woodchuck IFN-gamma (Ad-IFN) at weeks 4 and 8. In the control group, two animals received Ad-IFN alone, two received adenovirus vector expressing the green fluorescent protein reporter gene, and one remained untreated. In less than 2 weeks, all woodchucks that received L-FMAU plus FTC showed a rapid and marked inhibition of viral replication, with a 4-log(10) drop in serum WHV DNA. In two animals, viremia remained suppressed for several months after the end of treatment. Similarly, a dramatic decrease in intrahepatic replicative intermediates of viral DNA was observed in the L-FMAU/FTC-treated groups. The additional administration of Ad-IFN led to increased inflammation in the liver but did not enhance the antiviral effect of the L-FMAU/FTC combination. In conclusion, therapies combining L-FMAU and FTC in WHV-infected woodchucks resulted in a potent and sustained antihepadnaviral effect both in the liver and in the blood circulation. However, no extra benefit of adding IFN-gamma gene transduction to the L-FMAU/FTC combination could be detected.
Collapse
|
129
|
Wu QB, Ren S, Deng SZ, Chen J, She JC, Xu NS. Template-based synthesis of carbon nanofibres and their field emission characteristics. SURF INTERFACE ANAL 2004. [DOI: 10.1002/sia.1726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
130
|
Ren S, Schultz TW, Frymier PD. Evaluation of the Shk1 activated sludge bacterial luminescence inhibition assay: narcotic chemicals. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2004; 72:1187-1194. [PMID: 15362448 DOI: 10.1007/s00128-004-0369-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
|
131
|
Shen J, Shu N, Ren S, Zhou X, Zhou X. Development of a surface acoustic wave LB membrane immunity sensor. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 2003; 20:20-2. [PMID: 12845747 DOI: 10.1007/bf02887666] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A new kind of biosensor for immunology was developed by ultrasonic technique and LB membrane. A double delay-line resonator was made by using ST-cut quartz crystal with working frequency of 149.7 MHz. Then a layer of LB membrane was covered on it. When anti-IgM antibody of various concentrations was added to it, the sensor can be used to detect IgM antigen. The biosensor was highly sensitive, small and light. The experimental results showed that the working frequency change of the sensor was proportional to the concentration of antibody with its dilution ratio between 1:10,000 and 1:100. It was also first observed that the frequency curve of the sensor resulting from the reaction of IgM antigen and antibody undulated in the experiment.
Collapse
|
132
|
Li ZB, Liu XW, Xu NS, Deng SZ, Chen J, Wu MM, Ren S, Chen J, Zhao FL. Resonant field emission through amorphous diamond thin films (a model study). Ultramicroscopy 2003; 95:75-80. [PMID: 12535547 DOI: 10.1016/s0304-3991(02)00299-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A model for field emission through an amorphous diamond thin film with defects is constructed. Theoretical study shows that the emission is enhanced by attractive defects which would make the resonant emission observable for films with thickness of about 10nm. The emitted current density in typical parameters is calculated as functions of thickness, field strength and defect density. The energy distribution of emitted electrons is attained.
Collapse
|
133
|
Ren S. Classifying class I and class II compounds by hydrophobicity and hydrogen bonding descriptors. ENVIRONMENTAL TOXICOLOGY 2002; 17:415-423. [PMID: 12242671 DOI: 10.1002/tox.10074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The successful development of quantitative structure-activity relationships (QSARs) and the prediction of toxicity based on QSARs depend on the correct classification of the mechanism of toxic action of chemical compounds. The toxicity mechanism of a compound can be determined by a few existing methods, such as studying the chemical structure of the compound for certain substructures and assigning a mechanism accordingly. However, these methods are less reliable for compounds with complex structures and are usually complicated. A novel descriptor-based method employing a multivariate statistical technique--discriminant analysis--was developed in this study for the classification of class I and class II compounds. The discriminating variables used in discriminant analysis were the hydrophobicity descriptor log(K(ow)) and the hydrogen bonding descriptors E(LUMO), E(HOMO), Q(+), and Q(-). Because only numerical values of these descriptors are required for this method, which can be calculated, no additional experimental work was required for the toxicity mechanism classification of new compounds. A nonlinear discriminant function was generated that could not be expressed explicitly. Assessing the predicting ability of the discriminant function by the cross-validation method showed that a low total error rate, 4.2% was achieved.
Collapse
|
134
|
Ren S. Determining the mechanisms of toxic action of phenols to Tetrahymena pyriformis. ENVIRONMENTAL TOXICOLOGY 2002; 17:119-127. [PMID: 11979590 DOI: 10.1002/tox.10040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Phenols are environmentally important compounds that are widely used in agriculture and industry. Thus, phenols are of interest to environmental toxicologists, which has led to the development of several quantitative structure-activity relationship (QSAR) models. The most successful QSARs have been established for compounds having a common mechanism of toxic action (MOA). However, correctly determining the MOA of a compound is not easy. Discriminant analysis was used in this study to separate phenols by their MOAs. The working hypothesis of this study was that phenols with different MOAs lie in different regions in the response surface described by the ionization-corrected hydrophobicity descriptor, log D, the electrophilicity descriptor, ELUMO, and the interaction between hydrophobicity and electrophilicity, D * ELUMO. Results of discriminant analysis showed a total error rate of 15%. In addition, it was difficult to separate phenols that had a polar narcosis MOA from phenols that had a proelectrophile MOA.
Collapse
|
135
|
Picardeau M, Ren S, Saint Girons I. Killing effect and antitoxic activity of the Leptospira interrogans toxin-antitoxin system in Escherichia coli. J Bacteriol 2001; 183:6494-7. [PMID: 11591696 PMCID: PMC100147 DOI: 10.1128/jb.183.21.6494-6497.2001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report the first evidence of a chromosome-encoded toxin-antitoxin locus in spirochetes. This locus has been found in the pathogenic spirochete Leptospira interrogans and exhibits homologies with the pem/chp loci. The L. interrogans chp locus consists of two genes: chpK (for "killer protein") and its upstream partner chpI (for "inhibitory protein"). Expression of ChpK in Escherichia coli results in the inhibition of bacterial growth. The coexpression of ChpI neutralizes ChpK toxicity. By Southern blot analysis, chp homologs were found in all representative pathogenic strains of L. interrogans.
Collapse
|
136
|
Ren S, Lien EJ. Development of HIV protease inhibitors: a survey. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2001; Spec No:1-34. [PMID: 11548206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
In the treatment of infections caused by rapidly mutating viruses like human immunodeficiency virus (HIV), combination therapy with multiple drugs acting by different mechanisms offers several advantages over monotherapy. It may provide: synergistic effect, possible reduction of dosages and side-effects, and reduction of the chance of drug resistance. In the past few years, hundreds of HIV protease inhibitors have been synthesized and tested in order to overcome the limitations of reverse transcriptase inhibitors like zidovudine and others. In this review, emphasis is placed on the development of HIV protease inhibitors as antiviral agents against HIV, and structure-activity relationship analysis of saquinavir and related compounds. Limitations of some protease inhibitors and ways to overcome the shortcomings are presented. Among these many protease inhibitors five have been marketed during 1995-1999. They are saquinavir, ritonavir, indinavir, nelfinavir and amprenavir. Their different structural features, important physicochemical, pharmacokinetic and clinical profiles are presented in a table form for easy comparison. It is hoped that in the future new drugs based on additional mechanisms can be developed for the treatment of AIDS.
Collapse
|
137
|
Ren S, Tokes ZA, Csipke C, Zhou B, Yen Y, Lien EJ. Inhibition of tumor cell growth by Schiff bases of hydroxysemicarbazide. Anticancer Res 2001; 21:3445-51. [PMID: 11848507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The inhibitory activities of Schiff bases of hydroxysemicarbazide (HSC) against eight human and murine tumor cell lines and one non-cancer cell line were studied using MTS/PES microculture tetrazolium and methylene blue assays. Compounds 1 (1-[9-(10-methylanthryl)methylene]-4-HSC), 2 (1-[2-hydroxy-3,5-dibromobenzylidene]-4-HSC) and 3 (1-[2,3,4-trihydroxybenzylidene]-4-HSC), which have been shown to be active against murine leukemia L1210 cells in our laboratories, inhibited human leukemia CCRF-CEM cells with similar IC50s ranging from 2.7 to 7.0 microM. Of the compounds tested against attached tumor cell lines (B16, CHO, HT29, ZR75) at 50 microM concentration, compound 1 showed the strongest inhibition, followed by 4 (1-[2-(5-nitrothienyl)methylene]-4-HSC), 2 and 5 (1-[2-hydroxy-3,5-diiodobenzylidene]-4-HSC) with more than 50% inhibition. The IC50s of compound 1 were found to range from 2.7 to 12 microM against the attached tumor cell lines examined. As compared with hydroxyurea, compound 1 had more favorable selectivity against tumor cells. Further more, compound 1 was found to have IC50s of 2.8 and 6.5 microM against hydroxyurea-resistant and gemcitabine-resistant KB cells, respectively, but had no cross-resistance with hydroxyurea and gemcitabine (two known ribonucleotide reductase inhibitors acting at different sites of the same enzyme). In conclusion, several Schiff bases of HSC showed inhibition of tumor cell growth at micromolar concentration and had no cross-resistance with hydroxyurea-resistant KB cells.
Collapse
|
138
|
Liu Z, Short J, Rose A, Ren S, Contel N, Grossman S, Unger S. The simultaneous determination of diazepam and its three metabolites in dog plasma by high-performance liquid chromatography with mass spectroscopy detection. J Pharm Biomed Anal 2001; 26:321-30. [PMID: 11470209 DOI: 10.1016/s0731-7085(01)00404-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A fast, sensitive and specific LC/MS/MS method for the simultaneous determination of diazepam and its three metabolites, oxazepam, temazepam and desmethyldiazepam, in dog plasma is described. The method consists of an automated 96-well solid phase extraction procedure and electrospray LC/MS/MS analysis. D(5)-Diazepam is used as the internal standard for all the compounds. Intra-day and inter-day assay coefficients of variations are less than 12.7%. The lower limit of quantitation (LLOQ) is 1 nM for each analyte, based on 0.1 ml aliquots of dog plasma. The analytical run time was 5 min. Linearity is observed over the range of 1--500 nM. This method has been used to support the discovery of pharmacokinetic studies.
Collapse
|
139
|
Cai L, Lim K, Ren S, Cadena RS, Beck WT. Synthesis and in vitro antitumor activity of oligonucleotide-tethered and related platinum complexes. J Med Chem 2001; 44:2959-65. [PMID: 11520204 DOI: 10.1021/jm0002937] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three classes of hydroxy-tethered platinum(II) complexes have been synthesized from K(2)PtCl(4) and appropriate amino alcohols. A sequence of selective oxidation and hydrolysis has been developed to prepare hydroxy-tethered platinum(IV) complexes. A novel procedure for the synthesis of amminetrichloroplatinate(II) anion has been generated and used to synthesize a number of monohydroxy-tethered nonchelating platinum complexes. These tethered platinum complexes, including hydroxy-tethered, phosphoramidite-tethered, and monodeoxyribonucleotide-tethered platinum(II) and -(IV) complexes, have been examined in vitro for antitumor activity in both leukemia and ovarian cancer cell lines. Activity of some of these complexes was similar to cis-platin, and most of them showed much better potency than carboplatin. We observed an interesting structure-activity correlation for platinum(II) complexes for both PA-1 and SK-OV-3 ovarian cancer cell lines. However, platinum(IV) complexes showed much more diversified response among cancer cell lines studied. We observed enhanced selectivity among different cancer cell lines for some agents. The most promising is the monodeoxyribonucleotide-tethered platinum(IV) complex, which is the first analogue of the conjugates between a platinum fragment and monodeoxyribonucleotides, showing antitumor activity and selectivity among the cell lines. Finally, the p53 status of the cells appears to contribute to the effectiveness of these agents in that cells harboring wild-type p53 appear to be more sensitive to these agents.
Collapse
|
140
|
Duetz WA, Fjällman AH, Ren S, Jourdat C, Witholt B. Biotransformation of D-limonene to (+) trans-carveol by toluene-grown Rhodococcus opacus PWD4 cells. Appl Environ Microbiol 2001; 67:2829-32. [PMID: 11375201 PMCID: PMC92945 DOI: 10.1128/aem.67.6.2829-2832.2001] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The toluene-degrading strain Rhodococcus opacus PWD4 was found to hydroxylate D-limonene exclusively in the 6-position, yielding enantiomerically pure (+) trans-carveol and traces of (+) carvone. This biotransformation was studied using cells cultivated in chemostat culture with toluene as a carbon and energy source. The maximal specific activity of (+) trans-carveol formation was 14.7 U (g of cells [dry weight])(-1), and the final yield was 94 to 97%. Toluene was found to be a strong competitive inhibitor of the D-limonene conversion. Glucose-grown cells did not form any trans-carveol from D-limonene. These results suggest that one of the enzymes involved in toluene degradation is responsible for this allylic monohydroxylation. Another toluene degrader (Rhodococcus globerulus PWD8) had a lower specific activity but was found to oxidize most of the formed trans-carveol to (+) carvone, allowing for the biocatalytic production of this flavor compound.
Collapse
|
141
|
Lee AD, Ren S, Lien EJ. Purine analogs as CDK enzyme inhibitory agents: a survey and QSAR analysis. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2001; 56:155-93. [PMID: 11417113 DOI: 10.1007/978-3-0348-8319-1_4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Characterization of the cell cycle has introduced CDKs and other proteins as possible targets for inhibition of cell proliferation, such as, CDK1 and CDK2, whose inhibition may be useful in the treatment of proliferative disorders. Structure-activity analyses have been instrumental in the design and discovery of potent CDK inhibitors, such as purine analogs, which have increased in potency from the micromolar to the nanomolar level. X-ray crystallography and molecular modeling have provided evidence that these compounds act on the CDK target enzyme. Selected CDK inhibitors have successfully entered clinical trials. Further characterization of the cell cycle to identify molecular targets to inhibit cell proliferation, QSAR and SAR studies, and clinical trials may expedite the development of CDK inhibitors for therapeutic use. The ultimate goal of these studies is to determine whether specific CDKs, CDK1 or CDK2, are enzymes essential to cell proliferation that can be targeted for treatment of proliferative disorders. CDK1 and CDK2 are viable molecular targets for cancer therapies based on isolated-enzyme inhibition by CDK inhibitors, successful clinical trials of CDK1 and CDK2 inhibitors, and x-ray crystallographic confirmation of CDK inhibitors binding to the putative target enzyme active site. It is now reported that CDK1 inhibitory activities of purine analogs correlate with the physiochemical parameters of purine analogs. Enzyme inhibition [1-5], clinical trials (see Tab. 1), x-ray crystallographic [4, 6, 7] and QSAR correlation studies are evidence that specific CDK1 and/or CDK2 inhibitors are potentially useful agents for various cell-proliferation disorders. A brief overview of the cell cycle precedes a literature review of clinical applications of CDK inhibitors, followed by a new QSAR study, and a SAR and molecular modeling discussion.
Collapse
|
142
|
Gao CF, Ren S, Zhang L, Nakajima T, Ichinose S, Hara T, Koike K, Tsuchida N. Caspase-dependent cytosolic release of cytochrome c and membrane translocation of Bax in p53-induced apoptosis. Exp Cell Res 2001; 265:145-51. [PMID: 11281652 DOI: 10.1006/excr.2001.5171] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Activation of p53 induces apoptosis in various cell types. However, the mechanism by which p53 induces apoptosis is still unclear. We reported previously that the activation of a temperature-sensitive mutant p53 (p53(138Val)) induced activation of caspase 3 and apoptosis in Jurkat cells. To elucidate the pathway linking p53 and downstream caspases, we examined the activation of caspases 8 and 9 in apoptotic cells. The results showed that both caspases were activated during apoptosis as judged by the appearance of cleavage products from procaspases and the caspase activities to cleave specific fluorogenic substrates. The significant inhibition of apoptosis by a tetrapeptide inhibitor of caspase 8 and caspase 9 suggested that both caspases are required for apoptosis induction. In addition, the membrane translocation of Bax and cytosolic release of cytochrome c, but not loss of mitochondrial membrane potential, were detected at an early stage of apoptosis. Moreover, Bax translocation, cytochrome c release, and caspase 9 activation were blocked by the broad-spectrum caspase inhibitor, Z-VAD-fmk and the caspase 8-preferential inhibitor, Ac-IETD-CHO, suggesting that the mitochondria might participate in apoptosis by amplifying the upstream death signals. In conclusion, our results indicated that activation of caspase 8 or other caspase(s) by p53 triggered the membrane translocation of Bax and cytosolic release of cytochrome c, which might amplify the apoptotic signal by activating caspase 9 and its downstream caspases.
Collapse
|
143
|
Shen GX, Ren S, Fenton JW. Transcellular signaling and pharmacological modulation of thrombin-induced production of plasminogen activator inhibitor-1 in vascular smooth muscle cells. Semin Thromb Hemost 2001; 24:151-6. [PMID: 9579636 DOI: 10.1055/s-2007-995834] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Thrombin formation is increased at the sites of vascular injury. Previous studies by our group and other groups indicated that the generation of plasminogen activator inhibitor-1 (PAI-1), the major physiological inhibitor for plasminogen activators, from cultured vascular smooth muscle cells (SMC) is elicited by thrombin. The present study demonstrates that the thrombin receptor, pertussis toxin-sensitive G protein, genistein-sensitive tyrosine kinase, phospholipase C, and protein kinase C may be involved in thrombin-induced PAI-1 production in cultured baboon aortic SMC. Forskolin and 8-bromo-cyclic AMP inhibited thrombin-induced PAI-1 production in cultured SMC. Treatment with hirulog-1, a synthetic thrombin receptor inhibitor, suppressed thrombin-induced PAI-1 generation at mRNA and protein levels in SMC. The results of the present study suggest that transmembrane receptor and multiple signal transduction systems are involved in thrombin-induced increase in PAI-1 transcription in vascular SMC. The production of PAI-1 stimulated by thrombin in vascular SMC may be pharmacologically modulated by thrombin receptor inhibitor.
Collapse
MESH Headings
- 8-Bromo Cyclic Adenosine Monophosphate/pharmacology
- Animals
- Cells, Cultured
- Colforsin/pharmacology
- GTP-Binding Proteins/drug effects
- GTP-Binding Proteins/physiology
- Gene Expression Regulation/drug effects
- Hirudins/analogs & derivatives
- Hirudins/pharmacology
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Papio
- Peptide Fragments/pharmacology
- Pertussis Toxin
- Plasminogen Activator Inhibitor 1/biosynthesis
- Plasminogen Activator Inhibitor 1/genetics
- RNA, Messenger/biosynthesis
- Receptors, Thrombin/agonists
- Receptors, Thrombin/antagonists & inhibitors
- Recombinant Proteins/pharmacology
- Signal Transduction/drug effects
- Thrombin/antagonists & inhibitors
- Thrombin/pharmacology
- Virulence Factors, Bordetella/pharmacology
Collapse
|
144
|
Ren S, Li M, Cai H, Hudgins S, Furth PA. A simplified method to prepare PCR template DNA for screening of transgenic and knockout mice. CONTEMPORARY TOPICS IN LABORATORY ANIMAL SCIENCE 2001; 40:27-30. [PMID: 11300684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Polymerase chain reaction (PCR) amplification of DNA is the most widely used technique for screening of large numbers of genetically engineered transgenic or knockout mice (Mus musculus). In this report, we present a new DNA preparation procedure for running diagnostic PCR. In this procedure, mouse ear tissue was used directly for PCR after the tissue underwent brief digestion in a solution containing only proteinase K. Using this method, we have successfully screened several lines of single, double, and triple transgenic and knockout mice. The results are reliable and reproducible. The advantage of this new method is that DNA purification by organic extraction or isolation kit was omitted. DNA purification is the limiting factor in terms of time and money when screening transgenic and knockout mice by PCR. In addition, using ear instead of tail tissue can reduce distress of animals because the samples can be obtained when the mice are labeled by ear punch.
Collapse
|
145
|
Zhang ZR, Xu SQ, Zhou YK, Ren S, Lü B. [Construction of luciferase reporter plasmid which is under the control of dioxin-responsive enhancers]. SHENG WU GONG CHENG XUE BAO = CHINESE JOURNAL OF BIOTECHNOLOGY 2001; 17:170-4. [PMID: 11411225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
To improve the bio-detection of dioxin-type chemicals, we constructed a plasmid containing reporter under the control of dioxin-responsive enhancer. After connected the enhancer from the plasmid pHAV with the MMTV promoter of the plasmid pCatM, the connected segment was linked with the luciferase vector. Then the recombinant plasmid was transfected to the HepG2 human hepatoma cell line, and the luciferase activity was induced by 2,3,7,8-TCDD. The result suggested that expression of the recombinant luciferase was controlled by the dioxin-responsive enhancer, and there were a linear relationship between the activity of luciferase and certain range of 2,3,7,8-TCDD concentration. It is promising that the transfected cell line could be used for rapid screen and semi quantitation of dioxin-type chemicals, and a standard and routine method for the detection of dioxin-type chemicals by this recombinant plasmid is being under way.
Collapse
|
146
|
Xue M, Ren S, Welch S, Shen GX. Hirulog-like peptide reduces balloon catheter injury induced neointima formation in rat carotid artery without increase in bleeding tendency. J Vasc Res 2001; 38:144-52. [PMID: 11316950 DOI: 10.1159/000051041] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Vascular restenosis is one of the major concerns for the management of coronary artery disease using therapeutic vascular procedures. Treatments with thrombin-specific inhibitors, hirudin or hirulog-1, reduced ischemic events in coronary artery disease patients. Early started and prolonged infusions of these thrombin inhibitors partially prevented balloon catheter injury induced restenosis or neointima formation in experimental animal models, but increased the bleeding tendency. Hirulog-like peptide (HLP) was rationally designed to enhance the inhibition of the binding of thrombin to its receptor with less interruption of coagulation activity in comparison to hirulog-1. A single infusion of HLP for 4 h started 0.5 h before balloon catheter injury reduced neointima formation by 36% in rat carotid artery compared to vehicle controls. Tail bleeding time and activated partial thromboplastin time during HLP infusion were not significantly different from vehicle controls, but were significantly shorter than during heparin or hirulog-1 infusion. HLP treatment attenuated the expression of platelet-derived growth factor in the neointima of injured arteries. HLP also inhibited thrombin-induced thymidine incorporation in cultured baboon aortic smooth muscle cells. The findings suggest that HLP may substantially inhibit balloon catheter injury induced neointima formation without noticeable increase in bleeding tendency in rats. The inhibition by HLP of the expression of platelet-derived growth factor and of the smooth muscle cell proliferation in the vascular wall potentially contributes to the preventive effect of the new thrombin inhibitor on injury-induced neointima formation in the vascular wall.
Collapse
MESH Headings
- Angioplasty, Balloon/adverse effects
- Animals
- Anticoagulants/pharmacology
- Bleeding Time
- Carotid Artery Injuries/drug therapy
- Carotid Artery Injuries/metabolism
- Cell Division/drug effects
- Cells, Cultured
- Disease Models, Animal
- Hemorrhage/chemically induced
- Hemorrhage/prevention & control
- Hemostatics/pharmacology
- Hirudins/analogs & derivatives
- Hirudins/pharmacology
- Male
- Muscle, Smooth, Vascular/chemistry
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Partial Thromboplastin Time
- Peptide Fragments/pharmacology
- Platelet-Derived Growth Factor/analysis
- Platelet-Derived Growth Factor/biosynthesis
- Rats
- Rats, Sprague-Dawley
- Recombinant Proteins/pharmacology
- Thrombin/pharmacology
- Tunica Intima/chemistry
- Tunica Intima/injuries
- Tunica Intima/metabolism
Collapse
|
147
|
Ren S, Nassal M. Hepatitis B virus (HBV) virion and covalently closed circular DNA formation in primary tupaia hepatocytes and human hepatoma cell lines upon HBV genome transduction with replication-defective adenovirus vectors. J Virol 2001; 75:1104-16. [PMID: 11152483 PMCID: PMC114016 DOI: 10.1128/jvi.75.3.1104-1116.2001] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatitis B virus (HBV), the causative agent of B-type hepatitis in humans, is a hepatotropic DNA-containing virus that replicates via reverse transcription. Because of its narrow host range, there is as yet no practical small-animal system for HBV infection. The hosts of the few related animal viruses, including woodchuck hepatitis B virus and duck hepatitis B virus, are either difficult to keep or only distantly related to humans. Some evidence suggests that tree shrews (tupaias) may be susceptible to infection with human HBV, albeit with low efficiency. Infection efficiency depends on interactions of the virus with factors on the surface and inside the host cell. To bypass restrictions during the initial entry phase, we used recombinant replication-defective adenovirus vectors, either with or without a green fluorescent protein marker gene, to deliver complete HBV genomes into primary tupaia hepatocytes. Here we show that these cells, like the human hepatoma cell lines HepG2 and Huh7, are efficiently transduced by the vectors and produce all HBV gene products required to generate the secretory antigens HBsAg and HBeAg, replication-competent nucleocapsids, and enveloped virions. We further demonstrate that covalently closed circular HBV DNA is formed. Therefore, primary tupaia hepatocytes support all steps of HBV replication following deposition of the genome in the nucleus, including the intracellular amplification cycle. These data provide a rational basis for in vivo experiments aimed at developing tupaias into a useful experimental animal system for HBV infection.
Collapse
|
148
|
Ren S, Kambe N, Du Z, Li Y, Xia HZ, Kambe M, Bieberich E, Pozez A, Grimes M, Yu RK, Irani AM, Schwartz LB. Disialoganglioside GD3 is selectively expressed by developing and mature human mast cells. J Allergy Clin Immunol 2001; 107:322-30. [PMID: 11174200 DOI: 10.1067/mai.2001.112272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Disialoganglioside GD3 is expressed on the surface of selected cell types. Anti-GD3 mAb administered to human subjects with malignant melanoma produces signs and symptoms of immediate hypersensitivity reactions. OBJECTIVE The expression of GD3 by human mast cells was assessed during mast cell development in vitro and in samples of lung and skin. METHODS GD3 on tissue- and in vitro-derived mast cells was analyzed after double labeling of cells for tryptase (G3 mAb) or Kit (YB5.B8 mAb) and GD3 (R24 mAb). Glycolipids in extracts of fetal liver-derived mast cells were examined by using high-performance thin-layer chromatography. RESULTS Flow cytometry showed that the percentage of GD3+ cells increased in parallel to Kit+ cells during the recombinant human stem cell factor-dependent development of fetal liver-derived mast cells. Double-labeling experiments showed that GD3+ cells were also surface Kit+ and granule tryptase positive, identifying them as mast cells in preparations of lung-, skin-, fetal liver-, and cord blood-derived cells. The major acidic glycolipid detected was NeuAcalpha2-8NeuAcalpha2-3Galbeta1-4Glcbeta1-1'Cer (GD3). Among peripheral blood leukocytes, only basophils and about 10% of the T cells were labeled with anti-GD3 mAb. Anti-GD3 mAb-conjugated magnetic beads were used to purify mast cells to greater than 90% purity from dispersed skin cells enriched to approximately 12% purity by means of density-dependent sedimentation but were less proficient for dispersed human lung mast cells, most likely because of other cell types that express GD3. CONCLUSION GD3 is expressed on the surface of developing human mast cells in parallel to tryptase in secretory granules and, like Kit, can serve as a target for their enrichment by immunoaffinity techniques.
Collapse
|
149
|
Lin CH, Tallaksen-Greene S, Chien WM, Cearley JA, Jackson WS, Crouse AB, Ren S, Li XJ, Albin RL, Detloff PJ. Neurological abnormalities in a knock-in mouse model of Huntington's disease. Hum Mol Genet 2001; 10:137-44. [PMID: 11152661 DOI: 10.1093/hmg/10.2.137] [Citation(s) in RCA: 432] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mice representing precise genetic replicas of Huntington's disease (HD) were made using gene targeting to replace the short CAG repeat of the mouse Huntington's disease gene homolog (HDH:) with CAG repeats within the length range found to cause HD in humans. Mice with alleles of approximately 150 units in length exhibit late-onset behavioral and neuroanatomic abnormalities consistent with HD. These symptoms include a motor task deficit, gait abnormalities, reactive gliosis and the formation of neuronal intranuclear inclusions predominating in the striatum. This model differs from previously described HDH: knock-ins by its method of construction, longer repeat length and more severe phenotype. To our knowledge, this is the first knock-in mouse model of HD to show increased glial fibrillary acidic protein immunoreactivity in the striatum, suggesting that these mice have neuronal injury similar to that found early in the course of HD. These mice will serve as useful reagents in experiments designed to reveal the molecular nature of neuronal dysfunction underlying HD.
Collapse
|
150
|
Zhang X, Li Y, Ren S, Kuang P, Wu W, Zhang F, Liu J. Efficacy and effect of SI17 therapy on pancreatic polypeptide in vascular and tension-type headache. J TRADIT CHIN MED 2000; 20:206-9. [PMID: 11038985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND AND PURPOSE Vascular and tension-type headache is most commonly encountered, and SI17 therapy has been tested to treat headache with good results. The efficacy of SI17 therapy for vascular and tension-type headache was compared and the effect of SI17 therapy on pancreatic polypeptide (PP) was studied. MATERIALS AND METHODS 29 cases of vascular headache (20 cases in acute attack during the trial) and 27 cases of tension-type headache (19 cases in acute attack) were enrolled in the study. Plasma PP level before and 4th day after treatment was measured by radioimmunoassay. RESULTS SI17 therapy is better for the treatment of vascular headache. Vascular headache with higher PP level and tension-type headache with normal PP level had good therapeutic results. CONCLUSION The clinical efficacy is better for vascular headache with the increase of vagus tension and for tension-type headache with normal vagus tension.
Collapse
|