276
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Stepkowski SM, Kirken RA, Nagy ZS, Trawick BW, Wang M, Tejpal N, Wang ME, Tian L, Clark J, Kahan BD. The role of Stat5 in the induction of regulatory T cells in transplantation tolerance. Transplant Proc 2001; 33:3835-6. [PMID: 11750634 DOI: 10.1016/s0041-1345(01)02624-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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277
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Chuang SK, Tian L, Wei LJ, Dodson TB. Kaplan-Meier analysis of dental implant survival: a strategy for estimating survival with clustered observations. J Dent Res 2001; 80:2016-20. [PMID: 11759013 DOI: 10.1177/00220345010800111301] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The study's purposes were to estimate dental implant survival in a statistically valid manner and to compare three models for estimating survival. We estimated survival using three different statistical models: (1) randomly selecting one implant per patient; (2) utilizing all implants, assuming independence among implants from the same subject; and (3) utilizing all implants, assuming dependence among implants from the same subject. The cohort was composed of 660 patients who had 2286 implants placed. Due to the high success rates of implants, the five-year survival point and standard error estimates varied little among the three models. Patients at high risk for implant failure (smokers) manifested greater variation in the standard error estimates among the three models, 8.2%, 4.0%, and 5.6%, respectively. To obtain statistically valid survival confidence intervals when performing Kaplan-Meier survival analyses, we recommend adjusting for dependence when there are multiple observations within the same subject.
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Stepkowski SM, Chen W, Bennett CF, Condon TP, Stecker K, Tian L, Kahan BD. Phosphorothioate/methoxyethyl-modified ICAM-1 antisense oligonucleotides improves prevention of ischemic/reperfusion injury. Transplant Proc 2001; 33:3705-6. [PMID: 11750578 DOI: 10.1016/s0041-1345(01)02511-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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279
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Tian L, DellaPenna D. Characterization of a second carotenoid beta-hydroxylase gene from Arabidopsis and its relationship to the LUT1 locus. PLANT MOLECULAR BIOLOGY 2001; 47:379-88. [PMID: 11587509 DOI: 10.1023/a:1011623907959] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Xanthophylls are oxygenated carotenoids that perform critical roles in plants. Beta-carotene hydroxylases (beta-hydroxylases) add hydroxyl groups to the beta-rings of carotenes and have been cloned from several bacteria and plants, including Arabidopsis. The lut1 mutation of Arabidopsis disrupts epsilon-ring hydroxylation and has been suggested to identify a related carotene hydroxylase that functions specifically on epsilon-ring structures. We have used library screening and genomics-based approaches to isolate a second beta-hydroxylase genomic clone and its corresponding cDNA from Arabidopsis. The encoded protein is 70% identical to the previously reported Arabidopsis beta-hydroxylase 1. Phylogenetic analysis indicates a common origin for the two proteins, however, their different chromosomal locations, intron positions and intron sizes suggest their duplication is not recent. Although both hydroxylases are expressed in all Arabidopsis tissues analyzed, beta-hydroxylase 1 mRNA is always present at higher levels. Both cDNAs encode proteins that efficiently hydroxylate the C-3 position of beta-ring containing carotenes and are only weakly active towards epsilon-ring containing carotenes. Neither beta-hydroxylase cDNA maps to the LUT1 locus, and the genomic region encompassing the LUT1 locus does not contain a third related hydroxylase. These data indicate that the LUT1 locus encodes a protein necessary for epsilon-ring hydroxylation but unrelated to beta-hydroxylases at the level of amino acid sequence.
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MESH Headings
- Amino Acid Sequence
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Blotting, Northern
- Chromosome Mapping
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- DNA, Plant/chemistry
- DNA, Plant/genetics
- Exons
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Genes, Plant/genetics
- Introns
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Mixed Function Oxygenases/genetics
- Mixed Function Oxygenases/metabolism
- Molecular Sequence Data
- Phylogeny
- Plant Proteins/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Substrate Specificity
- Tissue Distribution
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280
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Conner KR, Cox C, Duberstein PR, Tian L, Nisbet PA, Conwell Y. Violence, alcohol, and completed suicide: a case-control study. Am J Psychiatry 2001; 158:1701-5. [PMID: 11579005 DOI: 10.1176/appi.ajp.158.10.1701] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Violent behavior may represent a risk factor for suicide. The authors tested the hypothesis that violent behavior in the last year of life is associated with completed suicide, even after controlling for alcohol use disorders. METHOD The authors analyzed data from the 1993 National Mortality Followback Survey, a nationally representative survey conducted by telephone interview with decedents' next of kin. Data on 753 victims of suicide were compared with data on 2,115 accident victims. Decedents ranged in age from 20 to 64. Dichotomous measures of violent behavior in the past year and history of alcohol misuse were derived by using the four-item CAGE questionnaire. Multiple logistic regression was used to evaluate the interactions of violent behavior with alcohol misuse, gender, and age, respectively, in predicting suicide versus accidental death. Education and race were included as covariates. RESULTS Violent behavior in the last year of life was a significant predictor of suicide; the relationship was especially strong in individuals with no history of alcohol misuse, those who were younger, and women. CONCLUSIONS Violent behavior distinguished suicide victims from accident victims, and this finding is not attributable to alcohol use disorders alone. Given that violent behavior increases the risk of suicide, violence prevention initiatives may serve to decrease the risk of suicide as well.
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281
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Wei YQ, Huang MJ, Yang L, Zhao X, Tian L, Lu Y, Shu JM, Lu CJ, Niu T, Kang B, Mao YQ, Liu F, Wen YJ, Lei S, Luo F, Zhou LQ, Peng F, Jiang Y, Liu JY, Zhou H, Wang QR, He QM, Xiao F, Lou YY, Xie XJ, Li Q, Wu Y, Ding ZY, Hu B, Hu M, Zhang W. Immunogene therapy of tumors with vaccine based on Xenopus homologous vascular endothelial growth factor as a model antigen. Proc Natl Acad Sci U S A 2001; 98:11545-50. [PMID: 11553767 PMCID: PMC58766 DOI: 10.1073/pnas.191112198] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Overcoming immune tolerance of the growth factors associated with tumor growth should be a useful approach to cancer therapy by active immunity. We used vascular endothelial growth factor (VEGF) as a model antigen to explore the feasibility of the immunogene tumor therapy with a vaccine based on a single xenogeneic homologous gene, targeting the growth factors associated with angiogenesis. To test this concept, we constructed a plasmid DNA encoding Xenopus homologous VEGF (XVEGF-p) and control vectors. We found that immunogene tumor therapy with a vaccine based on XVEGF was effective at both protective and therapeutic antitumor immunity in several tumor models in mice. VEGF-specific autoantibodies in sera of mice immunized with XVEGF-p could be found in Western blotting analysis and ELISA assay. The purified immunoglobulins were effective at the inhibition of VEGF-mediated endothelial cell proliferation in vitro, and at antitumor activity and the inhibition of angiogenesis by adoptive transfer in vivo. The elevation of VEGF in the sera of the tumor-bearing mice could be abrogated with XVEGF-p immunization. The antitumor activity and production of VEGF-specific autoantibodies, significantly elevated IgG1 and IgG2b, could be abrogated by the depletion of CD4(+) T lymphocytes. The observations may provide a vaccine strategy for cancer therapy through the induction of autoimmunity against the growth factors associated with tumor growth in a cross reaction with single xenogeneic homologous gene and may be of importance in the further exploration of the applications of other xenogeneic homologous genes identified in human and other animal genome sequence projects in cancer therapy.
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282
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Qu X, Kirken RA, Tian L, Wang M, Bennett CF, Stepkowski SM. Selective inhibition of IL-2 gene expression by IL-2 antisense oligonucleotides blocks heart allograft rejection. Transplantation 2001; 72:915-23. [PMID: 11571459 DOI: 10.1097/00007890-200109150-00029] [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: 01/01/2023]
Abstract
PURPOSE We tested the effects of selective inhibition of interleukin (IL)-2 gene expression by IL-2 antisense oligonucleotide (oligo) with phosphorothioate (PS)/phosphodiester (PD)/2'-methoxyethyl (ME) modifications (17359) on T-cell function and the survival of heart allografts in mice. METHODS The PS- (17328) or PS/PD/ME- (17359) IL-2 oligo was electroporated to mouse T cell lymphoma cells (TIB 155) stimulated with concanavalin A (Con A). Expression of IL-2 was analyzed by an ELISA spot assay and a reverse transcript polymerase chain reaction method. C3H (H-2k) mice transplanted with BALB/c (H-2d) heart grafts were treated i.v. with a 7-day osmotic pump with 20 mg/kg 17359 alone or in combination with sirolimus (SRL). RESULTS In comparison with untreated controls, 500 to 2000 nM 17328 inhibited IL-2 protein production by 21.8% to 47.2%, whereas 500 to 2000 nM 17359 did so by 35.5% to 83.5% (both P<0.001). In vivo, 20 mg/kg 17359 prolonged survivals to a mean survival time (MST) of 18.3+/-2.6 days (P<0.001) in comparison with only 8.2+/-0.8 days in untreated controls. Although 0.2 mg/kg SRL alone produced a MST of 18.8+/-6.0 days (P<0.01), addition of 20 mg/kg 17539 synergistically extended survivals to 54.3+/-12.1 days (P<0.001). As expected, IL-2 mRNA, but not IL-7, IL-9, or IL-15 mRNA, was reduced in allografts from recipients treated with 17359 compared with untreated controls. Lymph node cells from the same recipients displayed reduction in proliferative response to donor alloantigen and in generation of alloantigen-specific cytotoxic T cells. CONCLUSION Selective inhibition of IL-2 mRNA in vivo inhibits T-cell function and extends allograft survival.
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283
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Foster AM, Tian L, Wei LJ. Estimation for the Box-Cox Transformation Model Without Assuming Parametric Error Distribution. J Am Stat Assoc 2001. [DOI: 10.1198/016214501753208753] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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284
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Richter BW, Mir SS, Eiben LJ, Lewis J, Reffey SB, Frattini A, Tian L, Frank S, Youle RJ, Nelson DL, Notarangelo LD, Vezzoni P, Fearnhead HO, Duckett CS. Molecular cloning of ILP-2, a novel member of the inhibitor of apoptosis protein family. Mol Cell Biol 2001; 21:4292-301. [PMID: 11390657 PMCID: PMC87089 DOI: 10.1128/mcb.21.13.4292-4301.2001] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Inhibitor of apoptosis protein (IAP)-like protein-1 (ILP-1) (also known as X-linked IAP [XIAP] and mammalian IAP homolog A [MIHA]) is a potent inhibitor of apoptosis and exerts its effects, at least in part, by the direct association with and inhibition of specific caspases. Here, we describe the molecular cloning and characterization of a human gene related to ILP-1, termed ILP-2. Despite high homology to ILP-1, ILP-2 is encoded by a distinct gene, which in normal tissues is expressed solely in testis. In contrast to ILP-1, overexpression of ILP-2 had no protective effect on apoptosis mediated by Fas (also known as CD95) or tumor necrosis factor. However, ILP-2 potently inhibited apoptosis induced by overexpression of Bax or by coexpression of caspase 9 with Apaf-1, and preincubation of cytosolic extracts with ILP-2 abrogated caspase activation in vitro. A processed form of caspase 9 could be coprecipitated with ILP-2 from cells, suggesting a physical interaction between ILP-2 and caspase 9. Thus, ILP-2 is a novel IAP family member with restricted specificity for caspase 9.
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285
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Wu K, Malik K, Tian L, Hu M, Martin T, Foster E, Brown D, Miki B. Enhancers and core promoter elements are essential for the activity of a cryptic gene activation sequence from tobacco, tCUP. Mol Genet Genomics 2001; 265:763-70. [PMID: 11523793 DOI: 10.1007/s004380100478] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cryptic gene regulatory elements are sequences that are inactive at their native locations in the genome but have the ability to become functional when positioned adjacent to genes. We have recently isolated such a cryptic sequence from tobacco, tCUP, that can act as a promoter. A 135-bp fragment spanning extending from position -197 to -62, relative to the transcription start site, was found to promote GUS expression in all of the major organs of transgenic Arabidopsis plants. Furthermore, this 135-bp fragment complemented the -46 minimal promoter of CaMV 35S and conferred constitutive expression on transgenic Arabidopsis plants. An electrophoretic mobility-shift assay showed that nuclear proteins prepared from tobacco leaves interact with the 135-bp fragment. tCUP has a core promoter that lacks the TATA consensus sequence but addition of a TATA-box sequence increased the core promoter activity by three-fold. The sequence surrounding the transcription start site of tCUP has sequence similarity with the initiator element (Inr), and deletion of this sequence significantly reduced promoter activity, suggesting that an essential Inr element may exist in the tCUP core promoter. Fusion of the GCC-box enhancer element from pathogenesis-related genes to the core promoter elevated tCUP core promoter activity. Our study indicates that cryptic promoters are similar in composition and organization to promoters associated with expressed genes and that their promoter elements can be combined to create composite promoters that are fully functional. This data provides direct evidence that the expression pattern of plant genes can be influenced by cryptic gene regulatory elements when they are brought into juxtaposition with genes through DNA rearrangements.
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286
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Ma QP, Tian L. A-fibres sprouting from lamina I into lamina II of spinal dorsal horn after peripheral nerve injury in rats. Brain Res 2001; 904:137-40. [PMID: 11516419 DOI: 10.1016/s0006-8993(01)02420-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have examined the labeling pattern in the spinal dorsal horn by an intra-sciatic nerve injection of cholera toxin B subunit conjugated horseradish peroxidase (HRP) after transection of the posterior cutaneous nerve and inferior gluteal nerve, and found that the cholera toxin B subunit conjugated HRP labeling in lamina I was expanding into lamina II and there was a shrinking gap between lamina I and lamina III. This result suggests that A-fibre sprouting arise after peripheral nerve injury, but mainly from small calibre Adelta-fibres which terminate in lamina I.
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287
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Abstract
X-linked agammaglobulinemia (XLA), caused by mutations in Bruton's tyrosine kinase (BTK), typically presents in early childhood. We report here the case of a male diagnosed at age 23 years with hypogammaglobulinemia, originally classified as common variable immunodeficiency (CVID). On further analysis at age 40, flow cytometric analysis of lymphocytes showed only 0.1% B cells and Western blot analysis showed a deficiency of BTK protein in peripheral blood mononuclear cells, indicating the patient has XLA. BTK cDNA and genomic DNA analysis revealed a splice site mutation at the 3' end of intron 13. Multiple abnormally spliced mRNA species were identified, one of which was predicted to produce a protein with a 24-amino-acid insertion between the SH2 and kinase domains. In vitro kinase assay of this product showed weak kinase activity, perhaps resulting in milder than usual disease. XLA can present in adult males, and sporadic cases may be misdiagnosed as CVID.
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288
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Tian L, Duncan RR, Hammond MS, Coghill LS, Wen H, Rusinova R, Clark AG, Levitan IB, Shipston MJ. Alternative splicing switches potassium channel sensitivity to protein phosphorylation. J Biol Chem 2001; 276:7717-20. [PMID: 11244090 DOI: 10.1074/jbc.c000741200] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Alternative exon splicing and reversible protein phosphorylation of large conductance calcium-activated potassium (BK) channels represent fundamental control mechanisms for the regulation of cellular excitability. BK channels are encoded by a single gene that undergoes extensive, hormonally regulated exon splicing. In native tissues BK channels display considerable diversity and plasticity in their regulation by cAMP-dependent protein kinase (PKA). Differential regulation of alternatively spliced BK channels by PKA may provide a molecular basis for the diversity and plasticity of BK channel sensitivities to PKA. Here we demonstrate that PKA activates BK channels lacking splice inserts (ZERO) but inhibits channels expressing a 59-amino acid exon at splice site 2 (STREX-1). Channel activation is dependent upon a conserved C-terminal PKA consensus motif (S869), whereas inhibition is mediated via a STREX-1 exon-specific PKA consensus site. Thus, alternative splicing acts as a molecular switch to determine the sensitivity of potassium channels to protein phosphorylation.
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289
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Lan Q, Feng Z, Tian D, He X, Rothman N, Tian L, Lu X, Terry MB, Mumford JL. p53 gene expression in relation to indoor exposure to unvented coal smoke in Xuan Wei, China. J Occup Environ Med 2001; 43:226-30. [PMID: 11285870 DOI: 10.1097/00043764-200103000-00010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Lung cancer mortality rates in Xuan Wei County, which are among the highest in China, have previously been associated with exposure to indoor emissions from burning smoky coal. To determine if this association is stronger among lung cancer patients with abnormal expression of p53, we performed a population-based case-control study. Ninety-seven newly diagnosed lung cancer patients and 97 controls, individually matched by age, sex, and home fuel type, were enrolled. We used immunocytochemical methods to assess p53 protein accumulation in exfoliated tumor cells isolated from sputum samples. As expected, the amount of lifetime smoky coal use was associated with an overall increase in lung cancer risk. Compared with subjects who used less than 130 tons of smoky coal during their lifetime, the odds ratios (OR) for lung cancer were 1.48 (95% confidence interval [CI], 0.73 to 3.02) for subjects exposed to 130 to 240 tons, and 3.21 (95% CI, 1.23 to 9.03) for subjects who used more than 240 tons of smoky coal (P for trend 0.01). The effect was due almost exclusively to the pattern in women, almost all of whom were nonsmokers. Further, among highly exposed women, the association was substantially larger and achieved statistical significance only among patients with sputum samples that were positive for p53 overexpression (OR, 18.72; 95% CI, 1.77 to 383.38 vs OR, 4.80; 95% CI, 0.66 to 43.87 for p53-negative cases). This study suggests that exposure to the combustion products of smoky coal in Xuan Wei is more strongly associated with women who have lung cancer accompanied by p53 protein overexpression in exfoliated tumor cells.
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290
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Tian L, Qu X, Wang ME, Kirken RA, Bennett FC, Stepkowski SM. Selective inhibition of IL-2 mRNA blocks allograft rejection by limiting T cell clonal expansion. Transplant Proc 2001; 33:330. [PMID: 11266845 DOI: 10.1016/s0041-1345(00)02796-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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291
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Xie X, Tian L, Wei Y. [Progress in targeting gene therapy]. ZHONGHUA YI XUE YI CHUAN XUE ZA ZHI = ZHONGHUA YIXUE YICHUANXUE ZAZHI = CHINESE JOURNAL OF MEDICAL GENETICS 2001; 18:59-61. [PMID: 11172646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
In recent years the research on targeting in gene therapy has made much exciting progress. Many new technologies show great promising prospects such as the delivery of therapeutic gene to targeted cells by some antibodies or ligands, the use of specific gene promoter to tightly control gene expression within disease microenvironment, the use of some orally taken drugs for regulating expression time and expression level of DNA, and the targeted correction of deleted or mutated gene using RNA/DNA oligonucleotides. Yet, researchers still have a long way to go in order to reach the goal of applying the targeting gene therapy in clinical practice.
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292
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Chen W, Bennett CF, Condon TP, Stecker K, Tian L, Kahan BD, Stepkowski SM. Methoxyethyl modification of phosphorothioate ICAM-1 antisense oligonucleotides improves prevention of ischemic/reperfusion injury. Transplant Proc 2001; 33:854. [PMID: 11267100 DOI: 10.1016/s0041-1345(00)02803-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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293
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Guo WH, Tian L, Chan KL, Dallman M, Tam PK. Role of CD4+ and CD8+ T cells in early and late acute rejection of small bowel allograft. J Pediatr Surg 2001; 36:352-6. [PMID: 11172433 DOI: 10.1053/jpsu.2001.20715] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND/PURPOSE Results of small bowel transplantation remain unsatisfactory because of severe immune rejection. The current study aims to elucidate the role of activation of CD4+ and CD8+ T cells in early and late acute rejection of small bowel allograft and, hence, provide the immunologic basis for developing new therapeutic strategies. METHODS We used an MHC fully mismatched (DA to Lewis) heterotopic rat small bowel transplant model and a unique FK506-based immunosuppressive regimen, which suppresses early acute rejection but does not prevent late acute rejection. Flow cytometric analysis was used to quantitate the number of activated CD4+ and CD8+ T cells in graft and host mesenteric lymph nodes. RESULTS The survival (mean +/- SD) of intestinal allograft was significantly prolonged, from 6.6 +/- 0.84 days for the untreated group to 40.7 +/- 14.1 days for the FK506-treated group. Activation of CD4+ cells was suppressed significantly in the FK506-treated group on postoperative day 7 compared with the untreated group (29.4% +/- 3.55% v 52.83% +/- 11.9%; P <.01). Activation of CD8+ cells was similarly suppressed (31.5 +/- 10.34% v 48.53 +/- 14.34%; P <.05). Interestingly, at late acute rejection, activated CD4+ and CD8+ T cells remained at almost the same low levels as those on postoperative day 7 in the FK506-treated group. The spleen to body weight ratio was significantly increased in the untreated group (0.53 +/- 0.07), and slightly increased in the FK treated group (0.27 +/- 0.07, on postoperative day 7; 0.24 +/- 0.07 at late acute rejection) compared with the syngeneic group (0.18 +/- 0.02). CONCLUSION The activation of CD4+ and CD8+ T cells was suppressed effectively by early potent immunosuppressive treatment resulting in prolonged survival of intestinal allograft. At late acute rejection, the CD4+ and CD8+ T cells remained at low-level activation status, in contrast to the surge of CD4+ and CD8+ activation during early acute rejection. This suggests that persistent T cell activation even at low level is sufficient to cause the late acute rejection eventually. A therapeutic strategy targeting these cells is needed for long-term engraftment.
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294
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Moehs CP, Tian L, Osteryoung KW, Dellapenna D. Analysis of carotenoid biosynthetic gene expression during marigold petal development. PLANT MOLECULAR BIOLOGY 2001; 45:281-93. [PMID: 11292074 DOI: 10.1023/a:1006417009203] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Marigold (Tagetes erecta L.) flower petals synthesize and accumulate carotenoids at levels greater than 20 times that in leaves and provide an excellent model system to investigate the molecular biology and biochemistry of carotenoid biosynthesis in plants. In addition, marigold cultivars exist with flower colors ranging from white to dark orange due to >100-fold differences in carotenoid levels, and presumably similar changes in carbon flux through the pathway. To examine the expression of carotenoid genes in marigold petals, we have cloned the majority of the genes in this pathway and used these to assess their steady-state mRNA levels in four marigold cultivars with extreme differences in carotenoid content. We have also cloned genes encoding early steps in the biosynthesis of isopentenyl pyrophosphate (IPP), the precursor of all isoprenoids, including carotenoids, as well as two genes required for plastid division. Differences among the marigold varieties in the expression of these genes suggest that differences in mRNA transcription or stability underlie the vast differences in carotenoid synthesis and accumulation in the different marigold varieties.
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MESH Headings
- Blotting, Northern
- Carotenoids/analysis
- Carotenoids/biosynthesis
- Chromatography, High Pressure Liquid
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Gene Expression Profiling
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Plant
- Molecular Sequence Data
- Plant Leaves/genetics
- Plant Leaves/growth & development
- Plants, Medicinal/genetics
- Plants, Medicinal/growth & development
- Plants, Medicinal/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Analysis, DNA
- Species Specificity
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295
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Tian L, Chen ZJ. Blocking histone deacetylation in Arabidopsis induces pleiotropic effects on plant gene regulation and development. Proc Natl Acad Sci U S A 2001; 98:200-5. [PMID: 11134508 PMCID: PMC14568 DOI: 10.1073/pnas.98.1.200] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2000] [Indexed: 12/25/2022] Open
Abstract
Histone acetylation and deacetylation play essential roles in eukaryotic gene regulation. Reversible modifications of core histones are catalyzed by two intrinsic enzymes, histone acetyltransferase and histone deacetylase (HD). In general, histone deacetylation is related to transcriptional gene silencing, whereas acetylation correlates with gene activation. We produced transgenic plants expressing the antisense Arabidopsis HD (AtHD1) gene. AtHD1 is a homolog of human HD1 and RPD3 global transcriptional regulator in yeast. Expression of the antisense AtHD1 caused dramatic reduction in endogenous AtHD1 transcription, resulting in accumulation of acetylated histones, notably tetraacetylated H4. Reduction in AtHD1 expression and AtHD1 production and changes in acetylation profiles were associated with various developmental abnormalities, including early senescence, ectopic expression of silenced genes, suppression of apical dominance, homeotic changes, heterochronic shift toward juvenility, flower defects, and male and female sterility. Some of the phenotypes could be attributed to ectopic expression of tissue-specific genes (e.g., SUPERMAN) in vegetative tissues. No changes in genomic DNA methylation were detected in the transgenic plants. These results suggest that AtHD1 is a global regulator, which controls gene expression during development through DNA-sequence independent or epigenetic mechanisms in plants. In addition to DNA methylation, histone modifications may be involved in a general regulatory mechanism responsible for plant plasticity and variation in nature.
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296
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Heymsfield GM, Geerts B, Tian L. TRMM Precipitation Radar Reflectivity Profiles as Compared with High-Resolution Airborne and Ground-Based Radar Measurements. ACTA ACUST UNITED AC 2000. [DOI: 10.1175/1520-0450(2001)040<2080:tprrpa>2.0.co;2] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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297
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Kurtz DM, Tian L, Gower BA, Nagy TR, Pinkert CA, Wood PA. Transgenic studies of fatty acid oxidation gene expression in nonobese diabetic mice. J Lipid Res 2000; 41:2063-70. [PMID: 11108740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Type 1 diabetes mellitus is a devastating disorder affecting both glucose and lipid metabolism. Using the nonobese diabetic (NOD) mouse model, we found that diabetic mice had a liver-specific increase in steady state mRNA levels for enzymes involved in oxidation of fatty acids. Increased mRNA abundance was observed in very long-chain acyl-CoA dehydrogenase, long-chain acyl-CoA dehydrogenase (LCAD), medium-chain acyl-CoA dehydrogenase (MCAD), carnitine palmitoyltransferase I (CPT-1a), and the gluconeogenic enzyme phosphoenolpyruvate carboxykinase, whereas short-chain acyl-CoA dehydrogenase mRNA remained unchanged. In contrast, minimal elevations in LCAD and CPT-1a mRNA were observed in hearts of diabetic mice with no significant differences found for the other enzymes. We developed NOD mice with transgenes containing regulatory elements of human MCAD gene controlling a reporter gene to determine if the increase in MCAD gene expression occurred via the well-characterized nuclear receptor response element (NRRE-1). These results demonstrated that the transgene containing the NRRE-1 and adjacent 5' sequences had elevated liver expression in diabetic mice compared with prediabetic or normal control mice. Surprisingly, the transgene that contains NRRE-1 with adjacent 3' sequences and the transgene with the NRRE-1 deleted showed minimal response to the fulminant diabetic condition.Collectively, these results indicate that in type 1 diabetes there exists an excessive and liver-specific activation of fatty acid oxidation gene expression. Using human MCAD as a prototype gene, we have shown that this increased expression is mediated at the transcriptional level but does not occur via the well-characterized NRRE-1 site responsible for baseline expression in normal mice.
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MESH Headings
- Acyl-CoA Dehydrogenase, Long-Chain/genetics
- Acyl-CoA Dehydrogenase, Long-Chain/metabolism
- Animals
- Base Sequence
- Chloramphenicol O-Acetyltransferase/genetics
- DNA
- Diabetes Mellitus, Type 1/enzymology
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/metabolism
- Fatty Acids/metabolism
- Mice
- Mice, Inbred NOD
- Mice, Transgenic
- Molecular Sequence Data
- Oxidation-Reduction
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Regulatory Sequences, Nucleic Acid
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298
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Guo WH, Tian L, Yuen ZW, Chan KL, Wo JY, Nicholls G, Dallman M, Tam PK. Recipient FK506 pretreatment regimens in rat small bowel transplantation: allograft survival, function, and systemic infection. J Pediatr Surg 2000; 35:1600-5. [PMID: 11083432 DOI: 10.1053/jpsu.2000.18326] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE Successful small bowel transplantation requires effective immunosuppression that preserves intestinal function but avoids opportunistic infection. This study aims to evaluate FK506 as a single immunosuppressant in different pretreatment regimens in a rat high responder strain combination. METHODS Lewis --> DA rat heterotopic small bowel transplantation was performed. Studied groups were (1) untreated control, n = 12; (2) FK-1, n = 8; (3) FK-3, n = 8. FK506 (2 mg/kg/d, intramuscularly) was given to the recipients for 1 day (FK-1) and 3 days (FK-3) before small bowel transplantation, followed by 2 weeks of subtherapeutic treatment (0.3 mg/kg/d, intramuscularly) after small bowel transplantation. Syngeneic small bowel transplantation also was performed (n = 8). FK blood levels, maltose absorption test, histology, and bacteriology were performed at different postoperative days. RESULTS Allograft survival was prolonged significantly with FK pretreatment, being more so in FK-3 group (FK-1, 22.2 +/- 1.5 d; FK-3, 40.7 +/- 14.1 d; control, 6.6 +/- 0.8 d; P< .01). In the first postoperative week, FK blood level was significantly higher in FK-3 group (19.8 +/- 1.5 ng/mL) than in FK-1 group (5.0 +/- 0.4 ng/mL; P < .05). There was no evidence of systemic infection in either FK-treated group. For maltose absorption, control allograft was abnormal on day 7 correlating to severely damaged intestinal architecture. In contrast, FK-treated allografts showed well-protected intestinal structure and normal absorption on days 7 and 21. CONCLUSION High FK506 blood levels in the first postoperative week, achieved with FK pretreatment, prolonged intestinal allograft survival and preserved intestinal structure and function without allowing systemic infection.
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299
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Wei YQ, Wang QR, Zhao X, Yang L, Tian L, Lu Y, Kang B, Lu CJ, Huang MJ, Lou YY, Xiao F, He QM, Shu JM, Xie XJ, Mao YQ, Lei S, Luo F, Zhou LQ, Liu CE, Zhou H, Jiang Y, Peng F, Yuan LP, Li Q, Wu Y, Liu JY. Immunotherapy of tumors with xenogeneic endothelial cells as a vaccine. Nat Med 2000; 6:1160-6. [PMID: 11017149 DOI: 10.1038/80506] [Citation(s) in RCA: 198] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The breaking of immune tolerance against autologous angiogenic endothelial cells should be a useful approach for cancer therapy. Here we show that immunotherapy of tumors using fixed xenogeneic whole endothelial cells as a vaccine was effective in affording protection from tumor growth, inducing regression of established tumors and prolonging survival of tumor-bearing mice. Furthermore, autoreactive immunity targeting to microvessels in solid tumors was induced and was probably responsible for the anti-tumor activity. These observations may provide a new vaccine strategy for cancer therapy through the induction of an autoimmune response against the tumor endothelium in a cross-reaction.
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300
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Wu K, Malik K, Tian L, Brown D, Miki B. Functional analysis of a RPD3 histone deacetylase homologue in Arabidopsis thaliana. PLANT MOLECULAR BIOLOGY 2000; 44:167-76. [PMID: 11117260 DOI: 10.1023/a:1006498413543] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Histone acetylation is modulated through the action of histone acetyltransferase and deacetylase, which play key roles in the regulation of eukaryotic gene expression. We have screened the expressed sequence tag database with the yeast histone deacetylase RPD3 sequence and identified two Arabidopsis homologues, AtRPD3A and AtRPD3B. The deduced amino acid sequences of AtRPD3A and AtRPD3B show high overall homology (55% identity) to each other. AtRPD3A encodes a putative protein of 502 amino acids with 49% identity to the yeast RPD3. AtRPD3B encodes a putative protein of 471 amino acids and shares 55% amino acid identity with the yeast RPD3. Northern analysis indicated that AtRPD3A was highly expressed in the leaves, stems, flowers and young siliques of Arabidopsis plants, whereas the AtRPD3B transcript was not detected in these organs. An AtRPD3A fusion protein repressed transcription when directed to a promoter driving a reporter gene, indicating a role for AtRPD3A protein in gene repression. Arabidopsis plants were transformed with a gene construct comprising a truncated AtRPD3A cDNA in the antisense orientation driven by a strong constitutive promoter, -394tCUP. Antisense expression of AtRPD3A resulted in decreased endogenous AtRPD3A transcript and delayed flowering in transgenic Arabidopsis plants, suggesting that the transition from the vegetative to reproductive phase of development could be affected by histone acetylation. Our study demonstrates the important role of histone deacetylases in plant growth and development.
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MESH Headings
- Amino Acid Sequence
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Blotting, Northern
- DNA, Antisense/genetics
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Glucuronidase/genetics
- Glucuronidase/metabolism
- Histone Deacetylases/genetics
- Histone Deacetylases/metabolism
- Isoenzymes/genetics
- Isoenzymes/metabolism
- Molecular Sequence Data
- Phenotype
- RNA, Plant/genetics
- RNA, Plant/metabolism
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Tissue Distribution
- Transcription Factors/genetics
- Transcription Factors/metabolism
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