151
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Yang Y, Deng C, Peng J. [Vacuolation effect of Helicobacter pylori on gastric epithelial cells]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 2001; 41:646-9. [PMID: 12552817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
This study was designed to observe vacuolation effect of Helicobacter pylori on gastric epithelial cells. The H. pylori isolates derived from patients with peptic ulcer, chronic gastritis and gastric cancer were plated on common selective medium and their vacuolation effects on SGC-7901 cells were compared. The percentage of H. pylori(Tox+) strain in clinical isolates from different gastroduodenal diseases had no significant difference. The toxicity of the H. pylori (Tox+) strain from peptic ulcer was significantly higher than that from chronic gasritis.
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152
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Liao X, Wang Y, Deng C. [The relativity study of thrombopoietin and chronic idiopathic thrombocytopenic purpura]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2001; 22:473-5. [PMID: 11758228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To explore the relationship between thrombopoietin (Tpo) levels and reticulated platelet (RP), blood platelet count (BPC), maturity of megakaryocytes in patients with chronic idiopathic thrombocytopenic purpura (CITP), and the prediction evaluation according to Tpo levels. METHODS Serum level of Tpo was measured by a sandwich-ELISA procedure, RP by flow cytometry after stained with thizole orange (TO), and maturity of megakaryocytes by laser scanning confocal microscopy (LSCM). RESULTS The serum level of Tpo was (204.05 +/- 65.70) ng/L in 23 normal controls and (345.46 +/- 222.23) ng/L in 33 patients with CITP, being no significant difference between the two groups (P > 0.05). Compared with controls, serum Tpo levels in 22 aplastic anemia(AA) patients [(1427.62 +/- 468.84) ng/L] and 10 acute myelogenous leukemia (AML) patients [(596.09 +/- 462.95) ng/L] were increased significantly (P < 0.05). The RPC was significantly lower in AA and AML patients (P < 0.05). The RP% was increased significantly in CITP and AML patients (P < 0.05). The Tpo level was higher in CITP patients with no response to glucocorticoid therapy than in those with response (P < 0.05). CONCLUSION Serum level of Tpo was not increased in patients with CITP. The RP%, RPC and Tpo levels could reflect thrombocytopoiesis and differentiate the causes of thrombocytopenia. The serum level of Tpo could be useful in prediction of the response to therapy in CITP patients.
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153
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Deng C, Saunders WS. ADY1, a novel gene required for prospore membrane formation at selected spindle poles in Saccharomyces cerevisiae. Mol Biol Cell 2001; 12:2646-59. [PMID: 11553705 PMCID: PMC59701 DOI: 10.1091/mbc.12.9.2646] [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] [Received: 12/15/2000] [Revised: 04/09/2001] [Accepted: 07/08/2001] [Indexed: 11/11/2022] Open
Abstract
ADY1 is identified in a genetic screen for genes on chromosome VIII of Saccharomyces cerevisiae that are required for sporulation. ADY1 is not required for meiotic recombination or meiotic chromosome segregation, but it is required for the formation of four spores inside an ascus. In the absence of ADY1, prospore formation is restricted to mainly one or two spindle poles per cell. Moreover, the two spores in the dyads of the ady1 mutant are predominantly nonsisters, suggesting that the proficiency to form prospores is not randomly distributed to the four spindle poles in the ady1 mutant. Interestingly, the meiosis-specific spindle pole body component Mpc54p, which is known to be required for prospore membrane formation, is localized predominantly to only one or two spindle poles per cell in the ady1 mutant. A partially functional Myc-Pfs1p is localized to the nucleus of mononucleate meiotic cells but not to the spindle pole body or prospore membrane. These results suggest that Pfs1p is specifically required for prospore formation at selected spindle poles, most likely by ensuring the functionality of all four spindle pole bodies of a cell during meiosis II.
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154
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Ito Y, Sarkar P, Mi Q, Wu N, Bringas P, Liu Y, Reddy S, Maxson R, Deng C, Chai Y. Overexpression of Smad2 reveals its concerted action with Smad4 in regulating TGF-beta-mediated epidermal homeostasis. Dev Biol 2001; 236:181-94. [PMID: 11456453 DOI: 10.1006/dbio.2001.0332] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Members of the transforming growth factor-beta (TGF-beta) superfamily are critical regulators for epithelial growth and can alter the differentiation of keratinocytes. Transduction of TGF-beta signaling depends on the phosphorylation and activation of Smad proteins by heteromeric complexes of ligand-specific type I and II receptors. To understand the function of TGF-beta and activin-specific Smad, we generated transgenic mice that overexpress Smad2 in epidermis under the control of keratin 14 promoter. Overexpression of Smad2 increases endogenous Smad4 and TGF-beta 1 expression while heterozygous loss of Smad2 reduces their expression levels, suggesting a concerted action of Smad2 and -4 in regulating TGF-beta signaling during skin development. These transgenic mice have delayed hair growth, underdeveloped ears, and shorter tails. In their skin, there is severe thickening of the epidermis with disorganized epidermal architecture, indistinguishable basement membrane, and dermal fibrosis. These abnormal phenotypes are due to increased proliferation of the basal epidermal cells and abnormalities in the program of keratinocyte differentiation. The ectodermally derived enamel structure is also abnormal. Collectively, our study presents the first in vivo evidence that, by providing an auto-feedback in TGF-beta signaling, Smad2 plays a pivotal role in regulating TGF-beta-mediated epidermal homeostasis.
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155
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Collins MH, Montone KT, Leahey AM, Hodinka RL, Salhany KE, Kramer DL, Deng C, Tomaszewski JE. Post-transplant lymphoproliferative disease in children. Pediatr Transplant 2001; 5:250-7. [PMID: 11472603 DOI: 10.1034/j.1399-3046.2001.005004250.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Epstein-Barr virus (EBV)-driven post-transplant lymphoproliferative disease (PTLD) is an important cause of morbidity and mortality following transplantation, and it occurs more frequently in children than in adults. Of 22 (5%) children at our institution who developed tissue-proven PTLD 1-60 months (mean 16.5 months) following organ transplant, 11 died: nine of these 22 patients developed PTLD between 1989 and 1993, and seven (78%) died; the remaining 13 developed PTLD between 1994 and 1998, and four (31%) died (p = 0.08). All nine patients who developed PTLD < 6 months after transplant died, but 11 of 13 patients who manifested disease > or = 6 months after transplant survived (p = 0.0002). Ten of 11 (91%) survivors, but only two of eight (25%) children who died, had serologic evidence of EBV infection at the time of PTLD diagnosis (p = 0.04). EBV seroconversion identified patients at risk for developing PTLD, but also characterized patients with sufficient immune function to survive EBV-related lymphoid proliferation. In situ hybridization for EBER1 mRNA was diagnostically helpful because it detected EBV in tissue sections of all 20 patients with B-cell PTLD, including those with negative serology.
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156
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Deng C, Kaplan G, Rogers LJ. Similarity of the song nuclei of male and female Australian magpies (Gymnorhina tibicen). Behav Brain Res 2001; 123:89-102. [PMID: 11377732 DOI: 10.1016/s0166-4328(01)00200-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The organisation of the song control nuclei of the Australian magpie (Gymnorhina tibicen), a species with highly complex song, was investigated. In contrast to most of the songbirds studied so far, the Australian magpie sings throughout the year and both males and females sing. All of the forebrain song nuclei, including the high vocal centre (HVC), the robust nucleus of the archistriatum (RA), Area X and the lateral and medial magnocellular nuclei of the anterior neostriatum (lMAN and mMAN) were found to be well developed in both male and female magpies. Consistent with the known vocal competence of juvenile magpies, all of the song nuclei were also well-developed in juvenile magpies (2--3 months old). HVC in both male and female magpies consists of a rostrolateral and a caudomedial region. The ventromedial part of RA differs from the dorsolateral part by having medium-sized neurons packed in higher density. The HVC to RA projections were labelled anterogradely by DiI and DiA. However, no HVC to Area X projections were labeled by DiI or DiA, suggesting a possible difference from songbirds studied previously.
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157
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Piek E, Ju WJ, Heyer J, Escalante-Alcalde D, Stewart CL, Weinstein M, Deng C, Kucherlapati R, Bottinger EP, Roberts AB. Functional characterization of transforming growth factor beta signaling in Smad2- and Smad3-deficient fibroblasts. J Biol Chem 2001; 276:19945-53. [PMID: 11262418 DOI: 10.1074/jbc.m102382200] [Citation(s) in RCA: 335] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A prominent pathway of transforming growth factor (TGF)-beta signaling involves receptor-dependent phosphorylation of Smad2 and Smad3, which then translocate to the nucleus to activate transcription of target genes. To investigate the relative importance of these two Smad proteins in TGF-beta1 signal transduction, we have utilized a loss of function approach, based on analysis of the effects of TGF-beta1 on fibroblasts derived from mouse embryos deficient in Smad2 (S2KO) or Smad3 (S3KO). TGF-beta1 caused 50% inhibition of cellular proliferation in wild-type fibroblasts as assessed by [(3)H]thymidine incorporation, whereas the growth of S2KO or S3KO cells was only weakly inhibited by TGF-beta1. Lack of Smad2 or Smad3 expression did not affect TGF-beta1-induced fibronectin synthesis but resulted in markedly suppressed induction of plasminogen activator inhibitor-1 by TGF-beta1. Moreover, TGF-beta1-mediated induction of matrix metalloproteinase-2 was selectively dependent on Smad2, whereas induction of c-fos, Smad7, and TGF-beta1 autoinduction relied on expression of Smad3. Investigation of transcriptional activation of TGF-beta-sensitive reporter genes in the different fibroblasts showed that activation of the (Smad binding element)(4)-Lux reporter by TGF-beta1 was dependent on expression of Smad3, but not Smad2, whereas activation of the activin response element-Lux reporter was strongly suppressed in S2KO fibroblasts but, on the contrary, enhanced in S3KO cells. Our findings indicate specific roles for Smad2 and Smad3 in TGF-beta1 signaling.
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158
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Yung R, Ray D, Eisenbraun JK, Deng C, Attwood J, Eisenbraun MD, Johnson K, Miller RA, Hanash S, Richardson B. Unexpected effects of a heterozygous dnmt1 null mutation on age-dependent DNA hypomethylation and autoimmunity. J Gerontol A Biol Sci Med Sci 2001; 56:B268-76. [PMID: 11382789 DOI: 10.1093/gerona/56.6.b268] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
DNA methylation modifies gene expression. Methylation patterns are established during ontogeny, but they change with aging, usually with a net decrease in methylation. The significance of this change in T cells is unknown, but it could contribute to autoimmunity, senescence, or both. We examined the effects of a null mutation in DNA methyltransferase 1 (Dnmt1), a gene maintaining DNA methylation patterns, on immune aging. Whereas aged control mice developed hypomethylated DNA, autoimmunity, and signs of immune senescence as predicted, the knockout mice surprisingly increased DNA methylation and developed signs of autoimmunity and senescence more slowly. To identify potential mechanisms, we compared transcripts of DNA methyltransferase and methylcytosine binding protein family members in control and knockout mice. MeCP2, a methylcytosine binding protein involved in gene suppression and chromatin inactivation, was the only transcript differentially expressed between old knockout mice and controls, and thus it is a candidate for a gene product mediating these effects.
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159
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Deng C, Fang X, Wan C. [Investigation on an outbreak of Legionnaires' disease caused by Lboz in a suburb of Beijing]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2001; 22:182-3. [PMID: 11860872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To demonstrate the infectious rates and incidence rates through epidemiological investigation. METHODS Serum samples from 203 new soldiers were detected from Lboz by TAT. RESULTS Infectious rates was 33.00% (67/203), and the incidence rates was 8.87% (18/203) with 2 cases of pneumonic type and 16 cases of pontiac fever type. CONCLUSION The results suggested that an outbreak of Legionnaires' desease caused by Legionella bozemanii (Lboz) took place in a suburb of Beijing. However the report of the outbreak caused by Lboz had not been found in related references.
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160
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Hong JY, Wang YY, Mohr SN, Bondoc FY, Deng C. Human cytochrome P450 isozymes in metabolism and health effects of gasoline ethers. Res Rep Health Eff Inst 2001:7-27; discussion 95-109. [PMID: 11504148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
To reduce the production of carbon monoxide and other pollutants in motor vehicle exhaust, methyl tert-butyl ether (MTBE*), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME) are added to gasoline as oxygenates for more complete combustion. Among them, MTBE is the most widely used. The possible adverse effect of MTBE in humans is a public concern, but the human enzymes responsible for metabolism of these gasoline ethers and the causes or factors for increased sensitivity to MTBE in certain individuals are totally unknown. This information is important to understanding the health effects of MTBE in humans and to assessing the human relevance of pharmacokinetics and toxicity data obtained from animals. In the present study, we demonstrated that human liver is active in metabolizing MTBE to tert-butyl alcohol (TBA), a major circulating metabolite and an exposure marker of MTBE. The activity is localized in the microsomal fraction but not in the cytosol. Formation of TBA in human liver microsomes is NADPH-dependent and is significantly inhibited by carbon monoxide, which inhibits cytochrome P450 (CYP) enzymes. These results provide strong evidence that CYP enzymes play a critical role in the metabolism of MTBE in human livers. Human liver is also active in the oxidative metabolism of 2 other gasoline ethers, ETBE and TAME. We observed a large interindividual variation in metabolizing these gasoline ethers in 15 microsomal samples prepared from normal human livers. The activity level (pmol metabolite/min/mg) ranged from 204 to 2,890 for MTBE; 179 to 3,134 for ETBE; and 271 to 8,532 for TAME. The microsomal activities in metabolizing MTBE, ETBE, and TAME correlated highly with each other (r = 0.91 to 0.96), suggesting that these ethers are metabolized by the same enzyme(s). Correlation analysis of the ether-metabolizing activities with individual CYP enzyme activities in the human liver microsomes showed that the highest degree of correlation was with CYP isoform 2A6 (CYP2A6)+ (r = 0.94 for MTBE, 0.95 for ETBE, and 0.90 for TAME), which is constitutively expressed in human livers and known to be polymorphic. CYP2A6 displayed the highest turnover number in metabolizing gasoline ethers among a battery of human CYP enzymes expressed in human B-lymphoblastoid cells. CYP2A6 coexpressed with human CYP reductase by a baculovirus expression system was also more active than CYP isoform 2E1 (CYP2E1) in the metabolism of MTBE, ETBE, and TAME. Kinetic studies on MTBE metabolism with human liver microsomes (n = 3) exhibited an apparent Michaelis constant (Km) of 28 to 89 microM and a maximum rate of metabolism (Vmax) of 215 to 783 pmol/min/mg. Metabolism of MTBE, ETBE, and TAME by human liver microsomes was inhibited by coumarin, a known substrate of human CYP2A6, in a concentration-dependent manner. Monoclonal antibody against human CYP2A6 caused a significant inhibition (75% to 95%) of the metabolism of MTBE, ETBE, and TAME in human liver microsomes. Taken together, these results clearly indicate that, in human liver, CYP2A6 is a major enzyme responsible for metabolism of MTBE, ETBE, and TAME. Although CYP2E1 metabolizes diethyl ether and was previously suggested to be involved
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161
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Tang Y, Deng C, Du Q, Li G, Zeng Z, Zhang J, Miu S. [Hypermethylation of the calcitonin gene as molecular genetic marker in detecting minimal residual disease of leukemia]. ZHONGHUA NEI KE ZA ZHI 2001; 40:226-8. [PMID: 11798580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To explore whether detecting minimal residual disease (MRD) of leukemia with hypermethylation of the calcitonin gene as molecular genetic marker of leukemic clone may predict the prognosis. METHODS Polymerase chain reaction (PCR) in combination with digestion of DNA with HpaII was used to examine the methylation patterns of the calcitonin gene in 29 cases with acute leukemia and 8 cases with transformation of chronic myeloid leukemia. By using PCR, MRD was longitudinally detected in patients who were positive for hypermethylation of the calcitonin gene as molecular genetic marker. RESULTS Twenty patients with acute leukemia and transformation of chronic myeloid leukemia had MRD after complete remission. Bone marrow relapse occurred soon when MRD persisted or reappeared. It may predict bone marrow relapse two to eleven months earlier. The patients who were negative for MRD early and remained persistently negative may acquire prolonged survival. CONCLUSION MRD of leukemia may be monitored by using PCR with hypermethylation of the calcitonin gene as molecular genetic marker for leukemic clone. It may prove useful in predicting the prognosis of leukemia.
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162
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Kawai H, Allende ML, Wada R, Kono M, Sango K, Deng C, Miyakawa T, Crawley JN, Werth N, Bierfreund U, Sandhoff K, Proia RL. Mice expressing only monosialoganglioside GM3 exhibit lethal audiogenic seizures. J Biol Chem 2001; 276:6885-8. [PMID: 11133999 DOI: 10.1074/jbc.c000847200] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gangliosides are a family of glycosphingolipids that contain sialic acid. Although they are abundant on neuronal cell membranes, their precise functions and importance in the central nervous system (CNS) remain largely undefined. We have disrupted the gene encoding GD3 synthase (GD3S), a sialyltransferase expressed in the CNS that is responsible for the synthesis of b-series gangliosides. GD3S-/- mice, even with an absence of b-series gangliosides, appear to undergo normal development and have a normal life span. To further restrict the expression of gangliosides, the GD3S mutant mice were crossbred with mice carrying a disrupted GalNAcT gene encoding beta1,4-N-acetylgalactosaminyltransferase. These double mutant mice expressed GM3 as their major ganglioside. In contrast to the single mutant mice, the double mutants displayed a sudden death phenotype and were extremely susceptible to induction of lethal seizures by sound stimulus. These results demonstrate unequivocally that gangliosides play an essential role in the proper functioning of the CNS.
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163
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Tang Y, Deng C, Du Q, Li G. [Study on hypermethylation of the calcitonin gene in malignant hematological disorders]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2001; 32:86-8. [PMID: 12733364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To investigate the clinical significance of hypermethylation of the calcitonin (CT) gene in malignant hematological disorders (MHD). METHODS Polymerase chain reaction (PCR) in combination with digestion of DNA with Hpa II was used to examine the methylation patterns of the CT gene in 73 patients with MHD, 6 healthy people and 24 patients with nonmalignant hematological disorders (NON-MHD). RESULTS Hypermethylation of the CT gene occurred in 12 of 14 (85.7%) patients with acute lymphoblastic leukemia (ALL), 9 of 15 (60%) acute nonlymphocytic leukemia (ANLL), 8 of 10 (80%) chronic myelogenous leukemia (CML), 5 of 15 (33.3%) malignant lymphoma (ML), 2 of 5 patients with myelodysplastic syndrome (MDS), 1 of 2 malignant histiocytosis (MH), 1 of 3 chronic lymphocytic leukemia (CLL) and 1 of 9 multiple myeloma (MM). However, it did not occur in normal controls and NON-MHD. CONCLUSION Hypermethylation of CT gene may serve as an important molecular maker for tumorous cell clone and may be useful in diagnosing MHD, monitoring minimal residual disease and predicting prognosis.
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164
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Chen L, Li C, Qiao W, Xu X, Deng C. A Ser(365)-->Cys mutation of fibroblast growth factor receptor 3 in mouse downregulates Ihh/PTHrP signals and causes severe achondroplasia. Hum Mol Genet 2001; 10:457-65. [PMID: 11181569 DOI: 10.1093/hmg/10.5.457] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Missense mutations in fibroblast growth factor receptor 3 (FGFR3) result in several types of human skeletal dysplasia, including the neonatally lethal dwarfism known as thanatophoric dysplasia. An engineered Ser(365)-->Cys substitution in mouse FGFR3, which is equivalent to a mutation associated with thanatophoric dysplasia-I in humans, has now been shown to cause severe dwarfism but not neonatal death. The mutant mice exhibit shortened limbs as a result of markedly reduced proliferation and impaired differentiation of growth plate chondrocytes. The receptor-activating mutation also resulted in downregulation of expression of the Indian hedgehog (IHH) and parathyroid hormone-related protein (PTHrP) receptor genes, both of which are important for bone growth. Interactions between FGFR3- and PTHrP-receptor-mediated signals during endochondral ossification were examined with embryonic metatarsal bones maintained in culture under defined conditions. Consistent with the in vivo observations, FGF2 inhibited bone growth in culture and induced downregulation of IHH and PTHrP receptor gene expression. Furthermore, PTHrP partially reversed the inhibition of long bone growth caused by activation of FGFR3; however, it impaired the differentiation of chondrocytes in an FGFR3-independent manner. These observations suggest that FGFR3 and IHH-PTHrP signals are transmitted by two interacting parallel pathways that mediate both overlapping and distinct functions during endochondral ossification.
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165
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Deng C, Goluszko E, Christadoss P. Fas/Fas ligand pathway, apoptosis, and clonal anergy involved in systemic acetylcholine receptor T cell epitope tolerance. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:3458-67. [PMID: 11207304 DOI: 10.4049/jimmunol.166.5.3458] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cellular mechanisms of high dose systemic acetylcholine receptor (AChR) T cell epitope, alpha 146--162 peptide-induced tolerance in experimental myasthenia gravis were examined. CD4 cells are the prime target for alpha 146--162 peptide-induced tolerance. The expression of CD69, Fas, and B7.2 molecules on AChR-immune lymphocytes was enhanced within 4--12 h after tolerance induction. A high dose of alpha 146--162 peptide in IFA failed to suppress T cell proliferation and/or clinical myasthenia gravis in lpr and gld mice deficient in Fas and Fas ligand, respectively. A high dose of alpha 146--162 peptide in IFA in AChR-immunized mice induced apoptosis of BV6 cells. Further, reconstitution of IL-2 in vitro-recovered alpha 146--162 peptide tolerized T cell proliferation, IFN-gamma, and IL-10 production. The findings implicate the possible role of Fas-/Fas ligand-mediated apoptosis and the resulting clonal anergy as the mechanisms of high dose AChR alpha 146--162 peptide-induced tolerance on CD4 cells.
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MESH Headings
- Adjuvants, Immunologic/administration & dosage
- Amino Acid Sequence
- Animals
- Antigens, CD/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Apoptosis/genetics
- Apoptosis/immunology
- Autoantibodies/biosynthesis
- B7-2 Antigen
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- Clonal Anergy/genetics
- Clonal Anergy/immunology
- Cytokines/biosynthesis
- Dose-Response Relationship, Immunologic
- Drug Administration Schedule
- Epitopes, T-Lymphocyte/immunology
- Fas Ligand Protein
- Freund's Adjuvant/administration & dosage
- Freund's Adjuvant/immunology
- Injections, Intraperitoneal
- Injections, Subcutaneous
- Kinetics
- Lectins, C-Type
- Ligands
- Lymph Nodes/cytology
- Lymph Nodes/immunology
- Lymph Nodes/metabolism
- Lymphocyte Activation/genetics
- Membrane Glycoproteins/biosynthesis
- Membrane Glycoproteins/deficiency
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/physiology
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mice, Inbred MRL lpr
- Mice, Knockout
- Molecular Sequence Data
- Myasthenia Gravis, Autoimmune, Experimental/genetics
- Myasthenia Gravis, Autoimmune, Experimental/immunology
- Myasthenia Gravis, Autoimmune, Experimental/prevention & control
- Peptide Fragments/administration & dosage
- Peptide Fragments/immunology
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Cholinergic/administration & dosage
- Receptors, Cholinergic/immunology
- Signal Transduction/genetics
- Signal Transduction/immunology
- Species Specificity
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Th1 Cells/immunology
- Th1 Cells/metabolism
- Th2 Cells/immunology
- Th2 Cells/metabolism
- Torpedo
- fas Receptor/biosynthesis
- fas Receptor/genetics
- fas Receptor/physiology
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166
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Arredondo LR, Deng C, Ratts RB, Lovett-Racke AE, Holtzman DM, Racke MK. Role of nerve growth factor in experimental autoimmune encephalomyelitis. Eur J Immunol 2001; 31:625-33. [PMID: 11180128 DOI: 10.1002/1521-4141(200102)31:2<625::aid-immu625>3.0.co;2-h] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The expression of neural regulatory molecules by immune cells that infiltrate the nervous system upon injury may be a mechanism for cross-regulation between the nervous system and the immune system. Several lines of evidence implicate nerve growth factor (NGF) signaling through its receptors (TrkA and p75(NGFR)) as a potential source of communication between the two systems. We observed changes in NGF mRNA expression and protein secretion by T lymphocytes polarized toward the Th2 phenotype. The presence of NGF did not affect T cell proliferation or cytokine production in vitro. Mice treated with NGF by i. p. injection following induction of experimental autoimmune encephalomyelitis, an inflammatory, demyelinating disease of the central nervous system, showed a delayed onset of disease and lower clinical scores during the course of disease. These data suggest a role for NGF signaling in the regulation of the immune response, possibly by enhancing sympathetic innervation of lymphoid tissues.
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167
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Deng C, Kaplan MJ, Yang J, Ray D, Zhang Z, McCune WJ, Hanash SM, Richardson BC. Decreased Ras-mitogen-activated protein kinase signaling may cause DNA hypomethylation in T lymphocytes from lupus patients. ARTHRITIS AND RHEUMATISM 2001; 44:397-407. [PMID: 11229472 DOI: 10.1002/1529-0131(200102)44:2<397::aid-anr59>3.0.co;2-n] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Previous studies have shown that inhibiting T cell DNA methylation causes a lupus-like disease by modifying gene expression. T cells from patients with lupus exhibit diminished levels of DNA methyltransferase (MTase) enzyme activity, hypomethylated DNA, and changes in gene expression similar to those exhibited by T cells treated with methylation inhibitors, suggesting that DNA hypomethylation may contribute to human lupus. Since it is known that DNA MTase levels are regulated by the ras-mitogen-activated protein kinase (MAPK) pathway, this study sought to determine whether decreased ras-MAPK signaling could account for the DNA hypomethylation in lupus T cells. METHODS DNA MTase messenger RNA (mRNA) from lupus patients and from healthy controls was quantitated by Northern analysis, and ras-MAPK signaling was determined by immunoblotting with antibodies to the activated forms of extracellular receptor-associated kinase (ERK). Results were compared with those in T cells in which ras-MAPK signaling was inhibited with a soluble inhibitor of MAPK ERK I (MEK1). RESULTS T cells from patients with active lupus had diminished DNA MTase mRNA levels and decreased signaling through the ras-MAPK pathway. Inhibiting signaling through the ras-MAPK pathway with the MEK1 inhibitor decreased DNA MTase mRNA and enzyme activity to the levels seen in lupus T cells, and resulted in DNA hypomethylation resembling that seen in lupus T cells. CONCLUSION These results suggest that a decrease in signaling through the ras-MAPK pathway may be responsible for the decreased MTase activity and DNA hypomethylation in patients with lupus.
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168
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Goluszko E, Hjelmström P, Deng C, Poussin MA, Ruddle NH, Christadoss P. Lymphotoxin-alpha deficiency completely protects C57BL/6 mice from developing clinical experimental autoimmune myasthenia gravis. J Neuroimmunol 2001; 113:109-18. [PMID: 11137582 DOI: 10.1016/s0165-5728(00)00420-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A complete prevention of clinical experimental autoimmune myasthenia gravis (EAMG) was observed in lymphotoxin (LT)-alpha deficient (LT-alpha(-/-)) mice compared to LT-alpha(+/+) mice when immunized with acetylcholine receptor. However, only a partial prevention of clinical EAMG incidence was observed in LT-beta(-/-) mice compared to LT-beta(+/+) mice. LT-alpha(-/-)and LT-beta(-/-) mice had lower mean titers of total IgG, IgG(1), IgG(2a) and IgG(2b) and higher or equal mean titers of IgM anti-AChR antibodies compared to controls. Therefore, LT-alpha(-/-)and LT-beta(-/-) AChR immunized mice are capable of mounting a primary (IgM) humoral immune response to AChR, but are less capable of switching to the pathogenic anti-AChR IgG isotypes. LT could play a significant role in the pathogenesis of myasthenia gravis.
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169
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Deng C, Zhu R, Jackson M, Verosub K, Singer M. Variability of the temperature-dependent susceptibility of the Holocene eolian deposits in the Chinese loess plateau: A pedogenesis indicator. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s1464-1895(01)00135-1] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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170
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Abstract
When a dose-response experiment is conducted, the enhanced responses can be observed at low doses. This phenomenon is often called hormesis. The enhanced responses at low doses does not necessarily mean the existence of hormesis. It is important to conduct statistical analyses to determine whether a departure from monotonic relationships is significantly different from the chance occurrence. This paper introduces a non-parametric rank test to detect hormesis. To illustrate the use of this method, we apply it to the data from a Whole Effluent Toxicity test. We demonstrate that the occurrence of hormesis can be statistically evaluated by using this non-parametric rank test.
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171
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Yun J, Schöneberg T, Liu J, Schulz A, Ecelbarger CA, Promeneur D, Nielsen S, Sheng H, Grinberg A, Deng C, Wess J. Generation and phenotype of mice harboring a nonsense mutation in the V2 vasopressin receptor gene. J Clin Invest 2000; 106:1361-71. [PMID: 11104789 PMCID: PMC381460 DOI: 10.1172/jci9154] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The V2 vasopressin receptor (V2R) plays a key role in the maintenance of a normal body water balance. To generate an in vivo model that allows the physiological and molecular analysis of the role of V2Rs in kidney function, we have created mouse lines that lack functional V2Rs by using targeted mutagenesis in mouse embryonic stem cells. Specifically, we introduced a nonsense mutation known to cause X-linked nephrogenic diabetes insipidus (XNDI) in humans (Glu242stop) into the mouse genome. V2R-deficient hemizygous male pups showed a decrease in basal urine osmolalities and were unable to concentrate their urine. These pups also exhibited an enlargement of renal pelvic space, failed to thrive, and died within the first week after birth due to hypernatremic dehydration. Interestingly, female mice heterozygous for the V2R mutation showed normal growth but displayed an XNDI-like phenotype, characterized by reduced urine concentrating ability of the kidney, polyuria, and polydipsia. Western blot analysis and immunoelectron microscopic studies showed that the loss of functional V2Rs had no significant effect on the basal expression levels of aquaporin-2 and the bumetanide-sensitive Na-K-2Cl cotransporter (BSC-1). The V2R mutant mice described here should serve as highly useful tools for the development of novel therapeutic strategies for the treatment of XNDI.
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Mahlknecht U, Deng C, Lu MC, Greenough TC, Sullivan JL, O'Brien WA, Herbein G. Resistance to apoptosis in HIV-infected CD4+ T lymphocytes is mediated by macrophages: role for Nef and immune activation in viral persistence. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:6437-46. [PMID: 11086083 DOI: 10.4049/jimmunol.165.11.6437] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Apoptosis or programmed cell death may play a critical role in AIDS pathogenesis through depletion of both CD4(+) and CD8(+) T lymphocytes. Using a reporter virus, a recombinant HIV infectious clone expressing the green fluorescent protein (GFP), apoptosis was measured in productively infected CD4(+) T lymphocytes, in the presence and absence of autologous macrophages. The presence of macrophages in the culture increased the frequency of nonapoptotic GFP-positive productively infected CD4(+) T lymphocytes. The appearance of nonapoptotic productively infected CD4(+) T lymphocytes in the culture required intercellular contacts between macrophages and PBLs and the expression of the HIV Nef protein. The presence of macrophages did not reduce apoptosis when CD4(+) T lymphocytes were infected with a GFP-tagged virus deleted for the nef gene. TNF-alpha (TNF) expressed on the surface of macrophages prevented apoptosis in nef-expressing, productively infected CD4(+) T lymphocytes. Similarly, following TNF stimulation, apoptosis was diminished in Jurkat T cells transfected with a nef-expressing plasmid. TNF stimulation of nef-expressing Jurkat T cells resulted in NF-kappaB hyperactivation, which has been shown to deliver anti-apoptotic signals. Our results indicate that intercellular contacts with macrophages increase the rate of productively infected nonapoptotic CD4(+) T lymphocytes. The survival of productively infected CD4(+) T lymphocytes requires Nef expression as well as activation by TNF expressed on the surface of macrophages and might participate in the formation and maintenance of viral reservoirs in HIV-infected persons.
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173
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Kaplan MJ, Deng C, Yang J, Richardson BC. DNA methylation in the regulation of T cell LFA-1 expression. Immunol Invest 2000; 29:411-25. [PMID: 11130783] [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]
Abstract
Inducing T cell LFA-1 overexpression by transfection, or by treatment with DNA methylation inhibitors including 5-azacytidine, procainamide and hydralazine, causes MHC-specific T cell autoreactivity in vitro and autoimmunity in vivo. How DNA methylation inhibitors increase LFA-1 expression is unknown. In this report we identify a mechanism by which DNA methylation affects LFA-1 expression. Nuclear run-on assays demonstrated that inhibiting DNA methylation increased transcription of CD11a but not CD18 or beta-actin mRNA. CD11a mRNA stability was not affected. Transfection of hypomethylated cells with reporter constructs containing the CD11a promoter showed no role for overexpression of transcription factors. However, the CD11a promoter demethylated following treatment with DNA methyltransferase inhibitors, and in vitro methylation of the construct suppressed its expression. Together, these results indicate that DNA methylation inhibitors can cause LFA-1 overexpression directly by demethylating the CD11a promoter. This mechanism could contribute to T cell autoreactivity, and potentially to autoimmunity.
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Deng C, Niu T, Xiang X, Meng W, Li S. [Clinical study on interferon treatment of chronic idiopathic thrombocytopenic purpura]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2000; 31:392-5. [PMID: 12545843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The efficacy and mechanism of interferon alpha-2a (IFN alpha-2a) were assessed in the treatment of chronic idiopathic thrombocytopenic purpura (cITP). 20 patients with cITP (treatment group) were treated with IFN alpha-2a 3MIU i.m. once a week for 8 weeks; 28 patients with cITP (control group) were treated with prednisone 1 mg/(kg.d) for 4 weeks. Blood platelet counts (BPC), megakaryocyte number, immunnological parameters, percent and absolute counts of reticulated platelets (RPs) and megakaryocyte colony formation units were observed before and after therapy. The results showed that the efficacy of IFN alpha-2a was better than that of corticosteroid, P < 0.05. The RPs% decreased and the platelet-producing megakaryocyte percentage increased from 11.43% to 33.19% significantly after IFN alpha-2a therapy, but there were no significant changes in immunnological parameters. These indicate that IFN alpha-2a is effective in treating cITP, the mechanism may be based on promoting the megakaryocyte development and activating the production of platelets.
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Hu X, Deng C, Ma R. [Current status of study on reversal of leukemia multi-drug resistance]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 2000; 20:715-8. [PMID: 11789180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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