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Rao J, Ji X, Ouyang W, Zhao X, Lai X. Dilemma Analysis of China Agricultural Non-point Source Pollution Based on Peasants’ Household Surveys. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proenv.2012.01.206] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Xu Y, Li Y, Ouyang W, Hao F, Ding Z, Wang D. The impact of long-term agricultural development on the wetlands landscape pattern in Sanjiang Plain. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proenv.2012.01.186] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Corneth O, Mus AM, Asmawidjaja P, Ouyang W, Kil L, Hendriks R, Lubberts E. Impaired B cell immunity in IL-22 knock-out mice in collagen induced arthritis. Ann Rheum Dis 2011. [DOI: 10.1136/ard.2010.149005.3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Müller M, Ouyang W, Kessler B. Dichroic ATR-FTIR spectroscopy on oriented α-helical poly(l-lysine) multilayered with polyanions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:709-716. [PMID: 20833103 DOI: 10.1016/j.saa.2010.05.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 05/21/2010] [Accepted: 05/24/2010] [Indexed: 05/29/2023]
Abstract
The preparation and spectroscopic and microscopic characterization of oriented polyelectrolyte multilayers (PEM) interesting for defined nanostructured functional materials and surfaces are reviewed. Oriented PEM were generated by consecutively adsorbing α-helical poly(l-lysine) (PLL) and oppositely charged polyanions like poly(vinylsulfate) (PVS) or poly(styrene sulfonate) (PSS) at silicon substrates texturized by parallel nanoscopic surface grooves, respectively. Dichroic Attenuated Total Reflexion Fourier Transform Infrared (ATR-FTIR) spectroscopy was used to study the conformation and macromolecular order of stiff polyelectrolytes within PEM. High order parameters up to S=0.82 (S=1 for high, S=0 for low order) were obtained from the dichroic ratios of the Amide I and Amide II bands suggesting a significant alignment of charged α-helical polypeptides in PEM. For PEM consisting of PLL/polyanion the S values significantly increased with increasing molecular weight of PLL and with decreasing molecular weight of the polyanion. These spectroscopic findings were supported by SFM images on PEM-PLL/PVS with high molecular PLL and PEM-PLL/PSS with low molecular PSS, which both showed anisotropically oriented worm-like structures, while PEM-PLL/PVS with low molecular PLL and PEM-PLL/PSS with high molecular PSS showed no orientation features.
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Zhou Y, Xia L, He ZS, Ouyang W, Z H, Xie CH. Modulation of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in RAW264.7 cells by irradiation. Mol Med Rep 2010; 3:809-13. [PMID: 21472318 DOI: 10.3892/mmr.2010.326] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 06/02/2010] [Indexed: 11/05/2022] Open
Abstract
Radiation-induced pulmonary injury is a severe complication affecting the quality of life of patients. Although the pathophysiology of the process is not fully understood, we hypothesized that it is potentially related to macrophages and their secretion of matrix metalloproteinase-9 (MMP-9). Macrophages are a type of inflammatory cell that synthesize hundreds of bioactive substances and enzymes. MMP-9 is closely involved in the maintenance of the basilar membrane, and leads to increased extracellular matrix deposition within the lung, which is a characteristic feature of radiation-induced lung fibrosis. We examined the role of ionizing radiation in modulating the production of MMP-9 in a macrophage cell line. RAW264.7 cells were irradiated with various doses of γ-rays, and then MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were determined at several time points. RT-PCR revealed a marked increase in the levels of MMP-9 mRNA, which peaked at 24 h post-irradiation and had begun to decline by 48 h. By contrast, TIMP-1 mRNA experienced only a slight increase at 24 h post-irradiation, reaching significance at 48 h post-irradiation. Western blot analysis demonstrated an increased expression of MMP-9 protein in the irradiated cells, while TIMP-1 protein levels were not notably changed. Dexamethasone inhibited the increased expression of MMP-9 protein induced by ionizing radiation. These results indicate that MMP-9 expression by RAW264.7 cells, and an imbalance between MMP-9 and TIMP-1, may be involved in radiation-induced lung injury.
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Hu Y, Ouyang W, Wu F, Cao CH, Wang K, Liao ZK, Zhong YH, Zhou FX, Liu SQ, Xia L, Zhou YF, Xie CH. Enhanced radiosensitivity of SW480 cells via TRAIL up-regulation mediated by Egr-1 promoter. Oncol Rep 2009; 22:765-71. [PMID: 19724854 DOI: 10.3892/or_00000498] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Radiosensitization of cancer cells to irradiation could improve the efficacy of radiotherapy. The early transcriptional factor (Egr-1) promoter induced expression of downstream genes after irradiation. TNF-related apoptosis-inducing ligand (TRAIL) is known to induce apoptosis in malignant cells, but displayed little or no toxicity on normal cells. In this study, we constructed pcDNA3.1-Egr-1-TRAIL (pEgr.1-TRAIL) recombinant plasmid and evaluated its effect on human colon cancer cell line SW480. pEgr.1-TRAIL transfection combined with radiotherapy caused dramatically elevation of TRAIL expression both in mRNA and protein levels, much lower radiobiological parameters in clonogenic assays, accompanied by remarkably increase in apoptosis ratio. Furthermore, pEgr.1-TRAIL transfected cells displayed higher proportion in G0/G1 phase. Our results suggested that pEgr.1-TRAIL can sensitize SW480 cells to radiation, and the radiosensitization is related to cell cycle changes and apoptosis mediated by up-regulation of TRAIL expression. These findings support the potential future application of genetic radiotherapy against carcinoma.
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Müller M, Keßler B, Ouyang W. In-Situ-ATR-FTIR Detection of Protein Sorption at Polyelectrolyte Multilayers: Variation of the Thickness. Z PHYS CHEM 2009. [DOI: 10.1524/zpch.2007.221.1.127] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In-situ ATR FTIR spectroscopy was used to study protein adsorption at polyelectrolyte multilayers (PEM). PEM were fabricated by consecutively adsorbing poly(ethyleneimine) (PEI) and poly(acrylic acid) (PAC) analogously to the technique introduced by Decher at silicon internal reflection elements in an in-situ ATR cell. The thickness of PEM of PEI/PAC could be varied by pH value, concentration and number of adsorption steps. At this PEM system adsorption of human serum albumin was studied under electrostatically attractive conditions in dependence of the thickness. Evidence was found, that HSA was predominantly bound in the uncompensated outermost layer region rather than in the bulk phase of the PEM.
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Abstract
Recent studies in infectious disease and autoimmune disease models have revealed that interleukin (IL)-22 might have both proinflammatory and anti-inflammatory functions. There is, however, lack of evidence for IL-22 directly repressing immune responses of leukocytes. We propose that IL-22 promotes innate immunity of tissues, as well as repairing and healing mechanisms during inflammation. Consequently, the restoration of tissue homeostasis helps to attenuate the inflammatory responses involving various immune cells.
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Müller M, Ouyang W, Starchenko V, Keßler B. Polyelektrolytkomplex-Nanopartikel mit enger Größenverteilung: Präparation und Proteinbindung. CHEM-ING-TECH 2007. [DOI: 10.1002/cite.200750048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Chen H, Ouyang W, Jones M, Haque T, Lawuyi B, Prakash S. In-vitro analysis of APA microcapsules for oral delivery of live bacterial cells. J Microencapsul 2006; 22:539-47. [PMID: 16361197 DOI: 10.1080/02652040500162162] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Oral administration of microcapsules containing live bacterial cells has potential as an alternative therapy for several diseases. This article evaluates the suitability of the alginate-poly-L-lysine-alginate (APA) microcapsules for oral delivery of live bacterial cells, in-vitro, using a dynamic simulated human gastro-intestinal (GI) model. Results showed that the APA microcapsules were morphologically stable in the simulated stomach conditions, but did not retain their structural integrity after a 3-day exposure in simulated human GI media. The microbial populations of the tested bacterial cells and the activities of the tested enzymes in the simulated human GI suspension were not substantially altered by the presence of the APA microcapsules, suggesting that there were no significant adverse effects of oral administration of the APA microcapsules on the flora of the human gastrointestinal tract. When the APA microcapsules containing Lactobacillus plantarum 80 (LP80) were challenged in the simulated gastric medium (pH = 2.0), 80.0% of the encapsulated cells remained viable after a 5-min incubation; however, the viability decreased considerably (8.3%) after 15 min and dropped to 2.6% after 30 min and lower than 0.2% after 60 min, indicating the limitations of the currently obtainable APA membrane for oral delivery of live bacteria. Further in-vivo studies are required before conclusions can be made concerning the inadequacy of APA microcapsules for oral delivery of live bacterial cells.
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Abbas AR, Baldwin D, Ma Y, Ouyang W, Gurney A, Martin F, Fong S, van Lookeren Campagne M, Godowski P, Williams PM, Chan AC, Clark HF. Immune response in silico (IRIS): immune-specific genes identified from a compendium of microarray expression data. Genes Immun 2005; 6:319-31. [PMID: 15789058 DOI: 10.1038/sj.gene.6364173] [Citation(s) in RCA: 286] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Immune cell-specific expression is one indication of the importance of a gene's role in the immune response. We have compiled a compendium of microarray expression data for virtually all human genes from six key immune cell types and their activated and differentiated states. Immune Response In Silico (IRIS) is a collection of genes that have been selected for specific expression in immune cells. The expression pattern of IRIS genes recapitulates the phylogeny of immune cells in terms of the lineages of their differentiation. Gene Ontology assignments for IRIS genes reveal significant involvement in inflammation and immunity. Genes encoding CD antigens, cytokines, integrins and many other gene families playing key roles in the immune response are highly represented. IRIS also includes proteins of unknown function and expressed sequence tags that may not represent genes. The predicted cellular localization of IRIS proteins is evenly distributed between cell surface and intracellular compartments, indicating that immune specificity is important at many points in the signaling pathways of the immune response. IRIS provides a resource for further investigation into the function of the immune system and immune diseases.
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Müller M, Reihs T, Ouyang W. Needlelike and spherical polyelectrolyte complex nanoparticles of poly(l-lysine) and copolymers of maleic acid. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:465-469. [PMID: 15620340 DOI: 10.1021/la0483257] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report on the bulk and surface properties of dispersions consisting of nonstoichiometric polyelectrolyte complex (PEC) nanoparticles. PEC nanoparticles were prepared by mixing poly(l-lysine) (PLL) or poly(diallyldimethylammonium chloride) (PDADMAC) with poly(maleic acid-co-alpha-methylstyrene) (PMA-MS) or poly(maleic acid-co-propylene) (PMA-P). The monomolar mixing ratio was n-/n+ = 0.6, and the concentration ranged from 1 to 6 mmol/L. Subsequent centrifugation enabled the separation of the excess polycation, resulting in a stable coacervate phase further used in the experiments. The bulk phase parameters turbidity and hydrodynamic radius (R(h)) of the PEC nanoparticles showed a linear dependence on the total polymer content independently of the mixed polyelectrolytes. This can be interpreted by the increased collision probability of the polyelectrolyte chains when the overlap concentration is approached or exceeded. Different morphologies of the cationic PEC nanoparticles, which were solution-cast onto Si supports, were obtained by atomic force microscopy (AFM). The combinations of PLL/PMA-MS and PDADMAC/PMA-MS revealed more or less hemispherical particle shapes, whereas that of PLL/PMA-P revealed an elongated needlelike particle shape. Circular dichroism and attenuated total reflection Fourier transform infrared (ATR-FTIR) measurements proved the alpha-helical conformation for the PEC PLL/PMA-P and the random coil conformation for the PEC PLL/PMA-MS. We conclude that stiff alpha-helical PLL induces anisotropic elongated PEC nanoparticles, whereas randomly coiled PLL forms isotropic spherical PEC nanoparticles.
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Jones ML, Martoni C, Chen H, Ouyang W, Metz T, Prakash S. Deconjugation of bile acids with immobilized genetically engineeredLactobacillus plantarum80 (pCBH1). Appl Bionics Biomech 2005. [DOI: 10.1533/abbi.2004.0018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Qiu H, Zhu H, Ouyang W, Wang Z, Sun H. Clinical effects and mechanism of chanlibao in accelerating second stage of labor. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 2003; 19:141-4. [PMID: 12840859 DOI: 10.1007/bf02886896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To observe the clinical effects and the mechanism of Chanlibao (CLB, a preparation of Chinese herbal medicine) in accelerating second stage of labor, primiparae were divided into 3 groups at random. CLB or oxytocin (OTC) was given to the CLB group (n = 80) and the OTC group (n = 52) respectively. The third group served as controls (n = 29). The control group consisted of women experiencing natural labor and to whom no drug was given. The time of second stage of labor and prognosis of mother and newborn of different groups were observed and compared. And intrauterine pressure and fetal heart rate were monitored by means of electronic monitoring. Isolated uterine muscular tissue was used to observe the reactivity to CLB. The results showed that the time of second stage of labor and postpartum hemorrhage in the CLB group were less than those in the control group and the average intrauterine pressure in the former was higher than that in latter, so was the contraction strength of isolated uterine muscle, but with no difference as compared with the OTC group. No side effect of CLB was found. It is concluded that CLB could obviously strengthen uterine contraction and accelerate second stage of labor. Moreover, it is inexpensive, convenient and free of side effect. It can be used as a new, safe and effective alternative for improving prognosis of mother and newborn, especially those not indicated for oxytocin or profuse infusion.
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Zhou M, Ouyang W, Gong Q, Katz SG, White JM, Orkin SH, Murphy KM. Friend of GATA-1 represses GATA-3-dependent activity in CD4+ T cells. J Exp Med 2001; 194:1461-71. [PMID: 11714753 PMCID: PMC2193678 DOI: 10.1084/jem.194.10.1461] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The development of naive CD4+ T cells into a T helper (Th) 2 subset capable of producing interleukin (IL)-4, IL-5, and IL-13 involves a signal transducer and activator of transcription (Stat)6-dependent induction of GATA-3 expression, followed by Stat6-independent GATA-3 autoactivation. The friend of GATA (FOG)-1 protein regulates GATA transcription factor activity in several stages of hematopoietic development including erythrocyte and megakaryocyte differentiation, but whether FOG-1 regulates GATA-3 in T cells is uncertain. We show that FOG-1 can repress GATA-3-dependent activation of the IL-5 promoter in T cells. Also, FOG-1 overexpression during primary activation of naive T cells inhibited Th2 development in CD4+ T cells. FOG-1 fully repressed GATA-3-dependent Th2 development and GATA-3 autoactivation, but not Stat6-dependent induction of GATA-3. FOG-1 overexpression repressed development of Th2 cells from naive T cells, but did not reverse the phenotype of fully committed Th2 cells. Thus, FOG-1 may be one factor capable of regulating the Th2 development.
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Zhu H, Yang J, Murphy TL, Ouyang W, Wagner F, Saparov A, Weaver CT, Murphy KM. Unexpected characteristics of the IFN-gamma reporters in nontransformed T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:855-65. [PMID: 11441092 DOI: 10.4049/jimmunol.167.2.855] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Analysis of the IFN-gamma promoter has primarily been conducted by transient expression of reporter constructs in transformed cells. However, the activity of cis elements may differ when expressed transiently compared with their activity within native chromatin. Furthermore, the transcription factors and signaling mechanisms in transformed cells may differ from those in normal T cells. To analyze IFN-gamma promoter regulation in normal T cells, we developed a novel retroviral bottom-strand reporter system to allow the chromatin integration of promoter regions in primary developing T cells. As controls, both the IL-2 and IL-4 promoters were inducible in this system, with the IL-4 reporter having Th2-specific activity. Strikingly, the IFN-gamma promoter exhibited constitutive activity in both Th1 and Th2 subsets, in contrast to the behavior of the endogenous IFN-gamma gene, which is inducible only in Th1 cells. In mapping this activity, we found that the AP-1/GM-CSF site in the distal promoter element is the most critical element for the constitutive activity. Transgenic reporter lines for the IFN-gamma promoter confirmed the constitutive behavior of the isolated IFN-gamma promoter. This constitutive activity was resistant to inhibition by cyclosporin A and was independent of Stat4 and p38 mitogen-activated protein kinase. These results suggest that IFN-gamma promoter regulation may require cis elements residing either downstream or >3.4 kb upstream of the transcriptional start site, involving repression of constitutive activity.
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Murphy KM, Ouyang W, Ranganath S, Murphy TL. Bi-stable transcriptional circuitry and GATA-3 auto-activation in Th2 commitment. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2001; 64:585-8. [PMID: 11232335 DOI: 10.1101/sqb.1999.64.585] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Yang J, Zhu H, Murphy TL, Ouyang W, Murphy KM. IL-18-stimulated GADD45 beta required in cytokine-induced, but not TCR-induced, IFN-gamma production. Nat Immunol 2001; 2:157-64. [PMID: 11175814 DOI: 10.1038/84264] [Citation(s) in RCA: 207] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Interleukin-12 (IL-12) and IL-18 induce synergistic transcription of interferon gamma (IFN-gamma) that is T cell receptor (TCR)-independent, not inhibited by cyclosporin A and requires new protein synthesis. To characterize this pathway, we screened for genes that are induced in IL-12- and IL-18-treated T helper type 1 cells. GADD45 beta, which activates mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase kinase 4 (MEKK4), was induced by IL-18 and augmented by IL-12. GADD45 beta expression in naïve CD4+ T cells activated p38 MAPK and selectively increased cytokine-induced, but not TCR-induced, IFN-gamma production. Kinase-inactive MEKK4 and inhibition of the p38 MAPK pathway both selectively inhibit cytokine-induced, but not TCR-induced, IFN-gamma production. Thus, the synergy between IL-12 and IL-18 may involve GADD45 beta induction, which can maintain the MEKK4 and p38 MAPK activation that is necessary for cytokine-induced, but not TCR-induced, IFN-gamma production.
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Murphy KM, Ouyang W, Farrar JD, Yang J, Ranganath S, Asnagli H, Afkarian M, Murphy TL. Signaling and transcription in T helper development. Annu Rev Immunol 2000; 18:451-94. [PMID: 10837066 DOI: 10.1146/annurev.immunol.18.1.451] [Citation(s) in RCA: 480] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The recognition of polarized T cell subsets defined by cytokine production was followed by a search to define the factors controlling this phenomenon. Suitable in vitro systems allowed the development of cytokine "recipes" that induced rapid polarization of naïve T cells into Th1 or Th2 populations. The next phase of work over the past several years has begun to define the intracellular processes set into motion during Th1/Th2 development, particularly by the strongly polarizing cytokines IL-12 and IL-4. Although somewhat incomplete, what has emerged is a richly detailed tapestry of signaling and transcription, controlling an important T cell developmental switch. In addition several new mediators of control have emerged, including IL-18, the intriguing Th2-selective T1/ST2 product, and heterogeneity in dendritic cells capable of directing cytokine-independent Th development.
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Kang YM, Ouyang W, Chen JY, Qiao JT, Dafny N. Norepinephrine modulates single hypothalamic arcuate neurons via alpha(1)and beta adrenergic receptors. Brain Res 2000; 869:146-57. [PMID: 10865069 DOI: 10.1016/s0006-8993(00)02380-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The effects of norepinephrine (NE) on the electrophysiological activities of single hypothalamic arcuate neurons were studied using extracellular recording of 385 neurons from 169 brain slices in rats. The results showed that: (1) of 236 neurons selected randomly and tested with NE application, 137 (58.0%) were excited, 67 (28.4%) were inhibited, and 32 (13.6%) failed to respond; (2) substitution of low Ca(2+)-high Mg(2+) artificial cerebrospinal fluid (ACSF) for normal ACSF abolished the NE-induced inhibitory effect but failed to abolish the excitatory effect; (3) both the NE-induced excitatory and inhibitory effects were antagonized partly by phentolamine, prazosin, and propranolol but not by yohimbine; (4) naloxone and glibenclamide, a blocker of adenosine triphosphate-sensitive (K(ATP)) channels, blocked the NE-induced inhibitory effect; and (5) neurons that were inhibited by NE were also inhibited by morphine and cromakalim, an agonist of K(ATP) channels, and moreover, the morphine-induced inhibitory effect could be blocked by glibenclamide, while the cromakalim-induced inhibitory effect was not blocked by naloxone. These results imply that: (a) NE excites arcuate neurons through a mechanism that is insensitive to lowering the extracellular Ca(2+) suggesting a direct postsynaptic response through alpha(1)- and beta-adrenergic receptors, while NE inhibits cells through at least an inhibitory interneuron in arcuate and so is dependent on a Ca(2+)-sensitive presynaptic release mechanism; and (b) the inhibitory interneuron may be opioidergic, being excited first through alpha(1)- and beta-adrenergic receptors, after which the released opioids inhibit the neurons being recorded with an involvement of activation of K(ATP) channels. This possibility needs to be substantiated in much more detail.
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Ouyang W, Li Y, Liu Z. [Effect caused by uptake of different levels of calcium to enamel fluorosis in rats]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 2000; 35:47-9. [PMID: 11831964] [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 study the effects caused by uptake of different levels of calcium to dental fluorosis in rats. METHODS Weanling rats were raised on water containing 0.1 mol/L fluoride and food containing low, normal and high levels of calcium for 2 months. The concentration of fluoride in enamel was analysed by F-ion-selective electrode. The microradiographic examination and light-density analysis were performed. The enamel structure was examined under SEM. RESULTS The more calcium was ingested, the lower level of fluoride amount in enamel was observed (P < 0.01). With increasing food calcium ingestion, the light density value was decreasing, and the level of enamel mineralization was increasing (P < 0.01). CONCLUSIONS With increasing food calcium ingestion during the development of teeth, the level of dental fluorosis is decreasing. The calcium supply is effective in protection from fluoride toxicity to a certain extent.
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Ouyang W, Löhning M, Gao Z, Assenmacher M, Ranganath S, Radbruch A, Murphy KM. Stat6-independent GATA-3 autoactivation directs IL-4-independent Th2 development and commitment. Immunity 2000; 12:27-37. [PMID: 10661403 DOI: 10.1016/s1074-7613(00)80156-9] [Citation(s) in RCA: 530] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The initial source of IL-4-inducing Th2 development and the mechanism of stable Th2 commitment remain obscure. We found the reduced level of IL-4 production in Stat6-deficient T cells to be significantly higher than in Th1 controls. Using a novel cell surface affinity matrix technique, we found that IL-4-secreting Stat6-deficient T cells stably expressed GATA-3 and Th2 phenotype. Introducing GATA-3 into Stat6-deficient T cells completely restored Th2 development, inducing c-Maf, Th2-specific DNase I hypersensitive sites in the IL-4 locus, and Th2 cytokine expression. The fact that GATA-3 fully reconstitutes Th2 development in Stat6-deficient T cells indicates it is a master switch in Th2 development. Finally, GATA-3 exerts Stat6-independent autoactivation, creating a feedback pathway stabilizing Th2 commitment.
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Ouyang W, Jacobson NG, Bhattacharya D, Gorham JD, Fenoglio D, Sha WC, Murphy TL, Murphy KM. The Ets transcription factor ERM is Th1-specific and induced by IL-12 through a Stat4-dependent pathway. Proc Natl Acad Sci U S A 1999; 96:3888-93. [PMID: 10097133 PMCID: PMC22390 DOI: 10.1073/pnas.96.7.3888] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Interleukin 12 (IL-12)-induced T helper 1 (Th1) development requires Stat4 activation. However, antigen-activated Th1 cells can produce interferon gamma (IFN-gamma) independently of IL-12 and Stat4 activation. Thus, in differentiated Th1 cells, factors regulated by IL-12 and Stat4 may be involved in IFN-gamma production. Using subtractive cloning, we identified ERM, an Ets transcription factor, to be a Th1-specific, IL-12-induced gene. IL-12-induction of ERM occurred in wild-type and Stat1-deficient, but not Stat4-deficient, T cells, suggesting ERM is Stat4-inducible. Retroviral expression of ERM did not restore IFN-gamma production in Stat4-deficient T cells, but augmented IFN-gamma expression in Stat4-heterozygous T cells. Ets factors frequently regulate transcription via cooperative interactions with other transcription factors, and ERM has been reported to cooperate with c-Jun. However, in the absence of other transcription factors, ERM augmented expression of an IFN-gamma reporter by only 2-fold. Thus, determining the requirement for ERM in Th1 development likely will require gene targeting.
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Murphy KM, Ouyang W, Szabo SJ, Jacobson NG, Guler ML, Gorham JD, Gubler U, Murphy TL. T helper differentiation proceeds through Stat1-dependent, Stat4-dependent and Stat4-independent phases. Curr Top Microbiol Immunol 1999; 238:13-26. [PMID: 10087648 DOI: 10.1007/978-3-662-09709-0_2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Much of our focus in understanding Th1/Th2 development has been on the signals delivered by IL-12 and IL-4 as final determinants of terminal T cell differentiation. Because extinction of IL-12 signaling in early Th2 development could potentially be important in imprinting a more permanent Th2 phenotype on a population of T cells, we have also examined various parameters regulating the IL-12 signaling pathway. Whereas IL-4 appears to repress functional IL-12 signaling through inhibition of IL-12R beta 2 expression, IFN-gamma in the mouse, and IFN-alpha in the human appear to induce IL-12R beta 2 expression and promote IL-12 responsiveness. We propose that Th1 development can be considered in two stages, capacitance and development. Capacitance would simply involve expression of IL-12R beta 1 and beta 2 subunits, regulated by TCR, IL-4 and IFNs. The second stage, development, we propose is the true IL-12 induced developmental stage, involving expression of Stat4 inducible proteins. In the human, this may also occur via IFN-alpha, which is able to activate Stat4. It is perhaps possible that all of Stat4 actions on Th1 development may be exert directly by Stat4 at the IFN-gamma gene, however we suggest that, more likely, Stat4 may act to induce Th1 development through the induction of other non-cytokine genes, whose stable expression maintains the transcriptional state of a Th1 cell.
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MESH Headings
- Animals
- Antigens, Differentiation, T-Lymphocyte/physiology
- Cell Differentiation
- DNA-Binding Proteins/physiology
- Humans
- Immunologic Factors/metabolism
- Interferon-alpha/physiology
- Interferon-gamma/metabolism
- Interleukin-12/pharmacology
- Interleukin-12/physiology
- Interleukin-4/pharmacology
- Lymphocyte Activation
- Mice
- Mice, Inbred BALB C
- Mice, Inbred DBA
- Mice, Transgenic
- Phenotype
- Receptors, Interleukin/antagonists & inhibitors
- Receptors, Interleukin/metabolism
- Receptors, Interleukin-12
- STAT1 Transcription Factor
- STAT4 Transcription Factor
- Signal Transduction
- T-Lymphocytes, Helper-Inducer/drug effects
- T-Lymphocytes, Helper-Inducer/immunology
- Trans-Activators/physiology
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50
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Yang J, Murphy TL, Ouyang W, Murphy KM. Induction of interferon-gamma production in Th1 CD4+ T cells: evidence for two distinct pathways for promoter activation. Eur J Immunol 1999; 29:548-55. [PMID: 10064070 DOI: 10.1002/(sici)1521-4141(199902)29:02<548::aid-immu548>3.0.co;2-z] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
IFN-gamma produced by CD4+ T helper 1 (Th1) cells promotes protection against intracellular pathogens. Antigen activation of Th1 cells is an important mode of IFN-gamma induction, but here we analyze a second, antigen-nonspecific pathway capable of inducing full IFN-gamma transcription. IL-12 or IL-18 alone do not induce IFN-gamma mRNA, and only modestly augment antigen-induced IFN-gamma mRNA from Th1 cells. However, IL-12 and IL-18 together fully induce IFN-gamma transcription independently of TCR-activated signals, by a mechanism that does not simply involve Stat4 and NF-kappaB activation, but requires additional protein synthesis. Cyclosporin A inhibits TCR-induced IFN-gamma production, but not IL-12/IL-18-induced IFN-gamma production, biochemically discriminating between these pathways. These results suggest that the two pathways induce IFN-gamma production through functionally segregated but spatially overlapping cis-acting elements, similar to other genes under the control of two or more promoters.
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