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Yang C, He YL, Zhang L, Xu L, Yi Z, Wang Y, Li N, Zhu D. GLS/IL-12-modified Mycobacterium smegmatis as a novel anti-tuberculosis immunotherapeutic vaccine. Int J Tuberc Lung Dis 2009; 13:1360-1366. [PMID: 19861007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
OBJECTIVE To study the effects and mechanisms of recombinant Mycobacterium smegmatis (rMS) carrying pZM03 (a co-expression plasmid encoding human granulysin [GLS] and murine interleukin 12 [IL-12]) on murine M. tuberculosis infection. DESIGN BALB/c mice infected with M. tuberculosis were treated with normal saline, M. smegmatis, pZM03 or rMS. The number of viable bacteria in the lungs and spleens were counted to observe the therapeutic effects. The levels of IL-12 and interferon-gamma (IFN-gamma) in serum, and IFN-gamma and tumour necrosis factor-alpha (TNF-alpha) released from spleen lymphocytes were detected to observe the T-helper 1 (Th1) response. Secretory IgA (SIgA) in bronchoalveolar lavage fluid was measured to observe the mucosal immunity. The lungs and spleens were prepared for pathological analysis. RESULTS The rMS group showed a significantly reduced number of colony-forming units compared to the other groups. The expression of GLS in the tissue, and increased levels of IL-12, IFN-gamma, TNF-alpha and SIgA, were found in the rMS group. The pathological changes in the lungs of the rMS group were localised, while those in the control group were extensive. CONCLUSION rMS had immunotherapeutic effects associated with a switch to the Th1 response and the antibacterial activity of GLS.
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MESH Headings
- Animals
- Antigens, Differentiation, T-Lymphocyte/genetics
- Antigens, Differentiation, T-Lymphocyte/immunology
- Bronchoalveolar Lavage Fluid/immunology
- Cells, Cultured
- Disease Models, Animal
- Female
- Humans
- Immunoglobulin A, Secretory/metabolism
- Interferon-gamma/blood
- Interleukin-12/blood
- Interleukin-12/genetics
- Interleukin-12/immunology
- Lung/immunology
- Lung/microbiology
- Mice
- Mice, Inbred BALB C
- Mycobacterium smegmatis/genetics
- Mycobacterium smegmatis/immunology
- Mycobacterium tuberculosis/pathogenicity
- Spleen/immunology
- Spleen/microbiology
- Th1 Cells/immunology
- Tuberculosis Vaccines/genetics
- Tuberculosis Vaccines/immunology
- Tuberculosis, Pulmonary/immunology
- Tuberculosis, Pulmonary/microbiology
- Tuberculosis, Pulmonary/pathology
- Tuberculosis, Pulmonary/therapy
- Tuberculosis, Splenic/immunology
- Tuberculosis, Splenic/microbiology
- Tuberculosis, Splenic/pathology
- Tuberculosis, Splenic/therapy
- Tumor Necrosis Factor-alpha/metabolism
- Vaccines, Synthetic/immunology
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Zheng XF, Liu L, Zhou J, Miao MY, Zhou JR, Zhu D, Xia ZF, Jiang CL. Biphasic effects of dexamethasone on glycogen metabolism in primary cultured rat hepatocytes. J Endocrinol Invest 2009; 32:756-8. [PMID: 20009502 DOI: 10.1007/bf03346532] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Glucocorticoids (GC), the basic function of which is modulating carbohydrates metabolism, play a critical role in stress response by enhancing the organism's resistance. It is widely believed that they could promote glycogen synthesis. However, it is doubtful whether GC can still stimulate glycogen deposition in stress response, as it is known that glucose is imperatively needed at that time. Here, we used primary cultured rat hepatocytes to investigate the effects of GC on glycogen metabolism in vitro to exclude other influences in stress. The results showed that dexamethasone (Dex) played biphasic effects on hepatocytes glycogen metabolism depending on its dosage and the duration of stimulation. Dex could decrease glycogen content of hepatocytes in the higher concentration within a relatively shorter period of time, which could not be blocked by cycloheximide. Therefore, dual roles in hepatic glycogen metabolism played by GC were demonstrated, and a non-genomic mechanism might be involved in the glycogenolytic action of GC. We postulated that the biphasic effects of GC on hepatic glycogen metabolism might be of important significance in stress response.
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Li Q, Wang Z, Zhu D, Xu M, Chen X, Peng D, Iwata Y, Xie P. Detection and analysis of Borna disease virus in Chinese patients with neurological disorders. Eur J Neurol 2009; 16:399-403. [PMID: 19364367 DOI: 10.1111/j.1468-1331.2008.02516.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE Borna disease virus (BDV) is a neurotropic RNA virus that is known to cause neurological disturbances in various animal species, potentially even humans. However, the association between BDV infection and human neurological disorders remains unclear. METHODS Between August 2005 and March 2006, 65 patients with neurological disorders were enrolled into our study. The presence of BDV p24 RNA from peripheral blood mononuclear cells (PBMCs) was investigated by using nested reverse transcriptase PCR (RT-PCR) assay. RESULTS Borna disease virus p24 RNA was detected from PBMCs in six patients with viral encephalitis by using nested RT-PCR assay. However, BDV p24 RNA was not detected in patients with multiple sclerosis or peripheral nerve diseases. CONCLUSION There might be possible associations between BDV infection and human viral encephalitis.
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Rick R, Scherz A, Schlotter WF, Zhu D, Lüning J, Stöhr J. Optimal signal-to-noise ratios for soft x-ray lensless imaging. OPTICS LETTERS 2009; 34:650-652. [PMID: 19252581 DOI: 10.1364/ol.34.000650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We propose and demonstrate a method to gauge and optimize the signal-to-noise ratios (SNRs) in lensless imaging using partially coherent sources. Through spatial filtering we tuned the coherence width of an incoherent soft x-ray undulator source, and we deduce that there exists an optimal spatial filter setting for imaging micrometer-sized objects, while high-resolution imaging is best executed without spatial filtering. Our SNR analysis, given spatial coherence, allows for an estimation of the required exposure time at synchrotron sources and pulse fluence at x-ray laser sources.
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Xu J, Mar A, Lu J, Jin X, Zhu D, Zhu Y, Weber R. 83. Assessment of C7 nerve distribution with sensory nerve action potential after total C7 nerve transection. Clin Neurophysiol 2009. [DOI: 10.1016/j.clinph.2008.10.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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256
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Zhu D, Zhu Y, Chen X, Miro J, Xu L, Jin X, Alcuri R, Zhu Q, Lu J, Weber R, Xu J. 37. Vibration reduces human digital sensory nerve action potential amplitude. Clin Neurophysiol 2009. [DOI: 10.1016/j.clinph.2008.10.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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257
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Lu M, Zhu D, Lu Y, Hou Y, Tan B, Zhong G. Organocatalytic asymmetric alpha-aminoxylation/aza-Michael reactions for the synthesis of functionalized tetrahydro-1,2-oxazines. Angew Chem Int Ed Engl 2008; 47:10013. [PMID: 19072787 DOI: 10.1002/anie.200890274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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258
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Austerlitz C, Mota HC, Sempau J, Benhabib SM, Campos D, Allison R, deAlmeida CE, Zhu D, Sibata CH. Determination of absorbed dose in water at the reference point D(r0,θ0) for an Ir192 HDR brachytherapy source using a Fricke system. Med Phys 2008; 35:5360-5. [DOI: 10.1118/1.2996178] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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259
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Zhang L, Hu C, Ye W, Zhu D, Yu Z, Zhuo R, Sun M. The copper-resistant bacterium ACU isolated from the rhizosphere ofEichhornia crassipes(Mart.) increased the endurance ofPotamogeton crispusL. to copper toxicity. J Appl Microbiol 2008; 105:1034-43. [DOI: 10.1111/j.1365-2672.2008.03835.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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260
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Scherz A, Zhu D, Rick R, Schlotter WF, Roy S, Lüning J, Stöhr J. Nanoscale imaging with resonant coherent X rays: extension of multiple-wavelength anomalous diffraction to nonperiodic structures. PHYSICAL REVIEW LETTERS 2008; 101:076101. [PMID: 18764556 DOI: 10.1103/physrevlett.101.076101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2008] [Indexed: 05/12/2023]
Abstract
The methodology of multiple-wavelength anomalous diffraction, widely used for macromolecular structure determination, is extended to the imaging of nonperiodic nanostructures. We demonstrate the solution of the phase problem by a combination of two resonantly recorded coherent scattering patterns at the carbon K edge (285 eV). Our approach merges iterative phase retrieval and x-ray holography approaches, yielding unique and rapid reconstructions. The element, chemical, and magnetic state specificity of our method further renders it widely applicable to a broad range of nanostructures, providing a spatial resolution that is limited, in principle, by wavelength only.
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261
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Marini AM, Banaudha K, McCall S, Zhu D, Lipsky R. α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-mediated neuroprotection requires TRKB receptor activation. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.81.s1.11_6.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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262
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Zhu D, Austerlitz C, Mota H, Benhabib S, Gay H, Allison R, Campos D, Sibata C. SU-GG-T-381: Attenuation Due to Bronchial Stents in Photodynamic Therapy. Med Phys 2008. [DOI: 10.1118/1.2962133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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263
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Benhabib SM, Zhu D, Austerlitz C, Mota H, Sempau J, Allison R, Sibata C. SU-GG-T-03: Dosimetric Study of HDR 192Ir and LDR 125I Brachytherapy Sources Using the Penelope Monte Carlo Code. Med Phys 2008. [DOI: 10.1118/1.2961753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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264
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Nicholson GA, Magdelaine C, Zhu D, Grew S, Ryan MM, Sturtz F, Vallat JM, Ouvrier RA. Severe early-onset axonal neuropathy with homozygous and compound heterozygous MFN2 mutations. Neurology 2008; 70:1678-81. [DOI: 10.1212/01.wnl.0000311275.89032.22] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective: Severe early-onset axonal neuropathy (SEOAN) is a heterogeneous phenotype first delineated by Ouvrier et al., characterized by progressive axonal degeneration with gait problems often progressing to wheelchair requirement and later respiratory involvement. Most cases are sporadic single cases. Some have heterozygous mitofusin 2 (MFN2) mutations, many of which are de novo dominant mutations. The aim of this study was to investigate the mode of inheritance in three individuals with severe early-onset axonal neuropathy and homozygous or compound heterozygous MFN2 mutations.Methods: The clinical and molecular findings in the parents of three individuals with SEOAN with homozygous or compound heterozygous MFN2 mutations were examined.Results: All parents were asymptomatic or mildly symptomatic with some signs of peripheral neuropathy indicating a minimal phenotype. Two had hearing problems. All parents carried the relevant single base (heterozygous) MFN2 variations.Conclusion: Severe early-onset axonal neuropathy due to MFN2 mutations can present as an apparently recessively inherited neuropathy but the minimal phenotype in the parents suggests a semi-dominant mechanism.
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265
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Wang H, Gao J, Kou J, Zhu D, Yu B. Anti-inflammatory activities of triterpenoid saponins from Polygala japonica. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2008; 15:321-326. [PMID: 17951039 DOI: 10.1016/j.phymed.2007.09.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Bioassay-guided investigation was performed to identify the active constituents from a methanol extract of Polygala japonica, a folk medicinal plant widely used in China to treat inflammatory diseases. The n-BuOH and EtOAc fractions of the P. japonica methanol extract, which show significant anti-inflammatory activity in in vivo test, were further subjected to column chromatography to afford six triterpene glycosides, marked here as saponins 1-6. All compounds were evaluated for their anti-inflammatory activity in the carageenan-induced mouse paw edema test, and saponins 1, 4 and 5 showed significantly anti-inflammatory effects on both phases of carageenan-induced acute paw edema in mice. Saponin 5 was also found to significantly inhibit the production of inflammatory mediators - nitric oxide (NO) in LPS-stimulated RAW264.7 macrophages, with no obvious effects on macrophage viability.
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de Bono S, Laskey MA, Shaw CN, Zhu D, Laskey PJ, Prentice A. Could image analysis of pQCT scans provide additional information about bone strength? JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2008; 8:23. [PMID: 18398257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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267
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Schwab P, Zhu D, Banks MK. Heavy metal leaching from mine tailings as affected by organic amendments. BIORESOURCE TECHNOLOGY 2007; 98:2935-41. [PMID: 17157002 DOI: 10.1016/j.biortech.2006.10.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 10/02/2006] [Accepted: 10/03/2006] [Indexed: 05/12/2023]
Abstract
A column experiment was conducted to investigate Zn, Cd, and Pb leaching from mine tailings as affected by the addition of organic amendments. Composted yard waste, composted cattle manure, and cattle manure aged for one month increased heavy metal leaching from mine tailings when compared to an unamended control. Aged cattle manure and composted cattle manure significantly increased Zn concentration in the leachate. The maximum Zn concentration in leachate from the manure-amended treatments was as high as 3.7 mg/L, whereas Zn concentrations from the control were less than 0.7 mg/L. All organic amendments increased Cd leachate concentrations. The presence of aged cattle manure greatly increased Pb concentrations in the leachate from less than 10 microg/L for the control treatment to higher than 60 microg/L. Lead concentration in leachate was positively correlated with inorganic carbon, total organic carbon, total carbon and bicarbonate. Although organic amendments increased Zn, Cd, and Pb leaching when compared with the control treatment, Zn concentrations were lower than the 5 mg/L secondary drinking water standard, and Pb concentrations were only minimally higher than the 15 microg/L drinking water standard. Cadmium concentrations from manure treatments exceeded the 5 microg/L drinking water standard but only during the first 15 days. Organic amendments may encourage establishment of vegetation in mining areas that may minimize heavy metal contamination through runoff and erosion. However, increased risk due to heavy metal leaching in the presence of organic amendments should be carefully considered.
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Jiang H, Qu J, He L, Pan J, Chen X, Li L, Zhu D, Cao Y. Airway hyperresponsiveness induced by repetitive intraperitoneal injection of lipopolysacharide and the involvement of inflammation and nitric oxide in guinea pigs. Inflamm Res 2006; 55:286-92. [PMID: 16955391 DOI: 10.1007/s00011-006-0085-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE Airway hyperresponsiveness (AHR) is involved in bronchial asthma and chronic obstructive pulmonary disease (COPD) and produces respiratory symptoms. Lipopolysaccharide (LPS) has been found to be significantly related to the severity of asthma. However, its clinical mechanism still remains controversial. This study investigated the in vivo effect of repetitive intraperitoneal administration of lipopolysaccharide (LPS) on airway hyperresponsiveness (AHR) in guinea pigs and the possible involvement of inflammation, nitric oxide (NO) and nitric oxide synthase (NOS). METHODS There were two exposure groups for intraperitoneal LPS injection: (1) LPS was given at a dose of 1 mg x kg(-1), followed by sterile saline (NS) 1 ml x kg(-1) 8 h later every 24 h; (2) LPS was given at a dose of 0.5 mg x kg(-1) two times with an interval of 8 h every 24 h. Each exposure regime was repeated 4 times. Control animals were given NS and 6 naive guinea pigs were used as baseline control. Determinations were made 24 h after each exposure. RESULTS Persistent AHR occurred 24 h after the third and fourth exposures to LPS in the first exposure group (at one dose), but occurred earlier after the exposures to LPS in the second exposure group (at divided doses). The numbers of total cells and neutrophils were elevated initially but subsided subsequently in LPS-treated groups. No evidence of morphological changes in the small airways was found 24 h after any of the exposures. The Ca(2+)-dependent and Ca(2+)-independent NOS activities (mainly produced by iNOS) in the BALF, as well as the production of NO, were significantly elevated 24 h after any of third and fourth exposures in LPS-treated groups. CONCLUSIONS Our results demonstrate that repetitive intraperitoneal LPS can induce persistent AHR which occurs earlier when the frequency of injection increase, and an elevation of NO production and iNOS activity may be involved in is systemic-LPS-induced AHR.
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269
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Wang MD, Rahman M, Zhu D, Bäckström T. Pregnenolone sulphate and Zn2+ inhibit recombinant rat GABA(A) receptor through different channel property. Acta Physiol (Oxf) 2006; 188:153-62. [PMID: 17054655 DOI: 10.1111/j.1748-1716.2006.01617.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
AIMS We compared the antagonistic effects of state-dependent gamma-aminobutyric acid A (GABA(A)) receptor blockers picrotoxin, Zn(2+) and pregnenolone sulphate (PS) on GABA- and pentobarbital-activated currents in recombinant rat GABA(A) receptors in Xenopus oocytes. METHODS Experiments were performed with wild type rat alpha1 beta2 gamma2L and alpha1beta2 receptors, mutants alpha1V256S beta2 gamma2L and alpha1beta2A252Sgamma2L receptors by the two-electrode voltage-clamp technique. RESULTS In contrast to respective 3840- and 56-fold increases in Zn(2+) potencies to inhibit GABA- and pentobarbital-activated currents in the alpha1beta2 receptor, the corresponding potencies of PS remained unchanged in comparison with the alpha1 beta2 gamma2L receptor. A homologous mutation of the residue at 2' position closest to the cytoplasmic end of the M(2) helix to serine on both alpha1 and beta2 subunit, alpha1V256S and beta2A252S, abolished the inhibition of GABA(A) receptor by PS. In comparison with the wild type alpha1beta2gamma2L receptor, mutants alpha1V256S beta2 gamma2L and alpha1beta2 A252S gamma2L receptors did not affect the Zn(2+) inhibition. Furthermore, a significant increase in GABA potency was observed in the mutant alpha1V256S beta2 gamma2L receptor (P < 0.05), but not the mutant alpha1beta2 A252S gamma2L receptor compared with the wild type receptor. CONCLUSIONS Pregnenolone sulphate was a gamma2-subunit independent inhibitor in the GABA(A) receptor, whereas the Zn(2+) antagonism was profoundly influenced by the gamma2-subunit. It is likely that the 2' residue closest to the N-terminus of the protein at M(2) helix on both alpha1 and beta2 subunit are critical to the inhibitory actions of PS and the function of Cl(-) channels. These results are consistent with the hypothesis that PS behaves as a Cl(-) channel blocker that does not share with Zn(2+), the coincident channel property in the GABA(A) receptors.
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270
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Ma C, Zhang J, Durrin LK, Lv J, Zhu D, Han X, Sun Y. The BCL2 major breakpoint region (mbr) regulates gene expression. Oncogene 2006; 26:2649-57. [PMID: 17057736 DOI: 10.1038/sj.onc.1210069] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BCL2 expression is finely tuned by a variety of environmental and endogenous stimuli and regulated at both transcriptional and post-transcriptional levels. Our previous investigations demonstrated that the BCL2 major breakpoint region (mbr) in the 3'-UTR upregulates reporter gene expression, which implies that this region possessed intrinsic regulatory function. However, the effect of the mbr on BCL2 expression, and the underlying regulatory mechanisms, remain to be elucidated. To assess the direct effect of the mbr on the transcriptional activity of the BCL2 gene, we employed targeted homologous recombination to establish a mbr(+)/mbr(-) heterozygous Nalm-6 cell line and then compared the transcriptional activity and apoptotic effect on transcription between the wild type and targeted alleles. We found that deletion of the mbr significantly decreased the transcriptional activity of the corresponding allele in the mbr(+)/mbr(-) cell. The BCL2 allele deleted of the mbr had a slower response to apoptotic stimuli than did the wild type allele. The regulatory function of the mbr was mediated through SATB1. Overexpression of SATB1 increased BCL2 expression, while knockdown of SATB1 with RNAi decreased BCL2 expression. Our results clearly indicated that the mbr could positively regulate BCL2 gene expression and this regulatory function was closely related to SATB1.
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Zhu D, Su Z, Mu Z, Qiu Y, Wang Y. Synthesis, crystal structures and properties of five-coordinate Schiff-base Zn(II) complexes. J COORD CHEM 2006. [DOI: 10.1080/00958970500270877] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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272
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Rahman M, Zhu D, Lindblad C, Johansson IM, Holmberg E, Isaksson M, Taube M, Bäckström T, Wang MD. GABA-site antagonism and pentobarbital actions do not depend on the alpha-subunit type in the recombinant rat GABA receptor. Acta Physiol (Oxf) 2006; 187:479-88. [PMID: 16866778 DOI: 10.1111/j.1748-1716.2006.01593.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM The roles of alpha-subunits on the gamma-aminobutyric acid (GABA)-site antagonism and pentobarbital actions were examined in rat recombinant GABA(A) receptors in Xenopus oocytes. METHODS Experiments were performed with binary and ternary GABA(A) receptors containing alpha1-, alpha4- or alpha5-subunit by the two-electrode voltage-clamp technique. RESULTS The potency of GABA was significantly higher in the alpha1beta2, alpha4beta2 and alpha5beta2 receptors compared with the alpha1beta2gamma2L, alpha4beta2gamma2L and alpha5beta2gamma2L receptors. However, the alpha5beta2 receptor possessed significantly lower GABA efficacy compared with the alpha5beta2gamma2L receptor. While the gamma2-subunit was essential to the potency of GABA, its influence on the apparent GABA-site antagonism was less profound. The antagonist affinity constants (K(B)) of bicuculline inhibition and slopes of Schild plots were similar between all types of ternary and binary receptors except alpha5beta2 receptor which was not tested. The pK(B)s and IC(50)s of the GABA-site antagonism were not significantly different between the alpha1beta2gamma2L, alpha4beta2gamma2L and alpha5beta2gamma2L receptors. Bicuculline blocked pentobarbital-activated currents in a reversible and non-competitive manner with the alpha1beta2gamma2L, alpha4beta2gamma2L, and alpha5beta2gamma2L receptors, indicating an allosteric inhibition of the GABA-site. No significant difference of bicuculline potencies in inhibiting GABA- and pentobarbital-activated currents was found between the alpha1beta2gamma2L, alpha4beta2gamma2L and alpha5beta2gamma2L receptors. CONCLUSION The GABA-site antagonism does not depend on the subtype of alpha-subunits. Similarly, pentobarbital activates ternary receptors composed of different alpha-subunits in a bicuculline-sensitive manner. The potencies of bicuculline to inhibit pentobarbital-activated currents are identical with receptors containing alpha1, alpha4 or alpha5-subunit. The alpha1beta2 and alpha4beta2 receptors possess higher GABA potencies compared with the alpha1beta2gamma2L and alpha4beta2gamma2L receptors.
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Chen H, Li M, Campbell RA, Burkhardt K, Zhu D, Li SG, Lee HJ, Wang C, Zeng Z, Gordon MS, Bonavida B, Berenson JR. Interference with nuclear factor kappa B and c-Jun NH2-terminal kinase signaling by TRAF6C small interfering RNA inhibits myeloma cell proliferation and enhances apoptosis. Oncogene 2006; 25:6520-7. [PMID: 16702955 DOI: 10.1038/sj.onc.1209653] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The tumor necrosis factor receptor (TNFR)-associated factor (TRAF) family of six adaptor proteins (TRAF1-6) links the TNFR superfamily to the nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1) transcriptional activators. Unlike other TRAFs, TRAF6 is also involved in Toll-like/interleukin (IL)-1 receptor (TIR) signal transduction. Thus, inhibition of TRAF6 function could interrupt both CD40 (TNFR family) and IL-1 growth signals, pathways critical to myeloma proliferation. To block TRAF6-mediated IL-1 signaling, we constructed small interfering RNA (siRNA) against TRAF6. We found that siRNA targeting the TRAF6 C-terminal (siTRAF6C) receptor interaction domain specifically reduced only TRAF6 protein expression, without affecting TRAF2 or 5 levels, and substantially interfered with IL-1-induced NF-kappaB and c-Jun/AP-1 activation. Inhibition by siTRAF6C was concentration-dependent. SiTRAF6C also significantly reduced myeloma proliferation and enhanced apoptosis in a similar dose-dependent fashion in vitro. More importantly, marked siTRAF6C growth inhibition was detected in vivo when these cells were implanted into the bone marrow of irradiated normal mice. In contrast, introduction of siRNA derived from the TRAF6 Zn-finger domain or an irrelevant siRNA construct failed to alter cell growth or cell death. These studies suggest that TRAF6 may be a new molecular target to block cell signal transduction important for the survival and proliferation of multiple myeloma cells.
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Zhu D, Kennerson ML, Walizada G, Züchner S, Vance JM, Nicholson GA. Charcot-Marie-Tooth with pyramidal signs is genetically heterogeneous: families with and without MFN2 mutations. Neurology 2005; 65:496-7. [PMID: 16087932 DOI: 10.1212/01.wnl.0000171345.62270.29] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Li Y, Grubjesic S, Nikolic D, Zhu D, Kosmeder JW, Moriarty RM, Pezzuto JM, Van Breemen RB. In vitro assessment of intestinal permeability and hepatic metabolism of 4'-bromoflavone, a promising cancer chemopreventive agent. Xenobiotica 2005; 34:535-47. [PMID: 15277014 DOI: 10.1080/00498250410001713159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
1. The intestinal permeability and hepatic metabolism of the investigational cancer chemoprevention agent 4'-bromoflavone were investigated in vitro using human intestinal Caco-2 cell monolayers, human liver microsomes and human hepatocytes. Liquid chromatography-mass spectrometry and tandem mass spectrometry were used for quantitative analysis in support of the Caco-2 cell studies and for the characterization of metabolites of 4'-bromoflavone. 2. The Caco-2 cell model indicated that 4'-bromoflavone would be absorbed by the intestine at a moderate rate by means of direction-independent, passive diffusion. There was no indication of active transport or efflux. 3. Three monohydroxylated metabolites and one monohydroxylated, hydrated metabolite of 4'-bromoflavone were detected at relatively low levels in the human liver microsomal and hepatocyte incubations. The structures of these metabolites were confirmed by comparison with synthetic standards. Hydroxylation occurred on the A-ring of 4'-bromoflavone but not on the B-ring, probably due to deactivation of the B-ring by bromine. No phase II metabolites were detected following incubation of 4'-bromoflavone in these in vitro systems. 4. In conclusion, these studies predict that 4'-bromoflavone should show moderate oral bioavailability, and that it would probably be excreted as unchanged compound and monohydroxylated metabolites. The results might be helpful in the design of clinical trials and in the interpretation of pharmacokinetic studies of 4'-bromoflavone.
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