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Xiong F, Sun M, Zhang X, Cai R, Zhou Y, Lou J, Zeng L, Sun Q, Xiao Q, Shang X, Wei X, Zhang T, Chen P, Xu X. Molecular epidemiological survey of haemoglobinopathies in the Guangxi Zhuang Autonomous Region of southern China. Clin Genet 2010; 78:139-48. [DOI: 10.1111/j.1399-0004.2010.01430.x] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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52
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Tariq A, Ai J, Chen G, Sabri M, Jeon H, Shang X, Macdonald R. Loss of long-term potentiation in the hippocampus after experimental subarachnoid hemorrhage in rats. Neuroscience 2010; 165:418-26. [DOI: 10.1016/j.neuroscience.2009.10.040] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 09/29/2009] [Accepted: 10/19/2009] [Indexed: 12/01/2022]
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Ma T, Han L, Gao Y, Li L, Shang X, Hu W, Xue C. The endoplasmic reticulum stress-mediated apoptosis signal pathway is involved in sepsis-induced abnormal lymphocyte apoptosis. ACTA ACUST UNITED AC 2008; 41:219-25. [PMID: 18509246 DOI: 10.1159/000135631] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Accepted: 02/11/2008] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIM The mechanisms of abnormal lymphocyte apoptosis in sepsis are only partially defined. The present study was designed to investigate whether the endoplasmic reticulum (ER) is implicated in the extensive apoptosis of lymphocytes in sepsis. METHODS C57BL/6 mice were randomized into cecal ligation and puncture (CLP) and sham operation groups. Apoptosis was detected by the TUNEL method and flow cytometry. The expression of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) was detected by RT-PCR and Western blot. The splicing of X box-binding protein-1 (XBP1) mRNA was detected by RT-PCR. RESULTS A high degree of lymphocyte apoptosis was observed in the CLP group. Marked induction of GRP78 and accumulation of spliced XBP1 mRNA were observed in the splenocytes from septic mice, indicating activation of unfolded protein responses. Furthermore, both CHOP and its mRNA were markedly upregulated in the CLP group, suggesting that the ER stress response switched to a proapoptotic response. CONCLUSION These data demonstrate activation of the unfolded protein response in lymphocytes and that ER stress may contribute to abnormal lymphocyte apoptosis during sepsis. Accordingly, the ER stress-mediated apoptosis pathway may be a novel target in clinical prevention and therapy of sepsis-induced lymphocyte apoptosis.
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Affiliation(s)
- T Ma
- Department of Surgery, General Hospital, Tianjin Medical University, Tianjin, PR China
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Shang X, Gong X, Xiong J, Tong T, Zhang D. P3I-5 Study on SAW Characteristics of Amorphous- TeO2/128°Y-X LiNbO3 Structures. ACTA ACUST UNITED AC 2007. [DOI: 10.1109/ultsym.2007.476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
Cytoplasmic transfer is an assisted reproductive technique that involves the infusion of ooplasm from a donor oocyte into a recipient oocyte of inferior developmental competence. Although this technique has shown some success for couples with recurrent in vitro fertilization failure, it results in mitochondrial heteroplasmy in the offspring, defined as the presence of two different mitochondrial genomes in the same individual. Because the long-term health consequences of mitochondrial heteroplasmy are unknown, there is a need for appropriate animal models to evaluate any physiological changes of dual mtDNA genotypes. This longitudinal study was designed as a preliminary screen of basic physiological functions for heteroplasmic mice (NZB mtDNA on a BALB/cByJ background). The mice were tested for cardiovascular and metabolic function, hematological parameters, body mass analysis, ovarian reserve, and tissue histologic abnormalities over a period of 15 mo. Heteroplasmic mice developed systemic hypertension that corrected over time and was accompanied by cardiac changes consistent with pulmonary hypertension. In addition, heteroplasmic animals had increased body mass and fat mass compared with controls at all ages. Finally, these animals had abnormalities in electrolytes and hematological parameters. Our findings suggest that there are significant physiological differences between heteroplasmic and control mice. Because ooplasm transfer appears to be consistently associated with mitochondrial heteroplasmy, children conceived through ooplasm transfer should be closely followed to determine if they are at risk for any health problems.
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Affiliation(s)
- B M Acton
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Toronto, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada M5G 1X5
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56
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Akbar H, Kim J, Funk K, Cancelas JA, Shang X, Chen L, Johnson JF, Williams DA, Zheng Y. Genetic and pharmacologic evidence that Rac1 GTPase is involved in regulation of platelet secretion and aggregation. J Thromb Haemost 2007; 5:1747-55. [PMID: 17663742 DOI: 10.1111/j.1538-7836.2007.02646.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Rac1 GTPase, a member of the Ras-related Rho GTPase family, is the major Rac isoform present in platelets and has been shown to be involved in cell actin cytoskeleton reorganization and adhesion. Agonists that induce platelet secretion and aggregation also activate Rac1 GTPase, raising the possibility that Rac1 GTPase may be involved in regulation of platelet function. OBJECTIVES To rigorously define the role of Rac1 in platelet regulation. METHODS We have used a dual approach of gene targeting in mice and pharmacologic inhibition of Rac1 by NSC23766, a rationally designed specific small molecule inhibitor, to study the role of Rac1 in platelet function. RESULTS Platelets from mice as well as human platelets treated with NSC23766 exhibited a significant decrease in: (i) active Rac1 species and phosphorylation of the Rac effector, p21-activated kinase; (ii) expression of P-selectin and secretion of adenosine triphosphate induced by thrombin or U46619; and (iii) aggregation induced by adenosine 5'-diphosphate, collagen, thrombin and U46619, a stable analog of thromboxane A(2). NSC23766 did not alter the cAMP or cGMP levels in platelets. Consistent with the requirement of Rac1 for normal platelet function, the bleeding times in Rac1(-/-) mice or mice given NSC23766 were significantly prolonged. CONCLUSIONS Our data show that deficiency or inhibition of Rac1 GTPase blocks platelet secretion. The inhibition of secretion, at least in part, is responsible for diminished platelet aggregation and prolonged bleeding times observed in Rac1 knockout or Rac1 inhibitor-treated mice.
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Affiliation(s)
- H Akbar
- Division of Experimental Hematology, Cincinnati Children's Research Foundation, University of Cincinnati, Cincinnati, OH, USA
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57
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Mu ZG, Cao GT, Guo JG, Xu GX, Zhang PF, Han L, Yin G, Hao JC, Shang X, Cao J, Liu J. [Adjustment of blood coagulation during the perioperation period of emergency liver transplantation]. Zhonghua Gan Zang Bing Za Zhi 2007; 15:462-3. [PMID: 17594816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Affiliation(s)
- Zhen-guo Mu
- Department of Surgery, Rizhao Hospital of Traditional Chinese Medicine, Rizhao 276800, China
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Gaber MW, Aziz AM, Shang X, Penmetsa R, Sabek OM, Yen MRT, Gaber LW, Moore LW, Gaber AO. Changes in Abdominal Wounds Following Treatment With Sirolimus and Steroids in a Rat Model. Transplant Proc 2006; 38:3331-2. [PMID: 17175264 DOI: 10.1016/j.transproceed.2006.10.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Indexed: 11/22/2022]
Abstract
Wound healing complications have been observed in patients receiving sirolimus (SLR). This study examined the degree and duration of delayed healing in various protocols using SLR. Sprague-Dawley rats underwent a standard midline abdominal incision and wound closure. Groups of 6 rats each were randomized to receive different doses of SLR (2 and 5 mg/kg) with or without loading dose (10 mg/kg x3 days), and with or without steroids (20 mg/kg x3 days followed by 5 mg/kg for 2 weeks). Rats were humanely killed on postoperative days 5, 10, or 15. Wound breaking force was measured using the EHMI BIAX-II instrument and tensile strength was calculated. Wounds in control animals had gradual increase in tensile strength during the 15-day observation. In contrast, high and loading doses of SLR caused reduction in wound strength until day 10, but the wounds' tensile strength became equivalent to control by day 15. The addition of steroids prolonged wound recovery with low doses of SLR until day 15 and had very profound effects on healing in high-dose SLR-treated animals (>50% reduction) that continued beyond the 2 weeks of observation. Low doses of SLR in non-steroid-treated animals had a short-term (5-day) impact on wound healing; high dose and loading doses delayed healing for 10 to 15 days. The addition of steroids had a synergistic effect on delayed wound healing, particularly in animals receiving high-dose SLR, which demonstrated prolonged wound weakness. These results may provide practical guidelines for postoperative introduction of SLR in the context of various clinical protocols.
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Affiliation(s)
- M W Gaber
- University of Tennessee Health Science Center, Memphis Tennessee 38138, USA
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Pang X, Shang X, Lü J. [Application of the IFN-gamma ELISPOT assay for monitoring CD8(+) T cell response to specific antigen from hepatocellular carcinoma patients]. Zhonghua Yi Xue Za Zhi 2001; 81:1234-7. [PMID: 11825525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To study the specific CD8(+) T cell response to HLA-A2 binding peptide Flu p58-66 from HLA-A2-positive hepatocellular carcinoma patients and healthy donors. METHODS The CD8(+) T cells were separated with immunobeads from PBMC of HCC patients and healthy donors, respectively. The irradiated autologous CD8(-) PBMC or isolated dendritic cells were loaded with influenza matrix peptide as APC. After 7 days' culture, the frequency of effector cells to secrete IFN-gamma in response to Flu p58-66 was detected in ELISPOT assay. RESULTS With CD8(-) PBMC as APC, the frequency of effector cells to secrete IFN-gamma in response to Flu peptide was 22 +/- 9/well in HCC patients (n = 8) and 59 +/- 27/well in healthy donors (n = 12) when the effector cells were 5 x 10(4)/well (P < 0.01). To compare the antigen-presenting capacity of APC derived from 5 healthy donors, DC was better than CD8(-) PBMC. CONCLUSION Although the frequency of specific effector CTL to secrete IFN-gamma in response to Flu p58 - 66 was lower in HCC patients than in healthy individuals, the majority of HCC patients have the cellular immunity specific to antigen peptides.
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Affiliation(s)
- X Pang
- Department of Immunology, Peking University Health Science Center, Beijing 100083, China
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60
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Shang X, Shiono Y, Fujita Y, Oka S, Yamazaki Y. Synergistic enhancement of apoptosis by DNA- and cytoskeleton-damaging agents: a basis for combination chemotherapy of cancer. Anticancer Res 2001; 21:2585-9. [PMID: 11724325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Actinomycin D (AD)-induced apoptosis in CMK-7 cells is greatly accelerated by cytoskeletal poisons such as colcemid (CL) and cytochalasin D (CD). This phenomenon is important in the combination chemotherapy of cancer so that its generality was investigated. Four human leukemia and two human solid tumor cell lines were treated with combinations of one DNA-damaging agent [AD, mitomycin C (MMC), or etoposide (VP- 16)] and one cytoskeletal poison [CL, CD, or vinblastine (VBL)]. The apoptosis was monitored by assaying caspase-3 activity and the DNA cleavage ratio. The caspase-3 activation in all leukemia and HeLa S3 cell lines was, except for a few cases, 1.3-to 6.0-fold enhanced by combinations of the DNA-damaging agent with a cytoskeletal poison. The DNA cleavage ratio as well as the dead cell ratio was also 1.4-to 23.7-fold enhanced in CMK-7, U-937, HeLa S3, and Colo320 DM cell lines by the combinations of AD with CL, CD, or VBL. The combination index for caspase-3 activation by AD and CL in U-937 cells was smaller than 1 at Fa of more than 0.03. Thus, apoptosis in many tumor cell lines is synergistically enhanced by various combinations of DNA- and cytoskeleton-damaging agents.
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Affiliation(s)
- X Shang
- National Institute of Bioscience and Human Technology, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
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61
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Shang X, Qiu B, Frait KA, Hu JS, Sonstein J, Curtis JL, Lu B, Gerard C, Chensue SW. Chemokine receptor 1 knockout abrogates natural killer cell recruitment and impairs type-1 cytokines in lymphoid tissue during pulmonary granuloma formation. Am J Pathol 2000; 157:2055-63. [PMID: 11106578 PMCID: PMC1885763 DOI: 10.1016/s0002-9440(10)64844-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Mice with targeted mutation of chemokine receptor 1 (CCR1) were used to assess the contribution of CCR1 agonists to local, regional, and systemic inflammatory-related events during experimental pulmonary granuloma formation. Models of Th1 (type-1) and Th2 (type-2) cell-mediated lung granulomas were induced in wild-type (CCR+/+) and knockout (CCR1-/-) mice by embolizing Sepharose beads coupled to the purified protein derivative of Mycobacterium bovis or soluble antigens derived from Schistosoma mansoni eggs. Morphometric analysis indicated that granuloma sizes were unchanged in CCR1-/- mice, but flow cytometric analyses of dispersed granulomas revealed that natural killer cell recruitment to type-1 lesions was abrogated by 60%. Analysis of cytokine production by draining lymph node cultures showed altered expression in CCR1-/- mice characterized by reduced interleukin-2 and interferon-gamma in the type-1 response, and enhanced interleukin-5 and interleukin-13 in the type-2 response. Peripheral blood leukocytosis was also enhanced in the type-1 but not the type-2 response. These findings suggest that CCR1 agonists contribute to multiple immunoinflammatory events in the type-1 granulomatous response with natural killer cell accumulation being particularly sensitive to CCR1 disruption. Although functional efficacy of granulomas may be altered, chemokine redundancy and cytokine reserve seem to make the bulk of the exudative response resistant to CCR1 disruption.
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Affiliation(s)
- X Shang
- Department of Pathology, University of Michigan Hospitals, Ann Arbor, Michigan, USA
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Yamazaki Y, Dang Y, Shang X, Tsuruga M, Fujita Y, Tanaka H, Zhou D, Kawasaki K, Oka S. Acceleration of dna damage-induced apoptosis in leukemia cells by interfering with actin system. Exp Hematol 2000. [DOI: 10.1016/s0301-472x(00)00628-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Yamazaki Y, Tsuruga M, Zhou D, Fujita Y, Shang X, Dang Y, Kawasaki K, Oka S. Cytoskeletal disruption accelerates caspase-3 activation and alters the intracellular membrane reorganization in DNA damage-induced apoptosis. Exp Cell Res 2000; 259:64-78. [PMID: 10942579 DOI: 10.1006/excr.2000.4970] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In actinomycin D (AD)-induced apoptosis, caspase-3 activation and DNA cleavage in human megakaryoblastic leukemia CMK-7 cells were greatly accelerated by tubulin and actin polymerization inhibitors [e.g., colcemid (CL) and cytochalasin D (CD), respectively], but the acceleration was not found with Taxol or phalloidin. A decrease in mitochondrial transmembrane potential, release of cytochrome c into the cytosol, and cleavage of procaspase-9 to its active form preceded the activation of caspase-3 and, moreover, all of these events began earlier and/or proceeded faster in cells treated with AD plus CL or CD than in cells treated with AD only. These results suggest that cytoskeletal disruption in the apoptotic cells promotes damage of the mitochondrial membrane, resulting in the enhanced release of cytochrome c necessary for the activation of caspase-9 that initiates the caspase cascade. On the other hand, apoptotic bodies were rapidly formed from cells treated with AD and CL, but were suppressed when treated with AD and CD. Intracellular membranes and the actin system were reorganized to surround the nuclear fragments in the AD- and CL-treated cells, but such a membrane system was not formed in the presence of CD, implying that the apoptotic bodies are formed via reorganization of intracellular membranes under regulation by actin polymerization. Thus, the cytoskeletal change in CMK-7 cells has a strong effect on the early biochemical process as well as on the later morphologic process in AD-induced apoptosis.
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Affiliation(s)
- Y Yamazaki
- National Institute of Bioscience and Human Technology, Agency of Industrial Science and Technology, 1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan.
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64
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Ruth JH, Warmington KS, Shang X, Lincoln P, Evanoff H, Kunkel SL, Chensue SW. Interleukin 4 and 13 participation in mycobacterial (type-1) and schistosomal (type-2) antigen-elicited pulmonary granuloma formation: multiparameter analysis of cellular recruitment, chemokine expression and cytokine networks. Cytokine 2000; 12:432-44. [PMID: 10857756 DOI: 10.1006/cyto.1999.0595] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The contribution of IL-4 and IL-13 to inflammation and cytokine responses was compared in mice with types-1 or -2 pulmonary granulomas (GR) elicited by beads bound to antigens of Mycobacteria bovis (PPD) or Schistosoma mansoni eggs (SEA). Type-2 SEA-GR produced the most IL-4 and IL-13. Type-1 PPD-GR produced detectable IL-13, but not IL-4. Mice were treated with anti-IL4 or anti-IL-13 Abs, then lesion size/composition, cytokine/chemokine mRNA and lymph node cytokines were measured. Type-1 GRs resisted individual Abs, but combined Abs augmented lesions by 20%. In contrast, anti-IL-4 abrogated type-2 GR by 30-40% and eosinophil recruitment by 60%. Anti-IL-13 abrogated type-2 GR by 20-30% with no effect on eosinophils. Combined depletion reduced lesion area by 60% and eosinophils by more than 80%. In type-1 GR lungs, anti-IL-4 and anti-IL-13 augmented IFNgamma and TNFalpha mRNA. In type 2 lungs, anti-IL-13 did likewise, but anti-IL-4 decreased TNFalpha without affecting IFNgamma mRNA. In both responses, IL-4 promoted MCP-1 and MCP-5 mRNA, but IL-13 inhibited chemokines in type-1 GR. In lymph nodes, anti-IL-4, but not anti-IL-13, abrogated type-2 cytokines. In fact, IL-13 down-regulated itself and other type-2 cytokines. In summary, IL-4 and IL-13 have common and disparate regulatory functions in types 1 and 2 responses.
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Affiliation(s)
- J H Ruth
- Department of Pathology, Veterans Affairs Medical Center, Ann Arbor, MI 48105, USA
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Davis BG, Shang X, DeSantis G, Bott RR, Jones JB. The controlled introduction of multiple negative charge at single amino acid sites in subtilisin Bacillus lentus. Bioorg Med Chem 1999; 7:2293-301. [PMID: 10632039 DOI: 10.1016/s0968-0896(99)00167-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The use of methanethiosulfonates as thiol-specific modifying reagents in the strategy of combined site-directed mutagenesis and chemical modification allows virtually unlimited opportunities for creating new protein surface environments. As a consequence of our interest in electrostatic manipulation as a means of tailoring enzyme activity and specificity, we have adopted this approach for the controlled incorporation of multiple negative charges at single sites in the representative serine protease, subtilisin Bacillus lentus (SBL). A series of mono-, di- and triacidic acid methanethiosulfonates were synthesized and used to modify cysteine mutants of SBL at positions 62 in the S2 site, 156 and 166 in the S1 site and 217 in the S1' site. Kinetic parameters for these chemically modified mutant (CMM) enzymes were determined at pH 8.6 under conditions which ensured complete ionization of the unnatural amino acid side-chains introduced. The presence of up to three negative charges in the S1, S1' and S2 subsites of SBL resulted in up to 11-fold lowered activity, possibly due to interference with oxyanion stabilization of the transition state of the hydrolytic reactions catalyzed. Each unit increase in negative charge resulted in a raising of K(M) and a reduction of k(cat). However, no upper limit was observed for increases in K(M), whereas decreases in k(cat) reached a limiting value. Comparison with sterically similar but uncharged CMMs revealed that electrostatic effects of negative charges at positions 62, 156 and 217 are detrimental, but are beneficial at position 166. These results indicate that the ground-state binding of SBL to the standard substrate, Suc-AAPF-pNA, to SBL is reduced, but without drastic attenuation of catalytic efficiency, and show that SBL tolerates high levels of charge at single sites.
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Affiliation(s)
- B G Davis
- Department of Chemistry, University of Toronto, ON, Canada
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DeSantis G, Shang X, Jones JB. Toward tailoring the specificity of the S1 pocket of subtilisin B. lentus: chemical modification of mutant enzymes as a strategy for removing specificity limitations. Biochemistry 1999; 38:13391-7. [PMID: 10529215 DOI: 10.1021/bi990861o] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In both protein chemistry studies and organic synthesis applications, it is desirable to have available a toolbox of inexpensive proteases with high selectivity and diverse substrate preferences. Toward this goal, we have generated a series of chemically modified mutant enzymes (CMMs) of subtilisin B. lentus (SBL) possessing expanded S(1) pocket specificity. Wild-type SBL shows a marked preference for substrates with large hydrophobic P(1) residues, such as the large Phe P(1) residue of the standard suc-AAPF-pNA substrate. To confer more universal P(1) specificity on S(1), a strategy of chemical modification in combination with site-directed mutagenesis was applied. For example, WT-SBL does not readily accept small uncharged P(1) residues such as the -CH(3) side chain of alanine. Accordingly, with a view to creating a S(1) pocket that would be of reduced volume providing a better fit for small P(1) side chains, a large cyclohexyl group was introduced by the CMM approach at position S166C with the aim of partially filling up the S(1) pocket. The S166C-S-CH(2)-c-C(6)H(11) CMM thus created showed a 2-fold improvement in k(cat)/K(M) with the suc-AAPA-pNA substrate and a 51-fold improvement in suc-AAPA-pNA/suc-AAPF-pNA selectivity relative to WT-SBL. Furthermore, WT-SBL does not readily accept positively or negatively charged P(1) residues. Therefore, to improve SBL's specificity toward positively and negatively charged P(1) residues, we applied the CMM methodology to introduce complementary negatively and positively charged groups, respectively, at position S166C in S(1). A series of mono-, di-, and trinegatively charged CMMs were generated and all showed improved k(cat)/K(M)s with the positively charged P(1) residue containing substrate, suc-AAPR-pNA. Furthermore, virtually arithmetic improvements in k(cat)/K(M) were exhibited with increasing number of negative charges on the S166C-R side chain. These increases culminated in a 9-fold improvement in k(cat)/K(M) for the suc-AAPR-pNA substrate and a 61-fold improvement in suc-AAPR-pNA/suc-AAPF-pNA selectivity compared to WT-SBL for the trinegatively charged S166C-S-CH(2)CH(2)C(COO(-))(3) CMM. Conversely, the positively charged S166C-S-CH(2)CH(2)NH(3)(+) CMM generated showed a 19-fold improvement in k(cat)/K(M) for the suc-AAPE-pNA substrate and a 54-fold improvement in suc-AAPE-pNA/suc-AAPF-pNA selectivity relative to WT-SBL.
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Affiliation(s)
- G DeSantis
- Department of Chemistry, University of Toronto, Ontario, Canada
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Shang X, Yin H, Lu A, Zhang L. Application of recombinant human granulocyte colony stimulating factor in children with acute myeloid leukemia. Chin Med J (Engl) 1999; 112:620-2. [PMID: 11601256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
OBJECTIVE To evaluate the effect of recombinant human granulocyte colony stimulating factor (rhG-CSF) on accelerating neutrophil recovery and decrease fatal infections for childhood acute myeloid leukemia (AML). METHODS From November 1992 to March 1997, 45 patients were enrolled into our study and 15 were newly diagnosed. All were treated with high dose chemotherapy combined with rhG-CSF. RESULTS Of 15 newly diagnosed patients, 13 achieved complete remission (CR) after one course of therapy and 2 achieved CR after two courses of therapy. For newly diagnosed patients, the durations of absolute neutrophil counts (ANC) < 0.5 x 10(9)/L were 5 days and 10 days in rhG-CSF group and control group respectively (P < 0.05). The incidences of infection of these two groups were 40% and 60% respectively (P < 0.05). As for patients who received intensive therapy, the durations of ANC < 0.5 x 10(9)/L were 5 days and 8 days in rhG-CSF group and control group, respectively (P < 0.05), and the incidences of infection were 25% and 44.4% respectively (P < 0.05). CONCLUSIONS The application of rhG-CSF in children with AML after chemotherapy may hasten the hematopoietic recovery. The duration of neutropenia was shortened by 3-4 days, and the incidence of fatal infection was reduced. rhG-CSF does not stimulate AML growth in vivo.
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Affiliation(s)
- X Shang
- Department of Pediatrics, Second Hospital, Beijing Medical University, Beijing 100044, China
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Abstract
The reaction between methanethiosulfonate reagents and cysteine mutants of subtilisin is quantitative and can be used to prepare chemically modified mutant enzymes (CMMs) with novel properties. The virtually unrestricted structural variations possible for CMMs presents a preparative and screening challenge. To address this, a rapid combinatorial method for preparing and screening the activities of CMMs has been developed.
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Affiliation(s)
- E Plettner
- Department of Chemistry, University of Toronto, Ontario, Canada
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69
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He Y, Li M, Shang X. [The relationship between p53 mutation and esophageal cancer biological behavior]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 1998; 15:1-4. [PMID: 9456364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To investigate the relationship between p53 mutation and esophageal cancer biological behavior as well as its prognostic role in esophageal cancer. METHOD Mutations in exon 5-8 of p53 were screened in 30 sporadic esophageal cancers by a combination of PCR-SSCP and PCR-direct DNA silver sequencing. RESULTS Mutations were found in 11 cases (36.7%). There were 9 point mutations, including 4 missense mutations, 2 nonsense mutations, 3 silent mutations. The other 2 cases were frameshift mutations due to base insertion and deletion. With statistical analysis, the p53 mutation rate was 56.3% in moderately and poorly-differentiated esophageal cancers, 14.3% in well-differentiated cases, with a highly significant difference between the two groups (P=0.025). The mutation rate of the cancers with all layers invaded (52.6%) was remarkably higher than that of the cancers without all layers invaded (9.1%)(P=0.024). A significantly higher rate of p53 mutation was also seen in cases with lymph nodes metastasis (61.5%) than in cases with no lymph nodes metastasis (17.6%) (P=0.024). CONCLUSION The data suggest that there is a strong correlation between the presence of p53 mutation and the biological behavior of human esophageal cancer, such as histologic differentiation, invasion stage, and regional lymph nodes metastasis. Detection of p53 mutation can be helpful in identifying more progressive esophageal cancer and assessing prognosis. The study also discussed the dominant negative effect of p53 and the genetic effect of silent mutation.
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Affiliation(s)
- Y He
- Department of Biology, Nanjing Railway Medical College, Nanjing, 210009 P. R. China
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Zhang Z, Liu J, Shang X, Yang J, Chu J, Wang Z, Yao Z, Ma H, Li Q, Wang Y. [The effect of Rhodiola capsules on oxygen consumption of myocardium and coronary artery blood flow in dogs]. Zhongguo Zhong Yao Za Zhi 1998; 23:104-6, inside back cover. [PMID: 11596257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
It has been proved that Rhodiola Capsules can obviously decrease the oxygen consumption of myocardium and oxygen consumption index in anesthetic dogs, decrease the coronary artery resistance, but have no marked effect on the coronary artery blood flow. The Capsules also have the function of decreasing blood presure and slowing heart rate.
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Affiliation(s)
- Z Zhang
- Institute of Information on TCM, China Academy of Traditional Chinese Medicine, Beijing 100700
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Trolinder NL, Shang X. In vitro selection and regeneration of cotton resistant to high temperature stress. Plant Cell Rep 1991; 10:448-452. [PMID: 24221849 DOI: 10.1007/bf00233812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/1991] [Revised: 07/11/1991] [Indexed: 06/02/2023]
Abstract
Cell suspension cultures of cotton (Gossypium hitirsutum L. cv. Coker 312) were exposed to various temperature:time treatments in order to select cell lines resistant to high temperature stress. Cells were exposed to 45°C for 3 h each day until the total accumulated hours of stress were: 0 h, 10 h, 75 h, 100 h, or 105 h (81 h pulsed then 24 h continuous). After the stress treatments, the cells were plated onto embryo development medium and plants were recovered. The embryogenic calli that were recovered were subcultured monthly for 6 months and tested for increased resistance to the temperature:time treatments previously determined to be lethal and to water stress as imposed by PEG. All of the selected cell lines were more resistant to both types of stress than the control cell lines. Leaf tissue of stress selected (Ro) formed and maintained callus growth when incubated at 38°C; whereas, tissue excised from nonselected controls rarely formed callus and calli which did form quickly became necrotic. These cells and plants will provide a tool for determining the mechanisms involved in resistance to high temperature stress.
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Affiliation(s)
- N L Trolinder
- USDA-ARS, Cropping Systems Research Laboratory and Department of Agronomy, Horticulture, and Entomology, Texas Tech University, Route 3, P.O. Box 215, 79401, Lubbock, TX, USA
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