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Li-Sheng Wang

Publications and source records attributed to Li-Sheng Wang.

At least 19 recordsLinked to original sources
PubMed2006

Shp-2 tyrosine phosphatase is required for hepatocyte growth factor-induced activation of sphingosine kinase and migration in embryonic fibroblasts.

Shp-2, a ubiquitously expressed protein tyrosine phosphatase containing two Src homology 2 domains, plays an important role in integrating signaling from the cell surface receptors to intracellular signaling mechanisms. Previous studies have demonstrated that the Shp-2 is involved in hepatocyte growth factor (HGF)-induced cell scattering. Here we report that Shp-2 is required for the HGF-induced activation of sphingosine kinase-1 (SPK1), a highly conserved lipid kinase that plays an important role in cell migration. Loss-of-function mutation of Shp-2 did not affect the expression of SPK1, but resulted in its inactivation and the blockage of HGF-induced migration in embryonic fibroblasts. Reintroduction of functional wild type (WT) Shp-2 into the mutant cells partially restored SPK1 activation, and overexpression of SPK1 in these mutant cells enhanced HGF-induced cell migration. Inhibition of expression or activity of SPK1 in WT cells markedly decreased intracellular S1P levels and HGF-induced cell migration. Furthermore, we found that Shp-2 co-immunoprecipitated with SPK1 and c-Met in embryonic fibroblasts. These studies suggest that Shp-2 is an SPK1-interacting protein and that it plays an indispensable role in HGF-induced SPK1 activation.

Animals↗
PubMed2006

Efficient gene transfer into hematopoietic cells by a retargeting adenoviral vector system with a chimeric fiber of adenovirus serotype 5 and 11p.

OBJECTIVE: Adenoviral vectors (Ad) were widely used in gene therapy and study of gene function, but the commonly used serotype 5 adenovirus-based vectors (Ad5) could poorly transduce hematopoietic cells because of low expression of viral receptors on these cells. To overcome this limitation, we developed a retargeting adenovector with a chimeric fiber of Ad5 and Ad11p (Ad5F11p) and evaluated its gene transfer ability in hematopoietic cells. MATERIALS AND METHODS: An Ad11p fiber pseudotyped Ad5 vector was generated by modifying the fiber gene of pAdEasy-1 backbone plasmid. Ad5F11p-GFP encoding enhanced green fluorescence protein (GFP) gene was transferred into human leukemic cell lines, primary leukemic cells, and CD34(+) hematopoietic cells. The gene transduction efficiency was determined by fluorescence-activated cell sorting assay. RESULTS: More than 90% of U937 or K562 cells could be infected by Ad5F11p-GFP at a moderate multiplicity of infection (MOI). Ad5F11p-GFP is also significantly more effective than control Ad5-GFP in infection of primary myeloid leukemic cells. At 200 MOI, GFP-positive percentages of Ad5F11p-GFP transduced myeloid leukemic cells range from 10.58% to 92.63% with a median of 28.65%. Ad5F11p-GFP could transduce about 50% human hematopoietic stem/progenitor (CD34(+)) cells, while Ad5-GFP could transduce <15% at 200 MOI. CD46 was reported to be the receptor of Ad11p. Our data suggest that CD46 participates in the process of Ad5F11p-GFP infection but is not the unique molecule determining its gene transfer efficiency of host cells. CONCLUSION: We established a retargeting adenovector system, which could infect hematopoietic cells effectively and would benefit research work on Ad tropism.

Adenoviridae↗
PubMed2006

Genetically modified myeloma cell vaccine inducing antitumor immune response in vivo.

This study was aimed to evaluate the in vivo antitumor effect of genetically modified myeloma cell vaccine on human myeloma xenografts implanted into nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Human immune system was established in NOD/SCID mice by intraperitoneal injection of human peripheral blood lymphocytes (PBLs). After being inoculated subcutaneously with irradiated myeloma cell line sko-007, adenovirally transferred with GFP or p53, granulocyte-macrophage colony-stimulating factor (GM-CSF) and B7-1 genes, huPBL-NOD/SCID mice were challenged by subcutaneous injection of non-transferred sko-007 cells. The results indicated that Ad-p53/GM-CSF/B7-1-infected sko-007 cell vaccination significantly reduced local tumor growth compared with controls. Histopathological and immunohistochemical analysis showed that tumor tissues increasingly displayed diffuse necrosis, mainly caused by apoptosis, accompanied with significant fibroplasias and blood vessel hyperplasia, and human T cells infiltrated into the tumor tissues. It is concluded that transgenic p53, GM-CSF and B7-1 expression produces an immune response against myeloma cells and may be of therapeutic value for multiple myeloma in human being.

Adenoviridae↗
PubMed2006

[Impact of rhG-CSF on sphingosine 1-phosphate concentration in blood plasma of donors].

Sphingosine 1-phosphate (S1P), which can be impacted by different growth factors through sphingosine kinase (SphK), is a bioactive lipid produced by metabolism of sphingolipid with various biological responses. Recombinant human granulocyte-colony-stimulating factor (rhG-CSF) have been used widely in peripheral blood stem/progenitor cell mobilization. This study was aimed to investigate the effects of rhG-CSF on S1P concentration in plasma of donors. The peripheral blood mononuclear cells and blood plasma were collected from 8 peripheral blood progenitor cell donors before mobilization and on the fifth day of mobilization with rhG-CSF. The SphK mRNA expression of blood mononuclear cells were detected by RT-PCR. The changes of S1P concentration were assayed with SphK enzyme catalyzed reaction. The results showed that both kinds blood mononuclear cells collected before and after rhG-CSF mobilization expressed SphK mRNA. The S1P concentration is low in donor's plasma both before and after mobilization with rhG-CSF, and there was no markedly change of S1P concentration in plasma before and after mobilization (P > 0.05). In conclusion, mobilization with rhG-CSF does not impact S1P concentration in donors' plasma.

Blood Donors↗
PubMed2006

[Impact of mobilization with rhG-CSF on the proliferation and cytotoxicity of donor's T cells].

The study was to understand the impact on the proliferation and cytotoxicity of donor's T cells during mobilization with rhG-CSF. The peripheral blood mononuclear cells (PBMNC) were collected from 15 donors before mobilization and on fifth day of mobilization with rhG-CSF. After the PBMNC were activated with 500 ng/ml of CD3 monoclonal antibody and 500 microg/ml of rhIL-2 for 96 hours, the activated T cells were collected for testing proliferation, cytotoxicity, Fas expression, perforin and Fas ligand (FasL) mRNA expression, the IFN-gamma concentration in the culture medium of the activated T cells was determined by radioimmunoassay. The results showed that the proliferation activity of T lymphocytes and the cytotoxicity of T cells activated with CD3 monoclonal antibody and rhIL-2 were reduced markedly after mobilization with rhG-CSF (P < 0.05). The Fas molecule expression in the activated T cells was very high both before and after mobilization with rhG-CSF (P > 0.10). The activated T cells expressed perforin mRNA and didn't express FasL mRNA both before and after mobilization with rhG-CSF. The concentration of IFN-gamma in the culture medium of the activated T cells decreased significantly after mobilization with rhG-CSF (P < 0.01). It is concluded that activity of proliferation and cytotoxicity of donor's T cells is impaired after mobilization with rhG-CSF.

Adolescent↗
PubMed2005

Adenoviral-mediated transfer of human wild-type p53, GM-CSF and B7-1 genes results in growth suppression and autologous anti-tumor cytotoxicity of multiple myeloma cells in vitro.

Multiple myeloma (MM) remains incurable despite the use of high-dose chemotherapy and stem cell transplantation. However, immunotherapy is expected to offer long-term disease control, or even possibly a cure. We have previously demonstrated the suppressive effect of a recombinant adenovirus carrying human wild-type p53, granulocyte-macrophage colony-stimulating factor, and B7-1 genes (Ad-p53/GM-CSF/B7-1) on the growth of laryngeal cancer cells. In the present study, we evaluated the effects of an Ad-p53/GM-CSF/B7-1-modified myeloma cell vaccine strategy aimed to induce apoptosis and to augment the immunogenicity of MM cells. Both MM cell lines and purified primary myeloma cells were infected with Ad-p53/GM-CSF/B7-1. High expression levels of these three genes were confirmed separately by Western blot, enzyme-linked immunosorbent assay (ELISA), and flow cytometry. When wild-type p53, GM-CSF and B7-1 genes were introduced, the growth of MM cells was inhibited via enhanced apoptosis and the immunogenicity of tumor cells was augmented. The combinatorial effect of these three genes on inducing cytotoxic T lymphocytes (CTLs) was more evident than that of p53 individually or any combinations of two (p53 plus GM-CSF or p53 plus B7-1). Furthermore, significant proliferation of autologous peripheral blood lymphocytes (PBLs) and specific cytotoxicity against autologous primary MM cells were induced in vitro. These results suggest that myeloma cell vaccination co-transferred with p53, GM-CSF and B7-1 genes may be a promising immunotherapeutic approach against MM.

Adenoviridae↗
PubMed2005

[Membrane microparticles and their roles in the regulation of hematopoiesis - review].

Membrane microparticles are shed from the plasma membrane of most eukaryotic cells when these cells were undergone activation or apoptosis, and released into the extracellular environment. Their composition depends on the cellular origin and processes triggering their formation. Several lines of evidence suggest that membrane microparticles might be able to facilitate cell-cell cross-talk and play an important roles in the regulation of survival, proliferation, differentiation, adhesion and chemotaxis of hematopoietic cells. Here, the components, mechanism of formation and the regulatory roles of membrane microparticles in hematopoiesis were reviewed.

Caveolae↗
PubMed2005

[Effects of sphingosine 1-phosphate on functions of T cell - review].

Sphingosine 1-phosphate (S1P), a bioactive lipid produced by metabolism of sphingolipid, plays an important roles in the regulation of various biological responses. T cell expresses the S1P receptors, including S1P1, S1P2, S1P3, S1P4 and S1P5. Activation of S1P signal regulates multiple immunological functions of T cell, including proliferation, apoptosis, differentiation, migration and cytokine excretion. FTY720, a sphingosine analog, suppresses the S1P signal resulting in redistribution of lymphocytes from circulation to secondary lymphoid tissues, which has been applied as a potent immunosuppressive drug. In this paper, biosythesis and degradation of S1P, S1P receptor and its mediated signal pathway, S1P receptor expression of T-cells, regulation of S1P on T cell functions and immunosuppresion drugs involving S1P signal pathway were reviewed.

Fingolimod Hydrochloride↗
PubMed2005

[A new isoflavone from Huoxue Yiqi Tang].

OBJECTIVE: To study the chemical constituents in the active parts of Huoxue Yiqi Tang. METHOD: The silica gel, Sephadex LH-20 were used to isolate the compounds, El, FAB-MS and 1D, 2D-NMR were used to identify the obtained compounds. RESULT: 14 compounds were obtained from the prescription. CONCLUSION: They were all first time obtained from the prescription. Among them, 7, 3'-dihydroxyl-5'-methoxyisoflavone is new.

Anthraquinones↗
PubMed2005

[Influence of hepatocyte growth factor on biological characteristics of bone marrow-derived mesenchymal stem cells].

Hepatocyte growth factor (HGF) is one of major growth factors in the bone marrow microenvironments with which the proliferation, differentiation and migration of bone marrow-derived mesenchymal stem cells were closely contacted. However, its roles in the regulation of proliferation, differentiation and migration of bone marrow-derived mesenchymal stem cells remain unclear. This study was aimed to investigate the effect of HGF on biological characteristics of bone marrow-derived mesenchymal stem cells. Expression of c-Met, the receptor for HGF was detected by immunohistochemistry assay, cell proliferation was determined by MTT, activity of ALP was quantitatively assayed, cell migration and anoikis-induced MSC apoptosis were analyzed. The results showed that HGF not influenced the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells. Treatment of bone marrow-derived mesenchymal stem cells with recombinant human hepatocyte growth factor resulted in inhibition of anoikis-induced apoptosis. HGF significantly stimulated the migration of bone marrow-derived mesenchymal stem cells. Both PI-3 kinase and MAPK kinase were proved to be involved in HGF-induced migration. It is concluded that HGF/c-Met signal regulates the apoptosis and migration of bone marrow-derived mesenchymal stem cells.

Anoikis↗
PubMed2004

Sphingosine kinase activation regulates hepatocyte growth factor induced migration of endothelial cells.

Hepatocyte growth factor (HGF)-induced migration of endothelial cells is critical for angiogenesis. Sphingosine kinase (SPK) is a key enzyme catalyzing the formation of sphingosine-1-phosphate (S1P), a lipid messenger that is implicated in the regulation of a wide variety of important cellular events through both intracellular and extracellular mechanisms. The aim of this study was to investigate whether activation of SPK is involved in the migration of endothelial cells induced by HGF. The biological functions of HGF are mediated through the activation of its high-affinity tyrosine kinase receptor, c-met protooncogene. In the present study, Treatment of ECV304 endothelial cells with HGF resulted in tyrosine phosphorylation of c-Met and activation of SPK in a concentration-dependent manner. Either Ly294002 or PD98059, specific inhibitor of the PI3K and ERK/MAPK pathways, respectively, blocked the HGF-induced activation of SPK. HGF stimulation significantly increased intracellular S1P level, but no detectable secretion of S1P into the cell culture medium was observed. Treatment of ECV304 cells with pertussis toxin (PTX) has no effect on the HGF-induced migration, indicating extracellular S1P is dispensable for this process. Overexpression of wild-type SPK gene in ECV 304 cells increased the intracellular S1P and enhanced the HGF-induced migration, whereas inhibition of cellular SPK activity by N,N-dimethylsphingosine (DMS), a potent inhibitor of SPK, or by expression of a dominant-negative SPK (DN-SK) blocked the HGF-induced migration of ECV 304 cells. It is suggested that PI3K and ERK/MAPK mediated the activation of SPK and would be involved in the HGF-induced migration of endothelial cells. These results elucidate a novel mechanism by which intracellularly generated S1P mediates signaling from HGF/c-Met to the endothelial cell migration.

Cell Line↗
PubMed2004

[Suppressive effect of Notch signal activation on apoptosis of multiple myeloma cells].

The proliferation and apoptosis of multiple myeloma (MM) cells were regulated by bone marrow microenvironments in which Notch signal plays important role in mediating cell-cell communication. However, the regulatory effect of Notch signal on the proliferation and apoptosis of multiple myeloma cells remains unclear. In this study, regulatory effect of Notch signal on the apoptosis of MM cells induced by DMS (N, N-dimethylsphingosine) was investigated. RT-PCR was used to identify the expression of Notch receptor and related molecules such as Dll-1, Jagged-1, Deltex-1 in MM cell lines. The intracellular domain of Notch (ICN), active form of Notch, was transferred into MM cells by retrovirus. The apoptosis of MM cells was determined by trypan blue exclusion tests and TdT-mediated dUTP nick end labeling (TUNEL) assay. The results showed that multiple myeloma cells expressed the Notch-1 and its related molecules. Notch activated multiple myeloma cell lines were obtained. Activation of Notch protected the multiple myeloma cells from the apoptosis induced by DMS,which was determined by cell viability and TUNEL assay. In conclusion, Notch signal suppressed the apoptosis of multiple myeloma cells and would possibly be a novel therapeutic target.

Apoptosis↗
PubMed2004

[Progress of studies on enhancing efficiency of gene transfection into hematopoietic cells with the adenoviral vector--review].

Recombinant adenoviral vectors have been widely applied for the basic research and clinical trials of gene therapy. However, the inability of adenovirus to infect hematopoietic cells which lack the specific adenovirus receptors-coxsackie virus and adenovirus receptor (CAR) represents an important limitation in therapeutic applications. This limitation may be overcome by several approaches including modification of adenovirus vector and improvement of the susceptibility of hematopoietic cells. The current progresses in this field were summarized.

Adenoviridae↗
PubMed2004

[Progress in Notch signaling].

Notch signaling plays a vital role in cell fate decisions in both invertebrate and vertebrate development. Signals exchanged between neighboring cells through the Notch receptor amplify and consolidate molecular differences, which eventually dictate cell fates. In this review, the details of notch signaling will be discussed, with a focus on Lin/Notch repeats (CSL) independent modes.

Carrier Proteins↗
PubMed2004

[Recent advance on LFA-1/ICAM-1 costimulatory signal of T cell-review].

LFA-1/ICAM-1 costimulation plays an important role in immunologic reaction of many different T cell populations. After TCR/CD3 complex cross-linking MHC/peptide, LFA-1, expressed on T cell increases a higher affinity and avidity for ICAM-1 rapidly. LFA-1 is a key molecule in formation of the immune synapse. LFA-1/ICAM-1 costimulation can engage various signaling events of T cell by up-regulating the activities of PI 3-kinase, sphingomyelinase, and c-Jun NH2-terminal kinase. With the costimulation of LFA-1/ICAM-1, engagement of TCR molecules results in a significant increase of T cell activities, including higher Th1 cytokines production, strongly proliferative response and higher T cell cytotoxicity.

Animals↗
PubMed2004

[Isolation and identification of a new cucurbitacin from Picria fel-terrae].

AIM: To study compounds isolated from Picria fel-terrae. METHODS: The chemical constituents were separated and purified by column chromatography on silica gel and MCI. Their structures were identified on the basis of spectral data (IR, UV, MS, ID NMR and 2D NMR). RESULTS: A new cucurbitacin, along with a known one, were obtained from the 60% EtOH extract of the whole plant. CONCLUSION: The new compound was identified as 11, 24-dioxo-5, 21-diene-cucurbit-3alpha-O-beta-D-xylopyranosyl-16alpha-O-alpha-L-rhamnopyranoside (dehydrobryogenin glycoside). The known one, hexanorcucurbitacin F, was obtained for the first time from Picria fel-terrae.

Molecular Structure↗
PubMed2003

Treatment of myocardial ischemia with bone marrow-derived mesenchymal stem cells overexpressing hepatocyte growth factor.

Mesenchymal stem cells could differentiate into cardiomyocytes in vitro and have been shown to reconstitute the impaired myocardium in vivo. Hepatocyte growth factor, a recognized angiogenic factor and endothelial cell chemoattractant, has been applied in the treatment of myocardial ischemia. In this study, we used a ligation model of proximal left anterior descending coronary artery of rats to evaluate the effect of mesenchymal stem cells overexpressing hepatocyte growth factor in the treatment of myocardial ischemia. Bone marrow-derived mesenchymal stem cells were isolated, expanded, characterized, and infected with adenovirus carrying human hepatocyte growth factor cDNA (Ad-HGF). Mesenchymal stem cells infected by Ad-HGF released soluble HGF protein at a high level, which was maintained at least for 2 weeks. Implantation of mesenchymal stem cells overexpressing hepatocyte growth factor into left anterior descending risk areas improved the functions of impaired myocardium, including diminishing the area of ischemia, increasing the number of capillaries, and reducing collagen content. By using the sry gene as a marker, we also demonstrated that the engrafted cells or their progeny incorporated into ischemic cardiac muscle. These results showed that treatment of myocardial ischemia with bone marrow-derived mesenchymal stem cells overexpressing hepatocyte growth factor could be a novel strategy that can both restore local blood flow and regenerate lost cardiomyocytes.

Adenoviridae↗