Biomedical subjects

Ping Zou

Publications and source records attributed to Ping Zou.

At least 73 records · Page 4Linked to original sources

PubMed2004

[Inhibiting effect of vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotides on VEGF expression in U937 cell].

To study the effect of VEGF fully phosporothioated antisense oligodeoxynucleotide (VEGF-ASODN) on VEGF expression in acute monocyte leukemic cell line U937 in vitro, U937 cells were incubated with VEGF-ASODN at concentrations of 10, 20 and 30 micro mol/L or scrambled sequence as compared with negative control. The expression of VEGF mRNA was measured by semi-quantitative RT-PCR. The expression of VEGF protein was measured by Western blot. The result showed that VEGF-ASODN had obviously inhibitive effect on expression of VEGF in U937 cell, as compared with scrambled sequence and negative control (P < 0.05). Scrambled sequence group had no significant difference compared with negative control group (P > 0.05). It is concluded that the expressions of VEGF mRNA and protein in leukemic cell line U937 are down-regulated by VEGF-ASODN.

Humans↗

PubMed2004

[Distribution and efficiency of recombinant adenovirus mediated hVEGF165 gene transfer in bone marrow transplanted mice].

OBJECTIVE: To investigate the rapid construction of enhanced green fluorescent protein (EGFP) labeled recombinant adenovirus containing hVEGF165 and its distribution and efficiency in bone marrow transplanted mice. METHODS: The recombinant adenovirus Ad-EGFP/hVEGF165 was rapidly constructed by using AdEasy system based on the homologous recombination in bacteria, and its property was studied in vitro. Then 3x10(8) PFU adenovirus was injected into BALB/c mice via the tail vein accepted syngeneic bone marrow transplantation. The in vivo distribution of adenovirus and plasma levels of VEGF were measured at different phases. RESULTS: The adenovirus Ad-EGFP/hVEGF165 was quickly constructed by homologous recombination in bacteria using AdEasy system. The purified particles were homogenous hexagon with titers between 10(10) PFU/ml and 10(11) PFU/ml. The Hela cells infected with Ad-EGFP/hVEGF165 did not show cytopathic effects after several times passages. Under the fluorescent microscope, EGFP was revealed in the heart, lung, liver, spleen, kidney and intestine of mice at different phases. RT-PCR and immunohistochemistry showed hVEGF165 expressed significantly. No obvious damages were observed in different organs by HE staining. The plasma level of hVEGF165 was up to 866.67+/-97.13 pg/ml. CONCLUSION: These results suggested that the construction of adenovirus vector by homologous recombination in bacteria was an efficient and time-saving method, and high titer adenovirus could successfully mediate the safe and stable expression of hVEGF165 in post bone marrow transplanted mice. All these would make further gene therapy in bone marrow transplantation possible.

Adenoviridae↗

PubMed2004

[Study on the expression of hematopoietic growth factor gene in human umbilical vein endothelial cells using gene chip].

In order to detect the hematopoietic growth factor gene expressed in human umbilical vein endothelial cells using gene chip, human umbilical vein endothelial cells (ECV304) were cultured in vitro and divided into VEGF group and control group in same medium. 50 ng/ml hVEGF165 was added in the VEGF group. After culture for 24 hours all cells were collected for total RNA extraction. Then, cDNAs were marked with Cy3 and Cy5 for control group and VEGF group, respectively, and hybridized with gene chip. Hybridization signals were collected and analyzed following scanning by laser co-focal microscopy. The results showed that a large number of hematopoietic growth factor and receptor genes (Epo/R, GM-CSF/R, G-CSF/R, LIF, IL-3, TPO, Flt-3, SCF) were expressed in both groups, while many other growth factors (VEGF, IGF2, PDGFA, PDGFB, TGFbeta1) and receptors (neuropilin-1, neuropilin-2, TGFbeta-R1)were expressed. The differentially expressed genes amounted to 24. It is concluded that many hematopoietic growth factors and receptors expressed by hUVECs could be analyzed in a short period by using gene chip, which provides a powerful method for further studies on characteristics of vascular endothelial cells.

Cells, Cultured↗

PubMed2004

[Apoptosis of acute myeloid leukemic cells induced by human recombinant soluble tumor necrosis factor-related apoptosis inducing ligand (TRAIL)].

In order to investigate the effect of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) on acute myeloid leukemic (AML) cells, BMMNC or PBMNC of 39 cases of AML (patient group) and 21 normal persons (control group) were isolated; the cytotoxic effects of TRAIL at various concentration on the cells were evaluated by MMT, apoptosis were detected by flow cytometry. The results showed that TRAIL of various concentration could kill AML cells in various degrees, but had no killing effect on normal cells. It is concluded that TRAIL can kill AML cells through inducing apoptosis, and TRAIL has a promising prospect in clinical use.

Adult↗

PubMed2004

[Expansion of marrow hematopoietic progenitor cells ex vivo supported by culture system from mouse marrow embryonic fibroblasts and leukemia inhibitory factor].

The objective of this study was to explore the effect of culture system from embryonic fibroblasts and leukemia inhibitory factor (LIF) on expansion of mouse bone marrow hematopoietic progenitor cells ex vivo, and to observe its effect on the expression of homing-related cell adhesion molecules among VLA-4 (CD49e), VLA-5 (CD49e), LFA-1 (CD11a), HCAM (CD44) and L-selectin (CD62L). The culture system from the mouse embryonic fibroblasts inactivatd by mitomycin C and contained LIF was used to culture with mouse BMMNC for 7 days. The total number of BMMNC, CFC, Sca-1(+) cells, cell apoptosis rate and the expression of above cell adhesion molecules were counted. The results showed that culture system consisted of embryonic fibroblasts and LIF significantly enhanced the total number of BMMNC, CFC, Sca-1(+) cells, suppressed cell apoptosis (P < 0.05). In control without MEF and LIF, the total number of BMMNC was reduced remarkedly, CFC and Sca-1(+) cells were completely dead, the majority of cells produced apoptosis (P < 0.01). The expression of CD49d, Cd44 and CD61L on Sca-1(+) cells were similar to that befor expression (P < 0.05), but the expression of CD49e and CD11a on Sca-1(+) cells were remarkably increased (P < 0.05). It is concluded that culture system from embryonic fibroblasts and LIF can only significantly expand mouse bone marrow hematopoietic progenitor cells ex vivo, but the expanded hematopoietic progenitor may well sustain the expression of homing-related adhesion molecules. The homing functions of these expanded hematopoietic progenitors kept no change.

Animals↗

PubMed2004

[Experimental study of inhibiting CTLL-2 cell apoptosis and enhancing cytotoxicity to Yac-1 cell by hammerhead ribozyme].

OBJECTIVE: To investigate the inhibition role of anti-Fas hammerhead ribozyme on Fas expression and Fas-mediated apoptosis in mouse cytotoxic T lymphocyte (CTL) cell line--CTLL-2 cells, and explore a novel approach to enhance the ability of T cells against leukemia in donor lymphocytes infusion (DLI). METHODS: A hammerhead ribozyme targeting the Fas mRNA was synthesized and transfected into CTLL-2 cells by electroporation. Fas expression in CTLL-2 cells was detected by using RT-PCR, Western blot and flow cytometry, CTLL-2 cells viability was measured by MTT assay, caspase-3 proteolytic activity by caspase-3 detection kit, and cell apoptosis by flow cytometry. Killing activity of CTLL-2 was detected by LDH releasing assay in vitro. RESULTS: Expression of Fas mRNA and protein in CTLL-2 cells was reduced to 50% after transfection with anti-Fas ribozyme. Being treated with anti-Fas antibody (JO(2)), compared with control and mock-transfected cells, viability of CTLL-2 cells transfected with anti-Fas ribozyme increased by 1-fold, caspase-3 activity and apoptosis rate of ribozyme-transfected cells decreased to 50% and 37%, respectively, and cell killing activity was enhanced by 2-fold. CONCLUSION: Anti-Fas ribozyme can cleave Fas efficiently and inhibit Fas-mediated apoptosis of CTLL-2 cells, resulting in improvement of their viability.

Animals↗

PubMed2003

Observation of geometric phases for mixed states using NMR interferometry.

Examples of geometric phases abound in many areas of physics. They offer both fundamental insights into many physical phenomena and lead to interesting practical implementations. One of them, as indicated recently, might be an inherently fault-tolerant quantum computation. This, however, requires one to deal with geometric phases in the presence of noise and interactions between different physical subsystems. Despite the wealth of literature on the subject of geometric phases very little is known about this very important case. Here we report the first experimental study of geometric phases for mixed quantum states. We show how different they are from the well-understood, noiseless, pure-state case.

Journal Article↗

PubMed2003

[Apoptosis of human lung cancer cells induced by activated peroxisome proliferator-activated receptor-gamma and its mechanism].

OBJECTIVE: To explore the effects of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) on the growth of human lung cancer cell lines and its possible mechanism. METHODS: Human non-small cell lung cancer (NSCLC) cells of the A549 line and human small cell lung cancer (SCLC) of the LTEP-P line were cultured and were divided into 3 groups respectively: control group, 15d-PGJ(2) group (15d-PGJ(2), a PPAR-gamma activator, was added), and ciglitazone group (ciglitazone, am antidiabetic drug, was added). Twenty-four, forty-eight, and seventy-two hours later, nested RT-PCR was used to detect t the expression of PPAR-gamma mRNA, Western blotting technique was used to detect the expression of PPAR-gamma protein, MTT staining was used to observe the proliferation of cells induced by PPAR-gamma agonists, TUNEL method was used to observe the apoptosis of cells affected by the ligands of PPAR-gamma, the expressions of bax, and bcl-2 mRN and proteins were examined by in situ hybridization and immunohistochemistry, and the expression of caspase-3 was detected by immunohistochemistry. RESULTS: PPAR-gamma was expressed in the two lung cancer cell lines. The cell proliferation was inhibited by 15d-PGJ(2) and ciglitazone, especially the former, in dose-dependent and time-dependent manners. The apoptosis rates were (1.9 +/- 0.5)%, (9.8 +/- 1.5)%, and (5.6 +/- 1.1)% respectively in the control, 15d-PGJ(2), and ciglitazone groups with a significant difference between ant 2 groups (all P < 0.05). The expression rate of bax were (9,2 +/- 1.5)%, (63 +/- 10)%, and (31 +/- 6)% respectively in the control, 15d-PGJ(2), and ciglitazone groups with a very significant difference between ant 2 groups (all P < 0.01). he expression rate of bcl-2 were (18 +/- 3)%, (36 +/- 9)%, and (33 +/- 7)% respectively in the control, 15d-PGJ(2), and ciglitazone groups with a very significant difference between the control group and any of the agonist-treated groups (all P < 0.01) and without significant difference between the two treated groups. The expression rates of caspase-3 were (6.5 +/- 1.0)%, (65 +/- 11)%, and (40 +/- 7)% respectively in the control, 15d-PGJ(2), and ciglitazone groups with a significant difference between any 2 group (all P < 0.01). The caspase-3 level was positively correlated with the level of apoptosis. CONCLUSION: Activated by ligands, PPAR-gamma remarkably inhibits the growth of human lung cancer cells through inducing apoptosis. Caspase-3 and bax/bcl-2 play a role in this process, PPAR-gamma is so important in the pathogenesis and/or progression of lung cancer that it may be a novel therapeutical target against lung cancer.

Apoptosis↗

PubMed2003

[Cloning and biological activities of riboenzymes against major histocompatibility complex class II transactivator].

OBJECTIVE: To investigate the cloning and biological activities of riboenzymes against major histocompatibility complex (MHC) class II transactivator (CIITA) so as to explore the feasibility of using hammerhead riboenzyme to create immune tolerance. METHODS: Three riboenzymes against MHC CIITA were synthesized and their activities were evaluated in vitro. Rz464, the riboenzyme with a better digestion effect, was inserted into the vector pIRES2-EGFP (then called pRz464). Human B lymphoma cells of Daudi line were cultured and transfected with pRz464 (then called pRz464-D). Cultured Daudi cells transfected with riboenzyme without the ability against CIITA (Rz-D) were used as control group. The expressions of classic MHC CIITA (HLA-DR, DP, and DQ) on the surface of Daudi cells before and after transfection were examined by flow cytometry. RESULTS: The expressions of HLA-DR, DP, and DQ on the surface of cultured Daudi cells (Rz-D) were 97.9 +/- 0.8%, 94.3 +/- 1.1%, and 54.4 +/- 3.1% respectively. The expressions of HLA-DR, DP, and DQ were inhibited by 88.4%, 83.5%, and 93.4% respectively on the surface of pRz464-D cells. CONCLUSION: The hammerhead riboenzyme Rz464 inhibits the expression of CIITA mRNAs, thus inhibiting the expression of MHC II molecules. It may be used in antigen-specific tolerance induction in allo-transplantation.

Cloning, Molecular↗

PubMed2003

In vitro biological activity of anti-C II TA hammerhead ribozyme--a novel approach for autoimmune diseases.

This study investigated the feasibility of using an hammerhead ribozyme against C II TA, a major regulator of MHC II antigens, to repress the expression of MHC II molecules on Hela cells. A hammerhead ribozyme (Rz464) specific to 463-465 GUC triplet of C II TA and its target gene were transcribed, then mixed up and incubated in vitro. The cleavage products were analyzed by PAGE and silver-staining. Rz464 was then inserted into the pIRES2-EGFP vector (pRz464). Stable transfectants of Hela with pRz464 were tested for class II MHC induction by recombinant human interferon-gamma (IFN-gamma). mRNA of C II TA was measured by RT-PCR. Our results showed that Rz464 could exclusively cleave C II TA RNA. When induced with IFN-gamma, the expression of HLA-DR, -DP, -DQ on pRz464+ Hela was induced, and the mRNA content of C II TA decreased too. It is concluded that Rz464 could inhibit C II TA and thus the family of genes was regulated by C II TA:MHC II molecules. These results provided insight into the future application of Rz464 as a new nucleic acid drug against auto-immune diseases.

Autoimmune Diseases↗

PubMed2003

Selective depletion of the allo-antigen specific T cells by Fas/FasL pathway by cytokine IFN-gamma and IL-2.

To investigate the value of apoptosis of the allo-antigen specific T cells induced by Fas/FasL pathway in preventing graft-versus-host disease (GVHD), the CD34+ cells transfected with FasL or not, used as stimulus cells, were mixed with allo-antigen specific T lymphocytes in presence or absence of IFN-gamma and IL-2. After 5 days, apoptosis of T cells was detected by TdT nick end mediated dUTP labeling (TUNEL) and flow cytometry (FCM). The affects of these two cytokines on CD34+ cells in the graft were also compared. The ratio of apoptosis of T cells was 12.1+/-1.5% when CD34+ cells transfected with FasL was used as stimulus cells, much higher than that of CD34+ cells non-transfected (3.2+/-1.1%, P<0.01). And in presence of IFN-gamma or IL-2, the ratio reached 20.1+/-2.3%, 17.6+/-1.3% respectively (P<0.01). However, IFN-gamma up-regulated Fas expression of CD34+ cells and increased the sensibility of CD34+ cells to soluble FasL (sFasL); IL-2 showed no such effect. It is possible to induce apoptosis of the allo-antigen specific T cells of grafts activated by allo-antigen by exogenous Fas ligand expressed on recipient cells and this might provide a new approach for preventing GVHD and IL-2 may be more suitable for clinical application.

Antigens, CD34↗

PubMed2003

Peroxisome proliferator-activated receptor-gamma activated by ligands can inhibit human lung cancer cell growth through induction of apoptosis.

To study the expression of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in lung cancer cells, and to testify if the PPAR-gamma agonists can inhibit human lung cancer cell growth through induction of apoptosis, PPAR-gamma was detected in two lung cancer cell lines by RT-PCR and immunohistochemistry, the inhibition of human lung cancer cell growth was investigated by MTT and cell counts, and the apoptosis was assessed by TUNEL. The results showed that: (1) PPAR-gamma expressed on two lung cancer cell lines; (2) PPAR-gamma activated by ligands could inhibit human lung cancer cell growth remarkably; (3) PPAR-gamma agonists could induce apoptosis to inhibit lung cancer cell growth. It was concluded that PPAR-gamma expressed in lung cancer cell can be activated by ligands and can inhibit lung cancer cell growth through induction of apoptosis.

Antineoplastic Agents↗

PubMed2003

Induced differentiation of human cord blood mesenchymal stem/progenitor cells into cardiomyocyte-like cells in vitro.

The feasibility of using cord blood mesenchymal stem/progenitor cells (CB-MSPCs) to regenerate cardiomyocytes and the optimal inducing conditions were investigated. The CB mononuclear cells were cultured in low serum DMEM medium to produce an adherent layer. After expansion, the adherent cells were added into cardiomyocyte inducing medium supplemented with 5-azacytidine. Cardiogenic specific contractile protein troponin T staining was performed to identify the cardiomyocyte-like cells. The results showed that the frequency of CB-MSPCs clones in CB mononuclear cells was 0.5 x 10(-6) and about 1.3 x 10(7)-fold expansion was achieved within 20 sub-cultivation. After cardiogenic induction, 70% CB-MSPCs was differentiated into cardiomyocyte-like cells. It was indicated that low serum culture could expand CB-MSPCs extensively and the expanded CB-MSPCs could be induced to differentiate into cardiomyocyte-like cells in high efficiency.

Azacitidine↗

PubMed2003

Humanin peptides block calcium influx of rat hippocampal neurons by altering fibrogenesis of Abeta(1-40).

Humanin peptides (including HN, HNG and other mutants) were reported previously that antagonize neurotoxicity caused by various familial Alzheimer's disease (FAD) genes and Abeta derivatives. Herein, we describe the aggregation dynamics and the representative morphological characteristics of Abeta(1-40) after different time of addition humanin peptides, which revealed that (a) the interactions of both HN and HNG with Abeta(1-40) induced quick and significant increase of light-scattering intensity, and (b) HNG also caused obvious morphological alteration from fibrillary to amorphous. In the meantime, the experiments also revealed that the interaction of HNG with Abeta(1-40) could decrease Abeta(1-40)-induced calcium rise, an initial event accompanying Abeta(1-40)-induced apoptosis of cultured neurons. Our results indicate that HNG can protect neurons by altering Abeta(1-40) morphology.

Amino Acid Sequence↗

PubMed2003

Human herpesvirus 7 open reading frame U12 encodes a functional beta-chemokine receptor.

Human herpesvirus 7 (HHV-7), which belongs to the betaherpesvirus subfamily, infects mainly CD4+ T cells in vitro and infects children during infancy. After the primary infection, HHV-7 becomes latent. HHV-7 contains two genes (U12 and U51) that encode putative homologs of cellular G-protein-coupled receptors. To analyze the biological function of the U12 gene, we cloned the gene and expressed the U12 protein in cells. The U12 gene encoded a calcium-mobilizing receptor for the EBI1 ligand chemokine-macrophage inflammatory protein 3beta (ELC/MIP-3beta) but not for other chemokines, suggesting that the chemokine selectivity of the U12 gene product is distinct from that of the known mammalian chemokine receptors. These studies revealed that U12 activates distinct transmembrane signaling pathways that may mediate biological functions by binding with a beta-chemokine, ELC/MIP-3beta.

Amino Acid Sequence↗

PubMed2003

Repression of allo-cell transplant rejection through CIITA ribonuclease P+ hepatocyte.

AIM: Allo-cell transplant rejection and autoimmune responses were associated with the presence of class II major histocompatibility complex (MHC II) molecules on cells. This paper studied the effect of Ribonuclease P (RNase P) against CIITA, which was a major regulator of MHCII molecules, on repressing the expression of MHCII molecules on hepatocyte. METHODS: M1-RNA is the catalytic RNA subunit of RNase P from Escherichia coli. It were constructed that M1-RNA with guide sequences (GS) recognizing the 452, 3408 site of CIITA by PCR from pTK117 plasmid, then were cloned into the EcoRI/BglII or EcoR//SalIsite of vector psNAV (psNAV-M1-452-GS, psNAV-M1-3408-GS) respectively. The target mould plate (3176-3560) of CIITA was obtained from Raji cell by RT-PCR, and then inserted into the XhoI/EcoRIof pGEM-7zf(+) plasmid (pGEM-3176). These recombinant plasmids were screened out by sequence analysis. psNAV-M1-452-GS, psNAV-M1-3408-GS and its target RNA pGEM-3176 were transcribed and then mixed up and incubated in vitro. It showed that M1-3408-GS could exclusively cleave target RNA that formed a base pair with the GS. Stable transfectants of hepatocyte cell line with psNAV-M1-3408-GS were tested for expression of class II MHC through FCM, for mRNA abundance of MHCII, Ii and CIITA by RT-PCR., for the level of IL-2 mRNA on T cell by mixed lymphocyte reaction. RESULTS: When induced with recombinant human interferon-gamma (IFN-gamma), the expression of HLA-DR, -DP, -DQ on psNAV-M1-3408-GS(+) hepatocyte was reduced 83.27 %, 88.93 %, 58.82 % respectively, the mRNA contents of CIITA, HLA-DR, -DP, -DQ and Ii decreased significantly. While T cell expressed less IL-2 mRNA in the case of psNAV-M1-3408-GS(+) hepatocyte. CONCLUSION: The Ribonuclease P against CIITA-M1-3408-GS could effectively induce antigen-specific tolerance through cleaving CIITA. These results provided insight into the future application of M1-3408-GS as a new nucleic acid drug against allo-transplantation rejection and autoimmune diseases.

Base Sequence↗

PubMed2003

[Effect of angiotensin II on cord blood CD34(+) cells expansion in vitro].

Angiotensin II (Ang II) is one active substance of renin-angiotensin system. In order to explore the effect of Ang II combined with various cytokines on proliferation and differentiation of cord blood CD34(+) cells, in vitro experiments of cell cultures of Ang II with or without cytokines were taken place. The results showed that Ang II stimulated both BFU-E and CFU-GM expansion. The numbers of BFU-E and CFU-GM raised with increase of Ang II concentrations ranged from 0.01 - 0.1 micro mol/L. In semi-solid culture assay, Ang II stimulated CFU-GM production but no effect on BFU-E occurred. The multiple number of CFU-GM increased from 2.3 +/- 0.8 to 7.8 +/- 1.9 times when Ang II was added into SCF + G-CSF + GM-CSF + IL-3 combination. Similarly, the multiple number of BFU-E increased from 3.1 +/- 1.8 to 9.2 +/- 2.3 times when Ang II was combined with SCF + EPO + TPO + IL-3. In conclusion, Ang II stimulated cord blood hematopoietic stem/progenitor cell expansion in vitro the in presence of various cytokines.

Angiotensin II↗

PubMed2003

[A new method for construction of EGFP-labled recombinant adenovirus containing hVEGF(165) and its property in vitro].

By using AdEasy system, which is based on the homologous recombination in bacteria, an EGFP labled recombinant adenovirus vector containing hVEGF(165) was generated quickly and its property was studied in vitro. First, hVEGF(165) coding sequence was subcloned into the shuttle plasmid pAdTrack-CMV, then linearized and cotransferred with adenoviral backbone vector pAdEasy-1 into E. coli strain BJ(5183). After positive kanamycin-resistant colony was picked up, the recombinant adenoviral plasmid was identified by restriction analysis with PacI and transfected into HEK 293 cells to assembly replication-defective adenovirus Ad-EGFP/hVEGF(165). The further amplified recombinant adenoviruses were purified by CsCl banding at 32,000 rpm for 18 to 24 hours. Electron microscopy and PCR were performed for testing the recombinant adenovirus. The results showed that the purified particles were homogenous hexagon with a high titer up to 2 x 10(12)pfu/ml. An amplified band of 540 bp fragment demonstrated the successful insert of hVEGF(165). Under fluorescence microscopy, the expression of EGFP was easily detected in HEK 293 and other target cells. The maximal stimulating effect on the proliferation of hUVEC was obtained when the given multiplicity of infection (MOI) of Ad-EGFP/hVEGF(165) was 100. The rate of EGFP positive mouse bone marrow mononuclear cells analysed by flow cytometry was 27.3% after 24 hour-incubation with Ad-EGFP/hVEGF(165) (MOI = 100), and the expression of hVEGF(165) protein in the conditioned medium was 1385 +/- 332 pg/10(6) cells. It is concluded that the construction of adenovirus vector by homologous recombination in bacteria using AdEasy system can be quickly and easily performed, and the prepared high titer of Ad-EGFP/hVEGF(165) is an efficient helpful vector to transfer genes into target cells, all of which make the further in vivo experiments with VEGF(165) possible.

Adenoviridae↗