Biomedical subjects

Juan Xiao

Publications and source records attributed to Juan Xiao.

At least 19 recordsLinked to original sources

PubMed2006

[Thapsigargin-induced apoptosis of K562 cells and its mechanism].

The aim was to study the apoptotic induction effect of thapsigargin on leukemia cell line K562 and its possible mechanism. After the treatment of leukemia cell line K562 by thapsigargin, morphological change of apoptotic cells was investigated by AO/EB fluorescent staining under fluorescent microscope; apoptosis rate was determined with annexin V-FITC/PI double staining by flow cytometry; intracellular calcium concentrations ([Ca(2+)]i) were measured by fluorescence spectrophotometer with calcium sensitive fluorescence indicator Fura-2/AM; mitochondrial transmembrance potentials (Delta Psi m) was detected on flow cytometry through staining of Rhodamine (Rh123); the changes of caspase-3, -7, -9, -12, cytochrome C, GRP78 proteins were detected by Western blot. The results showed that K562 cells cultured in 4 micromol/L thapsigargin for 48 hours exhibited typical morphological changes of apoptotic cells under fluorescent microscope, including shrinkage of cell, condensation of chromatin, breakage of nuclear, formation of apoptotic bodies, fluorescence of yellow green and pellet observed in early apoptoyic cells and hyacinth fluorescence of chromatin showed in late apoptotic cells. 24 and 48 hours after exposure to 1, 2, 4, 8 micromol/L thapsigargin, the apoptotic rates of K562 were respectively 7.51%, 11.65%, 23.22%, 30.56% and 12.85%, 20.27%, 31.51%, 44.16%, in dose-dependent manner, and were statistically significant when compared with the controls (P < 0.05). The apoptotic rate of K562 was dose- and time-dependent in experiment range. The enhancement of [Ca(2+)]i and the decrease of the Delta Psi m in K562 cells were induced by thapsigargin and were dose-dependent in experiment range, compared with control, P < 0.05. Western blot results indicated that cleavage and activation of caspase-3, -7, -9, -12, releasing of cytochrome C from mitochondria, upregulation of GRP78 expression at the endoplasmic reticulum were induced in K562 cells after 24 hours exposure of 4 micromol/L thapsigargin. It is concluded that thapsigargin induces endoplasmic reticulum stress-induced apoptosis in K562 cells. Endoplasmic reticulum is a novel important initiatory site of apoptosis in cells; the cleavage and activation of caspase-3, -7, -9, -12 play very important role in endoplasmic reticulum stress-induced apoptosis of K562 cells and is one of the important mechanisms for thapsigargin-induced apoptosis. Thapsigargin-induced apoptosis in K562 cells is associated closely with the disruption of the Delta Psi m and the release of cytochrome C from mitochondria, mitochondria participates in endoplasmic reticulum stress-induced apoptosis in K562 cells.

Apoptosis↗

PubMed2006

Comparison of immunophenotype and clinical manifestations between patients with M5a and M5b of acute monocytic leukemia.

Acute monocytic leukemia is a distinct subtype of acute myeloid leukemia (AML) with characteristic biology and clinical features. This study was designed to compare the immunophenotypical features and clinical manifestations of the patients with AML-M(5a) to that of patients with AML-M(5b), and to identify differences between M(5a) and M(5b) and to explore their relations. A total of 58 cases of de novo adult patients with AML M(5) were investigated. Immunofluorescence analysis by flow cytometry was performed to determine the immunophenotype of the leukemic cells in all cases. Meanwhile, clinical data of these cases were studied retrospectively. The results showed that the immunophenotypes of monocytic leukemic cells in patients with AML M(5) were heterogeneous, and CD68 and CD11b were expressed higher in patients with AML M(5a), compared with that in patients with AML M(5b) (P < 0.01). The significant differences in sex, extramedullary infiltration, WBC counts of peripheral blood, complete remission rate and disease-free survival (DFS > 300 days) between the patients with AML M(5a) and M(5b) did not exist (P > 0.05). It is concluded that the special individual immunophenotype features can be detected in patients with either of AML M(5a) or M(5b), and that expressions of CD68 and CD11b were much higher in M(5a). It seems that the complete remission rate and disease-free survival of patients with M(5a) and M(5b) are not different from that of currently available therapy.

Adolescent↗

PubMed2005

[Blocking the escape of leukemic cells from killing of T cell by combining anti-Fas ribozyme and CD80-IgG fusion protein].

OBJECTIVE: To study Fas expression regulation of cytotoxic T lymphocyte(CTL)via anti-Fas ribozyme, increasing of CD80 epitope on the surface of acute myelomonocytic leukemia cells by CD80-IgG fusion protein and their effects on the apoptosis and killing ability against acute myelomonocytic leukemia cells of CTL. METHODS: A hammerhead ribozyme gene targeting the Fas mRNA was synthesized and its expression vector pEGFP-RZ596 was constructed and transfected into the mouse spleen T cells via electroporation. The Fas expression on T cells was detected by RT-PCR and Western bloting. In the meantime the eukaryotic expression vector pcDNA/CD80-IgG was constructed by gene recombinant technique and transfected into ovarian cells of hamster of the line CHO. The CD80-IgG fusion protein was purified from the supernatant of G418-selected CHO cells by Protein G affinity chromatography method. Then allogeneic mixed lymphocytes culture between the mouse spleen T cells transfected with pEGFP-RZ596 and WEHI-3 cells (mouse acute myelomonocyte leukemia cell line) incubated with CD80-IgG fusion protein was performed. The apoptosis rate of the T cells was detected with annexin V-FITC. The proliferation and killing ability in vitro against WEHI-3 cells of the T cells were detected by MTT colorimetry. RESULTS: The luminance of Fas Western bloting results from the mouse spleen T cells negative control, transfected with pEGFPC1 and transfected with pEGFP-RZ596 were separately 1, 0.98 and 0.45 (P < 0.01). After being cocultured with WEHI-3 cells, which has higher expression of Fas ligand (64% +/- 3%), the apoptosis rate and the killing ability against WEHI-3 cells of the mouse spleen T cells transfected with pEGFP-RZ596 were separately 37% and 67%. Whereas that of the mouse spleen T cells negative control and transfected with pEGFPC1 were separately 88%, 84% (P < 0.01) and 32%, 31% (P <0.01). The CD80 positive expression rate of WEHI-3 cells was upregulated from 5.1% +/- 0.4% to 27.4% +/- 2.2% after these cells were preincubated with CD80-IgG fusion protein (P < 0.01). The killing ability of the mouse spleen T cells against WEHI-3 cells preincubated and not preincubated with CD80-IgG fusion protein were separately 64% and 49% (P <0.01), but that of the mouse spleen T cells, which were transfected with pEGFP-RZ596, was further promoted to 82% (P < 0.01) CONCLUSION: The apoptosis of mouse CTL inducing by FasL-Fas pathway could be avoided and the killing ability of mouse CTL against WEHI-3 cells can be significantly promoted at the same time by combining anti-Fas ribozyme and CD80-IgG fusion protein.

Animals↗

PubMed2005

FAMCS: finding all maximal common substructures in proteins.

Finding the common substructures shared by two proteins is considered as one of the central issues in computational biology because of its usefulness in understanding the structure-function relationship and application in drug and vaccine design. In this paper, we propose a novel algorithm called FAMCS (Finding All Maximal Common Substructures) for the common substructure identification problem. Our method works initially at the protein secondary structural element (SSE) level and starts with the identification of all structurally similar SSE pairs. These SSE pairs are then merged into sets using a modified Apriori algorithm, which will test the similarity of various sets of SSE pairs incrementally until all the maximal sets of SSE pairs that deemed to be similar are found. The maximal common substructures of the two proteins will be formed from these maximal sets. A refinement algorithm is also proposed to fine tune the alignment from the SSE level to the residue level. Comparison of FAMCS with other methods on various proteins shows that FAMCS can address all four requirements and infer interesting biological discoveries.

Algorithms↗

PubMed2005

[Expression and its significance of TRAIL and its receptors in cells of patients with acute myeloid leukemia].

This study was aimed to detect the expression of TNF related apoptosis-inducing ligand (TRAIL) and its receptors on acute myeloid leukemic (AML) cells, and explore its possible role in leukemia therapy. RT-PCR and flow cytometry were used to detect the expression of TRAIL and its receptors on AML cells of 39 cases (patient group), AML cells of 18 cases with complete remission (CR group) and BMMNC or PBMNC of 21 normal persons (control group). The results showed that (1) TRAIL, DR4 and DR5 were highly expressed in both patient group and CR group, while the DcR1 and DcR2 were poorly expressed. (2) The level of DR5 expression in CR group was higher than that in patient group. (3) The level of DR5 was higher than DR4 in both patient group and CR group. (4) TRAIL and its receptors were expressed similarly in different subtypes of AML. In conclusion, there are differences between the expressions of TRAIL and its receptors in AML cells. DR5 may play an important role in TRAIL-inducing apoptosis of AML cells.

Adult↗

PubMed2005

Impact of trisomy 8 on cytobiological and clinical features of acute myelomonocytic and monocytic leukemia.

To evaluate the impact of trisomy 8 on cytobiological and clinical features of acute myelomonocytic and monocytic leukemia (M(4), M(5)), a total of 56 cases of acute myelomonocytic and monocytic leukemia were investigated. Karyotypes were analyzed by G-banding or R-banding. The immunotypes in all cases were detected by flow cytometry. And the clinical characteristics at the first visit were analyzed retrospectively. The results showed that thirty-four of 56 (60.7%) patients had normal cytogenetics; 10 (17.9%) patients had trisomy 8 in their karyotypes, including 3 (5.4%) patients with trisomy 8 as the sole aberration; and 12 (21.4%) patents had other cytogenetic abnormalities (except trisomy 8). All trisomy 8 cases demonstrated a increased expression frequency of surface markers of myeloid progenitor cells CD34 (P < 0.01) and CD117 (P < 0.05) and a decreased expression frequency of surface markers of mature monocytes CD11c (P < 0.01) and CD14 (P < 0.05), compared with normal cytogenetics cases. Patients with trisomy 8 were slightly older (P < 0.05), which had lower percentages of peripheral blasts (P < 0.05) and lower WBC (P < 0.05) than the patients without trisomy 8. Patients with trisomy 8 had a shorter disease-free survival time than that of patients with normal cytogenetics (P < 0.05). It is concluded that trisomy 8 may play an important role in the pathogenesis and progression of acute myelomonocytic/monocytic leukemia (M(4)/M(5)), whic seems to be related with a block in differentiation of monocytes. Therefore, trisomy 8 may be an adverse prognostic factor for patients with M(4) or M(5).

Adolescent↗

PubMed2005

[Experimental study on apoptosis in leukemia cells induced by econazole].

To investigate apoptosis of mouse leukemia cell (WEHI-3) induced by econazole and its mechanism, apoptosis induced by econazole was examined by flow cytometry, while free calcium ([Ca(2+)]i) was determined by Fura-2 fluorescein load technique. The protein was isolated from endoplasmic reticulum of WEHI-3 cells, and then the expression of caspase-12 and caspase-7 was evaluated by Western blot. The results showed that WEHI-3 exhibited typical change of apoptosis when it was treated by econazole, [Ca(2+)]i was significantly higher in comparison with the control. The expression of caspase-12 and caspase-7 enhanced as the econazole concentration increased. In conclusion, econazole can induce WEHI-3 cell apoptosis and the caspase-12 plays a key role in this process.

Animals↗

PubMed2005

[Expression and significance of melanoma antigen gene-3 in endoplasmic reticulum stress-induced apoptosis of K562 cells].

This study was aimed to explore the expression and significance of melanoma antigen gene-3 (MAGE-3) in endoplasmic reticulum stress-induced apoptosis. After the treatment of leukemia cell line K562 and its multidrug-resistant cell line K562/A02 by thapsigargin, intracellular calcium concentrations ([Ca(2+)]i) in K562 and K562/A02 were measured by fluorescence spectrophotometer with calcium sensitive fluorescence indicator Fura-2/AM; expression changes of glucose-regulated protein 78 (GRP78) were detected by Western blot; morphological change of apoptotic cell was investigated by AO/EB fluorescent staining under fluorescent microscope; apoptosis rate was determined by terminal deoxyribonucleotidyl transferase (TdT)-mediated dUTP nick end labelling (TUNEL) staining; the expression of MAGE-3 gene mRNA was detected by RT-PCR. The results showed that (1) thapsigargin induced the enhancement of [Ca(2+)]i with different extent in K562 and K562/A02 cells, and the enhancement of [Ca(2+)]i was dose-dependent in experiment range. At the same time, thapsigargin induced upregulation of GRP78 protein expression and typical apoptotic changes of K562 and K562/A02 cells, apoptotic rate was also dose-dependent in experiment range. The [Ca(2+)]i in K562/A02 cells were higher than that in K562 cells. (2) in the course of endoplasmic reticulum stress-induced apoptosis by thapsigargin, the expression of MAGE-3 gene mRNA was remarkably downregulated. Moreover, the expression of MAGE-3 gene mRNA in K562/A02 cells was higher than that in K562 cells. It is concluded that (1) thapsigargin induces endoplasmic reticulum stress-induced apoptosis of K562 and K562/A02 cells in experiment range, and this may be associated with downregulation of MAGE-3 mRNA expression or MAGE-3 gene may participates in the regulation of endoplasmic reticulum stress-induced apoptosis. (2) MAGE-3 gene may possess anti-apoptotic activity, multidrug resistance in K562/A02 cells can be associated with [Ca(2+)]i increase and upregulation of MAGE-3 expression.

Antigens, Neoplasm↗

PubMed2005

[Expression of BLM mRNA in six tumor cell strains].

The mutations of BLM gene may result in Bloom's syndrome which includes immunodeficiency, predisposition to malignant tumors and so on, and enhances sister chromati exchange (SCE), DNA replication failure, genome instability, and increases cancer susceptibility. This study was aimed to investigate the variability of mRNA expression level and cDNA structure of BLM gene in tumor cell strains so as to look for a new cancerogenic mechanism and to find a new therapeutic target. The expression level of mRNA and the structure of cDNA of BLM gene in six tumor cell strains and the normal human bone marrow mononuclear cells were detected with RT-PCR and DNA sequencing was performed. The results indicated that these tumors cells expressed BLM mRNA higher than the normal human bone marrow mononuclear cells (P < 0.01), but no cDNA sequence abnormality of BLM gene in these tumors cells was observed. It is concluded that the increase of expressing level of BLM mRNA may play an important role in the development of these tumors.

Base Sequence↗

PubMed2005

Cytobiological and clinicobiological features of AML with 11q23 chromosome abnormalities.

To investigate the interrelationship among morphology, immunology and clinical features in adult acute myeloid leukemia cases with 11q23 chromosome abnormalities, 210 newly diagnosed AML patients were retrospectively analyzed by cell morphology, immunophenotyping, G-banding or R-bamding analysis and clinical features. The results showed that 13 cases were found with 11q23 rearrangements or deletion (the incidence rate was 6.19%.), totally 84.6% showed the involvement with the monocytic lineage. Immunophenotyping tests indicated that AML cases with 11q23 abnormalities usually expressed the marker molecules of hematopoietic stem or progenitor cells, monocytic lineage cells, such as CD34, CD117, CD14, CD15 and CD11b. The complete remission rate of the cases with 11q23 abnormalities was comparable to that of the cases with normal karyotype (P = 0.075), but the median disease-free survival in the former was significantly lower than that in the latter (P < 0.001). It is concluded that the category AML with 11q23 abnormalities accounts for 6.19% of all the newly diagnosed AML cases, that seems to be closely associated with monocytic differentiation blocking with a dismal prognosis.

Acute Disease↗

PubMed2004

Inhibition of mouse hepatocyte apoptosis via anti-Fas ribozyme.

AIM: To investigate the effects of anti-Fas ribozyme on Fas expression and apoptosis in primary cultured mouse hepatocytes. METHODS: Mouse hepatocytes were isolated by using collagenase irrigation. A hammerhead ribozyme targeting the Fas mRNA was constructed, and transfected into mouse hepatocytes via Effectene. Then Fas expression in mouse hepatocytes was detected by RT-PCR and western blotting. After being treated with anti-Fas antibody (JO2), hepatocytes viability was measured with MTT assay. Caspase-3 proteolytic activity was detected, and cell apoptosis was measured according to Annexin V-FITC apoptosis detection kit. RESULTS: Fas expressed in primary mouse hepatocytes. Fas expression in hepatocytes transfected with anti-Fas ribozyme was decreased remarkably and correlated with the resistance to Fas-mediated apoptosis as determined by flow cytometry and caspase-3 proteolytic activity. CONCLUSION: Anti-Fas ribozyme can remarkably decrease the Fas expression in mouse hepatocytes, thus inhibit Fas-mediated apoptosis in hepatocytes. It is suggested that anti-Fas ribozyme could significantly increase the resistance of transplanted hepatocytes to apoptosis and improve the survival of transplanted hepatocytes.

Animals↗

PubMed2004

Attenuation of GVHD for allo-bone marrow transplantation recipient by FasL-Fas pathway in an H-2 haplotype disparate mouse combination.

In order to explore a new special and effective way to prevent graft versus host disease (GVHD) after allogenic bone marrow transplantation (allo-BMT), the stem cell antigen-1 (Sca-1) + early hematopoietic cells (EHC) from BALB/c mouse (H-2d) were introduced with exogenous mouse Fas ligand (mFasL) cDNA gene by the retrovirus-mediated gene transfer and expanded for one week, and then they were co-cultured with the spleen mononuclear cells (SMNC) from BAC mouse (H-2dxb) as one way mixed lymphocyte reaction (OWMLR). The cytotoxicity of treated BAC mouse SMNC against Na2 51CrO4 labeling SMNC from BALB/c mouse was observed. The bone marrow mononuclear cells (BMMNC) from BAC mouse treated by the above methods were transplanted into lethally-irradiated congenic BALB/c mice to observe the occurrence of GVHD. The results showed that the SMNC from BAC mouse after OWMLR with exogenous mFasL cDNA gene-transduced hematopoietic cells (HC) from BALB/c mouse in a ratio of 1 to 5 exhibited an obvious inhibition of the cytotoxicity against the BALB/c mouse spleen cells at different effector/target ratios as compared to the control group (P<0.01). The grade I GVHD or no GVHD and the 80% survival rate at day 60 post-BMT were observed in the BALB/c mouse receiving BAC mouse BMMNC treated with similar way, while the grade II - III GVHD and the 20% survival rate were noted in the control group (P<0.01). It is suggested that the attenuation of GVHD in allo-BMT recipient could be successfully achieved through FasL-Fas pathway in an H-2 haplotype disparate mouse combination.

Animals↗

PubMed2004

[Role of apoptosis in cryoinjury of cord blood hematopoietic stem/progenitor cells and its mechanism].

To investigate the role and mechanism of apoptosis in cryoinjury of cord blood hematopoietic stem/progenitor cells, apoptosis of CD34(+) cells, mitochondrial membrane potential (MMP) and Fas antigen expression were detected by flow cytometry (FCM), the Bcl-2 protein expression was detected by immunohistochemistry, caspase-3 expression was determined by Western blot and caspase-3 activity analysis, colony-forming units (CFU) was performed by semi-solid methylcellulose culture. The results showed that when cells were store at -196 degrees C for 2 weeks or 4 weeks, apoptotic cells increased, gel electrophoresis displayed typical DNA ladder, and CFU decreased by 25.2% and 30.1%. The value of MMP reduced and expression of Bcl-2 protein was down-regulated during the freeze-thaw process, but the Fas antigen expression was not effected. However, only the 32 kD inactive caspase-3 proenzyme was detected in freshly isolated CD34(+) cells. After freeze-thaw, caspase-3 was activated and a cleavage of 20 kD protein was detected. Cryopreserved cells showed a 1.2-fold and 1.5-fold increase in caspase-3 activity, respectively. It is concluded that apoptosis plays an important role in cryoinjury of cord blood hematopoietic stem/progenitor cells, which triggers a mitochondrial apoptotic pathway that is caspase-dependent but does not require death receptors, where caspase-3 is the key effector.

Antigens, CD34↗

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

[Application of double immunomagnetic positive sorting to ex vivo expansion of marrow CD34(+)CD59(+) cells from patients with paroxysmal nocturnal hemoglobinuria].

Since flow cytometry was not feasible for sorting a huge amount of cells for clinical use, the method of double immunomagnetic positive sorting was used for selection of CD34(+)CD59(+) cells from bone marrow mononuclear cells in patients with paroxysmal nocturnal hemoglobinuria (PNH), which laid the groundwork for clinical ABMT/APBSCT of patients with PNH. Immunomagnetic positive selection was used for two times, the microbeads were removed from the CD34(+) cells selected firstly by means of overnight culture, then the sufficient CD34(+)CD59(+) cells were used for ex vivo expansion. The results showed that the survival, proliferation and colony-forming units of the selected CD34(+)CD59(+) cells by double immunomagnetic positive sorting had no significant difference as compared with that of CD34(+)CD59(+) cells selected by flow cytometry technique. It is suggested that the double immunomagnetic positive sorting promotes the use for separation and purification hematopoietic stem/progenitor cells and other cells with double or multiple markers cells for autologous hematopoietic stem cell transplantation in PNH patients.

Antigens, CD34↗

PubMed2003

[Expression of survivin in cord blood CD34(+) stem/progenitor cells and its significance].

OBJECTIVE: To investigate the expression and significance of survivin protein and mRNA in cord blood (CB) CD(34)(+) stem/progenitor cells. METHODS: Survivin level in CB CD(34)(+) cells was assessed by immuno-histochemistry and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: Survivin expressed in fresh CB CD(34)(+) cells, its protein level was 9.4 +/- 1.2, faint signal of the mRNA transcript band was detected. In the in vitro culture of the cells, hematopoietic growth factors could upregulate survivin expression, especially the combination of SCF, FL and Tpo. After 3 days culture, its protein level was 25.2 +/- 5.3, and mRNA transcript increased significantly. Survivin expression dropped down 24 hours after withdraw of these cytokines. CONCLUSION: Survivin is not a specific anti-apoptotic protein of cancer, and also expressed in normal hematopoietic stem/progenitor cells. It plays important regulating roles in the process of hematopoiesis.

Antigens, CD34↗

PubMed2003

[Study of biological characteristics of the CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells from PNH patients' bone marrow].

OBJECTIVE: To explore the characteristics of CD(34)(+) CD(59)(+) cells from paroxysmal nocturnal hemoglobinuria(PNH) patients' bone marrow and the possible reasons of hematopoietic clonal dominance of PNH clones. METHODS: CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells from PNH patients and CD(34)(+) cells from normal control were selected from the bone marrow mononuclear cells by means of immunomagnetic microbead-flow cytometry two step sorting method undergone ex vivo expansion in liquid culture for two weeks and performed semisolid cultures before and after expansion. RESULTS: (1) Cultivation for seven days was the optimum for ex vivo expansion of PNH CD(34)(+) CD(59)(+) cells and normal CD(34)(+) cells, both cell populations remained CD(59) positive after expansion. (2) Normal CD(34)(+) cells had higher capacities of proliferation and expansion, and stronger potential to survival than that of both PNH CD(34)(+) CD(59)(+) and PHN CD(34)(+) CD(59)(-) cells. (3) In terms of semisolid culture, there was no significant difference in the yields of CFU formation between CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells. (4) In liquid culture with combinations of hematopoietic factors SCF + IL-3 + IL-6 + FL + Tpo or SCF + IL-3 + IL-6 + FL + Tpo + Epo, there was no significant difference in the capabilities of survival, proliferation and expansion between CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells; but with combination of SCF + IL-3 + IL-6 + FL + Tpo + Epo + GM-CSF, CD(34)(+) CD(59)(-) cells had better proliferation and expansion capacities and stronger potential to survival than that of CD(34)(+) CD(59)(+) cells. CONCLUSIONS: (1) Normal CD(34)(+) cells had better proliferation, expansion capacities and stronger potential to survival than that of PNH CD(34)(+) CD(59)(+)cells. (2) In semisolid and liquid culture with hematopoietic factor combinations, there was no significant difference in the capabilities of survival, proliferation and expansion between CD(34)(+) CD(59)(+) and CD(34)(+) CD(59)(-) cells. It was suggested that CD(34)(+) CD(59)(-) cells had no clonal hemotopoiesis dominance. GM-CSF might be one of the reasons for PHN clones to possess clonal hematopoiesis dominance.

Antigens, CD34↗

PubMed2003

[Apoptosis of fetus chondrocytes cultured in vitro and expression of caspase-3].

OBJECTIVE: To investigate apoptosis of chondrocytes cultured in vitro and related expression of caspase-3. METHODS: Apoptosis of chondrocytes were detected by flow cytometry analysis and TUNEL staining. The expression of caspase-3 was determined by RT-PCR and Western blot, and caspase-3 protein activity was determined by ELISA. RESULTS: Apoptosis was observed in chondrocytes cultured in vitro from passage 1 to passage 4 at various degrees. The percentage of apoptosis of chondrocytes on day 7 was much higher than that on day 3 (15.7% +/- 0.3% vs 8.9% +/- 0.6%, P < 0.01). caspase-3 mRNA and protein expressed in chondrocytes during whole culture process. Along with the culture time extension in vitro, caspase-3 expression and protein activity up-regulated, coincident with apoptosis of chondrocyte. caspase-3 was activated and a fragment of 20 kDa was detected after 7 days of culture. CONCLUSION: caspase-3 is involved in apoptosis of chondrocytes cultured in vitro.

Apoptosis↗