Prokaryotic Expression and Purification of the Notch Ligand and Its Effect on Hematopoiesis after Carbon Tetrachloride Damage / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To express and purify the mouse endothelial cell-targeted recombinant Notch ligand protein mD1R, and to investigate its effect on hematopoiesis after carbon tetrachloride damage.</p><p><b>METHODS</b>PCR was performed to clone and construct the expression vector pET22b(+)-mD1R. The mD1R successfully transformed into E. coli was induced by IPTG, and purified with Ni-beads affinity chromatography. The target protein was detected by SDS-PAGE. The fluorescence-activated cell sorting analysis (FACS), cell adhesion test, immunofluorescence staining and quantitative real-time PCR were employed to detect the endothelial cell-targeted and Notch signaling-activated biological characteristics of mD1R. The carbon tetrachloride mouse model was established to observe the effects of mD1R on the hematopoietic stem cell (HSC), myeloid cells and lymphoid cells by flow cytometry. The LinScal-1c-Kit cells were sorted by magnetic bead, FACS was performed to analyze the cell cycle, and RT-PCR was employed to observe the expression of interleukin (IL)-10.</p><p><b>RESULTS</b>The prokaryotic expression vector was successfully cloned and constructed. The purity and the activity were confirmed in mD1R recombinant protein. The purified mD1R activated the Notch signaling pathway of hematopoietic stem cells in carbon tetrachloride damaged mouse, and internally elevated the number of HSC and long-term HSC to 2.96-fold and 6.18-fold. In addition, mD1R improved the amplification of the myeloid progenitor cells and the myeloid-derived suppressor cells, particularly the granulocyte/monocyte into blood. Mechanistically, the further analyses suggested that Notch pathway could increase the proliferation of HSC and enhance expression of IL-10 after stress injury.</p><p><b>CONCLUSIONS</b>A new and activated recombinant Notch ligand protein has been obtained successfully to communicate hematopoietic stem cells and hematopoietic microenvironment. The Notch- mediated intrinsic hematopoiesis has been regulated by the anti-inflammatory factor after stress injury.</p>

Correlation between Plasma microRNA Expression and Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the microRNA (miRNA) expression in plasma of patients with aGVHD and without aGVHD after allo-hematopoietic stem cell transplantation (allo-HSCT).</p><p><b>METHODS</b>The miRNAs (miR-423, mirR199a-3p, miR93*, miR377) expression levels in peripheral blood plasma of 25 patients before and after allo-HSCT were detected by real-time PCR.</p><p><b>RESULTS</b>miR-423, miR199a-3p and miR-93* in aGVHD group were significantly upregulated (P<0.05); miR-377 expression was not significantly different between aGVHD and non-aGVHD (P>0.05).</p><p><b>CONCLUSION</b>The expression of miR-423, miR-199a-3p, miR-93* are upregulated in aGVHD group, which can be used as biomarkes to monitor and to diagnose aGVHD.</p>

Construction and expression of fusion protein TRX-hJagged1 in E.coli BL21 / 中国实验血液学杂志

This study was purposed to construct prokaryotic expression vector and to investigate the expression of Notch ligand Jagged1 in E.coli. An expression vector pET-hJagged1 was constructed, which can be inserted in Jagged1 with different lengths, but the DSL domain of human Jagged1 should be contained. Then the recombinant plasmids were transformed into the competent cell of E.coli BL21, and the expression of the fusion protein was induced by IPTG. Fusion protein was purified from the supernatant of cell lysates via the Nickel affinity chromatography. The results showed that prokaryotic expression vectors pET-hJagged1 (Bgl II), pET-hJagged1 (Hind I) and pET-hJagged1 (Stu I) were successfully constructed, but only pET-hJagged1 (Stu I) could express the soluble TRX-hJagged1. The purified TRX-Jagged1 protein could be obtained via the Nickel affinity chromatography, and then confirmed by Western Blot. It is concluded that prokaryotic expression vector pET-hJagged1 is successfully constructed, but only pET-hJagged1 (Stu I) can express the soluble TRX-hJagged1 and the TRX-Jagged1 fusion protein is obtained through the prokaryotic expression system, which laid a solid foundation for further to explore the effects of Jagged1 in hematopoietic and lymphoid system.

Clinical analysis on the mobilization and collection of peripheral hematopoietic stem cells in 198 healthy donors / 白血病·淋巴瘤

ObjectiveTo investigate the methods and effects on the mobilization and collection of peripheral hematopoietic stem cells.MethodsPeripheral hematopoietic stem cells of 198 cases of healthy donors were selected and mobilized by subcutaneous recombinant human granulocyte colony stimulating factor (rhG-CSF) by (5-10) μg·kg-1 ·d-1 and collected on the 5th day. The effects of gender, height, age and WBC count of donors on mobilization and collection were analyzed. ResultsAll the peripheral hematopoietic stem cells of donors were successfully mobilized.The average counts of mononuclear cells(MNC)and CD34+ cells were (4.19±1.96)×108/kg and (2.98±1.40)×106/kg, respectively, which had no correlation with gender, height and age.The counts of MNC and CD34+ cells collected were positively correlated with the WBC count of peripheral blood (r =0.9201, P =0.0035; r =0.8420, P =0.0149). The donors with WBC ≥20.0×109/L had moresignificant effect than thoseWBC＜20.0×109/L (F =4.688, P =0.0013; F =4.622, P =0.0006). Conclusion The WBC count of peripheral blood from healthy donors is a simple and feasible indicator to predict the quantity of CD34+ cells.

Clinical analysis of peripheral blood stem cell mobilization regimens in autologous transplantation for treating non-Hodgkin's lymphoma / 中国实验血液学杂志

The purpose of this study was to compare the efficacy of CEP plus G-CSF and CVP plus G-CSF regimens in the mobilization and collection of peripheral blood hematopoietic stem cells (PBHSC), and in the hematopoietic recovery. 57 patients with non-Hodgkin's lymphoma (NHL) underwent autologous PBHSC transplantation were analyzed retrospectively. The PBHSC were mobilized and collected by using CEP plus G-CSF and CVP plus G-CSF respectively, and were retransfused into these NHL patients after preconditioning, then the mobilization efficacy, adverse reactions and hematopoietic recovery were analyzed. The results showed that the WBC count decreased to ≤ 1.0 × 10(9)/L, platelet amount dropped to ≤ 40 × 10(9)/L during peripheral blood stem cell mobilization of all patients, which indicated successful collection of PBHSC. The mean value of (4.38 ± 3.40) × 10(8)/kg mononuclear cells (MNC) containing (2.79 ± 2.53) × 10(6)/kg CD34(+) cells were collected in CEP plus G-CSF group, while the mean value of (3.31 ± 1.23) × 10(8)/kg MNC containing (2.02 ± 0.87) × 10(6)/kg CD34(+) cells were collected in CVP plus G-CSF group. The efficacy of mobilization in CEP plus G-CSF group was significantly higher than that in CVP plus G-CSF group (p < 0.05). After preconditioning, bone marrow was suppressed in all patients. The average time of WBC count recovery to ≥ 1.0 × 10(9)/L was 11.4 days in CEP plus G-CSF group and 12.3 days in CVP plus G-CSF group; the average time of platelet amount recovery to ≥ 50 × 10(9)/L was 18.6 days in CEP plus G-CSF group and 19.3 days in CVP plus G-CSF group. The statistical analysis showed no significant difference in the average time of hematopoietic recovery between 2 groups. It is concluded that autologous PBHSC transplantation shows significant effect for treatment of patients with NHL. Either modified CEP or CVP plus G-CSF regimen is safe and effective in PBHSC mobilization. The CEP plus G-CSF regimen is better than CVP plus G-CSF regimen.

Research advance of notch signal in ex vivo expansion of hematopoietic progenitor cells - review / 中国实验血液学杂志

Ex vivo expansion of hematopoietic progenitor cells (HPCs) is valuable for clinical application, however, traditional ex vivo culture negatively affects long-term hematopoietic reconstitution ability. In the hematopoietic system, the expression of Notch receptors and their ligands has been widely reported. Active Notch signal inhibits the differentiation of HSCs while promotes their expansion, suggesting that ex vivo expansion of hematopoietic progenitor cells could be enhanced by manipulating Notch signal pathways. In this article the Notch signal pathways, Notch signal and maintenance of hematopoietic progenitor cells, Notch signal and expansion of hematopoietic progenitor cells and molecular mechanism of Notch signal maintaining undifferentiation of hematopoietic progenitor cells were reviewed.

Construction and expression of a fusion protein containing extracellular domain of human Jagged1 and Fc fragment of human IgG1 in Pichia Pastoris / 中国实验血液学杂志

In order to construct a pichia pastoris expression vector containing the extracellular domain of human Jagged1 and the Fc fragment of human IgG1 fusion gene, or containing only the Fc fragment of human IgG1 and to express them in pichia pastoris. The extracellular domain of human Jagged1 gene was cloned from normal human bone marrow cells. After DNA sequencing, the extracellular domain of Jagged1 gene was inserted into pIC-Fc vector constructed previously, which is Pichia pastoris expression vector containing only the Fc fragment of human IgG1. The constructed plasmid was transformed into yeast GS115 by means of electroporation. The recombinant transformants with a high copy number of the plasmid were selected on MD plate with G418. The expression of protein was induced by addition of methanol. Then, protein expression was analyzed by SDS-PAGE. The results indicated that the extracellular domain of human Jagged1 gene was effectively amplified. The DNA sequencing result showed that the constructed plasmid containing hJagged1(ext)-Fc fusion gene was the same as designed. The fusion protein was successfully expressed in Pichia pastoris. It is concluded that the hJagged1(ext) gene has been successfully cloned and expressed, which provides a new fusion protein for further experiments, the hJagged1(ext)-Fc fusion protein can be used as a new stimulator for proliferation of hematopoietic stem/progenitor cells in vitro.