Embryonic stem cells(ESCs) are pluripotent cells derived from the inner cell mass of blastocyst-stage embryos, possessing permanent self-renewal and indefinite proliferative capacity in vitro. And ESCs could differentiate into the hematopoietic cell fate. Therefore ESCs may provide an alternative for hematopoietic stem cell transplantation and blood cells transfusion. Furthermore, ESCs differentiation could also provide a powerful model system to better understand the hematopoietic development and the mechanism involved. The current status for efforts to differentiate ESCs into hematopoietic lineages were reviewed.

OBJECTIVETo discover the techniques for ex vivo generation and cryopreservation of erythroid progenitor cells (EPCs)derived from umbilical cord blood (UCB)mononuclear cells (MNCs).

METHODSUCB was chosen as the source of EPCs. Erythrocytes were precipitated by hydroxyethyl starch (HES). MNCs were separated by Ficoll density gradient centrifugation. Erythroid progenitor cell were generated from MNC ex vivo in suspension culture supplemented with stem cell growth factor, insulin growth factor, erythropoietin, Fms- liketyrosinekinase ligand, transferrin and dexamethasone. Cell maturation was evaluated by morphologic analysis and CD71/CD235a expression profiling. In vitro induced cells were cryopreserved using different cryopreservation media. The cell survival rate, phenotype and proliferation curves were detected after cell thawing.

RESULTSWith the extension of culture time, the total number of cells increased significantly accompanied with the elevation of CD71 and CD235 positive populations. After 14- day inducing, the cells reached to approximately 110 times of the starting number with the cell viability as (88.92±0.95)%. The percentages of cell surface markers were (86.77±9.11)% for CD71 and (64.47±16.67)% for CD71/CD235, respectively. With the extension of inducing time, wright- Giemsa staining showed that the middle erythroblasts appeared mostly at day 10, and the late erythroblasts were seen at day 14. The red pellets were present at day 14, which indicated the more production of hemoglobin. Colony forming assay showed that erythroid colonies at induction day 7 were higher than that for non-induced cells (326.00±97.96vs 61.60±20.03 per 2 000 cells). With the extension of culture time, the number of erythroid colonies decreased. Induced EPCs were preserved with different cryopreservation solutions, in which 10% DMSO were better than 5% DMSO. Additionally, 10% DMSO + 2% HSA showed no different with 10% DMSO + 5% HSA. Combined 50% plasma with 2% HSA was more effective.

CONCLUSIONSThis non- serum culture media could effectively induced and expanded EPCs, and 10% DMSO + 2% HSA + 50% plasma appeared to be a desirable cryopreservation solution for EPCs from UCB.

Cell Culture Techniques ; Cell Differentiation ; Cell Survival ; Cells, Cultured ; Cryopreservation ; methods ; Erythroblasts ; cytology ; Erythroid Precursor Cells ; cytology ; Fetal Blood ; cytology ; Humans ; Leukocytes, Mononuclear ; cytology ; Umbilical Cord

Objective: To observe the effect of poloxamer 188 (P188) on megakaryocyte cultivation and induction from cord blood mononuclear cells in order to obtain more megakaryocyte progenitor cells (MPC). Methods: The cord blood mononuclear cells were isolated and inoculated in cell culture bag or cell culture flask respectively. The WIGGENS shaker and cell culture bags were used to mimick WAVE Bioreactor for three-dimensional (3D) cell culture, and the P188 was added to induction medium, The cells were detected for morphology, surface marker, viability, and number on day 14. Results: In the two-dimensional (2D) culture, CD41⁺, CD41⁺/CD61⁺, CD61⁺ megakaryocytic numbers increased significantly after adding P188 (all P<0.01). And in the 3D culture of adding P188, the cell volume became larger and the nuclear shape was irregular, the cytoplasm appeared magenta granules, and the megakaryocyte cells became more mature. By 3D culture, the expression of CD41/CD61 was (36.30±1.27)% vs (23.95±1.34)%, hence the differentiation for MPC was significantly higher than that in the 2D group (P<0.01). Furthermore, adding P188 in 3D culture resulted in highest differentiation efficiency for MPC [(59.45±1.20)%]. There were no significantly differences in terms of cell viability and cell number among 3D culture containing P188, 2D and 3D culture groups (all P>0.05). Conclusion 3D culture was beneficial for the differentiation of MPC, but the cell viability was lower than 2D group; However, the satisfied cell growth and better induction efficiency were obtained by adding of P188, which might provide a new method of megakaryocytes production for clinical application.

Objective To construct HEK 293T cells that express tardigrade Dsup protein fused with green fluorescent protein copGFP in order to study the effect of Dsup protein on proliferation of HEK 293T cells.Methods The CRISPR/Cas9 gene knock-in system was constructed.The target gene fragments of Dsup,copGFP,EF1α and puromycin were amplified by PCR and inserted into pAAVS1-SFFV to construct the fusion vector of Dsup and copGFP,which was known as pAAVS1-SFFV-Dsup-copGFP-EF1α-Puro.pAAVS1-SFFV-Dsup-copGFP-EF1 α-Puro and pAAVS1-CRISPR-Cas9 vector were co-transfected into HEK 293T cells before Dsup gene was inserted into the AAVS1 region of HEK 293T cells via homologous recombination.The HEK 293T cells expressing Dsup gene were obtained following puromycin selection,flow cytometry sorting and genome identification.The expression of Dsup at mRNA and protein levels and proliferation-related genes(MCM2,MCM4,PCNA,Ki-67)were examined to investigate the effects of Dsup gene on the proliferation of HEK 293T-Dsup-copGFP cells.Results The pAAVS1-SFFV-Dsup-copGFP-EF1α-Puro recombinant vector was constructed,and the HEK 293T-Dsup-copGFP cells with Dsup gene inserted in the AAVS1 region were obtained,where both Dsup mRNA and protein were expressed.The cell proliferation rate of HEK 293T-Dsup-copGFP was higher than that of HEK 293T-Control-copGFP(P＜0.001).Further investigation revealed that the expressions of Ki-67 and MCM4 protein in HEK 293T-Dsup-copGFP were significantly higher than in the control group,indicating that the knock in of Dsup gene might enhance the proliferation ability of human cells by promoting the expression of Ki-67 and MCM4 protein.Conclusion A gene editing vector is constructed,and stable cell line HEK 293T-Dsup-copGFP for Dsup fusion expression with copGFP is established.The expression of Dsup gene in HEK 293T cells can promote cell proliferation,possibly by upregulating the expressions of Ki-67 and MCM4 protein.

Objective:To study the effects and the related molecular mechanisms of miR-148a-3p on the proliferation,invasion and migration of salivary adenoid cystic carcinoma SACC-LM cells.Methods:miR-148a-3p mimics and inhibitors,siRNA targeting EG-FR and their corresponding controls were transfected into SACC-LM cells.Bioinformatics was used to predict the potential target genes of miR-148a-3p.EGFR and miR-148a-3p mRNA expression levels were examined by qRT-PCR and the protein levels of EG-FR were detected by Western blotting.CCK-8,scratch,and Transwell assays were used to study the proliferation,migration,and invasion of SACC-LM cells,respectively.The direct targeting relationship between miR-148a-3p and EGFR was examined by using the double luciferase reporter gene assay.Statistical analysis of the data was performed by SPSS 22.0 software.Results:Overexpres-sion or inhibition of miR-148a-3p significantly inhibited or promoted the proliferation,invasion and metastasis of SACC-LM cells re-spectively(P＜0.05).Bioinformatics and double luciferase assay showed that miR-148a-3p directly targeted and regulated the expres-sion of EGFR(P＜0.001).Downregulation of EGFR inhibited the proliferation,migration and invasion of SACC-LM cells(P＜0.05)and partially reversed the promoting effect of miR-148a-3p inhibition(P＜0.05).Conclusion:The downregulation of miR-148a-3p leads to the abnormally high expression of its target gene EGFR,and promotes the proliferation,invasion,and migration of salivary adenoid cystic carcinoma cells.

OBJECTIVETo build a protocol of separation and induction of megakaryocytes derived from cord blood mononuclear cells.

METHODSRed blood cells were precipitated by hydroxyethyl starch (HES). Mononuclear cells were obtained by density gradient centrifugation with Ficoll. The inducing efficiencies of megakaryocytes by using of different cytokine cocktails and culture media were analyzed.

RESULTSThe best choice for erythrocyte sedimentation and high efficiency of nucleated cells retrieving were obtained by using of 1.5% HES. The isolated cord blood mononuclear cells were cultured with domestic serum-free medium supplemented with 116t (IL-11, IL-6, TPO), st36(SCF, TPO, IL-3, IL-6), pt36 (PDGF,TPO,IL-3,IL-6) or pst36 for 7 days. St36 group (50 ng/ml SCF, 50 ng/ml TPO, 20 ng/ml IL-3 and 50 ng/ml IL-6) yielded the most CD41/CD61 positive [(6.79±1.97)×10⁴]. The cell viability [(82.85 ± 0.64)%] of st36 group by using of imported serum-free medium was better than [(60.90±6.93)%] that in domestic medium on day 7 after induction, and CD41/CD61 positive cells count [(18.60±1.97)×10⁴] were more than domestic serum-free medium group. Therefore, we chose imported serum-free medium containing st36 to induce cord blood mononuclear cells. After a prolonged culture, the total cell numbers increased accompanied with an elevated percentage of CD41/CD61 positive cells, which reached (54.27 ± 6.31)% on day 14. Wright-Giemsa staining showed that different phase cells, such as megakaryoblast, promegakaryocyte and granular megakaryocyte, occurred after 10 days'culture. Clone forming unit-megakarocytes (CFU-MK) assay showed that the colonies count increased with the prolonged incubation. CFU-MK colonies were [1 236.0±32.9] on day 14, which was higher than that in medium without induction (P<0.01). Platelets from megakaryocytes showed agglutination function after 10 days'culture.

CONCLUSION1.5% HES was the best solution to precipitate erythrocytes. The combination of an imported serum-free medium with IL-3, IL-6, SCF and TPO showed better induction efficiency than domestic medium or other cytokine cocktails. Meanwhile, induced megakaryocytes produced functional platelets.

Cell Culture Techniques ; Cell Differentiation ; Cell Division ; Cell Separation ; methods ; Cells, Cultured ; Culture Media, Serum-Free ; Fetal Blood ; cytology ; Humans ; Megakaryocyte Progenitor Cells ; cytology