Factor analysis of effective platelet-producing ability of fetal liver-derived cells / 中华内科杂志

Objective:To study the different factors affecting platelet production post transplantation of hematopoietic stem cells (HSCs) isolated from different sources in order to explore novel options for treating platelet depletion following HSCs transplantation.Methods:HSCs and their downstream derivatives including myeloid and lymphoid cells (i.e., collective of mononuclear cells (MNCs)), were isolated from E14.5 fetal liver (FL) and bone marrow (BM) of 8-week-old mice by Ficoll separation technique. These cells were subsequently transplanted into the tibia bone marrow cavity of recipient mice post lethal myeloablative treatment in order to construct the FL-MNCs and BM-MNCs transplantation mouse model. Routine blood indices were examined in these recipient mice. The chimeric rate of donor cells in recipient peripheral blood cells were determined by flow cytometry. Different groups of cells involved in platelet reconstruction were analyzed. CD41 +megakaryocytes were sorted from fetal liver or bone marrow using magnetic beads, which were then induced to differentiate into platelets in an in vitro assay . Quantitative RT-PCR was used to detect the expression of platelet-related genes in CD41 +megakaryocytes from the two sources. Results:Both the FL-MNCs and the BM-MNCs transplantation groups resumed normal hematopoiesis at the 4th week after transplantation, and the blood cells of the recipient mice were largely replaced by the donor cells. Compared with the mice transplanted with BM-MNCs, the platelet level of mice transplanted with FL-MNCs recovered faster and were maintained at a higher level. At week 4, the PLT level of the FL-MNCs group was (1.45±0.37)×10 12/L, and of the BM-MNCs group was (1.22±0.24)×10 12/L, P<0.05. The FL-MNCs contain a higher proportion of hematopoietic stem cells (Lin -Sca-1 +c-Kit +)(7.60%±1.40%) compared to the BM-MNCs (1.10%±0.46%), P<0.01; the proportion of the megakaryocyte progenitor cells (Lin -Sca-1 -c-Kit +CD41 +CD150 +) and mature megakaryocyte cells (CD41 +CD42b +), also differ significantly between the FL-MNCs (3.05%±0.22%, 1.60%±0.06%, respectively) and the BM-MNCs (0.15%±0.02%, 0.87%±0.11%, respectively) groups, both P<0.01. In vitro functional studies showed that FL-MNCs-CD41 +megakaryocytes could produce proplatelet-like cells more quickly after induction, with proplatelet-like cells formation on day 3 and significant platelet-like particle formation on day 5, in contrast to bone marrow-derived BM-MNCs-CD41 +megakaryocytes that failed to form proplatelet-like cell on day 5. In addition, FL-MNCs-CD41 +cells expressed higher levels of platelet-related genes, Mpl (3.25-fold), Fog1 (3-fold), and Gata1 (1.5-fold) ( P<0.05). Conclusion:Compared with the BM-MNCs group, the FL-MNCs transplantation group appears to have a more efficient platelet implantation effect in the HSCs transplantation recipient in vivo , as well as a higher platelet differentiation rate in vitro. This might be related to a higher proportion of megakaryocytes and higher expression levels of genes such as Mpl, Fog1, and Gata1 that could be important for platelet formation in FL-MNCs-CD41 +cells. Further exploration of the specific functions of these genes and the characteristics of the different proportions of the donor cells will provide valuable clues for the future treatment of platelets reconstitution after HSCs transplantation clinically.

The effect of DNA hydroxymethylase Tet2 on γ globin activation in the treatment of β-thalassemia / 中华内科杂志

Objective To study the function of ten-eleven translocation 2 (Tet2) in γglobin gene expression in patients with β-thalassemia.Methods Gamma globin expression was induced by 5-azacytidine and Tet2 gene expression was knocked down by short hairpin RNA (shRNA) in a human immortalized myelogenous leukemia K562 cell line.The global 5-hydroxymethylcytosine (5hmC) level was measured by an ELISA kit.5hmC level of γglobin gene was quantified by sulfite sequencing.The mRNA level of Tet2,γglobin,and related transcription factors Nfe4 and Klfl were quantified by real-time PCR.Results Tet2 knockdown resulted in a decreased global 5hmC level from 0.14％ to 0.03％ as of the control group in K562 cells.The expression of γ globin was enhanced after 5-azacytidine treatment in vitro.However,γglobin mRNA level in Tet2 knockdown cells was only 55％ as that in control group.The CG sites on γ globin gene were unmethylated.As Tet2 was down-regulated,the expression levels of Nfe4 and Klf1 decreased by about 80％ and increased to 3.5 folds,respectively.Conclusions Tet2 appears to maintain 5hmC level and facilitates γ globin gene activation.Moreover,Tet2 more likely regulates γglobin expression via affecting transcription factors rather than the gene itself.Thus,Tet2 could be a potential therapeutic target for β thalassemias.

Two novel pathogenic mutations of GAN gene identified in a patient with giant axonal neuropathy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the disease-causing mutations in a patient suspected for giant axonal neuropathy(GAN).</p><p><b>METHODS</b>Target sequence capture sequencing was used to screen potential mutations in genomic DNA extracted from peripheral blood sample of the patient. Sanger sequencing was applied to confirm the detected mutation. The mutation was verified among 400 GAN alleles from 200 healthy individuals by Sanger sequencing. The function of the mutations was predicted by bioinformatics analysis.</p><p><b>RESULTS</b>The patient was identified as a compound heterozygote carrying two novel pathogenic GAN mutations, i.e., c.778G>T (p.Glu260Ter) and c.277G>A (p.Gly93Arg). Sanger sequencing confirmed that the c.778G>T (p.Glu260Ter) mutation was inherited from his father, while c.277G>A (p.Gly93Arg) was inherited from his mother. The same mutations was not found in the 200 healthy individuals. Bioinformatics analysis predicted that the two mutations probably caused functional abnormality of gigaxonin.</p><p><b>CONCLUSION</b>Two novel GAN mutations were detected in a patient with GAN. Both mutations are pathogenic and can cause abnormalities of gigaxonin structure and function, leading to pathogenesis of GAN. The results may also offer valuable information for similar diseases.</p>

An Expedient Reliable Double Fluorescent Reporter System for φC31 Integrase Function Evaluation / 生物化学与生物物理进展

A reporter system for φC31 integrase was developed in NIH3T3 cells. The reporter plasmid coding green fluorescent protein (GFP) coupled with red fluorescent protein (RFP) was eo-transfected with the plasmid coding φC31 integrase, to show the activity of integrase in the cells. Fluorescence activated cell sorter (FACS) was used to measure the proportion of the cells containing red and green fluorescence. The increment of green cells was positively related to the increase in the transfection with plasmid coding φC31 integrase. Approximately 90% of green cells were observed under a ratio of [plasmid-φC31-integrase]/[reporter plasmid] at 10 : 1. This suggests that the φC31 integrase reporter system provides a probe for the function of φC31 integrase in cells.

An Expedient Reliable Double Fluorescent Reporter System for ?C31 Integrase Function Evaluation / 生物化学与生物物理进展

A reporter system for ?C31 integrase was developed in NIH3T3 cells.The reporter plasmid coding green fluorescent protein(GFP) coupled with red fluorescent protein(RFP) was co-transfected with the plasmid coding ?C31 integrase, to show the activity of integrase in the cells.Fluorescence activated cell sorter(FACS) was used to measure the proportion of the cells containing red and green fluorescence.The increment of green cells was positively related to the increase in the transfection with plasmid coding ?C31 integrase.Approximately 90% of green cells were observed under a ratio of plasmid-?C31-integrase/reporter plasmid at 10∶1.This suggests that the ?C31 integrase reporter system provides a probe for the function of ?C31 integrase in cells.

Anti-tumor effect of ethanol extracts from Thymus quinquecostatus Celak on human leukemia cell line / 中西医结合学报

OBJECTIVE: To screen the anti-tumor fraction of ethanol extracts from Thymus quinquecostatus Celak and investigate its anti-tumor effect on human leukemia cell line. METHODS: Ethyl acetate, n-butanol and acetone fractions were separated from the ethanol extracts of wild Thymus quinquecostatus Celak. Growth inhibiting effects of these extracts on human leukemia cell lines K562 and HL-60 were determined by live cell counting and cell growth curve analysis. The possible anti-tumor mechanism was studied by morphological analysis with norcantharidin as a positive control. RESULTS: Ethyl acetate fraction could significantly inhibit the proliferations of K562 and HL-60 cells, and the inhibiting effect depended on the concentration of ethyl acetate fraction. Ethyl acetate fraction could induce apoptosis of K562 and HL-60 cells. The n-butanol and acetone fractions had no significant inhibiting effect on K562 and HL-60 cells. CONCLUSION: Ethyl acetate fraction is the major anti-tumor fraction in ethanol extracts from Thymus quinquecostatus Celak.

Internal fixation witah anatomical plate and bone graft for treatment of complicated comminuted fractures of distal femur / 中华创伤骨科杂志

Objective To report the clinical features and effects of internal fixation with anatomical plate in combination with bone graft in treatment of complicated comminuted fractures of distal femur. Methods There were 11 case of type C2 and 9 cases of type C3 fractures of distal femur according to the AO classification. When they were treated with anatomical plate, bone grafting from ilium or fibula or from both was done to repair their bone defects depending on specific defects of the patients. Results All the patients were followed up for a mean of 20 months (ranging from 10 to 24 months). Bone healed in all the cases. By Schatzker standards, the result was excellent in 14 patients, good in 5 and fair in 1. The excellent and good rate was 95%. Conclusion The authors consider that anatomical plate in combination with bone graft is an ideal treatment for complicated comminuted fractures of distal femur.

Original studies on anti-tumor and immunological effect of extracts from Thymus quinquecostatus Celak in mice / 中西医结合学报

OBJECTIVE: To study the anti-tumor and immunological effect of extracts from Thymus quinquecostatus Celak on mice transplanted S180 tumor cells. METHODS: Different doses of volatile oil and alcohol extracted substances from Thymus quinquecostatus Celak were given to mice bearing S180 tumor for 9 days. Tumor inhibition rates and coefficients of spleen and thymus were determined. RESULTS: Tumor inhibition rates of the groups with alcohol extracts (40 g crude drug.kg(-1).d(-1) and 20 g crude drug.kg(-1).d(-1)) were 51.5% (P<0.01) and 36.4% (P<0.05) respectively, and those of the groups with volatile oil (40 g crude drug.kg(-1).d(-1) and 20 g crude drug.kg(-1).d(-1))were both 39.4% (P<0.05). CONCLUSION: The extracts from Thymus quinquecostatus Celak have anti-tumor activities. The coefficient of spleen in group with alcohol extracts (40 g crude drug.kg(-1).d(-1))was close to normal value, and its coefficient of thymus was between that of the negative control group and the group with cyclophosphamide (0.02 g.kg(-1).d(-1)). The anti-tumor activity of the alcohol extracts was significantly higher than that of the control group and the tumor inhibition rate was depending on drug concentration. Depending on index of immunity,the extracts from Thymus quinquecostatus Celak may have some influences on immunity.