Human coagulation factor IX gene therapy in murine hemophilia B by hydrodynamic delivery and site-specific genomic integration / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate whether the plasmid bearing attB and human coagulation factor IX (hFIX) coding sequence could insert into hemophilia B mice genome and persistently express hFIX with co-injected integrase.</p><p><b>METHODS</b>The plasmid attB-hFIX-pIRES2-EGFP was constructed, which bore attB site and hFIX coding sequence and was proved in vitro to express hFIX. The plasmid and CMV-int expressing integrase was co-infused rapidly in a large-volume solution through tail vein of hemophilia B mice. Mice infused with the plasmid alone served as controls. ELISA was performed to determine serum hFIX level. Correction of coagulation defect in vivo by plasmid infusion was assessed by bleeding time. Genomic integration of the plasmid was determined by nested PCR.</p><p><b>RESULTS</b>The plasmid attB-hFIX-pIRES2-EGFP was successfully constructed. The hemophilia B mice produced (1533 ± 239) ng/ml hFIX at 24 hour after infusion of the hFIX encoding plasmid and the bleeding diathesis of the hemophilia B mice was significantly corrected as measured by clotting assays. However, whether or not co-injected with CMV-int, the serum hFIX level decreased to background level in 10 days after infusion. Nested-PCR results indicated that the integrase phiC31 resulted in the integration of the plasmid in the mouse liver chromosomes.</p><p><b>CONCLUSION</b>Integrase phiC31 can catalyze recombination of 34 bp attB and pseudo-attP. Human FIX driven by CMV promoter can be transiently and highly expressed after infusion, but rapidly silenced in vivo.</p>

Construction and identification of a novel adeno-integrase hybrid system for hemophilia B / 中国实验血液学杂志

This study was aimed to construct an adenovirus hybrid system with high transduction efficiency and site-specific integration. By a series of DNA manipulation, a hybrid system of two adenovirus vectors was constructed. One vector contains loxP-flanked transgene expression cassette, in which there are hFIX and DsRed coding sequences and attB for phiC31 recolonization. The other vector carries Cre and phiC31 gene. Vectors only expressing Cre or phiC31 were used as controls. 293A cells were constructed and transfected with the adenoviral vectors by Lipofectamine 2000, and the expression of target genes was identified by fluorescence microscopy and RT-PCR. The results showed that after being identified by PCR, restriction analysis and sequencing, an adeno-integrase hybrid system was successfully constructed. The system expressed RFP, GFP, hFIX, Cre and phiC31 in 293A cells in vitro. It is concluded that the adeno-integrase hybrid system is successfully constructed, which lays a good foundation for further investigation of its therapeutic application.

Combined deficiency of factors V and VIII caused by a novel compound heterozygous mutation of gene Lman1 / 中国实验血液学杂志

Combined deficiency of factor V and VIII (F5F8D) is a rare, autosomal recessive disorder caused by mutations of either lman1 or mcfd2. To identify mutations of these two genes in a Chinese F5F8D family, the samples of peripheral blood were collected from the proband and her parents. Coagulation tests were carried out, including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen (Fg) and coagulate activity of FV, FVIII (FV:C, FVIII:C). The genomic DNA was extracted, then all the exons and intron/exon boundaries of these two genes were amplified by polymerase chain reaction (PCR). The products were finally analyzed by direct sequencing. The results showed that the proband's APTT, PT, TT, Fg, FV:C and FVIII:C were 82.2 sec, 19.6 sec, 18.6 sec, 2.9 g/L, 7.1% and 18.7% respectively, while those parameters of the parents were all within the normal range. Two pathogenic mutations were identified in lman1 gene of the proband: one was the heterozygous c.912_913insA in exon 8 resulting in a frameshift of p.Glu305fsX20; the other was the heterozygous c.1366C > T in exon 11 resulting in p.Arg456X. The proband's father and mother were heterozygous for c.1366C > T and c.912_913insA respectively. It is concluded that F5F8D of the proband is caused by a novel compound heterozygous mutation of the lman1 gene, which has never been reported.

Genetic analysis of an inherited afibrinogenemia family caused by a novel frameshift mutation in FGA / 中国实验血液学杂志

Inherited afibrinogenemia is a rare autosomal recessive bleeding disease characterized by complete absence of fibrinogen in blood. To identify the genotype in a Chinese family with inherited afibrinogenemia, the samples of peripheral blood were collected from 6 members of 3 generations. The activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (Fg, clauss) were tested. Fg was also analyzed by using immunoturbidimetry method. DNAs of six members were extracted by using a DNA extract kit. All the exons and exon-intron boundaries of the three fibrinogen genes were amplified by using PCR and analyzed by direct sequencing. The results showed that the parents of proband were 3 degree consanguinity. A homozygous c.934_935insA in FGA was found in proband which results in the change of protein p.Ser312fsX42. The parents, grandmother, maternal grandmother and father's sister were all detected with heterozygous mutation which was same as that in proband. In conclusion homozygous c.934_935insA in FGA is a cause of inherited afibrinogenemia and a novel mutation being reported.

Comparative study of in vitro hematopoietic supportive capability of human mesenchymal stem cells derived from bone marrow and umbilical cord / 中国实验血液学杂志

The present study was aimed to isolate and identify human mesenchymal stem cells from adult bone marrow (BM-MSC) and umbilical cord (UC-MSC), and to compare their ability to support in vitro long-term hematopoiesis. MSC from bone marrow and umbilical cord were isolated by using density gradient centrifugation or enzyme digestion. MSC were further purified by adherent culture. Immunophenotype, adipogenic and osteogenic differentiation potential of BM-MSC and UC-MSC were detected. The hematopoietic supporting capacity of BM-MSC and UC-MSC was assessed by LTC-IC assay. Nonadherent cells in each group were collected for phenotypic analysis at 3, 5 and 7th week of culture. The results showed that BM-MSC and UC-MSC in culture shared a similar spindle-shaped morphology and adhered to the tissue culture substrate. They were both positive for CD90, CD105, CD73, CD29, CD54, CD166, HLA-ABC, and negative for HLA-DR, CD34 and CD45. BM-MSC and UC-MSC could differentiate into adipocytes or osteoblasts confirmed by oil red O staining and von Kossa staining, separately. LTC-IC assay showed that at 5th week of culture, the difference of the CFC yields between UC-MSC group and BM-MSC group was not statistically significant (p>0.05). At 6, 7, 9th week of culture, the CFC yields in the UC-MSC group were lower than those of BM-MSC (p<0.05). The phenotypic analysis of nonadherent cells at 3, 5, 7th week of culture indicated that along with prolongation of time, the percentages of CD34+ cells and CD117+ cells in each group decreased markedly, and the percentages of CD33+ cells, CD13+ cells and CD11b+ cells increased gradually. It is concluded that MSC from human adult bone marrow and umbilical cord can be successfully isolated and identified. UC-MSC are able to support long-term hematopoiesis in vitro, but its hematopoietic supportive capacity is weaker than those of BM-MSC.

Reversal of leukemia multidrug resistance by sequence-specific short hairpin RNA / 中国实验血液学杂志

This study was aimed to design and screen short hairpin RNA (shRNA) molecules targeting multidrug resistance gene (mdr1), as well as to investigate the effects of shRNA expression vector on K562/A02 cells. Mdr1-shRNA expression vector was transfected into K562/A02 cells by lipofectamine 2000, and G418 was added to screen and establish the stable expression cell strain. The expressions of mdr1 mRNA and protein were detected by real-time RT-PCR and Western blot respectively. The sensitivity of cells to chemodrugs after interference were tested by CCK8 assay. The function of p-glycoprotein was determined by Rhodamine 123 efflux experiment. The results showed that all of 4 mdr1-shRNA expression vectors could significantly knockdown the expression of p-glycoprotein as compared with control vector, moreover, the vector targeting 508 - 526 sites of mdr1 gene was the best one. It is concluded that the mdr1-shRNA expression vector gained by screening can significantly knockdown the expression of mdr1 gene and reverse leukemia drug resistance, paving the way for the application of RNAi in the following animal experiments.

Transfusion of allogeneic mesenchymal stem cells promotes progression of atherosclerotic plaque in rabbits / 中国实验血液学杂志

The present study was purposed to evaluate the safety of mesenchymal stem cell (MSC)-based therapy impacting on atherosclerosis. Allogeneic MSCs were obtained from rabbit bone marrow aspirates and expanded in vitro. New Zealand white rabbits were divided into three groups: 24 rabbits with hypercholesterolemia receiving intravenous injection of either 5 x 10(7) MSCs (n = 12) or saline (n = 12) after 5 weeks on a high lipid diet and additional rabbits (n = 6) fed with standard rabbit diet were served as controls. Body weight and blood lipids were measured at weeks 0, 5, 9 and 13 during the study. All rabbits were sacrificed at week 13. Atherosclerotic lesion size and vasa vasorum were evaluated by using pathological analysis and immunocytochemical technique. The results showed that the aortic sinus lesion size significantly increased in rabbits infused with MSCs as compared with controls receiving saline (23.35 +/- 3.51% and 11.39 +/- 3.08% respectively). The lesion size in whole aortas of MSC-treated rabbits was 76.64 +/- 12.70% versus 57.61 +/- 9.00% in saline-treated animals (p < 0.05). Moreover, vasa vasorum networks in MSC-treated aortas were more numerous and had increased capillary density. It is concluded that the allogeneic MSC transfusion may result in an increase in atherosclerotic lesion size. In cell therapy with MSCs or cell populations containing MSCs a strategy to attenuate the high potential of MSCs involved in atherogenesis of atherosclerosis should be taken in account.

Analysis of complicated anemia in 60 patients with systemic lupus erythematosus / 中国实验血液学杂志

The study was aimed to explore the characteristics of clinical manifestation, laboratory indicators and bone marrow examination of SLE patients with anemia. 60 SLE patients with anemia were analyzed for their clinical manifestation, laboratory indicators and bone marrow examination in comparison with 40 contemporaneous SLE patients without anemia. The results indicated that there were significant differences in clinical manifestations of fatigue between the SLE patients with anemia and those without anemia. The detection rate of the decreased Plt and C4 and the percentages of eosinophils, early normoblast, polychromatic normoblast and orthochromatic normoblast in bone marrow were all higher than that in those without anemia. The ANA with titer 1:320 in SLE patients complicated by anemia was lower than that in those without anemia. In conclusion, the clinical manifestation, experimental examination and bone marrow findings were significantly different between the SLE patients with anemia and without anemia.

Neovascularization potential of mobilized peripheral mononuclear cells from diabetes patients / 中国医学科学院学报

<p><b>OBJECTIVE</b>To determine whether mobilized peripheral blood mononuclear cells (M-PBMNCs) obtained from patients with diabetes was impaired in therapeutic neovascularization in limb ischemia, and to explore the pathological mechanisms of the impairment.</p><p><b>METHODS</b>Endothelial progenitor cells (EPC) were cultured in EGM-2MV, and then characterized by uptake of 1, 1-dioctadecyl-3, 3, 3, 3-tetramethylindocarbocyanine-labeled acetylated low density lipoprotein (Dil-AcLDL) and binding of ulex europaeus agglutinin (UEA). The number of EPC was compared between M-PBMNCs obtained from diabetic patients and those from normal subjects. M-PBMNCs obtained from diabetic patients, M-PBMNCs obtained from normal controls, or PBS were injected into the ischemic limbs of streptozotocin-induced diabetic nude mice. The limb blood perfusion was detected by laser Doppler blood perfusion imaging between these three groups in the following 1, 3, 7, 14, 21, and 28 days. Ambulatory score and ischemia damage were evaluated in the following 4 weeks. Capillary/fiber ratio was detected by CD31 or BS-1 lectin, and arteriole density was detected by alpha-smooth muscle actin (alpha-SMactin).</p><p><b>RESULTS</b>The number of EPC from diabetic patients were positively correlated with the blood perfusion (R = 0.486, P < 0.05) and capillary density (R = 0.491, P < 0.05), and the EPC number in diabetic patient were negatively correlation with their disease courses (R = - 0.587, P < 0.05). Transplantation of diabetic M-PBMNCs augmented the blood perfusion of ischemia hindlimbs, increased the capillary and arteriole densities, and promoted the collateral vessel formation. However, all the improvements were less significant in the diabetic patients than in the non-diabetic patients (P < 0.05).</p><p><b>CONCLUSION</b>Diabetes decreased the capability of M-PBMNCs to augment neovascularization in ischemia.</p>

Construction and Identification of a Single Chain Fv Phage Display Library Against Human Umbilical Cord Mesenchymal Stem Cell / 中国生物工程杂志

Objective :To construct and identify a ScFv phage display library against human umbilical cord mesenchymal stem cells.Methods: BALB/c mice were immunized with cultured UC-MSCs.After the third immunization,the total RNA was extracted from the spleen cells of the immunized BALB/c mice and purified by affinity chromatography with mRNA Purification Kit.The heavy-chain and light-chain variable region genes(VH and VL) were amplified by PCR using relevant primers.PCR products of VH and VL genes were cloned into the phagemid vector pSEX81 and electroporated into the XL1-Blue strain of E.coli.The ScFv phage display library against human umbilical cord mesenchymal stem cells was constructed and the capacity of library was measured.The library was panned by three cycles and screened with purified UC-MSCs.The percentage of clones containing a full-length scFv-encoding insert and their diversity was determined for unselected and selected libraries.Results: The amplified fragments of VH and VL genes by RT-PCR were about 399bp and 357bp,respectively.VH and VL genes were all successfully cloned into the phagemid vector pSEX81,which were confirmed by the amplication of 786bp full-length scFv fragments by PCR.The ScFv phage display library had a capacity of approximately 2?107 cfu.After three cycles of panning,PCR of plasmid DNA prepared from 15 individual phage clones showed that the recombination rate increased from 93% to 100%.BstN1 fingerprinting of insert DNA showed that the diversity of clones decreased with increasing rounds of selection.After three rounds of selection,3 clones showed an identical restriction enzyme pattern.There was a 330-fold enrichment of library phage after 2 rounds of selection and after 3 rounds,a further 8-fold enrichment of library phage was obtained.Conclusion: The ScFv phage display library against human umbilical cord mesenchymal stem cells was successfully constructed.It can be used for succeeding screening of specific antibody against human umbilical cord mesenchymal stem cells and further studying of the cell surface molecules of mesenchymal stem cells.