[Show abstract][Hide abstract] ABSTRACT: Recombinant human thrombopoietin (rHuTPO) is a drug that is used clinically to promote megakaryocyte and platelet generation. Here, we report the mitigative effect of rHuTPO (administered after exposure) against severe whole body irradiation in mice. Injection of rHuTPO for 14 consecutive days following exposure significantly improved the survival rate of lethally irradiated mice. RHuTPO treatment notably increased bone marrow cell density and LSK cell numbers in the mice after sub-lethal irradiation primarily by promoting residual HSC proliferation. In lethally irradiated mice with hematopoietic cell transplantation, rHuTPO treatment increased the survival rate and enhanced hematopoietic cell engraftment compared with the placebo treatment. Our observations indicate that recombinant human TPO might have a therapeutic role in promoting hematopoietic reconstitution and HSC engraftment.
[Show abstract][Hide abstract] ABSTRACT: Critical limb ischaemia is the most severe clinical manifestation of peripheral arterial disease. The circulating endothelial progenitor cells (EPCs) play important roles in angiogenesis and ischemic tissue repair. The increase of circulating EPC numbers by using mobilization agents is critical for obtaining a better therapeutic outcome in patients with ischemic disease. Here, we firstly report a novel small molecule, Me6TREN (Me6), can efficiently mobilize EPCs into the blood circulation. Single injection of Me6 induced a long-lasting increase in circulating Flk-1(+) Sca-1(+) EPC numbers. In a mouse hind limb ischemia (HLI) model, local intramuscular transplantation of these Me6-mobilized cells accelerated the blood flow restoration in the ischemic muscles. More importantly, systemic administration of Me6 notably increased the capillary density, arteriole density and regenerative muscle weight in the ischemic tissue of HLI. Mechanistically, we found Me6 reduced stromal cell-derived factor-1α level in bone marrow by up-regulation of matrix metallopeptidase-9 expression, which allowed the dissemination of EPCs into peripheral blood. These data indicate that Me6 may represent a potentially useful therapy for ischemic disease via enhancing autologous EPC recruitment and promote angiogenesis.
Full-text · Article · Aug 2014 · Scientific Reports
[Show abstract][Hide abstract] ABSTRACT: To build a protocol of separation and induction of megakaryocytes derived from cord blood mononuclear cells.
Red 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.
The best choicefor erythrocyte sedimentation and high efficency 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.
1.5% 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.
No preview · Article · Mar 2014 · Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi
[Show abstract][Hide abstract] ABSTRACT: Due to the low number of collectable stem cells from single umbilical cord blood (UCB) unit, their initial uses were limited to pediatric therapies. Clinical applications of UCB hematopoietic stem and progenitor cells (HSPCs) would become feasible if there were a culture method that can effectively expand HSPCs while maintaining their self-renewal capacity. In recent years, numerous attempts have been made to expand human UCB HSPCs in vitro. In this study, we report that caffeic acid phenethyl ester (CAPE), a small molecule from honeybee extract, can promote in vitro expansion of HSPCs. Treatment with CAPE increased the percentage of HSPCs in cultured mononuclear cells. Importantly, culture of CD34(+) HSPCs with CAPE resulted in a significant increase in total colony-forming units and high proliferative potential colony-forming units. Burst-forming unit-erythroid was the mostly affected colony type, which increased more than 3.7-fold in 1 μg mL(-1) CAPE treatment group when compared to the controls. CAPE appears to induce HSPC expansion by upregulating the expression of SCF and HIF1-α. Our data suggest that CAPE may become a potent medium supplement for in vitro HSPC expansion.
No preview · Article · Jan 2014 · Science China. Life sciences
[Show abstract][Hide abstract] ABSTRACT: Mobilization of hematopoietic stem and progenitor cells (HSPCs) from bone marrow into the blood circulation has been widely used for hematopoietic transplantation. However, the current methods of cytokine- or small-molecule-stimulated HSPC mobilization are far from satisfactory. New mobilizing agents are needed to increase the number of stem cells in peripheral blood for effective reconstitution of hematopoiesis. Here, we report that the molecule Me6TREN (Me6) can induce rapid mobilization of hematopoietic progenitor cells, and that Me6 exhibits more significant effects than G-CSF or AMD3100. Me6 also mobilizes long-term repopulating cells, which successfully engraft and expand in a multilineage fashion in primary and secondary transplant recipients. Mechanistically, Me6 inhibits both the SDF-1α-induced migration and VLA-4-mediated adhesion of mouse and human hematopoietic cells. Me6 appears to mobilize HSPCs by activating MMP-9 expression and disrupting the SDF-1α/CXCR4 axis. Therefore, Me6 may become a new, potent and efficacious mobilizing agent of HSPCs.
[Show abstract][Hide abstract] ABSTRACT: In vitro
models of human erythropoiesis are useful in studying the mechanisms of erythroid differentiation in normal and pathological conditions. Here we describe an erythroid liquid culture system starting from cord blood derived hematopoietic stem cells (HSCs). HSCs were cultured for more than 50 days in erythroid differentiation conditions and resulted in a more than 10
-fold expansion within 50 days under optimal conditions. Homogeneous erythroid cells were characterized by cell morphology, flow cytometry, and hematopoietic colony assays. Furthermore, terminal erythroid maturation was improved by cosculturing with human fetal liver stromal cells. Cocultured erythroid cells underwent multiple maturation events, including decrease in size, increase in glycophorin A expression, and nuclear condensation. This process resulted in extrusion of the pycnotic nuclei in up to 80% of the cells. Importantly, they possessed the capacity to express the adult definitive
-globin chain upon further maturation. We also show that the oxygen equilibrium curves of the cord blood-differentiated red blood cells (RBCs) are comparable to normal RBCs. The large number and purity of erythroid cells and RBCs produced from cord blood make this method useful for fundamental research in erythroid development, and they also provide a basis for future production of available RBCs for transfusion.
[Show abstract][Hide abstract] ABSTRACT: Adipose-derived adult stem (ADAS) cells can be easily obtained in large quantities. Previous studies have suggested that all-trans-retinoic acid (ATRA) plays an important role in the differentiation of mesenchymal stem cells toward an epithelial lineage. In order to verify that ADAS-cells can differentiate into an epithelial lineage retaining most of the characteristics of stem cells, ADAS-cells were isolated and cultured. They were induced to differentiate toward an epithelial lineage in vitro. Differentiated epithelial cells were assayed as to whether they retain characteristics of stem cells by RT-PCR and cell cycle stage analysis, and were further induced to differentiate toward an osteogenic lineage. RT-PCR analysis revealed that no CK5, CK10 or CK19 mRNA was detected in ADAS-cells, CK19 but not CK5 or CK10 mRNA was detected in differentiated cells at passage 1, CK10 and CK19 expression but not CK5 mRNA was detected in differentiated cells at passage 10. After induction, the expression of CK19 was observed by immunofluorescent staining. Positive staining with alkaline phosphatase (ALP) and Von Kossa staining verified that differentiated epithelial cells still had potential to further differentiate toward an osteogenic lineage. These experiments provide proof that ADAS-cells can differentiate into an epithelial lineage retaining most of the characteristics of stem cells.
No preview · Article · Dec 2012 · Annals of anatomy = Anatomischer Anzeiger: official organ of the Anatomische Gesellschaft
[Show abstract][Hide abstract] ABSTRACT: The Wnt/β-catenin signalling pathway is important in regulating not only self-renewal of haemopoietic progenitors and stem cells but also haemopoietic differentiation of ESCs (embryonic stem cells). However, it is still not clear how it affects haemopoietic differentiation. We have used a co-culture system for haemopoietic differentiation of mouse ESCs and iPSCs (induced pluripotent stem cells) in which the Wnt3a gene-modified OP9 cell line is used as stromal cells. The number of both Flk1+ and CD41+ cells generated from both co-cultured mouse ESCs and mouse iPSCs increased significantly, which suggest that Wnt3a is involved in the early stages of haemopoietic differentiation of mouse ESCs and mouse iPSCs in vitro.
No preview · Article · Mar 2012 · Cell Biology International
[Show abstract][Hide abstract] ABSTRACT: In guiding hES cell technology toward the clinic, one key issue to be addressed is to culture and maintain hES cells much more safely and economically in large scale. In order to avoid using mouse embryonic fibroblasts (MEFs) we isolated human fetal liver stromal cells (hFLSCs) from 14 weeks human fetal liver as new human feeder cells. hFLSCs feeders could maintain hES cells for 15 passages (about 100 days). Basic fibroblast growth factor (bFGF) is known to play an important role in promoting self-renewal of human embryonic stem (hES) cells. So, we established transgenic hFLSCs that stably express bFGF by lentiviral vectors. These transgenic human feeder cells--bFGF-hFLSCs maintained the properties of H9 hES cells without supplementing with any exogenous growth factors. H9 hES cells culturing under these conditions maintained all hES cell features after prolonged culture, including the developmental potential to differentiate into representative tissues of all three embryonic germ layers, unlimited and undifferentiated proliferative ability, and maintenance of normal karyotype. Our results demonstrated that bFGF-hFLSCs feeder cells were central to establishing the signaling network among bFGF, insulin-like growth factor 2 (IGF-2), and transforming growth factor β (TGF-β), thereby providing the framework in which hES cells were instructed to self-renew or to differentiate. We also found that the conditioned medium of bFGF-hFLSCs could maintain the H9 hES cells under feeder-free conditions without supplementing with bFGF. Taken together, bFGF-hFLSCs had great potential as feeders for maintaining pluripotent hES cell lines more safely and economically.
[Show abstract][Hide abstract] ABSTRACT: To supply references to tissue-engineered skin clinical applications with autogenic BMSCs composited collagen membrane to repair swine full-thickness cutaneous deficiency.
Twenty mL bone marrow were obtained respectively from 4 swine, autogenic BMSCs were cultured and passed to the 3rd passage. The fresh bovine tendon treated by means of chemically cross-linked was made 5 cm diameter collagen I (Col I) membrane. The 2 x 10(7)/mL P3 swine autogenic BMSCs labeled DAPI were planted to sterile Col I membrane for 24 hours incubation, then the tissue-engineered skin was constructed. The five full-thickness skin defect of 5 cm diameter was excised to the muscle from forward to backward on the back midline two sides of swine. The tissue-engineered skin were implanted in the experimental group, while Col I membrane was implanted in control group. After 3 and 8 weeks of implantation, the two swine wound surface healing circumstance was observed and further evaluated with histology analysis and TEM. After 3 weeks of implantation, the experimental group were observed with fluorescence microscopy and staining for glycogen.
After 3 weeks of implantation, the wound surface of control group were observed nigrescene, scab and putrescence, and after 8 weeks of implantation, also evident putrescence and scar. The wound surface of experiment group was alive after 3 weeks implantation, appearance was leveled off and flexible without evident scar. The wound surface recovered well after 8 weeks of implantation, wound surface healing rate was significantly difference between the two groups (P < 0.01). After 3 weeks of implantation, control group were observed acestoma hyperplasia and no epidermal coverage by histology analysis. The experimental group was showed integrity epidermis and dermis structure. The basal layer was crimson and continuously positive with glycogen staining. After 8 weeks of implantation, the experimental group and control group were emerged normal skin structure. After 3 weeks of implantation in control group, a lot of neutrophilic granulocytes and fibroblasts were noticed, but no epidermal structure was observed under TEM. In the experimental group, a lot of epidermal cells were observed, dermatome connection among epidermal cells and hemidesmosome connection between basilar membrane cells and basal membrane were observed in epidermis. In the dermis experimental group, blood capillary endothelial cells were noticed. Furthermore, considerable collagen fiber deposit was found in the surrounding tissue of fibroblasts. After 3 weeks of implantation, BMSCs labeled with DAPI were located reconstructed epidermal basement membrane and dermis by fluorescence microscopy.
Tissue-engineered skin which is composited with autogenic BMSCs as seed cells and collagen membrane were potential prospects in application of repairing swine full-thickness cutaneous deficiency.
Preview · Article · Mar 2009 · Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery
[Show abstract][Hide abstract] ABSTRACT: To compare the properties of collagen membranes before and after crosslinked and to establish the foundation of application of collagen membranes.
Fresh bovine tendons were separated and collagen was extracted by washing, smashing and acetic acid dissolving. The collagen protein was determined by ultraviolet spectrophotometer and its characteristics were analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), wavelength scanning and amino acids detecting. Collagen membranes were produced by lyophilization. And then the biocharacteristics of the membranes before and after glutaraldehyde crosslinked were compared. BMSCs separated from volunteer's bone marrow were seeded on collagen membranes before and after crosslinked by 2 x 10(3) in 100 microL medium, seven days after culture, the absorption spectrum of BMSCs was examined, and BMSCs were observed by scanning electron microscope (SEM).
The contents of collagen protein were 2 mg/mL. The maximum absorption wave length appeared at about 230 nm. SDS-PAGE suggested that molecular weight of main bands was more than 66.2 x 10(3), the same as collagen marker from calf skin. There were 21.47% glycine, 12.04% praline and 10.18% hydroxyproline. No tryptophan was found. Before crosslinked, collagen membranes were in shape of white sponges and with big holes and the range of pH value was from 4.5 to 5.0. SEM showed reticular conformation and pore structure of collagen membranes, but the bore diameter was bigger. Their water-absorbing capacity was 61 times as much as their weight. The mechanical strength was 210 g/cm3. The dissolution time of collagenase was 90 minutes. After crossl inked, collagen membranes became thin, colorless, semi-transparent and compact with better tenacity. Under SEM, compact collagen fiber appeared reticular. There was lower water-absorbing capacity and pH value ranged from 6.5 to 7.0. The mechanical strength was 3,400 g/cm3 and the dissolution time of collagenase became longer. BMSCs could grow better either on before-crosslinked collagen membranes or on after-crosslinked ones.
As biomaterial scaffolds, after crosslinked collagen membranes were better than before-crosslinked ones.
No preview · Article · Mar 2008 · Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery
[Show abstract][Hide abstract] ABSTRACT: To explore the feasibility of repairing clinical cutaneous deficiency, autogenic bone marrow mesenchymal stem cells (BMSCs) were isolated and differentiated into epidermal cells and fibroblasts in vitro supplemented with different inducing factors and biomaterials to construct functional tissueengineered skin. The results showed that after 72 h induction, BMSCs displayed morphologic changes such as typical epidermal cell arrangement, from spindle shape to round or oval; tonofibrils, melanosomes and keratohyaline granules were observed under a transmission electronic microscope. The differentiated cells expressed epidermal stem cell surface marker CK19 (59.66% +/- 4.2%) and epidermal cells differentiation marker CK10. In addition, the induced epidermal cells acquired the anti-radiation capacity featured by lowered apoptosis following exposure to UVB. On the other hand, the collagen microfibrils deposition was noticed under a transmission electronic microscope after differentiating into dermis fibroblasts; RT-PCR identified collagen type I mRNA expression in differentiated cells; radioimmunoassay detected the secretion of interleukin-6 (IL-6) and interleukin-8 (IL-8) (up to 115.06 pg/mL and 0.84 ng/mL, respectively). Further in vivo implanting BMSCs with scaffold material shortened skin wound repair significantly. In one word, autogenic BMSCs have the potential to differentiate into epidermal cells and fibroblasts in vitro, and show clinical feasibility acting as epidermis-like and dermis-like seed cells in skin engineering.
No preview · Article · Sep 2007 · Science in China Series C Life Sciences
[Show abstract][Hide abstract] ABSTRACT: The neovascularization of ischemic tissue is a crucial initial step for the functional rehabilitation and wound healing. However,
the short of seed cell candidate for the foundation of vascular network is still a big issue. Human adipose tissue derived
mesenchymal stem cells (hADSCs), which possess multilineage potential, are capable of adipogenic, osteogenic, and chondrogenic
differentiation. We examined whether this kind of stem cells could differentiate into endothelial-like cells and participate
in blood vessel formation, and whether they could be used as an ideal cell source for therapeutic angiogenesis in ischemic
diseases or vascularization of tissue constructs. The results showed that hADSCs, grown under appropriately induced conditions,
displayed characteristics similar to those of vessel endothelium. The differentiated cells expressed endothelial cell markers
CD34 and vWF, and had high metabolism of acetylated low-density lipoprotein and prostacyclin. In addition, the induced cells
were able to form tube-like structures when cultured on matrigel. Our data indicated that induced hADSCs could exhibit characteristics
of endothelial cells. Therefore, these cells, as a source of human endothelial cells, may find many applications in such realms
as engineering blood vessels, endothelial cell transplantation for myocardial regeneration, and induction of angiogenesis
for treatment of regional ischemia.
No preview · Article · Aug 2006 · Chinese Science Bulletin