Differentiation of hematopoietic progenitor cells towards the myeloid and B-lymphoid lineage by hepatocyte growth factor (HGF) and thrombopoietin (TPO) together with early acting cytokines

OBJECTIVES: The effect of stem cell factor (SCF), flt3-ligand (FL), and interleukin (IL)-3 (SF3) in combination with hepatocyte growth factor (HGF), thrombopoietin (TPO), and Hyper-IL-6 on maintenance and differentiation of early human peripheral blood-derived progenitor cells was investigated. METHODS: Single sorted CD34(+) 38(-) cells were cultured with various combinations of these growth factors in order to identify the most effective cytokine combination. Then, lineage-depleted cells were stimulated for 7 d in bulk culture before they were assessed by flow cytometry and in functional assays. RESULTS: The highest number of clones in the single-cell assay was obtained after culture with SF3 + TPO + HGF. Cell expansion with SF3 + TPO + HGF yielded an increase of the total cell number (11-fold), the number of CD34(+) cells (sevenfold), colony forming cells (CFC; 13-fold), granulocytes (CD15/66b(+); 45-fold) and B-cells (CD19/20(+); 55-fold). However, the number of long-term culture initiating cells (LTC-IC) decreased from 779 +/- 338 per 1 x 10(5) CD34(+) cells on day 0 to 253 +/- 115 on day 7. In parallel, the number of pluripotent mouse repopulating cells decreased by the factor 11, and no significant change in the proportion of human myeloid or lymphoid cells found in the mouse bone marrow was noted. CONCLUSION: The observation that mature cells of different lineages are generated and that transplantable multipotent hematopoietic cells are lost during culture suggests the differentiation of early hematopoietic progenitors toward lineage committed cells by the tested cytokines. The detection of cells expressing B-lymphoid markers after culture indicates a possible role in the propagation of B-cells.     

Cytokine production and hematopoiesis supporting activity of cord blood-derived unrestricted somatic stem cells

OBJECTIVE: Cytokine production and hematopoiesis-supporting stromal activity of cord blood (CB)-derived unrestricted somatic stem cells (USSC) in comparison to bone marrow mesenchymal stem cells (BMMSC) and hematopoietic progenitor expansion solely driven by recombinant cytokines were assessed. METHODS: USSC generation was initiated from fresh and cryopreserved CB. Cytokine production by USSC and BMMSC was determined qualitatively by cytokine mRNA expression array analyses or quantitatively by Multiplex or ELISA analyses. To evaluate hematopoiesis-supporting activity, CB CD34+ cells were expanded in cocultures with USSC and BMMSC or in the presence of Flt3-L, SCF, and TPO. Expansion of CD34+ cells, total cells, colony-forming cells (CFC), and LTC-IC were determined after 1, 2, 3, and 4 weeks of culture. RESULTS: USSC constitutively produced SCF, LIF, TGF-1beta, M-CSF, GM-CSF, VEGF, IL-1beta, IL-6, IL-8, IL-11, IL-12, IL-15, SDF-1alpha, and HGF. When USSC were stimulated with IL-1beta, G-CSF was released. Production of SCF and LIF were significantly higher in USSC compared to BMMSC. At 1, 2, 3, and 4 weeks, cocultivation of CD34+ cells on the USSC layer resulted in a 14.6-fold +/- 1.1-fold, 110.1-fold +/- 17.9-fold, 151.8-fold +/- 39.7-fold, and 183.6-fold +/- 40.4-fold amplification of total cells and in a 30.6-fold +/- 4.4-fold, 101.4-fold +/- 27.5-fold, 64.7-fold +/- 15.8-fold, and 29.4-fold +/- 3.1-fold amplification of CFC, respectively. LTC-IC expansion at 1 and 2 weeks was, with 2.0-fold +/- 0.1-fold and 2.5-fold +/- 0.3-fold, significantly higher for USSC than BMMSC (1.1-fold +/- 0.03-fold and 1.1-fold +/- 0.1-fold), but declined after day 21. Transwell cocultures of USSC did not significantly alter total cell or CFC expansion. CONCLUSIONS: USSC produce functionally significant amounts of hematopoiesis-supporting cytokines and are superior to BMMSC in expansion of CD34+ cells from CB. USSC is therefore a suitable candidate for stroma-driven ex vivo expansion of hematopoietic CB cells for short-term reconstitution.     

In vivo and in vitro regulation of thyroid leukemia inhibitory factor (LIF): marker of hypothyroidism.

Several cytokines regulate thyroid function and may be involved in the pathogenesis of thyroid disorders, including euthyroid sick syndrome. Leukemia inhibitory factor (LIF), a neuroimmune pleiotropic cytokine, was measured to assess its role in hypothalamic-pituitary-thyroid function. Mean circulating serum LIF levels in 10 hypothyroid patients [TSH, 23+/-0.5 mIU/L (mean+/-SEM); free T4, 0.77+/-0.1 ng/dL] was 0.29+/-0.04 ng/mL, 145% higher (P < 0.04) than in 20 normal subjects (LIF, 0.20+/-0.02 ng/mL; TSH, 2.23+/-0.21 mIU/L; free T4, 1.23+/-0.04 ng/dL) but was not different from those in 10 hyperthyroid patients (LIF, 0.21+/-0.03 ng/mL; TSH, 0.01+/-0.00 mIU/L; free T4, 3.63+/-0.51 ng/dL). Serum LIF concentrations linearly correlated with serum TSH in the 40 samples (r = 0.58, P < 0.001). When T4 (1-8 microg/kg x day) was administered to cynomolgus monkeys with methimazole-induced hypothyroidism, serum T4 and T3 levels increased appropriately, and TSH and LIF concentrations decreased. When methimazole was given alone, both serum TSH (146+/-30 mIU/L) and LIF (8.84+/-0.49 ng/mL) were markedly induced. When methimazole together with T4 (>2 microg/kg x day) was administered, both serum TSH (7.5+/-1.2 mIU/L) and LIF (6.22+/-0.31 ng/mL) were lowered (P < 0.01). Monkey serum LIF levels and log TSH levels also correlated (r = 0.72, P < 0.01). Cultured thyroid carcinoma cells produced LIF (9.2 ng/10(6) cells/48 h). TSH (100 mIU/mL) and interleukin (IL)-6 (10 nmol/L) stimulated in vitro LIF secretion from the cells by 170+/-12% (P < 0.05) and 261+/-8% (P < 0.05), respectively. Dexamethasone (1 micromol/L) inhibited basal LIF concentration by 83% (P < 0.05), whereas TSH and IL-6 stimulated LIF by 52% (P = 0.04) and 42% (P = 0.03), respectively. However, using Northern blot analysis, we could not observe induction of LIF mRNA by TSH, suggesting that LIF regulation by TSH may be due to stimulation of secretion. The results show that the thyroid gland is a source of LIF production; TSH, IL-6, and glucocorticoid influence thyroid cell LIF expression. The correlation between TSH and LIF suggests that LIF may participate in the physiologic regulation of hypothalamic-pituitary-thyroid function.     

A systematic strategy to optimize ex vivo expansion medium for human hematopoietic stem cells derived from umbilical cord blood mononuclear cells

OBJECTIVE: In this study, a serum-free, stroma-free, and chemically defined medium for hematopoietic stem cell (HSC) expansion was systematically developed and optimized using factorial design and the steepest ascent method. MATERIALS AND METHODS: Mononuclear cells (MNCs) were isolated from umbilical cord blood (UCB). HSCs were stimulated to proliferate ex vivo in the MNC culture system with variable serum substitutes, cytokines, and basal media according to experimental design. The expanded cells were assessed for cellular characteristics by surface antigen analysis, colony-forming cell assay (CFC assay), and long-term culture-initiating cell assay (LTC-IC assay). RESULTS: The optimal compositions of serum substitutes and the cytokine cocktail for HSC expansion in the MNC culture system were BIT (4 g/L BSA, 0.71 microg/mL insulin, and 27.81 microg/mL transferrin), and CC-9 (5.53 ng/mL TPO, 2.03 ng/mL IL-3, 16 ng/mL SCF, 4.43 ng/mL FL, 2.36 ng/mL IL-6, 1.91 ng/mL G-CSF, 1.56 ng/mL GM-CSF, 2.64 ng/mL SCGF, and 0.69 ng/mL IL-11) in the Iscove's modified Dulbecco's medium. After 6-day culture, the absolute fold expansions for white blood cells, CD34+ cells, CD34+CD38- cells, CFC, and LTC-IC were 1.4-, 30.4-, 63.9-, 10.7-, 2.8-fold, respectively. CONCLUSION: Using the statistic methodology to develop HSC medium, our formula had lower cytokine concentrations comparing to other literatures and commercial media, but had superior or comparable expansion ability on HSC growth.     

Vascular endothelial growth factor synergistically enhances bone morphogenetic protein-4-dependent lymphohematopoietic cell generation from embryonic stem cells in vitro

The totipotent mouse embryonic stem (ES) cell is known to differentiate into cells expressing the beta-globin gene when stimulated with bone morphogenetic protein (BMP)-4. Here, we demonstrate that BMP-4 is essential for generating both erythro-myeloid colony-forming cells (CFCs) and lymphoid (B and NK) progenitor cells from ES cells and that vascular endothelial growth factor (VEGF) synergizes with BMP-4. The CD45(+) myelomonocytic progenitors and Ter119(+) erythroid cells began to be detected with 0.5 ng/mL BMP-4, and their levels plateaued at approximately 2 ng/mL. VEGF alone weakly elevated the CD34(+) cell population though no lymphohematopoietic progenitors were induced. However, when combined with BMP-4, 2 to 20 ng/mL VEGF synergistically augmented the BMP-4-dependent generation of erythro-myeloid CFCs and lymphoid progenitors from ES cells, which were enriched in CD34(+) CD31(lo) and CD34(+) CD45(-)cell populations, respectively, in a dose-dependent manner. Furthermore, during the 7 days of in vitro differentiation, BMP-4 was required within the first 4 days, whereas VEGF was functional after the action of BMP-4 (in the last 3 days). Thus, VEGF is a synergistic enhancer for the BMP-4-dependent differentiation processes, and it seems to be achieved by the ordered action of the 2 factors.     

Myelopoietin, a chimeric agonist of human interleukin 3 and granulocyte colony-stimulating factor receptors, mobilizes CD34+ cells that rapidly engraft lethally x-irradiated nonhuman primates.

Myelopoietin (MPO), a multifunctional agonist of interleukin 3 and granulocyte colony-stimulating factor (G-CSF) receptors, was evaluated for its ability to mobilize hematopoietic colony-forming cells (CFC) and CD34+ cells relative to control cytokines in normal nonhuman primates. Additionally, the engraftment potential of MPO-mobilized CD34+ cells was assessed in lethally irradiated rhesus monkeys. Normal rhesus monkeys were administered either MPO (200 microg/kg/day), daniplestim (a high-affinity interleukin 3 receptor agonist) (100 microg/kg/day), G-CSF (100 microg/kg/day), or daniplestim coadministered with G-CSF (100 microg/kg/day each), subcutaneously for 10 consecutive days. The mobilization kinetics were characterized by peripheral blood (PB) complete blood counts, hematopoietic CFC [granulocyte-macrophage CFC (GM-CFC), megakaryocyte CFC (MK-CFC)], and the immunophenotype (CD34+ cells) of PB nucleated cells prior to and on day 3 to days 7, 10, 12, and 14, and at intervals up to day 28 following initiation of cytokine administration. A single large-volume leukapheresis was conducted on day 5 in an additional cohort (n = 10) of MPO-mobilized animals. Eight of these animals were transplanted with two doses of CD34+ cells/kg. A maximum 10-fold increase in PB leukocytes (white blood cells) (from baseline 7.8-12.3 x 10(3)/microL to approximately 90 x 10(3)/microL) was observed over day 7 to day 10 in the MPO, G-CSF, or daniplestim+G-CSF cohorts, whereas daniplestim alone stimulated a less than onefold increase. A sustained, maximal rise in PB-derived GM-CFC/mL was observed over day 4 to day 10 for the MPO-treated cohort, whereas the daniplestim+G-CSF, G-CSF alone, and daniplestim alone treated cohorts were characterized by a mean peak value on days 7, 6, and 18, respectively. Mean peak values for PB-derived GM-CFC/mL were greater for MPO (5,427/mL) than for daniplestim+G-CSF (3,534/mL), G-CSF alone (3,437/mL), or daniplestim alone (155/mL) treated cohorts. Mean peak values for CD34+ cells/mL were noted within day 4 to day 5 of cytokine administration: MPO (255/microL, day 5), daniplestim+G-CSF (47/microL, day 5), G-CSF (182/microL, day 4), and daniplestim (96/microL, day 5). Analysis of the mobilization data as area under the curve indicated that for total CFCs, GM-CFC, MK-CFC, or CD34+ cells, the MPO-treated areas under the curve were greater than those for all other experimental cohorts. A single, large-volume (3.0 x blood volume) leukapheresis at day 5 of MPO administration (PB: CD34+ cell/microL = 438 +/- 140, CFC/mL = 5,170 +/- 140) resulted in collection of sufficient CD34+ cells (4.31 x 10(6)/kg +/- 1.08) and/or total CFCs (33.8 x 10(4)/kg +/- 8.34) for autologous transplantation of the lethally irradiated host. The immunoselected CD34+ cells were transfused into autologous recipients (n = 8) at cell doses of 2 x 10(6)/kg (n = 5), and 4 x 10(6)/kg (n = 3) on the day of apheresis. Successful engraftment occurred with each cell dose. The data demonstrated that MPO is an effective and efficient mobilizer of PB progenitor cells and CD34+ cells, such that a single leukapheresis procedure results in collection of sufficient stem cells for transplantation and long term engraftment of lethally irradiated hosts.     

Thrombopoietin alone or in the presence of stem cell factor supports the growth of KIT(CD117)low/ MPL(CD110)+ human mast cells from hematopoietic progenitor cells

OBJECTIVES: Thrombopoietin (TPO) is known to promote platelet number, have growth-promoting potential for human megakaryocytes (HuMKs), and increase erythrocyte, monocyte, mast cell, and granulocyte numbers in the presence of additional growth factors. We explored the ability of TPO alone or in the presence of stem cell factor (SCF) to support human mast cells (HuMCs). METHODS: CD34+ pluripotent and CD34+/CD117+/CD13+ HuMC progenitor cells were cultured in rhTPO and examined for HuMCs. Similarly, we added rhTPO to CD34(+) cells cultured in stem cell factor (SCF), which promotes HuMC development. RESULTS: When CD34+ cells were cultured in 10 ng/mL rhTPO and 10 ng/mL rhSCF, TPO enhanced HuMC numbers compared to rhSCF alone. Higher concentrations of rhTPO (50 ng/mL) in the presence of 100 ng/mL rhSCF inhibited the rhSCF-dependent subpopulation of CD117high HuMCs, while promoting CD117low HuMCs. Human CD34+/CD117+/CD13+ cells cultured in rhTPO alone for 1 to 2 weeks differentiated into CD41+/CD110+ HuMKs (85-90%) and FcepsilonRI+/CD117low/CD13+ HuMCs (5-10%). RhTPO-induced HuMCs expressed the TPO (CD110) receptor, tryptase, and chymase and survived when recultured in rhSCF. CONCLUSION: The effect of TPO on HuMCs in the presence of rhSCF varies, depending on the relative concentration of each growth factor, while TPO alone or in combination with rhSCF supports a unique population of CD117low/CD110+ HuMCs.     

Enhanced detection, maintenance, and differentiation of primitive human hematopoietic cells in cultures containing murine fibroblasts engineered to produce human steel factor, interleukin-3, and granulocyte colony-stimulating factor

To determine whether the sensitivity of the human long-term culture- initiating cell (LTC-IC) assay could be increased, we have evaluated a spectrum of different fibroblast cell lines for their abilities to influence the number of cells detectable as LTC-IC, to influence LTC-IC maintenance, and/or to influence LTC-IC differentiation into colony- forming cells (CFC) in cocultures containing various sources of LTC-IC. In a series of initial experiments with highly purified subpopulations of CD34+ cells from normal human marrow, no significant difference could be found between any of 3 different murine stromal fibroblast cells in terms of their support of either LTC-IC detection (CFC production) or maintenance (over a 6-week period), and all were equivalent to primary human marrow feeders (HMF). On the other hand, murine M2-10B4 fibroblasts engineered to produce high levels of both human granulocyte colony-stimulating factor (G-CSF) and interleukin-3 (IL-3; 190 and 4 ng/mL, respectively), either alone or mixed 1:1 with SI/SI fibroblasts engineered to produce high levels of soluble Steel factor (SF), with or without production of the transmembrane form of SF (60 and 4 ng/ mL, respectively), stimulated the production of up to 20- fold more CFC in LTC of cells from normal human marrow, G-CSF-mobilized blood or cord blood when compared with parallel cocultures containing HMF. Limiting dilution analysis of the CFC output from all three sources of LTC-IC showed that most of this increase was due to an ability of the engineered feeders to increase the plating efficiency of the LTC-IC assay (approximately 14-fold for marrow LTC-IC and approximately 4-fold for cord blood or mobilized blood LTC-IC). Analysis of the phenotype of these additionally recruited LTC-IC from marrow showed they had the same primitive CD34+CD45RA-CD71- phenotype as conventionally defined LTC-IC. The limiting dilution studies also showed that the average number of CFC produced per LTC-IC was additionally and independently increased to yield values of 18 CFC per LTC-IC in marrow, 28 for LTC-IC in cord blood, and 25 for LTC-IC in G- CSF-mobilized blood. Replating of cells from primary LTC with different feeders into secondary LTC-IC assays containing the best combination of engineered feeders showed that LTC-IC maintenance could be significantly enhanced (up to 7-fold as compared with primary cocultures containing HMF). However, this enhancement was still not sufficient to amplify the number of LTC-IC present after 6 weeks above the input value. Thus, engineering murine fibroblasts to produce sufficient SF, G-CSF, and IL-3 can markedly enhance the detection as well as the maintenance in vitro of a very primitive population of human progenitor cells present in normal adult marrow, mobilized blood, and cord blood by providing the most sensitive assay conditions thus far described. The present findings also provide new evidence of biologic heterogeneity between different cell populations that can be operationally identified as LTC-IC, thus re-emphasizing the importance of limiting dilution analyses to distinguish between quantitative and qualitative effects on these cells.     

Macrophage migration inhibitory factor upregulates angiogenic factors and correlates with clinical measures in rheumatoid arthritis

OBJECTIVE: To investigate the relationship between macrophage migration inhibitory factor (MIF) levels and clinical measures in rheumatoid arthritis (RA), and the potential for regulation of angiogenesis in RA. METHODS: Serum and synovial fluid (SF) levels of MIF and vascular endothelial growth factor (VEGF) in patients with RA were determined by sandwich ELISA, and the relationships among MIF, VEGF, and RA clinical measures were analyzed. RA synovial fibroblasts were cultured with recombinant human MIF (rhMIF) and the production of VEGF and interleukin 8 (IL-8) were measured in the conditioned media. The angiogenic effect of MIF was examined using established measures of angiogenesis in vitro. RESULTS: Erythrocyte sedimentation rate, C-reactive protein, and the daily dosage of oral prednisolone were correlated with SF levels of MIF. The SF levels of MIF were found to be higher in patients with bony erosion than in those without (69.2 +/- 11.4 ng/ml vs 44.0 +/- 6.2 ng/ml; p = 0.045). MIF levels had good correlation with VEGF levels (r = 0.52, p < 0.001 in sera, and r = 0.6, p < 0.001 in SF). Production of the angiogenic factors VEGF and IL-8 was enhanced in cultured RA synovial fibroblasts stimulated by rhMIF. Endothelial tube formation was augmented when the endothelial cells were cultured with the conditioned media from rhMIF-pretreated SF mononuclear cells, and this phenomenon was reversed by anti-VEGF antibody. CONCLUSION: SF MIF may reflect the clinical activity in patients with RA, and rhMIF induces the angiogenic factors in RA synovial fibroblasts. These results suggest that MIF may be an important cytokine in the perpetuation of the angiogenic and inflammatory processes in patients with RA.     

Angiogenic synergistic effect of basic fibroblast growth factor and vascular endothelial growth factor in an in vitro quantitative microcarrier-based three-dimensional fibrin angiogenesis system

AIM: To develop an in vitro three-dimensional (3-D) angiogenesis system to analyse the capillary sprouts induced in response to the concentration ranges of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and to quantify their synergistic activity.METHODS: Microcarriers (MCs) coated with human microvascular endothelial cells (HMVECs) were embedded in fibrin gel and cultured in 24-well plates with assay media. The growth factors bFGF, or VEGF, or both were added to the system. The wells (n = 8/group) were digitally photographed and the average length of capillary-like sprouts (ALS) from each microcarrier was quantitated.RESULTS: In aprotinin-stabilized fibrin matrix, human microvascular endothelial cells on the MCs invaded fibrin,forming sprouts and capillary networks with lumina. The angiogenic effects of bFGF or VEGF were dose-clependent in bhe range from 10 to 40 ng/mL. At d 1, 10 ng/mL of bFGF and VEGF induced angiogenesis with an ALS of 32.13&#177;16.6 μm and 43.75&#177;27.92 μm, respectively, which were significantly higher than that of the control (5.88&#177;4.45 μm, P&lt;0.01),and the differences became more significant as the time increased. In addition, the combination of 10 ng/mL of bFGF and VEGF each induced a more significant effect than the summed effects of bFGF (10 ng/mL) alone and VEGF (10 ng/mL) alone when analyzed using SPSS system for general linear model (GLM) (P= 0.011), and bhat also exceeded the effects by 20 ng/mL of either bFGF or VEGF.CONCLUSION: A microcarrier-based in vitro threedimensional angiogenesis model can be developed in fibrin.It offers a unique system for quantitative analysis of angiogenesis. Both bFGF and VEGF exert their angiogenic effects on HMVECs synergistically and in a dose-dependent manner.     

Role of different medium and growth factors on placental blood stem cell expansion: an in vitro and in vivo study

Expansion of haemopoietic stem cells from placental blood has been obtained with a combination of flt3 ligand (FL), thrombopoietin (TPO), kit-ligand (KL) with or without interleukin-6 (IL6) in serum-replete medium. For clinical use, cell expansion in the absence of serum is a clear advantage. Therefore, stem cell expansion in serum-free (SF) medium with a combination of three (FL, TPO, KL) or four (FL, TPO, KL, IL6) growth factors was compared with the results obtained using fetal calf serum (FCS) or human serum (HS). Human CD34(+) placental blood cells were cultured in the presence of FL, TPO, KL +/- IL6 with SF medium, HS and FCS for up to 8 weeks. CD34(+), CFC, LTC-IC content was measured at intervals. To determine the in vivo repopulating capacity of expanded cells, CD34(+) expanded cells were transplanted in sublethally irradiated NOD/SCID mice. With the three growth factor combination the CD34(+) cell number increased steadily up to the 8 weeks of culture. CD34(+) cells were expanded 67.5-fold with SF, 11.7 with HS and 49.2 with FCS. However, when CFCs and LTC-ICs were considered, a continuous expansion was observed only with HS and FCS, whereas in SF medium after 6 weeks their number started to decline. The addition of IL-6 did not change the expansion significantly. Cells grown ex vivo for 14 days were transplanted into NOD/SCID mice. The engraftment of human cells in mice was higher for serum-replete than for SF expanded cells. Nevertheless, SF cultured cells were also able to engraft both marrow and spleen in all animals. In addition, engrafted human cells still maintained clonogenic ability. With KL, FL, TPO +/- IL6 it is possible to expand haemopoietic progenitor cells in a SF medium. Compared with serum-replete cultures, the absolute number of clonogenic cells and in vivo repopulating cells is lower. Although the degree of expansion remains significant, a clinical trial still needs to be carried out to address the question of whether this expansion might be useful in reducing post-transplant aplasia.     

Vascular endothelial growth factor protects hepatoma cells against oxidative stress-induced cell death

BACKGROUND: The aim of the present study was to examine coordination of the vascular endothelial growth factor (VEGF) and VEGF receptor (Flk-1) system and to study control of VEGF expression by oxidative stress, which is considered a model for chronic liver disease. METHODS: Cell viability was determined by test method with 3-[4, 5-dimethylthiazol-2-yl]-2, 5-dephenyl tetrazolium bromide (MTT). Expressions of cellular proteins were evaluated by western blot analysis. RESULTS: The c-Met tyrosine phosphorylation in PLC/PRF/5 hepatoma cells was increased by treatment with 20 ng/mL hepatocyte growth factor (HGF), and extracellular signal-regulated kinase (ERK) was also activated. Although Flk-1 was phosphorylated in response to VEGF (>50 ng/mL), phosphorylated ERK was not detected at these concentrations. A total of 5.0 and 10 micromol/L hydrogen peroxide (H(2)O(2)) caused cell death in a dose-dependent manner after 24 h. On western blot analysis at 1 h with H(2)O(2), rapid phosphorylation of both ERK1/2 and c-Jun NH(2)-terminal kinase (JNK) was observed. In the first 6 h, H(2)O(2) induced cell death for 58.4 +/- 6.8%, whereas the presence of 100 ng/mL VEGF improved the survival rate to 77.2 +/- 4.2%. The VEGF significantly decreased H(2)O(2)-induced cell death after 12 h, whereas HGF (20 ng/mL) did not have a similar effect. When cells were incubated with 5 micromol/L H(2)O(2), expression of VEGF protein was detected. Furthermore, H(2)O(2)-induced phosphorylation of ERK and JNK was also reduced by VEGF (100 ng/mL). In contrast, HGF did not induce phosphorylation of ERK and JNK. CONCLUSION: Hepatoma cells might be able to survive under continuous oxidative stress through expression of VEGF.     

Optimization of retroviral-mediated gene transfer to human NOD/SCID mouse repopulating cord blood cells through a systematic analysis of protocol variables.

Retroviral transduction of human hematopoietic stem cells is still limited by lack of information about conditions that will maximize stem cell self-renewal divisions in vitro. To address this, we first compared the kinetics of entry into division of single human CD34+CD38- cord blood (CB) cells exposed in vitro to three different flt3-ligand (FL)-containing cytokine combinations. Of the three combinations tested, FL + hyperinterleukin 6 (HIL-6) yielded the least clones and these developed at a slow rate. With either FL + Steel factor (SF) + HIL-6 + thrombopoietin (TPO) or FL + SF + interleukin 3 (IL-3) + IL-6 + granulocyte-colony-stimulating factor (G-CSF), >90% of the cells that formed clones within 6 days undertook their first division within 4 days, although not until after 24 hours. These latter two, more stimulatory, cytokine combinations then were used to assess the effect of duration of cytokine exposure on the efficiency of transducing primitive CB cells with a gibbon ape leukemia virus-pseudotyped murine retroviral vector containing the enhanced green fluorescent protein (GFP) cDNA and the neomycin resistance gene. Fresh lin- CB cells exposed once to medium containing this virus plus cytokines on fibronectin-coated dishes yielded 23% GFP+ CD34+ cells and 52-57% G418-resistant CFC when assessed after 2 days. Prestimulation of the target cells (before exposing them to virus) with either the four or five cytokine combination increased their susceptibility. In both cases, the effect of prestimulation assessed using the same infection protocol was maximal with 2 days of prestimulation and resulted in 47-54% GFP+ CD34+ cells and 67-69% G418-resistant CFC. Repeated daily addition of new virus (up to three times), with assessment of the cells 2 days after the last addition of fresh virus, gave only a marginal improvement in the proportion of transduced CD34+ cells and CFC, but greatly increased the proportion of transduced LTC-IC (from 40% to >99%). Transplantation of lin- CB cells transduced using this latter 6-day protocol into NOD/SCID mice yielded readily detectable GFP+ cells in 10 of 11 mice that were engrafted with human cells. The proportion of the regenerated human cells that were GFP+ ranged from 0.2-72% in individual mice and included both human lymphoid and myeloid cells in all cases. High-level reconstitution with transduced human cells was confirmed by Southern blot analysis. These findings demonstrate that transplantable hematopoietic stem cells in human CB can be reproducibly transduced at high efficiency using a 6-day period of culture in a retrovirus-containing medium with either FL + SF + HIL-6 + TPO or FL + SF + IL-3 + IL-6 + G-CSF in which virus is added on the third, fourth, and fifth day.     

Thrombopoietin responsiveness reflects the number of doublings undergone by megakaryocyte progenitors

To assess the variation of thrombopoietin (TPO) responsiveness associated with megakaryocyte (MK) progenitor amplification, TPO dose-response curves were obtained for normal human, single-cell plated CD34(+)CD41(+) cells. The number of MKs per well was determined in situ and expressed as number of doublings (NbD). Dose-response curves of the mean frequency of clones of each size versus log TPO concentration showed highly significant differences in the TPO concentration needed for half-maximum generation of clones of different sizes (TPO(50)): 1.89 +/- 0.51 pg/mL for 1 MK clones; 7.75 +/- 0.81 pg/mL for 2 to 3 MK clones; 38.5 +/- 5.04 pg/mL for 4 to 7 MK clones, and 91.8 +/- 16.0 pg/mL for 8 to 15 MK clones. These results were consistent with a prediction of the generation-age model, because the number of previous doublings in vivo was inversely correlated with the number of residual doublings in vitro. TPO responsiveness decreased in vitro by a factor of 3.5 per doubling, reflecting the recruitment of progressively more ancestral progenitors. In support of this hypothesis, the more mature CD34(+)CD41(+)CD42(+) cell fraction had a lower TPO(50) (P < .001), underwent fewer NbD (P < .001), and expressed a 2.8-fold greater median Mpl receptor density (P < .001) than the CD34(+)CD41(+)CD42(-) fraction. Progenitors that have completed their proliferative program have maximum factor responsiveness and are preferentially induced to terminal differentiation.     

新型血清型1型重组腺相关病毒载体携带血管内皮生长因子基因促血管生成的实验研究

目的探讨采用腺相关病毒血清型1型的衣壳蛋白构建的“假毒粒”型重组腺相关病毒（rAAV）1载体介导血管内皮生长因子（VEGF）促血管新生的可行性、有效性。方法以每个细胞10^5vg rAAV1-绿色荧光蛋白（GFP）及rAAV1-VEGF载体量感染C2C12细胞（小鼠成肌细胞）分化的肌管,荧光显微镜下观察rAAV1-GFP的转染效率。ELISA法检测rAAV1-VEGF转染后细胞上清中VEGF表达量。构建小鼠后肢缺血模型,术后10天每只小鼠股部缺血骨骼肌内注射3×10^11vg的rAAV1-VEGF载体,载体转染后1个月ELISA法检测小鼠缺血骨骼肌中VEGF蛋白表达量。载体转染后6周免疫组化检测小鼠缺血骨骼肌中毛细血管及小动脉新生情况。结果rAAV1-GFP感染后120h60％～80％的肌管可表达GFP。rAAV1-VEGF载体感染后第3天细胞上清中分泌的VEGF表达量达到高峰,VEGF浓度为（567．7±16．8）ps／ml。小鼠缺血骨骼肌中rAAV1-LacZ载体转染后1个月转染效率可达100％。rAAV1-VEGF载体转染后1个月平均VEGF浓度为（205．4±36．1）pg／mg总蛋白,与对照组相比差异有统计学意义（P〈0．01,n=5）。rAAV1-VEGF载体转染有效促进了血管新生（P〈0．001,n=6）,载体转染6周缺血骨骼肌中毛细血管计数与小动脉计数分别为（147．0±13．3）／mm^2,（17．0±1．2）／mm^2。结论新型“假毒粒”型rAAV1-VEGF载体可能是治疗缺血性心血管疾病更为优越的基因治疗载体。     

Rheumatoid synovial fluid contains bioactive leukemia inhibitory factor with cartilage degrading activity--another target for chondroprotective intervention

OBJECTIVE: To determine if the procatabolic activity of inflammatory synovial fluids (SF) from patients with rheumatoid arthritis (RA) could be attenuated by the cytokine antagonists murine leukemia inhibitory factor (LIF) binding protein (mLBP) and interleukin 1 receptor antagonist (IL-1ra). METHODS: Pig articular cartilage explants were cultured in the presence of either 20% v/v rheumatoid (RA) or osteoarthritic (OA) SF and varying concentrations of either mLBP and/or IL-1ra. The catabolic activity of the SF and the relative effects of mLBP and/or IL-1ra were assessed by determining the percentage release of sulfated glycosaminoglycans from cartilage explants. LIF concentrations were measured by ELISA. RESULTS: RA SF but not OA SF stimulated release of proteoglycans from pig cartilage explants in vitro (47.3 +/- 2.2% vs 24.6 +/- 2.0%; p < 0.0001). Murine LBP at 100 ng/ml and recombinant human (rh) IL-1ra at 5000 ng/ml produced a dose dependent inhibition of this proteoglycan release (p < 0.0067 and p < 0.0111, respectively). The RA SF stimulated proteoglycan release was attenuated by mLBP and rhIL-1ra independently. No additive effect of this attenuation was observed when maximal inhibitory doses were used in combination. The decrease in proteoglycan release produced by mLBP correlated significantly with LIF concentrations in RA SF. CONCLUSION: These findings are consistent with the concept that IL-1 stimulates cartilage proteoglycan resorption in RA. They also support the hypothesis that LIF, too, contributes to cartilage proteoglycan resorption in RA. The residual stimulation not accounted for by IL-1 or LIF suggests other cytokines may contribute. The role of LIF and related or unrelated cytokines may need to be taken into account to optimize chondroprotection in RA and other rheumatic diseases.     

Renal function and blood pressure in patients receiving long-term, low-dose cyclosporine therapy for idiopathic autoimmune uveitis.

OBJECTIVE: To determine the renal side effects of long-term, low-dose cyclosporine therapy (initial dose, 5 mg/kg body weight per day) in patients with autoimmune idiopathic uvetis. DESIGN: Cohort study with at least 2 years of follow-up. SETTING: A teaching hospital in Paris, France (H?pital Pitié-Salpétrière). PATIENTS: Sixteen patients with idiopathic autoimmune uveitis who were normotensive and had normal renal function before treatment. Cyclosporine was administered orally for at least 2 years at an initial dosage of 5 mg/kg body weight per day. RESULTS: After 2 years of treatment, the serum creatinine level increased by 35 +/- 5 mumol/L (0.40 +/- 0.06 mg/dL) (95% CI, 25 to 46 mumol/L, [73 +/- 4 to 108 +/- 4 mumol/L]). Creatinine clearance decreased significantly from 120 +/- 5 mL/min to 75 +/- 4 mL/min. Glomerular filtration rate decreased from 116 +/- 8 mL/min to 75 +/- 3 mL/min, and effective renal plasma flow decreased from 455 +/- 24 mL/min to 338 +/- 30 mL/min (P less than 0.05). Cyclosporine induced a significant increase in serum uric acid, total cholesterol, and serum potassium levels. Blood pressure was normal in all patients before treatment; 81% (95% CI, 64% to 98%) of these patients developed hypertension after 24 months of treatment. Blood pressure was controlled with a single drug in all but two patients. CONCLUSIONS: In patients with healthy native kidneys, long-term cyclosporine therapy, even at a low dose (5 mg/kg per day), is nephrotoxic and is associated with a high incidence of hypertension.     

Piascledine modulates the production of VEGF and TIMP-1 and reduces the invasiveness of rheumatoid arthritis synoviocytes

BACKGROUND: In rheumatoid arthritis (RA), hypertrophy of the synovial membrane generates a tumour-like pannus that invades the joint cavity and erodes cartilage and bone. Invasion of the extracellular matrix (ECM) is accompanied by angiogenesis, in which vascular endothelial growth factor (VEGF) and tissue inhibitors of metalloproteinases (TIMPs), produced by synoviocytes lining the pannus, have a primary role. Piascledine (PSD) is used in the treatment of osteoarthritis and has anti-inflammatory effects in vitro. OBJECTIVE: To study the effects of PSD on levels of VEGF and TIMP-1 and chemoinvasion in RA synoviocytes and healthy controls. METHODS: The effects of PSD 5, 10, and 20 microg/mL were evaluated, with/without interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNFalpha) 20 ng/mL, on synoviocytes. The levels of VEGF and TIMP-1 were assayed in the culture medium by enzyme-linked immunosorbent assay (ELISA). Chemoinvasion was measured by the Boyden chamber invasion assay. RESULTS: RA synoviocytes treated with PSD showed, compared to basal, lower levels of VEGF (41080+/-830 vs. 79210+/-920 pg/106 cells, p<0.001) and increased levels of TIMP-1 (23540+/-93.2 vs. 12860+/-42.9 ng/106 cells, p<0.001). PSD decreased dose-dependently IL-1beta and TNFalpha induced migration. CONCLUSIONS: In RA synoviocytes, and also to a lesser extent in control cells, PSD modulates VEGF and TIMP-1 and decreases chemoinvasion. PSD might have a role in the treatment of RA synovitis controlling invasiveness.     

Differential mechanisms in the regulation of endogenous levels of thrombopoietin and interleukin-11 during thrombocytopenia: insight into the regulation of platelet production

The regulation of megakaryocytopoiesis and thrombopoiesis appears to be under the control of an array of hematopoietic growth factors. To determine the relationship of endogenous thrombopoietic cytokine levels and circulating platelet (PLT) counts, we measured the levels of thrombo-poietin (TPO), interleukin-11 (IL-11), and interleukin-6 (IL-6) in patients with significant thrombocytopenia secondary to both marrow hypoplasia and increased PLT destruction. Increased endogenous levels of TPO and IL-11, but not IL-6, were detected in bone marrow transplant patients with thrombocytopenia following myeloablative therapy (BMT/MAT) (TPO: 1,455.5 +/- 87.3 pg/mL, [PLT 39,600 +/- 7,800/microL], P < .001, n = 12; IL-11: 227.9 +/- 35 pg/mL, [PLT 32,900 +/- 57,000/microL], P < .05, n = 19; IL-6: 25.8 +/- 8.4 pg/mL, [PLT 32,800 +/- 5,057/microL], P > .05, n = 4] v normal donors [TPO < 150 pg/mL, n = 8; IL-11 < 50 pg/mL, n = 9; IL-6 < 10 pg/mL, n = 5 [PLT 203,000 +/- 7,500/microL]. There was a significant inverse correlation between endogenous levels of TPO and IL-11, but not IL-6, and PLT counts in the MAT/BMT patients (TPO: r = -0.57, P < .0001, n = 188; IL-11: r = - 0.329, P < .0001, n = 249; IL-6: r = -0.1147, P > .05, n = 62). In patients with immune thrombocytopenia purpura (ITP), with decreased PLT survival, but intact bone marrow megakaryocytopoiesis, endogenous IL-11 levels were significantly increased (328.0 +/- 92.6 pg/mL, [PLT: 20,900 +/- 3,000/microL], P < .05, n = 25). However, endogenous TPO levels remained undetectable (< 150 pg/mL, [PLT 30,500 +/- 5,500/microL], n = 15). These results suggest that there may be differential mechanisms regulating endogenous TPO, IL-11, and IL-6 levels during acute thrombocytopenia and suggest that the absolute number of circulating PLTs may not always be the sole regulator of endogenous TPO levels. Other mpl-expressing cells of the megakaryocyte lineage may contribute to the regulation of circulating TPO levels as well. Our results also suggest IL-11 levels may in part, be regulated by a negative feedback loop based on circulating PLT counts, but also may, in part, be regulated by a variety of inflammatory agonists. Both TPO and IL-11, therefore, appear to be active thrombopoietic cytokines regulating, in part, megakaryocytopoiesis during states of acute thrombocytopenia.     

Activin-A inhibits progesterone production by macaque luteal cells in culture.

Since inhibin is produced during the luteal phase of the menstrual cycle in women and nonhuman primates, the primate corpus luteum (CL) may be a local site of inhibin/activin action. This study was designed to determine whether inhibin or activin altered steroidogenesis by macaque luteal cells in vitro. Luteal cells were obtained by enzymatic dispersion of CL from rhesus monkeys at midluteal phase of the menstrual cycle. Cells (2 x 10(4)/0.2 mL) were cultured in wells coated with extracellular matrix from bovine corneal endothelial cells in Dulbecco's modified Eagle's medium/F-12 medium (1:1 vol/vol) + insulin (2 ng/mL), transferrin (5 ng/mL), H2SeO3 (0.25 nmol), and aprotinin (10 micrograms/mL). Various concentrations (0-400 ng/mL) of recombinant human-inhibin-A, recombinant human-activin-A or human CG (hCG) (100 ng/mL; CR123) alone or in combination with inhibin or activin were added to the culture media (n = 5 Exp). Media were changed daily for 4 days and progesterone (P) concentrations were determined by RIA. Inhibin exposure did not alter P levels compared to that of control (untreated) cultures. In contrast, activin (10-400 ng/mL) suppressed P production (P less than 0.05) below controls and inhibin-treated cultures by days 3 and 4. Exposure to hCG increased P levels throughout culture (9 x control levels by day 4; P less than 0.05). hCG-stimulated P production was unaltered by inhibin, whereas activin (50-400 ng/mL) reduced (maximal inhibition of 40%; P less than 0.05) hCG-stimulated P production by day 4 of culture. Cell number on day 4 was not altered by any dose of inhibin or activin, but the number of cells staining for 3 beta-hydroxysteroid dehydrogenase was reduced (P less than 0.05) by 32.9 +/- 2.6% in activin-treated cultures. Since P levels declined during culture in all treatment groups, in a second series of experiments (n = 4), luteal cells were cultured for 4 days with or without hCG (100 ng/mL) and low density lipoprotein (LDL; 100 micrograms/mL) +/- 0-400 ng activin/mL. P production in the presence of hCG+LDL was greatly enhanced compared to other treatment groups and was sustained during days 2-4 of culture. Activin at doses of 50-400 ng/mL suppressed (maximal inhibition of approximately 35%; P less than 0.05) hCG+LDL-stimulated P production on days 3 and 4. These results suggest that the primate CL is a target for activin action to suppress luteal cell activities, including gonadotropin-regulated, lipoprotein-mediated steroidogenesis.